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THE JOU'RNAL

<$nritett

Microscopical Club,

EDITED BY
EDWARD MILLES NELSON,

SECOND SERIES.

VOLUME V.

1894-1897.

MARINE

BIOLOGICAL

LABORATORY

LIBRARY

WOODS HOLE MA:s.
W. H. I.

[Published for the Club]

WILLIAMS AND NOKGATE,

14, Henrietta Street, Covent Garden, London,
and 20, South Frederick Street, Edinburgh,

PRINTED Br

HAZELE, WATSON, &■ Y1NEY I,D.,

LONDON AND AYLESBURY.

THE JOURNAL

OF THE

tymlutt lp.er08£0pual €lnh.

The Fossil Diatomace^: Older than those of Virginia and
California, which are Older Miocene.

By Prof. Arthur M. Edwards, M.D., Newark, N.J., U.S.

{Read December 21st, 1894.)

I have found Diatomaceaa older than the Lower Miocene, and
I desire to place this on record, more especially as they are not
developing forms, but identical with those growing at the
preset time.

As some geologists have expressed a doubt of my finding
Diatomaceae in the Newark-period sandstone of Arlington
N.J., I will state how and when I did so, and trust that others
will collect the clay in which they were found, and repeat the
discovery. I should say that the Newark-period sandstone is
so called by Prof. T. C. Russell, and includes the red sandstones
that crop out in New Brunswick, at New Haven, Connecticut,
and in which the celebrated tracks were found by the late
Prof. Hitchcock, at Newark, N. J., and south into Virginia. It
has also been called the Jura-Triassic sandstone, and is supposed
to represent the upper part of the Keuper-Sandstein of
Germany.

It is now nearly twenty years since I came to reside at
Newark. I saw the sandstone and came to the conclusion it must
have been formed in shallow pools of fresh water, because
the plants found in it were those of the shores of fresh and
not salt water ; the Mollusca, scarce, of course, were fresh-water
forms also. I expected to find the remains of Diatomaceas if
they existed; they had been found in the coal of England, in
the Carboniferous coal by Castracane, and in the Tertiary by
Ehrenberg and Bailey, but I sought in vain. The fact was I
searched only in New r ark itself, in the sandstone alone, and not

Journ. Q. M. C, Series II., No. 36. 1

2 A. M. EDWARDS ON FOSSIL DIATOMACE^l.

the red shale that occurs in the sandstone elsewhere. Last
summer I examined the shaley sandstone at Arlington, or
between Arlington and Kearney, about two miles from
Newark, on the opposite or eastern side of the Passaic river,
where the clayey or shaley sandstone is intercalated in strata
with the ordinary red sandstone. In this clayey shale I found
the Diatomaceee occurring in spots of clay about one inch or less
across. The material was cleaned by washing in weak aqua
ammonia and subsequent boiling in acids. The species found
are as follows : —

Achnanthes subsessilis, Blir. (Achnanthidium) coarctatum, A. B.

Amphora ovalis, Ktz.

Cocconeis placentula, Ehr.

Epithemia iurgida, Ehr.

Melosira v avians, Ag.

Nitzschia (Hantzschia) amphioxys, Sm.

Synedra ulna, Ehr.

Achnanthes (Achnanthidium) coarctation, A. B., is the same as
Stauroneis constricta, Ehr., and should be called Achnanthes
constricta, Ehr. It was found in Chile and Mexico by Ehrenberg,
and published by him in the " Abh. Berl. Akad.," the reprint in
1843 being commonly known as the " America." I have seen
it only in this preparation from the Newark sandstone. The
above are all I have detected up to the present, but a con-
sideration of how the shale originated warrants me in the
conclusion that other forms will be discovered when this sand-
stone is searched more thoroughly, and at other places than
Arlington, N.J.

I have found every year, for the last four or five, in a run-
ning brook which is fed by the trickling of water down the
sandstone, coming from the glacial drift above it, the following
diatoms : — Nitzschia spectabilis, Ehr., not N. spectabilis, W. S., and
which includes N. linearis, W. S., N. multifasciata, Ktz., and
Synedra spectabilis, Ehr. There is also present a sigmoid form,
which looks like Nitzschia sigmoidea, Ehr. (= Navicula sigmoidea,
Ehr., = Nitz. elongata, A. EL H., = Sigmatella Nitzschii, Ktz). I
enumerate these to show they are not the same as those found
in the Newark sandstone.

Now I wish to point out the way in which I think the sand-
stone and shale were formed. There were shales and sandstones

A. M. EDWARDS ON FOSSIL DIATOMACE^I. .3

in the Carboniferous period, but I have not examined them as
they do not occur here. They were probably deposited in
comparatively quiet water of no great depth, and it was fresh
water, as there are no marine fossils. The Newark sandstone
was formed in damp meadows, not marshes, containing pools of
water of no great extent or depth ; for the DiatomaceaB in it are
not the same as now occur in wet, but merely moist meadows,
such as those around Newark, and the same diatoms exist
there now in the same circumstances. I think, too, the
temperature was the same in the Newark period as in the
meadows between Newark and Jersey City at the present time.
Ferns grew in the meadows, but no trees, and animal life was
scarce. This accounts for the occurrence of shaley sandstone
on the top of the red and white sandstone.

Now I have carried the Diatomacese down to the Newark
period, which is much lower than the Lower Miocene, the
Tertiary, to which Virginia, Maryland, New Jersey, and Cali-
fornia belong, if indeed they be as old. And I wish to show
they are in the Lower Silurian also, the oldest rocks except the
pre-Cambrian and Laurentian, in which M. Cayeux found
Eacliolaria and Sir W. Dawson Foraminifera, viz., the Eozoon.
In the Hudson River epoch of the Lower Silurian age I have
found Diatomaceae, and they are of the same forms as occur at
the present time. I believe, of course, in evolution, but why
certain Mollusca, Foraminifera, and Diatomaceae have remained
unchanged up to now I, of course, cannot tell.

They have been using for ballast and filling at Lyon's Farm,
N.J., on the Lehigh Valley railroad, material brought from
Jutland, N.J. It consists of shale mixed with slate. The
shale is yellowish or reddish, and breaks down readily w r hen
exposed to the air; the slate is blue-black in colour. The
shale sometimes passes into a yellowish clay, and in it occa-
sionally are spots of white clay. I have examined the latter,
and was delighted to find some Diatoruacese in it. They are
fresh-water forms corresponding with those growing in fresh
water now, and the species enumerated below are identical
with those now found in existing meadows which show no sign
at all of evolution. It is well to remember then that as evolu-
tion has not affected the Diatomaceas in all the millions of
years since the Hudson River epoch shale was thrown down, we

4 A. M. EDWARDS ON FOSSIL DIATOMACE.E.

cannot expect it to affect them now. And we must look foi
something into which they were developed if we believe in
evolution at all. The diatoms here are in small quantity mixed
with a high percentage of sand and clay, and in the white clay
only ; at least I have not been able to find them in the yellow.

I detail the method used in searching for the diatoms, so
that observers may see that care has been exercised. Filtered
water was always used. The rock is broken in pieces and
washed with filtered aqua ammonias; this is nearly all poured
off, and finely powdered bichromate of potassium added in
excess. After a time sulphuric and a small quantity of hydro-
chloric acid is poured on and let stand for about a quarter of
an hour. The whole is washed until colourless, treated with
aqua ammonias, and again washed. A portion of the deposit is
dried on a slide, and a freshly-prepared solution of gum Thus
in wood spirit or alcohol added ; the slide is then warmed to
drive off the spirit, the cover glass imposed and pressed down.

I do not see how foreign diatoms can be introduced in this
process unless by the acids, spirit, etc., used, but the forms are
always fresh-water ones, and the same solutions and acids have
been used to clean and mount marine Diatomacea3, and no fresh-
water forms have been detected amongst the latter. Moreover
the valves are often seen involved in the clay. Species identi-
fied are : —

Cy rubella cistula, Hemp. Navicula elliptica, Ktz.

Epithemia gihba, Ehr. „ viridis, Ktz.

„ turgida, Ehr. Nitzschia scalaris, Ehr.

Fragilaria striatula, Grev. Stauroneis plioenic enter on, Ehr.

Melosira cremdata, Ktz. Synedra ulna, Ehr.

Navicula dicephala, Ehr. Spicules of fresh-water sponge.

I have submitted this material to the examination of a well-
known geologist, and he thinks the Diatomaceae may have been
washed in by percolation. I do not see, however, that this can
be the case, for the clay was hard and came from the interior
of the specimen.

In conclusion I believe the loess was formed in the same way
as this, i.e., on large meadows, and not by the wind, in spite of
the opinion of Baron Von Richthofon to the contrary. The
loess of Germany, China, and America belongs to the Iceberg
period,

Second Note on a Method of Preserving Rotatoria.

By Charles F. Rousselet, F.R.M.S.

(Read January 18th, 1895.)

It is now just two years ago (" Quekett Journal," 1893, Vol.
v., p. 205) that I read before you a paper on preserving
Rotifers as permanent objects. Since then I have continued
my investigations, and have now made such progress and im-
provements in the method that a second communication on the
subject becomes desirable.

The principle of the process, consisting of narcotizing, killing,
fixing, and preserving in a watery fluid, not appreciably denser
than water, as explained in my first note, remains the same, the
improvements being chiefly made in the details of the process
and the choice of the fluids.

The first defect which became apparent was a darkening of
the specimens, due to the trace of osmic acid remaining in the
dilute Flemming's fluid used for preserving ; this was soon
remedied by omitting the osmic acid in the preservative fluid,
and the animals then kept their complexion very much better.

The yellow colour, however, produced by the chromic acid in
some animals displeased me very much, as it gave an unnatural
appearance to the usually perfectly white, glassy transparent
bodies of Rotifers. I made many experiments with a number
of different substances to get rid of the chromic acid. The
most promising fluid for preserving seemed to be a J n per cent,
solution of bichloride of mercury, but owing to its liability of
forming crystals, which could not be wholly prevented by the
addition of a little common salt, I had finally to abandon it, ex-
cept in a few special cases.

At the beginning of last year I noticed in the German
periodical "Biologisches Centralblatt" an article by Dr. Blumm,
on Formalin,* which was said to fix and preserve vertebrate
eyes and tissues without shrinkage and fairly transparent. I

* Formalin, or formol, is a watery (40 per cent.) solution of formaldehyde
(CH 2 0), a gaseous substance which is produced when methyl alcohol is
subjected to oxidation. It is used as a disinfectant, and iustead of alcohol,

G C. tf. ROUSSELET ON PRESERVING ROTATORIA.

procured some of tin's substance, and soon perceived that it
would be very useful for my purpose. Formalin by itself, I find,
does not fix the Rotifers at all well, as I was led to expect from
the above article ; it rather dissolves protoplasmic structures,
such as cilia, more or less completely, but it preserves them re-
markably well after they have first been fixed with Flemming's
fluid or osmic acid, and crystals are never formed. It has the
very valuable property of preserving the animals without the
least shrinkage or turgescence, and as perfectly transparent as
the fixing process leaves them. The thin and delicate loricaof
some Rotifers, such as that of Euchlanis triquetra, which I had
not been able to satisfactorily preserve in any other fluid tried,
remains perfect in shape and transparency in formalin. The
strength used is 2| per cent, in distilled water.

For fixing the Rotifers I have found that osmic acid alone
fixes as well as Flemming's fluid ; when used strong it darkens
the animals, but if a very weak solution of \ per cent, or less be
used, and allowed to act for a very short time only, half a
minute at most, the animals remain white and transparent, ex-
cepting only the maturing ova, which become more or less
darkened on account of the fat-like substance, lecithine, which
they contain. Moreover, if the animals have become coloured
a little by the osmic acid the colour can be removed by passing
them for a few (1-3) minutes through peroxide of hydrogen.*

For narcotizing I found the following mixture to give better
results than 2 per cent, cocain alone : —

2 per cent, solution of cocai'nf ... 3 parts
Methylated spirit £ ... ... 1 ,,

Water 6 „

for preserving museum specimens, is non-poisonous, and very cheap. The
solution obtainable in commerce being of thestrength of 40 per cent., dilute
2g volumes of this with 374 volumes of distilled water in order to get the
required solution of 2\ percent.

* Peroxide of hydrogen is simply water containing an excess of oxygen,
either in loose combination or only in solution, or more probably both'; the
oxygen is readily given off and bleaches by oxidizing the reduced osmic
acid to OsO 4 . This substance does not keep good very long, and it is best
to obtain a small quantity at a, lime and renew it after four or six months.

f Hydrochlorate of cocain is a very expensive drug; it is best to procure
only one gramme at a time, and dissolve it in 50 c.c. of water, which will
give a 2 per cent, solution. As this solution does not keep well I add at
once 12 c.c. of methylated spirit, then four parts of this mixture and six
parts of water will make the above narcotizing fluid.

X I mean the methylated spirit prepared with wood naphtha, not that now
generally sold, which is prepared with mineral naphtha, and becomes milky
■vhen mixed with water.

C. F. ROUSSELET ON PRESERVING ROTATORIA. /

It is used by adding first a few drops to the water in which
the Rotifers have been placed, then more and more at inter-
vals until the animals are sufficiently narcotized. The different
species vary very much in the length of time they require for
narcotization ; some patients require to be treated very slowly,
others very rapidly, to be able to kill and fix them fnlly
extended, and for this reason it is best to treat each species
separately. The general rule I follow is to add little of the
fluid at first, and then, if the animals continue to expand or
swim about, more and more at intervals of a few minutes,
until their movements begin to slacken. Most free swimming
species, I find, can be killed when still swimming about slowly,
but with some it is necessary to wait until the cilia have just
ceased beating. A few examples mentioned below will give
some more details. In order to ascertain the right moment for
killing an animal I have not before prepared, I usually separate
one or two individuals, and if these can be killed fully extended
with a drop of osmic acid, then the others are also ready. Of
course, it is very important to kill and fix the animals before
they are quite dead, as swelling and other post-mortem changes
begin at once after death.

My process, then, now consists of narcotizing the Rotifers
with above cocain-spirit mixture, killing and fixing with
£ per cent, osmic acid for half-a-minute or less, washing out
immediately and thoroughly in water for a few minutes to
half-an-hour, and finally preserving and mounting in 2| per
cent, formalin, or, in some cases, in bichloride of mercury and
salt solution.

Rotifers with shells having high ridges or mouldings, such as
Uuchlanis triquetra, Mastigocerca bicristata, Metopedia tripicra
and oxysternon, some species of Brachionus, etc., must not be
left long in water, as the lorica often swells a little and the
ridges and mouldings become more or less obliterated ; such
species must be washed quickly in water and transferred at
once to the formalin, which preserves the shell perfectly.

It is very necessary, in order to avoid greater trouble after-
wards and make satisfactory mounts, to transfer the living
Rotifers first of all into perfectly clean water, free from any
particle of foreign matter, living or dead. I keep some clean
filtered pond water, and pick out and transfer the Rotifers into
clean cells as many times as may be necessary. Small particles

8 C. F. ROUSSELET ON PRESERVING ROTATORIA.

become readily attached to the cilia of Rotifers when dead, and
it is then often very difficult to remove them ; for the same
reason it is not advisable to mount small species in the same
cell with larger ones.

Instead of micro-troughs, as recommended in my first paper,
I now use small square blocks of glass, with a hollow ground in
and polished, as much more convenient for all the necessary
manipulations. These blocks can be placed under the lens of
the dissecting microscope,* or the compound microscope, if
necessary, and the animals can be watched more closely, which
is indispensable with the smaller species. For the purpose of
washing, etc., I transfer the Rotifers from one glass block to
another by means of a small and very fine pipette, funnel-
shaped at one end, the funnel covered with an india-rubber
membrane. I have had such pipettes made of various sizes,
and can recommend them as the best yet devised for picking up
small animals of all kinds in water.

In killing it is merely necessary to introduce a drop of osmic
acid on to the animals under water, and then almost immedi-
ately transfer them to some fresh water in another block kept
ready, and then again to two or three more lots of distilled
water, so as to get rid of all traces of the acid, and finally in 2 J
per cent, formalin.

The following notes will give an idea of the treatment some
Rotifers require, and serve in some measure as a guide to the
treatment of other species : —

Stephanoceros and Floscules. — Although I had been occa-
sionally successful in preparing a few of these Rotifers, I have
only quite lately found the means of killing them fully extended
with some degree of certainty. I will describe the modus
operandi with regard to Stephanoceros; the Floscules must be
treated similarly, but are more difficult. Before beginning
the operation, cut and trim a very small piece of the weed to
which Stephanoceros is attached, ready for mounting, and place
it in a cell of perfectly clean water; then transfer the animal
to a hollow-ground glass slip, the hollow of sufficient size and
depth, in three drops of water, to which one drop of the
narcotizing fluid has been added. After five minutes the

* A dissecting microscope of some kind is necessary ; my tank micro-
scope, provided with an aplanatic lens of G or 10 power, can readily be
adapted as a dissecting microscope by screwing it to a suitable stand with
arm rests.

C. F. ROUSSELET ON PRESERVING ROTATORIA.

9

animal will have recovered from the first shock, and you can
add one more drop of the cocain- spirit mixture, and so on?
one drop every three minutes, until five drops have been added ;
wait then ten minutes longer, that is 25 to 30 minutes (not
more) from the beginning of the process, and Stephanoceros will
be ready to be killed with one good drop of J per cent, osmic
acid, which is to be placed right on the animal, not run in at
the side of the cell. The animal may contract into various
shapes during the process, but at the end of the 25 minutes
will generally be found fully extended. It is well to place
your watch on the table and follow these directions some-
what closely. After half-a-minute, wash out the osmic
acid, which must be done very carefully, and mount on the
same slip in bichloride of mercury and salt solution. It is not
advisable to mount more than one Stephanoceros on a slide, or, at
least, only one small piece of weed, to which, of course, several
animals may be attached.

It must here be stated that the gelatinous cases of Stephano-
ceros, the Floscules, and also of Melicerta tubicolaria seem to be
about the only structures which are not well preserved by the
formalin ; these cases seem to swell out in length, not in width,
squeezing the animals in the central opening. I had some very
well prepared Melicerta tubicolaria, the tubes of which have
grown to nearly three times their original lengths, showing the
heads of the uncontracted animals about the centre. Unless
the gelatinous cases are first removed, it will be better to pre-
serve and mount these Rotifers in dilute Flemming's fluid with-
out osmic acid, or in bichloride of mercury and salt solution.*

Melicerta ringens is easier to prepare, but requires patience ;
little of the narcotizing fluid must be added at first, and the
creature watched until the cilia move very slowly, then is the
time for killing with a drop of osmic acid.

Limnias presents no difficulty. After the first dose more and
more cocain mixture can be added rather quickly, and the
animals may be killed fully extended while the cilia are still in
motion.

GonocMlus volvox must be narcotized very quickly. The first
good dose of cocain-alcohol sends the colonies spinning round

* I recommend that this solution be made as follows, as least likely to
produce crystals :— Equal parts of bichloride of mercury, ^ per cent.
solution, and common salt, \ per cent, solution.

10 C. F. ROTJSSELET ON PRESERVING ROTATORIA.

at a great rate. This must be followed after one or two
minutes by continuous further doses until the cilia cease to
move and the colonies become motionless, which is accom-
plished in five to ten minutes. They are then killed quickly
with osmic acid, which must be allowed to act for half-a-
minute, washing out in water rather quickly, otherwise the
animals separate, although perfectly preserved. The gela-
tinous substance in which these Rotifers are embedded also
swells somewhat in formalin, and it is, therefore, advisable to
preserve the colonies in the sublimate and salt solution, and
mount them in that fluid.

Asplanchna priodonta can be narcotized very quickly. Five
minutes after the first dose the animals receive continually
fresh doses until they swim very slowly, and are killed whilst
still moving, all fully extended, almost without exception, the
whole process being finished in about ten minutes.

Asplanchnopus myrmeleo must remain about half-an-hour
under the influence of the narcotic, until the cilia beat very
feebly, and the animals are hardly able to move.

Not ops brachionus requires a good dose of coca'in- alcohol
mixture to begin with, and after ten minutes more and more
doses until they gradually fall to the bottom and are unable to
swim ; but as long as the cilia beat with force they will con-
tract, and they must, therefore, be closely watched and killed
at the moment when the cilia have stopped moving in some of
the animals.

Euchlanis. With coca'in alone I had no success at all with
the various species of Euchlanis, but with the cocam-alcohol
mixture I have been able to prepare all the species without
difficulty. They must be narcotized very quickly by adding
large doses, and killed whilst still swimming about, otherwise
they gradually contract.

Brachionus pala is readily killed fully extended, either by
narcotizing quickly or slowly.

Brachionus urceolaris, on the other hand, is quite spoiled by
the slow process, and must be narcotized as quickly as possible
with large doses of the narcotic until the animals become
motionless, when they are quickly killed and fixed with a drop
of osmic acid.

Synchwta tremula and similar illoricate free swimmers can be
narcotized fairly quickly in 10 to 15 minutes, and killed whilst

C. F. ROUSSELET ON PRESERVING ROTATORIA. H

still swimming about at a reduced speed; with a few only it
is necessary to wait until the cilia have ceased beating.

Notommatadce. Those members of this family which are
possessed of a slightly stiffened skin can be preserved easily
enough, but the very soft, larviform species present greater
difficulties, as they wriggle about constantly from one shape
into another when under the influence of the narcotic, and it
requires patience to kill them well extended. By trying
several times one succeeds in getting a few good ones, suffi-
cient for a slide ; so I have Notommata aurita with both auricles
fully extended. It must here be mentioned that the formalin
causes the black or opaque brain sac, which is so characteristic
of some species of Notommata, to clear up and disappear. This
is a drawback for these particular Rotifers, and I recommend
that these species be preserved in the bichloride of mercury and
salt solution, which preserves these structures.

The Philodinadce also offer considerable difficulties on account
of their very soft and contractile bodies. I think, however, these
difficulties are not insurmountable, but have not yet had many
opportunities, having been so much occupied with other species

I may remark in passing that infusoria can be preserved by
the same method. All those infusoria which have not the
power of contraction are readily prepared, without narcotizing,
by killing and fixing with j °/ osmic acid, washing out im-
mediately in water, and preserving in 2| 7 G formalin. The con-
tractile infusoria will have to be narcotized in some way, but
owing to the absence of a differentiated nervous system this
may prove somewhat difficult ; I have not investigated how far
this can be done with 2 D / coca'in and the cocai'n-spirit mixture,
but both these fluids should be tried.

A few hints and wrinkles on mounting Rotifers when killed
and prepared may prove useful.

Instead of cement cells I now use hollowed out glass slips,
which can be obtained of all sizes from Jin. to fin. in diameter,
and proportionately deep. These are always ready, and have
the great advantage that the often very minute animals cannot
go to the edge, where they cannot be properly seen in a cement
cell. Some difficulty may be experienced at first in closing the
cell with a cover glass without an air bubble. This will, how-
ever, soon be overcome by proceeding as follows : — Place a drop
of the 2\ per cent, formalin solution in the cell, just filling it

12 C. F. ROUSSELET ON PRESERVING ROTATORIA.

and transfer the prepared Rotifers with a pipette into the cell,
then place another drop on the slip by the side of the cell, about
half an inch to the left, lower your clean cover glass on to this
last drop, which will present no difficulty, then with a needle
push the cover glass slowly, and by little jerks, over the cell,
stopping short for a moment if the Rotifers show a tendency
to move to the edge of the cell. But before covering the cell
examine it under the dissecting microscope, and remove every
fibre and every particle of foreign matter, however small, with
a mounted bristle. The superabundant fluid is then removed
with blotting paper until none is left round the cover ; the cover
must not, however, stick too fast, and you must be able to move
it with a needle, otherwise the cement will be forced in at the
sides by atmospheric pressure. When ready the cover glass is
sealed down by tipping some Miller's caoutchouc cement* all
round the edge with a fine sable brush. The cement must not
be liquid, but thickened by exposure to the consistency of a very
soft jelly. The edge of the cover-glass must be carefully looked
over under the lens to see that the cement covers it everywhere,
and that no air bubble has been left at the edge. Cover-glasses
have frequently small cracks runninginward some little distance;
these must be carefully covered with cement to their ends,
otherwise the fluid will slowly evaporate through these cracks,
and in time an air bubble will appear in the mount When
the cement is dry, that is next day, the slide can be finished
with a ring of asphalt, or any other ornamental cement.

In conclusion, I wish to say that my object in this method of
preserving Rotifers is not to bring out any particular organs or
structures, but to preserve the animal as a whole, white and
transparent, and as life-like as possible, and suitable for identi-
fication and study at any time. The process as now explained
certainly does this for the great majority of species, and the
delicate organs even, such as the very fine flagella attached
to the vibratile tags in Asplanchna priodonta, are perfectly pre-
served, and can be seen more distinctly than in the living
animal. The red eyes and green food particles in the stomach

* Miller's caoutchouc cement is very good, and the best I know for scaling
all kinds of fluid mounts, except, of course, alcohol. Its composition is kept
a profound Becret by the inventor, but it probably consists of a mixture of
shellac (buttonlac) dissolved in strong alcohol (or possibly Venetian tur-
pentine) and caoutchouc dissolved in chloroform. The diluting fluid is a
mixture of e<pial parts of chloroform and strong or absolute alcohol.

C. F. ROUSSELET ON PRESERVING ROTATORIA.

13

are also well preserved when weak osmic acid is used as the
fixing agent, except perhaps when the eyes are only faint patches
of red pigment, which then may disappear more or less in time.
So far I have prepared and possess slides of 130 different
species of Rotifers, including some of all the families, which
is sufficient proof that this " unpreparabie " group, as Mr.
Bolles Lee has styled the Rotifers, is now fairly conquered. It
is my intention to prepare a similar series for the cabinet of
our Club, to form in time a complete type collection, if possible,
of all the known Rotatoria, and I trust the members will assist,
in this task. This will prevent in future the confusion which
exists with regard to a number of species which have been
described three or four times under as many different names.*
As a beginning, I have much pleasure in presenting to the Club
77 slides, which will form the nucleus of this collection; they
contain 72 different species, of which the following is a list . —

Stephanoceros eich-

hornii.
Melicerta ringens.

„ tubicolaria.

,, conifer a.
Limnias annulatus.

„ myriophylli.
Conochilus volvox.
(Ecistes stygis.
Asplanchna priodonta.

„ amphora.
Asplanchnopus myrme

leo.
Synchata tremula.

„ tavina.

„ stylata.
Triarthra longiseta.

,, mystacina.

,, breviseta.

Hydat na senta.
Phinops ritrea.
Phinops (?) orbiculodis-

cus.
Notops brachionus.

„ pygmceus.
Triphylus lacustris.
Notommata lacinulata.

Notommata aurita.
„ tripus.

„ cyrtopus.

Cyrtonia tuba.
Proales decipiens.

„ parasita, in
volvox.
Furcirfaria Longiseta.
Diglena forcipata.
Ploesoma lynceus.

„ Hudsoni.
Anapus ovalis.
Mastigocerca bicornis.
,, carinata.

,, bicrisiata.

Rattulus sejunctijpes.
Coelopus porcellus.

„ brachiurus.
Dinocharis tetractis.
Stephanops longispi-

natus.
Stephanops intermedins.
Diaschiza semiaperta.

„ exigua.

Salpina brevispina.

„ marina.
Euchlanis triquetra.

Euchlanis

„ parva.

„ deflexa.

,, pyriformis.

„ Lyra.

Cathypna ungulata.
Monostyla cornuta.
Distyla spinifera.
Metopedia solidus.

„ acuminata.

„ lepadella.
Pompholyx sulcata.
Brachionus pala.

„ urceolaris.

Noteus quadricornis.
Schizocerca diversicor-

nis.
Anurcea aculeata. var.

valga.
Anuraa cochlearis.

,, serrulata.

„ hypdasma.
Notholca acuminata.

„ scapha.
Pedalion mirum.

* Members who do not wish to mount the specimen themselves can
assist in this work by sending me living examples of rare species of Eotifers
when they happen to find them. The above list may be taken as an indi-
cation of what is not required, but the following species are particularly
wanted: — Apsilus lenliformis, Cephalosiphon limnias, Asplanchna Ebbes-
bornii, Microcodon clavics, Pedet.es sallator, Ptercessa surda, Scaridium
eudactylotum, Dinocharis Collinsii, Stephanops chlana and unisetatus,
Erethmia tetrathrix, Notogonia Ehrenbergii, and many others.

14

THE PRESIDENT'S ADDRESS.

By Edward Milles Nelson, F.R.M.S.

{Delivered February 15th, 1895).

Gentlemen, — I cannot proceed with the work of this evening
without alluding to the great honour you have done me in
again electing me your President in spite of my numerous
absences from this chair during the past year. I had the
comfort of knowing that you were in better hands than my
own through the kindness of Mr. Michael, and to you and him
I now give my best thanks.

In brass and glass the past year has been a busy one ; it
might, to use a cycling phrase, almost be called a record. The
new inventions and improvements in brass work have been
neither few nor unimportant, and although we have nothing
further to discuss with regard to the glass portion of the
subject, yet in the optical theory part we have had enough new
matter put before us to occupy our minds for some time to
come.

To proceed with the brass work from the point where we
left off last year, we must go back to the latter part of 1893,
when we find a microscope made by Leitz having a tripod
(claw) foot and a horse-shoe stage. This instrument is in-
teresting because of its divergence from the continental model,
and of its convergence towards the English. The grooving of
the substage focussing slide is peculiar, but as a special note
on 1 hat point has already appeared in this Journal, we may
pass on to Swift's four-legged microscope.

It is, however, difficult to follow the argument respecting
this novelty, for past experience has shown that both the
microscope and the telescope perform better the firmer their
stands are. It has been repeatedly said, and no one has ever
contradicted the statement, that the same optical lenses when
used od B portable .-land will not perform so well as on a rigid
stand. With the same objective, eye-piece, and condenser the
delicate points which can just be caught when using a Powell's

THE PRESIDENT'S ADDRESS. 15

No. 1 will be invisible if the stand is changed for their
portable. Leaving the portable instrument out of the question
the image with a large massive stand is always superior to
that obtained with a small and lighter stand, however well
made it may be, the optical apparatus being the same in both
cases. Now the objection to the claw foot is, first, insufficient
spread, and secondly, the breadth of the back foot. The first
fault makes the instrument easily capsizable sideways, and
the second tends to make it rock on four points. The proper
remedy for the first fault is to increase the base, and for the
second is to make the stand a true tripod. My objection to
the cutting and pivoting of the back leg is that it at once
degrades the instrument to the level of a portable stand ; but
if the instrument is put forward as a new portable microscope
it will probably be admitted that it is about the best form that
has yet been devised.

There is another innovation with regard to this stand, and the
former pattern brought forward by Messrs. Swift and Son,
which suggests an important question for the consideration of
microscopists, viz. : is it an advantage to make the legs of the
tripod or tetrapod hollow ? Lightness is of course gained, but
then it is at the cost of a higher centre of gravity, and more-
over how about rigidity ? If these stands are intended for
portable microscopes only, the lighter the better, and on that
account one is prepared to sacrifice something. If on the other
hand they are intended for the highest possible work, solid legs
would perhaps be better ; probably by filling up the tubes
with lead the necessary weight and rigidity would be secured.

With regard to the next two instruments, you will know
more about them than I, for they were exhibited here during
my absence, so unfortunately I have not seen them ; they
are dirties' instantaneous photomicrographic shutter, and
Leitz's low-power projection camera.

We now come to a great, and what we may venture to
think will prove a most useful invention, viz., Swift's
friction geared mechanical stage.* It has since its first in-

* Frictional gearing was first applied to the microscope by F. H. Wenham,
who says that " he found it answer perfectly well in lieu of the ordinary
rack-and-pinion of the body and stage of microscopes .... it works very
smoothly and lifts a weight of 161bs. without slipping." — "Quart. Journ.
Micro. Science," Vol. vii., p. 201, two woodcuts (1859).

16 THE PRESIDENT'S ADDRESS.

traduction been improved by bringing the friction wheels
nearer together, and also by fixing a milled head to each
end of the pinion for the horizontal movement. This stage
secures a maximum range of motion in each direction, and
at the same time the whole apparatus can be removed, leaving
the main stage perfectly plain. A copper ring is swedged on
the wheels which impart the horizontal movement to
the slide, and corundum powder is rubbed into it, which
increases the grip on the lower edge of the slide. Next
we have a series of microscopes, exhibited here by Messrs.
Ross ; they do not materially differ from the ordinary Anglo-
Continental pattern of students' microscopes except in the
foot. The limb is fixed by a compass joint to a pillar which is
attached to the periphery of a circular foot ; so far they are not
unlike Salmon's microscope (1853) described by Dr. Beale.
This pillar is, however, pivotted so that the foot may be turned
backwards, which gives great steadiness to the instrument
when in an inclined or horizontal position. This forms a
simple, inexpensive and thoroughly practical foot, and it is
strange that such an efficient design has not been oftener
employed in the construction of students' microscopes. This
idea was first suggested by Mr. A. McLaren.*

We next come to Baker's photomicrographic instrument.
Here we have a microscope which cannot be used in any other
but the horizontal position. The focussing racks of the body
and substage are all ploughed in the bedplate, and the foot and
arm are dispensed with. This seems to me the most solidly-
e< instructed photomicrographic instrument yet made. This
excellent design is due to Mr. E. Hartley Turner, of Man-
chester. It is an instrument that will be much appreciated by
those who do all their microscopical work on the photographic
bench. Personally I work on different lines, the magnification,
lens, adjustment, illumination, position, etc., of the object being
all determined before it is placed on the photographic bench, so
1 naturally prefer to photograph with the same instrument by
which those adjustments were made, and would find some
inconvenience in changing to another instrument; but this is a
mere raa1 fcer of detail.

The Last microscope is Watson's new model Van Heurck.

* "Journal It. M. 8.," 1884, p. J 11, Pig. 9.

THE PRESIDENT'S ADDRESS. 17

This in general resembles their older form, except that the
distance between the optic axis and the limb has been increased,
so that complete rotation is given to the stage. The foot is an
equilateral tripod of 10-inch side, and its height is such that
when the instrument is placed in a horizontal position the optic
axis is ten inches from the table. The stage movements are
similar to Powell's No. 1, and the instrument is thoroughly
well made and sprung throughout. Leaving the microscopes,
we pass on to apparatus, and we have Mr. R. Smith's rocker
microtome. This is similar to the Cambridge rocker, but it is
fitted with a movable knife-holder, which allows the edge of
the blade to be placed at any desired angle to the cut. Another
ingenious arrangement permits the instrument to assume a
vertical position, so the cut can be made in a spirit trough.
We have also from America clay wicks for microscope lamps,
which are said to give a greater intensity of white light, and to
be without smell. Finally there is my own camera, which has
been already described here.

We must now notice the improvement in coloured screens, a
very important branch of microscopy to which in the past it is
to be feared that sufficient attention has not been given. The
office of a screen in popular language is to improve the image
with apochromatics, strengthen the resolution, and at the same
time to soften the light when large illuminating cones are used.
They are of special service with cheap lenses (z.e., semi-apo-
chromats), because they remove the secondary spectrum,
making the lens as efficient as an apochromat. So markedly is
this the case that with equal apertures it is impossible to say
whether the objective on the nose-piece is an expensive
apochromat or a cheap semi-apochromat. In photomicrography
not only are the preceding remarks applicable, but also colours
difficult to photograph are rendered neutral. My reason for
dwelling at length again this year on the subject of screens is
not only because its importance is not so fully recognized as it
should be, but also because some improvements have been
effected during this past session. Mr. Lovibond, of Salisbury,
who has been both a member of this Club and also a Fellow of
the Royal Microscopical Society for twenty-nine years, has
given this subject much attention. He sent me a flashed glass
screen of peacock blue and a fluid screen of methylin blue,

Journ. Q. M. C, Series II., No. 36. 2

18 THE PRESIDENT'S ADDRESS.

and Mr. J. W. Gilford, who has also done excellent work in this
direction,* sent me subsequently a very fine fluid screen
of malachite green and picric acid. These were the screens
you heard about last year. Since then Mr. Lovibond has sent
me another sample of bluish green pot glass, which cuts the
red out more thoroughly than the peacock blue glass. Mr.
Gifford also has given me two more fluid screens, one a green
and the other a violet. f The violet screen is too dark for
visual purposes, and as yet I have not experimented with it
photographically, but the green screen passes a large quantity
of light. The results obtained with it are certainly up to, and
probably superior to those with monochromatic light from my
apparatus of the most approved pattern. There is one very
important point with regard to the use of screens for visual
purposes, viz., that if they are too dark they will obliterate
fine detail, and it will be found better to pass a wider band,
even should it contain some objectionable rays (i.e., not so
monochromatic), than cut down the intensity of the light too
much. In fact, there is a happy medium between the
monochromatism of the screen and the light intensity; for
example, Mr. Gifford's new green screen, which passes all
the green and a great deal of blue, is a much better screen
than that of Prof. Zettnow, which is more monochromatic.

Before entering on the subject of the evening, a few words
must be said regarding a pamphlet published last year by Mr.
Allan Dick, entitled, "Additional Notes on the Polarizing
Microscope."! Most of us are acquainted with his former
excellent pamphlet, and with the improvements he has made
in petrological microscopes. This new work, however, deals
largely with the manipulation and management of an ordinary
microscope, quite apart from petrological work. It is to this
portion of the book that we must, therefore, confine our atten-
tion.

In the book is described a new method for measuring the
aperture of a lens, which depends on the number of rings that
can be counted in a biaxial crystal when viewed under a wide-
angled axial cone of polarized light. The angles of the ring

* "Journal R. M. S.," 1894, p. 164, and PI. V., Pig. 4.

t An account of these will shortly appear in the " R. M. S. Journal/'

X Published by Messrs. Swift & Son, 81, Tottenham Court Road, W.

THE PRESIDENT'S ADDRESS. 19

distances are first measured by an apertometer, and when these
have been tabulated, the crystal takes the place of an aper-
tometer. The apparatus required, if one does not possess a
petrological microscope, is a Nicol polarizer, of a size not less
than that sufficient to fill the back lens of your condenser, (if
that happens to be an Abbe it will be rather a costly item), an
analyzer, a lens inside the tube of the microscope to convert
the instrument into a telescope, and a properly cut crystal.
Whether this extra apparatus is more costly than an ordinary
apertometer I am unable to say, but it is claimed for the new
method that it will measure the aplanatic aperture better than
the Abbe apertomer. On page 14 a very pretty experiment is
described by Mr. Dick, which visibly demonstrates in a most
conclusive manner that a greater angle of light is grasped by
an immersion than can possibly be by any dry objective.

Mr. Dick, it will be noticed, uses the sliders with his Abbe
apertometer ; these in my hands have always given very rough
and, in the case of large angles, erroneous results.

A preferable method of using the Abbe apertometer is to
rotate the hemispherical disc until the light is extinguished,
read off the angle of rotation on both sides of zero, take the
sine of the mean reading and multiply it by the refractive
index of the apertometer ; the result will be the N. A. of the
lens. If in this manner you measure wide-angled condensers
you will find curious effects. In some the flame image will dis-
appear before the periphery of the back lens has been
reached ; this shows that the front lens has not sufficient
aperture to fill the back lens of the combination. In others
the light, after extinction, will become visible again. In some
the image of the flame will continue to be in focus during its
passage over a large area of the back of the objective, in
others it will begin to go out of focus almost as soon as it has
left the centre of the back lens.

Mr. Allan Dick has fallen foul of that dreadful nightmare
of diatom structure interpreters, viz., images in the areola?.
Images in all kinds of areolations, whether of diatomic or other
structures, follow the laws of those arising from minute per-
forations. As this is an important and often misunderstood
subject, you will pardon me if it is treated at some length.

Procure a small piece of tinfoil and a fine-pointed needle,

20 THE PRESIDENT'S ADDRESS.

place the tinfoil on a smooth piece of cork and make several
fine punctures in the foil, then placing the foil in a compressor
view it under a f objective. When the image of the edge of
the flame is focussed by the substage condenser on the foil
the only image that can be obtained will be that of the
diaphragm at the back of the condenser. The image of this
will be erect when the hole in the foil is beyond the focus of
the objective, and inverted when within the focus of the objec-
tive. A better plan, however, is to rack the condenser so that
its focus shall be either within or without the plane of the foil,
because it will then be possible by altering the focus of the
objective to obtain an image of the edge of the flame itself. If
an opaque object, such as the flat of a paper-knife, be moved
up and down in front of and near the flame it will then at once
be seen whether the image is erect or inverted by watching the
direction in which the image of the flame is extinguished;
thus, if the paper-knife be moved upwards, and the image of
the flame is extinguished in a downward direction, the image
is an inverted oue, and vice-versa. The results obtained by the
above method are given in the following table : —

Condenser.

Objective.

Image.

Beyond focus.

Beyond focus.

Inverted.

Beyond focus.

Within focus.

Erect.

Within focus.

Beyond focus.

Erect.

Within focus.

Within focus.

Inverted.

We see, therefore, that when the foci of both the condenser
and the objective are either beyond or within the plane of the
object the image will always be inverted, aud that when one is
within and the other beyond it will always be erect.

Now, if we examine other structures, such as the eye of a fly
or beetle, diatomic structures, dry or in balsam, the bubbles in
the fluid cavities in quartz sections, or the fluid cavities them-
selves, we shall always find that the images will follow the rules
of those of minute perforations in an opaque substance as given
in the above table. It is difficult, therefore, to see how the
character of the image can decide the question as to whether
the minute structure under consideration is acting as a positive
or negative lens.

In the first paragraph of the appendix Mr. Allan Dick men-
tions a difficulty which has probably puzzled not a few. He

THE PRESIDENT'S ADDRESS. 21

correctly remarks that " the hexagons are always turned 30° "
to their positions in Fig. 63, in the last edition of " Carpenter on
the Microscope," when the spectra at the back of the objective
are represented as in Fig. 62.*

I think an explanation of the phenomenon will be found by
the examination of any hexagonal structure, such as a honey-
comb, fly's eye, or diatom ; by doing this we shall at once see
that the three directions of the rows of hexagons are at right
angles to the three directions of the sides of any particular
hexagon. In the above-mentioned erroneous Abbe-Eichhorn
figures the hexagons are turned, as Mr. Allan Dick has pointed
out, 30° from their proper position. These figures are, as I have
frequently remarked, incorrectly drawn. If you will examine
Figs. 63 and 64 you will observe that the directions of the rows of
hexagons are in an alignment with the angles of any particular
hexagon ; they are therefore 30° out of position.

With regard to the spectra, it is well known that the spectra
assume a direction at right angles to those of the lines causing
the interference. Now it is the rows of hexagons which
cause the interference, and not the edges of the hexagons them-
selves. If, therefore, we draw three lines at right angles to the
three directions of the edges of any particular hexagon, they
will represent the three directions of the rows of hexagons ; and
if we draw a line at right angles to each of these, they will re-
present the proper position for the spectra. And also because
the angle subtended by a side at the centre of a hexagon is 60°,
and that angle and a half makes a right angle, the spectra will
therefore lie in the same direction as the corners of the hexagon.
The term used above, "rows of hexagons and not the edges
of the hexagons themselves," requires explanation ; it much
simplifies this question by regarding in the first instance the
inter-spaces rather than the lines. Of course it is the
intercostal material that diffracts the light, and in the case of
diatoms such intercostal silex has been isolated by our well-
known member Mr. T. F. Smith. This intercostal material
forms a wavy line, composed of short pieces inclined 120° to
each other, being the sides of contiguous hexagons. It is there-
fore this It.ng and ccntinr.cus wavy line that deteimines the

* These figures, together with €4, are similar to tbcte in the "Journal
E. M. S." for 1881, p. 353-4, Figs. 1C5, ICG, and 107.

22 the president's address.

position of the spectra, and not the detached short pieces which
form the sides of the hexagons ; for every side of a hexagon
is separated by twice its own length from the next side that
is in a straight line with it. In order that a filament of this
structure should break off and become separated, as in Mr.
Smith's specimen, it is necessary that the silex forming the
sides of the hexagons in the third direction should be weaker
than that forming the other two.

We now pass on to the subject for the evening, and you will
probably agree with me that the one selected for your kind con-
sideration is the most important in the domain of microscopy
that has appeared since 1875, when the Abbe diffraction theory
of microscopic vision was first published in the "Monthly
Microscopical Journal." I, of course, allude to the physical
theory of microscopic vision written by my friend Mr. Lewis
Wright in the " English Mechanic " * during the months of
September, October, and November of last year.

The questions at issue are very large, for if Mr. Wright's
conclusions are correct the table of the " Limit of Resolving
Power" in the " R. M. S. Journal " is incorrect, because it is
only valid for spurious images, and the true limit for micro-
scopic vision becomes reduced, as we shall see later on. But,
before proceeding, we must first consider the Abbe theory,
both as it first appeared, and also in its present position. In the
first instance we had a dioptric image for structure larger than
the -5-5V0 °^ an incn > an ^ after that a diffraction image. In
accounting for other pictures recourse was had to a double
theory, a dioptric one for one portion of the image and a diffrac-
tion one for another part. In simple words we were told that
a cataclysm took place in the physical phenomena of light at
a point denoted by the Y5V0 °^ an incri - And we we re further
taught that it was impossible to know anything of minute
structures unless certain impossible conditions were fulfilled,
such as the grasping of the entire diffracted fan.

There was also the Eichhorn theory with its alleged predic-
tion of structure. This has been entirely refuted both prac-
tically and theoretically, and moreover it was shown to be quite
at variance with the fundamental laws of the diffraction theory.
The diffraction theory in its pristine condition was therefore
both incorrect and illogical. As it now stands, however, with
* " English Mechanic," Vol. lx. (1894), Nos. 1537-38-40-42-43-45-47.

THE PRESIDENT S ADDRESS.

23

those embellishments and errors removed, it is a consistent
working theory, its limit of resolving power agrees very well
with results practically obtained, and it also affords valuable
information for checking the interpretation of periodic struc-
tures.

Our next point is a digression, which I trust you will pardon,
for we must investigate the theory of telescopic vision before
we can proceed.

Mr. Wright has given a very clear explanation of the theory
of telescopic vision in the " English
Mechanic."* Very briefly stated it is
this : Let A B W (Fig. 1) be a long isos-
celes triangle with a narrow base A W.
Let B represent the focus, and A W the
diameter of a telescope objective.

Then, if light having travelled along
A B arrives at B in a certain phase, it
will also arrive there in the same phase
when it has come via W B, because W B
is equal to A B. Now let us take another
point D, at one side of and close to B,
and let us draw lines from D to A and
W, then it is clear that the triangle
ADW will not be isosceles, for one side
must be longer than the other, and the
greater the distance of D from B the
greater will be this inequality of the
sides A D, W D of the triangle ADW.
Let the point D be placed at such a dis-
tance from B that the difference in the
lengths of the two sides A D and W D
of the triangle ADW amounts to half a
wave-length, it is then obvious that light
arriving at D via A D will differ in
phase from that coming via W D by half a wave-length. In
other words, to use a familiar figure, at the point B the crests
of the waves will meet the crests, and the hollows will meet
the hollows, consequently there will be a reinforcement of wave
action, but at the point D the crests will meet the hollows, and
vice-versa, so that there the wave motion will be annihilated,
* "English Mechanic," Vol. \x., No. 1540, p. 125.

24

THE PRESIDENTS ADDRESS.

i.e., there will be darkness. If the point D is moved a little
further from B, so that A D is longer than W D by one whole
wave-length (see dotted isosceles triangle ADC), there will
be another reinforcement of light at that point, and so on.

Hitherto we have only been considering the effect of the
wave-action of light at a small spot on either edge of an

objective ; we must now take
into account its action over
the whole area. Let us, in
the first instance, suppose
that the object-glass is square,
and let us divide this square
into equal rectangular spaces
by drawing lines parallel to
one of the sides of the square
(Fig. 2) ; we can then easily
see that the light passing
through one rectangle will
Fm. ^- oppose that passing through

another; thus, if we divide our square objective into eight rec-
tangles, and name them consecutively EFGHIKLM, E will
oppose I, F will oppose K, Gr — L, and H — M. The case being that
of thedotted triangle AD C(Fig. 1), where the light passing at the
E or A edge of the object-glass to the point D has one wave-length
further to travel than that passing at the AC or W edge, therefore
that passing at the centre of the square, viz., at the line
between H and I to the point D, will have half a wave-length
less to travel than that at E, and half a wave-length more than
at M. Moreover, the rectangles being all equal to each other,
the opposition of the rays will consequently be equal in effect.
From this we learn that the image of a bright point, such as a
star, at the focus of a telescope is made up of a bright disc in
the centre of a dark ring, encircled by a bright ring, etc.
Now, so long as the objective is square, it is easy to calculate
the distance the dark point D is from B. When F is the focal
length of the objective, A its aperture, and A. the wave-lenoth,

A F

then the distance between D and B, $ is equal to . This

A
means that the least separable distance in the image at the
fouus bears the same propori ion to the local-length, as the wave-
length does to the diameter of the objective. But the ratio of

THE PRESIDENT'S ADDRESS. 25

the least separable distance in the image at the focus, to the
focal-length, is the same as that of the least separable distance
in the object itself to its distance from the telescope ; there-
fore, the least separable distance in the object bears the same
proportion to its distance from the telescope, as the wave-
length does to the diameter of the object-glass.*

* As it is important that even our most junior members should
thoroughly comprehend this exceedingly simple problem, which is a
common rule-of-thre i sum, and which precisely resembles, and requires no
more mathematical knowledge than, the well-known child's problem abouo
the herring-and-a-half which cost three-halfpence, this note is appended.
Cut out of a piece of paper two precisely etpaal triangles like A B W (Fig.
1), and placing one over the other, so that the lower is exactly covered by
the upper, stick a pin through both their corners at A. Now take hold of
the lower one at the point D and move it out at one side, as shown by the
dotted triangle (Fig. 1). It will then be seen that as the point D is moved
to one side, so the point C of the lower triangle will protrude beyond the
point W of the upper one. A moment's thought will show that the displace-
ment at D is proportional to the protrusion C W, and that this proportion is
that of the length of the line A B or AD (the focus of the object-glass) to
the length of the line A W (the diameter of the object-glass). For example,
if the focal length A B is four times as great as the diameter A W, and if 1) is
moved four-tenths of an inch from B, the point C of the lower piece will
protrude one-tenth of an inch beyond W the upper. Stating this simple
problem mathematically, let us call 5 the displacement of D from B, and \
the protrusion at W, let A C or A W, the aperture, be called A, and A B or
A D the focal length, F. Then

3 : X :: F : A (i)

and every school-boy knows that to find S we must multiply X by F, and
divide the product by A.

When the dotted line C D (Fig. 1) protrudes one wave-length beyond W,
then the remainder, W I), must be shorter than A I) by that one wave-
length, and we have seen in Fig* 2 that when the distance from the M side
of the object-glass to D is one wave-length shorter than that from the E
side, the light will be extinguished at the point D. The distance B D,
therefore, represents the minimum visible, when the protrusion of C D
beyond W is one wave-length. Now, as the wave-length, the focal length,
and the diameter of the object-glass are all known, £, the minimum visible,
can be determined.

Now one word with regard to the proportion between the size of the image
at the focus, which we have just been considering, and the size of the object
to which the telescope is supposed to be directed.

26 the president's address.

In order, however, to accurately represent the area of an
objective we must inscribe a circle in our square (Fig. 2), and we
shall see that the rectangles H and I in the centre of the circle
very nearly represent the true area of that portion of the objec-
tive, but at the opposite sides of the square the rectangles E
and M are ever so much larger than the corresponding portions
of the circular object-glass, therefore the effect of the light
passing through that portion of the objective represented by E
is insufficient to neutralize the portion passing through I. The

In Fig. 3 let O B be the object, and I M the image, A C the object glass,
A being the point where the lines O M and B I intersect. Because B I and
O M are straight lines the alternate angles O A B, I A M are equal, and the
triangles O A B, I A M are similar, therefore O B bears the same proportion
to B A that I M does to M A. But B A is the distance of the object from
the telescope, and A M is the focal length ; therefore we have

object : distance : : image : focus.
Let us call for brevity the object O, its distance D, the image (supposed to
be a minimum visible) 8, and the focal length F, then

O d

D F.

Next let us transpose our previous proportion (i.) thus —

5 : F : : A : A,
S \
that is — = — ... ... ... (ii)

F A,

8 O

but we have just seen that — = —

F D,

5 A O

therefore — = — = — (iii)

F AD.
Now because the angles in question are very small (about 5") these ratios

express the angles themselves, therefore — becomes the anule the object

D
subtends at the object-glass (1) being the distance between the object

x
and the telescope), and — the angle one wave-length subtends at a distance

A
equal to the diameter of the object-glass {i.e., A the aperture), therefore the
statement above is correct which says that the smallest object
that can be seen with a telescope is that which subtends an
angle at the object-glass equal to that subtended by one wave-
length at a distance equal to the diameter of the object-
glass.

In Fig. 4, A C or A W is the diameter of the objective,
and C W is one wave-length, then equation (ii) shows that
the angle C A W (Fig. 4) is equal to the angle I A M (Fig. 3)
for a minimum visible, but the angle I A M is equal to the
angle O A B, therefore the angle () A B is equal to the angle
C A W, provided that the image is a minimum visible, equa-
tion (iii).
Fig. 4

THE PRESr DENT'S ADDRESS. 27

distance from B to D must, therefore, be increased. The calcula-
tion of the distance between D and B (Fig. L), when the object-
glass is circular, is a much more laborious and complicated
problem. It was first solved in 1834 by Sir Gr. Airy,* the late
Astronomer Royal, who was the originator of this theory, of
which the above is a mere outline. He found that with a
circular objective, 8 the distance between D and B, was equal

1'2197 A. F

to r * It is not my intention to trouble you this evening

with any dry mathematical formulae, or repeat what I have

demonstrated elsewhere, but you may take it as correct that the

. ■ X F, .
formula for a square aperture given above, viz., 6 = —r~ * s

practically the same, that it yields the same numerical
values as Abbe's formula for microscopic vision, with which you
are all well acquainted.

Unfortunately, however, the apertures of both telescope and

Fig. 5.

In Fig. 5 the three triangles are superimposed ; it is a simple and easily
remembered picture which contains the whole germ of the theory. Let
A C be the diameter of the object-glass, A I its focal length, and A O the
distance of the object. Then when C W is one wave. length, I M is the size
of the minimum visible image at the focus, and O B is the size of the object.

This result I have expressed in a simpler and more handy form in
another place thus : — " One unit of Aperitive resolves one unit of Interval
at a distance equal to the Reciprocal of the Ware-length." Example: —
Let a wave-length be chosen between lines C and J), viz., ^o^eo iuch. Then

Aperture resolves Interval at Distance.
1 inch 1 inch 42,260 inches.

1J inch 1 inch 1 mile.

3 inches 1 inch 2 miles.

3 inches | inch 1 mile.

This table agrees with practical results obtained for terrestrial objects
seen by reflected light with the best telescopes.

When a wave-length of ^fIto (between lines 1) and E) is taken for bright
celestial objects the above rule agrees with Dawes' empirical formula for the
separating power of astronomical telescopes, viz., 4"56", divided by the
aperture of the object-glass in inches.

* "Cambridge Philosophical Society's Transactions," Vol. v. (1835).

28 the president's address.

microscope objectives are not square, but circular, and referring
to the formula for circular telescope objectives we see that it is
a trifle more than one-fifth larger than that for square apertures.
It therefore comes to this, that so long as the telescope objec-
tive is square, and the microscope objective is circular, the
mathematical formulae for both are numerically identical,
although the reasonings by which those formulas are obtained
lie along""wholly different paths; but when we have circular
objectives in both cases, the resolving power of a telescope,
according to the physical theory, is about one-fifth less than
that of a microscope, according to the diffraction theory. Now,
we know that it is impossible that light should act in one way
in a tube because it is called a telescope, and in another way
when it is called a microscope, and it was this glaring
discrepancy between the telescopic and microscopic theories
which led me to publish in 1893 a pamphlet on " The Theory
of Telescopic Vision." Thus it was my endeavour to bring the
theory of telescopic vision into harmony with that of the
microscope. This evening you have before you the converse
problem in Mr. Wright's articles, bringing the microscopical
theory into consonance with that of the telescope. There is
one thing for certain, that sooner or later either the Airy or the
Abbe theory will be abandoned, for both cannot possibly be
correct.

You must now know that with regard to these articles in the
11 English Mechanic " 1 am in a somewhat better position than
you, because, in reply to some notes, Mr. Wright most kindly
wrote to me at great length explaining several of his points,
and giving me fuller information concerning others. What
follows next with regard to the resolving limit will therefore
have more reference to his letter than to what has appeared in
print.

Lord Rayleigh, whose work on the undulatory theory is so
well known and appreciated by all, made careful experiments
with a telescope,* and obtained a somewhat smaller limit for
circular apertures, viz., one lying about half-way between those
calculated by Airy for circular and square apertures.

* " The Resolving Power of Telescopes," bj Lord Rayleigh. " Pliilo
gophical Magazine," August, 1880.

THE PRESIDENT'S ADDRESS. 29

We have therefore three limits, viz. : —
*Square aperture (same as Abbe) .. .„ $=

Circular „ (Rayleigh experimental) 8
Circular „ (Airy calculated) ... 8

A

109 AF

A
1-2197 AF

A

It is stated that there are certain theoretical considerations
which show that a star disc as seen in a telescope should be
smaller than that calculated by Airy ; this reference, however,
I have not been able to look up. Now it is quite reasonable to
expect that a limit obtained practically with instrumental
appliances should fall short of a calculated theoretical limit,
but it is difficult to understand how it can exceed it. This is
certainly a point upon which more explanation is required.
The actual resolving power of the microscope, therefore, accord-
ing to Mr. Wright's theory, for a full cone, adopting the middle
formula above, viz., that derived by Lord Rayleigh from actual
experiment with a telescope, and employing the same wave-
lengths as those given in the tables in the " R. M. S. Journal "
for white and monochromatic blue light, viz., for lines E and F,
will be

88,450 multiplied by the N.A. for line E.
and 95,880 „ „ „ F.

But, as before remarked, the line E is too high up the
spectrum for visual purposes ; it will be better to take one
somewhat similar to that selected for my table in the " R. M. S.
Journal " for 1893, p. 17, then the limit will be

85,630 multiplied by the N.A.

As, however, a full cone in practice can seldom be used,
and because with a 3/4 cone spectra are present in the
outer annulus, the table which is given presently will still hold
good.

To reduce this question to its simplest terms, the resolving
power of a microscope objective of N.A. TO, with a full cone,

* My own experiments with telescopes on terrestrial objects, as well as
those ofDawes on Double Stars, agree with this value,

30 THE PRESIDENT'S ADDRESS.

and with white light (line E, the same as used in R. M. S.
tables), will be

96,410 according to Abbe theory.

88,450 „ Rayleigh experiment.

79,044 „ Airy theory.

Now the results from experiments both with full and 3/4
cones go largely to corroborate Mr. "Wright's conclusions.
It is common knowledge that when a full cone is em-
ployed the resolving power falls off, and it has been cus-
tomary to account for this falling off in the resolving power by
the outstanding spherical aberration in the objective. To test
the accuracy of this current notion a critical image was set up,
and matters arranged so that access could be obtained to the
back lens of the objective without disturbing any of the adjust-
ments. When a full cone of light was used the resolving
power fell off, and when a 3/4 cone was employed it was
as usual restored again; a stop was then placed at the back
lens, cutting off the peripheral unilluminated annulus. We
had, therefore, an objective of less aperture, but illuminated by
a full cone. Under these circumstances one would have
expected to see a critical image, but not so, and this is the
crucial point. In order to obtain the maximum resolving
power for that reduced aperture the illuminating cone had to
be reduced until only three-quarters of the back lens was illu-
minated. This is a most important fact, because it shows that
spherical aberration is not playing the role commonly assigned
to it, and the blotting out of structure has a deeper meaning.
Reading this in the light of the new theory we see that when a
full cone is used the image comes under the physical or Airy
limit, but the moment we use a 3/4 cone we have diffraction
spectra in the peripheral annulus. The picture therefore
obeys the Abbe limit with its greater resolving power.

Probably spherical aberration is present as well, and pro-
duces a certain amount of indistinctness of image which helps
to obliterate the fine detail, but the above experiment proves
that spherical aberration does not account for the whole pheno-
menon as it was previously thought to do. With regard to the
3/4 cone illumination, it should be remembered that the areas
of circles are in the proportion of the squares of their diameters ;
therefore the area of the peripheral annulus where the spectra

THE PRESIDENT'S ADDRESS.

31

pass is only 12| per cent, less than the area of the central por-
tion illuminated by the 3/4 cone. The numerical values are: —
Darkened annulus ... ... ... 43' 75

Illuminated central portion ... 56 25

100

Because in practice we are bound to use a 3 4 cone we shall
therefore have an image compounded of a true image in the
central three-quarters of the whole aperture, according to Mr.
Wright's theory, and an Abbe diffraction, or " true false "
image, in the peripheral annulus, according to my nomenclature.
The resolving limit will therefore, as stated above, agree with
this table from the " R. M. S. Journal."

Table of Resolving Powers in Lines to an Inch with 3 [4 Gone
of Direct Illumination.

White Light.

Between lines D and

E 46,666 waves

per inch.

Monochromatic Blue

N.A.

Light and Photo-
graphy. Near line
E 53,333 waves per
inch.

o-i

7,000

8,000

0-2

14,000

16,000

0'3

21,000

24,000

0-4

28,000

32,000

0'5

35,000

40,000

0-6

42,000

48,000

07

49,000

56,000

0'8

56,000

64,000

0-9

63,000

10

70,000

The same as for

11

77,000

white light.

12

84,000

13

91,000

14

98,000

1*5

105,000

T6

112,000

The above table agrees remarkably well with results actually
obtained with the best lenses, and to show that this is so the
following table gives the actual resolutions made on diatoms in

32

THE PRESIDENT S ADDRESS.

balsam with a 3/4 cone from a Powell fluorite apochromatic
condenser (1/4 of 0'95 N.A.) : —

Objective.

Apochromatic lin. ...

1. Achromatic 4/ 10 (1875)

2. Apochromatic 12

3. Semi-apochromatic 1 4
Achromatic 1/4 (1875)
Semi-apochromatic 17

4. Achromatic 1/5
Apochromatic 1/4

5. Semi-apochromatic 1/12

6. Apochromatic 1/8

O.I.

28-9

1
NA.

•32

20-0

•04

320

■66

18-6

•71

165

•79

115

•86

16-3

•88

23-2

•95

9-7

1-26

170

143

White Light. | Blue Light.

22,000

40,000 strong

46,000

53,500

53,000 barely

60,000

60,000

65,000

90,000 barely

94,000

25,000
49,000
53,500

60,000 barely
60,000 barely;:
65,000
65,000 barely

1. Would resolve probably 42,000 with white light (construction same as
achromatic 1/4, viz., triple front and back, double middle).

2. A very fine lens.

3. A little more than 3/4 cone used ; this lens is a very strong resolver,
and stands blue light even better than some apochromatics.

4. A fine example of an achromatic by Gundlach.

5. Will not resolve the Nitzsehia curvula, 90,000.

6. Resolves Amphipleura pellucida, 93,000-95,000. Less than 3/4 cone
used.

To return to the diffraction theory, it has been recognized for
some time past that there is more than one kind of image, and
on a former occasion it was my endeavour to prove to yon that
there were three distinct kinds of images, one being a " true "
image, which went in and out of focus as a daisy under a 4in.,
the other two being " false " images, one of these a " true-false "
image, whose character was similar as regards the arrangement
of the elements of the periodic structure to that of the object
itself, but under focal alteration it passed into another kind,
called a "false-false" image, whose character entirely differed
from that of the " true " image. Now Mr. Wright's position,
if I have interpreted him correctly, is this, that his new " true "
image comes under the laws of the Airy or physical theory, but
the other two images, viz., the "true-false" and the "false-
false," conform to those of the Abbe or diffraction theory.
With regard to this last image, it is admitted by all genuine
microscopical workers that it is not only of no use, but is abso-
lutely a hindrance to the interpretation of microscopical struc-

THE PRESIDENT'S ADDRESS. 33

tures, and on this account it, as well as the small cone by which
it is produced, ought to be got rid of as far as possible. Mr.
Wright has assigned it to a class of physical phenomena known
as Fresnel's interference bands. These images therefore will
in the future be only regarded as interesting examples of
experiments in physical optics. It is important to consider for
a moment the " true-false " image and its influence on that
obtained by the only correct method of microscopical illumina-
tion, viz., a 3'4 cone. It is, as we have seen, one of the com-
ponents of the resultant image, and it is formed by spectra
passing through the peripheral annulus. The new theory
shows that this image also partakes of the nature of Fresnel's
interference bands, but because it is a " true-false " image it
strengthens, by its superior resolution, Mr. Wright's new
" true" image, and as we must put up with it, full cones being
impracticable, it is consoling to know that it is a " true-false "
image that we have to deal with, which will assist, and not
injure, our new "true" image.

Putting the case in another way we see that it is the image
formed by the central three-quarter portion of the whole objec-
tive that definitely fixes the focus, and consequently we are
unable to play upon focal adjustment for the formation by
means of the Fresnel bands of various pictures, which, however
beautiful they in themselves may be, yet have nothing what-
ever to do with the structure under the microscope. Some will
say that we have at last come back to Abbe's original theory,
which he has since abandoned, viz., that the microscopical
image is compounded of two superimposed images, one a
dioptric image and the other a diffraction image beginning at
23V0 inch- To this we reply that, although in words it may
be so, in meaning the case is far different. To mention two
differences : Abbe's double image was the essence of the micros-
copical image, but now the double image is an accident arising
from the impossibility of using full cones. Again the resolu-
tion in the centre conformed to the Abbe limit, whereas it now
possesses less resolving power owing to its dependence on the
Airy limit.

With regard to the action of the four kinds of illumination
by means of axial cones, the following are from results obtained

Journ. Q. M. C, Series II., No. 36. 3

34 the president's address.

in practical work. The order given is from the strongest to
the weakest resolver : —

Appearance at Bach of Objective.

1. Peripheral annnlus bright, 3/4 centre dark.

2. Peripheral annulus dark, 3 '4 centre bright.

3. The whole dark (dark ground).

4. The whole bright (full cone).

No. 1, which is made by placing an opaque central stop* at
the back of the condenser, is the strongest resolver of all
symmetrical systems of illumination. (This stop at the back
of the condenser must on no account be confused with a stop at
the back of the objective for the purpose of cutting out a
narrow central dioptric beam). It is nearly, but not quite, so
strong a resolver as the asymmetrical method by light in one
azimuth by means of a slotted stop. The resolving power of
No. 1 does not come under the new theory, because spectra are
formed in the 3,4 central portion ; the theoretical limit is there-
fore 96,410 times the N. A. of the objective, the wave-length being
the same as that used in the R. M. S. tables (line E.). No 1
cannot, however, be recommended for practical work, because it
is so liable to produce false images, and especially to double the
structure. Any structure near the limit for a lens of half the
aperture is likely to be doubled, e.g., an Angulatum, which can
be resolved by an objective of N.A. "7, is likely to exhibit inter-
costals when examined by a lens of N.A. 1*4, and illuminated
in this manner. This method will require a condenser whose
aperture must be fully equal to that of the objective.

No. 2. — This, which is known as 3/4 cone illumination, is the
best for general purposes, and because of the presence of
spectra it also does not come under the new theory. The theo-
retical resolving limit for line E is 72,307 times the N.A. of the
objective. The image, as we have seen above, is compounded of
the new " true " image, and the " true false " image of the old
diffraction theory. It may, therefore, be relied upon. The
aperture of the condenser need only be 3/4 that of the objective.

* It would be far better if the meaning of the word "stop" in micro-
scopical literature were coniined to the opaque central stops used at the back
of the condenser for producing dark grounds, etc. The common stops,
with central circular apertures, might be appropriately called "dia-
phragms."

THE PRESIDENT'S ADDRESS. 35

No. 3. — Dark ground obtained by a condenser and a stop ;
this is only available for the lower powers ; the apochromatic
| or | of -65 N.A. may be said to exhaust this method of
illumination. This case, in my opinion, comes wholly under
the new theory, because all the aperture is uniformly utilized.
To all intents and purposes an object such as a diatom may be
said to be self-luminous ; under these conditions the action of a
microscope most closely resembles that of a celestial telescope.
The practical resolving limit is only a trifle below that of No. 2 ;
theory, however, demands that it should be higher. Taking the
same wave-length the resolution for No. 3 should, according to
the new theory, be 79,044 times the N.A. of the objective,
against 72,307 times the N.A. for case No. 2. Practice, how-
ever, as we have seen, reverses the order, and gives No. 2 a
slightly higher resolving power. The condenser must, of
course, have far more aperture than the objective.

No. 4 comes entirely under the new theory, but resolution
falls off considerably; there is also an indistinctness in the coarse
structure. Theoretically the limit is the same as that of No. 3,
viz., 79,044 times the N.A. of the objective. This mode of
illumination is not practical. A condenser of larger aperture
than that for No. 2 is required, because it must, of course, equal
that of the objective.

It is interesting to notice that with No. 2, the 3/4 cone illumi-
nation, if the object is placed at the edge of the image of the side
of the flame, especially if the edge is somewhat undefined by the
condenser being brought a trifle within or without its focus, the
resolving power is increased. This well-known illuminating
dodge becomes an important confirmation of the new theory,
for Mr. Wright, with reference to the action of the illumination
from a wide-angled cone, says, in Art. 23, that a " plenum " of
rays "in the same phase" diverge from each point in the
structure, so that the points become centres of wave propaga-
tion, but along the edge of the cone diffraction phenomena arise.
Does not, therefore, the above experiment fully confirm the
statement in Art. 23, which should itself be read, as it is far
better expressed than in my condensation.

In this connection it will be found that a curious effect is
produced when examining fine-lined structures with the naked
eye, if an obstacle is held somewhat nearer the eye and the lined

36 the president's address.

structures be viewed through the haze at the edges of the
obstacle. For example, if the finger be held in front of the
eye at a distance of about four inches, when the vision is
normal, and if the eye be focussed on some object at a greater
distance, a haze will be seen surrounding the out-of -focus finger.
Now if a fine-lined object, nearly at the limit for resolution, be
examined, the resolution will be found to be strengthened when
it is viewed through the haze at the edge of the finger. A
black-edged card might with advantage replace the finger.
Some ridges, which counted 45 to the inch, on the black cover
of a cloth-bound book were examined, and it was found that
they became much more distinct when they were viewed
through the haze at the edge of a card.

After this digression, let us see what Mr. Wright says about
the Microscopic Image. In Art. 21 (6) he attacks the Eich-
horn intercostals from a point of view different to that I have
taken, and I heartily concur in all his conclusions. The next
paragraph (c), with regard to the statement that the striae of
A. Pellucida, which Mr. Sollit measured as 120,000-130,000
per inch, were ghosts, is not so clear for the following
reasons : —

First. — At that time there was no objective with a resolving
limit approaching such figures.

Secondly. — A false ghost must always be within the resolv-
ing limit of the lens.

Thirdly. — A false ghost must always be an integral multiple
of the true structure.

Therefore, assuming that Mr. Sollit had a coarse A. Pellucida
of say 90,000 striae per inch, the coarsest false ghost he could
have made must have had 180,000 lines per inch, and the next
one 270,000, and so on. Now, as 180,000 lines per inch was
beyond the limit of any lens then constructed, no one had ever
seen a ghost of the true striae on A. Pellucida. In some dry
mounts of this diatom, especially those burnt on cover, there
are apparently coarse wrinklings of some outer membrane,
which have nothing whatever to do with the striae in question ;
these can easily be seen with any quarter-inch objective. It is
more than probable that some running about 40,000 per inch
were doubled and afterwards erroneously measured, for it is

THE PRESIDENT'S ADDRESS. 37

only in comparatively recent years that accurate measurements
of the so-called striae on the diatomaceee have been made.*

The deductions which Mr. Wright has postulated in the next
Art., No. 22, is a most important addition to microscopical
literature. Speaking of the Fresnel interference bands, i.e.,
microscopical images formed by a small cone or beam, centric
or excentric, he says " that these lines are in no sense
images, but mere interference bands or fringes with no
definite focus ; that whenever thus really produced they are
a constant source of uncertainty and error, and to be got rid of
as far as possible by the use of large aplanatic cones ; that
when we use such cones we lose such fringes altogether and
get a real focussed image, true to the object so far as the
aperture and correction of the lens permit of its definition ; and
that this image is a dioptric image."

Further on, he says " that the narrow cone and the diffrac-
tion theory stand or fall together." This statement is per-
fectly correct, provided that it is the diffraction theory as
enunciated by Abbe and his exponents which is meant; and can
this be wondered at, seeing the theory at its inception was not
even a logically sound argument ?

With regard to Abbe's statement, quoted in this article, viz.,
" Strictly similar images cannot be expected, except with a
central illumination with a narrow incident pencil, because this
is the necessary condition for the possible admission of the
whole of the diffracted light," let me put before you a simple
experiment. Place a P. Angulatum under an objective of '65
N. A., and illuminate it by a narrow central incident pencil ;
you will see neither structure nor spectra. Enlarge the in-
cident cone until it fills three-quarters of the objective, and you
will now see both spectra and the angulatum pattern. This
proves that the wide cone is a better condition than the narrow
incident pencil for the admission of diffracted light.

I am perfectly aware of the imperfections of this brief review
on Mr. Wright's important articles, but it has been my endeavour
to discuss them fairly ; neither have I consciously slurred over
or omitted any difficulties or unexplained points for the purpose
of making the case appear stronger than it really is. The sub-

* "M. M. J.," Vol. xv. (187G), p. 223.

38 the president's address.

ject is so large that it would take a longer time than is at ray
disposal this evening to do it full justice, and I am also aware
that although it is a momentous question in the interests of
microscopy, it is, nevertheless — and from the nature of the case
must be — dry as dust. An apology, therefore, is due to you for
bringing it before you at an Annual Meeting, when it is naturally
expected that the address should be of a lighter nature, but I
felt that its importance was paramount, and therefore ven-
turpd to trespass on your good nature.

In conclusion, let me briefly sum up. In the first place, it
will be conceded by those who have studied his articles with-
out prejudice that Mr. Wright has been the first to give a cor-
rect theory of microscopic vision with large illuminating cones,
and, secondly, that he has disproved the theory, generally
accepted among microscopists for the past 20 years, with regard
to spectral images, and has shown that they belong to a class
of physical phenomena known as Fresnel's interference bands.

39

On a New Camera Lucida.

By Edward M. Nelson, F.R.M.S.

{Bead November 16^, 1894.)

The well-known neutral tint of Dr. Beale is such a simple
and inexpensive form of camera that it seemed a pity that the
only drawback to its coming into more general use, viz., that
of transposing its erect image, should not be corrected. This
drawback is a serious one, because a picture drawn by a Beale's
camera only becomes similar to the original object when it is
viewed as a transparency from the wrong side of the paper.
For instance it is well known that some insects have one leg
on one side of their bodies different to the corresponding leg on
the other side, and it is necessarily important that such micro-
scopic objects should be depicted correctly. Now all we have
to do is to correct the transposition without altering the image
in any other manner. Obviously this can be accomplished by
adding a lateral reflection. If, therefore, we place over the
eye-piece, at an angle of 45°, a small silvered mirror (a first
surface mirror is unnecessary, a piece of ordinary silvered
glass, such as is used in sextants, answers every purpose), so
that when the microscope is placed in a horizontal position the
image may be reflected at right angles to the body, either to
the right or left hand of the microscope in a plane parallel to
that of the table, and then if we intercept this horizontal beam
by an ordinary Beale's neutral tint, an erect image, with its
transposition corrected, will be reflected upwards to the eye,
and seen on the table through the neutral tint in the usual way.
In brief, the lateral reflection corrects the transposition, w^hile
the vertical reflection forms the first surface of the neutral tint,
the inversion of the image. The resultant image is, therefore,
precisely similar to the object on the stage of the microscope.
Anyone possessing a right-angled prism can produce the same
effect by placing it anywhere between the objective and the
eye-piece, and by placing an ordinary neutral tint on the eye-
piece ; of course, the horizontal position of the right-angled
body, when the microscope itself is in a horizontal position,
must be maintained.

40

PROCEEDINGS.

October 5th, 1894- Conversational Meeting.

The following objects were exhibited : —
Comatula rosacea, pinnae with ova ... Mr. G. E. Mainland,
Aulacodiscus evcavatus ... ... ... Mr. H. Morland.

Euchlauis triquetra, $ ?, mounted ... Mr. C. Rousselet.

October 19th, 1894. — Ordinary Meeting.

E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
members of the Club :— Mr. R. W. Howard, Mr. F. Hughes.
The following additions to the library were announced : —
" Journal of the Royal Microscopical ) ^ , tl S ' t

Society" ... ' J 101 e y '

" Proceedings of the Manchester )

Microscopical Society " ... J

" The Botanical Gazette " ... ... In Exchange.

" Proceedings of the Belgian Micro-
scopical Society " ...
1 ' Annals of Natural History " ... Purchased.

Series of reprints on " Infusoria " ... Monsieur Certes.
The Secretary said it was well known to members that the
specimens in the cabinet had for some long time been under-
going revision, but as it was a very tedious and laborious task,
owing to the large number to be gone over, and still very far
from completed, the Committee had deemed it advisable to
print a catalogue of the Williams collection, which was a fairly
representative and carefully-selected one, as a beginning, and
this was now ready and obtainable from the Curator, price
sixpence a copy. He thought it would prove a useful guide to
such of their junior members who might be putting together a

}

41

general collection of their own, as it was a classified catalogue,
and not merely a list'of preparations.

Mr. Goodwin thought that some greater facilities might be
afforded to the members of the Club for seeing what slides
were in the cabinet. If some microscopes could be kept there
as well as the slides it would enable them to do this without
the trouble of bringing their instruments with them.

The President said there was a drawback to this idea on
account of the high charges made for rental, and he really
thought with regard to these preparations the best thing to be
done was to select from the catalogue, and take the slides home
and study them at leisure.

Mr. Yezey said that fresh regulations as to borrowing slides
would be found printed inside the catalogue, which increased
the facilities hitherto given, and were much more to the advan-
tage of the members than those previously in force.

Mr. Watson exhibited a microscope which was similar in
design to the Yan Heurck microscope, but contained several
alterations and improvements. The stage could be rotated
completely either by the hands or by rack work. The milled
heads were fixed on one centre, and did not travel with the
stage. The optical centre was lOin. high from the table when
horizontally placed, and the spread of the feet also lOin., giving
great stability. There was also a centring motion which could
be clamped when required.

The President thought they were to be congratulated upon
having so fine an instrument upon the table before them. It
was beautifully made, and he was satisfied it was capable of
doing the highest work required to be done. The complete
rotation of the stage was an advantage, and it should be re-
membered that none of the movements in the old microscope
had been sacrificed in obtaining it.

Mr. Karop said he had received from Mr. Swift for exhibition
a new mounting for an Abbe condenser, which was made to
carry the usual iris diaphragm, but had a movement by which
it could be made eccentric and rotated in that condition. He
also exhibited a new pond weed grapnel which was made for
conveniently carrying in the pocket.

The President thought the Abbe condenser was a very
prettily contrived thing and thoroughly well made, but it was

42

designed for obtaining oblique light, and for making false
images of diatom structure. The pond weed apparatus was
just like a " centipede " used for grappling submarine cables.

Mr. Western thought it was a great improvement upon the
ordinary drag hook, which was an extremely inconvenient thing
to carry in the pocket and uncomfortable to sit upon.

Messrs. Ross and Co. sent also for exhibition a collection of
their latest instruments, representing nearly every class of their
work, from the small star microscope upwards.

The President said they were much indebted to Messrs. Ross
for sending down these instruments. The chief novelty was
the means for rotating the body on the round stand, by means
of which very great stability w r as secured when the body was
inclined or placed in the horizontal position. The second
novelty seemed to be in the substage, which was made some-
what on the Reichert plan, turning out on one side in a manner
which certainly had its advantages. He thought this arrange-
ment of the foot would make it very good for photography, for
though the base was circular it really rested on three points,
and therefore it was steady.

Mr. Karop could not help thinking that the position of the
iris diaphragm was a mistake, because it cut off the rays in the
wrong place, viz., too near the apex of the cone.

Mr. Ingpen said with regard to the diaphragm not being
used with the condenser, the old French plan was to have three
apertures, and these were adopted and used in the old Zeiss
instruments, but they were meant more to be used when the
condenser was out of use. The origin of the plan was the old
Varley dark chamber.

Mr. Western read a paper " On four Foreign Rotifers not
previously recorded as found in Britain."

Mr. Bryce said he had an opportunity afforded him of seeing
the form last mentioned by Mr. Western, and he came strongly
to the conclusion that it was not Rotifer mento, i.e., if any
reliance was to be placed upon Anderson's drawings. It was
very like Rotifer vulgaris, and required very careful observa-
tion to distinguish it.

The thanks of the meeting were voted to Mr. Western for
his communication.

Mr. Karop said that as the matter on the agenda paper was

43

somewhat short, he should like to read an interesting letter he
had received from Mr. T. H. Buffham earlier in the year,
relating to the organisms found in the estuary of the Thames
at a certain period, and which gave rise to the phenomenon
known as "foul " or " May- water." The subject was brought
forward at the May meeting of the R.M.S., by Mr. Shrubsole,
of Sheerness-on-Sea, who gave an interesting account of this
peculiar state of the water, and distributed samples. Knowing
Mr. BufBkam's active concern with anything relating to marine
algae, to which these organisms presumably were related, and
thinking he might be able to throw some light upon it, I wrote
to him, and he, after examining material provided by Mr.
Shrubsole, sent me this letter (read). The chief forms found
in the water were spheres, about the size of small volvox, or
cylindroids of transparent, gelatinous stuff, and containing
large numbers of greenish-yellow or brown crescentic bodies
imbedded in it. The exact nature of these organisms appears
to be, at present, quite undetermined. The matter was of
economic as well as of scientific importance, because Mr.
Shrubsole states that during their apparition the whole of the
fish precipitately retire from the mouth of the river and so put
an end for a time to one of the chief industries of the locality.
It seemed reasonable to suppose that the reason for this
emigration of the fish was either that the organism was
poisonous or unfitted for food, or, from its abundance and
slimy consistence, it would choke up the breathing apparatus
of the fish if they remained. I understand the phenomenon is
of yearly recurrence and it certainly deserves careful study.

Notices of meetings, etc, for the ensuing month were then
given, and the proceedings terminated. The following objects
were exhibited : —

Syringa, section of flower bud Mr. H. E. Freeman.

Floscularia campanulata, mounted ... Mr. C. Rousselet.

November 2nd, 1894. —Conversational Meeting.

The following objects were exhibited : —
Floscularia cornuta ... ... ... Mr. M. Allen.

Rotifer a, various species .. . ... .. Mr. W. Burton.

Corethra jplu unicornis ... ... ... Mr. J. A. JJaniell.

44

Stem section of a Brazilian Liana ... Mr. G. Dunning.

0scillaria,8v.? Mr. W. Goodwin.

Peueroplis pertusus ••• Mr. A. Jenkins.

Alcyonium palmatum Mr. G. Mainland .

Navicula tumescens Mr. H. Morland.

Corallistes BowerbanMa, Ceylon Mr. B. Priest.

Euchlanis lyra, mounted Mr. C. Rousselet.

Arrenurus buccinator ... ... ... Mr. C. D. Soar.

November 16th, 1894.— Ordinary Meeting.

E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
members of the Club :— Mr. Walter P. Shadbolt, Mr. Edwin
Wooderson, Mr. W. B. Stokes.

The following additions to the library were announced : —
11 Nova Acta Car-Leopold Akademie Nat. Cur.," two vols.
" Proceedings of the Literary and-\

Philosophical Society of Man- V From the Society.
Chester" ... ... ... J

" Annals of Natural History" ... Purchased.
"Photomicrography" Dr. VanHeurck.

"Synopsis of the Naviculoid")

_/. / „ -d . T \ Prof. Cleve.

Diatoms, Part I )

The thanks of the Club were voted to the donors.

Mr. Karop said the last on the list of additions to the
library deserved something more than a mere formal acknow-
ledgment. This was Prof. Cleve's Synopsis, the first instal-
ment of a very important work. He had taken one genus, the
Navicula?, which by the unnecessary and unscientific multipli-
cation of species had grown to most unwieldy proportions, and
endeavoured to reduce it to order. The literature was equally
colossal and scattered, and, therefore, a revision necessarily
involved very considerable labour and research, as well as
special knowledge of the subject, and those who worked at
diatoms would not be astonished to hear that it had occupied
Prof. Cleve i\\v besi pari of eight years. The present part

45

contained four plates, and he was informed the second would
not be long before it appeared.

A special vote of thanks to Prof. Cleve for his valuable
donation was unanimously passed.

The President said he had also received from a friend — Mr.
Marryat — two beautiful series of photomicrographs of Karyo-
Kinesis in Lilium bulbiferum. These were all taken by cheap
leuses with peacock-blue glass screen, the sections beiug stained
with blue haematoxylin.

The President said that he wished to make a remark with
regard to a note of his which was read on March 16th last. In
that note, in which he had made no claim to originality, he had
referred to common optical formulae, which could be found on
the first page of elementary text-books on the subject ; but the
alternative formula (vi.) was, so far as he knew, not given in
any text-book, and, therefore, might have been considered
original. Last night, however, while searchiag some back
volumes of the "R.M.S. Journal " for a reference on a totally
different subject, he came across the same formula in a paper
by Mr. C. R. Cross in the " M.M. J.," 1870, Vol. iv., p. 149,
and in the " Journal of the Franklin Institute " for June, 1870,
p. 401. So that to Mr. Gross must the honour be accorded for
first publishing this simple and very useful formula.

The President said he had lately come across an article
exhibited in a tobacconist's shop as a pipe cover. It was an
iris diaphragm, which might be used for cheap microscopes.
He had brought it to the meeting for inspection.

The Secretary said that at their last meeting Mr. Swift
exhibited a little portable pond drag which could be carried in
the pocket. Since then Mr. Allen had suggested a further
improvement by adding a cap to one end to which an eye was
fixed, so that a piece of string could be attached.

The President exhibited and described a new device which
he thought might prove of service in microscopical work. It
was an addition to the principle of Beale's neutral tint reflector,
which, though possessing great advantage over the Wollaston
camera or the Soemmering mirror, had the disadvantage of
exhibiting the picture laterally inverted. By means of a second
lateral reflector this inversion was got rid of and the image
appeared erect in both directions.

46

Mr. J. E. Ingpen thought this would prove a very useful
addition to the large number of drawing contrivances which
existed. He remembered that many years ago when the
subject was before the Club a number of these were exhibited,
and if he had known the sabject would be cropping up that
evening he could have brought up a considerable number of
examples.

Mr. Michael said it was difficult to estimate the importance
of this contrivance, because a camera which did not distort and
did not require the head to be held quite steady was what
everybody who made drawings in that way was most anxious to
possess, and if anything could be done to get rid of the fatal
error of Dr. Beale's camera it would be a most valuable
achievement.

The President said that Cook in 1865 tried a mirror for the
purpose of casting the image down upon the paper, but with
high powers there was insufficiency of light. With low powers,
however, it worked very well.

Mr. Ingpen said that an interesting illustration of this method
was found in the case of " Varley's Graphic Telescope," which
was an instrument of about 6in. focus, with a mirror in front of
the object glass. There was a large specially-constructed eye-
piece, and then another mirror at an angle of 45 degrees coming
half over the eye-piece. Varley wrote a book on drawing instru-
ments, and was going to publish it in conjunction with Mr.
Home, but they quarrelled over it and destroyed all the copies
except a very few, one of which he was fortunate enough to
obtain through his friend Mr. Ackland.

Mr. Karop thought anyone who could draw hardly required
any apparatus at all beyond cross-lines in the eye-piece and
some sectional paper. Possibly a camera might be useful for
making an outline, but all detail must be put in subsequently,
and it was to be borne in mind that the use of any special
appliance did not obviate inaccurate drawing in the least,
although it was often stated as a sort of guarantee.

The President said that a great deal of the correctness
depended upon the person who made the drawing. He remem-
bered once seeing Mi-. N. E. Green make a most perfect drawing
from the microscope without once looking at the paper.

Mr. Michael thought there could be no doubt that drawing
carefully upon square ruled paper gave more accurate results,

47

but a great deal of time was lost by tbis metbod, and a certain
amount of rougb detail as well as tbe outline could be done
witb the camera in a much shorter time. He thought, how-
ever, that this was a matter upon which one man could not be
taken as a rule for another. Many persons had a difficulty in
seeing the paper and the object equally well at the same time,
and a man who was a good draughtsman would naturally do
better than one who was not, and there was also a good deal in
the idiosyncrasy of the individual eye. Personally he might
say that he preferred the method with ruled lines.

Mr. Rousselet said he had a home-made camera, which he
found to answer very well. A small mirror of speculum metal
reflected the image upon a cover-glass, through which the paper
was seen. The image in this case was not reversed. The plan
was Mr. Usher's invention.

The thanks of the meeting were voted to the President for
his communication.

The President intimated that there was nothing further upon
the agenda paper, but as he saw Prof. Chas. Stewart present he
ventured to ask if he would favour them with a few remarks.

Prof. Stewart said that when he came into the room he had
no expectation of being called upon to speak, but as the
President had done so he would in response say a few words
upon what was to be seen in one particular section of the
Museum with which he was more especially connected, and he
thought it possible that some persons present might be interested
in the structural varieties of fish bones. In the case of fish
which had frames of rigid structure, they found these to be
composed of a substance which was different in many respects
from such bone as they found it in mammals, although
it was rather difficult not to regard it as bone. When examined
under the microscope it was found to be wanting in the
familiar so-called bone-corpuscles ; it had a somewhat fibrillated
matrix, and in that matrix were rows of large spaces much
larger than the ordinary haversian canals. These certainly
were not blood-vessels, and they did not contain cells, but if
they were hardened and sections were taken they were found to
contain fine granular material, but in not one which he had
examined had he ever succeeded in finding either a cell or a
blood-vessel. The cod, haddock, and fish of that class all had this
kind of bone. In other classes of fish a very different structure

48

was found. In the sword-fish the matrix was traversed by
tubes which were no doubt Haversian canals containing
blood-vessels, but around each canal were more or less defined
lamellae, but no corpuscles. In another group, which included
nearly all the flat fish, the structure differed again, and a typical
example was furnished by the " tobacco pipe fish," the bone of
which was found to contain numerous fine tubes like those of
dentine branching out, and usually terminating in two branches.
It was composed of lamellae, and had all the characters of a
thoroughly dentine-like structure. Then in the salmonidae a
further development was found, the matrix being occupied by
small spaces, lacunae, each containing a single cell, but there
were no canaliculi. In herrings, carps, and eels, etc., there
were lacunae with well developed canaliculi. As far as he was
aware, since the time of Kolliker, there had been very little
done in this direction. Most people seemed to be content to
make sections of the dry bone and to examine them, but there
was no paper, so far as he could ascertain, which treated of the
soft parts with which the hard parts were associated. If, there-
fore, anyone having leisure to do it would undertake the inves-
tigation, he would be adding important information to their
present knowledge of the subject. Prof. Stewart illustrated
his remarks throughout by drawings of the structures upon the
black-board, by means of which their peculiarities were made
readily apparent.

The President thought they were greatly indebted to Prof.
Stewart for his admirable and interesting lecture, for which he
had great pleasure in proposing a hearty vote of thanks. This
having ben carried by acclamation,

Mr. E. T. Newton inquired if the dentine was found in all
the bones of the pipe fish, or whether it was peculiar to those
only which Prof. Stewart had described.

Prof. Stewart said it was stated that all the bones had that
structure. Certainly this was the case with all those which he
had himself examined, and he thought it would be a new
observation if it was found that the other bones of the fish did
not possess the same character.

Announcements of meetings, etc., for the ensuing month
were then made, and the proceedings terminated with the usual
conversazione. The following objects were exhibited : —

49

Gallidina vorax, G. plena, C. ligula
Atherix crassicmnis. Mouth organs
Algie (various fresh-water species)
Daphnia (sp. ?)
Synchoeta tremula ...
Asplanchnopus myrmeleo ...

Mr. D. Bryce.
Mr. H. E. Freeman.
Mr. W. Goodwin.
Mr. G. Hind.

Mr. C. Rousselet.

December 7th, 1894.

Asplanchna priodonta
Hydatina senta
Vespa. Mouth organs ...
Schizocerca diver sicomia ...
Polyxenus lagurus...

Rock-section. Basalt dyke in lime- |
stone, Carlingford ... ... )

Mr. J. M. Allen.
Mr. W. Burton.
Mr. W. Goodwin.
Mr. C. Rousselet.
Mr. C. D. Soar.

Mr. G. Smith.

December 21st, 1894. — Ordinary Meeting.

E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
members of the Club :— Mr. Ferdinand Coles, Mr. Alfred
Howard, and Mr. R. Traviss.

The following additions to the library were announced :—
" The Rotatoria of Greenland " ... By Dr. Burgendal.

" La Nuova Notarisia " ... ... In Exchange.

" The Botanical Gazette "

" Transactions of the Norfolk and \

Norwich Naturalists' Society" J From the Society.
" Transactions of the Natural History")

Society of Northumberland " ) "

" Proceedings of the Nova-Scotian |

Institute of Science " ... J " "

" The American Monthly Microsco- *)

picalJournal" / In Exchange.

Journ. Q. M. C, Series II., No. 36. 4

50

The Microscope " In Exchange.

Le Diatomiste "

Annals of Natural History " ... Purchased.

Quarterly Journal of Microscopical")
Science" J

The thanks of the Club were voted to the donors.

The Secretary said that the paper before them that evening
was by Dr. A. M. Edwards, their oldest honorary member. It
dealt with the discovery of diatoms in shales older than the
Lower Miocene, and since this paper was written he believed
Dr. Edwards had claimed to have found them in Silurian
strata. He could not read the whole paper as received, some
of the geological details being of purely local interest, but Dr.
Edwards had given him permission to extract as much as he
considered of value, and the salient points of the original paper
were entirely preserved. Whether or no they agreed with Dr.
Edwards' conclusions was a matter for them to decide when
they had heard his views, but, personally, he must say that
great caution should be exercised before judging on the
presence of such ubiquitous organisms as fresh-water dia-
tomaceae. From their small size and general distribution in
running water they were liable to be carried by percolation far
from their place of origin, yet, as Prof. Cleve had lately
pointed out, in some cases they might be of great value in
geological determinations.

Dr. Edwards' paper was then read.

Mr. E. T. Newton said he had not made diatoms a special
study, but it was a well-known fact that they had been found
fossil, certainly in the Chalk, and possibly in the Coal Measures,
but he did not think there was any record of their presence in
the older rocks. He agreed with Mr. Karop that there was
always a great probability of their getting washed in, and
that the very greatest care was required before it would be
safe to say that they really belonged to the rocks amongst
which they were found. Still, there was nothing impossible
about it. Certain old rocks in Scotland and Cornwall were
largely made up of Radiolarians, and some chalky-looking rock
from Australia seemed nearly composed of the same small
organisms. In thin sections their structure could be very well
seen. He thought the subject was one worth looking into,

51

because there was no reason why diatoms should not be found
in the Silurian rocks, but, on the contrary, it might rather
be expected that they would.

Mr. Karop thought that the need for care which Mr. Newton
had insisted upon could not be too strongly enforced in making
any investigations in this direction; everything used should be
perfectly free from suspicion, and new pipettes must be used,
because the diatoms would cling to anything which once
contained them for an indefinite time.

The President said he remembered seeing some curious
diatoms in some kind of rock which was sent to them by Mr.
Shrubsole.

Mr. Karop said they were common enough in the Tertiary
strata, but had not until quite recently been found in strata as
old as the Silurian.

Mr. E. T. Newton said it was generally accepted that the
higher the grade of an animal the shorter the distance it went
back in time ; and it was of course also true, on the con-
trary, that the lower the grade the farther back it was found to
extend; if this were true they might expect to find diatoms
in the Silurian.

Mr. Karop thought it was understood that their age was
great, but being formed of colloid silica, which was soluble in
alkaline water, it seemed rather doubtful if they would be able
to persist in the manner expected.

Mr. Newton said that the evidences of their existence would
not necessarily be destroyed even if they were dissolved, because
they would leave their impress in the rocks, and this might
be filled up with other matter.

Mr. Morland could quite corroborate what Mr. Karop had
said as to the way diatoms had of clinging to tubes, etc. No
one could ever be sure that a tube was quite clear from them,
even after repeated washing and wiping.

The President made some remarks upon the subject of
coloured screens for use with the microscope, and pointed out
the advantages to be gained thereby. These could be of a
variety of tints, but all would not be found to work equally well
for all purposes. Colonel Woodward's screens were made with
a solution of ammonio-sulphate of copper, whilst his own were
of cobalt blue glass, and Mr. C. Haughton Gill used a Zettnow

52

screen of sulphate of copper and bichromate of potash. One
of the best screens was of a green glass of such a tint as to cut
out the red in a bright spectrum. Those who did not possess
a spectroscope could get a good spectrum by means of any coarse
diatom by using a narrow pencil, and viewing the spectra at the
back of the objective wlien the eye-piece was removed.

Mr. Ingpen said that a splendid spectrum could be obtained
in this way with a Cherryfield rhomboides.

The President said that when diatoms were examined on a
dark ground colours were often seen, red indicating a coarse and
blue a fine structure. In the early days of his microscopical
work he had noticed a blue line on the girdle of a Pinnularia
major, and he at once recognized this as indicating the presence
of fine structure. It was not long before he had resolved it into
60,000 stria? per inch. It was an interesting question whether
this consisted of rows of minutely perforated structure, if so it
must wait for an objective of the future to resolve it, as it was
beyond the reach of the best modern objectives. It would be
more difficult than the longitudinal stria? on the A, pellucida, as
there were no edges and raphae for the manufacture of false
ghosts.

Mr. Ingpen said that the medium piperine was irrational.
There were some high refractive media he could recommend,
among which he might specially mention that composed of one
part of bromide of antimony, one part of bromide of arsenic, and
one part of piperine. This mixture was rather yellow, but it
melted easily at a low temperature.

The Secretary announced that nominations for members to
serve on the Committee must be made at their next meet-
ing-
Announcements of meetings, etc., for the ensuing month
were then made, and the meeting terminated with the usual
conversazione, the following objects being exhibited : —
Stephanoceros Eichhornii ... ... ... Mr. W. Burton.

Tcwdigrada (sp. ?) Mr. C. Eousselet.

53

Jan cart 4th, 1895.

Cypris-stage of Balanus Mr. E. T.Browne.

Conochilus unicornis Mr. W. Burton.

Euchlanis pyriformis (mounted) ... Mr. C. Rousselet.

January 18th, 1895.— Ordinary Meeting.
E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
members of the Club :— Mr. G. E. Awde, Mr. B. Cox, Mr. A.
Harrison, and Mr. E. Hinton.

The following donations to the library were announced : —

The '' Botanical Gazette " In Exchange.

A series of reprints of papers by Herri

Lauterborn, " On the Marine and r Per Mr. Rousselet.

Fresh Water Flora of Helgoland" )
"Annals of Natural History "... ... Purchased.

The Secretary read the list of nominations by the Committee
for officers of the Club for the ensuing year.

The Secretary gave notice of an alteration of the Rules, pro-
posed by the Committee, to be submitted at the next Annual
General Meeting, viz., that an Hon. Editor be added to the list
of officers in Rules 2, 3, and 9.

The President announced that there would be four vacancies
for members of Committee, and invited the members present
to nominate gentlemen to fill the same.

The following nominations were then made : —

Mr. Dadswell, proposed by Mr. Hardy, seconded by Mr. Kern.

Mr. Parsons, proposed by Mr. Burton, seconded by Mr.
Hembry.

Mr. Bryce, proposed by Mr. Powell, seconded by Mr. Muiron.

Mr. Morland, proposed by Mr. Soar, seconded by Mr. Scour-
field.

Mr. Freeman, proposed by Mr. West, seconded by Mr. Lloyd.

The President said these names would be printed on the
ballot papers in the usual way, and the election would take
place at the next — which would be their Annual Meeting. It

54

was necessary for two auditors to be selected that evening, and

on behalf of the Committee they had appointed Mr. Bryce.

He now asked the members to appoint another on behalf of

the Club.

Mr. W. Chapman was proposed by Mr. Allen, and seconded

by Mr. Burton, and unanimously elected.

Mr. C. Rousselet read a paper " On the Preparation of

Rotifers as Permanent Microscopic Objects," supplementary
to a communication on the same subject made about two years

ago, and detailing the improved methods discovered and
adopted in the meantime. The paper was illustrated by the
exhibition of a large number of slides under microscopes in
the room, and Mr. Rousselet announced his intention to present
to the Cabinet of the Club a complete type collection of every
species. Already he had successfully mounted 130 species, and
he presented to the Club that evening 77 slides, representing
72 species, as a first instalment of his promised donation.

The President thought they were extremely fortunate in the
possession of such an active member as Mr. Rousselet, who
had thrashed out the subject of fixing and mounting these
very difficult objects so thoroughly, and had given a descrip-
tion of the process in a way which would always associate it
with the Club. It was hard work, like that which had been
described, which would always do more than anything else to
keep up their reputation. Their best thanks were due to Mr.
Rousselet for his paper, and also for the valuable donation
made that evening, and for the promise of a completion of the
series in due course.

Thanks to Mr. Rousselet were unanimously voted.
Mr. Goodwin communicated a note on an Alga found at Wan-
stead Park on October 5th, at the edge of the pond, which
seemed to him to be a new species of Oscillaria. The filaments
were very small, and the endochrome appeared green by trans-
mitted light, but under the microscope it was difficult to say
exactly what colour it was, the endochrome being very much
concentrated. So far as he could make out, it was a new
species, but he had not yet taken the opinion of any specialist
on this point, though he thought if it turned out to be new it
was worth recording. No new features had been developed in
it since the date on which it was found.

55

Mr. Karop said that if the object described by Mr. Goodwin
was really a new species it would, of course, be interesting, but
in such lowly plants as Oscillarige, where reproduction was
entirely asexual, they had only morphological characters to
depend upon, and therefore he thought it would be wise to wait
until it had been submitted to the judgment of an expert.
There was such a superabundance of species amongst the
protophyta that it was most undesirable to add to them un-
necessarily.

The Secretary said that the publication of the list of mem-
bers of the Club would be due this year, and asked that any
alterations in addresses might be communicated to Mr. Vezey.

Announcements of meetings, etc., for the ensuing month
were then made, and the proceedings terminated with the
usual conversazione, at which the following objects were
exhibited : —
Melicerta ringens ... ... ... ... Mr. J. M. Allen.

Stycoptera contaminata ... ... ... Mr. H E. Freeman.

Spirillum Mr. G. Hind.

Mr. C. Rousselet exhibited the following mounted objects
under several microscopes : —

Asplanchna priodonta.
Asplanchnopits myrmeleo.
Brachionus pal a.
Conochilus voir ox.
Copeus caudatus.
Diglena forcipata.
Euchlanis hyalina.

,, pyriformis.

,, triquetra.

Hydatina senta.
Limuias annulatvs.

,, ceratophylli.
Melicerta Ringens.

Koteus quadricornis.
Xotrsmmata aurita.

,, lacinulata.

Notops hracliionus.
Ploesom a Ilndsoni.
Proales parasita (in Volvox

globator).
Bhinops (?) orbicnlodixcus.
Sacculus viridis.
Stephanoceros Eichhoiuii.
Syuchcela iremala.
Triphylus lacustris.

February 1st, 1895.

Euchlanis diletata..
Surirella fastuosa ..
Cyclosis in Nitella

Mr. W. Burton.
Mr. H. Morland.
Mr. W. R. Traviss.

56

February 15th, 1895. — Annual Meeting.
E. M. Nelson, Esq., President, in the Chair.
The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
members of the Club:— Mr. H. Cheese, Mr. T. S. Davis, Mr. G.
J. Harris, Mr. W. J. Marshall, Dr. J. W. Measures, Mr. W. J.
Wonfor, Dr. Tatham.

The Secretary announced that the " Proceedings of the
Smithsonian Institution " had been presented to the library.

Announcements of meetings, etc., for the ensuing month
were made, and the business of the annual meeting was then
proceeded with.

The Secretary said that at their last ordinary meeting notice
was given that an amendment to Rules 2, 3, and 9 would be
proposed, to the effect that in future the Hon. Editor of the
Journal should be a member of the Committee. This could
hardly be called an innovation, because practically the Editor
had always attended, as he happened to be otherwise a mem-
ber of Committee, but to meet the case of anyone becoming
the Editor who was not one of the Committee this addition
seemed necessary. Of course, the desirability of the Editor of
the Journal being present at the meetings of the Committee
would be obvious to all.

The proposal to add the words " Honorary Editor of the
Journal " to Rules 2, 3, and 9 was then put from the chair and
unanimously agreed to.

The President having appointed Messrs. J. M. Allen and C.
L. Curties as scrutineers, the ballot was proceeded with for the
election of officers and four members of Committee. The
scrutineers subsequently reported that the whole of the officers
in the list of nominations had been duly elected, and also that
Messrs. Mori and, Dadswell, Bryce, and Parsons had been elected
members of Committee.

The Secretary read the report of the Committee for the past
year.

The Treasurer read his annual statement of accounts for the
same period.

The adoption of the report and balance sheet having been
moved by Mr. Richard Smith and seconded by Mr. J. G.
Waller, was put to the meeting and carried unanimously.

57

The President then delivered the customary annual address.

Mr. A. D. Michael said he rose to ask the members present
to do something which he felt they were ready to do spontane-
ously, and that was to pass a very hearty vote of thanks to the
President for the very able and learned address to which they
had just had the pleasure of listening. The subject dealt with
was one of first-class importance, for there could be nothing
more important to a microscopist than to know the exact
amount of light with which he could till his objective in order
to obtain the best possible results. It was also obvious that
this ought to be intelligently done, and not by mere rule of
thumb. Such an address as that, when they were able to read
it carefully for themselves, would do much towards enabling
them to decide as to what was the theory of microscopic vision
which they could most confidently rely upon. Until they knew
this they could not decide as to which was the best method for
using their microscopes to the best advantage. The subject
was one of leading importance to them as microscopists, and
they would all agree that it had been most ably treated by
their President in his address to them that evening.

Mr. W. Burton having seconded the motion, it was put to
the meeting by Mr. Michael, and carried by acclamation.

The President thanked the members for this vote of thanks,
and for the very kind wa} r in which it had been received and
carried. He also desired to thank them very heartily for the
honour which they had conferred upon him by electing him as
their President for another year.

A vote of thanks to the Auditors and Scrutineers was then
moved by Mr. Western, seconded by Mr. Rousselet, and carried
unanimously.

A vote of thanks to the President and Officers of the Club
for their services during the year was similarly honoured.

Mr. Karop said — It is my pleasant duty on these occasions
to reply, on behalf of the Committee and other officers, to the
vote of thanks just moved. During the Club's career of nearly
thirty years it is surprising to note how few changes, relatively
speaking, have occurred in its executive, a fact creditable to
both Club and officers. One reporter only— Mr. Lewis— has
held his post continuously since 1867, and, with very few
exceptions indeed, has attended every meeting. There have
been three Treasurers, Mr. Hardwicke, who died in office, Mr.

58

Gay, and Mr. Vezey, who, he hoped, would long remain ; two
Librarians, Mr. Jaques and Mr. A. Smith; fonr Curators,
Messrs. Ruffle, Hailes, Emery, and Browne ; and four Secre-
taries, Messrs. Bywater, White, Ingpen, and Karop. In regard
to the latter office, however, he thought it might be a mistake
for a Secretary to continue much over ten years ; he would be
apt to get into a groove and let things take their own way too
much. In all concerns probably, an infusion of fresh activity
was occasionally beneficial, and if the members at any time
were of opinion their present Secretary had held his post long
enough, he trusted they would just say so, and he should at
once be willing to make room for a more efficient successor.
There was another matter he should like to be allowed to
refer to. Some might have thought the penultimate paragraph
of the Report, concerning the non-payment of subscriptions,
was rather severe, and he did not suppose for a moment it
applied to anyone present that evening. At the same time it
was a hard fact, and one that had to be considered by those
responsible for the maintenance of the Club, but as probably
very few ever troubled about the balance sheet after hearing it
read, he would endeavour to show its importance by a few
figures. Up to the end of December, 1894, there were 345
members on the books, and if all pay their subscriptions, these
total £172 10s. Our chief items of expenditure are for rent and
attendance, and the Journal, which, taking last year's figures,
together amount to £150, thus absorbing the subscriptions of
300 members, leaving about £22, which, with other assets from
sale of Journal, advertisements, and investments, give us at the
very utmost £65 to pay for printing, stationery, postage, books
and binding, extra meeting, if held, and other petty expenses.
But, unfortunately, there are always a large number of sub-
scriptions in arrear, and considering the advantages the mem-
bers possessed of meeting in one of the best rooms in London,
well warmed and lighted, a Journal, and a Library and Cabinet
at their disposal for the absurdly small sum of ten shillings
pel' annum, it was not asking too much that at least it should
be paid with reasonable promptitude. On behalf of the officers
of the Club he thanked the members for the cordial manner in
which they had passed the vote.
The proceedings then terminated.

i?

59

TWENTY-NINTH ANNUAL REPORT OF THE
COMMITTEE.

Taking all circumstances into account, your Committee is
happy to state that the Club's career during the past year has
been, on the whole, satisfactory.

The number of new members is not so large as could be
desired, twenty-five only having been elected in the twelve
months ending December, 1894. A considerable number of
resignations have also been notified, and three have been lost
by deatb, leaving the total on the list somew hat smaller than
usual. Your Committee is of opinion that the advantages un-
doubtedly possessed by the Club, considering the extremely
small amount of the subscription, might be made more widely
known by members themselves, and so lead to an increase of
numbers.

The attendances at the meetings, however, have been notice-
ably good, aud much interest taken in the proceedings. The
papers read, although perhaps falling somewhat short of the
average in quantity, have been good and thoughtful contri-
butions.

The following is a list of the chief : —

February. — The Presidential Address, by Mr. E. M. Nelson.

March. — " On the determination of the Foci of Microscopic

Objectives," by Mr. E. M. Nelson. " On Ammba" by

Mr. H. W. King.

May. — " Notes on Foreign Rotifers since found in Britain,"

by Mr. G. Western.
June. — "On JDistyla spinifera" by Mr. Gr. Western. "On

Ilyocryptus agilis" (n. sp.), by Mr. D. J. Scourfield.
September. — " On Gyrtonia tuba,'" by Mr. C. Rousselet.
" Further notes on Macrotrachelous Callidince" by Mr. D.
Bryce.
October. — " Notes ou four Foreign Rotifers since found in

Britain," by Mr. G. Western.
November. — " An addition to Beale's Reflector," by Mr. E.
M. Nelson.

60

December. — ;i On the Diatomaceae older than those of Vir-
ginia, etc," by Dr. A. M. Edwards.

A Special Exhibition Meeting was held at Freemasons'
Tavern on May 4th, attended by 140 members and 390 visitors.
The arrangements of the cloak-rooms and refreshment depart-
ment were certainly very deficient, owing to the overcrowded
state of the building generally on this occasion, but the incon-
venience to many members and their friends, however unfor-
tunate, could not be foreseen when the room was hired some
four months in advance. The exhibits were generally good,
and the excellent orchestra, under the direction of Dr. Dundas
Grant, for whose services the Club is entirely indebted to the
kind offices of Mr. J. W. Reed, was greatly appreciated by
everyone present. The Committee desires to thank all who
assisted at this meeting, and most particularly Mr. Reed, Dr.
Grant, and the musicians. The expenses, as before decided,
were defrayed by the Club.

Two Journals have been issued since the last Report, com-
pleting the Fifth Volume of the Second Series. The October
Number was considerably delayed owing to the loss of a portion
of the MSS. in the post. The advertisements on the covers
have produced the sum of £15 19s. 6d., as will be seen in the
balance-sheet. As it is more than might have been expected,
it is only right to say this welcome addition to the Journal fund
is solely due to the energy of Mr. C. Rousselet.

Aware of the long time which necessarily must elapse before
the entire revision of the Cabinet can be completed, the Com-
mittee deemed it advisable to issue in the meantime a catalogue
of the preparations in the Williams' bequest, a fairly repre-
sentative collection of nearly 700 slides. The list of the
Diatomaceae in possession of the Club and the Foraminifera in
the Hailes' Collection being also finished, a catalogue of these
is in the press, and will shortly be ready. The thanks of the
Committee are due, and hereby offered, to Messrs. Browne,
Morland, and Priest, who severally undertook the whole labour,
and it is no light one, of making these lists, and also to Mr.
Nelson, who, in addition to the already long list of his benefac-
fcions to the Club, has most kindly undertaken the expenses of
printing the catalogue of the Hailes' Collection.
The finances may be said to bo in ;i Fairly satisfactory con-

61

dition ; the receipts from subscriptions are about the same as
for the previous year, while the sale of Journals has brought in
nearly £10 more. The item for advertisements has already
been referred to. The expenditure has been very carefully
watched, and the Journal kept within the sum assigned to it.
Several compounding fees have been paid during the past few
years, and the Committee has therefore thought it wise to add
a small amount to the investment in Consols, bringing- up the
total to £200.

.Many members appear to be under the impression that pay-
ment of their subscription need not be made until they have
received one or more applications for it. This entails an un-
necessary outlay for printing and postage, to say nothing of the
extra and disagreeable labour imposed on the Treasurer.
Members are therefore reminded that subscriptions are due in
advance on the 1st of January in each year, and should be re-
mitted within a reasonable time from that date.

Your Committee desire to thank the officers for their valuable
and indispensable services. In conclusion, they have every
confidence in the prosperity of the Club, and that it will con-
tinue to meet the requirements of the amateur and further the
advancement of microscopy, the objects for which it was con-
stituted thirty years ao"o.

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63

Q.M.C. Excursions, 1894.

I

1

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Dates.

Localities.

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April 7

Royal Botanic Gardens

44

14

22

80

i 2

„ 21

Chingford ...

13

1

—

14

3 May 5

Enfield

13

—

1

14

4 „ 19

Highains

9

—

—

9

5 June 2

Hertford Heath

6

1

1

8

6 ,„ 16

Whitstable

13

1

1

15

7 „ 30

Oxshott

9

—

1

10

8

July 14

Woking

7

1

—

8

9 „ 28

Richmond Park

5

—

—

5

10 Sept. 1

Keston

7

2

3

12

11 1 „ 15

Staines

4

—

4

12. „ 29

Snaresbrook

10

2

—

12

Names of members who sent lists of objects found by them : —

B. Burton, W. So. Southern, W. H.

D. Dunning, C. G- Th. Thompson, Percy

P. Parsons, F. A. T. Turner, C.

R. Rousselet, C. F. Wb. Webb, J. C.

Sc. Scourfield, D. J. W, Western, G.

S. Soar, Charles D.

64

List of Objects found on the Excursions.

Note. — The numbers following the names of the objects
indicate the excursions upon which they were found, and the
letters indicate the names of the members recording the same.
When an object is frequently recorded, the initials of the
names of the members are omitted.

CRYPTOGAMIA. ALGJE.
Eudorina elegans
Gonium pectorale .
Nostoc verrucosum .
Pandorina morum .
Prasiola calophylla .
Raphidium falcatum
Yolvox globator

Desmidiacejj.
Arthrodesmus incus
Closterium lunula .

,, rostratum

Cosmarium margaritiferum
Docidium baculum .

„ Ehrenbergii

Micrasterias denticulata .

„ rotata .

GB.AUAGEM.
Chara vulgaris

PROTOZOA.
Acineta mystacina .
Actinophrys picta .

sol
Actinosphaerium Eichhornii
^Egyria oliva .
Amphileptus anser .

,, flagellatus .

gigas .
Anthophysa vegetans

1, 2, W.

1, 2, 8, W.
8, T.

2, 5, 8, 11, YV.
10, 11, T.

10, 11, T.

1, 2, 3, 5, 7, 8, 9, 10, 11.

10, 11, T.

1, 2, 3, 5, 7, 8, 10, 11.

7, 10, 11, T.

8, 10, 11, T.
8, T.

11, T.
10, W.

10, T.

3, B.

1, P.
8, W.

I, D.; 7, 10, 11, 12, T.

11, T.

3, 12, P.

II, P., W.

4, P.
8, W.

5,W.; 8, P., W.; 11,12,

Arcella dentata

3, 7,T.;8, W.; 9,T.,W.;

11, w.

65

Arcella vulgaris

3, 5, 7, 8, 9, 11.

Bursaria truncatella

. 1, T. ; 3, B, P.

Carchesium polypinum .

. 1, T.

Centropyxis aculeata = Arcella

b

aculeata ....

8, 9, 11, T.

Clathrulina elegans

11, P.

Coleps hirtus ....

. 1, 2, 11, 12, T.

Condylostoma stagnale

. 1, 2, P. ; 3, B.

Cothurnia imberbis

1,T. ; 3, B.

Didinium nasutum .

3, P.

n.s. (J. G. Grenfell)

1, W.

Difflugia corona

9, W.

„ globulosa .

. 2, 8, 9, W.

„ oblonga

3, 11, T.

,, proteiformis

. 1, 3, 8, 10, 11, T.

,, pyriformis

. 3,B. ; 8, W. ; 9, T.

Dimastigoaulax cornuturn

. 11, P., T., W.

Dinobryon sertularia

3, 4, 5, 10, 11, 12.

Ephelota coronata ?

6, P.

Epistylis anastatica

1, D., W.

„ flavicans .

1, 4, P.

,, plicatilis .

. 10, T.

Euglena spirogyra .

. 8, 10, T.

,, viridis .

. 8, 10, T.

Euglypha alveolata

. 8, W.

,, ciliata

8, 10, W.

Euplotes patella

1, 3, T.

Litonotus fasciola=Dileptus folium

1,D.

Loxophyllum meleagris .

. 9, 11, P.

Mallomonas Plosslii.

7, P.

Nebela carinata

8, W.

„ collaris

8, 10, W.

„ flabellum .

10, W.

Noctiluca miliaris .

6,Wb.

Opercularia nutans .

1, 2, P.

Ophrydium versatile

9, P., T.

Ophryodendron abietinum*

6, P.

Paramecium aurelia

3, B., T„ W. ; 8, 11, T

* Ophryodendron abietinum had some of the tentacular filaments capitate.
Journ. Q. M. 0., Series II., No. 36. 5

66

Peridinium tabulatum

1, P. ; 3, 5, 11, W.

Phacus longicaudus , . •

1, 3, 8, 9, 10, 11.

Phialina vermicalaris ? .

1,P-

Platycola decumbens

2, P.

Pleurotrichalauceolata=Stylouichia

lanceolata. .

3, T.

Raphidiophrys elegans .

9, W.

Rhabdostyla sertularium ?

1, P.

Rhipidodendron Huxleyi .

7, P.

„ splendidum .

5,W.

Spirostomum ambiguum .

3, B.; 10, T., W\; 11, T.

Step tor cseruleus .

3,W. ; 4, 7, 8, P.

„ niger

3, 4, P. ; 5, P., W. ; 9, P. ;

11, P., T., W.

„ polymorphous

1, 2, 3, 4, 9, 11.

„ Rceselii .

11, W.

Stichotricha remex .

7, 11, P.

Strombidium Claperedi .

8, 12, P.

Stylonichia mytilus

1, T. ; 8, W. ; 9, 11, T.

Synura uvella .

8, 11, W.

Trachelius ovum .

2,P.,W.;3,B.,P.,T.,W.;

11, T., W.

Trachelocerca olor .

11, T.

„ versatilis .

8,W.

Trichodina pediculus

11, T.

Urocentrum turbo .

3, 11, P.

Vaginicola crystallina

1, 3, 8, 11, 12.

Vorticella chlorostigma .

3, 4, 9, P.; 10, 11. W.

„ citrina ? .

11, P.

„ microstoma

. 1, D.

„ nebulifera

11, W.

PORIFERA.

Grantia ciliata

6,D.

„ compressa .

6, D.

CCELENTERATA. HXDROZOA

Eudendrium insigne

. 6, P.

,, ramosum

6,D.

Obelia geniculata

6, D., P.

Plumularia halecioides .

6, P.

67
Plumularia pinnata = Sertularia

pinnata

.

. 6,D.

Thaumantias hemisphaerica

. 6, Wb.

Tubularia indivisa .

.

. 6, D., P.

ACTINOZOA. CORALLIGENA

Actinoloba dianthus =

Actinia

plumosa .

. 6, Wb.

CTENOPHOEA.

Pleurobrachia pileus

. 6, Wb.

VERMES. Rotifera.

Adineta vaga .

.

. 7,8, W.; 10, P., W.; 12, P.

„ var. .

.

. 7, W.

Anureea aculeata

. 1, 2, 3, 4, 5, 7, 8, 9, 11.

„ „ var. valga .

. 5, R.; 7, P., T., W.;8. P.

W.; 12, P.

„ brevispina .

.

. 3, 7, 10, 11,12.

,, cochlearis .

. 1, 2, 3, 4, 7, 10, 11.

„ curvicornis .

.

. 3, 7, 8, 10.

„ hypelasma .

. 1, 9, 10, 11, W.

„ serrulata

. 2, 5, 7, 8, 10.

„ tecta .

. 3, 11, P., W.

Anapus ovalis .

.

. 5, R. ;8, 11, W.; 12, R.

Ascomorpha ecaudis

= Sacculus

viridis .

. 3, 4, 5, 7, 8, 9, 10, 11, 12.

Ascomorpha saltans = Sacculus

saltans 8, 10, W.

AsplanchnaBrigbtwellii . . .1, R., So. ; 10, P., W. ; 11,

P.
priodonta . . 1, R., So., Th., T., W. ; 2,

So.;4,R., W. ; 10, W.
Asplanchnopns myrmeleo . .11, W.
Brachionus angularis . . .1, So., W. ; 2, R., So. ; 3,

P., W. ; 4, R.
Bakeri . . 1, R., Th., T. ; 3, 9, P.,

AY. ; 10, P.

. . 1,R, So., W. ; 3, P.; 4,
P.,R.;7, T.
„ var. amphiceros . 1, I)., Th., T.
rubens . . . . 2, So. ; 3, 4, W. ; 7, P.

68

Brachionus urceolaris

var.
Callidina constricta

„ elegans

,, lata .

„ magna-calcarata

„ musculosa

,, parasitica

,, plicata
, quadricornifera

, tridens

Qathypna luna

„ rnsticula .

„ ungulata .
Ccelopus brachynrus

„ cavia .

,, porcellus

„ tenuior
Colurus bicuspidatus

,, caudatus

„ deflexus
Conochilus unicornis

„ volvox .

Copeus caudatus
„ cerberus
„ Ehrenbergii = labiatus
„ pachyurus

Cyrtonia tuba (Rousselet) = Noto-

mata tuba (Ehr.) .
Diaschiza exigua .

„ globata .

,, pseta .

„ semi-aperta

male

„ valga
Diglena catellina

1, 2, 5, 6, 7, 8, 12.

2, R.
7, W.
7, W.

10, P., W.

11, P.

2, 3, W.
4, P., R.

7, 8, 10, W. ; 12, P.

8, 10, W.
8, W.

7, 8, 9, W. ; 11, P., W.

4, R.

8, R., W.

3, R., W. ; 4, 9, W.

5, 7, W.

3, W.; 5, P., R.,W.; 9,

P, W. ; 11, P. ; 12, R.
5, 10, W.

9, 10, W.

3, B.
11, W.

10, P., T., W.

5, R., W. ; 7, P., T. ; 8,

P., So., W.
8, W.

1, P.; 4, P.,R.;10, W.

8, P., R., W. ; 11, P. T.
5, W. ; 7. P. ; 9, W. ; 10,

P. w.

11, P., w.

2, R., W. ; 3, 7, 8, 9, W.

11, W.

10, W.

4, 7, W. ; 8, R., W. ; 9,
10, 11, W. ; 12, R.

8, W.

11, W,
1,R.

69

Diglena forcipita .

. 1,3, P.; 4, W.;5, P.; 10,

W.

Dinocharis pocillum

. 2,3,4, 5, 9, 10, 11, 12.

)>

te tract is

. 2, 3, 5, 7, 8, 9, 10, 11, 12.

Diplax

trigona

. 8,W.

Distyla

clara .

. 8, W.

»

flexilis

. 7, 8, 10, W.

))

inermis

. 8,W.

Elosa Worrallii

. 7, 8, W.

Eosphora aurita

. 2, W. ; 3, R. ; 8, R., W. ;

9, 10, W. ; 11, P., W.

Euchlanis deflexa .

. 4, R.

55

dilatata .

. 3, B.,T.,W.;8,R.; 11, T.

55

hyalina

. 11 W.

55

macrura .

11, P.

55

orapha

. 11, W.

1)

parva

. 4, R. W.

55

pyriformis

. 1, 3, P.

55

subversa .

. 5, 7, W.

55

triquetra .

. 3, 5, 7, 8, 9, 10, 11, 12.

55

„ male*

. 12, R.

55

uniseta

. 3, B., P.

Floscularia algicola .

. 8, 11, P.

55

campanulata .

. 1, R., Th.; 3, P.; 8, R.,
W.; 9, P., T., W.; 12,
P.,R.

55

cornuta .

. 2, P.,W.;3, P.; 7, W.;9,
P.,T.;11, P.

55

coronetta

. 9, W. ; 11, P.

55

cyclops .

. 7, P. ; 10, W.

55

longicaudata .

. 1, w.

55

ornata .

. 1, Th.; 2, So., T.; 3, R.
8, P.; 9, P,W.; 11, T.

55

pelagica

. 10, P., w.

5

regalis .

. 9, P, W. ; 11, P.

5)

trilobata

. 4, W.

* Euchlanis triquetra, male. Mr. Rousselet describes it as loricate, of
the same shape as the female, but only about one-third the size ; it has no
mastax and no digestive tract, the place of which is taken by the sperm sac.
This is believed to be the first male of the Euchlainda; observed.

70

Furculai

•ia forficula .

. 1, Tli. ; 9, 11, P.

j?

gibba

. 7, 9, T.

55

gracilis .

. 2, W.

»

longiseta

. 3, 5, 7, 8, 9, 11, 12.

55

melandocus

. 12, R.

Lacinularia socialis .

. 8, R., So., W.

Limnias

annulatus .

. 1, R. ; 11, P.

55

55

. 1, Th., W.

55

ceratopliylli

. 1, So. ; 9, W.

55

myriophylli

. 7, P., W. ; 8, R.

Mastigocerca bicornis

. 3, B. ; 5, P., R., W. ; 7,

W. ; 12, R.

55

bicristata .

. 4, R.; 11, P.

55

carinata

. 4, W. ; 11, T.

55

elongata

. 4, 8, R.

55

lophoessa .

. 5, R.; 8, 11, W.

55

rattus .

. 3, P., R., W. ; 5, W. ; 8,
P., W.; 10, W.; 11, P.,
W.; 12, P.

Melicerfca conifera .

. 7, P., W. ; 8, P. ; 9, P.,

W. ; 12, P.

55

ringens

. 1, 3, 4, 5, 7, 8, 9, 11, 12.

Metopid

ia acuminata

. 1, T.;3,B., T.; 5, P., R.;

9, 10, 12, T.

55

lepadella

. 1, T., W. ; 2, T. ; 3, W. ;
5, R., W. ; 7, W. ; 8, So.,
T. ; 9, T., W.

55

oxysternuui

. 3, P. ; 4, W. ; 10, T.

55

rhomboides

. 4, W.

55

solidus

. 3, P.; 5,R., W.; 8,9, W. ;
11, P., W.

55

triptera .

. 11, W.

Microclides orbiculodiscus

. 8, W. ; 10, P., W. ; 12, P.

Microcodon clavus .

. 10, W.

Monocerca rattus

. 9, T.

Monostyla bulla

. 9, W.

,,

lunaris .

. 8, W. ; 12, R.

Monura colurus

. . 6, P.

* Limnias annulatus"? This is

he Limnias described iu the lists of

71

Noteus quadricornis

. 3, B., R., T. ; 5,R.;7, P.;

8, So.; 10, P., T. ; 11,

P.

Notholca acuminata .

. 1, R., T. ; 3, 5, W.

„ scapha

. 1, R. ; 2, P. ; 3, B.

Notommata aurita .

. 1,P, T.;3,B.,R.,T,W.;

5, P. ; 8, 10, T.

„ bracbyota

. 5, R,

„ lacinulata

. 3, 7, P.; 9, P., W.; 11, P.;

12, P., R.

,, longiseta

. 11, 12, T.

tigris .

. 3, B., T. ; 7, 9, T.

,, tripus .

. 3, P. ; 4, W. ; 5, P., R.

„ tuba, see Cyrtonia.

Notops bracbionus .

. 3,B.,R,W.;5,W.;7,f\;

10, P., T., W.

„ male ....

. 10, P.

byptopus

. 2,3, P.; 5, R.; 7, P,W.;

10, w.

„ minor ....

. 2, P. ; 5, R. ; 10, P., W.

OEcistes crystallinus

. 1, D., Tb., T.; 3, P.; 4,

5, W.

„ „ var. ? .

. 1, w.

,, longicornis

. 9, W.

„ mucicola .

. 3, P.

,, pilula

. 7, P. ; 8, So. ; 12, P.

,, socialis

. 1, R.

Pedalion mirum

. 10, P., T., W.

Pbilodina citrina

. 3, P., W. ; 7, W.

„ erythroptbalma

. 1, W.

„ macrostyla

. 7, 8, P., W.

„ megalotrocba

. 2, 3, 9, P.

Polyartbra platyptera

. 1,2,3,4, 5, 7,8, 10,11.

„ ,, small form

. 10, P.

Pompbolyx sulcata .

. 4, R, W.; 10, P., W.

12, R.

Proales decipiens

. 1, 5, W.

„ felis ....

. 7, 8,10,11, W.

„ parasita

. 5,W. ; 11, T.

,, petromyzon

. 1,P.

72

Proales sordida
Pterodina patina
„ reflexa
,, valvata .
Rattulus cimolius .
„ lunaris
tigris
Rotifer citrinus

,, macroceros .

,, macrurus

„ mento ?

„ Roeperi

„ tardus

„ vulgaris
Sacculus saltans } gee Asoomorvha .

,, viridis )
Salpina brevispina .

,, marina
,, mucronata
„ mutica
„ spinigera
,, ventralis
Scaridium longicaudum .

Stephanoceros Eichhornii
Stephauops lamellaiis
,. muticus

,, unisetatus

Syncha^ta pectinata

,, tremula .

Taphrocampa annnlosa .
n Saundersite

Triarthra longiseta .

12, P.

1, 3, 4, 7, 9, 11, 12.
11, P.

7,W.; 11, P.

2, So.

3, T.

5, 8, W.

3, 8, P.

1, Th. ; 3, P. ; 4, R. W. ;

7, 8, P. ; 9, W. ; 12, P.
1, P., Th.; 3, 8, 10,

12, P.

7, 8, 10, P., W.

8, W.

8, P.; 9, W.; 11, P.
1, 2, 3, 7, 8, 9, 10.

4, P., W.; 5, R., W. ;
9,W.; 11, T.

I, 3, R.

3, 5, 7, 8, 9, 10, 11, 12.

8, R.

4, W. ; 11, P.

II, T.

4, W. ; 8, P., R, W. ; 9,
11, P., T., W.

3, P., R., W. ; 4, W.

5, R. ; 10, W. ; 11, P.
5, R.

7, P.

1, 2, 3, 4, 5, 7, 8, 10, 11,

12.
1, 2, 3, 4, 5, 7, 10, 11, 12.

9, 10, 11, 12, P.

10, W.

1, R., So., T., W. ; 2, P.,
So., T.;3, B. ; P., T.; 5,
W. ; 10, P.

73

Triophthalmus dorsualis*
Triphylus lacustris .

. 11, W.

. 5, R., W. ; 8, R., So., W. ;
11, P., W.
PLATYHELMINTHES. Trematoda.
Cercarian stage of a trematode worm 11, P.

ANNELIDA. Oligoch^ta.

^Eolosoma variegatum t . . . 8, P.

POLYCHJITA.

Polynoe squamata ?

. . 6, P.

GASTEOTBICHA.

Cha3tonotus acanthophoris . . 11, P.

„ hystrix .

. 9, 10, W.

,, larus

. 2, 3, 7, T. ; 9, 10, T., W

11, 12, T.

,, maximus

. 8, T. ; 11, T., W.

Dasydytes goniathrix

. . 3, P., W.

CRUSTACEA.

Carcina mamas

. . . 6, P.

Pisa tetraodon

. . 6, P.

Entomosteaca.

Alona intermedia

. 4, Sc.

„ quadrangularis

. 2, 4, Sc.

Bosmina longirostris

. 1,2,4, 12, Sc; 2,3, T.

Candona fabaeformis

. 4 1

„ lactea

. 4

„ pubescens .

. 1

Caiithrocamptus crass us

. 1, 12

>Sc.

= Attheyella spinosa
Canthocamptus pygmgeus
= Attheyella cryptorum

12

J

* Triophthalmus dorsualis. Mr. Western remarks that this is undoubtedly
the rotifer figured and described by Gosse. The orange eye-spots on top of
front processes, mentioned by Eckstein, but not seen by H. and G., were
plainly visible. Of the three cervical e}*es described, the centre one only is
a true eye-spot, the two outer ones being chalky masses on the brain lobes.
The animal is therefore an Eosphora. Gosse's original drawing, with the
above exception, is excellent.

Messrs. Rousselet and Western record from Hertford Heath an un-
described species belonging to the Notommatadse.

t JEoloswna variegatum (Vejdovsky). Xew to England.

74

Cautliocamptus staphylinus
= C. minutus

1, 2, 4, Sc. ; 3, B., T.

Ceriodaplmia quadrangula

4, Sc.

„ reticulata

9, 11, W.

Chydorus globosus .

. 1, 4, Sc. ; 2, T.

„ sphericus .

. 1, 2, 4, 12, Sc. ; 1, D. ; 2,
T. ; 3, B., T. ; 9, W.

Cyclops bicuspidatus = C.

Thomasi

1,2 ^

„ fimbriatus .

2

„ Leuckarti = C. simplex

1,2,4

„ oithonoides = C. hyalinus

4

,, serrulatus .

.

1,2,4

„ strenuns

.

2

„ „ vicinus form.

■ 1,4

„ temiicornis

2,4

> Sc.

„ vernalis * .

. 2, 12

„ viridis, var. brevicornis

. 2, 12

„ gigas

2,4

Cypria ophthalmica

.

1,4

Cypridopsis vidua .

1,12

Cypris fuscata .

. 2, 12

,, virens .

2 J

Daphnella brachyura

. 9, 11, W.

Daplmia hyalina

2, Sc.

,, longispina .

.

. 1, 4, Sc.

,, pulex

.

2, 12, Sc; 3, T. ; 11, W.

Diaptomus castor

.

. 2, 12, Sc; 3,8, T.

„ gracilis .

1, 2, Sc

Eurycercus lamellatus

9, W.

Ilyocryptus sordidus

4 ^

Leydigia acanthocercoides

1,2,4 |

Macrothrix laticornis

2, 4 y Sc.

Peracantha truncata

,

4 |

Pleuroxus trigonellus

1,4 j

PolypL emus pediculus

.

8, P., T.

Scapholeberis mucronata.

.

4, Sc

Sida crystallina

8, P., T. ; 9, W.

Simocephalus vetulus

1, 2, 4, Sc.

# Cyclops vernalis has in

previous

years been included with C.

bicuspid alns.

75

Sfep*^

I* 8, So.

Simocephalus vetulus, exspinosus

form ..... 12, Sc.

ABAGHNIDA. AcarixNA.
Bdellid^;.

Scirus insectoram * . . . . ^|
„ vulgaris

HVDRACHNID^:.

Arreuurus buccinator $ V

„ globator 3

„ maculator ? .

„ viridis ?
Arctisconidj;.
Macrobiotus Hufelandi .
INSECTA. D1PTERA.
Simulium sericium, lava of
MOLLUSCOIDA. POLYZOA
Amatkia leudigera .
Bicellaria ciliata
Bowerbaukia pustulosa
Crisia deuticulata .

,, eburnea .
Cristatella mucedo .
Fredericella sultana
Membranipora pilosa
Paludicella Ehrenbergii .
Pedicellina cernua .

„ „ var. glabra.

Plumatella repens .
Valkeria uva, var. cuscuta
TUNICATA.

Perophora Listeri . . . . 6, D.
Fredk. A. Parsons,

Hon. Sec. Excursions Sub-Committee.

. J

• 1,

T.

;3,

10,

12

P

. 9,

P

. 6,

D.

P.

• 6,

D.

P.

• 6,

P.

• 6,

P.

• 6,

D.

• 8,

R.,

w

• 1,

D.

;8,

w.

• 6,

P.

• 1,

R.

T.;

8,

P.,

R.

• 6,

D.,

P.

• 6,

P.

• 8,

R.

• 6,

D.

P.

Scirus insectorum, parasitic on a springtail.

76

OFFICERS AND COMMITTEE,
(Elected February, 1895.)

Edward Milles Nelson, F.R.M.S

Wxzt-*§m\ismt%.

Rev. W. H Dallinger, LL.D., F.R.S., F.R.M.S., &c.

Pkof. B. T. Lowne, F.R.C.S., F.L. C „ &c.

A. D. Michael, Pres.R.M.S., F.L.S., &c.

Prof. C. Stewart, M.R.C.S., F.L.S., F.R.M S., &c.

dxrmmittjfte.

F. W. Hembry, F.R.M.S. I J W. Reed.

G. Western, F.R.M.S. J. Spencer, F.R.M.?.
E. T. Newton, F.R.S., F.G.S.
J. E. Ingpen, F.R.M.S.
G. Mainland, F.R.M.S.
B. W. Priest.

H. Morland.

E Dadswell, F.R.M.S.

D Bryce.

F. A. Parsons

Hum. feasuwr*
J. J. Vezey, F.R.M.S. 21, Mincing Lane E.C.

G. C. Karop, M.R.C.S., F.R.M.S., 198, Holland Road, Kensington, W
DM*. #*r. for foreign €nTTM$onBmtt.

C. Rousselet, F.R.M.S 27, Great Castle Street Regent Street, W.

ikw. gfprter.

R. T. Lewis, F.R.M.S., 4, Lyndhurst Villa-, The Park, Ealin-, \V.

$011. ^ibrariiw. 'San, Curator.

Alpheus Smith, F. T, Buownk, F.R.M.S.

8,llanover Park, Peckhain, F.E. 141, Uxbridge Road, W.

|]foit. (irMtcrr.
E. M. NaLSOK, F.R.M.S., 0(3, West End Lane, N.W,

77

On Floscularia trifidlobata, Sp. Nov.

By Geo. M. Pittock, M.B., F.R.M.S., of Margate.

Communicated by C. F. Rousselet, F.R.M.S.

{Read March 15th, 1895.)

Plate I.

Since the publication of Hudson and Gosse's great work on the
Rotifera, many new species have been discovered and recorded.
A list of new Rotifers found and described since that date (1889)
has been furnished by Mr. C. F. Rousselet ("Journal Royal
Microscopical Society," June, 1893). I have now to announce
the addition of another Floscule to the list of new species given in
Mr. Rousselet's catalogue.

I will endeavour to follow his advice, that " when a new species
has been found, it should be figured and described in such a
manner that the animal may readily be recognized when found
again by a different observer, and a good figure is often worth
more than a good description."

Any shortcomings in the following description will, I believe,
be made up by the beautiful and characteristic drawing which
accompanies this paper, for which I am indebted to my very kind
friend Mr. Dixon-Nuttall, whose accurate sketches from life of
many new forms are well known to many members of the Society.

This small, but very distinct species, was discovered early this
year by my friend Mr. F. Daunou, of Margate, in hunting over
some water moss from the Minster Marshes, Thanet, a locality
which has already proved a very prolific hunting-ground to him
and to myself during the past summer. (See a short paper on
" Rotifer Hunting at Minster," in " Science Gossip," October,
1894.) At first sight this floscule somewhat resembles F.
longicaudata, in the length of the foot, and in the shape of the
long, pointed, dorsal lobe. Indeed, I sent a specimen to Mr.
Hood, of Dundee, for identification, in January last, believing it
to be an aberrant form of F. longicaudata.

Journ. Q. M. C, Series II., No. 37. 6

78 G. M. PITTOCK ON FLOSCULARIA TRIFIDLOBATA.

More careful examination, however, showed that it has five lobes,
of which the dorsal one is long, pointed, and trifid at the apex,
and crowned with three brushes of short setse. The other lobes are
small, being little more than slight projections of the coronal
rim, and not quite equi-distant from each other, and each crowned
with a brush of short setse. The two ventral lobes are close
together, and the lateral lobes close to the base of the larger
dorsal lobe, leaving a wider space than usual between the lateral
and ventral lobes. The setse are not continuous round the coronal
rim.

Three very small antennas can be made out, one dorsal and two
lateral, and the space between the integument is filled with
numerous brown granules.

Before attempting to describe or to name this floscule, I first
submitted it to Mr. Rousselet, Mr. Western, and Mr. Hood of
Dundee, all of whom pronounced it to be specifically distinct from
any other known floscule, and especially differentiated by the
trifid character of the dorsal lobe, which suggested the name
trifidlobata.

Spec. Char. — Lobes five, the dorsal one long, pointed, trifid
at apex, crowned with three brushes of short setse, the other
lobes small and inconspicuous, without knobs ; not quite equi-
distant round coronal disc, each with a brush of short setas.
Tube small and sometimes indistinct, antennas three, each with
tuft of short setse. Jaws as in other floscules. Eyes absent.
Length : total JL, of body T |_, foot twice the length of body.

79

What was the Amician Test ?

By George C. Karop, F.R.M.S.

{Read March lUh, 1895.)

In reading the earlier papers on microscopy, that is to say in
the modern sense of the word, when successive improvements
were being made in the construction of objectives by enlargement
of their aperture and hence in their defining power ; at a time
when the dilettanti were vying with one another in the resolution
of diatoms by the aid of condensers, prisms, oblique illuminators
and what not, one frequently comes across the phrase " Amician
test." It is used so definitely as a touchstone of excellence, either
in object glass or manipulative skill, that one must assume the
exact nature of this " test " was the common knowledge of every
microscopist of the period, but I must confess, after some amount
of search and personal inquiry from those most likely to remember,
it still remains to me a matter of uncertainty. I do not wish it
to be understood for a moment that I have made an exhaustive,
or even an extended, investigation on the subject ; I have not been
able to find any statement by Amici himself or by anyone whose
authority might be accepted as final, but I have looked through
the few text-books of the period and papers on manipulation in
various transactions, etc. It is simply for my own instruction
and with a view of eliciting information from others that I have
ventured to put this interesting question before you to-night.

The first, or most probable, solution that presents itself is that
Amici made use of several tests of increasing difficulty as he
improved the construction and resolution of his lenses. Indeed
it is certain, in his earlier efforts with specula and objectives, that
he employed scales of various LepiJoptera, Podurae and so forth,
which were the first test objects whatsoever for comparing the
quality of lenses. The use of these scales for the purpose of
testing the aperture of objectives was discovered by Dr. C. R.
Goring.

80 G. C. KAROP ON WHAT WAS THE AMICIAN TEST ?

Harting, " Das Mikroskop," First German edit., p. 288, says :
" Mohl particularly recommends the wing scales of ? Hipparchia
janira as a test, which he got to know from Amici." Although
Harting gives some information about diatoms as tests, and a
good deal about Amici and his instruments, there is no mention
of any specific " Amician test," a somewhat curious and rather
suspicious omission in a work which I regard as by far the best of
its day on the microscope. I say suspicious, for I am of opinion
that the test called Amician, one particular diatom as understood
later, was something got up, so to speak, for the English amateur
at a time when there prevailed a kind of mania here for increased
apertures solely for resolving the markings on certain diatoms,
which was quite without parallel on the continent, I fully
recognize the value of the diatom and its reaction on the wealthy
dilettante ; between them they are in great measure answerable
for the modern microscope and its magnificent objectives ; but the
early continental worker who employed the microscope as any
other tool, came to regard the Englishman's proceedings as childish
trifling, and looked upon his great, shining, complicated stand
with its wonderful accessory apparatus merely as " an expensive
peepshow," while he was quite indifferent to the sempiternal
checks, dots, lines and little else so painfully evolved by it. An
" Amician test," apparently, was not for him.

Be this as it may, however, the question for us is, which was
the particular diatom considered to be the Amician test par
excellence? A large number, perhaps the majority, of authorities
believe it to be Navicula rhomboides. This is first figured,
naturally in outline only, in Ehrenberg's "America," 1843,
according to Kiitzing, who copies it in his " Bacillarien." W.
Smith records it in 1849, but it is doubtful if any lens of that
date could have really resolved it, unless it chanced to be a very
coarse-lined variety. Mr. Ingpen informs me that he possesses a
slide of rhomboides thirty-five to forty years old, by C. M. Topping,
the best mounter of his day, labelled simply " Amician Test," and
Mr. T. Powell has kindly sent me a similar slide and also so
named. On examination it appears to have been mounted as
gathered, without any preliminary treatment with acids, between
two thin covers, but from lapse of time it has almost perished, and
the diatoms, chiefly a very small variety of rhomboides, are quite
unresolvable by any optical means in my possession.

G. C. KAROP ON WHAT WAS THE AMICTAN TEST? 81

In a paper by Mr. J. Newton Torakins " On Resolution of
Diatoms by Double Prism Illumination,"* he speaks of N. rhom-
boides as " the Amician test of the London, although, perhaps,
not of the American microscopists," a very queer expression
unless, indeed, as I suspect, the thing was a variable. Mr. E. G.
Lobb, a very well-known microscopist in his day, in a paper
entitled " Note on Illuminating Objects with High Powers,"
(" Trans. Mic. Soc," Lond., N.S. xiv., 1866, pp. 39-41), gives
minute directions for using a condenser of 170° (Powell's) in
resolving tests, stating the apertures and stops suitable for quite
a number of diatoms. He says : " To examine N. cusjridata, N.
rhomboides, P. fasciola, P. macrum, etc., use No. 11 aperture
and stop No. 2, which will require a slight alteration in position
only, when the checks will appear distinctly. For the Amician
test use the slots instead of No. 2 stop." From this it seems
quite clear that Mr. Lobb's Amician test, at all events, was not
N. rhomboides.

In the first three editions of the " Micrographic Dictionary,"
viz., 1856, 1860 and 1875, Amici's test is given as N. gracilis,
Ehr., which Smith, " Syn.," p. 75, refers, with a query, to his
Pinnularia gracilis. From the figure it appears to me very un-
likely. In the latest edition of the Dictionary, 1883, sub voce
Test Objects is given, " N. affinis, Amici's test object, that used
at the Exhibition of 1862, mounted in balsam, the transverse
lines. "t Mr. Ingpen thinks this would now be considered a form
of rhomboides, but both Van Heurck and Brun make it allied to
N. pi'oducta, W. S. It is evidently a variable species, but I
think the striation is coarser than any ordinary rhomboides ; more-
over, it is figured with the central and terminal nodules of a true
Navicula.

I have a, more or less, distinct recollection of a Grammatophora,
probably subtillisima, being given as the Amician test ; possibly
this is the American variant.

* When and where this paper was published I have been unable to find,
but it is quoted at some length in the Sixth Edition of Hogg, " The
M croscope," etc., 1867, pp. 175-8, and Eev. J. B. Eeade somewhere mentions
that Tomkins used a double prism illumination in 1861.

t Navicula affinis, sous le nom de Test d'Amici a ete' employee d'apres le
Prof. Yan Heurck a l'exposition de Londres a 1862 pour juger les Micro-
scopes. Robin, "Traite du Micros, et des inject.," 1877, p. 312.

82 O. C. KAROP ON WHAT WAS THE AMICIAN TEST ?

Obviously, therefore, I have not been able to satisfy myself that
there was a fixed or standard Amician test. The matter is, of
course, of archaeological interest only at the present time ; but
it is certainly singular how a term which thirty or forty years
ago was the common property of microscopists should have become
so obscure and mysterious, and I trust some here will be able to
explain it.

83

M5RARY

Roots and Some Growths Upon Them.

By E. B. Green, F.R.M.S.

(Bead April 19th, 1895.)

Plate V.

The drawings upon the table are intended to represent the
structure and rate of growth of some roots.

Root hairs drawn to a uniform scale ot 100 diameters, and

Parasitical and other growths, which I have found upon them.

The seeds of a large number of plants were sown in pots filled
with light soil, and put into a warm greenhouse, where the
temperature varied from 45° to 70°, and the seedling plants were
from time to time carefully taken up with a sufficient quantity of
adherent soil, plunged into a tank of water, and after gentle
washing floated on to a sheet of glass, or (if intended for micro-
scopic examination) upon a glass slide rather larger than the
ordinary size, and a covering glass was put on before the slide was
removed from the water, care being taken to exclude air bubbles.

The specimen was put upon the stage of the microscope as soon
as the outside of the covering glass was dry, and it was also
examined when the specimen had dried. I found this double
examination necessary, as some of the more delicate organisms
which could be plainly made out when first put upon the slide lost
all their characteristic form and structure when they became dry,
whilst others which were colourless could not be seen till all the
water had evaporated.

Some of the drawings, showing the rapidity with which roots
grow under favourable circumstances, are made the natural size.

A seed of maize, eight days after planting, produced 20 roots
of various lengths ; the longest six inches. Another fourteen
days from planting had upwards of 100 roots, and the longest of
which was eight inches. A seed of barley produced 70 roots in
eight days, and an oat upwards of 400 roots in 48 days ; several of
them were more than fourteen inches long, and all these roots
were densely covered with root hairs.

84

E. B. GREEN ON ROOTS AND SOME GROWTHS UPON THEM.

Root hairs are extensions of the walls of the outer circle of the
root cells, and continuous with them ; they spread out at their
base in some cases very considerably, but with this exception they
are tolerably uniform. They do not branch, but in some instances
divide into several short swollen projections at their extremities.
The hairs upon the roots of many ferns are of a rich orange brown
colour, but those of most plants are colourless or very slightly
tinted ; they are beautifully iridescent when viewed with a dark
ground illumination ; bright spots of organizable substance are
seen abundantly in some and very sparsely in others.

They are very glutinous and attach themselves firmly to the
glass slide. I have examples which have withstood much rough
usage. They were put upon glass four or five years ago, and
although they were uncovered they have suffered very little injury,
but the roots from which they sprung have long since disappeared.
They cling to grains of sand and other mineral and vegetable
substances in the soil, and exercise a very powerful chemical
action upon them. They differ greatly in character, dimensions,
and quantity in various plants, being abundant and of consider-
able length in the grasses, ferns, and most annuals, and few and
short in fleshy rooted plants.

The drawings of various hairs x 70 Will give some idea of
their different lengths, and others x 500 of their comparative
diameters and other characters.

The dimensions of the longest hairs shown are as follows : —

Length

Erica

l

7

Leek .

1

* 7 </

Oxalis

1
¥6"

Millet

1

• "25

Achillea

1
• "23"

Antirrhinum

l
* "577

Pteris serrulata

1
' "277

Pelargonium

i
* TT

Rye Grass .

1
• TT

Stellar ia

1

Rivina

l

Linum rubrum

1
T

Pteris longifoliu .

i

7

Diameter.

Leek

i

4577

Pteris serrulata

1

97777

,, longifolia

1
1000

Maize

TT7777

Pelargonium

7"27777

Achillea .

T47777

Stellaria .

T7TT777

Pyretlirum

W<777

Antirrhinum

747777

Oxalis

TS7J77

Cereua

1

2800

Adiantum caudatum .

55(577

E. ■ AMD SOKE

In : nmmavti

had c oem, bat a more c:

-aled the :
farther inv fi

. were frequently attached to one specimen, and
although differ- ^ere attached to plants differing

I hare not studied the subject sufficiently to g
whetl re peculiar I have found

Laany of them are common to
rjo found only upon individual sy may be com-

— 1 ^vhich are simp" 7 1 to and on the r ■;

hair, an : do not ceriv-: .it, and

2nd. — I uhs wh:c I and root-

:ructure.

many of thern pro-
bably Algae, some of which are o: able length, a qoarter of

an inch or more, flat and tapelike, from — ! — - to a J — of an inch

* - i . . .

in the . .

ghtly coloured, chiefly .
orange brown, and bearing rariously coloure;
branc ninal joints, divided from the main

stem by a distinct wall. A

j\e round thread, ni
upon the root hairs, until it s a dozen 01 more, and at

.gles, like those of a skein of silk. When
. mted t: uriaiully b

some time 1 hare

any §j them The ::. »ftom T ^ nr to„

inch in diameter ; a third g
I
.ular core, irregular and moi ed.

.:ure and markings ; they
ind flat-j . -^atly

•Tide, and abc
isiderably in -.-.
gring at a considers i raUel;

in mo e ^ngles lik e

links of a chain, colour bright

86

E. B. GREEN ON ROOTS AND SOME GROWTHS UPON THEM.

The second division consists of gelatinous growths which in
many respects resemble fungi ; they grow from the root or hair,
do not confine their attacks to the part from which they spring,
bat stretch from hair to hair, or from hair to root, and completely
destroy the hair and greatly injure the root ; some kinds traverse
the root-hairs, tilling them with delicate threads, which emerge at
intervals from it, and others nearly fill the cavity with a single
thread, and on emerging from the hair become branched.

In some cases they radiate in straight threads from a central
point, and in others form a dense network. The spores are very
minute and appear to be formed upon the threads, or in bunches of
six or more upon short stalks.

Spores are produced abundantly, and are greatly varied in shape
and colour. They are round, oval, disk-shaped, and sometimes
almond-like, black, white, green, brown, red or yellow in colour,
occasionally quoit-shaped, showing complementary colours (red and
green) in the outer and inner rings ; in some cases they appear to
be enveloped in a gelatinous mass, with slight indications of a
stalky attachment ; in others, smaller bunches upon short pedicels
attached to, or enclosed in, filmy branches quite distinct in sub-
stance and form from the stem, and divided from it by a well-
marked wall ; they are also seen in considerable groups upon the
stem, or closely ranged in single file upon it, or at considerable and
irregular intervals.

I have found crystals of three types upon the parasites of buck-
wheat, lunaria, and parsnip, each differing from the others.

The following is a list of some of the plants which I have
examined, with the number of different growths upon them as
shown in the drawings : —

1
2
1
1
1
I
2
2
1
2
2

Achillea

. 2

Cereus .

Adiantum caudatum

1

Celandine

Althea rosea .
Antirrhinum .

1

9

Dactylis
Endive

Beet

Begonia

Buckwheat

. 1
1

2

huphorbia
Flax .
Gooseberry

Cabbage

Calendula

Cranesbill

3

2

. 2

Hemp .
Impatiens
Linum rubrum

Cardamine .

1

Leek

E. B. GREEN ON ROOTS AND SOME GROWTHS UPON THEM

Lettuce .
Liverwort
Lin aria
Lunaria
Lupin .
Maize .
Millet .
Mullein
Oxalis .
Parsley
Parsnip
Pelargonium
Ph alar is
Poa

4
2

Pojrpy .

Pteris .

2
2

Pyrethrum
Ricinus

2

Rivina .

3

Rush

2
1

Ryegrass
Scabius

3

Silene .

reral

Stellaria

4

Tobacco

3

Tomato

1

Vetch .

1

Wallflowei

87

In conclusion the author hopes that he may be allowed to
express a wish that this subject, which he thinks is novel and full
of interest, may be taken up by some of your members.

Explanation of Plate V.

Fig. 1. Parasitical gelatinous growth with crystals upon roots of
Parsnip, x 300.

Fig. 2. Part of the same, showing rectangular celled structure,
interrupted by transparent crystals, X 1,000.

Figs. 3, 4, 5. Epiphytal growths of considerable length upon roots
of Antirrhinum, x 150.

Fig. 3. Cellular cells about 30 Vo - m - diameter and from 1^ to 10
or more diameters long, walls distinct, colour bright
brown, direct growth.

Fig. 4. Much branched, branches united, without division, except
those connected with the fructification, which is ter-
minal ; outer wall very thin, pale green, enclosing
irregular bright green patches.

Fig. 5. Tape like, greater diameter, about Q^^ in,, much twisted,
no apparent cavity, colour light brown.

Figs. 3a, 4a, 5a. Parts of the above, X 600.

88

On a New Species of Aleurodes.

By R. T. Lewis, F.R.M.S.

(Read April IWi, 1895.)

Plates II., III.

In the autumn of 1892 I received from a correspondent in Natal
a spray of asparagus infested with small scale insects of a kind
which he did not remember to have previously met with. The
plant in question was one cultivated for ornamental purposes in
the verandah of a house at Byrne, and it had become freely
covered with small white spots, which, to the naked eye, had
somewhat the appearance of mould, and were regarded by the
owner as a great disfigurement. It was noted, however, that
similar plants growing out in the open were not affected in the
same way. On examination under the microscope, the objects
were seen to be the pupal forms of some species of scale insect,
which, though themselves perfectly black, were covered with
plumes of pure white wax symmetrically arranged and present'ng
a very ornate appearance, especially when seen under the binocular.
The individual specimens varied as to size, but the arrangement
of the waxen plumes was practically the same in each. I believe
that I exhibited some specimens at one of the meetings of the
Club soon after they were received, but was at the time unable
either to give or to obtain much information concerning them, and
on submitting them to one of our best English authorities on the
subject of Coccididce, I found they were entirely new to him.

Following up the search for information, I forwarded some
specimens to Prof. W. M. Maskell, whose researches into the
history of the scale insects of New Zealand are no doubt well-
known to many of our members through the publication of his
valuable work upon the subject, as well as his numerous communi-
cations to the New Zealand Institute and to the Royal Society of
South Australia. Mr. Maskell had no difficulty in deciding that
the creatures were not Coccididce, as at first supposed, but that
they belonged to the allied family of the Aleurodidce, which may

R. T. LEWIS ON A NEW SPECIES OF ALET7RODE8. 89

be considered as intermediate between the Coccididce and the
Aphides. In the adult form they are distinguished at once from
the Coccididce by the fact that both males and females possess
four wings, whereas the male Coccids have two only, and the
females none whatever ; they also, in both sexes, are furnished
with two joints to the tarsus, and with two claws, whilst it is
characteristic of the Coccididce to have but one tarsal joint and a
single claw. A further distinction is also insisted upon as peculiar
to the adults of this family, namely, their possession of divided
compound eyes, but although this is to some extent indicated in
the new species, it is not so well seen as in some of the figures by
Mr. Maskell of other species. In the pupa condition, however —
with which alone up to that time I had become acquainted — the
distinction between members of these two families is not so well-
marked, since both are found attached to the leaves of the plants
they affect, and both may also be covered with a floury secretion
or with a more or less abundant coating of exuded wax ; hence
they are not infrequently mistaken, and Mr. Maskell himself tells
us that in 1878 he inadvertently placed two species of Aleurodes
amongst the Coccididce under the generic name of Astero chiton.
But on removing the wax and examining the dorsal surface under
the microscope, with about a 1" objective, a well-defined sub-ovate
orifice will be seen upon the last abdominal segment, and by this
only identification is usually possible.

Still greater difficulty, however, attends the effort to distinguish
between the various species of Aleurodes in their adult forms, and
a comparison between the larvas and pupa? is generally necessary
before a conclusion can be correctly arrived at. In the present
instance, the pupa alone had been found, and although it was
tolerably certain that the species was new, it could not be properly
described in the absence of the adult, and my correspondent in the
Colony was therefore asked to keep the plant under observation,
and specially to look out for the appearance of any quantity of
minute four-winged flies in its immediate neighbourhood.

In the following February the owner of the plant in question
reported that the white things on the leaves had turned into flies,
and my friend took the earliest opportunity of going over to Byrne
to investigate the matter. He found, as stated, that the asparagus
plant was now covered with minute flies, which rose in a cloud
when the leaves were touched, but settled again at once if not

90 R. T. LEWIS ON A NEW SPECIES OF ALEURODES*

further disturbed. Having no doubt that these were the adult
Aleurodes, he captured a quantity and forwarded them to me, and
although extremely dry and fragile on arrival, there was no
difficulty in determining that they were what we desired, and that
males and females were present in about equal numbers.

The condition in which they came to hand prevented any very
good mounts from being made, but by the examination of a
considerable number it has been possible to make out all necessary
details, though I regret I am unable to exhibit any specimen this
evening which shows all equally well.

The larval form I have not seen in its natural conditions, bnt a
few specimens of various ages, sent over mounted in balsam, and,
of course, with all trace of wax removed, lead to the inference that
they are inactive and that, as is the case with others of the genus,
they resemble the pupae in shape.

Of the pupa, however, I can speak more confidently, having had
the opportunity of examining some hundreds ; these are elliptical
in shape, measuring on an average 2 L T " X g^", with a thickness of
y^o'' in the middle of the central longitudinal ridge ; in colour
they are black when viewed by transmitted light, but when
mounted in balsam and seen by reflected light they appear brown.
The margin, as seen from above, appears to be beaded or corru-
gated, with the exception, in some specimens, of a small space at
the posterior extremity (immediately behind the ovate orifice
before mentioned), from which two fine setae proceed. These
apparent corrugations are, however, the extremities of a series of
minute tubes, through which the wax is excreted which forms the
delicate marginal fringe sunounding the pupa, but usually ob-
scured from view by the overhanging plumes of the more copious
secretions from the dorsal surface ; the number of these marginal
tubes is found to average about 245 on each specimen. Above
these and along each side are several rows of pores from which a
much more abundant supply of pure white wax is extruded at an
angle of about 45° to the surface of the leaf to which the pupa is
attached, the numerous filaments coalesce, and before their full
length is attained their extremities bend over in graceful curves
until they rest upon the leaf, entirely hiding the marginal fringe,
but not touching it. From the pores at the posterior end the wax
is thrown out horizontally in spiral curves, which meet and overlap

R. T. LEWIS ON A NEW SPECIES OP ALEURODE8. 91

in a characteristic manner on a prolongation of the median line,
those at the anterior end being projected in two parallel plumes for
about the same distance as those behind. On either side of the
elevated dorsal ridge other series of excretory pores are found, and
from these the "wax is discharged in a nearly vertical direction in
parallel lines, farming an elegant double crest above the central
line. The whole appearance of the pupa in its complete condition
is thus exceedingly ornate, forming as beautiful an object under
the binocular microscope as can well be desired.

The perfect insects, which I am now for the first time able to
describe, are very minute, the female not measuring more than
-j-Jo-ths" in length and the male being about £th less. In their
natural condition they are apparently a dull grey colour, with
wings of rather lighter shade, both body and wings being dusted
freely over with a waxy powder ; both sexes are furnished with
four wings, those of the female when expanded measuring about
-j^o" from tip to tip, and those of the male being slightly less. The
specimens sent to me were not quite in the condition which I could
have desired for successful mounting or examination, having been
caught in a paper bag, killed with tobacco smoke, and then sent
through the post in a small box, dry. On arrival, they were so
completely desiccated as to break to pieces with the least provoca-
tion, and though all attempts at relaxing them sufficiently to
display in good positions proved fruitless, I secured about sixty,
which, alter saturation in benzole, were mounted in balsam, and,
although all were of value for comparison, it is with difficulty that
I am able to exhibit a presentable slide this evening. When
mounted in this medium the insects became translucent and deep
yellow in colour, all trace of the waxy powder had disappeared in
the benzole, and the wings were perfectly transparent. The fore-
wing exhibits one median vein, with a single basal branch, the
hind-wing showing the median vein only with distinctness with a
1" power ; the margin of each wing appears to be minutely
beaded, and on examination with a power of about x 400 it is
seen that this is due to a number of small hemispherical elevations
"5 ~hnf a P ai % each bearing three or four extremely fine hairs.

The eyes are compound, constricted — but not actually divided —
across the middle, and there is one small ocellus above and
immediately contiguous to each compound eye. The antennae are

92 R. T. LEWI8 ON A NEW 8PECIES OF ALEURODES

seven-jointed, the first two being short and thick, the others
filiform and slender with many rings, the third being nearly as
long as the last four. The feet are long in proportion to the body,
tibia slender and twice as long as the femur, tarsus of two joints,
claws two. The male and female generative organs are well made
out and do not materially differ from those of other species already
described. But a curious organ, apparently not hitherto noticed,
is found upon the dorsal surface of the last abdominal segment in
both males and females in a position corresponding to that of the
oval orifice already mentioned as characteristic of the pupse of this
family. These, together with the distinctive features above-
named, are shown in the illustrations which accompany this paper
(Plates II., III.).

In his letter to me Mr. Maskell says : "I wish somebody would
take up Aleurodes seriously ; the study is difficult and has only
been scratched as yet by Signoret and myself," and I venture to
throw out this suggestion to members of the Club in search of a
line of study a little off the beaten tracks of the diatoms and
rotifers. There is but one genus in the family of Aleurodidce, and
as the various species known have, for the most part, been named
from the plants upon which they are found, I propose to call the
one which forms the subject of the present communication
Aleurodes asparagi.

In conclusion, I desire again to express my indebtedness to Mr.
Maskell for the information received from him upon this little
known subject, and to my Natal correspondent, the Rev. J. R.
Ward, for the trouble which he has taken in the matter of collect-
ing and forwarding the specimens.

With regard to the fact that this scale was only found upon an
asparagus plant cultivated for ornament, Mr. Ward makes the
suggestion that possibly this may be due to the protection afforded
by the verandah, and it seems extremely likely that the fragile
waxen plumes would speedily be broken down and washed away by
the heavy rains to which an infested plant growing out in the open
would be periodically subjected. In the absence of the white wax,
it would, of course, be very difficult to detect the presence of so
small a scale with the naked eye, and a casual observer might
readily, on that account, suppose an infected plant to be free.

r. t. lewis on a new species of aleurodes. 93

Explanation of Plates.

Aleurodes asparagi.
Plate II.

Fig. 1. Portion of leaf of asparagus with pupae in situ, x 20.

a, with wax intact • b, with dorsal wax removed,

showing marginal fringe.
„ 2. Adult male, x 45.
„ 3. ,, female, x 45.

Plate III.

Fig. 1. Pupa with wax removed, dorsal surface, x 25.
„ 2. „ „ ventral „ „

,, 3. Transverse section, showing arrangement of wax.
„ 4. Leg of adult.
„ 5. Abdominal extremity of female, side view ; d = dorsum.

x 300.
,, 6. Abdominal extremity of male, dorsal view, x 300.
,, 7. ,, „ „ side view ; d = dorsum.

X 300.
„ 8. Tarsus of adult. x 300.
„ 9. Antenna of adult, x 300.
„ 10. Portion of margin of wing, x 575.

Journ. Q. M. C, Series II., No. 37,

94

Examination of "Foul" Sea Water.

(From a sample given by Mr. Shrubsole, in May, 1894.)

By Walter P. Shadbolt.

{Read April \Qth, 1895).

Stroke and deep inoculations were made in agar and gelatine
tubes, and kept at 19-20° C, at which temperature all the following
observations were made. The growths were all aerobic, being visible
along the stroke in 24 hours faintly. The organisms were fo.;nd
to be mixed, and plate cultivations on gelatine for purposes of
isolation were made in the usual way. After several transfers from
plates to tubes, and from tubes to plates, isolation was effected.
Two kinds were occasional, and probably adventitious. Three
kinds were persistent.

The two occasional kinds were : —

1. A straight rod, motile during the first day, rapidly liquefying
gelatine ; soon becoming motionless, and breaking up into spores,
with a putrid smell.

2. Small round organisms, motile to some extent, with a move-
ment like Brownian movement, breaking up into spores, and
liquefying gelatine rapidly, with a putrid smell.

These were not observed further.

The three persistent kinds were all rounded bodies, of which
tube cultivations on agar are produced. They all liquefy gelatine
slowly. The tubes are marked respectively " Star," " White," and
" Yellow."

No 1, " Star," cultivated on a plate at 19-20°.

In 24 hours showed no visible growth. In 36 hours there
appeared numerous whitish spots, plainly visible under a lin.
glass. In two-and-a-half days the spots were "visible to the naked
eye, and in three days these had developed into star-shaped colonies,
whitish, and so far without perceptibly liquefying the medium.

The colonies at first grow from one or two round organisms,
which increase irregularly by budding. They are about T0 1 oTT m> m
diameter, some as large as -^-^q-q. As soon as these are numerous

W. P. SHADBOLT ON " FOUL " SEA WATER,

95

enough to form a crowded cluster of perhaps 20-30, the colony
throws out numerous arms of hyaline matter radially, and these
keep on increasing in length. Along the arms appear many, (say
a dozen or two), nuclear spots, not at regular intervals or in
regular lines, but here and there, sometimes two or more side by
side, and distributed in the direction of the length of the arm
These nuclei grow into round bodies like the parent, and of the
same size, then arrange themselves gradually in the direction of
the length of the arm or ray, and finally, as the medium liquefies
after about five to six days, or less, separate.

Neither in the resulting nor any other liquid medium have I
seen the star-shaped colony. In liquid the organisms divide
irregularly by fission or external budding, and in a few hours break
up into masses of minute spores. This organism is at no time
motile, and except in the case of the radial processes above
described, retains, as an individual, its rounded form.

No. 2 « White " 1 These are not visible on the plate for
No. 3 « Yellow" {about 36 hours. The colonies then appear
as white or yellow rounded, (sometimes kidney-shaped), spots,
which gradually increase in size. In some of them the edge is
definitely marked by a surrounding ring of organisms, packed
closely and regularly. In others the edge shows no such bounding
ring, and is fissured. These do not break up, are not confluent, and
consist of masses of extremely minute rounded bodies. On being
placed in a liquid medium they multiply rapidly and irregularly.

These two kinds are so similar, except in colour, and the dif-
ference in colour is so slight in the earlier stages of growth, that
it is not easy, especially by artificial light, to distinguish them.
They are non-motile, aerobic, and liquefy gelatine but slowly.

A temporary absence during the growth on the plates when I
had at last got them separated prevented my being ready with
more than the above very incomplete observations as to these last
two kinds. They are now, as will be seen, well differentiated in
the tubes shown, and are ready for further investigation.

The hanging drop cultures, one of each of the three kinds shown
herewith, are taken from the respective tubes, and are about 24
hours old.

The media have all been slightly alkaline. Trials were made on
agar and gelatine media, in which fish was used instead of meat,
but without any difference in the result.

96

On Scale Evolution, as shown in Ithomia diasia.

By J. E. Ingpen, F.R.M.S.

{Read May Vjth, 1895.)

Plate IV.

Variation of form in insect scales, though not considered
by systematic entomologists as of much importance, has always
been a subject of interest to microscopists, and the question of the
line of demarcation (if there be one) between scales and hairs has
frequently been discussed. The description of a specimen showing
an unusual number of gradations of form may therefore be not
altogether useless or uninteresting.

While hunting for illustrations of iridescence, I came across
some specimens of Ithomia diasia, a clear-winged Columbian
butterfly. Though not a showy form, it is very delicate and
pretty, the iridescence of the clear parts of the wings being set off
by the black ribs and borders. On the underside there is a dull
orange and yellow margin to the hind wings, and there are a few
dusky white spots on both front and hind wings. On examining
the clear parts to ascertain how far the iridescence might be due
to plates, lines, dots, etc., I could not help noticing the hairs
thinly scattered over them. Some of these were single, others
forked, some white, most of them black, the white hairs becoming
transparent when mounted in Canada balsam, the black ones a
dark brown. These hairs were only present on the clear parts, the
ribs and borders being thickly covered with well-defined scales, but
close to the ribs and borders numerous transition forms between
the hairs and the scales occurred, and it is to the illustration and
description of these that I desire to call your attention.

1 and 2. — Single and forked hairs, white and black. Apparently
-•tubular, as shown by the character of the air bubbles expelled in
tb£p. course of mounting. No appearance of interior granulation or
exterior marking.

8. — The part near the fork a little wider and thicker, showing a

J. E. 1NGPKN ON SCALE EVOLUTION. 97

few pigment granules. A more developed hair showed traces of
longitudinal markings.

4. — A sharp, slender, swallow- tailed scale, with strong longi-
tudinal lines, and short transverse lines between them.

5. — A wider scale, with the sides convex and the ends blunter.

6. — A shorter, wider scale, with two rounded ends.

7. — A similar one, with three rounded ends.

8. — A longer and narrower form, with two bluntly pointed
ends.

9. — A leaf-shaped scale, with a sharp point.

10. — A paddle-shaped scale, longer and narrower than the last,
and also sharply pointed.

11. — A scale longer, blunt at the end, and apparently thicker.

12. — Longer, narrower, and more solid in appearance.

13 and 14. — Scales or hairs at the margins of the wings, long,
bifurcated or trifurcated. All these varieties show strong longi-
tudinal markings.

The scales on the orange and yellow borders to the hind wings
and on the white spots are of an ordinary type, similar to 6, 7, and
8, but they have not the strong longitudinal markings charac-
teristic of the others.

15. — In a long oval depression on the upper front margin of the
hind wings is a bundle of what I believe are considered to be scent
hairs. These differ from any of those already described. They
average a quarter of an inch in length, and the largest are nearly t ^qo
of an inch in diameter. They are brown, cylindrical, slightly tapering
towards the rounded ends, and are firmly attached to the wing.
They lie on a bed of cream-coloured scales, somewhat of the shape
of No. 6, but with very obscure markings, These hairs have a cell
structure suggestive, in miniature) of that of the deer, with a
distinct medulla. This structure is probably well known to those
who have studied the characteristics of scent hairs. On the under
margin of the front wings are a number of scales, which, when the
wings are closed, are in contact with the scent hairs, and appear
to have a somewhat similar structure, but less developed. The
striae are only on one side, on the other are traces of cell-structure
and pigment dots.

The attachment of the hairs first described, 1, 2, 3, etc., to the
wing, is very pretty — the socket looking like the neck of a bottle
with a thickened rim.

98 J. E. 1NGPEN ON SCALE EVOLUTION.

Many more transition forms could be shown, but those illus-
trated will, I think, be sufficient for the purposes of this paper.

I have used the terms lines, striae, etc., in our ordinary micro-
scopical sense, to indicate general appearances rather than the exact
structure of the hairs and scales.

In conclusion, I must thank Mr. Karop for his kind assistance
and admirable illustrations.

9y

On Scale Evolution in the Lepidopterous Genus Ithomia.

By W. H. Nunney.

{Communicated by J. E. Ingpen, May 17th, 1895.)

In taking advantage of Mr. Ingpen's wish that I should supple-
ment his paper from the comparative and systematic aspect in
contradistinction to the purely histological, and his most interest-
ing observations having apparently opened up a new field of
inquiry, it was, of course, necessary for me to overlook a great
number of butterflies and moths for purposes of comparison. My
observations are, I believe, in the main correct, but it is possible
from their extent, and the little time I was able to devote to the
matter, that certain of them may need future modification, more
especially as I did not intend to render them exhaustive.

The question of scale evolution is one which unfortunately has
attracted little attention, notwithstanding its great interest.
Nowhere can it be more effectively studied than in butterflies and
moths. The occurrence in that order of every variety of scale
form, from the almost filamentous to the broadened plate known
as the " battledor," affords the widest possible scope for theory.
Till of late we needed to search through numerous species to
discover transition forms between hair and scale. The discovery
of nearly all the varieties on the wings of a single species of
Ithomia has, however, placed the matter in a better light, and
gives additional verification to the theory of the evolution of the
true scale from the simple hair.

The Ithomiae are an exceedingly concrete group of American
butterflies, characterized by the possession of clear or semi-trans-
parent wings, the lower ones provided with scent pouches, as in the
whole of the sub-family Danainee to which they belong. These
scent sacs during the insect's life diffuse an odour objectionable to
most insect-eating birds and reptiles, the species being thus
rendered less likely to be preyed upon. The whole group is
usually placed in an intermediate position between the white tribj

100 W. H. NUKNEY ON SCALE EVOLUTION.

of butterflies and a group of curious and evil-smelling forms
(Acreince) almost confined to the African continent. Bates and
some others have argued, and perhaps justly, that these insects,
being well protected from the attacks of their greatest enemies,
and being at the same time very frequently imitated by members
of other groups without this means of defence, should be placed at
the head of all the butterflies as possessing the highest organiza-
tion. Such view, however, is by no means generally accepted,
and the swallow-tailed species still hold their old place at the head
of the entire order. It is to the somewhat isolated genus Ithomia
to which the occurrence of the features mentioned in Mr. Ingpen's
paper are almost entirely restricted. I have sought long and
carefully for a parallel amongst the clear-winged species of all
groups of macro-lepidoptera, and so far have been quite unable to
find such. Each group — in fact, almost each species — has its own
peculiarities of wing-covering, and the whole forms a most interest-
ing and instructive study, but nowhere, even amongst Ithomia' 's
direct congeners, do we see the numerous variations of scale-shape
to which Mr. Ingpen has drawn attention.

Commencing our comparison with the typical family of swallow-
tailed butterflies, the clear-winged species of which are but few,
we find in the curious little Leptocircus (said when at rest to
mimic a dragon-fly) a peculiar disposition of the wing-covering.
The fore-wings alone are provided with clear spaces. Over the
whole upper surface of these long-stalked, bifid, wedge-shaped
scales are sparsely arranged in rows, whilst the lower surface
apparently has absolutely no scales, their place being occupied by
long and curved finely-pointed hairs. The attachments of both to
the wing membrane are so nearly coincident (in some cases exactly
so) as to render it extremely difficult to convince oneself, even by
the use of a good microscope, that loth hair and scale do not
actually proceed from an identical point of origin on the upper
surface of the wing. The accompanying Figure 1 shows this
appearance well.

Fig. 1. Fig.

W. H. NUNNEY ON SCALE EVOLUTION. 101

A few bifid scales with shorter stems occur as in Ithomia. In
the diaphanous fcurycus fan-shaped scales only occur, whilst in
some of the Apollo butterflies (Parnassias) scale-hairs and true
scales are found without connecting forms. Passing from the
Papilioninaa we come now to the sub-family to which Ithomia
itself belongs. With the exception of the pre-eminently clear-
winged group of which Ithomia is an essential member, we find
nothing remarkable in the character of the wing clothing.
Excluding these, nearly the whole of the other species have wings
well provided with scales of ordinary character. The typical
genus Danais has oval scales, whilst its off-shoot Amauris has
diaphanous scales of pronounced battledor type.

In the whole of the clear- winged genera to which Ithomia is
closely allied much the same character of wing-covering obtains
inter se, the members being mostly possessed of the bifurcate hairs
so prominently displayed in Ithomia, transition forms between the
hair and scale being rare.

The next following group of Heliconian butterflies from South
America differs entirely from Ithomia in the wing-covering, for I
have nowhere observed amongst them other than true scales. In
the closely-allied and evil-smelling Acreinon there are two main
types, one possessed of wings having a wholly-coloured surface
furnished with true scales only on the wing plane, with, however,
spiny hairs on the wing margins; and another, the members of
which have the greater portion of the wing semi-transparent. In
these latter the clear positions are furnished with scale-hairs,
whilst the coloured portions are provided, as is usual, with true
scales.

Passing to the woodland species, almost the only representa-
tives having the wings furnished with clear spaces are the wonderful
leaf butterflies. In these, the clear spots are covered with highly-
transparent true scales of an elongated oval form, notched very
slightly at the extremity. In Citherias, the most diaphanous
of all butterflies, the wing-covering exhibits none of that fine
gradation of structure existing in Ithomia, the transparent parts of
the wing being furnished with hairs pure and simple, no scales of
any kind being developed until certain eye-like markings are
reached. In fact, it may, I think, be taken as a fixed principle in
Lepidoptera that true scales alone normally play any part in the
chromatic ornamentation of the wing membranes, although Citherias

102 W. H. NUNNEY ON SCALE EVOLUTION.

is in itself an exception, as in C. aurora, for instance, the rosy patch
on the hind wings is caused entirely by the presence of pigmented
hairs. These hairs are connected with the normal fan-shaped
scales by a transition form of the shape shown in Figure 2.

In the members of this and the closely-allied genera Hastera,
Pierella, and Antirrhcea, the wings of all of which are clothed more
and more fully, the further we depart from Citherias, we also find,
as might be expected, a slight increase of transition forms of scale
and hair.

In Zeonia sylphtna, an American butterfly, remotely allied to the
" hairstreaks," and which, at first glance, has the appearance of a
clearwing moth, we find on the hyaline portion of the wing no hairs,
but singularly enough scales of the swallow-tail type so charac-
teristic of Ithomia. This is explicable, notwithstanding the
remoteness of the two groups, on the supposition that such form is
a primitive type, probably having occurred anciently on all species
alike, but now crowded out by later developments.

Turning from the butterflies to the moths, the most striking
forms for our purpose are, of course, the mimicking " clearwings."
The members of this group may be considered as comprising two
sub-groups, in the first of which the wings where clear are absolutely
so, as in some foreign and one or two British species, whilst the
other, by far the most numerous in species, possesses various forms
of scale, ranging from the peculiar strongly-ribbed, long-stalked
kind on the wing fringe of the currant clearwing, through the fan-
shaped to the almost circular and transparent form found commonly
upon the clear portions of the wings. Macroglossa marginalis, a
Columbian species, is peculiar, inasmuch as it combines the charac-
ters of these two groups ; the forewings are moderately covered
with true transparent scales, while the clear spaces of the hind
wings are entirely destitute of either scales or hairs. The transition
genus Cocytia has the glassy spaces of the wings, like the first
group of true " clearwings," entirely devoid of covering.

In other of the moths, notably the larger silk-making species,
clear spaces occur on the ordinarily thickly-covered wing mem-
brane. These in the great Atlas Moth are haired only, and
apparently no transition forms occur. Circular windowed species,
like the Tussore silk moth, have apparently neither hairs nor scales
on the clear portions of the wings, the " windows " being sharply
defined by a thick growth of true scales on the periphery.

W. H. NUKNEY ON SCALE EVOLUTION. 103

The foregoing comparisons lead ns to the conclusion that
numerous transitional forms of scale are very rare, such a phenome-
non as occurs in Ithomia being unique in its own group. The
question naturally arises, how is it that Ithomia3 alone show scale
evolution more perfectly than do other insects? On the supposition
that Ithomia is an extremely ancient type, if not indeed a truly
primitive form, this may be satisfactorily answered. Palasonto-
logical evidence, however, by no means bears this out. The earliest
occurrences of Lepidoptera in geological strata, excluding the
disputed Palceontina oolitica, are of a very different group, the hawk
moths or Sphingidae, and in no way allied to Ithomia?, although
such evidence is from the imperfection of the record not at all
conclusive. On structural evidence the primitive position may
probably be assigned to the Swift moths or Hepialidre. It is
then all the more singular that with such comparatively high
development in other respects, so many and curious transitional
forms of hair and scale should occur in Ithomia and its allies, and
it is worthy of passing note that the true battledor scale so charac-
teristic of the butterfly known as the Azure blue does not occur
in the Ithomian series. Perhaps we are altogether mistaken in
assigning so high a development to the battledor scale. This
negative view T is apparently borne out by a reference to some of the
lower scaled insects. Certain white-ants (admittedly a very
ancient group), found only in a fossil state, are furnished, not as
might be expected with coverings of the hair scale type or simple
hair, but are clothed with near approaches to the battledor type.
In Perientomum I believe this is markedly the case. Amongst the
Poduraa, or springtails, the body covering is almost without excep-
tion composed of scales of the crenate battledor type possessing a
high, possibly the highest development, notwithstanding that the
creatures themselves are of the most lowly degree, on this account
having been shelved from the insect series, and, indeed, considered
as insect prototypes. The question of the evolution of true scales
from simple hairs is thus thrown back immeasurably further into
the past. That this battledor type is really a development and not
a primitive form must, I think, be allowed when it is considered
that beetles, which are undoubtedly of a higher type than even
butterflies (Agassiz notwithstanding) possess hardly any other
description of scale. By the facts relating to the Poduras the
reverse is of course implied. There are great difficulties in either

104 W. H. NUNNEY ON SCALE EVOLUTION.

view, and that of evolution does not explain why, for instance, a
lowly creature like Polyxenus amongst the Myriapods should be
furnished with hairs so vastly more complicated than any that
occur on the Ox fly, or many beetle larva?. There are difficulties
almost insurmountable in the holding of views other than those
based on mere adaptation to circumstances, but it would certainly
seem that although we cannot point to Ithomia as a positive
example of scale evolution, yet the great number of intermediate
forms between the simple hair and the true scale tends to impress
the observer with the idea that we have here actually caught a
glimpse into the heart of the developmental process, and I, at least,
am unacquainted with any instance by which the subject is better
illustrated.

105

Notes on some Plants Collected in the Pyrenees.

By J. W. Reed.

{Read June 2\st, 1895.)*

It has been thought that the series of plants exhibited this
evening which were collected in the Central Pyrenees in June and
July of 1894, and found at heights varying roughly from 5,000
to 9,000 feet, may be of scientific interest to some Members of
the Club, and to others serve as a relaxation from the abstruse and
severe researches which usually engage their attention. At any rate,
the exhibit may more or less usefully help to fill up an evening not
otherwise fully occupied. In no wise do these rough and imperfect
notes aspire to the dignity of what is known as a " Paper," much
less to a place in a Journal amongst critical discussions of the
optical theories of the microscope, or of the relation of the refractive
indices of mounting media to the resolution of diatoms.

The plants now exhibited were collected either in the upland
meadows of and about Gavarnie, a tiny village in the heart of the
great range of the Pyrenees, or on the loftier heights and wilder
valleys in its neighbourhood. A few were collected during ascents
of the snow-peaks which here abound, but the majority were the
fruit of quiet though long rambles on days not devoted to laborious
climbing. Our visit to the Pyrenees was mainly for mountaineering
and photographic purposes ; but, though we also had some botanical
aims, no attempt was made to collect systematically. Whilst a
number of plants very common in England were not pressed, those
before us may, I suppose, be fairly considered as typical of the
particular locality and of its early summer flora as it presents itself
to the average traveller.

I am greatly indebted to Mr. G. Nicholson, the Curator of Kew
Gardens, for the careful naming of the various species, for much

* Mr. Reed wishes it to be understood that this paper was not written for
publication, but merely as a running commentary on his exhibition of
Pyrenean plants ; nevertheless, at the earnest request of several members,
he has consented to allow it to be published. — Ed.

106 J. W. REED ON PLANTS COLLECTED IN THE PYRENEES.

varied information with regard to many of them, and for his more
than kind offices in getting them so beautifully mounted for me.
Their being so well dried and displayed is mainly due to the
care and skill bestowed on them by Mr. F. H. Ward (my travelling
companion), and to the use of an admirable botanical press designed
by him, and described and figured in " Science Gossip," No. 280,
April, 1888, page 80 ; it was also described and figured in the
" Bulletin of the French Linnean Society " the same year.

My authorities for the number and distribution of the species are
Bentham and Hooker, whose "Genera Plantarum " has been
referred to throughout. It may be mentioned, also, that the
11 Mediterranean Region," for geographical and botanical purposes,
includes all the South Coast of Europe, North Africa, and Asia
Minor, and also the Isles.

Botanically, the Pyrenees is one of the most interesting regions
of Europe, and a point of special interest to the British botanist
is the existence of a colony of Pyrenean plants in the West of
Ireland. It is no doubt another of the woes of that " distressful
country " that even some of its plants appear " in a foreign garb."
Amongst these plants may be mentioned Arbutus unedo, Dabcecia
polifolia, Neotinea intacta, Saxifraga Geum, Saxijraga umbrosa,
Erica mediterranean and Meconopsis cambrica, and their presence
at once opens up the wide and difficult, but profoundly interesting,
question of plant distribution.

It has been suggested that this colony immigrated along a range
of now submerged mountains, which extended from Spain to
Ireland across the Bay of Biscay. Whilst the theory of this
particular continental extension has not been supported by sufficient
evidence to secure its general acceptance by geologists, it is
believed that in Tertiary times Britain was connected with France,
and Ireland was not so far removed from Great Britain as she is
now. Whether or not our flora had a continental origin, having
immigrated prior to the existence of the English Channel and the
German Ocean, Mr. J. G. Baker, Keeper of the Herbarium at
Kew, in his Presidential Address to the Yorkshire Naturalists'
Union in 1883, said that " the most important general character
of the British Flora is its utter want of any distinctive individuality.
Leaving out of count a few doubtful hieracia, willows, rubi, and
roses, I can give only two good instances of British plants that do
not occur in continental Europe." The two plants mentioned by

J. W. REED ON PLANTS COLLECTED IN THE PYRENEES. 107

Mr. Baker were Potamogeton lanceolatus and Eriocaulon septan-
gulare. Nor, in the consideration of any general question of plant
distribution, must we leave out the agencies of oceanic currents,
winds, and birds. Sir Joseph D. Hooker has told us that seeds
have germinated at Kew after floating in the sea for 3,000 miles,
and Darwin that dust is blown 1,000 miles over the ocean — the
dust of the Krakatoa explosion, as we all remember, was carried
much further — and the extreme minuteness of many seeds is well
known to everyone. Birds not only eat seeds directly, but also
prey on fresh- water fishes which eat them too, and, as Darwin has
also shown, carry seeds over the ocean " in their feet, beaks, and
stomachs."

This being so, it is not a matter for surprise that in many parts
of the world what are clearly immigrant forms should be found
side by side with an indigenous flora.

Whilst the interposition of seas, deserts, mountain ranges, and
even forest regions has done much to differentiate the floras of the
various portions of the earth's surface, climate has done more.
Generally speaking climate becomes more rigorous as we ascend,
and thus in climbing from the plain to the summits of mountains
like Mont Perdu, the Vignemale, or the Marbore (all about 11,000
feet high), we find well-marked zones of vegetation. From the
rich and fruitful one at the foot, we pass through fir forests, then
over green alps with their northern flora, until nothing but mosses
and lichens are seen — the latter at last appearing as splashes of
colour only, on the higher wind-swept rocks ; and finally on to the
eternal snows, their surface reddened here and there by the lowly
unicellular alga, Proto coccus nivalis. In some parts of the Pyrenees,
as in the Alps, it is possible to tell approximately the height to which
we have ascended by observing the plants ; but this is not always
so, for from various causes not yet fully determined, many upland
valleys and high passes of the same height have been found to vary
greatly in their mean temperature.

There is also, without doubt, an intimate relation between the
chemical composition of soils and distribution, but in this, as in
other directions, there is much left to be worked out. It may
here be stated as a fact which generally holds good that plants do
not always grow where prima facie they might be expected to
flourish, such growth often being prevented by the presence of other
forms of vegetation in some respects better equipped for the struggle

108 J. W. REED ON PLANTS COLLECTED IN THE PYRENEES.

for existence. It would be an impertinence were I for one instant to
suppose myself competent to deal critically with the complex prob-
lems of plant distribution, but I could scarcely forbear to mention
as above and thus briefly the striking connection of a special portion
of our flora with that of the Pyrenees.

In the Pyrenees we meet not only with plants well represented
in Britain, and belonging to large orders widely distributed, but
with others purely Pyrenean, or very rare, and of limited distribu-
tion. Some are seen which have been brought into general
cultivation, and plants as familiar as the common " London Pride "
of English gardens abound.

The following plants belong exclusively to the Pyrenean region,
viz., Ramondia pyrenaica, Galium pyrenaicum, Antirrhinum molle,
Asperula hirta, Geum pyrenaicum, Viola cornuta, and Silene ciliata.
As to Lonicera pyrenaica, the type is probably confined to the
Pyrenees.

I need scarcely add that, if one has travelled in Switzerland,
many old Alpine friends will also be found in the Pyrenees, and
here, as elsewhere, we cannot fail to notice the well-known ten-
dency of the flora at high levels to become smaller and low
growing, with stiff leaves and tough fibrous roots — the plants
generally being bitter to the taste and resinous. The flowers also,
in proportion to the size of the plants, are large and of brilliant
colour, due doubtless to their unconfined situation, the pure air,
and unobscured sunshine.

We notice also a certain correspondence between the flora of
mountains and of high latitudes. As one ascends mountains the
rule is that the forms of lower levels are replaced by Alpine forms.
For instance, the birch trees of the lowlands are represented at
high levels by Betula nana, often only three inches high, and the
willows — trees or big bushes of the plains — are represented on our
own mountains by Salix herbacea and Salix reticulata, prostrate
shrubs only an inch or two high. These plants are, of course,
found in the lowlands of high latitudes.

The rule referred to is not universal, for Sir Joseph D. Hooker,
in a lecture on " Insular Floras," has dwelt on the curious facts
that from a height of 4,000 feet on the mountains of Madeira to
their summits of 6,000 feet there is " little or none of that re-
placement," and that the mountains of the Canaries, nearly
11,000 feet high, contain no Alpine plants — that, indeed, the

J. W. REED ON PLANTS COLLECTED IN THE I'YRENEES. 109

mountains of islets, however lofty, present few Alpine or sub-
Alpine species.

Perhaps the plant which most attracted our attention in the
Pyrenees was the Ramondia pyrenaica. Its hairy, primrose-like
leaves and purple blossoms profusely adorned the rocks all around
Gavarnie. Although largely cultivated in the rockeries of English
gardens, the Ramondia has no near ally in our flora. Indeed, the
order to which it belongs — the Gesneracea? of Bentham and Hooker
— although extensively represented by about 700 species, widely
dispersed throughout the tropical and sub-tropical regions of both
hemispheres, has only four species in Europe, three of the four
being Ramondias. One species is Pyrenean, one Servian, and one
Greek. The Greek species introduced into this country has not,
up to the present, been successfully cultivated. It was introduced
by Max Leichtlin, of Baden-Baden, who obtained living specimens
from Mount Olympus, I believe at an expense of about £100, as,
owing to the presence of brigands, an escort of soldiers had to
accompany the botanist. The Ramondia pyrenaica grows from a
height of 5,000 to 6,000 feet roughly.

The fourth species, Haberlea rhodopensis, is a native of Thrace,
etc.

There is now in full flower at the south end of the rockery at
Kew a beautiful group of the Ramondia pyrenaica, the colours
varying from white to deep lilac. Local conditions have not been
without effect, for the leaves are not as hairy nor the flowers as
deep-coloured as those seen by us in the Pyrenees. Some plants
of Haberlea rhodopensis are also in flower quite near to the
Ramondias, and a plant nearly allied to the latter — Saintpaulia
ionantha — recently introduced from the mountains of East Tropical
Africa, is also in flower in one of the houses at Kew Gardens.

The high Alpine orchid, Nigritella angustifolia, found through-
out Continental Europe, from Sweden and Norway to Greece, also
grows abundantly near Gavarnie. Its head of blackish-purple
flowers and strong vanilla-scent are very noticeable. This plant
is now included by Bentham and Hooker under Habenaria. It
too may now be seen in flower at Kew.

The Welsh poppy — Meconopsis cambrica — is found in Ireland,
England, Central and Southern France, the Pyrenees, and Northern
Spain. When doing a little collecting some years ago I got
specimens from within the cliffs of the " Devil's Kitchen " in North

Journ. Q. M. C, Series II., No. 37. 8

110 J. W. REED ON PLANTS COLLECTED IN THE PYRENEES.

Wales, but have never seen its delicate yellow flowers displayed so
freely as at Gavarnie. There are only about nine species in the
genus Meconopsis, one belonging to Western Europe, two to N.W.
America, and six Himalayan.

Our old friend — Narcissus pseudo-narcissus — daffodil or Lent
lily, was found in myriads on the mountain slopes near the Col de
Vignemale. Of this species, about 200 forms are distinguished by
names by English growers. The mucilage of this plant was
formerly used as a violent emetic.

Astrocarpus sesamoides, belonging to the Resedacea, grows
freely on the banks of the glacier stream which comes down from
the mountains of the Cirque de Gavarnie. There are only five
species in the genus Astrocarpus, all South European. Our garden
mignonette belongs to the same order, but what was the origin of
this favourite plant is a mystery no one has yet solved ; it has
nowhere been found wild. This question may yet be cleared up
like that of the origin of the Common Onion (Allium Cepa).
Though cultivated from the earliest times, being mentioned on the
Pyramid of Cheops, where is inscribed, in Egyptian characters, an
account of the quantity consumed by the workmen, it was not
found wild until within quite recent years, when it was discovered
in Western Siberia by Dr. Regel.

Erinus alpinus, the only species in the genus, sometimes occurs
with white flowers, and it also is a favourite plant in cultivation in
English rockeries.

Iris xiphiodes, with which towards the middle of last July the
meadows and pastures of Gavarnie were everywhere blue, is a
native of the French and Spanish Pyrenees, and extends to
Asturias. It is the well-known so-called English Iris of gardens,
and of which several colour varieties were cultivated 250 years
ago.

Vincetoxicum officinale, the milky juice of which has been used
as an emetic, we had often seen in Switzerland. It belongs to the
order Asclepiadece, which is not represented in the British Flora.
Rhododendron ferrugineum, the " Rose des Alpes," the leaf-
scales of which are a beautiful microscopic object, is common in
the Pyrenees, Alps, Appenines, etc. Its buds are still used by
the natives of the Alps in preparing an anti-rheumatic liniment
called "Marmot-oil." There are about 130 species of the genus
distributed over the mountains of Europe, Asia, the Malay

J. W. REED ON PLANTS COLLECTED IN THE PYRENEES. Ill

Archipelago and North America — one is found in New Guinea.
This is another of the Alpine plants now well in flower at Kew.

In crossing the mountains of the Val d'Heas to the Cirque de
Trumouse, we found large areas quite rosy with the flowers (
Daphne Cneorum, a charming glabrous and procumbent little
shrub, the leaves and seeds of which, however, possess extremely
acrid and objectionable properties. This plant and our own Daphne
Laureola (or spurge laurel) were once regarded as of great
medicinal value ; but that was at a time when the efficacy of
therapeutic agents appears to have been adjudged by their nasti-
ness. No doubt these heroic medicines had their use, for their
violent action would, at least, serve to distract the patient's atten-
tion from the rapidly approaching dissolution which the treatment
of former days too often implied.

Anemone Hepatica is largely cultivated, and, in cultivation, the
flowers vary from pure white, mauve and red, to deep blue ; and
there are many double forms.

Hyacinthus amethystinus is a beautiful little garden plant.
There are about 30 species of Hyacinthus, with the exception of
three South African, all natives of the Mediterranean region and
the Orient.

The purely Pyrenean Viola cornuta has been largely propagated
in gardens, and has given rise to some of the so-called Violas or
Tufted Pansies. As we found it in its wild state, the flowers were
lavender, but under cultivation all sorts of colours have been
obtained by crossing.

Arnica montana is common on and near the rocks of the village of
Gavarnie. It is a striking plant, and its flowers are supposed to
contain a property stimulative of the action of the skin. The shep-
herds of the Alps may often be seen gathering the heads of Arnica,
Hypochaeris and other yellow-flowered composite, for the purpose
of making tincture of Arnica.

The much-talked of " Edelweiss " — Leontopodium alpinum —
is found freely distributed in the Alps, Pyrenees, Carpathians,
and other mountains of Europe. The dangers of gathering this
plant, though often the subject of much literary tail-lashing, are
quite imaginary. Our specimens were found near the right bank
of the stream known as the Ordesa, well down the Val d'Arras,
on the Spanish side of the Pyrenees. Some we obtained were
amongst the finest I had ever seen, and were growing at a height

112 J. W. REED ON PLANTS COLLECTED IN THE PYRENEES.

of, I should guess, about 4,000 ft. or 4,500 ft. above sea-level.
Edelweiss may grow as low down as that elsewhere, but I had never
before collected it except at a much greater altitude.

Globularia nana, common enough in the Pyrenees, is not found
in the Swiss Alps.

Draba aizoides, plentiful in the Pyrenees, and generally in the
mountains of Central and Southern Europe and West Asia, is a
doubtful British native. It is found only, I think, on the walls
and rocks of Pennard Castle, in Glamorganshire.

Dianthus plumarius has been naturalized in Britain, being found
on old walls in England and Wales. The origin of our garden
pinks is to be traced to this species ; Dianthus Caryophyllus, also
naturalized, being the progenitor of our garden carnations.

Helleborus viridis I had never seen growing so freely before. In
fact, the only spot where, up to last June, I had met with it in
any quantity, was in a wood in Kent, to which a little party,
including one whose name will long be held in kindly remembrance
by members of this Club — I refer to our late friend Mr. W. W.
Reeves — were guided by Mr. Carrington, now the editor of
" Science Gossip." Its distribution is from Holland southward ;
but, according to Ball, it is not well established north of the
Mediterranean region. This seems to point to this species being
of southern origin.

Memories of our old comrade and friend came thick upon us as
we collected Gentiana verna, Primula farinosa, Bartsia alpina,
Polygonum viviparum, and other plants which had also been
collected in his company during a short botanical tour in Teesdale
some years ago. I well remember his delight in our Teesdale
spoils. Myosotis alpestris, collected in the Pyrenees, was
obtained in Teesdale on the same occasion, and it grows also on
Ben Lawers in Scotland. It is, according to Bentham, the Alpine
form of M. sylvatica ; but most botanists regard it as a distinct
species.

Whatever may be thought as to the northern derivation of the
European flora generally, Bartsia alpina is one of the species
which, it is pretty certain, has worked south from Scandinavia,
which appears to have been and still is its home.

Polygonum viviparum, a circumpolar species, is found all through
the Arctic zone, in both hemispheres. It too has travelled south
from the Polar regions. Abundant in the North of Scotland, it

J. W. REED ON PLANTS COLLECTED IN THE PYRENEES. 113

becomes distinctly scarcer in England, until south of Yorkshire
and Carnarvon it entirely disappears.

A detailed list of all the species we collected is given below,
with their classification, number of species in the genera, and
distribution. In concluding I can only express my regret that my
knowledge has not admitted of my making these botanical jottings
more worthy of the occasion and of this Society.

List of Plants collected in the Central Pyrenees from June 19th
to July 24th, 1894:—

Ranunculaceae.

Ranunculus Gouani, Willd. Pyrenees. Species about 160.
Helleborus viridis, L. From Holland southward, but not well-estab-
lished north of the Mediterranean region (Ball). Species 10.

Two only British.
Aquilegia vulgaris, L. Europe, N. Africa, N. and W. Asia to W.

Himalaya. Species 5 or 6.
Anemone narcissiflora, L. Central and S. Europe. About 70 species.
Trollius europajus, L. Europe (Arctic) to the Caucasus. Species

about nine.
Aconitum Napellus, L. Mountains of Northern Hemisphere. Species

about 18.
Anemone Hepatica, L. Europe.
Papaveraceae.

Meconopsis cambrica, Vig. Say nine species in genus, one in Western

Europe, two in N. W. America, six Himalayan.
Crucif erae .

Brassica Cheiranthus, Vill. W. and S. Europe, N. Africa. Species

about 100.
Noccaea alpina, Reichb. Alps of Europe. Species two.
Draba aizoides, L. Mountains of Central and Southern Europe, W.

Asia. Species 80.
Resedaceae.

Astrocarpus sesamoides, Gay. Five species. All South European.
Violaceae.

Viola sylvatica, Fries. Species say 100. Europe, N. and W. Asia,

N. America, etc.
Viola cornuta, L. Pyrenees.
Viola biflora, L. Pyrenees to Arctic Russia.
Polygalaceae.

Polygala amara. Arctic Europe, and from Sweden southwards. Very

rare British plant. About 200 species.

114 J. W. REED ON PLANTS COLLECTED IN THE PYRENEES.

Caiyophyllaceae.

Gypsophilarepens, L. Pyrenees to Carpathians. Species about 50.
Dianthus plumarius, L. Var. Central Europe. Species about 70.
Dianthus deltoides, L. Europe.
Silene acaulis, L. All Arctic regions, Alps of Europe, W. Asia and

N. America. Species 800.
Silene ciliata, Pourr. Pyrenees.
Cerastium arvense, L. Europe, N. Africa, Siberia, W. Asia to

Himalaya, N. America, Chili, Fuegia. Say 40 species.
Geraniaceee.

Geranium cinereum, Cav. Pyrenees and Italy. Species about 100.
Geranium pheeum, L. Central and W. Europe.
Geranium sylvaticum, L. Europe (Britain), Siberia, W. Asia.
Papilionaceae.

Anthyllis montana, L. Europe, N. Africa, W. Asia. Species 20.
Vicia pyrenaica, Pourr. Spain, Pyrenees, Dauphine'. Species 100.
Ononis repens, L. Europe, W. Asia, N. Africa. Species 60.
Astragalus monspessulanus, L. Pyrenees to Dalmatia. Species 500.
Rosacea.

Rosa pyrenaica, Gouan. Pyrenees, etc. Species about 30, fide

Hooker (sub-species of R. alpina).
Dryas octopetala, L. Arctic and Alpine regions of N. temp. zone.

Species two or three.
Alchemilla alpina, L. Europe, N. and W. Asia, Greenland. Species 30.
Geum pyrenaicum, Willd. N. and S. temp., and cold regions.

Species 30.
Potentilla splendens, Ram. Spain, W. and Central France, Pyrenees.

Species 120.
Saxifragace*.

Saxifraga granulata, L. Say 160 species in genus. Principally

Alpine plants, distributed chiefly in temp, and Arctic regions of

Northern Hemisphere. Species [ few in^ Asia, very few in S.

America. Nyman makes 107 species for Europe alone.
Saxifraga Aizoon, Jacq. Dis. widely throughout Europe. Some

authors split up this species into about a dozen.
Saxifraga umbrosa, L. Dis. W. Europe.
Saxifraga muscoides, Wulf. W. Europe.
Parnassia palustris, L. Say a dozen species in genus. Nearly

all Europe. Natives of temp, and cold regions of the Northern

Hemisphere and mountains of India. Often marsh-loving plants.
Umbellifexae.

Eryngium Bourgati, Gouan. About 150 species in genus. Dis. over

warm and temp, regions of both Hemispheres. None in S. Africa.

J. W. REED ON PLANTS COLLECTED IN THE PYRENEES. 115

Astrantia major, L. Five species represented in European flora.

Dis. throughout Europe and Western Asia.
Capxifoliacese.

Lonicera pyrenaica, L. 80 species in genus. Natives of the temp, and

sub-tropical regions of the Northern Hemisphere.
Stellatae (Tribe of Kubiacese).

Galium pyrenaicum, Gouan. Pyrenees only. Nyman gives 94 species

as European.
Asperula hirta, Ram. About 80 species described, but many badly

defined. Pyrenees. Nyman gives 40 species as European.
Valerianae.

Valeriana montana, L. About 150 species in genus. Dis. of V. montana,

Mountains of Central, Southern, and Eastern Europe. Dis. of

genus, temp, and cold regions, Northern Hemisphere, Old World,

and in N. America and along Andes, in extra tropical S. America ;

a few in Brazil and India.
Composite.

Aster alpinus, L. Europe, etc. Species about 150.

Erigeron alpinum, L. Alps and Arctic Europe, Asia, N. America, S.

Chili, Fuegia. Species about 80.
Arnica montana, L. Species about 10.
Leontopodium alpinum, Cass. Pyrenees, Alps, Carpathians, etc.

Species five.
Antennaria dioica, Br. Temp, and Arctic Europe, N. Asia, N.

America. Species about 10.
Homogyne alpina, Cass. Mountains of Europe. Species three.
Campanulaceae.

Phyteuma orbiculare, L. Europe (Britain). 30 species. 19 in Europe
Jasione perennis, Lam. Europe (Britain). Species about 13.
Campanula glomerata, L. Europe (Britain) and N. and W. Asia.

Species about 230. All temp, and most tropical climates.
Ericaceae.

Khododendron ferrngineum, L. Pyrenees, Alps, Appenines, etc

Species about 130.
Plumbagineae.

Armeria alpina, Willd. Mountains of S. and Central Europe, etc.

30 species.
Fximulaceee.

Primula viscosa, Vill. Pyrenees to Tyrol. Say 100 species. 40 in

Europe.
Primula elatior. Britain, from Gothland to Siberia and southwards.
Primula integrifolia, L. Pyrenees to Switzerland and Lombardy.
Primula farinosa, L. Arctic Europe, N. Asia, Thibet, Greenland, N.

United States.

116 J. W. REED ON PLANTS COLLECTED IN THE PYRENEES.

Douglasia vitaliana, Benth. and Hooker. Mountains of Central and

W. Europe. Species four.
Androsace carnea, L. Pyrenees to Tyrol. Species 40. Half European.
Androsace villosa, L. Alps, Pyrenees, etc.

Soldanella alpina, L. Alps, Pyrenees, Tyrol. Species three or four.
Asclepiadeae.

Vincetoxicum officinale, Moench. Europe. About 70 species.
Gentianaceae.

Gentiana verna, L. Say 180 species in genus. Teesdale, Ireland,
Pyrenees, N. Italy, mountains of Central and E. Europe, Greece.
Gentiana acaulis, L. Nearly same distribution as last, except England
and Ireland.
Boragineee.

Myosotis alpestris, Schm. Alps, Pyrenees, etc. Species about 30.
(Ben Lawers in Scotland).
Scrophulaxineae.

Linaria alpina, L. Nyman enumerates 93 species as European.
Mountains of Southern and Central Europe. Species 130. Europe
and W. Asia.
Pedicularis tuberosa, L. 150 species. Nyman gives 42 species as

European. Pyrenees to Tyrol.
Veronica serpyllifolia, L. 200 species. Nyman gives 60 species as

European. Dis. Europe (Britain).
Linaria snpina, Desf. S.W. Europe.
Antirrhinum molle, L. Species 95. Nyman "gives 13 in" Europe.

Pyrenees.
Erinus alpinus, L. Only one species in genus. Pyrenees, Dauphine,

S. France, Switzerland, N. Italy.
Scrr phularia canina, L. Species 120. Nyman gives 37 as European.

Portugal to Montenegro, etc.
Bartsia alpina, L. Mountains of Europe (Britain). Species 60.
Iientibularineae.

Pinguecula grandiflora, Lam. W. France, Alps, Pyrenees, Spain,
Portugal (Ireland). About 20 species.
Gesneraceae.

Bamondia pyrenaica, Lam. Three species in genus. One in
Pyrenees, one in Servia, one in Greece.
Selagineae.

Globularia nana, Lam. Pyrenees, etc. Not found in Swiss Alps.

Species about 12.
Globularia nudicaulis, L. Pyrenees, Alps, etc.
Labiates.

Teucrium pyrenaicum, L. Pyrenees, Dauphine'. Speeies300 '?).
Sideritis scordioides, L. S. France, etc. Species about 45.

J. W. REED ON PLANTS COLLECTED IN THE PYRENEES. 117

Thymus Serpyllum L. Europe (Arctic), N. and W. Asia, Himalaya,

Greenland. Species 40.
Horminum pyrenaicuni, L. Pyrenees, Alps to Tyrol. Only species

in genus.
Lamium maculatum, L. Unspotted var. Temp. Europe, Asia, and N.

Africa. Species 40.
Ajnga genevensis. Europe, etc. Species 30.
Polygoneae.

Polygonum viviparum, L. Europe (Britain). 50 species in genus.
Thymeleae.

Daphne Cneorum, L. Mountains of S. and W. Europe. Species about

50.
Daphne Laureola, L. Europe (Britain), from Belgium southward, N.
Africa, W. Asia.
Salicineae.

Salix incana, L. Nyman, in " Conspectus Florse Europse," enumerates
51 species as European, and there are very numerous hybrids. A
most intricate and difficult genus. 160 species.
Euphorbiacae.

Euphorbia Cyparissias, L. Europe. Species 600. Nyman gives
107 as European.
Santalaceae.

Thesium alpinum, L. Europe. Species 100.
Or chide ae.

Nigritella angustifolia, Rich. Dis. throughout Europe (Continental),
from Sweden and Norway to Greece. Say 400 species.
Xrideae.

Iris xiphiodes, Ehrh. Say 181 species. Genus is spread over Europe,
N. Africa, temp. Asia, and N. America.
Amaryllideae.

Narcissus pseudo-narcissus, L. Baker, in his " Amaryllidese," makes
16 species. Nyman, in " Conspectus Flora? Europae," 42.
Liliaceae.

Hyacinthus amethystinus, L. Pyrenees, etc. Not Swiss. Species

about 30 ; all but three Med. region and Orient.
Scilla verna, Huds. Coasts of Norway, France, Pyrenees, Spain.

Species about 80.
Asphodelus albus, W. Central and Southern Europe. Species six or

seven.
Tofieldia calyculata, Whlb. Europe. Species 14.
Anthericum Liliago, L. Europe, etc. Species about 50.
Filices.

Asplenium septentrional e, Hull. Europe, N. and W. Asia,
Himalaya, N. America. Pare in Britain. Species 280.

118 J. W. REED ON PLANTS COLLECTED IN THE PYRENEE8.

Asplenium Trichomanes, L. Europe, N. Africa, N. and W. Asia

N. America, S. temp, regions.
Asplenium viride, Huds. Europe (Arctic), N. and W. Asia, N

America.
Polypodium Kobertianum, Hoffm. Sub-species of P. Dryopteris.

Extends to Thibet. Species 450.
Aspidium Lonchitis, Sw. Arctic Europe, N. and W. Asia, Himalaya

and N. America. Species 55.
Aspidium angulare, Kit. Sub-species of A. aculeatum.
Cystopteris fragilis, Bernh. Arctic, N. and S. temp, regions. Species

five.

119

On Diploj-'s Trtgona, n. sp., and Other Rotifers.

By Charles F. Rousselet, F.R.M.S.

(Read September 20th, 1895.)

Plates VI., VII.

Diplo'is trigona, n. sp. (PI. VI., Fig. 2).

This new loricated Rotifer was found at our Club excursion to
Ealing on the 6th April of this year. The shape of the animal is
long and narrow, nearly parallel-sided, pointed behind, and higher
than broad ; the flat ventral plate is separated by a distinct lateral
inangulation and is not excavated behind. The lorica is finely
stippled, truncate in front with a deep ventral sulcus ; behind it is
cut off obliquely with a small sulcus on each side. Dorsally it is
split down the middle, forming a double dorsal ridge, which may
be parallel and close together, or separated and gaping, in the
manner of a salpina. The foot is short, three-jointed ; the toes,
long, narrow, straight and parallel-sided, and finely pointed at the
ends, about half as long as the lorica, and often carried turned
upwards.

The head protrudes some distance and seems covered with fine
thin, hyaline, chitinous plates, of which the dorsal is the stoutest;
the whole head can be retracted within the lorica. The brain is a
long, rounded hyaline sac, and carries two small red eyes close to-
gether on the very front. The dorsal antenna protrudes close
above the eyes ; the lateral antennas were not seen. The remainder
of the organs are quite normal ; the shape of the jaws will best be
seen from Fig. 2c.

In placing this animal in this genus I am guided by Mr.
Gosse's figure of Diplo'is daviesice. The characters of the genus,
however, will have to be amended, especially as it has been
established some time ago that Mr. Gosse made a mistake with
regard to D. propatula, which is a true Euchlanis, and has been
renamed Euchlanis sabversa by Mr. D. Bryce (see " Science
Gossip," 1890, pp. 77-8).

The specific characters may be summed up as follows : — Lorica

120 C. F. ROUSSELET ON DIPLOIS TRIGONA.

compressed, elongated, and narrow ; dorsal cleft narrow, parallel-
sided, and open throughout ; ventral plate narrow and flat,
separated by lateral inangulation ; toes long, narrow, of uniform
thickness ; eyes two, frontal and close together.
Size, total T £y ; without toes, ^ ; toes alone, ^o-

Microcodides doliaris, n. sp. (PI. VII., Fig. 4.)

This is another new Rotifer which has been discovered at one
of the Club's excursions to Hertford Heath on the 6th July last.

In appearance it is very stout and plump, with a small head and
prone ciliated face. The integument is soft and flexible, the body
barrel-shaped, with the usual longitudinal and transverse muscular
bands. The mastax is small, and contains jaws with broad sub-
square-toothed rami, and broad unci with six or seven teeth and
stout manubria (Fig. 4a.). The oesophagus is a thin, long tube,
arising near the middle of the dorsal side of the mastax, and
leading to the stomach and intestine of usual form. The brain is
a stout square mass, carrying a fairly large red eye on its under
surface. The dorsal antenna protrudes at the apex of a very
obvious dorsal prominence, while the lateral antenna? are situated
in the lumbar regions, rather small and difficult to see. The
lateral canals with tags are normal ; the contractile vesicle is
large when fully extended ; the ovary is a rounded mass with
obvious germ cells.

The foot is peculiar; it is three-jointed, fairly long, the second
joint with a distinct bend ventralwards, the third joint a little
swollen, and ending in a single, soft, pointed toe ; the foot is very
flexible, and moves, or rather swings, from one side to the other
somewhat like a pendulum. Although the toe is single there are
two distinct and well- developed foot glands.

In swimming the animal moves about very leisurely, as if the
small ciliary wreath were too weak for the large fat body behind ;
young specimens are somewhat less plump round the waist. Size,
total T i^ in., of which the foot is about one-fourth. A mounted
slide of this new Rotifer will be placed in the cabinet of the Club.

In placing this Rotifer in Bergendal's genus Microcodides I do
so because I really do not exactly know where to put it. Here it
will be in company with two other illoricate Rotifers which have the
common character of possessing a single toe, but differing in some
other important particulars.

C. F. ROUSSELET ON DIPLOIS TRIGONA. 121

After careful consideration I have come to the conclusion that
Gunson Thorpe's Rhinops orbiculodiscus * and Bergendal's Micro-
codides dubius t are one and the same species. Unfortunately
Surgeon Gunson Thorpe has made some errors in the description
and figure of his species, some of which he has already corrected
himself. I have often seen this animal of late, and can affirm that
it resembles M. dubiusmwth more closely than the published figure
shows. My animals were identified by Surgeon Gunson Thorpe
himself, to whom I sent a mounted slide on board his ship, cruising
in Australian waters. The following are the points requiring
correction in Gunson Thorpe's description : — First, Rhinops orbi-
culodiscus has a red cervical eye ; secondly, the corona consists of
a closed outer ciliary wreath, having a second wreath within it,
leading to the mouth, which is situated in a depression a little
below the centre of the Corona, as fairly well indicated by Bergen-
dal's diagrammatic figure 11; thirdly, it has only one toe ; the
second toe-like structure is smaller, nearly always carried at right
angles to the toe, and better termed a spur ; fourthly, the lateral
antennse do not issue from the tip of the projecting lateral points
in the lumbar regions of the body, but in the angle between these
and the body ; fifthly, the animal is not a Rhinops. These
corrections in the description of R. orbiculodiscus practically effect
a complete agreement with M. dubius. Adopting Bergendal's
generic name the correct designation of this animal will therefore
be Microcodides orbiculodiscus, and I have placed a mounted slide
of it in the cabinet of the Club for reference.

Microcodides rolustus (Glascott), PI. VI., Fig. 1.

In her list of some of the Rotifera of Ireland (] 892) Miss L.
S. Glascott has described, under the name of Microcodon robustus, a
new one-toed Rotifer, which, unfortunately, cannot be identified
from her figures ; the description of the animal, however, is much
better, and by it I have been able to identify it with a Rotifer I
have found in water received in December last from Mr. F.
Daunou, of Margate, from his garden tub. I am, therefore,
enabled to give a good figure of this pretty Rotifer, which had a
few months previously been seen also in Germany by Mr. L.
Bilfinger, of Stuttgart.

* " Journal Koyal. Micr., Soc," 1891, p. 304.

t "Zur Rotatorien Fauna Gronlands," pp. 34-43, 1892.

122

C. F, ROUSSELET ON DIPLOIS TRIGONA.

The integument is smooth, soft, and flexible, but yet possesses a
certain stiffness, so that a number of folds behind and along the
sides of the body remain constant. In contraction the body is a
perfect ball, but the foot is not retractile. The corona is as broad
as the body, oblique, and consists, as in M. orbiculodiscus, of two
concentric bands of cilia (Fig lb) ; the outer wreath bends
inwards on the frontal side, and seems to be continuous with the
smaller inner wreath which surrounds the mouth. The middle
part of the trochal disc rises into two elongated fleshy prominences,
and between these the mouth is situated at the bottom of a funnel-
shaped depression, clothed with very fine and dense cilia. When
treated with a little cocaine-spirit mixture many Rotifers often swim
for a long time with their heads closely pressed against the cover
glass of the compressor, and in this way I obtained very good
views of the front of the head, which is otherwise difficult to see.
There is a gap in the frontal part of the ciliary wreath, and just
there are two style-like seta3 which do not vibrate. The brain is a
large, rounded, clear cellular mass, carrying a crimson eye with a
minute crystalline sphere on the under side ; the sphere is turned
towards the brain, so that all rays of light reaching it must pass
through part of the transparent brain. The dorsal antenna pro-
trudes from a well-marked prominence above the brain, and the
lateral antenna? are readily seen in the usual position in a little
fold of the skin in the lumbar region. The mastax is large, and
the jaws of peculiar form, as will best be seen by the drawing (Fig.
Id and le). One maleus only has been drawn, but, of course,
there are two of the same shape. A short, narrow oesophagus leads
to a wide stomach and intestine, the former carrying the usual
gastric glands. The stomach has thick walls, and the cells are
mostly granular, which gives it a dark appearance. The contractile
vesicle is large ; the lateral canals, ovary, longitudinal, and trans-
verse muscular bands are as usual in allied species. The foot is
stout, three-jointed, ending in a single toe. With a high power, I
was, however, able to see a line dividing the toe longitudinally in a
larger ventral and smaller dorsal portion, as if there were present
a small vanishing spur, closely appressed to the toe (Fig. lc).
Two foot-glands are present.

When swimming in the open water this Rotifer has usually an
upright position and moves forward in frequent little jerks. The
movements and mode of swimming are very constant in Rotifers,

C. F. ROUSSELET ON DIPLOl's TRIGONA. 123

and form valuable helps in the identification of obscure species.
The little jerks forward, regular and without apparent reason, are
very characteristic of this species.

Size T-4-rr, of which the foot is a little less than one-third.

A mounted slide of this species will also be placed in the
cabinet of the Club.

Diaschiza megalocephala (Glascott), PI. VII., Fig. 5.

At the Club's excursion to Totteridge on the 4th of May last I
found a Rotifer which I think I can identify with Miss Glascott's
Furcularia megalocephala. Her description of the animal is good
as far as it goes, but her figure is hardly sufficient for recogni-
tion.

The most prominent feature of this species is the very large
head, which is larger and broader than the body. The body is
compressed laterally, higher than broad ; the face is very oblique,
and the whole front densely ciliated ; two bundles of larger cilia
or styles are placed on the frontal part of the head. Behind the
head the body becomes sensibly narrower, and tapers thence to the
short two-jointed foot and toes, which are of moderate size,
decurved and finely pointed. The body behind the head seems
invested with a very thin and flexible, but distinct, lorica, slit
dorsally and open ventrally. The possession of this lorica makes
this species a Diaschiza, to which genus I therefore transfer it.
The mastax is large and peculiar, the rami having the appearance
of an angular forceps, and the jaws look as if they could be pro-
jected out of the centre of the face with a snap, as stated by Miss
Glascott, but this I have not seen done. Having only a single
specimen, which I mounted, I have not had an opportunity of
dissolving out the jaws and making out all the details of their
structure. There is a long tubular brain, but I could detect no
eye. The alimentary canal, ovary, and contractile vesicle are all
normal. The dorsal and lateral antennas were not observed, and I
neglected to search for them. The whole body of my animal was
very white and hyaline, with no food in the stomach, and it may
have been a young one, especially as the size was somewhat less
than that given by Miss Glascott.

Size, according to Miss Glascott, about y^, whilst my animal
measured, total yi^, of which the toes formed about one-sixth.

124 C. F. ROUSSELET ON DIPLOIS TRIGONA.

Furcularia longiseta, var. grandis (Tessin-Biitzow), PI. VII.,

Fig. 3.

Furcularia longiseta of Ehrenberg, with its long unequal glassy
toes, twice to three times as long as the body, is a small Rotifer
often met with, crawling, or rather stalking, amongst the water
weeds. At our excursion to Hertford Heath, however, I came
across a startling variety of this pretty Rotifer. Not only was
the size of the animal fully twice as large, measuring -g^in. in total
length, of which the longer toe formed exactly one-half, but it was
adorned with two very large red spots in the lumbar regions,
exactly where the lateral antennas should be. The nature of these
spots is a mystery, as they can hardly be supposed to have a
visual function. A cervical eye situated on the under side of the
brain, a little distance from the tip, was present as usual. The
colour of the spots resides in two large vesicles, one on each side,
apparently attached to the integument ; these vesicles are clearly
seen in the mounted specimen, though the red colour has dis-
appeared, but I could not detect the lateral antennse. I observed
numerous examples ; in some the colour of the spots was a dark
crimson, in others a paler red, and in young forms the spots were
very minute but distinctly red. The integument is very soft and
flexible, and shows numerous close, longitudinal furrows when the
animal is extended, but these furrows disappear with the least
contraction. The toes are stout at the base, then tapering
gradually. Two or three very distinctly striated muscles enter
the hollow toes, traverse the wider part, and are attached to the
sides where the toe becomes narrower ; they do not traverse the
whole toe from end to end as depicted by Tessin-Butzotv. By
means of these muscles the animal is able to make sudden skips
forward or sideways out of the way of an enemy. The muscles
are of course also present in the smaller species, and were ob-
served by Ehrenberg, although he could not recognize the nature
of these bands. With the exception of the large red spots and the
size, this animal is exactly the same in structure as the smaller
species, and I have adopted as a principle not to make a new
species on account of size alone. I find, however, that Dr. G.
Tessin-Biitzow, in his pamphlet " Rotatorien der Umgegend von
Rostock," describes and figures F. longiseta as Monommata longi-
seta, and another very similar, but much larger species, ^in. long,

C. P. ROU88ELET ON DIPLOIS TRIGONA. 125

under the name of Monommata grandis. This animal had not the
red spots, bat Dr. Biitzow figures the lateral antennas exactly
where the red spots are situated in my animal. The red colour of
the spots disappeared at once upon treatment with osmic acid,
whilst the colour of the cervical eye remained. This leads me to
think that the colour of these spots is very unstable, and may
sometimes be absent. I have no doubt that the two animals are
the same, and as Dr. Tessin- Biitzow has given it a specific name
I have adopted it as a variety.

The rejected genus Monommata was formed by Bartsch for the
reception of this and another very dissimilar species — Notommata
tigris, and Bergendal, in his " Rotatoria of Greenland," strongly
advocates the retention of this generic name for Furcularia longi-
seta. The genus Furcularia no doubt contains a number of dis-
similar animals, some with a frontal eye, some with a cervical eye,
and some with no eye at all. This, however, will be a question
for the future, and in the present note I will describe my Rotifer
by the name by which it is best known.

A mounted slide of both F. longiseta and of the var. grandis will
be deposited in the cabinet of the Club.

Anurcea cruciformis (Thompson), PI. VII., Fig. 6.

In the " Proceedings of the Liverpool Biological Society " for
1892 (p. 77) Mr. J. C. Thompson described this marine Rotifer,
which was found in large numbers off the coast of Norway, but
without giving a figure. Mr. Thompson has been good enough to
send me a mounted slide of the lorica, from which I have made the
drawing on PI. VII., Fig. 6. The lorica is subovate and flat,
armed in front with six short, equal, acute, nearly straight spines,
and no spines behind, and tessellated so as to show a cruciform
marking. The tessellation is formed by one central longitudinal
line crossed by two transverse lines, dividing the lorica into
six nearly equal parts; a number of smaller tessellations occur
at the margin and behind. The shell of the animal, which was
preserved in spirit, is thin, white, transparent, and very finely
stippled.

Size, t !~q in. by y^- in. wide ; some specimens smaller.

Professor K. M. Levander in his recently published contribution
to the Sea and Freshwater Fauna of the neighbourhood of

Journ. Q. M. 0., Series II., No. 37. 9

126 C. F. R0US8ELET ON DIRLOIS TRIGONA.

Helsingfors, # describes a new Anursea under the name of A.
eichicaldi, which seems identical with the above species, but his
figure does not show the two transverse lines. These ridges are
very low and fine, and probably not readily visible until the shell
is empty. Levander gives the size of his animal as '162
mm. = T -i T in.

Explanation of Plates VI. and VII.

Fig. 1. Micrcodides robnstus, side view.

„ la. „ ,, dorsal view.

„ lb. ,, „ corona, diagrammatical,

lc. ,, ,, the toe, exact shape.

Id. „ „ the jaws, front view.

,, le. „ „ ditto, side view.

,, 2. Diplo'is trigona, dorsal view.

„ 2a. „ „ side view.

5J 2b. „ ,, transverse section of lorica.

„ 2c. „ „ the jaws.

„ 3. Furcularia longiseta, var. grandis, side view.

„ 3a. „ ,, „ dorsal view.

„ 4. Microcodides doliaris, side view.

„ 4a. „ „ the jaws.

„ 5. Diaschiza mega locephala, side view.

„ 5a. ,, „ ventral view.

,, 6. Anuria cruciformis.

* K. M. Levander, " Materialen zur Kenntniss der Wasserfauna in der
Umgebung von Helsingfors," "Acta Societatis pro Fauna et Flora
Fennica," xii., No. 3, pp. 1-72, 3 PI. Helsingfors, 1894 (published
July, 1895).

127

A Preliminary Account of the Entomostraca of North

Wales.

By D. J. Scourfield.

{Read September 20th, 1895.)

Plate VIII.*

The following list of fresh and brackish water Entomostraca is
based mainly upon the results of a personal examination of some
of the lakes, etc., of North Wales, principally in the Snowdon and
Cader Idris districts, made during two short visits at the end of
July and beginning of August last year and at the end of May
and beginning of June of the present year. I have been enabled,
however, to considerably increase the number of species recorded,
through the kindness of Prof. G. S. Brady, F.R.S., who gener-
ously placed at my disposal several preserved collections obtained
in 1888 and 1891, for which, and also for valuable assistance in
connection with the identification of doubtful species, I wish to
express my sincerest thanks. A few further species have been
added on the authority of records in Prof. Brady's " Monograph
of British Copepoda " and " Revision of the British Species of
Freshwater Cyclopidae and CalanidaB."

Cladocera.

Sida crystallina, 0. F. Miiller. This does not seem to be a
very abundant species in North Wales. I only have notes of its
occurrence in Llyn Ogwen,f Llyn Cwm-ffynnon, Llyn Creigenen,
and Llyn Gwernan. In each of these it was obtained by working
the net among clumps of horse-tails and other aquatic vegetation.

Daphnella brachyura, Lievin. (D. Wingit, Baird, " Nat. Hist.
Brit. Ent.") Llyn Padarn, Llyn Peris, Llyn Cwm-ffynnon, and
Bala Lake are the only places where this species has been found.

* Plate VIII. is unavoidably held over for the next number. — Ed.

f The lakes, etc., referred to throughout this paper can be identified by
a reference to Baddeley and Ward's u North Wales." (Thorough Guide
Series. Dulau and Co.).

128 D. J. SCOURFJELD ON THE ENTOMOSTRACA OF NORTH WALE8.

It occurred in parts of Llyn Peris in August, 1894, in great
abundance, and almost to the exclusion of everything else.

Latona setifera, 0. F. Miiller. Only seen from Llyn Padarn,
where it was obtained in August, 1894, by bringing up sediment
from the bottom of the lake at some distance from the shore.

This fine species (one of my specimens was iin. in length and
most beautifully coloured) was first added to the British fauna by
Mr. Conrad Beck, who found it in the Lake District in 1881.
More recently Mr. T. Scott has reported its occurrence in Loch
Morar, Inverness-shire. These are the only British records known
to me.

Ceriodaphnia pulchella, G. 0. Sars. (Plate VI1L, Figs. 1 and
2.) The form here referred to is extremely close to that recorded
by me as C. quad rang it la, Miiller (see the previous volume of this
Journal, p. 65, PI. IV., Figs. 4-7). It differs from that species,
however, in that the post-abdomen lacks the two short inner rows
of pre-anal spines. The head, too, is somewhat smaller than in the
" quadrangula" form, and does not project so far ventrally, while
the forehead in front of the antennules is produced into a more
noticeable angle. Altogether, it seems to agree very well with
Sars's C. pulchella, and that name has, therefore, been adopted.
The following are the localities where it has been found : Reservoir-
Penmaenmawr (G. S. B.), # Llyn Cwm-ffynnon, Llyn Ogwen,
Llyn Teyrn, and marsh near Barmouth Junction.

Ceriodaphnia reticulata, Jnrine. (Daphnia reticulata, Baird,
" Nat. Hist. Brit. Enfc.") Only recorded from the marsh near
Barmouth Junction.

Simocephalus vetulus, 0. F. Miiller. {Daphnia vetula, Baird,
" Nat. Hist. Brit. Ent.") All the specimens of Simocephalus have
been of the typical " vetulus " type. They have only occurred in
marshes, ditches, and small tarns.

Daphnia iongispina, 0. F. Miiller. Llyn Padarn is the only
lake that has yielded this species in any abundance, but it has been
seen in several other localities, including Bala Lake.

Daphnia hyalina, Leydig. Limited to Llyn Padarn so far as
yet observed.

Bosmina Iongispina, Leydig. This large species is in a certain
sense a characteristic of the North Welsh Entomostracan fauna,
at hast as contrasted with that of our south-eastern portion of

* The records marked (G. S. 13.) refer to Prof. Brady's collections.

D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES. 129

England,* for it occurs plentifully, and apparently to the complete
exclusion of B. longirostris, which is the typical representative
of the genus in the latter district.

Acantholeberis cuxvixostxis, 0. F. Miiller. I have only seen
this in a collection from Arthog Marsh (G. S. B.).

Drepanothrix dentata, Euren. Two localities have yielded this
peculiar species, viz., a tarn near the summit of Allt Wen (G. S.
B.) and Llyn Padarn.

Euxycexcus lamellatus, 0. P. Miiller. A fairly common
species, but not usually found in the larger lakes.

Acxopexus haxpae, Baird. Not very common, the role it plays
in the south-eastern part of England being partly undertaken
perhaps by Alonopsis elongata.

Camptocexcus macxurus, 0. F. Miiller. The few examples
seen were from Llyn Padarn. They were of the type called
" rectirostris " by Schoedler, which is probably the common
British form, for the drawings given by Baird and also by Norman
and Brady seem to indicate this variety, and, so far as I can
remember, it is the only one I have ever taken.

Alonopsis elongata, G. 0. Sars. (Lynceus elongatus, Norman
and Brady, " Mon. Brit. Ent.") This is one of the most abundant
and most widely distributed of the Cladocera of North Wales, but
it was not found either in Llyn Padarn or in Bala Lake. Most
of the specimens seen were of a very dark colour, some, indeed
being almost black.

Leydigia acanthocexcoides, Fischer. Only one locality has
yielded this species, viz., a tarn near the summit of Allt Wen (G.
S. B.). The specific mine acanthocercoides has been retained
because it is believed that Fischer's species is the same as Leydig's
Alona quadrangularis. If there is a genuine difference between
the two, as asserted by some authors, then there is no doubt that
the present, which is the common British form, should be called
L. quadrangularis, Leydig.

Alona quadxangulaxis, 0. F. Miiller. Examples of this
species have only been obtained from a " pool above high-water
mark" east of Penmaenmawr (G. S. B.).

Alona affinis, Leydig. This species, which is probably the
same as P. E. Miiller's A. oblonga, has been noted in company

* By this phrase is intended the whole district lying to the east of a line
drawn from The Wash to the Isle of Wight.

130 D. J. SCOURFIELD ON THE ENT0M0STRACA OF NORTH WALES.

with the foregoing and also from Conway Marsh (G- S. B.), Llyn
Padarn, and Llyn Creigenen. As it has not previously been
recorded as British, it may be useful to give a few of the details by
which it can be distinguished from A. quadrangularis, the species
to which it is most nearly related. In the first place, it is a some-
what larger animal, measuring g^~5V* n, j wn ^ e ^-« quadrangularis
rarely reaches ^in. Another difference is that it possesses, in
addition to the coarser lines on the shell, a series of closely-set
longitudinal stria?, which, although very variable in intensity, are
always extremely fine and difficult of detection, except with high
magnification. The arrangement of the olfactory hairs on each
Antennule is a further point of distinction, for while J., affinis has
one of these hairs much longer than the others, and also one inserted
a little farther back than the rest, in A. quadrangularis all these
hairs are sub equal and all are inserted on the end of the Antennule.
Again, in A. affinis each of the two longest setaa on each branch of
the swimming Antenna? is provided with a little thorn at the point
where it is imperfectly jointed. These thorns are absent in A.
quadrangularis. Lastly, each of the terminal claws, with its acces-
sory basal tooth, is much more plainly setose in the present species
than in A. quadrangularis.

Alona guttata, G. 0. Sars. This little species has only been
seen from Cwm Glas, Snowdon. It was there found inhabiting
some masses of wet alga in company with Canthocamptus pygmceus
and C. MacAndrewcB.

Alona intermedia, G. 0. Sars. Only recorded from Llyn
Peris, where it was found in some alga taken from among clumps
of horse-tails.

Alonella excisa, Fischer. I found this in several localities in
May last, and it also occurs in three of Prof. Brady's collections,
but I did not notice it in 1894. The living specimens seen by me
were usually much darker than 1 find them here.

Alonella nana, Baird. (Acroperus nanus, Baird, "Nat. His*.
Brit. Ent.") " Tarn near the summit of Allt Wen " (G. S. B.) is
the only place where this has been found.

Pleuroxus trigonellus, 0. F. Miiller. This also depends on a
single record, viz., one from Llyn Padarn in August, 1894.

Feracantha truncata, 0. F. Miiller. A fairly common species.
Very dark- coloured examples were taken in several of the
lakes.

D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES. 131

Chydorus sphericus, O. F. Miiller. In North Wales, as in
most other parts of the British Isles, this is probably the
commonest of all the forms of Cladocera.

Chydorus caelatus, Schoedler. Seen only in two localities, viz,,
Llyn Padarn and Llyn Dvvythwch.

This species was first recorded as British by Prof. G. S. Brady,
in 1868, in the "Intellectual Observer," Vol. xii., p. 423, under
the name of Lynceus sphericus, var. favosa. It does not appear to
have been subsequently noted, and has most probably been
mistaken for the common C. sphericus. It is easily distinguished
from the latter, however, by its shell sculpture, which consists of
rows of deep pits (most plainly developed on the ventral and
posterior portions of the valves) unaccompanied by any evident
reticulation. The valves of typical C. sphericus, on the other
hand, are never pitted, but always reticulated. In other respects
the present form is extremely close to C. sphericus.

Chydorus latus, G. 0. Sars. This is the same as recorded by
me in 1892 as C. ovalis, Kurz. (" J. Q. M. C," Ser. II., Vol. v., p.
68). I now think that this form agrees better with C. latus
than C. ovalis, and I have, therefore, adopted the former name.
The two species, however, seem to be very closely allied, and have
even been considered identical, as by Hellich, for example. The
records for this species have been Llyn y Own, Llyn Teyrn, and
Bog near Llyn Peris. All the specimens seen were rather
smaller than those recorded from Leytonstone in the above-
mentioned paper.

Polyphemus pediculus, De Geer. During August, 1894, this
species occurred pretty frequently in the Snowdon district, but I
saw very few specimens in May last.

Bythotrephes longimanus, Leydig (B. Cederstromii, Beck —
" Some New Cladocera," &c.) Recorded only from Llyn Padarn and
Llyn Peris. It no doubt lives in many of the larger and deeper
lakes, but owing to its exclusively pelagic habits it is not easily
captured without the aid of a boat.

Leptodora hyalina, Lilljeborg. Like the foregoing, this species
is difficult to capture from the shore, but I managed to get it in
this way in Llyn Llydaw. The other localities where it has been
noted are Llyn Padarn, Llyn Peris, and Bala Lake.

132 D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES.

OSTRACODA.*

Cypria ophthalmica, Jurine. Only seen from Arthog Marsh
(G. S. B.), Bala Lake, and Llyn Padarn.

Cypria serena, Koch. Apparently the commonest of the
Ostracoda of North Wales. For all that, however, it is not
particularly abundant, as it has only been seen in seven localities.
Some of the specimens were exceptionally dark-coloured.

Cypris obliqua, G. S. Brady. Llyn Cwm-fTynnon and Bar-
mouth Junction Marsh are the only places where this has been
obtained.

Cypiis prasina, Fischer. As a species having a decided pre-
ference for water with a trace of salt in it, this finds a congenial
home in the Marsh near Barmouth Junction, and there it occurred
plentifully in May last. It has not, however, been noted in any of
the other brackish water collections.

Herpetocypris reptans, Baird. Recorded only from Conway
Marsh (G. S. B.).

Cypridopsis vidua, 0. F. Muller. This was found in the
marsh below Llyn Padarn and also in the portion of the same lake
which is cut off by the railway embankment.

Cypridopsis aculeata, Lilljeborg. A brackish water species,
and found consequently in such places as Arthog Marsh (G. S. B.),
pools near high-water, Llanfairfechan (G. S. B.), and Barmouth
Junction Marsh.

Notodiomas monacha, 0. F. Muller. This was pretty abundant
in the marsh and ditches near Barmouth Junction last May, and it
also occurs in a gathering made by my friend, Mr. Soar, in July,
from Llyn y Gader, Cader Idris.

Limnicythere inopinata, Baird. Pools above high-water,
Llanfairfechan (G. S. B.).

Cytheridea torosa, Jones. Brackish pond, Pwllheli (G. S. B.).

In addition to the above a single, probably immature, specimen
of a Candona was taken among alga, etc., near Llangollen, but
the species is uncertain.

* The nomenclature of this Order is in accordance with Brady and
Nor nan's " Monograph of the Ostracoda of the N. Atlantic and N.W.
Europe.''

T>. J. SC0T7RFIELD ON THE ENTOMOSTRACA OF NORTH WALES. 133

CoPErODA.*

Eurytemora Clausii, Hoek. Seen from one locality only, viz.,
Brackish pond, Pensarn, Merionethshire (G. S. B.).

Diaptomus gracilis, G. 0. Sars. This is an extremely com-
mon form, and often occurs in enormous numbers. As a rule,
according to my observations, specimens inhabiting the more
elevated lakes (say 800 feet and upwards) are of a brilliant red
colour, while those in the lower lakes are not abnormally coloured.
Males with and males without a process on the antepenultimate
join

int of the right first antenna have been seen, but the former

seem to be more abundant than the latter.

Diaptomus hire us, G. S. Brady. Presumably a rare species,
specimens having been taken only from Llyn Padarn and possibly
a few also from Llyn Idwal. Those from the latter lake were
immature and could not be quite certainly identified.

Cyclops fuscus, Jurine. (C. signatus, Koch). Only recorded
from the following localities : Llyn yr Afon (G. S. B.), pool above
high-water east of Penmaenmawr (G. S. B.), Llyn y Cwn, Llyn
Ogwen, and marsh at southern end of Llyn Cynwch, Dolgelley.

Cyclops albidus, Jurine. (C. tenuicornis, Clans.). Conway
Marsh (G. S. B.), Llyn Padarn, Llyn Peris, and Llyn Dwythwch.

Cyclops oithonoides, G. O. Sars (C. Scour fieldi, var., G. S.
Brady). Found only in marsh ditches near Cwm y Glo.

Cyclops strenuus, Fischer. This species is more capable of
being "pelagic " in its habits than almost any other of the genus,
and maybe found, as in Llyn Padarn, in company with such forms
as Bythotrephes longinianus and Leptodora hyalina. On the other
hand, it may often be found in the smallest of pools. Corres-
ponding to this diversity of habitat is its remarkable variation,
which has led to the formation of several so-called species, e.g., C.
victims, C. abijssorum, etc. In the present state of our knowledge,
however, these cannot be considered as good species, scarcely even
as permanent varieties, and it seems best, therefore, to group all
these forms under the one name, C. strenuus, as is done by several
recent writers, e.g., Schmeil, Richard, Mrazek, etc.

* As far as possible the nomenclature used in Schmeil's " Deutschlands
freilebende Siisswasser-Copepoden" has been adopted.

134 D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES.

In North Wales this is a moderately common species in the
mountain lakes and tarns.

Cyclops viridis, Jurine. All the examples seen, representing
nine localities, were of the " gigas " type.

Cyclops vemalis. Fischer. With the exception of the mere
mention of the name in this Journal among the lists of objects
found at the excursions of the Club during 1894 (ante, p. 74), this
species has not been previously recorded as British. It is, however,
a fairly common species, but has hitherto been included under the
comprehensive name of C. bicuspidatvs. In North Wales it has
been seen from five different localities.

Cyclops bisetosus, Rehberg (C bicuspidatvs, Brady, " Rev.
Brit. Species of Cyclopida? and Calanida? "). This has only been
recorded from a bog pool on Y Garn and from the margin of Bala
Lake.

Cyclops bicuspidatus, Claus, var. Lubbockii, G. S. Brady (G.
insignis, Brady, " Mon. Brit. Copepoda," and " Rev. Brit. Sp.
Cyclopidaa and Calanida3|"). There can be no doubt that the Cyclops
referred by Prof. Brady to C. insignis, Claus, is not really that
species, but the variety of C. bicuspidatus (=C. T/io?nasi, Herrick),
described by Rehberg as C. helgolandicus and by Schmankewitsch
as C. odessanvs. As, however, Prof. Brady had, as early as 1868,
described the form under review as C. Lubbockii (" On the Crus-
tacean Fauna of the Salt Marshes of Northumberland and
Durham," in "Nat. Hist. Trans., North, and Dur.," Vol. iii.), it
seems only right to use this name for the variety, instead of that
of either Rehberg or Schmankewitsch. The importance of having
a recognised varietal name in this instance depends upon the fact
that the variety is exclusively a brackish water form, while the
typical bicuspidatus is exclusively an inhabitant of fresh water.

The following are the places where this variety has been found
in North Wales : — Brackish pond, Pwllheli (G. S. B.) ; brackish
pond, Pensarn (G. S. B.), and the marsh near Barmouth Junction,

Cyclops languidus, G. 0. Sars. This has only been previously
noticed as British in lists of objects found at excursions given in
the previous volume of this Journal, pp. S98 and 400. It has now
been seen from a bog by side of Llyn Teyrn, and from Llyn y Gader,
Cader Idris.

Cyclops bicolor, G. 0. Sars. (C. diaphanus, Scourfield,
" J. Q. M. C," Vol. v., p. 407). Like the preceding this has only

D. J. SCOURFIELD ON THE ENTOMOSTRACA OP NORTH WALES. 135

previously been recorded as British in the lists given in the last
volume of the Club's Journal.

The marsh below Llyn Fadarn and the portion of the same lake
cut off by the railway embankment are the only places where it
has been obtained.

Cyclops serrulatus, Fischer. Undoubtedly the commonest
Copepod of North Wales. It seems rarely to be absent from any
piece of water whatever, whether large or small, high or low,
brackish or fresh. In the case of Llyn du'r Arddu, Snowdon, it
was the only species of Entomostraca that could be found after
most diligent search.

Cyclops affinis, G. 0. Sars. Only seen from the side portion
of Llyn Padarn already referred to.

Cyclops fimbriatus, Fischer. Recorded in Prof. Brady's " Re-
vision, etc.," from pools near high water, Penmaenmawr. No
other record.

Cyclops eequoreus, Fischer. This is essentially a brackish
water species. It has only been seen from brackish pools at
Pensarn (G. S. B.) and Pwllheli (G. S. B.).

Tachidius brevicomis, 0. F. Miiller. This is another exclu-
sively brackish water species. Brackish pond, Pensarn (G. S. B.),
is the only record.

Canthocamptus staphylinus, J urine. (C minutus, Baird,
Brady, etc.) Curiously enough this, which is usually considered
to be a very common form, has only been seen in North Wales
from the margin of Bala Lake.

Canthocamptus minutus, Claus. (Not G. minutus, Miiller).
Like the preceding this was taken from the m irgin of B-ila Lake,
and nowhere else.

My friend Mr. T. Scott, F.L.S., has quite recently announced
the discovery of this little species in Scotland — ("Annals of
Scottish Nat. Hist.," July, 1895, p. 173) — otherwise it has not
previously been placed on record as British.

Canthocamptus hirticornis, T. Scott. Full details of this new
species will be published by Mr. Scott in the Annual Report of
the Fishery Board for Scotland for the current year. In North
Wales it was obtained from the marsh near Barmouth Junction.
This does not necessarily indicate that it is a truly brackish
water species, and Mr. Scott informs me that in nearly all the
localities where he has found it (in Barra, North Uist, Shetland,

13G D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES.

etc.) the water has been fresh. Nevertheless it is a noticeable
fact that it has not yet been found far from the sea.

My specimens seemed to lack the " down " of fine setse on the
first and second joints of the first pair of antenna?, otherwise they
agreed very well indeed with the original figures, proofs of which
have been kindly sent to me by Mr. Scott.

Canthocamptus crassus, G. 0. Sars. (Attheyella spinosa,
Brady). Mentioned in the Monograph of British Copepoda as
being found in the river a little west of Pwllheli.

Canthocamptus pygmaeus. G. 0. Sars. {Attheyella cryptorum,
Brady). In wet mosses and bogs this is almost constantly present,
thougli I have not often seen it in great numbers. It has also
been recorded from the margins of several of the larger lakes.

Canthocamptus MacAndrewae. T. and A. Scott. (Attheyella
Mac Andrews, T. and A. Scott, " Annals and Magazine of Nat.
Hist.," Ser. VI., Vol. xv., June, 1895, p. 457). A few examples
of this quite newly described species were found in wet alga from
Cwm Glas, Snowdon.

Mesochia Lilljeborgii, Boeck. Brackish pond, Pensarn
(G. S. B.).

Laophonte IVXohammed, Blanchard and Richard. (Plate VIII.,
Figs. 3-9). Prof. Brady, who very kindly identified this species
for me, says that it does not seem to have been met with since
first described by MM. Blanchard and Richard from certain Salt
Lakes in Algeria. ("Mem. Soc. Zool. France," Vol. iv., 1891,
p. 526, PI. VI., Figs. 1-15).

At the time of its description it was the only known brackish
water species of the genus, but in 1893 a second brackish water
species, L. littorale, was described by Messrs. T. and A. Scott
from several localities in Scotland. (" On some New and Rare
Crustacea from Scotland," " Annals and Magazine of Nat.
Hist.," Ser. VI., Vol. xii., p. 238). All the other species are
exclusively marine, except that, very rarely, L. similis has been
taken in estuarine pools.

The figures given on the accompanying Plate will, I think, be
sufficient to enable anyone to recognise this species without the
aid of a long description. The lengths of my specimens were,

Dactylopus tisboides, Claus. This, although typically a
marine species, is sometimes found in brackish water, when it

D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES. 137

varies slightly from the marine form, as noticed by Prof. Brady
in his Monograph of British Copepoda. Recorded only from
pools near high water, Llanfairfechan (G. S. B.).

The foregoing list shows that np to the present the total num-
ber of Entomostraca recorded from North Wales has been 67,
made up as follows : — Cladocera, 30 ; Ostracoda, 10 (of which
three are brackish water forms) ; and Copepoda, 27 (of which
seven are brackish). Considering the very moderate amount of
work that has as yet been done, these figures, at least as regards
the Cladocera and Copepoda, must, I think, be considered as
satisfactory. The comparative smallness of the list of Ostracoda
is no doubt somewhat surprising, but I am inclined to think that
it corresponds to a real deficiency in the number of these animals
actually living in the district.

The list also shows a more than usually large proportion of
species which may reasonably be considered either as rare or
specially interesting. Two of the Cladocera, Ceriodaphnia pul-
chella and Alona affinis, and one of the Copepods, Laophonte
Mohammed, are new to the British fauna, while there are quite a
number of species, e.g., Latona seti/era, Acantholeberis curvirostris,
Drepanothrix derdata, Ghydorus latus, C. ccelatus, Bythotrephes
longimanus, Diaptomus hircus, Cyclops languidus, C. bicolor,
Canthocauiptus miniitus, Claus, C. Mac Andrews, and C. hirticornis,
which have at most only been recorded a few times in the British
Isles.

It is certainly premature to make any serious attempt to com-
pare the Entomostracan faunas of different districts of the United
Kingdom, but in looking over this record from North Wales, I
cannot help noticing a few points in which it differs from that of
the district with which we are most familiar, viz., the South-east of
England. Among the Cladocera, some eight species appear in the
present list, i.e., more than one-fourth of the whole, that have never
been seen, so far as I am aware, in this part of the country. These
are Latona setifera, Ceriodaphnia pulchella, Bosmina longispina,
Acantholeberis curvirostris, Drepanothrix dentata, Alonopsis elongata,
Bythotrephes longimanus, and Leptodora hyalina. On the other

138 D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES.

hand we have many forms living here which do not figure in the
Welsh list, but of course it would be very unwise, looking to the
large amount of collecting that has been done here compared with
North Wales, to put these forward as evidence of the difference
between the two faunas. Nevertheless one cannot help being
struck by the fact that such familiar species to us as Daphnia
pulex, Bosmina longirostris, etc., should be conspicuous only by their
absence from the records from North Wales. It is also very
strange, by the way, that the list of Cladocera should contain no
representative of the so-called Hyalodaphnias, e.g., Daphnia
Jcahlbei'gensis, etc. Of all places in the United Kingdom where I
should have thought it perfectly safe to predict the occurrence of
these typically "pelagic " creatures, it would have been the lakes
of North Wales. The list of Ostracoda shows no peculiar forms,
as every one of the species given has also been found in this part
of the country. Of Copepoda, however, the present record contains
three species that are characteristic so far as the present comparison
is concerned, viz. : Diaptomus hii-cus, Canthocamptus MacAndrewce,
and Car,thocamptns hirticornis. The essentially brackish water
species have been left out of account, as I do not think they have
been properly worked on our coasts. It may further be interesting
to note that not a single characteristic species of Cyclops has been
recorded.

I should have liked to have given some details as to the charac-
teristic Entomostracan faunas of the larger lakes, of the high
mountain tarns, of bog-pools, of mosses and algse, etc., but my
records from individual localities are necessarily for the most part
so meagre that it is useless to attempt anything of the kind at
present. The most that can be done will be to give an account of
the fauna of the Llanberis Lakes, Llyn Padarn and Llyn Peris,
which have been more worked than any of the others. They may
probably be taken as typical examples of the larger Welsh Lakes,
and, as they are so intimately connected, it will be quite good
enough for present purposes to consider them together. I will
attempt to classify the species according to whether they were
found to belong to the " pelagic," " littoral," or '• bottom" fauna.
The phrase " bottom " fauna, it should be explained, includes those
species collected from the bottom of the lakes at some distance
irom the shore, in depths var)ii.y from ^5 to 100 feet, or there-
abouts.

D. J. SOOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES. 139

Entomostracan Fauna op Llyn Padarn and Llyn Peris.
Pelagic Fauna.

CLADOCERA.

Daphnella brachyura.
Daphnia longispina.

,, hyalina.
Bosmina longispina.
Polyphemus pediculus.
Bythotrephes longimanus.
Leptodora hyalina.

OSTRACODA.

Nil.
COPEPODA.

Diaptomus gracilis.
,, hircus.

Cyclops strenuus.

Littoral Fauna.

CLADOCERA.

Eurycercus lamellatus.
Acroperus harpoe.
Alonopsis elongata.
Alona intermedia.
Alonella excisa.
Pleuroxus trigonellus.
Peracantha truncata.
Chydorus sphericus.
,, cadatus.

OSTRACODA.

Cypria ophthalmica.

„ serena.
Cypridopsis vidua .
COPEPODA.
Cyclops albidus.

,, viridis (gigas).

„ bicolor.

„ serrulatus.

„ affinis.
Canthocamptus pygmceus.

Bottom Fauna.

CLADOCERA.

Latona setifera.
Drepanothrix dentata.
Camptocercus macrurus.
Alona affinis.

Chydorus sphericus (also
littoral).

OSTRACODA.

Cypria serena (also littoral) .
COPEPODA.

Cyclops serrulatus (also lit-
toral).
Canthocamptus pygma?us (also
littoral).

It will be seen from the above, that these two lakes alone have
yielded practically half of the recorded species, viz. 32 out of G7,
and no doubt this falls considerably short of the number of species
actually living in them.

140 D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES.

I do not think my records, and observations justify any further
remarks directly dealing with the Entomostraca of North Wales,
but before concluding- I would like to say a few words on two
points having an important, if indirect, bearing upon the subject
in hand, viz., the general character of the lakes, and the methods
of collecting.

As regards the first point, the most noticeable feature is that the
lakes of North Wales are remarkably uniform in type, and in
complete contrast to all those of this South-eastern part of Eng-
land. They are almost without exception collections of the clearest
and purest water, lodged in rocky basins of considerable depth, and
surrounded by stony margins, which may, however, be more or less
obscured by peat and bog-moss. They are, moreover, practically
free from macro-vegetation. Micro-plants, especially free swimming
alga?, are probably not less common in the lakes of North Wales
than they are here, but the luxuriant masses of Myriophyllum,
Elodea, Starwort, Duckweed, etc., found in the majority of our lakes
and ponds are quite without parallel there so far as my experience
goes. Many of the lakes are absolutely destitute of any visible
vegetation, except perhaps some bog-mosses or a rather weak
growth of filamentous alga on the stones near the margin, and
where higher forms of plant life do occur they are generally limited
to horse-tails (/iquisetuni), Lobelia (X. Dortmanna), or more
rarely buck-bean (Menyanthes trifoliatd) . Probably in the depths
of many lakes members of the Characea? flourish, but the only
direct evidence I have of this is that I obtained a species of
Nitella pretty plentifully from several parts of the bottom of Llyn
Padarn.

Such being the general features of the lakes and their vegeta-
tion, it could not be expected that the littoral fauna, which in all
branches of pond-life includes the bulk of the species, should be a
very rich one, and this accounts, no doubt, for the absence of many
of what are to us the commonest species. On the other hand, the
lakes seem eminently suited to the pelagic forms, and these, as
regards the Entomostraca, have already been shown to be well re-
presented,* for although the number of species recorded (10 or 11)

* This is probably true also of the Rotifera. I have repeatedly found
C on ochilus unicornis in the lakes of North Wales, and Asplanchna prio-
donta, Notholca longispina, Anurcea aculeata, etc., have also been seen.

D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES. 141

does not sound very formidable, it must be remembered that from
the point of view of individuals these forms far outweigh all the
others put together. It is the capture of these pelagic animals,
too, which constitutes the chief peculiarity of "pond-hunting"
in North Wales, and this leads to the consideration of the second
point I wish to mention. It is quite useless to think that, with a
net attached to a stick, worked by hand from the shore, any idea
of the pelagic fauna of a lake can be obtained. The only really
reliable method of getting the creatures belonging to this group is
by the use of a boat. From this the net can be used not only at
the surface, but by means of a line and plummet can also be lowered
to various depths, or dragged along the bottom. It is absolutely
necessary to be able to use the net in these various ways, for it
often happens that while the surface is almost devoid of life, a rich
collection of pelagic forms may be secured at a considerable depth.
But boats are only to be had on a few lakes, and if we want to
study the pelagic fauna in the others some different means of
collection must be adopted.

Under favourable conditions some specimens of this fauna can
usually be obtained by the simple means of attaching the net to a
line and throwing it out as far as possible. Of course the net must
be weighted in some way, and I found it a good plan to substitute
for the usual glass tube at the end of the net a small cylindrical
tin into which some molten lead had been run. With the majority
of the higher lakes this method of throwing out the net is
perhaps the only one open to a person who, like myself, simply
does his collecting incidentally during a holiday. In North Wales
however, I found a most fatal objection to this method to be that
very commonly, even in lakes known to be of considerable depth,
there was a margin of comparatively shallow water, extending well
beyond the point to which the net could be thrown, and thus effec-
tually preventing the examination of the deeper water. Several
more complicated methods of collecting, by means of floats etc.
have been proposed for this kind of work, and have, I believe,
proved fairly successful. At some future time I hope to be able to
give some of these a trial, at least in the more accessible lakes.
In the meantime if anyone interested should be willing to continue
this subject of the Entomostraca of North Wales, in any of its
branches, I shall be only too glad to do anything I can to help in
the work.

Jouen. Q. M. C, Series II., No. 37. 10

142 D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES.

Books and papers (British only, as far as possible) containing
figures and descriptions of the species recorded.

Baird, W.— " The Nat. Hist, of the British Entornostraca."
— Ray Society, 1850.

Beck, C. — " On some new Cladocera of the English
Lakes."— Journ. Royal Micro. Soc, Ser. II., Vol. iii., 1883,
p. 777.

Blanchard, R., and Richard, J. — " Faune des lacs sales
d'Algerie, Cladoceres et Copepodes." — Memoires de la Societe
Zoologique ale France, Vol. iv., 1891, p. 512.

Brady, G. S. — " Monograph of Recent British Ostracoda."
— Trans. Linnean Soc, Vol. xxvd., 1868, p. 353.

Brady, G. S. — " Monograph of British Copepola." — Ray
Society, 1878-18S0.

Brady, G. S. — " Revision of the British Species of Fresh-
water Cyclopidee and Calanida3." — Nat. Hist. Trans, of Northum-
berland, etc., Vol. xi., 1891, p. 68.

^ Brady, G. S., and Norman, A. M. — " Monograph of the
Marine and Fresh-water Ostracoda of the North Atlantic and of
North Western Europe." — Scientific Trans, of the Royal Dublin
Society, Ser. II., Vol. iv., 1889, p. 63.

Forrest, H. E. — " On the Anatomy of Leptodora hyalina."
— Journ. Roy. Micro. Soc, 1879, p. 825.

Norman, A. M., and Brady, G. S. — " Monograph of the
British Entomostraca belonging to the families Bosminidae,
Macrothricidaa, and Lynceidee." — Nat. Hist. Trans, of Northumber-
land and Durham, Vol. i., 1865-7, p. 354.

Schmeil, 0. — " Deutschlands freilebende Siisswasser-Cope-
poden." — Leuckart and Chuns Bibliotheka Zoologica, Heft xi.,
1892 (Cyclopidse), and Heft xv., 1893 (HarpacticidaB).

Scott, T. — " The Invertebrate Fauna of the Inland Waters of
Scotland," Part V. — Annual Report of the Fishery Board for
Scotland, 1895, Part III.

Scott, T. and A. — " On some new and rare Crustacea from
Scotland." — Annals and Magazine of Nat. Hist., Series VI.,
Vol. xv., 1895, p. 457.

Scourfield, D. J. — " Some new records of British Clado-
cera." Journal Quekett Micro. Club, Ser. II., Vol. v., 1892,
p. 63.

D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES. 143

Explanation of Plate VIII.

Fig. 1. Ceriodaphnia pulchella, $ x 80.
,, 2. „ „ Post-abdomen, <j> .

,, 3. Laophonte Mohammed, Antenna of 1st pair, ?.

ft *• 55 55 55 55 55 3*

.,5. „ „ Accessory branch of Antenna

of 2nd pair.
,, 6. ,, „ Foot of 1st pair.

,, 7. ,, ,, Foot of 5th pair, <j> .

»> "• 55 '5 55 55 55 <? •

„ 9. „ ,, End of abdomen and Furca,

ventral side, $ , X 240.

144

Note on Fine Markings on Navicula Major.

By Edward M. Nelson, F.R.M.S.

{Read March \bth, 1895.)

About twenty years ago I discovered two narrow bands of so-
called stria? on the hoop of this diatom, and curiously these were
noticed before they were resolved by perceiving their blue sheen,
when the diatom was examined on a dark ground with an objective
whose aperture was insufficient to resolve it into stria?.

At that time Messrs. Powell and Lealand had just brought out
(December, 1874) their new formula water immersion |, and when
that lens was tried on this test the so-called stria? were readily seen ;
subsequently they were resolved with a P. and L. dry £ of 90°;
the diatom was then kept for many years as a test for lenses of
about that aperture ; afterwards the diatom yielded to the same £
with central, and to a P. and L. T 4 F of 80°, with oblique light.

Coming to more recent times, Zeiss' apo. \ of "65 N.A. resolves
it with a -| cone of central light. These stria? will be found to be
fairly constant at 60,000 per inch ; they therefore resemble the so-
called transverse stria? on a Cherryfield Rhomboides. Arguing
by analogy we may conclude that these stria? are composed of rows
of closely adjacent minute apertures ; therefore for some time past
this diatom has been examined with a view to the resolution of
these smaller details when any new instrumental improvement
appeared.

When the fluorite condenser was fitted with a correctional
collar, this object was the first it was tried upon, and after a little
perseverance the structure was at last fully resolved by the Zeiss
apo. -I- of 1*4 N.A., using a| cone of central light.

You will notice that this diatom affords an exceedingly good
test, because there is no rapha? present to yield false ghosts, and
also a marked difference will be observed between this and other
similar diatomic structures, inasmuch as the minute apertures are
not in rows,* so there are no so-called longitudinal stria?. On this

* A rough sketch will be found in the " R.M.S. Journal " for 1895, page
231. (Notice the square appearance of the holes.)

E. M. NELSON ON FINE MARKINGS ON NAVICULA MA JOE. 145

account oblique light fails ; it is, therefore, exclusively a central
light test, and one of the best, for the minute points form a test for
the widest angled objectives of a modern microscope in its highest
development, and the transverse stride one for that most useful lens,
the Zeiss apo. ^ N. A. - 65, as well as one for cheap semi-apochromatic
quarters on second-class instruments, central light being employed
in both cases.

This diatom can be readily procured, as it is common in
" Sozodont " tooth powder ; it should be mounted in quinidine, and
Mr. Gilford's latest F line screen should be used.

UG

Note on Some Recent Observations op the Foot of the

Hodse-Fly.

By A. C. E. Merlin.

(Read April 19^, 1895.)

Since finding that the hairs of the Pulvillus of the house-fly's
foot are terminated by a delicate scythe or sickle-shaped filament,
and not by a knob or sucker as hitherto supposed, it occurred to
me that it would be interesting to endeavour to confirm the exist-
ing theory that the hairs in question are the real agents by which
flies attach themselves to and walk upon smooth glass surfaces.

For this purpose I imprisoned a fly in a Rousselet live box,
leaving the insect plenty of room to walk over the large cover glass
of the apparatus, intending merely to study its movements with a
powerful aplanatic hand lens. While doing so I noticed that it
suddenly appeared to have difficulty in removing one of its feet
from the clean surface of the glass, ani the next instant the leg
gave a violent jerk and the foot was torn off at the fourth tarsal
joint, and was left adhering to the under surface of the cover,
while its owner walked off, apparently undisturbed by the accident.
On releasing the fly and replacing the cover I was able to view the
expanded pulvillus under the microscope exactly as left by the fly.

On examination with Zeiss's 16*0 mm. and 4*0 mm. objectives
with 12 and 18 eye-pieces, using a f cone from an Abbe achromatic
condenser, it was clearly seen that the end of each tenent hair was
attached to the glass by a comparatively large globule of some
transparent fluid which enveloped the sickle filament.

I secured a photograph of this object with the 4*0 mm. apochro-
matic objective, using a 12 compensating eye-piece for projection,
and a J axial cone. The illumination was from the edge of the
flame of a small paraffin lamp. Annexed hereto is a platinum
print taken from the untouched negative thus obtained, showing
some of the hairs adhering to the under surface of the cover.
Near the edge of the print two hairs can be seen joined to each
other at their extremities by a mass of the gummy fluid.

A. C. E. MERLIN ON THE FOOT OF THE HOUSE-FLY. 147

After carefully studying a fine specimen of the house-fly's foot,
mounted in balsam, with a Powell and Lealand -^ oil immersion
of 1*28 N.A., I have come to the conclusion that the tenent hairs
of the pulvillus show a marked appearance of being hollow or
tubular, but it is difficult to decide whether the appearance is a
mere optical effect or real.

148

Note on an Aquatic Hymenopterous Insect.

By W. Burton.

(Read May 17th, 1895.)

On looking over some weeds collected from a small pond at
Totteridge, on the occasion of onr last excursion, I saw a small
fly threading its way amongst a tangled mass of conferva and
rootlets at the bottom of a small stage tank. Thinking it strange
that, although seemingly out of its proper element, it did not
seem in any way distressed, I continued my observations. Shortly,
on coming to a small open space in the water, I saw it very
deliberately spread its tiny wings and fly. I say fly advisedly, for
it was certainly more like flying than swimming. This enabled
me to see that it bore some resemblance to the fairy flies
(Mymaridse), possessing, as usual with them, a pair of anterior
club or battledore shaped wings, exquisitely fringed and covered
with hairs, as were also the posterior, which are simply narrow
bands, and also the slender waist and pointed extremity common
to the Iclmeumonidse. I at once isolated it, and consulted our
mutual friend, Mr. Fred. Enock, who at once identified it as the
same form found by Sir John Lubbock, at Chiselhurst, in 1863,
and described and figured by him in the Transactions of the
Linnean Society in 1864 as Polyncma natans, and which has
rarely been found since. I am unfortunately not able to give you
a scientific account of this find, as my entomological education
has been somewhat neglected, but thought it my duty to bring it
under the notice of our Club, as it was unearthed at one of our
excursions, and in hopes that it might interest some of our
members who are conversant with this form of insect life. I may
mention that Mr. Enock and myself visited the pond on several
occasions since, and have succeeded in obtaining many more speci-
mens, both male and female, which he is now keeping under obser-
vation with the view of publishing the results later on.

149

Note on a Spirit-Proof Micro-Cement.
By Charles F. Rousselet, F.R.M.S.
{Read June 2\st, 1895.)

Everyone here will know the great importance of a thoroughly
reliable cement for fluid mounts. All cements which become quite
dry and hard in time are then also slightly porous, and allow the
fluid to evaporate slowly through the pores. Asphalt, on this
account, is quite useless for fluid mounts, and even Miller's
caoutchouc cement can only be depended upon for a time. After a
few years it becomes quite dry, and sooner or later an air bubble
appears in the mount.

It is my pleasure this evening to announce the discovery of a
cement which is not only reliable for objects in watery fluids, but
which will also keep in permanently strong and even absolute
alcohol. I do not mean to imply, however, that I have myself
discovered the cement in question. I have only discovered its
existence, which seems almost as great a merit, for it has been
used by some for the last fifteen or sixteen years, and yet the fact
of its existence has not penetrated to our Microscopical Societies in
London. Dr. Dallinger's " Carpenter " recommends the periodical
addition of a layer of cement to prevent its becoming quite dry,
and only knows Lovett's a very troublesome cement for spirit
mounts. Mr. Bolles Lee, in his latest (1893) edition of the
" Microtomist's Yade Mecum," says, in speaking of alcohol as a
preservative fluid : " Not very recommendable for mounting, as if
taken weak it is not a very efficient preservative, and if taken
strong it attacks tbe cement of mounts."

The cement which I wish to bring before you is called Clarke's
Cement, and has been used by Mr. Thos. Clarke, of Birmingham,
for the last sixteen years for mounting objects in methylated
spirit, and his slides are quite good and sound now. I have here
a slide of Leptodora hyalina mounted in alcohol by this gentleman
in 1887, or eight years ago, and it is perfect at present. This is
sufficient proot that the cement is leliable for spirit mounts, and,

150 C F. ROUSSELET ON A SPIRIT-PROOF MICRO-CEMENT.

of course, also for all watery fluids. It is black, and used like
asphalt. The diluting fluid is turpentine or benzole, both of which
dissolve it very readily. It sets quickly, but takes two to three
weeks to get sufficiently dry for handling the slides. It is very
tenacious, and never becomes quite hard and brittle. I usually fix
the cover glass of fluid-cells with thickened Miller's cement, and
when dry make a ring of Clarke's cement over that. Of course
with alcohol mounts Miller's cement cannot be used, and the cell
can be made, and must be closed, with Clarke's cement alone.
It is best to use the smallest oil-colour sable brush, putting on the
cement very gradually and little at a time. The brush can be
washed out from time to time in some benzole kept for the purpose
in a separate little bottle.

The composition of the cement is quite unknown to me and is a
trade secret. The cement itself can be obtained from Mr. Thos.
Bolton, 25, Balsall Heath Koad, Birmingham.

151

Messrs. Watson and Sons' New Cheap Centring Substage
for Elementary Microscopes.

{Exhibited June 2Ut, 1895.)

This, as the cut shows, is a serviceable centring substage.

The screws acting against opposing springs enable the optic
axis of the condenser to be aligned to that of the microscope with
celerity and precision.

When we remember that it is not so many years ago when
anything in the form of a centring substage cost £10, we shall
the more readily appreciate this simple, yet efficient device.

It can be adapted to almost any form of student's microscope.

152

in jffflemorfam.

FREDERIC KITTON.

It is with the greatest possible regret that we have to record
the death of our esteemed Hon. Member Mr. F. Kitton, which
occurred at his residence, 8, West Kensington Terrace, W., on
July 22nd last. Born at Cambridge in April, 1827, as a youth
he entered a lawyer's office ; force of circumstances, however,
compelled him to leave the University town for Norwich, and to
associate himself with a wholesale and retail tobacco business, with
which an uncle was also connected. The proprietor, Mr. Robert
Wigham, was well known in Norwich as a practical botanist, and it
was doubtless he who first inspired Mr. Kitton with a love of botany
and kindred subjects, more particularly such as required the aid of
the microscope, an instrument already beginning to take its place
as an indispensable companion in such pursuits. Somewhat later
he took up the special study of the Diatomacea?, a field in
which he soon distinguished himself, and became everywhere
regarded as an expert in this department of microscopy. It is to
be feared, indeed, that this peculiarly fascinating study somewhat
interrupted, or caused him to neglect his ordinary business con-
cerns, which really never possessed any attractions for Mr. Kitton ;
but, be this as it may, it is certain that his place of business in
Norwich was frequented by many to whom the purchase of tobacco,
either wholesale or retail, was of very subordinate importance to
the views or opinions of the proprietor on matters which had no
relation whatsoever with commerce. The activity of Mr. Kitton
in his favourite pursuit is best shown by his numerous papers in
various scientific publications and Transactions of Learned
Societies, a complete list of which, we understand, will be put
together by his son, Mr. F. G. Kitton, and also by his very large
correspondence with almost every diatomist of eminence in all
parts of the world. With advancing years, and latterly from

IN MEMORIAM. 153

impaired vision, his microscopic studies naturally became some-
what intermittent, although they never really ceased until quite
shortly before his death, which happily was painless and peaceful.
Mr. Kitton was an Hon. Member of the Roy. Mic. Soc. ; the
Amer. Mic. Soc. ; the Soc. Beige de Micros. ; the Quek. Mic.
Club; and of the Dublin Mic. Club.

154

PROCEEDINGS.
March 1st, 1895. — Conversational Meeting.

Stephanoceros eichhornii ...
Sphcerozoum punctatum ...
Navicula rectangulata
Synchceta pectinata (mounted)
Diatoms (various species)...

Mr. W. Burton.
Mr. Mainland.
Mr. H. Morland.
Mr. C. Rousselet.
Mr. J. C. Webb.

March 15th, 1895. — Ordinary Meeting.

E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following new members were balloted for and duly elected :
Mr. F. Daunou and Mr. John E. Shaw.

The following donations were announced : —

" Proceedings of the Manchester Literary and) FrQm the gociet
Philosophical Society "... ... )

1

Editor.

}

Mr. J. J. Vezey.
In exchange.

"The Botanical Gazette"

Part VI. (concluding) "Anatomy of the Blow") « , ...

Prof. Ray Lankester's contributions to the")

" Encyclopaedia Britannica " ... )

" The Microscope "
" The Journal of the Royal Microscopical

Society"

"The American Monthly Microscopical)

Journal " ... ... ... ... )

"Transactions of the Eastbourne Natural")

History Society " ... ... ... )

" Journal of the Plon Biological Station" ... ,,

The thanks of the Society were voted to the donors.
Mr. Karop caused considerable amusement by reading an ex

155

tract from the report in a newspaper of a lecture by Dr. Dallinger,
the reporter referring to some wonderful creatures found in water
which were possessed of stentors or living trumpets.

Mr. Hill brought down for exhibition a very small portable
microscope made many years ago by Nachet, of Paris, which he
thought the members might be interested in seeing.

The President thought this was an exceedingly ingenious and
beautifully made little instrument, and, although so small, it seemed
very complete and efficient so far as could be expected within its
limits.

Dr. Measures exhibited a new Abbe-Czapski drawing instru-
ment fitted to a microscope, together with a form of desk for use in
connection with it, designed by Dr. Bernard. The apparatus
would be found very efficient and reliable, as it was not necessary
to keep the eye in position all the time until a drawing was com-
pleted. The work could be left, if desired, and resumed later on
without the least difficulty arising.

Mr. Swift brought for exhibition a new half-inch objective of
.5 N.A.

The President said he had the opportunity of seeing this objec-
tive a short time since, and was greatly pleased with its perform-
ance. It was beautifully corrected, and its resolution was very
fine.

Mr. C. Rousselet read a paper " On a New Floscule," by Dr.
Pittock, of Margate.

A vote of thanks to the author and to Mr. Rousselet were unani-
mously passed.

Mr. Karop read a paper entitled " What was the Amician
test ? "

Mr. J. E. Ingpen said that two test objects used commonly to
have this name applied to them, one of which was Grammatophora
subtillisima, and the other a form of Rhomboides ; but the one that
was generally regarded as the Amician test was the one introduced
by Charles Topping, which was certainly a Rhomboides. He had
seen this, and also another slide marked " Amician test," which
belonged to Mr. Delferrier, upon which he had exercised his y^-in.
objective, and found that this must certainly be regarded as very
delicate.

The thanks of the meeting were roted to Mr. Karop for his
communication.

156

Mr. E. B. Green exhibited his drawings of the root hairs of
plants and their so-called parasites, all drawn to a uniform scale of
1 5.°, and explained the peculiarities observed.

Mr. Karop thought that the question as to whether the green
colour referred to in these bodies was chlorophyll could readily be
settled by the spectro-microscope, since the characteristic bands of
that substance were easily recognized. It seemed so exceedingly-
doubtful whether chlorophyll was ever formed quite beyond the
influence of light that it was very desirable to ascertain whether
what Mr. Green thought was that substance really was so or
whether these bodies were simply some green unicellular algEe or
spores washed into the ground by rain.

The President thought the subject was full of interest and
opened up many new lines of research, and he hoped one result of
Mr. Green's communication might be that some of their members
might feel interested in the questions raised, and start for them-
selves on some of these investigations.

The thanks of the members were, on the motion of the President,
voted to Mr. Green.

The President mentioned that he had after many attempts suc-
ceeded at length in resolving some very minute structure on
Navicula major.

The thanks of the meeting were voted to the President for his
interesting communication.

Announcements for the ensuing month were made, and the
meeting terminated with the usual conversazione.

April 5th, 1895. — Conversational Meeting.

Mr. D. Bryce.

Brachionus urceolaris ... ... ... Mr. J. M. Allen.

Callidina eremita ...
Callidiiia alpiurn ...

JSIctops brachionus... ... ... ... Mr. W. Burton.

Vordcella, fed with carmine ... ... Mr. G. Hind.

Triceratium division ... ... ... Mr. H. Mori and.

Synchceta ... ... ... ... ... Mr. C. Rousselet.

')

157

April 19th, 1895. — Ordinary Meeting.
E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and confirmed.

The following gentlemen were balloted for and duly elected
members of the Club : — Mr. J. C. Wright, Mr. Thos. A
Delcomyn, Mr. Jas. Neville.

The following additions to the library were announced : —
" Journal of the Royal Microscopical ]

Society " J From the Societ 7-

" Bulletin of the Belgian Microscopical

Society"

" Journal of the Q.M.C." „

"British Moss Flora," part 16 ... From the Author.

" Le Diatomiste " ... ... ... Exchange.

" Annals of Natural History " ... Purchased.

" La Nuova Notarisia " ... ... From the Editor.

" The Botanical Gazette " „

" Larvas of British Beetles and Moths " Subscription.

The thanks of the Club were voted to the donors.

The Secretary said they had received a communication with
respect to a Photographic Exhibition which it was proposed to
hold at the Imperial Institute from May to August next ; any
member of the Club desiring to exhibit was asked to communicate
with the Secretary of the Institute, Sir Freclk. Abel.

The Secretary said there was a further important donation to
announce, and that was the gift of two dozen lamps and a cabinet
of slides from the Committee of the South London Microscopical
and Natural History Society, which after 24 years had experienced
the fate of some other kindred societies, and owing to the falling off
of its members had been finally dissolved. The Committee had
decided upon distributing their property amongst existent societies
to whom it was likely to be of service, and the items before men-
tioned had fallen to the share of the Quekett Club. The lamps
would no doubt be extremely useful, and the slides would be ex-
amined to see what use could be made of them. He proposed
that they should pass a hearty vote of thanks to the Committee
of the Club, and also to Mr. Dadswell, who he thought had been
largely the means of securing this donation for them.

Journ. Q.M.C, Series II., No. 37. 11

158

The vote of thanks was put to the meeting and carried
unanimously.

Mr. Ingpen said he could not withhold an expression of regret
that a Society like the South London had ceased to exist, and he
felt as if he should like to propose a vote of condolence with those
who had been connected with it, when he bore in mind the useful
work it had done and the friendly relations which had always
existed between it and the Quekett Club, from which it originally
sprang. He had in former years been brought into close associa-
tion with this Society, and being personally aware of the very
friendly relationship which formerly existed, he could only now
say how sorry he had been to hear of its demise.

Mr. Karop said he had another announcement to make which
would be received with regret by many members of the Club, and
that was the death of their old friend Mr. F. W. Gay, which had
occurred since their last meeting. To many who had lately joined
the Club Mr. Gay would not be known, as it was now some time
since he had been able to attend any meetings, but he was one of
its founders and was in office as their treasurer for nearly 16
years, resigning at length through failing health. Mr. Gay was
one of those quiet men who never put himself forward, but whose
work was done with a thoroughness only known to those who
were closely associated with him. The Committee had that even-
ing passed the following resolution of condolence to be forwarded
to the family : —

" The Committee of the Q.M.C. have heard with great regret
of the death of Mr. F. W. Gay, one of its earliest members,
who held the responsible post of treasurer for more than 16 years.
They beg to tender their most profound sympathy with his widow
and family in their loss, a feeling which is shared by every member
who knew and valued his long and faithful services to the Club."
Mr. Ingpen said he should like to add to what Mr. Karop had
said, one or two words of a personal character, since he was
mainly instrumental in putting the burden of the treasurership
upon his old friend Mr. Gay. He could bear testimony to the
admirable way in which he carried out his work as regarded their
finances, and to the interest taken in their earlier excursions, and
his share in the work connected with them. Everyone who
attended on such occasions was sure to find a ready helper in Mr.
Gay, as well as a genial friend, for he was one of the most club-

159

able men that ever belonged to the Society. He had felt the loss
of his old friend very much, although it was some years since he
had been actively associated with him.

Mr. Terry exhibited to the meeting a large number of photo-
micrographs, which had been brought by his brother, who would
be very pleased to give any information concerning them.

Tne President said they were greatly obliged to Mr. Terry for
bringing these beautiful photographs. From the very slight
glance he had been able to give them, he was sure they would be
well worth careful study.

Mr. R. T. Lewis read a note " On a New Species of Aleurodes,"
which was illustrated by drawings, and by the exhibition of
specimens under the microscope.

Mr. Hardy inquired if the wax with which the pupge were
covered was exuded in a liquid condition.

Mr. Lewis said it could hardly be liquid seeing the shapes
assumed by some of the plumes, and the vertical position of others,
but there could be little doubt that it was excreted in a more
plastic condition than that in which it was found after exposure to
the air.

The thanks of the meeting were voted to Mr. Lewis for his
communication.

Mr. Shadbolt read a paper " On some Bacteria found in the
Thames," illustrating the subject by diagrams and cultivations of
the species described.

Mr. Karop said the Club was greatly indebted to Mr. Shadbolt
for the trouble he had taken in connection with this matter. The
water was some of what was termed " foul water " sent up by
Mr. Shrubsole from Sheerness some time ago, and the small
round bodies which chiefly contributed to that condition had been
described in a paper by Mr. Buffham. Unfortunately Mr. Shrub-
sole had left Sheerness, so that they would not be able to get any
more observations from him this year, which he regretted, as the
time was now approaching when this condition of the water would
again be noticed.

The thanks of the meeting were voted to Mr. Shadbolt for his
paper.

Mr. Karop read a note from Mr. A. Merlin entitled " Some
Recent Observations on the Pulvillus of the House-fly," a photo-
graph being sent to show the specialities of structure referred to.

160

The President thought that there was yet a good deal to be
done in the observation of the structure of the pulvilli of insects.
Since he had read Mr. Merlin's interesting communication in the
" English Mechanic " of March 8th, he had examined the pulvilli
of many insects, and he could strongly recommend this fascinat-
ing subject to anyone in search of something to take up. The
figure in " Carpenter on the Microscope," referred to by Mr.
Merlin, was copied from Fig. 11, PI. V., in Vol. ii. of the
"Quarterly Journal of Microscopical Science" (1854), X 225
diameters, illustrating a paper by Mr. Hepworth, " On the Foot of
the Fly." That figure was the origin of the knobbed or trumpet-
shaped terminations of the hairs on the pulvillus, and the view put
forward by the author that the sticky fluid which the insect
secretes exudes through these trumpet-shaped hairs has been held
up to the present time. Mr. Merlin has now, by first-rate micro-
scopical observations, shown that the knobbed or trumpet-shaped
appearance is an optical ghost, and that the terminations of the
hairs are in reality filamentous. Out of a number of insects he
had examined, the only one that had trumpet-shaped terminations
to the hairs on its pulvillus was a male nettle fly, Platystoma
seminationis S . The Nycteribia Hopei (parasite of the Indian
flying fox) had large trumpet-shaped hairs which seemed more
numerous on the male than on the female. This insect, however,
could hardly be called a fly. The question then was, where did
the sticky fluid exude? Minute tubules could be traced from the
last joint of the tarsus to the teruiinal hairs of the pulvillus, but
although he had examined these hairs with the highest powers he
was unable to discover the orifice at which the fluid escaped,
although their roots and shafts appeared, as Mr. Merlin had said,
hollow or tubular. He was sure they would give Mr. Merlin a
hearty vote of thanks for his very interesting communication.

The President said they bad a number of photographs sent
by Mr. Keevil, of Bath, who it would be remembered sent a
curious specimen of flint section which was illustrated by Mr.
Karop in No. 34 of the present series of the Journal. There was
also another series by Mr. Marryat, of Salisbury, illustrating
karyokinesis in the lily ; these were remarkable because they were
all taken with a cheap lens.

Mr. Karop said these were some of the finest of the kind he
had ever seen ; all the usual features were well shown. The diaster,

161

ribbons, connective and barrel-shaped forms were all well shown.
Mr. Gilbert read a paper on this subject which appeared in the
1st volume of the Journal, 2nd series.

The President exhibited a form of lens mirror, combining the
principles of the pocket lens and Lieberkuhn. In its simplest form
it was a plano-convex lens with the convex side silvered, and the
silvering removed from the centre to form an aperture through
which the object could be viewed — another lens of suitable form
being added to it — it was held up towards the light and became
its own illuminator by converging a strong beam upon the object.
He had just computed an achromatic form which he hoped to
show them at some future meeting.

He thought the members of the Club who were interested in
optical matters would be glad to know of a new photographic
camera lens which had recently been brought out. Of late years
camera lenses had made enormous strides, chiefly owing to the
introduction of the Jena glass, by the use of which astigmatism
had been more perfectly corrected. The latest development came
from Munich ; this was a lens of 8J focus, fitted with an iris
diaphragm, and the price of the whole thing was 25s. It was about
the same as the cost of an English iris diaphragm, and they got
the lens thrown in. The novelty of the thing was that there were
no compound lenses in it, and so far as the photographic results
were concerned it was one of the sharpest lenses he ever saw.
In use the lens was first focussed in the usual way for the
visual rays, and then it was pushed back and turned into a slot
which gave them the exact focus of the actinic rays, and then
the picture was taken, which covered a ^ plate well. He brought
the matter before the Club because of the novelty in the con-
struction of this lens, and the question arose, could not this or
some similar plan be adapted to photo-micrographic lenses ?

Mr. E. B. Green again exhibited a number of specimens and
drawings of his so-called parasitic growths on the root hairs
of plants. The thanks of the Club were voted to Mr. Green for
his beautiful exhibition.

The Secretary said that since their last meeting the Journal had
been issued, and he hoped that every member had received his copy.

Announcements of excursions and meetings for the ensuing
month were then made, and the meeting terminated with the
usual conversazione.

162
May 3rd, 1895. — Conversational Meeting.

Xoteus quadricornis ) Mr. W. Burton.

Evchlanis deplexa... ... ... J

Campylodiscus californicus ... ... Mr. H. Morland.

BracJdonus pala, with eggs (mounted) ... Mr. C. Ronsselet.

Asplanchna priodcnta ... ... ... Mr. W. R. Traviss.

May 17th, 1895. — Ordinary Meeting.
A. D. Michael, Esq., P.R.M.S., Vice-President, in the Chair.

The minutes of the preceding meeting were read and confirmed.

The following gentlemen were balloted for and duly elected
members of the Club : — Mr. F. R. Greg, Mr. Henry Groves, Mr.
E. Macer, and Mr. Michael E. Swan.

The following donation to the Club was announced : —

" Journal of the Royal Society of Cornwall."

The Chairman said he had to announce to the Club the death of
a gentleman who was one of their past Presidents, and who —
though not seen amongst them for some years, he thought not
since he took the chair at one of their dinners — was at one time
a very well-known figure at their meetings ; he referred to the
late Mr. Arthur E. Durham, F.R.C.S. It could scarcely be said
of him, perhaps, that he was a great microscopist, but he was, no
doubt, well remembered by all the older members of the Club,
who would doubtless also hear of his death with considerable
regret.

Mr. Swift exhibited a new form of the Nelson-Dallinger micro-
scope lamp, fitted with mechanical movements in two directions,
for the better adjustment of the position of the flame without
disturbing the position of the stand.

Mr. Karop thought that lamps like that were only for the
"great and good," and were likely to be regarded as luxuries
confined to the few specialists who were not content to move the
lamp along the table in the ordinary way.

Dr. Tatham, having had some experience in the use of one of
these lamps, found it to be remarkably well adapted to the
purpose. It could be brought down to the level of the table or
raided, if required, high enough to use with a full-sized microscope,
and the rack and pinion were very well constructed. The metal

163

chimney was not fixed to the lamp fitting, but to the rod, and he
thought that great credit was due to Messrs. Swift for bringing
out this improved form.

Mr. Michael said he had used one of these lamps for some time,
and certainly thought the rack was an advantage. He also found
that the rod by which the chimney was attached conducted away a
great deal of the heat which came down it for a certain distance,
but not sufficiently to prevent the chimney from being removed by
the rod as soon as the lamp was put out.

Mr. Randall exhibited an improved form of sounding apparatus,
which was fitted with a valve instead of indiarubber, ensuring much
greater certainty of bringing up samples of sea-bottom in good
condition than the methods hitherto adopted.

The Chairman thought this would act admirably for bringing up
specimens from moderate depths, but it would hardly be of much
use as a deep-sea sounder, the essential requirements of which
were that it must carry a heavy weight which would be released
as soon as the bottom was touched. If the weight were not very
heavy, it would be carried away by the currents, and if it were not
detached it would prove too heavy to haul up. He thought the
construction of this apparatus was extremely ingenious, and that
it would be extremely useful in comparatively shallow water.

Mr. Karop said he held the same view as the Chairman; the
reeling in of a weight sufficient to sink to great depths took a long
time and caused enormous strain on the line. He believed the
most perfect sounding apparatus was one invented by Commander
Sigsbee, U.S.N., described in the voyages of the U.S. Coast
Survey vessel Blake, where piano-wire was used instead of line,
and the sinker, a 601b. or 1001b. shot, was automatically detached
as soon as it touched bottom. They were greatly obliged to Mr.
Randall for bringing the apparatus for their inspection.

Mr. VV. Burton read a note " On Polynema natans," found at the
last excursion of the Club in a pond at Totteridge, a specimen
being exhibited under the microscope in the room.

Mr. F. Enoch said he had very little at present to add to what
Mr. Burton had told them about this very interesting find. This
insect was one which he had been looking for without success for
the last 19 years, but he found there was truth in the adage that
everything came to him who knew how to wait. Sir John
Lubbock was looking at some things in a basin of water in 1862.

164

and found about 24 of these insects in it, but though he himself
had searched for them in tLe place where Sir John told him the
water came from, he could not find one. It was next found by a
Mr. Ditches, of Stepney, and in 1881 at Stone, in Staffordshire.
He had no doubt that it did not belong to the genus Polynema,
but felt almost sure it would prove to be identical with Carafractus
ductus, Halliday's description of which he hoped shortly to get
from Dublin. If anyone succeeded in discovering the eggs it
would be a most important thing in connection with its life
history.

The Chairman said this was certainly a very beautiful creature
under the microscope. He recollected Mr. Bostock's specimen
quite well. It was said to fly under water, but its movements
were really true swimming, the wings being used as tins in the
same way as those of a diving bird. It was an extremely interest-
ing creature, but he was under the impression that it might not be
so rare as had been thought.

Mr. Enoch said that the movements of the wings in the water
were just the same as in flying ; it just moved them up and down,
but of course not so rapidly.

The thanks of the meeting were voted to Mr. Burton for his
communication, and to Mr. Enoch for his remarks upon the
subject.

Mr. J. E. Ingpen read a note " On the Scales of Ithomia" with
regard to the gradations found between hairs and scales, the
subject being illustrated by drawings on the board showing the
gradations which had been found, and by specimens exhibited
under the microscope.

Mr. Nunney said that he had taken considerable interest in the
subject which had been brought before them by Mr. Ingpen.
Many distinct forms were usually to be found upon the wings of
the same insect, but he had not yet found any other than the one
mentioned, upon which the whole series were to be met with.

The President inquired if the observations made gave any sup-
port to Mr. Wonfor's old idea that the battledore scales were
indicative of sex ? Receiving a reply in the negative, he pro-
ceeded to remark that when a person saw, for instance, an egg and
an oak tree, there could be no mistake made as to the difference
between them, but when they came near to the borders of the
animal and vegetable kingdoms, it was not always an easy matter

165

to decide to which of these an object belonged. Precisely in the
same way, if they took an extreme scale and an extreme hair,
there could be little doubt as to the difference, but if they followed
them down through the various forms met with, they came at last
to a point where it was extremely difficult to say which was hair
and which was scale. When they talked of hairs and scales, they
should remember that both these terms were rather vaguely used
— the hair of an insect was a totally different structure from the
hair of a mammal, and there was an equal difference between the
scale of an insect and the scale of a lizard, so that when they came
to look into the question they would find far more analogy between
the hairs and scales of an insect than between either the hairs or
the scales of insects and those of other creatures. It was very
interesting to find, as in the instance before them, a specimen
upon which the whole course of the development could be worked
out in the manner shown.

The thanks of the meeting were voted to Mr. Ingpen for his
communication.

Announcements of meetings, etc., for the ensuing month were
then made, and the proceedings terminated with the usual con-
versazione, at which the following objects were exhibited : —
Polynema natans ... ... ... ... Mr. W. Burton.

Ithomia diasia — scales ... ... ... Mr. J. E. Ingpen.

Plonsoma hudsoni ... ... ... ... Mr. C. Rousselet.

June 7th, 1895. — Conversational Meeting.

Melicerta tyro ... ... ... ... Mr. W. Burton.

Aulacodiscus petersii ... ... ... Mr. H. Morland.

Arenaceous Foraminifera (sections) ... Mr. G. Smith.

June 21st, 1895. — Ordinary Meeting.
E. M. Nelson, Esq., F.R.M.S., President, in the chair.

The minutes of the preceding meeting were read and confirmed.

The following gentlemen were balloted for and duly elected
Members of the Club :— Mr. F. Newstead and Mr. Christopher
Poulter.

The following additions to the library were announced : —
" Annals of Natural History" ... ... Purchased.

166

" Le Diatomiste " ... ... ... ... In exchange.

" Quarterly Journal of Microscopical Science " Purchased.

"Journal of the Roval Microscopical Society " From the Society.

"The American Monthly Microscopical) „ . „,.

, „ t From the Editor.

Journal ... ... ... )

" The Microscope " ... ... ... ... „ „

The President exhibited and described an improved form of his
new reflector loup, which he had now achromatised ; it had a focus
of nearly lin. and a magnifying power of 12. The optical con-
struction and principles of the lens were explained by reference to
a diagram drawn upon the board. He also exhibited two new
apochromatic low-power objectives, one of ljin. focus by Powell
and Lealand, and the other a 36 mm. by Zeiss. He had not yet
been able to test Messrs. Powell's, although he had not the least
doubt that it was up to their usual standard, but his examination
of Messrs. Zeiss's showed it to be a very excellent lens, and he was
very glad to find that Continental makers were at last beginning to
recognize the use of a good glass of low power.

Mr. Ingpen said that Zeiss many years ago made low-power
objectives of 32 mm. focus, but gave them up soon afterwards, as
they said there was no demand for them. He inferred from their
bringing out another that they had discovered at last the value of
it. As regarded the achromatic loup he felt sure this would prove
to be of the greatest value. He was much reminded by these
lenses of Zeiss's a*, which it was intended should supersede all
other low powers, say from 2in. to 3in.

Mr. Davis very much admired the reflector loup in its new form,
but thought its usefulness would be much increased if it could be
fitted with a reflector below the object, to obviate the neces^ty for
holding it up to the light.

The President said that the idea of using it as a lens for field
purposes was an after- thought, the original intention being to use
it as a dissecting lens, with a small mirror below. The a* was a
most valuable lens, but the drawback to it with regard to its use
with the microscope was that its apertu e was absolutely nil, and,
therefore, it was practically useless. This new lens of Zeiss's with
a standard tube was a charming one to use, having a numerical
aperture of -186, with a minifying power of x 6 on a lOin.
tube — its optical index was 31, and it quite equalled their old
English objectives. The only other maker on the Continent who

167

made anything of the kind was Seibert, whose No. was a little
higher than a ljin.

Messrs. Watson and Sons exhibited an adaptation to the
" Student " class of microscope of a centring under-stage fitting,
conveniently worked by means of two screws and two opposing
springs.

The President thought this was an addition much required, and
supplied a want which he had himself tried to meet on two or three
occasions. None of these cheaper microscopes could be regarded
as complete without some kind of centring sub-stage fitting, and
the one which Mr. Watson had shown appeared to be a simple and
at the same time a very efficient form.

Mr. C. Rousselet described a spirit-proof micro-cement which he
had found efficient, a slide exhibited having been mounted with
it about eight years ago.

Mr. J. W. Reed read a paper on " The Flora of the Pyrenees,"
illustrating the subject by the exhibition of a large and extremely
well-preserved and mounted collection of the plants described.

Mr. H. Groves thought all present must have listened with
great interest to Mr. Reed's description of the flora of this
district, with which everyone who had visited it was sure to
have been delighted ; and he was sure that all must have admired
the beautiful collection of specimens exhibited upon the tables
before them, more especially when they realized what w r ere
the difficulties met with in collecting and preserving during
a holiday trip in such a district. This was not, of course, a
representative collection, but it was certainly a very interesting
one, and he had been rather struck by the fact that so many of the
species were British — he thought that out of the 110 represented
in this collection 43 were common to the British Islands. It was
also curious to notice that many of our common genera when found
so much further south were then found growing at a much greater
altitude, seeming to indicate the remnants of a much wider
distribution, and that an alteration of temperature had been taking
place by the increase of which these plants had been driven more
and more up the mountains. TLe remarks as to the British Flora,
quoted from Mr. Baker, were very interesting, but were not very
surprising, for, as geological time was reckoned, we bad not been
separated from the Continent long enough to have a distinct Flora of
our own. The existence of plants in the West of Ireland common to

168

America had been noticed, and it was very interesting to note that
many Scotch plants, such as Dryas and others, were to be found so
far south as the Pyrenees. Of the ferns shown he found that
there were seven species, all British. He was also somewhat struck
with the absence of many plants from this collection, but this was
certainly not a matter either for surprise or complaint, because
he knew how impossible it was to get a representative collection
during a visit of this kind. He felt very much obliged to Mr.
Reed for the opportunity afforded of seeing this collection, and
also for the very interesting way in which he had brought the
subject before them.

Mr. E. T. Newton did not like to let the opportunity pass
without expressing his and the Club's indebtedness to Mr. Reed for
his paper and for the opportunity of seeing this beautiful collection
of plants — for, putting on one side the labour of the collecting, Mr.
Reed had taken a large amount of trouble in order that the members
might have the pleasure and privilege of seeing the specimens.
With regard to the botanical portion of the subject he had little to
say, but the similarity of the flora of Ireland to that of Spain was
of great interest to him. The idea that these two countries might
in geological times have been united was not at all an impossibility,
and that the British Islands were once a portion of what was now
the main land of Europe was a supposition which did not rest upon
mere conjecture. There was no doubt that England and Ireland
were originally peopled from the East, and it seemed probable that,
before all the animals made their way so far west, Ireland was first
cut oft from the main land and then England ; hence they found
that the fauna of Ireland was much poorer than that of this
country, whilst England itself was poor by comparison with the
Continent of Europe. When did this separation occur ? This was
a question not very easy to answer with certainty — some authorities
claiming it for Pleistocene times whilst others contend for the
Pliocene. The birds were, of course, not so restricted, but the
animals must have come over when the countries were united, and
the period could not have been much farther back than the earlier of
these periods, because if beyond that limit the animals would have
been different from those known to have inhabited the country. If
it was so with the animals, might it not have been so also with the
plants ? There was, of course, the possibility of plants being intro-
duced in other ways, but he thought the probability lay on the

169

side of the supposition that their distribution occurred chiefly in
the same way as that of the animals. He felt sure that the
members of the Club would feel greatly indebted to Mr. Reed and
would derive great pleasure from an inspection of his very beautiful
collection.

Mr. Reed expressed his indebtedness to Mr. Groves for coming
down to the meeting and for the information and hints he had
previously given. He regretted, of course, that the collection was
not representative, but it must be borne in mind that the object of
the trip was mainly mountaineering, and that they were only there
for about five weeks ; they could, however, have got more flowers,
but their paper gave out, and no more could be pressed ; and, as
everyone knew who had made excursions of the kind, however good
might be the resolutions made at starting, these were very apt to
give out, too, under stress of circumstances. He thanked the
members present for the kind attention which they had given to the
paper.

The President said their thanks were heartily due to Mr. Reed
for his paper and for bringing this very beautiful collection for
their inspection. He hoped that as they had now reached the end
of their session and were thinking of holidays some of their
members might feel stimulated to follow Mr. Reed's example by
collecting or doing something, and giving the Club the benefit of
the results when they met again.

A hearty vote of thanks to Mr. Reed was unanimously carried.

The proceedings then terminated with the usual conversazione.
Plcesoma lynceus ... ... ... .. Mr. C. Rousselet.

These objects were exhibited at the following Conversational
Meetings : —

July 5th, 1895.

Pedalion mirum ... ... ... ... Mr. W. Burton.

Lepidodiscus elegans ... ... ... Mr. H. Morland.

Stephanops lamellaris ... ... ... Mr. W. R. Traviss.

July 19th, 1895.

Pedalion mirum ... ... ... ... Mr. W. Burton.

Lacimdaria socialis
Notops clavulatus (mounted)

| Mr. C. Rousselet.

170

August 2nd, 1895.
Hydatina senta ... ... ... ... Mr. W. Burton.

Aulacodiscus sturtii, with 3, 4, 5, and 6
processes

I

Mr. H. Morland.

Ordinary Meeting. — September 20th, 1895.
E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

In the absence of the Hon. Secretary, the minutes of the pre-
ceding meeting were read by Mr. J, J. Vesey and were duly con-
firmed.

Mr. Vezey said that Mr. Karop was away for a holiday in
Germany, and had recently been visiting Jena, where he seemed
to have met with a most pleasant and cordial reception from Dr«
Zeiss and others, who took him all over their works and spared
no pains to make his visit thoroughly enjoyable. He said in his
letter that he felt the honour done to him was largely due to his
official connection with the Club, and he wished to let the members
know of the kind of feeling which had been manifested towards
him on that account. No doubt when he returned they should
hear more about his visit.

Mr. Vezey said they had also received a copy of the " Evening
Observer" of Brisbane, from which he read an extract with
reference to the work which was being done out there by their
member Mr. C. J. Pound, who was Bacteriologist to the Stock
Institute in Queensland. From this it appeared that the discovery
of the bacillus of chicken cholera had been recently made in
Australia, and it was expected that the knowledge gained would
lead to an important and effective means of dealing with the rabbit
plague in that country.

Mr. C. Rousselet's paper " On some New Species of Rotifers
found at the Excursions of the Club," was, in the absence of the
author, read by Mr. Western, who, having had the opportunity of
examining the specimens, was able to speak to the accuracy both
of the descriptions and of the drawings by which they were
illustrated.

The President felt sure the members would join in according
a hearty vote of thanks to Mr. Rousselet for his interesting paper
and the plates which accompanied it, and also to Mr. Western for
so kindly reading it on that occasion.

171

Mr. Scourfield read a paper entitled " A Preliminary Account of
the Entomostraca of North Wales," in which he recited a list of
sixty-seven species found either in fresh or brackish water.

The President, in proposing a vote of thanks to Mr. Scour-
field for his paper, said he was very pleased to note that he had
not forgotten the Club during his holidays, and he ventured to
hope that other members had been similarly mindful.

Announcements of the meetings and excursions for the ensuing
month were then made and the proceedings closed with the usual
conversazione. Object exhibited : —
Flower of Asparagus, trans, and vert.

sections Mr - H ' E " Freeman -

}

October 4th, 1895. — Conversational Meeting.
Melicerta ring ens ... ... ... ... Mr. W. Burton.

Auliscus mirabilis, Grev. ...
Periphragella elisce (Japan)
Schizocerca diversicornis ...
Mastigocerca selifera
Polyarthra platyptera, var. Euryptera

Mr. H. Mori and.
Mr. K. W. Priest.

Mr. C. Rousselet.

172

NOTICES OF RECENT BOOKS.

The Anatomy, Physiology, and Development of the Blow-
Fly. By B. T. Lowne, F.R.C.S. 2 Vols. London : R. H.
Porter. £3 3s. net.

Although it would be quite impossible in this place to give any-
thing like a review of Prof. Lowne's great monograph, yet we
cannot forbear making some remarks, however inadequate, on a
work which has taken up five years of the author's time, and is the
most copious and extensive work ever written on a single insect.
Perhaps the best idea of the progress of biological science in recent
times may be gained by a comparison of the present volumes with
Prof. Lowne's original book on the blow-fly, a thin 8vo. of 120
pp. and ten plates, published in 1870, or exactly twenty-five years
ago, while the one just completed occupies no less than 780 pp.
and is illustrated by 52 plates and 108 figures in the text. The
subject is treated in the fullest possible manner from beginning to
end, and the conclusions arrived at are based on the author's own
investigations into the most minute details of structure, yet it
does not represent his personal views alone, as the book contains a
very complete resume of the labours of others and an extensive
bibliography, which will be invaluable to every student of this
department of biology. As is well known, Prof. Lowne holds
certain opinions on some much-controverted subjects, notably on
the structure and functions of the compound eye and on the homo-
logies of the mouth-organs and the parts of the brain, which have
not yet obtained universal assent ; but it cannot be said that he has
failed to do justice to those who differ from him, for the con-
clusions of his chief opponents are given at great length, and the
reader must decide for himself on the evidence submitted to him
on both sides of the questions at issue. A copious index and full
reference to 370 memoirs combine to render it an invaluable work,
and we recommend it most heartily to everyone who desires to
obtain precise information in this important branch of science.

The Natural History of Aquatic Insects. By Prof. Miall,
F.R.S. London: Macmillan & Co. 6s.

In this work will be found a description of all the commoner and
some of the rarer insects which pass either the whole or a part of

173

their existence in water, whether ponds, ditches, rivers, lakes, or
the sea, with their structure, metamorphoses, and general life-
history. Many of these, in one or other of their stages, are
favourite microscopic objects, and the very complete account which
Prof. Miall has given of the various aquatic beetles, flies, caddis-
worms, Ephemeridaa, stone-flies, dragon-flies, pond-skaters, water-
boatmen, and other insects should render it extremely useful to all
who take an interest in this fascinating branch of natural history.
Besides the descriptions in the text there are pretty full references
to special works, which undoubtedly increase its value. The illustra-
tions are generally good, many of them being drawn by our former
member, Mr. A. Hammond, F.L.S., whose skill as a draughtsman
is well known. The book may confidently be recommended.

Texte et Tables de la Collection des Diatomees du Monde
Entier. Par MM. Tempere et H. Peragallo, Paris. Price
18 francs, or 14s. post free.

This work should certainly be of use to collectors of Diatoms.
It is an analysis of the principal species and varieties contained in
625 gatherings and deposits obtained from all parts of the world,
and the relative abundance of the various forms in each is indicated
by different styles of type, which is a very convenient arrangement.
There is also an alphabetical list of localities showing the nature
of the Diatomaceaa in each, whether recent or fossil, freshwater,
brackish or marine, and finally an index of species, with one to
four references to the places where they will most frequently be
met with, leaded figures indicating that the particular form is
almost unmixed or preponderates, and italics that it is rare. It
may be useful to know that either the cleaned material or mounted
preparations as well as the book can be obtained of Monsieur
Tempere, 168, Rue Saint- Antoine, Paris.

Introduction to the Study of Zoology. B. Lindsay. London :
Swan, Sonnenschein & Co. Price 6s.

This little book is chiefly intended for those who have taken up
the study of Zoology for the first time in later life and who require
an elementary and at the same time sufficiently reliable guide to
put them on the right track. " The commercial man, the clerk,
and the well-educated artisan help to make up the class of students
I refer to — students whose enthusiasm for knowledge is such as to

Journ. Q. M. C, Series II., No. 37. 12

174

lead them to seek it, self-taught and self guided, in their short
intervals of leisure " (Author's Preface). The book is divided into
three parts — General Principles, Systematic Zoology, and Advice
to Students, illustrated with 124 figures and diagrams, and is
provided with a glossary and index. Naturally to deal with so
much in such a comparatively small compass necessitates very
considerable compression, but Miss Lindsay has contrived to give
a very good idea of modern zoological notions, and if the class she
appeals to will intelligently assimilate what the book is capable of
affording they will not despise their own acquirements nor the able
and industrious compiler of their first Introduction to Zoology.

Rambles in Alpine Valleys. J. W. Tutt, F.E.S. London :
Swan, Sonnenschein & Co. Price 2s. 6d.

Although from its title this work would appear to be scarcely
adapted for notice in this Journal, anyone acquainted with Mr.
Tutt's many contributions to the literature of Natural History and
Entomology would expect to find a large amount of reference to
such topics in any book by him.

This expectation is fully realized in the present instance, and the
reader will meet with botanical or, more particularly, entomological
remarks on nearly every page, and if the descriptive part is perhaps
of greater importance to those who have, or intend visiting these
charming places, the stay-at-home naturalist will find plenty of
suggestive matter treated in a popular and pleasant style.

Hidden Beauties of Nature. By Richard Kerr, F.G.S.
London : Religious Tract Society. Price 3s. 6d.

A little book written in a very simple manner, and only designed
as a first introduction to such as are yet almost entirely ignorant
of the beauties revealed by the microscope. As a gift for any
young person who may show some inclination to know a little more
about the marvels which surround him on sea and land the work
will, no doubt, be acceptable, the more so as it is well illustrated
by reproductions of photographs and other figures of Sponges,
Radiolaria, Diatoms, etc.

Das MiKRosivor. Ein Leitfaden der wissenschaftlichen

MiKRosKoriE. Yon Dr. A. Zimmermann. Leipzig : F.

Deuticke. London : Williams and Norgate. Price 9s.

We much regret that, by an oversight, this extremely valuable

work did not come into our hands until so nearly the time of

175

publication of the Journal as to preclude a notice of the length that
its merits deserve. The optical part is written so clearly and
without any parade of imposing mathematical formulas, except
where such are imperative or easily understood, that, instead of
causing weariness, as is generally the case, it is a pleasure to read.
The properties of lenses, the images formed by single and com-
bined systems, angular and numerical aperture, aberration and the
whole theory of secondary images, are all treated in a masterly
way. The various details of the microscope, particularly the
objectives and eyepieces, their construction and action, are
exhaustively and practically described, but if it is allowable to
indicate, from onr point of view of course, one little blemish
where nearly everything is excellent it is in the matter of the sub-
stage condenser. Abbe's chromatic is the only apparatus of the
kind mentioned, and it appears strange to us that, while the
aperture of the objective is treated with such scientific insight
and its value so thoroughly grasped, the equally important factor
of the illumination is yoked to such a comparatively inefficient
means of utilizing such aperture as is afforded by this widely-used
but optically unsound condenser. Nevertheless, it must not be
forgotten that Dr. Zimmermann is writing for German readers,
and that up to quite recently they universally regarded the sub-
stage condenser as a mere English ' fad,' so if they are content
for the time with an inferior form it is still an advance on their
former attitude, and we must not complain.

So far as we have had time to judge the practical portion of the
book is equally good and to the point as the more theoretical,
while space has not been wasted on a host of staining and chemical
processes, which can easily be found elsewhere. It concludes with
a chapter on Microscopical perception, dealing with the images
given by an opaque reflecting sphere, as a globule of quicksilver,
an air bubble, and a drop of oil in water. There is a short biblio-
graphy and index. For such microscopists as read German, and
particularly those that employ German instruments, the work will
be of very considerable service.

A Popular Handbook to the Microscope. By Lewis
Wright. The Eeligious Tract Society. 2s. 6d.

This excellent work, which contains 256 pages, two plates, and
186 woodcuts in the text, can be strongly recommended to the
rank and file of the ever-increasing army of microscopists as well

176

as to those beginners who are about to enlist therein, and who
wish to know what kind of microscope and apparatus to buy, for
they will find in it the unbiased opinion of a first-rate niicroscopist.

Chapters I. and II. deal with the optics of the microscope, a
most important subject, for under the new conditions of things
which have arisen during the past twenty years it is impossible
for anyone to become a microscopist without some knowledge of
the fundamental theories of microscopical optics. An acquaint-
ance with these theories is the best safeguard against false inter-
pretation of structure. The author has been most judicious in
the selection of matter in these two chapters. He has given
enough for all practical purposes without going too deep and
beyond the scope of the book.

Passing over the simple, we come to the compound microscope
in Chapter IV., of special interest to those about to purchase an
instrument. Second and third class instruments only are dealt
with, viz., those costing from £1S without objectives to three
guineas with two. With almost the whole of the opinions ex-
pressed in these chapters we most fully concur ; the only points of
divergence would be with regard to the horse-shoe foot and the
direct acting screw fine adjustment. As to this last point, any
direct acting screw fine adjustment, however well made, will be
found too quick for wide-angled objectives when illuminated by
large cones ; as regards its durability the new form, as now made
by Zeiss, Reichert, and Leitz, is vastly superior to the old model,
which was, after a little use, incapable of critically working a
student's J-inch objective.

The latter part of this chapter deals with accessories, including
objectives, eye-pieces, and condensers, etc. The reader will find
it full of sound advice and practical hints. Chapter V. is full of
excellent information on manipulation, but in the next we must
notice a slight omission in not pointing out the inversion but non-
transposition of an image drawn with a Beale's camera. The fol-
lowing chapter is on the preparing and mounting of objects, and
the remaining half of the book is devoted to the objects them-
selves. With regard to this part we think the selection very
appropriate ; a careful study of it ought certainly to whet a student's
appetite for more knowledge. The book is written in Mr. Lewis
Wright's well-known lucid style, and the figures etc., are all that
can be desired.

)ourn

.

Id Ad. 114

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177

O.Y BONNEMAISOSIA HAMIFEBA, HARIOT, IN CORNWALL.

By T. H. Buffham, A.L.S.

{Read Nov. \5th, 1895.)
Plate IX.

I was collecting marine alga3 at Falmouth, in Aug 1893
when I found floating in the sea a red plant which I failed to
identify on the shore. With the microscope, however, it was
seen to be a specimen of Bonnemaisonia, but of snch a bizarre
appearance as to raise doubts of its relation to B. asparagoides
Ag. Afterwards I picked up two other floating specimens
similar in size and appearance, although differing slightly in
the degree of development. The following notes are therefore
applicable to the three specimens. They were extremely
bushy, branching thickly, about 4 cm. (l£ inches) high, and
having a dense cortex of small cells. It was also noticed that
the ultimate ramuli were not arranged in the regularly disti-
chous order of B. asparagoides, although, as in that species, a
reproductive organ was almost always opposite to a ramulus.
The most noticeable feature, however, was the occurrence of
pseudo-cystocarps, some being of the normal form, with a
regular ostiole (ceramidium of the older authors), but many of
abnormal growth, and considerably distorted. I failed to find
any carpospores in these bodies, although procarps with tricho-
gynes of quite normal character existed in abundance

I have noted (<< Quek. Jour.," Vol. v., ser. 2, p. 297) that in
a considerable number of specimens of B. asparagoides everyone
was monoecious, and it appears doubtful if any unmutilated
specimen, purely female, has been found. In the Falmouth
plants I could not detect any antheridia. I consequently
leaned to the conclusion that these were abnormal female
plants of B. asparagoides which had had no opportunity of
becoming fecundated by the approach of pollinoids.

One specimen was preserved in a saturated solution of
sodium chloride, one in glycerine, and one was dried. Pressure
ot other algological subjects of study postponed any re-exami-

Journ. Q. M. C, Series II., No. 38. 13

178 T. H. BUFFHAM ON BONNEMAISONIA HAMIFEBA.

nation nntil this year, when I became very doubtful that the
cireumstances just referred to eonld account for the raminca-
tion and dense cortex. At this juncture I sent a portion of a
plant to Dr. Ed. Borne*, of Paris, who was kind enough to
lend me a small piece of S. hamifera Hariot from Japan winch
he considered my plant much approached by its ramifica ion
its mucronate ramuli, and its cortex. Later on he a so lent me
a dried specimen (see Fig. 1) on which are pWyseen the
peculiar branches ending in a hook (h) winch led M. Hariot to
adopt the specific name. This induced mc to search my
specimens for similar branches. I found one almost exactly
like the one shown in Fig. 2, but with the actual pomt broken
off exposing the cells of the interior. All three specimens
showed them, but of reduced size ; evidently all my plants are
younger than the Japanese specimen. Fig. 3 represents my
dried plant, the smallest of the three, but a hamose branch can
be detected a short distance from the bottom of the figure
(indicated by h). Meantime I had detected on the perfectly
developed ramuli near the growing summits of the branchlets
of my plants some minute hyaline recurved spines-2-5 on a
ramulus-and always secund near the pointed apices. These
project only about 10 ^ from theramulus, and are consequently
visible only when presented in profile (Fig. 5). I then found
similar spines on the small portion originally received from Dr.
Bornet. The Japanese plant has procarps and perfect cysto-
carps with carpospores, but no antheridia. These various
features, notwithstanding that the Falmouth plants have not
been fecundated, establish the specific identity of the Cornish
plants with those of Japan.

' I have been led into the foregoing rather prolix statement on
account of the peculiar circumstances of the case.

B. hamifera was first published by Hariot in 1891.* A few
specimens were found in a collection of algse made by Dr.
Savatier at Yokoska in Japan. The diagnosis given by M.
Hariot is very clear, and he adds some remarks upon the
differences between it and B. asparagoides. He gives no figures,
however, and I may be permitted to enlarge the original
description.

» " Mem. de la Soc. dos Soi. Nat. et Mathematiques de Cherbourg," T.
xxvii., p. 223.

T. H. BTJFFHAM ON BONNEMAISONIA HAMrFERA. 179

The arrangement of the ramuli has already been referred to,
and Fig. 4 shows a portion of a branchlefc of a Falmouth plant
below its summit where the axis is about *3 mm. thick, the
ramuli being about '15 mm. thick at the base, and 2 mm. long.
These are produced quadrifariously, and on these wholly
female plants there is almost always either a procarp or (in
the Japanese plant) a cystocarp exactly opposite to a ramulus.
The larger bodies (a) at the lower part of the figure are
pseudo-cystocarps in which only barren filaments exist instead
of carpospores. It is remarkable that notwithstanding the
absence of fecundation the pericarp should be so largely
developed. I am not aware that any analogous case is known.

The hamose branches rapidly become thicker up to *6 mm.,
and are 3*5-5 mm. high. The structure and cortex are exactly
like those of the part from which they are produced.

M. Hariot appears to have been unable from lack of material
to describe the " root " which he indicates thus : " Radix ..."
The abrupt termination of the axis in Fig. 1 clearly shows its
absence in this specimen. One of my plants has a base spirally
coiled round a filament of Ahnfeltia plicata J. Ag. The coils
of the spiral have coalesced, but the attachment to the Ahnfeltia
was not close, for I took the Bonnemaisonia off without damage
to either. Within 6 mm. from the spiral the branching com-
mences (Fig. 6).

The cortical cells have a polygonal outline, and on both the
ordinary and hamose branches vary in size from 10 to 27 /a,
being generally 16 yu, and have richly- coloured contents (Fig.
7). I am unable to give more precise indications of the chroma-
tophores. In the lowermost portions of the plant the cells are
very irregular in form and size, and there are numerous narrow
red filaments meandering just below them. Near the apex of
a ramulus (Fig. 5) — which is frequently more decidedly mucro-
nate than is shown in the figure — the cells are 10-15 /x.
Beneath the cortex of the thicker axes there are larger cells
up to 45 fi, in diam., and possessing paler contents, the rest of
the interior consists of very large cells up to 150 /x, devoid of
coloured contents, amidst which is a stout articulated axis
with granular contents.

The question will already have arisen : How came this alga,
known only in Japan, to be found in Cornwall ? Yokoska

180 T. H. BUFFHAM ON BOtfNEMAISONIA HAMIFERA.

(Yokosuka on the Admiralty charts) is on the south coast of
Nipon (Japan), Long 138° E., and Lat. 34° 41' N. Un-
doubtedly in this latitude the sea would be warmer than any
British waters. We do not know the limits within which B.
hamifera can exist. It is noteworthy, however, that the gather-
ing of Dr. Savatier, which comprised altogether only 54 species
and varieties, contained 21 species which had not previously
been recorded from Japan, and that these new records included
some of our common British species, such as Monostroma Lac-
tuca, Ulva Linza Harv., Chorda Filum, Chordaria divaricata,
Dictyota dichotoma, Padina Pavonia, Bictyopteris polypodioides,
Asperococcus bullosas, Laminaria flexicatdis, Chylocladia Jcali-
formis, Fastigiaria furcellata, Melobesia membranacea, M. cortici-
formis, Gracilaria compressa, Halurus eqnisetifolius. This would
rather indicate that, so far as temperature is concerned, the
Japanese station may differ not considerably from our southern-
most coasts.

It is impossible that the Falmouth specimens can have been
brought from Japan, and it is certain that they grew near the
station where they were found, for they were quite fresh (and
anyone familiar with Bonnemaisonia will know how evanescent
is its fresh beauty), of rich colour, and the delicate procarps
with trichogynes were abundant and in perfect condition.
Nevertheless I am disposed to think B. hamifera is not truly
indigenous to Britain. It has frequently occurred to me that
the algal flora of many parts may be temporarily, or even per-
manently, enriched by the unwitting agency of man. The com-
mon algae which grow on the submerged portions of ships may
very well harbour the spores of plants, although the plants
themselves could not survive the voyage. Moreover, small
portions of some algae might possibly endure the changes. The
spiral base of one of my specimens (Fig. 6) suggests the possi-
bility that the curious hamose branches, in the absence of other
means, may propagate the species. This is not altogether with-
out analogy in the Florideoe. Dr. Bornet states that portions
of the thallus of Polysiphonia furcellata Harv., and P. atro-
rubescens Grev., become detached and are capable of growing
into plants.*

* "Les Algues de Sehousboe " in "Mem de la Soc. des Sci. Nat. et
Math, de Cherbourg," T. xxviii., p. 311.

T. H. BUFFHAM ON BONNEMAISONIA HAMIFERA. 181

M. Hariot refers (loc. cit.) to a specimen of a Bonnemaisonia
from California, sent by Prof. Farlow, of Harvard University,
in 1887. This plant was doubtfully referred by M. Hariot to
B. hamifera. This specimen is in the possession of Dr. Bornet,
who kindly lent me it, and I am therefore able to offer a figure
of it (Fig. 8). Prof. Farlow marked this B. asparagoides ? Near
the base it bears two or three slender branches with hooked
extremities, which certainly seem analogous to those of the
typical B. hamifera. I have searched the herbaria at Kew and
the British Museum for any specimens of Bonnemaisonia bear-
ing hamose branches, with the result that I found none at Kew
and only one plant at the Museum. This is almost exactly like
two of the present fig. joined together near the base. On it
also there are two or three hooked branches precisely similar
to those in our fig. I have compared a small portion of this
specimen with the preparation of Farlow's made by Dr. Bornet,
and have no hesitation in concluding that they are one and
the same species. The following remarks are equally applicable
to the two specimens.

The branches (pinna?) are in one plane, generally of linear
form. These are almost regularly pectinate, the ramuli
(pinnulae) alternating with a cystocarp or procarp (occasion-
ally two, as in Fig. 9), which are opposite to the ramuli. These
ramuli are short, thorn-like in form, and taper quickly, not
mucronate, and are devoid of spines ; the cortical cells near the
point being 15-20 fx in diam. (Fig. 10). No antheridia have
been seen.

The British Museum specimen was received there in Dickie's
herbarium in 1884. It appears to have been contained in a
bundle of plants labelled " N. America." This specimen was
marked by Dickie

Ptilota Calif omica filicina? N". America,
but bears neither the date nor the collector's name. There
can be little doubt that this was from California. Mr. Gr
Murray had placed it with other specimens of Bonnemaisonia.

Here are its characters : —

Bonnemaisonia Califomica. (Ptilota Californica in Herb.
Dickie.)

Frond 10 cm. high, with one or two principal axes, com-
pressed, pinnate, the pinnae 1-3 cm. long, erect, regularly

182 T. H. BUFFHAM ON BONNEMAISONIA HAMIFEKA.

alternate, nearly linear, distichously pectinate with thorn-like
ramuli alternating with one or two female organs, a
ramulus always opposite to these organs. Ramnli tapering,
acute. Some of the lower pinnae are prolonged into a hook
bare of ramuli. Plant densely corticate. Cystocarps pedicel-
late. Antheridia unknown.

Hab. California (Dickie, Farlow).

Explanation of Plate IX.
Fig. 1. Bonnemaisonia hamifera Hariot. Portion of female
plant from Japan, h, h, hamose branches. Nat.
size.

2. Ditto. Hamose branch x 5.

3. Ditto. Young unfecundated plant from Falmouth.
h, a hamose branch. Nat. size.

4. Ditto. Part of branchlet with ultimate ramuli,
procarps, and pseudo-cystocarps (a) x 10.

5. Ditto. Apex of mucronate ultimate ramulus with
secund spines x 200.

6. Ditto. Spiral base coiled round Ahnfeltia plicata
x 5.

7. Ditto. Cortical cells of a portion of a branch
x 200.

8. B. Califomiea (Dickie) Buffham. Female plant
from California, h, h, hamose branches. Nat.
size.

9. Ditto. Portion of pinna with ultimate ramuli and
young cystocarps x 10.

10. Ditto. Apex of ultimate ramulus x 200.
Figs. 1, 3, and 8 from photographs of dried specimens.

183

Notes on some Florideje.

By T. H. Bdfpham, A.L.S.

(Taken as read January 17th, 1896.)

Plate X.

The following Notes may be considered as a continuation of
a paper On the Antheridia etc. of some Floridece, read in June,
1893 ("Journal," Vol. v., series ii., p. 241), as they refer
chiefly to the male organs of some of the red marine algae.

Since then I have not been able to make a large addition to
the British records of these organs, but, such as they are, they
may not be without interest. None of the species now figured
have, to my knowledge, been drawn before, and most of them
have apparently escaped notice hitherto. When the present
names differ from those in Harvey's Phycologia Britannica, the
latter are placed in parentheses.

Chondrus crisjpus Stackh. (Irish Moss) is one of our com-
monest species, and I have, through many years, unsuc-
cessfully sought for the antheridia. The male plant in no
way differs in habit from an ordinary barren specimen, and the
only indication of the difference is a faint sinuous line crossing
the frond a short distance below the apices, and seen most
readily on a half-dried plant. This line is the oldest boundary
of the antheridial layer which extends upwards in an irregular
patch, with here and there smaller spots, and fades off towards
the last divisions of the plant (Fig. 1). The surface view
differs very slightly from that of the ordinary cells of the
surface, and these male organs are certainly amongst the most
difficult of detection. Careful examination with a moderate
power at the edges of the frond where the layer occurs will
show a very narrow gelatinous border, but even this might
still leave the matter in some doubt. If a transverse section
through both the antheridial layer and the unchanged thallus
be taken the male organs are readily demonstrated. Fig. 2
shows the cells extraneous to the layer, and Fig. 3 those of the

184 T. H. BUFFHAM ON SOME FLORIDE^.

antheridial layer itself. It will be seen that in the latter case
there is an elongated gelatinous body about 20 /x high, and 7 /z
thick, enclosing each male cell, near the apex of which the
pollinoid — about 3x2 yu — is formed. (Hastings, Oct., 1893,
in a gathering by my wife.)

Another alga, Gigartina mamillosa J. Ag., is almost as
abundant as the preceding species, but the male organs have
escaped my search until recently. This is the more remark-
able as, although tetraspores are unknown, cystocarps are
seldom absent from any specimen. My male example was
plucked from a rock by my wife. The appearance is strikingly
different from that of the ordinary female plant, for it is
thickly beset from near [the base with flattened leaf-like
branches arising just within the edges of the main portions of
the frond, and with smaller ones from the other portions of
the thallus. In short, the plant has some resemblance to
Chcetangium ornatum in G. Murray's recently published In-
troduction to the Study of Staivceds, Fig. 68. It is on some
of these leaf-like branches that the antheridia appear (Fig. 4).
They may sometimes be just detected by the naked eye. They
assume various forms : circular, dumb-bell, lobed ; and the
surface, with a low power, appears mottled as if made up of
numerous rounded groups (Fig. 5). The layer when seen at
the edge of the thallus projects noticeably, and portions seem
slightly pushed outwards (Fig. 6). There is but a thin
gelatinous covering, and on such a spot one may just see that
the structure differs from that of Chondrus, although the
opacity of the thallus makes it difficult. If a thin tangential
slice of the layer be taken the view from above is that of small
groups of darker bodies, about 9 /a from centre to centre (Fig.
7). A vertical section shows that the groups aie the pollinoids
in minute bunches at the extremities of articulated threads
arising dichotomously from the coloured cells of the thallus
(Fig. 8). The structure of this layer has some resemblance to
that of Choreocolax Polysiphonice Reinsch, figured by me (loc.
cit. Fig. 2), but Gigartina mamillosa is on a smaller scale, the
pollinoids scarcely reaching 2 /u. (Salcombe, Sept , 1895.)
Caution is requisite in examining this species as the antheridial
layer is liable to be overlaid with young Dermocarpa. This is
readily noticed when near the edge of a flattened branch.

T. H. BUFFHAM ON SOME FLOKIDE.E. 185

The antheridia of Ehodymenia Palmetto, Grev. of the normal
character were figured (loc. cit., Fig. 15). Since then a parti-
cularly fine male plant was collected, and at the same station
another with antheridia having 3 or 4 small male proliferations
on each, and some elongated antheridia of clavate form pro-
ceeded from near the lower portions of the thallus instead of
forming the apices of the branches. (Hastings, Oct., 1893,
Mrs. T. H. B.)

In Chylocladia oralis Hook, the antheridia form irregular
patches on the ultimate obovoid branchlets. Over the un-
changed portions of the thallus there is always a hyaline
coating of considerable thickness, and the male cells at the
border are seen to project almost through this pellucid border
(Fig. 9). The surface view shows the layer to be formed of a
congeries of rounded groups (Fig. 10). In a vertical section
the larger cells near the cortex are found to bud into smaller
ones which put forth cells about 25 fx high that emit the polli-
noids. These are about 4 jj. in diam., and they and the
elongated cells are loosely placed in the gelatinous invest-
ment just mentioned (Fig. 11). (Torquay, August, 1894.)

Ptilothamtiion Pluma Thur. (Callitham?iion Pluma Ag.)
is a very minute plant, sometimes only 2 mm. high, growing
on the stipes of Laminaria. It was separated from Callitham-
nion by Thuret on account of the difference of the procarp
and fruit. The male organs are terminal on the branches, and
consist of a short jointed axis surrounded by a gelatinous
layer containing the pollinoids. The antheridia are 50 — 70 //,
long, and 35 /x in diam. These bodies are drawn by Bornet in
Notes Algologiques, PI. 46. (Swanage, June, 1892. Also found
by Mr. E. A. Batters at the same station, August, 1891.)

Compsothamnion gracillimum Schmitz (Callitliamnion gracil-
limum Ag.) is an exceedingly beautiful alga which has been
only recently removed from Callith amnion, and the antheridia
are very different from those of the latter genus. In a male
plant they are produced on a pedicel of one to several cells, a
pedicel arising from almost every cell of a branchlet. In some
cases there are several antheridia in a group (Fig. 12). Even
with a low power the appearance is rather striking, for minute
dots arranged transversely are seen along the antheridium
giving a glistening appearance to the specimen. The repro-

186 T. H. BUFFHAM ON SOME FLORIDE.E.

ductive body is ellipsoidal, 40-45 /x long, and 25-28 p. diam. The
cells of the axis destined to be changed begin by dividing
longitudinally into four (generally three only of these are
visible), and from these segments gelatinous extensions are
made in which the pollinoids, which are about 2 /x in diam., are
produced. The antheridium has a rather delicate and unde-
fined outline outside the 6-8 transverse rows of cells (Fig. 13).
(Torpoint, Sept., 1895.)

In Ceramium acanthnotum Carm. the antheridia form small
cushion-like projections round the nodes of the upper parts of
the filaments. They have the character usual in this genus (in
which I have recorded most of the British species, and figured
several), and were seen in French specimens long ago by Thuret.
(Paignton, Aug., 1894.)

Microcladia glandulosa Grev. is one of our rarest species, and
even when found is too frequently barren. After a gale a con-
siderable number of specimens were thrown up and amongst
them some bearing male organs. These, without the micro-
scope, are not distinguishable from quite barren specimens.
Owing to the density of the thallus they are easily overlooked
even with it. They form irregular patches on the uppermost
portions of the frond, and are usually more developed on the
inner edges of the dichotomous frond, where they project a little
(Fig. 14). They are in character very similar to those of
Ceramium, as might have been anticipated from the relations of
the two genera. The "pile" is, of course, seen better in a
transverse section of a division of the frond (Fig. 15). Where
such a section falls near the irregular boundary of a patch it
may be seen that a cell of the cortex buds into smaller ones
which emit the long cells (about 20 //,) which produce pollinoids
about 3 fi in diam. There is no general gelatinous investment
of the bodies, but these are free (Fig. 16). (Paignton, Aug.,
1894.)

The early stages of the female organs will afford much interest
to the student, and in some cases may tax his skill in dissec-
tion. Only the most cursory notes on some observed since the
previous paper (loc. cit.) can be given here. When the pro-
carps with trichogynes are observed the succeeding stages
should be sought out and the development followed to the
mature cystocarps. In most of the instances here given the

T. H. BUFFHAM ON SOME FLORIDE^. 187

pollinoids attached to the trichogyne in the act of fecundation
were noted.

Ptilothamnion Pluma Thur. The development of the female
organs is fully described by Bornet in Notes Algol., p. 179,
Plate XL VI.

Griffithsia 'setacea Ag. The trichogyne is very slender and
delicate.

Halurus equisetifolius Kiitz. (Griffithsia equisetifolia Ag.). It
is of a similar character in this species.

Callitliamnion friiticulosum J. Ag. (Not in Phyc. Brit.)

Compsothamnion gracillimum Schmitz. A figure of this is
given by Schmitz as Callithamnion gracillimum (Untersuch
ilber die Befruchtung der Floridece). The trichogyne is swollen
near the base. The fruit differs considerably from that of the
typical Callitliamnia.

Ptilota plumosa Ag. The trichogyne is stout, but not very
long.

Bumontia filiformis Grev. The trichogyne is long, stout,
brown, and conspicuous. It arises from cells very little below
the cortex. Naccarria Wiggii Endl.

1 will conclude with a few notes including some observations
of the association of two kinds of organs.

Gonimophyllum Buffhami Batt. I have a specimen where a
male leaflet is growing laterally out of the pericarp of a nearly
mature cystocarp. In another case there arise from the same
basal cushion one leaflet covered with procarps, and three
tetrasporic leaflets. When this curious parasitic alga was first
published {Journal of Botany, 1892, March, Plate CCCXIX) it
had not been observed on female specimens of Nitophyllum
laceratum, and only from Deal. Since then I have seen it on
cystocarpic specimens of that host, and also on the plant called
N. rejptans Crn./and have taken it myself at Torquay (Aug.
1894)

With regard to N. reptans, described and figured by the
brothers Crouan (Florule du Finistere, p. 152, Plate XXI.), and
distinguished by its prostrate habit and its adhering to the
substratum by numerous root-like processes from its inferior face,
I received from Mr. J. T. Neeve, of Deal (October, 1891), some
specimens of N. laceratum Grev. in situ. It would appear that
usually this species is torn from the substratum and thrown up

188 T. H. BUFFHAM ON SOME FLORIDEM.

by the waves. This circumstance may have led to some
uncertainty as to the base of the plant. Harvey says : "Root a
small disc, often throwing out creeping fibres." In the speci-
mens just named several of them were unmistakably N. reptans
below, and N. laceratum above. No one but Crouan seems to
have observed reproductive organs on N. reptans, but his figures
appear to enormously exaggerate the size of a cystocarp, and
only one is shown on each specimen. In some cases, unless a
previous acquaintance with the parasite has been made, Goni-
mophyllum Buffhami might be taken as a proper product of the
Nitophyllum. Mdlle. N. Karsakoff has kindly sent me speci-
mens of G. Buffhami collected at Roscoff, Finistere, and
possibly the cystocarp drawn by Crouan was that of the parasite,
but that would not explain the unprecedented size given in the
figures. It might, however, account for the isolated body. Be
that as it may, I am led to the conclusion that N. reptans is not
of specific value, and further that it is not even a variety, but
only the early stage of N. laceratum. Probably the reptans
portion is less developed on a narrow substratum where it can
more readily become free of contact. Reinsch founded a new
genus — Rhizophyllum — on what appear to be only very young
specimens of this early stage of N. laceratum (Gontributiones ad
Algologiam etc., p. 53). I have compared the dimensions he
gives of the cells of his two species — Rh. enervium and Rh.
nervosum {Op. cit., pp. 53, 54, Rhodophycea?, Tab. 38 and 39),
and find both agree sufficiently with those of the so-called N.
reptans. The absence or presence of "nerves" is not constant
in all the lobes, and Rh. enervium is almost certainly "N
reptans" and if Rh. nervosum be not also the same it is, in my
opinion, only a similar stage of some other species of Nitophyllum.

Spermothamnion hermaphroditum Nag. was referred to (p.
298) in the paper mentioned at the commencement of these
Notes. I may add here another association of organs, namely,
that of antheridia with tetraspores. The male organs are, like
the usual specimens, terminal on a unicellular pedicel, and
placed near tetraspores. (Swanage, June, 1892).

In Compsothamnion gracillimum Schmitz (Callithamnion gracil-
limum Ag.) Harvey shows the tetraspores of the usual tripar-
tite character. In a recent gathering comprising a number of
specimens I observed in all those that would be called tetra-

T. H. BUFFHAM ON SOME FLORIDE^. 189

sporic the sporangia which approached maturity contained
more than four spores. After immersion in either glycerine,
or a saturated solution of sodium chloride, the appearance is
like that of Fig. 17 6, where five or six spores are readily seen
with a confused centre of the group. This central part appears
to be the end of one or two other spores. The nearly mature
sporangia are ellipsoidal, about 65 //. long and 55 \x thick. Even
when much smaller the divisions can generally be traced (Fig.
17a), but frequently the earlier stages assume the normal pre-
sentation of a tetrasporangium of the typical tripartite character.
A scrutiny of the larger of these will, however, generally show a
trace of the further division of each quarter visible, so that I
am led to doubt the existence of true tetraspores in this species,
and to regard the sporangia as octosporangia, and the production
of eight spores as normal. (Torpoint, September, 1895).

In Ptilota plumosa Ag. some tetraspores have been seen on
the same plant with procarps ; and the involucre of an old
cystocarp (or possibly of an unfecun dated procarp) became
branched near the tips, and developed tetrasporangia.

Explanation of Plate X.

Fig. 1. Chondrus crispus Stackh. Portion of plant with

antheridia, natural size.
„ 2. Ditto. Transverse section of unchanged portion of

thallus x 400.
,, 3. Ditto. Vertical section of antheridial layer x 400.
„ 4. Gigartina mamillosa J. Ag. Three branches bearing

antheridia, natural size.
,. 5. Ditto. Surface view of circular antheridial spot

x 50.
„ 6. Ditto. Antheridia seen near the edge of thallus

x 200.
,, 7. Ditto. Surface view of tangential section of anthe-
ridial layer x 400.
„ 8. Ditto. Vertical section of antheridial layer x 400.
,, 9. Ghylocladia ovalis Hook. Antheridial patches on

branchlet x 20.
„ 10. Ditto. Surface view of portion x 50.
„ 11. Ditto. Vertical section x 400.

190

T. H. BUFFHAM ON SOME FLORIOE.S.

Fig. 12. Compsothamnion gracillimum Schmitz. Branchlet

bearing antheridia x 50.
„ 13. Ditto. Antheridium x 400.'
,, 14. Microcladia glandulosa Grey. Portion of male plant

X 20.
„ 15. Ditto. Transverse section of thallus showing two

portions of antheridial layer x 100.
„ 16. Ditto. Portion of same x 400.
,, 17. Compsothamnion gracillimum Schmitz. a. Young

Octosporangium. b. Mature ditto. Both X 200.

191

PRESIDENT'S ADDRESS.

«

By Edward Milles Nelson, F.R.M.S.

(Delivered February 2lst, 1896.)

Gentlemen, — In our customary review of the work of the
past year, before my data had been collected, I thought that
the list of those things which concern my own particular
branch of microscopical work would be small, but when it was
completed it was seen that that opinion could not be maintained.
Although the work of the past year may be said to be up to an
average, yet neither in amount nor novelty can it be compared
with the previous year, which might justly be called phe-
nomenal.

To begin with, we have a second valuable paper by Mr.
Rousselet, " On the Preservation of Rotatoria ; " also a note
by the same author, " On a Spirit Proof Cement for Micro-
scopical Purposes," a glue which many of us have long
searched for in vain.

The improvements in the mechanical part of the microscope
are the addition of the Powell- Tyrrell mechanical stage to
Baker, Watson, and Zeiss microscopes.* With regard to stage
movements it is by no means certain that the best form has
been devised yet, and we may look for further improvements in
the near future.

A great deal of attention has been given to this portion of
the microscope during the past two years. It will probably be
conceded that the Powell-Tyrrell stage is the best that has
been designed for first-class stands, which are intended more
for the critical examination of a specimen than for rough
work, and it would seem that for all such critical work sliding
plates are necessary ; bat for smaller microscopes, on which
more rough and ready work and the preliminary examination of
objects is accomplished, it would appear that the better plan is

* "Journ. R.M.S.," 1895, pp. 98, 688. The Tyrrell stage was used on
Engiscopes in 1837.

192 PRESIDENT S ADDRESS.

to push the slide about on the fixed stage, much in the same
way as is done by the fingers. It must be remembered that
serial section cutting has made great strides during the past
few years, and as farther progress in this direction is to be
expected in the future, the advanced student's microscope must
be supplied with a good mechanical stage, giving a range of at
least 2 inches transverse, and 1^ inch of vertical movement, if
it is to keep pace with the times. Messrs. Zeiss have given atten-
tion to this subject and have fitted their large microscope with
a mechanical stage * possessing the above range of movement.
It has, however, that which seems an objection, viz., the
pinion for the transverse movement is placed nearly vertically
on the stage, somewhat after the method employed by Tolles,t
and which, it must be feared, proved a failure. The same firm
have also introduced an improved Mayall stage which is of
much practical merit.

In substages we have a cheap centring one by Watson. X As
this can be fitted at small cost to the most elementary micro-
scope it will supply a much needed want.

We have a new portable microscope by Swift on the lines of
their new four-legged microscope, exhibited last year,§ only
further portability is secured by folding up the stage and the
front legs. The one Messrs. Swift and Son have made for
me has my horse-shoe stage, no less than 5 inches wide by 4^
deep, the body being capable of extension from 4J- to 12|
inches, yet this packs in a case only 6 inches wide, 5 \ deep, and
8 high. The weight of the instrument, with mechanical stage,
all brass, is 7Jlbs.

A pretty little microscope, || VIa, of the Hartnack type, is
made by Messrs. Zeiss ; it is supplied with a chromatic con-
denser and iris diaphragm. This stand seems to be the limit to
which those built on the Hartnack plan should be carried. It-
is difficult to understand the advantage that arises from over-
loading a microscope built on defective lines with all kinds of
elaborate and expensive movements which can never yield the

* Tom. cit., p. 99, 3 figs.

f " Journ. B.M.S.," 1881, p. 117, 2 figs.

X This Journal, 1895, p. 151, 1 fig.

§ " Journ. R.M.S.," 1894, p. 506, fig. 33.

|| "Journ. R.M.S.," 1895, p. 224, fig. 26.

PRESIDENT S ADDRESS.

193

highest results ; but when this model is confined to small, un-
pretentious, well-built instruments, such as VIa, it serves the
purpose very well indeed.

Messrs. Beck and Co. have brought out a penological star
microscope,* as well as one of a more advanced type, and
Messrs. Swift and Son have improved their Dick microscope.f

The Zeiss erecting prisms, which are used in the new
binoculars, have been applied to a dissecting microscope, J
which has also been made binocular after the plan of Cherubin
d'Orleans, viz., by using two objectives.

There is an object-finder § by Herr R. Feuss, which is
somewhat similar to that of Bridgman,|| and is for the purpose
of scratching a small circle with a diamond point round any
desired object. That of Bridgman fits on the objective itself,
and must therefore be concentric to it ; but this new device is
a separate piece of apparatus, placed on the nose-piece when
the objective is removed, and not necessarily concentric.

In the optical department we have an apochromatic 1-| inch
objective by Powell, and a semi-apochromatic of the same
power by Zeiss, their optical indices being 27 and 31
respectively.

Mr. J. W. Gifford has produced a beautiful F line screen,
which far surpasses all previous attempts in this direction. It
passes plenty of light, and while it does not interfere with
vision, so far as the eye is concerned, it nevertheless sharpens
up even apochromatic objectives, and brings the cheap semi-
apochromats almost to the same degree of efficiency as apochro-
mats. Finally, it slightly increases the resolving power by
shortening the wave length, that is by filtering out the visually
more luminous longer waves. I cannot too strongly urge mem-
bers to supply themselves with so cheap and efficient piece of
apparatus.

Two articles have appeared in the " Journal R.M.S." on
" Brownian Movement."^ Will not some member take up and

* Tom. cit., p. 226, 3 figs.

f Id., p. 96, fig. 6.

t Id., p. 5S0, 3 figs.

§ " Journ. R.M.S.," 1895, p. 587, 2 figs.

|| " Quart. Journ. Mic. Sci.," 1855, Vol. iii., p. 237.

IF "Journ. E.M.S./' 1895, pp. Ill, 591.

Journ. Q. M. C, Series II., No. 38. 14

194 president's address.

experiment on this still dimly understood phenomenon ? The
last in the list is the most bizarre piece of apparatus that has
appeared in the microscopical world for many years. Of course,
in the annals of a patent office, any number of the most mad
and impossible inventions may be seen, but it is almost in-
credible that such a device as that of Heir A. van Delden
should appear seriously in an}' scientific journal. Strange as it
may seem, it has nevertheless been published in Germany, and
is extracted without comment and inserted with three figures in
the "Journal R.M.S."* The title of the article is " An Auxiliary
Apparatus for the Adjustment with Immersion Objectives."
The appliance, in spite of its high-flown title, is of the nature
of a safety stop to prevent the owner of the instrument either
crashing through the slip or driving his front lens through a
back combination while focussing an oil immersion objective.
The following is a description of the manner in which this is
effected : —A block is fastened to the body of the microscope
above and in a line with the top of the limb. A 50-thread
micrometer screw passes through this block in a vertical direc-
tion. The head of the screw is divided, and alongside there is
a graduated post, on which can be read whole revolutions of the
screw head. When the body is racked clown by the coarse
adjustment this micrometer screw comes in contact with the
top of the limb and prevents the body being racked down any
further. If it is required to lower the body still more the
micrometer screw must be raised by unscrewing it, when of
course the body can be racked down until the screw is again
brought into contact with the top of the limb. Before the
apparatus can be employed it is necessary to find the co-efficient
of the instrument; this is arrived at in the following manner.
A particular low-angled dry objective is placed on the nose-
piece, and an object on the stage is brought into focus. The
micrometer screw is now lowered until its point butts against the
top of the limb, the number of revolutions and parts of a revolu-
tion of the micrometer screw are read off on the post and screw
head respectively and noted, after which the fine adjustment of
the microscope must not be touched. The dry objective is then
removed and the oil immersion put in its place ; this is now

* Tom. cit., p. 585, three figs.

president's address. 195

brought into focus on the same object, and the micrometer
screw is again made to butt on the top of the limb, its position
read off on the scales and noted as before. The co-efficient of
the instrument is the difference between these two readings, in
other words it is a micrometrical measurement of the difference
in position of the body with respect to the limb when a low-
angled dry and a wide-angled oil immersion objectives are
focussed on the same object by means of the coarse adjustment
only. For instance, let us suppose that the first reading was
27 - 38 and the second 39'24, the difference is 11*86, the required
co-efficient. The method of using the instrument is as follows :
— Suppose we wish to examine an object with an oil immersion
objective, the object is first focussed by the special low-angled
lens mentioned above, and when that has been precisely arrived
at the micrometer screw is turned until it butts against the
top of the limb, the scales are then read, the co-efficient ob-
tained above is then added to this reading, the micrometer
screw is now turned until it registers the sum of these read-
ings. The low-angled objective is then taken off, the oil
immersion objective placed on the nose-piece, and the body
racked down by the coarse adjustment until the micrometer
screw butts against the limb. The oil immersion objective will
now be in focus, provided that all the various steps have been
accurately performed ; the consequences would, however, be
disastrous if one made a slip in addition or an error in the read-
ing of one of the scales. Can anything be more ridiculous than
this setting and reading of a micrometer screw, the application
of a co-efficient, and the resetting of the micrometer screw
merely for the purpose of focussing an oil immersion objective,
an operation which a tyro in microscopy of a fortnight's stand-
ing could accomplish in a fourth of the time required for a single
reading of the micrometer. All this throws a flood of light —
first, on the state of microscopy on the Continent, and, secondly,
on the inefficiency of the continental stage, with its small hole
and spring clips.

Before proceeding to the other part of the address two further
points may be considered. The first is, " How would you define
the size of a microscope ? " Obviously it is not its power,
neither the length or diameter of the body ; nor is it its weight
or the size of its stage. What then is it ? Practically the size

196

PRESIDENT S ADDRESS.

of a microscope depends on two things — first, the distance of
the optic axis from the limb ; and, secondly, its distance from
the table when the microscope is placed in a horizontal position.
Although a simple it is an important and suggestive question,
which has not received much attention hitherto.

The second point has reference to the conversion of metric
into English linear measures, and vice versa.

The best determination of the length of the metre by Colonel
Clarke in 1866 made it equal to 39-37043196 inches, but as
few people can remember a numerical co-efficient for reduction,
a well-known rough and ready substitute, sufficiently near
for practical purposes, and with a memory catch in it, is used in-
stead of the correct figure. It is as follows : One metre is
equal to three feet, three inches, and one-third. If you work
this out you will find that it is too short by five feet in a mile.
Now could not a much nearer equivalent be found which, like
the precpding, possesses some sort of memory catch ? After a
little search I succeeded in finding one that will probably meet
most requirements. The number to be remembered is six and
a half inches. This should not be difficult to a microscopist,
because it is the length of the continental tube. Now all that
is necessary to convert this into metrical measure is to write a
one in front and a one behind it. Therefore 65 will become
1651, that is six and a half inches is equal to one hundred and
sixty-five decimal one millemetres. The error in this co-
efficient is only five and a half inches in ten miles ; it is, there-
fore, about 110 times more accurate than the other memory
co-efficient.

All microscopists who have to reduce metrical measures, or
convert English measures, or to work with micrometers, should
most certainly invest in a slide rule. With a slide rule any
reduction becomes supremely easy ; all that is required in the
present case is to set 1651 on the slide in a line with 65 on the
rule ; when that is done any conversion of metric into English,
or English into metric measure, is performed by inspection
without any further movement of the slide. For example,
when the slide is so set 3 on the slide will be in a line with 118
on the rule, therefore 3 mm, equals "118 inch, or 30 mm. 118
inch; again, 315 on the rule is in a line with 8 on the slide,
therefore 3*15 inch is equal to 80 mm., or '315 to 8 mm., and

president's address. 197

so on. In brief, when the slide is once set everything on the
slide is metrical, and everything on the rule is inches.

The subject chosen for this evening is on the construction of
lenses. I will endeavour to make it as interesting as the nature
of the case will permit, and will leave out all mathematical
formulas.

We will first touch on spherical aberration in lenses, and in
particular in that known as Herschel's doublet. There can be
no reason or need for a chromatic doublet made of one kind of
glass for visual purposes when an achromatic aplanat might be
constructed for the same cost ; nevertheless, for illuminating
purposes the subject is of much importance. This doublet
appears in the "Ency. Metrop. " in that classical article on
"Light " by Sir John Herschel, who was a Senior Wrangler.
Coddington, also a Senior Wrangler, quotes it in his excellent
treatise on " Optics," where he gives the radii but not the foci.
Sir D. Brewster gives it in the " Ency. Brit.," 7th ed., and
interpolates an error in one of the radii. Parkinson, a fellow
and tutor of St. John's, quotes it in his " Optics." That it has
attracted so much attention is therefore not to be wondered at.
I have worked out the aberrations of both Herschel's doublets,
and find that neither of them is free from aberration ; the

aberration of the high power is — "296 — and the other has

F
just a trifle more. The focus of the high power combination is
also wrong,* and this mistake is copied both by Brewster and
Parkinson.

There is no doubt that the aplanatism of this doublet cannot
any longer be maintained. It is very easy to generalise on this
subject and say that as both the lenses of which the doublet is
composed are converging ones, therefore they both must have
the same kind of aberration ; the case, however, is not so simple.
For example, let us suppose that a pencil is converging directly
on the plane surface of a block of glass (refractive index
//, = 1 '5) to a point on the axis inside the glass and one inch
from that surface ; on entering the glass these rays will be

* This is, of course, a very serious error, for any optician constructing a
lens of any given focus from this formula would use this erroneous focus as
a divisor ; the result would be that all his radii would be wrong.

198 president's address.

refracted to another point on the axis /x times further into the
glass, viz., one-and-a-half inches from the surface; this second
point is called the geometrical focus. This geometrical focus is
only true for rays very close to the axis ; rays that are more
distant from the axis are aberrated. In this respect refraction
differs from reflection, because there is no aberration in a ray
reflected at a plane surface. The effect of aberration is to send
the ray further into the glass than the position of the geome-
trical focus. If the point where any particular ray strikes the
plane surface of the glass is distant y from the axis then the
aberration of that ray will be T \ y 2 ; therefore, if y in our
example is one inch, then that ray will be refracted to a point
T 5 ^ inch further into the glass than the geometrical focus, viz..
T9167 inch from the surface.

This kind of aberration is called positive. Sometimes rays
are brought to a focus less distant from the surface than the
geometrical focus, in which case the aberration is known as
negative.*

Now let us suppose that instead of a plane surface we have a
convex spherical surface of very long radius, the radius being
so great that the surface is almost plane, we can see then that
the aberration will be similar both in direction and nearly in
amount to what it was before, but it will now be called spherical
aberration. Next let us make the curve more convex by
shortening the radius until the radius is equal to the focus of
the incident light, viz., one inch. The incident light now falls
on the glass normally or perpendicular to the surface ; there is
therefore neither refraction nor aberration ; the rays pass
through the glass and meet the axis aplanatically at the centre
of curvature. So we see that the rays which were refracted
nearly two inches into the glass block get nearer and nearer to
the surface as the curvature is deepened until they arrive at the
centre of curvature, which is also the point to which the in-
cident light converges ; at the same time the aberration, which

Some writers, however, reverse these terms. In hardly any other science

does such a difference of nomenclature exist. In some works Hie focus of a
converging, or common biconvex, lens, will be called negative. The utmost
confusion prevails with regard to the signs attached to conjugate foci and
radii of lenses. Changes are sometimes made in the nomenclature of the
signs in the same book without any intimation in the text !

president's address. 199

was 4- "4167 y 2 , gets gradually smaller until it vanishes. If we
further deepen the curvature the focus of the refracted rays
gets nearer the surface than that of the incident rays. But
what about the aberration? you will naturally ask. As the
calculation for the aberration at a spherical surface depends on
the solution of an equation of the third degree, the subject can
hardly be put in a popular form ; all that can be said is that
if you solve this cubic equation for our own particular example
you will find that the aberration is still positive, and that it
increases slowly until the radius is *526 inch, when it arrives at
a maximum of + 0213 y 2 ; it then rapidly declines until it
vanishes for the second time. You w r ill notice that the aberra-
tion at this second maximum is only a twentieth of that at a
plane surface.

We now come to a very important point, viz., when the
spherical surface has two aplanatic foci. You will remember
that at our former aplanatic point both the foci coalesced at the
centre of curvature ; in this instance, however, they are
separated. When the radius is equal to the focus of the in-
cident light, divided by the refractive index plus one, then
those incident rays will be aplanatically refracted to another
point, whose focus w r ill be equal to the same distance (i.e., the
focus of the incident rays), divided by the refractive index.

In simple words, in order to find the radius, we must divide
the focus of the incident rays by the refractive index plus one ;
and to find the focus of the refracted rays, we must divide the
focus of the incident rays by the refractive index. Therefore,
in our example, the radius is one divided by two-and-a-half and
equals -| inch, and the focus of the refracted rays is one divided
by one-and-a-half and equals § inch.

The reason why this rule is so important in microscopy is
because it is the basis for the construction of homogeneous
immersion objectives.* The immersion front is made of such
a radius that it will refract the rays proceeding from the
object aplanatically to some other and longer focus, this longer
focus being the focal point of the second lens. The radius is
found, therefore, by dividing the distance from the apex of the
front lens to the object by (//, -f 1), and the longer focus by
dividing the same distance by /x.

* " Jouni. E.M.S.," 1878, p. U2, fig. 2.

200 president's address.

Important as this may be, it is nevertheless a digression, so
we must return to the example before ns. We found that
when the focus of the converging incident rays was an inch, and
the radius of the convex surface four-tenths of an inch, that
the aplanatic focus of the refracted rays was two- thirds of an
inch.

Now, if we further increase the convexity of the surface, we
shall find that the refracted rays are still brought nearer to the
surface, but the aberration will now be no longer positive, but
negative, and will increase rapidly; that is to say, the spherical
aberration will bring the refracted rays nearer to the surface
than the geometrical focus. Thus, with a radius of two-tenths,
it amounts to no less than — '544 y 2 , a quantity greater than
any we have yet had. As it is so important, let me sum up
the results concisely. Let us call the focus of the incident rays

P

P, then if the radius is less than , the aberration is

ju + 1

P

negative and considerable. If the radius is equal to ,

/*+ 1
there is no aberration, but there are two aplanatic foci. If the
P

radius is greater than , the aberration is positive : there is,

^ + 1
however, one exception to this last rule, viz., when the radius
is equal to P, then there is no aberration. Finally, in our
example, where P = 1, the positive aberration never exceeds
+ -4167 f.

The next step is this. Having obtained positive aberration in
a block of glass with a convex surface, how is it to be preserved
when the block of glass is made into a lens ? All that is neces-
sary is to make the back curve of the lens a radius measured
from the focal point of the refracted rays ; the rays will then
pass out of the glass normally to the surface, so there will be
neither refraction nor aberration.

We see, therefore, that a meniscus constructed on this plan
cannot have more positive aberration than '4167 y 2 , and, more-
over, the lens will be a diverging meniscus, because the convex
front surface will have a much flatter curve than that of the
concave back. We must now consider the first lens of the
doublet upon which the parallel rays impinge. The best form

president's address. 201

for this lens is that known as a crossed lens, and for the kind
of glass we are using the radii will be in the proportion of 1 : 6
for minimum aberration. The lens must be of one inch focus,
so that the rays may converge on the second lens to a focus one
inch from the surface ; the lenses are assumed to be in contact.
If we now calculate the spherical aberration of this crossed
lens, we shall find that it is — T0714 y 2 , but we have seen
above that the utmost amount of positive aberration from one
spherical surface that we can bring to oppose this is something
less than + '4167 y 2 , a quantity insufficient to balance even
half the negative aberration of the crossed lens, therefore a
doublet of no aberration cannot be constructed on this plan.

Being baffled in our attempt to neutralise the negative
aberration of the crossed lens by the positive aberration of a
single surface, let us examine the conditions we shall obtain by
placing an aplanatic meniscus behind a crossed lens, so that the
longer focus of the meniscus shall be coincident with the focus of
the crossed lens. Applying the law we have just investigated,
and making the focus of the crossed lens unity, the front curve of
our meniscus will be, as we have seen, -§, and the back curve
will be the same as the conjugate focus we found for the
refracted rays, viz., f. The meniscus by itself will have a
focus of two inches, and as that of the crossed lens is one inch,
the focus of the combination will be f inch. It is usually more
convenient to transpose this into a combination of one inch
focus, then we shall have the focus of the crossed lens I and
that of the meniscus 3 inches.

Now, as the aberration of the second lens is 0, the aberration
of the combination is that of the first lens in terms of the focus
of the combination, thus the aberration of the first lens,

2 9

y y-

— 1 0714 — , becomes — 317 — , which is the aberration of the

/ F

doublet, a result a shade more than that of Herschel's.

You will probably by this time have had enough of the
aberration of a single spherical surface, but the problem is
important for two reasons : First, because it is the point on
which those rely who say that an aplanatic doublet can be com-
posed of two converging lenses ; secondly, the calculation is so
long that few attempt it.

The usual method of calculating the form of such a lens

202 president's address.

would be by an ordinary adfected quadratic equation, neither
very long nor troublesome. If anyone goes through this they
will find that when the second is a converging lens, i.e., has a
positive focus, the roots are imaginary. One should judge
from this that it is impossible to construct an aplanatic doublet
of this form ; if, however, the second lens is allowed to have a
negative focus, the roots become real and two forms of lenses
are possible.

In the first doublet the second lens is a biconcave, the
anterior curve being deeper than the posterior ; the other
doublet has a diverging meniscus for its second lens, with its
posterior curve deeper than its anterior; but both these
doublets have such steep curves that they are practically
useless. We now come to the last case, viz., that when the
equation has no real root it can be solved for a minimum value.
This is a very simple matter ; the curves of a doublet so calcu-
lated are given in the appendix.

Having constructed our lens, we can compute the amount of

y 2

its aberration, and it will be found to be — *214 — or 27 per

F
cent, better than that of Herschel's. To sum up our work

1. We have seen that Herschel's doublet has an aberration

of — -296 —
F.

2. We have investigated aberration at a single spherical
surface, and have found that in our example it did not ex-
ceed + -4167 ?/.

3. We found that no lens thus constructed could neutralise
the negative aberration of a crossed lens for parallel rays.

4. We have investigated the construction of an aplanatic
front of a homogeneous immersion objective.

5. We have seen that an aplanatic meniscus, when combined
with a crossed lens, yields a result somewhat similar to that of
Herschel's doublet.

6. That the quadratic equation for aberration has no real
roots for a lens of positive focus with the given conditions.

7. That two doublets of no aberration may be constructed
when the second lenses have negative foci.

8. That when we are contented with a minimum of aberra-

president's address. 203

tion, a doublet may be very easily constructed with only

— '214 — of aberration, a result 27 per cent, better than

F.
anything hitherto realised in doublets of this form.

There can be no doubt that Sir John Herschel's doublets
have played an important part in the evolution of the micro-
scope, as evidenced by the references made to them in almost
all microscopical text-books since their introduction in 1821 up
to recent times, say, for example, " Ency. Brit.," 9th edition,
art. " Microscope," p. 260. Although these doublets are now
of no use for visual purposes, never having equalled the per-
formance of a Brewster's grooved sphere, they are, and will
probably continue to be, of service for Bull's eyes and condens-
ing lenses. The so-called Herschel's doublets in the market
are not made on Herschel's formula, nor, in fact, on any
formula at all, but are for the most part composed of any two
lenses chosen at haphazard, and consequently have far more
aberration than two pianos of proper foci. In the following
Appendix there is

1st. Sir John Herschel's doublet transposed to a combination
whose combined focus is 1*0.

2nd. A doublet of no aberration of the same focus. The
second lens of this doublet is a bi-concave. You will observe
the very small radius of the incident surface of the crossed
lens. The arrangement has no practical value.

3rd. My new doublet of the same focus. You will notice
that the deepest curve is the incident surface of the meniscus,
but it is not so deep as that of the corresponding curve in
Herschel's form.

4th. The curves of the best form of microscope Bull's eye,
made of Boro- Silicate crown. It has 62° of aperture, and only
a total aberration of — '103 ; its working distance is 1*5.

I understand that some other microscopist before me has
pointed out that Herschel's doublet was not free from aberra-
tion, but I am not aware if he proposed a better alternative
form.

The authorities who have upheld the aplanatism of this
doublet so long before the microscopical world, have done so
because they have merely inspected the equations and have not

204 president's address.

worked out a definite problem. By inspection you may see that
the aberration is positive, but it is only when you work out an
example that you find the smallness of the positive aberration
at a single surface by the cubic equation, and tbis is what they
have not done.

In conclusion, I must apologise for having, on this second
occasion, brought such a dry subject before you.*

Appendix.

Sir John Herschel's doublet (high power form), as given in
" Ency. Metrop.," art. " Light," p. 391, transposed to a com-
bination whose focus is -f 1*0. Refractive index 1*50
1st lens crossed r = + 1'644

s = — 9-866 / = + 2-819
2nd lens, meniscus r = + "579

s= + 2-291 /= + l-55

Aberration = — '296 —
F.

* The following information may be of service to those beginning to com-
pute the curves of lenses : —

1st. One of the greatest labour-saving machines is a good slide rule. An
ordinary 12-inch slide rule may be obtained for 10s. or 12s. These are
accurate to two places, and the third may be approximated. By far the
best slide rule is that of Prof. Puller. It has a logarithmic scale nearly 42
feet long ; its price is £3, and it is accurate to four places ; a fifth may be
approximated. A smaller one is made with a scale nearly 17 feet long ; its
price is £1. Both these are sold by Stanley. Turnstile, Lincoln's Inn
Fields, W.C.

2nd. Logarithm Tables. — An excellent five-place logarithm table by E.
Sang, published by Blackwood ; price is, I think, -Id. A seven-place
table, published by Chambers, price 2s. 6d. ; this is sufficient for all pur-
poses. A very fine table by Sang of numbers up to 200,000, to seven places,
published by Williams and Norgate, price £1 Is.

3rd. One of the most useful books for optical work is Barlow's tables,
published by Spon, price 4s. 6d. It contains squares, cubes, square roots,
cube roots, and reciprocals of all numbers up to 10,000.

A very fine but more elaborate reciprocal table is that of Oake's of all num-
bers from 1 to 100,000 to seven places. Published by Laytou, price £1 Is.

Of these the smaller Fuller slide rule, Chambers' and Barlow's tables are
sufficient for most practical purposes. For accurate work the larger
Fuller slide rule is best, and O. ike's reciprocal tables are very useful.

president's address. 205

Doublet of no aberration. Refractive index = 1*50
1st lens, crossed r = + 291

s = — 1750 /=+ -5
2nd lens, bi-concave r = — '683

s = + 1-865 /=— 1*0
Focus of the combination = + 1*0. Aberration = 0.

New doublet of minimum aberration. Refractive index
= 1-50

1st lens, crossed r = + 1'166

s = — 7-000 / = + 2-0
2nd lens, meniscus r = + '636

s = + 1-750 /= + 2-0
Focus of combination = +1-0

2/ 2

Aberration = — -214 —

F.

Best form of chromatic doublet for a microscope Bull's eye.
Boro-Silicate crown. Jena Catalogue O. 144. Refractive
index 1*51

1st lens, crossed r = + 2"359

s = — 15-078 diameter 2*1

2nd lens, meniscus r = + 1*280

s = + 3*434 diameter 1*8

Distance between lenses '05 ; equivalent focus 2*0 ; back
focus 1*55; total aberration — -103; clear aperture 2'0 ; angle
62°. Note the second Gauss point of the combination is close
to the posterior surface of the crossed lens.

This combination is eminently suitable for photomicrography
in those cases where a Bull's eye is necessary.

20

Use of Ordinary Binocular fob Dissecting.
By John Tatham, M.A., M.D.

{Read December 20, 1895.)

For many years past I have been trying to hit upon some
simple method of using the stereoscopic binocular instrument for
purposes of dissection, and of mounting slides for the microscope,
because I have repeatedly found that the use of the best simple
microscope for long periods does seriously impair the sensitive-
ness of the retina for observation with the compound instrument.

I have brought with me the stand which I now employ. It
is a very small binocular, on the Rousselet model, and is fitted
with a rack-work substage. Into this substage is fitted a brass
ring carrying a plate, or supplementary stage, of the form now
shown. This supplementary stage is made of exactly the same
width as the principal stage of the microscope, and the sliding
object carrier of the latter is made to slide easily over the supple-
mentary stage. The object of this arrangement will be shown
hereafter. When used for dissecting or mounting, the instru-
ment is placed in the vertical position, on a table only so high
as is necessary to allow of work in a sitting posture. A low
power, say an inch, two inch or three inch, is screwed into the
nose-piece. The objective is then racked down through the
aperture of the principal stage, and is focussed on the object
lying on the supplementary stage already described, a bulls-
eye condenser, of the aplanatic form suggested by Mr. Nelson,
being used in the case of opaque objects.

Two wedges, or inclined planes of wood, are arranged as
supports for the wrists, one on either side the microscope, or in
default of these a couple of thick books can be similarly used.

It only remains to be said that with the above simple arrange-
ment, which certainly is not an expensive one, any small
binocular can readily be converted into a dissecting microscope,
or a mounting instrument, or it can be used with a four-inch or
lower power, for the examination of animal or vegetable forms

J. TATHAM ON USE OF ORDINARY BINOCULAR FOR DISSECTING. 207

in sea water ; and thus, the mechanical adjustments of one's
larger and more delicate instrument are preserved from harm.
The advantages that may be claimed for this " adaptation,"
which by the way may possibly be as well known to some
others as to myself, are as follows : —

1. The use of the simple form of microscope, with all the
discomforts incidental thereto, is avoided, and the binocular is
available in place of the single tube.

2. The same "hack" microscope may be used, either for
ordinary high power work or for dissecting purposes, by simply
transferring the object and the sliding clip from the ordinary
to the supplementary stage.

3. An instrument of relatively small size, and consequently
with short rack work, may be used with long focus lenses,
which otherwise can only be used in connection with full-sized
stands.

4. An instrument such as the one I show this evening can
be used with very great comfort in the sitting posture, with the
arms and wrists resting on the inclining planes above described.
This would be impracticable with a full-sized stand racked up
so as to focus a three or four-inch power on an object lying on
the ordinary stage.

208

Note on an Optical Rule.
By Edward M. Nelson, F.R.M.S. .

(Bead December 20th, 1895.)

The rule is made of box, is 20 inches long and square in
section. On one face there is a scale of inches and tenths, and
on the opposite side centimetres and millimetres. On one of
the sides at right angles to these is a scale of dioptrics marked
D, and on the remaining side opposite to it is a new scale of
powers marked P. All the scales read from the same end and
are ruled on both edges of the rod. This is important, because
any two contiguous scales can be read and compared together ;
thus dioptrics can be converted into inches by the inspection of
one edge of the rod, and into centimetres by viewing the other,
and vice versa. On the opposite face of the rod the scale of
powers can be treated in a similar manner. The following are
some examples of the use of the rule : —

(1.) "When the focus of a lens is measured on the P side of
the rule, its magnifying power, when the eye is held at the back
principal focus, is indicated. By adding one to this figure the
power, when the eye is held close to the lens, is found ; but if
one be subtracted from it, the enlargement of an image on a
screen distant 10 inches from the lens is given. Example: A
lens measures four on the P side of the rule ; this will be its
magnifying power when the eye is held at the back principal
focus of the lens. Its power, when the eye is held close to the
lens, will therefore be five, and an image projected on a screen
distant 10 inches from the lens will be enlarged three times.

(2.) When the power of any lens is known, its focal length
can be determined by inspection, either in inches or mm.
Thus a lens of two-power has a focal length of five inches or
127 mm.

(3.) The focal length of a diverging lens can be easily found
by overpowering it with a converging lens and measuring the
power of the combination ; this power, less the power of the

E. M. NELSON ON AN OPTICAL RULE. 209

converging lens, is the power of the diverging lens. Its focal
length can then be determined in either inches or mm. by
inspection. Example : The power of a double concave, when
combined with a bi-convex, is 085, as measured on the P side
of the rale. The power of the bi-convex alone is 30 ; then
0*85, minus 30, equals minus 215. The focal length of the
double concave is therefore minus 4'65 inches or 118 mm., these
being the figures in a line with 2 15 on the rod.

(4.) The rule is very useful as a ready reckoner. Example
(a) : A lens of 8| inches focus is combined with one of 94 mm.
focus — required the power and focus of the combination in
inches and mm. ; 8| inches is in a line with 1*175 P, and 94
mm. in a line with 2*7 P. The power of the combination is,
therefore, 1175, plus 2 7, equals 3875 ; this is in a line with
2 58 inches and 653 mm., the foci required. Example (6) :
I have a lens 178 mm. focus — what must be the focal length
of the lens in inches that added to it will yield a power of
5? In a line with 178 mm. is 1425 P; then 5 minus
1*425 equals 3"575, the power of the lens required ; this is in a
line with 2*8 inches, which is its focal length.

Journ. Q. M. 0., Series II., No. 38- 15

210

THOMAS HUGHES BUFFHAM.
Born December, 1840; Died February, 1896.

Every member will, we are sure, learn with the utmost
regret of the loss the Club has sustained by the death of Mr.
T. H. Buff ham, A.L.S., which occurred on February 9th.

Born and educated at Long Sutton, Lincolnshire, in early
life he entered business in a small country town where he
remained until he became manager of the concern. During
this period he became greatly interested in Astronomy, and
possessing a good telescope he did some excellent work on
double and coloured stars, many of his observations being
recorded in the "Astronomical Notices " and other periodicals.
On removing to London his health began to fail, and he was
compelled to give up night work with the telescope and turned
his attention to the microscope, joining the Quekett Club in
1877. Starting, as most amateurs do, without any fixed plan
he simply employed the instrument in a general way until on a
visit to Teignmouth in 1881, when finding an alga with anthe-
ridia, not described in Harvey's work, he soon found how much
remained unknown in this department, and took up the study
of the marine alga? in earnest. Having received much help
from the Club in his early microscopical days he considered
that it had the first claim on anything he produced, and thus
the larger part of his work has appeared in the pages of this
Journal, some other papers being published in "Grevillea"
and the " Journal of Botany." Mr. Buffham was a man of
great intellectual capacity and wide reading, and when it is
considered how much he accomplished, in spite of the anxieties
involved in the management of a large business, joined to
persistent bad health following a most serious illness, this
affords the highest testimony to his unremitting energy,
perseverance and strength of will. His removal is a serious
loss to us all and will long be felt.

21]

As an appendix to the above, I have been permitted to subjoin
a few remarks upon the services rendered by our late regretted
colleague, Mr. T. H. Buffham, to algological science, in which
my chief purpose has been to make his labours in their entirety
better known. It was the reproductive organs of the Florideae
which mainly attracted the attention of our deceased friend.
In a large . number of these algoe the fecundating organs,
that is to say the antheridia or, as they are designated by
Schmitz, the spermatangia, were either unknown or imperfectly
described. Mr. Buffham had the repeated good fortune to
collect many species provided with the male apparatus, and his
descriptions of them are to be found in four memoirs published
in the Journal of this Club between the years 1884 and 1893.
(" Journ. Q.M.C.," Ser. II., Vol. i., p. 337-344, Plates X.-XII.
[1884] ; Vol. iii., p. 257-266, Plates XX.-XXII. [1888] ; Vol. iv.
p. 246-253, Plates XV.-XVI. T1891] ; Vol. v., p. 291-305, Plates
XIII. XIV. [1893].) Amongst the species in which Mr. Buff-
ham has represented the spermatangia may be mentioned the
following, arranged in the chronological order of the publica •
tions in which these organs are illustrated : — I. (1884). Galli-
thamnion tetricum, Gallith. byssoides, Spermothamnion Turneri,
Antitliamnion plumula, Griffithsia corallina, Ptilota elegans, Gera-
mium diaphanum, Geramium striatum ; II. (1888). PLelminthora
divaricate Callithamnion brachiatum, Geramium tenuissimum,
Spyridia filamentosa, Delesseria Hypoglossum, Gatenella Opuntia,
Lomentaria reflexa, Ghondriopsis tenuissima, Bhodomela subfusca,
Dasya coccinea, Bostrychia scorpioides ; III. (1890). Griffithsia
barbata, Lomentaria Tidlifornis, Chrondriopsis dasyphylla, Plo-
camium coccineum, Phyllophora membranifolia ; IV. (1893).
Ghoreocolax polysiphonio3, Rarveyella mirabilis, Phyllophora
rubens, Cystoclonium purpurascens, Spha-'rococcus coronopifolius,
Gracilaria confervoides, Bhodymenia pahnata, Ehodym. palmetta,
Lomentaria articulata, Nitophyllum Gmelini, Delesseria alata,
Deless. ruscifolia, Hydrolapathum sanguineum, Bonnemaisonia
asparagoides, Odonthalia dentata, Ralarachnion ligulatum.

Besides the spermatangia of the species given above and
figured by him, Mr. Buffham has furnished us with a descrip-
tion of the male organs (in a certain number of species), in
which the morphological type corresponds with those of some
of the forms illustrated. He succeeds perfectly in making us

212

recognise the extreme utility which an intimate acquaintance
with the spermatangial form affords in facilitating the sys-
tematology of the red algae, and this according to a method
most nearly allied to nature. In another communication
(" Journ. Q.M.C.," Ser.II., Vol. v., p. 24 26, Plate III. [1892])
Mr. Buff ham described and figured a new species of Chantransia
epiphytic on Cladophora — Chantransia trifila, which , he says, must
be the smallest Floridean known, its height being only 27-30 /x.
In the same number of the Journal our learned friend, who had
already in 1885 studied the conjugation of Bhabdonema arcuatum
("Journ. Q.M.C.," Ser. II., Yol. ii., p. 131), described the
phenomena of reproduction in another marine diatom, Orthoneis
binotata, Grun., which, in its mode of multiplication, conforms to
Smith's first type, in which " we have two parent f rustles and
two sporangia (i.e., sporangial frustles) as the result of their
conjugation" (" Brit. Diat.," II., p. xii.). Whatever doubts may
still be entertained, in spito of the labours of Pfitzer, Petit,
Schmitz,* Castracane, Schuett, and others as to the physiology
of reproduction in the Diatomaceae, we are persuaded that
these contributions on the subject by our late frieL& are of
remarkable interest. Mr. Buffham has also given proofs
of his activity as a conscientious observer of the brown
sea-weeds. Here again it is to the reproductive organs
that he has for the most part directed his investigations,
giving us several notes on the plurilocular zoosporangia of
Asperococcus ballostis, Lamour, and of a plant which he attributed
to Myriotrichia clavoeformis, Harv. (" Jour, of Botany," Nov.,
1891, plate 314), but which Mr. Batters has recently found
advisable to distinguish from the genuine species of Harvey.
Our late colleague discovered a new species of Ectocarpus
(Algol. Notes, " Grevillea," March, 1893), which has now been
placed in the e^enus Giffordia, erected by Mr. Batters, as
Giffordia padince ; he has likewise given some details on the
plurilocular sporangia of Chorda filum. Amongst the Chloro-
phyceae he studied the conjugation of the zoogametes in Clado-
phora lanosa, Ktz., and the formation of the spermatia in
Prasiola stipitata, Suhr., a most interesting observation, which
has been brought into prominence by F. Schmitz (" Nuova

* Cf. G. B. De-Ton ; , " Alia meinoria di Federico Schmitz, Cenui bio-
grafici.'' " Nuova Notarisia," vi., 1895, p. 62-3-

213

Notarisia," v., 1894, p. 717). According to this latter author,
who has also been unexpectedly removed by death, the forma-
tion of these spermatia greatly resemble those of the genera
Bangia, Porphyra and Wildemannia, and appear to have a special
bearing on the definitive systematic position of the Bangiaceae.
This sketch of Mr. Buffham's career as an algologist, com-
pressed as needs must be into a few lines, gives us the impres-
sion of great originality. Apart from the works here enumerated,
the remembrance of our regretted colleague will survive by the
dedication to him of a new genus, Buffhamia, which Mr. Batters
has recently erected in honour of him whose loss we all
deplore.

Dr. G. B. De-Toni, Padua.

214

PROCEEDINGS.

October 18th, 1895. — Ordinary Meeting.

E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected

members of the Club:— Mr. Harold A. Baugh, Mr. William

L. Bros.

The following donations were announced : —

" Proceedings of the Manchester Microscopical Society."

"Proceedings of the Royal Society."

" Proceedings of the Belgian Microscopical Society."

' Proceedings of the Academy of Natural Sciences of Phila-
delphia."

" The Botanical Gazette."
The American Monthly Microscopical Journal."

' The Microscope."

' Proceedings of the Geologists' Asssociation."

" Proceedings of the Wagner Institute of Science."

' 'Studies in Artificial Cultures of Entomogenous Fungi."

' Manual of Histology," Scatterthwaite. "1

" Angiocarpous Lichens," Ray Society.

"British Coleoptera," Fowler.

" Microscopic Bacillaria," Ehrenberg.

An account of the diatomacese from [ From the President,
in and under the city of Mexico
(copy formerly belonging to Dr.
Bowerbank, and containing the auto-
graph of Ehrenberg)

"Molluscs and Brachiopoda," Cambridge Natural History
volume.

*' The Microscope, etc.," by Lewis Wright.

11 Natural History of Aquatic Insects," Prof. Miall.

215

The thanks of the meeting were voted to the donors, especially
to the President for his valuable contribution to the library.

Mr. Swift exhibited a folding microscope made entirely of
aluminium, the weight of which was about 21b. as against 5^1b.
for the same instrument in brass.

Mr. Goodwin inquired whether there was enough weight to
keep the microscope steady.

The President said that he had often remarked that to ensure
steadiness they must must have a proper sized base. In con-
tinental instruments they got the steadiness by having a solid
foot, and depended chiefly upon weight, but the one before
them had such an enormous spread of foot that without beino*
heavy it was absolutely steady.

Mr. Karop thought everyone would be pleased to see this
microscope, which he believed was only the second which had
been made entirely of aluminium. The difference in weight
would be appreciated by those who wanted an instrument
which they could carry about easily. He found that one of
the chief donations to the €lub that evening was one not
mentioned in the list which had been read, and that was a
further gift of 57 slides of Rotifers from Mr. Rousselet, bring-
ing up the number already presented to 117. As a type
series these slides would possess a unique value, and they
were very greatly indebted to Mr. Rousselet for his valuable
gift.

Mr. Karop exhibited on behalf of Mr. Curties a simple
method of attaching microscope objectives, by which when the
objective was placed in position a quarter turn sufficed to
tighten it, or loosen it as the case might be. He felt sure the
members would hear with very great regret that their friend
Mr. Curties was at that moment lying very seriously ill.

Mr. Ingpen said he had used this method for some time, and
found it extremely good ; it sometimes happened that the three
small projections did not at the moment catch the objective
but he had used a very similar contrivance designed by their
President, and had found this also to be most satisfactory.

The President said he also had tried it, and thought it a use-
ful nose-piece.

Mr. Richard Smith exhibited a microscojoe almost identical
with that already shown by Mr. Swift except that the lower

216

portion was made of gun metal to ensure greater stability,
whilst the upper part was of aluminium.

The President said it would be obvious that by making the
lower part of a heavier metal the centre of gravity would be
lowered and the steadiness consequently increased.

Mr. Goodwin exhibited a small microscope lamp, in which
the chimney and reservoir were of metal. The chimney had
two apertures, one closed by a coloured glass and the other by
a piece of plain glass, either of which could be used by turning
the lamp round. The weight of the lamp was only 3ozs., and
though so small it was quite powerful enough for ordinary use,
and held enough paraffin to burn about three hours. He found
that for the wick nothing answered better than a piece of folded
blotting-paper.

Mr. Karop inquired if the pieces of glass were turned into the
metal of the chimney ?

Mr. Goodwin said they were fitted into a small ring cap.

The President thought this was a charming little lamp ; he
suggested, however, that it would be improved by making the
glass-covered apertures long shaped instead of round, so that a
microscope could be worked direct without a mirror.

Mr. Ingpen thought the idea of using blotting-paper as a wick
was an extremely good one. He had tried several thicknesses
of tape with some success, but thought the blotting-paper likely
to answer better.

The President said there was a new lamp just coming out,
which was fitted with a carbon wick, one of the most extra-
ordinary things about which was that if it was held at an angle
of 45° it went out, so that under these conditions it was really a
self-extinguishing lamp. Whilst on the subject of lamps, he
might mention that the best he had ever met with was the Hitch,
cock mechanical lamp, which burnt without any chimney, the
draught being supplied by the rotation of a rapidly revolving
fan. It was supplied with a patent feeder, with which it could
be filled without any risk of pouring over or of soiling the
fingers, and the light it gave was most extraordinary; the wick
was less than lin. wide, and as compared with one of Hink's
duplex lamps the light was in the proportion of 14 to 18. It
would be a great thing if they could get a lamp on this principle
small enough for microscopical purposes.

217

Mr. R. T. Lewis said he had used these lamps for the last
twenty years. They were made in New York, and he did his
best to induce the maker to bring out one on a smaller scale,
which he hoped to be able to adapt not only to the microscope
but also as a miner's lamp. He had made designs for these
about fifteen years ago, but could not get Hitchcock to take
up the idea.

Mr. J. M. Offord said he had used one of these lamps for
about fifteen years, and it was still in good order ; for photo-
micrography it was a great success, certainly the best for the
purpose he had ever made use of.

Mr. Goodwin inquired if the Welsbach incandescent gas light
was of any use for this purpose.

The President said this was quite useless, since the image of
it in the microscope was not a solid flame, but simply a number
of red-hot lines. The incandescent electric lamp was also use-
less for the same reason, giving the image of the carbon fila-
ment.

The President gave an interesting account of some of the
phenomena attending the production of false images in the
microscope, and illustrated his remarks by drawings on the black-
board.

Mr. Ingpen inquired if the President had been able to get the
same effects with the Abbe diffraction plate ? He had been
able himself to double and triple these images, but had never
been able to halve them.

The President said he had never been able to halve them,
although he had of course doubled them.

Mr. Yezey read an extract from a Brisbane newspaper relating
to the bacteriological work carried on by their member, Mr.
Pound, at the Stock Institute of S. Australia.

The usual announcements were then made, and the proceed-
ings terminated.

October 18th, 1895.

Respiratory organs of Dero ... ... Mr. W. Burton.

Dissections of Linyphia .. ... ... Mr. H. Freeman.

Pedalion mirum (mounted) ... ... Mr. C. Rousselet.

218

November 1st, 1895.

Notommata collaris ... ... ... Mr. W. Burton.

Nemesia strumosa (seeds) ... ... Mr. G. E. Mainland.

Coscinodiscus elongus ... ... ... Mr. H. Morland.

Gephalosiphon limnias ... ... ... Mr. C. F. Rousselet.

November 15th, 1895.— Ordinary Meeting.
E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the previous meeting were read and confirmed.

The following gentlemen were balloted for and elected mem-
bers of the Club :— Mr. Alfred E. Hilton, Mr. J. Pillischer, Mr.
Alfred J. Robertson.

The following donations to the Club were announced : —

Six Slides From Mr. Hinton.

One Slide From Mr. Dounou.

"The American Monthly Microscopical")

Journal" t j In ™ ch ™% e -

" The Microscope "

" Proceedings of the Portland (Maine)'

Society of Natural History " ...
"The Botanical Gazette "...
Recent Freshwater Diatoms from Lule"
Lappmark, Sweden

The thanks of the Club were unanimously voted to the
donors.

Mr. Karop read a characteristic extract from the Echo on
the natural history of Bats, in which, amongst other items,
the vampire was referred to as a reptile having a stretch of
wing of 5ft., and presumably penetrating the veins of its
victim by the tip of its tongue.

Mr. Karop called attention to a Microtome by Reichert,
which was exhibited in the room. So far as he had been able
to examine it, he thought it seemed almost the same as Jung's,
except that it was plated and got up in a somewhat better
style. It was, no doubt, well adapted for cutting sections of
frozen substances, but, as far as his experience went, it would
not work well upon those which were imbedded in paraffin, for
which a direct, rather Hum a sloping cut, was necessary.

'} ■

' j- By Miss Cleve.

219

Mr. Buffham read a paper " On a New Sea Weed found in
Cornwall," Bonnemaisonia hamifera, Har., the subject being
well illustrated by drawings and lantern slides.

The President being obliged to leave the meeting, the chair
was taken by Mr. A. D. Michael, who expressed the hearty
thanks of the Club to Mr. Buffham for his very interesting
paper, furnished under difficult circumstances at short notice.
How it was that these plants and even animals did somehow
get across the seas and appear in places at great distances from
their native habitats, was a matter which had often puzzled
naturalists. As Mr. Buffham had suggested, it was quite
possible that the spores might be carried with other things
upon the bottoms of ships, and eventually get deposited in
places which were favourable to their development, and he
also thought it was very probable that they might sometimes
be brought upon the feet of wading migratory birds, which
often came from great distances. But whatever the cause
might be, there could be no doubt that plants did sometimes
turn up in a very remarkable manner at great distances from
their known habitats, an instance of which occurred to him in
the case of a spotted Arum, which was found growing in some
profusion on a small rocky island off the coast of Corsica, and
nowhere else nearer than South America.

The thanks of the meeting were unanimously voted to Mr.
Buffham for his paper.

Mr. J. E. Ingpen read a note " On the Scent Hairs of
Lepidoptera," illustrating the subject by drawings upon the
board and specimens exhibited.

Mr. Karop said he should like to know upon what grounds
these modified scales were regarded as scent-emitting organs.
It was certainly true that on emerging from the chrysalis some
few lepidoptera, sometimes the <?, sometimes the ?, were
known to emit an evanescent odour which was reasonably
supposed to attract the opposite sex. The phenomenon of
"assembling," well-known to all entomologists, showed that in
some cases at least there was an attractive influence which was
very powerful and appeared to act at considerable distance, but
were these hairs or scent patches found in every case where
" assembling " was known to occur ? Fritz Miiller, he believed,
was the first who drew attention to these hairs and indicated

220

their possible function, whilst Scudder had described some
glandular structures which might produce the scent, but there
did not seem much in either case which amounted to a proof.
A resume of the matter was given in a paper entitled
" Secondary Sexual Characters in Lepidoptera," by J. W.
Tutt, F.E.S. The subject was highly interesting and he
should like to hear more from any entomologist who might
have studied it.

Mr. Tngpen suggested that as the attractive scent seemed
only to last a short time, might it not be due to something
analogous to the pith found in the feathers of birds, which
after a time became dried up.

Mr. Karop said there could be no possible homology between
the structure of a bird's feather and that of an insect's scale.

The Chairman said the subject of insects' scales was a very
elaborate question and too wide for them to go into on that
occasion ; indeed, he thought it was one which had been so well
thrashed out that they would be likely to get very little to add
to what was already known.

Mr. J. D. Hardy described a form of Melicerta found in his
aquarium, the peculiarities of which he illustrated upon the
board. He would be glad to hear from any of the members
present if the species was new, as in that case he would try to
find some more of the same kind.

Mr. Rousselet had not seen anything similar to it, and should,
therefore, be very glad to have a specimen for examination.

Mr. Neville said it was a common thing for Melicerta to have
the lobes presented in the horizontal position described, and the
condition of the tube was often due to the surroundings. As
this specimen was found in an aquarium, it was possible that
the difference observed in the pellets might in some way be due
to a deficiency of ordinary material in the water.

Mr. Hardy said this was clearly not so in the present case, as
he had a quantity of Melicerta in the aquarium of the common
kind which were building their tubes quite in the ordinary way

The thanks of the Club were voted to Mr. Ingpen and to Mr
Hardy for their communications.

Announcement of meetings for the ensuing month were made
by the Secretary, and the proceedings terminated with the
usual conversazione.

221

November 15th, 1895.

Marine Algas —

Bonnemaisonia hamifera, with procarps
and abnormal cystocarps, from Fal-
mouth, and a specimen with normal j> Mr. T. H. Buffham,
cystocarps, from Japan

Califomica, with procarps and

cystocarps, from California...

Bracltionus bidens ... ... ... Mr. W. Burton.

Scaridium eudactylotum ... ... ... Mr. C. Rousselet.

Arrenurus globator ... ... ... Mr. CD. Soar.

December 6th, 1895.

Trachelitis ovum ...
Euchlanis lyra
Polysiphonia, from Cromer
Diatoms, Atlantic Ocean
Goscinodiscus oblongus
Microcodon clavus...
Nescea decorata
Euchlanis dilatata

Mr. J. M. Allen.
Mr. W. Burton.
Mr. W. Goodwin.
Mr. G. E. Mainland.
Mr. H. Morland.
Mr. C. F. Rousselet.
Mr. C. D. Soar.
Mr. W. R. Traviss.

December 20th, 1895. — Ordinary Meeting.
E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
members of the Club :— Mr. W. C. Fullicks, Mr. Walter J.
Wood.

The following donations were announced : —
" The Microscope "
"The American Monthly Microscopical")

Journal" ... ... ... ... )

" Le Diatomiste "

"Proceedings of the Belgian Micro-")

scopical Society "... ... ... )

Three Slides of Mounted Rotifiers ... [

From the Editor.

„ Society.

Mr. Bilfinger per
Mr. Rousselet.

The thanks of the Club were voted to the donors.

222

The Secretary said it would no doubt be remembered he had
announced at a previous meeting that two nieces of the late
Mr. J. Gr. Tatem had presented the Club with 1,000 slides of
insect preparations in memory of their uncle. These had now
been received, and the cabinet containing the slides was before
the members in the room that evening. He felt they were
greatly indebted to the Misses Harman for this very handsome
donation.

Mr. C. L. Curties said the slides were preparations of the
kind usually made by Mr. Tatem — entomological specimens
and dissections — selected from a total number of about 3,000.

On the motion of the President a hearty vote of thanks was
unanimously passed to the Misses Harman for their gift.

The President said there was at present no catalogue of these
slides, but if anyone would volunteer to make one it would be
rendering a very useful service.

Dr. Tatham exhibited a device for rendering the stereo-
scopic binocular microscope available for dissecting purposes,
the advantage of which would be at once obvious. A brass
ring with a plate formed a supplementary stage sufficiently
large for the purpose.

Mr. Rousselet inquired if the principal stage could be re-
moved so as to facilitate getting at the other.

Dr. Tatham said that this was hardly necessary as it could
be got at quite readily.

Mr. Michael said he had very considerable experience in
dissecting with the binocular, but the instrument before them
would, he feared, be practically useless to him, owing to the
fatal objection interposed by the principal stage which would
block out the light and interfere with the hands, and for dis-
secting purposes the stage provided was inconveniently small.
He entirely agreed with Dr. Tatham that a binocular must be
used if there was much work to be done, but it must of neces-
sity be used upright, and that meant a craning of the neck
which was soon felt to be irksome. All this was avoided by
using the Stephenson form, with which the head could be up-
right and the stage at the same time flat, but what was really
wanted was a means by which they could dissect under a ^in.
in the case of delicate dissections. It was of course a great
improvement to be able to use a binocular of this kind for dis-

223

secting purposes, because it so greatly relieved the strain upon
the eyes, and his own view was that if anyone wanted to do
practical dissection for serious work the Stephenson binocular
was the most convenient form. He must, however, express his
admiration at the ingenuity of this invention and of the way in
which it had been carried out.

Mr. Karop thought the great obstacle to using an ordinary
compound microscope for dissecting purposes was the inversion
of the object and the transposition of the hands, which required
considerable practice to overcome. The Stephenson form at
least did away with this.

The President said that he gathered that Dr. Tatham did
not put forward this device as an invention of a new dissecting
microscope, but he brought it there as a makeshift, and he
showed how an ordinary Rousselet portable travelling binocular
might be pressed into service for dissecting purposes. Dr.
Tatham's idea as far as he understood it was to supplement
and not in any way to supersede existing dissecting microscopes
which had been designed as such. For his own part he thought
the Stephenson binocular on the whole the best designed form
they could have for the purpose, because of its large stage and
the comfortable position in which it could be used, but on the
other hand he never saw a really good image with it, for this
there was nothing like the Wenham up to fin. or |in. There
were probably too many reflecting surfaces in the Stephenson
form to give the same quality of image as they got in the
Wenham. The main fault of the one before tbem seemed to be
the non-removability of the upper stage, but he did not see why
it should not be made removable.

Mr. Michael thought the greater objection was the reversal
of the image. Some people did not appear to notice this, but
to him the erect image was of the utmost importance.

Dr. Tatham said his object in bringing this design before
the members was to show them something which he thought
was likely to be of practical value. He did not pretend it to
be in any way a substitute for Stephenson's, which was amongst
other things very expensive. Personally he preferred the
Wenham because he had always found that the increased
number of surfaces had the effect of blurring the image, and
for this reason he had never been able to enjoy using the

224

Stephenson. What he had brought before them was a simple
adaptation to an ordinary microscope which only cost a few
shillings and therefore was within reach of all. The objection
taken by Mr. Michael would be of force if the stage was one
of the ordinary kind, but this was so small, and of the horse-
shoe form, so that any amount of light could get at the object.
He had found it a very great convenience as a special adap-
tation to an ordinary microscope.

Mr. Swift said he made a Stephenson binocular for the late
Mr. Tarn, which worked exceedingly well up to Jin. Mr.
Stephenson gave him the formula for two sets of prisms, one
for high and one for low powers.

The President moved a vote of thanks to Dr. Tatham for
bringing this matter before them. He was glad to hear that
the Stephenson form had been made with two sets of prisms,
as this would probably greatly improve its performance. His
own experience with it had been unfortunately not very satis-
factory ; he had seen a good many binoculars, but never one so
good as Wenham's.

Mr. Michael would not like to say that even in the finest
instruments the Wenham was not the best, but when the
Stephenson form was made as well as the Wenham, the result
was far from unsatisfactory. The highest definition was not
perhaps to be had with the Stephenson form, but for its
working properties it was beyond all comparison the most
desirable.

Mr. Nelson exhibited a Swift's portable microscope, and said
that he would not detain the meeting by going over the points
in this excellent design, which had been brought to their
notice on a former occasion. He would, therefore, confine his
remarks to what was novel in the instrument before them.
The stage has been increased to a size of 5in. in width and
4^in. in depth. This extra depth allows the use of a long
guide on the left hand side of the frictional mechanical stage.
The body being fitted with three draw-tubes gives a range
of adjustment of 8in., namely, from 4|in. to 12 J in. The
case is not much increased in size, being Gin. by 5|in. by 7|in.
The fine adjustment is on the Campbell differential plan. The
threads are cut to foreign gauges, on the metrical system, so
that a revolution of the head indicates some integral fraction

225

of a millemetre of movement. The mirrors are burnished
loosely in their settings, which allows them to be turned round
to get rid of the multiple images. The weight of the instru-
ment in its case is 9|lbs.

Mr. Ingpen said he did not often refer to anything which
Dr. Pigott did, but he certainly did achieve something in this
direction, for he had a tube cut down to 3in. and had some
sections of tube which fitted into it so that he got tube lengths
of 3in., 6in., 9in., 12in., and 15in. on a Powell stand. It would
be impossible to do this on many stands, but with a Powell it
was done quite easily.

The President said he had a short and a long body which he
could exchange as desired. He liked this telescopic arrange-
ment of the tube with two draws and had found it per-
fectly satisfactory. He then read a note on a new optical
rule which he had designed, and exhibited the same to
the meeting and explained the way in which it was used.

A vote of thanks to the President for his communication
was unanimously passed.

Mr. Goodwin inquired if the President would tell them what
parts were measured to ascertain the tube length.

The President, by means of a drawing on the black-board,
explained the difference between the mechanical and optical
tubo lengths.

Mr. Karop said they were to have had a lantern exhibition
of photomicrographs by Mr. T. C. White, but he was un-
fortunately too unwell to be with them that evening as pro-
mised.

Announcements of meetings for the ensuing month were then
made, special attention being called to the fact that at their
next ordinary meeting nominations to fill vacancies upon the
Committee would be asked for and an Auditor would have to
be elected.

December 20th, 1895,

Hydra viridis Mr. J. M. Allen.

Euohlams lyra Mr. W. Burton.

Journ. Q. M. C, Series II., No. 38. 16

226

January 3rd, 1896.

Asplanchna prodonta ... ... ... Mr. J. M. Allen.

Plumularia similis ... ... ... Mr. F. Bedford.

Perophora listen ... ... ... ... ,,

Palcemon (Zoaea) ... ... ... Mr. Gr. T. Harris.

Foraniinifera (type slides) ... ... Mr. A. J. Jenkins.

Pterotheca aculeifera ... ... ... Mr. H. Morland.

' £ }

January 17th, 1896. — Ordinary Meeting.
E. M. Nelson, Esq., F.R.M.S., President, in the chair.

The minutes of the preceding meeting were read and con-
firmed.

Mr. Robert Sillar was balloted for and duly elected a member
of the Club

The following additions to the library were anounced
" The Cambridge Natural History,'

Vol. v., Peripatas — Myriapods-

and Insects, Part I

" Proceedings of the Croydon Micro- )

scopical Society " ... ... f

''Annals of Natural History "... ... Purchased.

" The American Monthly Micro- 7

scopical Journal" ... ... j

The Secretary gave notice, on behalf of the Committee, that
at the ensuing Annual Meeting it would be proposed to make a
slight alteration in Rule VII., so far as regarded the last clause,
which at present reads as follows : — " That any member
omitting to pay his subscription six months after the same
shall have become due (two applications in writing having been
made by the Treasurer) shall cease to be a member of the
Club." It was found that as no distinct power was given to
remove the names from the list they often remained for a con-
siderable time, and when arrears were applied for the Treasurer
was told, " Oh, I did not know my name was still on the list as
I had not paid my subscription," although Journals had been
supplied as usual. It was therefore proposed to insert the
words "That the Committee shall have power to remove the
name of any member" omitting to pay his subscriptions, etc.

227

Mr. Hardy said it struck him that there might be some reason
occasionally why a member had not paid. He might be away
from home for instance, and it would be rather hard to have
his name struck off in that case.

The President said the Committee would be able to use their
discretion in such cases. What was desired was to give them
the power of removing names if necessary.

Mr. Goodwin thought it would be well to suspend a member
who had not paid up — without removing the name — so that he
might be reinstated afterwards if he sent in his subscription.

The President pointed out that the rules already provided for
the suspension of a member, but this was a notice of a proposed
alteration that was before the meeting at present, and members
were not in order in raising a discussion on the alteration of a
Rule which was not before the meeting ; they could, of course,
discuss it when it came before them at the Annual Meeting.

The Secretary said that as the Annual Meeting would be held
next month it would be necessary for the members to nominate
four gentlemen to fill vacancies on the Committee, and also to
elect one auditor.

The nominations made by the Committee were as follows : —
As President, Mr. J. Gr. Waller ; as Vice-Presidents, Messrs.
Nelson, Dallinger, Michael, and Newton; the other officers as
before ; and as Auditor on behalf of the Committee, Mr. Chap-
man.

The following nominations were then made for members of
Committee : —

Mr. J. E. Ingpen, proposed by Mr. T. C. White, seconded by
Mr. R. T. Lewis.

Mr. Hembrey, proposed by Mr. Dunning, seconded by Mr.
Powell.

Mr. Western, proposed by Mr. Allen, seconded by Mr.
Jacques.

Mr. Scourfield, proposed by Mr. Southon, seconded by Mr.
Tabor.

Mr. J. M. Allen was proposed by Mr. Burton, seconded by
Mr. Soar, and duly elected Auditor on behalf of the members.

Mr. Orfeur exhibited and described a combination substage,
which contained polariscope, selenites, iris diaphragm, tinted
glasses, etc., fitted in such a way that either could be used with-

228

out removing any portion from the stage, whilst the whole
fitting could be removed from the ring whenever this was
desired.

Mr. Karop inquired what was the weight of this combination
fitting. The object of it was, no doubt, a very useful one, to
avoid the trouble and time usually required in changing the
apparatus when fitted into the substage in the ordinary way ;
but he thought the difficulty here, as in some other cases, would
be to get the stops as near as was desirable to the lower com-
bination of the condenser.

Mr. Orfeur did not know what the weight of the whole fitting
was, but it was in its present form the outcome of several
attempts to carry out the dea he had in view. The weight
could possibly be reduced if it were found necessary.

The President thought it was certainly a great advantage to
have these things together, especially as regarded the stops,
because it would prevent them from being lost or from getting
left at home. They were greatly obliged to Mr. Orfeur for
bringing the new arrangement to the meeting and showing it to
the members.

The President exhibited another of his series of lenses, a
triple achromatic with great working distance, extremely sharp
in definition and flat in the field. It was made by Mr. Watson,
and was a cemented Steinheil triplet.

Mr. Karop said it was really a splendid lens, sharp up to the
very edge, and certainly one of the very best of the series.

A paper by Mr. Buff ham was, owing to the unavoidable
absence of the author, taken as read.

Mr. T. C. White exhibited on the screen a large number of
photo-micrographs, giving a short explanation of the methods
by which they had been taken, and pointing out anything of
special interest in each picture as they were somewhat rapidly
passed in review.

The President expressed the hearty thanks of the meeting to
Mr. White for bringing down these slides and showing them in
such a very beautiful and interesting way, the vote of thanks
being carried by acclamation.

The following objects, etc., were afterwards exhibited.
Phimatella repens ... ... ... ... Mr. W. Burton.

Limnesia fulgida (Koch)... ... ... Mr. C. D. Soar.

February 7th, 1896.
Euchlanis pyriformis
Stephanoceros Eichhornii...
Section of an eye of a Butterfly
Gorethra plwmicornis (pupa)
Biddulphia rhombus, var. trigona
Aulacodiscus orientalis

229

Mr. J. M. Allen.
Mr. W. Burton.
Mr. W. Goodwin.
Mr. G. E. Mainland.
Mr. H. Morland.
Mr. J. C. Webb.

February 21st, 1896. — Annual Meeting.
E. M. Nelson, Esq., F.R.M.S., President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following donations were announced : —
" La Nuova Notarisia " ... ... ... In exchange.

" Proceedings of the Belgian Microscopical")

Society" )

" Syllogie Algarum," a complete list of the ]

whole of the Fucacese up to the present > Dr. De Toni.
time ... ... ... ... J

Mr. Karop said he had with very great regret to announce the
death of one of their members, Mr. Buffham, which had occurred
since their last meeting. It would be remembered that Mr.
Buffham had been announced to read a paper, but that he was
unable to be present at the last meeting, and consequently his
communication was taken as read. There was no idea at the
time that he was so near his end. His loss would be greatly
felt, as he was recognised as one of the best workers they had
upon the subject of the red seaweeds.

The President said they were very sorry to hear of Mr. Buff-
ham's death. He had received the corrected proofs from him of
the paper taken as read at the last meeting only a day or two
before his death. He might also mention the death of Mr.
Marryat, of Salisbury, who was an extremely good worker with
the microscope, although not directly connected with any society.
He had a letter from him only a short time ago enclosing some
very beautiful photographs which he would hand round for in-
spection as the best memorial of the skill of his late friend ; all
these were taken with a <=• in. dry lens, and he thought it would be
agreed that they were a great deal better done than many which

230

had been taken with the best oil immersions. Mr. Marryat
was a man who never kept anything to himself, and no one ever
approached him in vain who wanted any kind of information
which it was in his power to afford.

Mr. Karop reminded the members that at their last meeting-
notice was given of a proposed alteration to Rule XII., so as to
give the Council power to remove from the list of members the
name of anyone whose subscription was in arrear, and to whom
repeated applications had been unsuccessfully made. Having
read the rule as it stood and also the proposed alteration, he
moved that the alteration be made as suggested.

Mr. J. E. Ingpen seconded the proposal, and said that during
his rather long experience of secretarial work in the Club he
had found this was a weak spot in the rules, and did not at the
time see his way to remedy it. He thought the difficulty would
now be met by this alteration in a very satisfactory and happy
manner.

The President then put the motion to the meeting and declared
it carried unanimously.

The President having appointed Messrs. R. Macer and W.
Burton to act as scrutineers, the ballot for Officers and Council
for the ensuing year took place, The scrutineers having subse-
quently handed in their report, the President announced that
the following gentlemen had been duly elected : —
As President ... ... J. G. Wallee, F.S.A.

E. M. Nelson, F.R.M.S.

Rev. W. H. Dallinger, LL.D., F.R.S.

A. D. Michael, Pres. R.M.S.

E. T. Newton, F.R.S.

J. J. Vezey, F.R.M.S.

G. C. Karop, M.R.C.S., F.R.M.S.

C. Rousselet, F.R.M.S.

R. T. Lewis, F.R.M.S.

Alpheus Smith.

E. T. Browne, B.A., F.R.M.S.

E. M. Nelson, F.R.M.S.

F. W. Hembrt, F.R.M.S.
J. E. Engpen, F.R.M.S.

J. SCOURFIELD.

G. Western, F.R.M.S.

Four Vice-Presidents

55

Treasure)' ...

55

Secretary ...

55

Foreign Secretary ...

55

Reporter ...

55

Librarian ...

55

Curator

55

Edit<>r

/<;

ur Members to fill

Vacancies on the

Committee.

VPx.

231

The Secretary then read the 30th annual report.
The Treasurer read his annual statement of accounts, and
presented the duly audited balance sheet, pointing out at the
same time the difference in some items as compared with former
years, and showing that some additional expense on account of
the Journal had arisen from the greater number as well as the
improved character of the plates.

Mr. Ingpen thought that no regret need be expressed as to
the small additional cost of the Journal, which was well worth
what had been spent upon it.

Mr. Measures having moved that the report and balance
sheet be received and adopted,

Mr. Neville seconded the motion, and as representing those
who had recently joined the Club, he wished to say how greatly
they appreciated the advantages which it afforded them, and
the pleasure they had derived from attendance at the meetings.
In spite of the rival attractions of photography and cycling he
had no fear that their hobby would become neglected, or their
Club deserted. He thought it was also of great advantage to
the members to have such a Journal as they possessed, and he
entirely agreed that any money spent in that direction was well
spent.

The motion was then put from the chair and carried unani-
mously.

The President then read his annual address (see p. 191).
Mr. A. D. Michael said he rose to express their thanks to
their President for the interesting and valuable address to
which they had just had the pleasure of listening. At the same
time, as this was the last occasion on which they would have a
Presidential Address from Mr. Nelson, he should like to couple
with this a vote of thanks to him for his highly efficient services
to the Club during the whole of the period that he had occupied
the chair, and with an expression of regret that these services
were not to be longer continued. He was not in any way
intending to disparage an old friend who had been elected to
succeed to the chair; they welcomed him cordially and would
serve under him with pleasure, but they could not see the
President of the last three years leave the chair without regret,
and more especially that they were unable to see him leave it
in better health than was the cue at the present time. Their

232

thanks were heartily due to him for the ability with which he
had managed their proceedings, and for the able way in which
he had conducted the Journal, as well as for the many commu-
nications he had made in addition to his address that evening.

Mr. J. D. Hardy had very great pleasure in seconding the
vote of thanks to the President, not onl} 1- for his address, but
also for the great efficiency of his services during his period of
office. Looking upon what Mr. Nelson had done for microscopy he
might say that no one had done more towards making it a science
than he had by the character of the papers he had read, and the
demonstrations he had given. He should like to suggest that
it would be well if the whole of Mr. Nelson's communications
on the subject could be collected and printed together in a
separate form.

Mr. Michael said the President could not put this motion to
the meeting himself ; he therefore called upon them to carry it
with hearty acclamation.

Mr. E. M. Nelson said he was extremely obliged to Mr.
Michael and to Mr. Hardy and to all who had joined so cordially
in carrying this vote of thanks, for the very kind way in which
they had referred to the manner in which he had endeavoured
to carry out duties which he only wished had been better per-
formed. They knew quite well how fond he was of the pursuits
which chiefly engaged their attention there, and his only desire
had been to clo all he could to promote an increased interest in
the microscope, and to induce others to carry on the work in the
most efficient possible ways. He felt quite sure that in the ad-
vances which had been made in this direction the Q.M.C. had
been a great centre of influence in this country.

Mr. Nelson, in resigning his position to his successor, said : —
I cannot vacate this chair without thanking both your officers
and yourselves for the kindness and assistance 1 have received
during the three years I have occupied it. Next month I enter
my twentieth year of membership, and, looking back, I can see
a steady and continuous improvement in the work done by this
Club. A few years ago we passed through very hard times,
but owing to the tact and management of your able Secretary,
Mr. Karop, aided by the sound judgment of that veteran micro-
scopist, Mr. Michael, who at the time was President, they were
tided over. After this the affairs of the Club began to improve,

233

«
and the brilliant presidency of my predecessor, Dr. Dallinger,
completely put an end to our period of depression. It was
therefore in auspicious times that I took my seat here, and I
trust that no act of mine has in any way retarded this forward
current. It is with great pleasure that I now hand over the
chair to my friend Mr. Waller. Mr. Waller, you must know,
became a member of this Club three years after it was started;
he therefore requires no introduction from me, but as a member
of your Committee I can witness that for many years this Club
has greatly benefited by his counsel and advice, no less than by
his ever ready assistance. It was Mr. Waller who housed a
large part of your library when we were turned out at Grower
Street, thereby relieving your Librarian and Committee of much
anxiety. In bidding }^ou adieu, let me say that the prosperity
of this Club is in your hands ; your officers may do all they can,
but it is the effort of each individual member that has achieved
what has been done in the past, and to which the future must
be entrusted.

Mr. J. G. Waller then took his seat as President, and was
heartily cheered by the members on so doing. He said he must
express to them his thanks for the honour they had done him,
and his desire to do all that he could to further the interests of
the Club. He must also express his thanks to Mr. Nelson for
the very kind way in which he had referred to him, and was
only sorry to note the condition of his health, which he sincerely
hoped would be speedily restored.

A vote of thanks to the Auditors and Scrutineers was moved
by Mr. Powell, seconded by Mr. Southon, and carried unani-
mously.

Mr. H. Groves then moved that the best thanks of the Club
be given to the Officers and Committee for their services during
the past year, and in a humorous speech recounted the indebted-
ness of the members to the various officers, to whom he referred
seriatim. To their Secretary he felt sure all would feel
specially indebted for the arduous work he had j^erformed for
the benefit of all, and whose tact and skill were, perhaps, best
manifested by the general smoothness with which everything
had worked. He had seen something of what these duties in-
volved, and sincerely hoped that the success of the Club would
continue to be assured by the continued performance of these

234

duties by their indefatigable friend Mr. Karop, to whom they
owed so much.

Mr. J. M. Allen having seconded the motion, it was put to
the meeting by the President, and unanimously carried.

Mr. Karop said it always fell to his lot to return thanks on
behalf of the Officers and Committee, and in doing so he could
only assure the members of the Club that it was a matter of the
greatest pleasure to do all they could to advance its interests,
and so long as they were able to do this to the satisfaction of the
members it would give them great pleasure to continue their
efforts in this direction.

235

THIRTIETH ANNUAL REPORT OF COMMITTEE.

At the end of another year your Committee is again in a
position to present a favourable account of the Club's affairs

During the twelve months ending December, 1895, twenty-
nine new members were elected, a slight increase on the
number for the previous year. By resignation and death our
losses amount to twenty-five. Amongst the latter are two past
Presidents, viz., Prof. Huxley and Mr. A. Durham, and two
distinguished Honorary Members, Prof. Williamson and Mr. F.
Kitton, and our former esteemed Treasurer, Mr. F. W. Gay.

The attendance at the meetings has been remarkably good,
showing an average at the ordinary business nights of 52, and
at the conversational meetings of 27. This is distinctly
encouraging and goes to prove that, in spite of the recent
popularity of certain other branches of science and art, micro-
scopy still holds attractions for many.

The chief communications at the meetings have been as
follows : —

Jan. " On the Preservation of Rotifers," 2nd )
paper... ... ... ... )

Feb. "President's Address"

Mar. " On a New Floscule "

,, " What was the Amician Test ? "
Apr. " On a New Species of Aleurodes "

„ " On Bacteria from Thames Foul-water"

,, " Roots and Growths upon them "
May " On an Aquatic Hymenopterous Insect " Mr

,, " On Scale Evolution"...

„ "Idem"

June " On Pyrenean Plants '"

Sept. " On Diplo'is Trigona, etc." ...

,, " On the Entomostraca of North Wales
Nov. " On Bonnemaisonia hamifera, Har." ..

Besides these papers a number of informal communications

Mr.

Rousselet.

Mr.

Nelson.

Dr.

Pittock.

Mr.

Karop.

Mr.

Lewis.

Mr.

Shadbolt,

Mr.

Green.

Mr.

Burton.

Mr.

Ingpen.

Mr,

Nunney.

Mr.

Reed.

Mr.

Rousselet

Mr.

Scourfield,

Mr.

Bu fih am.

236

were given on specimens, methods, and apparatus which
provoked useful discussions and comments. An abstract of
these will be found in the Proceedings.

The Cabinet has been enriched by the following dona-
tions : —

Mr. Rousselet... ... ... ... 66

Mr. Hinton 6

Mr. Daunou ... ... ... ... 1

Mr. Bilfinger ... ... ... ... 6

Total 79

Deserving particular mention is the series of mounted Rotifers
presented mainly by Mr. Rousselet. As every member knows,
the art of preserving these fragile organisms in a life-like manner
is the discovery of this gentleman, and in course of time we
may now look forward to possessing a more or less complete
collection which will be invaluable for reference and study.
The chief addition, however, is the gift by the Misses Harman
of a handsome cabinet containing 1,000 specimens, mostly
entomological, prepared by their uncle, the late Mr. J. G. Tatem
of Reading, who was for twenty years a member of the Club.
His skill as a mounter was very considerable, and when arranged
and catalogued this extensive collection will be of great service.
The best thanks of the Club are due to the Misses Harman for
their most kind and valuable benefaction, which was intended
and will be kept as a memorial of their late relative.

The following books and periodicals, acquired by gift,
purchase, or exchange, have been added to the library : —
Wright, L., " Handbook to the Microscope " From the Author.
Braithwaite,Dr. R.," British Moss Flora," )

Part 16 J

Lankester, Prof. Ray, Zoological articles -\

contributed to " Encyclopedia Britan- 1 Mr. J. J. Vesey.

nica" (reprint) ... ... ... '

Latterthwaite's "Manual of Histology"... Mr. E. M. Nelson.
Leighton's " Angiocarpous Lichens " ... ,,

Fowler's " British Coleoptera " ... ••• , 5

Ehrenberg's " Microscopic Bacillaria " ... ,,

Miall, Prof., " Natural History of Aquatic) Publishers.

Insects " ... ... ... ... J

237

of

Purchased.

'J

Raj Society.
In Exchange.

Lowne, Prof. B. T., » Anatomy, etc.,

the Blow Fly," Part 6

" Cambridge Natural History— Mollusca "
"Cambridge Natural History— Insects ")

Part 1 ' J

"Quarterly Journal of Microscopical)
Science "... ... ... C

"Annals and Magazine of Natural History"

" Grrevillea '...

Buckton's "Larvae of British Butterflies)
and Moths," Vol. vi j

"Journal of the Royal Microscopical
Society "...

" Proceedings of the Royal Society

" La Nuova Notarisia "

"Le Diatomiste"

"International Journal of Microscopy"

'• American Botanical Gazette "...
American Monthly Microscopical Journal "

" The Microscope "

"Essex Naturalist"

Proceedings of various Societies and)
sundry Pamphlets ... ... j

The usual two numbers of the Journal have been issued and
posted to all members whose subscriptions are not in arrear

I he October part was exceptionally heavy in both letterpress
and plates, and the expenses of its production for the year have
therefore somewhat exceeded the average. On the other hand
the revenue accruing from advertisements has increased, being
£24 4s., as compared with £15 19s. 6d. last year. For this
welcome addition the Clubis chiefly indebted to the kind offices
ot Mr. Kousselet.

The financial position of the Club does not call for any
detailed reference, though attention may be drawn to one or two
items. The subscriptions received last year amount to only
£152, as against £173 in 1894. Thi.s is partly accounted for by
the fact of there beiug a large sum collected for arrears in the
latter year but a great part of the difference is due to non-
payment. This is greatly to be regretted, and with a merely
nominal subscription like ours should not occur. It is sincerely

238

hoped that the good sense of members will not allow this state
of things to continue, as, putting it on no higher grounds, it
imposes a very heavy task on the Hon. Treasurer, as well as
considerable expense to the Club itself for postage and
stationery. The other items of extra expenditure over the
previous year are in the Journal account and for bookbinding,
which is included in the amount for purchase of property.

The excursions last season were very well attended, and
although the dry weather had somewhat reduced the water in
the ponds, a few new, rare, or interesting organisms were
obtained, which will be found recorded in the November
Journal.

Your Committee beg to thank the officers of the Club for
their continued and indispensable services in their several
departments.

In conclusion the Committee venture to express the hope and
belief that in spite of periods of elevation and depression, which
appear to be inevitable in scientific matters as in other human
concerns, the Quekett Club will continue to carry on its work
in the present year based upon the best traditions of the thirty
which have preceded it.

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240

Q.M.C. Excursions, 1895.

s

3
u

1

Dates.

Localities.

93

"Sii
S.S

■gq

3

a

H

.2
o *

1l

to

O

©
u

<u
XI

e

3

1

1

March 23

Snaresbrook...

21

1

22

2

April 6

Ealing

11

1

—

12

3

„ 20

Royal Botanic Gardens ...

42

5

18

65

[

4

May 4

Totteridge ...

18

—

2

20

5

„ 18

Staines

9

—

1

10

6

Jnne 8

Enfield

15

-

—

15

7

„ 22

Woking

8

1

—

9

8

July 6

Hertford Heath

9

—

1

10

9

„ 20

Whitstable

10

—

2

12

10

Sept. 7

Chingford

5

—

—

5

11

.. 21

Oxshott

9

1

2

12

12

Oct. 5

Keston

11

—

1

12

Names of members who sent lists of objects found by them : —

B. Burton, W.

C. Culshaw, Rev. Geo. H.
Da. Dadswell, Ed.

Dk. Dick, J.
M. Measures, ,T. W.
P. Parsons, P. A.
R. Iiousselet, C. F.

Sch. Sclierren, H.

Sc. Scourfield, D. J.

S. Soar, C. D.

So. Southern, W. H.

T. Turner, C.

Wb. Webb, J. C.

W. Western, G.

241

List of Objects found on the Excursions,

Note. — The numbers following the names of the objects
indicate the excursions upon which they were found, and the
letters indicate the names of the members recording the same.
When an object is frequently recorded the names of the
members are omitted.

CRYPTOGAMIA. ALGJE.

Chsetophora elegans . . . .4, Dk.

,, endivaefolia . . .5, W.

Drapernalclia glomerata . . .4, W.

Eudorina elegans . . . . 1, 2, 3, 4, W.

Gloiotrichia pisum . . . .5, W.

Gonium pectorale . . . . 1, W. ; 3, Dk. ; 4, B., Dk. ;

6, 7, Dk.

Nostoc commune . . . . 4, 5, W.

Oscillaria tenuis . . . . 7, T.

Pandorina morum . . . .3, Dk. ; 4, B. ; 5, W. ;

6, 7, Dk.
Pediastrum Boryanum . . . 1, C. ; 3, 4, 7, Dk.

,, granulatum . . . 7, T. ; 12, B.

,, pertusum . . .10, P.

Protococcus viridis .... 12, B.
B-aphidium falcatum = Ankistrodes-

mus falcatus . . . . .3, Dk.

Scenedesmus acutus . . . . 10, P.

quadricauda . . .3, Dk., Sch. ; 4, Dk. ;

7, T. ; 10, P.
Spirogyra nitida .. . . . 3, 4, Dk.
Spirulina oscillariodes . . . 12, B.
Staurospermum quadratum (in conj.) 4, B.

Volvox aureus, Ehr. = V. minor.

Stein 11, M.

Volvox globator . . . . 1, 3, 4, 5, 11.
Zygnema cruciatum . . . . 3, 4, Dk.

Desmidiaceje.

Closterium lunula . . . . 3, 4, 6, 8, 11, 12.
moniliferum . . . 3, 6, Dk. ; 11, M.

,, setaceum . . . 1, C ; 11, M.

Journ. Q. M. 0., Series II., No. 38. 17

242

Closterium striolatum

. . 1, C.

Docidium baculum

. 8, T.; 12 B.

Micrasterias denticulata .

. 1,W.; 11, M.

,, rotata .

. 1,C.; 4, Dk. ; 8, T.

Staurastrum gracile .

. 1, W.

DlATOMACBJl.

Cocconema lanceolatum

. 3, 4, 6, Dk.

Diatoma vulgare

. 3, 4, 6, Dk.

Epithemia turgid a

. 1, W.

Gomphoneraa acuminatum

. 3, 4, Dk.

Meridion circulare

. 2, W.

Navicula rhomboides.

. 4, Dk.

Pinnularia nobilis

. 3, 4, Dk.

Pleurosigma attenuatum

. 4, Dk.

Synedra radians

. 3, 4, Dk.

CRARACEM.

Chara fragilis .

. 6, Da.

Nitella flexilis .

. 6, 7, Da.

PROTOZOA.

Acineta mystacina

. 3, Dk., Sch.; 6, Dk.

Actinophrys sol.

. 1, 2, 3, 4, 6, 7.

Actinosphrerium Eichhornii

. 1, 2, W. ; 3, Dk., Sch.,

W. ; 4, 7, Dk.

^Egyria oliva .

. 2, W.

Amoeba diffluens

. 3, Dk.

„ radiosa

. 3, B.

Amphileptus anser .

. 2, W. ; 4, Dk.

,, flagellatus .

. 1,0.; 7, Dk. , 12, P.

gigas .

. 3, Sch.

,, meleagris

. 7, Dk.

Anthophysa vegetans

. 3, B.; 5, P.; 12, B.

Arcella dentata .

. 6, Dk., T.; 8, T. ; 11, W.

,, vulgaris

. 1, 3, 4, 5, 6, 7, 11, 12.

Archerina Boltoni

. 11, W.

Blepharisma lateritia

. 2, W.

Bursaria truncatella .

. 1, T. ; 3, Sch., T. ; 4, T.;

11, P.; 12, B., T.

Carchesium polypinum

. 1, B.; 3, B., Dk., Sch.;

6, 7, Dk.

243

Centropyxis aculeata = Arcella

aculeata.

. 7, Dk.; 11, W.

Coleps amphacanthus

. 8, T.

„ hirtus

. 1, 2, 3, 4, 6, 7. 8.

Condylostoma patens

. 2, 3, W.

,, stagnale

. 1,W. ;3,B.; 4,T. ; 11, P.

Cothurni a imberbis .

. 1,C; 3, B., Dk. Sch.,T. ;

4, Dk. ; 6, Dk., T. ;

7, Dk.

Dendrosoma radians .

. 11, W.

Difflugia globulosa

. 5, W. ; 6, 8, T. ; 11, M.

,, oblonga

. 6, 8, T.

„ proteiformis

. 1, C. ; 6, 7, Dk.

„ pyriformis .

. 4, Dk. ; 6, Dk., T. ; 11,

M. ; 12, B.

,, spiralis

. 11, W.

Didinium nasutum .

. 4, P.

Dimastigoaulax cornutus .

. 5, 11, W.

Dinobryon sertularia

. 1, 2, 3, 4, 5, 6, 7, 8.

Enchelys pupa .

. 7, Dk.

Epipyxis utriculus .

. 3, 6, Dk.

Epistylis anastatica .

. 1, C. ; 7, Dk.

„ flavicans = E. grandis

. 2,W. ; 3, B.,Sch. ; 6, Dk.

Euglena acus . . . .

. 4, P.

,, viridis.

. 1, 3, 4, 6, 7, 12.

Euglypha ciliata

. 11, M.

Euplotes patella

.1,0.; 2, W.; 3,B.,W.;

6, 7, Dk.

Gymnodinium fuscum = Peridinium

fuscum 3, 4, 12, B

Gyrocoris oxyura . . . . 6, P.

Litonotus fasciola = Amphileptus

fasciola, and Dileptus folium . 6, Dk., T.

Loxophyllum meleagris

Nassula ornata .

Noctiluca miliaris

Opercularia nutans
Ophrydium versatile
Paramecium aurelia

1,2, W.; 3, Sch,W. ; 5, P.

11, w.
9, P.
3, Sch.
5, W. ; 6, T.

3, Sch., Wb. ; 4, W. ;
6, T.j 11, W.

244

Pelomyxa palustris .

12, P.

Peridiuium tabulatum = P. cinctum

1, B., W. ; 4, 5, W. ;

11, M., W.

Phacus longicaudus .

3, B. ; 7, Dk. ; 8, P.

pyrum .

7, Dk.

Pyxicola affinis .

3, P.

„ Carteri

3, P.

Raphidiophrys elegans

8, P.

Rhipododendron Hnxleyi

11, P.

Spirostomum ambiguum

4, 6, T. ; 12, B.

Stentor Barretti

4, P.

,, csemleus

5, P.

niger .

l,B,T. ; 2,T,W.; 6,8,T.

,, polymorphic = S

Miilleri

1, 2, 3, 4, 5, 6, 8, 12.

Stichotricha remex .

1, P. ; 2, W. ; 3, P. ; 12, B.

Stylonichia mytilus .

2, W. ; 3, Dk., Sch. ;
7, Dk.; 11, P.

Syimra uvella .

1, 2, 4, 5, W.

Thuricola valvata

3, Sch,

Trachelius ovum

2, W. ; 3, Sch. ; 6, Dk. ;
8, T. ; 10, 11, P.

Trachelocerca olor = T. vi

ridis .

.2, P.; 3, Dk., Sch.
4, 7, Dk.

Trichodina pediculus .

4, 6, Dk. ; 11, P.*

Urocentrum turbo

6, P.

Uroglena volvox

1, 2, W.

Uroleptus piscis

1, W.

Uronychia transfuga

9, P.

Vaginicola crystallina

1, 3, 4, 5, 6, 12.

Vorticella campanula

.

5, W.

,, clilorostigma

5, W.; 11, T.

„ microstoma

. 3, 4, 6, 7, Dk.

„ nebulifera

1,3,4,6,7,12.

,, striata

11, P.

Zootliamnium arbuscula

1,B.;11, T.

CCELENTERATA. 11 Yj

DROZOA.

Coryne pusilla .

9, P.

„ vaginata

9, P.

* Trichodina pediculus on Syuchaeta pectinata.

245

Hydra f usca

. 10, P.

„ viridis .

. 10, P. ; 12, B.

„ vulgaris

. 12, B.

Plumularia similis .

. 9, P.

CTENOPHOBA.

Beroe fulgens .

. 9, P.

Pleurobrachia pileus

•

. 9, P.

VERMES. BOTIFEBA.

Actinurus neptunius

. 4, 6, T.

Adineta vaga .

. 1, W. ; 7, T., W.

Anursea aculeata

. 1, 3, 4, 5, 6, 8, 10.

var.

brevispina

. 1, 2, 4, 5, 6, 8, 10, 12.

>J 5> 5)

valga

. 1,R., W. ; 5, W.; 7, R. ;
8, R., W.; 12, W.

,, cocblearis .

. 1, 3, 4, 5, 6, 7, 8, 10, 11.

„ curvicornis

. 1,2,3,4,8,11,12.

,, hypelasma .

•

. 6, R. ; 8, R., W. ; 11,
12, W.

„ scbista

.

. 5, T.

,, serrulata

. 1,R,,T., W; 11, W.

„ tecta .

. 1, T.; 4, So., W.; 6, R. ;
7,W. ;8, So.

Anapus ovalis .

. 5,R.

Ascomorphaecandis = Sacculns viridis 1, R., T. ; 4, B., T., W. ;

8, R,, T., W. ; 12, T.
„ saltans = „ saltans 8, R.

Asplanchna Brightwellii . . 1, R. ; 3, R., Sob., So.,

W.; 5, R, ; 8, P.; 11>
W.
3 . • 8, So.
,, priodonta . . • 2, 3, 5, 6, 7, 10, 11.

„ » . . io, p.

Bracbionus angularis . . . 1, 2, 3, 4, 5, 6, 8, 10, 11.
* • • 3, R.

Bakeri . . . . 6, R, T. ; 8, R., W. ; 11,

W.
pala . . • • 1, 3, 4, 6, 11.
„<?.... 3,R.,So.
,, var. ampbiceros . 3, P. ; 7, Dk. ; 11, P.

246

Brachionus quadratus
„ rubens .

„ urceolaris

Callidina elegaus

„ parasitica .
Cathypna luna

,, rusticula .

,, sulcata
Cephalosiplion limnias
Chromogaster testudo

Ccelopus bracbyurus .

„ porcellus
,, tenuior
Colurus bicuspidatus
,, caudatus
,, deflexus
„ obtusus
Conocbilus dossuarius
„ unicornis

,, vol vox
Copeus caudatus
,, cerberus
„ Ehrenbergii = C
(Gosse)
Copeus pacbyurus.

Diaschiza exigua
globata
"f r Hoodii
poeta
semi-aperta

Diglena birapbis
,, catellina
,, caudata
,, dromius (Glascott)

. 3, W.

. 3, 5, 7, 8, 10, 11.

. 2, 3, 4, 5, 6, 7, 8, 11.

. 7, W.

. 11, W.

. 5, 6, 7,8, 11, 12.

. 6, R.

. 7, P.

. 3, Sell. ; 8, P.

. 4, 5, W.; 8, R., W.; 11,

W.
. 1, R. ; 2, W. ; 4, R. W.

8, 11, 12, W.
. 2, 4, P. ; 5, W.
. 4,B. ; 11, W.
. 1, 2, 4, 5, 6, 8.
. 4, B.

. 6, R.* ; 12, B.
. 2, 11, W.
. 12, P.
. 12, B., T.

. 7, P.; 11, M., T., W.
. 4, B.

. 8, R. ; 11, W.
labiatus

. 4, So.

. 2, P. ; 4, 8, R. ; 10, P.

11, T., W.
. 1, R., W. ; 5, 7, W.
. 1, 2, W.
. 4, R.
. 12, W.

. 1, 4, R., W. ; 5, W.
. 1, W.
. 11, W.
. L, T. ; 8, W.
. 12, B.
. 11, W.

C>>lurns deflexus, with two frontal eyes.

247

Diglena forcipita .

1, T.; 2,W.; 3, T. ; 5, 11,

W.

?»

grandis „

2, W.

»5

rosa .

1,T.

55

uncinata .

11, W.

Dinocliaris pocillurn .

2, 4, 5, 6, 7, 8.

>j

tetractis .

1, 2, 4, 5, 6, 8, 10, 11.

Diplois

trigona (Rousselet) n.s.

2, B,, W.

Distyla

flexilis .

1, 3, 11, W.

55

striata .

11, W.

Elosa Worrallii .

7, W.

Eosphora aurita .

1, 2, 5, 8, 11, 12.

Euchlanis deflexa

3, 4, B. ; 8, So.

55

dilatata .

2, T.; 3, Sch., T. ; 5, So.,
T. ; 7, T.

55

hyalina .

5, R.

55

parva

4, 5, 6, R.

55
55

pyriformis

subversa (Bryce) = Dip-

3, T.

lois propatula (Gosse) .

3, B.

55

triquetra .

1, R., W. ; 3, B. ; 4, T. ;
5, R., So., T.,W.

Floscul

aria ambigua

4, R. ; 11, W.

55

campanulata .

1, C, W.; 5, W.

55

cornuta .

1, 2, 3, 4, 5, 10, 11.

55

coronetta

1, 11, W.

55

cyclops .

11/W.

55

edentata .

11, P.

55

ornata .

1, B. ; 3, B., Dk., T. ; 4, 7,
Dk.; 11, W.

55

trilobata .

11, p.

Furcularia ensifera .

2, T.

55

forficnla .

1, T. ; 3, T. W. ; 6, P.

55

gracilis .

2, 5, W. ; 8, R., W. ; 12,

w.

55

longiseta .

1, 2,T.,W.;3,R.;4,W.;
5, R. ;8, T.; 11, W.

55

„ var. grandis

(Tessin-Butzow) .

8, R., W.

55

megalocephala (Glascott)

4, R.

248

Fnrcularia micropus

Hydatina senta . . .

Lacinularia socialis .
Limnias annul atus .
,. ceratophylli

„ myriophylli (Western) =
Limnioides myriophylli (Tatem)
Mastigocerca bicornis

bicristata
carinata
elongata
rattus .
scipio .
stylata
Melicerta conifera

„ janus

„ ringens

„ tubicolaria
Metopidia acuminata

„ lepadella .

„ oxysternum

,, solidus

„ triptera

Microcodides doliaris (Roussele

„ orbicalodiscus

Monostyla bulla

,, cornuta .

„ lunaris

„ quadridentata .

Noteus quadricornis

Notholca acuminata .
„ Leptodon .

t)

. 12, B.
. 2, TV.

. 7, Da.
. 3, W.

. 3, B., Dk., Sch. ; 6, Dk.,
T. ; 7, Da. ; 12, B.

. 11, M., W.

. 1, R. ; 4, T., W. ; 5, W. ;

12, B.
. 4, 5, 11, W.

. 4, T.; 5,R., T, \V.;8, So.
. 8, T.

. 1, 2, 3, 4, 5, 6, 8, 11.
. 11, W.

4, 8, So.

. 1, B., C, R.,T.; 2, W. ;
8, T., W. ; 10, P. ; 11,
W.
11, W.
1, 3, 4, 6, 7.
. 8, W.

. 1, 3, 4, 5, 8, 11.
1,T. ; 2,W.;4, So.;5,T.,
W. ; 6, R. ; 8, W.
. 2, R., W. ; 4, So., T, W. ;
6, R.

1, W.;2,R.;3,B.;4,B.,
R. ; 5, 8, R. ; 11, W.

5, W.

. 8, R., W. ; 11, W.
1, W.; 4, P.

6, R.
4, So.

1, W. ; 8, So.

3, So.

4, So., T.j 5,R. ;6, T.;8,

P.; 12, B.

2, T., W. ; 5, R., T., W.

5, W.

249

Notholca scapha
Notommata ansata .
„ aurita

„ brachyota

,, cyrtopus

,, forcipita

,, lacinulata

„ naias

„ saccigera

„ tripus

Notops bracliionus

clavulatus
hyptopus

„ minor

OEcistes crystalliims
„ longicornis
„ mucicola
,, pilula .
„ stygis .

Pedalion mirum

PLilodina aculeata
„ citrina

„ macrostyla

,, megalotrocha

Polyarthra platyptera

. 1, 2,R., W. ; 3, B.,R., W.
. 1,T.

. 1, T. ; 3, R. ; 4, B., R.,

W. ; 5, P. ; 6, R.
. 1, W.
. 1, R.
. 2, W.
. 1, R., W. ; 2, T., W. ; 3,

Sch., W. ; 4, 5, T.,

W. ; 7, T.
. 2, R., W.
. 1, R., W.; 11, T.
. 1, T.;5, P.
. 1, B., R. ; 4, R., So., W. ;

8, R., So., T., W. ; 10,

P. ; 12, W.
. 8, R.
. 1, B., R., T. W.; 2, R.,

W. ; 4, B., R., So., T.,

W.;8,R., T,W.;11,

W.
. 1, R.

. 1,R.,W. ;2,T.;4,11,W.
. 3, B., Sch, So.
. 1, W.;3, P.
. 6, R.

. 11, M., T., W.
. 1, R., W.
. 8, R., So., W. ; 11, W.

12, B. W.
. 2, W.
. 2, W. ; 3, T., W., 6, P. ;

7, W. ; 11, P.

. 7, W.

. 3, B., So., W. ; 6, P. ; 7,

W.
. 1, 2, 3, 4, 5, 6, R * ; 7, 8,

10, 11, 12.
. 4, W.

Pompholyx complanata .

* Polyarthra platvptera, with fertilised resting eggs

250

Pompholyx sulcata .

. 10, P. ; 12, B.

Proales decipiens

. 3, R.

„ felis

. 1, W. ; 2, T. ; 11, W.

„ gibba .

. . . 1, T.

„ parasita

. 3, Dk. ; 4, B., Dk., So.

„ petromyzon .

. 1, 3, T. ; 5, R.*

„ sordida

. 8, W.

„ tigridia

. 11, T.

Pterodina patina

. 3, Dk. ; 4, W. ; 5, P ; 6,

Dk., R., T.;8,T. W. ;

11, M.

„ reflex a

. 2, W.

,, truncata

. 3, R.

Rattulus bicornis (\\

estern) . . 7, W.

Rhinops vitrea

. 4, R., W.

Rotifer macroceros

. 1, R., W.; 5, W.; 6, P.:

8, W. ; 11, T., W.

,, macrurus

. 1, W. ; 3, So, W. : 4, So. ;

8, R,

„ mento ? .

. 11, P.

„ tardus .

. 2, T, W.;8, T.; 11, W.;

12, B.

,, vulgaris

. 1, 2, 3, 4, 5, 6, 7, 8, 11.

Salpina brevispina

. 4, R.; 5, R., So., W.: 6,

R. ; 11, P.

,, eustala

. 8, W.

„ macracantln

i . . . 6, T.

„ marina

. 1, W.

,, mucronata

. 2, 4, 5, 6, 8, 11.

,, mutica

. . . . 1, 2, R.

„ spinigera

. 4, B.

,, sulcata

. 8, W.

Scaridium longicauc

urn . . .2, T, W.

Stephanoceros Eichl

lorciii . . 1, B, 0, R, W. ; 3, W. ;

4, Dk.

Stephanops lamellar

is . .2, 3, T. ; 4, It. T.

Synchista longipes

. 7, W.

,, pectinata

. 1, 2, 3,4, 5, 6, 7,8,10,11.

* Proales petromyzon in volvox.

251

Synchaeta treruula
Taphrocampa annulosa

,, Saundersise .

Triarthra breviseta .
,, longiseta .
Triphylus lacustris ....

GASTEOTBICHA.
Chsetonotus hystrix ....
,, larus ....

„ maximus

Dasydytes fusiformis

,, goniathrix

PLATYEELMINTHES, Turbellaria

1, 2, 3, 4, 5, 6, 7, 8.

1, 5, 11, W.

2, 4, W. ; 8, P.; 11, 12,

w.

11, M.

3, 4, 6, 8, 10, 11, 12.
8, R, ; 11, W.

LI, W.

3, 4, B. ; 6, Dk. ; 8, T. ;

12, B.
8, T.

12, B.

6, T. ; 11, W.; 12, B.

Planaria lactea .

. 1, L2, B.

nigra .

. 1,B.

ANNELIDA.

Leucodore ciliatus

. 9, P.

ARTHROPODA. CRUSTACEA.

Gammarus locusta .

. 9, P.

J sera Nordmanni

. 9, P.

Entomostraca.

Alona guttata .

• 1, 11. 1

,, intermedia

. 10, 11. J

,, quadrangularis

■ I- 1 „

. io, ii. [ Sc -

Alonella excisa .

,, nana .

. 1, 10.

Bosmina cornuta*

. 3, 10. )

,, longirostris

. 1, B., Sc. ; 3, B., Dk.,
Sch., Sc. ; 12, B.

Candona pubescens .

. 3, Sc.

Canthocamptus pygmsens .

. 11, Sc.

,, staphylinus =

= 0.

minutus

. 1, C, Sc; 3, B., Dk.,
Sch.,Sc; 4,B.;5,W.;
11, Sc. ; 12, B.

* Bosmina cornuta has been included in former lists with B. longirostris.

252

Ceriodaphnia megops

,, quadrangula

. 10, 11, Sc.
. 10, 11, Sc.

„ reticulata = Dapl
reticulata

mia

. 5, W. ; 11, Sc; 12, B.

Chydorus latus = C. ovalis

. 11, Sc.

,, sphericus .

. 1, Sc. ; 3, B., Sch., Sc. ; 4,
B.; 10, 11, Sc; 12, B.

Cyclops albidus = C. tenuicornis . 1,0.; 3, 11, Sc.

,, bicuspidatus.
,, bisetosus

. 1,3, 11. i
. 1.

„ fimbriatus .

. 1.

,, languidus

. 1.

,, Leuckarti = C. simplex . 3, 10,11.

„ prasinus = C. magnoctavus. 10.

- Sc.

„ phaleratus .
,, serrulatus

. 3.

. 1, 3, 10, 11.

,, strenuus

. 10.

,, „ vicinus form

. 3.

,, vernalis

. 1, 11.

„ viridis, var. brevicornis

5 . 1, 10.

» gigas
Cypria ophthalmica .
,, serena .

. 1, Sc. ; 3, B. ; 10, 11, Sc.
. 1, 10. ^|
. 1, 3, 11. [ gc

• 1,11. J

. 1,0.; 5, W.; 10, Sc.

Cypridopsis vidua
Cypris fuscata .

virens = tristriata.

Dapbnella brachyura = D. Win
Daphnia hyalina

,, longispina .

„ pulex .

gii 5, TV.
. 10, Sc
. 3, Sc
. 1, C, Sc; 3, Dk., Wb.;

4, Dk. ; 11, Sc

,, Schcefferi .

. 4, Dk. ; 10, Sc.

Diaptomus castor

. 1, B., C, Sc; 4, B. W.j
5, W. ; 12, B.

,, gracilis .
Eurycercus lamel latus

. 3, Sch., Sc. ; 10, Sc
. 12, B.

Grapfcoleberis testudinaria
Ilyocryptus sordidus .

. 11, Sc.

. 1, Sc; 3, B., Sc: 10, Sc

Uyocypris gibba

L • . 1 i Sfia acanthocercoides

. 3, 10.^
. 1, 3. [ Sc

Macrotlirix laticornis.

253

Polyphemus pediculus

. 7, P.

Scaplioleberis mucronata = Daplmia

mucronata ....

. 10, Sc.

Sida crystallina

. 7, P.

Simoceplialus exspinosus .

. 10, 11, Sc.

,, vetulus

. 3, 11, Sc.

ABA C II N ID A . Acarina.

Hydrachnidj;.

Arrenurus caudatus $

. 5. }

?

. 1.

,, emarginator cT ?

. 6.

,, globator $

. 4, 5, 6, 11.

„ ¥ .

. 4, 6, 11.

„ maculator $ ° .

. 1,11.

,, sinnator $

. 11.

,, tubulator ?

. 2

Atax, sp. .

. 6.

Axona versicolor $ °

. 4, 5, 7.

Diplodontus, sp.

. 5.

Eylais extendens

. 6.

Hydrachna geographica $ ?

. 1.

^So.

Hydrodroma umbrata

. 11.

Hygrobates rufifrons ?

. 7.

Limnesia fulgida ? .

. 4, 6, 11.

„ sp. ¥ and nymph

. 11.

Limnochares holosericeus .

. 5.

Marica musculus

. 11.

Neseea carnea °

. 5.

„ decorata $

. 11.

,, longicornis $ °

. 5.

,, mirabilis $

. 6.

Piona affinis $ ?

. 5.

,, ovata 9 .

. . 5.

Arctisconid^:.

Macrobiotas Hufelandi

. 2, 4, 5, 7, 8, P.

INSECTA. Diptera.

Corethra plumicornis, larva of

. 1, B. ; 4, Dk. ; 12, B

Tanypus maculatus, „

. 12, B.

254
Hymenoptera.

Polynema natans (Lubbock)

. 4, B.

Nburoptbra

Sialis lutaris, larva of

. 12, B.

MOLLUSCOIDA. Polyzoa.

Bowerbankia citrina .

. 9, P.

Fredericella sultana .

. 1, W. ; 3, B., Dk., Wb.,

W. ; 7, Da.

Membranipora pilosa

. 9, P.

Paludicella Lhrenbergii .

. 3, B.

Pluraatella repens

. 3, B., Sch., Wb. ; 11, M.

Valkeria uva, var. cuscuta

. 9, P.

MOLLUSC A.

Chiton, sp. ....

. 9, P.

Scyllsea pelagica

. 9, P.

Fredk. A. Parsons,
Hon. Sec. Excursions Sub-Committee.

255

($uchcit HUemscapixal Club,

RULES.

I. — That the Quekett Microscopical Club hold its Meetings at
20, Hanover Square, W., on the third Friday Evening in every
month, except July and August, at Eight o'clock precisely, or at
such other time or place as the Committee may appoint.

II. — That the business of the Club be conducted by a Com-
mittee, consisting of a President, four Vice-Presidents, an Hono-
rary Treasurer, one or more Honorary Secretaries, an Honorary
Secretary for Foreign Correspondence, an Honorary Reporter,
an Honorary Librarian, an Honorary Curator, an Honorary
Editor, and twelve other Members — six to form a quorum. That
the President, Vice-Presidents, Treasurer, Secretaries, Reporter,
Librarian, Curator, Editor, and the four senior Members of the
Committee (by election) retire annually, but be eligible for re-
election. That the Committee may appoint a stipendiary Assistant-
Secretary, who shall be subject to its direction.

III. — That at the ordinary Meeting in January nominations
be made of Candidates to fill the offices of President, Vice-
Presidents, Treasurer, Secretaries, Reporter, Librarian, Curator,
Editor, and vacancies on the Committee. That the President, Vice-
Presidents, Treasurer, Secretaries, Reporter, Librarian, Curator,
and Editor be nominated by the Committee. That the nomina-
tions for Members of Committee be made by the Members on
resolutions duly moved and seconded, no Member being entitled
to propose more than one Candidate. That a list of all nomina-
tions made as above be printed upon the ballot paper; the nomi-
nations for vacancies upon the Committee being arranged in such
order as shall be determined by lot, as drawn by the President and
Secretary. That at the Annual General Meeting in February
all the above Officers be elected by ballot from the Candidates
named in the lists, but any Member is at liberty to substitute
on his ballot paper any other name or names in lieu of those
nominated for the offices of President. Vice-Presidents, Treasurer,
Secretaries, Reporter, Librarian, Curator, and Editor,

256

IV. — That in the absence of the President and Vice-Presi-
dents the Members present at any ordinary Meeting of the Club
elect a Chairman for that evening.

V. — That every Candidate for Membership be proposed by
two or more Members, who shall sign a certificate (see Appendix)
in recommendation of him — one of the proposers from personal
knowledge. The certificate shall be read from the chair, and the
Candidate therein recommended balloted for at the following
Meeting. Three black balls to exclude.

VI. — That the Club include not more than twenty Honorary
Members, elected by the Members by ballot upon the recommen-
dation of the Committee.

VII. — That the Annual Subscription be Ten Shillings, payable
in advance on the 1st of January, but that any Member elected in
November or December be exempt from subscription until the
following January. That any Member desirous of compounding
for his future subscription may do so at any time by payment of
the sum of Ten Pounds; all such sums to be duly invested in
such manner as the Committee shall think fit. That no person be
entitled to the full privileges of the Club until his subscription
shall have been paid ; and the Committee shall have power to
remove from the List of Members the name of any Member who
shall have omitted to pay his subscription six months after the
same shall have become due (two applications in writing having
been made by the Treasurer).

VIII. — That the accounts of the Club be audited by two
Members, to be appointed at the ordinary Meeting in January.

IX. — That the Annual General Meeting be held on the third
Friday in February, at which the Report of the Committee on
the affairs of the Club, and the Balance Sheet, duly signed by
the Auditors, shall be read. Printed lists of Members nominated
for election as President, Vice-Presidents, Treasurer, Secretaries,
Reporter, Librarian, Curator, Editor, and Members of the Com-
mittee having been distributed, and the Chairman having appointed
two or more Members to act as Scrutineers, the Meeting shall then
proceed to ballot. If from any cause these elections, or any of
them, do not take place at this Meeting, they shall be made at the
next ordinary Meeting of the Club.

257

X. — That at the ordinary Meetings the following business be
transacted : — The minutes of the last Meeting shall be read and
confirmed ; donations to the Club since the last Meeting announced
and exhibited ; ballots for new Members taken ; papers read and
discussed; and certificates for new Members read; after which the
Meeting shall resolve itself into a Conversazione.

XI. — That any Member may introduce a Visitor at any ordinary
Meeting, who shall enter his name with that of the Member by
whom he is introduced in a book to be kept for the purpose.

XII. — That no alteration be made in these Rules, except at an
Annual General Meeting, or a special General Meeting called
for that purpose; and that notice in writing of any proposed
alteration be given to the Committee, and read at the ordinary
Meeting at least a month previous to the Annual or Special
Meeting at which the subject of such alteration is to be con-
sidered.

APPENDIX.

Form of Proposal for Membership.

Quekett Microscopical Club,

20, Hanover Square, London, "W.
I desire to become a Member of this Club. In the event of my
being elected, I hereby undertake, so long as I remain a Member,
to submit to and be bound by the Rules and Regulations now or
at any future time made and provided ; and I further undertake
to pay to the Treasurer for the time being the Annual Subscription
as it becomes due in each year.

Full Christian and Surname

Occupation

Postal Address

We recommend the above Candidate for Election.

(On my personal knowledge.)

This Certificate was read 18

The Ballot taken 18

Journ. Q. M. C, Series II., No. 38. 18

258

NOTICES OF RECENT BOOKS.

The Cambridge Natural History. Vol. v. Peripatds, by

Adam Sedgwick, M.A. Myriapoda, by F. G. Sinclair.

M.A. Insects, part 1, by David Sharp, M.A., M.B.

London: Macmillan. 17s.net.

This volume, the second of the series already published, is

one the value of which, as a text-book and work of reference

for students, and also for more advanced naturalists, can hardly

be overstated.

To the microscopist the first section, comprising 26 pages, is
likely to be of special interest from the excellence of the
descriptions and of the illustrations of the minute structure and
anatomy, as well as w r hat is known of the life history of that
most remarkable of creatures, Peripatus, so different in its
characters from the Anthropods on the one side and the
Annelids on the other, that a separate class had to be created
for the sole occupancy of its single genus.

The species most particularly described is P. Capensis, with
which the author is from personal examination thoroughly
acquainted, but a list of the other recorded species is given,
together with a map showing their geographical distribution.

The 50 pages devoted to the Myriapods are, perhaps, some-
what less satisfactory, the first 20 pages on classification being
mainly derived from Koch, the 11 illustrations being copied
from his figures in "Die Myriapoden" some of which — notably
that of Polyxemis Lagurus — are sadly deficient in detail, and
neither in these nor in the subsequent illustrations of the
internal structure and embryology is any indication given of
the scale to which they are drawn.

The third section of the volume — Insects, part 1 — consisting
of nearly 500 pages, illustrated by more than 300 figures, is in
every way worthy of the reputation of its author, and is,
indeed, a work which no true entomologist can afford to be
without. Its value will, perhaps, not be very great to the mere

259

collector — i.e., the man who does his best to exterminate species
by filling his cases with rows of impaled specimens of the same
kind in the vain attempt to show to what extent variety exists
in Nature — but the student will find it a text-book such as he
has hitherto yearned for in vain.

The first three chapters deal in a remarkably lucid manner
with the general characteristics of insects, their external
features, the structure and functions of their internal organs,
their embryology, development, and metamorphosis ; the fourth
chapter treats of classification, and the remainder are devoted
to the natural history of the Aptera, Orthoptera, Neuroptera,
and a portion of the Hymenoptera.

The system of classification adopted is mainly that of
Linnaeus, " based primarily upon the nature of the organs of
flight and of the appendages by which the food is introduced
to the body of the image." The author, however, "does not
attempt to disguise the fact that this method is open to most
serious objections, but nevertheless believes it to be at present
the most simple and useful one, and likely to remain such as
long as knowledge of development is in process of attainment."
The systems of classification proposed by Packard and by
Brauer are, however, well summarised. Whilst agreeing with
the author in the main upon this point, we can hardly help
regretting that some revision was not attempted where ample
justification would appear to exist. Surely a definition of
Locustidce which excludes all the locusts will, to the beginner,
appear as great an anomaly as would be a definition of the
Felidae which excluded cats. The definitions which precede
the descriptions of each family are, however, stated with
remarkable clearness, and are in themselves by no means the
least valuable portions of the book.

The illustrations are well chosen and executed, many of them
being from original drawings of type specimens of the genera
described. Many singular forms not frequently met with are
also brought under the notice of the reader, but here, as in the
preceding section, the student would be greatly helped had the
magnifying power been indicated in all cases where the object
is not depicted of the natural size.

An excellent indexgfacilitates reference to any special portion
which it may be desired to consult. We shall look forward

260

witli great interest to the ajopearance of Vol. vi., in which the
remaining orders of insects are to be described.

Evenings at the Microscope. By P. H. Gosse, F.R.S. A new
edition, revised by Prof. F. J. Bell, M.A. 8vo. London :
S.P.C.K. Price 5s.
Although not one of the most successful works of the late
Mr. Gosse, yet it has long held a place in popular estimation
on account of a certain charm of style which all his writings
possess, and also because some of the objects described were
ones he had particularly studied and made, as it were, his own.
In bringing up the book to a more modern standpoint, Prof.
Bell has been careful to alter it as little as possible, and,
except where changed zoological views rendered a revision
imperative, it remains much as before. For the information of
those to whom the book is unknown, it may be as well to state
that its subject matter is entirely confined to the animal king-
dom ; but the microscopist will find in its pages delightful
descriptions of an extensive series of animate objects, with all
their beauties of structure and marvels of function dealt with
in the fresh, vigorous, and independent manner which was
peculiar to the author.

Modern Microscopy. By M. I. Cross and M. J. Cole. Second
edition. 8vo. London : Bailliere, Tindall, and Cox. Price
3s. 6d.
We are very pleased to welcome a second edition of this
excellent manual, which has been enlarged by about 80 pages.
The first part, by Mr. Cross, deals with the microscope and its
accessories, and although comparative^ brief, nothing of im-
portance has been omitted in treating of the instrument itself,
the objectives, eye-pieces, and methods of illumination. In
any future editions we would, however, recommend either the
deletion of Fig. 6 or that the makers be applied to f