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THE MONTHLY
-MICROSCOPICAL JOURNAL:

TRANSACTIONS
ROYAL MICROSCOPICAL SOCIETY,

RECORD OF HISTOLOGICAL RESEARCH

AT HOME AND ABROAD.

EDITED BY

HENRY LAWSON, M.D., F.R.MS..

Assistant Physician to, and Lecturer on Physiology in, St. Mary’s Hospital.

VOLUME VI.

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BOTANICAL

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LONDON:
ROBERT HARDWICKE, 192, PICCADILLY, W.

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THE

MONTHLY MICROSCOPICAL JOURNAL.

JOLY 1,. 1871,

I.—On Bog Mosses. By R. Brarrnwarre, M.D., F.LS.
(Read before the Royau Microscopicau Society, June 7, 1871.)

Part I.

For a considerable time the plants known as bog mosses have
attracted attention, not only by the masses in which they are found
growing, but by their peculiarity of structure, and the difficulty of
finding characters by which to establish the species, for the varieties
are endless, and such a common facies is impressed on the whole
group that Linneus regarded them all as one species, which he
named Sphagnum palustre. In our own time, however, the careful
use of the microscope has revealed to us their wonderful organiza-
tion, and enabled us to establish many species.

Up to the publication of Professor Schimper’s magnificent trea-
tise,* the bog mosses had been universally associated with the other
mosses in one class, but in that work they are placed apart, and

EXPLANATION OF PLATE XC.

Fic, 1.—Prothallium with young plant.
2.—Sphagnum cymbifolium. Vertical section of stem passing also through two
leaves, and the base of a branch fascicle.

» 3.—Ditto. Transverse section. These show the pith, the woody cylinder,
and the four layers of bark cells.

» 4—Cells of pith.

5, 0—Ditto of wood.

», 6.—Ditto of bark.

» 7—Cells of a branch leaf of S. cymbifolium.

», 72.—Transverse section of a leaf of S. squarrosum.

» 8—Cells of a branch leaf of S. acutifolium, seen from the back.

», 8x.—Transverse section of same.

», 9.—Male flower catkin of S. cymbifolium.

», 10.—Ripe antheridium with paraphyses.

,, 11.—Vertical section of a capsule still enclosed in the calyptra. c, calyptra ;
s, cavity of sporangium; p, pedicel of capsule enveloped by the
vaginula,

(Fig. 1 from a specimen lent by Mr. Howse, the rest from Schimper’s work.)

* ¢Rntwickelungs-geschichte der Torfmoose,’ 1858.
VOL. VI. B

2 _ Transactions of the

hold equal rank with Mosses and Hepatic; the three classes,
Bryinz, or frondose mosses, Sphagnine, or bog mosses, and Hepa-
ticine, or liverworts (the Laubmoose, Torfmoose, and Lebermoose of
the Germans), thus forming one great muscal alliance.

As it may be of interest to know something of the histology of
the Sphagnums, and except the late Mr. Wilson’s admirable sketch
of the family in ‘ Bryologia Brit.’ we have little in our own
language bearing on the subject, I purpose on this occasion to point
out the chief characters which distinguish them from mosses, and at
a future time, with your permission, give an account of all the
British species, with illustrative figures of their structure.

Commencing with the spore, we find that on germination it does
not produce the much-branched confervoid prothallium of mosses,
but if growing on the wet peat, a lobed foliaceous production results,
exactly like one of the frondose Hepatice, as Anthoceros, and from
this the young plants grow. This was first observed by Hofmeister
in 1854. If germination occur in water, the prothallium is a fine
filament, the lower end of which forms roots and the upper enlarges
into a nodule from which is developed the young plant. As-soon
as branches form on the plants, in both cases the prothallium and
roots wither away. Next, the stem, which in mosses consists of uni-
form texture throughout, is in Sphagnums much more differentiated,
for we observe—Ist, a medulla, or central pith, of long cylindric cells
by which a current of sap is constantly passing to the growing
apex ; 2nd, a woody cylinder of firmer prosenchymatous cells; and
3rd, an outer, or bark-layer of one to four strata of thin walled cells,
always larger than the rest, and which in S. eymbifoliwm alone
contain spiral threads and foramina. The branches also are quite
pee and differ altogether in arrangement from those of mosses.

n the young state they are crowded into a capitulum at the top of
the stem, and as the internodes elongate they become separated, and
are then seen to be in lateral fascicles of three to ten, the bundle
originating at one side of a leaf base, every fourth leaf in the spiral
giving rise to a branch fascicle.

Of these branches, one part spread out horizontally and then
arch down, the rest being attenuated, pendulous, and pressed back
to the stem, and by these water is conducted to the very apex; in-
deed, Professor Schimper compares their action to a hydraulic
pump, fora tuft of plants placed dry in a flask of water immediately
carry on the fluid by the lower bark cells, and empty the flask by a
discharge of drops from the down-bent capitulum, but if some of
the branches and bark be removed, no passage of fluid takes place
beyond the injured part.

Of the sponge-like retention of moisture by Sphagnums, we have
often unpleasant experience when stepping on the green turf-like
surface of its beds, only to plunge deep into their interior, and

Royal Microscopical Society, 3

emerge soaked with the water concealed therein. They can also
absorb atmospheric moisture and transmit it downward, thus taking
up again at night what they had lost during the day ; and by this
perpetual interchange the stagnant pools in which they flourish
never become putrid. ‘The bark of the branches consists only of a
single layer of cells in communication with the innermost layer of
the stem bark ; but these are of two forms, for besides the ordinary
kind, there are others of a flask shape, larger, and with a circular
orifice, one of which always falls at a leaf-insertion.

The leaves of bog mosses are very peculiar, and are well known
as an elegant microscopic object ; those of the stem are more remote
from each other than in mosses, and in all the species two complete
spirals contain five leaves (phyllotaxy 2); their form is ovate or
tongue-shaped, with the base frequently more or less auricled.
Those of the branches are much narrower, and not only vary on
the two forms of branch, but on different parts of each. If we
look at a Sphagnum leaf in fluid with a sufficient power, the first
thing that strikes us is the beautiful sigmoid form of the areolation,
or cellular network; and next, the presence of a delicate fibril
forming spirals or rings on the inner wall of each cell, and by which
the thin membrane is kept expanded, while perforating the mem-
brane are distinct apertures or pores through which it is common
enough to find infusoria have passed, which may be seen sporting
about in the cell cavity ; and thirdly, that these large prosenchyma-
tous cells are always void of chlorophyl, and hence want the lively
green colour so noticeable in true mosses.

_ This, however, is not all. A more careful examination will
show that between the walls of these hyaline cells are placed
extremely narrow parenchymatous cells, which do contain chloro-
phyl. Moldenhawer first detected these in 1812; yet Carl Miiller,
in his ‘Synopsis Muscorum, terms them intercellular ducts; in no
case is there any approach to the formation of a nerve or midrib.
According to the colour of the chlorophyl in these parenchym cells,
is the colour of the Sphagnum tuft, only seen, indeed, in the living
or moist state, but presenting endless shades of rosy red, purple,
vinous red, bluish green, olivaceous, apple-green, and straw colour.
When dry or dead, the hyaline cells lose their transparency, and all
the species become more or less a dirty white. The spiral threads
are nothing but thickenings on the inner wall of the cell membrane,
such as occur frequently in the tissues of phzenogamous plants; in
one species only are they altogether absent, viz. the American
S. macrophyllum, which Professor Lindberg separates as the genus
Tsocladus.

The male flowers of Sphagnums differ also from those of mosses,
and in their arrangement, and the form of their antheridia, resemble
those of Hepatice; they are grouped in catkins at the tips ¢ lateral

B

+ Transactions of the

branches each of the imbricated perigonial leaves enclosing a single
slobose antheridium on a slender pedicel, which is inserted at the
side of the leaf base. Paraphyses surround them, but instead of
being simple, as in mosses, they are very long, much branched, and
of cobweb-like tenuity.

The perigynium of the female flower-sheath terminates one of
the short lateral branchlets at the side of the capitulum, and is of a
deep-green colour, with large sheathing leaves; the archegonia do
not differ from those of mosses.

After impregnation the fruit receptacle enlarges and extends
itself into a pseudopodium, on which the capsule is sessile; the
vaginula was thought to be absent from these plants, and hence
Bridel formed for them a section “ Musci evaginulati.” It is, how-
ever, very distinct, being the disk-shaped enlargement at the apex
of the receptacle in which the expanded bulbous rudiment of the
pedicel of the capsule is completely buried.

The calyptra, or outer cell-layer of the archegonium, has not
the definite form common to mosses, but is a very thin colourless
membrane closely investing the capsule, by the enlargement of
which it is torn irregularly into shreds, the lower portion being left
attached to the vaginula.

The capsule up to maturity remains in the perichetium, but
after that the receptacle elongates and carries it upward on this
pseudopodium, which does not correspond to the pedicel of a moss,
that being always found above the vaginula; still, a pedicel does
exist in Sphagnum, but it is bulb-shaped, and enveloped by the
vaginula. ‘The capsule itself is very uniform in all the species,
being almost spherical, the lid only slightly convex, without any
beak or point, and we never find any trace of a peristome. The
sporangium, or spore sac, does not attain the development found in
mosses, for it appears like a hollow hemisphere in the interior of
the fruit, its outer wall bemg coherent with the inner cell-layer
of the capsule, its inner wall with the columella lying beneath it.

The spores somewhat resemble those of Lycopods in being of
two kinds—macrospores produced by fours in a mother cell and
tetrahedral in form, and microspores which are more spherical, and
not half the size. .

With respect to the function of these plants in the formation of
peat, I cannot do better than quote Professor Schimper’s words.
He says :—“ Unless there were bog mosses, many a bare mountain
ridge, many a high valley of the temperate zone, and large tracts
of the northern plains, would present an uniform watery flat, instead
of a covering of flowering plants or shady woods. For just as the
Sphagna suck up the atmospheric moisture, and convey it to the
earth, do they also contribute to it by pumping up to the surface of
the tufts formed by them the standing water which was their cradle,

Royal Microscopical Society. 5

diminish it by promoting evaporation, and finally, also by their own
detritus, and by that of the numerous other bog plants to which
they serve as a support, remove it entirely, and thus bring about
their own destruction. Then, as soon as the plant detritus formed
in this manner has elevated itself above the surface water, it is fami-
har to us by the name of turf, becomes material for fuel, and all
Sphagnum vegetation ceases.”

Little noticed, then, as these plants may be, they perform func-
tions in the economy of nature which cannot be overlooked ; and it
is for the purpose of inviting more general observation of their
structure that I bring forward these remarks. Some seventeen
British species are known, all of which I hope to illustrate; and in
carrying out this object, I shall feel thankful for good specimens of
any of our species, but especially those occurring in the north
of Scotland, for the wild moorlands of Northern Europe have so far
proved to be the most prolific in new species.

ey

Il.—Structure of Podura Scales.
By F. H. Wenuaw, Vice-President R.M.S.

Mr. Molnrire has kindly presented me with a number of slides ;

two of them are superb specimens of the test Podura, L. ewrvicollis,

with markings remarkably dark and distinct. In one of the best

scales there is a singular case of fracture, evidently caused by the

slipping of the cover, which has dragged the specimen asunder near

one-third from the upper end, which is separated to a short dis-

tance. Projecting from

the largest portion is a

fragment, partly torn

away, as shown by

the accompanying cut,

\ \ which i ae outline

; NSS sketch taken by the

( SS camera lucida, 4000

N — diameters. On the

SSS right-hand extremity

the longitudinal tear

has taken place close

to a rib, or marking,

which is nearly iso-

4,090 lated. The transverse

tear at the bottom leaves most of the ends of the ribs exposed and

projecting, as the membrane has torn away from behind them. The

extremities of ribs 4 and 5 (counted from the right) are particularly

plain and prominent. I am willing to submit this specimen to the
inspection of anyone doubting the fidelity of the tracing.

How it can be maintained or admitted that these waved or con-
stricted ribs which give rise to the “ note'of exclamation” markings
are “illusory,” I am at a loss to imagine.’ The question can only
be determined by fragmentary pieces; but in the Podwre, from
the toughness and absence of brittleness in the scales, these are very
difficult to obtain, and it is seldom that a fortunate accident occurs
in the way shown. It was by fragments that the structure of the
diatoms became known, wherein the silicious nodules could be
traced down to a single atom, and their form is not now a question
of dispute.

Mr. Hennah, and others, have demonstrated how a number of
different patterns, not the least indicative of real structure, may be
produced by transparent bodies of regular form, such as glass rods
and bosses, &c. Much more incomprehensible would these appear-
ances be if the transparent ribbings were twisted, lobated, or in the
peculiar form of a Podura marking. The patterns would be innu-
merable with oblique light, and the whole area might be made to

Structure of Podura Scales. t

consist apparently of ‘‘ illusory beads,” and the belief now appears
to be, with the most unbiassed observers, that they are such.

The Degeeria domestica, or speckled Podura, when shown
opaquely * under a 7'sth or upwards, is a specially beautiful object.
The scales are apparently much thicker than in other species, and
the ribbings or !!! markings are of a reddish-brown colour—not
beaded, but slightly constricted at regular intervals, like the short
antennee of some insects, and in the deep intercostal spaces there
are numerous thin septe, or transverse bars, very fine and distinct,
of a greyish tint. Both these and the slightly “ varicose” spaces
on the ribs may be displayed in the form of beads, by dodging the
illumination. Where practicable, some form of opaque illumination
should always be employed for verifymg the structure of these
objects, for we are im this case quite free from the errors of
diffraction, which more or less accompany objects seen by trans-
mitted light, and cause an indistinctness of outline.

* The only plan at present known to me of illuminating these and other dry
test-objects is the one that I recently described, and consists in mounting them,
not on the cover, but on the slide itself. When the light is totally reflected from
- the upper surface of this at the part where the object is in contact, total re-
flexion will not occur, but the light will pass into the object, and in many cases—
as with some diatoms and the Podura—illuminate it with sufficient brilliancy on a
black field to be plainly seen with the highest powers and eye-pieces.

There are several methods of securing this total reflexion, some of which are
described in my paper “On a Method of Dluminating Opaque Objects under the
Highest Powers of the Microscope,” read before the Microscopical Society on
March 26th, 1856, and published in the ‘ Transactions.’ One of them consists of
a solid glass parabola with a flat top, upon which the slides were placed, with an
intervening film of highly refractive medium ; this was made at the time, and ever
since has been in use, mostly for viewing aquatic animalcules and living diatoms,
&e., for which it is especially convenient. The parabola is first lowered so as to
bring its top below the level of the brass table, and the object in a drop of water is
covered with thin glass. The parabola is then screwed up till the object is secured.
The rotifers are beautifully shown this way; but I have found that for objects on
slides its use is not so convenient as the small truncated or nearly hemispherical
lens and the ordinary parabola, as this arrangement affords greater facility for
traversing the object, as there is sufficient play for the lens for this purpose in the
hollow top.

As some have complained of a difficulty in using this, I repeat the directions.
The little lens is first patched on under the slide with a minute drop of oil of
cloves or turpentine where the Podura scales or other objects lay thickest. The
slide is then put on the stage with the lens in the top of the parabola. The next
thing is particularly to obtain parallel light. A large bull’s-eye condenser should
be employed with its flat side towards the lamp: hold a sheet of paper over the
plane mirror, and see that the light falls in the centre, and is of the same area as
the bull’s-eye or about fills the mirror; then go through the ordinary adjustments,
and if the field is not quite black raise the stop of the parabola: look at the objects
with a low power, those only that are brilliantly luminous are on the slide. Select
a proper one, and if it does not appear nearly in the centre of under lens, shift
this beneath it. One cause of failure may be the absence of objects detached from
the cover on the slide; but in English mounted objects, either of diatoms or scales,
I have in most cases found a few straggling specimens that have left the cover.
Possibly the figure of some of the paraboloids may have degenerated since I sup-
plied the original steel template near twenty years ago, which must have been
worn out before now; but this I will see to.

( 8 )

III.—On some New Parasites. By T. Granam Ponton, F.ZS.,
Honorary Secretary Bristol Microscopical Society.
PuatE XCI.

Some time ago I described a new parasite from the tiger, in the
pages of this Journal. I now propose to present to its readers
four parasites, which I believe to be hitherto undescribed, or new.

Menopon ptilorhynchi (mihi) (Plate XCL, Fig. 1).—Colour
bright fulvous. Head obtusely subtriangular; clypeus rotundate,
vertex rounded, base concave. Two broad irregular chestnut mark-
ings extend from the insertion of the antennz to the eyes, which
are connected at that point by a semilunar chestnut line, a chestnut
spot in the centre of the clypeus; prothorax elliptical ; metathorax
transverse ; abdomen ovate, hairy ; all the segments, except the last,
have a chestnut spot; legs long, tarsi clavate. Length 2°115 mil.
Habitat, Pélorhynchus holosericeus.

Nirmus Nitzschit (mihi) (Plate XCI., Fig. 2).—This species is
probably the same as that mentioned in Giebel’s list of the Halle
Collection, without either name or description. Supposing this to be
so, and that it is undescribed and unnamed, I have ventured to call
it Nitzschit, after the indefatigable student of these peculiar insects,
C. L. Nitzsch, and beg to give the following description of it :—Colour
pale yellowish-white. Head panduriform, clypeus rounded, antennz
rather long, second joint longest. Prothorax not so wide as the head ;
metathorax oblong, trapeziform. Abdomen lanceolate, a long fascicule
of hair between each of the four last segments. Legs somewhat
clavate. Length 2'538 mil. Habitat, Péclorhynchus holosericeus.

Docophorus Dennyti (mih) (Plate XCI., Fig. 3).—This species
I have dedicated to the late Mr. Denny, of Leeds, to whom I am
indebted for much kind advice and assistance in the study of the
Anopleura. Colour tawny. Head triangular, clypeus produced
entire; trabecule large, broadly truncated; antennz rather long.
Clypeus bordered by a chestnut line, with a transverse semilunar
marking of the same colour, a similar one on the occiput; a broad
irregular chestnut mark extends from the eyes to the prothorax.
Prothorax transverse, angles rounded, metathorax transverse. Abdo-
men ovate, hairy; pale fulvous, with a chestnut border. Length,
3:173 mil. Habitat, Prismites Mexicanus.

Trichodectes leporis (mihi) (Plate XCI., Fig. 4).—Colour bright
fulyous yellow, a dark chestnut spot at the eyes connected by a
diagonal line with a line of the same colour on the occiput. Head
suborbicular ; clypeus rounded, vertex convex, lateral margin deeply
sinuated ; eyes prominent ; antenn small, last joint broadly clavate ;
prothorax transverse ; metathorax not so wide as the head. Abdo-
men ovate, fulvous, hairy. Tibize clavate. Length, 2-538 mil.
Habitat, Lepus cannabinus,

Curton, May, 1871.

Sy

Wi) J ‘ e

ade")

IV.—On some Improvements in the Spectrum Method of Detecting
Blood. By H.C. Sorsy, F.R.S., &e.

In the following paper I shall give a condensed account of what I
have been able to learn in connection with this subject, and omit
everything that does not bear directly on determining whether any
stain is, or is not, due to blood. There does not appear to be any
probability of our being able to decide by this means whether it is,
or is not, human.

The spectrum-microscope used in these inquiries should have a
compound prism, with enough, but not too great, dispersive power,
or else the bands would be as it were diluted, and made less dis-
tinct. A combination of two rectangular prisms of crown glass,
with a rectangular of very dense flint, and another of less dense, of
such an angle as to give direct vision, turned towards the slit, as
lately made for me by Mr. Browning, appears to be the proper
medium, and has other important advantages. The cells used for
the experiments should be made from barometer tubing, and be
about one-eighth of an inch in internal diameter, and half an inch
long, one end being fastened to a piece of plate glass with purified
gutta-percha, like an ordinary cell for mounting objects in liquids.
It is, however, a very great advantage to insert between the plate
and the cell a diaphragm of platinum foil, having a circular hole
about two-thirds of the internal diameter of the tube, fixed so that
its centre corresponds with that of the cell. This prevents any
light passing upwards that has not penetrated through the whole
length of the solution, which is very important when using direct
concentrated sunlight to penetrate through turbid or very opaque
liquids. A small spatula made of stout platinum wire, flattened at
the end, is very convenient for adding small quantities of the re-
agents ; and they should be stirred up in the cells with a platinum
wire, flattened and turned up square at the end, like a small hoe.
The reagents commonly employed are a somewhat diluted solution
of ammonia, citric acid, the double tartrate of potash and soda, used
to prevent the precipitation of oxide of iron, and the double sul-
phate of the protoxide of iron and ammonia, employed to deoxidize ;
but in some special cases diluted hydrochloric acid, carefully-purified
boric acid, and sulphite of soda are required.

The character of a stain varies much with its age, and with the
nature of the substance on which it occurs. If quite recent, and if
the substance has no immediate influence on blood, the stain would
contain little or no colouring matter but hemoglobin. This is
easily dissolved by water, and when properly diluted—neither too
strong, nor too weak—it gives the well-known spectrum, with two
dark absorption-bands in the green. The addition of a very little

10 On some Improvements in the

ammonia and a small quantity of the double tartrate produces no
change, but on adding a small piece of the ferrous salt, about oth
of an inch in diameter, and carefully stirring, so as to mix without
much exposure to the air, these bands gradually fade, and are replaced
by the single broad and fainter band of deoxidized haemoglobin.
When stirred up so as to expose well to the air, the two original
bands of oxidized hemoglobin can be seen again. On gradually
adding a little citric acid, until the colour begins to change, these
bands slowly fade away; and, if the amount of blood was consi-
derable, a faint band would make its appearance in the red. When
previously deoxidized, this solution may be turbid, but not so as to
interfere with the result. The addition of excess of ammonia makes
all clear again, but does not restore the original bands, or only to a
slight degree, thus showing that a permanent change is produced
by citric acid—the hemoglobin is changed into hematin. This
alone serves to distinguish blood from by far the greater number of
coloured substances, which after being changed by acid, are restored
by alkalis to the original state. On deoxidizing with the ferrous
salt, we obtain the well-marked spectrum of deoxidized hematin,
with one very dark and another much fainter band in the green,
almost or quite invisible when the quantity is small. If too much
citric acid or double tartrate had been added, this solution might be
turbid; but, if all had been properly managed, it would be quite
clear. Since the deoxidization takes place rather slowly, especially
in cold weather, it is well to slightly stir up the ferrous salt at the
bottom, completely fill up the cell, cover it with a piece of thin
glass, remove the excess of liquid with blotting paper, and mix the
solution by turning the tube upside down, over and over again. On
reoxidizing the solution by stirring, the bands of deoxidized heematin
disappear, and the two bands of hemoglobin will probably be recog-
nized, owing to citric acid not changing the original merely into
hematin, but also giving rise to some methemoglobin. The whole
of these facts may be seen with a single cell, containing about 7)oth
of a grain of blood, and any experimenter should become quite
familiar with them before applying this method to suspected stains
in cases of importance. Very faint bands are best seen by lamplight.
On exposure to the air in a damp place, a blood-stain may be
completely decomposed by the growth of mould, but when not thus
destroyed it is partly altered into hematin. If, however, kept dry,
the hemoglobin gradually changes into a variable mixture of methe-
moglobin, hematin, and a brown substance not yet much studied.
This change takes place far more rapidly in the acid atmosphere of
towns and houses, especially when gas 1s burned, than in the open
country ; but it does occur even in the purest air, and in glass tubes
hermetically sealed. The presence of a weak acid in perspiration
may also cause a stain on a worn garment to be completely changed

Spectrum Method of Detecting Blood. 11

in a very short time, and the presence of a stronger acid on dirty
clothes may at once alter the hemoglobin into hematin.

On digesting in water a stain that has been kept until all the
hemoglobin has disappeared, the methemoglobin dissolves. When
the solution is sufficiently strong, this shows a band in the red, and
two fainter in the green. The addition of ammonia removes that in
the red, makes those in the green much darker, and develops a spe-
cial very narrow band in the orange. When deoxidized this solution
gives deoxidized hemoglobin. Since methemoglobin is formed at
once from hemoglobin by the action of a great number of different
oxidizing reagents, and since it can be reconverted into oxidized
hemoglobin by slight deoxidization, I am inclined to look upon it
as a peculiar oxidized modification. On adding a little of the double
tartrate and of the ferrous salt to even a dilute solution from an old
stain, the methemoglobin is deoxidized, and the well-marked spec-
trum of fresh blood can be seen. If left too long, the spectrum of
deoxidized hemoglobin is developed, but on well stirring, that of the
oxidized reappears, and the various other spectra may afterwards be
obtained, as described above. That part of the stain, insoluble in
water, which is chiefly hematin, may be dissolved in dilute citric
acid or ammonia, and when deoxidized the spectrum seen to even
greater advantage than when fresh blood is employed, because there
is no general shading in the green, due to there having been
methemoglobin mixed with the hematin. We may thus obtain an
excellent spectrum from a blood-stain nearly fifty years old. In
very old stains all the methemoglobin has disappeared, and some-
times even a considerable part of the hematin has been altered into
another brown colourmg matter, which does not give any well-
marked spectrum.

When a blood-stain has been made sufficiently hot to coagulate
the albumen, neither water, citric acid, nor cold ammonia will dis-
solve it, but by heating in dilute ammonia the hematin is easily
dissolved, and may be detected either before or after concentrating
the solution by evaporation. I may here say that the spectrum of
deoxidized hematin can in no way be better seen than by deoxidizing
a solution of fresh blood that has been boiled with dilute ammonia,
which gives rise to a very pure hematin.

In applying these principles to the detection of suspected stains,
it is desirable in the first place to examine a portion of the unstained
fabric, to ascertain whether any colour is dissolved from it by water,
and whether the solution has an acid, or alkaline, reaction. It-is
also important to ascertain whether colour is dissolved from the
fabric by dilute citric acid or dilute ammonia, and if so, to deter-
mine whether this would in any way interfere with the recognition
of blood by the processes described above. In the case of scarlet
cloth and of some other red fabrics, much colour is dissolved out by

12 On some Improvements in the

ammonia, but not by citric acid, which ought therefore to be used,
whereas in other cases ammonia is the best solvent.

Unless the stain is faint, a portion should be soaked in a few drops
of water in a watch-glass, the liquid squeezed out, allowed to stand a
short time in the glass, so as to deposit any small portions of the fabric,
and poured into one of the experiment cells. If the stain had been
recently made, and had not been changed by any special action, a
solution of hemoglobin would be obtained, and the various spectra
could be seen one after the other, as already described. If, however,
the stain were a few days or a few weeks old, we should obtain a
mixture of hemoglobin and methemoglobin, or the latter alone.
The various spectra could then be developed, and compared side by
side with those from fresh blood, to be sure that there is complete
correspondence in the position and relative intensity of the bands.
The residue insoluble in water should then be dissolved in dilute
citric acid or ammonia, according to the nature of the fabric, and
the spectrum of deoxidized hematin developed. If insoluble in cold
citric acid or ammonia, hot ammonia should be tried, since the stain
might have been so heated as to coagulate the albumen. If it be
desirable to keep the specimen of deoxidized hzematin for subsequent
reference, the cell may be covered with a piece of thin glass, and,
after removing the excess of liquid, the edge of the cover painted
round with gold-size. When properly managed, such an object
will show a perfectly good spectrum, even after many weeks.

If therefore we have a sufficient amount of a moderately old
stain, we may easily see in succession the seven very different
spectra of the following solutions:—1. Neutral methemoglobin.
2. Alkaline methemoglobin. 3. Deoxidized hemoglobin. 4. Oxi- -
dized hemoglobin. 5. Acid hematin. 6. Alkaline hematin.
7. Deoxidized hematin. If the amount was very small, only
Nos. 4 and 7 would show distinct bands, and the rest would be
characterized rather by their comparative absence; and it must
always be borne in mind that Nos. 1 and 2 may be modified by
the presence of unaltered hemoglobin, No. 3 by that of dissolved
hematin, and Nos. 5, 6, and 7 by that of undecomposed heemo-
globin or methemoglobin.

It would be easy to obtain other preparations, and to see several
other spectra derived from blood, but it appears to me unneces-
sary, since the above are so remarkable and unique in the manner
in which they are produced, one after the other, especially by
deoxidization and reoxidization on stirring, which seldom occurs in
other colouring matters, that they afford as satisfactory a test for
blood as could be desired, and still more so when we consider not
only the general character of the spectra, but also the exact position
of the absorption-bands, and that some are so most unusually dis-
tinct.

Spectrum Method of Detecting Blood. 13

The above directions apply to simple cases, where the amount
of material at command is amply sufficient, and the fabric on which
the stain is found does not contain anything that makes the blood
insoluble, or interferes with the various tests. I shall, however, now
describe what should be done in cases which are made specially
difficult by various causes. If the stain were very faint, from the
presence of very little blood, or if the greater part had been re-
moved by washing with water, it might be desirable not to divide
the material, but to examine the whole at once. The stained por-
tion should therefore be digested in a few drops of dilute citric acid
or ammonia, and the presence of hematin determined, as already
described. If faint and spread over a considerable surface, it might
be well to digest in citric acid or ammonia diluted with much more
water than would fill the experiment cell, and afterwards concen-
trate the solution by gentle evaporation. By this means blood
could be detected, even when considerable effort had been made to
remove it, and only a faint brown tinge left, just visible on white
linen. ‘There would generally be no difficulty in the case of a
stain on cloth which had been sponged, for enough blood solution
would be left in the fabric.

The presence of mordants in cloth or prints may require us to
somewhat modify our proceedings, especially if the stain had been
made wet, and to a great extent removed, so that we have only the
dried-up solution of blood, thoroughly incorporated with the mor-
dant. Certain kinds of brown cloth are of such a character, and
about seven years ago portions of a wetted stain were sent by me
to a number of the highest authorities in the detection of blood, and
they said that neither they nor anyone else could recognize it.
However, by proper care, I found that after a lapse of six years it
could be detected by the spectrum method. The best plan was to
digest a portion of the cloth in dilute ammonia, and to squeeze it
well over and over again, with a pair of forceps, and finally with
the finger and thumb, so as to obtain as much of the solution as
possible. This was very turbid, but when deoxidized in the usual
manner, and illuminated by concentrated light direct from the sun
itself, the band of deoxidized hematin was quite distinct. When
the cell was kept for a while, so that the insoluble part settled to
the side, no band was visible, and therefore the hematin was eyi-
dently combined with the mordant. It will thus be seen that it
may be most important not to filter or allow the insoluble matter to
subside, but to overcome the opacity by means of a sufliciently
intense light. If the sun could not be made use of, the lime or
electric light would no doubt be the best substitute.

When fresh blood solution is agitated in a test tube with vege-
table soil, and left until quite clear, the colouring matter is com-
pletely carried down with the earth. Dilute ammonia, however,

14 On some Improvements in the

dissolves out hematin, and therefore, in testing portions of soil,
they should be digested in considerably more of that solvent than
will fill an experiment cell, and after the solution has become quite
clear it should be concentrated by evaporation. The spectrum of
deoxidized hematin may then be seen by following the ordinary
method. The same process should be adopted in examining stains
on clothes impregnated with earth or earthy dust, and marks on
iron contaminated with much rust, if water will not dissolve out
unaltered blood or methzemoglobin.

The importance of being able to detect blood-stains on leather
was prominently brought before me by a case in which the trial of
a suspected person depended on the nature of certain dark marks
on his gaiters. The presence of tannic acid so completely mordants
the blood, that neither water nor citric acid will dissolve it, and am-
monia gives rise to a most inconveniently dark solution. If the
stain is on the surface, and has never been wetted, a thin shaving
should be cut off, so as to have as much blood and as little leather
as possible, and the blood should be dissolved off without exposing
the solution to the action of the leather itself. This may be accom-
plished by taking one of the experiment cells, nearly filled with
water, bending the shaving, and inserting it into the upper part of
the tube, so as to touch the water, being careful to arrange it so that
the stain may be on the convex side of the leather, and in contact
with the water. When a drop of blood falls on leather, many red
globules are filtered out from the serum and left on the surface,
and, when thus treated, they dissolve, and the coloured solution
sinks at once to the bottom of the cell, without coming in contact
with the leather. The various spectra may then be observed in the
usual manner. This method would be of little or no use if the
stain had been wetted, and for a long time I concluded that after
such treatment it would be impossible to recognize blood. How-
ever, after many experiments, and after having again and again
almost given up the inquiry in despair, I found that the difficulty
could be overcome in a very simple manner. The best solvent for
the insoluble compound of the colouring matter of the blood with
tannic acid, is hydrochloric acid diluted with about fifty times its
bulk of water. If stronger or weaker, the result is not so good.
When a portion of unstained common brown leather is digested in
this dilute acid, the solution is scarcely tinged yellow. On adding
excess of ammonia, the colour becomes pale purple, or neutral tint,
made deeper when the double tartrate and the ferrous salt are
added, but remaining nearly clear. This gives a spectrum very
dull all over, but without any trace of definite bands in any part.
The depth of colour varies much with different specimens of
leather. A portion of similar material soaked with wetted blood,
gives a yellow solution, made brown-purple and turbid by the

Spectrum Method of Detecting Blood. 15

double tartrate and ammonia, and remains so when deoxidized.
The band of deoxidized hzematin can however be distinctly seen with
a light sufficiently strong to penetrate the turbid and dark solution.
Before examining the suspected stain, 1t would be well to make out
how much of the unstained leather could be used without giving
too dark a solution, and to use no more of the stained. If the deoxi-
dized solution be too turbid, the cell may be kept for a while hori-
zontal, until the deposit has subsided sufficiently to allow the
principal absorption-band to be seen ; but it is not so distinct, when
all has subsided, as though the greater part of the hematin still
existed as a compound insoluble in dilute ammonia.

The presence of tannic acid in wood and other substances might
make it necessary to employ a similar process, if the relative amount
of blood were so small, that none couid be dissolved out by water,
or dilute citric acid.

Cases might occur when it would be necessary to decide whether
blood were present, along with some other coloured substance,
soluble in water. The method to be employed would depend much
on the nature of this impurity. If it were a colouring matter,
belonging to what I have described in former papers as group A,
in which the absorption is removed by sulphite of soda, in an
alkaline solution, there would be no difficulty in seeing all the
spectra. Thus, for example, it is easy to add so much magenta to
the solution of a little blood, that its absorption-bands are entirely
hid; but a small quantity of sulphite of soda so completely removes
the colour of the magenta, that the various spectra of the blood
may be seen almost as well as if it had been pure.

The colouring matters of my group B that are most likely to
occur, are those of fruits, and in them the presence of the free acid
would be almost certain to have changed the hemoglobin into
hematin. The best plan would then be to add excess of ammonia,
and, if the solution were made too dark, to dilute it with so much
water that the strongest light at our command would show the
green part of the spectrum sufficiently bright to prove that no
absorption-band occurred there. On deoxidizing in the usual
manner, the solution may be made somewhat darker by the presence
of tannic acid, but the darker band of deoxidized hematin could
be recognized without material difficulty.

By far the greater number of the colouring matters belonging
to my group C are yellow and orange-coloured ; and, since these
chiefly absorb the blue rays, they do not interfere with our seeing
the bands of the blood spectra, which occur in the green. Cochineal
is one that requires special attention. The addition of ammonia to
its solution in water gives rise to two bands in the green, which,
though differmg materially from those of blood, are yet so nearly
in the same situation, that they completely disguise the presence of

VOL. VI. Cc

16 Spectrum Method of Detecting Blood.

a small amount of blood. However, on adding a small excess of
boric acid, the bands of the cochineal are made more faint, and very
considerably raised towards the blue end, so as to leave the red end
of the green clear, whilst those of oxidized hemoglobin are not
changed, and that nearer the red end, if not both, can be seen
perfectly well. By proceeding in the usual manner, there is no
great difficulty im recognizing the darker band of deoxidized
hematin.

Other special difficulties might occur in particular instances,
but I trust that these examples will suffice to show how they may be
overcome. Ido not now know of any that require special remarks ;
and, as far as I am able to judge, we need never despair of detecting
blood, so long as any hematin remains undecomposed. Fortunately
it resists decomposition so well, that this would rarely happen in
ordinary circumstances; but yet there are cases in which it does
occur, as, for example, when acted upon by strong ozone, or other
powerful oxidizing reagents.

It is quite possible that stained garments might have been
washed, and some of the water employed might be obtained. If
no soap had been used, this water could be examined in a long tube
of thick glass, ten inches or more in length, and a quarter of an
inch in internal diameter, permanently closed at one end with a
circular piece of plate glass, and, when filled, covered over at the
other with another glass. For examining solutions in such tubes a
small pocket spectroscope, such as recently made for me by Mr.
Browning, is extremely convenient, and suitable in every respect.
If only two or three days old, the bands of oxidized hemoglobin
might be seen; but if the solution had been kept longer, and they
could not be detected, it should be concentrated by evaporation at a
gentle heat, and tested for hematin. If during evaporation any
deposit be formed, insoluble in cold dilute ammonia, it should be
dissolved by the aid of heat. When soap is used in washing off
stains, the alkali soon changes the hemoglobin into hematin, and
the soap makes the solution inconveniently turbid and opaque. It
is best in such a case to agitate the suspected soap and water with
ether, remove it with a pipette, after the two liquids have com-
pletely separated, and repeat the process over and over again, with
fresh ether, until the aqueous solution at the bottom has become
quite clear and free from soap. It should then be concentrated by
evaporation, and examined for hematin, as usual. Of course in all
such cases it would be desirable to test the solution as soon as pos-
sible, lest decomposition should occur, but by these means a very
small quantity of blood, that would show no colour, might be recog-
nized within a week or two, but probably not after.

For the detection of blood in urine, a tube about ten inches
long is very suitable. If turbid it should be filtered ; but, since a

Cellular Structure of the Red Blood Corpuscle. 17

considerable number of red globules might be separated, the deposit
on the filter should be dashed with a little water, and this solution
either examined by itself, or added to the filtered urine. If the
depth of colour in the ten-inch tube be so great, that the yellow end
of the green part of the spectrum is absorbed, the urine must be
somewhat diluted, or examined in a shorter tube. When the depth
of colour is about an average, I find that by this means as little as
tosooth part of blood can easily be detected in fresh urine, wuich is
equivalent to about one drop in a pint. |

V.—On the Cellular Structure of the Red Blood Corpuscle.

By Josupu G. Ricnarpson, M.D., Microscopist to the Pennsylvania
Hospital, Philadelphia, Pennsylvania.

For many years after the magnificent cell theory was first accepted
by physiologists, the doctrine of Schwann, who regarded the red
blood disks as minute membranous sacs containing a coloured fluid,
passed almost unquestioned ; but of late, especially since more care-
ful microscopic observations have become customary, it has been
found that the supposed bursting of these little bladders, long
looked upon as one of the strongest proofs of their cellular nature,
does not take place, and at the present time some of our leading
authorities, both in America and in Great Britain, assert positively
that the coloured blood disks are non-vesicular, and deny any dif-
ferentiation of their substance into cell wall and cell contents.

Thus, for example, Professor Austin Flint, jun., in the second
volume of his great work on the ‘Physiology of Man,’ p. 116,
remarks :—“'The structure of the blood corpuscles is very simple.
They are perfectly homogeneous, presenting in their normal condi-
tion no nuclei or granules, and are not provided with an investing
membrane. A great deal has been said by anatomists concerning
the latter point, and many are of the opinion that they are cellular
in their structure, being composed of a membrane with viscid semi-
fluid contents. Without going fully into a discussion of this point,
it may be stated that few have assumed actually to demonstrate
this membrane, but they have for the most part inferred its exist-
ence from the fact of the swelling, and, as they term it, bursting on
the addition of water ; and particularly, as it seems to me, to make
the blood corpuscles obey the theoretical laws of cell development
and nutrition laid down by Schwann. Their great elasticity, the
persistence with which they preserve their bi-concave form, and
their general appearance, would rather favour the idea that they
are homogeneous bodies of a definite shape, than that they have

c 2

18 On the Cellular Structure

a cell wall with semi-fluid contents; especially as the existence of a
membrane has been inferred rather than demonstrated.”

Professor Lionel Beale observes, on p. 169 of his work entitled
‘The Microscope in Practical Medicine :—* The red blood corpuscle
of man, and mammalia generally, consists of a mass of soft viscid
matter, perhaps of the consistence of treacle, composed of heemato-
crystalline. It is, at least in certain states, soluble in water, but is
only dissolved by serum and the fluid part of the blood very slowly.
The outer part of this matter is of firmer consistence than the
interior, especially in the older corpuscles. When the latter are
placed in water the more soluble matter is dissolved, leaving the
harder external portion.” Dr. Beale further recounts sundry con-
siderations which, he says, prove conclusively “that the red blood
corpuscle is not a cell.”

The distinguished French physiologist, Professor Ch. Robin,
supports similar views, asserting, on p. 697 of ‘ Dictionnaire de
Médecine, de Chirurgie, &c.,’*—“ The red blood corpuscles are con-
stituted of a homogeneous mass of globulin which is imbibed by or
united molecule by molecule to the colouring matter, or heematosine,
and a certain quantity of fat and saline materials. In mammals,
the whole mass is homogeneous, and without any nucleus after the
period when the human embryo, for example, attains a length of
about an inch; but previous to that the globules, having a magni-
tude of from '010 to +011 of a millimetre, possess a little round
granular nucleus. In all the oviparous vertebrates the globule,
whatever its form, encloses a colourless,’spherical or oval nucleus,
insoluble in water and acetic acid, while the red mass is soluble in
these menstrua.”

In the course of some researches of my own, however, “ On the
Detection of Red and White Corpuscles in Blood Stains,” + I have
shown, first, that if a few drops of fresh blood be stirred up in
many times its bulk of pure water, the coloured hemato-erystallin
will be dissolved, while a whitish insoluble residue, found under the
microscope to be composed of transparent hyaline spheres about
zsooth of an inch in diameter, subsides to the bottom of the vessel ;
secondly, that if a fragment of dried blood-clot is exposed to the
action of a current of fresh water, the hemato-erystallin will, after
a few minutes, be washed away, leaving an aggregation of what
appear to be similar delicate cells, altered in shape by mutual pres-
sure, but still preserving much of their rounded contour; and
thirdly, by a calculation of the superficial area of the human red
blood disk, based upon accurate measurements of its dimensions
when magnified nearly 1800 times, that supposing a cell wall to
exist, there would be almost precisely enough membrane contained

* KE. Littré et Ch. Robin, Paris, 1865.
+ ‘Am. Jour. of Med, Sciences,’ July, 1869.

a,

of the Red Blood Corpuscle. 19

in it to cover the surface of a sphere having the exact diameter of
the red corpuscles when rendered globular by the action of water.

In one of my experiments on the action of water upon blood, as
detailed in that paper, the development of Bacteria so obscured
these supposed membranous cell walls that they became unrecog-
nizable after standing seventy-two hours, so that, in order to deter-
mine whether their apparent insolubility could be overcome by
prolonged maceration, | made the following additional investiga-
tions :—

On the 24th of March, 1870, I thoroughly stirred two fiuid-
drachms of blood into two fluid-ounces of fresh water, and allowed
the mixture to stand undisturbed for forty-eight hours, when a
light and flocculent deposit of a pale pink colour, occupying about
half a fluid-ounce of the liquid, had fallen to the bottom of the
vessel. On examination under the 34-inch objective, this was
found to be ‘chiefly composed of very transparent spherical bodies,
about zz'soth of an inch in diameter, which became beautifully dis-
tinct and quite visible with an ordinary }-inch when tinted by a
minute portion of aniline solution introduced at the margin of the
cover. In order to prevent the development of Bacteria, about two
fluid-drachms of carbolic acid solution were added, and the mixture
kept covered in a room of ordinary temperature for four weeks, at
the end of which time the delicate colourless spheres were still dis-
tinctly visible, although they had a little further diminished in size,
only measuring about 5 9'soth of an inch across.

From these various observations, it appears that human red
blood corpuscles are composed of two different ingredients, the one
hemato-crystallin, of a crimson colour, and dissolving freely in
water, the other of a whitish hue, and insoluble in water, even on
prolonged maceration ; but so minute are the blood disks in mam-
malia generally, that it is extremely difficult to determine the exact
relation of these constituents to each other. It occurred to me,
however, that investigations upon the large blood globules of rep-
tiles might be more successful, and after numerous disappointments
I procured, in November last, from a former patient near my late
residence on Cayuga Lake, in Western New York, two specimens
of the Menobranchus or Proteus, whose red blood disks, as far as
known, with a single exception, exceed those of all other animals in
magnitude, measuring about 35th of an inch in length by gtoth
of an inch in breadth, and actually visible, in a strong light,
to the naked eye of a myopic person like myself. The gigantic
corpuscles being about six times the diameter, and consequently
216 times the magnitude of those of man, evidently afford much
better opportunities for the detection of their membranous parietes,
if such exist; and in addition to this great advantage, I discovered,
quite unexpectedly, in the course of my experiments upon them,

20 On the Cellular Structure

that their coloured portion possessed the remarkable property of
crystallizing with great readiness within its envelope, and so
enabling us to analyze, as it were, the corpuscle, by furnishing a
singularly positive demonstration of the existence of a cell wall,
totally distinct from the cell contents which undergo crystallization.
These crystals, as often happens with those produced in the pre-
sence of organic matter, are frequently irregular, but their typical
form appears to be that of a quadrangular prism, with dihedral
summits, the angles sometimes being truncated. They may be
easily prepared, as I have now done at least fifty times, by deposit-
ing a drop of blood from the Menobranchus upon a slide, allowing
it to remain uncovered about ten minutes, or until a mere line of
desiccation appears at the margin, and then covering it with a thin
glass ; on examination with a power of 200 diameters, numerous
corpuscles along the edge of the drop where the liquor sanguinis
has become most concentrated, will be frequently discovered to con-
tain one, two, or more crystals; and under the most favourable cir-
cumstances of temperature and hygroscopic condition of the sur-
rounding air, I have seen this process of crystallization go on until
the contents of almost every corpuscle assumes the crystalline form,
either wholly or in part, the cell wall being left in the former case
perfectly colourless and transparent.

The effect of these crystals as they gradually elongate is very
remarkable and interesting, being precisely that which would be
produced by sticks of similar shape contained within an ordinary
bladder partly filled with fluid; thus, for example, I have several
times seen a single crystal, as if increased in length, thrust out the
ends of the oval corpuscle, until the conjugate diameter of the cell
became one-third greater, while its transverse dimension diminished
to less than half its original magnitude, the nucleus bemg com-
pressed closely against the side of the prism. Or in cases where
one or more crystals happened to le across the long axis, that
decreased until the whole corpuscle assumed a lozenge-shaped or
rectangular form, as in a very perfect specimen which I have
mounted dry, the folded edge of whose capsular membrane may be
seen supported by the crystals, like a washerwoman’s clothes-line
upon its prop.

It may in the first place be objected to this demonstration, that
the appearance which it affords of a plicated membrane around
the extremities of the crystals is caused by partial desiccation of
the surface of the corpuscle while the specimen was being pre-

pared; that such cannot, however, be the case, is proved by the
fact that if, to blood freshly drawn from the reptile upon a slide,
water is added, beneath the microscope we can produce an exos-
mosis of the coloured material into the diluted liquor sanguinis,
leaving the same transparent cell wall, which becomes visible when

of the Red Blood Corpuscle. 21

the cell contents are crystallized within it; and it is obvious that a
membranous envelope, which is equally distinct under the opposite
states of dryness and moisture, cannot be considered the result of
either condition. Again, perhaps it will be asserted, secondly, that
the appearances here presented might be simply the result of par-
tial crystallization in such a drop of viscid material as Professors
Flint and Beale consider the red blood disks, which drop, if the
process were complete, would haye entirely assumed the crystalline
form; but I think I can quite destroy the force of that or any
similar argument by the aid of other mounted preparations, some
of them showing that well-developed crystals, which happen to lie
in favourable positions, may include almost all the coloured portion
of the corpuscle, without in the least affecting the contour of its
cell wall.

I regret exceedingly that the difficulty of obtaining and preserv-
ing the Menobranchus alive, has prevented me from attempting to
exhibit specimens of its fresh blood; but in the hope that other
microscopists will repeat and correct or confirm my researches
upon it, [ am desirous of recording them and the conclusion which
they seem to involve.

After a great many attempts, on which I spent altogether about
eight hours’ steady work, I have twice succeeded in cutting a cor-
puscle in two with sharpened needles upon a stage of the micro-
scope, and beneath a half-inch objective, combined with a No. 2
eye-piece. On penetrating the vesicle with the edge of the needle,
its coloured contents were instantly evacuated, and disappeared at
once in the surrounding fluid, while the cell wall immediately
shrunk together, and became twisted upon itself, and around the
nucleus into a perfectly hyaline particle, which showed some ten-
dency to adhere to the point of the instrument. It would there-
fore seem that the hemato-crystallin was neither viscid nor semi-
solid, and that the cell wall was structureless, and possessed only
moderate tenacity, but of course the observations were too few in
number to be accepted as conclusive.

When the corpuscles remained for two or three hours under
observation, those which did not crystallize, often showed the
wrinkled appearance figured by Hassal in his Illustrations, and
described by Rollett, in Stricker’s ‘Handbuch der Lehre von den
Geweben,’ Zweite Liefrung §. 286, and which seemed to me due to
the tendency of their colourless envelope, as the contained heemato-
crystallin condensed around the nucleus, to accommodate itself to
the diminished contents of the cell by falling into folds frequently
ramifying from the nuclear centre. When pressure was made by
means of a mounted needle upon the covering glass, almost directly
over a red disk, whose contents had undergone this contraction,
the first effect was to round out the contour of the corpuscle, and

29 On the Cellular Structure

unfold the creases in its walls, the globule behaving as you might
expect a bladder half full of water to do if you stepped firmly upon
its centre ; on continuing the process, however, no rupture of the
walls could be detected, the contained fluid appearing to rapidly
transude through its former envelope, which, on the needle being
removed, collapsed to perhaps half its former size, and presented
the aspect of a loose bag, almost without coloured contents, sur-
rounding the nucleus. These changes were also examined under the
yy-inch objective, giving a power of almost 1200 diameters, by
adjusting its component lenses, for a covering glass slightly thinner
than that actually employed, and then cautiously screwing down
the objective, so as to compress a blood disk beneath it; under
this finely graduated pressure and high magnifying power, the
apparent expanding of fold after fold, in the plicated wall of a per-
viously wrinkled corpuscle, became strikingly evident. After
tinting the external portion of the red disk with aniline solution, and
then applying considerable force to the covering glass, either by
means of a mounted needle under a low power, or, with the ex-
tremity of a high objective itself, so as to empty out all the heemato-
crystallin, the shrivelled envelope could be traced after the
removal of the pressure closely applied to the surface of the nucleus,
and under such circumstances occasionally presented an obscurely
granular appearance.

Sometimes a few of the corpuscles situated near the edge of the
thin glass, and therefore most exposed to the action of the air,
appeared, after three or four hours, to become cracked in various
places from the circumference to their centre; those fissures seem
to involve not only the cell contents, but also the supposed cell
wall; although at first sight this phenomenon may be deemed
inconsistent with the older theory, in regard to the structure of
the red disk, yet I think that it can be explained by supposing
that the hemato-crystallin had in these cases undergone a sort of
troubled crystallization, causing it to form a mass of tolerable
firmness, which split into fragments as it became dry, and at the
same time cracked its membranous envelope, just as a piece of
muslin frozen fast to a lump of ice is sometimes broken with the
fracture of the surface to which it is attached. In some instances,
the delicate and transparent cell wall could be detected in the flaw
of the hemato-crystallin, its outer edge showing a concave line
across the peripheral extremity of the fissure.

The addition of water to the fresh blood gave very interesting
results, and occasionally afforded an admirable proof of the exist-
ence of a membranous envelope. ‘The first effect of diluting the
liquor sanguinis was to increase the thickness of the corpuscle, and
under its further action the disk gradually became less elongated,
until it assumed a spheroidal form, the coloured portion bemg

of the Red Blood Corpuscle. 23

rapidly dissolved out, and leaving the nucleus and cell wall more
distinctly visible. In one instance, a corpuscle which had become
quite decolorized attached itself to some little mass of granular
matter, so that it could be retained under observation while I set
up currents beneath the cover by tapping the latter with a mounted
needle. On changing the direction of these currents so as to
strike the disk upon various parts of its surface in succession, I
was enabled to satisfy myself conclusively that it possessed a
bladder-like cell wall, perfectly flexible (now that it was no longer
distended with hemato-crystallin), and capable of being dimpled
in, as it were, by the force of the current impinging upon any side
until it applied itself accurately to the subjacent surface of the
nucleus, thus furnishing strong evidence against the doctrine of a
sponge-like stroma (or oikoid), as taught by Bricke and Stricker,
being a constituent of the red blood corpuscle.

If water was allowed to flow in upon a specimen, whose disks
had undergone the curious crystallization above described, diluted
liquor sanguinis seemed to rapidly enter the corpuscles by endos-
mosis, and dissolved the contained crystals which generally assumed
a foliaceous appearance, such as we often see crystals of triple phos-
phate put on, when macerated in alkaline urine. As the hemato-
crystallin dissolved, the natural colour of the corpuscle was
restored ; its walls, if they had been previously propped out upon
the points of the crystals, reassumed their normal shape, and in
some instances these shortened cr broken crystals were observed to
move freely in the cavity between the nucleus and the cell wall.

Before attempting to make any deduction from the above experi-
ments upon the blood of the Menobranchus, it may not be amiss
to refer briefly to the views entertained by most German writers in
regard to the red blood corpuscle. According to Rollett, in Stricker’s
‘Handbuch’ above referred to, p. 296, Hensen was led, from the
apparent retraction of the cell contents from the membrane as
seen in the blood corpuscles of reptiles, to ascribe to the red disks a
protoplasm which, accumulated especially around the nucleus and
over the inner surface of the envelope, was bound together by
delicate radiating crossed threads, and in its interstices contained
the coloured liquid cell contents (gefiirbte zellflissigkeit) ; but in
the opinion of Rollett, this thing is untenable in view of the
knowledge we have lately obtained in regard to the properties of
protoplasm, from the researches of Max Schultze and Kihne.

Briicke, who has observed these appearances after the action of
a 2 per cent. boric acid solution, pictures to himself in explanation
thereof, in the first place, “a porous form element, consisting of a
motionless, very soft, colourless, and perfectly transparent sub-
stance ; further, he represents to himself the body of the corpuscle
as composed of a living organism, whose central portion forms the

24 On the Cellular Structure

nucleus of all nucleated red blood globules, and is free from
hemato-globulin, while the remaining portion contains the entire
mass of the latter. The last-mentioned part Briicke considers as
lying in the interspaces of the porous mass, filling them completely,
but at the same time forming a continuous whole with the non-
pigmented portion. The colourless porous substance he calls
Otkoid, all the remainder he names Zootd; and considers that, by
the partial or complete withdrawal of the Zooid from the Oikoid,
the occurrence of the above-mentioned appearances is explained.
Stricker himself believes in the Oikoid of Briicke, but calls the
remainder of the corpuscle its body (der Lieb).”

Recapitulating now the facts which I have detailed, militating
against the views of Flint, Beale, and Ch. Robin, who hold that the
red blood corpuscles of mammals are homogeneous drops of a jelly-
like substance, we find first, that when human blood is diluted with
pure water, the bi-concave disks in general gradually assume a
bi-convex and finally a globular form, their coloured portion being
entirely dissolved, sometimes in the course of a few minutes, while
the transparent colourless constituent which retains the spherical
shape is completely insoluble in water, even during the prolonged
maceration of over thirty days; and second, that when a mass of
desiccated corpuscles, such as occurs in a dried blood-clot, is washed
with pure water, so as to remove all the hemato-crystallin, the
outlines of the compressed red blood disks may be readily de-
tected on examination with a sufficiently high power; further, that
in the red globules of the Menobranchus, which may be supposed
to bear a more or less close analogy in their constitution to those of
mammals, it is possible to analyze the corpuscle by separating the
coloured cell contents from the colourless cell wall, either by punc-
ture of the membrane, by crystallization of its enclosed fluid, or by
pressure upon the corpuscle, forcing out its contents apparently
through the pores of the membranous capsule in the same manner
that quicksilver is strained by pressure through the sides of a
buckskin bag. :

In opposition to the theories of Hensen, Stricker, and Briicke,
who consider the red blood corpuscles are made up of a colourless
porous substance called Oikoid, and a coloured more fluid ingredient
denominated Zooid, may be enumerated the following circumstances :
—First, if, on the one hand, we consider that a porous substance
of the definite bi-concave form, analogous to a disk of compressed
sponge, exists, it seems impossible to account for this stroma
assuming a globular shape when acted upon by water, since the
full diameter of the sphere, when formed, is occupied by the least
amount of distended matter, while the dimension, in which lay the
greatest bulk of stroma previous to the addition of water, is actually
diminished ; on the other hand, any hypothesis that the porous

of the Red Blood Corpuscle. 25

substance coalesces, on the removal of its hemato-crystallin, into
a jelly-like drop, is negatived by the fact that occasionally, as is
also described by Professor J.C. Dalton, one side of a corpuscle, ren-
dered colourless by water, fails to assume a convex form, being
apparently sucked in by the other side, which becomes exaggeratedly
convex, until the whole corpuscle resembles a bell, or more accu-
rately a liberty cap, in shape, without any tendency to present the
outline of a sphere. Second, the appearance of the specimens I
have examined strongly indicates the existence of a dense mem-
brane, thrown into folds around the extremities of projecting crys-
tals, just as a loosened tent cloth would be around the point of a
cane thrust against it from the inside; and further, the movement
of the crystals, when partly dissolved, around the nucleus but con-
fined within the corpuscle as described in the early part of this
paper, both tend to show that the cavity of the corpuscle between
the nucleus and the membranous envelope is quite unoccupied by
solid matter. Third, the perfect freedom with which one side of
the cell wall of a red blood globule from the Menobranchus when
acted upon by water may float in until it touches the nucleus, and
out again to its own place, will, I think, furnish conclusive evidence
to anyone who sees it as I have done, against the existence of a
porous substance which maintains the shape of the blood disk.

From these‘ researches I therefore conclude that the older
theory, which asserts that the red blood corpuscles of the vertebrata
generally are vesicles, each composed of a delicate, colourless, in-
elastic, porous, and perfectly flexible cell wall, enclosing a coloured
fluid, sometimes crystallizable, cell contents, which are freely soluble
in water in all proportions, explains the physical phenomena pre-
sented by red blood globules far more satisfactorily than any other
hypothesis which has hitherto been advanced; and, moreover, that
the usual bi-concave discoid form of the corpuscles in most mammals,
as well as the changes of shape which they undergo in fluids of
greater or less specific gravity than the liquor sanguinis, becoming
crenated in denser, and globular in rarer liquids, are such as to be
perfectly explicable by the light of our present knowledge in regard
to the laws of the exosmosis and endosmosis of fluids through mem-
branes; the equilibrium of these forces being maintained in normal
serum, and one or the other being rendered preponderant if the
specific gravity of that fluid is disturbed.—Tvransactions of the
American Medical Association.

cen»

VI.—On the Use of the Nobert’s Plate.
By Assistant-Surgeon J. J. Woopwanp, U. 8. Army.

I vo not think the question of priority as to the resolution of the
nineteenth band of the Nobert’s plate, about which Mr. Charles
Stodder makes such warm reclamations in the March number of this
Journal,* possesses in itself enough general interest to make it worth
while for me to add anything to what I have heretofore written on
this head. If, however, as seems very probable, the Nobert’s plate
is to be much employed in ascertaining the comparative defining
power of fine objectives, it is important that those who use it should
have some reliable means of knowing whether they have actually
resolved any given band; and such loose ideas appear to be enter-
tained with regard to the matter in many quarters that it seems not
undesirable to offer a few remarks on the difficulties involved, and
the best means of overcoming them.

The satisfactory resolution of the Nobert’s plate is, as is well
known, complicated by the readiness with which spurious lines make
their appearance parallel to the real ones, and simulating them
more or less closely according to the character of the illumination
employed. This difficulty is greater with the higher bands than
with the lower ones, and with oblique light is more deceptive than
with central ulumination.

Three criteria for distinguishing the spurious lines from the true
ones have been offered.

The first is the unaided judgment of the individual microgcopist,
who is supposed to be able instinctively to distinguish the false from
the true lines without any special help.

The second is the enumeration of the lines in a measured por-
tion of the band, and the comparison of the results attained with the
statements made by Nobert as to their real distance. :

The third is a count of all the lines in the band supposed to be
resolved.

With regard to the first of these plans I must continue to think
that it is utterly untrustworthy, and that should it unfortunately
be generally accepted the plate would cease to possess any value as
a measure of resolution, for individual enthusiasm would lead many
to suppose they had succeeded, when in fact they were provided with
utterly inadequate means.

It may be granted that an observer who has many times effected
the true resolution of any given band will at length have its appearance
so firmly impressed upon his mind that he will recognize it when-
ever he sees it as he would the face of a familiar friend, but this

cel ere (Sy

On the Use of the Nobert’s Plate. 27

familiarity which all acquire with any appearance which they have
many times reproduced, will only serve to mislead, if at the begin-
ning spurious lines have been confounded with the true, for then the
deceptive spurious appearance will be sought for as eagerly as
though it were the true one.

A realization of this circumstance has led several eminent ob-
servers to propose a criterion of resolution which appears at first
sight to meet the case, but which I must really think is more diffi-
cult and less accurate than the third method. This plan is very
well described in the letter of President Barnard quoted in the
article to which I have referred.* ‘‘ When, for instance, I found
that the value by micrometer of twenty spaces on the nineteenth
band as counted, was exactly equal to the value by the same micro-
meter of ten spaces on the ninth band, I could not doubt that the
nineteenth band was resolved.” This method presupposes of course
that the lines are ruled at exactly the distances Nobert intended,
viz. those of the ninth band 5,;);,th of a Paris line from centre to
centre, and those of the nineteenth ;,3 pth from centre to centre.
It also presupposes absolute accuracy in comparing the portion of
the two bands selected.

Now, the supposition that Nobert’s estimate of the distances
between the rulings is mathematically correct, appears to me
highly improbable from many considerations; but when the attempt
is made to demonstrate the precise degree of success attained, many
difficulties are encountered. For example, as the ninth band con-
tains twenty-seven lines and the nineteenth fifty-seven, if the dis-
tance of the lines of the nineteenth band from centre to centre is
exactly half that given to those of the ninth, it follows of course
that the nineteenth band ought to be broader than the ninth by the
space of four of its lines. I have, however, been quite unable to
satisfy myself that this is the case; repeated measurements of the
nineteenth band of my plate inclining me to think rather that it is
somewhat narrower than the ninth. It is indeed extremely difficult
to make such comparison with the requisite precision, so difficult
that I do not believe anyone could tell merely by the count and
measurement of twenty lines whether he was examining the seven-
teenth, the eighteenth, or the nineteenth band. In the most careful
and experienced hands, therefore, this plan offers at the best greater
difficulties than a simple count across the band, and except in such
hands it is only liable to mislead.

On the other hand, the third method is more positive, for the
number of lines in each band being now known, a complete count
gives results which cannot reasonably be questioned. But two
objections have been made to this plan. First, that an. objective of

Pe 23s

28 On the Use of the Nobert’s Plate.

high angle may have exquisite definition combined with such cur-
vature of field that a part only of any given band may be resolved
at a time; and secondly, that in the case of the higher bands at
least, a count of the whole band from edge to edge is so difficult as
to be almost impracticable unless special costly and troublesome
apparatus is employed.

The first of these objections falls to the ground if the actual width
of the bands is considered in connection with the aperture of the ob-
jectives employed. It is asked, “If Nobert had covered a whole inch
with the 112,000 and some odd lines, would anyone claim that all
must be seen at once?” Now, the fact is that each of the bands on
the plate is really only about the sj4,th of an inch in width; and
the question is not whether an imaginary band of greater width
could all be resolved at once, but simply whether the modern objec-
tives as actually made have a field sufficiently flat to resolve from
edge to edge a series of lines occupying a space the two thousandth
part of an inch wide in breadth. I have already expressed my
opinion on this matter, but desire here to offer a few considerations
in its support.

My Powell and Lealand’s immersion sixteenth, with the short

eye-piece I generally employ on the plate, gives a field -004 of an
inch in diameter, or eight times the width of one of the bands.
The Tolles’ ~j>th, belonging to the Museum, with the same tube
and same eye-plece, gives a field -008 of an inch in diameter, or
sixteen times the width of a band. The Tolles’ 1th, belonging to
the Museum, under the same circumstances, gives a field -017 of an
inch in diameter, or thirty-four times the width of a band.

With such an eye-piece only the central portion of the actual
aperture of the objective is utilized ; and I find that with the fifteenth
band sharply in focus at one side of the field I get at the same
time complete resolution of the fourteenth and thirteenth bands
with both Powell and Lealand’s immersion };th and Tolles’ ;>th.
I cannot, therefore, admit that the actual curvature of field is such
as to prevent any given band from being resolved from edge to
edge by an objective capable of resolving any part of it, and pass on
to consider next the question of the difficulty of a count.

I have published elsewhere* what appeared to me to be a very

easy and simple method of counting the lines. The circumstance ~

that no one appears to have adopted it, on account probably of its
requiring some special apparatus, induces me to mention some still
simpler methods, which I have frequently employed with success.
If after resolution is attained, a cobweb micrometer be substituted
for the ordinary eye-piece, the well-known difficulties resulting
from tremor will be encountered if any attempt be made to turn
the screw and move the cobweb from line to line, as is ordinarily

* ‘Quarterly Journal of Microscopical Science,’ October, 1868.

On the Use of the Nobert’s Plate. 29

done. But if instead, the blackened brass teeth which serve to
record the movements of the cobweb be used simply as reference
points to enable the eye to keep its place in counting across the
band, a little practice will soon enable the observer to count the
whole band with certainty and precision. ‘The micrometer not
being touched, there will be no tremor. It will of course be under-
stood that a little strip of brass furnished with fine teeth, gummed
to the diaphragm of an ordinary eye-piece, will answer the same
purpose. A glass eye-piece micrometer will be found to impair
definition too much. After a little experience, however, even the
specks on the ordinary eye-piece and on the plate itself can be em-
ployed as reference points, and will render a successful count fea-
sible, though not so easy as with the help of the economical con-
trivance I have described. Of course it is best in any case to
begin with practice on the lower bands.

Having acquired the degree of skill necessary to enable him
with such help to count a number of fine lines without losing his
place, the conscientious student of the Nobert’s plate has not, how-
ever, disposed of all the difficulties in his path. With such oblique
light as is necessary for the resolution of all the higher bands with
our present objectives, he will find a certain number of spurious
lines on both sides of the band, and he will have to learn some
method of determining where to begin and where to end his count.
Nothing gave me greater difficulty in my earlier investigations of
the plate, and I hope, therefore, that a short account of the prac-
tical results at which I arrived may prove of service to other
microscopists.

If one of the higher bands of the plate be examined by an
objective capable of resolving it, while it is illuminated by a pencil
of insufficient obliquity, a mere tint or shade of the width of the
band will be observed; with more oblique illumination a wavy
irregular appearance comes into view; increasing the obliquity of
the pencil still further, a series of lines make their appearance,
-occupying about the width of the band, but fewer in number than
the real lines; finally, when the degree of obliquity necessary for
actual resolution is attained, the true lines start into view, accom-
panied, however, by certain spurious lines on the margins of the
bands. Four appearances of the bands are thus indicated, viz. a
mere tint or shade, a wavy irregular appearance, spurious lines
occupying the place of the band, and true lines with spurious lines
on the margins.

The last two of these appearances require consideration.

A. Spurious Lines occupying the Place of the Band.—These are
generally clean smooth lines, quite sharp, and much narrower than
the apparent interspaces. They are well calculated to deceive the
unwary, as they have often done. On a count, however, they will

30 On the Use of the Nobert’s Plate.

be found too few; for instance, twenty to forty in the nineteenth
band, instead of fifty-seven. The laws governing the production of
these false lines and the relation of their number to the aperture
of the objective and the obliquity of the illuminating pencil, have
perplexed the most eminent students of optics, and are well worthy
of future investigation. It is enough for my present purpose to
state that while false lines of this character may be seen in the place
of the true lines of the higher bands with objectives perfectly
capable of resolving them with more oblique illuminating pencils,
a similar appearance is often the best that can be produced with the
most oblique pencils, if the resolving power of the objective is in-
adequate. These thin spurious lines differ in several particulars
from the real ones of the higher bands. The latter are not smooth,
they are irregular, they are thicker than the interspaces, they are
wavy. The cutting tool has moved with a certain tremor ; some of
the lines are ploughed deeper than others, the distances from centre
to centre are not always equal. Such inequalities might be ex-
pected in ruling such fine lines, and with adequate defining power
they will readily be recognized.

B. Spurious Lines seen on the Margins of the Resolved Bands.
—These require careful consideration by those who attempt to count
the higher bands ; but by selecting for study at first a moderately
fine band, say the eleventh or twelfth, their characters can be
learned, and the method of distinguishing them from the true ones
mastered.

Suppose, for example, the twelfth band is under observation ;
when the pencil is sufficiently oblique to show the true lines, a series
of fine spurious lines, closely resembling true ones, are seen adjoin-
ing the band, which, when the objective is in the lowest focal posi-
tion compatible with definition, appear on the side from which the
oblique light comes (as the microscope reverses, they are of course
really on the opposite side). Of these spurious lines those next
adjoining the real ones measure from centre to centre the same as
the real ones, but the more distant ones grow gradually fainter and
more separated till they disappear from view. On the opposite side
of the band are a few coarser spurious lines, easily distinguished
from the real ones. Such is the condition of things shown in my
photograph of the nineteenth band. I do not think anyone could
tell by mere inspection either of the photograph or of the image in
the microscope, if the focal adjustment remains unaltered, which
was the last true line, and which the first spurious one, on the side
of the fine spurious lines; on the other side it is easy enough. But
if now the direction of the light is reversed, the fine and coarse
spurious lines change places, and what is still more important, a
similar change can be effected by a mere change of focus. In fact,
when the band is seen as above, if the fine spurious lines are on the

On the Use of the Nobert’s Plate. 31

right and the coarse ones on the left, it will be found that on very
slightly withdrawing the objective from the plate the fine and coarse
false lines change place almost exactly as though the direction of the
light was changed. This change is not a sudden one; fine spurious
lines begin to be seen on the second side before they have all dis-
appeared from the first, and there is no intermediate position such
as may be attained with the lower bands, in which there are abso-
lutely no spurious lines to be seen on the edges.

These results of a change of focus enable the observer to dis-
tinguish in the microscope the position of the last real line on either
side, and thus to attain accuracy in his count; and if a successful
photograph be compared with the object as seen in the microscope,
there will be no great difficulty in determining, first on one side
and then on the other, the portions of the picture which correspond
to the true limits of the band. It was in this way that I deter-
mined the limits to be given to the enlargement of my photograph
of the nineteenth band, which was distributed in every case pasted
on the same card with a print from the unmodified original negative.
The object of the limitation given to the enlargement was to make
it serve as a representation of conclusions, readily obtained in the
microscope by change of focus, but which the possessors of the pho-
tograph could not arrive at without repeating my observations,
since the photograph represented of course but a single focal posi-
tion.

If the first and last real lines are fixed in such a photograph by
comparing it with the appearances in the microscope, the photo-
graph will answer a useful purpose in verifying the count. Even
if the observer is not sure as to this, if he can find, as he generally
can, any reference points in the microscope and in the photograph
by which fixed points in the band can be identified, a count of the
intermediate lines will serve as a useful check. I have made use of
all such aids in my study of the Nobert’s plate, but I desire to say
expressly that my statement of the number of lines in each band
rests essentially on my counts in the microscope, and that I have
repeatedly counted in the microscope the lines of each of the bands,
from edge to edge. I may also make a single remark in this place
with regard to our knowledge of the number of lines in the bands.
I believe I was the first to state the actual number for the higher
bands of the new nineteen-band plate. Nobert gave the distance of
the lines apart in fractions of a Paris line, the actual width of the
bands and the number of lines in each was not stated. From his
figures the number of lines per millimetre and per inch has been
computed. But the practical difficulty of measuring the width of a
band with sufficient precision to deduce the number of lines from
these figures has caused all the writers on the subject, whose papers
I have seen, to observe a judicious reticence as to the actual number

VOL. VI. D

32 On the Use of the Nobert’s Plate.

of lines. If this has been anywhere stated, I should be glad to
learn it, but my counts were all made in perfect ignorance of any
enumeration but my own. Nobert, to whom I sent the photographs
with my count, acknowledged the resolution in handsome terms.
If there are any persons who still remain unsatisfied, I much hope
that a better acquaintance with the subject will lead them to modify
their opinion.

I pass by here the question of intermediate spurious lines
between the real ones, since this concerns chiefly the lower bands of
the plate.

It has, however, been suggested that if the criterion I have pro-
posed be accepted, it ought to be applied also to the diatoms, and
that it would invalidate all claims as to the resolution of these which
are unaccompanied by a count and actual measurement. As to this,
I would say that the optical conditions in the case of the diatoms
are so different from what we have to deal with on the plate, that I
cannot see that the one conclusion follows from the other.

The lines of the plate are minute grooves on the under-surface of
the thin glass cover, and the point is to distinguish them from the
spurious Images to which they give rise. The striz of the diatoms
are the optical expression of sculpturings on frustules of silica. The
appearance of lines is now generally conceded to be an illusion.
What seem to be such are generally the optical expression of minute
elevations, most probably hemispherical in shape, though the ques-
tion of their form cannot be regarded as settled. These elevations
are arranged in rows, to which the apparent stric correspond.
False lines of greater or less number are occasionally produced, and
have in some instances been described as real ones, but this does not
occur with facility on the frustules of most species, and on many
does not occur at all. The question of the resolution of the diatoms,
however, is too complex for further discussion in this place.

In closing this paper, I trust I may be pardoned a few remarks
which appear to me to be warranted by the tone of Mr. Stodder’s
reclamations. He is quite right in his allegation that I have done
“ something more” than ignore his claims. I controvert them. I
do so, first, because 1 have carefully tried a number of objectives
made by olles, and have been unable to see with them any but
spurious lines in the nineteenth band. Among those which I have
tried is the much-talked-of ;'5th and the new 73th belonging to Dr.
Josiah Curtis. Secondly, because Mr. Stodder has never yet offered
any sufficient evidence that the lines he saw were not spurious also.
He rests on a simple supposition, and in his recent paper supports
this supposition by the mere opinion of several gentlemen to whom
he has shown lines in the nineteenth band, but who, like himself,
have taken no precautions to determine whether the lines seen were
spurious or real.

On the Use of the Nobert’s Plate. 393

I have never, however, expressed a doubt of Mr. Stodder’s good
aith in his claims, and will not do so now. Still I must call atten-
tion to some inadvertencies into which he has fallen. Thus on page
120 of his article he passionately denies having made any error as
to the matter of counting fine lines, and quotes in proof the passage
in his original paper, leaving out the part which contains the error.
The whole passage reads, “ either the micrometer or the stage must
be moved, and it is neat to impossible to construct apparatus that
can be moved at once the yooloooth part of an inch and no more.”
His error, of course, consisted in supposing that if the micrometer
is moved, its motions must correspond with the real distance of the
lines, instead of the dimensions of the magnified image. The re-
marks on tremor which he introduces in this place have nothing
to do with the question.

On the same page he insinuates that I have misrepresented the
meaning of Professor Hagen’s paper, but here his confessed igno-
rance of the language misleads him. I quote a single passage in
reply. “ Big jetzt keines der objective von Tolles die 16 bis 19
Bande in Nobert’s Platten vollig auflést, was mit 4th von Powell
und Lealand gelungen.”* I might quote several other examples of
what I must hope is unintentional unfairness, especially his criticism
of my photographs, of which I will only say that it contains con-
clusive internal evidence that he is unacquainted with the appear-
ance of the true lines of the nineteenth band. But I am quite
willing to leave this matter in the hands of conscientious students
of the plate, and have neither time nor inclination to discuss hig
errors seriatim. I will close by a brief reply to his demand for
my opinion as to Tolles’ lenses.

T have always felt great admiration for the excellent workman-
ship of Mr. Tolles. I think his }ths and {'5ths will compare favour-
ably with the like powers of the best makers, but I have not found
that they excel them, and regard the claim that the }th of Tolles
will do the work of the 75th, or his ;yths that of the j;ths of other
makers as utterly unfounded. I have long thought that if Mr.
Tolles would apply himself to the construction of an immersion
lens of shorter focal length than those he has hitherto made, the
result would be gratifying to his warmest friends. Some time prior
to the appearance of Mr. Stodder’s paper, therefore, I sent through
him an order for such an objective. When it reaches me I will
endeavour to do it full justice; in the meantime I reply directly
to Mr. Stodder’s question, that I have two ths by Powell and
Lealand now in the Museum, each capable of resolving the six-
teenth band of the plate, which is all I have ever been able to do
with Tolles’ y5th or z';th. With this I take leave of the subject.

* Max Schultze’s ‘ Archiv,’ Bd. vi., p. 217.

( 384 )

VII.— On the Employment of Dammar in Microscopy.
By Prof. AnrHur Mrap Epwarps, New York.

In the London ‘Quarterly Journal of Microscopical Science’ for
January, 1871, appeared an extremely interesting and valuable
paper by Mr. Henry N. Moseley, “On the Use of Nitrate of Silver
and Chloride of Gold in Microscopy,” in which he calls attention
to the use of “ Dammar-firniss” by Stricker in place of Canada
balsam as a medium with which to mount objects, the more
especially histological preparations. And it is remarked that in
this, Stricker’s, laboratory, as well as in those of Briicke and
Rokitansky, this medium has entirely supplanted Canada balsam.
Mr. Moseley points out that well-made Dammar varnish possesses
several advantages over the microscopist’s old friend Canada balsam ;
and proceeds to point out that it is “ clearer, more free from colour,
and when used cold, as it always is, it dries quicker, though it is
much thinner and more limpid.” He also remarks upon the
difficulty of obtaming good Dammar varnish in London, although
the gum from which it is prepared is common enough.

As I have had some experience in the use of this material in
microscopy, I will take the liberty of transcribing a paper read by
me on this subject before the American Microscopical Society,
April, 29, 1865, and which has never been in print as yet.
Hereafter I will give some of my later acquired knowledge in this
connection. The paper is entitled—

On a New Material for Mounting Microscopic Objects.

“ Although I have called the material for mounting microscopic
objects, which I am about to describe, new, it may not be so to
some of the many students of the microscope ; but, so far as I have
been able to ascertain by inquiry among our own immediate
members, it has not been as yet brought into use in this country ;
and as I am of opinion that it possesses in some respects superior
characters, fitting it for the special purpose to which I have applied
it, to Canada balsam, I venture to bring it to the notice of this
Society, hoping that such of our members’as will give it a trial will
be as well pleased with it and obtain as satisfactory results as I
have.

“T was more particularly drawn to ascertain if it might not
be used in mounting microscopic specimens on account of a
lengthened series of investigations undertaken for the purpose of
ascertaining the improvements accomplished in the manufacture
of modern objectives, and the consequent use of such glasses to
determine, if possible, the character of the markings to be found
upon the silicious cell walls of certain of the Diatomacez.

On the Employment of Dammar in Microscopy. 39

“ Having then examined, with the various objectives which passed
in review under my scrutiny, the specimens I possessed mounted
in the two ways most commonly in use—that is to say, dry in air
and in Canada balsam—it struck me that it would be well to try
the effect of various media in assisting the performance of the
instrument used ; and, to that end, I mounted several specimens in
different ways and in various varnishes and liquids, amongst which
one may be particularized as very difficult to manage—that is to
_ say, benzole. Amongst all the varnishes which I tried, I obtained
the best results with a specimen of very old Dammar, which I was
lucky enough to meet with in a small quantity, and which I was
assured, by the person from whom I procured it, was of superior
quality as a varnish, on account of its having been made some time,
and at a period when spirits of turpentine and not- petroleum
naphtha was used in its manufacture; the latter material being
used at the present time for dissolving gums and resins in varnish
making, the war haying rendered turpentine extremely scarce, as
is well known.

“ Old Dammar varnish, then, is the medium which I wish to re-
commend to the notice of the members of the microscopic fraternity ;
and as to the points in which it is superior to Canada balsam, I
would state that its refractive power is such that markings which
are with difficulty seen in balsam with a }th objective are with ease
brought out sharply and distinctly when mounted in the Dammar
with a ysths. It also dries almost immediately and without the
use of much heat; in fact, much heat is rather detrimental, and I
find the best method of procedure to be to dry the specimens
of diatoms upon either the slide or thin cover as is desired,
although the latter plan is the best, and slightly warming, drop
upon them a very small quantity of pure spirits of turpentine, and,
before it has all evaporated but has permeated throughout the
mass of diatoms, to add the Dammar and bring the cover and slide,
both slightly warmed, together. When mounting a number of
specimens (say a dozen or so), as soon as we have put the cover
upon the last the first is ready for cleaning, which can then be
done with a small bradawl so as to remove the superfluous varnish,
and the slide finished with turpentine. For cleaning slides the
so-called “camphene” is the best material, as it is pure spirits of
turpentine. Another great recommendation, as I consider it, to
the use of Dammar for mounting microscopic objects is its great
toughness, never becoming brittle by age, as is well known to be
the case with Canada balsam. Besides, Dammar is commonly much
lighter in colour than such Canada balsam as is generally to be
found in the shops. When mounting specimens containing cavities
—such as the Isthintze—perhaps even a little more care is necessary
when using Dammar than Canada balsam; but when the effect

36 Experiments on Angular Aperture.

produced is taken into consideration, I am sure that microscopists
will be willing to spare a little more time and labour over their
manipulations so as to procure a superior quality of specimens.”
Since this paper was written I have had much more experience
in the use of Dammar varnish in microscopy, and mostly in pre-
paring specimens of diatoms; but, all things considered, I think
Canada balsam is the best material to use for that purpose. But
as a cement, Dammar ranks very high, and I have put up a pre-
paration of it for our principal dealer in microscopic objects and |
requisites, Mr. Miller, and he has found it extremely serviceable in
the fastening together of glass as in constructing zoophyte troughs
and growing slides. So my fellow-member, Dr. Arnold, favours
very strongly its use as a cement in anatomical preparations. After
haying used it for some time and experimented considerably with this
medium I consider that the reason why the first specimen I had was so
clear was that it was thick. Dammar of good quality dissolved in
coal-tar benzole and concentrated is very clear, otherwise it is milky
until it thickens on the slide. Canada balsam, and, in fact, almost
all solutions of resins in essential oils—7.e. varnishes—can be
readily bleached by a few days’ exposure to the sun in a closely |
stopped bottle. ‘They are then much improved for use in micro-

SCOpy.

VIII.— Experiments on Angular Aperture. By R. B. Toutzs.

Tue following is given to illustrate the comparative available angle
of dry and immersion objectives.

In the figure, “A” represents a plano-convex lens, nearly hemi-
spherical, applied centrically to an objective at its front face. The
objective used had an angle of over 170°.

When the hemispherical lens is thus applied to the objective an
air space of course exists between the plane surfaces. On testing
the angle only 80° (or at most less than 82°) was obtainable.
Were the plano-convex removed, the angle indicated would be 170°
upwards. This was verified at the time carefully.

Haperiments on Angular Aperture. ov

When the air in this interspace is replaced by water, the angle
becomes 100°, or a little more.

In this experiment the slide and cover are thrown out as of
no importance to the solution of the question, viz. of the actual
angular dimension of the pencil traversing the object, and trans-
missible by the objective.

It seems incontestable at all events that more than 82° of
angular pencil can traverse the balsam-mounted object, and be
transmitted by the immersion objective to the eye of the observer.

Incidentally to this proposition, the following is given when the
object is actually 7 si¢w and well defined.

Thus, instead of the water in the above experiment, human blood
was introduced between the plano-convex lens A, and the front
surface of the objective.

As this necessitated, in order to bring the blood disks into view,
separating the systems of the objective (by means of the cover
adjustment) considerably, the apparent angle of this 170° objective,
¢. é. the angle taken in the ordinary way, proved to be only 128°.
But the extreme ray transmitted when the blood was compressed
by the plano-convex lens upon the front surface of the objective,
proved to be less (a little) than 100°.

This form, just detailed, of the immersion objective is a
“clinical” method, a year or two in use here, and wherein the front
surface of the objective becomes the stage of the microscope, a glass
“cover,” or a lens as above, being applied to thin out the substance
viewed, be it blood, urine, or other material fit to be thus put under
view.

A natural sequence of all this is the application of such a plano-
convex lens at the lower surface of the object slide, the primary
object of it being to avoid the excessive reflexion that takes place at
the immergent surface of an object-slide in all cases as now used.

Of course, in such an objective as used in these experiments,
170° upwards, the pencil incident upon the immergent surface of
the slide must be to reach the full angle of the objective, very
nearly parallel with the face of the slide. Immense reflexion is
inevitable.

The application of the plano-convex lens to the under immergent
surface of the object-slide allows the extreme incident pencil to
enter at a perpendicular incidence very nearly. To be sure the
convexity of the plano-convex lens has influence to modify this.
But by placing upon the plano-convex lens a plano-concave facet
lens (Fig. B), the incident rays meet a plane surface and pass on
to the object without suffraction.

The increase of light in this latter case is necessarily large, and
the influence of that increase upon the result, z. e. the appearance
and demonstration of the object, is remarkable.

38 Experiments on Angular Aperture.

The convenience of using an incidence of only about 50° to 60°
on each side of the axis, instead of nearly 90°, is evident enough.
That this plano-convex lens fixed in the centre of the stage,
perhaps preferably made achromatic, will be utilized as a condenser,
there seems no doubt. In my own hands it seems to doubly de-
monstrate difficult tests.

Certainly the use of immersion condensers is abundantly in-
dicated in the above simple experiments.

Boston, Mass., U.S.A., May 24th, 1871.

Dr. Henry Lawson,
Editor. Boston, May 25th, 1871.

Dear Sir,—I yesterday mailed to your address a paper by Mr.
Tolles on immersion objectives. I now wish to make one correction
in that paper. The angle of the rays entering the objective with this
arrangement is 110° instead of 100° as written. This makes the
angle nearer to Dr. Pigott’s statement, and farther from Mr. Wen-
ham’s. Please make the change when printing the paper, which I
hope is in season for the July issue.

Respectfully,

Cuas. STODDER.

( 39 )

PROGRESS OF MICROSCOPICAL SCIENCE.

A Giant Gregarine.—We have just received from M. Van Beneden
a copy of his memoir on the development of gregarines, in which the
structure of Gregarina gigantea is fully described and figured. The
pamphlet has reached us too late for any fuller notice at the present;
but we shall dwell upon it more extensively in our next issue. It
seems a most valuable addition to the literature of the subject, and
it treats very fully upon the development of this very curious group.
The author dwells upon Professor Beale’s views on development of
tissues. The work is published in the ‘ Bulletins de l Académie royale
de Belgique,’ 2me série, tome XXXI., No. 5, 1871.

The Embryos of Calopteryx, Agrion, and Diplax.—One of the finest
and most advanced memoirs that we have seen on these subjects is that
just published in the ‘ Memoirs of the Peabody Academy,’ by Mr. A.
S. Packard, jun. It is extremely elaborate. After dealing at length
with the subjects, the author thus sums up the characters :—Since the
observations on Diplax were made, and abstracts read at the meeting
at Burlington (August, 1867) of the American Association for the
Advancement of Science, and published in the ‘ American Naturalist’
for February, 1868, and in the ‘ Proceedings of the Boston Society of
Natural History’ (vol. xi.) for January 22nd, 1868, he has received,
through the kindness of Dr. Alexander Brandt, of St. Petersburg, his
admirable paper “On the Embryology of Agrion, Calopteryx, and certain
Hemiptera.” Brandt’s studies were directed chiefly to the development
of the embryonal membranes. His conclusions are: “1st. Calopteryx
and Agrion are developed according to the type of the development as
shown by Metschnikow to exist in the Hemiptera, namely, the germ or
primitive band is internal to the yolk. 2nd. In those insects with an
internal germ we need to distinguish an embryonal membrane, which
is divided into a visceral and a parietal layer. 3rd. The visceral layer
(veiled or plaited layer of Metschnikow) does not become united with
the extremities, but enters, together with the parietal layer (amnion of
Metschnikow), into the formation of the yolk sac. 4th. The formation
of the yolk sac, together with the revolution or turning of the embryo
on its transverse axis, consists in an independent contraction of the
parietal layer of the embryonal membrane.” As Mr. Packard’s atten-
tion was directed to morphological points, he can only infer from the
few data given above that Diplax and Perithemis have the same
arrangement of the embryonal membranes, and that these membranes
later in the life of the embryo form the yolk sac, through the contrac-
tion of the parietal layer of the embryonal membrane, as in Agrion,
Calopteryx, and certain Hemiptera. As regards the changes of the
embryo after the rudiments of the appendages have appeared, they
seem in Diplax and Perithemis to be the same as in Calopteryx and
Agrion. The embryo of Diplax is much thicker and shorter, corre-
sponding to the shorter, more ovate egg. The attitude of the germ
during its turning in the egg is identical with that of Agrion and

40 PROGRESS OF MICROSCOPICAL SCIENCE.

Calopteryx. Finally, Brandt’s figure 19 may be compared with his
figures 8, 8a, and 9, the yolk now being confined to a small area on
the back of the embryo, which is now segmented and nearly ready to
hatch, the claws being indicated, the eyes formed, the appendages
partly jointed, and otherwise much as in the larva,

A New Method of producing Stereoscopic Effect.—In a recent number
of ‘Zehender’s Monatsblat’ there is an account of this new experiment
of Listing, who has already done so much in physiological optics.
It brings out stereoscopic effect with only one picture, which consists
of figures arranged in a peculiar way, and seen with vertical double
images. ‘The simplest experiment is to view two lines crossing each

other at an angle of about 30°, with a prism of 4° or

A B 5°, its base vertical before one eye. No effort must be

\ made to correct the vertical diplopia. If the prism be

\ ii put before the left eye, its base upward, the line B B’

seems nearer to the eye than A A’. If the prism be turned

Hf with its base downward, and before the same eye, the line

\ A A’ seems nearer, and B B’ more remote. It is found

\ that with the base downward the prism must be weaker

/ than when turned with the base upward. In gaining

the effect by prisms so weak as these, no double vision

is produced except for horizontal lines—the oblique lines

appear to be only two. The same phenomenon may be produced in a

common stereoscope by having two similar figures, and pushing one

alternately up and down. Two rows of the same letters are arranged on

a page like the limbs of the letter X, and viewed as above stated with

a vertically deflecting prism; a sudden removal of one now takes place

to a considerable depth, while this appearance is at once reversed on

turning the prism around 180°. These curious effects can be best

produced and understood by means of the diagrams accompanying the
article.

The Red Blood-globule-—Dr. Richardson, of America, who has
lately been inquiring into this subject, publishes some observations in
the American ‘Medical Times.’ He desires to allude briefly to one of
the minor points among his observations, which doubtless has been
overlooked,—viz. that recorded to the effect that blood crystals of the
Menobranchus, when partly dissolved, could be seen to move rapidly,
and as if with perfect freedom, in various directions, between the
nuclei and external borders of certain corpuscles. This fact appears
to his mind much more consistent with the hypothesis of a cell wall
enclosing fluid contents than with the doctrine of a homogeneous
jelly-like constitution (Beale), or the theory of a crystalloid element
“contained in an albuminous framework of paraglobulin” jirm enough
to preserve the shape of the red disk (Briicke, Stricker); and it seems
to him the indication furnished by this circumstance resembles in
kind the evidence which sudden dartings of a gold-fish across his vase
would be that he was not imbedded in jelly or entangled within a net.
Fully recognizing, however, the wisdom of caution against considering
any one series of experiments (or, he may add, indeed, any one man’s

PROGRESS OF MICROSCOPICAL SCIENCE. 41

unaided observations, however numerous) as “conclusive proof,” and
trusting, therefore, that these researches will lead others to investi-
gate the subject and correct or confirm his results, he concludes his
observations.

A Specimen of Diplograpsus pristis with Reproductive Capsules.—Mr.
John Hopkinson, F.R.MLS., has recently described a curious grapto-
lite. The chief peculiarity seems to be the presence of reproductive
organs. ‘These, which Mr. Hopkinson considers to be representations
of the gonothece of the recent Sertularian zoophyte, are developed
almost immediately opposite each other, from each side of the peri-
derm and throughout its whole length. Though at equal intervals
from each other, they are in no even numerical relation to the hydro-
thecee, there being ten to the inch. They appear to have budded from
the periderm at right angles to the hydrothecx, and thus have caused
the polypary to be unevenly compressed. The most perfect are pear-
shaped in form, 3th of an inch long; and at their narrow end, by
which they are attached, about ;,th of an inch wide. They have
apparently been bounded by a single marginal fibre, which is slightly
thickened at its edges, and, where the pyrites are removed, has im-
pressed a fine double groove on the surface of the shale. If the fibres
were slender tubes, this appearance would naturally be presented ; for
their outer margins would offer the greatest resistance to compression.
The so-called solid axis of the graptolite frequently presents a similar
appearance. At the proximal end of the polypary these fibres only
are preserved, the oldest or first-formed gonothece having fulfilled
their function and perished. The distal extremity of even the most
perfect is not clearly defined, the impression of the capsule in most
cases becoming gradually less perceptible from the proximal to the
distal end. Sometimes the capsules are irregularly ruptured, their
torn jagged edges being distinctly seen, while one has split along its
marginal limit, along the line of the marginal fibre, which appears to
have parted abruptly near the distal end of the capsule at one side,
and split acutely for some distance along the other side. This would
appear to indicate that the capsule may be composed of two mem-
branes joined together at their edges, through which the fibre, if it be
not merely a tube formed by a kind of double marginal seam, has run.
In no case can a distinct unruptured distal orifice be traced. The
gonothecz present other peculiar appearances. Towards their prox-
imal end they are sometimes longitudinally corrugated or crumpled,
or traversed by fibres which extend for some distance into the body of
the polypary. Some are much twisted and bent about, occasionally
overlapping each other. Between two which thus overlap, or perhaps
only come into contact with each other, just at the point of contact
and apparently within one of the capsules, are two minute young
graptolites, one lying across the other. Each consists of a thin mem-
brane, probably forming the first partially developed pair of hydro-
thecz, a minute radicle, and a slender solid axis which is prolonged
beyond the membrane. They are similar in form and proportions;
but one is a little larger than the other. Its length, from the extreme
point of the radicle to the distal end of the axis, is jjth of an inch.

42 PROGRESS OF MICROSCOPICAL SCIENCE.

The membrane itself is about this length, and ,1,th of an inch wide,
tapering towards the proximal end. The smaller specimen is 35th of
an inch in entire length, and ,,th wide. If these young forms had
not been in connection with a mature graptolite, they would have
been considered to belong to the genus Diplograpsus, but it would
have been impossible to refer them to any species. In their present
position he thinks we may without hesitation infer that they are the
young of the graptolite with which they are associated. That they
have not yet entered upon independent existence we cannot conclude ;
for they are in different stages of growth, and young graptolites are
frequently met with in a less advanced state than either; indeed, on
the same piece of shale there are several young graptolites referable
to the same species, and no more developed, some even less so.—
Annals and Magazine of Nat. History, May.

When is a Blood Corpuscle in Focus ?—Dr. Tyson has* a very in-
teresting note, accompanied by a diagram, which we regret we cannot
reproduce, on this optical and physiological subject. After explaining
the diagram, he says it can easily be carried in the mind’s eye, and at
once the facts can be thought out without burdening with their recol-
lection the memory, which is here peculiarly apt to be treacherous.
Indeed, he said he could never himself promptly recall the cireum-
stances under which the centre had been bright and the periphery
dark, and vice versd, until he had called to his aid this diagram. And
that the exact truth is liable at least to escape attention, is seen in
the circumstance that “in a volume no less highly valued than the
seventh edition of Carpenter’s ‘Human Physiology,’ 1869, is con-
tained a misstatement of the facts. We find here, on page 200,
the statement that the corpuscle is rather beyond the focus of the
microscope when the periphery is dark and the centre bright, and within
the focus in the opposite appearance—that is, when the centre is dark
and the periphery bright. 'The reverse is correct. In the last edition
of Carpenter (1868) ‘On the Microscope, however (pages 166, 167),
we find the principle applied, and the fact correctly stated, though a
few lines farther we find it asserted that the hexagonal areole in dia-
toms appear dark when the surface is slightly beyond the focus, though
they are described as hexagonal elevations. If this latter be the case,
then they should appear dark when within the focus, as is the case with
the periphery of the corpuscle. So, too, on page 710 of this latter
volume there is reproduced the same drawing referred to in the text-
book on physiology, but with the description reversed, and therefore
correct. The corpuscle is, however, described as in focus when the
periphery is in focus, whereas we have presumed that the entire cor-
puscle is in focus when there is least shadow. Of the other text-books
now within our reach, Dalton has it correctly on page 214 of his third
edition ; Flint, Kirke, Ranke in his ‘ Grundziige der Physiologie, and
Rollett in Stricker’s ‘Handbuch der Lehre von den Geweben, refer
to the reversal of light and shadow, but do not state the circumstances
under which it takes place ; Marshall makes no allusion to it.”

* Philadelphia ‘ Medical Times.’

PROGRESS OF MICROSCOPICAL SOIENCE. 43

Extraordinary Microscopy.—In a journal published in Philadelphia
called the ‘ Medical Times,’ which is remarkable for several able and
interesting medical papers, we find an extraordinary communication
(March No.) by Dr. Neulenz. The following quotation will give our
readers some idea of this gentleman’s opinions. We are a little sur-
prised at their making their way to so great an extent as a column
and a half in such a paper as the ‘ Medical Times’ :—“ Having
constructed a one-seventieth immersion objective, on a new prin-
ciple, having 191° aperture,—the immersion liquid being fluoric
acid,—and, for illumination, having invented a new eccentric
parallelopiped, to be used with fluorescent rays exclusively, some
remarkable results have been obtained. I take great pleasure in
stating that, with regard to test-objects, all previous observers have
been totally wrong in every particular, and that Pleurosigma angulatum
is, in the first place, constructed on the plan of the Nicholson pave-
ment, and, in the second place, that it is not a Pleurosigma at all.
The most certain test-object is the Newlenzia difficilissima, a very rare
and remarkable diatom, in which my one-seventieth with the parallel-
opiped shows four kinds of beads and six sets of cross-lines, one of
which sets contains 147,229,073 lines to the inch: hence, by the

L. SSS :
well-known formula of Brewster, = =/0.x.p.y, it is impossible
that the undulations of light should pass without being previously
deflagrated, and therefore no other lens can possibly show these lines,
nor is it probable that this lens would with any other observer. The
immense superiority of this test to Nobert’s plate is apparent.”

Note on Amphipleura pellucida.—Assist.-Surgeon Woodward, who
may be said fairly to take first rank among American microscopists,
has contributed a paper on this subject to ‘Silliman’s American
Journal’ for May. He says the attention of microscopists has fre-
quently been directed, of late years, to the Amphipleura pellucida or
Navicula acus, as a test-object well suited to try the defining powers
of the very best object-glasses. The length of this diatom is stated
by Pritchard as ranging from j1,th to z1,th of an inch. The
average length is given by the ‘ Micrographic Dictionary’ at -0044 of
an inch. The striz, which are exceedingly difficult, were first
described by Messrs. Sollitt and Harrison, who estimated them at
from 120,000 to 130,000 to the inch. Their estimate has been
adopted by the ‘Micrographic Dictionary’ and by the majority of
modern writers who have referred to this test; but so many difficul-
ties beset the resolution that few microscopists appear to have
attempted to verify the original estimates. Indeed, most observers
would seem to have been unsuccessful in their efforts to resolve the
Amphipleura even with the best objectives, and some have gone so far
as to deny the existence of any strie upon the frustules of this
species. Among the microscopists who claim to have seen the striae,
several would seem to differ from the original estimates of Sollitt and
Harrison as to their fineness. Dr. Royston-Pigott, whose papers on
“high-power definition” in the ‘Monthly Microscopical Journal’ have

tt PROGRESS OF MICROSCOPICAL SCIENCE.

recently attracted much attention, sets down their number at 150,000
to the inch. Dr. Carpenter, on the other hand, in the fourth edition
of ‘The Microscope and its Revelations, expresses the opinion that
even the estimates of Messrs. Sollitt and Harrison are too high: and
we are told by Mr. Lobb (‘ Monthly Microscopical Journal,’ vol. iii.,
p- 104) that Mr. Lealand has recently “succeeded in counting the
Amphipleura lines and finds them 100 in ;75,th of an inch. A few
months ago two slides of Amphiplewra pellucida were received at the
Army Medical Museum from Messrs. Powell and Lealand, and he
succeeded in obtaining excellent resolution by the immersion 7th of
these makers. The frustules on the two slides were found to measure
from ;1,th to ;}oth of an inch in length. Resolution could be satis-
factorily effected and the strie counted on any of them. He took eight
successful negatives from medium size and small frustules, and veri-
fied the counts made in the microscope by counting the striz on the
glass negatives. He found the strize on medium-sized frustules, say
sith of an inch in length, counted usually from 90 to 93 striz to

the +,5,th of an inch; in that selected for the two photographs
which were sent to the editors, the number was 91 to the ,,5,th
of an inch. Larger frustules exhibited rather coarser, smaller ones
rather finer strie. On the smallest frustules at his disposal, several
of them only ;1,th of an inch in length, he found no example in which
the number of strize exceeded 100 to the ;,);5th of an inch. The
strie of these smallest and most difficult frustules do not then rival in
fineness the nineteenth band of the Nobert’s plate, as has been
asserted by some; they compare rather with the sixteenth and seven-
teenth bands. After making the photographs, he extended his obser-
vations to a number of other slides of Amphipleura pellucida, including
two of the original specimens from Hull, kindly sent to the Museum
some time since by Mr. W. 8. Sullivant, of Columbus, Ohio, and the
example in the First Century of Eulenstein. He found that different
slides varied considerably in the ease with which he could resolve
them, chiefly as he thinks on account of the thickness of the glass
covers, which in several instances did not permit the best work of the
immersion ;/,th. Perhaps, however, the markings on some frustules
may be shallower than on others whose striz count the same number
to the ;,)5,th of an inch. In any event he has found, as yet, no
slides the covers of which permit the ,,th to be approximately
adjusted, on which it was impossible to resolve the frustules, and no
frustules the strie of which exceeded 100 to the z)5,th of an inch.
The best resolution he was able to obtain by ordinary lamplight was
not very satisfactory. He used therefore, during the investigation,
direct sunlight, rendered monochromatic by passage through the solu-
tion of ammonio-sulphate of copper. A parallel pencil of such light
was concentrated by the achromatic condenser, which was suitably
decentred to attain obliquity. The same illumination was employed
in making the photographs. He has since had the pleasure of exhibit-
ing the resolution in quite as satisfactory a manner to several micro-
scopists by monochromatic light obtained from the electric lamp.

oo)
NOTES AND MEMORANDA.

No Meeting of the Royal Microscopical Society this Month.—
We beg to notice that, contrary to what has already appeared, there
will be no meeting of the Royal Microscopical Society this month.
It was intended to have held one, but the College being occupied on
both the first and second Wednesdays in the month, the Council has
been compelled to give way. Consequently, Fellows will observe that
there will be no meeting of the Society held this month.

Contributions to the Journal. We may state that various papers
remain on hand. Among others, a long French communication,
which cannot appear this month. We mention this fact to allay any
anxiety which may be felt by persons who send contributions which
do not immediately appear. We do our utmost in all cases to insert
the articles which are sent to us, as well as the Reports of the local
Societies; but of course cases occur wherein even for two or more
numbers papers do not appear. We mention this fact merely to re-
assure our correspondents as to their communications.

CORRESPONDENCE.

Totes’ Stereoscopic Bryocutar EyeE-PIEce.
To the Editor.of the © Monthly Microscopical Journal.

Hopart Couiece, Grenrva, N.Y., U.S.

Sir,—I wish to correct as widely as possible a statement in regard
to the stereoscopic binocular eye-piece, which attributes the invention
to me instead of Mr. Tolles, to whom really the whole credit belongs.
Dr. Carpenter* has made, unintentionally, such a statement, and it has
been copied by others.t I doubt not it will be rectified in future
editions. This misstatement was unknown to me until within a few
weeks. If it had been known I should have made the correction
promptly. It is not difficult, perhaps, to account for the mistake,
inasmuch as I first exhibited this eye-piece in England at the soirées
of the Microscopical Society and the Royal Society, and to numerous
individuals, among them Dr. Carpenter himself, who expressed his
satisfaction at its performance. Mr. Ladd, the well-known philo-
sophical instrument maker, 11 and 12, Beak Street, Regent Street,
had it for some time in his possession, and indeed made one, which
however was much inferior to Mr. Tolles’, as Mr. Ladd had not time
to determine the proper curves, if indeed the lenses were achromatics

* ‘Microscope,’ 4th ed, p.85. + ‘The Microscope, by J. Hogg, 7th ed., p. 119.

46 CORRESPONDENCE.

at all. He understood, however, that it was Mr. Tolles’ eye-piece ;
and I have by me the original “ exhibitor’s card ” at one of the soirées
named, reading distinctly, “'Tolles’ binocular eye-piece, exhibited by
Prof. Smith.” I feel very anxious to have the mistakes corrected.
The first eye-piece of this form which Mr. Tolles ever made was
purchased by me, and I gave some account of its performance and
peculiarities in the ‘ American Journal of Science,’ July 1864, p. 111.
And, in the same journal shortly after, Mr. Tolles himself described
its construction. Now, although we cannot expect everyone to read
an American journal, or to be posted in all that is done this side of
the Atlantic, even in the microscopical line (except to notice the
trash, e.g. the mean little sheet issued by manufacturers and sellers
of the Craig !!! microscope, recently attempted to be palmed off as the
organ of the Illinois Microscopical Society), it is a little surprising,
considering the length of time these two articles have been published
in a most prominent journal, that such a blunder should occur. Of
course it is inadvertence. Dr. Carpenter, I am quite sure, is ready
and willing to do full justice, and in so doing it will be proper to
state-the real principle of the eye-piece in question. It is not, as he has
stated, U. c., merely an arrangement of prisms similar to MM. Nachet’s,
for in reality the prime part of the eye-piece may be this, or Riddell’s,
or Wenham’s; and, in fact, in the first eye-piece made for me was
different from either of these. Mr. Tolles finally—partly at my sug-
gestion, though I believe he had already decided upon it—adopted
the Nachet form, and he claims nothing for this. What he does
claim, and is justly entitled to claim, is the construction of a first-
class achromatic erecting eye-piece, and a division of the pencil, for
stereoscopic vision, at, or very near, the point of crossing of the rays
in such a combination. Now, it is well known that the difficulty in
using the Wenham, or Nachet arrangement with high powers, arises
from the necessity of dividing the pencil so far behind the objective,
a difficulty which it seems cannot be got over, except upon Mr.
Tolles’ plan, viz. making a secondary image, and dividing the pencil
here, or near the point of crossing of the rays. The binocular eye-
pieces invented by President Barnard, and by myself, are simply bino-
cular, like Powell and Lealand’s arrangement for high powers, though
superior as to equality in illumination of the two fields, they are not
stereoscopic. Perhaps the fact of my having made such an eye-piece,
and published an account of it, as also Dr. Barnard’s notice of it, in
his report upon the Paris Exposition, may have assisted to mislead in
attributing the really stereoscopic binocular of Mr. Tolles tome. If
I had been the originator of this eye-piece, which is yet destined to
replace most binoculars, I should feel I had contributed a much
greater boon to microscopy than anything I have yet done. The
instrument, as made now by Mr. Tolles, is very perfect; the loss of
light is trifling, easily remedied by a little more illumination. The
loss in definition is not so much as in the Wenham and Nachet forms ;
not merely from the care with which Mr. Tolles works the prisms,
but owing to the much shorter distance which the reflected ray has to
travel. This part of Dr. Carpenter’s objection is practically without

Ee eS ee ae

CORRESPONDENCE. 47

force. The eye-piece is expensive. Not only is it, at least so far as
regards all below the prisms, perfectly achromatic, but of very peculiar
and perfect construction, and as to lability of derangement, I can
safely say it is as firm as any binocular arrangement now known,
and easily adjusted if it should become deranged. I am told that
M. Hartnack has made a similar eye-piece. During the Exposition
I placed Mr. Tolles’ eye-piece in his hands for inspection, and it
remained with him for several days. I cannot say whether he copied
it, or whether his arrangement is different in principle, or the same,
as I have not seen it. M. Hartnack appeared to me to be far too
honourable a man, as MM. Nachet, to whom also I showed it, most
certainly were, to take any credit for an invention truly belonging
to another.
H. L. Surru,

Formerly of Kenyon College.

Tae French Erectrna Prism A Camera Luoma.
To the Editor of the ‘ Monthly Microscopical Journal.’

Reavine, June 5th, 1871.

Sir,—Needing greater amplification for minute dissections and
diatom selection than I could obtain from the simple lens of the
dissecting microscope, and unable to overcome life-long habit and to
reverse every movement which the inverted position of the object
under the compound instrument necessitates, I applied to Mr. Curties
for an erector, who furnished me with a French eye-piece erecting
prism, which effects my object very completely.

I find, however, that it subserves another purpose, for which cer-
tainly it was never originally designed, and, so far as I know, has
hitherto remained unsuspected—that of an effective camera lucida,
with which very satisfactory outlines can be made, either in the ver-
tical position of the microscope, on a screen placed behind it, or in
the ordinary horizontal one (by far the most convenient in practice),
on a paper extended below it on the table, the usual focal distance of
ten inches being in both cases maintained. Probatum est! But how
is the image produced and the sketch obtained? Backed by metal
plates, with the image of the object on the stage refracted by the prism
through the small circular opening of the front plate, on to the retina
of the observing eye alone, it is obvious that the image seen on the
screen or on the table cannot be due to any reflexion. It must, therefore,
as suggested by my friend and neighbour, Dr. Shettle, be illusion only
—a spectre, a brain phantom —though definite and capable of delinea-
tion. Have we not here a clear demonstration of the physiological
fact, “ that though the image of an object be impressed on the retina
of one eye exclusively, through the decussating nerve fibres of the optic
commisure, it makes an equal visual impression on that of the other”?
It may be objected, I know, that the one eye sees the image, the other
the point of the pencil only; that the one records what the other

VOL. VI. z

48 CORRESPONDENCE.

sees, and that it is merely another application of the well-known
method of taking rough micrometric measurements from a scale placed
on the stage by the side of the object. But does not this also imply
the transference or interchange of the retinal impression made on
the one eye to that of the other, with an equal visual result? Or,
would not the inference necessarily follow that it must be the purely
cerebral perception which we subject to mechanical measurement and
delineation ? Can such a solution be accepted ?

The proof, however, that I here offer, the more plausible explana-
tion of the observed fact is, I believe, readily afforded by a simple
experiment. Hold before the non-observing eye a lucifer-match, or
something similar, in the same plane as the prism, an inch or so on
one side of it, the spectral image of the match will then be seen inter-
posed between the observing eye and the image of the object on the
stage refracted into it by the prism.

To you, sir, as a most competent authority, I submit the matter.

Yours, &e.,
J. G. Tatem.

Liyear Prosection AND Rortirers.
To the Editor of the ‘ Monthly Microscopical Journal.’

Dear Sir,—Permit me to express all due thanks to Mr. Charles
Cubitt for his proffered lessons in linear projection, as applied to the
delineation of rotifers. And respectfully to decline. That he should
select me as his “frightful example,” and take so much trouble with
the “sole object” of assisting me, is a flattering mark of attention
to excite some gratitude, as it certainly does considerable surprise.
While giving full credit for excellent intentions, I am constrained
to notice some misapprehensions and mistakes into which he has
unwittingly fallen. He assumes that some, or all, of the figures
illustrating my description of Ccistes intermedius are incorrectly
drawn, because he fails to reconcile one with another, in accordance
with his reading of the laws of linear projection. Well, so much the
worse for Mr. Cubitt, for I can assure you that the portraits in
question are most excellent—thanks to artistic skill not my own—
and, without exhibiting affectation of extreme correctness, are yet
perfectly amenable to the rules of linear projection when properly
applied. It is almost impossible, without a diagram, to show the
source of Mr. Cubitt’s error and its correction, but a hint or two may
suffice. The disk in the ventro-latera] view is inclined at a sharp
angle, while those of the other two are foreshortened, and not so much
turned dorsally. Thus, any one set of projection lines applicable to the
former should, and do, break down with the latter. The side view
was not “created” from the back and front views, but drawn under
the microscope from another and a finer specimen, without reference
to compasses or T squares, and yet with a result almost photographie
in its truth.

CORRESPONDENCE. 49

When we have to represent an active, elastic, ever-changing
creature from different points of view, I cannot think it well to
treat it as a petrifaction, and draw it in precisely the same attitude
in each view. It generally happens that a variation in the position
brings into sight some organ or characteristic feature of the animal,
and these surely should not be sacrificed in order that rigid rules
may find easy application by beginners.

As Mr. Cubitt has put on a high power, his finest illumination and
aplanatic searcher to view the supposed mote in my eye, allow me
gratefully to note—without any magnifying—the rather obvious beams
in his own. His Fig. 9, Plate LXXXIIL,, is called by him the “dorsal
view” of Melicerta; it is really the ventral aspect.* Nor is this
blunder a mere slip of the pen, for it is repeated, and with an imagi-
nary “dorsal lobe” applied to every rotifer he speaks of, causing a
confusion impossible to be worse confounded. He may—probably
does—mean the ciliated prominence in the ventral aspect as his
“dorsal lobe”; but fancy a describer of the elephant giving the trunk
as an appendage of the back! Again, in an attempted partial classi-
fication, Mr. Cubitt calls Lacinularia a “free” form; it is no more or
less free than is Melicerta (called “ fixed”), it has its little fling in
very early life, then takes a weed, and settles down quietly while yet
a youth, like all its builder kindred (except Conochilus). Nor, by
any stretch of imagination, can Cephalosiphon be recognized as a
Philodine. Had Mr. Cubitt ever seen the former it would have been
impossible for him to group them together.

Fain would I follow this gentleman in his more ambitious writings
concerning rotiferous nerves, brains, osmosis, and sundry laws of
physiology, but he occupies most boldly the ground on which, with
angelic timidity, I “fear to tread.”

I remain, dear Sir, yours faithfully,
H. Davis.

Coat Puants.
To the Editor of the ‘ Monthly Microscopical Journal.’
Goats SHaw, OLDHAM.

Dear Str,—It will be remembered by some of the readers of this
Journal that Professor Williamson read a memoir some time ago,
before the Manchester Philosophical Society, on a new fossil fruit
found by me in one of the lower coal-seams of the Lancashire Coal-
field: this fruit he described as belonging to his new plant called
Calamopetus.

Since then he has read another memoir before the above Society
on another but very different fossil fruit found by me in the same
coal-seam. I believe this memoir is now in the press.

I have been very fortunate in finding another coal fruit, very dif-

* See Gosse in ‘ Phil. Trans.,’ Pritchard, and elsewhere.

E 2

50 PROCEEDINGS OF SOCIETIES.

ferent from either of the above. The sporangia in the two first fruits
are protected by bracts, which pass between the sporangia from the
axes. When they reach the outside, they ascend and overlap each
other, as is seen in Lepidostrobus. This fruit I have just found seems
to be void of these bracts altogether, and appears to be a naked cone.
The spores are those of a Calamite, and the sporangia are very nume-
rous and densely packed together. If the above features are borne
out by the cutting up of this specimen, it will be made public in a
future memoir.
I am yours respectfully,

Joun BurrekwortuH.

PROCEEDINGS OF SOCIETIES.*

Royat Microscortcan Society.

Kine’s Coniran, June 7, 1871,

W. K. Parker, Esq., F.R.S., President, in the chair.

The minutes of the last meeting were read and confirmed.

It was announced in reference to the proposed meeting in July
that as the College authorities were unable to grant the use of the
rooms in consequence of their being occupied for examinations, &c.,
the meeting could not conveniently be held as proposed.

A list of donations to the Society was read, and a vote of thanks
passed to the respective donors.

A letter was read from M. Ernst, of Caraccas, describing a speci-
men of diatomaceous earth found in that locality.

The Secretary stated that Mr. Slack had added some notes to
this letter. He found the earth rich in specimens; but up to the
present nothing decidedly new had been detected.

The Secretary announced that it had been proposed in council
to confer the honorary Fellowship upon a distinguished microscopist,
Dr. Maddox, who had contributed largely to the ‘ Transactions’ of the
Society. As Dr. Maddox resided in the country, the Council thought
that they would not be doing wrong to confer this mark of respect
upon him.

Mr. J. Hogg read a paper “On Mycetoma, or the Fungus-foot
Disease of India.”

Mr. Stewart said he had had an opportunity of examining a speci-

* Secretaries of Societies will greatly oblige us by writing their reports legibly
—especially by printing the technical terms thus; H y dra—and by “ underlining ”
words, such as specific names, which must be printed in italics. They will thus
secure accuracy and enhance the value of their proceedings—Eb, ‘M. M, J.’

~

PROCEEDINGS OF SOCIETIES. 51

men of this foot. The appearance which it presented was precisely
that of caries of the tarsal bones. On the surface of the foot were a
number of openings and sinuses leading down to the broken-down
remains of the bones. A longitudinal section of the foot revealed the
condition of the bones, which were simply indicated by some soft
masses, which readily broke down with the slightest touch. The
bones were much blackened; and on cutting through them for ex-
amination under the microscope, he found a large quantity of mycelia.
He did not observe any fungi in the skin. The bones were literally
one mass of fungus, occupying all the cavities.*

In reply to a question from the President, Mr. Stewart said there
could be no doubt about the thing found being a true fungus. No
tissue in the body ever presented any resemblance to the dark strips
so characteristic of fungus. It was a true vegetable that he had seen ;
there was nothing in the human body like it.

The President thought the fungus was not the cause of the disease ;
but that the disease previously existed, the form which it ultimately
assumed being a rapid downhill degeneration. The changes which the
skeleton underwent in the course of nature would lead to softening of
the bones, and degeneration would naturally follow where there was
any tendency to disease.

Mr. Stewart said he should mention one fact in which the disease
described differed from caries of the bone, viz. that in the cavities
amongst the tissues which contained the fungi, instead of there being
larger granulations the cavities were perfectly free from them.

The President remarked that it would seem as if there was no
power of reparation in the bone, or capability of producing any new
tissue, but it was simply the existing tissue going from bad to
worse.

Mr. C. Brooke said he could not conceive that any spores of a
fungus should make their way through the surface of the foot into the
interior of the bone, so as to be developed at the depth named, and so
as to cause the disease. They might run along the sinuses made
for them ; undoubtedly the existence of sinuses involved the supposi-
tion that there was pre-existent disease.

The President remarked that no number of spores would affect any
healthy foot.

A vote of thanks was then given to Mr. Hogg.

Dr. Braithwaite read a paper “On the Structure of Bog Mosses.”

A vote of thanks was then passed to Dr. Braithwaite, who took
occasion in his acknowledgment to remark that the new school of
bryologists now studied mosses entirely by the leaves, which are so
definite and unchangeable in their characters, that every moss can be
distinguised by its own peculiar leaf.

The meeting was then adjourned till the 4th October.

Notice was given that the library and reading-room would be closed
during the month of August.

* 'These masses have since been examined by several independent observers,
none of whom have been enabled to discover fungus in their composition —J. H.

52 PROCEEDINGS OF SOCIETIES.

Denshions to the Library and Cabinet from May 4th to June 7th,
1871

From

Land and Water. Weekly wo, 2 be 40, ae) toy veel Cheers
Society of Arts Journal. aired cos be jee | else aes moe
Nature. Weekly... ... ne as se) aly Ue Smee ees
Athenzum. Weekly x Peer ty i ih
Journal of the Royal Institution, No.6 ... Institution.
On a Specimen of Diplograpsus pristis with Reprodue-

tive Capsules. By J. Hopkinson, F.G.S. ye Author.
The Medical Directory for 1870 as ae oe) oe oe a ds We Sep Ren Serpe era Te
The Peerage and Baronetage for 1870 .. .. ,. .. Ditto,
Journal of the Linnean Society, No.56 .. .. .«. .» Soctety,
The Canadian Journal, No. 73.
Five Slides from Tasmania.. .. .. .. .. « « 4. D. Harrop, Esq.

John Stuart, Esq., and R. G. McLeod, Esq., were elected Fellows
of the Society.
Water W. REeEvEs,
Assist,-Secretary.

_

Croypon MicroscoprcaL CLs.

At the meeting on Wednesday, February 15th, the President,
Henry Lee, Esq., in the chair, Dr. Strong read a paper “On Bone
Structure,” which the President afterwards described as clear, concise,
instructive, and one on which he could desire the contributions of
other members to be modelled. Dr. Strong took as the heads of his
subject :—I1st, the appearance seen in ordinary transverse and longitu-
dinal sections of bone; 2ndly, the varieties of bone, and in what they
differ; 3rdly, the development of bone, how it is formed, how nou-
rished, and finally, its chemical composition. A section of the human
thigh or arm bone (taken from the centre of the shaft, because the
ends present a different appearance) shows that it is covered by a
membrane, the periosteum, and that there is a hard layer or ring of
bone surrounding a central cavity containing the medulla, fat or
marrow—this hard layer or compact tissue, as it is called, being lined
on the interior by a membrane, termed the medullary membrane,
which serves to support the fat and the nutrient vessels. A thin slice
of the “compact tissue” placed under the microscope, exhibits, 1st,
some ovoid or circular holes, called ‘‘ Haversian canals,” after their
discoverer, Clopton Havers, surrounded by concentric rings. Among
these rings, or lamelle, are dark specks, called lacune, which are in
reality minute spaces. From these radiate still more minute pores or
tubes, called canaliculi, which communicate with those from neigh-
bouring lacune. 'The Haversian canals are the means by which the
blood-vessels are carried into the interior of the bone. Of lacune and
canaliculi there is little to be said beyond the fact that they are
arranged concentrically round their own Haversian canals, and that
the lacune occupying the outer margin of the ring have their canaliculi
only on that side nearest the Haversian canal. Dr. Strong alluded to
the views of Dr. Lionel Beale, on the nutrition of bone by particles of

PROCEEDINGS OF SOCIETIES. 53

protoplasm, occupying the lacune, and conveyed in minute streams
through its structure by the canaliculi, and then described the cancel-
late structure of those portions of a bone where considerable strength
is required, combined with lightness. Describing the development of
bone, he said that it is formed in two ways—from membrane and from
cartilage. The bones of the skull are an example of the first method,
being first deposited in the centre, and then radiating in all directions.
Where bone is developed from cartilage, it commences from several
centres, which, by the constant addition of earthy particles, gradually
approach each other till they meet. After some additional observa-
tions of the nutrition of bone by the periosteum on the exterior and by
the medullary membrane on the interior, the lecturer proceeded to
consider the chemical constituents of bone; and in the course of his
remarks mentioned that in adult life human bones are composed of
one-fourth of animal and three-fourths of earthy matter; that in
infancy these constituents are about equal, whence their liability in
children to bend rather than break; whilst in old age, the earthy
matter being greatly in excess (seven to one), bones are much more
liable to fracture. Dr. Strong concluded by recommending his hearers
to adopt Mr. Squeers’s method of investigation, by eating the flesh
of their next leg of mutton, and converting the bone into a micro-
scopic object.

The thanks of the meeting having been given to Dr. Strong for his
interesting communication, the President remarked that microscopical
comparison of the size, form, and proportionate number of bone cells,
and the canaliculi radiating from them, had been productive of very
important results in contributing to our knowledge of some of the
remarkable animals which existed on the earth in former ages. Asan
example of this, he would mention that about the year 1845 Professor
Owen read a paper before the Geological Society, on some Ornitholites
(fossil remains of birds) from the chalk, the bone especially described
being a portion of the humerus of a (supposed) longi-pennate bird.
Subsequent discoveries of similar bones led Dr. Bowerbank to believe
that these so-called bird bones were those of the great flying reptile,
the Pterodactyl. By one of those strange coincidences of thought
which not unfrequently happen in scientific investigation, Professor
Quekett was also impressed with their similarity, and he and Dr.
Bowerbank—neither of them aware of the experiments which the
other was pursuing—determined upon a close microscopical examina-
tion of the structural peculiarities of the bones, in the hope of eliciting
some characters which would, in conjunction with their external forms,
point out with some degree of certainty the class of animals to which
these remains in reality belonged. They arrived independently at
the same conclusion—that the bones of birds, reptiles, fishes, and
mammals, each possess marked peculiarities which furnish a means of
deciding disputed relations of obscure and difficult tribes of existing
animals, as well as of ascertaining the true relations of such paleon-
tological remains as it might be otherwise difficult or impossible, from
their dilapidated condition, to refer to their real position amongst
animals. In illustration of Dr. Strong’s paper, Mr. Lee also exhibited

54 PROCEEDINGS OF SOCIETIES.

the head of a boy’s thigh bone, which had come away from the patient
after three years’ suffering from scrofulous disease of the hip-joint ;
and a large portion of the shaft of the tibia of another boy, whose leg
was injured by a kick whilst playing at football. In both cases a most
successful cure had been effected under the surgical care of his friend,
Dr. Wm. Price, of Margate.

Mr. Cushing exhibited a series of three selenite plates superposed
on each other, and revolving at different speeds, capable of giving
remarkably beautiful combinations of colour in conjunction with the
polariscope, arranged by Mr. Becker; and read a carefully-composed
paper “On the Polarization of Light, and the Methods of employing
it in connection with the Microscope.” The concluding paragraphs
of it elicited some observations from the President on the value of
having the polar axis of the selenite marked on the plate, as a means
of determining the direction of tension of muscular fibre and other
objects examined with it.

Mr. Cushing kindly presented to the library of the club a treatise
“On Polarized Light,” and “On the Use of the Oxy-hydrogen Micro-
scope and Polariscope,” by Mr. Chas. Woodward, F.R.S.

The thanks of the meeting haying been given to Mr. Cushing,

The President next directed attention to Dr. Matthew’s recently-
invented turn-table, for making and varnishing cells, which, by an
arrangement on the principle of the parallel rule, keeps the slide,
whatever may be its diameter, perfectly concentric, and also admits of
two cells being formed on the same slide if required. He also exhi-
bited a pretty and portable microscope lamp, by Moginie, of 35,
Queen Square, Holborn. It was packed in a tubular case, like that of
a pocket folding telescope, and had the great advantage over a some-
what similarly fitted but much more expensive lamp, that, whereas the
latter could only be carried in a vertical position without the oil
escaping, Mr. Moginie had, by a simple contrivance, secured his lamp
from leakage, even if turned bottom upwards.

Mr. F. Baldiston sent to the meeting some scorpions and an enor-
mous spider from the West Indies, which had been received from Mr.
John Gibson, of Canning Road, Addiscombe. The President made
some interesting remarks on the stinging powers of the scorpion, and
the nature and influence of its poison; and described some observa-
tions made by Mr. Frank Buckland and himself on the effect produced
on a Gallago, by scorpion poison, and read a laughable account by
Mr. Buckland of a fight between a scorpion and a mouse.

The following members exhibited sections of bone in illustration
of Dr. Strong’s paper, and other objects, with their microscopes :—
Messrs. H. Lee, P. Crowley, T. Cushing, H. Long, C. Bonus, EK. T.
Jones, F'. West, jun., C. W. Hovenden, J. D. Wood, H. McKean, and
Dr. Strong.

Mr. Harry Townend, of Cheam, was elected a member of the club.

At the monthly meeting of this club, March 15th, Mr. J. §. John-
son, M.R.C.8., read a paper on “ A Microscopical Examination of the
Oyster.” He went over the ground to be met with in most treatises
on the subject of mollusca, and finally described various interesting

PROCEEDINGS OF SOCIETIES. ae

organisms which he had found on the shells of oysters, and exhibited
several of them, such as sertularia, foraminifera, and Serpula triquetra,
mounted for the microscope.

The President, Mr. H. Lee, having invited discussion amongst the
members,

Mr. J. W. Flower said there was one singular feature about the
oyster, namely, that in former days the species were much more
abundant than at the present time, and that this was so had been
abundantly proved by the enormous variety of fossil oysters found
in the chalk and in the London clay.

Mr. Long said he had examined the liquor of oysters, and, by spon-
taneous evaporation, he had obtained some beautiful crystals.

Dr. Strong asked whether the body of the oyster, when the mantle
was removed, was homogeneous.

The President said he did not believe that when once the young
had escaped from between the valves of the parent they ever re-entered
them ; nor was it correct, as had been stated in a recently-issued
official report, that they adhered-immediately. This was the critical
period of their existence. Oysters still bred and spawned just as
freely as ever they did, but the young ones did not adhere. This
was the cause of the scarcity of oysters. Why this took place no one
could definitively say; but warmth and tranquillity were undoubtedly
the great conditions of the prosperity of the young fry, and cold nights
at the spatting season were fatal to them. At Herne Bay, in June,
1861, he found the whole water of the sea full of young oysters in
their swimming condition; but during that month the nights were
very cold, and there was no fall of spat that year. That a low tem-
perature was unfavourable to the development of the young oysters
had been proved by an experiment made by Mr. Buckland and him-
self. Some of them were placed in sea water in a glass jar, and whilst
they were swimming vigorously about, a piece of ice was dropped into
the vessel. The immediate effect was that they all sank to the
bottom, apparently exhausted ; but on the withdrawal of the ice, and
restoration of the former temperature, they revived. He agreed with
Mr. Flower that all the British oysters were varieties of one species,
and had satisfied himself that the formation of their shell depended
on the conditions and necessities of their habitat, and en the chemical
constituents of the water, mud, &c., in which they existed. He placed
some Swansea oysters in the experimental ponds, owned by Mr. Buck-
land and himself, at Reculvers. The shells of the oysters, from the
former locality, were particularly heavy and clumpy; but the new
growth put on all the characteristics of the true “native.” They had
also had American oysters in their beds, but the growth of the shells
had not been sufficiently marked to be conclusive, and, in fact, these
American oysters were totally different in character and form from
the British oyster.

A cordial vote of thanks was given to Mr. Johnson for his lecture ;
which had given rise to an interesting discussion.

The President announced that since the last meeting three new
Microscopical clubs had been formed; namely, “ The Sydenham and

56 PROCEEDINGS OF SOCIETIES.

Forest-hill Microscopical Club ;” “The Margate Microscopical Club,”
at the inauguration of which he had assisted on the previous Monday
evening; and “ The South London Microscopical and Natural History
Club,” a preliminary meeting of which he had also attended on the
11th inst. This latter society would especially direct its attention
to the Natural History of the county of Surrey. He was sure that
the members of the Croydon Club would be glad to fraternize with
all these newly-formed societies; and he had no doubt arrangements
might be made for their co-operation with each other in systematic
work, and for the members of all of them joining in excursions under
the leadership of the most experienced men belonging to each.

The following presents had been received ;—The ‘ Transactions of
the Quekett Microscopical Club, from that club. Davies’s work ‘ On
the Preparation and Mounting of Microscopic Objects,’ from the Pre-
sident. Johann’ Nave ‘On the Collection and Mounting of Alge,
&e.,’ from the President.

Messrs. W. H. Beeby, J. 8. Crowley, and W. T. Loy, were elected
members of the club.

The following members exhibited objects with their microscopes :—
Messrs. H. Long, J. W. Flower, F. W. Gill, J. T. Johnson, K.
McKean, F. West, jun., G. Manners, J. D. Wood, H. Long, and
C. W. Hovenden.

BRIGHTON AND Sussex Natrurat History Soctery.

April 13th. Ordinary Meeting. Mr. T. H. Hennah, Vice-Pre-
sident, in the chair.—Messrs. W. Jackson, W. H. Ross, and H. Saun-
ders were elected ordinary members.

Mr. Wonfor announced the receipt of the 7th Annual Report of
the Lewes Natural History Society, and the April number of the
‘ Quekett Club Journal, from the secretaries, and ‘“ Mitten’s South
American Mosses” (‘ Linnean Society’s Journal’) from Dr. Addison.
Votes of thanks to be given to the donors.

An interesting communication from Dr. Stevens, of St. Mary Bourne,
“On certain Types of Flint Implements’ found in Hampshire,” was
read, and a vote of thanks passed to Dr. Stevens.

Mr. Wonfor then read a paper “On What is Coal?” in which,
among other interesting matter, he pointed out that the true vege-
table origin of coal was not only determined by observing the con-
ditions under which it occurred, but by the fossil remains associated
with it, and by the results of microscopic examination. These showed
that coal was simply vegetable matter, altered and compressed.

The vegetation which helped to form coal was characterized by an
almost absence of that kind of wood now found in our forest trees,
and by a preponderance of ferns, calamites, and club-mosses, very
few of which retained their form sufficiently to admit of a satisfactory
demonstration of what they were really like, though fern fronds, more
or less mutilated, detached roots and stems, occasional cones, fruits,
fragments of flowers and fructification helped to determine some of
the orders of plants.

PROCEEDINGS OF SOCIETIES. 57

The researches of Professors Morris and Huxley, Mr. Carruthers,
and Dr. Dawson of Canada, pointed to the fact that the great bulk of
the bituminous coal consisted of sporangia and spores of plants allied
to our existing club-mosses, while thin sections of coal which he
would show at the Microscopical Meeting revealed the fact that the
chief elements in their a were these said spores and spore-
cases, the latter about j,rd of an inch in diameter, somewhat resem-
bling bags or sacs, more or less flattened, and containing the former,
irregularly-rounded bodies about ~},th of an inch in diameter.

The processes by which coal was supposed to have been found
from vegetable matter, and many other interesting points, were dis-
cussed, and the paper illustrated by specimens and fossils from
different coal- fields.

A vote of thanks was given to Mr. Wonfor.

April 27th.—Microscopical Meeting. Mr. T. H. Hennah in the
chair.

Mr. R. Glaisyer announced the receipt of two slides, one a section
of the morel, for the cabinet, from Mr. Wonfor.

Mr. Hennah read a very interesting communication from Dr.
Addison “On the Water Flea” (Daphnia pulex), containing original
observations on the moulting of the carapace of the female and the
birth of young Daphnia from agamic eggs, from which it would appear
that the two acts are simultaneous.

Mr. Marshall Hall exhibited a new pocket-lamp by Moginie, of
London, which appeared to be a very compact and portable apparatus.

Mr. Wonfor exhibited a fresh specimen of the morel (Morchelia
esculenta) obtained near Brighton.

The meeting then became a conversazione, when

Mr. Marshall Hall exhibited spicules of the new sponge (Phero-
nema Grayii), dredged up by him off the coast of Spain.

Mr. Sewell exhibited scalariform tissue of fern, sections of cocoa-
nut wood, whalebone, &c.

Mr. Hennah, under one of Beck’s new 5th immersion lenses,
exhibited living diatoms. The performance of this lens was pro-
nounced perfect, the definition being very precise, while the distance
at which it worked was an ordinary live-box cover. The same objects
were also shown with a Gundlach’s ;,th, which gave very good defi-
nition.

Mr. Wonfor exhibited sections of the morel, showing the spores in
their receptacles; sections of coal fossils, by Norman, of City Road,
London, in which leaves, roots, and stems of Lepidodendra, &ec., were
well seen ; sections of coal made by Mr. Slade, and described in the
January part of the ‘Quekett Club Journal,’ and kindly lent for the
occasion ; and a series of sections of coal and lignite made by himself,
including Torbane hill, white coal of Tasmania, brown coal of
Bohemia, the Bradford Belter Bed, &c., in which not only woody fibre,
but also spores and sporangia, were distinctly made out; these were
in illustration of his paper “On Coal,” read at the last Ordinary
Meeting.

In the course of the evening Mr. Wonfor illustrated the method

58 PROCEEDINGS OF SOCIETIES.

by which he had made and mounted thin sections of coal, which was
a modification of the different published methods.
It was announced that the next Microscopical Meeting, being the
Anniversary Meeting, would be a General Evening and conversazione.
It was also announced that the first Field Excursion would take
place on Saturday, May 6th, to Balcombe for Tilgate Forest.

May 11th.—Ordinary Meeting. Mr. 'T. H. Hennah im the chair.

Mr. T. M. Fowler was elected an ordinary member.

It was resolved that a letter of condolence be written to Mrs. Peek
on the death of her husband, formerly a member of the Society.

Mr. Wonfor reported on the success of the Field Excursion of
May 6th to Balcombe, and gave an account of some of the objects seen
and obtained.

The Rey. J. H. Cross exhibited and presented for the Society’s -

album, sketches he had made on the occasion.

Mr. J. Dennant exhibited a series of marbles from the Pyrenees,
and large acorn cups of the Smyrna oak, Quercus egiolops, the Valonia
- of commerce.

Mr. J. Howell exhibited fossil Silurian corals, vertebra of Plesio-
saurus, from the bone bed of Aust; and shells from the lias at Bristol,
and the Upper Eocene, Isle of Wight.

Mr. Saunders exhibited red organ coral and other recent corals ;
pottery from the tombs at Bengazi and Pompeii; and sand from the
Bays of Valentia, Malta, and Taranaki.

Mr. Elphick exhibited a couple of piebald mice, taken from a rick,
and believed to be a cross between the common and white mice.

Mr. Wonfor exhibited a specimen of the silicious sponge Huplectella
mirabilis ; specimens of yellow wagtail ; grey-headed ditto ; and a state
either intermediate between the two or in the immature plumage of
the second. While the first is common, the second is uncommon, and
the last very rare. These birds were kindly lent by Messrs. Pratt
and Sons, and had been obtained in the neighbourhood of Brighton ;
also a very dark variety of the northern oak eggar moth, Bombyx
callune. It was resolved that the next Field Excursion be on Satur-
day, June 8rd, to Barcombe for Plashett Wood.

May 25th.—Microscopical Meeting. Mr. M. Penley, Vice-Pre-
sident, in the chair.

Being the Anniversary Microscopical Meeting, Mr. R. Glaisyer
reported that 122 slides and a Moller’s diatom type slide had been
added to the cabinet during the year.

Mr. Wonfor, Hon. Sec., gave a brief abstract of the ‘ Proceedings,’
with an account of the papers read and the work done, which, he said,
had exceeded their anticipations, when it was determined twelve
months since to hold monthly microscopical meetings. Judging from
what they had done in advancing microscopical inquiry among the
members during the past year, augured well for increased exertions
in the forthcoming year.

Mr. Wonfor then gave an account of a method for obtaining thin
sections of soft rocks, and illustrated it by making and mounting

PROCEEDINGS OF SOCIETIES. 59

sections. He first cut with a saw (the one used was the common fret
saw) slices of oolite, &c., ground down one surface on glass-paper
of different degrees of fineness, and fastened them by the ground
surface with moderately stiff heated Canada balsam to glass slides.
As soon as cold the other surface was ground down to as thin a degree
as required, always finishing on very fine glass-paper. The super-
fluous balsam was then cleared away and the powdery matter cleaned
off with spirits of wine, when the slide was ready for the cabinet, or
could be covered with thin cold balsam and a glass cover and left to
harden. The specimens of oolite, which were used to illustrate, were
part of the stone employed in making the Brighton aquarium. He
had at present only worked on different oolites, Portland stone, dolo-
mite, and nummulites from Egypt. By the same process he had made
very thin sections of coal—in fact, the examples of coal shown at the
last meeting were made by this process. It was at the suggestion of
Mr. Marshall Hall, who asked him to try how it would act on oolitic
limestone and dolomite, that he was led to attempt the process. In
the case of Portland stone, he had found it advisable to rub it down
roughly first on a piece of paving stone, and to finish it off on glass-
paper. Some sections he had cut, ground, and finished for the cabinet
in twenty minutes.

The meeting then became a conversazione, when

Mr. J. Dennant exhibited deep-sea Atlantic soundings, fossil and
recent diatoms, antenne of drinker moth, «&e.

Mr. T. Cooper exhibited crystals of hematoxylin, tartrate of soda,
and other salts.

Mr. R. Glaisyer exhibited sections of Hozoon Canadense, Purbeck
and encrinital limestones.

Mr. Turner exhibited sections of Indian rice-paper, root of Osmunda
regalis, and spores of morel.

Mr. Wonfor exhibited sections of different oolites, dolomites, Port-
land stone, nummulites from Ben Hassan, and crystals of salicine in
silicate of soda, and crystals of silicate of soda, mounted in the same.
These latter formed very beautiful polariscope objects, and, with one
of Ackland’s selenite stages, gave a wonderful variety of colour.

It was announced that the subject for the next Microscopical
Meeting on June 22nd would be “ Vegetable Hairs and Scales.”

State Microscorican Society or ILutnois.

On the evening of March 17th the State Microscopical Society of
Illinois celebrated its third annual réunion by a magnificent exhibi-
tion in Farwell Hall. The main floor was crowded with a large and
delightful audience, who moved in steadily-recurring streams from
table to table. There were about 100 instruments on exhibition, and
at least 1000 slides, though there was neither time nor opportunity
to make all of them available for use.

Such has been the accomplished labour of the Microscopical So-
ciety, a labour whose greatness can be more readily appreciated when
it is recollected that the Society was only organized about three years

ee a So oe

60 BIBLIOGRAPHY.

since. At its first conversazione, held at the house of Mr. Joseph T.
Ryerson, about thirty instruments were exhibited, estimated to have
cost, in connection with their appurtenances, about $7000. On the
date of its third conversazione, more than 100 instruments were exhi-
bited, representing a value of $30,000. Such has been the growth of
our Microscopical Society, of which it may be said that it stands the
first of its kind in the United States.

While the slides were being changed on the instruments, Prof.
H. Peabody performed interesting electrical experiments, and Prof.
Delafontaine and Mr. Boerlin showed several beautiful Geissler tubes
lit by the electrical current.

Tue Tounpripce Weis Microscorican Socrrety.*

The monthly meetings of this Society have been held regularly
under the able presidency of Dr. Deakin.

The subjects for discussion have been Sections, Vegetable and
Animal, the careful consideration of which has occupied the members
for several meetings, and elicited much useful information.

The next meeting will take place on October 3.

BIBLIOGRAPHY.

Die Praxis der Naturgeschichte. Von P. L. Martin. Weimar.
Voigt.

Martini und Chemnitz Systematisches Conchylien-cabinet. In
Verbindg. m. Dr. Phillippi, Dr. Pfeiffer, Dr. Dunker, und Dr. E.
Romer, neu. hrsg. und vervollstindigt von Dr. H. Kiister. Niirnberg.
Bauer & Raspe.

Archiv fiir Mikroskopische Anatomie herausgegeben von Max
Schultze. 6 Band, 4 Heft, mit 8 Taf. Bonn. Cohen & Sohn.

Untersuchungen uéber Bau und Entwicklung der Arthropoden.
Von Dr. Ant. Dohrn. 2 Heft. Leipzig. Engelmann.

Uéber d. Wirkung v. Borsiiure auf frische Ganglienzellen [Aus
dem physiolog. Institute der Wiener Universitat]. Von Ernst
Fleischl. Wien. Gerolds Sohn.

Physiologish-anatomische Untersuchungen uéber den Uterus.
Von Dr. Carl Friedlinder. Leipzig. Simmel & Co.

Die Achnlichkeit im Baue der aiisseren weiblichen Geschlechtsor-
gane bie den Locustiden und Akridiern dargestellt auf Grund ihrer
Entwickelungsgeschichte. Dr. L. Graben. Wien. Gerolds Sohn.

* From the Rey. Mr. Whitelock.

TheMonthly Microscopical Journal Ang§.118771.

te
mm

The Madure., Fungus foot of India.

THE

MONTHLY MICROSCOPICAL JOURNAL.

AUGUST 1, 1871.

I—Mycetoma: the Madura or Fungus-foot of India. By
JaBez Hoac, Hon. Sec. R.M.S., Surgeon to the Royal
Westminster Ophthalmic Hospital, &., &e.

(Read before the Royau Microscopican Society, June 7, 1871.)
Puate XCII.

A Few years ago Dr. Vandyke Carter, of the Bombay army, made
us acquainted with a certain specific form of microscopic fungus,
which he alleges produces, among the native inhabitants of Madura,
and certain other districts in India, a peculiar disease, and since re-
cognized as the Fungus-foot of India (Mycetoma). A number of
specimens of the foot have been examined in this country, and it is
thought by some histologists and pathologists that most of them
exhibit the ravages of a fungus. It appears, however, that now
and then specimens have failed to satisfy those into whose hands
they have fallen of the fungoid character of the disease; Dr. Carter
speaks of such specimens as a variety, and in place of a living
fungus he says ‘‘numerous rounded bodies of a structureless or
finely granular appearance are seen, in which the fungus particles
were free from crystalline fringe, but still showing a cellular
structure, the true nature of which is degenerate fungi.”* A

DESCRIPTION OF PLATE XCILI.

No. 1.—Altered fibrous tissue, mulberry-shaped fat-cells, &c., x 150.

2.—Fat-vesicle and molecular matter, chiefly fat; a few mother-cells filled
with fat-granules, and granular contents of others distributed over field.
x 150.

3.—Crystalline matter (stearine ? &c.), fat-globules; vegetable hairs, &. x 150.

4.—Algoid filaments in matrix or stroma with fatty molecules and pigment
granules, x 150. This specimen was taken from the second or more
frequently recurring form of diseaséd foot.

5.—Portion of a foot bone, the compact tissue and lamelle of which have
been removed, and the cancellous structure occupied by blacked masses
of inorganic matter, x 50.

6.—Papille hypertrophied, and filled with granular matter; remains of a
capillary seen running over the field; connective tissue and fat-cor-
puscles filled with crystalline particles. x 150.

”

* “Trans. Bombay Medical Soc.,’ 1860, ’61, and ’62; ‘Medico-Chir. Review,’
vol. i, 1868.
VOL. VI. F

62 Transactions of the

specimen of this “variety” appears to have perplexed Dr.
Ballingall, as well as the late eminent microscopist, Professor
Quekett, both of whom were in consequence unable to pronounce
the disease to be fungoid; due to the growth and ravages of a
fungus. At the end of the year 1869, a foot of the doubtful
kind was placed for examination in my hands, and those of a well-
known excellent pathologist and histologist: I was requested to
report on the specimen. You may imagine, therefore, 1 was most
anxious that everything should be conducted with the care and
caution which so responsible a position would naturally inspire. I
will tell you at once I was not a little surprised and disappointed
to be obliged to come to the conclusion that no trace of a fungus
could be found in any part of the foot ; I say disappointed, because
from what I had read about the fungus-foot disease of India, I ex-
pected no difficulty whatever in the matter, and I will add more by
way of caution, that the first few sections which were made and
washed in distilled water, for the purpose of freeing them from some
apparently crystalline and fatty matters, showed both the spores
and mycelium of a fungus. Here then I thought there could be
no mistake, and put the specimens away to further examine at a
more convenient opportunity. The next day I resumed my work,
and made other sections from the foot, which I at once transferred
to a weak solution of spirit and glycerine. On examining them I
was not a little puzzled to find abundance of fatty matters, but not
a particle of anything like a fungus. Subsequent examinations
convinced me an error had occurred somewhere in my first observa-
tions, and I then examined the distilled water. A single dip from
the bottle gave me a plentiful crop of fungus, exactly resembling that
found in my first specimens. On taking up a well-corked bottle of
arsenical solution standing near the distilled water, I saw it con-
tained numerous tufts of a fungus, which, as you know, abound
everywhere, and spread with amazing tapidity upon almost every-
thing, ripening and depositing their spores, with powers of self-
increase so rapid as to be almost incredible. The naked-eye
appearances of this fungus-foot may thus be briefly stated. The
foot was greatly enlarged and swollen; all fair outline being lost.
There were numerous excrescences or raised bodies over the upper
surface; none on the lower; which at first sight might be sup-
posed to communicate with the internal parts; but on attempting
to pass a small silver probe through the centre of any one of them,
it could not be made to penetrate more than a very short distance,
and I doubt very much whether there could have been any actual
sinus leading to the bone at any time. There might, however,
have been an ulcerating sore during life, which the hardening
nature of the methylated spirit, in which the specimen was pre-
served, had entirely obliterated. On making a vertical section of

Royal Microscopical Society. 63

the foot, so much confusion of parts existed, that the muscular,
fibrous, and other tissues seemed to be blended in a gelatinous mass ;
on removing portions of the bony mass, the cancellated interspaces,
which were much larger than usual, were occupied by numerous
whitish granular bodies, somewhat resembling millet seeds. These
bodies, which are described by Dr. Carter as pink in the fresh
foot, were apparently mixed up with a crystalline material. But
fatty matter so predominated that it was almost impossible to free
any section from it, without resorting to boiling in ether, or
liquor potassee. When boiling in the latter was continued for a
few minutes, nearly the whole was held in solution, the residue
being a very small quantity of fibrous tissue. Even fragments of
bone almost disappeared when treated in the same way ; whereas,
if the spores and mycelium of a fungus are subjected to the same
process, the fragments that remain enable us to recognize them
without difficulty. Fungi resist the action of boiling fluids as
they do prolonged and intense cold, so that we need be under no
apprehension of losing all trace of them, if they ever had an
existence, while subjecting animal matters to the crucial test of
boiling in destructive reagents. A prolonged and exceedingly
careful microscopical examination yielded only negative results, so
far as fungi were concerned. The cells and fibres which Dr. Carter
says “are imbedded in black masses of matter,” could nowhere be
traced; neither could I see “the fish-roe-like substances made up
of defaced fungus structure.” The little rounded bodies in this
specimen were not uniform in structure, and were mostly imbedded
in a gelatinous fatty matter in the interspaces of the bones. The
pigment of the skin, generally so abundant in the black races, was
entirely removed; while the papillae were so much hypertrophied,
swollen up, that all trace of ordinary structure seemed lost, not
even a perfect epithelial cell remaining. The extraordinary way in
which the pigment had disappeared induced me to think that even
“black fungus masses” might owe much of their colour to
disintegrated pigment granules, and even take up new forms in
the interspaces of the metamorphosed muscular and fibrous tissues.
Portions of the subfilamentous material presented, at first sight, an
appearance somewhat resembling ciliated epithelium ; these masses
easily separated and floated about, and there was no nucleus seen, and
only a slight fibrillation. Fat abounded and was often arranged
and massed in cells, in which were groups of smaller corpuscles,
in some instances presenting a false appearance of nucleated cells.
The subcutaneous infiltration of fatty matter, and the disintegra-
tion of nervous matter, muscular and other tissues occasioned
thereby, gave to all the specimens examined a confused resemblance ;
and although some few bodies of “a spindle shape” were seen, 1t
would require a considerable stretch of imagination to pe that
r

64 Transactions of the

they were either “ciliated epithelium,” “ degenerate fungi,” or the
altered forms of “a true oidium,” the material contents of “the
branching tubular canals” of which had become altered through
some kind of natural quiescence or encystment. If it be possible
for such encystment to take place, it must, in my opinion, be a
complete disguise of all known fungus characteristics, and
under such a disguise it was not at all surprising the late
Professor Quekett should fail to come to “any definite opinion of its
character.” I would not have you suppose that a doubt exists in
my mind about the finding of fungi by Dr. Carter, in connection
with the remarkable form of disease with which he has made us
acquainted. I have placed a section under a microscope, taken
from a recent specimen sent over to this country, and now in
the possession of Dr. Tilbury Fox. It belongs to the more fre-
quently occurring form of disease, and in which are seen many
black, or deep-brown coloured masses, either closely aggregated, or
having a radiating aspect, branching out in every direction ;* and
what to me seems very curious, several spore-like bodies closely
resembling “ Puccinia” have been found; which being a vegetable
feeder, should not, according to the Rey. Mr. Berkeley, occur among
animal matter. On the same authority we are assured “there is
not the slightest ground for supposing that the disease depends on
inoculation with the spores of the true parasitic fungi belonging
to the rusts and mildews.” + Nevertheless I believe such spores, as
well as the conidial form of oidium, have been found in a few of
the specimens; these may, however, have been accidentally intro-
duced from without. Dr. Carter does not tell us whether the less
frequently observed variety of diseased foot, that is, the foot in
which “degenerate fungi” and numerous rounded bodies are seen
to be the chief elements of destruction, is a more advanced, has
existed longer, or is a worse stage of disease. It ought to be so if
the fungi are in a more advanced condition; but it certainly is
not, that is, if ordinary appearances can be accepted as any guide
to a conclusion on such a point. I can hardly believe, however,
that what he describes as “ degenerate fungi” are fungi at all. I
am ready to admit, however, so much of Mr. Berkeley's argument,
that at times “they so nearly simulate fungus growths, that it is
difficult to get rid of the notion that they are really vegetable
growths.” But if they were, I see no proof anywhere adduced
to show that the diseased condition, described as due to a fungoid
growth, is really so; and this is the important point, one which

* Since my paper was read, my friend Mr. Bell has made a chemical analysis
of these “ black masses,” and finds them to consist “ of fatty matter, phosphates of
iron and lime, a little carbonate of lime, and a minute quantity of an organic
substance, albumen or fibrine.”

+ Rev. M. J. Berkeley “On the Fungus-foot of India,” ‘ Intellectual Observer,’
vol. ii., 1863, p. 248,

Royal Microscopical Society. 65

should, if possible, be cleared up. Are not the algoid filaments
another instance of a vegetable growth rapidly developed after
death in a putrescible substance? It is a matter of some moment
in a scientific point of view, that this question should be carefully
investigated and answered, for I find the eminent Mycologist
already referred to accepting Dr. Carter’s hypothesis as a demon-
strated fact, describing the fungus as a new species, and assign-
ing to it a name; remarking, at the same time, that “although the
fungus resembles closely the genus Mucor, there is no columella in
the sporangium, a character which accords with Chionyphe rather
than Mucor ;” nevertheless he places it with the latter, while he
admits that Chionyphe is one of those species only found under
snow. He concludes with what I should regard as a bit of special
pleading for a pet hypothesis, because you must remember while we
are discussing the action of a fungus in a living animal, Berkeley
refers solely to its action on dead matter; and whatever that
action may be, there can be no similarity in the two processes.
“Tt is,” he observes, “highly probable that many of our common
moulds commence with a similar condition. The first indication
of a change in tainted meat, is seen to commence with little
gelatinous spots of vegetation of various colours, the early stage of
some curious species of Aspergillus, or Penicillium.”’* Hospital
gangrene may, he thinks, also depend upon a similar cause. I
think, neither Mr. Berkeley nor anyone else can bring forward
a particle of proof in support of such a probability, and which
is after all no nearer the truth than the many guesses that have
been made at a germ-theory of disease generally. To establish
Dr. Carter’s fungoid origin of disease, it is absolutely necessary to
show that the spores of a vegetable fungus can get into the dense
structures of the animal body during life, there germinate, and
destroy the hard bony tissues, and ultimately kill the patient. At
a glance, the character of the tissues might seem to make this
impossible; and Mr. Berkeley evidently has his misgivings on the
point, for he writes, “the little granular bodies are so closely
involved in stearine, that their germination is scarcely probable.”
If we next take the symptoms and appearances which usher in the
disease as described by Dr. Carter, we shall see how far it may
become possible for fungi to pass in through the sinus openings.
“The foot swells up, is of a dark colour, numerous sinuses appear,
with pink stains or streaks, which penetrate the subjacent tissues,
and end in spherical groups of bright orange-coloured particles.
The sinuses are more or less lengthy and tortuous, and will not

* In the ‘ Intellectual Observer’ we are favoured with a somewhat remarkable
series of illustrations, of some very curious matters. A whole page is given,
resembling nothing in the shape of fungi, but rather what I should regard as
extraneous vegetable particles in a specimen,

66 Transactions of the

usually yield to presswre of the probe,’ &c. Nevertheless we are
expected to see that the soft, yielding spores of a fungus will find
their way through these tortuous smuses, passing along in an
opposite direction to a strong outward flow of a sanious discharge,
which usually accompanies such a condition of disease. Again, the
existence of a sinus presupposes a grave state of disease. Dr.
Carter does not for a moment believe that the sporules, although
minute enough, could possibly enter through the circulation. A
more generally expressed opinion, and an equally probable mode of
conveying the contagium to the internal parts of the body, the
endemic character of the disease, would, in this way, be more easily
accounted for in districts where the growing crops of rice were at
one time seen to be devastated by “smut,” and thought to be the
cause of the cholera visitation. But it could not be believed to
enter through the blood, because in such a case it would be impos-
sible to understand why the spores of a fungus should select a hand
or a foot, and find in them a more congenial soil than in other parts
of the human frame; why one foot should be destroyed and the
other escape; or why the poison should stop at the part where the
bones of the leg join the foot, and so forth.

The constant occurrence in the internal organs of algoid growths
has long been noticed—Sarcina, for instance, m the stomach and
bladder ; but after the disease has existed for years, it has not been
observed to destroy life; indeed it often produces so little dis-
turbance, that it is only detected after death. The other so-called
fungoid diseases, such as those which some believe to be the cause
of gangrene, cholera, &c., I need not dwell upon, because they rest
their claims to consideration upon the most inconclusive of experi-
ments and observations.

The incubation of the disease demands a passing notice; as,
according to Dr. Carter, it more frequently affects the agricultural
classes, men in the vigour of life; is not associated with any con-
stitutional causes, and is not known to be transmitted. But as
agricultural labourers go about barefooted, and seldom wash their
feet thoroughly, it therefore happens that the spores of a fungus
penetrate the hardened skin, and produce “ worse ravages than the
dreaded guinea-worm.” I must confess I do not understand this
peculiar line of argument; for although I can easily see how the
guinea-worm makes its way through the skin, particularly if
softened by standing in water, I cannot see how the spores of a
fungus should be capable of exerting the same force as an animal
parasite provided with a mouth and jaws, and a strong desire to
provide a comfortable lodging in the leg or foot of the first animal
that comes in its way.

It must be admitted, if the disease originates in a fungoid
growth there should be no instance of a foot which does not

Royal Microscopical Society. 67

bear evidences of the characteristic poison. Such a specimen as I
have been discussing, without a particle of fungus, is enough to in-
-validate and destroy the superstructure upon which Dr. Carter
builds his hypothesis of the “ fungoid foot”; and my objection is in
no wise met by saying that this form of disease is exceptional, and
the appearances observed are those of “degenerate fungi,’ &c. To
this I reply, it is apparently a form often met with. Mr. Henry J.
Carter, F.R.S., in his early investigations of the disease, found only
a large quantity of albuminoid and fatty matters, and attributed
the changes observed to fatty degeneration. He, however, subse-
quently examined other specimens in which he discovered fungi,
and changed his opinion, but he adds, “I could scarcely overcome
the difficulty in believing it possible for a fungus to destroy the
bones as well as the other tissues of the foot.” Another excellent
observer, Dr. Bristowe, a gentleman who has examined several
specimens of the disease, writes :—“ Although the soft parts are in-
filtrated with a lump of trufjle-like bodies, I am not prepared to
say that the fungus causes the disease ; it rather seems to me pro-
bable that the primary disease was caries of the bones, and that the
fungus became developed subsequently and accidentally. The
latter view is supported by the nature of the foot which you
examined.” I feel bound to believe with Dr. Bristowe that the
disease is due to caries of the bones; occurring, perhaps, in a
strumous, scrofulous, or syphilitic constitution. In caries, we find
a similar train of pathological appearances; the bony structures
are filled with a sanious, or glary fluid, soft granulations springing
up, and a deposit of tuberculous material, with an increase of fat,
causes complete destruction of the bones. The slow disintegration
of the various structures in the Madura foot disease is exaggerated
by the ordinary effects of a tropical climate, often an important
factor in disease, and one well exemplified in those remarkable
forms elephantiasis and leprosy, both of which seem to originate in
a metamorphosis of cell contents, a condition not unfrequently
noticed in pathological anatomy. The deposition of fat in cells and
structures of all kinds is perhaps of all changes the most curious
and universal. A beautiful series of transformations is often traced
in fat-cells, which, according to the deficiency or excess of nutritive
fluid, lose, in the former case their contents, and eventually con-
tain only serum, in the latter become distended with fat-globules ;
further, in the cells of glands secreting fat, which, at first poor in
fat, are ultimately quite distended with it. Also in the ova of all
animals which deposit fat and proteine within themselves.

In the case before us of the Madura foot, the fatty degeneration,
or disintegration, commences in the bones of the foot, and physio-
logical phenomena are gradually merged into pathological. A
similar instance is presented in the amyloid “ Lardaceous” disease,

68 Transactions of the

which invades various parts of the body. Large quantities of a fatty
material accumulate from a supposed deficiency in the quantity of
alkali in the blood. Complexity of structure in the known cha-
racters of organic compounds seems to be never better exemplified
than it is when large quantities of fatty matters enter into nitro-
genous compounds. As an example, the decompositions effected by
butyric acid seem to be endless, and more especially so when con-
nective and fibrous tissues enter into these decompositions, and
give new shapes and characters to the organic molecules. These
again are immensely changed, and other transformations effected
by the putrefactive process. Animal matter in a state of putrefac-
tion acts as a ferment, rapidly changing albuminoid and fatty
particles into a fungus, and is capable of causing their metamor-
phosis into sugar, alcohol, and carbonic acid. It may be possible
that an allied process is going on in connection with the Madura
foot disease, a putrefactive ferment, a process of chemical disintegra-
tion while the limb is still m connection with a living body,
although itself dead. I have before ventured to affirm that
parasitic fungi are characterized throughout nature by feeding on
effete or decayed matters, and I see no reason for changing my |
opinion. This view of them seems to have been floating in the
mind of the Rey. Mr. Berkeley, for he concluded the paper I have
already referred to, by observing :—“ In some cases it would seem
as if the foot was already in a diseased state when the fungus was
introduced: at least the history of one case which apparently
commenced with a boil in the imstep, and opened by a thorn, indi-
cates such a lesion as might well encourage the growth of a fatal
parasite.”

I readily admit that Dr. Carter’s great experience of Mycetoma,
and the many opportunities he has had of making examinations
soon after amputation of the foot, entitles his opmion to great
weight. I should indeed have been much inclined to accept his
views from this circumstance, provided he could have furnished
indisputable or reasonable evidence that “ Mycetoma stands for a
form of swelling which is caused by the growth of a fungus.” I
have endeavoured to place the matter before you in an impartial
spirit, hoping thereby to assist in the elucidation of an important
question, at the same time trusting I may have made the subject
sufficiently interesting to induce the Fellows of this Society to in-
vestigate it for themselves: if they do I can promise this much,
that they will find it of far more importance, if not more interesting,
than the markings on Diatoms and Podura scales.

Royal Microscopical Society. 69

II.—Diatomaceous Earth from the Lake of Valencia, Caracas.
By A. Ernst, Esq., and H. J. Suacx, F.G.S.

(Read before the Royat. Microscopicau Society, June 7, 1871.)

Tue following letter accompanied a present to the Society of dia-
tomaceous earth from the Lake of Valencia, Caracas :—

To the Secretary of the Royal Microscopical Society, London.
CARACAS (VENEZUELA), Dec. 4th, 1870.

Sir,—Allow me to present to the Royal Microscopical Society the
included specimen of diatomaceous earth from the neighbourhood of
the Lake of Valencia in this country. This lake is known for the
progressive diminution of its waters, and was formerly very much
larger than it is at present. An interesting account of it is given by
Humboldt, ‘Personal Narrative, ii., 1-20 (Bohn’s edition), All
round the lake, to a very considerable distance, extends a deposit
called by the inhabitants tierra de caracolillo, i.e. earth (formed) of
small shells, undoubtedly the old bottom of the lake. It forms a layer
of several feet of thickness, in which there are imbedded numberless
specimens of small shells. I have hitherto found six different species,
of which I add samples. Nos. 1-4 are very abundant; 5 and 6 are
very rare. I hope one of your conchologists will have the kind-
ness to determine the species. The remainder of the layer has the
appearance of a greyish blue marl, and contains so great a number of
fossil diatomacez that it may be said to be entirely formed out of
them. Being myself not sufficiently acquainted with diatomacee, I
must leave the closer inspection of this earth to others, and I feel sure
that one of the members of the Royal Microscopical Society will
kindly give us a list of the species it contains.

I shall be very happy to send a sample of the tierra de caracolillo
' to any microscopist or geologist who would like to have some.

I have the honour to be, Sir,
Your obedient servant,
A. Ernst.

Humboldt visited the Lake of Valencia about the beginning of
the present century. He describes the lake as then resembling
that of Geneva in appearance, and that of Neufchatel in size, and
makes many remarks on its progressive diminution, which he
ascribed to local changes, increasing evaporation, and diminishing
the water supplies. He remarked, “The land that surrounds the
Lake of Valencia being entirely flat and even, what I daily observed
in the lakes of Mexico takes place here; a diminution of a few
inches in the level of the water exposes a vast extent of ground
covered with fertile mud and organic remains.”* He advised the

* ‘Personal Narrative,’ Helen Maria Williams’ trans., vol. iv., p. lol.

70 Transactions of the

rich landholders to place columns of granite in the basin of the lake,
and note the mean height of the waters from year to year. At the
time of his visit the mean depth of the lake was from twelve to
fifteen fathoms, and in the deepest parts thirty-five or forty feet.
He said, “ It is impossible to anticipate the limits, more or less
narrow, to which this basin of water will one day be confined, when
an equilibrium between the streams flowing in and the produce of
evaporation and filtration shall be completely established. The idea,
very generally spread, that the lake will soon entirely disappear,
seems to me chimerical. If in consequence of great earthquakes,
or some other causes equally mysterious, ten very humid years
should succeed to long drought; if the mountains should clothe
themselves anew with forests, and great trees overshadow the shore
and plains of Aragua, we should probably see the volume of the
waters augment and menace the beautiful cultivation which now
branches on the basin of the lake.”

The diatomaceous deposit of which Mr. Ernst has sent a speci-
men is remarkably rich in quantity of specimens ; and it will interest
microscopists to note some of the conditions, described in the pre-
ceding quotations, under which it has taken place.

A shallow lake, fed by numerous small rivers, having no sea
outlet, and a warm temperature such as that of Valencia, seems
very favourable to diatom life, and the preservation of the shells.
Humboldt thought much of the water in the interior of Australia
was in a similar condition; and friends of science who may have
opportunities of visiting such localities will do well to follow Mr.
Ernst’s example, and forward specimens to the Society.

The fresh-water shells sent by Mr. Ernst have been named by
Mr. Henry Woodward, and consist of the following species, the
numbers being those on the little bottles containing them :—
1. Planorbis; 2. Paludina (pygmea?); 3. Bithynia; 4. Melania ;
5. Physa; 6. Ancylus.

The diatoms, so far as they have been examined, do not seem to
present any unusual forms. They will be still further investigated
By Score of the Society who devote attention to this particular
subject.

Royal Microscopical Society. 71

IiIl.—The Silicious Deposit in Pinnulariz.
By Henry J. Suacr, F.GS., Sec. R.M.S.

(Received during the Recess, and taken as read.)

In making Max Schultze’s artificial diatoms, all sorts of patterns
and gradations of size of the spherules are obtained, as the writer
has called attention to in a former paper. This, with other facts,
suggests the probability that in natural diatoms the silica may
always be deposited in spherules, and that what have appeared
plane surfaces, have the same structure as dotted ones, but on too
minute a scale to be discerned with the means employed.

The uniformity of plan in the silicious deposits of diatoms is to
a great extent shown, and to a still further extent suggested by
examining one of Moller’s admirable “ type slides,” with a good
immersion 4th or higher power. The gradations from large beads
distinctly separated, to smaller beads closely approximating, are
readily and instructively exhibited, so that it is easy to trace a
series, beginning with large forms that present no difficulty of
resolution, and concluding with the most delicate that tax the
utmost power of the optical apparatus. When beading appears
minute under high magnification, and each bead seems in contact
with its neighbour: the outline of a section made by a plane passing
through the bead rows perpendicular to the uppermost point of their
circumference, would exhibit a delicate wavy line, the depressions of
which would be extremely small, as they would correspond with
the radii of the little spheres, while the width of the curves would
correspond with their diameters. All that can be done under these
circumstances, by the best adjustments, and the most careful
unilateral illumination, is to exhibit minute, and often very faint,
alternations of light and shade, indicating rather than demonstra-
tively showing the character of the structure. When the best has
been done with any objective, it becomes evident that a slight
increase of the difficulty, from greater minuteness of the structure,
would render it invisible, and make the surface look plane.

From these considerations it would be evident that if we can
trace the spherule structure on similar parts of a series of diatom
valves, and view the spherules in various gradations, from com-
paratively large sizes to the smallest our glasses will show, we are
justified in supposing, if not in assuming, that similar parts of
diatoms in which no structure at all can be made out, really possess
the same structure as the preceding, though it eludes our view.

An examination of a number of species belonging to the genus
Pinnularia has confirmed this view. At one time it was supposed
that the Pinnulariz were distinguished from allied forms by solid
costz replacing beaded bands. More recently this distinction has

72 Transactions of the

not been deemed valid, but the writer is not sure that it has been
overthrown as respects many species.

An examination of the Pinnulariz on Moller’s “ type slide,” led
to the belief that the coste of such diatoms as P. viridis, nobilis,
&c., had been misunderstood. That instead of broad irresolvable
ribs, a truer view exhibited fine lines of beads springing from the
median band, with a furrow between them, and in that furrow
another line of beads at a lower level. The curvature of these
valves not only renders the exhibition of this structure very difficult,
but presents it under perspective aspects by no means easy to
understand. Occasionally a valve is met with that proves com-
paratively easy, and then no one would doubt the complexity of the
so-called coste, though much speculation would arise as to the most
correct interpretation of the various perspective views that can be
obtained.

The general aspect of valves whose cost can be resolved is that
of a number of lines or rows of beads springing from the median
band in a series of narrow arches with long sides, in shape some-
thing like ladies’ hair-pins, with hollows between them, in which
one or more rows of beads may be discerned.

To investigate these appearances and the various gradations in
different species was found impracticable with solids obtainable in
London, and accordingly Herr Moller was applied to through Mr.
Baker, and a considerable series, mounted dry, was lately received,
and forms the subject of the following remarks :—

PINNULARIA INTERRUPTA.—The curves of this diatom prevent
its coming well into focus with high powers. The beading of
the so-called costz is not difficult to show; but the relation of the
“cost” to the median band is not clear.

P. yrriis shows fine ribs composed of rows of dots ; depressions
between each pair of beaded ribs, with beaded rows in depressions.
The beaded ribs spring from the median band in various planes,
and give its edges a serrated aspect. When a pair of the hair-pin
shaped ribs are reddish, the intermediate bead rows are bluish. The
median band composed of beads in various planes.

P. nopriis.—Very difficult, except in lucky parts, and valves.
Much like viridis. The beadings curve down to a furrow in the
median band. Median band beaded in complicated pattern. The
beads only visible when the light comes exactly at the right angle.
The rows then seem to go down in a curve, and up again towards
the central keel ridge. It is to be expected that the perplexing
perspective presented by this object will occasion considerable
difference of opinion as to its real shape, but those who have
sufficiently good glasses, and take the requisite pains with the
illumination, will see that the so-called costz are very different
from any published drawings, and that there are beads in the sup-

Royal Microscopical Society. 73

posed clear spaces of the median band. Different valves vary
considerably in minute detail.

P. masor.—The curves present less difficulties than those of
nobilis. The beaded ribs very delicate; they commence in curves
along margin of median band, something like hooked sticks. Rows
of beads in median band.

P. mesotepta.—The best view of this elegant diatom resolves
the whole surface into rows of beads, median band included. In
form this diatom approximately resembles two skittles from a child’s
toy box, jomed at their bases. The rows of beads run obliquely
from median band. Crossing the median band in the centre is
another broad band, like two isosceles triangles with truncated
apices joined at their narrow ends. The spaces in these bands look
clear spaces with insufficient power or imperfect illumination. The
lines in the triangular cross-spaces run parallel to the long diameter
of the valve.

P. PEREGRINA.—Median band and costz resolvable into rows of
beads.

P. rapiosa.—Side rows of beads fall in oblique curves from
median band that rises like a keel. Median band exhibits rows of
fine beads.

P. arppa.—Curves different, but structure like nobilis, &e.

P. rata.—This plump little diatom makes the relation of the so-
called costs to the median band very clear. What appear broad
costze under low powers, are found to be loop-like bands of beads,
with several rows of beads in the furrows or depressions. Median
band consists of rows of fine beads at right angles to coste. Very
troublesome to show the median dots well.

P. rapERATA.—AlI the surface beaded ; beads in central nodule
arranged in curves. Central nodule difficult.

P. pIveRGENS.—Median band peculiar. As seen with moderate
power it looks like a broad, clear space, with two narrow longitudinal
furrows, extending one from each end, and not meeting in the
middle. Each furrow expands a little at the ends nearest centre.
Crossing the centre are two narrow bands. With D eye-piece the
th resolves the median band into rows of beads which curve round
the expanded ends of the two furrows. The so-called cost re-
semble those of nobilis, but are less out of the horizontal plane.

P. optoneA shows relation of so-called coste to median band
very clearly. Symptoms of resolution in median band.

In the preceding cases the structures described are seen with
various degrees of distinctness, and some under conditions more or
less favourable to optical illusion. It is only by comparing the
most distinct and clear exhibitions of the beaded structure with
others that are less definite that any prudent microscopist would
place much reliance upon the latter.

74 Transactions of the Royal Microscopical Society.

No tolerably good observer with recent appliances of immersion
lenses and condensers can fail to see the composite character of the
so-called costs, though there will be considerable variety of opinion
as to the most probable interpretation of the various aspects.
Tracing the beading on the median bands is, on the whole, much
more troublesome than exhibiting the composite character of the
costs, and it is probably on this point that most doubt will arise.
If, however, anyone with good tools and a suitable stock of
patience will go through a series of species, it will be readily
admitted that in some this medial beading cannot be denied, and
others may succeed in seeing it better than the writer has done in
the most difficult cases.

The preceding observations have been made with a remarkably
fine immersion 3th by Powell and Lealand on their new system.
The condenser employed is a ;4,ths one of Ross, and the usual stop,
one radial slot, aperture 109°. The most serviceable eye-pieces
were C and D of Ross’ scale.

Should these observations meet the eye of Colonel Dr.
Woodward, it may induce him to examine some of these diatoms,
and give microscopists the benefit of his very remarkable photo-
graphic skill. It would be impossible to make drawings that
would be accepted as satisfactory, until several good observers of
this troublesome class of object have compared notes and decided
which, out of many appearances, that look as if they corresponded
with fact, may be most prudently trusted.

(7.75%)

IV.—Observations and Experiments with the Microscope, on the
Chemical Effects of Chloral Hydrate, Chloroform, Prussie
Acid, and other Agents, on the Blood. By Tuomas SHearman
Raueu, M.B.C.S., Eng.

On a former occasion, now five years ago, I had the honour of
reading before the Medical Society of Victoria a paper entitled
“ Observations and Experiments with the Microscope, on the effects
of Prussic Acid on the Animal Economy,” in which I pointed out
the specific or chemical action of that agent on the blood, vez. that
the iron was laid hold of by the cyanogen, and the result was the
formation of prussian blue, or some cyanic compound of iron.
Accompanying this remarkable change was another, which I also
pointed out, that certain oval bodies, closely resembling starch
grains, were formed. These bodies turning blue under the action
of iodine, and polarizing, were seen to form in the field of the
microscope.

After my communication on the effects of prussic acid, I inves-
tigated the action of another chemical agent, which exhibits decided
effects on the corpuscles of the blood when applied to them out of
the body; namely, ammonio-sulphate of copper. When blood is
allowed to flow into a solution of this compound, it is found that
the contained matter of the red corpuscles cannot pass out; for
when blood is drawn and placed in a thin film on glass, and exa-
mined under the microscope, it is found that the major part of the
corpuscles gives up the contained matter, and the empty cell walls
or coverings remain behind. This is well seen on applying a solu-
tion of magenta to blood under the microscope ; the field becomes
occupied by a vast amount of granular matter, coloured red by the
dye; while the cell walls or envelopes lie in abundance uncoloured,
or at the most presenting to the eye of the observer the red molecule
first pointed out by Dr. William Roberts, of Manchester, in 1863,
and also brought further into notice by Professor Halford, in 1864,
before the Australian Society.* My experiments with this agent,
ammonio-sulphate of copper, go to show that while the corpuscles
are so acted on that they cannot pass out their contents, yet when
magenta is applied, this dye can pass in and colour them ; and this
coloration shows by its tint the degree of emptiness or fulness of
each corpuscle, proving that at the moment when the cupreous
solution was added to the fresh-flowing blood, the corpuscles were in
different conditions, some perfectly full, while others were partially
empty. By means of water the cupreous compound can be washed
away, and then these same corpuscles are able to part with their
contents, as they do under ordinary circumstances.t

* © Australian Medical Journal,’ vol. ix., 1864. + Ib., vol. xi., 1866.

VOL. VI. G

76 On the Chemical Effects of Chloral Hydrate,

Subsequently I offered some observations on the action of snake
poison on the blood, ¢.¢. that it could be compared to that brought
about by prussic acid ; that this agent, while it attacks the iron in
the blood, yet sets up a further action—that of causing the newly-
formed red corpuscles to retrograde, as it were, to the condition of
the white.*

Here are three important chemical agents, which have been ~
applied to the blood in order to elicit information regarding either
its structure or its chemical character, namely :—

Magenta ; which was first taken in hand, and which attacks the
nuclei of the white corpuscles and colours them; also the granular
matter exuded from the red.

Ammonio-Sulphate of Copper ; which prevents the egress of the
solid portion of the red corpuscles ; while at the same time magenta
can pass in and colour them effectually.

Prussic Acid; which lays hold of the iron in the blood, with-
drawing it from some organic state of combination, giving rise also
to the formation of corpora amylacea, or starchy bodies, by some
further change effected on the blood constituents.

I feel it is necessary thus to enter upon a réswmé of what has
been done, in order that what follows may be rendered more clear,
and that the minds of those to whom I address myself may be
satisfied that all the following observations and experiments have
proceeded gradatim, and owe their origin, and are connected, with
my former labours in this field of observation.

In bringing forward the present communication, I feel more and
more satisfied of the importance of that mode of investigation which
I have employed, that it is one which opens another avenue to the
study of physiology, as well as leading us to the ultimate or chemical
action of agents on the animal economy.

Experience and observation, based on the separate and combined
action of the above-mentioned agents, have satisfied me that some
reliable chemical effects may be traced out regarding other agents,
whose action on this portion of the animal economy is as yet
unknown.

The difficulty hitherto has been to find an agent the effects of
which either exceed or distinctly differ from those of any substances
hitherto recognized; while, at the same time, the nature and pro-
bable action of the new agent should be such as we can trace out
without encountering serious difficulty as to its interpretation.

I now proceed to the demonstration of some chemical changes
in the blood produced by means of different agents, the effects of
which have been hitherto entirely unknown, and which will prove
suggestive to the mind of the medical practitioner as soon as he
shall have presented to him a further series of experiments carried

* ¢ Australian Medical Journal,’ vol. xii., 1867.

Chloroform, Prussie Acid, de., on the Blood. 77

out after the mode of investigation which I have endeavoured to
follow, namely, the general action of a chemical substance on the
blood withdrawn from the body, and traced out by the microscope ;
and also the investigation of the action of the same agent on the
blood after it has circulated through the animal economy, having
been thereby subjected to the continuous action of air during its
passage through the lungs. In the former instance we obtain a
general kind of action on the blood ; in the latter, more positive or
distinct effects are presented to our notice, as I shall endeavour to
point out by-and-by.

The examination of the blood drawn from the circulation and
subjected to the action of a chemical agent does not suffice to show
us all that may be produced on it by that agent, and we need, if it
is possible, to ascertain and compare its effects after it has circulated
in the system. ‘This is true, however, only to a certain extent, for
we know that magenta has a remarkable effect on the blood when
added to it; but we find no trace of its effects on that fluid when
we inject it under the skin, or pass it into the stomach with a view
to its absorption and subsequent action on the blood, as the experi-
ments of Professor Halford go to show.

I now pass on to the examination I have made of the action of
one important chemical agent, which has only lately been brought
before the notice of the medical profession, both here and at home,
or rather in Europe. I mean chloral, or as its more chemical name
is supposed to be, “ Trichloric Aldehyde.” This substance is now in
use as a hydrate, and its action has been stated to be somewhat
like chloroform. When an alkaline solution is added to it, chlo-
roform is set free ; hence its proposer, Liebreich, suggested its use :
that meeting with alkaline elements in the blood, it might become
decomposed into chloroform. This theory, which is a very taking
one, was no doubt the cause of the experimental use of this sub-
stance. The general experience, however, of the profession is
against the idea that it acts as an anesthetic, but only as a true
hypnotic.

I feel inclined to the opinion that though it appears almost
certain that chloroform is eliminated in the blood by its decomposi-
tion, yet that the action of that agent is considerably modified by
the attendant chemical change which necessarily accompanies the
decomposition of this agent in the blood. If it is correct that
the hydrate of chloral is decomposed by the alkaline state of the
blood, then it follows as certainly that the resulting compounds
must be chloroform and a formate of some alkali. And if we regard
the presence of alkalinity to be normal in the blood, then we obtain
not only the chemical or physiological action of chloroform, but we
have also to consider what may be the physiological effect of the
formate of an alkali, whether of ammonia or potassa, and on such

a 2

78 On the Chemical Effects of Chloral Hydrate,

grounds we may fairly deduce that the physiological effects of
chloral on the animal economy must be somewhat different to that
of chloroform by itself; hence, perhaps, hypnotism, in place of
anzesthesia.*

At the risk of being tedious, I now approach the demonstration
I have proposed to make, by reference to the lie of my own expe-
rience in this matter; and I extract the followmg from my micro-
scopical note-book :—“ August 22nd, 1870.—Hydrate of chloral is
a remarkable chemical substance, producing a singular effect on the
blood when applied directly to it. A small portion placed on a
glass slide and slightly moistened, and then fluid blood added; about
one-third of the corpuscles appear to corrugate their solid contents,
which then take colour from magenta.”

This was the first fact which attracted my notice: the red cor-
puscles of the blood, when acted upon by magenta, under ordinary
circumstances pass out or give up their contents, which then become
coloured by the dye. In this instance the dye penetrated the cor-
puscles, and coloured the material within them.

This effect was sufficient to indicate to my mind the remarkable
chemical action of hydrate of chloral; and having made a note of
it, I waited until this agent was within my reach for further expe-
riment ; for when I made'this observation I could only obtaim a few
grains of it for experimental purposes.

In the following October I had occasion to administer it in small
doses, with the view of relieving pain. This enabled me to examine
the condition of the blood. The blood, drawn two or three hours
after its exhibition, presented a remarkable appearance. In several
parts of the field of the microscope, besides garnet-colowred amor-
phous particles, a number of red-colowred globules (double the
diameter of white corpuscles, and many smaller) were seen; some
of these were dark red. This was experiment the first.

Experiment 2.—Hydrate of chloral was exhibited by the stomach
to a rabbit ; within an hour red masses were seen in the blood, also
the presence of starchy bodies was noticed. :

Lzxperiment 3.—A frog was subcutaneously injected with hydrate
of chloral, with the same results.

* The decomposition of chloral hydrate by ammonia is curious to witness
when carried out in the following manner :—A solution of the hydrate should be
placed in a narrow tube, about seven or eight inches long, and ammonia added,
and the mixture shaken and slightly warmed, when a white cloudiness will make
its appearance, and bubbles of gas rise to the surface. If now a little superstratum
of water is added, and not allowed to mix with the contents of the tube, the
bubbles of gas will be seen passing through this stratum of water, and with a
pocket lens the decomposition will be well seen. So soon as a bubble reaches
the surface and disappears, from that point there descends an oily-looking fluid
(chloroform); but before this reaches the cloudy portion, an amorphous or semi-
crystalline material is formed—formate of ammonia; what the gaseous portion is
I have not ascertained.

Chloroform, Prussie Acid, &c., on the Blood. 79

Experiment 4.—Frog immersed in a four-grain solution of the
hydrate for some hours, when it was found hypnotic. Blood, nuclei
of corpuscles appeared greenish, red particles also seen.

Experiment 5.—Frog killed by hydrate of chloral, after some
hours of sleep. Blood from heart decidedly tinged redder than
usual; some corpuscles presented reddish dots on their surface ; red-
coloured masses were noticed all through the blood, as seen before.

Experiment 6.—On self. Three grains of hydrate of chloral
were taken about two hours after a meal; the blood was examined
every quarter of an hour; at the end of an hour it exhibited
decided reaction ; blue as well as red particles were seen. When
the blood had dried on the glass slide and under the covering glass
(which was about two hours after), some spaces, where coagulation
had taken place, were filled with fluid presenting either a bluish or
reddish tint. The urine also exhibited some dark-coloured and
reddish particles.

Experiments 7 and 8.—Two rats were killed, one by chloroform,
the other by hydrate of chloral, injected subcutaneously. This last
took a grain and a half before. deep sleep was induced. Blood
exhibited ruby-red particles; a few bluish ; also starchy bodies in
abundance. The urine also showed the same. .

The chloroformed rat.—Urine with abundance of starchy
bodies, and some blue-coloured particles ; blood from lungs—plasma
reddish ; few starchy bodies; some blue particles; scarcely any
reddish.

Experiment 9.—Rat injected with hydrate of chloral. Deep
hypnotism ; blood gave the same results; starchy bodies and red-
coloured masses. Ammonia inhaled appeared to increase the pro-
duction of the red matter. A solution of ammonia injected under
the skin appeared to give rise to bright red smears, or fluidity,
between the corpuscles. The blood, under the action of ammonia,
in both forms of exhibition, seemed to have assumed a redder tint
than usual.

Experiment 10.—A newly-born rat was placed in a solution of
hydrate of chloral. After some hours the blood exhibited redness in
the liquor sanguinis; also some fine red particles and red patches.

Experiment 11.—Hydrate of chloral was evaporated from a
slide on to fresh blood held over it; bright red-coloured particles
were formed in it.

Experiment 12.—Blood exposed to the vapour of chloroform
gave some evidence of red-coloured matter. It appeared to me, at
this point of my experiments, that the chemical action of hydrate of
chloral on the blood was mainly due to formyl, or formic acid,
produced by its decomposition. When more ammonia was intro-
duced into the experiment, a larger production. of the red material
resulted.

80 On the Chenical Effects of Chloral Hydrate,

Experiment 13.—Formic acid (obtained from ants) added to
blood gave rise to the formation of dark red globules and particles.

Experiment 14.—Lactic acid added to blood yielded red par-
ticles; these appeared to increase on the addition of prussic acid ;
the fiuid or plasma appeared redder.

Experiment 15.—Blood, with prussic acid added and then
oxalic acid, yielded red-coloured particles.

Experiment 16.— Blood exposed to vapour of hydrate of chloral
gave red particles as before; these lost their colour on addition of
oxalic acid.

Experiment 17.—Prussic acid and ammonia were mixed to-
gether on a slide, and fresh blood added; red particles made their
appearance ; no starchy bodies; blood corpuscles and plasma redder
than usual.

Experiment 18.—Blood, exposed to ammonia vapour, became
slightly reddened ; prussic acid added in fluid form ; blood became
decidedly redder ; red particles and red plasma resulted.

As far as these experiments had gone, I considered it reason-
able to conclude that the decomposition of hydrate of chloral in the
blood gave rise to the liberation of formyl, or else formate of
ammonia. But what becomes of it? Is it likely to remain in a
free and uncombined state? or rather does it not combine with
that important element in the blood—iron, producing a formate of
iron; or perhaps ammonio-formate of iron ?

These decompositions in a highly complex material, as blood,
are most difficult of explanation ; and it is here I feel we must
advance with caution.

The next point to which I directed my attention was to ascer-
tain the action of hydrate of chloral upon a salt of iron; and the
following experiments appear to me to support the view I haye
just expressed.

Ezaperiment.—Chloral dissolved in a little water with ammonia
added, was followed by the decomposition of the former ; a crystal
of sulphate of iron was added, and the effect watched under the
microscope ; red-coloured particles and amorphous masses of diffe-
rent depths of tint, closely resembling those seen in the blood in
the forementioned experiments, made their appearance.

A solution of ammonio-citrate of iron also gives similar results,
and somewhat similar also is the action of prussic acid and ammonia
conjointly acting on a salt of iron.

Again, being aware from experiments performed in times past,
that the presence of iron in vegetable tissues was demonstrable by
means of prussic acid and prussic salts, I proceeded to make the
following experiment, which, if it does not convince by its single
testimony, yet is to my mind highly satisfactory ; it is also one of
the most remarkable of the kind which I can adduce, in relation to

Chloroform, Prussie Acid, &c., on the Blood. 81

chemical action on vegetable tissues as revealed by the microscope ;
when once witnessed it can never be forgotten.

Ezxperiment.—A section of a tender vine was made and placed
on a glass slide with water, and chloral hydrate added ; a reddish
tint pervaded some of the cells; but when ammonia and chloral
were added together, the tissue became tinged with a dirty red.

Again: prussic acid and ammonia combined were added to
another vine section, and produced a most beautiful and striking
reaction. The woody ducts were seen filling up with bright red
fluid. In both these instances I have no doubt formyl, or formic
acid, attacks the iron combined with the fluids or tissue of the plant.

I can adduce a number of similar experiments, carried out
with the same chemical agents, which more or less yield evidence
of a similar kind of reaction ; but this would prove tedious and
superfluous.

I now proceed to sum up my experiments. Hydrate of chloral
administered by the stomach or subcutaneously injected, gives rise
to the production of bright red or dark red particles, masses, or
globules in the blood. Starchy bodies are also met with accom-
panying these charges. The urine also exhibits these bodies. The
same results follow when vapour of hydrate of chloral is applied to
fresh-drawn blood.

Ammonia, administered by the lungs, or subcutaneously injected
during the action of hydrate of chloral on the animal economy,
appears to heighten these effects.

Formic acid added to fresh blood also causes the production of
dark red globules and particles.

Lactic acid conjoined with prussic acid does the same.

Prussic acid and ammonia conjoined yields the same results.

The action of hydrate of chloral, while decomposing under
ammonia on a salt of iron, presents changes which to my mind are
identical.

The chemical effects of hydrate of chloral and ammonia, of
prussic acid and ammonia, on some vegetable tissues, appear to be
much the same in character as those produced in the blood, minus,
of course, the solid albuminous matter. All these results I refer to
the action of formyl or ammonio-formate on the iron in the blood,
or in the vegetable tissues.

The decomposition of lactic acid with prussic acid can supply
chemically the elements necessary for the production of formyl or
formate of ammonia ; as also prussic acid and ammonia.

There are one or two more experiments to which I must refer,
z.e. the chloroformed rat, in which the blood was noticed to be
reddish, but scarcely any red matter was seen. It would appear the
chemical condition of the blood is not capable of readily decom-
posing chloroform ; such also is the case, I believe, with hydrate of

82 Chemical Effects of Chloral Hydrate, &c., on the Blood.

chloral applied to the blood out of the body ; but when the vapour
of chloroform, or the hydrate of chloral is applied, then the red
particles make their appearance.

Here is another remarkable occurrence which receives its solution
from the forementioned experiments. Some blood was accidentally
examined after wine (Reisling) had been taken ; this was with the
view of exhibiting the action of prussic acid on iron in the blood ;
but it was noticed little or no reaction could be found after its
application ; but a good many red-coloured globules and particles
were seen, just as if chloral had been taken. In consequence of
this, a small drop of the wine was added to a little blood fresh
drawn ; the changes seen under the microscope were most remark-
able. Abundance of globules of a dark-red or brown colour made
their appearance, as also red amorphous masses or particles. Gas
also was given off in the neighbourhood of the globules. Some of
these bubbles contained a bluish fluid; the nuclei of the white
corpuscles were bluish.

The experience I have already gained in carrying out these
experiments leads me to see that the condition of the blood recog-
nizably varies from day to day, from the effects of food, &.; for
the varying degrees of success which have attended a number of
experiments performed with the same chemical agent, on the same
individual, point to the great probability of the variable condition of
the blood, when that individual has been the subject of variety in
diet, or degrees of fatigue of mind or body.

Another consideration which presents itself to my mind is, that
just as we now test the condition of the urine in order to ascertain
what is being eliminated from the body of a patient, so will the
physician find it useful occasionally to test, by means of reagents,
the condition of the blood of his patient, in order to verify the
character of some obscure symptoms.’ Even at this period of my
experience, I have reason to believe it is possible by means of agents
previously administered, to prolong the hypnotic action of chloral,
or to prevent or modify it in a great degree.

Thus, I believe, I have at least been able to give demonstration
to the theory of Liebreich, who, by his chemical knowledge, has
enabled the medical practitioner to employ a remarkable agent, one
which promises to be a sister companion to chloroform in alleviating
the ills to which flesh is heir. I hope I may be fortunate enough
to arouse the attention of my professional brethren to the investiga-
tion of the chemical action of remedies on the blood, and thereby,
perhaps, lead on to a more rational and satisfactory mode of treating
some diseases, which in time to come, I believe, will be attacked
directly through the blood itself—Read before the Medical Society
of Victoria.

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V.—Floseularia Cyclops: a New Species.
By Cuartes Cusirr, F.R.MS.

(Taken as read before the Royau MicroscopicaL Sociery.)
Puate XCIII.

I wave lately found associated with F’. coronetta another and a
larger floscule than that elegant species, and it is impossible to
apply the specific title of any known floscule to this particular form,
for while the disk resembles somewhat that of F’. ornata, this new
species differs essentially from that in many important details,
which will be clearly seen and appreciated on comparing it with
F. ornata, by referring to Plate XCIII., Figs. 1 and 2, which figures
have been drawn to the same scale and placed in juxtaposition for
the purpose of conveying a clear perception of their respective
forms and proportions ; and in preparing these I have assumed the
altitude of F’. ornata to be 35th, a length they frequently though
not constantly attain, due no doubt to different localities and habits,
for in some places they never exceed ;\5th, or just half the size shown
by Fig. 2.

y The first point which must strike the observer is the extraordinary
height of the animal, and while the size of the whole form greatly
exceeds that of F’. ornata, there is a striking resemblance between
the disks of these two species; but while the disk of F’. Cyclops is
proportionately larger, the so-called dorsal lobe is considerably
smaller than that of F’. ornata, and the investing case is increased
in a still greater degree than the occupant itself. The case is very
distinct, and is seen to be palpably invaginated by every retraction
of the occupant, especially after acts of evacuation, when portions of
the voided matter remain clinging to the sides of the case within the
invaginated portion, and are not dispersed throughout the hyaline
medium which fills the integument.

I do not consider it necessary to enter into a more detailed
account of this particular form, which is essentially of the same
organization as the other members, but I desire to claim the pri-
vilege of identifying it in this record by a specific title, and, in con-
sequence of its great bulk, have selected that of Cyclops; and how-
ever this may be objected. to, on a first consideration, in the generally
accepted notion of the possession of a single eye by the Gods in
question (for there were three of them), this traditionary assumption
of a single eye is erroneous ; these three brothers adopted the custom
of wearing small bucklers of steel wherewith to cover their faces,
and these bucklers had one small opening in the centre, and only
so far corresponded with a single eye ; and like the brothers Arges,
Brontes, and Steropes, our valiant Cyclops has two eyes.

( 84 )

VI.—WMr. Tolles’ “ Experiments on Angular Aperture.”
By F. H. Wenuam, Vice-President R.M.S.

Tue above essay would not have required any special notice from
me, had not reference been made to my name. I consider that I
have already said enough to settle the question in minds familiar
with optical science, but there are others who might suppose, from
the evidence of these experiments, that I have assumed things
incorrectly, for there appears to be a lack of discrimination in this
subject that quite justifies the remark made by the Rey. 8. L.
Brakey “as showing the incredibly low level at which the scdentifie
knowledge of optics exists amongst microscopists.”

Mr. Tolles’ communication is set forth in an unassuming way,
that does not provoke any hard strictures, but it enters within the
lines of a controversy that has been long and hotly contested in
reference to a subject which it would seem remains yet to be
understood.

As shown by the figure, Mr. Tolles fixes before the front lens
of an objective, a plano-convex lens nearly hemispherical, and then
measures the aperture. “On testing the angle, only 80° (or at
most, less than 82°) was obtainable. Were the plano-convex
removed, the angle indicated would be 170° upwards. This was
verified carefully.” There is a simple honesty and truth im this
experiment that is very pleasing. Half of 82°, or 41°, would be
about the angle of total reflexion from the flat surface of the
plano-lens, at which a veil of utter darkness would be thrown
between the object-glass and the light, and none could pass beyond,
so that after this the plano-convex had nothing whatever to do
with apertures exceeding 82°.

We next come to the immersion question. I must compliment
Mr. Tolles on the accuracy of his little diagram. The hemi-
spherical lens is, I have no doubt, correct, and so is the front of the
objective, both for diameter and thickness, as it should be, coming
from a professional maker. Mr. Tolles says, “ When the air in this
interspace (7. e. between the lenses) is replaced by water, the angle
becomes 100°, or a little more (an after-note states it as 110).
. . . It seems incontestable, at all events, that more than 82° of
angular pencil can traverse the balsam-mounted object, and be
transmitted by the immersion objective to the eye of the observer.”

Though I saw at a glance why this assertion must be incorrect,
and could explain the reason in a few words, yet as Mr. Tolles has
given me facilities for doing so, I elucidate the point by the aid of
a diagram, exactly copied, four times the size of his own figure.
a, Fig. 1, is the front lens of the object-glass; 6, b, rays; these,
after being refracted by the convex and flat surfaces, would con-

Mr. Tolles’ “ Experiments on Angular Aperture.” 85

verge in the dry lens at an angle of 170°, as shown by the dotted
lines. Now let us introduce water between the lenses. Instantly
a change takes place ;

no one, I think, will FIG

have the hardihood
to maintain that the
rays will hold their
former position: on
the contrary, they
will converge at an
angle of near 80°, and
meet at a point in
the body of the under
lens. ‘They cross and
reach the lower hemi-
spherical surface ;*
here they are re-
fracted more out-
wards, and form an
angle with each other
of 108°, only two
degrees short of the
110° given by the
experiment. This
angle is obtained by careful projection of the rays, and is the one
mistaken by Mr. Tolles for the representative of the extreme rays
of the immersion objective. The microscope body is presumed to
have been rotated on a sector as usual, but in order to make the
thing more plain to those who do not perceive such matters very
clearly, we will suppose the light itself to be traversed instead
(which is very frequently done); it must be evident that this will
have to be moved a greater distance, on account of the bending
outwards of the rays by the lower surface of the hemispherical lens,
and so give a false indication of increased aperture.

The loss of aperture on balsam-mounted objects was demon-
strated by me on correct optical laws known ages ago, and I am
astonished that in the nineteenth century anyone can dare to dis-
pute it as a fact; but as it seems necessary to give an experiment
to convince the sceptical that when the refraction of the front
surface of an object-glass is partly neutralized by water contact, or
destroyed by balsam, and the angle of aperture most woefully
reduced on objects immersed therein, I have done this as follows :—

* A slight displacement of the ray, too small to be shown in the diagram,
will be caused by the water-film; but this does not alter the angular direction
in the hemispherical lens, though it may slightly increase the angle on finally
leaving it.

86 Mr. Tolles’ “ Kaperiments on Angular Aperture.”

a, Fig. 2, is a tank with a plate-glass bottom filled with water,*
b is the light some distance below on the floor; the sector for
measuring the apertures is set ver-
FIC.2 tically, so that the nose of the
object-glass ¢, may remain immersed
_* in the water during the rotation.
s The following are some results :—
A 5th of 170° (¢mmersion front)
showed an apparent aperture of
100°; a ith of 180°=87°, and a
voth of 90°= 67°. If a.higher
refractive medium than water had
been employed, the angles would
have been still less, and with Canada
balsam, or something of the same
refractive power of the glass, the
aperture from 170° could not exceed
80°. This experiment would have
been more inconyenient to try, and
I did not think it worth while to
run the risk of imjuring my object-
glasses for demonstrating a simple
'B fact in known optical laws quite
wy incontrovertible. About 80° is the
WA 2
= (= utmost aperture that we can expect
ne to obtain for an object mounted in
balsam ; and the principle does not
differ, whether we employ an immersed front or not. The latter,
of course, has the advantage in transmitting more light, and allows
greater control over the aberrations. A tank might be used with
a glass side, and the sector kept horizontal as usual, but this
requiring an elastic water-tight connection from the object-glass,
would be troublesome.

Messrs. Tolles and Stodder have girded on a convex front, and
then ventured forth to make a stand against my unwelcome state-
ments—that the aperture of object-glasses 7s reduced on balsam-
mounted objects, and that there is no subsequent increase of this
aperture by using an immersion lens. I had not the pleasure of
shaking hands with them before the collision, but in the absence
of this ceremony, I hope they may take the reception that they
have met with in good part.

* The glass-bottomed metal pot, used by fastidious beer-drinkers, will answer
the purpose, but I do not know whether our Transatlantic friends are familiar
with this.

‘
.

roe)

VII.—On the Microscopical Structure and Composition of a
Phonolite from the “Wolf Rock.” By 8. Atuport, F.G:S.
With a Chemical Analysis by Mr. J. A. Pumurs.

Tue rock described in the following paper is, I believe, new to
British petrology ; and as the value of microscopical analysis is not
yet fully recognized, a detailed description may be acceptable to
many readers. The specimens examined were kindly sent to me
by Mr. J. A. Phillips, together with a chemical analysis, which,
with his permission, 1s also added.

The “ Wolf” is a rugged rock lying about nine miles south-east
of the Land’s End, and covered by the sea at high water. At low
water of spring tides its length is about 175 feet, and its breadth
150 feet. Its highest point at low water is 17 feet above the level
of the sea, whilst at high water it is covered by it to a depth of
2 feet.

Examined by the eye or simple lens, the rock is seen to consist
of a yellowish-grey compact base, in which crystals of clear glassy
felspar are imbedded ; they exhibit no striz ; their fracture is sharp
and splintery.

A thin section examined in polarized light with crossed prisms
exhibits a beautiful group of crystals of felspar and nepheline por-
phyritically imbedded in a fine-grained matrix composed of minute
crystals of nepheline, felspar, and hornblende ; when cut very thin,
the hornblende alone exhibits colours, the hexagonal sections of
nepheline being black, the rectangular white; the felspar is also
either dark or light, and the general appearance ig that of a mosaic
of dark and light stones interspersed with small brilliant-coloured
erystals of hornblende ; the whole forming a matrix in which the
larger crystals are set. In thicker sections the felspar and nephe-
line display fine colours, but the minute structure is not so well
seen.

The microscopic constituents are for the most part evenly dis-
tributed throughout the base, but not unfrequently they are crowded
together along the sides of the larger crystals and irregular grains of
nepheline. Thisisan important fact, as it clearly indicates that both
the nepheline and the smaller crystals hid been formed while the
surrounding mass was still in a plastic state; it would also appear
that the felspar was the last to crystallize, as it frequently encloses
crystals of nepheline and hornblende, which must have been caught
up in it at the time of consolidation.

The nepheline occurs in the sections in hexagonal and rectangular
forms, or as imperfect crystals and irregular grains; some are per-
fectly clear and transparent, but the greater number appear to be
filled with a fine grey dust; it is sometimes equally distribute, but

88 On the Microscopical Structure and Composition

is also frequently collected together so as to form a dark, or even
black mass in the centre, the edges of which are sharply defined, and
correspond exactly with those of the crystal. Hexagonal crystals,
for example, exhibit a border filled with fine grey dust, and a central
portion occupied by a well-defined black hexagon ; or there is some-
times a black band running parallel with and at some distance from
the sides, the central and outer portions of the crystal being occu-
pied by the grey dust. With a magnifying power of 800, a portion
of the dust is resolved into minute granules, having a translucent
centre surrounded by a dark ring; they are therefore probably glass
cavities. It is especially worthy of remark that this grey dust occurs
in precisely the same way in the nepheline of the basalts and phono-
lites of Tertiary age, and from widely separated localities. The clear
crystals frequently exhibit faint lines parallel with the sides, and
they often enclose slender acicular prisms; compound and twin
crystals are not uncommon.

The felspar is perfectly clear and transparent, and evidently be-
longs to the orthoclase group; no striz are observable, and one or
two crystals give an angle of 90° by measurement with the gonio-
meter. The prisms are frequently much fractured transversely to
the long axis, and in this respect, and in their optical character, they
closely resemble the sanidine of some trachytes and phonolites.
Twin crystals showing different colours on opposite sides of the
plane of junction are not uncommon. The felspar contains numerous
glass cavities and extremely minute crystals, which are sometimes
irregularly distributed, but are also frequently arranged in rows
parallel with the edges of the larger crystals; the latter have also
caught up crystals of nepheline, and a few long slender prisms,
probably apatite.

The hornblende occurs in minute green prisms, varying in length
from ;h,5 to s}oth of an inch, and in width from z)g55 to yop m.
They are regularly interspersed with the other constituents of the
base, but occasionally great numbers of them are crowded together
in closely compacted groups, having a nucleus of black grains of
magnetite ; a few prisms may also be seen imbedded in the nephe-
line and felspar.

There may perhaps be some little uncertainty whether this
pyroxenic mineral be hornblende or augite. I have not met with
any reliable angles, as most of these minute prisms appear to be
broken or imperfectly formed at the ends; a few of larger size are,
however, distinctly dichroic, and would therefore appear to be horn-
blende.

The greater part of the mass of the rock is seen to consist of
nepheline ; the crystals forming the base vary in size from the 745
to zoo in. across, but there are perfect hexagons which do not
measure more than the sg5yth of an inch; most of them are

of a Phonolite from the “ Wolf Rock.” 89

indistinct in outline when seen by ordinary light, but become well
defined when examined with a half-inch objective between crossed
prisms.

Two analyses of this rock afforded Mr. J. A. Phillips the

following results :—

Sp. Gr. = 2°54.
1E 1.

aber Ee eM es oie es OONDEPICCH bya qaten 05
Sita: oo os. ee hOae ee 56-40
Alumina oa Bay H2ZZE29 F te ey 22020
Peroxide of iron... .. 2°70 a ay Eee eo Ol
Protoxide of iron as SOT eins con MBE “97
Manganese .. .. .. ‘Trace eo eer brace
MON» Haast Adee TOW he Sq oe ee
Magnesia <:. .. .. ‘Trace FCT ACE,
Phosphoric acid .. .. Trace aC LACE
IRGIABBA ee to tee eS 3 Fol eee he
Sodar eesinhs sees! lisds 3 Salta, MSS

99°88 99°42

Anyone who has made a careful examination of the Tertiary
phonolites, or is acquainted with Professor Zirkel’s researches on
them, will at once recognize the identity of their mineralogical com-
position with the rock here described, and will be struck with the
thoroughly characteristic appearance of the nepheline, which is ab-
solutely the same in both. In fact, no one would hesitate to call it
a phonolite, if it were known to be of Tertiary age. The age,
however, is unknown, and likely to remain so, for the rock stands
alone in the sea, and its actual relations with others cannot be ob-
served. Situated between the Land’s End and Scilly Islands, it is
in a Paleozoic district, disturbed and penetrated in all directions by
granites, porphyrites, and diorites ; few, therefore, will hesitate to
place it among the older series of igneous rocks. It is at present
the practice among many petrologists to name rocks according to
their supposed geological age; a dark-coloured augitic rock, for ex-
ample, would be a basalt if of Tertiary age, but must be a melaphyr
or aphanite, if of some indefinite early age. In accordance with
this absurd system, the rock in question would probably be called a
Foyaite, if it were known to be old, as it agrees well with descrip-
tions of that rock, except that the eleolite is here represented by
nepheline crystals which cannot be distinguished from those of true
phonolites.

After some hesitation, I have adopted the name of porphyritic
phonolite for this rock, and will take the present opportunity of sug-
gesting that one name only should be assigned to all igneous rocks
composed of the same constituent minerals, irrespectively of their
age ; or, in other words, that we should assimilate the nomenclature

* Of which *94 was lost in water-bath.

90 On Spore-cases in Coals.

to that employed in the sedimentary rocks. We speak of Carbon-
iferous or Tertiary sandstones, &c., why not Carboniferous or Tertiary
dolerites or melaphyres? When the age cannot be precisely ascer-
tained, an approximation may generally be made, and such terms as
post-Carboniferous, ante-Triassic, &c., might be used.

If some such system were adopted, all the basic, augitic rocks
containing much iron oxide, would form one group, and we should
get rid of a number of useless names which have been applied to
rocks in utter ignorance of their mineralogical composition or
structure.

Until quite recently such a suggestion could not have been
adopted, as there were no means of ascertaining with certainty the
constituents of the fine-grained rocks; but now that improved
methods of microscopical research are available, it is quite time that
the unscientific nomenclature still in use should be supplanted by
one more in accordance with the present state of knowledge.—
Geological Magazine, June.

VIII.—On Spore-cases in Coals.
By J. W. Dawson, LL.D., F.RS.

Wuen in London, last year, Prof. Huxley was kind enough to
show me some remarkably beautiful slices of coal mounted by his
assistant, Mr. Newton, and showing with great distinctness multi-
tudes of spore-cases and spores, some of them very well preserved.
He further stated to me his belief that such material had been
largely or mainly instrumental in the production of Coal. At the
time I declined to accept this conclusion, on the ground that the
specimens probably represented layers of coal exceptionally rich in
spore-cases ; and that even in these specimens a large quantity of
matter was present which long experience in the examination of
coals enabled me to recognize as cortical or epidermal matter, which
I had previously shown by my examination of the coals of Nova
Scotia to be the principal ingredient in ordinary coal. I promised,
however, on my return to Canada, to look over my series of prepa-
rations of coal, with a view to the occurrence of spore-cases, and also
to make trial of the somewhat improved method of preparation em-
ployed by Mr. Newton. On my return I gave the results of my
examination to Prof. Huxley, in a letter which he has quoted in the
brilliant exposition of his observations and conclusions in the ‘ Con-
temporary Review’ for November,* and which will probably give a
tone to the representations of popular writers on this subject for

* In the quotation the word “cubical” has been substituted for “ cortical.”

On Spore-cases in Coals. 91

some time. While, however, admitting the great interest and im-
portance of Prof. Huxley’s observations, and prepared to contribute
some additional illustrations of the occurrence of spore-cases in coal,
I think it well to direct attention anew to the actual composition of
the substance, as proved by its mode of occurrence, and illustrated
by my own extensive series of observations on the coals of Nova
Scotia and Cape Breton, including the series of eighty-one seams
exposed at the South Joggins, the whole of which I have examined
am situ and under the microscope.

The occurrence of bodies supposed to be spore-cases in coal, is,
as Prof. Huxley states, no new discovery ; but in reality these may
be said to be the first organisms recognized by any microscopic
observer of coal—that is, if all the clear spots and annular bodies
seen in slices of coal are really spore-cases. They were noticed by
Morris as early as 1836, and they had been observed and described
long before by Fleming in Scotland. Goeppert mentioned and
figured them in his ‘ Treatise on Coal’ in 1848. Balfour described
them in 1859 as occurring in Scottish coals, and Quekett figured
them in his account of the Torbane Hill mineral in the same year.
In 1855 the latter microscopist showed me in London slices exhi-
biting round bodies of this kind, very similar to those now described
by Huxley; but at that time I regarded them as concretionary,
though Prof. Quekett was disposed to consider them organic. Mr.
Carruthers has summed up most of these facts in his account of his
genus F'lemingites in the ‘ Geological Magazine’ for October, 1865.
The subject has also attracted the attention of microscopists in con-
nection with the Tasmanite, or “ white coal” of Tasmania, which is
composed in great part of the spore-cases of ferns.

I suppose that the oldest spore-cases known are those described
by Hooker, from the Ludlow formation of the Upper Silurian ; but
these, if really spore-cases, are different in structure from those or-
dinarily found in the coal formation, more especially in the great
thickness of their walls, and I am not aware that they have any-
where been found in considerable quantities.

The oldest bed of spore-cases known to me, is that at Kettle
Point, Lake Huron. It is a bed of brown bituminous shale, burn-
ing with much flame, and under a lens is seen to be studded with
flattened disk-like bodies scarcely more than a hundredth of an inch
in diameter, which under the microscope are found to be spore-cases,
slightly papillate externally, and with a point of attachment on one
side and a slit more or less elongated and gaping on the other. I
have proposed for these bodies the name Sporangites Huronensis.
When slices of the rock are made, its substance is seen to be filled
with these bodies, which, viewed as transparent objects, appear yel-
low like amber, and show little structure, except that the walls can,
in some cases, be distinguished from the internal cavity, and the

VOL. VI. H

92 On Spore-cases in Coals.

latter may be seen to enclose patches of floceulent or granular matter.
In the shale containing them there are also vast numbers of rounded
translucent granules which may be the escaped spores.

The bed at Kettle Point is stated in the report of the Geological
Survey to be 12 to 14 feet in thickness; but to what degree either
in its thickness or horizontal extent it retains the characters above
described, I do not know. It belongs to the Upper Devonian, being
supposed to be a representative of the Genesee slates of New York.
It contains stems of Calamites inornatus and of a Lepidodendron,
obscurely preserved, but apparently of the type of L. Veltheomianum,
and possibly the same with L. primxvwm of Rogers. The spore-
cases are not improbably those of this plant, or of the species
L. Gaspianum, which belongs to the same horizon, though not found
at this locality. The occurrence of this bed is a remarkable evidence
of the abundance of Lycopodiaceous trees, whose spores must have
drifted in immense quantities in the winds, to form such a bed. It
is to be observed, however, that this is not a bed of coal, but a bitu-
minous shale of brown colour, and with pale streak, no doubt ac-
cumulated in water, and even marine, since it contains Spirophyton*
and shells of Lingula. In this it agrees with the Australian Tas-
manite, which, though composed in great part of spore-cases of
ferns, is, as I am informed by Mr. Selwyn, an aqueous deposit,
containing marine shells.

There is, however, one bed of true coal known in the Devonian
of Eastern America, that of Tar Point, Gaspé, and it is curious to
observe that this is not composed of spore-cases, but of successive
thin layers of rhizomata and stems of Psilophyton, with occasional
fragments of Lepidodendron and Cyclostigma. Rounded disks,
which may be spore-cases, occur in it, but very rarely. In the
bituminous shales associated with this coal the microscope shows
amber-coloured flakes of irregular form, but these are easily ascer-
tained to be portions of the epidermis of Psilophyton, or of the
chitinous crusts of crustaceans which abound in these beds.

Ascending to the Lower Carboniferous (sub-carboniferous), there
are great quantities of rounded spore-cases of the size of mustard
seeds (Sporangites glabra of my papers) in the rocks of Horton
Bluff and Lower Horton, Nova Scotia. They are sometimes glo-
bular, and filled with pyrite of a granular texture which perhaps
represents the original cellular structure or the microspores. In
other cases they are flattened and constitute thin carbonaceous layers.
They are almost without doubt the spore-cases of Lepidodendron
corrugatum, which abounds in the same beds, and constitutes in one
place a forest of erect stumps. I described them in a paper “On
the Lower Carboniferous of Nova Scotia,” in the ‘ Proceedings of the
Geological Society of London’ for 1858, though not then aware of

* The well-known Cauda-qalli fucoid,

On Spore-cases tir Coals. 93

their true nature, which was, however, recognized by Dr. Hooker in
some specimens which I had sent to London.

In my paper “On the Conditions of Accumulation of Coal,” * I
proposed the name Sporangites for these bodies, in consequence of
the difficulty of referrmg them certainly to any generic forms. Car-
ruthers had, in Oct. 1865, described a cone containing rounded spore-
cases of not dissimilar type, under the name Mlemingites. In the
paper above referred to, I stated that out of eighty-one coals of the
South Joggins Section examined by me, I recognized these bodies
and other fruits or sporangia in only sixteen ; and of these only four
had the rounded Lycopodiaceous spore-cases similar to those of
Flemingites. These are the following :—

(1.) Coal group 12, of Division IV., has a bed of coal one foot
thick, of which some layers are almost wholly composed of Syo-
rangites papillata.

(2.) Coal group 13, Div. IV., has in some layers great quantities
of Sporangites glabra, especially in the shaly part of the coal.

(3.) In Coal group 14, Div. IV., a shaly parting contains great
numbers of similar sporangites.

(4.) In Coal group 15a, Div. IV., the shaly roof abounds in
sporangites, but I did not observe them in the coal itself.

In addition to these cases, all of which curiously enough occur
in one part of the section, and among the smaller coals, I have noted
the occurrence of clear amber spots in several of the compact coals,
but I did not regard these as certainly organic, suspecting them to
be rather concretionary or segregative structures.

The great coal beds of Pictou are, in so far as my observation
has extended, remarkably free from indications of spore-cases, and
consist principally of cortical and ligneous tissues with layers of
finely comminuted vegetable matter. A layer of cannel, however,
from a bed near New Glasgow has numerous flattened amber-coloured
disks, which may be of this character. In those of Cape Breton,
the yellow spore-case-like spots are: much more abundant ; but these
coals 1 have less extensively examined than those of the mainland
of Nova Scotia. Of American coals, the richest in spore-cases, that
I have seen, is a specimen from Ohio, which contains many large
Spore-cases, and vast numbers of more minute globular bodies
apparently macrospores. It quite equals in this respect some of the
English coals referred to by Huxley. I have also a specimen of
anthracite from Pennsylvania, full of spore-cases, some of them
retaining their round form and filled with granular matter which
may represent the spores.

It is not improbable that sporangites or bodies resembling them,
may be found in most coals; but the facts above stated indicate
that their occurrence is accidental, rather than essential to coal accu-

* * Proceedings of Geological Society of London,’ May, 1866.
H 2

94 On Spore-cases in Coals.

mulation, and that they are more likely to have been abundant in
shales and cannel coals, deposited in ponds or in shallow waters in
the vicinity of Lycopodiaceous forests, than in the swampy or peaty
deposits which constitute the ordinary coals. It is to be observed,
however, that the conspicuous appearance which these bodies, and
also the strips and fragments of epidermal tissue, which resemble
them in texture, present in slices of coal, may incline an observer,
not having large experience in the examination of coals, to overrate
their importance, and this I think has been done by most micro-
scopists, especially those who have confined their attention to slices
prepared by the lapidary. One must also bear in mind the danger
arising from mistaking concretionary accumulations of bituminous
matter for sporangia. In sections of the bituminous shales accom-
panying the Devonian coal above mentioned, there are many rounded
yellow spots, which on examination prove to be the spaces in the
epidermis of Psilophyton through which the vessels passing to
the leaves were emitted. ‘To these considerations I would add the
following, condensed from my paper above referred to, in which
the whole question of the origin of coal is fully discussed.*

(1.) The mineral charcoal or “ mother coal” is obviously woody
tissue and fibres of bark ; the structure of the varieties of which and
the plants to which it probably belongs, I have discussed in the paper
above mentioned.

(2.) The coarser layers of coal show under the microscope a
confused mass of fragments of vegetable matter belonging to various
descriptions of plants, and including, but not usually largely, spo-
rangites.

(3.) The more brilliant layers of the coal are seen, when sepa-
rated by thin lamine of clay, to have on their surfaces the markings
of Sigillariz and other trees, of which they evidently represent
flattened specimens, or rather the bark of such specimens. Under
the microscope, when their structures are preserved, these layers
show cortical tissues more abundantly than any others.

(4.) Some thin layers of coal consist mainly of flattened layers
of leaves of Cordaites or Pychnophyllum.

(5.) The Stigmaria underclays and the stumps of Sigillaria in
the coal roofs equally testify to the accumulation of coal by the
growth of successive forests, more especially of Sigillariz. There is
on the other hand no necessary connection of sporangite beds with
Stigmarian soils. Such beds are more likely to be accumulated
in water, and consequently to constitute bituminous shales and
cannels.

(6.) Lepidodendron and its allies, to which the spore-cases in
question appear to belong, are evidently much less important to coal
accumulation than Sigillaria, which cannot be affirmed to have pro-

* See also ‘ Acadian Geology,’ 2nd edit., pp. 138, 461, 493.

On Spore-cases in Coals. 95

duced spore-cases similar to those in question, even though the
observation of Goldenberg as to their fruit can be relied on; the
accuracy of which, however, I am inclined to doubt.

On the whole, then, while giving due credit to Prof. Harley and
those who have preceded him in this matter, for directing attention
to this curious and no doubt important constituent of mineral fuel,
and admitting that I may possibly have given too little attention to
it, I must maintain that sporangite beds are exceptional among
coals, and that cortical and woody matters are the most abundant
ingredients in all the ordinary kinds; and to this I cannot think
that the coals of England constitute an exception.

It is to be observed, in conclusion, that the spore-cases of plants,
in their indestructibility and richly carbonaceous character, only
partake of qualities common to most suberous and epidermal matters,
as I have explained in the publications already referred to. Such
epidermal and cortical substances are extremely rich in carbon and
hydrogen, in this resembling bituminous coal. They are also very
little hable to decay, and they resist more than other vegetable mat-
ters aqueous infiltration ; properties which have caused them to remain
unchanged and to resist the penetration of mineral substances more
than other vegetable tissues. These qualities are well seen in the
bark of our American white birch. It is no wonder that materials
of this kind should constitute considerable portions of such vegetable
accumulations as the beds of coal, and that when present in large
proportion they should afford richly bituminous beds. All this agrees
with the fact, apparent on examination of the common coal, that the
greater number of its purest layers consist of the flattened bark of
Sigillariz and similar trees, just as any single flattened trunk im-
bedded in shale becomes a layer of pure coal. It also agrees with
the fact that other layers of coal, and also the cannels and earthy
bitumens appear, under the microscope, to consist of finely com-
minuted particles, principally of epidermal tissues, not only from the
fruits and spore-cases of plants, but also from their leaves and stems.
The same considerations impress us, just as much as the abundance
of spore-cases, with the immense amount of the vegetable matter
which has perished during the accumulation of coal, in comparison
with that which has been preserved.

I am indebted to Dr. T. Sterry Hunt for the following very
valuable information, which at once places in a clear and precise light
the chemical relations of epidermal tissue and spores with coal.
Dr. Hunt says :—“ 'The outer bark of the Cork-tree and the cuticle of
many if not all other plants consists of a highly carbonaceous matter,
to which the name of suberin has been given. The spores of Lyco-
podium also approach to this substance in composition, as will be
seen by the following, one of two analyses by Duconi,* along with

* Liebig and Kopp, Jahresbuch, 1847-48.

96 On Spore-cases in Coals.

which I give the theoretical composition of pure cellulose or woody
fibre, according to Payen and Mitscherlich, and an analysis of the
suberin of Cork, from Quercus suber, from which the ash and 2°5
per cent. of cellulose have been deducted.*

Cellulose. Cork. Lycopodium.
Carbon ..° uo!) (44°44 ae 16D See
Hydrogen 5 amea), OOLT os ese) SGSSN aes nets
INGIPORCD css s\ occ = PRE 1°30" eee 6°18
Oxygen )" .. °.. 49°39 1. 0. 2a ee
100°00 100-00 100-00

“This difference is not less striking when we reduce the above
centesimal analyses to correspond with the formula of cellulose,
C,,H.,O.), and represent Cork and Lycopodium as containing 24
equivalents of carbon. For comparison | give the composition of
specimens of peat, brown coal, lignite, and bituminous coal.f

Cellulose PTET Ree
Cork oP ee we) Re, lee ea
Lycopodium .. .. .. «.. «. « « Co Hise NOss,
Peat (Vaux) -. .- -. os ae , ss 59 | AOoeIEsmeena
Brown coal (Schrother) .. .. .. .. C24 His}, 01055

Lignite (Vaux) .. , C24 Hi13, O63

Bituminous coal (Regnault) eyes olan « LOREEN 0335

“Tt will be seen from this comparison that, in ultimate composi-
tion, Cork and Lycopodium are nearer to lignite than to woody
fibre; and may be converted into coal with far less loss of carbon
and hydrogen than the latter. They in fact approach closer in
composition to resins and fats than to wood, and moreover like those
substances repel water, with which they are not easily moistened,
and thus are able to resist those atmospheric influences which effect
the decay of woody tissue.”

I would add to this only one further'consideration. The nitrogen
present in the Lycopodium spores no doubt belongs to the protoplasm
contained in them, a substance which would soon perish by decay ;
and subtracting this, the cell-walls of the spores and the walls of the
spore-cases would be most suitable material for the production of
bituminous coal. But this suitableness they share with the epidermal
tissue of the scales of strobiles, and of the stems and leaves of Ferns
and Lycopods ; and above all, with the thick corky envelope of the
stems of Sigillarie and similar trees, which, as I have elsewhere
shown,{ from its condition in the prostrate and erect trunks con-
tained in the beds associated with coal, must have been highly car-
bonaceous and extremely enduring and impermeable to water. In
short, if instead of “spore-cases” we read “epidermal tissues in

* Gmelin, ‘ Handbook,’ xv., 145. + ‘Canadian Naturalist,’ vi., 253.
{ “Vegetable Structures in Coal,” ‘Journ. Geol. Soc., xv., 626; “ Conditions
of Accumulation of Coal,” ib., xxii., 95; ‘ Acadian Geology,’ 197, 464.

On Spore-cases in Coals. 97

general, including spore-cases,” all that Huxley has affirmed will be
strictly and literally true, and in accordance with the chemical com-
position, microscopical characters, and mode of occurrence of coal. It
will also be in accordance with the following statement, which I
may be pardoned for quoting from my paper “On the Structures
in Coal,” published in 1859 :—

“A single trunk of Sigillaria, in an erect forest, presents an
epitome of a coal-seam. Its roots represent the Stigmaria under-
clay ; its bark the compact coal; its woody axis, the mineral char-
coal; its fallen leaves (and fruits), with remains of herbaceous plants
growing in its shade, mixed with a little earthy matter, the layers of
coarse coal. The condition of the durable outer bark of erect trees
concurs with the chemical theory of coal, in showing the especial
suitableness of this kind of tissue for the production of the purer
compact coals. It is also probable that the comparative impermeability
of the bark to mineral infiltration, is of importance in this respect,
enabling this material to remain unaffected by causes which have
filled those layers, consisting of herbaceous materials and decayed
wood, with pyrites and other mineral substances.”—-American
Journal of Science, No. 4, Vol. I.

(08: .)

PROGRESS OF MICROSCOPICAL SCIENCE.

The Retrograde Development of Marine Bryozoa.—In the first number
of vol. xxi. of Siebold u. Kélliker’s ‘ Zeitschrift, Claparéde, who with
the exception of Nitzsche is the only writer who has studied the Bry-
ozoa since the publication of the capital papers of Smitt, gives us most
interesting contributions to their history. While on the main points
he completely agrees with the views taken by Smitt of the polymor-
phism of the species, their mode of budding and general embryonic
development, yet in some points not satisfactorily determined by Smitt,
such as the relations of the various cells (zocecia) to one another, the
nature of Smitt’s “mérka kroppar,” dark bodies, and “ fett kroppar,”
he has new observations differing somewhat from those of Smitt. The
most interesting facts (which are recorded in ‘ Silliman’s American
Journal, by a writer who signs himself L. L. G., and who is perhaps
Agassiz) are those concerning a sort of retrograde development, a re-
sorption of the digestive cavity in the older cells, the gradual disap-
pearance of the lophophore, resulting in cells usually considered as
dead but in reality having latent life, and where alone the fatty bodies
of Smitt, which play such an important part in the embryology of
Bryozoa, are developed. These cells apparently pass through stages
identical with those produced by budding at the youngest extremity
of the colony, with the difference that in one case the cell is immature,
while in the other it is fully developed. The resorption is frequently
accompanied by peculiar changes in these cells, and is confined to the
older portions of the Bryozoan colony in which the lateral connection
between the cells for exchange of fluids between the cells provided
with digestive cavities and those cells containing latent life, is very
strikingly shown, thus forming a complete circulation between the
most distant parts of the colony. He also confirms the nature of the
colonial nervous system, first traced by Fritz Miller, and shows its
existence among the Chilostomata, where it had only been traced by
Smitt before. Claparéde closes this interesting paper by giving us the
complete development of Bugula, with larger, more accurate, and at
the same time more intelligible figures than we have had of the early
development of any one species of marine Bryozoa thus far. He has,
however, not been able to decide positively the nature of the ova, said
in one case to owe their origin to a sexual process, and in the other
cases to point to the existence of parthenogenesis among Bryozoa, under
certain circumstances. Claparéde has not confirmed the observations
of Schneider on the development of Membranipora, but from what
Nitzsche has observed of the early stages of Bugula, he appears to
have seen the same retrograde development in the youngest stages of
its larva which Schneider observed in Cyphonantes during its develop-
ment into Membranipora.

The Coccoliths are Plants according to the recent inquiry of Mr.
H. J. Carter, F.R.S. They are what Professor, Huxley first thought
them to be, not what he subsequently supposed in connection with his

PROGRESS OF MICROSCOPICAL SCIENCE. 99

Bathybius. Mr. Carter says, considering that the coccolith is so abun-
dant in the Laminarian zone, and so voraciously fed on by the Echino-
dermata and Ascidiz, also that it is so nearly allied to Melobesia
calcarea, that it forms the bed of the Atlantic and is found fossilized
in the chalk, he cannot help inferring that it is a vegetable organism
which contributes chiefly to form the calcareous deposits of the present
day as it has done in the past, at all events in the chalk.

A Mineral Silicate injecting Palceozoic Crinoids.—Dr. T. Sterry Hunt,
F.R.S., states that a Silurian limestone from near Woodstock, New
Brunswick, lately examined microscopically by Dr. Dawson, was found
by him to consist almost wholly of comminuted organic remains, in-
cluding fragments of trilobites, gasteropods, brachiopods, and joints of
small encrinal stems and plates; the whole cemented by calcareous
spar in a manner similar to many organic limestones. He observed,
however, that the pores of the crinoidal remains were injected by a
peculiar mineral, readily distinguishable in thin transparent sections,
or on surfaces which had been exposed to the action of an acid, which
dissolves the carbonate of lime and places in relief the injecting mine-
ral. The minute structure thus revealed is precisely similar to that
of recent crinoids studied by Carpenter, and will soon be described and
figured by Dawson. Decalcified specimens exhibit a congeries of
curved, branching and anastomosing cylindrical rods of the replacing
mineral, sometimes forming a complex network, which under the mi-
croscope resemble the coralloidal forms of aragonite known as flos
ferri, and present a frosted crystalline surface. The same mineral, as
observed by Dr. Dawson, occasionally occupies larger interstices among
the fragments, and was evidently deposited before the calcareous spar
which cements the whole mass. When this limestone is dissolved in
dilute hydrochloric acid, the residue, washed by decantation, equals
from five to six per cent. of the weight of the mass, and is seen under
a microscope to consist entirely of the casts composed of the mineral
just noticed, mixed with about one-fourth of coarse silicious sand. This
matter is pale greyish green in colour, but when calcined becomes of
a bright reddish brown, without change of form. Heated in a close
tube it gives off water, and becomes much darker in colour. It is
partially attacked by strong hydrochloric acid, which takes up much
protoxide of iron; but is readily and completely decomposed by hot
concentrated sulphuric acid, leaving a skeleton of silica which, by a
dilute solution of soda, is readily separated from the intermingled
grains, more or less rounded, of colourless vitreous quartz.

The Mineralogy of Eozoon.—lt is stated in ‘Silliman’s American
Journal,’ in a note, we think, by Professor Sterry Hunt, that Dr. Robert
Hoffmann, of Prague, has submitted to chemical and mineralogical
investigation the Hozoon Canadense, found at Raspenau in Bohemia.*
He describes the Eozoon mass as having a superficial resemblance to
that of Canada, appearing in waved or concentric bands, oval in form,
or else in irregular acervuline aggregates. In the oval banded
portion the shell of the Eozoon, a nearly pure, finely granular calcite,

*« Jour. fiir prakt. Chemie,’ May, 1869.

100 PROGRESS OF MICROSCOPICAL SCIENCE.

can be separated from the mineral representing the sarcode, which
is described by Hoffmann as a cast of the soft parts of the Eozoon,
formed through infiltration of watery solution either durimg the
growth or immediately after the death of the animal. It is a pecu-
liar silicate, fine-grained, greyish white, and somewhat translucent.
Associated with this is a finely granular dolomite, destitute of any
traces of organic structure, which sometimes appears to have served
as a centre or point of attachment to the growing Eozoon. In other
cases, however, broken fragments of older Hozoon had served as nuclei,
and become surrounded with a fresh growth. These materials, which
constitute what Hoffmann has described as the Eozoon reef, are asso-
ciated with two other silicated minerals. One of these, allied to fah-
lunite, has a specific gravity of 2°687, is greyish brown or greenish
black in colour, dull, or with a somewhat fatty lustre, and nearly
opaque. This substance forms nearly parallel streaks in the central
parts of the Hozoon reef, and moreover surrounds it, intersecting and
wrapping around the Eozoon mass in multiplied layers, a line or more
in thickness, which are interlaminated with a light green mineral,
transparent, with a somewhat vitreous lustre, and a density of 2°56.
It is a hydrous silicate allied to picrosmine, and is more or less pene-
trated by magnesite.

Observations on Surirella gemma.—Col. Woodward has published
some recent observations on this species. The Surirella gemma has
been recommended by Hartnack as a test for immersion objectives of
high powers. Col. Woodward has not gained access to his original
description, but finds accounts of his views, with figures, in the works
of Drs. Carpenter and Frey.* Hartnack observed fine longitudinal
.striz im addition to the fine transverse ones previously known to
exist between the large transverse ribs; he supposed the true mark-
ings to have the form of elongated hexagons. Two handsome slides
of this diatom were received at the Army Medical Museum a few
months since, from Bourgogne, of Paris. A careful study of these
by monochromatic sunlight inclines Col. Woodward to the opinion
that Hartnack’s interpretation is erroneous, and that the fine striz
are in reality rows of minute hemispherical bosses; from which, as
in the case of other diatoms, the appearance of hexagons would
readily result if the frustule was observed by an objective of inferior
defining power to that he used, or if the illumination was unsuitable.
This memorandum was accompanied by two photographs exhibiting
what he saw; one was magnified 1034, the other 3100 diameters.
The principal frustule shown in these photographs was 545th of an
inch in length. (The mean length of S. gemma is stated by the
‘Microscopic Dictionary’ at ;1,th of an inch.) The fine transverse
strie counted longitudinally at the rate of 72 to the ; oth of
an inch. 'Transversely these were resolved into beaded appearances
which counted laterally 84 tothe ,,5 5th of an inch. If the structure
consists, as he supposes it does, of fine hemispherical bosses, project-
ing from the surface of the frustules, the fact that these bosses are set

* <The Microscope and its Revelations,’ 4th edition, p. 182. ‘ Das Mikroskop,’
3rd edition, p. 40.

PROGRESS OF MICROSCOPICAL SCIENCE. 101

together more closely in the transverse direction than in the longitu-
dinal would account for the elongated form of the pseudo-hexagons
when seen. Some parts of the photographs closely approach Hart-
nack’s description, but it is easy to observe that these are not the parts
which are most nearly in focus. He has also resolved this diatom by
monochromatic light derived from the electric lamp. The appear-
ances obtained were identical with those above described.

Mr. Lowne on Pangenesis.—At a late meeting of the Quekett Club,
Mr. Lowne, in making some observations on the white blood corpuscles
of the newt, made some forcible remarks on the subject of Pangenesis.
He recorded the experiment of Cohnheim on the blood corpuscle.
If the swim bladder of a fish be filled with a solution of common salt,
containing one per cent. of salt, tied and inserted under the skin of
a rabbit or frog, after a short time, say twelve or twenty-four hours,
it would be found filled by a large number of leucocytes, which had
found their way into the bladder by permeating its walls. These were
alive when they left the living tissue of the animal, but after going
through the bladder their movements no longer continued, as they died
in the saline solution; hence they were unable to escape from the
bladder, and a large number became entrapped. This result not only
applies to the swim bladder of the fish, for, according to Cohnheim, if
the cornea of a frog’s eye be taken (it must be quite fresh) and inserted
under the skin of a living frog, in the course of twenty-four or forty-
eight hours it will be found upon examination to contain a large
number of leucocytes at various depths in the tissue of the cornea.
Mr. Lowne considered these to be very remarkable properties, and he
Jaid much stress upon them as throwing a great deal of light upon the
doctrine of Pangenesis, as enunciated by Charles Darwin, by which
doctrine it was supposed that particles or gemmules were given off
from every part of the organism, capable of reproducing like parts
under certain conditions, and of being collected in the ovum. The
whole animal was thus permeated by particles passing off from the living
tissue. It had been objected to by Dr. Lionel Beale that these parti-
cles, being solid, could not pass through the walls of a living cell; but
if leucocytes could pass through solid tissues he could not see why
minute gemmules, which might be solid or semi-solid, like leucocytes,
should not pass through cell walls. He could not see why there should
be any serious objection to the doctrine of Pangenesis. There was
great difficulty in distinguishing a solid from a fluid. If the Protozoa
be examined, many of them would be found to exhibit a series of gra-
dations of solid matter, harder externally and softer internally; but
no lines of demarcation could be drawn between the solid and more
fluid parts of those animals, as one portion of the protoplasm shaded
insensibly off into another.

The Darwinian Theory applied to Plants.—Certainly the best paper
which has yet been published by the ‘ American Naturalist’ is that in
the July number on the above subject. It is of considerable length,
abundantly supplied with notes, and is under the joint authorship of
Dr. E. Muller and Professor F. Delpino. It has been translated into
English by Mr. R. L. Packard, a gentleman who is himself familiar

102 PROGRESS OF MICROSCOPICAL SCIENCE.

to all the Natural History world. It is of such great length and so
numerously annotated, that we cannot do more here than recommend
it to the attention of our readers.

Scales of Butterflies and Gnats.—There would appear to be a sin-
gular resemblance between the scales of these two insect groups. In
the above-mentioned paper the author says:—A fact casually dis-
covered by me, and of which I find no mention hitherto, seems to me
of great importance in the systematic disposition of this order. In
the spring of 1868, while engaged in examining the head of a gnat,
with a view to ascertain whether or not the valves of its proboscis had
the transverse bands of chitine, I was surprised to discover that the
proboscis and palpi were clothed with scales entirely like those of but-
terflies. I find no mention of this important fact in the special works
of Meigen and Schiner which are in my possession. Meigen simply
points out that in Culex, Anopheles, and Corethra, scaly productions
are observed on the venation of the wings, and he figures some of them,
which, however, being quite narrow and with two sharp’ points, have
no analogy with real lepidopterous scales. The gnat-scales observed
by me closely resemble the most characteristic lepidopterous scales.
They suddenly dilate from a short and narrow peduncle to a large
scutiform surface which is traversed longitudinally by a few parallel
ridges, between which, when more highly magnified, transverse wavy
lines, very fine and numerous, are seen. The only difference which
these scales present compared with those of butterflies is, that in the
former the transverse lines are not so fine, so regular, nor so regularly
distributed over the whole surface ; also these lines are entirely want-
ing upon the scales of some species of Tipularie. Finally, while the
real lepidopterous scales are always deeply crenate at their truncated
extremity, the scales of gnats are not; and their truncated extremity
terminates in a very fine margin, from which the points of the longi-
tudinal ribs sometimes project.

The Position of the Brachiopoda.—At a recent meeting of the
Boston Society of Natural History, Professor Hyatt said his objections
to Professor Morse’s classification of Brachiopoda had heretofore rested
wholly on the presumed affinities of the Polyzoa and Ascidia. He had
been led by the similarities of the adult animals of the two groups to
partially follow Professor Allman in his opinion that these two groups
were closely related. In a paper “On the Fresh-water Polyzoa”* he
had compared them, but had at the same time shown that the differences
were much greater between the Polyzoa and Ascidia than between the
former and the Brachiopods. Thus, there is no muscular system in
the Ascidia which can compare in any sense with that of the Polyzoa;
and in transforming the Polyzoon into an Ascidian, Professor Allman
is obliged to violate this obvious difference, as well as to effect many
changes which are not consistent with their organization. The nearer
affinity of the Polyzoa and Brachiopoda is hardly questionable since
the investigations of Koraleusky, who has shown us that the young
Ascidians are apparently more like young vertebrata than they are
like the young of the Polyzoa. The importance and value of the

* « Proceedings [American] Essex Institute,’ vol. iv.

PROGRESS OF MICROSCOPICAL SCIENCE. 103

resemblances existing between the adult Polyzoon and the adult
Ascidian, so far as they may be supposed to indicate any close affinity
or community of origin, are thus doubly denied by the differences of
form and structure, both in the adults and in the larve. The Ascidians
are also likely to be removed by these new discoveries, not only entirely
away from the Polyzoa, but to an equal or greater distance from all the
rest of the Mollusca; and even if we could in the face of embryology
still maintain our comparison between the two structures, we should be
contrasting the Polyzoa, not with a typical mollusk, but with an animal
whose own position is very uncertain. He can think of no fundamental
molluscan characteristics, either in the Brachiopods or Polyzoa, which
ally them with the Lamellibranchs (clams), except those which join
them still more closely to the Ascidians. Therefore, it seems clear,
that if we separate the Ascidians from the Lamellibranchs, which they
so closely resemble in their general adult characteristics, on account
of their different developments, we must also, in turn, remove the
Polyzoa from the Ascidians, and should logically regard the similarities
of the two as analogies arising in different structures, and not as affinities
derived from some common ancestor. Thus cut off from its quondam
molluscan allies, our Polyzoon has but one refuge; its development
points concisely to a vermian ancestor, and to this source we must
relegate both it and its nearest ally, the Brachiopod.

Professor Agassiz’s Future Dredging Operations.— Professor Agassiz
has accepted an invitation extended to him by the American Coast
Survey Bureau to take passage on the iron coast-survey steamer, which
has just been built at Wilmington, Delaware, and which sails for the
Pacific coast in September next. The expedition will take deep-sea
soundings all the way, and extensive collections of specimens will be
made for the Museum of Comparative Zoology at Cambridge. Secretary
Boutwell has written to the Secretaries of State and Navy, asking that
naval and other officers may be instructed to afford such courtesy and
assistance to the exploring party as may be desirable. We learn also
that Count Pourtales, of the Coast Survey, and Dr. Hill will accompany
the expedition.

Structure of Stephanurus dentatus, or Sclerostoma pinguicola.—
Dr. W. Fletcher gives a somewhat lengthy account of this worm. It
appears not to have been correctly known in America till last year. A
specimen was brought to Dr. Fletcher in 1866 by a farmer whose
hogs were dying of cholera. He had removed the lungs of several, and
also cut out fragments of the liver, all of which were spotted over with
little cysts containing the worms ; in the bronchial tubes down to the
minutest branches, they were found in abundance and in situations
where no one could have placed them. With these specimens his
conclusion was that they were the Filaria bronchialis of Owen, or
Strongylus bronchialis of Cobbold; and not having at this time made
microscopic examination of this well-known kidney worm, the relation-
ship between them did not occur to him at that time. In November,
1870, while demonstrating the portal circulation in the liver of a pig,
full grown, he observed a worm which measured an inch and a half in

104 PROGRESS OF MICROSCOPICAL SCIENCE.

length, and in all respects resembled the kidney worm, and also
reminded him of the worms he had examined five years before. Upon
further dissection of the liver he found the worms not only free in the
_ portal veins, but in cysts in various portions of the organ; also some

were found in freshly-cut holes, directly across the hepatic lobules.
The gall-bladder was distended with a dirty, yellowish fluid, the
consistency of soft-boiled eggs. and although no worms were found,
yet the ova were abundant, as they also were in the fluid of the cysts.
Being convinced that the worm formerly examined in the lungs was
the same as the worm now found in this new locality, and finding
it oviparous, he gave up his opinion as to its being a Filaria bron-
chialis. From the date of this discovery, he frequented the slaughter-
houses and pork-packing establishments, and found the worm in most
instances in the pelvis of the kidney, or in cysts in the fat around
them. Four times he has found the worm in the bronchial tubes,
twice in the hepatic vein and in the right side of the heart; also
in cysts throughout the fatty part of the animal. Frequently, when
no worms were discovered, the eggs were abundant in the thick
mucous-looking fluid in the pelvis of the kidney. This fluid con-
tained, besides eggs, desquamated renal tubules, or casts and oily
granules. In no instance has he found worms in an immature state,
which shows that the eggs, in all probability, go through some other
beast before they enter the swine, to become sexually mature. The
symptoms in hogs which are referred to the “ kidney worm,” are due to
a paralysis of motion in the hind legs; the hog drags the hind quarters
along the ground from place to place in search of his food, although
it is by no means proven that the worm is the real cause, unless some
one is able to demonstrate its existence In some cerebro-spinal centre,
or some point more likely to destroy the reflex power in the cord
itself. The head and oral cavity are alike in male and female. The
oral cavity is rather oval than round, and is surrounded by a hexagonal
frame, each corner having a papilla and hooklet, while each side is
armed with six serrate teeth. Looking into the oral cavity, it is
funnel-shaped, having three openings at the back, one of which con-
nects directly with the cesophagus, while the others appear to connect
with the water vessels. The intestine is long and contains some
pigment granules, arranged in dendritic forms, throughout its length ;
the whole is thrown into convolutions, and gives an almost black
appearance to the worm, except when the white oviducts distended
with eggs, or the seminal vessels of the male are folded over the
intestine, when it has a white, mottled appearance. The caudal
extremity of the female is spindle-shaped, but has two little bursz
higher up. In the male it is formed by three-lobed burse, above
which are two well-developed flexible spicula.— The American Journal
of Science and Art, June, 1871.

The Gregarinida and their Development.—M. Edouard Van Beneden
has very fully worked out this subject in advance, one may say, of
Lieberkiihn, and the other observers who have devoted themselves to
it. Indeed in the case of Gregarina gigantea, with which the present
essay is almost alone concerned, he has watched all its successive

NOTES AND MEMORANDA. 105

transformations, from the time of its being a small protoplasmic mass
sprung from the Psorospermia, until its completion was arrived at, till
in fact it attamed 16 mm. in length. He has found in the! lobster’s
intestine multitudes of small protoplasmic masses resembling the
Protameba primitiva of Haeckel, with certain distinctions from it
however. They are distinguished from the true Ameeba by the absence
of a nucleus and a contractile vacuole. These have no projections from
them. There are, however, others which have one, or more frequently
two prolongations in the form of arms, which M. Van Beneden says
resemble the mobile stem of Noctiluca, and these forms he calls gene-
rating cytodes. He then describes the movements of them, one of the
arms or projections of which is motionless. After a time the other
increases in length till at last it breaks away, and having specially an
undulating motion, it is like a nematoid worm. Curiously enough,
when the movable arm has been discharged, the further development
of the arm at rest begins, and it goes through the same process of
development and motion as the preceding, with this difference, that
instead of becoming detached from the central mass it gradually
absorbs it as a vertebrate embryo absorbs the contents of the vitelline
sac. The resemblance of the animal thus formed to the Nematodes
has led the author to style them pseudofilarie. He then proceeds
to describe the further development of those peculiar bodies into
Gregarina gigantea. After this comes a discussion of various ques-
tions connected with the subject. These are as follows: “‘ Monera and
the monerien phase of the Gregarinide,” in this Dr. Beales’ germinal
matter theory is discussed; “The evolution of Gregarinide put in the
light of an example of endogenous generation ;” “ Importance of the
nucleolus ;” ‘Are the gregarines a regressive development of the
Ameeba ?” and lastly, “Do the gregarines present an alternate genera-
tion?” Thus concludes a memoir of nearly forty pages, and with an
excellent plate. We think it is one of the most important papers that
have appeared for some years, and we commend it to our readers.

NOTES AND MEMORANDA.

How to close Cells filled with Glycerine This important sub-
ject, and one which too little is generally known about, was discussed
lately before the Quekett Club.* The question was asked by Mr. Henry
Lee, as to how cells were filled with glycerine, so as to prevent the
glycerine after a while from escaping. Mr. Sufiolk said that he was
one of those who had been extremely successful in keeping glycerine
in. His plan was as follows :—When the cell was closed he varnished
it with a coating of common liquid glue, and when this was dry he put
it under the tap, and thoroughly washed it, in order to remove any
glycerine which might remain outside. After carefully drying the
slide with blotting paper, he gave it another coating of the liquid
glue, and when dry repeated the washing process, and after having

* Journal of the Club, July.

106 NOTES AND MEMORANDA.

given it a third coating in the same manner, he gave it a final coat of
gold size, and he had never had any trouble with cells closed in this
manner. He believed that the secret of success in a great measure
was owing to the washing; the gold size was also removed from
contact with the glycerine by the elastic varnish under it. Glycerine
would do no harm to gold size when it could not get at it. Subse-
quently, at the Secretary’s request, Mr. Hislop said that his experience
was that of Mr. Suffolk, for he had found no difficulty in keeping in
glycerine. His plan was to make a good seat for the cover, first_by
a thick ring of gum dammar, allow this to become sticky, and then
put in the glycerine, lay on the cover, and then carefully wash off
all superfluous glycerine. When perfectly washed and dried, put on
two or three coats of gum dammar to finish it. He had in this way
mounted slides which had kept well for more than two years, and he
strongly recommended gum dammar for the purpose. Care must be
taken that the glass was perfectly clean, and if this were attended to,
and a good bed was made of cement on which to place the cover, there
would be no doubt as to the result. He had some large preparations
—such as a whole frog or toad passing from the tadpole condition—
which had been put up in this way, and they were perfectly intact,
and not the slightest exudation had ever been observed. Finally, Dr.
Matthews mentioned that it was from Mr. Hislop that he derived the
idea of making a ring upon the slide ; in doing this it was necessary to
wait before putting on the cover until the gum dammar became “tacky,”
because if this were not done it would be found that tears of dammar
would run in and spoil at least the appearance of the slide around the
edge. If, after making the ring, the slide were put aside for an hour
before proceeding to mount, there would be no danger of this occur-
rence.

A New Sub-stage for a 4-inch Objective ——At the meeting of the
Quekett Club on May 26th, Mr. James Smith exhibited a simple con-
trivance designed to obviate a difficulty frequently met with in using
Ross’s 4-inch objective, in consequence of the great length of focus
required. It consisted of a small mahogany sub-stage, attached to the
wooden stand of the microscope, and jointed so that it could be set at
any angle required to make it parallel with the ordinary stage when
the body of the instrument was inclined. The object to be examined
was placed upon the sub-stage, and viewed through the orifice in the
upper stage, by which means an ample length of focus and a great
degree of steadiness were obtained. For the illumination of opaque
objects in this position, the concave mirror was admirably adapted,
and the lamp did not in that case require to be placed so near to the
instrument as to cause any inconvenient amount of heat to the observer.
The habits of living insects could be most advantageously studied by
this arrangement; and he had recently observed, when examining a
spider, that, in attacking a fly, and enveloping it in a quantity of web
previously to finishing his meal, a silken thread was spun from each of
the five spinnarets, instead of from one only, as under ordinary cireum-
stances.

er 0n }

CORRESPONDENCE.

On some New ParasirEs.
To the Editor of the ‘ Monthly Microscopical Journal.

July 8, 1871.

Dear Sir,—May I be permitted to draw attention to some para-
sites named and figured in the July number of the ‘Monthly Micro-
scopical Journal, by Mr. T. Graham Ponton, F.Z.S.

Having been engaged in collecting and studying these insects
for some years, I am well aware of the difficulty of making out the
genera and species from dried or mounted specimens, and of the con-
sequent necessity of carefully exact drawing in the illustration of
these minute forms.

Without entering upon the many structural inaccuracies with
which Mr. Ponton’s plate is literally crowded,* I wish simply to
notice two errors, which, if uncorrected, are enough to throw the whole
subject into confusion.

In Fig. 3, a presumed new species of the sub-genus Docophorus,
the legs end in single claws,—whereas all the species of Docophorus
and the allied sub-genera have a pair of claws proceeding from their
short two-jointed tarsi.

The Trichodectes, Fig. 4, is figured with double claws; the chief
character of the genus being that they are single. In fact, all the
species of the obsolete order “ Anoplura,’ which infest mammals,
have single tarsal claws.

A Trichodectes with double claws is as absurd to anyone familiar
with the genus as a horse with cloven feet.

I remain, dear Sir, yours faithfully,
H. C. Riconrer.

Tae New Meratuic Coverep Guass CHIMNEY.
To the Editor of the ‘ Monthly Microscopical Journal.

Srr,—Some short time since it occurred to me that a very useful
addition to our microscopic appliances might be made by having the
ordinary glass chimney silvered on the outside, and covered with some
protective substance.

I had one made on this principle, and showed it to Mr. Swift,

* [It is almost unnecessary to observe that the author is alone to blame.
Proofs of the plate were sent to him, and his corrections were carefully carried
out: the original drawings were such as to render the artist’s task one of no
small difficulty; but for the points referred to by Mr. Richter, Mr. Ponton is
solely to blame.—Ep., ‘M. M, J.’]

VOL. VI. I

108 CORRESPONDENCE.

of University Street, who suggested that a covering of copper would
be the best protection.

It will be seen by this arrangement that the whole of the chimney
is covered with the exception of a small space through which the
light passes, so that it acts as an ordinary chimney-silver-reflector and
lamp shade, and in one.

Thus saving much time, trouble, expense, and space.

It is supplied by Mr. Swift at the trifling cost of fifteen pence.

T remain, yours &c.,

FREDERICK BLANKLEY.

How to Setect SpectacLes FoR NEAR-SIGHT AND FAR-sIGHT.

RocHEFORT-sUR-MER.

Sir,—I take the liberty of sending you a note, which you will
please insert in the ‘Monthly Microscopical Journal,’ if you think it
suitable.

I am, Sir, yours,

Movc#Her.

Note concerning certain Micrographical Measures, and containing some
information useful to persons suffering from Myopia and Presbyopia.

I do not know the instrument employed for measuring the thick-
ness of the thin glass plates used for covering microscopic objects, nor
do I know if there is one for valuing the relief of those objects. In
every case, I use my microscope for both purposes, and also for point-
ing out to sufferers from Myopia and Presbyopia the glasses suitable
to their sight; and the object of the present note is to describe the
process that I employ. ,

In every microscope of a certain price there is, besides the tube
which is worked by friction, or by a rack movement, or by both, a
micrometric screw for finishing the focussing, that is, one with a very
fine movement, and consequently possessing great delicacy. It is
important to have this screw made with great care. This screw is
what I use for measuring the thickness of covering glasses, and of
microscopical objects. For this purpose I have fixed on its head,
which, as in most instruments of this kind, is placed in the upper part
of the tube,* a dial divided into 100 parts, and high enough above the
moletée part not to impede the movement of the fingers, when focussing.
On the canon which supports the tube is a ring, slit like the canon
itself, and kept in its place by its own elasticity. This ring carries
an index opposite the dial, and can be turned so as to bring back the

* In this respect differing from English instruments,

CORRESPONDENCE. 109

index, before the commencement of a measurement, exactly opposite a
division of the scale; in this way there are no fractions to be noted
down at the starting point, but only at the end of the operation.

A turn of the micrometric screw of my microscope being equal to
half a millimetre, each division of the scale, in consequence of the
whole being divided into 100 parts, is equivalent to 54, of a millimétre.
In order to measure the thickness of a round thin glass cell cover for
example, I begin by drawing with a diamond a very small stroke on
the edge of one of its surfaces. I make a similar mark on the opposite
surface, in such a way that the two marks may form a cross; this is
in order not to confound them. If the glass is square, the cross will fit
much more easily in one of the angles. One of the marks (the upper
one) is then brought into focus, and the division of the scale opposite
the index noted down. The body of the microscope is then moved down
by turning the head of the screw from left to right, until the second
mark comes into focus, while the first disappears. I now find out the
thickness of the glass by ascertaining how many divisions of the scale
have been passed over, counting from the starting point already noted.
As regards microscopic objects, however thin they may be, provided
they have two faces distinct enough, I bring one face into focus as
starting point, then examine the scale of the screw, and proceed as
before described. I measure in this way the thickness of diatomacee,
those interesting little beings with silicious envelopes, whose stric, to
use the old term, are not in the same focus. When I wish to show a
preparation to anyone not much accustomed to use a microscope, this
process enables me to regulate the focussing for other objects also,
after I have once determined the difference between our sights, by
means of an examination, made by us both, of the first preparation. I
can also determine with much greater facility whether the focus of
both eyes differs in either of us, and in what proportion.

I come naturally to spectacles next. When the sight is not in its
normal state, biconvex and biconcave lenses, with both faces similarly
curved, are usually employed to remedy imperfections arising from
defective refrangibility of the eye, or from disturbance in its accom-
modating power. Lenses of those kinds are the most powerful, their
construction is the simplest, and the focal distance is most easily cal-
culated, as it is equal to the radius. Each of the two surfaces of those
lenses is a segment of a sphere of known diameter. The shorter it is,
the greater is the convexity or concavity.

Medium sight is estimated at 10 English inches, or 25 centimétres.
By experience, I find my own to be 80 inches, or 75 centimetres. Those
both being known serve as the basis of the following calculation. I
multiply 10 inches (the number in normal or medium sight) by 30
(that is my own), and find as result the number 300, which, when
divided by the difference, that is by 20, gives 15 inches as quotient.
This quotient indicates both the focal distance of the lens suitable for
my sight, and the radius of the sphere, which is the same thing. We
speak of inches, because the lenses of spectacles are still marked
according to the old measure. This method of measuring the focal

tr 2

110 CORRESPONDENCE.

distances of lenses, pointed out by Messrs. McKenzie, Wharton Jones,
and Michael Levy, is, according to M. Desmarres, not perfect, but I
believe that it may be corrected by the microscope.

The value of each division of the dial of the micrometrie screw
already mentioned, must now be ascertained in the special case which
occupies us. There is a difference of 20 inches between normal vision
and mine. I assume that it may be represented on the dial by ten
divisions, each of which will be equal to 2 inches: 10 x 2=20. Let
us take an example. I wish to find out for a presbyope the lens suit-
able for his sight. I begin by putting in focus an object, which for
this purpose will serve as a type. I next observe on what division the
index is, and then cause the dial to turn ten divisions from left to right
(from right to left when the patient is myopic) in order to bring it to
normal sight. This being done, I ask the person in question in his
turn to bring the object into focus. If we find that there is between
the two sights a difference of eleven divisions on the dial, each of which
is equal to 2 inches, we have 22 inches as the result. This we mul-
tiply by 10 (the number of inches for normal sight), and obtain the
number 220, which, when divided by the difference, that is by 12, gives
as quotient 18 inches (and a fraction which may be omitted) as the
focal distance of the lens, or the radius of curvature.

The operation is evidently simple and easy. Unfortunately, opti-
cians do not all mark their spectacle lenses according to a uniform
system of numbers. Some numbers indeed indicate the focal distance
or radius of curvature, but others indicate the diameter of the sphere on
which the lenses are formed. Other numbers, again, belong to series
peculiar to certain manufacturers, and do not afford the least informa-
tion. There are even a great many lenses not marked with any num-
ber. Hence arises an amount of confusion, very perplexing to those
who are compelled to have recourse to spectacles to aid the eyes, in
their efforts at accommodation, at short distances. We know at least
through the foregoing operation, when the two surfaces have the same
curvature, the focal distance of the lenses suitable for our sight, and
we can select them ourselves at the optician’s, or better still at home,
if he will intrust them to us, by means of the following very simple
process. One of the lenses is exposed to the solar rays in such a posi-
tion that its axis is directed towards the sun, that is, that the plane of
the circle bounding the lens is perpendicular to the rays. If the lens
is convex, and a screen is held parallel to this plane, the image of the
sun is seen to form a circle on the screen. This circle varies in size
according to the distance between the lens and screen, and the screen
must now be moved farther or nearer, without destroying its parallel-
ism, until the point is found at which the circle appears smallest and
brightest. The screen is then at the focus, occupied by the little
luminous circle, and the distance from the lens to the focus can be
easily measured.

It should be remarked that the numbers of spectacle lenses indicat-
ing the focus, either for myopian or presbyopian sight, are not conse-
cutive. Naturally that one must be selected which approaches nearest
to the figure given by the operation; and although this operation may

PROCEEDINGS OF SOCIETIES. PEE

be performed without the microscope, it is evident that far more
satisfactory results will be arrived at with the aid of this instrument.
Such is my conviction.

Movcuer.

[M. Mouchet’s letter contains some peculiar expressions which
have rendered its translation by no means an easy task. We trust,
however, that it will be intelligible to our readers.—Eb. ‘M. M. J.’|

PROCEEDINGS OF SOCIETIES.*

BriGHTON AND Sussex Naturat History Socrery.

June 8th. Ordinary Meeting. Mr. T.H.Hennah, Vice-President,
in the chair.

Mr. Wonfor announced the receipt of fourteen volumes of works
on Natural History, from Mr. T. Davidson, F.R.S., the Proceedings of
the Maidstone and Mid-Kent Natural History Society, and the three
last papers of the Eastbourne Natural History Society from the Secre-
taries. Votes of thanks were passed to the donors.

Mr. Wonfor announced the discovery of a human skeleton at a depth
of five feet in the works of the Intercepting Sewer, opposite Bruns-
wick Terrace, and reported on the success of the Field Excursion of
June 3rd to Plashett Park. Votes of thanks were passed to Lord
Gage for granting permission to visit Plashett, and to Mr. Grantham
for piloting the Society on the occasion.

Mr. Robertson exhibited a specimen of Sepiola oceanica.

Mr. Perley presented a water-colour drawing for the Society’s
album, from a sketch made near Staplefield, at the Annual Excursion
last year, for which a vote of thanks was given.

Mr. G. Scott then read a very able and interesting paper “On Rude
Flint Implements.” The immediate occasion of the paper was the
receipt of a parcel of such implements from D. Stevens, of St. Mary
Bourne, by the Hon. Secretary, who had handed them over to Mr.
Scott to bring the subject before the Society for discussion.

June 22nd. Microscopical Meeting. Mr. T. H. Hennah, Vice-
President, in the chair.

Mr. Wonfor announced that one of the honorary members, Mr. T.
Curties, of Holborn, had kindly sent for exhibition a large number of
slides of hairs and scales of plants, from his private collection, as his

* Secretaries of Societies will greatly oblige us by writing their reports legibly
—especially by printing the technical terms thus: H y dra—and by “ underlining ”
words, such as specific names, which must be printed in italics. They will thus
secure accuracy and enhance the value of their proceedings.—Ep. ‘M. M. Jv

112 PROCEEDINGS OF SOCIETIES.

contribution towards the evening’s business, with a promise that at all
times he should be pleased to help in the way of specimens.

In the course of a discussion on the nature and uses of hairs and
scales in the economy of plants, Mr. Hennah mentioned that most
plants possessing hairs, if properly manipulated, showed the circula-
tion or rotation of the cell contents, a state of things admirably seen
also in the rootlets of the frog-bit Hydrocharis morsus-rane, and sug-
gested, as the Society, on the occasion of its annual excursion to
Arundel, would be in a district especially rich in pond life, that, if the
next meeting were without subject, many interesting things might be
obtained for exhibition.

Mr. Wonfor considered the suggestion a very good one, because, in
addition to Arundel, they would, before their next Microscopical Meet-
ing, visit Plumpton, a locality very fertile in pond life,

The meeting then became a conversazione, when

Mr. Hennah exhibited the specimens lent by Mr. Curties, the
most noticeable among which were hairs of different species of Alyssum,
Tillandsia zonata, Loasa, Onosma taurica, and sections of the stems of
different Solanacee, &c.

Mr. R. Glaisyer exhibited some very beautiful scales of different
ferns in situ and as transparent objects, and the silicious scales of
Deutzia scabra and gracilis.

Mr. Wonfor exhibited various scales and hairs, chiefly of a stellate
character, some of which, from different ferns, such as Niphobolus
bastata and lingua, the stag’s horn Acrostichum alcicorne and Ehodo-
dendron ferruginum were much admired, as were also some of the same
scales seen under polarized light. Later in the evening he showed the
rotation of the cell contents in the beaded hairs in the stamens of Tra-
descantia, the blue spider wort.

Bristot Microscopican Society.

At a meeting of this Society held the 18th of May last, being the
first held since January in consequence of the removal of the collec-
tions from the Bristol Museum, in which building the Society meets,
Mr. R. M, Bernard, President, occupied the chair.

Mr. T. G. Ponton, F'.Z.8., read a paper “On some rare Parasites,
together with a Description of Four New Species.”

Reapine Microscopicat Society.*

April 4th, 1871.—Mr. J. C. Simpson read a paper “On a Simple
Method of Producing the Fibrillation of Albumen: and can Coagula-
tion and Fibrillation be Considered Electrical Phenomena ?”

The former was thus described :—Place some egg-albumen on a
glass slide, touch a thin glass cover with a speck of nitric acid, bring it
down on the albumen, and place the slide under the microscope. A
whitish opaque spot is at once seen, and this the microscope resolves

* Report furnished by Mr, B, J, Austin,

PROCEEDINGS OF SOCIETIES. 113

into the appearance of fine granular matter, exactly resembling albu-
men coagulated by heat. The outward diffusion of the acid may
then be detected, under a high power, by the gradual formation
of a cloud of fine particles and by a peculiar faint line which marks
the boundary of the acid. At the same time masses of fine fibre are
formed in the central white granular matter, and between it and the
boundary of the acid ring, but never beyond.

This method of producing coagulation and fibrillation, and the
fact of their production by a current of electricity, led the writer to
consider the question as to whether or not the formation was a purely
electrical phenomenon.

The evidence adduced—to show that coagulation and fibrillation
were merely chemical phenomena, and that, though produced by a
current of electricity, they were but secondary effects of that current,
due to the decomposition of the fluid—was,

Istly. That the arrangement of the coagulated or fibrillated matter
is not in accordance with electrical laws, which it should be if an
electrical phenomenon. The writer stated that by the aid of the
galvanometer a current of electricity could be detected on the addi-
tion of acid to albumen; but argued that there was no necessary
connection between the current and the fibrillation, as the union of
acids and alkalis always produces a current, whether the liquid be
coagulable or not.

2ndly. That if coagulation and fibrillation were electrical, then
such phenomena, when produced by other means than electricity or
acid, ought to give rise to an electrical current. The writer stated
that he had made careful experiments with the galvanometer and
found that such was not the case.

3rdly. That if coagulation and fibrillation were purely electrical,
then such phenomena (and especially fibrillation, which is a continuous
act of growth), taking place within the magnetic field, ought to pro-
duce the fibrillated matter in some definite direction according to the
lines of magnetic force. The writer stated that he had performed
experiments by means of an electro-magnet, and under the microscope,
but could not perceive that the arrangement of the fibrillated matter
was at all influenced by magnetism, and hence concluded that these
phenomena could not be regarded as, in any sense, electrical.

Mr. Tatem exhibited a series of tests of Difflugia acanthophora
from Bulmershe Lake, and lately, for the first time in this neighbour-
hood, detected there. It appears to be a very variable species ; not
only were the examples shown more globular than D. acanthophora is
described to be and figured by Pritchard, but the spines vary also
very much in number, direction, and position. The testa may have
three, four, five, two outcurved spines, a single stout, straight central
spine, or may be altogether spineless, in which last condition the
species has improperly received the name of D. areolata.

May 2nd.—Mr. Tatem, in the absence of Dr. Shettle, and at his
request, read an extract from the ‘Atheneum’ of April Ist, 1871,
which stated that, M. Becquerel, sen., had laid on the table of the
Academy of Sciences, of Paris, a MS. work, in which the author had

114 PROCEEDINGS OF SOCIETIES.

demonstrated, amongst other things, “the influence of electric action
in the transformation of the blood, in the body, from venous to arte-
rial,” and explained also, “ by electric currents, an action which
chemistry has been unable to account for, that is to say, the transport
of materials within the organism, that is to say life, for life resides
in movement.”

Mr. Tatem exhibited mounts of diatoms from Duckpond Falls, and
the Secretary exhibited Antennaria (?) semiovata, a minute fungus.

MicroscopicAL Soctery or LiIveRPooL.

The third meeting of the Session was held at the Royal Institu-
tion, on Friday, 3rd March, the Rev. W. Banister, B.A., President, in
the chair.

Mr. J. H. Day made a donation of twelve slides of seeds, and
Capt. J. A. Perry of a large collection of dredgings, insects, &c.,
from the Brazils; the thanks of the Society were voted to the donors.

Capt. Perry exhibited a mechanical turn-table, devised and con-
structed by him on his homeward voyage; in this ingenious little
instrument the revolution of the table is effected by clockwork, and is
controlled by a catch regulated by the finger of the operator.

Mr. W. Wood exhibited a microscope lamp made by Messrs.
Abraham and Co.

Mr. Thomas Higgin sent for exhibition a number of photographs
of diatoms and other test-objects by Lieut.-Col. Woodward.

Mr. T. J. Moore exhibited some young shrimps hatched that day
in the Museum.

Mr. G. F. Chantrell exhibited and illustrated by a diagram a sin-
gular confervoid growth that had made its appearance in a glass cell
in which he had kept rotifers for upwards of three months: the
rotifers attached themselves to the filaments and became encysted.

Mr. A. C. Cole exhibited a new diatom which he had found in the
Nottingham (Maryland) earth, and mounted with his usual perfection.
The diatom is not only new as a species, but in all probability is
entirely unknown, certainly unnamed, generically. It combines some
of the characteristics of Aulacodiscus and Triceratium, but is evidently
very distinct from either. In form it is a hexagon, with the sides
arched inwards; has a finely-developed convex umbilicus, from which
proceed radial lines terminating in club-shaped bosses, which do not
reach the border. The position of these lines may be understood by
supposing a letter X to be laid horizontally upon a letter I, so that
the intersection of the X may coincide with the centre of the I.

Three other lines proceed from alternate angles of the hexagon,
but are not continued to the centre.

The surface of valve when viewed with the 1th or }th objective
appears beautifully watered.

The Rev. W. H. Dallinger called the attention of the Society to
the fact that Mr. H. J. Carter had found that the coccoliths of Huxley
were abundant in the Laminarian zone of the Devonshire coast, and
after careful study had determined them to be vegetable organisms

PROCEEDINGS OF SOCIETIES. 05

entirely and independent of the so-called Bathybius, being indeed
calcareous alge.

The coccospheres were considered by Mr. Carter to be the spo-
rangia of the above genus.

The proceedings concluded with the usual conversazione.

Souta Lonpon MicroscopicAL AND Natrurat History Cuus.*

A meeting was held on Saturday, March 11th, at Glo’ster Hall,
Brixton Road, for the purpose of organizing a club for microscopical
research, combined with the study of natural history. Dr. Braith-
waite, F.L.S., F.R.MS., &c., presided.

Mr. Hovenden, F.A.8.L., acted as Secretary for the evening. The
Chairman, in stating the object of the proposed society, remarked that
Mr. Hovenden was the real originator of the club. This gentleman
thought that a society of the kind would find a sufficient number of
supporters in the district, and he therefore communicated with several
gentlemen well known in the microscopical world, whose names were
eventually appended to a circular letter which was issued for the pur-
pose of calling together the present meeting. Dr. Braithwaite then
spoke of the advantages of the microscope in investigation, and of the
usefulness of a club for the purpose of diffusing microscopic know-
ledge, collecting objects, &e. By comprehending natural history in
their study, they would include the two great sections, botany and
micro-zoology ; in this way the younger members would be instructed
in natural history.

Mr. Stephenson proposed “That a society be and is hereby formed,
to be called the South London Microscopical and Natural History
Club.”

Mr. Stewart seconded this motion, which was carried unanimously.

Mr. Henry Lee (of Croydon), F.LS., F.G.S., said that he was glad
to see that the number of microscopical societies was fast Increasing.
He mentioned that within the last few months three new societies had
been formed; one at Forest Hill, numbering forty-four members, one at
Margate, of thirty-three members, and now this one in South London
which he hoped to see the most important ofall. He then complimented
the Society upon the number of eminent names that were down on the
subscription list, and was glad to see that they were all thorough good
working members. He recommended to the Society a systematic mode
of working, the subject of the next meeting always being announced,
as desultory work seldom led to good ‘results. He thought that each
member should bring his microscope, and mentioned that at Croydon
a rule was made that the microscopes of all the members should be at
the disposal of the lecturer for the evening. Respecting the subscrip-
tion, he thought that the experience of all other microscopical socie-
ties taught that it should not be a less amount than 10s. This sum
excludes nobody, while a smaller sum will not allow the club to carry
on its business. He also mentioned that the club at Croydon had been
invited by Mr. Saunders of the Holmsdale Club to assist them in work-

* Report furnished by the Secretary.

116 PROCEEDINGS OF SOCIETIES.

ing up the fauna and flora of the county of Surrey, and he advised the
new club also to take part in this. Mr. Lee concluded by saying that
he did not agree with some who said that these local clubs interfered
with the Royal and other large societies, but rather believed that many
were induced to join the large societies by first becoming members of
the local clubs.

Mr. Deane, F.L.S., F.R.MS., quite coincided with the views ex-
pressed so ably by Mr. Lee, and in confirmation thereof recapitulated
his experience since first he became a founder of the “ Royal” Society.
He believed that these societies did a vast amount of good, by bringing
together young and old, to unite in one common fellowship of love.
On his first joining the “ Royal,” he was delighted to see the strong
tendency such societies had to break up all feelings of clique among
scientific men. All were put on an equality, each vying with the
other in the acquirement of microscopical knowledge. He was certain
that those who took any interest in microscopical study were better
members of society in consequence; their minds began to expand ;
they would find that the microscope in one hour’s labour preached a
sermon to them that would last through the whole of the day; and
this influence would be felt all through life. He therefore hailed this
Society as one calculated to do an immense amount of good in the
district.

Mr. Soper recommended excursions on the principle of the Holms-
dale Club.

Mr. Jackson moved “ That the subscription of the club be 10s. per
annum, payable in advance.”

Mr. Deane seconded the motion, which was carried unanimously.

Mr. Ackland moved the election of Mr. Deane as provisional Pre-
sident.

This motion was seconded by Mr. Rutter, and carried unanimously.

Mr. Deane, in accepting temporarily the post of President, said
that he quite approved of the suggestions that had been put forward,
as to excursions, and although he feared that he should be unable per-
sonally to take part in them, he felt sure that they would be found of
great importance in the club.

Motions were then passed appointing (provisionally) Dr. Braith-
waite and Mr. Stephenson as Vice-Presidents; Messrs. Ackland,
How, Jackson, Neighbour, Rogers, Stuart, and Suffolk, as Committee ;
Mr. Robinson as Treasurer ; and Mr. Hovenden as Honorary Secretary.

It was also proposed and carried unanimously, “That a list of
subscribers be opened,” and “That the Committee be requested to
frame suitable rules, and present them for approval at the next
meeting.”

It was arranged that the next meeting should be held on Saturday
April 1st, at 8 o’clock in the evening, at the same place (Glo’ster
Hall), when the recommendation of the Committee as to the future
place of meeting will be laid before the members. The meeting then
separated, thirty-eight names having been placed on the subscription
list as members of the club.

The first Ordinary Meeting of this Club was held on Saturday,

PROCEEDINGS OF SOCIETIES. LiF

April 1st, at Glo’ster Hall, Glo’ster Place, Brixton Road; Mr. Deane,
F.L.S., F.R.MLS., presided.

The minutes of the inaugural meeting were read and confirmed.

Mr. Hovenden, F.A.S8.L., the Honorary Secretary, read the report
of the Provisional Committee, which was as follows :—

“Your Committee beg to report that in accordance with the reso-
lution of the club, made on the 11th ult., they have carefully framed
and considered a set of Rules for the guidance of the club, which are
this evening placed before you for your consideration and approval.

* On the inaugural meeting thirty-six gentlemen subscribed their
names as members, and since that time thirty-two have been added,
thus making the number of members up to this evening sixty-eight.

* Your Committee beg to recommend that on this the first ordinary
meeting of the club, the subscription list be kept open, but that here-
after all new members shall be balloted for in accordance with the
4th Rule.

* And, having carefully considered the place for future meetings,
recommend that for the present the club meet at Glo’ster Hall,
Glo’ster Place, Brixton Road.”

Mr. T. Sebastian Davis moved, “That the report be received,
adopted, and entered upon the minutes.”

This motion was seconded by Mr. Reynolds, and carried unani-
mously.

The Rules drawn up by the Committee next occupied the attention
of the meeting, and, as all present had received copies of these Rules,
it was agreed that they should be taken as read.

Mr. Davis said that he was sure that all present would agree with
him that the Committee had done their work in a very satisfactory
manner. There was one thing that he,as a member of the Council of
the Photographic Society, wished to mention, and that was, that if
the meetings of the club were held on the second Tuesday in each
month, as proposed, many members of the Photographic Society would
be unable to attend, as this was the day fixed for their meetings. He
therefore proposed that the meetings of the club should be held on
the third Tuesday in each month, instead of the second.

This proposition having been agreed to,

Mr. Davis then moved, “That the Rules proposed by the Pro-
visional Committee be adopted, with the alteration, that the meetings
be held on the third Tuesday, instead of the second Tuesday, as
provided therein.”

Mr. Hardess seconded this motion, which was carried unanimously.

Mr. izard proposed, “ That the provisional officers of the club be
elected permanent officers for the ensuing year, with the addition of
the following gentlemen :—Mr. James M. Cottrell, Dr. Hector Hel-
sham, Dr. N. W. Ord, to complete the members of the Committee,
according to Rule 2.”

This motion was seconded by Mr. West, and carried unanimously.

It was arranged that the next meeting of the club should be held
on Tuesday, April 18th, at half-past seven o’clock in the evening, Mr.
Suffolk having kindly consented to read a paper on this date.

118 PROCEEDINGS OF SOCIETIES. —

The meeting then resolved itself into a conversazione. And it is
evident that a society of the kind has been much needed in the neigh-
bourhood, as so many microscopes were brought by the members of
the club that it was impossible to exhibit all. Twenty-five of these
instruments were, however, shown, the various objects being viewed
with much interest by the members and visitors present, who did not
separate until a late hour.

In the course of the evening fifty-six additional names were entered
upon the books of the Society; thus making a total, since the forma-
tion of the club, of ninety-two members.

An Ordinary Meeting of this Society was held on Tuesday, May
16th, at Glo’ster Hall, Glo’ster Place, Brixton Road; Henry Deane,
Esq., F.LS., &., in the chair.

The minutes of the last meeting were read and confirmed. Seven-
teen new members, whose certificates had been read at the last meeting,
were balloted for, and elected unanimously. The certificates of thirteen
new members were also read.

Dr. Robert Braithwaite then read a paper “On the objects of the
Society, and the best methods of promoting them.” We are sorry to
be unable to give the whole of this interesting paper, of which the
following is an abstract :-—

In speaking of the objects to be carried out by associations lke
the present Society, it is scarcely necessary to dwell upon the advan-
tages resulting from an acquaintance with science and natural history,
for it must be profitable to everyone to know something of the struc-
ture and functions of the organic world around us, and especially
in the young is it laudable to foster those habits of observation and
orderly arrangement which hereafter will be of service in every walk
of life. And, since we must presume that those who know most of
God’s works are indeed living nearer to himself, can we believe that
he would have granted to man the skill and thought required to
construct this glorious instrument, the microscope, placing him at the
gates of a new wonderland, and then that its exploring powers should
not be used to the uttermost ?

And this leads me at once to what I should wish especially to see
cultivated, the natural productions of the district, the vegetation of
the soil, and the living things, particularly the insects, which are
found there also ; and I trust an herbarium and cabinet in which these
may be preserved will at no distant date form an important feature
in the objects of the club.

Biology, or the study of living things, naturally divides itself into
two parts, the animal and vegetable kingdoms. Taking a rapid
survey of the vegetable kingdom, we place the Alge, or water-weeds
at the bottom of the scale, together with the minute forms (Diatoms
and Desmids) found in our ponds. Following these come the Fungi,
and above these the Lichens and Mosses. Next we place the Ferns.
These form the Cryptogamous, or non-flowering plants. From these
we pass to the Phenogamous, or flowering plants, in which pollen is
produced. As well-known objects for the microscope, I may just
refer to the pollen, to the cuticle, or skin covering the leaves, with its

SS

PROCEEDINGS OF SOCIETIES. 119

stomata, or breathing pores, and various forms of hair, and to
the modifications we may notice in divers seeds. Passing next to the
animal kingdom, we find the lowest animals, like the lowest plants,
are of the simplest structure, as a type of which I may mention
Ameba, a little gelatinous speck we find gliding on the surface of
ponds. After this we get species invested in a thin flexible shell, and
so we pass on to those beautiful perforated organisms dredged up
from the ocean bed. Next come the Sponges, and after these we have
the great group of Infusoria, the animalcules par excellence, for some
of them are the most minute of living creatures, all of them interest-
ing to watch when living, but unfortunately not capable of being
preserved satisfactorily. The great division of Articulata embraces
animals whose limbs are composed of jointed segments, and organs in
lateral pairs. Lowest of these, and passing as it were from the last
group, are the Worms, which have of late acquired considerable
importance, from the mode in which even human beings may be
infested by them,—I refer to the Trichina spiralis, that minute worm
which, sometimes by millions, inhabits the muscles of animals used for
our food, and which thus get introduced into the human economy.
The Rotifera include many beautiful microscopic animals; there is
still much to be learned respecting their anatomy and life-history.
Above these comes the group comprising the Crab, Shrimp, and Lobster,
as well as many minute forms which abound in our ponds. Follow-
ing these is the group comprising the Spiders and Mites. Both are
especially worth investigation. We now arrive at the great class of
insects, the study of which, or Entomology, has now become most
ardently pursued. As objects of interest, even to the young, few sur-
pass a well-mounted collection of insects; and I do look forward to the
time, I trust not far distant, when the insect fauna of the district shall
be represented in the cabinets of this club by actual named specimens.
The last great division of the invertebrate animals are the Mollusca
or Slugs and Shell Fish, but of these time does not permit me to
speak. I may at least mention the names of the vertebrate animals,
these being Fishes, Amphibia, Reptiles, Birds, Mammalia, and by
these we reach the prince and head of all creation—Man. And what
does the microscope teach us with regard to ourselves ? Not that we
stand apart from the rest of the organic world, but that of the many
thousands of living beings, each forms a link in the vast chain by
which even Man and the Amceba form one harmonious whole. To
man, however, is given something more—knowledge, reason, and con-
sequently responsibility, and by these we are led far beyond the
limits of the small circle in which we travel, still to find ever out-
reaching the farthest grasp of instrumental power, yet present every
moment to our unaided vision, one Creator and Preserver of all, by
whom, and through whom, we, and all things, live, and move, and
have our being.

A vote of thanks was unanimously accorded to Dr. Braithwaite
for his interesting paper.

The Chairman announced two excursions—one to Elstree, on May
27th ; and another to Homerton (for Hackney Marshes) on June 10th.

120 BIBLIOGRAPHY.

The meeting then resolved itself into a conyersazione, when many
interesting microscopical objects were shown, after examination of
.which the members and visitors separated, the next meeting being
announced for Tuesday, June 20th, at half-past seven o’clock in the
evening.

BIBLIOGRAPHY.

Archiy fiir Mikroskopische Anatomie herausgegeben von Max
Schultze. 6 Band, 4 Heft. Bonn. Cohen & Sohn.

Biologische Studien, Studien uéber Moneren und andere Protisten
nebst e. Rede uéber Entwickelungs-gang und Aufgabe der Zoologie.
Professor Dr. Ernst Haeckel. Leipzig. Engelmann.

Zur Kenntniss der nerven des Froschlarvenschwanzes. Dr. E.
Klein. Wien. Gerold’s Sohn.

Untersuchungen uéber den Bau d. Knéchernen Vogelkopfes. Dr.
Hugo Magnus. Leipzig. Engelmann.

Bryozoi Pliocenici italiani. Dr. A. Manzoni. Wien. Gerold’s
Sohn.

Beitrige zur vergleichenden Neurologie der Wirbelthiere. Von
N. Miklucho-Maclay. Leipzig. Engelmann.

Beitriige zur Histologie d. Gehérorganes. Professor Dr. Riidinger.
Miinchen. Lentner.

Grundziige e. Spongien-Fauna d. atlantischen Gebietes. Professor
Dr. Oscar Schmidt. Leipzig. Engelmann.

WACTOSC

ANI

D® Hudson.

Pedalion mira Anew Rotifer

THE

MONTHLY MICROSCOPICAL JOURNAL.

SEPTEMBER 1, 1871.

1.—On a New Rotifer. By C. T. Hunsoy, LL.D.
PuiatE XCIV.

A norirer hunter should never pass a pond without trying it, no
matter how often he has been disappointed before. For example,
here is a pond close to my house, which, so far as I can remember,
has never yielded anything worth catching for many summers, and
yet this July I have taken in it in one dip several specimens of
Syncheta, Asplanchna, Brachionus, and Anurea, as well as of a
new and very extraordinary rotifer.

On hunting over the bottle with a hand lens before taking it
home, I readily recognized the first four, while the latter I sup-
posed to be some new and unusually large species of Polyarthra ;
but on placing a specimen under the microscope I for a moment
doubted whether it was a rotifer at all, and not a larva of some one
of the Entomostraca. A brief examination showed the animal to
be a true rotifer with a splendid trochal disk and ciliated chin, and
with internal organs much like those of Triarthra, but with an
external form of a most unusual character; for it possesses six
well-defined limbs containing powerful muscles, and terminated not
by cilia but by fan-shaped plumes of fringed hairs, and is in these
respects so utterly unlike any other rotifer, that, though it has
many points of resemblance to the Hydatinxa, I am quite puzzled
where to place it.

I propose to call it Pedalion mira, from the oar-shaped limb
with which it steers its way like an ancient trireme; occasionally
however improving on its antique type by striking a succession of
vigorous slaps with all its limbs in concert, and darting through the
water with such speed as to clear quite sixty times its own length

EXPLANATION OF PLATE XCIV.

Fic. 1.—Front view, showing the dorsal antenna, eyes, double row of cilia
round the trochal disk, and the mouth lying between them and
above the ciliated chin.

», 2.—Side view.

5, 3.—Dorsal view.

, 4.—Pseudopodium ; ventral surface.

All the figures are on the same scale, and represent a magnification of about

300 linear.

VOL. VI. K

122 On a New Rotifer.

in a second, that is to say, at a rate which in a man would be
upwards of 200 miles an hour.

Every new rotifer is a new difficulty. Hydatina is troublesome
enough, for it is never still, and will not bear compression. Syn-
cheta has in addition the charming habit of turning over head and
heels. Tvriarthra and its small cousin Polyarthra by help of
their spines and plumes add skipping to their other accomplish-
ments, and were, till I found Pedalion, the most vexatious of all
the rotifers.

But while they are chary of using their full powers—reserving
them for great occasions, such as when they fall foul of each other
or run against the sides of their prison—Pedalion skips habitually
without the slightest provocation, and at tolerably regular intervals,
so as to drive an observer into a fit of nervous irritation.

Now it is hopeless to attempt to make out its shape or internal
structure unless the creature can be kept tolerably still, and yet I
found it impossible to hit upon any way of ensuring this at my
own pleasure. If I secured Pedalion between the two plates of the
compressorium, it was only to see its limbs reversed and thrown
into unnatural attitudes, hiding often the very things I wanted to
look at. If I placed it in a very tiny drop of water and gave it
just room to swim in, before many minutes had elapsed it either
jerked itself half out of the drop and lay sprawling, helpless, and
disfigured ; or with its back adhering to the concave boundary of
the water it kept “squirming around” (as a young American lady
described it to me) like a horse in a circus.

It was clear that, unless the rotifer would of its own accord sit
for its portrait, there was no Plate to be had for the ‘ Microscopical
Journal,’ so I abandoned the heroic methods and tried coaxing and
patience.

I first placed one or two scraps of conferva on the under-glass
of the compressorium so as to cross each other, and then I went to
my tank in which the rotifers were, and, watching till the currents
that are always rising and falling in it, had swept into one corner
a tolerably dense crowd of them, I drew up a score or two with a
pipette, and dropped them with as little water as possible on the
interlacing weed.

On placing the cover over them, and gently compressing the
weed, I had of course many rotifers entrapped in small live cages
deep enough for them to swim in pretty freely without getting far
out of range. It was a pretty sight to see them darting about,
diving, skipping, and rolling in every direction; but I began to fear
that my scheme would fail, for I seemed to have made them more
restless than ever. After a while, however, they seemed to get tired,
or to be reconciled to their prison, and then one or two settled down
to exploring the confervz, sailing along with their mouths and

On a New Rotifer. 128

chins close to the stems. At last one got its head into the angle
where two stems met, so as to prevent its swimming farther, and,
to my delight, made no attempt to flap itself away in the usual
fashion. I at once slipped a circle of ruled glass into the eye-piece,
seized my paper, ruled also with squares, and had the good fortune
to complete the side view given in Fig. 2 before Pedalion stirred ;
when it did go, it went with one bound utterly out of the field.

The sitting being at an end I had leisure to consider my sketch,
and once again I could scarcely credit what I had seen and drawn.
Here was a rotifer with six good-sized limbs all worked by muscles
contained within them, and terminating in fans of long rigid fringed
hairs, more like the extremities of a Daphnia than those of the
rotifers. Many rotifers have one limb—the pseudopodium—which
is attached somewhere or other to the ventral surface, and is in
Pedalion the grand oar, acting as flapper and rudder, which springs
from under the chin. Synchxta, too, has a small movable projec-
tion at each side of its head bearing its ciliary paddles; but where
are the links that connect Syncheta’s rudimentary stumps with
Pedalion’s well-formed limbs? It is very possible that such links
exist, and may yet be discovered ; for the world of the free-swimming
rotifers is a comparatively unexplored one still, and everyone who
ventures into it is pretty sure to find something new, even if he can-
not hope to rival the achievements of Ehrenberg, Leydig, or Gosse.

I once caught at Guernsey, in the upper mill-pond at Petit Bot,
some rotifers whose ciliated disks were of the shape of the top joint
of a thumb, and were densely covered on their ventral surfaces with
fine cilia, like fur, leaving bare only a straight pathway, as it were,
through the cilia, in a line with the animal's length.

I am perfectly certain that I never saw the creature before, and
I can discover no account of anything like it in the text-books.
Unfortunately I delayed one day before I examined and sketched
my captives, and on the next they were dead. I returned to Petit
Bot for a fresh supply, and found that the miller had let out the
water to clean the pond.

I have dwelt on Pedalion’s external form, partly because I have
not yet had time to thoroughly examine its internal organs, but
mainly because this rotifer appears to be a weighty witness on the
side of those (to wit, Owen, Leydig, Gosse, &c.) who would range
the Rotifers rather with the Crustacea than with the Annelida, &c.
One of the arguments of Vogt (as quoted by Pritchard) against the
Crustacean nature of the Rotifers is that “a pair of jomted locomo-
tive organs is never found among the Rotifers at any period of their
existence.” Now,as Pedalion has ¢wo pairs of such organs, besides
its pseudopodium and another limb on the dorsal surface, the above
statement must be modified, and the argument will in consequence
be considerably weakened.

K 2

124 On the Examination of

Into the question of the affinities of the Rotifers I do not intend
to plunge. I shall consult my own tastes and capacities better by
hunting for a four-legged rotifer, now that I have found a six-legged
one. At some future time I hope to return to the examination of
Pedalion’s structure. Its length is about 735th of an inch from the
front of the trochal disk to the extremities of two curious ciliated
projections at the posterior end of its body.

Il.—On the Examination of Mixed Colouring Matters with the
Spectrum Microscope. By H. C. Sorsy, F.BS., &e.

In studying the colouring matters soluble in water that may be
obtained from various kinds of Algz, for which special names have
been proposed, as though they were single and simple substances, I
have been led to conclude that they are in some cases mixtures of at
least four, which are readily distinguished by their spectra. ‘The
facts which have thus presented themselves have so impressed me
with their importance in such inquiries, that I think it may be well
to make the study of mixed colouring matters the subject of a
special communication. The interest of this question, in connection
with certain branches of botany, will, I trust, be made fully apparent
when I have shown that various kinds of marine and fresh-water
Algz, and even some Lichens, though differing very much in general
tint, may contain one or more particular colouring matter in com-
mon, and differ in the presence or absence of others. There is thus
a bond of union between somewhat remote members of certain
natural orders, whereas without proper attention each of these
mixed colours might be thought to be a special kind, and no such
connection between the plants would be recognized.

The manner in which the mixed nature of some colouring matters
may be ascertained from their spectra has been already described
by Professor Stokes* and others, as well as in previous papers by
myself; but in order to make this communication complete in itself,
I must be allowed to again describe some of them, I shall not
attempt to enter into the chemical part of the subject, or to treat of
the separation of different substances by purely chemical methods,
such as the solubility or insolubility in various reagents, but con-
fine myself almost entirely to those processes in which the exami-
nation of the spectra is of primary importance. I scarcely need say
that the coloured material should be separated, as far as can be con-
yeniently managed, into that which is soluble or insoluble in such
simple solvents as water or alcohol ; but at the same time there are
cases in which such a difference in solubility does not appear sufficient

* ¢ Journal of the Chemical Society, June 2, 1864 (New Ser.), 1i., pp. 304-318,

Mixed Colouring Matters with the Spectrum Microscope. 125

to prove that the colouring matter itself differs essentially. The
spectra seem to show that occasionally the presence of some other
substance, insoluble in water, which has a strong affinity for the
colouring matter, is the true cause of this variation. I shall there-
fore presume that we have to deal with colouring matters separated
from any others that differ materially in their solubility.

There are few cases in which the mixed nature of a coloured
aqueous solution can be more easily ascertained than when the con-
stituents differ so much in character that the addition of some
reagent will more or less completely destroy the spectrum of one
without having any effect on that of the other. For this purpose
no substance is superior to sulphite of soda. Without producing
any real decomposition, this almost entirely removes the detached
absorption at the red end of the spectrum of certain colours, but has
no effect whatever on that of others. In the case of some colours
it thus acts when the solution contains excess of ammonia, but in
the case of others it has then little or no action, but removes the
absorption when the solution contains excess of such a moderately
weak acid as citric. The application of this principle to the exami-
nation of the colouring matters of plants is extremely simple and
satisfactory. If, for example, we obtain the red colouring matter
from the leaf-stalks of the common red rhubarb, or from the petals
of the crimson Calceolaria, as described in my paper “On the
Colouring Matter of Leaves,”* and to its solution in water add a
little citric acid, the colour is clear, deep pink, made almost or quite
colourless by the addition of a little sulphite of soda, which change
in colour is due to the complete removal of the broad absorption-
band in the green. If, however, this same red colouring matter is
mixed with some of the yellow substances found in many leaves,
the spectrum of the said solution, in addition to the same broad
absorption-band in the green, shows absorption at the blue end;
and on adding the sulphite, this yellow colour, which absorbs the
blue. end, may be distinctly seen alone. A similar plan may be
adopted in the case of some substances which are changed when the
solution contains shght excess of ammonia. I could not give a
more striking example than that of a solution of blood mixed with
so much magenta that the absorption-bands of the blood are com-
pletely hidden. On adding a small quantity of sulphite, they are
seen as well as if no impurity had been present. It may, however,
happen that there is a mixture of two colours, both of which are
acted upon in the same manner by the sulphite, but one more
rapidly than the other. Thus, for example, the colouring matter of
the petals of the blue Lobelia gives a spectrum with two remarkably
distinct absorption-bands. So also does that of the petals of the

* “Quarterly Journal of Microscopical Science’ (New Ser.), xi., 1871, pp. 215-
234.

126 On the Examination of

crimson Cineraria, but the bands are so placed that on mixing the
two colours a band of one covers up the clear space between the
bands of the other, and thus the mixture may show merely a broad
absorption, very like that in the colouring matter of many plants.
However, on adding a little sulphite of soda to a very slightly acid
mixed solution, and examining it at once, the bands of the Cineraria
may be seen for a short time, since those of the Lobelia are more
rapidly destroyed. ven in the case of those colouring matters
which are not immediately changed in an acid solution by the
addition of sulphite, one may slowly fade, whilst the other is scarcely
changed, and thus evidence may be obtained of the existence of a
mixture. Numberless illustrations might be given of the application
of such a method, but these will I trust explain sufficiently well the
general principle. In particular instances we may of course make
use of other reagents to destroy one colour and leave another, but
in the case of closely-allied substances the difficulty is that few or
no reagents will act sufficiently on one without changing both, and
we are compelled to rely on the comparison of the spectra of the
colours partially separated artificially, or met with naturally in
varying proportion.

For effecting a partial separation of colouring matters soluble in
water no reagent is more convenient than ether. On agitating the
aqueous solution with more of this than can be dissolved, the excess
rises to the top, and the aqueous solution subsides to the bottom.
In the case of some colouring matters the greater part remains dis-
solved in the water ; whereas, in the case of others, the greater part
rises to the top, dissolved in the ether ; whilst occasionally nearly
the same amount is dissolved in both. It will thus be seen that, if
a mixture were thus treated, a partial separation might often be
effected,'and on evaporating to dryness, redissolving in water, and
comparing the spectra, either in the natural state or after reagents
had been added, the differences might clearly prove that two or more
colouring matters were present. In order to make this more intel-
ligible, it will be well to enter into a few general principles involved
in the method. For example, suppose that in some particular state,
acid, neutral or alkaline, whichever it might be, the original solution
gave a spectrum with two absorption-bands, A and B, and that when
separated artificially into two portions one gave the band A and the
other B, in precisely the same conditions as before, it would be quite
certain that the original was a mixture of two substances. But
since such a complete separation would only occur in a few instances,
it might happen that both the products showed both the bands, only
in a very different degree. Thus, for example, on making the solutions
of such a strength that the band A was equal in both, the band B might
be so much darker in one, that in experiment tubes of the same
depth the solution might have to be diluted to four times the volume

Mixed Colowring Matters with the Spectrum Microscope. 127

before it gave that band no darker than in the other solution. Ex-
pressing this by figures in front of the letters, we may say that the
spectra were as follows :—

The original solution .. .. .. A +B
The part soluble in ether .. .. 2A + B
The part soluble in water .. .. A +2B

We have here very good proof of the existence of two substances.
If there had been only one, however much we might have divided it
into different portions, the relative intensity of the two bands would
have remained the same, that is to say, in solutions of equal strength,
in all the above cases we should have had simply A+ B. Of
course the extent of this separation might be more or less than what
I have supposed, but on detecting any such difference we should
endeavour to effect a still further separation, and may perhaps ulti-
mately succeed in obtaining both colouring matters in a comparatively
pure state. The same principles are equally applicable in the case
of substances insoluble in water, but soluble in alcohol, which can be
more or less completely separated by the use of bisulphide of carbon.
For example, I found that on. agitating an alcoholic solution of
chlorophyll from green holly leaves with excess of bisulphide of
carbon, the part carried down in solution in the bisulphide did not
give the same spectrum as that left in the alcohol. Making certain
absorption-bands seen at the blue end, equal in both cases, other
bands at the red end were so much darker in the part carried down
in the bisulphide, that the solution had to be diluted about eight
times, before they became equal. There being thus evidence of a
mixture, I tried the experiment over and over again, in order to
ascertain whether a more complete separation could be effected, and
found that, if the leaves were well crushed and then heated in SN
the solution rapidly filtered, and treated with the bisulphide as soon, —
as cold, it could be separated into a deep green, carried down by the
bisulphide, and an almost clean yellow, left in the alcohol, which
corresponded to the xanthophyll of yellow leaves. The separation
was indeed go complete, that for an equal amount of xanthophyll
this yellow solution did not contain above ;\,th the amount of
chlorophyll contained in the other solution, so that a mixture of
these two colours in ordinary green leaves was placed beyond all
doubt, as also shown by Professor Stokes in the paper already cited.

Such a case as this leads me to the consideration of the spectra
of substances giving several absorption-bands. For example, sup-
pose the original solution showed four bands, A, B, C, and D, and
when partially separated, as described above, the spectra became as
follows,—

Original solution .. A+B+C+OD
One product 2A+2B+ C + D
Another A+B 4+2C+2D

128 On the Examination of

We might conclude that very probably two substances were
present, one giving the bands A and B, and the other C and D.
Similar principles would of course apply to cases where more or
fewer bands were present. Very often one colouring matter might
give well-marked bands, and the other only a general absorption.
We might then separate it with two products, and on making the
solution of these of the same general depth of colour, one might
show a spectrum with well-marked bands, and the other scarcely
any trace of them. The same general facts may be seen when
the characteristic bands are only developed by the addition of
different reagents, which completely alter the colouring matter, but
then more care is required to avoid any differences that may result
from the varying action of more or less of the reagents. To attempt
to describe all the necessary precautions would make this paper
most unreasonably long, and therefore I trust that the above rough
and general account will at all events suffice to pomt out the sort of
plan that may be followed, premising that in all cases the results
should be checked by other experiments, in order that no accidental
peculiarities may lead to error. As illustrations of the application
of these principles I would refer to those colouring matters of kino,
and of Gummi rubra, which are soluble both in ether and in water.
The kino contains two such, one more soluble in ether, of pink
colour, which in its natural state gives a well-marked absorption-
band between the yellow and green, and the other, more soluble in
water, of orange colour, which gives a broad absorption-band between
the green and blue on the addition of bicarbonate of ammonia.
Gummi rubra contains this same orange colour, without the
pink, mixed with another orange or yellow substance, relatively
more soluble in water, not yielding a spectrum with decided bands .
in any state that I have yet seen.

When a solution contains more than two colouring matters the
recognition of each becomes somewhat more difficult; but still,
by following out this system, and dividing the material into more
than two portions, a very good opinion may be often formed of the
general optical properties of each substance. When some of them
give well-marked and characteristic absorption-bands, and when the
absorption of others may be removed by the addition of sulphite
of soda, the study of a complex mixture is very greatly facili-
tated, and especially if the spectrum of one or more of the con-
stituents is of such a marked character that it can be at once recog-
nized as that of some substance already known in a pure state. A
tolerably good opinion may then be formed of the spectrum of the
rest, by, as it were, subtracting that of the known constituent. This
leads me to the description of the spectra of certain colouring matters
which are met with so far separated naturally that their compound

Mixed Colowring Matters with the Spectrum Microscope. 129

character may be inferred without reasonable doubt, and confirmed
by a more extended examination.

I have lately found that many interesting facts may be observed
by examining the spectra of substances in their natural state, with-
out extracting the colouring matter. Frequently they are so opaque
that it is requisite to use a very bright light to penetrate through
them. I employ, as a condenser, a plano-convex lens about 7 inch
in diameter, and of about the same focal length, over which is
placed a conical cap with a round hole a‘little larger than the field
of the microscope as seen through the slit in the spectrum eye-
piece, at such a distance from the lens within the focal point that
the image of the sun illuminates the entire hole. By placing the
object on a piece of thin glass, and bringing this hole close up to it,
sufficient light may be driven through a comparatively opaque
object, and none which has not penetrated through it can pass up
the microscope, even when the specimen is small. In this manner
the petals of flowers may be examined direct; and if the colour is
too pale with one petal, two or more may be pressed flat, one over
the other. We may thus readily see two well-marked absorption-
bands in the blue in the light transmitted through the petals of
several species of Brassica, of Helianthemum vulgare, Geum urba-
num, and several other yellow flowers ; but in the case of many others,
as Viola lutea or Ranunculus bulbosus, though similar bands are seen
in exactly the same part of the spectrum, they are so much more
faint on account of general absorption at the whole of the blue end,
that there must certainly be a second yellow colour present. Some.
yellow flowers, like Chelidoniwm majus, give well-marked absorp-
tion-bands in such a different position as clearly to show that they
are due to another substance; but on the whole the spectra of very
many can be readily explained only by supposing that they are
coloured by a very variable mixture of at least two yellow sub-
stances. ‘I'he facts seen in the case of the spectra of various Algz
are; however, so much more striking, that it appears to me that
I could not possibly choose a better illustration, and that a some-
what detailed description will serve well to explain the method which
I think should be followed in such inquiries.

The following woodcut shows the spectra of the light trans-
mitted by the various plants themselves, so far as relates to the
colourmg matters soluble in water. I have left out all such absorp-
tion as is due to chlorophyll and xanthophyll, for the sake of sim-
plicity. I may here remark that it is most important to study the
spectra of the plants themselves, since in some cases the colouring
matters are decomposed so rapidly in solution that they are almost
or entirely lost, and new absorption-bands are developed, due to
products which do not occur in the living plants.

130 On the Examination of

DIAGRAM OF THE SPECTRA OF THE LIGHT TRANSMITTED THROUGH VARIOUS ALG,

Red end. Blue end.
i, Ss Z

1. Palmella cruenta,

2. Red Floridea.

3. Purple Floridea.

4. Oscillatoria grown in water.

5. Oscillatoria (Microcoleus ?)
grown on a damp wall,

(Fraunhofer’s lines.)

1. Palmella cruenta is a microscopic plant, closely allied to the
so-called “red snow,” found growing over the surface at the bottom
of damp walls, and looking as if blood had been spilt on the ground.
The spectrum may be seen by scraping off the external red part,
and keeping it for a while damp on thin glass, so that the red
granules may extend over the vacant spaces. It is, however, still
better to keep a quantity of the impure mass quite wet in a bottle,
when in the course of time the comparatively pure red material
will grow up the surface of the glass, aid may be collected together
and examined on a piece of thin glass with concentrated sunlight.
The spectrum is characterized by the single well-marked band X.
When the plant is kept in dilute bicarbonate of ammonia it is killed,
and the colour dissolved. It is a fine pink by transmitted light,
and gives the same absorption-band as seen in examining the plant
itself. This substance is extremely fluorescent, of orange colour,
giving a spectrum with a remarkably bright green-yellow band,
lying just on the red side of the band X in the transmitted light,
and not coinciding with it, as has been inaccurately said to be the
rule in such cases. This remarkably bright green-yellow band of
the fluorescence enables us to recognize this substance, even when
mixed with so much impurity that the absorption-band of the trans-
mitted light is almost or entirely hid.

2. What I have named red Floridea is one of those normally
purple Algze which appear to turn red in a manner similar to the

Mixed Colowring Matters with the Spectrum Microscope. 131

leaves of many terrestrial plants in autumn.* The chlorophyll has
disappeared, and perhaps more xanthophyll has been formed. How-
ever, confining our attention to the colouring matters soluble in
water, it will be seen that the band X is visible, but that instead of
being isolated as in the spectrum of Palmella cruenta, there is a
broad absorption-band Y extending from it some distance towards
the blue end, and also another well-marked band Z, between the
green and the blue.

3. The purple Floridea is a similar plant to the red, only in
an unchanged condition. The spectrum shows a band W in the
red, due to a blue colouring matter, which along with the chloro-
phyll causes the plant to be of a peculiar dull purple colour, and
not red, as in the former example. It will be seen that the band Z
is the same as in the red specimen, but that Y is relatively so much
darker that the narrow band X is almost entirely obscured, and yet
that it does really occur is proved by the bright green-yellow band
in the spectrum of the fluorescent light of the colouring matter
dissolved out by water.

4. The spectrum of Oscillatoriz is seen to the greatest advan-
tage by examining a mass of the healthy living fronds which creep
up the sides of a bottle containing the impure natural material.
They are then free from Diatomacee and particles of mud, and by
collecting them together on a piece of thin glass with a little water,
so that there are no vacant spaces to signify, concentrated sunlight
penetrates through them, and gives a spectrum with the two well-
marked absorption-bands, shown in the figure, as described by Ray
Lankester.t When the plant is of that kind which forms a dark
velvety mass on the surface of shady troughs supplied with water
from cold springs, we have the well-marked band W, and the broad
band Y, which is so dark that it almost hides the narrow band X,
and thus, as far as that part of the spectrum is concerned, it corre-
sponds with the purple Floridea, but differs in the absence of the
broad band Z. The presence of the substance which gives the
narrow band X is, however, proved by the spectrum of the light of
fluorescence.

5. The Oscillatoria which grows on damp walls and ground is
perhaps not the same plant as that growing under water, and may
belong to the genus Microcoleus of some authors. The spectrum
of the pure living plant, separated as described above, shows the
band W, and also the narrow band X, without the broad band Y,
seen in the case of Oscillatoria grown under water. Much more
might be said about the changes that occur at different seasons of

* See my paper “ On the Various Tints of Autumnal Foliage,” ‘ Quart. Journ.
of Science’ (New Ser.), i., 1871, pp. 64-77; and that in the ‘Quart. Journ. of
Micros. Science’ already cited.

+ ‘Monthly Micros. Journ.,’ iv., 1870, pp. 14-17.

132 On the Examination of

the year; but since I am only using these facts as illustrations of
another subject, and am not writing a paper on the colouring matters
of Alge, I wish to confine myself to what is requisite on the present
occasion. What I therefore now contend is that a simple comparison
of these five spectra shows that they are due to the variable admix-
ture of four different colouring matters, which, for convenience, I
will call W, X, Y, and Z, from their respective absorption-bands, as
shown in the woodcut. In the first place there can be no doubt
that there is a simple substance X which gives rise to the single
band seen in spectrum No. 1. This same band occurs in No. 5, but
along with it is another, due to a blue-purple colour W, which is
obtained separate in solution by keeping the plant for some time in
a little water. The spectrum of the light transmitted by this solu-
tion shows the single band W and that of the splendid rose-coloured
fluorescence a single rose-coloured band, just on the red side of the
absorption-band. As will be seen on comparing the spectra, No. 4
differs from No. 5 in haying a broad absorption-band Y. That both
the substances W and X are really present is shown by the spectrum
of the fluorescence of the aqueous solution obtained from that kind
of Oscillatoria, which shows both the narrow rose-coloured and the
narrow green-yellow bands, and thus, though I have not yet been
able to procure the substance Y separate from all others, I do not
hesitate to conclude that it does exist as a third independent colour-
ing matter. That there is a fourth, giving rise to the band Z, is
also clearly shown by comparing either spectra Nos. 1 and 2, or 3
and 4, and this conclusion 1s established by the fact that, on keepmg
for a few days the mixed colouring matters dissolved by water from
the purple Floridea, and removing the deposit by filtration, a flesh-
coloured solution may be obtained, which gives a spectrum with
this single band Z.

According to these principles the colouring matter of the various
plants may be expressed as follows :—

1. Palmella cruenta xX

2. Red Floridea Sf are X+Y+Z
3. Purple Floridea rr ermrrmr errs) ote ak
4. Oscillatoria grown in water .. .. .. «| « W+X+4Y

5. Microcoleus grown on a damp wall w+xX

The substance described by Kiitzing, Stokes, and Askenasy by
the name Phycoerythrin appears to have been a mixture similar to
2 or 3, along with perhaps another substance, which I have not yet
seen. Cohn’s Phycocyan must, I think, have been a mixture of
W, X, and Y with another, which was possibly an altered product,
giving an absorption-band not seen in the spectrum of the plants
themselves. I may here say that I have met with at least four
such products, and one, which gives a narrow band in the red, is

Mixed Colouring Matters with the Spectrum Microscope. 133

formed so readily that it is sometimes almost impossible to obtain
an aqueous solution of the mixed colours free from it.

All these substances belong to a single natural group, dis-
tinguished by certain marked characters, and since the mixture of
several of them has been named Phycoerythrin, it may be well to
call it the Phycoerythrin group. It differs entirely from the Hry-
throphyll group, described in my paper “On the Colouring Matter
of Leaves,” in the fact that the position of the bands is very little,
if at all, changed by the addition of weak acids or alkalies; but when
they are stronger, actual decomposition occurs, some of them being
more easily changed by acids and some by alkalies. The difference
in the spectra shown in the woodcut cannot therefore be caused by
any variation in the acid reaction of the juice of the plants, as is
the case in the colouring matter of the petals of some flowers.
The possibility of this must always be borne in mind in applying
such a method of comparison, and the effect of various reagents
must always be ascertamed before the actual identity of the colour-
ing matters can be inferred from the agreement in the bands in
only one particular condition. Much may be learned by acting
directly on the plants themselves.

The consideration of the various spectra described above seems
to lead to the following conclusions :—

1. When a spectrum shows two absorption-bands, like No. 5,
they should not he considered due to one single substance until
satisfactory evidence of the fact has been obtained. The solution
should be allowed to undergo slow decomposition, and be repeatedly
examined, in order to ascertain whether both bands disappear in the
same proportion, and also the action of various reagents observed,
in order to learn whether one band can be permanently removed
without the other, making of course due allowance for any change
that may depend merely on an acid or alkaline reaction.

2. When more than two bands are seen in the spectrum, as in
No. 3, and they are not at nearly equal intervals, the compound
nature of the substance may be considered so probable, that further
examination should certainly not be neglected.

3. When there is broad shading about a narrow absorption-
band, as in No. 2, it is important to ascertain whether or not it is
due to the same substance. There are certainly many cases in
which I have always concluded that both are due to the same, but
examples like this evidently show that such an opinion ought not
to be formed until after further examination.

The occurrence of so many assgciated colouring matters, as in
Algez, may be rare. It must not be supposed that I imagine that
whenever there are two or more absorption-bands they are due to
two or more independent substances. As an example of what I
look upon as satisfactory proof of the contrary, I wall describe some

134. On the Examination of Mixed Colouring Matters.

facts connected with the well-known spectrum of blood. If after
exposure in a dry state to the air for some weeks, until the hemo-
globin has been changed into methemoglobin, a small quantity of the
double tartrate of potash and soda be added to the aqueous solution,
and afterwards a very minute portion of the double sulphate of
protoxide of iron and ammonia, the methemoglobin is deoxidized
and reconverted into hemoglobin, as described in my late paper “On
Blood-stains.”* Here then we have a decomposition gradually effected
by the atmosphere, and if two different substances had been present,
it is extremely probable that they would have varied in the rate of
change, so that there would finally have been an alteration in their
relative proportion, and thus when deoxidized there would not have
been the same relation between the absorption-bands as in fresh
blood. I find, however, that the agreement is complete. More-
over, if the colouring matter had been a mixture of two substances,
it is extremely probable that there would have been some such
variation in their relative amount in the blood of very different
animals, as occurs in the colouring matters of different Alege. In
order to ascertain whether this is the case, I carefully compared
side by side the spectra of human blood and that of the small
annelids so common in stagnant pools, and found that the position
and relative intensity of the two bands was exactly the same.

Such then are the principal conclusions that have been forced on
my attention in carrying out these investigations. For my own
part I must say that they make me think that many of my previous
observations require further examination, in order to ascertain
whether I have not sometimes believed that I was examining a
single substance when it was really a mixture. For the future I
shall certainly be quite alive to the importance of the principles
described in this paper, and trust that what I have said will serve
to impress it on others, and assist them in carrying out similar
inquizies.

* Monthly Micros. Journ.,’ vi., 1871, pp. 9-17.

The Monthly Microscopical Journal, Sept 1.1871. PL XCV.

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Yellow Green Indigo
Red Or. Yel.
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Red Oranawe Yellow Green Blue Indago

Rect Orange Yellow Green Blue Indigo
Laates , 7 ;

Red Orange Yellow Gee Blue Indigo

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Tuffen West sc W.West& C2 ump

Spectra by polarised light through doubly-
refracting crystals.

(B55

III.—On Spectra formed by the passage of Polarized Light
through Double-refracting Crystals seen with the Microscope.

By Francis Dzas, M.A., LL.B., F.R.S.E.
PLATE XCV.

Iv is familiarly known as one of the commonest experiments in
optics that when a beam of polarized light is passed through a thin
film of mica or selenite, and subsequently analyzed either by re-
flexion or by double refraction, two colours are seen complementary
to one another, and alternating with one another at each 90° of a
revolution of the analyzing plate or prism.

It might be expected that the coloured light thus obtained
would, if thrown into the form of a spectrum by means of disper-
sion prisms, exhibit some peculiarities, and such is the case, as will
be seen from the following experiments :—

To make the experiments intelligible, it may be well in the first
place to say a few words about the instrument employed, and the
method of using it.

Any spectrum microscope ought to answer the purpose, provided
that in addition to the spectroscopic arrangement a pair of Nicol’s
prisms can be attached, one below the stage and the other over the
eye-piece. Both should be capable of being rotated, and it tends
much to facility of working as well as to exactness of result that
both the polarizing and the analyzing prism should carry graduated
heads, so that their axes may readily be turned to any required
degree of inclination to one another.

The instrument I employed was a large Smith and Beck. The
spectroscopic arrangement consists of an adjustable slit attached to
the under-part of the sub-stage below the achromatic condenser, and
a set of direct-vision prisms which are inserted in the body of the
instrument immediately above the object-glass.

By proper focussing, an image of the slit is thus formed by the
achromatic condenser in the focus of the object-glass, and a fine
spectrum obtained filling the whole field.

; EXPLANATION OF PLATE XCV.
Fic. 1.—Illustrating the dividing and re-union of the bands, as described.

», 2.—Spectra formed by ordinary and extraordinary ray, partly overlapping.
The blue of the upper spectrum seen through the black band belong-
ing to the lower spectrum. The yellow of the under-spectrum seen
through the black band of the upper.

», 3—Rings and brushes of crystal of sugar-candy.

» 4.—Showing displacement of the rings and absence of brushes of same crystal
when light circularly polarized before and after its passage through
the crystal.

», 9.—Lemniscates and brushes of crystal of nitrate of potash,

VOL. VI. L

136 On Spectra formed by the passage of

This arrangement, it will be seen, differs considerably from the
spectrum microscope in common use in which the dispersion prisms
are placed close to the observer's eye, the slit being in the focus of
the eye lens. The former arrangement has this manifest advantage,
that owing to the distance of the prisms from the eye, the spectrum
fills the whole field ; also, that the apparent breadth of the spectrum
can be varied at pleasure by a change of the magnifying power em-
ployed. Each form of arrangement has, however, its advantages as
well as disadvantages, which it would be out of place to discuss here.

The polarizing part of my apparatus consists of two Nicol’s
prisms, for one of which, when desired, a double-image prism can
be substituted.

The polarizing prism is carried on the sub-stage. It is inserted
just above the slit in a short tube in which it can be freely turned
by a graduated head. The analyzing prism is placed in the usual
way—in a cap over the eye-piece.

The film of selenite to be examined, having first been mounted
in balsam between two thin glasses, is placed on the stage of the
microscope like an ordinary object.

It isa great convenience in this class of experiments to have
the stage of the microscope not only capable of rotation in the
optical axis of the instrument, but graduated.

By this means we can at any time, without displacing the film
under examination, adjust its neutral axes at any required angle to
the plane of polarization.

With regard to the mounting of the selenite films for examina-
tion the following method will be found convenient :—Make in the
turning lathe several wooden disks about two inches diameter and
one-eighth of an inch thick. Through the centre of each a hole
must then be bored of about half an inch diameter. A small por-
tion round the hole is then scooped out so as to form a cup, and in
this the selenite is placed and secured with sealing-wax.

The axes of the selenites are then determined and marked on
the rims of the disks.* In this way any two or more selenites can
be used in combination with their axes set at any required angle to
one another.

It remains only to trace the course of a beam of light in pass-
ing through the foregoing combination. First the ray, having been
reflected from the mirror, passes through the slit. It is then
polarized by the first Nicol’s prism, after which it passes through
the lenses of the achromatic condenser, and appears as an image of
the slit in the focus of the object-glass. Having passed through
the selenite and the object-glass, the ray enters the dispersion prisms
and is drawn out into a spectrum. This is magnified by the eye-

* The graduated rotatory stage above mentioned, and which is supplied by
Smith and Beck, affords a ready means of doing this.

Polarized Light through Double-refracting Crystals. 137

piece through which the ray, having passed, is lastly analyzed by
the second Nicol’s prism.

The loss of light from the number of the above media is not so
great as might be supposed, still an intense source of light is desirable
for satisfactory results. A good artificial light placed close to the
mirror will be found the best. In diffused daylight rays are apt
to enter the object-glass by reflexion from the brasswork without
first passing through the polarizer, by which the beauty of the
spectrum is impaired.

To understand the bearing of the experiments, it is necessary
to keep in view the different effects of a doubly-refracting film upon
polarized light, according to the position of its axes, with respect to
the planes of polarization.

Suppose we take a film of selenite, such as those commonly sold
as an adjunct to the polarizing microscope, giving, as its two colours,
a pinkish red and its complementary green. Such a film will, if
examined between two Nicol’s prisms, act on the light according to
the following laws :—

1st. When a neutral axis of the film is in the plane of primitive
polarization, the film will exercise no influence on the light ; if
therefore the prisms are set with their axes perpendicular the field
will remain dark, if the prisms have their axes parallel the field will
contain only white light.

2nd. If the prisms are placed with their axes perpendicular,
and the film is made to rotate, there will be four points of darkness
at each quarter of a revolution, vz. when an axis of the film is in
the plane of polarization, and between these four points, the same
colour (say green) will occur.

3rd. If the prisms are set with their axes parallel, and the
selenite is rotated, the field will be white at the four points where
it was previously dark, and of the complementary colour (red) be-
tween each of these four points.

4th. If the selenite is fixed with its neutral axis inclined 45°
to the plane of primitive polarization, and the analyzer made to
rotate, the field will be alternately red and green in the four
quadrants.

5th. The colours are always of maximum brightness when the
axes of the prisms are perpendicular or parallel, and the axes of the
selenite inclined 45° to the plane of polarization.

Suppose, now, we repeat the above experiments, using the
polarizing spectrum microscope above described, and let us call the
point in the revolution of the selenite at which either of its axes is
in the plane of primitive polarization, the zero point, from which
the number of degrees through which it is turned are measured.

Let the prisms be set with their axes perpendicular to one
another, and the selenite rotated on the stage. The spectrum will

L 2

138 On Spectra formed by the passage of

of course vanish at the four zero points. Between these points,
however, remarkable phenomena occur. A person unacquainted
with the true nature of the colours of polarization, and proceeding
on the analogy of homogeneous light, might expect to get a spec-
trum consisting only of green rays, seeing that that is the colour of
the field when the spectrum arrangement is removed. This how-
ever is not the case, and the result very beautifully illustrates to
the eye what is well known theoretically to be the true nature of
these colours. What we obtain is a continuous spectrum consisting
of all the prismatic colours, in greater or less mtensity, with the
striking peculiarity that there is a well-marked dark band in the
red, similar in appearance to the well-known absorption-bands which
many substances produce in the spectrum, only blacker and better
defined than these are ever seen.

The following is the mode in which the band makes its appear-
ance. As the zero point is passed, the light first makes its appear-
ance in the green of the spectrum, from which point, as the selenite
is rotated, the light opens out in both directions. When the light
reaches the red, the black band makes its appearance, and attains a
maximum blackness when the selenite is at 45°, viz. when, without
the use of the dispersion prisms, the field would contain green light
of maximum brightness. When this point of revolution is passed,
the band again fades, the spectrum becomes obscured at each end,
the darkness creeping in towards the green, till at 90° the spectrum
has again vanished. The same phenomena recur at each quarter of
a revolution.

Let the Nicol’s prisms now be set with their axes parallel, and
the same selenite rotated on the stage as before. The result is what
we should be led to expect from the last experiment. At the zero
points the selenite exercises no influence, and we have a continuous
ordinary spectrum. As a zero point is passed, however, a dark
band makes its appearance, but this time in the green rays. The
band is at first faint and nebulous, but becomes blacker and sharper
as the stage is rotated, till at 45° it attains its maximum. The
spectrum in this experiment never vanishes, but is apparently quite
continuous throughout, save for the appearance of the black band.

Lastly, let the selenite be fixed at 45° from the zero point, and
the analyzer rotated. We have now a combination of the two
previous experiments. The band in the red appears alternately
with the band in the green at each quarter revolution, the former
being at its maximum when the axes of the prisms are perpendicular,
the latter when these axes are parallel.*

* If the axis of the selenite makes a greater or less angle than 45° with the
plane of polarization, the result is that while the same band still recurs after 180°
of a revolution of the analyzer, the complementary band is no longer separated
from it by 90°, but by a greater or less angle,

Polarized Light through Double-refracting Crystals. 139

The above are the appearances which present themselves in the
case of most films of selenite of a medium thickness. In some cases
however, two, or even three, black bands occur simultaneously,
these being always followed by as many complementary bands,
when the analyzer is turned through 90°. The number of bands
can generally be multiplied by using two or more films in com-
bination, and the appearances can be still further varied by chang-
ing the degree of inclination of the axes of the two films to one
another. If the two films are placed with their similar axes coinci-
dent, we obtain of course the spectrum appropriate to a film equal
to the sum of the thicknesses of the two films, while, if dissimilar
axes are superposed, the spectrum is that due to the difference of
the same. I have two films which, when properly combined, give
no less than six well-marked bands simultaneously.

But the most striking of the phenomena presented by films
which give more than a single band, remains still to be noticed, wiz.
the motion of the bands along the length of the spectrum. This
can generally be easily seen by using two films in combination, and
properly adjusting their axes.

The following may be taken as an illustration of this experi-
ment, of which many varieties may be made. (Fig. 1, Plate XCY.)
Suppose the two films are so adjusted as to give two black bands,
one in the orange and one in the blue, which we may call @ and b
respectively. On rotating the analyzer, each band is seen to divide
into two halves. The right-hand half of band a runs along the
spectrum, and unites with the left-hand half of band b, which
advances to meet it, the two coalescing into a single band in the
green. At the same time that this has been going on, two entirely
new bands have made their appearance. These seem to originate
respectively beyond the visible rays at each end of the spectrum,
and to advance in opposite directions till they are met respectively
by the left-hand half of the original band a and the right-hand half
of the original band b. The result is, that when the analyzer has
been turned through 90°, we have a spectrum with three black
bands, one in the extreme red, one in the green, and one in the
indigo.

Continuing still further to turn the analyzer the above phenomena
are reversed. Each of the three bands split into two, moving in
the reverse of their former directions, until when 180° is reached
the original spectrum with its two bands recurs.

A curious variety of this experiment occurs when a circularly
polarizing film is imterposed between the analyzer and the film
producing the bands. The nature of the movements of the bands
is now entirely changed, the order of motion being all in the same
direction, and the bands appearing to chase one another along the
length of the spectrum, making their appearance at one end and

140 On. Spectra formed by the passage of

disappearing at the other. To produce this effect, the “band-
producing” film should be set with its neutral axis at 45°, and the
circularly polarizing film superposed with its neutral axis in the
plane of primitive polarization. If the axis of either film is turned
through 90°, the motion of the bands is reversed; ¢.¢. if the bands
formerly moved from left to right, they now move from right to
left. If the two films are both placed with their axes at 45° to
the plane of polarization, the only effect of the circularly polarizing
film is to alter the position of all the bands by a corresponding
amount (7.e. to increase or diminish their refrangibility), without
affecting the nature of their motions.*

A very pleasing and beautiful variety of the foregoing ex-
periments may be obtained by using a double-image prism as the
analyzer instead of the Nicol’s prism. Two spectra formed re-
spectively by the ordinary and extraordinary ray are thus obtained,
which by rotating the double-image prism may be made to lie
parallel to one another, or be partially superposed at pleasure, while
by turning the polarizing prism the spectra can be made of any
desired relative intensity. Suppose that we adjust the two prisms
with their axes at right angles, and interpose the selenite used in
the first experiment, which gave a band alternately in the red and
in the green, we get now two spectra parallel to one another, the
band in the red of the one occurring simultaneously with the band
in the green of the other. ‘The two bands are thus seen to be
strictly complementary, for the band in the red of the one spectrum
appears, attains its maximum, and vanishes simultaneously with
the similar changes of the band in the green of the other spectrum.
This coincident appearance of the bands, moreover, is independent
of the inclination of the axis of the selenite to the plane of
polarization, the only effect of a change in which is to increase or
diminish the maximum intensity of both bands alike, a result which,
as has been noticed, does not hold with regard to the alternation of
the two bands in the same spectrum.f (Fig. 2, Plate XCV.)

When the two prisms are placed with their axes parallel, so
that the two images of the slit are seen alongside one another, and
consequently the two spectra partially superposed and different
colours mixed, the appearance of the bands is very striking. A
band occurring in either spectrum is no longer black, but of the
colour of that part of the other spectrum which coincides with it.
The appearance is, in fact, as if a stripe had been cut out of the
one spectrum through which the colour of the other spectrum is
seen, while on either side of the band we have im striking contrast

* The effect of circularly polarizing the light before it passes through the
selenite, is simply that the occurrence of the bands is irrespective of the inclina-
tion of the axis of the selenite to the plane of primitive polarization, and depends
solely on the position of the analyzer.

+ See note on p. 158.

Polarized Light through Double-refracting Crystals. 141

the colours due to the compounding of the different parts of the
two spectra.

The beauty of the effect depends of course greatly on the
extent to which the double-image prism separates the two images.
It should be so cut that the compound colours caused by the over-
lapping of the spectra shall be as different as possible from either
of their constituent colours. The selenite should then be set at 45°,
so as to make the spectra of equal and the bands of maximum
intensity.

With films which give numerous bands the effect is very
beautiful, and may be still further enhanced by rotating the
polarizer, when the bands will shift their position, at the same time
changing their colours.

Eaperiments with Sections of Double-refracting Crystals giving
Colowred Rings.

The coloured rings produced when polarized light is transmitted
through a double-refracting crystal cut perpendicularly to its axis,
have always been admitted to be among the most beautiful of the
phenomena which the science of optics can produce.

When homogeneous light is used it is well known that the rings
assume entirely the colour of the light used, the spaces between
the coloured rings being black.

The splendour of the phenomena, however, obtained by the
use either of ordinary or of homogeneous light, is incomparably
inferior to that displayed by projecting the rings against the
spectrum. The spectrum microscope is admirably suited for this
exhibition.

The method I adopted was simply to place the section of the
crystal immediately over the eye lens of the microscope, and between
it and the analyzing prism.

The rings are thus seen of every colour in the spectrum, alter-
nating with jet-black rings between each, those in the red being
the broadest, and the breadth of the rings gradually diminishing to
the most refrangible end of the spectrum.

It is impossible to give any satisfactory idea of the appearances
by mere description, and no little skill or labour would be required
to paint any adequate representation of the effects seen im some of
the following combinations.

Take, as an example, a section of a crystal of sugar which
gives a very fine system of rings. (Fig. 38, Plate XCV.) I have
counted easily as many as forty-five when projected against the
spectrum. This crystal is one of those which gives in polarized
hight two black brushes, not a black cross like Iceland spar. When
the Nicol’s prisms are at right angles the brushes are at their

142 On Spectra formed by the passage of

maximum intensity, and the spectrum with its series of rings is
seen to be cut in two by the jet-black brushes. When the analyzer
is turned through 90° the brushes which would now, if seen by
ordinary polarized light, be white, are of every colour in the spec-
trum according to the part of it they fall upon, and shaded off at
their sides by a nebulous haze of colour through which the black
rings are visible.

“In intermediate positions of the analyzer the brushes become
entirely nebulous, so that the rings can be seen through their
whole extent. In this position of matters the circle appears divided
into four quadrants, and the rings are distinctly seen to be dis-
located so to speak, z.e. the rings in the alternate quadrants are
pushed out so that each coloured ring in the one quadrant is
continuous with a black ring in the next.

This effect is still better seen by circularly polarizing the light
before its passage through the crystal. (Fig. 4, Plate XCV.) The
effect of this is a curious one. Instead of the circle being divided
into four alternate quadrants, it is now divided into two semicircles,
the rings in the one being alternate with those in the other. The
semicircles are separated — by two narrow coloured brushes which
revolve with the analyzer, and seem as if they swept out the black
rings in the one segment to be replaced by the coloured rings of
the next. If we again circularly polarize the light by interposing a
second circularly polarizing plate between the crystal and the
analyzer, the brushes entirely disappear, and both the black and
the coloured rings are continuous throughout, forming perfect
circles,

When the analyzer is rotated through 90°, the centre of the
system which was formerly black is now coloured, and, at the same
time, all the black rings have exchanged places with the coloured
rings, the change being effected by a lateral displacement in opposite
directions of the two halves of the circle.

If for the second circularly polarizing film we substitute a film
of a different thickness, the rmgs assume curiously distorted forms.
With one film which I used the’ rings became ellipses, with another
they all united so as to form a circular helix, which appeared to
unwind like a screw as the analyzer was turned.

The appearances produced by using different crystals are of
course similar, mutatis mutandis.

By circularly polarizing the light before and after its passage
through a crystal of nitre (Fig. 5, Plate XCY.), the brushes are
wiped out, and the lemniscates are beautifully seen, unbroken
throughout,

When a crystal of Iceland spar is used, and the Nicol’s prisms
set with their axes inclined 45° we get eight segments, of which
the four light segments look as if they stood out in relief against

Polarized Light through Double-refracting Crystals. 143

the dark segments, while the sections of the black rings, especially
near the centre of the system, look more like straight lines than
circular arcs, and form a system of octagons.

The effect upon the rings, produced by placing on the stage a
film of selenite in the position in which it should give the black
bands previously described, is a strange one. Instead of a black
band occurring, the coloured ring belonging to that part of the
spectrum is seen to split into two. It sends off a branch as it were
from its lower part, which shoots across the adjoining black ring,
and joins itself with the lower part of the next coloured ring.
This last ring then in turn sends off a branch from its middle
part, which in like manner unites with a third ring, which in turn
does the same to its neighbour. All this takes place within the
space which should be occupied by the black band.

The beauty of these last experiments, wonderful as it is, may
be still further enhanced by the use of a double-image prism as the
analyzer. The result is analogous to that obtained with the same
arrangement in the case of the selenite previously described. We
now get not only two spectra, but two systems of rings, which, by
superposing the spectra, may be made to interlace with one another.
Wherever a black ring of the one spectrum crosses a black ring of
the other, the intersection is of course still black. Where a coloured
ring of the one system crosses a black ring of the other, it retains
its original colour ; but if a coloured ring crosses a coloured ring,
the intersection is of the resultant colour of the two combined.

Still more complex figures are got by employing two or more
crystals in combination.

Indeed, there is no end to the variety of exquisite beauty, both
in colour and in pattern, which a little ingenuity may produce.
Pigments would be almost as helpless as words in representing
many of these. The appearance produced by a single crystal with
a double-image prism as analyzer, may be not inaptly compared to
a tesselated pavement of every colour made for a fairy palace, while
that produced by combining two crystals may be said to resemble a
suit of chain armour wrought for a fairy king, in jewels of which no
we are of the same hue.—Read before the Royal Society of Edin-

urgh.

( 144 )

IV.—Remarks on some Parasites found on the Head of a Bat.
By R. L. Mappox, M.D.

Puate XCVI.

In the early part of the month of April was received from my friend
Dr. P. Davidson, Staff Surgeon, late of Royal Victoria Hospital,
Netley, the head of one of those strange creatures which have fur-
nished, in times long past, the pattern for the aéronautical addenda
to man’s mythical image of the “ Evil one.” See a plate in W. Young
Otley’s fine series, entitled ‘The Italian School of Design,’ published
1823, of part of a fresco by Giunta Pisano, of the thirteenth century,
in the church of St. Francisco at Assisi, on the high road between
Perugia and Foligno, dedicated to St. Francis, the founder of the
order of monks that pass by his name, where the sorcerer, Simon
Magus, is represented as being borne away by no less than seven of
these imps ; possibly his beautiful concubine Helena travelled by a
similar mode of transport, though on this we are not enlightened.
The wings, when compared to lke appendages furnished to the
saints, are noticed as very different in structure, as seen in the
colossal figures by Cimabue in the same church, and copied by Mr.
Otley in his valuable work. Now, it is curious to notice, the artist
in his design has given to the expansion of the interfemoral mem-
brane eight metacarpal and digital prolongations, whereas in the
usual figures of the bat in works on natural history we find only
five.

This “ unclean animal ” of the Hebrews—Attaleph—of the mam-
malian division, was placed in the forbidden list amongst birds: from
this, and being so active in the period of darkness, so anomalous in
the general appearance, so destructive in some countries, and so
strange in their habits and haunts, we may possibly find some
reason why this form of wing should have been engrafted on the

DESCRIPTION OF PLATE XCVI.

Fic. 1—A group of parasites, and the openings made by those detached.

» 2 and 3.—The dorsal and ventral aspect of two of the insects slightly com-

pressed, after remaining in glycerine and sweet spirit of nitre.

», 4.—The ventral aperture surrounded by wavy lines in the skin; there were

four hairs near, but these were not figured.

», 9.—A torn part of the skin showing the wavy lines, also the inner surface and

some muscular (?) trabeculee.

», 6.—The third leg with the plumose hairs and the trifid claw.

» 7—The buecal apparatus more highly magnified.

» 8.—Two of the openings in the dermis where the insects had been attached,
showing the thickening resulting from the irritation, and a well-
marked bundle of nerves, * *.

9.—The single minute insect found with Figs. 2 and 3, but free and amongst
the hairs (? immature male).
», 10, 11.—The two inferior maxille. Fig. 10, side view of the left one; Fig. 11,
view of the right one as seen from above, in the natural closed position
when the insect is forcibly removed from the skin.

1000. x 430

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Remarks on some Parasites found on the Head of a Bat. 145

figure of Satan. The head sent belonged, I believe, to Vespertzllio
prpistrellus, of the European species of Vespertillionide, a series of
creatures that even still, in the minds of the vulgar, continue to
inspire a singular dread, from superstitious feelings about the blood-
sucking propensities of the vampire. Though fruit and insect
feeders, the latter do not object in confinement to the dainties of
raw meat. Hxamining this head carefully, which had travelled
from Scotland, numerous small insects were found attached to the
basal portion of the ears internally, and to one of the earlets. Two
or three of these little parasites showed signs of life when touched ;
they were of a light fuscous colour, with dark irregular patches, and
one darker than the rest, that passed down the body in a some-
what wavy manner; they were grouped at the feast in batches,
almost mouth to mouth, one batch containing upwards of twenty
(vide Fig. 1), others numbering fewer, and one only five.
Unfortunately, being at the time pre-occupied, it became a
serious question how best to preserve the head for future observation.
The ears and earlets were cut off at the base, and divided near those
parts showing the presence of the parasites; the head and other
parts of the ears were placed in Verril’s solution, A, and the portions
with the insects in two small bottles, one with glycerine and sweet
spirit of nitre, equal parts; the other, in rectified spirit and acetic
acid, equal parts, and set aside. They were not looked at until the
end of July when the specimens were found in each in good condition.
For closer examination several of the parasites were detached from
the skin by means of force, and the deposit in the liquid employed,
carefully observed for any that might have detached themselves ;
but only two were thus found. The insects, seeing they were all
hexapods, were at first taken for some of the Ixodide, the “ degraded
diptera,” as Dr. Duncan calls them, in his ‘ Transformations of
Insects,’ that form the “connecting link between the true insect,
the spider, and the mite.” A nearer study of them has led to
the following remarks, which I feel some hesitation in offering to
the readers of the Journal of the Society, seeing I cannot find a
satisfactory clue to the different stages of life, nor indeed, in any of
the books at my command, the correct name of the insect or rather
insects, for there are two figured in the Plate. ‘The average size of
those in the group may be fixed at the 58th of an inch. The body
is thick, somewhat oblong in shape, truncated at the anterior part,
divided by three fine transverse lines or divisions, and presents a
few rows of stiff plumose hairs, set on the back, sides, and poste-
riorly: it has the appearance of being filled with dense irregularly
granular and fatty matter, besides the dark band of recent nutriment
before alluded to. When pressed, the body is found to be rugose,
and covered with wavy lines as in the palm of the hand, and beauti-
fully seen in many of the Acaride. No eyes were seen that could

146 Remarks on some Parasites

be satisfactorily claimed as such. ‘The head is very much depressed
—if head it can be called—is somewhat of a pentagonal figure, the
two stout chelicerze forming four of the sides (the apex projects as
a double point), the base or remaining side being made by the attach-
ment to the body (vide Figs. 1, 2). The ‘instrumenta cibaria ”
(Fig. 7) are placed within a sort of neck, like the top of a tied
sack; the labrum appears to consist of a thin chitinous plate united
posteriorly to the cervico-thoracic ring, and in the middle on the
under surface, to two long stylous processes, a1, connected with
the maxille a, situated either side of the median line, and laterally
to the basal jomt of the chelicere. It overlies a complicated
framework that forms or supports the maxille, and that branches
backwards by two curved processes, to be apparently hinged
to two incurved processes arising from the thoracic attachment.
The middle portion of this framework looks to be enfolded inter-
nally, and to be connected to two stout inwardly-curved parts, a,
strongly tipped with chitine at the ends, and supporting on the:
anterior and outer portions a feathery bristle—which pieces taken
together may probably be said to form the labrum, superior maxille,
and maxillary palpi, a1, a,b. Beneath are two portions, e, form-
ing the basal joints that support each a stout curved tooth, slightly
indented (Figs. 10, 11). In the natural position they are placed
side to side; but when in action cut or tear horizontally, and repre-
sent the inferior maxille: applied together and with the inner
portions of the upper maxill, they form a more or less perfect suc-
torial tubular cavity; situated laterally and strongly attached to
the cephalic framework at their bases are two stout conical che-
liceree, four jomted, and supporting a long"bifid tooth or claw, ec,
having at its base on the inner side a compound feathery brush, d.
The inferior lip seems to consist of a thinnish chitinous membrane
that unites these parts inferiorily and laterally, to which is attached
what appears to be a saccular eversion of the ligua or pharynx under
compression, as in the example from which the figure was taken,
almost the whole of the granular contents of the abdominal cavity
were ejected through the mouth from the pressure. This ligua (?)
has two conical processes (? glandular) and a circular opening, f.
At the cervico-thoracic junction on the upper surface, behind, is a
thin chitinous plate with a waved or curved outline, supporting three
fine hairs on the front and four near the back edge, the two lower
central ones beg much larger than the others, (?) ocellar at the
base; though more laterally on the same line are seen two some-
what opaquish oval projections, which may be visual organs, and
beyond these on the same sweep of curvature, two equal if not a
trifle larger areas than the central ones are visible, which are sus-
_ pected to be tracheal orifices. The laxity of the tissues after the
use of liquor potassz, and the great displacement that occurs in

found on the Head of a Bat. 147

neighbouring parts from slight compression, almost prevent the
possibility of assigning to each the proper position; while in the
natural state, being often covered with exudation from the wound
and filled with dense grumous matter, exactitude in the description
is by no means easy. At Fig. 3 is given the ventral aspect of
another insect and the mode of attachment of the legs: one, the
hind leg, is shown at Fig. 6; it is furnished with numerous stiff
and branched hairs; the tarsus, which is longer than in the other
legs, terminates, as each one does, in three claws, the outer two
uncine being expanded, stronger, and more curved than the middle
or long one. The ventral aperture is shown in Fig. 4. In Fig. 5
is depicted a portion of the dermic tissue of the saccular body, dupli-
cated at one part, and also showing the inner surface, to which can
be seen attached five (?) muscular bands,* stretching between the
surfaces. No transverse striaze were seen on these bands, but they
are supposed to be muscular in action.

This description differs in several particulars from the small
hexapod mite, 1mm. in length, the Argas pipistrelle, found
attached to the body of the bat, and described by Lucas in his
‘Cours Complet d’Histoire Naturelle, tome xii., p. 483, but bor-
rowed from M. Audouin’s observations, the tarsi terminating in
two small hooks, &c. Not finding any satisfactory description of
this insect I felt much puzzled whether these mites shovld be
considered as belonging to the “ degraded diptera,” or whether they
were merely the larval form of some psoreptes, or itch mite.
Accordingly, considerable time was spent in looking for more
advanced specimens, as the whole of those grouped together
appeared to belong to only one sex, and were possibly the early
stage of some well-known form. After much patience I was
rewarded by finding among the hairs, one, and only one specimen,
very much smaller, differing greatly in appearance from the rest,
and approaching more nearly the character of the male itch insect.
Yet on higher magnifying, it was seen to differ considerably (vide
Fig. 9). Its size is about 165th of an imch. The dermic tissue is
plain, or shows no transverse lines. Six of the legs are provided
with a small disk ; the other two of the hind legs (for in all they are
eight in number) consist apparently of two long joints, one being
setigerous; their position, distant from the anterior pairs, 1s similar
to the itch mite—possibly an immature male—though in the male
itch insects I have examined, if I remember correctly, the outer
hind legs are provided with bristles, the inner with disks, which is
the reverse in the insect under consideration. Looking at these
points, and not knowing whether the single insect had any relation
to the rest, under present circumstances it will, it is thought, be
better to leave the matter open, as to their position in the family
of Arachnide.

148 Remarks on some Parasites

It must not be lost sight of, that amongst some fifty insects
found on the two ears, we can scarcely suppose some of them
should not be mature, if they belonged to the family of Acarea.
This view led me to seek carefully for some ova beneath the skin,
or the shells attached to the hairs; yet nothing was found beyond
portions of the inflammatory exudation carried up by the young
hairs, or adherent where the hairs had touched the irritated sur-
faces; nor was any trace of an ovum found in the bodies of those
cut open or crushed under the dissecting microscope ; though in the
mass of granular matter, four small nuclear-looking and granular
masses, larger and more firm than the rest of the large granules,
were found, two on opposite sides of the lower half of the abdomen,
but what they were it was impossible to say correctly. If the
foregoing view be correct, amongst some of the ova we may expect
the male to be reproduced. Again, we have no evidence they were
not, in the full sense of the word, adventitious—just passing one
part of their lives in a luxurious feast; yet, if they belong to the
Ixodex, may we not suppose either that one or more females at-
tached themselves to the bat, and then gave birth to the colonies,
for they are described as depositing or producing by a continuous
pont of many days, upwards of a thousand glutinous eggs(?). Yet
the gestative state of the Ixodes is said to be continued by the insect
detaching itself and falling to the ground for completion; so this
hardly admits of its performance on the bat.

The singularly peculiar, if not almost unique character of the
generative act of the Ixodide, described by Professor Gené, of
Milan, and translated in abstract by Mr. A. Tulk, in the ‘ Annals
and Magazine of Natural History,’ vol. xvii., to which I beg
reference for those interested in the history of these minute
creatures, and which will amply repay a perusal, I can only in
part quote here. In brief it may be stated, the male inserts its
rostrum into the orifice, situated upon the middle of the sternum,
between the coxee of the last pair of legs. Mr. Tulk points out
the “very striking relation, if only approximative in kind, between
the organ employed by the male Ixodes to copulate with the female,
and the palpi as ministering to similar uses in the Araneides, or true
spiders.” That the female afterwards depresses upon the sternum
all the palpi that compose the rostrum, when there is seen to be
“ protruded from the duo-cephalic plate, a turgid vesicle,” terminated
by two lobes, “-vesica biloba,” having at the apex a most minute
aperture. ‘ When this organ has been well dilated, so as to pass
beyond the rostral palpi, the animal erects the pectoral canal, and
gives exit to the oviduct,” and “proceeds at once to disemburden
itself, between the lobes of the vesica. ‘This clasps, compresses,
and appears as if sucking the oviduct for a few seconds ; but often
the oviduct is retracted, and re-enters the sternum, leaving an egg

found on the Head of a Bat. 149

between the lobes of the vesicle, which clasps it firmly, turning it
to and fro in all directions, and vibrating now and then in a
spasmodic manner. Four or five minutes having elapsed, during
which time the ovum remains between its lobes, the vesicle dis-
appears by re-entering its internal situation. The ovum is left
upon the inferior labrum, and this being elevated, along with all
the palpi that compose the rostrum, thrusts the ovum upon the
duo-cephalic plate, or in front of the body—these acts being
renewed for as many ova as the female may have to discharge.”
A series of very interesting experiments made by Professor Gené
are then related, bearing upon the correctness of the foregoing.

Before drawing this lengthy article to a conclusion, it is neces-
sary not to omit noticing that the parasites of the bat’s ear prefer
the inner surface, where the hairs are fewest and the glands most
numerous. They collect in companies (vide Fig. 1, where twenty
are seen, and seven apertures made through the dermis left by the
detached insects). This figure represents a very hungry lot, and
they generally, so far as could be judged, seek those parts of the
inner surface of the ear that are well provided with nerves; a
nerve bundle is shown at **. Moreover, they appear to prefer
to use the aperture through which the hair protrudes, than to be
at the trouble of tearmg one open. ‘They seem to fix themselves
much in the same way as the tick to one spot, and by their pre-
sence cause a considerable amount of mischief, inducing much con-
gestion and thickening of the tissues beneath. Two such apertures
are represented more highly magnified at Fig. 8, one having a
minute hole at *; the other, ***, showed no such opening. ‘The
hair follicle and sebaceous glands appear totally destroyed in most
of the openings; the cartilaginous tissue seemed to suffer only
shghtly; the vessels looked enlarged; a large nerve bundle is
seen at **,**, Jn these examinations the skin was dissected off
both sides of the cartilage, to obtain the necessary transparency ;
portions were subjected to various reagents, and showed that the
ear of the bat seems almost in its amount of nerves, &c., to rival its
wing, described in abstract in the June number of the Society’s
Journal, p. 272, from Dr. Joseph Schobl’s most interesting obser-
vations. However, it would be only in recent and injected speci-
mens any attempt could be satisfactorily made in the examination
of these organs. The incompleteness of this paper is regretted,
but it is hoped sufficient has been stated to induce other observers,
when opportunity offers, to give us the benefits of a more extended
examination.

(oeio0°\")

V.—Note on the Resolution of Amphiplewra pellucida by a Tolles’s

Invmersion 1th.
By Assistant-Surgeon J. J. Woopwarp, U. 8. Army.

In my paper on the use of the Nobert’s plate, written in April
last, and published in the July number of this Journal, I found
myself compelled to make a few remarks on the objectives of Mr.
Tolles, of Boston. While complimenting this maker on his excel-
lent workmanship, I felt constrained to say that I had not found
that his objectives excelled those of like powers by other first-class
makers.

Late in June of the present year, however, I received from Mr.
Tolles a 3th, the performance of which is so remarkable that I take
pleasure in drawing attention to it.

This objective is so made as to work either dry or immersion,
and it is of its performance when used wet that I desire to speak.
Its magnifying power at 48 inches distance between micrometer and
screen (without an eye-piece) is 250 diameters when corrected for
immersion uncovered, 275 diameters when corrected for the thickest
cover through which it will work. It is therefore of rather higher
power than a 3th, but less than a 1th.

Now, with this objective I find no difficulty in resolving Am-
phiplewra pellucida, the objective successfully displaying the trans-
verse striz on all but the most minute and difficult frustules.

To illustrate the character of the performance, I send you here-
with two positives on glass from negatives taken by this }th.*

The first shows two frustules magnified 256 diameters. It is
of course necessary to use a lens, or a low power of the compound
microscope, to see the striz, which will be found to be quite sharp.

The second shows the same two frustules magnified 920 dia-
meters. ‘The strize can be seen with the naked eye, still better with
a lens.

I send no paper prints of these negatives, because, on account
of the fineness of the striz, as seen with the above powers, they
would not be satisfactory.

I add, however, a third positive, representing the same frustules
magnified 1140 diameters by the immersion 74th of Powell and
Lealand.

This picture certainly shows that the new 3th cannot be claimed
to supersede the highest powers at present in use, yet nevertheless
is not, in my opinion, injurious to the 4th, for it must be mentioned
that the immersion sth of Powell and Lealand, with which this
picture was taken, magnifies at 48 inches distance, without an eye-

* The photographs are admirable, They are at the Society’s rooms, where
they may be seen.—Ep, ‘M. M. J,’

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Miero-ruling on Glass and Steel. 151

piece, 900 diameters when used wncovered, and 1100 when used
covered ; and it is certainly highly creditable to an objective of so
much lower power to be capable of resolving so difficult a test as the
Amphipleura.

From this performance I expected that the new 3th would at
least resolve the sixteenth band of the Nobert’s plate; but in this I
have hitherto been unsuccessful, getting indeed handsomely through
the fifteenth band with it, but no further. Now, as the objective
resolved Amphipleura frustules with striz as fine as 96 to the
yovoth of an inch, I can only account for this circumstance by
supposing a greater difficulty in the case of strize of equal fineness
on the plate, as compared with Amphipleura. This circumstance,
which had previously escaped my notice, I have since confirmed by
comparison with a number of different objectives.

In conclusion, I beg you to show the photograph accompanying
this note to any of your readers who may take an interest in the
performance of objectives of moderate power. I should be very
happy to hear from them how this result compares with the work
of the best modern English 3ths, particularly as I have access at
present to no English glass of this power constructed within the
last two years.

V1.—Mero-ruling on Glass and Steel. By Joun F’. SranisTREET,
F.R.A.S. With Illustrative Remarks by Henry J. Stack,
F.G.S., Sec. R.MS.

Puate XCVILI.

By the kindness of John F. Stanistreet, Esq., F.R.A.S., of Liver-
pool, I have lately been able to examine some very beautiful speci-
mens of ruling on glass, and also on steel, executed by him with a
machine of his own contrivance and making, of which some par-
ticulars are subjoined.

The first specimen which I received was a star exquisitely ruled
on a small circle of covering glass (74," diameter), and it cannot
be better described than in Mr. Stanistreet’s own words :—“ The
mounted disk, which I herewith enclose, has a star of 50 rays, or
bands of lines, placed radially, each band consisting of 26 lines
ruled parallel and equidistant, the s;'5oth of an inch apart. The
star therefore contains 1300 of such lines. ‘The lines are pur-
posely scored very strongly to increase the intensity of the diffrac-
tion spectra, as I find that lines very much finer and closer (which
are just as easy to rule up to about 10,000 to an inch) are not so
effective for this purpose.”

Some beautiful diffraction spectra can be obtained with this star,

VOL. VI. M

152 Micro-ruling on Glass and Steel.

but to the microscopist it is instructive from the various perspective
appearances it presents. From the principle on which it is ruled
the lines composing each ray proceed for some distance before
coming in contact with the lines belonging to adjacent rays, as
shown in Fig. 1, Pl. XCVII. Each ray, at its peripheral end, com-
mences with what looks like a sharply-cut dot, the first impact of
the diamond point with the glass, and the lines composing each ray
gradually diminish in length, giving the wedge-shape shown in the
figure. When the star is viewed with a low power (say 3”), with
dark-ground illumination, the optical effect of the rows of bright
dots, with which the lines commence, is to suggest that each ray
stands up from the general plane of the glass, that all look like a
number of spokes of a fan placed, more or less, vertically on the
table. A higher power (3rds) makes this more striking, as in
Fig. 2. The position of each ray, with reference to the angle
at which a light strikes it, determines how much it slopes either
right or left of the vertical plane, and one or two rays will
appear nearly in that plane. Keeping the illuminating apparatus
stationary, and revolving the stage, causes the apparent slope of
each ray to vary, and if any pair of rays be selected for particular
observation, they will be seen to undergo curious apparent changes
of position. At one point of the stage rotation it will appear as
if the eye beheld the outsede of one ray and the znside of its neigh-
bour, while at another point the appearance will be reversed, and it
will look as if the outside of the first and the inside of the second
had come into view. If the object is then moved so that the wedge-
shaped ends of the rays are thrown out of field, the eye is somewhat
tempted to consider adjacent rays as not quite in the same plane, but
the striking illusion just described has disappeared.

After proceeding separately for some distance, the rays com-
mence their contact, and the intersections of the several lines com-
posing them produce a secondary star, with finely-pointed rays,
gradually broadening towards their bases. It is easy to illuminate
these secondary rays so as to make this star appear in a plane
higher than that of the primary star, and to give an appearance of
solidity to each ray.

Near the centre of the star, where the rays meet, the aspect is
beautifully watered and the lustre is silvery, or delicately iridescent,
according to the illumination. In the centre is a clear space, and
this has the aspect of a deep hole, an appearance much assisted by
the curvature of the lines as they come to the point.

The appearance of concentric scorings seen on the secondary
star arises from intersections. It is striking with powers under
4 inch, but with 4 inch and upwards they grow fainter, and dis-
appear in a conflict of cuts.

Not to enlarge further on this particular star, it will be seen

Miero-ruling on Glass and Steel. 153

that in addition to being an object of great beauty it throws light
upon causes of deceptive appearances, which may usefully warn us
against errors of interpretation.

A simpler glass ruling shows the tendency of the eye to be best
satisfied with such a mode of focussing and illuminating intersect-
ing lines as gives the aspect of one set being above or below the
other. When the lines are smoothly cut, there is also a tendency
to prefer that mode of viewing them which gives the aspect of solid
threads raised above the surface. The smoothest cuts preserve this
character, more or less, with high powers; and as I have shown in

_a former paper, the very smooth cracks of silica films are exceed-
ingly deceptive.

In a glass star of another description, I find bands of converging
lines in alternate sets with parallel lines. There are 12 bands
of 20 parallel lines each, in each of 10 rays, besides 25 radial lines.
“Thus,” as Mr. Stanistreet says, “the intersections are extremely
numerous.” The twelve bands of parallel lines prevent the appear-
ance, described in the first star, of a number of spokes of a fan
composed of numerous silver wires, and arranged more or less
vertically. These fan-spokes are crossed by the radial lines, and
with dark-ground illumination it is easy to show the latter as dis-
tinctly overlying the fan-spoke lines. It is also easy to get an
opposite appearance in some parts of the same field, and to see the
fan-spokes raised above the radial lines. It should be mentioned
that the radial lines are far apart as compared with the close bands
that form the fan-spokes. If this object were a great deal smaller,
and nothing known of its real structure, the difficulty of interpret-
ing the optical appearances would be great.

In a star composed entirely of closely radial lines, those which
catch the most brilliant light appear to stand above the rest.

Having suggested to Mr. Stanistreet that beautiful and curious
effects might be expected from applying his ruling apparatus and
remarkable skill to steel, I soon received from him an exquisite star,
much like the one first mentioned, on glass. This star is composed
of ‘50 radial bands of 40 parallel lines in each band ;” the general
pattern being like Fig. 1.

Held in a bright light this star exhibits a very elegant appearance
of watered silk, with delicate prismatic tints. Under the microscope,
with 3 or 4 inch power and illumination with a silver reflector, the
star appears as if suspended in a dark atmosphere, or in a bright
one, according to the angle at which the light strikes the bright por-
tions of the steel. When these portions throw the light they receive,
out of the field, the former is the case, and the latter when they send
it to the eye. When nicely illuminated each ray gleams with delicate
iridescent tints, and the secondary star produced by the intersecting
lines can be made to look distinct from the primary star, or as if it

M 2

154 Micro-ruling on Glass and Steel.

were formed by the fan-spokes of the primary having the shape
Shown in Fig. 3, where each secondary spoke shows a knife edge near
its outer margin, which thickens when the intersections begin, and
broadens towards the centre of the disk. The transverse or nearly
concentric markings arising from intersections are more striking
than in the glass star, and exhibit an iridescence differing from that
of adjacent parts.

The primary and secondary stars are easily made to look semi-
transparent, as if those parts where the lines are thickest were com-
posed of extremely fine silver gauze.

The most remarkable work which I have seen of Mr. Stanistreet’s,
is a star on steel, about half an inch in diameter, displaying 10 rays,
each consisting of 12* bands of 40 lines each, making 4800 lines.
Each ray has what Mr. Stanistreet calls a “serried edge” (as shown
in Fig. 4), caused by the diamond point commencing each stroke a
very little nearer to the centre, and so on in each band of 40 parallel
lines. Then the next band of 40 lines is commenced at an angle of
1° 26’ 24” from the preceding band, and ruled in like manner
towards the centre of the star, and so in each of the twelve bands
which constitute one ray of the star. These bands of parallel lines,
by their mutual intersection at the above angle, give the wavy, or
watered-silk pattern crossing each stellar ray, of which there are 10.
In addition to the lines of the highly complex rays, there are groups
of radial lines between each pair of rays, 250 im all. These radial
lines, added to the 4800 parallel lines, make a total of 5050 lines in
the whole pattern. The highly complex character of this star, the
closeness of the lines composing the bands, and the very numerous
intersections, give rise to very remarkable optical effects. Lit up
with a silver reflector, the bands all stand up more or less vertically ;
the upper surface of these bands, or what seems such, is exquisitely
watered when seen with a 35-inch objective, and the transverse bands
produced at recurring distances by multitudinous intersections, look
irregularly raised above the general surface, and the whole seems a
fine tissue of glass threads, more or less iridescent. ‘The secondary
star produced by intersection is very striking in this specimen,
and where two secondary rays intersect, a tertiary one will be seen.
If a group of the radial lines is observed near the circumference of
the star, they all look in one horizontal plane ; but where they inter-
sect the lines of the bands they look above or below, according to
position and angle of illumination.

With a power of 3rds and the useful vertical illuminator devised
by the late Joseph Beck, the view which best satisfies the eye repre-
sents the lines as solid threads one under the other when simple,
intersection takes place, and a tendency is created to view the spots of
complicated intersection as higher than the rest. With a power of 3th

* By accident the engraver has made 18 bands instead of 12.

Miecro-ruling on Glass and Steel. 155

and Powell and Lealand’s modification of Professor Smith’s vertical
illuminator for high powers, the complex portions of the pattern are
resolved, but with decided suggestion that the cuts are elevations, or
threads laid upon a semi-transparent surface like white porcelain.

There is an advantage in studying the appearances that can be
obtained with objects of this description, because the illusions can be
corrected by higher powers and various modes of managing the
light. They suggest causes of misinterpretation, and may thus
prevent mistake, and the objects which are of great beauty illus-
trate a variety of diffraction effects.

On showing Mr. Stanistreet’s exquisite work to several friends
well acquainted with delicate mechanical operations, the remark has
uniformly been, He must have costly and complicated apparatus to
produce such results; but in reply to my inquiries, he writes, “ My
little ruling machine is a very homely and inexpensive affair, having
been planned by myself, and constructed entirely by my own hands
of such materials as came within my reach—crinoline wire, broken
watch-springs, copper coins, and the heads of carpet pins, with some
pieces of brass and steel, forming the entire structure.’ He adds
that “ the machine consists essentially of two separate parts: the first
for giving equable motion to a minute fragment of diamond ‘ bort’
set in the cleft of a piece of softened brass wire. This point is
moved by a very fine steel screw of 100 threads per inch, which I
made as perfect as my means admitted, and it moves the diamond
through the agency of a simple lever z,455th of an inch for each entire
rotation of the screw.”

“The disk of glass to be engraved is suspended over the diamond |
by a spring (crinoline wire), and is made to move across it by a
revolving coin—a penny-piece, having an inclined plane of thin
brass soldered to one-half its cireumference—and this, when rotated,
raises and develops the glass disk very gently, drawing it across
the diamond through a space limited by adjusting screws, letting
down the glass very gently and lifting it off suddenly at the end of
each half revolution of the coin.”

Mr. Stanistreet works very quickly with this machine. He is
able to rule 100 parallel lines from 1—1000” to 1—10000" apart
in one minute of time, but, as may be supposed, does not attempt
very delicate work at sucha pace. The complicated star last
described—an exquisite specimen of delicacy and skill—occupied
three hours and twenty minutes, which seems a short period for
such a number of lines and so complicated a pattern.

T should add that the preceding description applies to the machine
as first made. Before the specimens described were ruled, an addition
was made to the apparatus with a more delicate means of motion
than the screw. I am informed it would require accurate drawings
to make the structure intelligible. Mr. Stanistreet informs me that

156 The Fungoid Origin of Disease,

his last addition “enables him to rule lines at any required angle
with the line of movement given to the diamond point; so that,
assuming the latter to move—as in my machine—1 in 1000" for each
rotation of the leading screw, I can rule lines closer to each other in
the relation of the cosine of the angle from a perpendicular to the
path of the diamond.”

The glass or steel disk is rotated through any azimuth angle by —
means of a “ worm-wheel” and endless screw.

In a note received after the preceding remarks were written,
Mr. Stanistreet says, “I think I ought to mention a fact connected
with the last specimen that I sent you. After completing the ten
rays of the star I went on ruling another ray, supposing that I had
still one to do, and I had ruled ¢hvee supernumerary lines before my
eye caught the index which told me that I had completed the cir-
cumference. I expect that the work would be marred by this
excess, but on removing it from the machine I was unable to per-
ceive any trace of irregularity, and it was only under the microscope
that I found the three supernumerary lines occupying almost
exactiy the site of the three first lines.” The error is of no prac-
tical value; it would escape all ordinary notice, and serves to show
the accuracy of the apparatus.

Mr. Stanistreet speaks most modestly of his machine, and of his
work, as if it were easy. We may congratulate him on such a
happy imperviousness to difficulty, and wish his further labours all
SUCCESS. '

VII.—The Fungoid Origin of Disease, and Spontaneous Generation.
By Jasez Hoae, Hon. Sec. R.M.LS.

In the report of the medical officer of the Privy Council just issued,
the origin and pathology of contagion is ably discussed, and the
crude hypothesis of Haller bearing upon this point, who, it will be
remembered, sought to prove that the microzymes and sporules of
fungi which he found in the fluids of persons affected with cholera
caused the disease and explained its contagious nature, is finally
disposed of. This vexed question, one of no small importance to the

ublic, and of great interest for the medical profession, receives at
the hands of Dr. Sanderson, the writer of this part of the report,
all the care and attention it really deserves. His experiments and
investigations fully bear out all I have stated on this subject, and
conclusively show that neither bacteria nor microzymes are con-
cerned in the production of any specific form of disease in the
living animal body, and therefore when found must be looked upon
as an indication of a putrefactive process occurring after death. A

and Spontaneous Generation. 157

drop of water, a glass slide, or even a finger coming into contact with
a fiuid or tissue under examination, is quite sufficient to cause the
development of either bacteria or microzymes, in an incredibly short
space of time. In this way a disturbing element is introduced
which mars and mystifies the most carefully made investigations of
the histologist.

Admitting that the spores of fungi are always present in the
atmosphere, although at some periods not in very great multitudes,
it by no means follows, nor can it be shown that they are the cause
of any specific form of disease. And, if it be true that so slight a
contamination as that spoken of by Dr. Sanderson when brought
into contact with a fluid is sufficient to change its character and
start organic germs into life, then experiments said to prove that
living matter can begin de novo in solutions subjected to long boil-
ing must be accepted with extreme caution. For who can under-
take to say with any degree of certainty that the breaking of a
becker, in which a vacuum has been produced, can be conducted
with sufficient care to prevent the possibility of a rush of air,
carrying with it some organic particles, which shall contaminate
or impregnate the whole? This, a point of the utmost importance,
has not received much attention, although it is sufficient to embar-
rass and confound the results arrived at in the investigations of
Dr. Bastian.

The ingenious way in which it is sought to explain experiments
made by submitting a solution to a temperature of 160° F., alleged
to be sufficient to destroy all evidence of life, while in another sub-
jected to a much greater heat, ranging from 260° to 302° F.,
living creatures have reappeared, is by no means satisfactory. This
admits of a different explanation, which will at once suggest itself
to those who have thought over the phenomenon. Neither does it
prove that because the elements of non-living matter are known to
group themselves anew, so as to produce living matter under the
influence of those physical forces which are concerned in bringing
about the growth of a plant; that the same forces can be made to
combine by long boiling to reproduce life or reconstruct the disinte-
grated particles of dead matter, and convert them into higher organisms
than had previously existed. It seems to me impossible to attempt
in this manner the settlement of a point of so much importance as
that of the origin of life. And since we cannot undertake to say
with anything like certainty that we have succeeded in destroying
every living germ in any experiment we may institute, then, I fear,
the spontaneous generation hypothesis is hardly worthy of further
serious consideration. But with regard to Dr. Sanderson’s investi-
gations of certain contagious forms of disease, he produces positive
evidence that nothing like bacteria or microzymes can be discovered
in the blood of persons affected with scarlatina. This is an important

158 The Fungoid Origin of Disease,

and interesting fact, one very suggestive as to the cause of particular
forms of disease, and seeming to lead to the conclusion that contagious
affections are produced by a putrefactive change, a contamination
introduced from without into the circulation.

From whatever stand-point we view the important question of
contagion, or the origin of life, I am quite sure it will ultimately
end in a gain to our scientific knowledge; and as every additional
contribution will I am sure be acceptable, I shall offer no apology
for introducing a very interesting letter, written by Henry J.
Carter, F.R.S., some four or five years ago, as a criticism on a paper
of mine which appeared in the ‘ Intellectual Observer,’ “ On Phases
in the Developmental History of Infusorial Life,’ a great portion
of which is quite pertinent to the question under review at this
moment,

BUDLEIGH SALTERTON, DEvonsHIRE, March 14th, 1867.

My pear Si,—I do not yet believe in spontaneous generation,
nor will the theory, if ever substantiated, be so until a knowledge of
the ultimate forms of the phenomena called “life” is obtained; while
it seems to me that we are as far from this as from the ultimate atoms
of matter.

When we see, under the microscope, insect forms almost as small as
the smallest animalcules, and know, from inference, how complicated
their structure must be; when we find their limbs as transparent as
glass, and thus, apparently, as structureless, yet know that there is
structure even in glass.

When we find that there is no extent to the slowness of change of
form and movement in organized matter, that with the highest magni-
fying power possessed we can limit; that even unmelted iron is said to
flow : when, on the other hand, the power of determining the velocity
of bodies diminishes with the magnifying power, so that distance and
magnitude itself are required to make us sensible of the rate at which
comets travel, even if not of the presence of the atoms of matter en
masse which form their nebulosities, so that neither one nor the other
could be seen if close to us, any more than electricity or uncondensed
steam.

When, I repeat, our perceptions in these respects remain so finite,
how can anyone come forward with the assertion that there is such a
thing as “spontaneous generation,” based upon the presence of ani-
malcules which, produced under any circumstances, may be, and pro-
bably are, far more complicated in their structure, and therefore higher
in the scale of organic development, than a host of living beings with
whose forms even we have as yet no means of becoming cognizant?

Progressive knowledge may lead the human mind to the beginning
of vitality, to the quickening power of matter and its processes, but
until this is reached, it seems to me premature to assume as a fact
that there is such a power as spontaneous generation.

With reference to the next point in your paper, the transformation
of the protoplasm of the vegetable cell into ameeboid forms, who shall

and Spontaneous Generation. 159

limit the extent to which such forms may not penetrate into and live
passively in the protoplasm of both animal and vegetable cells, until
a favourable opportunity arrives for their further development ? I, of
course, include in the amceboid forms, the Myxogostres, now called by
Du Bary “ Myxozoa.” Just before leaving Bombay, I found the brown
stains in some cotton which was submitted to me for microscopical
examination, to arise from the development of a mycelium originating
in cells or germs of a mycetozoon, which were probably introduced
into the cell of the cotton fibre when fresh, and which, on the moisture
of the cotton during exposure to the rainy monsoon finding the vitality
of its host extinct, naturally appropriated its protoplasm, and produced,
while growing, the stains mentioned and consequent injury to the
staple.

I am glad that we are at one accord as to the origin of protozoa in
the cells of organized beings.

It appears to me that Dr. Hicks is in the same zone (so to write) of
investigation in this respect as I was before I renounced my opinion
of the “fancied” transformation of the vegetable protoplasm into
amoeboid animalcules. It was only after studying the mycelizoa fungi
that I began to see the unlimitable extent to which such beings com-
mencing their existence and even feeding themselves up to maturity,
might enter into, and develop themselves upon the remains of their
dead or dying host.

The contents of the root-like extremities, filamentous mycelium,
and pin-head-like capsules of the Mucoridee may issue, when their
cellulose covering is ruptured, in the form of amceboid cells (that is,
of course, as regards the sporidia before they are capsuled), and so creep
away. Then the Mucoride are closely allied to the Myxogostres or
Mycetozoa ; and here no doubt the protoplasm of the Mucor-cell or fila-
ment, &c., issues in amoeboid forms from its cellulose investment, which
seems to be, as in many other instances, secreted by, and common to,
a congeries of amceboid bodies, thus assuming the specific form of
Mucor.

But there is no “ transformation” here of the protoplasm, no perish-
ing. The ameeboid cells come forth at once and do not bore holes
through the cell-wall as the Mycetozoa family when developed in the
vegetable cell.

Hence, unless the protoplasm issues at once in an amceboid form,
or forms, as a whole, as from the cell of Gidogonium, &c., or in plu-
rality, as from the filaments and pin-head-like capsule of unmatured
sporidia in Mucor, &c., I should still be inclined to view the product
as not of the same, but of a different organism.

No doubt you saw the statement I last made of the probable repro-
ductive process by impregnation in the Rhizopoda in the xyth vol.
of the ‘ Annals,’ p. 172.

I found in a pair of Diflugia urceolata (Carter) in zygosis, when
crushed under the microscope, a number of monad-like monociliated,
polymorphic bodies in active movement; the usual nucleated celis
much larger; and apparently some of the latter which had become
polymorphic or amcebiform.

160 PROGRESS OF MICROSCOPICAL SCIENCE.

The origin of the nucleated cells I had not been able to ascertam—
that is, from what part of the Difflugia they come. That of the monad-
like bodies I knew to have come from the nucleus, which frequently
(under reproductive circumstances ?) breaks up into these bodies, and
therefore, in this case, was not present—had thus disappeared; while
the amceboid bodies without cilium seemed to be but a more advanced
state of the passive nucleated or ovi-like cells.

Thus I inferred that the small monociliated bodies coming from
the nucleus were the male elements, and the larger nucleated cells
the female elements, which, meeting together in the body of the
parent, were, in their plastic state, thus brought together at the most
favourable moment for impregnation, i.e. for the blending of the two
elements. While the active amceboid bodies without cilium might have
been the product after impregnation, thus prepared for independent
existence when the parent might choose to throw them off, or might
become effete and thus by dissolution allow them to escape into the
water.

I have much more that I could state to you on the subject, but
neither my leisure nor your patience, I fear, admits of the extension.
Sufficient however has been written to show you the amount of interest
I still take in these matters, and thus to prove to you how acceptable
was the copy of your paper.

I am, my dear Sir,

Yours very truly,

Henry Carter.

PROGRESS OF MICROSCOPICAL SCIENCE.

The Spectroscope in Microscopy.—T hose who are interested in this
peculiar department of the microscope will be interested in reading a
very useful paper on the subject in Max Schultze’s ‘ Archiv,* pub-
lished in May last. Messrs. Sorby and Browning have their earlier
labours very fully recognized by the author, Herr 8. Valentin.

The Anatomy of the Retina.—This is a subject which is taken up
by Herr Max Schultze, who has a new paper on the subject in the May
number of his ‘Archiv.’ It is illustrated by a very admirable plate,
and is of considerable length. This work also contains a paper on
micro-photography. It is illustrated by a couple of photographs, one
of blood, the other of bone, which however do not reflect very much
credit on the photographer, being in no way to be compared with Col.
Woodward's efforts.

The Embryology of Scorpions—One of the finest memoirs that
have for years been published on this subject is the splendid essay

* 7 Band, 3 Heft.

NOTES AND MEMORANDA. 161

of Dr. Elias Metschnikoff on this subject. It fills nearly 40 pages
of Siebold and Koélliker’s ‘ Zeitschrift,* and is illustrated by four ad-
mirably choice plates. The development of the scorpion has been
pursued from the very earliest stage of the ovum through all the series
of changes by which it reaches the adult condition. ‘These are very
many in number, and deserve to be carefully studied by those interested
in these animals.

Mitraria and Actinotrocha—The above author has contributed
also to the same journal as the above, a very valuable paper on these
two species. He goes into the question of their development, and
affords a very excellent plate in illustration. It is quite out of our
power to produce such plates as these in this country.

Development of the Radiolaria.—Dr. W. Donitz gives an excellent
paper on this subject in the ‘Archiv fiir Anatomie.t The plate
illustrating the author’s remarks has been very carefully drawn.

Structure of the Chorda dorsalis—A very long and important paper
on this subject will be found in the ‘ Zeitschrift fiir Medicin, &c.,t
by Wilhelm Miller. Indeed the whole number, which is a special
one, is by him, and it contains several very valuable contributions.

The Structure and Nature of Diatomacee.—This is an interesting
paper contributed to the Vienna Academy by Dr. Adolf Weiss, and
published with two plates in the ‘Sitzungsbericht.’§ It deserves
perusal by some of our microscopists devoted to minute structure.

Mediterranean Bryozoa, by Dr. Manzoni, is another good paper
also in the same number of the Vienna Transactions.

On the Development of Plant-organs.—This is likewise a paper in
the same number of the Vienna Journal. It is by H. Leitgeb, and is
of considerable importance. It goes minutely into the question of
what particular cells go to form special parts. In fact it relates to the
development of the whole plant. There are four plates of engravings
accompanying the paper.

NOTES AND MEMORANDA.

Royal Microscopical Society. Addresses Wanted.—It is believed
that the following gentlemen no longer reside at the addresses given
in the last edition of the ‘ Royal Microscopical Society’s List of Fel-
lows, and as a new edition is in preparation, they are requested to
forward to the Assistant-Secretary, Mr. Walter W. Reeves, King’s
College, London, their present address as early as possible. Should
they be abroad and this request be not likely to come under their
notice, perhaps some friend will be kind enough to give the required

* Band 21, Heft 2. t Reichert and Du Bois-Reymond, 1871, Heft 1.
t Band 6, Heft 3. § LXIII. Band 1 and 2 Heft.

162 CORRESPONDENCE.

information:—William Timbrell Elliott; James Robey; William
Henry Spencer, M.A. Cantab.; John Shepherd.—Kine’s Coxtzce,
August 4, 1871.

‘The Lens;’ a Quarterly Journal of Microscopy and the Allied
Natural Sciences: with the Transactions of the State Microscopical
Society of Illinois, is the title of a new journal which it is proposed
to publish in Chicago, America. The State Microscopical Society of
Illinois proposes to issue on the 1st of October next, the first number
of a Scientific Journal, to be called ‘The Lens.’ While ‘The Lens’
will be devoted chiefly to the interests of Microscopical Science, no
communication of value, relating to any department of Natural History,
will be excluded. Without trespassing on the fields so ably occupied
by ‘Silliman’s Journal’ and the ‘ American Naturalist,’ the only publi-
cations of like character in the United States, the pages of ‘The Lens’
will contain :—1. Original contributions consisting of papers read
before some Scientific Society, or communicated directly to the Journal ;
2. Original papers, elaborate or otherwise, illustrative of the Natural
History of the Mississippi Valley, and the Far West; 3. A comprehen-
sive résumé of the latest foreign inquiries, and critical reviews, with
brief notices of the latest microscopical publications in this country and
Europe; 4. Descriptions of all new forms of Microscopes and Micro-
scopic Apparatus; and 5. Correspondence on matters of Histological
controversy. Contributions requiring illustration will be accompanied
by carefully-drawn plates, and the text will be printed on good paper
in clear and legible type. ‘The Lens’ will be thoroughly scientific,
advanced and comprehensive, and will be issued under the auspices,
and in the interests of this Society. The size of page, 8vo; and each
number will contain at least 48 pages of reading matter. Terms, 8s.
per annum, in advance. In view of the fact that there are so few
journals published in America, in these interests, the committee
hope for the strong support, both contributional and financial, of all
lovers of Science. Correspondence relating to the business manage-
ment of the Journal should be addressed.to Charles Adams, Secretary
of the Publishing Committee, 1000, Michigan Avenue, Chicago. All
other communications to the editor, 8. A. Briggs, 177, Calumet Avenue,
Chicago. Officers of the Society: H. A. Johnson, M.D., Pres.; 8. A.
Briggs, Ist Vice-Pres.; H. H. Babbock, 2nd Vice-Pres.; Geo. M. Hig-
ginson, Treasurer ; O. 8. Westcott, Sec.; Charles Adams, Cor. Sec. ;
E. H. Sargent, Charles Biggs, Charles Adams, Publishing Committee. —

CORRESPONDENCE.

OBSERVATIONS ON SURIRELLA GEMMA.

Dear Srr,—The fact should not be lost sight of with regard to the
interpretation of the markings on Surirella gemma, that Mr. John
Mayall, in his paper “ On Immersion Lenses and Test-Objects,” pub-

PROCEEDINGS OF SOCIETIES. 163

lished in the Royal Microscopical Society’s ‘ Transactions,’ February,
1870, vol. i. p. 92, points out Hartnack’s error, and observes, in place
of elongated hexagons represented by this optician, and copied without
comment by Dr. Carpenter, the frustule “is analogous to that of the
Grammatophora subtilissima, and with Hartnack’s immersion ,},th this
latter frustule” appears to be similar to G. marina, or P. angulatum.
Mr. J. Mayall subsequently convinced Hartnack of the error into
which he had fallen, and concludes his paper with these words,
“Surirella gemma may truly be called a touchstone for a high-
power objective.” I should add that Dr. Woodward’s admirable micro-
photographs of this and other frustules, are more nearly perfection
than anything I have ever seen.
Yours, &e.,

J. Hoag,
Hon, Sec. Royal Microscopical Society.

PROCEEDINGS OF SOCIETIES.*

BrotocicaL AND Microscopican SEcTION oF THE ACADEMY OF
Natura Scrences, PamapELpHiA.

At a stated meeting held April 3rd, 1871, the Director, 8. Wier
Mitchell, M.D., in the chair,—

A donation was received from the Surgeon-General’s office at
Washington of Colonel J. J. Woodward’s interesting report, entitled
“ A Memorandum of the Test Podura,” with five photo-micrographs.

Dr. James Tyson exhibited slides of the deposit from two speci-
mens of urine from a case of so-called intermittent hematuria, which
were interesting, if not important, from the fact, that the first speci-
men, though containing granular casts, did not contain blood cor-
puscles, and that the second, between the discharge of which and the
first the urine had become quite clear, contained, in addition to
granular casts, blood corpuscles and blood casts.

The importance of this observation lies in the circumstance that
in the cases of intermittent hematuria reported by Harley{ blood
corpuscles were exceedingly rare, being found in a single case, and
not more than one or two in the field of the microscope. So rarely,
indeed, have corpuscles been present, that Dr. Beale, in the first
volume of ‘The Practitioner,’ August, 1868, says: “It is, therefore,
improbable that in these cases there is any hemorrhage, as in acute
inflammation of the kidney, and they ought not to be spoken of as
cases of hematuria.”

* Secretaries of Societies will greatly oblige us by writing their reports legibly
—especially by printing the technical terms thus: H y dra—and by “ underlining”
words, such as specific names, which must be printed in italics. They will thus
secure accuracy and enhance the value of their. proceedings.—Eb. ‘ M. M. J.’

+ ‘Medico-Chirurgical Transactions,’ vol. xlviii., 1865,

164 BIBLIOGRAPHY.

In the present case all the other phenomena of intermittent
hematuria attend; and in the second specimen of urine there were
many free blood corpuscles and blood casts; while in the first the
most careful searching detected none.

The treatment found most useful in intermittent hematuria—that
by anti-periodic doses of quinine, preceded by a purgative dose of
calomel—has here also been the most satisfactory, there being no
recurrence since its adoption, although four weeks have now elapsed,
while other modes of treatment adopted since October, 1870, when the
affection first appeared, have signally failed.

Dr. J. G. Richardson exhibited a slide charged with pulmonary
elastic tissue from the boiled sputa (according to Dr. Fenwick’s
method) of a phthisical patient in the Episcopal Hospital, and called
the attention of the Section to two characteristics of its elastic fibres :
first, the delta (A), rather than simple Y-shape frequent among the
fragments, which he attributed to the greater resistance, at the meeting
point of the walls of three air-vesicles, to any disintegrating process ;
and second, the transverse fracture of its component elastic filaments,
resembling that of an india-rubber thread, instead of a frayed-out
appearance, similar to that presented at the extremity of a broken
cotton or linen string.

By these peculiarities pulmonary elastic tissue can generally be
distinguished from objects which occasionally counterfeit its aspect,
as, for example, folds in the walls of boiled starch corpuscles, mycelial
threads of fungi (which, when dichotomous, often have stem and
branches of nearly the same diameter), and vegetable fibres, which
seldom break transversely, and which, when split, generally assume
the Y and not the delta shape.

BIBLIOGRAPHY.

Beitrige zur Anatomie d. Hylobates leuciscus u. zu e. vergleich.
Anatomie der Muskeln der Affen u. d. Menschen. Prof. Th. L. W.
Bischoff. Miinchen. Franz in Comm.

Handbuch der Anatomie der Hausthiere. Prof. Lud Franck,
Stuttgart. Ebner & Seubert.

Botanische Abhandlungen, aus dem Gebiet der Morphologie und
Physiologie. Herausgegeben von Prof. Dr. Johs, Hanstein. Bonn.
Marcus.

Grundriss der Physiologie d. Menschen. Prof. Dr. Karl Vierordt.
Tibingen. Laupp.

Beitrige zur Anatomie und Physiologie. C. Eckhard. Giessen.
Roth.

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MONTHLY MICROSCOPICAL JOURNAL,

OCTOBER 1, 1871.

IL—A Rare Melicertian; with Remarks on the homological posi-
tion of this Form, and also on the previously-recorded new
species Floscularia coronetta.* By Cuartus Cusrrt, F.R.M.S.

Puate XCVIIL.
Introductory.

OccurreD in the prosecution of certain investigations on the
homological position of the members constituting the so-called Families
of Ehrenberg’s Class Rotatoria, with the view to the establishment
of a correct natural Classification as the basis of a work on which I
am at present engaged, I find myself fortuitously placed in com-
mand of a field of operations in the instance of a small streamlet, a
tributary of Northbourne Brook, in Kent, overgrown with the
bladder-wort (Reticularia), which streamlet is literally swarming
with every member of the following genera of Ehrenberg’s system,
viz. Stephanoceros, Floscularia, Melicerta, Tubicolaria, Limnias,
and Ciczstes, together with several of the fresh-water polyzoa; and
amongst the former I find a rare Form, or at all events one which
has hitherto escaped the notice of observers generally ; and with
the object of establishing the correct position of this elegant Form
as well as that of Floscularia coronetta, it is incumbent on me
herein to review briefly the homologies of the particular Families in
which they will respectively be placed.

TERMINOLOGY AND ASPECTS.

The Terminology and Aspects which have hitherto been em-
ployed, do not apply appositely to the several Forms embraced ; the
term lorica, for instance, signifying in its literal interpretation a coat
of mail or an armour, is illogical and absurd when indiscriminately
used to represent the simple hyaline investments of the solitary
Floscularians, the clustered forms of the Lacinularians, or even the
compound sheaths of the Melicertians. I have therefore adopted
certain modifications which will be employed throughout these
remarks ; and for lorica we shall substitute the term Vagina. The
word disk, as signifying alike the region of the tentacular crown of

* “M, M. Journal,’ September, 1869.
VOL. VI. N

166 A Rare Melicertian.

the Floscules and the ciliated lobes of the Melicertians is equally
absonant, and for this we shall substitute and henceforth apply the
term Corona. And following a good example* in the matter of
aspects, we shall employ Newral to indicate the ganglion side and
Hzmal the opposite, and further, shall characterize the active
vibratile appendages of the corona as Cilia in contradistinction to
the Setx, which perform an intermittent action when investing the
corona; and for want of a more appropriate term we must apply
this also to the delicate hairs which furnish the pistons of the
antennée.
Stephanoceros Horatit.

The obvious diversity of the form and position of the corona of
the Floscularians clearly and indisputably separate them from a
Family association with the Melicertians m which the corona sub-
tends the mouth ; and moreover, while the members of the former
manifest a true bilaterality by the preponderance of the neural
margin of the corona, no such bilaterality obtains either with
Stephanoceros or with the miscalled F’. coronetta. The corona of the
Floscularia is, as generically characterized in reference to the lobes,
short, broad, knobbed, expanded ; while the tentacles of both
Stephanoceros and this species are long, slender, and erect ; we see
further that the corona of the Floscules is, with one exception, beset
with setee upon the lobes only, while the whole margin of the
corona of Stephanoceros and of this species is invested in one con-
tinuous series. We see also that these two Forms are identical in
other points of their economy, and are of a higher type of organiza-
tion than that of the Floscules, first as regards their nervous, mus-
cular, alimentary systems, and further in the fact that the stage
which supports the tentacles of Stephanoceros and F’. coronetta acts
in the double capacity of the caliv and lophophore of the Fresh-
Water Polyzoa, and like these Forms they possess an epistome,
which is situated just above the ganglion, they both manifest an
organic attachment of the tunicle, and perform palpable invaginations .
of what may, for the sake of argument, be termed the endocyst with
every retraction of the corona—points which establish a homological
identity with the so-called F’. coronetta, and Stephanoceros Hichornit,
and as such it will in future be denominated Stephanoceros Horatit.

Tre Fammy Meicertap™.

We now come to a consideration of the Melicertians, and with
these we find that the corona subtends the mouth, that, whether
simple or serrated, its periphery is continuous and unbroken, and is
furnished with an uninterrupted range of active yvibratile cilia,

* Allman’s ‘ Fresh-water Polyzoa,’

A Rare Melicertian. 167

whose procession, or the appearance of such is seen to be in one and
the same direction from left to right when viewed in a neural
aspect, and that it is supplemented by a secondary range of more
minute cilia, whose procession is divided into two channels, ema-
nating from the under-side of the corona in its expanded condition,
and progresses, so to speak, in opposite directions, conveying the
captured particles to the mouth, where they are subjected to the
scrutiny of a bilobed ciliated organ, situated immediately above it,
though, unlike the epistome of Stephanoceros, it is placed in a hemal
position, but it exercises a similar function in selecting the nutritive
particles from the general mass, and in rejecting others, as the
scrutiny may determine. This secondary range of cilia obtains, in
a more or less developed condition, in every individual member of
the Melicertians, whether it be Limnias, Gicistes, or Lacinularia,
and it terminates in a process projecting from the ganglion side,
and in most, but not all of the members, it is supplemented by
a fabricating organ, which is employed in the construction of their
compound tunicles, an exceptional instance occurring in a little
Melicertian, which employs her voided excremental pellets to cover
the otherwise hyaline investment. This fabricating organ, in its
normal position, is also wanting in the instance of the elegant Form
which has induced these remarks, Plate XCVIIL., Fig. 1, and in
bringing them to a close it will be only necessary to add that the
genus Melicerta must include all those members in which the
foregoing points are permanent, and that Limnias, Cicistes, and
Tubicolaria are essentially Melicertians, and will be referred to
as such ; retaining, however, their hitherto specific appellations as
for the sake of facility of recognition.

Melicerta annulatus.

My attention was first drawn to a vagina of this species, which
at a glance exhibited proportions differing from any hitherto known
Form, containing within it an ovum of a magnitude equally sur-
prising. I at once applied the micrometer, and for the moment
failed to notice the corrugations which, singularly enough, coincide
exactly with the 2000th divisions of the micrometer; they occur
as little ridges formed around the circumference of the vagina, which
in all young, and young adults is perfectly hyaline, manifesting
a decided and brilliant orange tint, but seen at the two sides
when in proper focus they are rendered very distinct, the orange
tint becomes condensed into a deep carmine. How these ridges
become formed with such marvellous precision is a matter that must
strike all with wonder and admiration; and although I do not feel
myself prepared at once to state anything definite as to their
formation, I can only suggest it as worthy of attention that the
anterior regions manifest a considerable and somewhat coupe

N

168 A Rare Melicertian.

departure from those of the other Melicertians, to which we shall
give some consideration in a subsequent paragraph.

The footstalk is most frequently wrinkled, and it manifests
very distinct muscular bands, see Plate XCVIIL, Fig. 1; but not-
withstanding the presence of these, they do not produce sufficient
contraction of the stalk to enable the animal to withdraw itself
within the vagina without producing folds in the footstalk, as shown
by the rough sketch, Plate XCVIIL, Fig. 5. The integument,
which is corrugated all along the footstalk, ascends to the corona,
where it forms an orifice into which the corona becomes retracted
by an invagination, the line of demarcation being very distinct even
during the eversion of the corona, leaving, however, the two re-
spiratory tubes the most prominent objects in view, as is the case
with every one of the Melicertians, whether these tubes are rudi-
mentary, or otherwise highly developed.

In its retracted condition, Plate XCVIII., Fig. 2, the corona
manifests two distinct projecting processes beyond the setiferous
tubes which, though they present the same general appearance, are
not provided with set, but manifest at their extremities a bright
red spot under the illumination of the Wenham parabola; we do not
expect to find eyes in a hemal aspect as these spots are situated ;
beneath them there are three other processes which are less highly
developed, and the distance between these two upper processes and
the three lower ones corresponds precisely with the “ pitch,” or
distance apart of the annulets of the vagina, and we see that although
the corona is frequently protruded far above the margin of the
vagina, it never remains in that position for periods of long duration,
except in the instances of old animals, whose vagine are coated
with extraneous matter, but with younger animals, the corona on the
act of eversion is seen to emerge somewhat above the margin, and
then to subside to such a position that these two processes become
identical with its margin, suggesting the not unreasonable notion
that these peculiar organs are employed in the act of constructing
this delicate investment, but further investigation is necessary to
confirm this supposition ; it certainly seems somewhat inconsistent to
find that while in every other member of the Family the fabricating
organ is situated on the neural side, it should in this particular in-
stance be placed on the opposite; but if their capacity as such
be truly surmised, they certainly produce an effect differmg essen-
tially in the nature of the vagina so produced, which in this instance
is more brittle than viscid.

While hastening for the press, I must conclude these obser-
vations with a cursory notice of the action of the marginal cilia,
which, from the tardiness of their action in this particular Form, offer
every opportunity for correctly appreciating their action, and of
representing them on a drawing, though it is of course impossible

Photographing Histological Preparations by Sunlight. 169

to convey the appearance of objects in motion; however impressive
may be their appearance, the onward procession is but an optical
illusion ; I assume therefore that for the instant they are fixed when
by the employment of linear projection the individual positions of
the cilia are found to be as indicated on the drawing, which I sub-
mit is correctly represented, and shows more clearly and truly the
actual appearance assumed in life.

II.—On an Improved Method of Photographing Histological
Preparations by Sunlight.*

By J. J. Woopwarp, Assistant-Surgeon, U. 8. Army.

GENERAL: In January, 1870, I had the honour to submit to you a
report in which I detailed the results of a series of experiments,
which showed the superiority of the Electric and Magnesium lights
over sunlight, as heretofore employed, for the production of photo-
micrographs of the soft tissues. In June of the same year I made
a report in which I showed that similar results could be obtained
with the Oxy-Calcium light. With these various artificial sources
of light I obtained pictures which appeared to me to be “clearer
and better defined than any photographs of similar objects I had
hitherto seen produced by sunlight.”

So many cloudless days are offered to the photographer in
Washington that I could not but regret these results; yet they
appeared to be final at the time of writing. During the last few
months, however, I have found improved methods of using the light of
the sun for photographing the soft tissues, and have arrived at results
which must materially modify the conclusions of my former reports.

Not that I have anything to withdraw from the opinions I have
expressed, as to the certainty and success attending the use of arti-
ficial lights for the purpose named, but I have much to add with
regard to the most advantageous methods of using the light of the
sun for obtaining satisfactory pictures of tissue preparations, and
such other objects as approximate them in optical characteristics.

If a well-made preparation, of some normal tissue, or of some
pathological growth, stained with carmine, silver, or gold, and
mounted temporarily in glycerine, or permanently in Canada balsam,
be illuminated by white cloud illumination, or by lamplight, and
found to be all that could be desired, it will nevertheless appear very
unsatisfactory if illuminated by the direct rays of the sun.

The eye glancing through the tube of the instrument, dazzled by
the powerful light, discerns amidst the blaze innumerable coloured

* The report is made to Brigadier-General J, K, Barnes, Surgeon-General
U.S. Army.

170 On an Improved Method of

rings, produced by diffraction and interference, which disturb the
normal appearances of the preparation and render its interpretation
impossible.

If the image be received upon a white screen similar phenomena
obtrude themselves, destroying the clearness of the picture, though
no longer injuriously affecting the eye; and if monochromatic light
is employed, although the disorderly play of colour disappears, black
rings and lines of the most manifold character and direction take
their place. Pictures produced under these circumstances are of
course quite useless, and the difficulty occurs not merely in the case
of tissue preparations, but in a very large number of other objects.

To escape these disagreeable results it has heretofore been the
practice to pass the solar pencil through a piece of ground glass.
This plan is recommended in all the treatises on photo-micrography,
and has hitherto been employed in the solar work done at the Army
Medical Museum. The method is effectual in getting rid of the
diffraction and interference phenomena complained of; an image is
obtained which is clear and satisfactory to the eye looking down the
tube, but it appears very weak on the screen and is sadly deficient
in contrast. These faults are reproduced in photographs of objects
thus illuminated, and, moreover, the time of exposure is enormously
increased. Such pictures are decidedly inferior to those which can
be obtained by the Magnesium, or even by the Calcium light, with
which no ground glass is used.

I desire now to call your attention to the fact that in the course
of some recent experiments I have ascertained that the diffraction
and interference phenomena above complained of, may be prevented
by the use of a suitable condensing lens, even better than by the
ground glass; that by this plan the exposure may be greatly
diminished, say from three minutes for five hundred diameters, to a
fraction of a second, and that the resulting pictures are not merely
quite as free from diffraction and interference phenomena as the
best that can be obtained when the ground glass is used, but are
characterized by greater contrast and superior sharpness of defi-
nition.

The details of my new method are as follows :—The microscope
being placed on a shelf at the window of the dark room, and its
body made horizontal, the achromatic condenser is illuminated by a
solar pencil reflected from a heliostat upon a movable mirror outside
the shutter and thence into the dark room, precisely as described in
my original paper on photo-micrography.* No ground glass is
used, but imstead a lens mounted in a suitable tube is fixed in the
opening of the shutter through which the solar pencil enters. This
lens is an achromatic combination about two inches in transverse

* * American Journal of Science and Arts,’ September, 1866.

Photographing Histological Preparations by Sunlight. 171

diameter and of about ten inches focal length. It is placed at such
a distance from the achromatic condenser that the solar rays are
brought to a focus and begin again to diverge before they reach the
lowest glass of the achromatic condenser.

For anatomical preparations requiring for their display from two
to five hundred diameters I use a 1th of an inch objective, without
an eye-piece, obtaining the precise power desired by variations in the
distance of the sensitive plate from the stage of the instrument. I
have lately given the preference to immersion objectives, the cor-
rections of which I find are generally well suited to photographic
requirements.

Now, with a 1th objective and the arrangement above described,
the field is so briliantly illuminated that the eye cannot safely be
permitted to look down the tube. The image is therefore received
on a piece of white cardboard, and sitting by the microscope to
make the adjustment I view the card with both eyes precisely as in
the case of the ordinary solar microscope. With these arrangements,
the cardboard placed from two to four feet from the stage of the
microscope is sufficiently well illuminated to permit distinct vision,
even when objectives of the shortest focus are used and powers of
five to ten thousand diameters obtained. While the object is thus
seen on the white screen in its natural colours, the cover corrections,
focussing, management of the achromatic condenser, and selection of
the portion of the preparation to be photographed, are readily
managed. When all is satisfactory I insert an ammonio-sulphate
cell between the large lens and the achromatic condenser, and draw
down the velvet hood which prevents leakage of light from about
the microscope into the dark room ; then going to the plate-holder
I make the final focussing in the usual way on the ground glass, or
on plate glass with the help of a focussing glass, according to the
nature of the object.

With powers of five hundred diameters or less I at first ex-
perienced some difficulty in giving the right exposure; for as the
time required was but a fraction of a second it was a matter of some
difficulty to regulate it with precision. At length I succeeded by
arranging a sliding shutter, with a transverse slit of variable width,
so adjusted as to fall with its own weight before the tube of the
microscope, the exposure being made during the passage, and the
time of exposure regulated by the width given to the slit.

Of course it occurred to me that for such short exposures the
heliostat might be dispensed with, and I found on trial without it
that a large right-angled prism used in the position of total re-
flexion, or even an ordinary mirror, gave excellent results; the
exposures being even shorter than when the heliostat was used,
since there was but a single reflexion. I could not satisfy myself,
however, that the quality of the pictures differed from those

172 On an Improved Method of

obtained with the help of the heliostat, except perhaps that in
certain cases the prism seemed to offer advantages which will be
referred to hereafter. Under these circumstances the heliostat
appears desirable for ordinary use, since the solar pencil being
thrown in a constant direction, the trouble of adjusting the illumi-
nation of a series of objects is considerably diminished, but 1 have
convinced myself by trial that equally good pictures can be pro-
duced without it, even with very high powers, a circumstance of
considerable interest where motives of economy preclude the
microscopist from procuring this convenient instrument.

A few remarks with regard to certain points in the procedure
above sketched seem called for.

First, with regard to the selection of objectives suitable for pho-
tographic work of this kind. The power of the objective to be used
will depend of course upon the details it is desired to display. I
find it best to use the naked objective without eye-piece or amplifier,
and not as a rule to fix the sensitive plate more than three or four
feet from the stage of the microscope. A 1th objective may be
conveniently employed to obtain powers of from two to five or six
hundred diameters, a 74th for higher powers up to twelve or fifteen
hundred diameters. Suitable amplifiers or even eye-pieces may be
used in either case, with great increase of the magnifying power,
and often with admirable scenic effect, but there is always a certain
loss of definition. Still such amplifications may sometimes be
advantageously resorted to, especially in the case of objects which
present very minute details ; for in these cases the paper prints will
often lose many of the fine details of the negative, and the loss of
definition incurred by the amplifier or eye-piece is not unfrequently
less than that encountered in attempting to transfer to paper a
negative prepared with insufficient magnifying power. Thus far
my experience is decidedly in favour of using sufficient power in the
first instance, rather than attempting to enlarge negatives taken
with less power.

The objective selected should of course be unexceptional in
defining power, and should always be specially corrected for photo-
graphy. It has been erroneously stated by Moitessier* that if an
ammonio-sulphate or other blue cell be interposed in the solar pencil,
all special corrections of the objective may be dispensed with. ‘This
proposition, which has been adopted by many other writers, appears
plausible, but a little consideration will show it to be quite erroneous.

Everyone knows that a good objective must be free from
spherical as well as from chromatic aberration. Of course the use
of monochromatic light disposes of the chromatic trouble. Not so
with the spherical aberration. Now this aberration, like the

* ‘Ta Photographie Appliquée aux Recherches Micrographiques.’ Par A.
Moitessier, Paris, 1866, p. 180 ct seq.

Photographing Histological Preparations by Sunlight. 173

chromatic, is corrected mainly by the just combination of flint with
crown glass in the several pairs which constitute the objective. If
these are so adjusted as to correct spherical aberration as nearly as
possible for white light, they will no longer do so for light which
has passed through the ammonio-sulphate of copper. Until objec-
tive makers take this fairly into consideration the microscopist who
desires to photograph what he sees is left to a happy chance in the
selection of his objectives. For even those makers who profess to
prepare objectives “specially corrected for photography” do not
deal any too well with the problem. If they would test their
objectives, while making them, with violet light, we should have
better results ; for with such illumination the eye can see all that
photography can execute and no more.

But this circumstance fortunately enables the microscopist to
select from the objectives in the market those which are suitable for
photography. It is only necessary to test their performance when
illuminated by sunlight which has passed through an ammonio-
sulphate cell. Now it fortunately happens that the high-power
immersion objectives of certain makers, especially those of Powell
and Lealand, possess very nearly the corrections which theory would
indicate as best adapted for photographic use. Nevertheless it can
hardly be doubted that even these objectives could be greatly
improved if the makers would take into consideration the principles
involved in the foregoing remarks.

A second point, which deserves attention, is the use of the large
condensing lens above described. This lens, it will be understood,
corresponds with the large condensing lens of the ordinary solar
microscope, while the achromatic condenser takes the place of the
so-called field-glass of the same instrument. It has already been
mentioned that this lens should be placed at such a distance from
the achromatic condenser that the solar rays may be brought to a
focus, and begin again to diverge before they reach its lowest glass.
A different arrangement is usually employed in the solar microscope,
the field-glass being placed at such a distance from the first
condenser that the solar rays impinge upon it before they come to
a focus. As a consequence, the convergent pencils proceeding from
the first lens are still further converged by the field-glass, and a
burning focus of heat, as well as of light, is produced, which is
damaging to the preparation as well as to the balsam cement of the
objectives used. If, however, the rays from the first lens are per-
mitted to come to a focus and to begin to diverge before striking
the second, this latter can readily be adjusted so as to bring the
illuminating rays to a handsome focus, while the heat rays, after
passing the second lens, become parallel or even divergent according
to the position of the achromatic condenser, and all trouble from the
solar heat is thus completely avoided. So successfully may this

174 On an Improved Method of

separation be effected, indeed, that I have frequently obtained light
enough to give distinct vision and admirable definition on the card-
board screen with five thousand linear diameters or even higher
powers (obtained by the immersion ',th, an amplifier, and four
feet or greater distance), while the heat was so slight that the drop
of water used with the immersion lens did not require renewal
oftener than about once in two hours.

I had employed this device for several months, and supposed it ~
to be quite novel, when I read the paper of the late distinguished
President of the Royal Microscopical Society of London, the Rey.
J. B. Reade, “On the Separation of the Rays of Heat from the Rays
of Light in Solar and Oxy-hydrogen-gas Microscopes.”* I learned
from that article that Mr. Reade had devised this very plan as an
improvement to the solar microscope as long ago as 1836. The
advantages attained may be stated in his own lucid words :—

“Tt is evident by this arrangement of lenses we convert the
parallel solar beam first of all into a cone of light-giving rays within
a cone of heat-giving rays, and the principal focus of heat 1s farther
from the condensing lens than the principal focus of ight. But
after these rays cross the axis we have, conversely, an equal and
opposite cone of heat-giving rays within a cone of light-giving rays,
and a plano-convex lens or hemisphere, if placed m this second
cone at the distance of its own focal length from the principal focus
of heat, will be at a distance greater than its focal length from the
principal focus of light; and consequently the rays of heat, after
passing through this lens, will become parallel, while the rays of
light converge to a second focus. I have approximately measured
the heating power of the thermal rays of the second cone when
rendered parallel by the plano-convex lens, and I found in the
month of December that the mercury in a sensitive thermometer,
when placed in the second focus, did not reach 90° Fahr., while at
the same time the heat at the focus of the first cone was sufficient
to discharge gunpowder.”

Mr. Reade appears to have experimented with low-power objec- .
tives only, for he speaks merely of such preparations as the head of
a flea. He therefore succeeded very well by using a single lens in
his field-glass. With such powers as the immersion 3th and th
I find it better to use an ordinary achromatic condenser instead.
The principles involved are of course identical. For the first con-
denser also, I have been using an achromatic combination of the
dimensions and focal length above mentioned, taken from the back
of an ordinary photographic portrait tube, but I am not sure that
a simple plano-convex lens of the requisite diameter and focal length
would not answer every purpose.

* ‘The British Journal of Photography,’ December 16, 1870, p. 590.

Photographing Histological Preparations by Sunlight. 175

The introduction of the ammonio-sulphate cell would of itself
prevent the passage of most of the heat rays falling upon it, but if
this were the only means of excluding them it would not be possible
to focus primarily with white light on the cardboard screen in the
manner which I have found so convenient.

I have already stated that the time of exposure required for the
production of pictures magnified five hundred diameters or less,
was a fraction of a second. With higher powers it increases, vary-
ing with the management of the achromatic condenser. For four
thousand diameters I have sometimes needed as much as twenty-
five seconds.

So long as the exposure is greater than a second, the requisite
time may readily be given with a piece of velvet, or a cardboard
screen held in the hand. For shorter exposures some mechanical
contrivance is indispensable. That alluded to above seems to
answer every purpose, and is arranged as follows:—A wooden
screen is fixed between the microscope and the sensitive plate, as
close as convenient to the microscope. To prevent side lights reach-
ing the plate, the screen is connected with the window-shutter by
velvet curtains, which can be turned aside to manipulate the instru-
ment, and be let down at the proper time. A circular hole, three
inches in diameter, is made in the screen opposite the tube of the
microscope for the transmission of the image. In front of this a
light shutter slides loosely up and down, held in place by a cleat of
wood on each side, the design being to permit the shutter to fall
edge foremost with as little friction as possible. The shutter may
be made of thin metal, of wood, or even of cardboard. I am using
one of pine wood the ;';th of an inch thick ; I have used one of card-
board with equal success. In the shutter is an opening, three inches
wide by ten long, covered with a cardboard slide, by means of
which any width of slit, from a fraction of an inch to ten inches,
can be given. The part of the shutter below the slit closes the
aperture through which the image passes when the shutter is fixed
in place before the exposure is made. On drawing a wooden trigger
the shutter is started on its fall, which is arrested by a piece of
string of suitable length. The exposure has now been made, but
the aperture through which the image passes is again closed, this
time by the part of the shutter above the slit. The shutter is so
light that the jar caused by the sudden arrest of its motion by the
string is too trifling to do any damage to the microscopic apparatus,
and as it occurs after the exposure is over it cannot affect the image.
I find that if when the shutter is started the lower edge of the slit
is an inch above the aperture through which the image passes, a
convenient velocity is attained for a magnifying power of two to
five hundred diameters, arranged as I have described. For still
shorter exposures, necessitated by lower powers or other circum-

176 On an Improved Method of

stances, it would be best to start the shutter from a greater height,
which would give greater velocity to the passage of the slit, and
any available fraction of time desired might thus conveniently be
obtained. The whole arrangement is inexpensive, and may be
manufactured in a few hours by anyone, out of a deal board, a few
pieces of cardboard, and a yard or two of cotton velvet.

Of course the fractional measures of time obtained in this way
are not absolute, since the friction must be variable, unless the
apparatus were made in a more costly manner of metal. But I
have found that the variations thus introduced are so small that
they may be disregarded, and that while the starting-point remains
the same, the width of the slit in the falling shutter indicates frac-
tions of time which may confidently be counted upon to give pro-
portional photographic results.

The next subject for remark is the arrangement employed when
the heliostat is dispensed with.

For this purpose the contrivance usually employed for the solar
microscope answers very well. A circular disk of brass, with
toothed edges, is let into a square plate of the same metal, and is
turned by a small toothed wheel, to which a suitable button or
milled head is attached. Through the centre of the disk passes a
tube six or eight inches long and two inches in diameter, the outer
extremity of which is fitted to receive the large condensing lens.
Just below this tube an arm is firmly attached to the outer surface
of the disk for the purpose of carrying the mirror or right-angled
prism, to which any desired inclination can be given by a rod passing
through the disk by the side of the tube. The whole arrangement
is quite lke the similar parts of the ordinary solar microscope, and
hence needs no minute description; it is fitted into a window-
shutter, which must of course face to the south, and the room being
darkened the motions of the mirror, or prism can readily be con-
trolled from within. If the condensing lens is used I do not think
any material advantage can be obtained from the prism, and its
expense is a decided objection. In the winter season in this latitude
a prism of over five inches hypothenuse is required, and its cost is
a serious item, An ordinary glass mirror answers, I think, quite
as well for the tissues and most other purposes. There are, how-
ever, certain objects, such as the Pleurosigmata and some other
diatoms, the Nobert’s Test-plate, and the scales of certain insects,
for which the condensing lens is unnecessary. The achromatic
condenser, illuminated by a parallel solar pencil, answers better in
these cases, and if it is properly managed no diffraction or inter-
ference phenomena are produced. I am satisfied that in such cases
the pure parallel pencil obtained from the prism gives better defini-
tion to the image than can be obtained by the double pencil reflected
from an ordinary glass mirror. A mirror silvered on the reflecting

Photographing Histological Preparations by Sunlight. 177

surface would, I suppose, answer the same purpose; but such
mirrors are not permanent, and are troublesome to keep in order
while they last. Moreover, if the prism is used only for this pur-
pose, a very small and cheap one will answer, since a pencil half an
inch in diameter is all that is required. Such a small right-angled
prism is furnished with most large microscopes, and can readily be
mounted outside the brass disk so as to answer the special purpose
indicated. For all those objects which require the large condensing
lens to avoid diffraction and interference, a common glass mirror
will answer well enough. For lower powers than two. hundred
diameters, however, the ordinary mirror will often be found to
reflect too much light, and the image on the cardboard screen will
be found too brillant to be conveniently observed for any length of
time. In such cases a piece of plain unsilvered plate glass may be
substituted for the mirror. The greater portion of the solar light
passes through it and is lost, but enough is reflected to make pic-
tures of four hundred diameters in from two to three seconds expo-
sure, and these pictures have all the qualities of those made with
ordinary mirrors. I have tried instead to diminish the light by
absorbing a part, using for this purpose an ammonio-sulphate cell
of considerable thickness, but find that this plan diminishes the
contrast and definition of the image, which is not the case when a
mirror of simple plate glass is used as above described.

With regard to the management of the plate-holder, the appa-
ratus for focussing, and other accessory arrangements, I need only
say that I employ for the solar light the same simple plan which I
have described in full in my reports on the use of artificial lights in
photo-micrography.

Since making the experiments which have led to the foregoing
results I have modified my method of dealing with the electric light
in photographing the tissues. I first render the divergent pencil
proceeding from the carbon points as nearly parallel as possible by
means of the condenser, usually supplied with electric lamps for
this purpose, and then introduce into the parallel pencil, instead of
a ground glass, the very same condensing lens described above for
the process with solar light. The image is received primarily on a
cardboard screen, and the remaining details do not differ from what
has been related above. The time of exposure does not exceed a
single second for four hundred diameters, and the sharpness of the
pictures exceeds any of my former results. Indeed, with this new
arrangement I must say that the electric light appears to me to
retain the apparent superiority over sunlight, remarked in my paper
on the use of this method of illumination in photo-micrography, at
least in the case of all those objects which in themselves possess but
little contrast. For well-made tissue preparations, however, I find
the best work I can do with the electric light, so similar to the best

178 On an Improved Method of

attainable by sunlight, used as above described, that I should rarely
take the trouble to set up the battery and work the electric lamp,
unless it was desirable to work at night or in unfavourable weather.

It only remains to append some examples of the results attained
by sunlight employed in this manner. In selecting a few negatives
for this purpose I have preferred to confine myself to those which
represent normal tissues, magnified to the moderate extent of four
or five hundred diameters. I have done so because I believe that
the greatest practical results are to be anticipated from the repro-
duction of similar objects with like powers. I would refer those
who are curious as to the possibilities with higher powers, to the
photographs accompanying my “ Memoranda” on the Test Podura,
and on Plewrosigma angulatum and P. formoswm, the majority of
which were produced by the methods above laid down. Among
the views will be found one of P. angulatum and one of P. formo-
sum, each magnified 4500 diameters. The following is a brief
description of the subjects represented in the photographs which
accompany the present paper.

[The following photographs have been received by us, but of course are not
reproduced, being representations of objects familiar to most anatomists. They
are, some of them, very correctly done ; but we fear they do not yet represent
all that is seen with the eye. Some of them, as for example Nos. 3, 4, 5, are,
we fancy, rather imperfect representations of the objects they are intended to
represent.—Ep. ‘M. M. J.”]

No. 1. Photograph representing a bundle of the striated mus-
cular fibres of the mouse. Magnified 500 diameters by Powell and
Lealand’s immersion }th. Negative No. 368, New Series. From
preparation No. 2338, Microscopical Section. The preparation was
made by Dr. J.C. W. Kennon. The capillaries were injected with
carmine, and the fragment selected is mounted in Canada balsam.
For photographic purposes the focal adjustment was arranged to
display the transverse striz, and hence the capillaries appear some-
what out of focus.

No. 2. Portion of the peripheral wall of one of the alveoli of the
lung of a frog. Magnified 500 diameters by Powell and Lealand’s
immersion ith. Negative No. 8365, New Series. From preparation
No. 38639, Microscopical Section. The preparation was made by
Dr. EK. M. Schaeffer, one of the assistants in the Microscopical Sec-
tion. The vessels were injected with a dilute silver solution, and
the preparation, after staining with carmine, was mounted in Canada
balsam. The photograph represents a small artery breaking up
into a network of capillaries. The cells of the endothelium are
mapped out by the silver, and the carmine-stained nuclei appear in
many places. This picture is introduced for comparison with the
best of those obtained with artificial light appended to my report on
the Histology of Minute Blood-vessels.

Photographing Histological Preparations by Sunlight. 179

No. 3. A section of the eyelid of a calf, showing sebaceous glands
surrounding a hair. Magnified 500 diameters by Powell and Lea-
land’s immersion 3th. Negative No. 367, New Series. From pre-
paration No. 3640, Microscopical Section. The preparation was
made by Dr. EH. M. Schaeffer. The section was stained with car-
mine, and mounted in Canada balsam. The lobules of the sebaceous
glands have been focussed upon for the display of the glandular
epithelium ; the hair and adjacent portion of the hair follicle appear
of course somewhat out of focus.

No. 4. Section of the kidney of a frog. Magnified 400 diameters
by Powell and Lealand’s immersion Ith. Negative No. 373, New
Series. From preparation No. 8018, Microscopical Section. The
preparation was made by Dr. J. C. W. Kennon. The section was
stamed in carmine, and mounted in Canada balsam. The photo-
graph shows some of the ¢ubuli wriniferc cut transversely ; others
more or less obliquely.

No. 5. Section of the liver of a pseudo-triton. Magnified 500
diameters by Powell and Lealand’s immersion 1th. Negative
No. 371, New Series. From preparation No. 3573, Microscopical
Section. The preparation was made by Dr. J. C.W. Kennon. The
section was stained in carmine, and mounted in Canada balsam.
The photograph shows the polygonal cells and their nuclei. The
double contours between some of the cells indicate the position of
the ultimate gall ducts.

No. 6. Section of the ovary of a cat. Magnified 400 diameters
by Powell and Lealand’s immersion 1th. Negative No. 292, New
Series. From preparation No. 3051, Microscopical Section. The
preparation was made by Dr. J. C. W. Kennon. ‘The section was
stained with carmine, and mounted in Canada balsam. The photo-
graph shows the connective tissue of the ovary, with a number of
immature ovules imbedded. The nuclei of the connective tissue are
well defined, and in several of the ovules the germinal vesicle is
distinctly seen.

No. 7. Another portion of the section shown in No. 6. Same
power. Negative No. 293, New Series. The photograph shows in
the centre an ovule, with germinal vesicle and germinal spot well
defined. The ovule is surrounded by several layers of cells, the
nuclei of which are best seen on the right side. These belong to
the immature zona granulosa. Externally is the connective tissue
of the ovary.

No. 8. Another portion of the same section. Same power.
Negative No. 294, New Series. This photograph represents a
nearly ripe Graafian follicle, lmed by a layer of cells (the zona
granulosa) four to six deep—the nuclei of this layer are well defined.
On one side an ovule is imbedded, in which the germinal vesicle and
germinal spot are distinctly shown. The portion of the zona

VoL. VI. 0)

180 Photographing Histological Preparations by Sunlight.

granulosa reflected over the ovule is composed of two layers of cells,
as shown by the nuclei. On the exterior of the Graafian follicle
the connective tissue of the ovary and its nuclei can be seen. In
the cavity of the Graafian follicle is a quantity of ill-defined granu-
lar matter. .

No. 9. An epithelial cell and several salivary corpuscles from
fresh human saliva. Magnified 960 diameters by Powell and Lea-
land’s immersion jth. Negative No. 408, New Series. One of
the salivary corpuscles is very satisfactorily displayed.

In conclusion, I cannot but express the hope that my work in
this direction may induce other microscopists, and especially those
who are conducting original researches, to resort to photography as
a means of bringing their results in a tangible form before their
fellow microscopists. It will be seen from the statements now made,
that, with the exception of the mounting of an ordinary solar mirror,
no special apparatus is absolutely needed for this purpose which
may not be made by the microscopist himself, or at least produced
at a very trifling cost. Nothing more than a knowledge of the
principles of photography is required. In every case the services
of a good dark-room man should be procured, and if the prepara-
tions are carefully selected beforehand and the highest wages paid
to the best operator attainable, the average cost of the negatives
will be far less than that of the cheapest and most indifferent draw-
ings. Accuracy of representation in these objects can only be
satisfied by photography, and photography is not only the most
accurate, but the cheapest and least troublesome method of repro--
ducing microscopic objects. Of course much of the beauty of the
result will depend on the character of the preparation selected.
But in a general way the preparations best fitted for study are
those best fitted for photography. If photographic representation
was universally demanded, a higher class of preparations than those
which now satisfy too many microscopists would become indis-
pensable, and the vague description, based on clumsy or imperfect
preparations, which too often disfigures microscopic literature, would
be replaced by a more accurate representation of the actual facts.

Army Mepicat Museum, Microscopical Section.

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Ill.—Hematozoa in Blood of Ceylon Deer.
By Boyp Moss, M.D.
PuatTe XCIX.

Apout two years since, while examining the blood of various
animals, I had one day a specimen of that of a Ceylon red deer
(the Muntjac of India) under the microscope. To my great
astonishment I saw vigorously swimming across the field several
oval ciliated bodies, such as I have represented in Fig. 1 in the
accompanying Plate. The front pointed half of the body was
covered with cilia in active motion, and as it swam forward through
the mass of red blood corpuscles, it was impossible to avoid com-
paring it to a steam vessel forcing its way through a crowd of small
boats. The specimen of blood had been taken about three-quarters
of an hour after the death of the animal, while it was still warm—
from a wound made by a bullet which had passed through the liver,
and I thought it possible that the entozoa came from that organ,
but on a careful examination of its substance none of them were
found. I had no further opportunity of looking for their bodies
for ten or eleven months, when I procured another red deer.
About half an hour after death I placed a drop of the warm blood
with which the cavity of the abdomen was filled (in opening the
animal), under the microscope, and there again was the same
curious sight of these entozoa swimming actively across the field.
There were generally two or three to be seen at once when using
Smith and Beck’s 1th objective. They lived under the thin glass
cover for about an hour. I now carefully removed the heart of the
deer, closing the aorta, as I cut it, with my fingers, and then
squeezed out a drop of blood from the ventricle on to a slide; this
again presented the same appearance, proving that the entozoa did
not come from the cavity of the abdomen. A month or two later
I examined the blood of another Muntjac, with similar results.
Now, these bodies are of course far too large to pass through the
capillaries, and must evidently inhabit the heart and larger vessels,
and I had hoped before this to have been able more thoroughly to
investigate the matter, and therefore delayed sending this communi-
cation to the ‘ Microscopical Journal,’ but I have as yet had no
further chances, and the above must be taken quantum valeat for
the present. The appearance Fig. 2 in the Plate is that presented
in all cases by the Heematozoa about twenty-four hours after death.
When the drop of blood still remained partly fluid beneath the
glass cover, they showed three curious bands, which much resemble
muscular fibre, but which are not visible during life. They (the
bodies themselves) have no colour, being perfectly translucent; a
distinct double membrane is to be seen round them. They all
0 2

182 Microscopical Fissures in the

have two or three large spherical bodies like ova towards the
posterior half, the remaining portion being filled up with small
cells and granules. ‘The cilia are raised on a substructure of a cave-
like appearance. The red blood corpuscles of the Muntjac agree in
size with those of the musk deer, being only about goo inch in
diameter, many of them on being placed on the glass slide assume
the curious semilunar form represented in the Plate (Fig. 3). I
have once or twice examined the blood of the Sambur deer for these
bodies, but have seen none.
Cryion, May, 1871.

With reference to my communication in your Journal for Decem-
ber last, I have shown specimens to Mr. Thwaites, of the Botanical
Gardens in Kandy, and it is his opinion that the organisms can be
nothing but spores of some description of fungi. I am quite
certain that they existed imbedded in the muscular fibre, and were
not accidentally derived from without, and in the Plate facing page
48 of your Journal for February, in the present year, there are
some drawings of spores (Figs. 2, 3, 4, 5,6, 9,10, 14, 22, and 24),
the very counterparts of which I can show in specimens of mus-
cular tissue.

IV.—Microscopical Fisswres in the Masticating Surface of
Molars and Bicuspids. By J. H. M‘Quitten, M.D., D.DS.,
Professor of Physiology in Philadelphia Dental College.

In a recent communication to an American periodical attention
was directed to the fact that the minute openings or fissures found
in the grinding approximal, buccal, palatine, and lingual surfaces
of molars and bicuspids frequently lead to cavities of some size.
Through the kindness of my friend, Dr. R. W. Varney, of New
York, who placed in my hands some time since a number of micro-
scopical preparations, 1 have an opportunity of demonstrating in
the most conclusive manner the necessity of immediate attention to
such cases.

In the accompanying illustration (which I had made of a
longitudinal section of an inferior molar, as seen under an 7%, ob-
jective and No. 1 eye-piece, magnifying sixty diameters), it will be
observed that a minute fissure, invisible to the naked eye in the
section, extends from the bottom of the sulcus on the grinding
surface of the tooth, through the enamel, almost to the dentine,
and enlarging at the lower part into an oval cavity. This is entirely
the result of defective formation, the enamel prisms having failed
to coalesce at that point, and thus a condition is presented favourable

Masticating Surface of Molars and Bicuspids. 183

to the retention of fluids and semi-solids, which undergoing decom-
position would speedily destroy the thin septum of enamel covering
the dentine. In the latter tissue, closely contiguous to the enamel,
a number of black spaces (the
interglobular spaces) will be
seen. Here again is located
defective structure and a
prolific predisposing cause of
decay. The large space re-
presents a carious cavity com-
mencing on the approximal
side of the tooth.

In a paper read before the
American Dental Association
at the meeting held in Boston,
August, 1866,* giving the
results of a personal examina-
tion of the <interglobular
spaces, I remarked, “As
evidence of the practical bear-
ings of these investigations, if | (QW
may be well to direct attention WY
to the fact that the existence “A
of the spaces in teeth which have completed their growth must
be regarded as an abnormal condition, predisposing such teeth to
decay, and that when either by mechanical action, as by a fall or
blow, or by the penetration of external caries, such spaces are
reached, the disease here would run riot ; hence the importance of
care on the part of patients and operators to have the most minute
cavities filled ; for though reached only through a microscopical
opening, the result would be the same, while, if protected from the
action of external influences or the exciting causes of decay, this
predisposition might remain dormant for a lifetime, as is sometimes
the case with other diseases.”

With no disposition to revive a useless discussion, or to dwell
upon the very unreasonable, not to say absurd, objections and
denials which were offered to the communication by doubtless well-
meaning but mistaken men, at the same time I cannot but regret
that they influenced the opinions of others who, reposing implicit
faith in their acuteness and judgment, very naturally regarded the
objections as of a valid character, until an opportunity for observa-
tion convinced them to the contrary. Such was the case with the
gentleman who handed to me the specimen under consideration.

It is to be hoped that the illustration offered will teach a
valuable lesson to those who have been in the habit of dismissing

* ‘Dental Cosmos,’ vol. viii., p. 113.

184 Transmutation of Form in certain Protozoa.

their patients with the statement that “there are some small cavities
in the teeth which can be left without disadvantage until another
time.” It also shows most clearly the necessity of following up
the fissures, which generally extend from a central cavity of decay
in the grinding surfaces of molars; careless operators contenting
themselves with only removing the caries from the central cavity,
leave these fissures untouched, and, as a consequence, decay pro- —
gresses unobstructed and unnoticed, until the tooth is rendered a
mere shell.

V.—Transmutation of Form in certain Protozoa.

By Mercatre Jounson, M.R.C.8.E., Lancaster.
Puate C.
Part I,

On Thursday, August 3rd, 1871, Professor Huxley congratulated
the British Association at Edimburgh on the fact that two gentle-
men of high attainments, Prof. Thompson and Sir William Thomp-
son, had declared themselves in favour of the doctrine of evolution.
It cannot therefore be less a matter of satisfaction to the humbler
labourers in this department (the working bees in the hive), that
such eminent minds give their support to doctrmes which it is the
object of their (the working bees) comparatively insignificant re-
searches to establish.

While the savans are attending the great annual scientific car-
nival, held this year in “ Auld Reekie,” I shall content myself with
sitting at home and writing to the ‘Monthly Microscopical Journal’
on this (to me) important subject of thought and inquiry.

I had proposed to myself, in this next report to the Journal, to
trace the origin of some of the more important members of the
group of Infusoria to the simple elements known as Monas and its
congeners, but owing to the kind sympathy of Mr. G. F’. Chantrell,
of St. James’s Mount, Liverpool, I am induced to devote this paper
to the tracing in greater detail the bearing of Paramcecium to Calli-
dina and its allies, the Philodinea, trusting to reserve the other sub-
ject to a future communication.

In a recent letter, Mr. Chantrell writes as follows :—“I have
thought a good deal of your papers, and am particularly interested -
in your subject. I think (on) the first meeting of our private
Microscopical Society (the Liverpool Natural History and Miecro-
scopical Society) after your last paper appeared, I exhibited a Car-
chesium polypinum, in which the evening before I had noticed some
of the Vorticella heads had disappeared, and in their place, amongst
the branches, I noticed a globular-shaped substance. On this
evening, to my amazement, all the Vorticella heads were gone, and

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Transmutation of Form in certain Protozoa. 185

four more globe-forms added, all clustered together. One of our
members thought he observed a little ciliary action on one, and when
J looked at it again, I saw that it was a Trachelius, and similar to
your sketch 63, but minus the ciliary marks. The snout was there,
and full of revolving vesicles. It quietly stretched itself out and
swam away, and after short intervals all the others made off. Since
then I have had an instance of a Trachelius rubbing itself amongst
the branches of a Carchesium, and.a few of the heads gone and
other heads becoming encysted and assuming a pyriform shape; but
unfortunately my tank gave way, and there was an end of my expe-
riences. What I have observed in my trough is strongly confirma-
tory of your observations. I have sometimes had nothing but
Amoeba; at another time Paramecium, Kerona M. Vorticella in
abundance; at another Philodina, Rotifer vulgaris, and sometimes
Floscularia, &c.”

It is in the highest degree satisfactory to find that observers of
the careful class to which this gentleman belongs not only sympa-
thize in the researches to which I have now devoted some little time,
but are enabled to confirm my suggestions by kindred observations
of their own, assisted by their microscopical friends and associates.

In the Plate accompanying this paper (Plate C.) will be found
the rough delineation of forms which I have observed in various
liquids containing vegetal matter, and which I have watched during
their transmutations to forms which have eventually proved them-
selves to belong to the class Philodinza. It will be my object to
endeavour to show that the members of this class are not forms
having specific distinction, such as in tracing their origin we should
find derived from separate sources, but simply stages of develop-
ment of one common form of animalcular existence.

I will first, then, proceed to give some explanation of Plate C.

Figs. 1 to 7 are the varying forms of an Amoeba, which, com-
mencing as an Actinophrys Sol, passed through its stages, termi-
nating in a form which closely resembles a Paramecium.

Figs. 8, 9, 10, and 11 are varying forms of a species of Para-
meecium, possibly Lowodes Bursaria. Fig. 8 represents the Infu-
sorium in the natural state, the revolving vesicles being in active
motion. Figs. 9, 10,and 11 are under the influence of opium, in
which the revolving vesicles are separated from the other part,
which is intended to represent globules of sarcode, which in Fig. 11
so closely resembles an Amceba as to render it very interesting in
relation to Figs. 1 to 7.

Fig. 12 is a globular condition of a Philodina, showing the
vesicles well developed.

Fig. 13 is a more adyanced stage of the same Infugorium or
Rotifer.

186 Transmutation of Form in certain Protozoa.

Fig. 14 is an interesting form, as exhibiting a stage of progress
towards Philodina.

Fig. 16 is a Paramcecium, or Loxodes, in which the rudiment
of the tail-foot is very evident by reflexion of light, while

Fig. 15 shows the tail-foot more fully developed.

Fig. 17 is a globular form of Philodina, with the telescopic tail
just making its appearance. All these forms I have repeatedly
verified as transitional, having seen them evolve into Callidina,
Philodina, Rotifer, or in the other direction to Amceba, &c.

Fig. 18 is simply inserted as a beautiful globular Infusorium,
whose whole surface is covered with cilia, which work in regular
order, so as to revolve itself slowly and gracefully over the field.
It is here magnified, as are all the other specimens, by 250 to 300 x .*

Fig. 20 is an elementary, probably early, stage of Philodina,
the tail-foot being very distinct.

Fig. 19 is a still more developed form of the same Infusorium.

Fig. 21 is possibly Enteroplea hydatina, found among a num-
ber of Philodinza in water containing Valisneria, sent from Liver-
pool by Mr. Chantrell.

Figs. 22 and 23 are forms of Philodina modified by opium.

Figs. 24 and 25 are the fully-developed forms which I am
accustomed to find in water containing vegetable growths. I shall
have to refer to them at greater length when speaking of the dis-
tinction without a difference which seems to me to have been made
by classifiers.

Fig. 26 is another form of Philodina which I frequently find
the Callidina assuming in its changes.

Fig. 27 is a perspective view of a Callidina, with the proboscis
in the centre.

Fig. 28 is another form, intermediate between Carchesium and
Callidina.

Figs. 29a and b are some rudimentary forms of Infusorium, pos-
sibly passing to Floscularia in water containing Sphagnum palustre.

I have no further history of this Infusorium.

Before proceeding to the general remarks, I will offer a few
observations on the subject of the Plate.

In the first place, it has long been my opinion that Actinophrys
Sol is only a phase of the life-history of Amceba.

It will be observed that Mr. Chantrell speaks of the form of -
Infusortum found in his researches, as varying at different times
between Amoeba and other forms. I have often referred to the
change from Globular to Amceba.f

* If any of your readers will kindly name it for me, either by letter or through
‘M. M. J.,’ I shall feel obliged.

+ See ‘M. M. J.,’ Aug., 1869, p. 104, line 2; May, 1871, p. 255, lines 16,17, «
and 18.

Transmutation of Form in certain Protozoa. 187

April 22, 1871, I found Actinophrys Sol and Amoeba in the
same water in which Sphagnum palustre had been put.

The observation recorded in the Plate (Figs. 1 to 7) was made
July 20th, 1871, and is interesting and important as having been
made, not by myself, but by a perfectly disinterested person, a friend
of mine, Mr. F. Housmann, who is a very accurate draughtsman,
but who, in consequence of his being deaf and dumb, and not a
microscopist, is not in a position to have any preconceived views,
and was not aware of what my own were upon the subject. I
simply observed the Actinophrys Sol (from water sent me from
Liverpool containing Valisneria), and its first change to an Amceba.
I then left my friend to make drawings of any changes he might
see. On my return home, he presented me with the piece of paper
which I herewith enclose,* on which were the drawings of changes
in the Amoeba until the water dried up.

The information derived has two points of interest; the first,
the probable identity of Actinophrys with Amceba; and second, the
association of Parameecium with the other two forms of Infusorium.

In Fig. 9 (which I watched passing to its present state of
protruded sareode from a form similar to Fig. 8) will be observed
the two depressions aa, which give a resemblance to forms 52
and 53 in Plate LXXXV., May 1871, and which I am accustomed
to recognize as decidedly transitional forms of Callidina.

In Fig. 10 aa, similar depressions give rise to a central tongue-
like process in the middie.

The white portion represents the protruded sarcode, which in
Fig. 11 presents such a close resemblance to an Amceba.

If we compare Fig. 14 with some of the figures in the former
Plate, LXXXY., we shall see reason to consider it a transitional
form, especially when associated with Fig. 16, which shows the
white spot which reflects the light, and is in all probability a
rudimentary tail-foot, especially when viewed in connection with
Fig. 15, in which it is more marked.

Figs. 14 and 15 were drawn at the same sitting, March 29,
1871, from the same drop of water, which I had prepared by
inserting a handful of dead leaves, in December, 1870, into about a
pint of water in a glass beaker, in the light and air of my study.

Figs. 19 and 20 are forms which I recognize daily as progres-
sive towards the more mature forms shown in 24 and 25.

Fig. 21 is a developed form, which I do not doubt is traceable
in its origin to the same source as the rest.

In Figs. 22 and 23 we have a strong resemblance in form to
Fig. 50, Plate LXXXYV., which presented a very interesting phase
of change as a Vorticella.

* Mr. Johnson sent us the piece of paper which contained drawings exactly
similar to those in the accompanying Plate.—Ep. ‘M. M. J’

188 Transmutation of Form in certuin Protozoa,

Fig. 26 is another similar change, which I have often seen
from decided Callidina or Philodina. |

Fig. 27 shows the profile view, which as it turns again in the
drop of water reveals the perfect animalcule in its most active form.

It would seem here as if there were much reiteration, but in a
position such as mine I feel as if every step requires the utmost
detail in its construction, lest I should suddenly find myself over
head and ears in a quicksand, with only a mare’s nest to reward
the venture; but if, as it seems to me, there is firm and solid truth
near at hand, the journey to it is worth the attempt.

It is now my duty to undertake a part of the question which
is more than usually difficult, vz. to show that the great system of
classification is on an uncertain basis, and I will take the family of
Philodinzea as an example, and I think the Figs. 24 and 25 may
assist in showing my point.

The family is divided by Griffith and Henfrey, in the ‘ Micro-
graphical Dictionary,’ into Callidina, Hydrias, Typhlina, Rotifer,
Actinurus, Monolabis, and Philodina. ‘The characters of some are
sufficiently doubtful to admit of removal at once. Thus Griffith
and Henfrey say, p. 358, of Hydrias cornigera, pl. 34, fig. 39,
“probably a young and imperfectly examined Philodina,” and of
Typhlina, “an imperfectly examined genus of Rotatoria, of the
family of Philodinea ;” and p. 463, of Monolabis, “Eyes two,
frontal; tail-like foot with two toes; horns absent.”

Dismissing the former two, Hydrias and Typhlina, as “im-
perfectly examined,” we come to Monolabis. Now it is evident to
all observers of these Infusoria, that the perfectly formed animal-
cules, such as Fig. 24, are very frequently observed to present these
marks, tail-like toes two, horns absent, simply because the creature
does not remain long enough under inspection.

I have frequently seen Fig. 24 in such a condition, and the next
minute protrude another joint of the tail and expose the two lateral
horns above the foot as well as those in the cervical region. Jam
therefore of opinion that these characters in animalcules of such
changeable form are not sufficient to warrant a separation into a
fresh class. Let us therefore temporarily dismiss this division, and
look at the remaining four.

Callidina, then, is distinct from Philodina, by the rotatory
organ not being furnished with a stalk; but m the two Figs. 24
and 25 (which I have repeatedly seen transmutable) we have no
characters by which to divide them. Here we have eyes absent
often, because we have not that part sufficiently developed, as in
Figs. 25, 22, 23, or in Figs. 19 and 20. But I cannot persuade
myself that these points, either absent or present, visible or in-
visible, at any one observation, are any other indication than the stage
at which the animalcule has arrived at the moment of inspection.

Transmutation of Form in certain Protozoa. 189

Rotifer is described (p. 603) as having eyes on the proboscis,
foot with two terminal toes, and lateral horn-like processes.

These characters, again, I say are so variable, according to
the stage of development, or even temporary elongation, as to be
valueless as points of distinction.

Actinurus (Griffith and Henfrey, p. 14) “ agrees with Rotifer in
general structure.” ‘The point of difference being three and five
points to the toes. But this question appears to me so entirely to
depend on stage of development and state of projection as to be
entirely unreliable as a distinctive mark.

So far as my few observations have enabled me to form an
opinion, I consider that the facts give colour to the opinion that
the objects figured in the accompanying Plate (Plate C.) are not
only stages of development of one and the same Infusorium, but
that these and several other forms are merely developed states of
some earlier and more simple forms, which I trust soon to be able
to call attention to.

The subject in all its bearings is a very large one, and has so
close a relation to the Darwinian hypothesis, as well as so important
a bearing upon the various schemes of classification, that one is
inclined to hope that some sympathy is felt amongst certain classes
of microscopists who, like Mr. Chantrell, are able and willing to
bear testimony for or against the opinion. Facts “against” are as
welcome as facts “for,” where truth is the object of search. I trust
I shall not be exceeding my privileges in addressing the ‘ Monthly
Microscopical Journal, if I here take the liberty to say, that if
among the readers of the Journal there are those whose pleasure
has led them to investigate this question, and whose leisure will
permit of their writing upon the subject, if they will, either through
the pages of this valuable channel of intercommunication, or by
private post, express their opinion either for or against these views,
it would confer a favour on all who are solicitous for the publica-
tion of truth. It is, I am quite aware, in so difficult a subject as
the education of the eye in microscopy, and with the temptations of
prejudice to lead one astray, a most easy and probable result of
inquiry that it should end in error. But since “ex nihilo nihil fit,”
and “nothing venture nothing have,’ are proverbs which have
stood the test of experience, I trust I shall be held excusable for
having cast loose the anchor of faith in old systems, and venturing
my little boat upon the great sea of speculation and inquiry.
There is one writer, whose name is unknown to me, but who is the
author of a paper in the ‘Quarterly Review’ under the title of
“ Higher and Lower Animals,” whose opinion upon classification
seems to me so very near the truth, that if this venture should
meet his eye it will be esteemed a favour if he would kindly permit
me to hear from him, either under a “nom de plume” or otherwise.

190 Transmutation of Form in certain Protozoa.

My own view of the great question involves what I venture
to term the Unity of Nature, that is to say, that so far as our
senses will at present carry us, we see no separation of nature's
works into classes, except in a very broad and rough investigation ;
and whatever class we examine, whether of the animal or vegetal
kingdom, there are always some members whose characters approach
so closely to those which are considered as indicative of another
class, that we are perpetually brought face to face with objects
which it is impossible to affix the distinct section to which they
properly belong. Thus, whether we divide nature into animal,
vegetal, and mineral—into organic and inorganic, or the animal
world into vertebrate and invertebrate, or the vegetal into endogen,
exogen, and cryptogam, or whatever way we choose to divide it, in
no case can the boundary line be so drawn as to decide definitely
where to place every specimen of nature’s products. This is due
to the limits which are drawn around our senses, and in that
section of nature to which our attention is at present directed the ~
highest powers of the microscope are unable to reveal to us the
smallest of nature’s organisms which develop the phenomena of life.
Testimony is borne by Dr. Lionel Beale to this effect, and he is
understood to make use of the highest powers that have at present
been produced. But independent of this extreme minuteness of
particles of matter, we have reason to consider it as certain as any-
thing we may be said to know, that there is a definite pomt at
which the unit condition of matter commences its existence, and
within the limits of these two considerations we seem to arrive
at a view of life consistent with law, with harmony, and with what
we call “creative wisdom.”

This view, as supported by the principal savans at the Edin-
burgh Congress, is in accordance with Harvey’s law, “‘ Omne vivum
ab ovo.”

In the consideration of the objects to which our attention is’
directed in the present remarks, we are led only to the contem-
plation of them as passing through various stages of growth, and —
possibly in some cases of transmutation somewhat allied to those
imago changes of which the insect class furnish us with such
beautiful and instructive examples. In dealing with the further
details of the progress of growth from less developed forms we
shall have occasion to notice that there is considerable evidence
to show that the form in which the Infusoria commence life as
independent organisms is not always the same, for there is some
reason to believe that considerable development may take place
within the parental cavity before the proles is extruded for inde-
pendent growth. Although this subject must be deferred for more
mature consideration in another paper, yet it may help us to con-
template some of the forms which we have now before us with

Transmutation of Form in certain Protozoa. 191

greater correctness if we bear in mind that this may take place.
Thus the Euglena, which possesses some of the properties of change
of form which are homologous of those here witnessed, is evidently
capable of arriving at the condition of green bodies containing
chlorophyll masses with the red eye before it is extruded from the
parent organism, while it is also capable of arriving at a similar
stage of existence through several conditions, as proved by my early
experiments detailed in my first communication to this Journal.*

The present view of the Infusoria has two points of importance ;
in the first place, if accepted, it reduces the classification to a simpler
and less confusing state, and in the second, it offers a self-evident
explanation of their constant appearance under all circumstances in
which atmospheric air is a factor of the accidents of life. The
first of these points is one of importance, as may be shown by
reference to any book of scientific classification and nomenclature,
from which it will be seen that the same object is often indicated
by different names given by the early or original observer, and in
the case of the Infusoria, since for so long a time Ehrenberg was
their principal if not sole expositor, it has become matter of course
that where this great naturalist had in the first instance given a
name and a class which subsequent investigators have found it
necessary to modify, much confusion has arisen from one and the
same object being spoken of and classified under two different plans.
Thus Loxodes Bursaria is called by another observer Paramecium |
Bursaria, Pleuronema is called Paramcecium, and many others in
similar manner.

I trust that I have now shown some cause for believing that
transmutation of form applies very freely to this class of nature’s
objects, and that we shall thus the more readily enter upon the
consideration of the origin of the Infusoria generally in Monas and
its congeners

Lanoaster, August, 1871.

Many plants are known by two or three names, according to
the observer, e.g. Gongosira clavata (Kiitzing) is Conferva multi-
capsularis (Dilwyn), Protococcus wridis is Chlamidomonas of
Ehrenberg and Diselmis of Dujardin: Protococcus and Chlorococcus
are also liable to much confusion.

* See ‘M. M. J.,’ Aug., 1869, p. 101, line 41.

( 192 )

VI.—On Gnats’ Scales. By Januz Hoaa, Esq., Hon. Sec. R.M.S.

Ir is said that history repeats itself decennially : if this be a truth
in the progress of nations, it appears to be scarcely less true with
regard to science, which not unfrequently furnishes to the pages of
our periodical literature an old discovery furbished up in so attrac-
tive a dress that it sometimes passes as a newly-recorded fact. This
is certainly the case with a supposed discovery referred to at page
102 of the August number of the ‘ Microscopical Journal.’ The
writer mentions that “in the spring of 1868, while engaged in
examining the head of a gnat, he was surprised to discover that
the proboscis and palpi were clothed with scales entirely like those
of butterflies.” The paper on this subject appears in a German
scientific journal, “under the joint authorship of Dr. E. Muller
and Professor F. Delpino,” and it has been translated for the
‘American Naturalist’ by Mr. R. L. Packard, a gentleman well
acquainted with the Natural History world, who therefore should
have known that there was nothing novel in placing on record
observations which appeared in my book on the Microscope pub-
lished in 1854, and repeated in all subsequent editions, some
60,000 copies of which have made their way to every part of the
civilized world. A drawing of the proboscis, clothed with scales,
is given page 287 first edition, 599 of the sixth edition; a
single scale detached is seen near it; and again, at page 611,
another scale, more highly magnified, and exhibiting the “ wavy
appearance” spoken of by the German authors, but which curiously
enough does not quite accurately represent the structural charac-
teristics of the scale. The waviness is owing to the under surface
being seen rather out of focus. I stated, however, that “the
curiously-formed proboscis is covered with feathers or scales ;” and
in the woodcut a scale is placed side by side with other test-scales
from Lepidoptera and Spring-tails, in order that their structural
similarity might be noticed. It is not perhaps so very surprising,
after all, that this fact should have escaped the observation of
German authors, since it has received so little recognition from
English writers on either entomology or microscopy. So far as 1
have been able to ascertain, no one has described this peculiarity of

DESCRIPTION OF PLATE CLI.

Fic. 1.—Battledore scale from proboscis of Culex pipiens.
» 2.—Flattened out scales from body.
» %—Pointed scale from margin of wing.
», 4—Trumpet scale from thorax, each x 350 diameters.
», 0—Portion of leg and foot.
,, 6.—Clothed proboscis.
» 7—Arrangement of scales on wing.
5 8.—Scale, Culex , variety unknown.

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On Gnats’ Scales. 193

the proboscis of the Gnat; and indeed no one would expect to
find so curious a departure from the ordinary characteristic of the
- order Diptera as that presented by the Culicide. Francis Walker,
F.L.S., mentions in his ‘ Insecta Britannica,’ 1856, that the veins
of the wings of Culex, Anopheles, Corethra, Mochlongx, and Aédes,
“are fringed with scales,” but he omits to notice their occurrence on
other parts of the insects. As both German authors and American
translator have repeated my error of the “ wavy appearance” of
the scale, and made sundry other slight mistakes, it may be as well
to enter a little more fully than I have hitherto done into the
structure and variety of “ Gnats’ scales.”

Scales are a generic characteristic of the Culicide, and although
presenting pretty much the same appearance differ essentially in
form. ‘There are four distinct kinds: the proboscis, palpi, and legs
are entirely covered over with the battledore scales, represented at
Fig. 1. The nervures or venations of the wings, and portions of
the body of the insect, have regularly arranged rows of scales, shown
at Fig. 2; while from the marginal edges of the wings project
slender scales, which terminate in a point, Fig.3. The intermediate
portions of the wings and body are covered with fine hairs, the
thorax with tufts of feathery scales somewhat peculiar in form,
Fig. 4, the pedicles of which are considerably longer than the rest,
while the upper part gradually widens out and terminates abruptly
in a crenated edge. These may be briefly described as trwmpet-
shaped scales. In each case the scale is inserted by a narrow
pedicle into the chitinous membrane, gradually assumes a scutiform
appearance, and terminates in a crenate or pointed edge. The base-
ment membrane is homogeneous, and the upper layer is corrugated
or traversed by longitudinal ribs, and these again are regularly and
finely striated throughout in the horizontal plane. It is the stria-
tions on the ribs which, when seen slightly out of focus, give to the
scales a wavy appearance.

It is curious to find portions of C. pipiens completely clothed,
and other parts free from scales. The legs are covered throughout,
as shown in Fig. 5, and the feathers seem to take the place of hairs
in other families of the Diptera. The proboscis, which is half the
length of the male insect, is used as a prehensile organ and as
a sheath or scabbard to the exquisitely-formed set of penetrating
instruments. A slender needle-like piece, seen in the drawing, Fig. 6,
just projecting out of the sheath, is serrated towards the tip, and
thickened at the back like a scythe. It is said to be employed as a
suctorial apparatus, or, when the insect is irritated, for conveying
a fluid which is thought to be poisonous, from the minute receptacle
situated at the base of the proboscis. The feathered sheath can,
by a little careful dissection, be drawn off the slender set of instru-
ments. To secure perfectly good scales, and preserve them in an

194 The Examination of Nobert’s Nineteenth Band.

undisturbed state, the Gnat must be secured as it is seen issuing
from the larva case. The scales should also be mounted dry, as
when immersed in balsam or fluid they become too transparent.
They are an excellent test for a $-inch objective.

It is not improbable that the scales of even the various species
of Culex will, after a more careful examination than I have been
able to make, be found to differ, as upon going over the collection of
Gnats in the British Museum, I discovered the scale represented at
Fig. 8. This form closely resembles the scales of Lepidoptera.

The body of C. annulatus is entirely covered with alternate rings
of dark brown and white-coloured battledore scales; and the hairs
projecting from its sides are longer and more numerous than in
C. pipiens or C. musquito. The “feathered antlers” pectinate
antenn of the male insects, although destitute of scales, are exceed-
ingly handsome objects: they surmount the most brilliant set of
compound ocelli it is possible to find. In short, he wears finer
clothes and is better dressed throughout than his female companion.
When the piercing apparatus is sent into the flesh of a victim, the
proboscis appears to divide, it is then thrown up and turned back
upon the head like the trunk of an elephant.

The Gnat-like midges, so common in this country, and which
belong to the Tipulidse, very closely resemble Culicide. Chironomus
plumosus, often mistaken for a Gnat, has plumed antenn ; but on
no part of wings or body can scales be found; the same remark
applies to the rest of the species. The resemblance between many
of the perfect insects belonging to the genus is striking, while
their larve differ very considerably from each other. The club-
shaped balancers, halteres, are more developed in Tipula than in
Culex. The genus Psychoda have been thought to be clothed with
scales, however they are not ; their wings and bodies, on the contrary,
are thickly covered with long, peculiar hairs. Some of these little
creatures present under the microscope a gorgeous appearance.
The various parasites infesting Diptera deserve the attention of
microscopists.

VII.—The Examination of Nobert’s Nineteenth Band.
By F. A. P. Barnarp, of Columbia College, New York.

A PARAGRAPH in the article “On the Use of the Nobert’s Plate,”
by my friend Colonel J. J. Woodward, of Washington, published
in the July number of the Journal, which has just reached me,
deserves some notice. The paragraph is upon page 27 of the
Journal, and relates to a plan employed for settling the question
whether the lines seen by me in the nineteenth band of Nobert’s
plate, in a series of observations made some years ago, were true or

The Examination of Nobert’s Nineteenth Band. 195

spurious. The personal question involved is of no consequence
whatever; but the trustworthiness of the method employed is
another matter; and this, I think, is not at all invalidated by the
argument of Colonel Woodward.

This method may be briefly explaimed thus:—In ruling his
nineteen-band plate, Mr. Nobert has designed to make the spaces
between the lines of the ninth band, measured from centre to
centre, just sooth part of a Paris line each; and those of the
nineteenth band ystpoth each. When I found, by micrometer,
that twenty spaces on the nineteenth band, or any other carefully
counted number, had the same aggregate value as half as many
spaces on the ninth (where the counting is easy), I considered
myself justified in concluding that the nineteenth band was truly
resolved; and did nof think it necessary, in order to prove this,
that I should actually count the band clear across.

Colonel Woodward, however, says that this method will not do,
because the spaces have not probably the values nor the relations
intended by Nobert, and stated by him to exist. That the absolute
values of the divisions are not exactly what was designed is pre-
sumable enough; because it is not possible to construct a scale or
anything else in so strict accordance with the intention as to be
without error altogether; but in respect to the relations between
the spaces of two scales ruled by the same machine, there is hardly
room for the same degree of uncertainty. The parts of a ruling
machine by means of which the distances between the lmes ruled
are regulated, are not microscopic. They are so large that any
minute irregularity in them would bear no appreciable ratio to
their total magnitude. Moreover, when we consider that the same
part of the machine—a ratchet, for instance—bears the divisions
by which both the larger and the smaller spaces are regulated, so
that—to take the case before us—the very same instrumental
measure determines the aggregate value of ten spaces of the ninth
band, and of twenty spaces of the nineteenth, we shall see that
_there can be no sensible error in assuming that the ratio between
the mean breadths of these spaces is as two to one. There can be
none, at least, except on the supposition of wilful mis-statement by
Mr. Nobert—a supposition which his known integrity makes
inadmissible, and which is, moreover, abundantly disproved by
Colonel Woodward’s own photographs and measurements.

Colonel Woodward, however, thinks that the ninth band is
broader than the nineteenth; whereas, since the former has but
twenty-six spaces, while the latter has fifty-six, the nineteenth
should have the greater breadth if the spaces are truly to each
other in the ratio of two to one. Supposing the total breadths of
the bands equal, the numbers just given enable us to state the real
ratio to be as two and two-thirteenths to one; or, as Colonel

VOL. VI. P

196 The Examination of Nobert’s Nineteenth Band.

Woodward thinks the ninth band really the narrowest, we may be
justified in saying that his hypothesis makes this ratio as great as
21:1. Is it for a moment conceivable that a ruling engine of any
sort—to say nothing of one of such exquisite workmanship as that
must be which has turned out these miraculous achievements of
Mr. Nobert for so many years—should be capable of making errors
in its divisions to the extent of one part in thirteen ?

If we suppose, however, the relation of the spaces in these two
bands to be such as Mr. Nobert intended, then the ninth band is
not the broader of the two, but the nineteenth. The difference
would be yoésoths of a line, or topoooths—say sotooth of an
inch. This small space is undoubtedly measurable; but in the
present instance it is rather difficult to measure, because, first, the
ruled lines themselves are heavier and broader in proportion as the
spaces are wider; and because, secondly, when the lines are truly
in focus, the false lines on the margin make it often rather doubtful
where the band begins.

But now, without making any question about the absolute or
the relative values of these spaces, any further than to assume that,
in the latter particular, the deviation from the intention is not
greater than Colonel Woodward supposes, though I am willing to
allow it, if necessary, to be as great as 24:1, I think I may
reasonably claim that my list was a perfectly trustworthy one for
the purpose for which alone it was applied, ¢.e. to settle the ques-
tion whether the nineteenth band was or was not truly resolved.
Anyone who has studied close rulings under the microscope, with
varying obliquity of illumination and parallel rays, will have
observed two species of illusion so perfect as to deceive the most
practised eye, and even his own if he happens not to know the
object at which he is looking. One of these presents the number
of lines exactly doubled, and the other shows exactly half the true
number. ‘The physical cause of these appearances I believe I am
able to explain; but the explanation would be here out of place.
Whenever either of these illusive appearances presents itself, the
lines are perfectly smooth and clear, and continuous from one end
of the band to the other. They will imevitably be taken by the
unpractised observer for the real lines. But the ordinary appear-
ance of the unresolved bands is not this. The spurious lines which
appear before resolution are in general rough, irregular, and, to
use a word which best expresses the appearance, blotchy. The
number of these rough lines which may be seen in a given band is
not very easy to count; but when I have succeeded to a certain
extent in counting, I have found that it is never with me in a
simple ratio of 2: 1, or of 1 : 2 to the number of real] lines known
to be present. On the other hand the ratio is as inconstant as
possible.

The Examination of Nobert’s Nineteenth Band. 197

Now for the bearing of this fact of observation upon my test.
In looking at the nineteenth band, I saw it as a series of per-
fectly regular, well-defined, uniformly distant lines, covering its
whole surface, and extending unbroken across the entire field of
view of my microscope. The question with me was, Do I see the
true lines, or is this appearance the illusion in which only half the
true number are present? In the latter case, I shall find in a
given space the same number of lines which I find in the ninth
band in the same space; in the former, I shall find twice as many.
Now, if I had not found exactly twice as many (which I did), I
should have still believed the band to be resolved; for it was
impossible to suppose that I saw only half the number of the true
lines; and equally impossible to suppose I saw twice the number
of the true lines; therefore, if I had observed (as I did not) any
seeming deviation from the ratio of 2:1, I should have been
compelled to account for it on a hypothesis such as Col. Woodward
has suggested, vzz. that the relations between the spaces in these
two bands are not exactly in accordance with the intention of the
constructor.

There is a peculiarity of this plate brought to view by this
discussion which has never been noticed, though apparently intro-
duced with a purpose. The first band has seven lines, and purports
to measure from centre to centre of the bounding lines just +,%oths
of a Paris line. The next has ten lines, and similarly measures
zr2soths of a Paris line. The third has thirteen, and measures
syooths. All these fractions, reduced, give the same value s%,ths
of a Paris line, as the common total breadth of the bands. But
the fourth band has fifteen lines only, or fourteen spaces. The
spaces Mr. Nobert states to be 2500th parts of a Paris line; so
that if there had been sixteen instead of fifteen rulings in the band,
the total breadth would have been 3}%,ths = =3,ths as before.
On the other hand, if fourteen spaces occupy s%oths of a Paris line,
each space must be greater than s;5,th. Considering that, with
a dividing machine, it would be much easier to follow up the series
000» 1500» s0002 Zs00, than to substitute, in place of this last
term, za, 28 the second supposition would require; and con-
sidering that this substitution would be a contradiction of Mr.
Nobert’s express statement of values marked on every one of the
plates, we may fairly conclude that the dropping of a space argues
no interruption of the law regulating the values of the divisions,
but does argue a reduction of the total breadth of the fourth band.
The sixth band contains seventeen lines, or sixteen spaces. If the
rulings had been nineteen, and the spaces eighteen, the total
breadth of the band would have been 333,;ths = s%sths as before.
In short, if the aim had been to keep the total breadth of the band
always the same, there would have been added always three lines in

p 2

198 The Examination of Nobert’s Nineteenth Band.

proceeding from each band to the next. The nineteenth band
would in that case have had sixty-one lines and sixty spaces, and
its breadth would have been +;8%oths or 52,ths of a line like all the
rest. In point of fact, the number of lines added in passing from
band to band is three in only twelve instances, two in five instances,
and four in one instance. An apparent law regulates this matter —
till we approach the more difficult bands. Thus, there are first
two threes, then two twos, then two threes again, and then two
twos once more; but then follow three, four, three, and we are
now at the twelfth band where the difficulties become serious. My
opinion is that Mr. Nobert introduced this irregularity to make it
impossible for anyone to state with certainty the number of lines
in any of the higher bands without having actually counted them.
Had the law of threes been followed throughout, it would of course
have been easy to ascertain the number of lines in any band by a
simple calculation. He did not believe that any band beyond the
fourteenth would ever be optically resolved. He stuck at that
band for a long time himself, and in its divisions he had reached
the limit of visible magnitude assigned by Fraunhofer. Knowing
then himself, and he only knowing, the numbers of lines on these
higher bands, and having made it impossible with certainty to
calculate them, he had an infallible criterion for determining
whether an imagined resolution had been real. Colonel Woodward
having met this difficult test, and having counted for him his lines
in every band, he has been satisfied, and has frankly admitted that
the thing he deemed impossible has been accomplished.

July 19th, 1871.

( 199 )

PROGRESS OF MICROSCOPICAL SCIENCE.

Experiments on Spontaneous Generation.—Mr. F. Crace-Calvert,
F.RS., has been recently making some experiments in this direction
which have led him to conclude that spontaneous generation is an
impossibility. They are published in the ‘ Proceedings of the Royal
Society,’ No. 128. The more interesting were those made relative
to the heat which the lower organisms can tolerate. The first series
of experiments was made witha sugar solution. Sugar was employed,
being a well-defined organic compound free from nitrogen, which can
easily be obtained in a state of purity. To carry out the experi-
ments he prepared a series of small tubes made of very thick and
well-annealed glass, each tube about four centimétres in length, and
having a bore of five millimétres. The fluid to be operated upon was
introduced into them, and left exposed to the atmosphere for sufficient
length of time for germ-life to be largely developed. Each tube was
then hermetically sealed and wrapped in wire gauze, to prevent any
accident to the operator in case of the bursting of any of the tubes.
They were then placed in an oil bath, and gradually heated to the re-
quired temperature, at which they were maintained for half an hour.
A solution of sugar was prepared by dissolving 1 part of sugar in 10
parts of water. This solution was made with common water, and ex-
posed all night to the atmosphere, so that life might impregnate it.
The fluid was prepared on the 1st of November, 1870, introduced into
tubes on the 2nd, and allowed to remain five days. On the 7th of
November twelve tubes were kept without being heated, twelve were
heated to 200° Fahr., twelve to 300°, and twelve to 480° Fahr. The
contents of the tubes were microscopically examined on the Ist of

December, twenty-four days after heating, with the following re-
sults :—

. Heated for
: Shem Solutiou half an hour
" at 212° Fahr.
Therewereabout| A great portion

thirty animalcules' of the life had
under each field, disappeared; no
of the microscope, | animalcules were
principally small swimming; _ still
black vibrios, two this temperature
or three micro- had not completely
zymes swimming)
slowly about, three ,
or four ordinary
swimming vibrios,
and a few Bac-
teria.

or five small black
vibrios were ob-
served moving
energetically to
and fro; two or
three ordinary vi-
brios were also
observed moving
energetically in
the same position
of the field; that
is, without swim-
| ming about.

destroyed life. Four |

Heated for
half an hour
at 300° Fahr.

The sugar was
slightly charred,
but the life was
not entirely de-
stroyed, as one or
two ordinary vi-
brios and one or
two small black
vibrios were ob-
served in motion
under the field of
the microscope.

Heated for
half an hour
at 400° Fahr.

The sugar was
almost entirely
decomposed; no
trace of life was
observed.

Heated for
half an hour
at 500° Fahr.

No life observed,

200 PROGRESS OF MICROSCOPICAL SCIENCE.

Recent Foreign Papers.—Professor Stricker’s ‘New Year-Book of
Medicine,’ of which two parts have been published, contains a series
of valuable papers on microscopy. Among them may be mentioned
the following :—There is one by Dr. Hausen on the results of inflam-
mation in the corneal tissue; another by Dr. Giiterbock on the effects
of inflammation of tendons; by Dr. Yeo on the pathology of inflamed
lymphatic glands; by Stricker himself on the nature of the poison of
pus, and another paper in conjunction with Dr. Albert—an account
of traumatic fever; Dr. Lang gives the pathology of inflammation of
the bones, and Dr. Kimdrat a paper on the inflammatory changes in
the endothelia of serous membranes.

Researches on Inflammation and Suppuration.—At a meeting of the
Royal Irish Academy, held on May 8th, Dr. J. M. Purser read the
second part of his report on the above subject. It is reported by the
‘British Medical Journal,’ which gives a very full account of the
paper. Herr Cohnheim believes that the two following propositions
are established. as the result of his investigations :—1. In an inflamed
part, the white corpuscles of the blood pass through the walls of the
vessels in great numbers, and, having become free in the tissue, con-
stitute the cells of pus. 2. The cells of the inflamed part itself have
no share in the formation of pus; they persist for a time unchanged
among the emigrated blood-corpuscles, and, if the inflammation last
long enough, or attain a great intensity, they undergo a series of
changes of a purely regressive or degenerative nature, ending in their
death or destruction. Dr. Purser, in the first part of his report, read
twelve months since, stated that his own observations fully bore out
Professor Cohnheim’s views as enunciated in the first of the above-
quoted propositions. So far back as the year 1846, Dr. Augustus
Waller had described the passage of the leucocytes of the blood through
the walls of the vessels. With regard to the second proposition of the
German physiologist, however, Dr. Purser found that the experiments
conducted by himself gave negative results, and in them he was borne
out by the opinions of Virchow and of’ Goodsir. Having described
Professor Cohnheim’s mode of procedure in experimenting on the
corner and tongues of frogs, Dr. Purser proceeded to give in detail
the results which he had himself obtained. His observations were also
made on the cornex and tongues of frogs. Inflammation was excited
either by cauterization with nitrate of silver, or by the insertion of a
seton. In some instances, the occurrence of a spontaneous ulcerative
keratitis obviated the necessity of causing irritation. Phenomena,
essentially the same in kind, but varying much in degree and as to the
time of their development, showed themselves in every case. On no
occasion did the connective-tissue cells remain unaltered among the
pus-corpuscles. The first well-marked change observed in the former
consisted in a tendency to become elongated, and, in doing so, to lose
their equally stellate shape. Their nuclei underwent a similar modi-
fication of form, and the protoplasm assumed a more decidedly granular
appearance than in health. In the next stage of the inflammatory
process, the cells have completely lost their primitive form, and have
become perfect spindle-shaped bodies, while the number of nuclei

CORRESPONDENCE. 201

increased, and amounted sometimes to four or more in a single cell.
The third change consisted in the division of the spindle-shaped
corpuscles. These first assumed an hour-glass appearance, and finally
divided across in one or more than one place. Sometimes the spindles
did not divide, but formed movable, multi-nucleated masses, like those
described by Stricker. Dr. Purser believed, too, that the researches of
this physiologist on inflammation confirm his own observations.

NOTES AND MEMORANDA.

Mr. Wenham and Mr. Tolles.—In reference to Mr. Wenham’s
last communication, we have received a letter from Mr. Charles Stodder,
of Boston, relative to his supposed share in the controversy. He
thinks that Mr. Wenham does him “too much honour when he
associates” his name with that of Mr. Tolles, in the matter of the
angle of light admitted to an objective. He does not presume to
have or express any opinion either on one side or the other. It seems
that his note, which we published, was intended to be a private note,
containing a correction. As, however, it was not marked private,
we could not imagine it was intended as such, and hence, for full
correction sake, we published it. Mr. Tolles does not wish to have his
name mixed up in the discussion. Hn passant, we beg to point out
that there was an error in Mr. Tolles’ paper, the word suffraction
being printed by a stupid mistake for refraction.

CORRESPONDENCE.

Nozert’s NineteentH Banp.—Coxu. Woopwarp.—Mr. Stopper.
To the Editor of the ‘ Monthly Microscopical Journal,’

Boston, July 20, 1871.

Mr. Eprror,—I have no longer any controversy with Col. Dr.
Woodward on the question whether he or Mr. Greenleaf and myself
were the first to resolve the nineteenth band of Nobert’s plate. I have
said on that, all that I need to say.

But his last paper, in the July number of the ‘ Monthly Microsco-
pical Journal, has some propositions that are subjects of fair criticism
—some that I dissent from, and must point out, or my silence would be
claimed as assenting. Therefore I ask the privilege of submitting my
views to the “ goodly company” of microscopists, who must decide.

Dr. Woodward opens his case, by saying that he does not think
that the question of priority as to the resolution of the nineteenth band
possesses sufficient general interest to make it worth while for him to

202 CORRESPONDENCE.

add anything to what he has already written. What he has written is
evidence that he then thought it was a matter of great interest. It is
true the question does not, outside of the circle of microscopists, possess
the interest that the invasion of France by Prussia did in the political
world ; but within that circle it does possess as much interest as does
the cession of Alsace to Prussia in the political.

The first construction of an instrument capable of that feat marks
an event, an era in optics, as important and remarkable as the re-
nowned improvements of Lister and Andrew Ross.*

Dr. W. says, three criteria for distinguishing the spurious from
the true lines have been offered. He specifies, “ The first is the un-
aided judgment of the individual microscopist, who is supposed to be
able instinctively to distinguish the false from the true lines, without
any special help.” By whom was such a criterion ever offered? Cer-
tainly not by me.

On the same page—in the same breath, so to speak—Dr. W. con-
tinues: “It may be granted that an observer who has many times effected
the true resolution of any given band, will at length have its appear-
ance so firmly impressed upon his mind that he will recognize it
whenever he sees it, as he would the face of a familiar friend; but this
familiarity, which all acquire with any appearance which they have
many times reproduced, will only serve to mislead, if at the beginning
spurious lines have been confounded with the true, for then the decep-
tive spurious appearance will be sought for as eagerly as though it
were the true one.” Good! Dr. W. having granted that, has granted
all I ask for. That has been my principle of observation, caution
and all. I could recognize the true lines as the face of a familiar
friend.

A few other passages in Dr. W.’s paper require notice. He says
the question is “simply whether the modern objectives as actually
made have a field sufficiently flat to resolve from edge to edge a series
of lines occupying a space of the 2000th part of an inch wide.” No
question like that has ever been offered or, suggested by anyone before to
my knowledge, not even by Dr. Woodward himself. Flatness of field
is a desideratum in an objective, but not the sine qué non, The real
question is, can an instrument be made of such defining power as to
separate or to show the lines or the spaces between two lines ruled
to the fineness that the nineteenth band is ? Mr. Huxley said, “ Histo-
logists, he feared, had come to the end of their work unless. .
they could obtain microscopes which would enable them to separate
two points the 100,000th part of an inch apart.”t Mr. Huxley can
scarcely be posted as to what modern microscopes can do. If the lines
of the nineteenth band are as wide as the spaces between them, they
are only 1—224,000th of an inch apart.

The problem is strictly analogous to that of separating double
stars—a matter of definition. If the microscopist can see the spaces

* See Carpenter, ‘The Microscope and its Revelations,’ 1st ed., 1856, p. 197,
Philadelphia, and every edition since to 1868; also Dr, H. H. Hagen’s Remarks,
‘Proc. Boston Soc. Nat. Hist.,’ 1869, vol. xii., p. 359.

~ ‘M. M. Journal, Nov., 1870, p. 291. ;

CORRESPONDENCE. 203

between two, three, five, or ten lines of a certain band of the plate he
has resolved it. If he doubts the ruling, or wishes to verify he
may count and measure until he is satisfied. It was entirely optional
with the artist to rule ten lines or ten hundred—the problem of rego-
lution is the same. There is no special virtue in fifty-seven lines. Dr.
Woodward’s criterion of the resolution is as much a test of the “ flat-
ness” of the glass on which the lines are ruled, as of the “ flatness” of
the field of the objective. It will readily be perceived by anyone who
has tried the resolution, that so minute and delicate are the lines, that
any curvature of the glass, or variation even in the thickness, will throw
some of the lines out of focus.

I readily acknowledge the justness of one of Dr. W.’s criticisms
on my original paper. It was an oversight to suggest that the micro-
meter must be moved the 100,000th of an inch only. That, however,
does not remove the difficulty of counting “such fine lines.” I never
said it was impossible.

I regret exceedingly that Dr. W. should think that I have shown
unfairness to him in representing his remarks: it was my endeavour to
represent them fairly, and I believe I have represented them as they
were understood by all my friends. I was acquainted with Dr.
Hagen’s assertion which Dr. W. quotes, though I do not read the ori-
ginal I know that Dr. Hagen wrote that none of Tolles’ objectives had
resolved the nineteenth band, and wrote it after he had been positively
told by several accomplished microscopists that they had seen it re-
solved; equivalent to saying that they did not know what they had
seen so well as Dr. H. did himself; and since that time Dr. Hagen has
said that he had seen the true lines of the nineteenth band with a
Tolles’ ;,th. It of course is a question what constitutes a resolution,
but he did not suggest that. I have defined my problem, and submit
it to the microscopical world for their approval or rejection.

It is a misfortune that so much time elapses between the making
observations, and writing and the publication. My inquiry of Dr. W.
was written in September, 1870, though it was from causes beyond my
control in my hands until November, and it was not published until
March, My question referred of course to the time (May, 1869) when
Dr. W. tried the Tolles’ objectives. He replies (April ?) 1871, stating
what the objectives will do that he has then. If he had delayed until
July, a change had occurred. He has now ascertained that the Powell
and Lealand so-called jth objectives are really jth; the so-called
ygth is a th ;* that his description of the appearance of the true
lines of the nineteenth band on his plate is not a correct description
of the appearance of lines of the same band on the plate I used. All
these facts, I presume, Dr. W. will in due time communicate to the

ublie.
; In conclusion, Dr. Woodward is entitled to the thanks of all
microscopists, who may undertake the excessively difficult task of re-
solving these lines, for the admirable manner in which he has described

* Objectives are named when adjusted for uncovered objects, a fact not
generally known by purchasers. The power increases, ¢.e. the focus is shorter
as the collar is turned to work through the covering glass.

204 PROCEEDINGS OF SOCIETIES.

the difficulty of the undertaking, and the obstacles they must en-
counter. His paper should be read in connection with Dr. Pigott’s
paper in the ‘ Monthly Microscopical Journal’ for June, 1870. The
two papers afford the most complete account of these wonderful lines
that I have yet seen.

CHARLES STODDER.

PROCEEDINGS OF SOCIETIES.*

Royat MioroscopicaAL Socrery.

The first Evening Meeting will take place on Wednesday, the 4th
inst., when the President will read a Paper.

BRIGHTON AND Sussex Naturau History Society.

July 13th.—Ordinary Meeting. Mr. J. J. Sewell, Vice-President,
in the chair.

Messrs. Ireland, D. B. Friend, and Dr. Tuthill Massy were elected
ordinary members; and the names of seven gentlemen were proposed
for election in August.

Mr. Gwatkin reported the receipt, for the Society’s album, of seven
very beautiful photographs of microscopic objects, made and presented
by Dr. Hallifax, including sections of proboscis of blow-fly showing the
rasping teeth, poison bag of spider, teeth of medicinal leech, &c., and
a water-colour drawing, by Mr. Penley, of Swanbourne Lake, Arundel,
from a sketch taken by him on the occasion of the annual excursion.

Votes of thanks were passed to these gentlemen.

Mr. H. C. Malden gave an account of the great difficulties he had
encountered in killing a female puss moth, until she had laid her eggs.
Apparently killed on a Friday, after laying 175 eggs, she recovered,
and though repeatedly, to all appearance, killed on that and the three
following days, she did not die until she had laid in all 298 eggs.
Many examples were given by the gentlemen present of the extrusion
of eggs by moths, not only before death, but even in articulo mortis or
when the thorax was stiff, and to all intents dead; so great is the effort
of nature to propagate the species.

Mr. Wonfor then read a paper ‘‘ On the Annual Excursion to Arun-
del, on June 30th,” in which the chief incidents of the day, and the
various objects seen and obtained, were very graphically and happily
described, and especial reference made to the courtesy and hospitality
of the Mayor of Arundel (W. W. Mitchell, Esq.), who invited them to
luncheon, and of his Grace the Duke of Norfolk, who granted permis-
sion to see the gardens and private grounds attached to the castle.

Votes of thanks were passed to the Mayor of Arundel and to his
Grace the Duke of Norfolk.

* Secretaries of Societies will greatly oblige us by writing their report legibly
—especially by printing the technical terms thus: H ydra—and by “underlining”
words, such as specific names, which must be printed in italics. They will thus
secure accuracy and enhance the value of their proceedings—Ep.‘M.M. J’

PROCEEDINGS OF SOCIETIES. 205

July 27th.—Microscopical Meeting. Mr. J. J. Sewell, Vice-Pre-
sident, in the chair. Subject, “ Pond Life.”

Mr. R. Glaisyer reported the receipt, for the Society’s cabinet, of
twelve slides from Mr. C. Neate, four from Mr. Gwatkin, and four from
Mr. Wonfor.

Votes of thanks were passed to the donors.

Mr. Robertson announced that a dip made in the moat at Plumpton
Place revealed the presence on the American weed Anacharis alsinas-
trum of Cristatella mucedo, besides several mollusks, larvee of ephemera
and caddis, four species of Planaria, two species of water beetles,
Daphnia, &c.

Mr. Wonfor remarked that though there was not time to go to the
marshes when at Arundel, he had made a dip in the lake at Swan-
bourne, and obtained various desmids, including Euastrum, Micrasteria,
and Closterium, several of the commoner diatoms, Rotatorie, Floscula-
rie, &e., and globules of Chara vulgaris, containing spermatozoids, some
of which he had mounted for the cabinet. From a pond near the Has-
sock’s Gate Station, in addition to various forms of Daphnia, Cyclops,
&e., he had obtained young tritons, which exhibited the circulation of
the blood very beautifully; plenty of Hydra viridis, some of which
showed developed young hydra attached to the parent, and Planaria.
On Monday, Mr. Sewell and he, upon the occasion of going to Lewes
to assist at a conversazione of the Lewes Natural History Society, had
obtained in the marshes, at Southover, plenty of Volvow globator ; on
the frog-bit egg masses of different mollusks, some of which were so
advanced that the young mollusks might be seen through the jelly-like
substance enclosing them ; a few specimens of Hydra fusca and vulgaris,
red and other water spiders, &c.; and that afternoon, from a pond on
Furze Hill, he had obtained plenty of Volvox globator in all stages,
several varieties of Daphnia, Pleuroxus, Alona, Rotatoria, &c., as well
as a Melicerta, Spirogyra, and many other minute organisms which he
had not time to identify. He had never seen a pond so rich in Volvox
as the one he had visited that afternoon.

After a discussion on the nature and generation of Hydra and
Volvox, in which Messrs. Sewell, Wonfor, Robertson, and Dr. Hallifax
took part, the meeting became a conversazione, when

Mr. R. Glaisyer exhibited various entomostraca, including Daphnia
pulex and D. vetula, Planaria, and Anguillula.

Mr. Sewell exhibited Volvow globator, Cyclops quadricornis, &e.

Mr. Wonfor exhibited Hydra viridis in different conditions of
development, Volvow globator in different stages, Spirogyra, Hy-
drachna, &e.

It was announced that the subject for the next Microscopical Meet-
ing, August 24th, would be “ Polyzoa”; and that at the next Ordinary
Meeting, August 10th, Mr. Wonfor would read a paper on “Is Bombyx
callune a variety or a species ?”

206 PROCEEDINGS OF SOCIETIES.

Soutn Lonpon MicroscoprcaAL AND Naturat History Cxivus.*

An Ordinary Meeting of this Club was held on Tuesday evening,
July 18th, at Glo’ster Hall, Glo’ster Place, Brixton Road. Henry
Deane, Esq., F.L.S., in the chair.

Mr. Britten, F.L.S., of the Herbarium, Kew, read a paper “On
the Work of Local Societies, especially in connection with Botanical
Science.” The following is an abstract of this paper :—

The primary duties of local societies are briefly these :—to bring
together those persons, residing in a given district, who have paid at-
tention to any group of natural objects, that they may, with mutual
advantage, compare specimens and notes; to encourage others in the
formation of similar tastes, and to put them in the way of following
them out in the manner most likely to be of practical use to them-
selves; and to investigate, as far as possible, the natural productions
of the district, either with a view to the publication of a local fauna and
flora, or merely for the purpose of self-instruction. The mere fact of
joining such a body indicates a taste for the study of nature, which
is in itself a good sign, but it must be remembered that no mere
accumulation of money can make a local: society successful: you
may be rich in cash, but bankrupt in matters of greater value; while
if your storehouses of knowledge be full, empty coffers will matter
little.

A book upon the flora of Surrey was published eight years ago by
the Holmsdale Natural History Club. It may be considered a fairly
complete work, but one point in which it is deficient is its want of his-
torical interest. It is exceedingly interesting for a botanist to note
the influence of civilization upon the flora of a region. To the anti-
quarian, what memories of old times are conjured up by the records
of the fathers of English botany, of the London plants such as they
were in those days; when we might find on our evening rambles in
the fields near “a theatre by London” (that is, the first public theatre
in London, built in Shoreditch about 1570) wonderful double butter-
cups ; when Penny-Cress grew in the “streete of Peckham”; when
the small autumn hyacinth grew “upon a banke by the Thames side
between Chelsey and London.” One can picture to oneself Gerarde
poring over the plants growing in his large garden in Holborn “ within
the suburbs of London,” or John Parkinson, the king’s herbarist, whose
garden was in Long Acre, going down to Westminster to inspect the
famous collection of carnations of his friend Ralph Tuggy, and one
is tempted to wander off into speculations as to what these worthy
men of bygone days would say were they suddenly to return to life
and see all the changes that have taken place since that time, or
what we'should do or say if put back in an equally sudden manner
for 300 years or so! This question of “antiquarian botany,” as it is
sarcastically called, shows us the immense influence exercised by
man upon the flora of a country, simply in a destructive manner.
There is no need to go back to Gerarde and Parkinson for this:
fifty years ago interesting plants grew at Battersea, and some of

* Report by T. Hovenden, Esq.

PROCEEDINGS OF SOCIETIES. 207

them even yet hold their ground. The White Meadow Saxifrage,
for instance, appears on the grassy banks surrounding the ditch which
runs through part of Battersea Park, just as it did in days before the
park was thought of. A list of Forest Hill plants, only forty years
ago, contains many even rare species, but they have all doubtless long
since perished. But it must not be supposed that it is only by its
destructive agency that the advance of civilization affects the flora of
a county or country. Surrey is especially notorious as a county in
which, through drainage or other circumstances, fresh plants have
been introduced. A long list of plants which appeared on some waste
grounds at Wandsworth, where the sweepings of Watney’s Distillery
had been deposited, was published some years since; and a similar
list of foreigners at Mitcham has appeared more recently. Most of
these plants merely appear for a year and fail to perpetuate
themselves ; others last for three or four years, and then disappear,
while a few find their new locality suited to their permanent existence,
and eventually claim admittance to our flora. Here we have a branch
of observation well fitted to occupy the attention of a local society,
and especially of a society in the neighbourhood of London. So, if
we have to lament the disappearance of our plants, we have received
others in exchange, equally worthy of notice ; and although we cannot
botanize in the “pasture and meadow grounds about Pancridge
Church,” or expect much to reward our search in “ the village neere
London called Kentish Towne,” or the “‘ bankes about Pickadilla,” we
have full compensation in the facilities afforded us by our numerous
railways, which enable us to visit places where bricks and mortar
have not as yet extinguished plants, with as little trouble as our old
writers found in arriving at their chosen localities for “ herboriza-
tions.” That we have full compensation as to number of species may
be gathered from the ‘Flora of Middlesex, where it is stated that,
although no less than 58 species are probably extinct in that county,
91 are catalogued as more or less perfectly naturalized, to say
nothing of 120 which have been observed in a subspontaneous
condition, although as yet they have not succeeded in establishing
themselves.

Another important object of the club would be systematic work.
This is absolutely necessary for the results to be of any practical
value, and I should advise that the observations of the members
should be recorded, for comparison with the notes of other observers.
All malformations, and deviations from typical forms, should also be
carefully noted ; and the times of the flowering and pliation of plants
should be entered in a calendar, and may be useful for comparison with
past records. Lists of mosses and fungi (which do not appear in the
published ‘ Flora of Surrey’) might be compiled by the members.
Should the club publish transactions or reports of proceedings, it is
most important that they should be confined strictly to local matters.
In connection with local lists of plants, it would be most desirable to
ascertain the local names, as well as any superstitions or traditions
locally connected with them, more especially as these latter are fast
dying out. I sincerely hope that the club will flourish, and that it

208 BIBLIOGRAPHY.

will not be an excuse for spending an evening in pleasant and intel-
lectual chat, but will lead to actual work being done by the members,
individually and collectively. It is just in proportion to the amount
of work done that the Society ought to and will flourish, and while
feeling sincerely sorry that I have been able to say so little which has
been worth your attention, I shall also feel that my time and yours
have not been quite wasted if anyone should be urged by my remarks
to assist with greater energy in promoting the work and welfare of the
Society.

Mi. Deane remarked that the paper they had just heard was, in
his opinion, a most valuable one. With regard to the extinction of
plants, and the introduction of fresh ones, he might mention that
when he first came to Clapham, there were at least six varieties of
ferns to be found on the Common. There was now, he believed, only
one kind, all the rest having become extinct. He believed also that
the weed Anacharis, which now grew to profusion in the ponds on
Clapham Common, had been introduced within the last few years.
In a book which he had lately seen, it was remarked that many years
ago a gentleman at Wimbledon grew a number of beautiful tulips, of
which he was very proud. He believed that the wild tulip was now to
be found on parts of Wimbledon Common; this would probably owe
its introduction to the number of tulips kept by this gentleman, some
of which had doubtless gone wild and spread over the Common.
Mr. Deane concluded by moving a vote of thanks to Mr. Britten for
his valuable and interesting paper, which was unanimously accorded.

Six members were balloted for, and duly elected, and the certifi-
cates of four new members were read by the Secretary.

Excursions were announced, on July 29, to Barnet (for Totteridge),
and on August 12, to Thames Ditton.

The meeting then resolved itself into a conversazione; a paper
having been announced for the next meeting (on August 15, at half-
past 7 o’clock in the evening), by Dr. Hector Helsham, ‘On the
Employment of the Microscope in Analysis.”

BIBLIOGRAPHY.

Die Aufzucht d. Eichenspinners [Antherea yama Mai]. Prof.
Fred. Haberlandt. Wien. Gerolds Sohn.

Untersuchungen uéber die Gehérschnecke der Saugethiere. A.
von Winiwarter. Wien. Gerolds Sohn.

Jenaische Zeitschrift fiir Medicin und Naturwissenschaft hrsg. v.
der medicinisch-naturwissenschaftl. Gesellschaft zu Jena. Leipzig.
Engelmann.

Berichte des Nutuewiseenschaftlich -mediaasaiieee Vereines in
Innsbruch. Innsbruch. Wagner.

Beitrige zur Biologie der Pflanzen. Dr. Ferd Cohn. Breslau.
Kern’s Verl.

The Monthly Microscopical Journal, Nov.1 1871. Pl, CIL

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THE

MONTHLY MICROSCOPICAL JOURNAL.

NOVEMBER 1, 1871.

I.—An Incident in the Life of a Chelifer.
By 8. J. McIntinz, F.R.M.S.

(Read before the Royau Microscoricau Society, Oct. 4, 1871.)
Puate CII—B.

For some time past, as some readers may be aware, I have been
watching the habits, whenever I got opportunity, of the British -
Pseudoscorpions, and the results are recorded in the Journal of the
Quekett Microscopical Club and the pages of ‘Science Gossip’; but
lately a circumstance happened in relation to the subject which
may be worthy of more special mention.

About April last I procured from Theale two chelifers, one of
them full-sized, and the other a young one. I secured them, as is
my wont, in one of the cork cells already brought before the notice
of microscopists, and which I find indispensable to prolonged obser-
vation of such creatures. The large one perambulated the cell with
considerable activity, but the small one, with commendable pru-
dence, selected a crevice in it, rather out of the track taken by the
adult specimen, and here it abode quietly. Now and then its peace
was disturbed by the too near approach of the large chelifer’s claws,
but it cunningly evaded their grasp, and settled down again when
the danger was past. As I dieted them upon their proper food,
Podure (of the genus Lepidocyrtus, the common sort of which I
was able to obtain a supply of at the time), they throve well, and
about the middle of May the growth was noticed upon the under-
side of the larger one’s abdomen of the egg-case, leading me to
expect a repetition of former experiences, namely, that I should
soon have an addition to my stock, if all went well, of seventeen
or eighteen young chelifers, which, on extricating themselves from
the egg-case, would climb their mother’s back, and there seat them-
selves, secure from most enemies, after the manner of true scorpions,
as Natural History books tell us.

But accidents will happen; and so when the egg-burden was
of full size, and the shape of the young chelifers therein could be
roughly traced out, the mother cast her load off. Whether the
young chelifer, whose claws were daily gaining strength, had at-
tacked her in her weak condition, or whether I had disturbed her

VOL. VI. Q

210 Transactions of the

in roughly agitating the cell,—for either of these causes is sufficient
to produce such a result,—I cannot say. I found her load appro-
priated by five or six mites (apparently allied to Gamasus), under
whose active attacks it soon disappeared entirely, while she, in a
very emaciated and excited state, was hurrying to and fro in the
cell. To calm and soothe her agitated feelings, I introduced some -
five or six lepidocyrti, which quickly fell victims to her appetite,
and afterwards she appeared decidedly better.

The months of June and July passed, and she lived on, and
quite recovered meanwhile. At the beginning of August, however,
to my great surprise, a second egg-burden began to show itself on
the same chelifer. It went on rapidly increasing in size till about
the 8th August, when it ceased to grow larger, though the progres-
sive development of the contents inside it might be observed daily.

Lest any mischance like to the other should happen, I carefully
removed the suspected young chelifer to a solitary cell, and was
very careful in handling that containing the pregnant one. A rough
sketch of her appearance at this period is given* (Plate CIL., Fig. B).

But all in vain, for during the night of the 17th August, just
when I was expecting, from the advanced development of the con-
tained young, that the experiment would be successful, the irritable
mother again detached her burden from her body. While I write,
some twelve hours afterwards, the contents of the egg-case seem
still alive, for slight movements within can be detected; but yet
I doubt if the attacks of predaceous mites alone will not prove
too much for the further development of the young, even if the
separation of the egg from the body of the chelifer is not fatal to
its development.t

The fact of two broods of young, for such I consider it to be,
from a chelifer in one summer is, I think, curious and worthy of
attention ; moreover, the fecundation of the female is an obscure
subject. I must conclude it took place previous to April, since I
quite exculpate the little chelifer, which was her companion for a
long period, for the obvious reason of its youth.

Beyond noticing these points, I will not hazard any speculations
on them.

Sir John Lubbock says, if I may be permitted to quote from
his letter, “The case seems like one of Parthenogenesis, or perhaps
the spermatozoa are retained awhile, as in the bees, &.” The same
authority has written a paper in ‘ Phil. Trans.,’ “On the Develop-
ment of the Egg in the Annulosa,” containing a vast amount of
matter bearing upon the subject, which those who feel interested
should read.

* T believe the species is C. Latreillii. + This proved to be the case afterwards,

Royal Microscopical Society. 211

I1.—On the Form and Use of the Facial Arches.
By W. K. Parker, F.R.S., President R.M.S.
(Read before the Roya Microscoricau Society, Oct. 4, 1871.)
PuatTe CII.—C.

Havine had an unusual amount of leisure this summer, I have
been able to work with the microscope once more, and thus be the
recipient of no little pleasure and profit; but, as my time is very
swift-winged, it is not proper that I should run from one pretty thing
to another. I have had, this time, one subject—the Salmon’s Skull.

Those who consider the salmon from merely a dietetic point
of view will be shocked to hear that my friends, Messrs. Water-
house Hawkins, F. Buckland, and Henry Lee, have, together,
supplied me with some two hundred specimens. These, however,
were not full-grown individuals, but fry and embryos, as yet
unhatched. These last have lost their chance of living as salmon,
but I hope that they, many of them, will live for ever in the
Transactions of the Royal Society ; their portraits and descriptions
of their personal appearance will be offered to that great good
mother of all our Scientific Societies.

It occurred to me, however, that a sketch of the face of one of

these water-babies might be acceptable to this pleasant daughter-
society.
And here let me say that, when once we know all about the
face of infantile salmon, we shall be well prepared to discuss
the form of the first foundation of our own face and features.
I have not made many alterations in my mode of working this
time, but one or two “ wrinkles” have been developed.

Firstly, it is better to preserve the eggs and fry in strong
spirit, and then to place them in a solution of chromic acid for
a week or two before they are dissected ; except in some instances,
when I want to use high power on thin slices as transparencies, I
eschew glycerine. It is better to keep the little preparations in a
watch-glass, still preserved in a solution of the acid. This saves
them from losing their good yellow colour; in glycerine they
become bluish-white, and are bad for examining as opaque objects.

Another thing is the comfort of using only clean water; great
irritation of the nerves, to say nothing of the temper, is apt to be
produced by the discomfort of feeling one’s fingers sticky when
working with the glycerine. This is no little matter to a worker
with the microscope, for the eyes and brain become intensely weary
in such sharp-sighted researches, and the least interruption is apt
to injure the calmness of the observer when he is highly strung.
One most excellent effect of the chromic acid is, that it preserves,
and even increases the lilac tint of hyaline cartilage ; that it makes

Q 2

212 Transactions of the

the soft brain substance as solid as cheese without shrinking it ;
and that it gives a rich umbre tint to thin lamine of bone, so that
in opaque sections the finest layer—the merest trace of a membrane-
bone—can be seen. I have tried a solution of chromate of potassee
with a little sulphate of soda added, as recommended in ‘Stricker’s
Histology, but I have not found any particular advantage in its
use above that possessed by the acid.

Now for the facial arches. The young salmon has one more
arch in front of the mouth, and one more behind, than the frog,
that is to say, the larval frog: it has, under the head, nine arches
in all, two in front of the great mouth-slit, and seven behind it. The
first arch, or pair of rods, is the trabecular arch formed by the
“rafters of the cranium”; the second is the pterygopalatine ;
the third, the mandibular; the fourth, the hyoid ; and the remain-
ing five are the branchial. The last arch is imperfect and function-
less as to respiration.

Speaking of the science of “form,” or morphology, let me say,
in passing, that it would be a very simple matter if the primary
form were fixed; but this is seldom the case, and the original
parts undergo a large series, in many cases, of changes, both in form
and tissue. This is the case most remarkably in the facial arches
of the osseous fish, especially in the two in front and the two
behind the mouth. Yet the primary form of these nine arches is
the same, as my simple diagram will show (Plate CII., Fig. C).

My earliest observations on these have been made upon very
young, thin, unsymmetrical embryos, with a rudimentary solid heart,
and with the head flat at the top, and just projecting free from
the yolk-membrane. The arches were distinguishable by being
granular, but hollow, lying in the midst of, and enclosing, nearly —
liquid protoplasm. The foremost point most forwards, below, and
the hindermost are placed almost transversely across the rudi-
mentary throat; but they all have one shape, wz. that of the
letter 8, the upper part beng most hooked inwards.

The first pair, the “rafters,” together, have a lyre-shaped
appearance as they diverge a little in front, and are strongly
bowed behind. The next, or palatine pair, are at first merely
semicircular, but they become S-shaped afterwards. All those
behind the mouth have a remarkable similarity of form, although
the two first of these are larger than those that follow; they all
gradually decrease in size, from before, backwards. In the verte-
brate anmnals, generally, these arches have the same form, that is,
as far as our researches go; the amount of modification possible is
therefore something marvellous. I was not at all surprised to find
this S-shaped hooked form of arch in the gill-apparatus of the fish,
because there it is persistent, and the inturned tops of the bars are
bare of gills and carry teeth, which are antagonized by the teeth of

Royal Microscopical Society. 213

the fifth or gill-less arrested arch. Here the primordial form serves
throughout life, and is very gently specialized for life-function.
But it was the first pair which most struck me with the beautiful
prospective harmony between morphology and final purpose, for the
same curve inwards at the top, which is so apt for the formation of
the crushing apparatus of the fish’s throat, here serves to wall-in the
punitary body, and thus form the primordial “Sella turcica” or
Turkish Saddle. Again, the next arch, which crescent-like, forms
an elegant ledge for the huge eye-ball to rest upon—this arch must
needs, as soon as it is freed from the pressure of the precocious
visual organ, curve itself inwards at the top. By doing this, it
exactly applies itself to the front edge of the succeeding arch, to
which it is soldered in a week or two after hatching. The arch of
the lower jaw and the arch of the tongue have the same advan--
tage in the upper hook, and all the secondary attachments and
delicately beautiful adaptations, as they become specialized, all
these, I say, give voice to the morphological importance of the
primary curve. It would be endless to go into the use of the facial
arches in the various tribes, for, when there are no gills developed,
as in reptiles, birds, and mammals, the two pairs of horns attached
to the bone of the tongue (hyoid), the arch of the lower jaw, the
arch of the palate, and all the base of the nasal septum, and of
the skull itself, as far backwards as to the exit of the optic nerves
—all these parts are derived from the simple S-shaped facial
rods. But there is an exquisite instance of special use which I
cannot pass over; it is in the class of birds. In these, as in all
vertebrates above the amphibia (newts and frogs), the only gill-
arch developed is the first, and this ig gill-less, but is made to
subserve other functions. In most birds, this arch reaches as far as
the occipital plane, but in humming-birds and woodpeckers these
horns are of extreme length and slenderness, and reach as far as to
the fore-end of the cranial roof. These elongated rods form the
skeleton of the long worm-like protrusible tongue, and enable it to
be shot out without a moment's notice, so that the nimblest of
insects are caught “or ever they are aware.” A function so new in
a gill-arch would seem to ask for a large amount of metamorphic
change of form. It is not so; this arch in those birds retains
exactly its primordial curve. We must still study form free from
all final purpose, bias, and preconception ; but a new and delightful
phase of teleology will set in when the laws of form have been
mastered. A man may run whilst he is reading the large plain
characters in which final purpose is written, but he must be as
good a sitter as the best hen in a farmyard if he would add any-
thing of value to the science of form.

( 214 )

ITIl.—On the Angular Aperture of Immersion Objectives.

By Roszert B. Torzzs, of Boston, U.S.
PuatTe CII.—A.

Fig. 1 represents a section of two hemispherical lenses balsam-
cemented, with a diatom or other small object at the centre, together
constituting a nearly homogeneous transparent globe.

Fig. 2. The same, represented as (in section) the front lens of
an immersion objective, 7.¢e. as to the part a, while the portion a’
corresponds to the last (front) lens of an immersion condenser, both
much exaggerated.

In Fig. 2, rays are traced as immergent and emergent at a per-
pendicular incidence, and therefore without any bending at either
surface.

The case is thus completely simplified, and the fact is evident
enough that the rays traversing the balsam-mounted object and
emerging at the upper surface of the front lens a, have materially
more than 82° maximum angle. In Fig. 2, the courses of extreme
rays for 90°, 120°, and 170° respectively are traced.

In each case the real angle of the zmmersion objective would be
the same as the angle of the appropriately applied systems above
taken separate from the front lens measured as and constituting a
dry objective, and (for the sake of simplicity of the case) adjusted
for a dry object.

An objective, such as is above indicated, inclusive of the front
hemisphere a, of course could not, as adjusted, work dry, or only so
far as actual contact of the object with the plane surface should
happen.

On the contrary, the objective used in the experiments described
in my communication to this Journal, July, 1871, did work as a
dry objective, and of 170° incident pencil, but by construction was
limited to about 220° transmitted pencil when the first plane surface
was eliminated, or nearly so, by water in the interspace. .

The above diagrams and comments are given, not from actual
trial-proof, but as an illustration too clear, perhaps, to need the
demonstration of experiment.

Let this be added, however,—“ No one will have the hardihood
to” deny that an object homogeneously cemented centrally between
the hemispherical lenses a a can be seen (looking through the
sphere diametrically with a simple magnifier) from every point of
view, thus giving “ image-forming rays.”

The case is totally and most obviously applicable to that of the
ordinary balsam-mounted microscope object for an aperture far
above 82° of angular pencil actually traversing the object and made
available in the view to the eye of the observer. For obtainment

Note on Pedalion mira. DANS,

of extremest angle, however, let one precaution be taken, viz. that
balsam be used above the slide and balsam below! ‘The case will
then correspond to that given in the diagram.

Of course in practice the upper convex surface of the front lens,
or system, has a curvature and distance to positively and consider-
ably refract the transmitted rays, but the case I have given ig the
easiest elucidated.

Boston, August 22nd, 1871.

IV.—Note on Pedalion mira. By C. T. Hupson, LL.D.

In my paper on Pedalion mira, in the September number of the
‘ Microscopical Journal,’ I purposely omitted to give any sketch or
detailed account of the internal structure of this new and singular
rotifer, for I had not had time enough to investigate it thoroughly ;
but as some doubt has been expressed as to whether Pedalion is a
rotifer at all, I wish to state that it has a trilobed mastax, with a
manducatory apparatus similar to that of Triarthra, and the usual
convoluted tubes carrying at least two vibratile tags on each side,
though most probably there are more. I have not seen any con-
tracticle vesicle; but then I have equally failed to see it in
Triarthra, 1n which rotifer, as well as in Pedalion, either the dense
corrugated walls of the posterior extremity of the stomach overlie
the vesicle, or the vesicle itself (as in Pterodina) is evanescent.

Pedalion’s rouscles are, for its size, enormous; at least two
broad and coarsely striated muscles run transversely round the body
below the neck, and the longitudinal muscles for retracting the
trochal disk are unusually powerful.

I had intended in the course of September to complete my
investigation of Pedalion’s structure; but the creatures diminished
in number rapidly throughout August, and have now, I believe,
entirely disappeared—to return, I hope, next summer.

V.—Another Hint on Selecting and Mounting Diatoms.

Communicated by Capt. Frep. H. Lane, President of the Reading
Microscopical Society.

My paper “On Selecting and Mounting Diatoms,” read to the
members of the Reading Microscopical Society in October, 1870,
and published in the December number of the ‘Monthly Micro-
scopical Journal,’ has been, I have every reason to believe, of con-

216 Another Hint on Selecting and Mounting Diatoms.

siderable use to amateur microscopists. In last April’s number of
the same Journal appeared a friendly notice of it in a letter from
Capt. Knight, in which, acknowledging the advantage of making
classified collections of diatoms, he speaks of the difficulty of pro-
curing the material for so doing, and observes that professional
mounters and opticians will only sell you their mixed gatherings,
set, as a general rule, in balsam; though occasionally, but seldom,
a dry mount may be obtained, when it is an easy matter to remove
the cover and select the required forms. He does not, however,
appear to think it possible to utilize for the purpose the balsam-
mounted material, and I suspect others as well as myself have till
now been of the same opinion. My friend Mr. Tatem has, however,
turned his attention to the subject, and has discovered a very easy
plan for picking out any desired forms from such slides for the
purpose of remounting them. THe has kindly communicated his
method to me, and permitted me to publish it as an addendum to
my former paper. Having both of us given it a fair trial we can
confidently recommend the plan, which is as follows :—

Place the balsam-mounted slide on the hot plate, and when it is
sufficiently warmed tip over the cover by means of a needle; the
diatoms will be either on it or the slide, it matters not which.
Apply over them at once, whilst still on the hot plate, a drop of
turpentine, remove the slide to the stage of the dissecting micro-
scope, and add more turpentine. Have ready a clean slip of glass
on which has been placed a drop of turpentine. In the case of
large discoid and other forms, having applied plenty of turpentine,
they can be easily transferred by means of a fine sable-hair brush
from the original slide to the pool of turpentine on the clean one.
In the case of finer forms it is better to place less turpentine on the
original slide, collect the diatoms into a heap, allow the turpentine
to dry a little, and then by a twist of the brush to transfer them
en masse to the new slide. In either case, having got them there
push them together and mop up the superfluous turpentine, and
then, still under the dissecting microscope, slant the slide by placing
a piece of folded paper under one end, and apply a little benzole
either by means of a clean brush or glass rod immediately above
them, that is, on the end of the slide that is raised, and allow it to
float gradually over them, care being taken that it does not flow
with too great a rush and carry away the diatoms with it. Repeat
this process some half-dozen times, till the whole of the turpentine
and balsam has been washed away, and till the valves are left dry
and black after the benzole is evaporated. They can then be trans-
ferred in the usual way to any other slide, and even with greater
ease than from an ordinary dry gathering. I may as well add that
if gum has been used to fix the diatoms, it may be found that some
of the valves, especially the discoid ones, remain obstinately adherent

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The Monad’s Place in Nature. 217

to the glass after the turpentine has been placed over them. In
such a case, the process, as above detailed, must be carried out on
the original slide, and then, after the benzole is thoroughly evapo-
rated, water must be applied two or three times in the same way as
the benzole for the purpose of washing away the gum and freeing
the diatoms, which can then, when dried, be lifted one by one and
transferred in the usual manner.

By this simple and easy method we can not only select from
balsam-mounted gatherings any particular valves we may require,
but we can reset any spoilt or unsatisfactory mounts of our own.

VI—The Monad’s Place in Nature.
By Mercatre Jounson, M.R.C.S.E., Lancaster.

Puate CIII.

Amone the objects in the department of Protozoa one sees at the
same time groups of organisms having attained a certain degree of
perfection, and other living forms in a more elementary condition.
The object of the present remarks is to show a connection between
the earlier forms, which we call Monads, and those higher and more
complicated organisms at present recognized under the name of
Infusoria, Mucedinz, Confervee, Oscillatoria, &e.

The following record of experience, taken together with the
previous papers in ‘Monthly Microscopical Journal,’ will be found
to contain some evidence bearing on the tendency of certain or-

DESCRIPTION OF PLATE CIII.

Fig. 1—A tubule of Vaucheria, containing :—a, mass of chlorophyll; }, bursting
of tubule and discharge of Monads, &c.; c, a green oval Gonidium ;
d, two Monads moving within the tubule; e, an immature Pseudo-
gonidium; f, an Euglena; g, a mass of chlorophyll giving off, h, a
globular extension of the primordial utricle; 7, the terminal vacuole
of the tubule containing Monads in active motion; & #, two Pseudo-
gonidia being discharged from the tubule; /, a transparent primor-
dial utricle, or empty cell-wall; m, the same, containing: chlorophyll ;
n, one of these in the act of bursting, and liberating, p, the Monads,
which at once take an independent cyclical movement.
» U.—A piece of Conferva rivularis: a, the hole through which the Euglene,
b, are escaping. This observation was made April 11th, 1869.
m1.—A pin-point Monad in its transformation to Confervoidza.
1v.—A pin-point Monad in its transformation to Penicillium.

v.—A pin-point Monad in its transformation to Chlorococcus : «, Gonidium ;
b, Gleocapsa; c, commencement of Soridium; d, e, bifissation; /, division
into 4; g, division into 16; /, formation of Thallus or Apothecium.

vi.—A pin-point Monad in its transformation to Euglena: «, Gonidium ;
b, oval cell with vacuole; c, Euglena; d, with filament; ¢, intersus-
cepted form. (Fic. vu.

218 The Monad’s Place in Nature.

ganisms to develop progressive change from a lower to a higher
form of structure, and will in this instance tend to establish the
probability that the Monads which we meet with in various states
are the sources whence spring some of the more developed forms of
life to which I have referred.

In the air caught by trickling water over a sheet of glass,* I
find a large number of Monad forms about s¢ooth of an inch in
diameter.

In November, 1867, I found bodies having the same appearance
and the same cyclical movement, moving within the tubules of Vau-
cheria (Pl. CIIL., Fig. 1.d). In April, 1868, I confirmed the ex-
periences (Fig. 1.2). In July, 1870, I saw similar bodies moving
freely in the vacuole of a desmid (Closteriwm lunula). In 1867 I
watched the primordial utricle in the tubule of Vaucheria protrude
from the general mass of chlorophyll, and form a round globular
vesicle into which the Monad forms escaped from the mass (Fig.1. 9, /).
I also saw the Pseudo-gonidia attached to the side of the tubules of
Vaucheria containing chlorophyll particles and a vacuole (see the
diagram, Fig.1.kk). Also I witnessed the primordial utricle of a
Pseudo-gonidium burst, and the Monads liberated from the interior,
each being transparent, about the size of those found in air, and
having their own independent cyclical movement (Fig. 1. n, p). Now
it seems to me that these organisms are in all likelihood similar to
those referred to by numerous observers, such as Samuelson, Dancer,
Angus Smith, and others of recent date, who have confirmed the
experience of Pasteur, which in all likelihood relates to a form of
life similar to that to which I have here referred.

Now in the bursting of a tubule of Vaucheria, which I witnessed
in November, 1869, the size of the particles varied from visible

2

Fic. vi.—A pin-point Monad in its transformation to Infusoria: a, granular cell ;
b, showing vacuole formed by contraction of sarcode; c, first change
to Amceba; d, perfect Amceba; e, change to Vorticella; f, Vorticella ;
g, Kerona. See also Fig. 1x., which represents an observation made
August 12th, 1871, in which I saw the globular body throw out cilia,
and then swim away as a perfectly formed Kerona.

» vVul.—A_ pin-point Monad in its transformation to moss: a, Oscillatoria Nigro
Viride ; b, Lyngbya; c, moss cell as given off from the surface in drops
of rain.

», 1X.—Change from a spherical cell to a distinct Kerona: a, the spherical
shape; 6, throwing out cilia, c; d, fully formed Kerona.

» X—A few Parameecia (Kolpoda cucullus) swimming in a fluid composed
of Vibrions and Monads: a, Vibrions; 5, Monads.

», Xi—An Infusorium (probably Paramecium Aurelia), showing cilia placed
diagonally: a, ventral ; 6, dorsal view.

» XuU.—A mass of pin-point Monads: 1, becoming, 2, Vibrions; 3, Bacteria ;
4, Monads and Uvelle; 5, Amcebxe; 6, Parameecia; 7, more highly
developed Infusoria, as Ko/poda cucullus, &c.; 8, Vorticelle.

* See ‘M. M. J.,’ Aug., 1870.

The Monad’s Place in Nature. 219

masses having a green colour, to minute specks which were only
visible by scintillating in reflected light (see Fig. 1.b); and in all
examinations of matter containing organisms, certain particles are
seen to revolve upon their own axes, and to present what appear
to be signs of life. These solutions, if watched from day to day,
present objects having the same movements, which gradually deve-
lop until they present the same appearance as the Monads before
referred to, as being caught from the air and being discharged from
the Pseudo-gonidia and the tubules of Vaucheria.

An examination of the experiments recorded in my earlier papers
in this Journal shows these same Monad forms as always the first
to make their appearance.

In the experiment, March 5, 1868,* bottle b, with only a limited
quantity of air, develops first Monads and Mucedo on cork; and
after more air had been admitted, successive observations showed
Monads, Vibrions, and ultimately Paramcecium.

In Experiment e, the ultimate development from the same source,
but under different circumstances of light and air, was green Gonidia,
Euglena, and green filaments.

But in g the result was an immense number of full-sized
Kuglene.

The sources of all these developments seem to me (who watched
the liquids daily for two months) to be the same minute pin-point
Monad which Dr. Bastian refers to in his papers in ‘ Nature.’ An
examination of my note-book during the watching of these liquids
shows numerous forms which the Monads presented (Fig. x11. 6),
evidently transitional from the round pin-head Monad to oval young
Parameecia, until we come to sufficient size to give it a name such
as Kolpoda cucullus, &e. (Fig. x11. 7).

In the vacuole of Vaucheria I observed that organisms in se-
veral stages of development existed in active motion at the same
time (Fig.1.¢,d,e, f), and [have since been able to verify this opinion
by observing full-grown Euglenz in the tubule actively moving ;
but on April 11th, 1869, I saw the birth of Euglene from a tubule
of Conferva rivularis, and on escaping they took on all their poly-
morphic changes, and although small in size were full of life (see
Fig. I1.).

The important deduction from this fact is that there are various
stages at which the organism enters upon its independent existence,
and it may fairly be presumed that as the stage is early or deve-
loped, so will the amount of heredity vary, and the tendency to
resist the choses eatériewres, or accidents of life, become greater.

The “pin-pomt” Monad being in an earlier stage, and pos-
sessing less heredity, may, and most likely does vary more under
the influence of these accidents of life, such as light, air, &e.

* <M. M. J.,’ Aug., 1869.

220 The Monad’s Place in Natwre.

It has been noticed that in almost all substances or liquids exa-
mined, the first evidence of life is found in the movement of most
minute bodies. An instance of this and the subsequent develop-
ment is well shown in the following case :—

On the 1st August, 1871, I took a piece of fluff from under a
carpet and book-case, which had for some time remained undis-
turbed.

On examination, it consisted mainly of the coloured broken
pieces of wool from the carpet, as well as pieces of flax, together
with the ordinary contents of dust, such as soot-flakes, splinters of
flint, and amorphous particles—starch grains, &c.

I then took six drachm-bottles, put a small piece of the fluff
into each bottle, and half filled it with water. (This was taken
from the tap in which no organisms are perceptible, nor do organ-
isms develop from it when placed under similar circumstances to
the present experiment. It may therefore be inferred that any
living things which should from time to time appear, were due to
the dust, and not to the water). The bottles were then tied over
with carded cotton, and examined as follows, with the results
named.

The bottles were marked A, B, C, D, E, and F.

August 3rd (after two days).—Nothing but Brownian movements
visible in bottle A.

August 4th.—Bottle B, unmistakable movements among the par-
ticles in a cyclical direction. One particle circulated first in one
direction, and afterwards in another. The larger particles seem to
be moved by some smaller but invisible objects.

August 5th.—Examined bottle C, and found very active Monads,
apparently attached by a pedicle to some particle of amorphous
matter.* Movements undoubtedly voluntary. The appearance of the
Monad is round at first, but apparently changing shape from time to
time, as if of an amceboid form. The size, under 300 x , is of a good-
sized pin’s head. Under 700 x , I found one having the movement
and appearance of a young Paramcecium.

August 8th.—Examined bottle D, with similar results.

, 10th.—Examined bottle E: the Monads smaller.

, 12th.—Examined bottle F, and found most unmistakable
Kolpoda cucullus ; movements cyclical and rotating on their own axes,
apparently about 2 inch long by } inch in diameter when magnified
250 times (about <4, inch in length).

One or two points here require observation. It is a question
sub judice as to the cause of the Brownian movements. I am in-
clined to the belief that they are due to the presence of life in some
objects too small for independent vision by the microscope. I have

* My friend Mr. Chantrell, of Liverpool, informs me that he has watched the
growth of Vorticelle, and finds the stallk developed before the head.

The Monad’s Place in Nature. 271.

often found that liquids which under low powers appeared quite
free from organisms have, on the application of higher powers, re-
solved themselves into moving masses of organisms, and this, I
believe, will most frequently be found to be the case where the
power is able to detect the life. In the case of August 4th this is
palpably the case.*

I am also inclined to the belief that the lower forms of life are
amoebiform, from the numerous observations I have made of them
when the focus of the instrument has been clearly adjusted.

The cause of the circular movements may be due to cilia all
over the body, as shown in Fig. 18, Plate C., of my last paper in
‘M. M. J.’

But the cause of the cyclical movements may be explained by
an examination I have occasionally made of some form of Para-
meecium, of which I have given a diagram in Fig. x1. a, b, Plate
CIIL., possibly Paramecium Aurelia. Here the cilia are placed
in a diagonal manner across the body, and give it by successive
action that peculiar motion which we observe as cyclical, and which
was so in the objects from which the drawing was made. :

From observations I have made I am induced to believe that
the pin-point Monad, when developed under absence of light and
only a limited quantity of air, gives rise to the class of plants
known as Mucedine.t

The results of the experiment, March 5th, 1868, g, shows
Euglena as the result of cow-dung in much water in free light and
air in a tall glass jar, while the same medium in d, gives only
Paramcecium as the result, the air and light being both applied in
a different proportion.

For these and other reasons I am induced to look upon Monas
in its earliest forms to be the starting-point whence, when its
heredity is small, several products may result, and among the
number are Infusoria, Mucedine, Euglene, Oscillatoria ; and since
I think there is evidence to show much transmutation of form, the
facts seem to me to show that while from the lower Infusoria many
of the Rotatoria may be traced, so also from Palmella cruenta may
be traced Oscillatoria, Lyngbya, and many mosses (see Figs. m1.,
Iv., V., VL, VIL, and vir). A close and frequent examination
of plants of Palmella cruenta has convinced me that Osczllatorra
Nigro Viride is simply a developed form of the same plant.
Instances are of very frequent occurrence in which the plants are
so intermixed, and the cells under the microscope so evidently
transitional, that I have now no longer any doubt upon the subject.

* See also Fig. x., in which the liquid was one moving mass of Vibrions and
Monads.

+ See p. 197‘ M.M. J.,’ April, 1870. Note of an experiment in which the
results of growth in a dark cupboard is compared with that in an open window
exposed to light and air.

222 The Monad’s Place in Nature.

A similar examination of Oscillatoria with Lyngbya reveals the
same transition. Were it not that the forms are too common for
a diagram, I have abundant evidence in my notes in proof of my
opinion. The point, however, is one capable of investigation by
comparatively low powers of the microscope, and may form a very
interesting point for young observers to commence a systematic use
of microscopical investigation by means of notes and careful drawing.
And here I would trespass upon the pages of ‘ M. M. J.’ by offering
this suggestion, that young microscopists, instead of using their
instrument as a mere toy to look at strange and beautiful objects
without system, might confer great benefit upon the cause of science
by taking up this subject and carefully working it out. It is a
mistake into which many men fall when they suppose that they are
unable to help the cause of science by microscopic research. I am
convinced that honest and careful tabulated experience is always
valuable, and the more so as it is multiplied by many experimenters.

If we look upon the broad face of any landscape we are at once
struck with the growth of green verdure upon all surfaces which
are rough enough to receive the air-borne seed of plants, and have
remained long enough undisturbed to allow of the development of
this verdure.

An observation of it under various conditions shows various
forms of development, and as it is in most cases evident to the
simplest consideration that the product is air sown, so it also
becomes evident from the facts before us that the source of it is
some matter of constant existence in the air. Now, an examination
of the air shows us occasional green Gonidia which manifestly have
sprung from lichens or mosses, from the elastic membrane concerned
in the bursting of apothecia of lichens on the one hand, and the
bursting of tubules of mosses as shown’ by Dr. Hicks on the other ;
and the facts adduced in this paper relative to the bursting of
vacuoles of Vaucheria, Pseudo-gonidia, and of the tubules of Con-
ferva rivularis, give us evidence of a source whence the seeds of
these plants may be ejected into the air. This being the case, it
becomes necessary to observe the results of this sowing of seed
under proper means of observation. I have in my study at the
present time a large quantity of green Lyngbya, which owes its
existence to a small number of cellules of Chlorococcus, which was
sown by the air upon a lint siphon which I used for the purpose
of collecting air-borne seeds about two years ago.

In a previous number of ‘M. M. J.’ I showed how four distinct
species of moss gave off similar Gonidia, which produced Chloro-
coccus and Lyngbya, and every day’s experience confirms these
observations.

But the experiment upon the fluff and dust as detailed in this
paper points more distinctly to the pin-poimt Monad as the source

- The Monad’s Place in Nature. 223

at least of Infusoria, and taken in connection with the other expe-
riences seems to show at least a probability that in this minute form
a great process of the most gigantic importance is taking place in
nature.

I think it is not making too extravagant a demand upon the
imagination or the credulity to suggest that here, in the border-land
of the two kingdoms, animal and vegetal, nature is performing a
vast operation in converting the dead matter of the universe to
living forms, by a process of cell-growth which is so universal as
to reveal to us some of the workings of a vast law.

We may fairly consider the living cell, in its initial state, to be
a vesicle (too minute for the highest powers) which by dialysis
absorbs to its cavity the elementary atoms of which the dead organic
matter had been composed, and which it is now ready to part with
in consequence of its vitality having ceased. Upon this pabulum
the living cell grows and increases until it is able to give off proles,
either as the pin-point Monad, the visible Monad, from the Pseudo-
gonidium, or the Euglena, born of Conferva rivularis, Vaucheria,
or some other plant of this nature.

The proles, starting at the most minute point, becomes either
the Mucedo (converting by its growth the dying particles of hydro-
carbon compounds to the alcohols and zthers of animal or vegetal
decay), or the Infusorium (gradually developing to Rotifer, and
thence probably to higher organisms), or the beautiful green
Euglena (on the rank hotbeds of farmyards and other nitrogenous
depéts), or the delicate Chlorococeus (whence arise Parmelia Col-
lema, or Lichens hanging in graceful festoons from the “ formed
matter” of old tree barks), or through Palmella cruenta, Oscil-
latoria, Lyngbya, to mosses, forming those sponge-like reservoirs of
moisture which in their decay give a suitable nidus to the air-borne
seeds of the sycamore or other trees, as may be seen on the towers
of many of our older churches. There many a good-sized tree
grows in the débris of vegetable matter mixed with the silica flakes
of dust wind-borne from the dry roads.

It will here be seen that this branch of study bears as it were
the seeds of one of the most important investigations which can
occupy the thought of the reflective. It seems as it were to open
out a page of the world’s history which shows that from the smallest
beginnings the greatest of results follow. It serves to show that
there is no part too small to be of the highest importance, and
that the decay of nature is but the other side of the portal of lite
—equally beautiful, equally honoured by the Creator with the
most minute detail of perfection. Man is apt to look upon that
which is ceasing to possess life as disagreeable, offensive, unworthy
of attention—to be, in fact, cast away as used up and belonging to
the despised condition of waste. Let such a thinker then turn his

VOL. VI. R

224 Mapping with the Micro-spectroscope, He.

thoughts hitherward for a short time, and learn that nature knows
no waste; each particle of which the universe is composed is every-
where and at all times performing a duty and serving a purpose,
and though it may change its shape from the beautiful rosebud or
the gaudy butterfly to the destructive mildew or the more homely
erub or caterpillar, yet here when viewed through the microscopic
lens every part is full of beauty and perfectly fitted for its destina-
tion, either as a carrier of life or a destroyer of the dead—Genesis
and Exodus—I say again, both equally honoured by the Maker,
equally perfect, equally beautiful.

VII.—Mapping with the Micro-spectroscope, with the Bright-line
Micrometer. By H. G. Brives.

Puate CIV.

Now that spectrum analysis receives so much attention, as the
means of furnishing information in solar chemistry, and also in
researches in the spectral lines afforded by the combustion of metals
by the electric spark, and the absorption bands given by fluids, &c.,
the bright-line micrometer so ingeniously contrived by Mr. John
Browning has greatly added to the efficiency of the micro-spectro-
scope.

The devising a reliable means of determining the relative posi-
tions of lines and bands given in the spectrum in a direct rigid
spectroscope was a problem of no little difficulty, but Mr. Browning
has solved it; and while it may be admitted that the use of this
micrometer, in order to obtain reliable results, requires some care,
as from the nature of the whole instrument it is necessarily
delicate, yet mapping by its aid is perfectly practicable, and if
attention be given to a few directions which I purpose adding for
the guidance of surgeons and others engaged in studying spectral
analysis, anyone can furnish himself with maps of the spectra of
his instrument, mapping many of the Fraunhdéfer lines, and the
absorption bands of tinctures, solutions, &c., for reference and com-
parison. In short, to show how far the use of the micrometer is
practicable, it is perfectly feasible to construct a map of lines whose
positions shall be correct to the unit of the micrometer circle. The
accompanying map is correct for any instrument to this degree—of
course this applies only to the lines and such of the absorption
bands as are well defined, the rest are as correct as the, in some
cases, somewhat nebulous nature of the bands admit of.

It is necessary, when the instructions given in Mr. Browning’s
pamphlet on the instrument have been attended to, to focus on the
object under ‘examination, and that the slit be also focussed by the

T

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4 pirat J
WLOVLLALDA

Remarks on a “ Note on Amphipleura pellucida,” &e. 225

eye lens; and for registering the readings of the lines the direct
rays of the sun should be thrown up into the slit, made as narrow
as is compatible with sufficient light, and when the prisms are put
in place it is best to focus on the E line as sharply as possible, this
line being near the middle of the spectrum; this is best done by so
focussing as to be able to see as many of the fine lines in the neigh-
bourhood of E as possible. Now by means of the reflector make
the bright line or spot of the micrometer visible, bring it over E,
just above the spectrum, focus it by its lens so that it 1s sharp and
quite free from flame, and go that a lateral to-and-fro motion of the
eye does not displace it by parallax; this is most important, all ac-
curacy will depend upon it. Now see that all the fittings of the
instrument are firm and as free from spring as possible, and with a
light hand bring the spot over E, taking care that no part of the
instrument but the micrometer screw is touched, and do not let
the eyebrow touch the eye-piece, as this may shift the spot. Having
registered the best reading by many averages of H, that of ABCD
and F G should be each separately and directly determined from EK,
and bringing the spot back again to E to test its reading. It
great care is taken in the first instance in determining the true
relative positions of these principal lines it will be well bestowed,
and any of the smaller lines can be registered by taking the nearest
principal line as a standard.

It may be found necessary to adjust the focus of the micrometer
lens when the spot is over the extreme positions; it must then be
started again from E as a point of departure.

It will be found on using the instrument another time that the
spot will not give the exact registered reading of E; it must be
made to do so by a slight side pressure or twist given to the eye-
piece cap carrying the micrometer. Hence the importance of having
the instrument in its firmest condition before finally determining the
reading of H.

The accompanying Plate (CIV.) has been carried out on the
plan described above, and explains itself sufficiently.

VIII.—Some Remarks on a “ Note on the Resolution of Amphi-
pleura pellucida by a Tolles’ Immersion 3th. By Assistant-
Surgeon J. J. Woodward, U.S. Army.” By Enwin Bicknet.

THERE are some points in the “Note” of Dr. Woodward under

the above title, which, I think, will bear a few remarks. I have

been much interested for the past three years in comparing and

measuring different objectives by different makers, in order to

ascertain how near the “nominal power,” as rated by the maker,
R 2

226 Remarks on a “ Note on Amphipleura pellucida,” &e.

corresponded with the “actual power” when the magnifying power
was measured by any proper method.

In the majority of cases I have found the “error” to be in
favour of the objective; that is, the “nominal power” was less
than the actual power, and the objective consequently “underrated ”
in power, sometimes to quite a large amount.

Dr. Woodward in his note is very careful to give the proper
rating of the Tolles’ objective, after giving its magnifying power
at 48 inches distance between the micrometer and screen ; he says,
“Tt is therefore of rather higher power than a 3th, but less than
a 4th,” which is undoubtedly correct.

A little farther on in his note Dr. Woodward gives the power
of another objective by means of figures; I allude to the so-called
immersion ;'sth of Powell and Lealand. Applying Dr. Woodward's
rule to his figures giving the “actual power” of the so-called ,'cth,
would make it “therefore of rather higher power than a s'sth, but
less than a sth; at any rate Dr. Woodward’s figures make Powell
and Lealand’s objective just four times the power of Tolles’; and
according to my way of figuring, the above would be correct, that
is, the Powell and Lealand objective would be between a ='5th and
a yzth, depending upon the position of the “ cover adjustment.”

I call it nothing more nor less than deception in Powell and
Lealand (or any other maker) in marking an objective nearly 33 per
cent. less than its actual power, thus misleading people who cannot
make actual comparisons ; and I consider Dr. Woodward guilty of
an equal amount of deception in knowingly putting forth work done
by that objective as having been done by a y/gth.

Dr. Woodward says “ that the new 3th cannot be claimed to
supersede the highest powers at present in use ” (meaning the so-
called sth, the j3;th, and the =oth of Powell and Lealand, I
suppose), “yet nevertheless is not, in my opinion, injurious to the
3th.” Such innocence is refreshing ; the fact of the 1th not “super-
seding” objectives of from four to ten times its power not being
“injurious ” to it is decidedly rich.

No one, so far as I know, has claimed that Mr. Tolles’ 4ths
were to “supersede the highest powers now in use”; but if Mr.
Tolles, Powell and Lealand, or any other maker should make a }th
that would do better than the best ~>ths or y,ths of the present
day, it would be “glory enough.”

1X.—Infusorial Cirewt of Generations.
By Turon. C. Hinearp.

Tue soft and “naked,” transparent and really animal* forms here
to be considered, have some very striking and peculiar features in
common. ‘Their bodies are delicate, transparent, gelatinous, granu-
lar, and evidently sealess, although studded with reproductive yolks
and locomotive molecules of the most varied description. On con-
tact with air, when drying up, they do not leave behind any coherent
coat or tissue whatever ; but so soon as they are affected by incipient
exsiccation, at once, by some sudden internal commotion, as if
melting away, they become liquid, and entirely dissolve into a
“sauce” of quite uniform, hyaline molecules, about so'o> line in
diameter. They are all evidently emmature forms, subject toa vast
cycle of progressive and retrograde developments, and infinitely mul-
tiplying the molecular germs at every individual dissolution.t <A
little salt, glycerine, or sugar destroys their present form; but they
seem to be hardly affected by morphia or atropia, even in strong
solutions.

It is this feature of the non-endurance in drying up, which
renders it at once certain that no such sarcode bodies can continue
to exist in integro, when exposed to the full heat of summer, on a
cracking dry tub, or on a roof, likewise as torrid as a blazing July
sun can render it within four weeks. The same applies to all the
confervaceous, palmellaceous, protococcous, desmidiaceous, &c., fresh-
water spawns, of true Mosses; which, once collapsed by drought,
rarely continue growth in a progressive sense. With the exception
of their common “ nostoc” phase $ (specially adapted to endure even
excessive dryness), they “revive” only by starting anew from very
reduced, but immensely multitudinous constituent particles of their

* 7, ec. exclusive of all the chlorophyll-endowed, silica-coated, and automatous,
or cellular cell-like sarcodic bodies, and also the clear and vibrionic forms which
belong to the algoid bryaceous developments. They are partly classed as green
“ Tnfusoria,” and also constitute the “ Chlorospermex ” of “ Algee

+ The same doubtless applies to a small “Stentor Roe,” seen hovering up and
down in water taken from ponds, aquaria, &c. It is of a hazy white colour,
scarcely perceptible to the naked eye, and remarkable for never touching the
surface. When placed under the microscope, ina drop exposed to air, this animal
germ (in shape resembling a Cyprea or a coffee bean) is seen violently throwing
open its “cloak” or mantle, exhibiting an intense ciliary (fingered) vibratory
action, all over the interior surface. It then throws out hyaline constitutive brood-
balls of various sizes, each endowed with the same “ fingered” action—(as if “ kneaded
about ” in invisible hands)—and ultimately entirely flows apart into such fleshy cilia,
on leaving the intestine behind.

{. This form of self-multiplying, serial chlorophyll bead-strings enveloped in a
foliaceous slime is common to Lichens (particularly the genus Collema) and various
brooding phases of the algoid (chlorospermous) moss-spawns. With the Lichens,
the internal chlorophyll of their thallus often develops, as is well known, in similar

bead-strings, borne on the end of colourless (fungoid) tissue-fibres; in a manner
also represented in the anatomy of Blodgettia confervoides, in Harvey's ‘ Nereis.’

228 Infusorial Cirewit of Generations.

own, which perdure exsiccation. In the class of Fungi we meet
with similar examples, as e. g. in the case of the yeast-plant, which
can endure a considerable degree of exsiccation without impairing
the vitality of those cell-contents, which actually exercise the fer-
mentive energies and also consume the old cell-coat (not common
cellulose, by the way) in this process of reviving. Likewise, the
vermilion, gummose (tubercularia) pimples on rotting Black Oak
branches can endure a baking process in the burning sun, but still
revive on contact with water. Its spicular “spermatia” (fusediwm,
resembling Naviculee or magnetic needles) at once assume an oscil-
latory motion and swell up to the size of those didymous (trichothe-
cium) spores which presently stand erect on pedicels, as a pink
velvet, in the chinks of the bark and collapse at the first touch of
the sun ; while their ultimate subcortical development into a mature,
“black enamel” Spheeria again perdures in the heat.

Under the circumstances above mentioned, the rain water and
dry dust carried by the wind to the roof, and thence collected into
a perfectly dry tub, itself standing on a similar roof, within a few
days was found swarming with all the minor phases of the Vor-
ticello-planarian germ-developments. Both the bodies and the yolks
or gemmee of the latter occasionally become reduced, by spontaneous
dissolution, into very minute particles, each in the wet state capable
of resuming the regeneration of individual germs. Judging from
analogy, it is but reasonable to suppose that it is this reduced nube-
cular and molecular condition, which adapts them to last and survive
in a dry condition, as we find it not only with the Fungi, but also
in the case of the pruinose-pulverulent, primitive moss-spawns, all
three agreeing in this feature of being “reduced to dust,” out of
which they are again resuscitated. This evanescent condition, how-
ever, where gelatinous particles of about sso of a line diameter
shrink alike to imperceptible dimensions, affords no pretext what-
ever for assuming identities, just because we ourselves lose the means
of discrimination. Whenever the identity of substance is preserved,
each of these various molecular organisms preserves its cyclar de-
velopments distinct from similar, corresponding ones as true species,
so far as my observations go.

There being, at present, no comprehensive pictorial works avail-
able to fall back upon for reference, that are sufficiently correct,
even in their designs, to identify the forms, allowance must be made
for the liberties of comparison taken in the following descriptive
representation of the most frequent infusorial processes.

On extensive clay formations, all over the central part of the
Mississippi valley, the first appearance, in the warm season, of
vegetable life, e. g. im water-pools recently formed by rain, &c., is
mainly that of “ Chlamydococcus pluvialis,” even where the clay is
immediately taken from the deepest excavations. As the sequel of

Infusorial Circuit of Generations. 229

my papers will show, this particular form belongs to the common
Silver-moss (Brywm argentewm) which is widely disseminated all
over the surface of the globe, and that, by the way, rather scantily
“fructifies” m a “sexual” fashion, z.e. by the development of a
theca ; but on clayey soils fills all the sluggish and stagnant waters
with its virescent uliginous spawns; while it covers the surface
of fields, by millions of acres, with a minute crust, or “ brick-red
leprosy,’* whose fine, molecular dust is swept aloft by every wind.
Immediately before the frost, the same fields are densely covered
witha small crop of minute moss, doomed to perish in this form, but
revived in its spawns at the first thaw in the shape of a universal
chalk-white “clay-bloom,” or pruinose efflorescence from the soil,
and that in water at once re-develops into the so-called Protococcus
(or Chlamydococcus) pluvialis in the form of green flagellate-roving
beads.

These minute, but in this instance coated, swarming cells are
replete with chlorophyll, and are globular ovoid in shape. They
have at their smaller end, just where the motor flagellwin (or vibra-
tory lash) arises, a clear point of substance; wherein, in a small
percentage of these cells, a parasite is found to develop.

This parasite is a perfectly colourless globule, apparent in the
clear nayel-point of the cell, and exhibits a faintly opalescent hue.
As it grows, the cell which harbours the “incubus”’ loses its own
individual vitality. It ceases to swarm about and dissect into living,
chlorophylliferous and automatous progenies, as the live ones do.
Instead of spontaneously dissolving as in the living process the cell-
coat remains firm; and as the parasitic animal yolk grows and
occupies more space, executing tremulous and vibratory contractions,
the chlorophyll is pressed into the rear, a lifeless mass. At last the
cell is ruptured in front, and the cupular-compressed, dead, chloro-
phylline mass remains inert and void of life until devoured by Infu-
soria or the zymotic fungus. The cell-coat, likewise, is effete, while
the larger globular and somewhat acicularly-granulated imeubus,
after a few very wry contractions, at once widely opens a large,
ciliate mouth, gaping across the sphere’s surface ; and disengaging

* See ‘St. Louis Med. Reporter,’ Jan. 1st, 1867, pp. 522, 527, 528. Also ‘ Proc.
St. Louis Ac. Sc.’ (July, 1861), vol. ii., No. 1, p. 160; and vol. i, p. 156. For
‘“‘Chlorococcum” read “ Spherocarpus” (ately renamed “ Protuberans” Ag.) and
its “botrydium” progenies. The latter collapse and turn red. This pulverulent,
miniate “ Lepraria kermesina” Auct., must, however, by no means be confounded
with the darkly purpureous, uliginous moss-spawns which cover, e. g. the hilly
“ Orange-sand ” regions of the State of Mississippi. It is prevalent in winter in
damp weather, and consists of matted red “‘ Microcoleus” or lumbricoid (sheathing)
moss-cells, each one containing a central brood-fibre which is medullary-dotted,
dissecting, and fascicularly surrounded by a stratum of (automatous, prorepent)
“ Oscillaria ”-fibrils. Not only the ultimately enlarged (chlorophylliferous) brood-
segments, but also the dark undulating fibre, form brood-balls (terminally). Its

gelatine forms a cement of the loose sandy clay, and a home or abode for the
Cladonize (or bright-green foliolate lichens) as well as for grasses, Xe.

230 Infusorial Cirewt of Generations.

or displaying a girdle of cilia round the rear part of the body, it
immediately represents the free-roving Vorticella in full equipment.

Its subsequent “encystment” into a spherical cyst densely
covered with short prickles (somewhat like the rim of a Heliopelta)
and containing entrail-like designs, is well known.* Also, that it
eventually bursts—occasionally, at least—and disgorges a peculiar
sort of wafer-shaped, elliptical (not ellipsoidal!) cells, or nuclei,
whose ulterior fate and abode, however, hitherto remained unknown.

The fact is, that they rise to the swrface, where, on account of
their shape, they imhere, as an almost imperceptible pellicle or
stratum, which to the microscopic observer is the instantaneous
index of the precise focality of the surface.

In this state, when no food is supplied, they long remain unal-
tered. When meat, bread, or other nutritive matter is added, how-
ever, they develop (particularly where the absence of light prevents
the confervaceous or green, chlorophylline growths from becoming
paramount) into the smallest Vorticelle. The centre of the wafer-
shaped disk, inherent in the denser surface of the water, protrudes
downward into a little clear knoll or navel, which soon begins to
jerk, representing as it were a pin-head of +)55 lime diameter on a
little thread or coiled stalk; and, as the whole increases in size, it
now constitutes the well-known spirally peduneulate Vorticella ;
pyriform bell-shaped, somewhat pitcher-mouthed, with cilia around
the orifice and a clear granular nucleus or “ germinal speck” inside.

The multiplication of the pedunculate Vorticelle, by fission,
lengthwise, and by budding-out, sideways, at the rear end, is suffi-
ciently known. As the bud tears loose, there is yet no oral aper-
ture visible. There is, however, a girdle of cilia at the rear, where-
with it performs an undulatory vibration, until it tears loose by
spinning round; and after irregularly prancing about, and rebound-
ing at headlong speed, within a few minutes it “settles” upon
some suitable surface, with the ciliated rear end; and spinning out
a podetiwm, or peduncle, often within a quarter of an hour, the
rear cilia get applied downward to the body and disappear; while
after a little time a fully ciliated mouth now opens in front.

As for its retrograde multiplications, when a Vorticella gets
“sick,” for want of air or food (as when kept between glass-plates
held apart and glued round about, or cemented, to prevent evapora-
tion), the body contracts to a perfect globe, with a big germinal
point, “eye,” or nucleus in the middle; the throat contracted, and
the lifeless cilia standing around like the limb of a rose-calyx. The
germinal speck, ogle, or nucleus soon becomes immensely bloated,
protruding out of the crown or ciliate aperture like a dim, hazy
balloon, and then being either suddenly or gradually exploded, its
almost invisible granular contents settle around and increase into a

* In fig. 215, Carp. ‘ Mier.,’ p. 446, the short prickles are omitted, B to E.

Infusorial Cirewt of Generations. 231

rather densely punctuated cloud, run up like a cumulus ; its tips
mostly warty as with (dotted) strawberries, a sort of primordial
“framboésia.” It is to this form that I wish to call particular
attention, since it represents the most minute phase of individual
animate life visible at present under the known powers of the
microscope: being the ultimate retrograde development-phase, as
well as the first manifestation, common to all such soft primitive
sarcode bodies, from the “ Vorticellan” to the most bulky “ Para-
mecian” forms. And from each little dot in these “ clouds of life ”
a separate Vorticella can be seen to develop! It is here, indeed,
at this first visible advent or exordium of animate life, and the
resurrection of millions of germs through the spontaneous dissolu-
tion of a single one, that the last nubecular microscopic perceptions
closely resemble the last nebular telescopic as well as the theoretic
ones of Laplace’s cosmogony.

For the present let us call such often-repeated forms of retro-
erade self-dissolution and self-multiplication a germinal nubecula.
Such likewise occur in a very closely analogous form in the self-
maceration (of the engulfed pencil-beads and the enlarged “oidium”-
jomts) of the yeast or “zymotic” fungus. The difference being,
that in the case of animal infusoria the dots remain affixed, and,
after jerking apart, rapidly travel on separately with a vacillating
motion resulting from their warped surface (true Zoogloea Termo
Cohn; not that of Klob), while in the case of the mucous or poly-
poid fungine diffluence (erroneously called by the above name by
Klob), the component blunt-cylindrical Cacteria are not mutually
fixed, but all simultaneously slowly move onward and apart in slimy
trails, without a perceptible rotation, simply quivering, and ulti-
mately enlarge into fibres. Of the black or “indissoluble ” nebula-
form of the zymotic or yeast-fungus I have already treated in the
‘St. Louis Medical Reporter,’ Jan. 1st, 1868 (Zymotic Condition,
&e.), and ‘Proc. A. A. A. S.,’ 1870, e ante. Neither the animal
molecules nor the (coated) “ Cacteria ” join into file, as do the fer-
mentic sarcode-vibrios, being naked.

The watchful observer will have opportunity of witnessing
another sort of “fertile dissolution ” of the more bulky Vorticelle,
by the discharge of certain globular, granular “ pellets,” surrounded
with other adhering and jerking particles—(probably the “ acineta”
of some authors)—while containing the “ currant-shaped ” yolks,—
hereafter to be described, together with its “amoeba” or pseudo-
podial dissolution, when treating of the so-called “ Paramecowm
Aurelia.”

A direct onward evolution of Vorticella I had occasion to realize
on the fetid scum cuticle of a putrescent aquarium. All the
Vorticellze which, in dense clusters, lined the under surface of that
membrane, or animal pellicle, were found to elongate into a sort of

232 Infusorial Circuit of Generations.

roughish, but very hyaline, cucumber-shaped form; each “cucum-
ber ” at first crowned with a true vorticellan pitcher-mouth, mostly,
however, closed and rounded over, occasionally gaping or as it were
yawning spasmodically, at intervals only, and which finally “ shut
up” for good. The little glassy knobs—like so many trunk-nails—
that covered the surface, grow into soft jerking-bristles ;* the mouth
into the well-known mustachioed slit of barbiform celia; and the
wan, limpid, empty and now entirely flattened, ligulate or sandal-
shaped body tears loose as a young fluttering, pallescent Oxytricha
(Pelionella), or so-called “ hackle-animaleule”; darting by the
jerks of its stiffish marginal bristles, and by the constant “ plying ”
of the long-barbed, ciliate slit effecting its slower progress. It
never revolves, but often crawls; both in contradistinction to the
fleeced, revolving, and vacuole-propelled “ Paramecium ” form.

This is probably the “short-line” development of Oxytricha,
directly from the germinal clouds or the parasite of Chlamydococcus
through Vorticella. I have no good figures to refer to, since even
the detailed ones of Ehrenberg, in ‘Trans. Berlin Acad. Sc.,’ 1833,
tab. iii, figs. ii, iii, and iv., which belong here (as well as
tab. xxiv. and xxv. of A. Pritchard’s ‘ Hist. Inf.,’ 1861), are too
inaccurate to serve as a guide, or to be readily identifiable even by
those acquainted with the real natural object-material itself.

At first the bristles of the (tongue-shaped, flat, and elongate-
elliptical) Oxytricha are fluttering and tremulous; but as it feeds
and rapidly increases in bulk, all the well-known characters of the
complete ‘‘ Oxytricha,” its stiffish darting-bristles, its grumose,
obscured body, irregularly replete with granular yolks, and very
frequently cross - dividing, become typified. When thus cross-
divided (a process well known and abundantly figured) the front
part alone retains the barbed mouth, which, from the apex, switches
down like a mustachio on a longitudinal sht about a quarter of
the whole length. The blunt rear-part, on the contrary, separates
with an incurrent angle which soon contracts into a new mouth,
whereby the rear animal takes a blunter shape (like the cotyledon
of an almond, the flat side downward).

The Oxytricha is by no means, however, to be considered as
an adult form, since it is never seen to exhibit a continuity as of a
membrane, or of internal ducts or viscera. Neither is it seen to
“copulate ” or adhere lengthwise, or in any other fashion to one
another except in the process of self-division. Nor does it readily
divide by longitudinal fission in this state. I have seen this only

* In their onward development these softish bristles are indurated into “ styles”
(of specialists). The attentive reader will observe that on such alterations of growth
alone a great many colloiding false genera and species have been formed. Sap. sat.
We have naturally to reject all, of which the mode of development remains unknown,
as indicating a false stand-point.

Infusorial Cirewit of Generations. 233

once. Crawling and darting by an apparatus of marginal bristles,
prolonged in front and particularly in the rear, it is destitute of the
“ propulsive vacuoles,” as found, e.g. in the large “ Paramecium
propulsi es,” as found, ¢. 7. in the large:
Aurelia ;” but besides being studded, particularly in the rear por-
tion, with a great number of larger and smaller granular pellets,
its body exhibits near the middle a large, clear, and granular
“ oerminal speck” or nucleus, which is often observed to swell,
protruding globularly over the surface, below and above, when seen
crawling in profile.*

Occasionally it is seen to extrude suddenly that turgid germinal
nucleus or yolk (vitellus), which, as in all these cases, is itself coat-
less, but hung around with divers jerking molecular fragments torn
loose from the parental body, which is ruptured on the spot, but
readily “ re-cemented,”’ as it were.

The larger of these coatless granular yolks (constituting the
original pseudo-genus, and species “ Zooglea Termo Dujard”) t
mostly consist of two parts, v2z. a general “albumen” of a granular
and evidently trabecular texture, enclosing one or two distinctly
coated, quite hyaline and perfectly globular vesicles. The latter
resemble in shape a very clear white currant, as it were, by having
a sharply-defined circlet inscribed near one side, that is caused
by a local cnversion of contents (somewhat like the air-vesicle
within a hen’s egg).

(To be continued.)

* The transformation of the “rear-part” of Oxytricha, as given by J. Haime
in ‘Ann. Sci. Nat.,’? Ser. 3, tom. xix., p. 109 (and represented in Carp. ‘ Mier.,’
pp. 447 and 448), I have not been able to verify myself; it must not, however, by
any means be confounded with the encystments (1) of Vorticella, producing wafer-
like molecules; (2) of the non-pulsating, tear-shaped “Paramecium kolpoda”
grub, producing free Oxytricha; nor (3) with that of the “oyster” or “ porte-
monnaie” grub, producing paramecium-like bodies, Gregarina-fashion ; nor either
(4), with some large Oxytricha “currants,” containing the revolving “ crucible.”

+ As represented by Cohn in ‘Nov. Act. Nat. Curios,’ 1854, vol. i, tab. xv.,
fig. ix. In Klob’s ‘ Microscopie Researches on Cholera’ the term is misapplied to
engorged joints of dissected corruptive fibrils (or “ Oidium lactis”) replete with
bacterial daughter-cells. , :

( 284 )

PROGRESS OF MICROSCOPICAL SCIENCE.

Difficulty of Experiments on Spontaneous Generation.—Myr. Crace-
Calvert, F.R.S., cites the following experiment in his first paper “On
Protoplasmic Life,” read before the Royal Society (received May 8) :—
Although he was prepared, by the perusal of the papers of many
workers in this field, to experience difficulties in prosecuting the study,
he confesses he did not calculate on encountering so many as he met,
and especially those arising from the rapid development of germ-life, and
of which he had hitherto seen no notice in any papers which had come
under his observation. Thus, if the white of a new-laid egg be mixed
with water (free from life), and exposed to the atmosphere for only
fifteen minutes, in the months of August or September, it will show
life in abundance. From this cause he was misled in many of his
earlier experiments, not having been sufficiently careful to avoid even
momentary exposure of the fluids to the atmosphere. To the want of
the knowledge of this fact may be traced the erroneous conclusions
arrived at by several gentlemen who had devoted their attention to the
subject of spontaneous generation.

Regeneration of the Corneal Epithelium.—Dr. Hjalmar Heiberg, of
Copenhagen, has written a very valuable paper on the above subject
which is reproduced in the ‘Lancet. A paper recently appeared
in Virchow’s ‘ Archiv,’ by Julius Arnold, on the same subject, who
came to the conclusion that the new cells which replaced the old, when
these had been detached, were derived from a finely granular blastema
that changes into protoplasm, and that in this protoplasm the new cells
arise by a process of free cell-formation. The correctness of this con-
clusion is contested by Dr. Heiberg, who maintains the view that
young cells are developed from the old, in which certain changes have
taken place. His mode of procedure was to scratch the surface of the
cornea with a cataract needle in animals (frogs, birds, rats), and, after
the lapse of from eighteen to forty hours, to remove the eye andlexamine
the cornea both by means of fresh sections and after careful prepara-
tion in solutions of chloride of gold (maceration for from three to five
minutes in a one-half per cent. solution of the salt). In certain prelimi-
nary experiments it was found that the injured part immediately after
the injury presented sharply-defined irregular borders ; after six hours
the margins were considerably flattened, so that the boundary of the
abrasion was much less distinct. After eighteen hours it was difficult
to tell the seat of the injury with the naked eye, and its diameter had
become reduced to one-half or one-third; and after forty hours reco-
very was complete. He convinced himself by microscopic investiga-
tion that the process of regeneration of the epithelium proceeds from
the margins of the abrasion, the layers of cells immediately bounding
the seat of injury becoming elongated, and, as it were, sending forth
processes towards its centre; so that the margins are rendered very
oblique, whilst at the same time the exposed surface of the cornea is
raised considerably above the level of that which is still covered by
the cells. Sometimes the cell-processes become detached and contract

PROGRESS OF MICROSCOPICAL SCIENCE. 235

into glassy, clear, rounded masses; but he has never noticed the free
formation of cells in a blastema, and does not believe that the white
corpuscles of the blood or “migrating cells” play any part in the
regeneration of the cells, though he has occasionally met with them
between the epithelial cells and in the substance of the cornea in the
vicinity of the injury. In no single instance has he observed any
appearance leading him to think that they undergo conversion into
epithelial cells. The processes thrust forth by the cells, as above
mentioned, were found, from observations extending over many hours,
during which the cornea was placed in a current of serum, to undergo
slow changes of form and size, the movements however being in no
way comparable in activity to those of amceboid cells. The cells situ-
ated at a greater distance from the injured part often became granular,
and their margins more distinct. In rats both the upper flattened and
the deeper, more columnar cells seemed alike to thrust forth the pro-
cesses destined to cover the floor of the injured part. Dr. Heiberg
expressly remarks that he has not satisfactorily followed the separation
of the cell-processes to form new cells, which again push out new out-
growths, to be again detached, though he obviously thinks this is what
really occurs. Dr. Heiberg gives several drawings to illustrate the
points mentioned in his paper, which is in every respect a most valu-
able contribution.

The Microscopie Structure of Cotton-seeds.—This is a paper, pub-
lished in the ‘ Neues Jahrbuch fiir Pharmacie,’ * by Dr. F. Fliickiger.
It is a long paper, and contains, in the first place, a succinctly-written
botanical description of the several kinds of shrubs and trees from
which cotton is obtained; next, we meet with a histological and
morphological minute description of the microscopical structure of the
cotton-seeds, illustrated by coloured lithographs. The latter portion
of this essay is devoted to a well-condensed and very complete review
of all that has been done in various parts of the world in reference to
the scientific, as well as industrial, researches on cotton-seeds, and the
oil it yields. According to the author, the quantity of cotton-seed
annually gathered amounts to 1,000,000,000 of kilos., which, under the
least favourable conditions, would yield 150,000,000 kilos. of oil.

Discovery of the Animal of the Spongiade confirmed.—Mr. H. J.
Carter, F.R.S., sends a line to ‘Silliman’s American Journal’ (July),
“just to tell you what you will be glad to learn, viz. that I have con-
firmed all that Professor James Clark, of Boston, has stated about
the sponge-cell, and much more too. It is after all only what was
published and illustrated in the ‘Annals’ in 1857. Indeed I am
astonished now at the accuracy and detail of that paper,t now all con-
firmed by an examination of a marine calcareous sponge. I have not
only fed the sponge with indigo, and examined all at the moment,
but the sponge so fed was put into spirit directly afterward, and now
shows all the cells (monociliated) with the cilium attached and the
indigo still in the cells. This, I think, will break down Hiickel’s
hypothesis, which is as imaginative and incorrect as it is beautiful.
His “ Magosphera” too is figured in the ‘ Annals’ (1856), and de-

* Double number, May and June, 1871.
+ “ Ultimate Structure of Spongilla,” &c.

236 PROGRESS OF MICROSCOPICAL SCIENCE.

scribed in extenso as the amceboid cell which inhabits the mucus of
the cells or internodes of the Bombay great Nitella. But there are no
people in England, if on the Continent, who seem to be able to show
this, if even they be cognizant of it. wx oriente lux used to be the old
phrase; the light is now being reflected back from America. It is
from there that we must expect novelties now.”

The Anatomy of the Graafian Follicles in Man.—These have been
very fully explained by Dr. Kronid Slavjansky in Virchow’s ‘ Archiv,’*
and are well abstracted by the ‘Lancet’ in a late leader. The
author’s observations have been made on subjects of all ages brought
to the Anatomical and Pathological Institute of the Medico-Chirurgical
Academy of St. Petersburgh. The preparations were macerated imme-
diately after removal from the body (which was usually effected in from
three to eight hours after death) for a week or a fortnight in Muller's
fluid, then placed in a 70 per cent. solution of spirits of wine, and then
in a 90 per cent., after which fine sections were made. In the exami-
nation of the ovaries of children he recognizes three forms of follicles
—(1) primordial follicles, which are the youngest ; (2) a transitional
form to the mature follicles; and (3) more or less developed mature
Graafian follicles.

The primordial follicles are of roundish or elliptic form. They
consist of the primordial egg, with the yelk, the germinal vesicle, and
germinal spot surrounded by a series of small round cells in contact
with one another, and without any intermediate substance. In very
young follicles a spot can always be found where these cell-series are
interrupted, and where the egg apparently is in direct contact with -
the wall of the follicle. This is the follicle-pole of Pfliiger. At a
subsequent period this spot is covered by a layer of cells. The wall
of the follicle presents no characters distinguishing it from other parts
of the ordinary stroma of the ovary. On its inner surface, however,
he admits the presence of a lustrous layer, similar to that found in
acinous glands, in which sometimes a few fusiform cells may be dis-
covered, and thus differs from Waldeyer, who in his description of the
structure of the primordial follicles states that they are destitute of a
membrana propria, and that the stroma tissue lies in immediate contact
with the contents of the follicle, the fibres being arranged circularly
around it. Thus it appears that in the very youngest follicles the egg
is surrounded by a series of epithelial cells representing the future
membrana granulosa. The delicacy and instability of these cells
explain the circumstance of their being denied by Klebs, Schron, and
Florinsky. Such follicles as those that have just been described may
be seen in certain parts of the ovary, at every age from the eleventh
week of intra-uterine life to the grand climacteric. In embryos they
are usually found between the cortical and medullary layers ; in new-
born children they are found in all parts; in adults they are met
with only in the most superficial layers of the cortex, where they are
closely packed, and when badly prepared, in consequence of the
destruction of the epithelium, look like rows of large cells from which,
near the centre of the ovary, the follicles appear to develop. Slav-
jansky accepts and corroborates Waldeyer’s description of the origin

* Band 51, Heft. 4.

PROGRESS OF MICROSCOPICAL SCIENCE. ry f

of the primordial follicles from tubes. He describes a somewhat
complicated histological process in which the follicles undergo a
physiological destruction; this commences with a fatty degeneration
of the follicular walls, and proceeds with contraction of the cavity till
it is completely obliterated. The young tissue by which this ob-
literation is effected is considered by M. Slavjansky to proceed from
the white corpuscles of the blood. In regard to the formation of the
corpus luteum (verum and spurium) he concludes that in this process
only the so-called granulation layer of the follicular wall is active, the
membrana granulosa undergoing fatty degeneration and atrophy. In
conclusion, he describes the pathological conditions of the ovary, with
the exception of dropsy of the Graafian follicles. He divides them
into affections of the parenchyma, and affections of the wall of the
follicle. The former are included under the heads of fatty meta-
morphosis and colloid metamorphosis; the latter he considers may be
embraced under the general head of sclerosis.

The Structure of Stigmaria has been most fully gone into in a paper
by Professor Williamson, F.R.S. (of St. John’s College) in the last
number of the ‘ Proceedings of the Royal Society.’ Stigmaria is shown
to have been much misunderstood, so far as the details of its structure
are concerned, especially of late years. In his memoir of Sigillaria
elegans, published in 1839, M. Brongniart gave a description of it,
which, though limited to a small portion of its structure, was, as far as
it went, a remarkably correct one. The plant now well known to be
a root of Sigillaria, possessed a cellular pith without any trace of a
distinct outer zone of medullary vessels, such as is universal amongst
the Lepidodendra. The pith is immediately surrounded by a thick
and well-developed ligneous cylinder, which contains two distinct sets
of primary and secondary medullary rays. The primary ones are of
large size, and are arranged in regular quincunctial order; they are
composed of thick masses of mural cellular tissue. A tangential
section of each ray exhibits a lenticular outline, the long axis of
which corresponds with that of the stem. These rays pass directly
outwards from pith to bark, and separate the larger woody wedges
which constitute so distinct a feature in all transverse sections of this
zone, and each of which consists of aggregated lamine of barred
vessels disposed in very regular radiating series. The smaller rays
consist of vertical piles of cells, arranged in single rows, and often
consisting of but one, two, or three cells in each vertical series; these
latter are very numerous, and intervene between all the numerous
radiating lamine of vessels that constitute the larger wedges of woody
tissue. The vessels going to the rootlets are not given off from the
pith, as Goeppert supposed, but from the sides of the woody wedges
bounding the upper part of the several large lenticular medullary
rays, those of the lower portion of the ray taking no part in the con-
stitution of the vascular bundles. The vessels of the region in question
descend vertically and parallel to each other until they come in contact
with the medullary ray, when they are suddenly deflected, in large
numbers, in an outward direction, and nearly at right angles to their
previous course, to reach the rootlets. But only a small number reach
their destination, the great majority of the deflected vessels terminating

238 PROGRESS OF MICROSCOPICAL SCIENCE.

in the woody zone. A very thick bark surrounds the woody zone.
Immediately in contact with the latter it consists of a thin layer of
delicate vertically elongated cellular tissue, in which the mural tissues
of the outer extremities of the medullary rays become merged. Ex-
ternally to this structure is a thick parenchyma, which quickly assumes
a more or less prosenchymatous form and becomes arranged in thin
radiating lamine as it extends outwards. The epidermal layer con-
sists of cellular parenchyma with vertically elongated cells at its
inner surface, which feebly represents the bast-layer of the other
forms of Lepidodendroid plants. The rootlets consist of an outer
layer of parenchyma, derived from the epidermal parenchyma. Within
this is a cylindrical space, the tissue of which has always disappeared.
Tn the centre is a bundle of vessels surrounded by a cylinder of very
delicate cellular tissue, prolonged either from one of the medullary
rays or from the delicate innermost layer of the bark, because it
always accompanies the vessels in their progress outwards through
the middle and outer barks. It is, he says, evident that all these
Lepidodendroid and Sigillarian plants must be included in one common
family, and that the separation of the latter from the former as a group
of Gymnosperms, as suggested by M. Brongniart, must be abandoned.
The remarkable development of exogenous woody structures in most
members of the entire family indicates the necessity of ceasing to apply
either to them or to their living representatives the term Acrogenous.
Hence the author proposes a division of the vascular Cryptogams into ~
an exogenous group, containing Lycopodiacew, Hquisetacee, and the
fossil Calamitacee, and an endogenous group, containing the ferns ;
the former uniting the Cryptogams with the Exogens through the
Cycadee and other Gymnosperms, and the latter linking them with
the Endogens through the Palmacee.

Passage of Corpuscles through the Blood-vessels.— A long and
important paper on this subject has been lately read before the Royal
Society, by Dr. R. Norris, Professor of Physiology in Queen’s College,
Birmingham. He says that on a careful consideration of the hypo-
theses which have been propounded by Waller, Cohnheim, Stricker,
Bastian, and Caton, to account for the curious phenomena in question,
it will be found that all these hypotheses fall short in one important
particular, inasmuch as they afford no explanation whatever of by far
the most singular part of the process, viz. the fact that the apertures
through which the corpuscles pass again close up and become invisible.
The question, indeed, is not so much how the corpuscles get out, as
how they get out without leaving any permanent trace of the apertures
through which they have so recently passed, and which were so pal-
pable during the period of transit. Before proceeding to elaborate
his own views, he restates succinctly the various points upon which
observers are agreed. Ist. Both white and red corpuscles pass out of
the vessels through apertures which can neither be seen before their
ingress into or egress from the vessel wall, but only during the period
of transit. 2nd. An essential and primary step in the process is, that
the corpuscles shall adhere or, more properly, cohere to the wall of
the vessel. 38rd. These cohering corpuscles shall subsequently be
subjected to pressure from within.

PROGRESS OF MICROSCOPICAL SCIENCE. 239

From this he proceeds to consider the various physical conditions
involved in the question, and eventually he states that all that is
essential for a rigid or plastic body to pass through a colloid film is:
—\st, an intimate power of cohesion, either mediately or immediately,
between the film and the body; 2nd, a certain amount of pressure from
within ; 3rd, power in the substance of the film to cohere to the sur-
face of the body (or to some intermediate matter which already coheres
tothe surface) during its passage ; 4th, cohesive plasticity of the parti-
cles of the material of which the film itself is composed, so that the
breach in it may again become reunited as it descends upon the oppo-
site surface of the body which is being extruded. These conditions
he thinks are prevalent in the case of the minute blood-vessel and the
corpuscle; since he considers that the passage of the corpuscle
through the vessel is precisely analogous to the passage of a body
through a soap bubble. Unfortunately in parts the author’s language
is not sufficiently clear to enable one to find his exact meaning, but we
believe that we have found it correctly as above.

The Structure of Lepidodendron is stated by Professor Williamson
to be inthe case of Lepidodendron selaginoides as follows :—It consists
of a central medullary axis composed of a combination of transversely
barred vessels with similarly barred cells; the vessels are arranged
without any special linear order. This tissue is closely surrounded
by a second and narrow ring, also of barred vessels, but of smaller
size, and arranged in vertical lamine which radiate from within out-
wards. These lamine are separated by short vertical piles of cells,
believed to be medullary rays. In the transverse section the inter-
sected mouths of the vessels form radiating lines, and the whole struc-
ture is regarded as an early type of an exogenous cylinder ; it is from
this cylinder alone that the vascular bundles going to the leaves are
given off. This woody zone is surrounded by a very thick cortical
layer, which is parenchymatous at its inner part, the cells being with-
out definite order; but externally they become prosenchymatous, and
are arranged in radiating lines, which latter tendency is observed to
manifest itself whenever the bark-cells assume the prosenchymatous
type. Outside the bark is an epidermal layer, separated from the rest
of the bark by a thin bast-layer of prosenchyma, the cells of which
are developed into a tubular and almost vascular form; but the vessels
are never barred, being essentially of the fibrous type. Externally
to this bast-layer is a more superficial epiderm of parenchyma, sup-
porting the bases of leaves, which consist of similar parenchymatous
tissue. Tangential sections of these outer cortical tissues show that
the so-called “ decorticated” specimens of Lepidodendra and of other
allied plants are merely examples that have lost their epidermal layer
or had it converted into coal, this layer, strengthened by the bast tissue
of its inner surface, having remained as a hollow cylinder when all the
more internal structures had been destroyed or removed.—Proceedings
of Royal Society, vol. xix., No. 129.

VOL. VI. 5

( 240 )

NOTES AND MEMORANDA.

The Darwinian Question. A Prize Essay.—It seems that by the
provisions of the late Dr. William J. Walker’s foundation two prizes
are annually offered by the Boston Society of Natural History for the
best memoirs, written in the English language, on subjects proposed
by a committee appointed by the Council. For the best memoir pre-
sented, a prize of sixty dollars may be awarded; if, however, the
memoir be one of marked merit, the amount may be increased, at the
discretion of the committee, to one hundred dollars. For the memoir
next in value, a sum not exceeding fifty dollars may be given; but
neither of these prizes are to be awarded unless the papers under con-
sideration are deemed of adequate merits.

Memoirs offered in competition for these prizes must be forwarded
on or before April 1st, 1872, prepaid and addressed

“ Boston Society of Natural History,
for the Committee on the Walker Prizes,
Boston, Mass.”

Each memoir must be accompanied by a sealed envelope enclosing
the author’s name, and superscribed by a motto corresponding to one
borne by the manuscript.

Subject of the Annual Prize for 1872.—* The Darwinian Question ;
its bearings on the development of animal life.”

The Application of Mr. Darwin’s Theory to Flowers and the
insects which visit them, by Dr. Erm Miller, with notes by Prof. F.
Delpino, is now published in English. It has been translated from
the Italian by an American naturalist, and may be had for 25 cents by
addressing to the Naturalists’ Agency, Salem, Massachusetts,

Dr. Dudgeon’s Microscope.—A writer in the ‘American Natu-
ralist’ for September, comments on this instrument: he says that while
the common “ tank microscope” can be worked best somewhat hori-
zontally, through the side of the tank, this arrangement, besides being
applicable to much higher powers, is adapted to give a more or less
vertical view, being entirely free from any tremor on account of the
motion of the top of the water, and is therefore especially useful for
dissecting purposes. Its object, though not its method, is identical
with that of Tolles’ immersion objective for low powers, published
more than two years ago; though the latter naturally possesses—being
constructed especially for this use, and dispensing with two unneces-
sary surfaces of glass—some optical superiority, as well as a much longer
working focus. The submersion tube, being applicable to ordinary
lenses, only slightly lowering their magnifying power and considerably
shortening their working focus, will doubtless be extensively useful ;
though the statement that it may be always retained in position as a
protecting cover to the lens without impairing the definition or illu-
mination in ordinary work, must be considered as too enthusiastic. It
is especially applicable to lenses of from one inch to one-quarter inch

CORRESPONDENCE. 241

focus (the latter limited to a very small angle), and the objects should
be placed in a jar or tank having the bottom and at least one side quite
smooth and transparent.

How to study Embryology.—This is well shown by the recent
observations of Dr. Elias Metschnikoff upon the development of scor-
pions. This author has recently published in Siebold and Kélliker’s
‘Zeitschrift,’ a paper which is abstracted by the ‘American Naturalist.’
The subject is the embryology of the Scorpio Italicus and of a species
from Tyrol. The embryology of insects and crustacea as pursued at
the present day by zoologists, who are directing especial attention to
the provisional membranes of the egg and embryo, depends almost as
much on the skilful use of the chemicals as the microscope itself. The
author says “ the methods which I employ in these researches are not
complicated. I study the eggs removed from the ovarian tubes ; or,
place the living embryo in a drop of a weak solution of salt (salzlésung) ;
or I at first submit them to the influence of solutions of chromic acid
of different strengths, and then examine them either with a simple or
compound microscope. Out of embryos hardened in this way I can
make sections. Much of the time I have to work with dissecting
needles, while the embryos or portions of them treated in this way,
and in an equal mixture of fresh and salt water, afford very good
objects for study.” The embryology of scorpions was sketched out in
a general way by the distinguished German embryologist Rathke.
Metschnikoff extends these researches very greatly, and considers as
the most important results of his studies the discovery that “im the
embryo of the scorpions three embryonal membranes are developed,
which in many respects are very strikingly similar to the Remakian
embryonal membranes of the vertebrates.”

CORRESPONDENCE.

Wuat is THE APERTURE OF ToLLES }TH?
To the Editor of the ‘ Monthly Microscopical Journal.’
Sept. 18th.

Sir,—In the very interesting account given by Colonel Woodward
of Mr. Tolles’ fifth there is one important omission. He has not told
us what is its aperture. As a general rule a one-fifth by any of the
best of our English makers does not exceed 100° in aperture; but it
would not “surprise me to hear” that Mr. Tolles’ fifth has an aperture
of 150° or 160°. At the close of his paper it is suggested that trials
should be made with recent English glasses of the same focus, so as
to compare the results with those obtained with Mr. Tolles’; but
until the respective apertures are known, such comparisons would be
without meaning. Perhaps Colonel Woodward, if this should meet
his eye, will be kind enough to supply the omission.

As I am writing on the subject, I may take the opportunity to
point out more generally the confusion which exists in the minds of

g 2

242 CORRESPONDENCE.

most microscopists about the classification of glasses. It so happens,
and it is a convenient arrangement, that they are named from their
focal lengths. The focus, therefore, has come to be considered the
essence of the glass, the aperture being counted only one of its
accidents or attributes; like, for example, good or bad workmanship.
And so, for comparison of performance, we see objectives tried against
others of the same focus only. But there is, scientifically, no reason
whatever why glasses should not receive their rank or denomination
from their apertures instead of their foci. Thus, for example, a glass
of 90° with half-inch focus may be compared with a glass of 90°
quarter-inch focus with just as much fairness as against another half-
inch of 45°. Not only so, but it is even more reasonable, scientifically,
to compare by apertures than by foci, for the want of amplification
may be not ill compensated by the action of the eye-piece ; whereas by
no subsequent manipulation of the eye-piece can the peculiar qualities
depending on difference of angle ever be balanced. Focus and aperture
are in fact both essential factors in the denomination of an object-
glass, and where a difference exists in either we must keep in mind
that we are comparing different things and not the same things with
differing qualities. A curious illustration of the confusion I have
commented on may be seen in a pamphlet or little book about micro-
scopes, rather widely circulated, I believe, some years ago—a reprint
from a paper read before the Royal Microscopical Society. The
author in a learned note undertakes to prove that objectives with wide
apertures are the best; his reason being that with a half-inch of 90°
he can see things which he cannot see with a half-inch of 55°. It
does not seem to have occurred to him that, if this be all, an eighth
of an inch will show him more than either of them; and therefore
with equal wisdom of logic he might have drawn the conclusion that
an eighth is preferable to a half-inch.

It is customary in your Journal to sign with the writer’s name;
but as the purpose of this letter is only to ask a question, it will do
equally well, when asked, by a letter of the alphabet.

Yours, &c.,
B.

To the Editor of the ‘ Monthly Microscopical Journal.’
October 20, 1871.
Dear Sir,— Will you permit me through your columns to say, in
answer to inquiries as to where Dr. Sanderson’s paper “On the Patho-
logy of Contagion ” appears, and to which I refer in my observations
on the “ Fungoid Origin of Disease,” page 156, September number of
the Journal, that it is part of an Appendix to the Thirteenth Annual
Report of the Medical Officer of the Privy Council, published by
Hansard, Great Queen Street, for the small sum of fourpence-half-
penny.
Yours very faithfully,

Dr. Lawson, JABEZ Hoae.
Editor ‘ Microscopical Journal, §c., §c.

( 243 )

PROCEEDINGS OF SOCIETIES.*

Royat Microscopican Socrety.

Krne’s CoLince, Oct. 4, 1871.

Wn. Kitchen Parker, Esq., F.R.S., President, in the chair.

The minutes of the last meeting were read and confirmed.

A list of donations was read, and a vote of thanks passed to the
respective donors. Among the donations was a series of prepara-
tions of intestinal worms from Australia, which Dr. Cobbold had been
requested by the Secretaries to report upon.

To the President of the Royal Microscopical Society, London.

137, CASTLEREAGH STREET, SYDNEY, July 12, 1871.

Str,—By this mail I have sent to your Society twenty-four micro-
specimens prepared by me, in order that your Society may identify
and name the several entozoa hereby forwarded.

Our Agricultural Society have also sent you a copy of their journal,
in which you will see that I have given a description of the lung,
intestinal, and tape worm infecting our sheep, with illustrations of
the principal characteristic features of said worms. In looking over
the illustrations, please make a note of x 35 instead of x 25 (an inch
objective being used with the camera lucida).

At the present time our cattle, sheep, and pigs, are all infested
with parasites, and within the last few days another new worm has
been sent me to investigate, its habitat being in the fat (or flip) sur-
rounding the kidney of the pig. I have sent you six different pre-
parations: a male and female; caudal extremity of the male, showing
cup-like bursa with a double (V-shaped) spiculum; -head, showing
oral orifice with six papille leading into the cesophagus—the papille
are armed with minute lancet-pointed teeth ; also two preparations
showing the different stages of the development of the eggs.

Ihave also sent you what I take to be an “ Amphistoma conicum ”
from the rumen of the sheep. Mr. Krefft (our curator of the Museum)
says it is a larva of a distoma. I maintain that it is a sexually mature
animal, and have named it “A. conicum.” Your opinion on it will be
received with thanks.

T have also sent you four preparations of a “shrips” which has
attacked the whole of our deciduous trees and shrubs, causing the
leaves to assume a brownish colour. The segments of its body do not
correspond to the shrips I have been accustomed to examine. I have
isolated one of its wings, and prepared it for your inspection: no
doubt of its being a “ Thysanoptera,” but I have declined to name it.

No, 24 is a pretty little aphis (larva) from the gum (Eucalypti)
leaf ; it is generally found between two leaves glued together. I do
not know its name, therefore would feel obliged if you could name it
for me. All the other preparations you will find described in the

* Secretaries of Societies will greatly oblige us by writing their report legibly
—especially by printing the technical terms thus : H ydra—and by “underlining”

words, such as specific names, which must be printed in italics. They will thus
secure accuracy and enhance the value of their proceedings——Ep. ‘ M. M. J’

244 PROCEEDINGS OF SOCIETIES.

journal sent you by our Society, therefore I shall devote the rest of
my remarks to the pig-worm.

This worm when seen in the fat surrounding the kidney is of a
greyish-brown colour, with a red head (the colour of the head is
caused by the fresh blood). It is about 14 inch in length, the male
being somewhat less than the female. It is found in the fat in a free
and encysted state, the encysted state being its final stage of existence.
When once it becomes encysted the solid parts of the worm ultimately
disappear, leaving a greyish-brown fluid containing thousands of eggs.
No. 17 are the eggs when the worms (generally from three to six
found in a cyst) are beginning to break up. No. 18 are the eggs
when the worms have entirely disappedred. The cyst from which
this specimen was taken was of about 13 of an inch in length and
4an inch diameter. By carefully examining this specimen you will
see that the contents of the egg-case are already taking on the charac-
teristic features of young worms. Probably in a few days more these
young worms would soon have been so far developed as to undertake
an independent existence in the flesh of their host. As several pigs
have died lately from some mysterious disease, it is possible that this
worm or its brood may be the cause, and I think I shall be put in pos-
session of facts which in a few days may clear up the whole history
of this parasite. If physiologists had not settled the Trichinz theory,
I think this worm would have played an important part in giving
conclusive evidence as to how the worms might get into the flesh of
an animal. Here we have got a worm already in the flesh of the
animal, it becomes encysted, leaving its eggs to be hatched; when
hatched where do they go to? evidently into or through the substance
of the body of their host.

It is just possible that some pigs may survive the irritation such a
swarm of young worms must set up; others again may die from peri-
tonitis, hence the sudden deaths amongst the pigs. In the Trichine
theory as at present accepted by physiologists, an animal must eat the
meat containing the encapsuled trichine. In twenty-four hours the
capsules burst, liberating the young trichine. In forty-eight hours
the young trichina has become a sexually mature worm containing
eggs and young embryos. Then these young trichine must pass through
the walls of the intestinal tract to get to the muscle and then become
encysted. Which of these two cases is the most feasible ?

Examine this female worm, you will find its intestinal and uterine
canals looped up into a series of convolutions. The trichina has the ~
same characteristic feature. However, I merely throw out the hint to
induce others to investigate, and not be content with the opinion of
compilers. :

Trusting you will excuse this freedom I have taken in asking you
to identify the various specimens I have induced our Society to for-
ward you,

I am, yours very truly,
Wm. Morais, L.F.P.G.S.

P.S.—I am a subscriber to your ‘ Monthly Microscopical Journal,’
and also to the ‘ Quarterly Microscopical Journal.’

W. M.

PROCEEDINGS OF SOCIETIES. 245

Report on Dr. Morris’ Paper.

The Secretary of the Society having done me the honour to submit
Mr. Morris’ excellent series of preparations to my scrutiny, I have
to state that the nineteen slides of entozoa comprise six distinct
species of parasites. These are severally referable to the Tenia ex-
pansa, Strongylus filaria, Strongylus contortus, Dochmius hypostomus,
Stephanurus dentatus, and lastly, as the author correctly surmised,
Amphistoma conicum.

Though not one of these helminths can be said to be entirely new
to science, yet all of them are of considerable interest, and much
remains to be worked out in reference to their developmental history.

By far the most interesting parasite is the form which I have un-
hesitatingly referred to the hitherto little-known Stephanurus, first
discovered by Natterer, some thirty-five years since, in Brazil. This
helminth has recently been found abundantly in the pigs of the United
States, where it has been generally regarded as an entirely new species
of entozoon. Professor Verrill, of Yale College, Connecticut, has
thus been led to describe it under the new name of Sclerostoma pin-
guicola ; but the specific and generic titles assigned to the worm by
Diesing, in the ‘Annalen des Wiener Museums’ for 1839, must, of
course, be allowed to hold priority.

In the pages of the ‘British Medical Journal’ for Jan. 14th of
the present year (pp. 50, 51), I first announced the true history of this
supposed new worm, from an examination of specimens sent to me for
identification by Professor W. B. Fletcher, of the Indiana Medical
College, U.S. ; and it is therefore extremely interesting to me to find,
from an inspection of Mr. Morris’ contributions to the Society, that
the Stephanurus dentatus likewise infests the pigs which are reared in
Australia.

(Signed) T. S. Cosson, M.D., F.R.S.

To the President of the Royal Microscopical Society, London.

Sypney, N.S. Wats, July 11, 1871.

Smr,—I am instructed by the Council of the Agricultural Society
of New South Wales to forward by this mail a small case containing
micro-specimens of intestinal worms and insects, which Dr. Morris,
L.F.P.G.S., has submitted to our Scientific Committee, with a view of
obtaining information on a subject now becoming of great moment
for all those who are interested in farming and pastoral pursuits.

Our Council will feel obliged to you if you will have the kindness
to lay these specimens before your Society, and furnish us with the
result of your deliberations on the matter.

I have the honour to be, Sir,
Your obedient servant,

JULES JOULUST,
Secretary.

246 PROCEEDINGS OF SOCIETIES.

A List of Twenty-Four Micro-specimens of InrestrnAL Worms and Insects,
sent by W. Morris, L.F.P.G.S., sent through the Agricultural Society of
New South Wales, Sydney, to the Royal Microscopical Society, London, for

identification.
Nos. CLASSIFICATION.
1 | Head of tape-worm.
2 | Segment of tape-worm.
3 | Ditto ditto, further developed.
4 | Female lung-worm.
5 | Ditto ditto, prepared to show eggs and embryo worms in situ.
6 | Male lung-worm.
7 | Embryo worms in mucus from the bronchi.
8 | Female intestinal worm from third stomach of the sheep, prepared
to show spiral canals, eggs, &e.
9 | Female intestinal worm (natural state), showing barb-like appen-
dages near the head.
10 | Male intestinal worm.
11 | Female intestinal worm found in the fcecal matter in the rectum of
the sheep.
12 | Male ditto ditto. The sheep in which these two worms were got,

Nos. 8 and 9 were not found, but a very large number of the
Amphistoma were seen in the rumen of said sheep.

13. | Female worm found in the fat surrounding the kidney of the pig.
14 | Male ditto ditto.

15 | Head, the worm showing oral orifice with the papille armed with
minute lancet-pointed teeth.

16 | Caudal extremity of the male.

17 _ | Eggs of the pig-worm.

18 | Ditto ditto, taken from a cyst 2 in. in length and 2 in. in
diameter, the solid parts of the worm having disappeared, leay-
ing a brownish fluid in the cyst, this, No. 18, being a specimen
of said fluid.

19 | Amphistoma conicum, this worm being disputed by Mr. Krefft,
curator of the Museum, as to its being an Amphistoma, he
stating it to be a larva of a distoma, I maintaining that it is a
sexual mature worm on account of its eggs, &e.

This fly has attacked the

Invarious(29 | Small insect from the Isabella vine. whole of our dlecsndas

stages of 191 | Ditto ditto, embryo wings oe te seme

develop- F spyee cae Sepals tre Ni

a ees 22 | Ditto ditto, without wings. nee ticdencae 3 i
23 | Wing of insect showing it is a Thysanoptera, but we decline to

name it.

24 | Aphis (larva) from the leaf of the Eucalyptus, found generally
between two leaves, gummed together.

Mr. McIntire contributed a paper entitled “An Incident in the
Life of a Chelifer.”

Dr. Cobbold then proceeded to give an extended comment upon his
Report on the Specimens of Intestinal Worms from Australia. Passing
in rapid review the various species which were well known in this
country, and therefore needed no description, he came to the less
known forms, one of which (Stephanurus) was first discovered by Nat-
terer, the traveller, on one of the Brazilian rivers (the Barra do, Rio
Negro), on the 24th March, 1834, Since then no one appeared to
haye seen this parasite, or if seen, it had not been recognized. Thirty-

PROCEEDINGS OF SOCIETIES. 247

seven years had thus passed without the parasite being discovered.
Recently, however, he had received a letter from Prof. Fletcher, of
Indiana, describing this very animal; and in a second communication
from that gentleman, he hazarded the opinion that this parasite was
the cause of the cholera, which had created such havoc in the pork-
producing parts of America within the last ten years. The special
interest attaching to this statement of Prof. Fletcher was, that in all
probability the parasite, though so large (the male being one inch, and
the female an inch and a half long), had been overlooked hitherto.
Now it so happened that in the communication from Mr. Morris,
which the Secretaries had placed in his (Dr. C.’s) hands, the opinion
was also given that Stephanurus was the cause of the mysterious disease
now rife in Australia. Pathologically, another point of interest was
that, whereas this parasite was found originally in the adipose tissue
of the hog, Prof. Fletcher has found it in all the organs of the body—
a statement which is in a measure borne out by the researches of Mr.
Morris, who had found that it was not confined to the fat alone. Ina
third communication, Prof. Fletcher stated he had discovered the
parasite in the urine of the animals he had examined. It was there-
fore very reasonable to suppose that this worm had given rise to the
formidable disease referred to. In answering the question how it was
brought about, we might be guided by our knowledge of the structure
and development of Trichina ; and it was not difficult to perceive that
Stephanurus must set up an enormous amount of irritation during its
migration through the tissues of the animal in which it had taken up
its residence. But whereas, in the case of Trichina, the parasite
migrated from without, and passed from the intestinal canal through
the connective tissues towards the muscles, thus causing death by the
small wound produced, Stephanurus did not, as far as is at present
known, thus migrate from without, but from within ; for, as Mr. Morris
states, he has found individual parasites singly, and not encysted, in
all parts of the fat. The most complete condition of the animal, how-
ever, was the encysted form. Dr. Cobbold then described the manner
in which the female parasite probably formed a cyst, depositing the
eggs in its interior; the diseased symptoms being produced by the mi-
gration of the progeny. He proceeded to say that as swine will eat
swine, it followed that a cyst existing in one pig could be swallowed
by another pig, and in that way the cyst could be taken into the intes-
tinal canal, and be the means of propagating disease. This singular
parasite, therefore, which had only once before been described, and
which was mentioned only in an old book, now turned out to be one
which would probably excite as much attention as Trichina. Further,
no one could say that this parasite may not eventually find its way
into our own bodies, for if we eat underdone American pork we should
be liable to swallow the embryos, and they are just as likely to be
developed in the human body as some other parasites found in the
pigs. There was, however, this protection in the case of Stephanurus,
that the most ordinary care in inspecting the meat brought to our
tables would enable us to avoid swallowing any portion which contained
a cyst. Dr. Cobbold then expressed his thanks for the opportunity

248 PROCEEDINGS OF SOCIETIES.

which had been afforded to him of examining this parasite, the genetic
relations of which, though obscure, were full of interest to those who
pursued this department of science.

The President, alluding to Mr. Hope’s memoir “ On Sewage Irri-
gation,” asked Dr. Cobbold what were his views on the subject, specially
in regard to the paper.

Dr. Cobbold replied, briefly stating that the British Association Com-
mittee having invited him to inspect an animal fed on Mr. Hope’s farm
on sewage-grown grass, he had carefully examined the animal, and had
not found a single parasite of any description in it; whereas in the ox,
under ordinary circumstances, one would expect to come across one or
more of the score of different species lable to infest that ruminant.
Here, however, there were none. But although this fact was, as far
as Mr. Hope was concerned, an agreeable one, it did not, he thought,
alter his (Dr. C.’s) original position in regard to the question, because
it so happened that Mr. Hope’s farm was a perfect model of what a
sewage farm ought to be; and because the soil, being very porous, was
eminently favourable for taking in any germs that might happen to be
in the sewage. The case, however, was exactly the reverse on the
Croydon farms, where there was a pestilential swamp, on which the grass
was covered with deposits, and where eggs must inevitably be present if
such eggs existed in the sewage. And though some people thought that
because those eggs had not been found in the sewage after it had been
distributed, no eggs were there; he asserted that millions of ova of
entozoa were passed by persons in this metropolis, and it followed that
numbers of those entozoa must find their way into the sewers, and be
thence conveyed to the fields. To the question, Are ova carried like-
wise ? the only answer that could be given was, that the common mode
of the propagation of germs of entozoa must be through those channels,
for they could go through no others; and under ordinary cireum-
stances the eggs must go into the animal feeding upon the sewage-
grown grass. His original statement therefore as to the mode in
which the germs were spread abroad was not overthrown. The
animal exhibited by Mr. Hope had been so carefully tended and
reared, that it was next to impossible that any ovum could be brought
into contact with it; and indeed the assiduous care bestowed upon it
had served to deprive the animal of the privilege of harbouring even
those parasites which would otherwise have been found in the body.

The President read a paper “On the Form and Use of Facial
Arches in the Salmon.”

Mr. H. Lee asked the President at what stage or period of the
development of the embryo salmon the “ blow-hole-like ” organ which
it was known did not exist in the adult fish was obliterated and ceased
to be perceptible. ;

The President said, in the specimens of embryo salmon which he
had examined he had been able to get at a very early stage in which
he could discern a flat white band going round the yelk, and one eye-
speck was visible. Before hatching he got two more stages, and in
the second stage the ear-opening or spiracle became obliterated.
There was a great difference between the salmon and the frog, for

PROCEEDINGS OF SOCIETIES. 249

he got his fourth stage in the development of the salmon when the
first stage of the frog was observable. In the salmon, a few days
after the yelk mass had undergone segmentation, the form of eye-
ball and the involution of the eye-ball was very rapid. . So also the
after changes were intensely rapid. He had seen a little head, about
the size of a pin’s head, which began to emerge as the egg burst, and
then the brain vesicles took their proper form. He would say one
word in reference to the salmon. It was much nearer to the reptile
or bird than the frog. The frog was very gradually developed, was
of a very low type, and yet was so ambitious that it underwent meta-
morphoses near the parts of the face which brought it near to the
mammal. The salmon was about half-way between the ganoid fishes
and the perch. It seemed to form a much better connecting link
between birds and reptiles than the frog did.

Mr. Stewart said he understood the President to say that he first
used spirits to harden the preparations, and then put them into chromic
acid. He (Mr.§8.) had made a few experiments on reagents lately.
He put a piece of brain into chromic acid, and in the course of a few
weeks it had become completely vacuolated and hardened into a
spongy-looking mass. It struck him that it would be well to recog-
nize the possibility of such changes occurring in the transfer from
alcohol to chromic acid.

The President said, care must be taken not to keep the prepara-
tions too long in the chromic acid, as under such circumstances they
became very friable.

Mr. J. Beck wished to say a word or two in regard to a subject
which had come before the Fellows in the Journal of the Society.
There had been a review of a work purporting to be the ‘ Trans-
actions of the Microscopical Society of Chicago.* He had promised
his friends there to take the earliest opportunity of informing the
Society that they had not the slightest connection with the publica-
tion in question. It was a mere printer’s speculation. He took the
opportunity also of bearing testimony to the deep interest shown in
microscopical research in America. The Americans displayed on this
subject the same energy which characterized them in all matters in
which they engaged. 'They made some very good instruments, and a
very large number of persons were interested in their practical use.
In a great many of the large cities of the States microscopical
societies flourished, and conducted their affairs in a most admirable

* We regret that, owing to our absence, Mr. Beck’s remarks were left uncon-
tradicted. His statements contain a series of errors, and so far as any accuracy
pertains to them they are a mere repetition of what has been already in print in
the Journal. In the first place, there has not been any statement made to the
effect that the journal reviewed—which was most severely reviewed—had any
connection with the Chicago Society. In the next place, in our number for May
last we published a letter from the Corresponding Secretary of the State Micro-
seopical Society of Illinois (not of Chicago, as Mr. Beck has incorrectly expressed
it) thanking us for his knowledge of the journal in question, which he was igno-
rant of till our notice appeared. Finally, in our September number we gave a
full account of the nature of the ‘Lens’ which Mr. Beck alluded to at the
October meeting. We regret being compelled to call attention to the matter,
but Mr. Beck’s charge leaves us no alternative-—Ep. ‘M. M. J.’

250 PROCEEDINGS OF SOCIETIES.

manner. He adduced the conduct of the Government at Washington
as an example for our own to follow, in taking note of any of their
naval officers who displayed scientific tastes, and in furnishing them,
when sent to foreign stations, with microscopes; the results of their
researches being regularly transmitted to head-quarters, and, after
being carefully examined by competent judges, were preserved, if con-
sidered worthy of preservation.

Mr. E. Richards exhibited a novel and simple form of “erecting
mirror,’ made to surmount the eye-piece. It consists of a glass
reflector, platinized on the front surface, thus getting rid of the
second image, always seen when an ordinary silvered surface is
employed. The little “erector” can be adapted for the small sum
of five shillings to any instrument, and, it need scarcely be explained,
will be of great service in making dissections or in viewing live
objects, in a trough, as the microscope can be maintained in the
upright position. The dissecting needles or knives are not reversed
by it, as might have been expected; for after having adjusted the
focus, by simply turning the mirror on its axis one quarter from the
right hand, the needle held in the right hand is immediately brought
into a proper position. The definition or perfection of the image is
in no way impaired, and therefore it will be found useful in drawing
as well as dissecting.

Donations to the Library and Cabinet, from June 7th to Oct. 4th,
1871 :—

From

Land and Water. Weekly i ecaissictays Mecase The Editor.
Journal of the Society of Arts. caer, ot Society.
Nature. Weekly.. : 39 Editor.
Athenzeum. Weekly . 5 W. W. &.
Journal of the Linnean ‘Society, No.3) 4, Society.
Transactions of the Linnean Society, Vol. XxXyiL,

Part 3 Society.
Observations and Experiments with the “Microscope on

the Chemical Effects of Chloral Hydrate, &c., on the

Blood. By T. 8. Ralph, M.R.C.8.E. : Author.
Transactions of the Natural FER pongey of North-

umberland and Durham Society.
Popular Science Review, No. 40 Editor.

Kalendar Companion to the Peerage and E Baronetage, &e,
1870 st 00 2 vere) Pe

J. W. Stephenson, Esq.

Clergy List for 1870 din Ditto.
Proceedings of the Academy of Sciences of # Philadelphia,

1870 3c Academy.
Smithsonian Report for 1869. Institution.
Transactions of the Connecticut Academy of Arts and

Sciences, Vol. I., Part 2; and Vol. IL., Part 1 . Academy.
Zum Bane und der Natur der Diatomaccen. Von Dr.

Adolf Weiss .. Author.
Bulletins de ’Académie Royale des Sciences, &e., de

Belgique. 1870 .. .. Academy.
Annuaire de 1 Académie Royale des Sciences, &e., de

Belgique. 1870 . Ditto.
Sull’ ultimo Stadio del Colera Asiatico. “Del Professor

F. Pacini Has Ag, Ms ote Author.
Le Globe. Tome X. 1871.

PROCEEDINGS OF SOCIETIES. O51

Donations to the Library and Cabinet—continued.

From
Berichte des Naturwissenschaftlich - medizinischen
Vereines in Innsbruck. 1870 and ’71. >
Journal of the Quekett Club... . The Club.
Quarterly Journal of the Geological Society, No. 107 .. Society.
Report on Photographing the Soft Tissues Bee Sunlight, Hi Surgeon-General’s Office,

&e. . : U.S.
Intellectual Observer, 47 numbers ey M, C. Hardy, Esq.
Quarterly Journal of Microscopical Science, 28 numbers Ditto.
Monthly Microscopical Journal, 24 numbers .. .. .. Ditto.
Sioleines) (COs, G7 mine Ge ye oo An “oe oc Ditto.
Recreative Science, 10 numbers soi lo6 Ditto.

Set of Ten Original Drawings of Insect Scales. “es Dr.

Maddox... .. Author.

Three Photographs on Glass showing the strix on Am-
phipleura pellucida taken with a + y objective of Tolles.

By Col. J. J. Woodward, U.S 7. eed ee tUt0
Fourteen Photographs of the Podura Scale. By Dr.

Maddox . Be no) oie
The Cruise of the ‘Norna.’ “By Marshall ‘Hall a8 Logo
Journal of the London Institution, No. 7 .. Institution.

Mud from Narakol, near Cochin, West Coast of India .. Major-Gen. Worster.
On the Structure and Development of the Skull of the
Common Frog. By Wm. Kitchen Parker, F.R.S. Author.
{ James N. Logan, Esq.,
; U.S.A.
The Agricultural Society
of New South Wales.

Logan’s Simple Microscope, with three Powers

Twenty-four Slides of Intestinal Worms, &c. ..

Four Slides of Fossil Sponge spicules... W. Vicary, Esq.
Four Slides of Diatoms from the Valencia a Deposit.
Mounted for the Society by .. .. C. J. Fox, Esq.

R. L. Maddox, Esq., M.D., was elected an Hon. Fellow of the
Society.

Watter W. Reeves,
Assist.-Secretary.

BRIGHTON AND Sussex Naturaut History Socrety.

August 10th.—Ordinary Meeting. Mr. Hennah, Vice-President,
in the chair.

Messrs. Boxall, A. H. Cox, W. H. Hallett, Hamblin, Walsh, and
Dr. Knightley were elected ordinary members.

Mr. Wonfor read a paper entitled “Is Bombyx callune a distinct
species, or only a variety of Bombyx quercus ?”

After describing the differences between moths and butterflies,
pointing out the peculiarities of the Bombycide, and minutely de-
scribing the life history of the two insects, B. callune and B. quercus,
Mr. Wonfor classified the distinctions drawn by entomologists between
the two: as of size, the first named being considered larger ; of time
in coming to maturity, the one taking two years, the other only one;
of the difference in the plants; of the difference in the markings of
the young larve, the one having orange triangles, the other orange
and white lozenges; and of the different coloration and markings of
the perfect insects. On the point of size, he had found an average of

a2 PROCEEDINGS OF SOCIETIES.

either showed great diversity in size, colour, and markings. Differ-
ence of time was of little account, for undoubted southern insects
had taken two years to complete their life history, and all entomolo-
gists knew that insects of the same brood, in this and other families,
would stay one, two, three, and even five years in chrysalis. Even
as regarded the difference in markings among the young larve, the
greatest variety was noticed in larve taken from the same hedge-row ;
in fact all the points of difference pointed to a climatic variety; even
in the case of colour, the tendency with insects, like other animals,
was to acquire darker and duller hues as they advanced north, and
lighter and brighter as they went south. A stronger point than all
was the fact that he had succeeded in drawing up southern males with
a northern female.

Taking advantage of the wonderful power possessed by the females
of some groups of attracting the males from long distances and in
great numbers, he had, by retarding, in a cold room, the time of
emergence, got a female out on the 20th of July. This, taken to
Hassock’s Gate the same afternoon, about 4 o’clock, when there was
but little sun and wind, had attracted males of the southern insect.
On the principle that, among the insect tribe, the males of the same
species only were attracted by the female, he considered this went far
to prove the point that B. callunw was only a climatic variety of
B. quercus, and not a distinct species. Though occasionally hybrids
were found in nature, the rule was for members of the same species
only to pair. Had he been able to keep a female back a fortnight
later, he doubted not he might have brought up nearly a hundred
males of B. quercus, drawn by a sense either of smell of a very acute
character, the organ of which had not yet been satisfactorily pointed
out, or by some other sense, not yet localized or named by the natu-
ralist.

The point had not been cleared up earlier simply because, relying
on some of the points of difference before mentioned, no one, as far as
he knew, had kept back northern females, and tried the experiment of
seeing whether they would attract southern males.

August 24th.—Microscopical Meeting. Mr. M. Penley, Vice-
President, in the chair; subject “ Polyzoa.”

Mr. R. Glaisyer announced the receipt for the Society’s cabinet of
12 slides from Dr. Hallifax, 12 from Mr. T. Curties, of Holborn, 6
from Mr. Sewell, 6 from Mr. C. P. Smith, and 9 from Mr. Wonfor.

Votes of thanks were passed to the donors.

Dr. Hallifax, introducing the subject for the evening, said the
Polyzoa were a proof of what might be done by patient investigation,
for though at one time supposed to occupy an obscure position in the
animal series, being classed among the polyps, by the comparatively
recent researches of the last forty years they had been raised into a
higher class of the animal kingdom. The greater number of them
being contained in a horny polypidom, this, and not the animals con-
tained therein, was chiefly studied, and the animal, or more important
part, overlooked. By close observation and attentive study during
the last forty years, Thompson, Farre, Milne Edwards, Grant, and

as

PROCEEDINGS OF SOCIETIES. 253

others, had removed them from the radiata in which they were placed
by Cuvier, and elevated them to the mollusca, simply from the fact
of their being proved to possess a higher organization. For some
time they were known to possess a mouth and retractile tentacles, but
no second or anal aperture could be detected, hence it was thought the
one opening served both purposes. It had clearly been made out that
the alimentary canal, or stomach, folded on itself, and was terminated
by a second orifice close by, but distinct from the mouth, thus proving
they were of a higher organization than the lower zoophytes, which
had but one orifice. In the Bowerbankia, which possessed a very
transparent envelope, a muscular structure, nervous ganglia, a repre-
sentative of the liver, and a circulation of the nutritive fluid through
the whole body had been made out, thus bringing them in connection
with the mollusca; the more interesting, because, in external character
and mode of growth, they were considered identical with the zoo-
phytes; but microscopical examination had proved that the sea-mats
of our shore were closely allied to the oyster and mussel. The ten-
tacles, too, in which circulation could be detected, were ciliated—a
state of things not found among the polyps.

The mode of reproduction was threefold: by germination, i.e. by
buds; by ova; and by fissure or division; the last the most rare, the
first the most common method.

To the microscopist they were exceedingly interesting, for while
the skeleton exhibited great variety of form and beauty, scientifically
they possessed a higher value, as showing what patient and enduring
observation and skill might accomplish.

The Black Rock was a good hunting ground, but the masses of
sea-weed washed up from deep water after stormy weather would
supply many forms.

Mr. Wonfor mentioned that two methods were adopted for pro-
curing and preserving specimens with their tentacles expanded; one
was by plunging the specimen in cold fresh water, which killed and
often caused them to exsert their tentacles, the other was to watch for
the protruding of the tentacles in salt water, and to add spirits of wine
drop by drop; this had the effect of killing the creatures with their
tentacles expanded.

The meeting afterwards became a conversazione, at which some
very beautiful preparations of Polyzoa and Anthozoa. were exhibited
by Dr. Hallifax, Messrs. Sewell, R. Glaisyer, and Wonfor.

Mr. Wonfor also exhibited specimens of Polyzoa and Anthozoa
mounted on paper to show the form of the Polypidom.

September 14th.—Annual Meeting. Mr. F. Merrifield, President,
in the chair.

The following gentlemen were elected officers for the ensuing
year :—President, Mr. W. M. Hollis, J.P., M.R.C.S.; Committee, Dr.
Badcock, Messrs. Haselwood, Sawyer, C. P. Smith, G. Scott, and R.
Glaisyer; Treasurer, Mr. T. H. Horne; Hon. Secretaries, Messrs. T.
W. Wonfor and J.C. Onions; Hon. Librarian, Mr. Gwatkin. The
name of Mr. Merrifield was added to the list of Vice-Presidents.

From the Eighteenth Report of the Committee it appeared the

954 PROCEEDINGS OF SOCIETIES.

affairs of the Society were in a prosperous condition, there being a
balance in the hands of the treasurer of 121. 0s. 1d., after spending
191. 5s. 11d. in the purchase of new books and periodicals, the com-
mittee retaining a balance to defray the expenses of printing a new
catalogue. Considerable additions had been made to the library,
which now numbered over 700 volumes, by purchase, and by donations
from Drs. Addison, Stevens, Wallich, Messrs. T. Davidson, Hennah,
Roper, and the Secretaries of the Belfast, Eastbourne, Lewes, Maid-
stone and Mid Kent, and Quekett Societies. Additions had been
made to the microscopical cabinet of 129 slides from Messrs. Curties,
Eden, Gwatkin, Marshall Hall, Hennah, Neate, C. P. Smith, Wonfor,
and Dr. Hallifax. The Monthly Microscopical Meetings had added
greatly to the value of the Society. The committee recommended the
holding a conversazione during the year. The thanks of the Society
were due to the Brighton and Hove Dispensary and to the Medico-
Chirurgical Society for the use of their room, and to those gentlemen
who had exhibited microscopes and specimens, read papers, and con-
tributed to the library, album, and cabinet. There had been seven
field excursions, one by special invitation from Mr. Grantham. The
annual excursion was to Arundel, where the Mayor, W. W. Mitchell,
Esq., hospitably entertained the Society at luncheon, and His Grace
the Duke of Norfolk granted permission to see the private gardens and
grounds attached to Arundel Castle. An abstract of the Scientific
Proceedings showed that papers had been read by Dr. Badcock on the
“ Gulf Stream,” by Dr. Addison on “ Daphnia pulex,” Dr. Dawson on
“‘Sphores,” Dr. Hallifax on “ Bone” and “ Polyzoa,” Mr. Ackland on
“ A Neutral Tint Selenite Stage,’ Mr. Hennah on “ Ilumination” and
“ Gundlach’s Objectives,” Mr. Howell on “ Excavations through the
Post Pliocene at Brighton” and the “ Brighton Cliff Formation,” Mr.
Merrifield on “ Tree Planting in Brighton—suggested improvements,”
Mr. G. Scott on “ Rude Flint Implements,’ Mr. Sewell on the “ Use
of the Polariscope in the Determination of Structure,” Mr. C. P. Smith
on “ Lichens,” and Mr. Wonfor on “ Shell Structure,” “ What is Coal ?”
“The Annual Excursion,” and “Is Bombyx callune a Species or a
Variety ?” There had been three evenings for exhibition of speci-
mens, when many interesting objects had been exhibited, and at the
Microscopical Meetings practical instruction had been given to the
members in “ Mounting,” “ Section Cutting and Making,” “ Illumina-
tion,” &c., by Dr. Hallifax, and Messrs. Hennah and Wonfor. Votes
of thanks were passed to the Secretaries, Librarian, President, and
outgoing officers. :

The meeting then became ordinary, when the new President, Mr.
W. M. Hollis, took the chair, and Messrs. D. Friend, Dick, and W. 8.
Smith were elected members.

A number of very interesting specimens were then exhibited by
Messrs. Penley, Saunders, Hennah, Howell, Ardley, Sewell, Nourse,
Goss, and Wonfor; among the most striking were a specimen of the
new burnet moth Zygena exulans, exhibited by Mr. Goss, and of the
rare moth Deiopeia pulchella, crimson speckled, taken by Mr. Wonfor
in a stubble field at Hove, on September 4th.

PROCEEDINGS OF SOCIETIES. 2p

September 28th.—Microscopical Meeting. The President, Mr.
W. M. Hollis, in the chair. Subject “ Diatoms.”

Mr. Wonfor, who introduced the subject for the evening, said he
approached it with some diffidence in the presence of some, especially
of Mr. Hennah, who had devoted much time to the study of diatoms,
and who knew much more about them than he did.

Diatoms were unicellular alge of a peculiar character, distinguished
from other unicellular plants, and especially the desmid, to which
they bore a great resemblance, by the possession of a silicious covering
which, while it rendered them exceedingly brittle—hence their name
brittle worts—also made them all but indestructible under ordinary
circumstances. One great peculiarity with them was the fact that if
the internal cell membrane became exposed to water, it secreted a sili-
cious covering, and if the plates forming the frustule became separated
a plate of silex began to form, and became what was termed the con-
necting membrane.

The frustules were either free, 7. e. moved freely in the element in
which they were found, from which circumstance they had been called
animals; adherent or attached to the substances on which they grew, or
aggregated ; in this last case they cohered either by their angles, were
provided with a gelatinous pedicel, which united the frustules together ;
or they were enclosed in great numbers in a general thallus.

The separate frustules as seen from a front or side view presented
very different appearances; in fact, some like the coscinodisci were
circular in a front and nearly rectangular in a side view, with a line
down the centre, which showed the junction of the two frustules. The
cell contents of the frustule were a viscid protoplasm called the en-
dochrome, generally of a brown or yellowish colour, containing globular
and granular bodies, of which the latter had been: seen in some cases
to rotate within the cell, so forming a species of cell-circulation.

The mode of increase was by self-division and by conjugation; in
the former, the valves separated, the cell contents aggregated on op-
posite sides of the frustules, the primordial utricle folded in, became
contracted, and eventually separated, at the same time a new silicious
valve was secreted by each half, and the result was two diatoms in the
place of one. This mode of growth was very rapid. In multiplica-
tion by conjugation, two frustules lying near each other opened at
their sutures and exuded their cell contents, which coalesced, while
the whole was involved in a gelatinous substance, from which sprung
a frustyle of larger size than the parents, to which the name sporan-
gial frustule was given.

The silicious valves had, from their markings, always been
favourites with microscopists, and though some complained of too
much time being devoted to diatoms, yet the question of the nature of
their markings had been the means of improving objectives, and had
also led to the designing various forms of illuminating apparatus more
or less simple or complicated.

A discussion ensued, in which the President, Messrs. Horne,
Robertson, Wonfor, Glaisyer, and Hennah took part, the last-named
gentleman drawing especial attention to the researches of Dr. Maddox,

VOL. VI. dt

256 PROCEEDINGS OF SOCIETIES.

which, when published, would throw great light on the life history
of diatoms.

The evening then became a conversazione, when living diatoms and
a great variety of silicious valves from different localities were ex-
hibited by Dr. Hallifax, Messrs. Hennah, R. Glaisyer, and Wonfor.

Mr. Hennah also exhibited some exquisite micro-photographs of
diatoms taken by Dr. Maddox, some of them magnified 3000 dia-
meters.

Sourtn Lonpon MicroscopicAL AND Naturant History Cuus.

An Ordinary Meeting of this Club was held at Glo’ster Hall,
Glo’ster Place, Brixton Road, on Tuesday, August 15th, at half-past
seven o'clock in the evening. Dr. Braithwaite, F.L.S., presided.

Four new members were balloted for,’and duly elected.

Dr. Hector Helsham, F.R.C.S., read a paper “On the Employ-
ment of the Microscope in Analysis,” of which the following is an
abstract :—

The subject of analysis embraces a vast field, for the microscope is
pre-eminently the instrument of analysis, and every application of it
an act of analysis, whether working out the minutie of structure,
developing the growth of the smallest organism, or defining the con-
stitution of some inorganic particle. It will be advantageous therefore
to limit the application of the term to the investigation into the quali-
ties of things, leading up to the establishment of facts, in contradis-
tinction to the tracing down to the originals of form and structure in
physiological and biological sciences.

It is my purpose, then, to consider the application of the micro-
scope to the detection of the minutest organisms in nature, its applica-
tion to the detection of the results of diseased action, to adulteration,
and the detection of crime.

To our unaided vision, animals and plants present differences of
form and structure by which we are able to distinguish one from the
other, and by closer examination we find deeper evidences of variety
in their organization, and when we extend our survey still deeper, the
more extraordinary is the amount of minute organization in every
animal or vegetable production. These differences rightly observed
and rightly interpreted by the microscopist furnish an unfailing iden-
tity to every portion, however minute, of vegetable and animal tissues,
and enable us to refer them to their origin. Observe how much has
grown out of the study of the starch-granule, how every structure
that contains it may be distinguished; contrast, for the sake of dis-
tinction, the starch-granule of the potato with that of rice, and note
the ready point of difference here established—applicable easily to
the examination of the purity of wheaten flour; contrast also the
granules of Maranta, or West Indian arrowroot, and the granules of
the turmeric-root, favourite articles employed in adulterating spices.
We have thus by their study a reliable typical character on which to
verify our judgments. The starch-granule will also illustrate the
extent of study which may concentrate around one special object as to

PROCEEDINGS OF SOCIETIES. 257

its constitution and structure, and the many opinions that may originate
from the observations upon it; whether the hilum, or central point
seen on its surface is due to the adhesion of the starch-granule to the
cell-wall which contains it; whether it is a cavity, or a nucleus, or
simply resulting from a phenomenon of the refraction of light;
whether the concentric markings are due to layers superimposed
on the first-formed material, or deposited within each other as newly
formed, or are merely due to the plaitings or foldings-in of a vesicular
membrane; whether the granule is contained in an envelope of denser
material, or whether it is of a homogeneous structure throughout. It
illustrates also the effects of various modes of illumination as seen by
transmitted, reflected, or polarized light.

The origin of life is now a very prominent study, and embraces
very many hypotheses which depend very much on microscopic obser-
vation for their tenure ; the question of the mode of origin of living
matter being inextricably mixed up with another problem as to the
cause of fermentation and putrefaction. Baron Liebig holds that fer-
mentation is purely a chemical process, but the doctrine of M. Pasteur
maintains that fermentation can only be initiated by the agency of
living things—omne vivum ea vivo—the theory of spontaneous genera-
tion. Again, there is the theory of heterogenesis, which imagines
that when the vital activity of any organism is on the wane, its consti-
tuent particles, being still portions of living matter, are capable of
individualizing themselves, and growing into the low organisms in
question ; and, again, a new theory by Professor Bastian, that new life
may burst forth, de novo, in certain fluids containing organic matter.
These hypotheses, however, really range themselves under the vital
and the material doctrines, and it is for the microscope to solve the
question.

Of all subjects of immediate and vital interest to the community at
large, in which the microscope must necessarily again be the principal
and chief arbitrator, there is none so important as the consideration of
contagious diseases. With the Asiatic cholera at our gates, it is indeed
well that we should know what we have to contend with, for the know-
ledge of a disease is its cure. At present the germ theory of disease
is the prevailing one, and disinfectant treatment, and disinfecting pre-
cautions, are the chief reliances of the day; but we fail to find from
late experiences that the totality of zymotic diseases is diminishing,
and there are many who have yet held back from the acceptance of
this theory, denying the proofs as not yet demonstrated ; and here we
have again the never-failing aid of the microscope in its analytical
power to judge of what we can apply to its investigation. If we can
only prove the existence of these germs as a modus propagandi, we
have not only a ready means of explaining the spread of these diseases,
but should also be armed with the means of destroying them, and the
prevention of the scourging epidemics with which the world has ever
been afflicted. The vital importance of these inquiries may be realized
by the known results, for we learn from statistics that the deaths from
zymotic diseases in England and Wales amount to upwards of 111,000
per annum, out of a population of 22,000,000, the total deaths being

258 PROCEEDINGS OF SOCIETIES.

under 500,000; and the want of knowledge, even among very intel-
ligent persons, concerning the practical requirements for limiting the
spread of contagious diseases is deplorable, so that in epidemics the
scourge is sometimes fostered and spread by the very persons in charge
of the sick, sometimes by the patients themselves being allowed to mix
with the healthy and distribute far and wide the germs of disease.
Heads of families are not always aware that a child who has completely
recovered from scarlet fever, and is in fact well, may communicate it
to half the children he comes in contact with, unless he be placed in
quarantine for three months at least, by which time there is reason
to believe that all active contagious particles will have become obli-
terated.

This germ theory of disease has lately been brought into consider-
able notice in consequence of Professor Tyndall’s lectures at the Royal
Institution on dust and haze, in which he sought to prove that the
particles floating therein are germs of animal and vegetable, probably
the seeds of infectious disease. Professor Beale, however, has, by the
aid of a =, inch objective, discarded the vegetable germ theory, and
propounded a bioplasm or minute morsel of germinal matter, possess-
ing a separate vitality, distinct from the organism into which it may
become absorbed, and developing within the fluids of the containing
organism.

Passing on now from these subjects to one of more domestic interest,
the detection of adulteration in our foods, drinks, and drugs, opens up
to us all a ready and useful application of the microscope. Until some
legislative act shall provide public analysts and inspectors, so long
will adulteration greatly prevail. It is exceedingly difficult, if not
impossible, to procure wholesome, unadulterated food: and although
an Act of Parliament has existed since 1860, not a single conviction
has been obtained under it in the metropolis.

The adulteration of tea gives us a very good example of the extent
to which what is called sophistication is carried on. Tea is doubly
dealt with in the way of fraud, for it receives a first instalment at
the hands of the producers, and a second at the hands of the dispensers
at home; although the latter may receive the credit of doing nothing
very venomous, but chiefly by way of diluting a good with an inferior
article, and colouring up a common caper into fine gunpowder by refac-
ing the tea with chalk and prussian blue. The adulterations practised
by the exporters in China are in the glazing, the use of many delete-
rious mineral substances, such as plumbago (carburet of iron), chrome
yellow (chromate of lead), Scheele’s green (arsenite of copper), in
drying up the leaves of other plants with the tea, such as those of the
willow, the beech, the elm, the plane, the sloe, &c., and in redrying
the leaves of tea that have already passed through the pot. But the most
startling, because the newest, is what is called the Maloo mixture,
from its resemblance to the tan with which the Maloo race-course is
strewed. It is extensively employed for mixing with tea, or even sold
as tea itself; and it is said that 30,0001. worth of this wretched com-
pound was recently on its way to this country. The Chinese collect
all the used-up tea-leaves they can get, and keep them in heaps

PROCEEDINGS OF SOCIETIES. 259

near their residence ; these heaps are at the right time spread out to
dry and shrivel; and, after facing, are leaded, packed, and sold for.
dispatch to this country, often mixed with iron-filings, sand, &c., to
increase the weight of the chest. As with tea, so with coffee; chicory
is made up in the form of the coffee-berry, so as to deceive even the
diligent housewife who grinds her own; and in ground coffee you get bad
flour, roasted beans and peas, acorns, and even mahogany saw-dust ; and
the chicory itself is diluted (the mild term) with black-jack or roasted
old sea biscuits, and croats, the spent tan of the tan-yard. Our bread
is such dry innutritious stuff as inferior starches and alum can make
it; our milk a sky-blue fiction, with cream that falls to the bottom, a
thief in the nursery, and a robber of the invalid. Our microscopes
may be our own inspectors, and surely something of a wholesome
check to tradesmen would arise from the constant practice of analyza-
tion of food, as the notice of any particular specimen of adulteration
would act as a caution to check the tide of imposition from which we
all so severely suffer, both in health and pocket.

Turning now to the detection of crime by the aid of the microscope.
In cases of poisoning, the crystals may be obtained from the victim,
and shown to the jury; in poisoning by arsenic, by strychnine, by
opium, by corrosive sublimate, oxalic acid, and other mineral poisons,
this may be, by care, easily effected. And in many other cases’ of
judicial inquiry the microscope brought to the analysis may positively
decide the verdict. In a notorious case that has lately been before the
public, the presence of blood-stains was proved on the dress of the
accused, and here the utility of the spectroscope was manifestly shown—
a scientific adjunct to the microscope, which is yet only in the infancy
of its application, but yields such well-marked and characteristic
spectra, that there are few subjects to which the spectrum microscope
can be more advantageously applied than the detection of blood-stains.
A millionth of a grain will show the characteristic absorption-bands.

Thus we have passed in review the generalities of the subject of
microscopic analysis, and it is my hope that sufficient has been shown
to impress on the minds of my hearers how deeply important it is, to
those who are engaged in any such pursuit, or to those who have not yet
commenced some systematic investigation, to at once determine not to
follow in paths already well trodden, but to open up new ones; not
to seek to use our microscopes here by repeating experiments, but
rather let us all vie in seeking to show the results of new and original
work.

A vote of thanks was unanimously accorded to Dr. Helsham for
his interesting paper.

Excursions were announced on August 26th to Rainham, and on
September 9th to the Victoria Docks.

The meeting then resolved itself into a conversazione, a paper being
announced for the next meeting, on Tuesday, September 19th, at half-
past seven o’clock in the evening, by Charles Stewart, Esq., M.R.CS.,
“ On some of the Lower Forms of Animal Life.”

260 PROCEEDINGS OF SOCIETIES.

Huui Screntiric Association.”

The inaugural address was delivered before the above association
on the 13th instant by the President—subject: The Work of the
Microscope. The speaker pointed out that the proper work of a local
society was local, that the flora and fauna of the locality should be its
first care, and hoped that the members of the new association would
carefully examine and, as far as possible, tabulate the microscopic
organisms of the neighbourhood. A list of the microscopic fauna
and flora of each district occupied by a Field Club or Natural History
Society would, he thought, be of great service to professional botanists
or zoologists engaged in the study of the distribution of animals or
plants in time and space; but he hoped that members would carefully
remember that cataloguing was not very intellectual work, and that
no member would be content unless he learned something of the life
history of the organisms whose names and external morphology he
studied. Passing from this branch of his subject, the speaker glanced
briefly at the departments of work in which certain members of the asso-
ciation were engaged, and pointed out how interdependent all branches of
science were now seen to be. The member who studied crystallography
with the aid of the polariscope would soon discover that the botanist
and zoologist made demands upon his knowledge, because they found
when they used the polariscope in the investigation of organic struc-
tures, the same phenomena of interference and refraction with which
the crystallographer was so familiar. The greater part of the address
was occupied by a dissertation on the use of the microscope in
unravelling the mystery of plant life, or rather of the life history of
plants. The speaker began with a Torula cerevisse, and having
described its mode of multiplication, passed on to the development of
some of the lower alg, such as Palmogloea, and thence to the de-
velopment of cells in the young leaves of Anacharis, and concluded by
pointing out some direction in which microscopic botany might do
great service. At the conclusion of the address, the meeting resolved
itself into a conversazione.

* This is a new association, and is formed for the purpose of affording mutual
aid and instruction in science. The constitution of the Society is open, but at
present nearly all the members are devoted to microscopy. The report is furnished
by Mr. C. P. Gibson, M.P.S., Hon. Sec.

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THE
MONTHLY MICROSCOPICAL JOURNAL.

DECEMBER 1, 1871.

I.—Notes on Prof. James Clark’s Flagellate Infusoria, with
description of New Species. By W. Savitix Kent, F.ZS.,
F.R.M.S., British Museum.

(Read before the Royau MicroscoricaL Society, Nov. 1, 1871.)

Tue following is a brief synopsis of certain genera and species of
Flagellate Infusoria described by Professor James Clark, of Penn-
sylvania, U.S., in the ‘ Memoirs of the Boston Society of Natural
History,’ vol. i, 1866,* with the diagnostic characters of new
species interpolated and those of other previously-described ones

EXPLANATION OF PLATE CV.

Fic. 1.—A colony of Codosiga echinata, magnified 500 diameters.
» 2.—A single zooid, detached, magnified 1500 diameters.

3.—A colony of Codosiga wmbellata, magnified 400 diameters.

» 4—A detached zooid, magnified 800 diameters.

»» 9.—Another colony of the same species, exhibiting a bi-tripartite ramifica-
tion of the supporting pedicle, magnified 75 diameters.

5 6.—A colony of Codosiga pulcherrima, magnified 500 diameters.

» 7.—Another colony of the same species consisting of only two individuals.

» 8.—Salpingeca marina (after Jas. Clk.).

» 9.—Salpingeca gracilis (after Jas. Clk.).

10, 11.—Two solitary and shorter individuals of the same species as observed

by the author, magnified 1200 diameters.

12.—A colony of still shorter individuals, in which the elongate, hollow

peduncle is entirely suppressed. Magnified 1200 diameters.

13.—A variety of Salpingeca amphoridium, attached by a short pedicle, and in

this character approaching the stalked species S. marina. Magnified
1200 diameters.
», 14.—An ordinary sessile individual of the same species, magnified 1200
_liameters.

=a Gay o zooids of Bicoseca lacustris in the condition of full extension, mag-

nified 1200 diameters.

» 16.—A single individual of the same species, further enlarged, with the zooid
retracted within its lorica, and exhibiting the spiral manner in which
the flagellum is then disposed.

5, 17.—Two zcoids of Bicoseeca socialis, magnified 800 diameters.

», 18.—Bicoseca inclinata, magnified 600 diameters.

», 19.—Two compound colonies of Anthophysa solitaria, magnified 400 diameters.

5, 20.—Two zooids of the same species, derived from the longitudinal fission of
a single individual, and still connected with one another at their base.
Magnified 1500 diameters.

», 21.—A compound colony of Anthophysa laxa, magnified 900 diameters.

* Reprinted in the ‘Annals and Magazine of Natural History,’ 4th ser., vol. i.,
1868.

VOL, VI. U

262 Transactions of the

amended in accordance with the author’s personal experience.
Without exception the material furnishing these descriptions was
obtained from a pond of moderate dimensions on the estate of
Thomas Randle Bennett, Esq., of Wentworth House, Stoke
Newington.

CODOSIGA, Jas. Clark (revised).

Bodies of animalcules ovate, one or a number seated at the ter-
mination of a fixed, slender, unretractile, simple or branching pedicle ;
the anterior and distal portion bearing a membranous, infundibular,
retractile collar; the single attenuate, flexible flagellum originating
from the centre of the area which it cireumseribes. Contractile
vesicles conspicuous, one or more in number. Increasing by longi-
tudinal fission.

Codosiga pulcherrima, Jas. Clk. (revised), Pl. CV., Figs. 6, Ke

Animalcules from one to as many as eight or nine in number,
attached to the primary pedicle through the medium of very short
secondary ones; surface of the body smooth, length of the same,
exclusive of the collar, 73> mm. (ss'o9 Eng. inch), breadth >> mm. ;
length of the primary pedicle, four or more times that of the body,
of the secondary ones about half its diameter. Contractile vesicles
conspicuous, two or more in number.

Hab. Fresh water, attached to Myriophyllum and Conferva.
oie cae US., Jas. Clark. Stoke Newington, London,

Codosiga echinata, n. sp., Pl. CV., Figs. 1, 2.

Similar to C. pulcherrima, but the individual animalcules haying
the surface of their body beneath the collar beset with verticels of
evenly-disposed stylate processes. Length of the body y}> mm.,
breadth s35 mm.

Hab. Fresh water, on Myriophyllum and Conferva. Stoke
Newington, London, W. 8. K.

Codosiga wmbellata, n. sp., Pl. CV., Figs. 3, 4, 5.

Bodies of animalcules similar in structure to those of C. pul-
cherrimus, but of double the length (45 mm.) and more elongate
outline, seated in groups at the terminations of a rigid tripartite,
bi-tripartite, or occasionally quadri-partite, branching pedicle.

Hab. Fresh water, on Myriophyllum and Conferva. Stoke
Newington, London, W. S. K.

SALPING/ECA, Jas. Clk. (revised).

Animalcules inhabiting a transparent lorica or sheath, the ante-
rior portion of the body provided with a membranous retractile

Royal Microscopical Society. 263

collar and bearing a single attenuate flexible flagellum. Lorica
attached, sessile or pedunculate. Contractile vesicles conspicuous,
one or more in number.

Salpingeca gracilis, Jas. Clk. (revised), Pl. CY.,
Figs. 9, 10, 11, 12.

Lorica cylindrical, solitary or in groups; expanding anteriorly,
attenuate, in the form of an elongate hollow peduncle, or abruptly
truncate posteriorly. Bodies of animalcules cylindrical, rounded at
the two extremities. Average length of lorica z'5 to z'5 mm., breadth
+30 mm., animalcules occupying one-third to one-half the length of
its internal cavity.

Hab. Fresh water. Pennsylvania, U.S., Jas. Clk. Stoke New-
ington, London, on Conferva, W. 8. K.

Salpingzca amphoridium, Jas. Clk. (revised), Pl. CV.,
Figs. 13, 14
Lorica flask-shaped, having an inflated posterior portion and an
attenuate narrow neck, sessile, or attached by a short pedicle. Body of
irregular form, adapting itself to the outline of the lorica. Length
of the lorica git. min., breadth of the expanded base 5}5 mm.
Hab. Fresh water, attached to Conferva. Pennsylvania, US.,
Jas. Clk. Stoke Newington, London, W. 8. K.

BICOSAICA, Jas. Clk. (revised).

Body enclosed within an ovate membranous lorica or sheath,
to the bottom of which it is attached through the medium of a con-
tractile ligament; no collar; one or two flagelliform appendages
originating from the anterior extremity. lLorica usually peduncu-
late. Contractile vesicles one or more in number.

Bicosxea lacustris, Jas. Clk. (revised), Pl. CY., Figs. 15, 16.

Lorica elongate oval, narrowing at the anterior extremity, at-
tached by a short pedicle. Body rounded posteriorly, rostrate
anteriorly and bearing a single flagellum originating excentrically,
curved and rigid in extension and a shorter stylate appendage.
Length of lorica 30 mm., breadth =}> mm.; body occupying one-
third to two-thirds of its internal cavity. Contractile vesicles two
in number.

Hab. Fresh water, on Conferva. Pennsylvania, U.S., Jas. Clk.
Stoke Newington, London, W. 8. K.

Bicosxca socialis, n. sp., Pl. CV., Fig. 17.

Lorica elongate oval, half as long again as that of B. lacustris ;
pedicle not exceeding one-third or half its length. Body rounded
u 2

264 Transactions of the

posteriorly, pointed anteriorly, not rostrate, and bearing two flexible
attenuate vibratile flagella. Length of lorica 75 mm., diameter
10 mm.; body occupying about one-half of its internal cavity.

Hab. Fresh water, attached to Conferva. Stoke Newington,
London, W. S. K.

Bicoszca inclinata, n. sp., Pl. CV., Fig. 18.

Lorica ovate, set obliquely on a slender pedicle of twice its
length. Body occupying two-thirds of the cavity of the lorica,
flagellum single. Length of lorica ¢> mm., greatest diameter
10 mm.

Hab. Fresh water, attached to Conferva. Stoke Newington,
London, W. 8. K.

ANTHOPHYSA, Duj. (revised).

- Animalcules pyriform, obliquely truncate anteriorly and fur-
nished with two flagelliform appendages, attached singly or in
clusters to a simple or branching uncontractile stem. Increasing
by longitudinal fission.

Anthophysa solitaria, Bory, Pl. CV., Figs. 19, 20.

Animalcules grouped in a cluster of forty or fifty at the ex-
tremity of a simple flexible thread-like stalk. Length of bodies
soo mm.

Hab. Fresh water, on Conferva, &c. European Continent,
Bory and Tresenius. Stoke Newington, London, W. 6. K.

Anthophysa laxa, n. sp., Pl. CV., Fig. 21.

Animalcules disposed singly, excepting during fission, at the
extremities of a loosely and irregularly branching flexible stalk.
Length of bodies +35 mm.
ae Fresh water, on Conferva. Stoke Newington, London,

Anthophysa Bennettit, n. sp.

Animalcules stationed singly or in pairs (during fission) at the
extremities of a slender, rigid, and repeatedly dichotomously dividing
stalk, Length of bodies 25> mm., of the branching stalk 1 mm.
and upwards.

Hab. Fresh water, attached to Conferva. Stoke Newington,
London, W. 8. K.

Monas termo, Ebr.

Having encountered the attached form referred to this species
by Prof. James Clark, I differ from him in his assumption that

Royal Microscopical Society. 265

the animalcule possesses a distinct mouth, having on many occasions
observed it to take in food on the lateral as well as the anterior
surface of its body, it investing and engulphing its prey with an
expansion of its protoplasm after the manner of Amoeba. On
numerous occasions I have also certified the presence of two instead
of only a single flagelliform appendage.

ADDENDA.

In Anthophysa the interception of food is similar to that of
Monas. In Codosiga and Salpingxea it takes place anywhere
within the area circumscribed by the membranous collar, the dis-
charge of foecal matter being effected within the same limits.

266 Transactions of the

II.—Note accompanying Three Photographs of Degeeria domes-
tica, as seen with Mr. Wenham’s Black-ground Illumination
and a Power of 1000 diameters. By Dr. J. J. Woopwanrp,
U.S. Army.

(Read before the Royau Microscorican Society, Nov. 1, 1871.)

Mr. Wennam haying very kindly sent me one of the small trun-
cated lenses designed by him to obtain, under certain conditions,
black-ground illumination with high powers, I carefully tried it on
the Degeeria domestica in the manner described in his paper in the
July number of the ‘Monthly Microscopical Journal,* using the
immersion yth of Powell and Lealand as the objective. I had
no difficulty whatever in obtaining the appearances of the scale
described by Mr. Wenham and also several other aspects, and must
regard the contrivance as a valuable addition to our means of
studying semi-transparent objects with high powers.

The illumination of the scale by this method, when a coal-oil
lamp was the source of light, was so brilliant that I thought pro-
bably it would be possible to photograph some of the more striking
appearances. I obtained on the first trial three negatives, of
which I send prints. The same scale is shown in each magnified
1000 diameters. The objective (the immersion ;',th) remained at
the same cover correction, the position of the truncated lens and
parabola was unaltered, and the different appearances exhibited
resulted from trifling alterations in the position of the plane mirror
by which the parallel solar pencil was thrown upon the parabola,
and slight modifications of the fine adjustment. Of the prints sent,
No. 2 agrees pretty well with Mr. Wenham’s description. The
same can hardly be said of No. 3, however, and Nos. 1 and 3 are
only examples of some of the manifold results attainable by this
method with which, indeed, almost as many appearances can be
seen as with transmitted light.

The time of exposure required for these negatives was but three
minutes. I infer from this and many other circumstances, that the
semi-transparent scales are simply made luminous by the light
passing into them from below, whence it results that the surface
appearances are necessarily complicated by the optical properties of
the structures beneath.

I understand this to be substantially Mr. Wenham’s view
also, and am therefore at some loss to comprehend the sense in
which he speaks of the scales as being shown “ opaquely” by this
method.f

PES fe + P. 7, and note loc. cit.

Royal Microscopical Society. 267

Note on the above. By F. H. Wenuam.

In inadvertently making use of the term “shown opaquely,”
I did not wish it to be inferred that I considered this method as
strictly an opaque illumination, which is understood when the light
is thrown only on the upper surface of the object.

The truncated lens, or flat-topped parabola, first used by me in
the way referred to above, gives such a brilliant luminosity to the
object, on a jet-black field, that it has all the appearance of an
opaque illumination, and perhaps on many objects the difference
in apparent structure would not be material, and may be illustrated
in this way: Suppose some semi-transparent body, such as a green
grape, be let into a piece of black card; on holding this against
a strong light, so that it enters sideways, the seeds and internal
structure will be shown satisfactorily. If a side light is condensed
down upon the object, the same internal structure will be seen, though
not so perfectly on account of surface glare. When a side light
is thrown into the body of an object either way, each dense particle
that intercepts it serves to illuminate its neighbour, and so the rays
are diffused in every possible direction, and if the structure contains
particles actually impervious to light, they will not be seen like
dark shadows as by direct light, but luminous, and in their natural
colours. I consider this is the main principle—to send the light
into the object in any or all directions beyond the angle at which
rays from the source can enter the eye.

Dr. Woodward has kindly sent me the photographs referred to
in the above note. No. 2, which quite agrees with my description,
is in places very sharp and distinct, showing the intercostal strize
or bars plainly. Nos. 1 and 3 are somewhat blurred, and to my
mind do not show structure satisfactorily. Knowing the difficulty
of obtaining a photograph of an object of this character, merely
from its own diffused light, I was much surprised at Dr. Woodward’s
remarkable skill in producing a perfect picture—a feat that I should
have thought scarcely possible.

268 Transactions of the

IIIl.—On Bog Mosses. By R. Brarruwarre, M.D., F.LS.

(Read before the Roya Microscoricau Society, Nov. 1, 1871.)

Part I.

BEForE commencing the descriptive portion of our subject, it may
be well to enter a little more into detail with respect to the his-
tology of the interesting plants constituting the Sphagnacee. The
published materials of which I have availed myself in the study,
are the following, and to Prof. Lindberg, of Helsingfors, I am
also deeply indebted for beautiful specimens of some of the rarer
species.

1. Dozy—Bijdrage tot de Anatomie en Phytographie der
Sphagna. 1854.

2. Schimper—Entwickelungs-geschichte der Torfmoose. 1858.

8. Lindberg—Torfmossornas byggnad udbredning och syste-
matiska uppstallnng. 1862.

4, Russow—Beitrige zur Kenntniss der Torfmoose. 1865.

The roots, which form only on the young plants, are chiefly of
use in fixing them to floating objects, for as soon as branches shoot
forth, a part of these forming each fascicle drop perpendicularly
downward, and becoming appressed to the stem, are from their
hygroscopic quality far more effective than true roots, in trans-
mitting fluid to the other parts of the plants ; while the dense masses
formed by the aggregation of stems equally supersede the use of
roots as fixing organs. As the stem increases in size, the simple
flageller branches arise laterally from the uppermost leaves, and are
crowded together into a head or capitulum, which supplies fascicles
of branches to the stem below, by elongation of the internodes,
and keeps up its stock of young branches by constant renewals from
the growing point at the apex. The dichotomous ramification of a
Sphagnum depends on the annual production of an innovation,
which is a perfect repetition of the stem of the previous year, and
derives its origin from one of the lateral branches of the capitulum,
which rises upward and becomes elongated into a main axis.

The number of branches in a fascicle seems tolerably constant in
each species, a part of these we may call the divergent branches,
which proceed at a right angle from the stem, then bend about the
middle and arch gracefully downward ; the rest we will term the
pendent branches, and these are longer, more attenuated, and fall
down from their point of origin in the fascicle, and lie close to the
stem. A part of the divergent branches become condensed and
club-shaped to form the catkins of male flowers, and a few others
become fruit branches.

The leaves of Bog mosses vary considerably on different parts
of the plant: the stem leaves are distant from each other, and usually

Royal Microscopical Society. 269

reflexed against the stem, probably pushed back by the descent of
the pendent branches; at their basal angles we also frequently
observe appendages or auricles formed of larger perforated cells.
The areolation of the stem leaves is wider than that of the branch
leaves, and the prosenchym cells of the lower part are often alto-
gether threadless, while one or more rows at the extreme base are
small, hexagonal, vesicular, and coloured red or yellow.

The branch leaves are small, more densely reticulated, closely
imbricated over each other, and very variable in form and size; this
variability, however, is greatest in the pendent branches, where both
they and their component cells become extremely elongated.

Russow, however, points out that the leaves on the centre of the
divergent branches are very constant in form in the individual
species, and that they all become narrower and more distant as they
approach the apex of the branch. Moreover, the 3—5 lowest leaves
at the base of the divergent branches are remarkably different in
form from those which succeed them, and stand midway between
them and the stem leaves; the typical form of these intermediate
leaves is an irregular-sided, obtuse-angled triangle, and they are
always much smaller than the succeeding branch leaves; the margin
of narrow cells which borders these leaves is widest at the base of
the longest side. The peduncular leaves, or those found at the
base of the naked branch which bears the fruit, differ from the
others both in form and structure, sufficiently to render their de-
scription necessary.

As an aid to our examination of leaf structure, certain colouring
agents are of advantage in enabling us to obtain a better definition
of the delicate textures of which the leaves are composed. Iodine
and sulphuric acid or a solution of biniodide of zinc, have been used
for this purpose, the latter of these being most convenient, an im-
mersion of the leaf for two to twenty-four hours being required.
Transverse sections of the leaves are also necessary in order to deter-
mine the relative positions of the chlorophyllose and hyaline cells ;
these are best prepared by immersing a branch in thick mucilage of
gum arabic, and when sufficiently dry, enclosing between two pieces
of elder-pith, and slices of the whole cut and placed in water.

Anatomy of the Leaf—Hedwig, in his ‘Fundam. Hist. Nat.
Muse.,’ i., p. 25 (1782), evidently noticed the composite character
of the Sphagnum leaf, for he mentions the large areole, void of
chlorophyll, traversed by very fine vessels, running double, which
he thinks may possibly correspond to the ducts of flowering plants,
and these anastomosing vessels containing parenchyma. Molden-
hawer first pointed out the true nature of the two kinds of cells, and
the presence of threads and pores in the vesicular cells, and Von
Mohl afterwards confirmed his views and elaborated the whole or-
ganization of the Sphagna. A Sphagnum leaf consists of a single

270 Transactions of the

stratum of cells, the framework of which is constituted by network
of extremely slender coloured or chlorophyll cells, into each of the
meshes of which we might fancy one of the vesicular cells had been
dropped. By section we see that the relative position of these two
kinds of cells to each other may vary, for the chlorophyll cells may
lie midway between the anterior and posterior surface of the leaf,
and their section shows us that they are lenticularly compressed, or
they may take part in forming the anterior or posterior surface of
the leaf, their transverse section being triangular, so that they re-
semble a wedge pushed in between each pair of hyaline cells : minute
as this structure is, we must admit its importance, since it originates
in the fundamental formation of the leaf.

The hyaline cells are more or less united by their adjacent walls,
and nearly always contain threads attached to their internal walls ;
these threads may form complete spirals, composed of one or several
fibrils, or they may be broken up into rings and spiral fragments,
and sometimes run across diagonally so as to unite two spirals.
Threads, however, are not always present in all the leaves, for in
S. fimbriatum they are wanting in both the stem and peduncular
leaves, and others have them in one part of the leaf while they are
absent from the rest; in S. (Isocladus) macrophyllum no threads
are seen except those forming a ring round the orifices of the pores.
The threads are firm and intimately united to the inner wall of the
cells, so that in S. subsecundum, the walls of the hyaline cells are
strongly contracted by them.

The apertures or pores are most abundant on the back of the
leaf, and stand near the adjoining cell-walls ; they vary in size and
number according to the species, and no doubt originate by the
resorption of the delicate cell-wall, within the boundary of a small
thread-ring. Besides these, Russow calls attention to larger open-
ings which become visible after treatment with iodine, and indicating
more extensive resorption of the cell-membrane. Thus in the lower
part of a branch leaf of 8. fimbriatwm so treated, these large
apertures reach across the whole width of the cell, and stand be-
tween each pair of thread spirals; in the corresponding leaves of
the nearly allied S. Girgensohnii this resorption appearance does
not occur. In leaves from the pendent branches of S. intermediwm,
a hole is always seen at the apical end of each cell. In S. Lind-
bergit, fimbriatum, and Girgensohnit, whose stem leaves are fringed
at the apex, this appearance is due to complete resorption of the
membrane of the hyaline cells, and consequent projection of the
intermediate parenchym cells.

The chlorophyll cells of peduncular leaves usually have de-
ficiencies in the thickening layers of their walls, and these standing
opposite to each other, resemble imperforate dots, not unlike the
dotted pleurenchyma of coniferous wood; a similar condition is

Royal Microscopical Society. 271

observable in the walls of young axile cells of the Sphagnum
stem.*

In most peduncular leaves the hyaline cells are less evident than
in those from other parts of the plant, and are often confined to the
upper third of the leaf.

Development of the Plant—To the investigations of Nigeli
and Hofmeister are we principally indebted for an account of this
interesting process. It not unfrequently happens that in floating
Sphagnum plants, whose capsules are submerged, that the spores
germinate in the capsule, where their delicate pro-embryos are so
closely packed, that the whole contents are caked together into a
solid mass, which first becomes free by the breaking up of the
capsular wall, and in this condition swims about until the individual
plantlets have separated from one another to establish themselves
on some floating object and undergo further evolution.

The spores of capsules maturing out of the water, germinate on
damp earth in two to three months. Prof. Schimper rarely noticed
the pro-embryonal cell break through the exospore in less than five
weeks.

In water the pro-embryonal cell elongates and ramifies as
confervoid filaments formed of nearly globose cells, and the terminal
or some other cell becomes the mother cell of the young plant,
while the rest ramify and put forth brood-gemme, which develope
into young plants, the radicles bemg always distinguishable by the
oblique commissural walls of the cells.

The spores germinating on damp earth behave in quite a
different manner, the pro-embryonal cell goes on subdividing in
a horizontal plane, so that an expansion results resembling the
prothallium of LEquisetum, or the perfect plant of Blasia or
Anthoceros. This hepaticine frond throws out radicles from the
under surface and margins, and from these again brood-gemmz
ie out, from which arise prothallia precisely resembling the

rst.

The first commencement of the young plant originates in a
tuberculoid aggregation of cells, some of which develope downward
into hair-like radicles, while the upper cell elongates and sub-
divides to form the young stemlet, some of the cells, laterally
becoming free, form the first rudiment of leaves.

The young stem, at first transparent, soon acquires minute
chlorophyll granules, and a differentiation into medullary, ligneous,
and cortical layers is early set up. When it has reached a
height of about 5 mm., it begins to throw off at the sides single
flagellar branches, which arise laterally from the uppermost leaves,
and are crowded together at the top of the stem. The branches
come off at every fourth leaf, as an obtuse bud of few cells, on

* Hofmeister, ‘ Higher Cryptogamia,’ pl. xvii., fig. 95.

272 Transactions of the

which, when three cells high, leaves also form, and division into
branches takes place. The growing point of the stem is conical, its
terminal cell apparently subdividing in five directions, and thus
continually elongating the stem; by longitudinal division and
transverse extension of newly-formed cells the terminal cone
thickens itself from above downward, and the base, constantly forming
anew, attains the diameter of the already completed stem.

The rudimentary leaves are arranged in five rows on the young
stemlet ; the mother cell of the leaf acquires its first segmentation
by a septum springing laterally from the longitudinal axis and
perpendicular to the surface, the apical cell again dividing by a
septum in the opposite direction, meeting the first at an angle of
90°, and by repeated division of the apical cell the leaf extends, and
we have a simple areolation of large quadrate cells, those at the
margin being more elongated, and all filled with a slimy fluid, in
which float small pale-green chlorophyll granules, chiefly grouped
around the large nucleus. With the formation of the fifth leaflet,
however, begins that regular differentiation into two constant cell
forms, which gives to the Sphagnum leaf its peculiar character ;
each of the square cells divides unequally by a septum parallel to
one of its walls, the larger portion is then divided, by a septum
parallel to the narrow sides, into two unequal cells, the larger
square, the others elongated; and the leaf now consists of a system
of square cells, each of which is surrounded by four oblong cells.
In the latter, chlorophyll granules rapidly increase in number and
size, while the pale-green mucilage filling the larger square cells
disappears, and their contents become clear as water. The
prosenchym cells extend themselves more and more at the expense
of their protoplasm, and receive fibres on the interior of their
walls, which at first are only fragments of rings, but afterwards run
together into complete rings or spirals ; finally, also, small scattered
rings appear on the internal surface, which become thickened by
resorption of the included disk, and form the margins of circular
foramina. In the young leaves the central cells multiply and
extend themselves after those at the margin have ceased to do so,
hence the young leaf acquires a cucullate or hooded form; the
process still continuing, the hood becomes split and the leaf flattens
out, but the apex bears evidence of this splitting in the lacerated or
strongly-toothed margin.

The male flowers in Sphagnums are arranged in amentula,
which occupy the termination of a certain number of the divergent
branches, and under their covering leaves, which are somewhat
broader and more coloured, are concealed the antheridia. Fre-
quently these branches do not terminate with the flower catkin,
but continue their growth with the ordinary leaves, and in
S. rigidum and Lindbergii the flowering branch elongates and

Royal Microscopical Society. 273

hangs downward like the pendent branches. Each male flower of
the catkin consists of one archegonium, which stands laterally to the
supporting bract, to which it bears precisely the same relation as a
branch fascicle does to its stem leaf. The covering leaves are usually
more closely imbricated than the branch leaves, and in S. acuti-
folium are of a fine carmine colour; in S. cuspidatwmn, ochreous ;
in 8. fimbriatum, lively green ; in S. subsecundum, olive green, &c.

The perigynium or sheath of the female flower is readily recog-
nized by its long conical form and deep-green colour, and stands on
one of the short lateral branches of the capitulum ; the inner leaves
are much elongated, and enclose one to four archegonia, only one of
which, however, developes into fruit. As the pseudopodium, or
peduncle of the fruit receptacle elongates, it usually happens that
the leaves it supports are also drawn farther apart.

In the young capsule the sporangium only reaches a little way
below its middle, the rest of the cavity being filled with a soft pale-
green cell-mass; in the ripe capsule, on the contrary, we find
nearly the whole internal space empty, the columella has broken
away from the vault of the sporangium, and along with the cellular
mass has shrivelled back to the base of it, but the sporangium,
firmly cohering with the lining stripped from the inner wall of the
capsule, is left hanging in its upper orifice, where it stays, until by
contraction of the capsule the lid is forced off with a little explosion,
by which the contents are expelled. The outer wall we find
consists of cells forming longish hexagonal meshes, presenting a
nodule at each angle, brittle, thickened, and yellow-brown in colour,
scattered among which are numerous small stomata.

Frequently the lid remains fixed at one point to the rim of the
capsule, which it closes again when moistened, moving as if on a
hinge; and when.the fruit remains under water, the lid often does
not open, but the capsule, with its contents, falls away from the
vaginula, and as the columella decays, the spores escape through
the aperture, or if they have already begun to germinate, their
expansion forces off the lid also, leaving the old capsule wall with a
large round opening at each pole, one corresponding to the lid, the
other to the insertion of the pedicel, and such frequently come into
the field of our microscope when operating on tufts of Sphagnum.

(274)

IV.—An Instrument for Micro-ruling on Glass and Steel.
By J. F. Sranistreer.
Puate CVI.

[Although an illustration in the form of a woodcut of this ingenious little
machine has appeared elsewhere, we have thought it worth while for the benefit of
our readers to reproduce a plate of the apparatus on a larger scale and in clearer type.
The adjacent Plate is copied from a photograph of the machine.—En. ‘ M. M. J.’]

To the ‘English Mechanic’ Mr. Stanistreet sent the following
description, as it was in its pages that he first saw a reprint of Mr.
Slack’s paper, which appeared in this Journal some months ago,
“On Optical Appearances of Cut Lines in Glass.” Mr. Stanistreet
says :—

‘ It may encourage your more able readers to know that my
lathe and tools, as well as my experience in using them, have been
all self-acquired within the last two or three years, during my
confinement to the house as a permanent invalid, and that I never

EXPLANATION OF PLATE CVI.

Fie. 1.—Diamond, set at an angle of 60°.
2.—Mandril, to which the disk to be ruled is cemented.
3.—Worm-wheel of 250 teeth worked by endless serew—the wheel is gradu-
ated with index, and has spring stops for one-half or one-fourth of a
revolution, thus dividing the periphery of the circle into 1000 parts,
or to 0° 21’ 36”.
4.—Leading screw of 100 threads per inch.
5.—Winch turning the leading screw, with spring stops for subdividing to
the ~,25o5th of an inch, if a diamond fine enough for such a scale
should ever be obtained.
6.—Spring made from pianoforte wire.
7.—Pressure spring working on glass roller.
8, 9, 10.—Springs for delicate adjustment of pressure—one above, one below,
and one lateral.
11.—Graduated are of circle from 0° to 90°, giving divisions from the —3,;th
to the ;}5cth of an inch apart, in the ratio of the cosine of the angle
at which the ruling bar is set. When placed at 0° it rules lines the
tdsoth of an inch apart. The machine when photographed was set at
an angle of 60° for ruling 2000 lines per inch (the cosine of 60° being
0:5, or one-half of the radius). To rule 10,000 lines per inch it is
placed at an angle of 84° 15’ 39” (the cosine of which is 0°10, or one-
tenth of the radius).
12.—Double-handled winch for winding up the self-acting machinery. This
consists of a train of wheels and pinions driven by the spring of a mu-
sical box, and ending in a fly, which regulates and controls the rota-
tion of the cam plate. The fly makes 3840 revolutions for each turn
of the spring wheel; and the machine will rule more than 1000 lines
without being re-wound. Since the photograph was done an addition
has been made of a wheel and index for recording the number of lines
actually ruled.
» 13.—F ly, regulating the rotation of the cam plate.
» 14.—Trigger and springs for starting the machine.

([Notr.—The spirit lamp, match box, and oil bottle, &c., ought to have been
removed ; but being let into the stand of the machine they have been copied by
the photographer. }

”

‘The Monthly Microscopical Journal. .Dee 1.1871.

ab

imp.

W.Weat &Co

lass and steel.

i
J
Cm)

MP. Stamistrest’s machine for micro- ruling on &

On the Conjugation of Ameeba. 275

had a lesson in mechanics. Every part of my machine (even to
the screws and smallest details) has been made by me without
assistance. I hope, therefore, some of your readers more favourably
circumstanced, may improve upon wy first trials, and far excel me
in this beautiful and interesting art.

My machine was originally planned for ruling micrometer
scales for use with microscopes and telescopes, -and its application
to ruling diffraction patterns (however beautiful) was quite a
secondary object with me, but Mr. Slack has, by his valuable
researches and papers, invested these ruled patterns with a practical
value and interest which I had not originally attached to them,
and as a microscopist I appreciate very highly the teachings
conveyed by his papers, showing the necessity of educating the eye
and judgment to enable the observer to interpret and correct the
illusory appearances so constantly met with in working under the
higher powers of the microscope.

The Plate shows the machine with the self-acting machinery
added since Mr. Slack’s paper. “This self-acting machinery consists
of a spring (from a musical box) driving a train of wheels and
pinions, ending in a fly, which regulates and controls the rotation
of the cam described by Mr. Slack, all the wheels and pinions being
(like the machine) made by my own hands, except one little steel
pinion which I purchased from a watchmaker.”

The machine is constructed for ruling lines from y;/;5th to the
robsoth of an inch apart, and I have added to it the means of
further subdivision to the ,5j55,th of an inch; but I have not yet
been able to procure any diamond fine enough for ruling distinctly
more than about 5000 lines per inch.

V.—On the Conjugation of Ameba. By J. G. Tarem, Esq.

I wisx to recall to the recollection of the members a paper brought
before them in a previous year,* “ On Free-swimming Amcebe,” of
which two species were described, but to which, under the impres-
sion that they presented phases only of Amceba life no specific
names were assigned. I then stated “that we had no further
knowledge of Amceba propagation and reproduction than that by
fission. An oyer-extended pseudopodum, perhaps larger than
common, remains attached to the spot to which it has been pro-
jected, separates from the parent mass and creeps off as an inde-
pendent living creature,” and that this summary and somewhat
rude process, actively as it might be carried on, could only account
for the presence of a vast number of individuals within a limited

* Vide ‘M. M. J., June, 1869.
VOL. VI. x

276 On the Conjugation of Ameeba.

space, and not for their dispersion over an extended area; and
ventured the assertion, though no evidence was then forthcoming
in support, “that those large Amcebe so frequently met with in
the autumn months are actually the incorporation of two individuals
in a copulative act,” from which free-swimming ciliated germs
might eventually issue. Since that communication was made to
the Society, I have had an opportunity of obtaining strong cor-
roborative, if not entirely convincing, proof that that which was
then conjecturally advanced, is absolutely true as to the fact of con-
jugation, and I submit to your inspection a diagram of a large

Ameba villosa. a, a, pseudopoda.

Ameeba villosa which presents the appearance of the semi-union of
two individuals, both externally and internally, in the circulation
of their granules and food contents, at the moment preceding com-
plete mutual interpenetration. Moving rapidly by broad, rounded
pseudopoda thrown out from either side of the broader rounded
anterior portion—though never crossing a median line, clearly
defined by the circulating particles flowing in parallel lines within,
as indicated by the direction of the arrows in the diagram, no other
impression could be received than that a semi-conjugated condition
here presented itself. Unhappily its disappearance under a mass
of dirt, from which it never again emerged, precluded the possibility
of determining whether or not the amalgamation would in time
have become more perfect, and whether the sarcode masses of the
two would have so completely intermingled that it would have
ultimately borne the aspect of one large but ordinary Ameeba.
Assuming this to be an instance of true Amceba conjugation, can

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Crystallization of Metals by Electricity. 277

we doubt that such a reproductive process must eventuate in the
evolution of some kind of germ? but what such may be it would
be idle to speculate. I desire only to put the observed fact upon
record, and to engage the efforts of our members in the elucidation
of that most recondite, though most interesting subject—the repro-
duction and distribution of our fresh-water Rhzzopoda.

VI.— Crystallization of Metals by Electricity under the Microscope.
By Pamir Branaw, Esq.
Puate CVI.

Durina some years of scientific investigation I have been in the
habit of submitting every eligible experiment to microscopic
examination, and during an investigation concerning a metal tried
the effects of electricity on it in connection with an acid solution.
I was delighted to find a brilliant crystallization start into life, but
shortly becoming dull. Following up that experiment by using
neutral salts, and terminals of the base, have succeeded in crystal-
lizing gold, silver, copper, tin, zinc, and lead, and have every reason
to believe I shall be able ere long to crystallize every other metal.

The instrument used I give a sketch of, and the electrical
stage (a diminutive double discharger, which does excellently for
spectrum analysis in connection with an induction coil) and gal-
vanic battery, with fittings for varying the quantity and intensity
of the electric current. The sketch of the discharger shows the
manner in which it is fitted. The two short pillars A A are of ivory,
turned to a cup-shape on the top to fit the balls; the springs
BB keep the balls in their place, and are fastened to the side of
the ivory pillars by the binding screws C C, to which the wires
from the poles of the battery are connected; the ends of the dis-
charger rods are split to receive the short wires of the metal under
electrolysis.

The battery issimilar in its construction to Smee’s, but with
carbon plates instead of platinized silver, and excited with bichro-
mate of potash and sulphuric acid, it has the advantage of not
evolving fumes or acid spray. The wheel at the end D is provided
with a break E, to keep the plates at any required depth in the
solution. The spring clip G connects any number in the series of
six cells. The solutions of the salts should be as strong as possible,
without a tendency to crystallize.

A drop of the liquid is placed on a microscopic slip, and the
ends of the wires fitted into the discharge rods {dipped into it, and
kept apart not more than a tenth of an inch, lowering the battery
into the solution, and carefully watching the terminal in connection
with the zine pole: the instant action is observed clamp the wheel,

Kies

278 Infusorial Cirewt of Generations.

and watch the result. Practice will show the best power of quan-
tity and intensity to use.

The use of a drop of liquid necessitates the microscope being in
a vertical position: to obviate this inconvenience I have adapted a
rectangular prism, and turned the eye-piece part of the tube hori-
zontally, as in Amici’s, and also made the prism to revolve con-
centric with the optic axis of the instrument, which enables several
persons sitting round the table to see the experiments at any
particular time by turning the eye-piece towards them.

The light must be entirely reflected. By placing coloured glasses
~ in the diaphragm frame, and sending light through them from the
mirror, a clear outline is given to the crystals, and an illuminated
background, which produces an exceedingly beautiful effect.

I am still pursuing the investigation, and hope to publish
further interesting results.

VII.—Infusorial Circuit of Generations.

By Tuxop. C. Hincarp.
(Continued from p. 233, No. XXXV.)

TuxsE “currant ”-yolks enlarge in size, and soon at the (darken-
ing) circlet or rim of the introversion reveal a rapid rotation and
“ ciliary motions,” and still later, a contortion and volubility of
contents really perplexing to the attentive beholder, who in vain
attempts to determine its form, or at least to detect it in the moment
of hatching, “anxiously wasting whole nights and half days”
thereon, as Ehrenberg has expressed himself on a similar subject.
At last the membrane bursts and extrudes a globe or halo of
gelatine, containing a crucible-shaped body, gently moving, which,
when finally set free by the rupture of that gelatinous halo, at
once elastically extruding the inverted part, takes a shape resembling
a rice-palea or the fore-wing of a thunder-fly (Thrips), travelling
broad-end foremost with great velocity and steady as an arrow.
After a while a somewhat ludicrous scene ensues, when the little
animal, by shedding its fissured skin or scabbard, is seen violently
struggling to disentangle its large jerking bristles hidden in the
veins of the sheath, and its small body. It thus appears like a
little dwarf, frantically floundering about in a Spanish cloak, spurs,
and sword too large for their owner. It now represents. a very
small Oxytricha with comparatively very long, stout, but as yet
softish, bristles.

This formed the more direct evolution from the Oxytricha
pellet, vz. out of its circular “ currant-vesicles.” Its enveloping

Infusorial Circuit of Generations. 279

grumose mass of “trabeculated albumen,” however, keeps still in-
creasing to the appearance of a loose snow-ball as it were, and each
single trabecular joint assuming a sort of warped §-form and a
jerking spasmodic commotion, they at last tear loose singly, and
escape each as a lanceolate, warped and finely-tailed “ Vibrio Termo
Dujard.”* In consequence of its twisted shape, it makes its way
with a vacillating archimedian motion, being constantly turned
round as it is rushing onward. When about sj, line long, it
already clearly reveals the (still warped, but finally flat) wafer-
shaped body ; and the longitudinal stri#, fringed with an undu-
lating fleece, as well as the oblique, ciliate mouth, which also
characterize its later stages. From an oblong orbicular pouch-
shape, when about 5 of a line, it becomes round like “navy ”-
beans (up to =), of a line) only a little tapering at the upper end ;
the small oblique mouth being a little above the middle. The
delicate longitudinal strize all over the body—melon-fashion—give
them an iridescent appearance, both under the microscope, singly,
and when swarming in masses on the surface, e.g. of aquaria, or of
the draining-pans of flower-stands. The striz are apparently set
with very soft widulating threads, resembling wool, nearly half a
diameter long, in likeness of “ ginned” cotton-seed. This feature
is absolutely overlooked in most of the figures from Ehrenberg up
to the present day; otherwise the former's “ Paramecium kolpoda”t
would seem to represent a few of its onward developments.

The body now commences to bisect, at first crosswise ; becoming
waisted, across the mouth, so that each half has a part of the old
one. After assuming the form of an 8, they, after long struggling
-and toiling, bisect, often spinning out a long gelatinous thread (as
of a limpid gum) and jerking each other most lustily; but after
disruption they presently round off.

In this condition, and the following, the bodies contain one
larger and a great many smaller granular pellets—“ yolks” or “ ger-
minal specks,” which I have not distinctly seen discharged. But
now the surface of the water becomes clouded with such granular
balls, of uniform molecules (about +5155 line in thickness) that like-
wise germinate into the fragiform clouds, alluded to in connection
with Vorticella, &c., and is covered with an apparently amorphous,
most delicate but cohesive pellicle (as of collodion) at the superficial
contact with air. All these forms, as above stated, when caught on

* The name of “termo” (repuwy, a boundary-pole or stake) probably referred,
originally, rather to the cylindric “‘ battering-rams,” extruded from diffluent “ cur-
rant”-vesicles (or ameba) of the paramecium cloud-dissolution, as below detailed.
The albuminous Oxytricha-pellet is pretty well represented in A. Pritchard’s ‘ A
History of Infusoria,’ tab. xviii., fig. 69. The indistinct §-shaped (constituent or)
developing particles, however, are there technically represented by shading with
cross-strise, conveying a false impression of their shape and structure.

+ ‘Abhandl. Berlin Acad. Wiss.,’ 1834, tab. iii., fig. 3.

280 Infusorial Cireuit of Generations.

a dry surface (e.g. by their undulating floss), instead of forming
into a dry scab, suddenly become liquid (like fusing lead), with an
immense internal commotion of parts, and bodily dissolve into such
cloud-molecules. The “wool” itself becomes quasi-“ dropsical,”
and each single fibril diffluent into a series of such uniform globular
molecules, which at first are endowed with an independent motion,
vibrio-like. Besides this, most of the encystments, moultings and
yolk-extrusions take place under the isolating cover of that uniform
protoplasm-membrane, which seems to exale a sort of bituminous
odour (like the fumes of burning flesh, sun-baked carrion, or the rank
smell of miry river banks). Membranes, as thin but chemically
homogeneous organic substances, being impermeable to certain gases,
while permeable to others, a good deal of physiological interest is
involved in the study of this protoplasm-membrane, and its relation
to the swamp-gases. The particles of the nubecula are uniformly
lobular.

; After repeated cross-segmentations, these undulate fimbriate
bodies, always revolving about the long axis (while evidently travel-
ling onward by the action of the ciliate mouth) divide lengthwise,
from below upward; thereby becoming somewhat purse or tear-
shaped ; the mouth being split in two, so that both stand “ plying”
mouth to mouth, while yet connected at their foreheads, as it were.
These finally tear asunder by indentures, after which each has the
shape of a crooked glass-tear. When more adult, and about ,’> of
a line long, the internal yolks and designs have disappeared ; the
sarcode assumes a uniform yellowish tinge; its mouth forms deep
cavities, while its front is toppling over like the hood of an Indian
turnip (Arum triphyllum) or of a Sarracenia leaf. It now con-
tracts to a globe and encysts. When asmooth, transparent crust is
formed, gradually an inward gyration of cilia (as of an enclosed
centipede), which ultimately becomes very violent, is observable ;
and at last the excessive fatigue of watching this tantalizing gyra-
tion may be rewarded by seeing the inmate emerge, either as quite
a large but excessively limber, fluttering and transparent, full-size
single Oxytricha ; or else several smaller, mostly narrow, triangular
slips* escape, with the same exceedingly restless volubility ; the
marginal bristles not yet being stiffly extended in a plane, but
ruffled up and down like the bristles on the undulating borders of a
thistle-leaf. As they feed and the tissues become scatent, the en-
tire form of an Oxytricha is presently acquired.

I have observed still another development of Oxytricha ; its first
source, however, being as yet unknown to me. There appear on
the field of action numbers of quaint-looking, big-eyed balls, about
roo line thick, snouted, as it were, with a sort of “hair-lip” re-—
sembling a duck’s bill; the stiff bristles within the bill-shaped

* The figures L and M, p. 447, in Carp. ‘ Micr.,’ seem to belong here.

Infusorial Cirewt of Generations. 281

mouth quivering with a sort of expressive smirk, and looking
altogether odd.

They come full-sized and booming upon the stage, and in this
respect argue a direct derivation from certain haw-shaped, five-
costate vorticellan buds, with a contracted pappus of stiffened cilia
around the orifice, spinning and rebounding like humming-tops.
The “goggle” now soon becomes stationary, and shortly after,
rapidly expanding, and its germinal speck or nucleus (the “ eye”)
particularly enlarging, within half an hour it dropsically flattens
out into a pretty well-sized Oxytricha,* by a similar sort of internal
fluxile commotion of particles as when the animals dissolve into
molecular “ sauce.”

But Oxytricha is not a perfect animal. It has no membranes,
and evidently no fibrous tissues at all. The entire texture appa-
rently remains in an embryonic, vitelline condition, as yet.

I have in a single instance witnessed what appeared to be the
moulting of a perfect Oxytricha. The front border was somewhat
removed from the body, which it crowned like the crest of an
ancient helmet, and within each rigid bristle (“style”), as within
the fingers of a glove, was contained the far more delicate corre-
sponding one of a clear (and now entirely yolkless-bodied) animal,
the lower quarter being in a like manner hidden in a part of the
old coat. I thought it was plainly identical with the following
animal, whose development brings us up to “ Paramecium Aurelia.”
As I have not been able to chance upon such a moulting process
again, I reserve the decision.

A clear (internal) animal is apparently developed by this
moulting of the Oxytricha. Of the latter, the very bristles, when
detached, seem to possess individual vitality, singly beating about
for quite a while, and even empty coats (apparently shed) some-
times behave as if they had a life of their own. At all events, at a
certain epoch there appears at once the next form in question,{ in
full size upon the field; the transparently clear bodies sometimes
showing a scalloped border, and alveoli, as of former yolks, extruded
—that soon smooth over. In outline, the animal appears somewhat
like the soft parts of an oyster, being flat, somewhat lop-sided, in
the shape of a human ear—tip foremost. It is “doubled up” at
the straight border, the broader lower rim being overlapped, as by
a lid, with a smaller, but thicker, upper flap (“lorica”) containing
one clear germinal speck. This animal opens like a book, un-
doubling its flaps; and it is thus that it devours its prey (such as

* This somewhat resembles fig. F, turning, by fluid expansion, into fig. E
(Carp. ‘ Micr.,’ ibid.) ; fig. F, however, requiring to be duck-billed, as it were,
and fig. E to be lop-sided and the nucleus more central.

+ Perhaps the “ Huplotes” of authors. Their descriptions and figures, however,

offer nothing that sufficiently resembles this very common form, so as to be readily
identifiable,

282 Infusorial Cirewit of Generations.

conferval spawns, &c.), by bodily enveloping them like a ray-fish
(Raya), enfolding the nourishment as if fused around it, and the
whole surface exhibiting an incredibly rapid cilary commotion
during the whole process of digestion. This done, the cloak again
unfolds, often appearing like two stipules, e.g. of a Liriodendron,
and then closes up again. On drying up, or in search for air and
moisture, the animals are often seen to mutually enfold each other’s
flaps. This cannot, however, be interpreted as a sexual copulation,
seeing that in the first place they neither develop any eggs, nor
in the second place do they even extrude yolks; but their onward
development is by encystment.

Within a few minutes such a full-grown “ oyster-grub” is seen
contracting its big flap, so as to present the shape of a hat with a
warped rim and hemispherical crown, the latter formed by the
blunter lobe, which contains the “speck” or “eye,” and, contracting,
gets hemispherically rounded. Very soon (with a constant ad-
justive quivering of the cilia-like bristles) the whole is rounded into
a globe, wherein the doubled inside forms a ciliate hiatus. The
latter, soon contracting, closes over. Nothing is now seen but a
ball with a clear “ germinal speck.” In a few hours a double con-
tour (the outer one granular) is exuded. The speck or “eye”
itself now becomes dusky and granular. It increases. It bisects
“Gregarina’-fashion. Hach pear-shaped segment again acquires
a clear speck or “eye.” They elongate, being connected by the
blunt ends,—each one tapering to a very soft apex; and these very
large germs or pseudo-Gregarinas at last become liberated, probably
as “ Paramecium Aurelia,” which now appears full-grown on the
scene.*

It is about the length of the Oxytricha, about three times the
length of the revolving wool-fringed grubs of the Oxytricha, and
by all means more complexly organized than either. It has the
shape of the (shoemaker’s) /ast for a very elegant lady’s shoe.
From one side it therefore gives the figure as of a foot-print (with-
out the toes); but viewed on edge has a pointed rear end, and in
this profile it “takes the name” of Paramecium caudatum! The
ankle of that “last,” however, is bevelled away, leaving the instep a
ridge. Its oral aperture, not clearly distinguishable, is in the
middle, slanting almost longitudinally for about one quarter of the
length of the body. It seems to work its way, dashing by vacuole-
contraction, while at the same time revolving by a roundabout coat
or film of short pubescence, almost too delicate to be made distinct.
In what appears to be the abdomen it has the well-known circular
pulsatory vesicle, wherewith it propels itself, and around which
point it is often seen spinning like a wheel. A system of fusiform

* The developmental experiments were made in small parcels, forming a drop
(between glass slips, somewhat held apart) and preserved from exsiccation.

Infusorial Cirewt of Generations. 283

or bulbous vessels radiating around the pulsatory vesicle, contract
as the vesicle expands, and vice versd, as 1s well known; and some
seem to have several such pulsatory “vacuoles.” The body is
turgid with rather small germinal yolks. These animals I have
never seen bisecting either lengthwise* or across, nor copulating
sexually. The latter, however, seems to take place with the Pla-
nariz, which also show the staghorn-shaped entrails analogous to
those of the marine (true) Planariz and joints of the tape-worm,
whose detached individuals are also known to hover freely in a
liquid, like these Ciliata. It is supposable that the large Para-
mecium, with pulsatory organs, is the young Planaria; but it is
certainly not itself an adult body.

The further and most remarkable of all these progressive and
retrograde developments is the following. The well-fed and full-
grown but entrazlless Paramecium Aurelia becomes slow and lazy,
greyish with the teeming germinal contents, and in a few hours
may be seen motionless as the fabulous “ Kraken” of ancient
Norway. Its entire substance now commences swelling forth into
compact, fragiform “ germinal clouds,” while a great many of the
germinal specks, now become less obscured, are plainly discernible
as of the clear “cwrrant-shaped yolks” kind. These in a short
time, however, commence moving, and while some of the smaller
ones are being propelled by adherent motile granules (probably the
“ Acineta” Auct.), the larger ones move by contraction, viz. their
“ circles” becoming everted, they now crawl forth, like a very
limpid grub—resembling a sort of tumbling sac! This “tumbling”
is produced by the most marvellous facility it possesses of protruding
long, blunt branches (like little stove-pipes) on any part of its
surface by eversion, so that in a few moments its form is entirely
changed. Its contents are a visibly and rapidly circulating so-called
“ rotating protoplasm,” composed of mostly very transparent endc-
vidual vibrionic particles, partly bulky, but mostly very small.
Some dark (red or brownish) vibrionic dots are also discernible.

It now takes the form which has been called “ Amceba.” This
form, however, likewise occurs when similar yolks or “ acinetze ”
are expelled from vorticellan bodies. In either case the “ tumbling
sac” lastly attains a versatile-campanulate star-shape with “ pseudo-
podia,” from which break forth volumes of minimal vibrios, and
quite large, cylindric bits of rods, or (pseudo)-“ bacteria.” The
latter here are thicker than fungine bacteria, and are neither coated
nor ellipsoidally shuttle-shaped, but bluntly cylindric, like car-
tridges or butting rams. They possess a very forcible automatous
motion, and like to congregate, and with great violence keep butting
all together, one against the other, in a heap; and within a few

* Ehrenberg’s figures, however, show it in that process (if not a mistake),
+ Pritchard, &c., figure the planaria-like form as “ adult Paramecium.”

284 Infusorial Cirewit of Generations.

minutes the whole appearance has dissolved and passed into a
“ germinal cloud” of molecular “ vibrionic ” cell-life.

Besides the above circuits of generations, which probably com-
prise both the pulsatory Paramecians proper (Aurelia) and the
Vorticello Oxytrichans (through the mediation of the “oyster” or
‘* porte-monnaie-grub”), there occur frequently some analogous
forms, such as “ Kerona” and “ Trachelium.”

The last form of all to appear in infusions, &., seems to be the
well-known Rotzfer, the developments whereof are perhaps related
to some of those above detailed. It is, however, most probable,
according to the observations of Prof. L. Agassiz,* who saw forms
resembling the undulate-fleeced (“Paramecium kolpoda”) grubs
bred from the eggs of Planariz,{ that such are the adult forms (if
adult). I have only occasionally met these swelled and pear-shaped
dusky bodies, travelling both back and forward with equal facility,
and remarkable for the staghorn-like designs of their entrails,
thereby evincing something like a membrane in their organization,
but the organ being itself of a sort of glandular structure. They
are also said to bisect, like the Oxytricha. Some young ostensibly
planarian forms, larger than Paramecium Aurelia, blackish, and
shaped like a short broad lancet blade, which I have seen “ bisect-
ing,” did so only while encysted, rotating in the manner of mill-
stones, and the escaping animals had as yet no trace of the visceral
organization, as found in the adult Planariz (and also observably
developed in Rotifer).

Weare therefore stillin doubt as to the true ultimate genus and
species, and therefore have to suspend classification ; the points of
interest here submitted being the important physiological pro-
cesses and transformations on the one hand, and the fallacy of
foregone diagnostic terminology on the other. ‘The description of
the genetic phenomena of the so-called Fresh-water Algze in their
unbroken continuity of developments, as experimentally ascertained,

I reserve for a future paper.—Silliman’s American Journal,
August, 1871.

* ‘ Ann. Nat. Hist.,’ vol. ii., 1850, p. 157.

t This is no doubt what authors figure and describe as the “ adult Paramecium
Aurelia,” with its staghorn-shaped intestines and swelled bodies. I am also
under the impression that it was this form which I had formerly frequently
observed in what appeared to be spontaneous coitus.

chor BL, fy Ob
ate» y

* rem 2
“ih ea® ry
ty) au

7 Mi Lely Ane

id

W West & Coa
voumy

( 285 )

VIII.—On the Connection of Nerves and Chromoblasts.
By M. Grorces Poucuer.
Puate CVIII.

Srvox we have shown by direct experiments the influence of the nerves
upon the pigment cells of the skin of fishes, and especially of the skin
of flat-fish (Plewronectes maximus, Linn.), the relations between
these elements and the nerves naturally attract our attention. Herr
Kiihne [untersuchungen tiber protoplasma] in 1864 figured the
larger connections between the nervous tubules covered with myeline,
and the connective cells of the cornea. But beyond that the iden-
tity of these cells and the pigment cells is not established further
than the doubtful effect of a reagent used by Herr Kiihne, nitrate of
silver, it does not appear that the conclusions of his memoir have
been definitely adopted by anatomists.

The pigmentary cells or chromoblasts are situated below the
skin, which is represented in many fishes, as in the Batrachia, by a
delicate hyaline membrane, about 19 to 20 Paris lines in thickness.
It is beneath the membrane properly so-called that the chromoblasts
are found mixed with other elements, which seem of a connective
tissue-like character. The chromoblasts themselves are essentially
composed of a mass of sarcodic substance (or protoplasm), usually
surrounding a nucleus, but being able probably to subsist without
it. In the midst of this sarcodic substance is deposited the colouring
matter, which is consequently a true pigment. This colouring
matter is of various tints, but generally it is, in the least refrangible
half of the spectrum, yellow, orange, red, brown, and black. Some-
times this colouring matter is liquid, and forms—as one sees it
in the embryos of crustacea—a coloured drop in a portion of the
sarcodic substance near the nucleus. When it extends in its
amoeboid movements, it draws over it the coloured drops.

At other times, and indeed most frequently, the colourmg matter
is spread out in granulations throughout the mass of protoplasm,

EXPLANATION OF PLATE CVIII.

Enlargement x 1000.
Fic. 1—lLaminous elements of the membrane of the pectoral fin of a turbot,
4 centimetres long. Jn situ.
» 1 bis—Three laminous elements isolated.
5, 2.—Elements of the same membrane at another point. Jn situ.
5» 3.—Nervous fibre.
», 3a,—Chromoblast without nucleus in contact with a nucleus of nervous fibre,
5, 30.—Chromoblast in continuity with a nervous fibre.
» 2 ¢.—Idem.
» 3d,—Nervous fibre in continuity with a nucleus of a chromoblast.
», 3 ¢.—Chromoblast in continuity with a nervous fibre.
5, of.—Idem.
» 4—Nervous thread accompanying a capillary.

286 On the Connection of Nerves and Chromoblasts.

which draws them with it in its different movements. But it
sometimes happens that the finest expansions in turning upon them-
selves leave these granulations in the midst of the surrounding
tissues.

Our observations, made to investigate the relation between the
nerves and the chromoblasts, have been carried out upon the pectoral
fin of young flat-fish, about 4 centimetres long. The organ taken
from the living fish is treated with dilute acetic acid, about 1 to 14
per cent.; then very slightly tinted with carmine. The preparation
thus made has been examined with an object-glass of 10 mm., of
Nachet, which admits of one seeing through the whole thickness of
the fin. In all cases it is treated with chloride of gold, feebly
acidulated with acetic acid ; it was placed under this reagent after
having been in acetic acid a sufficient length of time to admit of the
detachment of the epidermis.

The only elements of a connective nature that I have seen are
nuclei, surrounded by a greater or lesser quantity of a hyaline sub-
stance, which appears resistant, and affects a bi-polar disposition
of the two extremities of the great axis of the nucleus. These cells
without a trace of apparent membrane nevertheless differ much ;
in fact, as much in relation of form as in that of size of the nucleus
as well as the polar substance.

Fig. 2, Plate CVIII., represents exactly one region of the inter-
posed membrane with two rays. The nuclei affect a distinctly
parallel relation; they are narrow with regard to their length.
The polar substance 1s there, and recalls the appearance of the
fusiform bodies of the superior vertebree. In other imstances the
same elements show themselves disposed in a quite different man-
ner. They are at the same time more voluminous, more closely
related, and they affect a parallel disposition. Their position is
then ordinarily perpendicular to that of the rays. In some parts
it is not rare to see a certain number of these elements affect a
definite (determinée) direction, whilst others have a perpendicular
direction.

The nuclei of those contiguous conjunctive cells, as shown in
Fig. 1, vary considerably in volume, like the elements themselves,
almost from the single to the triple. They assume in preparations
treated as we have directed, an ovoid form, and seem to exhibit in
their interior the trace of a voluminous spherical nucleolus. The
diameter of the nucleus may be estimated on an average at 6—7” ;
its volume is always proportional to the quantity of polar substance.
Two nuclei are sometimes seen in these fusiform bodies, which seem
to prove that they multiply by fission. We have represented an
example, and also some aberrant forms in Fig. 1.

Capillaries are rare, and are sometimes ,accompanied by a thin
nervous thread, Fig. 4. The latter is recognizable by narrow

On the Connection of Nerves and Chromoblasts. 287

nuclei, four or five times longer than wide. They are filled with
very small black granulations. The outlines are ill-defined.
Their substance fixes carmine with great energy. The nervous
bundles of the fins present only a very small number of those
fibres, but they may be followed when isolated, during a very long
course, as shown in the Figure. They may be recognized in this
case by their continuity, for the fineness of those elements is extreme,
and at the same time, by the presence on their course of nuclei
sometimes near and sometimes remote from one another. Some-
times the fibre seems to grow wider in order to contain the nucleus,
and at other times the latter seems to be thrown off laterally, in a
kind of floating membrane. It must not be forgotten that we speak
here only of the specimen prepared according to our directions.

Without asserting here the existence of a direct relation be-
tween the nervous fibres and the chromoblasts, we will limit our-
selves to a statement of the result of our researches. The ques-
tion is a very difficult one to solve, owing to the nature of the
sarcodic element, which is usually recognizable by its granulations,
but is for that very reason impenetrable to the eye, so that all
observation must be summed up in investigating the continuity of
a nervous fibre, characterized either by its length, and the physical
peculiarities of its substance, or better, by the presence of its nuclei,
with the sarcodic substance, without any hope of tracing the ner-
yous fibre into the midst of the contractile element.

An auxiliary, however, presented itself, which might help to
determine this continuity. The granulations of pigment given up
by the expansions of the chromoblast, may in their contraction
become an excellent point de repere. Let us suppose that every
appearance indicates the continuity of the sarcodic substance and of
the nervous fibre; this appearance will become almost a certainty,
if, on the course of the nervous fibre, in the neighbourhood of the
chromoblast, we discover granulations of pigment which have
evidently been given up by the sarcodic extensions returned on
themselves. We have endeavoured to represent all the cases of
this kind that we have been able to meet.

As the inquiry regards parts which had not been dried, but
were observed 77 situ in the thin lamina which extends from one
ray of the fin to the other, the relations observed between the
parts can only be natural. If the instances are so rare, it is first
because the continuity which we try to observe exists in a plane
perpendicular to the visual one, and secondly because only a small
number of chromoblasts show themselves in a state of isolation
favourable for observation, even in the case which we bring for-
ward ; we have not thought it right to dissemble the considera-
tions which might plead against an appearance evidently conform-
able to the theory, but the demonstration of which we shall not,

288 On the Connection of Nerves and Chromoblasts.

however, regard as rigorous, so long as it will not have been drawn
from embryogenic study.

In Fig. 3 ¢, we have evidently to deal with a nervous thread,
characterized by the presence of a nucleus. We must remember
that there is not a trace of laminous fibres in all this tissue. This
nervous fibre appeared to us to continue directly with a pale chro-
moblast having numerous ramifications. The union seems to be
proved by some granulations scattered over the nervous thread near
the chromoblast. Fig. 3 f shows a similar arrangement, although
less clearly.

The same arrangement is seen also in Fig. 2 and Fig. 3 6.
There, however, the filaments which appear really to continue with
the chromoblast, were not, so far as they were visible, provided with
nuclei. The same may be said of Fig.3e, which is certainly the
most characteristic of all those that we have observed. The
chromoblast was large, and very much retracted on itself like a
sphere. From the edge of the chromoblast was seen to extend a
thin filament, which could be traced pretty far, and which it was
hard to avoid considering as a nervous thread, although it pre-
sented no characteristic nuclei. But it offered, on the other hand,
certain interesting peculiarities near the outside of the chromoblast,
inside which the latter's opacity of course prevented the pursuit.
This thread offered in this place strongly-marked sinuosities, which
are not usual on the course of the nervous fibres. But, besides,
we discovered easily on those sinuosities pigmentary granulations
analogous to those contained in the sarcodic substance. Error was
impossible. Beyond the first sinuosity especially were seen two of
those granulations, isolated and perfectly recognizable. Those
sinuosities, those granulations, appeared really to indicate that the
fibre there approaches its termination, enveloped in the sarcodic
substance when the latter displays itself. ‘There exists there, then,
intimate contact, if not continuity of substance between the nervous
fibre and the chromoblast.

One difficulty indeed appears. The influence of the nervous
element on the contractile element is unquestionable, but it in no
way indicates what may be the relations or the connections between
the two elements. Does the nervous fibre become lost in the midst
of the contractile substance on coming into contact with the nucleus
of the chromoblast? ‘This is a first hypothesis, which we confess
appears to us highly probable, but which has not been demonstrated.
Influence exerted at a distance from the chromoblast by adjacent
nervous elements appears improbable, and besides, in opposition to
what we know to exist in the other parts of the organism. There
remains a third hypothesis: that the chromoblasts are merely
arranged on the course of a nervous element, and in contact with
it, and that only through the effect of this contact they enter into

On the Connection of Nerves and Chromoblasts. 289

contraction whenever the nerve is acted on. In this case there
would remain to be found the termination of the nervous elements,
on the course of which the chromoblasts would be thus arranged.
Fig. 3a appears on this subject to deserve attention. It exhibits
a nervous thread which, it is true, is not characterized by the
presence of a nucleus. This filament came in contact with a
chromoblast, having quite a peculiar aspect. The contractile sub-
stance seemed loaded with pigmentary granulations on one side of
a long and narrow nucleus, which presented all the characters of a
nucleus of nervous fibre, and not at all those of the large irregular
nuclei which usually accompany sarcodic bodies, and which are
represented in Fig. 36, Fig. 2, Fig. 3d.

Are we to suppose that the nuclei of the nervous fibres may in
certain circumstances themselves become nuclei of chromoblasts, by
changing their characters and undergoing a true metamorphosis.
Or must we see, in the representation which we had under our eyes,
only a chromoblast deprived of nucleus, and lying close to a ner-
vous fibre at the level of one of the nuclei of the latter, giving us
an instance of the simple union by contact of which we spoke.

We repeat, that these observations may require to be extended
in certain directions ; and although we are of opinion that we may
now infer from them the reality of the connection between the
nervous and the sarcodic elements, a connection conformable to
theory, we cannot assert that the nature of this connection is yet
completely known.

PROGRESS OF MICROSCOPICAL SCIENCE.

Rodent Cancer of the Upper Eyelid.In describing a case of this
kind to the Clinical Society (October 27), Mr. Hulke described the
minute features of the stroma as follows :—It was composed chiefly of
small round spherical cells like those of rete mucosum without inter-
cellular substance, and, although differing from epithelioma, resembled
it so far that he could not draw a sharp line of distinction between
the two.

The Microscope in the Detection of Adulteration in Food.—A good
paper on this subject appeared recently in the ‘Chemical News.’ It
is by Mr. Walter Morris, and it deals with the subjects of coffee,
cocoa, sugar, mustard, pepper, and bread. It points out the principal
adulterations, and shows how they may be readily detected by the
microscope. The paper is too long for an abstract.

( 290 )

NOTES AND MEMORANDA.

Tolles’ Immersion }th.—In a letter to Mr. Slack, Dr. Woodward
says:—“The Tolles’ immersion }th, by which the Amphipleura pictures
were made, works either dry or wet, the compensation being effected
simply by altering the distance of the front lens from the other two,
by means of the screw collar. There is also a low-angle extra front
for ordinary work.

“J find with the high-angle fronts the following measurements :—

Magnifies at 4 ft. focus ;
Micrometer screen and

Angle. without eye-piece.
Dry: uncovered, 110° | 25. 2s.) ss) sa! on gene
5; for thickest:cover, 140° .. 3. <2 2. meezoOmmmre
Immersion : uncovered, 140° .. .. .. . «. 200 4,
. for thickest cover, 170° upwards .. 275 ,,

“ With central light, and on Podura, or anatomical objects, I find
this objective admirable.

“ T wish I could speak as favourably of Mr. Tolles’ higher powers.
They are very good indeed, but I have yet to see one of them which will
rival the so-called 1,th immersion of Powell and Lealand.”

American Microscopical Apparatus.—The following brief account
of the apparatus at the last American Association is given in the
September No. of the ‘American Naturalist’ :—Among the novelties
may be noticed the observation of the electric induction spark by the
micro-spectroscope, by Prof. Vander Weyde; the oblique illumi-
nation of transparent objects under high powers by means of light
reflected from a plane mirror lying upon the stage and directly
beneath the mounted object—a little expedient of great practical
convenience, also by Prof. Vander Weyde; the adoption of the
Wenham Binocular arrangement by Zentmayer; and the somewhat
general introduction into use of the eye-piece condensers with a wide
horizontal illumination (for binoculars) upon the plan proposed by
Prof. Ward at the Troy meeting last summer. Mr. Bicknell places
the stop-plate between the lenses of the condenser, instead of below
them ; and Prof. Ward, while retaining the eye-piece arrangement for
use with low powers, for high powers combines the centring adjust-
ment, Iris diaphragm, and stop-plate, with an achromatic combination
of larger angle and more perfect corrections. The committee on
uniform standards in the powers of objectives and eye-pieces being
unprepared to report, Messrs. Ward and Bicknell reported verbally,
and the committee was continued until the next meeting. While an
exact uniformity in the amplifying power of lenses in the same
denomination is not to be looked for, it is believed that much of the
existing confusion may be remedied. Many microscopists, the
speakers among the number, have long been accustomed to alter the
denomination of their lenses so as to represent, as nearly as prac-
ticable, their amplifying power when in actual use; and probably the
principal makers in this country will freely co-operate with micro-

CORRESPONDENCE. 291

scopists attaining this very desirable result. The introduction already
partially accomplished, of a grading of the eye-pieces by comparison
with equivalent single lenses, 2 in., 1in., } in., &c., may render this
part of the subject, which seemed almost unattainable, the easiest and
first to be accomplished.

CORRESPONDENCE.

Grinpinc Diamond Pornts.
To the Editor of the ‘Monthly Microscopical Journal.’

Sir,—Mr. Wenham having been asked the best method of grinding
diamond points for fine ruling, or writing on glass, kindly gave the
following valuable information, with permission to publish it.

Yours faithfully,

Henry J. SLAck.

“Many years ago I tried some very fine-line ruling by a very
beautiful little machine, made by the celebrated Tully. At first I
used fragments and splinters of diamond, but found that I could not
do any good with them, after working till my patience was exhausted.
No two pieces acted alike : some with the lightest pressure that it was
possible to give tore and shattered up the surface of the glass, breaking
all the lines into a mass. Other pieces that required more pressure
gave irregular lines. A piece might be found that would suit for
ruling lines of one degree of fineness, but would not do for others.
I therefore had to give up broken splinters as impracticable, and use
turned points.

“ A fragment of diamond was imbedded in a short piece of copper
wire, +}; in diameter, in the way described in my paper ‘ On the Con-
struction of Object-glasses. This was chucked in the bow lathe or
‘jigger, and another splinter of diamond, similarly mounted, was held
against it as a turning tool. Both were, I suppose, about equally
ground away, and you could see the dust flying off; in fact, diamonds
rubbed together abrade each other just like two pieces of slate pencil
will do. It is very easy with a delicate touch at last to bring the
rotating diamond to a point as fine as a needle. This is the right
thing for glass ruling, and I have no doubt that Nobert uses the same.

‘Jn Peter’s writing machine turned points are employed, as these
only will mark in every direction. At first he used to buy his turned
points from the diamond workers at one guinea each, and few of them
good even at that. I explained my way of turning the points, at
which he succeeded at the first attempt, and ever after that made them
with his own hands. He told me afterwards that what before cost
him 21s. did not now cost him 1s. He did not, however, mount them
quite in my way, but thus: he split the end of the wire with a fine
saw, then closed the split end on the fragment of diamond with pliers,
so as to nip it fast; then wound the end round with a few coils of

VOL. VI. rs

292 CORRESPONDENCE.

very fine platinum wire, and finally with the blow-pipe run the whole
together with silver solder and borax. The solder insinuated itself
between the coils, filled the saw kerf and ran round the diamond,
uniting the whole as a solid mass. This made a very firm and sub-
stantial job of it. Of course a very clumsy piece of diamond will
serve as the turning tool or rather rubber. I assure you that this
is a very easy operation.

“T hope that this contains a hint that may be of service to you.
You can make any use of it that you think proper. Publish it if you
like, for these little dodges arg too often kept as trade secrets, to the
detriment of their utility.

“ Yours sincerely,

“H. J. Stack, Esq.” “F, H. Wrennam.

Mr. Tottes anp Mr. BicKNeEtt.
To the Editor of the ‘ Monthly Microscopical Journal.’

November 6, 1871.

Dear S1r,—Enough has been said to convince minds conversant
with optical science of the loss of aperture on objects in balsam or
fluid. Mr. Tolles, however, still disbelieving, puts a case. If he is
clever enough to mount a diatom in balsam, between two hemispherical
lenses, or enclose it in the centre of a tiny spherule of hard balsam,
or gum, then of course it can be illuminated from all angles, and seen
by the full aperture of an object-glass (the refraction of the material
will not influence the result, as the rays proceed in straight lines
through the surface). But if I understand Mr. Tolles’ not very per-
spicuous summary correctly, he brings this profound illustration for-
ward to show that the angle of aperture is in no way diminished, when
the object and front lens are both immersed in fluid. Does he really
expect us to believe that he can obtain all his aperture by the back
combinations alone, and that these are capable of receiving or trans-
mitting 170°, or even anything near the least angle of 90° that he has
shown? or that any of his objectives, duly adjusted for an immersed
object, and thus showing a large aperture when measured in air, will
retain the same angle when the front is immersed in a body of water ?
If so, further comment is useless, as it would no longer be a scientific
discussion of any general interest, but merely an individual one—a
rather hopeless attempt to convince him, by explaining primary laws
of refraction, or the very a, b, c, of optics. His position is an impos-
sible one. In a corrected high-power object-glass, when immersed,
the focus does not fall in the centre of the hemisphere of the front
lens, but is considerably beyond it.

In the last Journal there are some remarks by Mr. E. Bicknell.
At page 226, paragraph 4, he applies the terms “ deception” and “‘ mis-
leading people” to Messrs. Powell and Lealand, and the same to
Dr. Woodward, for “ knowingly ” putting forth work done by a higher
objective as that from a th. I consider that this is hardly fair, and
is uncourteous to the gentlemen named. A scientific microscopist
gives the diameters with his illustrations, states the aperture, and the

PROCEEDINGS OF SOCIETIES. 293

nominal power of the object-glass ; this quite meets the case. In such
a difficult and complex arrangement as a high-power object-glass, it is
almost impossible for all the makers to work to the same magnifying
standard. From an early date, iths were }ths or +/,ths, and some now
approach to ;';ths in power. There is almost the same discrepancy
as in the nominal and real horse-power of steam-engines, by makers
who vie with each other to give the best measure, and anyone that
now obtains a +,th for what was formerly an 4th, may congratulate
himself in getting more for his money.
Yours sincerely,

F. H. WrEnuAM.

A Mryzratoaicat Microscopr.
To the Editor of the ‘ Monthly Microscopical Journal.’

New University Cius, Nov. 8, 1871.

Srr,—Dr. Lawrence Smith contrived a form of microscope for
examining minerals, one of the features of which is that objects are
viewed from the lower side. My own pursuits are such as to require
this, but I can obtain no definite answer as to form and price of
instrument from those London microscope makers whom I have con-
sulted.

I should be very glad if your readers, both here and in America,
would forward my chemico-mineralogical work by giving me any
information. Of course it is an object to use such apparatus as I have,
which can be adapted to the new instrument.

I would also ask whether this form of microscope might not be
made to take the place of the laboratory spectroscope.

I am, Sir, your faithful servant,

MarsHaAtL Hatt.

PROCEEDINGS OF SOCIETIES.*

Royaut Microscorican Soctery.

Kin@’s CoLLeGE, Nov. 1, 1871.

W. Kitchen Parker, Esq., F.R.S., F.Z.S., in the chair.

The minutes of the last meeting were read and confirmed.

A list of donations was read, and a vote of thanks given to the
respective donors.

The Secretary announced that he had received from Mr. Stanistreet,
for the Society, two beautiful specimens of his engraving, or Micro-
ruling, on glass. Also a photograph of his machine. There was an
engraving from the photograph which was rather more intelligible

* Secretaries of Societies will greatly oblige us by writing their report legibly
—especially by printing the technical terms thus: H ydra—and by “underlining”
words, such as specific names, which must be printed in italics. They will thus
secure accuracy and enhance the value of their proceedings.—Ep., ‘M. M. J?

Y 2

294 PROCEEDINGS OF SOCIETIES.

than the photograph in the ‘English Mechanic.’ Both the specimens
of ruling were very beautiful, but the one on the slide was much more
elaborate than that in the ornamental circular frame.

The Secretary also stated that the Council proposed, if they could
obtain the use of the room in which the Society’s meetings were held,
to have another Scientific meeting on the Wednesday of the third week
in January next, the meeting to consist of the Fellows and a few
visitors. The Council hoped that every Fellow would endeavour to
bring all that was new or fine in reference to recent discoveries. The
precise date of the meeting would be fixed as early as possible, and then
communicated to the Fellows by circular without delay. He believed
it most probable that the room could be used on the day already men-
tioned.

Dr. Braithwaite then read a paper “On the Structure of Bog
Mosses.”

In answer to a question from the President, Dr. Braithwaite said
that the leaves whose characters he had been describing were not all
constant throughout the species, but that they do vary on the plant.

The Secretary announced that three very fine photographs of
Degeeria domestica had been received from Dr. Woodward of the U. 8.
Army Medical Department, accompanied by a short descriptive paper.

Mr. Slack said he had hoped Mr. Wenham would have been pre-
sent that evening, in order that he might have given an explanation of
his method of illumination to which Dr. Woodward had alluded.
He (Mr. Slack) believed that the action of that mode of illumination
depended upon the fact that the object must rest upon the bottom of
the glass slide, and that the covering glass was made to act as a mirror
throwing light down upon it; consequently there would be opaque
illumination just as the object was opaque. But if the object was
partially transparent a portion of light would go through it. Some
of the light might enter the object and reach the eye by internal re-
flexions, or refractions. He thought Mr. Brooke would be able to
confirm this explanation. ,

Mr. Brooke said he believed Mr. Slack had correctly described the
effects that would be produced by Mr. Wenham’s mode of illumina-
tion. The explanation of it was, that the objects were partially seen
by reflected light thrown down upon them from the covering glass, and
they were therefore so far seen opaquely: they might also transmit
certain rays that came less obliquely, and they would thus be rendered
visible both by the transmitted and the reflected rays.

Mr. Slack said the photographs showed characters very near to
those described by Dr. Pigott, and similar to the sketches he had
published in the ‘ Student.’

Mr. W. Saville Kent then read a paper “On Professor James
Clark’s Flagellate Infusoria, with description of New Species.”

Mr. Kent, replying to the inquiries of the President, said that he
considered the presence of the flagellum seen in Monas, would place
it in a higher class of Protozoa than the Rhizopoda ; that some of the
forms he had described had a kind of chitinous sheath, as in Cothurnia;
that the bell-shaped “ collar” shown in his (Mr. Kent’s) diagrams was

PROCEEDINGS OF SOCIETIES. 295

an expansive membrane of extreme tenuity modified from the sarcode ;
and that with regard to certain individual portions of sponges bearing
flagellate appendages, those organisms ought to be classed among the
higher Protozoa, combining the characters of the Flagellate Infusoria
and ordinary Rhizopoda, with a skeletal superstructure, and complex
canal system essentially their own.

Mr. Slack said he would venture to remind the President of a spe-
cialized organ in the Ameeba, first discovered by Dr. Wallich, who
came ultimately tothe conclusion that it was developed in a stage of
the creature’s existence. He (Mr. Slack) had seen this organ, and it
was certainly much more specialized than a simple flagellum.

Mr. Stewart said a short time since he was examining a specimen
cf a calcareous sponge in the early spring months, and he observed
that on withdrawing it from the water, a milky fluid escaped from it.
On submitting this to the microscope he found the milkiness was really
due to little masses of the amceboid particles of the sponge moving
actively in the water by the aid of from one to three, or (he fancied in
some cases) even four flagella attached to each particle of the com-
pound masses. He did not notice the funnel-like membrane. He kept
these particles alive some time, and noticed that the flagella were
gradually absorbed, and that motion was then effected by pseudopodia
the same as in Amcebe. He thought it possible that these bodies
might rather represent a form of gemma, than a mere detached group
of the ordinary particles of the sponge. With regard to the connection
between sponges and ccelenterates, the setting aside of certain of these
particles to perform a special function for the good of the entire or-
ganism, seemed by this first indication of tissue formation to point to
an affinity with some more complex animal.

Mr. Slack then reminded the Fellows that some time since their
attention had been called to a creature called a Stentor, and named
after the gentleman who had sent an account of it to the Society,
Stentor Barrettiti. He (Mr. 8.) had then pointed out that if Mr. Bar-
rett’s statements were confirmed the creature could not possibly be a
stentor. Mr. Kent had been kind enough to bring down a drawing of
what he thought was the animal not quite correctly described as a stentor.
It certainly seemed to be the same creature. The appearance of spines
was not at all uncommon. According to Stein they belonged to the
ordinary stentors, were protruded on certain occasions, and on being
withdrawn left no mark behind. He thought it probable that Mr.
Barrett had from some cause or another overlooked the body cilia
characteristic of stentor, and had misinterpreted appearances which led
him to assume that his creature possessed organs not found in any
stentor. Mr. Kent submitted to the meeting a drawing of Stentor
polymorphus, Claparéde (published 1861), and in reply to Mr. Slack
stated that he had recently met with the same form himself, and con-
sidered it to be identical with the species introduced to the Society
last year, and figured in the Society’s ‘Transactions’ by Mr. Barrett
under the name of S. Barrettii, The author quoted considered it dif-
fered from previously described species in inhabiting a tube, in the
possession of stiff sete, and in having no vibratile cilia distributed over
the surface of the body. The two positive characters given, Mr. Kent

296 PROCEEDINGS OF SOCIETIES.

affirmed, were common to the species of which he submitted a drawing,
while the non-detection of vibratile cilia by Mr. Barrett he attributed
to the insufficiency of magnifying power, or inadequacy of the means
of illumination he had employed.

Mr. T. Charters White, in answer to a question from Mr. Slack, said
he had once seen a stentor as large as that described by Mr. Barrett,
but he could not say that it was identically the same; in length it
occupied the whole width of the field of the microscope, when examined
with a 2rd of Smith and Beck’s, and was abundantly supplied with cilia ;
it had a mucous agglomeration about its foot something like Tubicularia,
into which it retreated if the stage of the microscope was struck.

The President announced that at the next meeting Dr. Carruthers
would continue his description of the “ Fossils of the Coal Measures,”
and that a communication would be read from Mr. J. Bell, “On Fer-
mentation and its results.”

The meeting was then adjourned to the 6th day of December next.

Mr. Joseph Beck stated that a note referring to him in the last
number of the Journal was founded on misapprehension of what he
had said.

Donations to the Library and Cabinet, from Oct. 4th to Nov. Ist,

1871 :— From
Land and Water. Weekly do: casi ao veiee, wie's adorn eee en aiagtes
Society of Arts Journal. Weekly ie ces 00" enaien pe DEREEnE
Watnure. (Weekly... <. . ie sas eds aa ge eee noes
Atheneum. Weekly .. oe WE Weree
Physical Optics. By Thomas Exley, iN M.,, 1834... .. Dr. Millar.
Annual Report of the Commissioner of Patents for the

year 1868. 4 Vols. Washington, 1869... .. .. U. States’ Patent Office.
Journal of the Linnean Society, No.53 .. .. .. .. Society,
Popular Science Review, No. 41 Peo meD ris ean L255 2.
Catalogue of Scientific Papers. Vol. V. BP Royal Society.

Three “Photographs of Degeeria domestica, as seen with
Wenham’s Black-ground Illumination. By Dr. J. J.

Woodward, U.S. “Army ; ot ee, ne A Ore
Two Specimens of Micro-ruling on Glass. By John 8.
Stanistrect, Wsq.) 06 25 55> a eee

The following gentlemen were elected Fellows of the Society :—

Thomas Armstrong, Esq.
John Sumsion Townsend, Esq.
John Cretney Sigsworth, Esq.
Joseph Needham, Esq.
Frederick John Marriott, Esq.

Water W. REsEvEs,
Assist,-Secretary.

CORRECTIONS TO VOL. V.

Page 152, bottom line, for prevent, read present.
», 154, line 4 from bottom, for Joseph Beck read Richard Beck.
» 155, ,, 12, for coin, read cam.
» 9 3 14, for develops, read depresses.
» 9» 9» 17, for coin, read cam.

( 297 )

INDEX TO VOLUME VI.

——_+#-

A.

ADDRESSES wanted for the Royal Micro-
scopical Society, 16].

Agassiz’s, Professor, Future Dredging
Operations, 103.

Auport, S., F.G.S., on the Micro-
scopical Structure and Composition
of a Phonolite from the Wolf Rock,
87.

Ameeba, on the Conjugation of. By J. G.
Tatem, Esq., 275.

Amphipleura pellucida, Note on. By
Dr. J. J. Woopwarp, 43.

, Note on the Resolution of,

by a Tolles’ Immersion !th. By Dr.

J. J. Woopwarp, 150.

, ‘Note on the Resolution of,
by a Tolles’ Immersion 1th. By Dr.
J. J. Woodward.” Some Remarks
on. By Epwin BIcKNELL, 225.

Angular Aperture, Experiments on.
By R. B. Toues, 36.

Anthophysa solitaria, laxa, and Ben-
nettii, 264.

Apparatus, American Microscopical,
290.

B.

Barnarp, F. A. P., The Examination
of Nobert’s Nineteenth Band, 194.
BrenevEN M. Epovarp on a Giant

Gregarina, 39.

on the Gregarinida and their
Development, 104.

Bibliography, 60, 120, 164, 208.

BickNELL, Epwry, Some Remarks on
a “ Note on the Resolution of Amphi-
pleura pellucida by a Tolles’ Im-
mersion 2th. By Dr. J. J. Woodward,”
225.

Bicoseca lacustris and socialis, 263.

inclinata, 264.

Blood, on Some Improvements in the
Spectrum Method of Detecting. By
H. C. Sorsy, F.R.S., 9.

— of Ceylon Deer, Mematozoa in.
By Boyp Moss, M.D., 181.

—— Globule, the Red.
RicHarpson, 40.

— Corpuscle, on the Cellular Struc-
ture of the. By J. G. Ricnarpson,
ni Ci Dele

Corpuscle. When isit in Focus?

By Dr. Tyson, 42.

By Dr.

Blood-vessels, Passage of Corpuscles
through the. By Dr. R. Norris, 238.

Bog Mosses. By Rost. BratrHwalte,
M.D., 1, 268.

Brachiopoda, the Position of the, 102.

BrauaM, Puixtp, on the Crystallization
of Metals by Electricity under the
Microscope, 277.

BralTHwaite, Rosr., M.D., on Bog
Mosses, 1, 268.

Briper, H. G., Mapping with the
Micro-spectroscope, with the Bright-
line Micrometer, 224.

Bryozoa Marine, the Retrograde De-
velopment of. By CiapareEDg, 98.

Mediterranean, 161.

Butterflies and Gnats, the Scales of,
102.

C.

Calopteryx, Agrion, and Diplax, the
Embryos of. By A. S. Packarp,
jun., 39.

CaLvert, Crace-, F.R.S., Difficulty of
Experiments on Spontaneous Gene-
ration, 234.

——, Experiments
Generation, 199.
Carter, H. J., F.R.S., on Coccoliths,

98

on Spontaneous

Chelifer, an Incident in the Life of a.
By S. J. McIntire, F.R.M.S., 209.
Chloral Hydrate, Chloroform, Prussic
Acid, and other agents, Observations
and Experiments with the Micero-
scope on. By Tuomas S. Ra.pu,
M.R.C.S., 75.

Chorda dorsalis, Structure of the, 161.

CLAPAREDE on the Retrograde Develop-
ment of Marine Bryozoa, 98.

Coal Plants. By Jonny Burrerwortn,
49.

Coals, on the Spore-cases in. By J. W.
Dawson, LL.D., 90.
Coccoliths are Plants.
Carter, F.R.S., 98.
Codosiga pulcherrima, echinata, and

umbellata, 262.
Corrections to Vol. V., 296.
CORRESPONDENCE :—
B., 241.
BLANKLEY, FREDERICK, 107.
BuTTERWORTH, JOHN, 49.
Davis, Henry, 48.
Hai, MARsHALL, 293.

Mrs Be:

298

CorRESPONDENCE—continued,
Hoee, JaBez, 162, 242.
Movcuet, M., 108.
Ricuter, H. C., 107.
Sxack, Henry J., 291.
Smirn, H. L., 45.
SroppER, CHARLES, 201.
Tatem, J. G., 47.
Wennay, F. H., 291, 292.

Cotton-seeds, the Microscopic Structure
of, 239.

Crinoids, a Mineral Silicate injecting
Paleozoic. By Dr. Srerry Hunr,
E.R.S., 99.

Crystals, Double-refracting, on Spectra
formed by the Passage of Polarized
Light through, seen with the Micro-
scope. By Francis Deas, M.A., 135.

Cusirr, Cuar.es, F.R.M.S., on Floscu-
laria Cyclops, a New Species, 83.

on a Rare Melicertian, with

Remarks on the Homological Posi-

tion of this Species, and also on the

previously - recorded New Species

Floscularia coronetta, 165,

Dz.

Darwinian Question, the, a Prize Essay,
240.

—— Theory, the, applied to Plants,
101.

Darwin’s Theory applied to Flowers,
240.

Dawson, J. W., LL.D., on Spore-cases
in Coals, 90.

Deas, Francis, M.A., on Spectra formed
by the Passage of Polarized Light
through Double-refracting Crystals
seen with the Microscope, 135.

Diamond Points, on Grinding. By F.
H. WenuHAM, 291.

Diatoms, Another Hint on Selecting and
Mounting. By Captain F. Lane, 215.

Diatomacez, the Structure and Nature
of, 161.

Diatomaceous Earth from the Lake
of Valencia, Caracas. By A. Ernst,
Esq., and H. J. Suck, 69.

Diplograpsus pristis with Reproductive
Capsules. By Mr. J. Hopxinson, 41.

Docophorus Dennyii, 8.

EK.

Epwarps, Prof. A. Mean, on the Em-
ployment of Dammar in Microscopy,
34.

Embryology, How to Study, 241.

Eozoon, the Mineralogy of. By Prof.
Srerry Hunt, 99.

Epithelium, Regeneration of the
Corneal. By Dr. H. Hersere, 234.

INDEX.

F,

Facial Arches, on the Form and Use
es ne By W. K. Parker, F.E.S.,

Fiercuer, Dr., on Stephanurus den-
tatus, 103.

Floscularia Cyclops, a New Species.
By Cuarues Cusirt, 83.

coronetta, Remarks on, by CHas.

Cusitrt, F.R.M.LS., 165,

G.

Generations, Infusorial, the Circuit of.
By Tueop. C. HinGarD, 227, 278.
Glass Chimney, the New Metallic

Covert By FrepErick BLANELEY,
07.
Glycerine, How to close Cells filled
with, 105.
Graafian Follicles in Man, the Anatomy
of the, 236.
aed a Giant, M. van Brnepen,
9.
Gregarinida, the, and their Develop-
ment, By M. E. Van Benepen, 104.
Gum Dammar in Microscopy, on the
Employment of. By Prof. A. Mrap
Epwarpbs, 34.

Jel

Heteerc, Dr. H., on the Regeneration
of the Corneal Epithelium, 234.

Hintearp, THeop. C., Infusorial Circuit
of Generations, 227, 278.

Histological Preparations, an Improved
Method of Photographing by Sun-
light. By Dr. J. J. Woopwarp, 169.

Hoge, Jasez, on the Mycetoma or
Fungus-foot of India, 61.

— on the Fungoid Origin of Dis-
ease and Spontaneous Generation,
156.

ie ci on Surirella gemma,
162.

——, Hon. Sec. R.M.S., on Gnats’
Scales, 192.

Horxin:on, Mr. Jonny, on a Specimen
of Diplograpsus pristis with Re-
productive Capsules, 41.

Hupson, C. T., LL.D., on a New Roti-

__ fer, Pedalion mira, 121.

—., Note on Pedalion mira, 215.

Hu.ke, Mr., on Rodent Cancer of the
Upper Eyelid, 289.

Hont, Dr. Srerry, on a Mineral Sili-
ae Injecting Paleozoic Crinoids,

a:

on the Mineralogy of Eozoon, 99.
Hyarr, Professor, on the Position of
the Brachiopoda, 102,

INDEX.

I.

Immersion Objectives, on the Angular
Aperture of. By Roserr B. Toues,
214.

Inflammation and Suppuration, Re-
searches on. By Dr. J. M. Purssr,
200.

Infusoria, Notes on Prof. James Clark’s
Flagellate Infusoria, with Descrip-
tion of NewSpecies. By W. SaviLLe
Kent, F.Z.8., 261.

Infusorial Generations, the Circuit of.
By Turon, C. Hincarp, 227, 278.

J.

Jounson, Mercatrs, M.R.C.S.E., Trans-
mutation of Form in Certain Proto-
zoa, 184.

the Monad’s Place in Nature, 217.

?

1

Kent, W. Savitue, F.Z.S., Notes on
Prof. James Clark’s Flagellate In-
fusoria, with Description of New
Species, 261.

L.

Lane, Capt. F., Another Hint on Se-
lecting and Mounting Diatoms, 215.

Lens, the, a Quarterly Journal of
Microscopy, &c., 162.

Lepidodendron, the Structure of. By
Prof. WILLIAMSON, 239.

Linear Projection and Rotifers. By
H. Dayis, 48.

List1nG, on a New Method of Producing
Stereoscopic Effects, 40.

Lowne, Mr., on Pangenesis, 101.

M.

Manppox, Dr., Remarks on some Para-
sites found on the Head of a Bat,
144,

Man, the Anatomy of the Graafian
Follicles in, 236.

Mapping with the Micro-spectroscope,
with the Bright-line Micrometer.
By H. G. Brings, 224.

Matters, Mixed Colouring, on the Ex-
amination of, with the Spectrum
Microscope. By H.C. Sorsy, F.R.S.,
124.

McIntire, §. J., F.R.M.S., an Incident
in the Life of a Chelifer, 209.

McQuitten, J. H., M.D., on Microsco-
pical Fissures in the Masticating
Surface of Molars and Bicuspids,
182.

299

Melicertian, a Rare; with Remarks on
the Homologieal Position of this Form.
By Cuarzes Cusirt, F.R.MLS., 165.

Menopon ptilorhynchi, 8.

Metals, Crystallization of, by Electricity
under the Microscope. By Purp
Branam, 277.

Microscope, Dr. DupGEon’s, 240.

, the, in the Detection of Adultera-
tion of Food. By Mr. Waurer
Morris, 289.

——,a Mineralogical.
Hatt, 293.

Microscopy Extraordinary, 43.

Micro-ruling on Glass and Steel. By
Joun F.. Sranistreer. With Illus-
trative Remarks. By H. J. Stack,
Sec. R.M.S., 151.

, an Instrument for. By
J. F. STANISTREET, 274,

Micro-spectroscope, Mapping with the.
By H. G. Brines, 224.

Mitraria and Actinotrocha, 161.

Molars and Bicuspids, Microscopical
Fissures in the Masticating Surface
of. By J. H. McQumen, M.D., 182.

Monad, its Place in Nature. By
Mercatre Jounson, M.R.C.S.E., 217.

Monas termo, 264.

Moss Boyp, M.D., on Hzematozoa in
Blood of Ceylon Deer, 181.

Movcuet, M., on How to Select Spec-
tacles for Near-sight and Far-sight,
108.

Mycetoma: the Madura or Fungus-foot
of India. By Jasrz Hoaa, 61.

By MarsHau

——

N.

Nerves and Chromoblasts, on the Con-
nection of. By M. G. Poucuer, 285.

Nirmus Nitzschii, 8.

Nobert’s Plate, on the Use of the. By
Dr. J. J. Woopwarp, U. 8. Army, 26.

Nineteenth Band, the Examina-
tion of. By F. A. P. Barnarp, 194.

aa By Mr. Cuarzes Stopper,

Norris, Dr. R., on the Passage of Cor-
busles through the Blood-vessels,

8.

1e

PackarD, A.S§., jun., on the Embryos of
Calopteryx, Agrion, and Diplax, 39.

Pangenesis, Mr. Lown on, 101.

Papers, Recent Foreign, 200.

Parasites, on some New. By T. Gra-
HAM PontTon, F.Z.S., 8.

found on the Head of a Bat,

Remarks on, By R,. L. Mappox,

M.D., 144.

300

Parker, W. K., F.R.S., on the Form
and Use of the Facial Arches, 211.
Pathology of Contagion, Dr. Sander-
son’s Paper on the. By Jasrez Hoae,

242.

Pedalion mira.
LL.D., 121.

, Note on. By C. T. Hupson,
LL.D., 215.

Pures, Mr. J. A.,a Chemical Analysis
of a Phonolite from the Wolf Rock,
89.

Phonolite from the Wolf Rock, on the
Microscopical Structure and Compo-
sition of a. By 8. ALLporT; with a
Chemical Analysis, by Mr. J. A.
PHILLIPS, 87.

Pinnulariz, the Silicious Deposit in.
By H. J. Suacs, 71.

Plant-organs, on the Development of,

By C. T. Hupson,

161.

Plants, the Darwinian Theory applied
to, 101.

Podura Scales, the Structure of. By
F. H. WenuaM, 6.

Ponton, T. GraHam, F.Z.S., on some
New Parasites, 8.

Poucuet, M. Grorces, on the Con-
nection of Nerves and Chromoblasts,
285.

Prism, the French Erecting, a Camera
Lucida. By J. G. Tarem, 47.

PROCEEDINGS OF SOCIETIES :—
Brighton and Sussex Natural His-

tory Society, 56, 111, 204, 251.

Bristol Microscopical Society, 112.

Croydon Microscopical Club, 52.

Hull Scientific Association, 260.

Illinois State Microscopical Society,
59.

Liverpool Microscopical Society, 114.

Philadelphia Academy of Natural
Science, 163.

Reading Microscopical Society, 112.

Royal Microscopical Society, 50, 204,
248, 293.

South London Microscopical and
Natural History Club, 115, [206,
256.

Tunbridge Wells Microscopical So-
ciety, 60.

Protozoa, Transmutation of Form in.
By Mercaure Jonnson, M.R.C.S.E.,
184.

Purser, Dr. J. M., Researches on In-
flammation and Suppuration, 200.

R.

Radiolaria, Development of the, 161.
Rauru, Tuomas S., M.R.C.S., Observa-
tions and Experiments with the Mi-

INDEX.

croscope on the Chemical Effects of
Chloral Hydrate, Chloroform, Prus-
sic Acid, and other Agents on the
Blood, 75.

Retina, the Anatomy of the, 160.

Ricuarpson, J. G., M.D., on the Cel-
lular Structure of the Red Blood
Corpuscle, 17.

——., Dr., on the Red Blood Globule,
40 :

Ricuter, H. C., on some New Parasites,
107.

Rodent Cancer of the Upper Eyelid.
By Mr. HvLKE, 289.

Rotifer, a New. By C. T. Hunson,
LL.D., 121.

s.

’ Salpingseca gracilis and amphoridium,
263,

Scales of Butterflies and Gnats, 102.

of Gnats. By Jasez Hoae, 192.

Scorpions, the Embryology of, 160.

Stack, H. J., on some Diatomaceous
Earth from the Lake of Valencia,
Caracas, 69.

— on the Silicious Deposit in Pin-
nularie, 71.

——, Illustrative Remarks on Mr.
Stanistreet’s Micro-ruling on Glass
and Steel, 151.

Sorspy, H. C., on some Improvements
in the Spectrum Method of Detect-
ing Blood, 9.

on the Examination of Mixed
Colouring Matters with the Spectrum
Microscope, 124.

Spectacles, How to Select for Near-
sight and Far-sight. By M. Mov-
CHET, 108.

Spectroscope in Microscopy, 160.

Spongiade, the Discovery of the Animal
of the, confirmed, 235.

Spontaneous Generation, the Fungoid
Origin of Disease and. By Jasrz
Hoae, Sec. R.M.S., 156.

, Experiments on. By Crace-
Catvert, F.R.S., 199.

—— ——,, Difficulty of Experiments on.
By Cracre-Catvert, F.R.S., 234.

STANISTREET, JOHN F., Micro-ruling on
Glass and Steel, 151.

——, an Instrument for Micro-ruling
on Glass and Steel, 274.

Stephanurus dentatus, or Sclerostoma
pinguicola, the Structure of. By Dr.
FLEtTcuHER, 103.

Stereoscopic Effect, a New Method of
Producing. By Lisrine, 40.

Stigmaria, the Structure of. By Prof.
Wiiu1aMeon, F.RB.S., 237.

INDEX.

Stopper, Mr. CHarzes, on Nobert’s
Nineteenth Band, 201.

Sub-stage, a New, for a 4-inch Objective,
106.

Surirella gemma, Observations on. By
Col. Woopwarp, 100.
————. By Jasez Hoae, 162.

AN

Tarem, J. G., Esq., on the Conjugation
of Amooba, "O75.

To.Es, R. B. , Experiments on Angular
Aperture, 36.

, on the Angular Aperture of
Immersion Objectives, 214.

Tolles’ Stereoscopic Binocular Eye-
piece. By H. L. Smirn, 45.
—, Mr., “ Experiments on Angular
Aperture.” By F. H. Wrenuaw, 84.
—— ae What is the Aperture of it ?
By B., 241.

Immersion 1th, Note on the Angle
of. By Dr: J. cor ‘Woopwarp, 290.

Trichodectes leporis, 8.

Tyson, Dr., When is a Blood Corpuscle
in focus? 42.

W.

Wenuay, F. H., on the Structure of
Podura Scales, 6

301

Wenuay, F. H., on Mr. Tolles’ Experi-
ments on Angular Aperture, 84.

—,, Mr., and Mr. Tolles, 201, 292.

, F. H., Note on Dr. J. J. Wood-
ward’s “ Note accompanying Three
Photographs of Degeeria domestica,”’
267.

— on Grinding Diamond Points,
291.

Witiramson, Prof., F.R.S., on the
Structure of the Stigmaria, 237.

on the Structure of Lepidoden-
dron selaginoides, 239.

Woopwarp, Dr. J. J., on the Use of
the Nobert’s Plate, 26.

, Note on Amphipleura pellucida,

43,

——, Colonel, Observations on Surirella
gemma, 100.

—., Dr. J. J., on the Resolution of
Amphipleura pellucida by a Tolles’
ith, 150.

on an Improved Method of Photo-

graphing Histological Preparations

by Sunlight, 169.

, Note accompanying Three Photo-
graphs of Degeeria domestica, as seen
with Mr. Wenham’s Black-ground
Illumination and a Power of 1000
diameters, 266.

—, Note on the Angle of Aperture
of Tolles’ Immersion 1th, 290.

END OF YOLUME VI.

LONDON: PRINTED BY WILLIAM CLOWES AND SONS, STAMFORD STREET AND CHARING CROSS.

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