^m.

«?«'>-!-

\^

THE

K^ X

Ml OF MICROSCOPY

AND

NATURAL SCIE

R'

THE JOURNAL OF

THE POSTAL MICROSCOPICAL SOCIETY,

EDITED BY

ALFRED ALLEN,

Honorary Secretary of the Postal Microscopical Society ;

ASSISTED BY

SEVERAL MEMBERS OF THE COMMITTEE.

VOL. I. (NEW SERIES).
VOL. VII. (OLD SERIES).

XonDon :

BAILLIERE, TINDALL, & COX, 20 KING WILLIAM ST.,

STRAND, W.C.

Bat!) :

I CAMBRIDGE PLACE.

1888.

C. SEERS, PRINTER, 2 ARGYLE STREET, BATH.

fO)

N completing our first volume of the New
Series of The Journal of Microscopy and
Natural Science, we feel justified in saying
that considerable advance has been made in
interest and usefulness, both as regards the subject-matter
of the papers published and of the explanatory plates
accompanying them.

Many of our readers have already given us their good
opinions, and doubtless many others who have not actually
so expressed themselves will credit us with having redeemed
the promises we made twelve months ago. Our desire is to
keep on improving the Journal by admitting into its pages
only such papers as shall be of substantial worth to workers
in science, and such items of scientific interest as shall be
worth registering for future reference.

To those writers who have favoured us with such papers
our especial thanks are due, and we best acknowledge our

IV. PREFACE.

obligations to them by assuring them of our earnest desire
to further improve the Journal and render it more worthy of
their contributions.

Our readers who have enabled us to carry out these
improvements by their subscriptions and recommendations
are also thanked for their kindness, which has enabled us to
realise our plans and justified our resolution to still further
advance the usefulness of the Journal. These improvements
must involve considerable outlay ; but in full reliance upon
the promises of increased support, we unhesitatingly under-
take the additional labour and expense.

Experience in the past will enable our readers to appre-
ciate the value of our promises for the future.

5^ /i^p« /^^<-jr\

THE

JOURNAL OF MICROSCOPY & NATURAL SCIENCE:

the journal of
The Postal Microscopical Society.

" Knowledge is not given us to keep, but to impart : its tvorth

is lost in concealment."

Iprcsibential Hbbrces.

By the Hon. J. G. P. Vereker, September 8th, 1887.

auies and gentlemen,—

Allow me to thank you very
much for the honour you have
done me in electing me as Presi-
dent of the Postal Microscopical
Society for this year. I feel great
diffidence in accepting this post,
and must ask your kind indulgence
for any shortcomings I may be
guilty of.

I have for many years had the
privilege of belonging to the
Society, and have derived much
pleasure and profit from it. I
think we may now consider its
position as firmly fixed, and that
if we go on as we have begun we
shall always hold a good place
among the scientific societies of
England.

Our Journal has done a good
deal for us in this direction, and whenever I look into it I feel

New Series. Vol. I, B

188S.

2 PRESIDENTIAL ADDRESS.

proud to be a member of a Society which issues a periodical so
good in both text and illustrations.

I am certain that you all agree with me how grateful we ought
to be to our Secretary for the trouble and care he takes in its
issue and in the welfare of the Society, and feel that it is our
bounden duty to assist him in this task to the utmost of our
ability. Perhaps one of the best ways of doing this would be to
try and get more new members, which ought to be done pretty
easily, as our subscription is very small, and we occupy a position
with reference to microscopy which ought to be most serviceable
and agreeable to many of us quiet students of nature. Our
method of communication being by post, we are enabled to reach
all parts of the kingdom with great facility, and thus being
brought into direct communication with each other are able to
mutually assist members both in theory and practice.

It seems superfluous to remind microscopists of the great
charms of the study of the " infinitely little," but as there may be
some present who have not engaged in that study, perhaps those
familiar with microscope work will allow me briefly to summarise
Avhat are some of its great attractions. Microscopical work is one
of those studies which can be pursued everywhere, for there is
no place where objects for study may not be found, added to
which it is cjuite independent of the weather or of the time of
day, as artificial light can always be used, and in fact many
microscopists seldom use any other.

Then it is a silent work, and disturbs no one, and requires but
a small space for the apparatus. It also tends to develop habits
of care and neatness, as the smallest speck of dirt shows most
prominently under the lens, and without neatness it is impossible
to keep the instrument in order, much more so to make any
accurate observations. Again, the patient investigation required,
the measuring and drawing of those objects under examination,
create very careful habits of observation, which react on the
observer and make him more careful in other matters.

Finally, the field of microscopical research is so large that all
tastes may be satisfied. The exactness of forms of crystals,
diatoms, etc., the different methods of strengthening cell-walls,
and many other points, are of great interest to the mathematical

PRESIDENTIAL ADDRESS. 3

mind ; the various modes of assimilation of food and reactions of
substances used in microscopy interest the chemist ; the marvel-
lous adaptations of means to an end, and countless varieties of
forms are of great interest to the scientist ; the wonderful play of
colour under the polariscope, the scales of butterflies, the great
beauty of the forms of lower life, the varieties of small insects,
and, if I may be permitted the word, their various expressions (I
have never forgotten the expression of cruel ferocity of the head
of a spider — a diamond spider, I think — sent round mounted dry
and uncrushed in one of the boxes some years back), and many
other points too numerous to mention, are a source of endless
enjoyment to the artist ; as for him of a speculative turn of mind,
the curious metamorphoses and various developments of life, the
strange world of microscopical life, the curious effects their micro-
scopical eyes must give, with a thousand other points, enables him
to imagine worlds more strange than any fairy tale, and to weave
romances wilder, yet possible, than any of Jules Verne's works.

Yet all this while time is not being wasted, for knowledge is
being increased and the mind is being strengthened. With advan-
tages like these I have so cursorily glanced at, is it to be won-
dered at that microscopists very soon become enthusiasts in their
work, for they find that the microscope has practically given them
a new sense with all the delights attached thereto, and none of
the disadvantages ?

All this pleasure can now be obtained at a much lower price
than was possible some years back. English opticians have also
awakened to the fact that there are many inherent advantages in
the short foreign tube of five or six inches, especially when the
instrument has to be used upright, as it must be when there are
liquids on the stage. Everyone is not a diatomist, and for many
purposes low-angled lenses are as good as wide-angled ones,
besides being more convenient in use, and of course cheaper.
All this is an undoubted advantage to those who want a micro-
scope for use and not for show.

If, however, the intending purchaser would take the advice of
a competent friend and be more careful about getting good eye-
pieces, and also remember that a good low power is better than a
bad high power — in fact, that good lenses are pleasanter in use,

4 PRESIDENTIAL ADDRESS.

really show more detail, and are not so trying to the eyes as bad
ones often are — we might find more enthusiasts, and fewer of
those who buy a microscope, and then get tired of its use. The
members of the Postal Microscopical Society might do a great
deal of good by popularising the use of the microscope, sweeping
away the mystery which surrounds it, and save people from
wasting their money in the purchase of inferior instruments.

AVe should probably thus increase the number of students and
acquire new members, by infusing fresh blood into the Society,
give it new life and a large addition of brain power. An import-
ant advance in practical optics has just been made which will
probably have a great effect on microscopes — namely, the manu-
facture of a specially dense glass by Messrs. Schott and Co. This
glass has already been utilised by the well-known opticians,
Messrs. Zeiss and Co., in the manufacture of a special series of
lenses known as the " apochromatic objectives," and experiments
are now being carried on in England with the same glass. The
great advantage claimed by its use is the abolition of the second-
ary spectrum which exists in lenses at present, and gives rise to
the colour corrections of different opticians, the best of which is
the well-known ruby correction, which I believe was introduced
by Messrs. Powell and Lealand. A tertiary spectrum remains,
but its colouring power is weak, so the images of objects are prac-
tically free from colour, and a nearer approach is made to achro-
matism. The images thus produced are clearer and sharper, and
show their natural colouration better. The objectives themselves
thus approach much nearer to their theoretical performances, and
in consequence will bear much stronger eye-pieces.

This is, of course, a great improvement. We all know by
experience the great nuisance of perpetually changing the objec-
tive in an investigation, an inconvenience which is not satisfacto-
rily obviated by any form of nose-piece that I have ever seen. For
instance, suppose a botanical section is being examined wanting
powers of about 40, 1 00, and 200. Formerly a one-inch, a half-
inch, and a quarter-inch were required for this. Now, with this
new advance, one power of an inch and three eye-pieces will answer
the purpose. I do not mean to say that high powers will no
longer be required, but that now we will be able to suit the

PRESIDENTIAL ADDRESS, O

aperture to the object better than formerly, and I am inclined to
think that the one-tenth inch will be the highest required.

It is too early, however, to give any decided opinion on this
subject, as often these matters do not come up to the general
expectation. Besides this, the only lenses at present in the market
are those of Messrs. Zeiss and Co. — at least, so I believe — and
they are dear and not easily obtainable. I got a dry i — 6th inch
from them just before leaving England, and during the short time
I was able to use it, it seemed to be very satisfactory.

One result of this invention is that probably a very fair number
of good second-hand lenses will come into the market and be sold
cheaply. Those, however, who are thinking of buying a high-
power lens, but are not in immediate need of it, would act wisely
in waiting a short time to see if lenses made of this glass can be
more easily procured. Messrs. Zeiss and Co. have produced a
series of lenses under Professor Abbe's calculations of this new
glass and a series of eye-pieces to go with them. Both objectives
and eye-pieces are corrected respectively for the foreign six-inch
tube and for the ten-inch English tube. The objectives are all of
wide angle, and are rather expensive, especially if compared with
Zeiss's other list of lenses, though not so if compared with
English and American first-class prices. The oculars known as
" compensating eye-pieces " are all numbered on a new system,
recommended by Professor Abbe, which give their magnifying
effect on the simple magnification of the lens. For example, an
inch lens magnifies alone ten times ; if the eye-piece marked 8 is
used with this, the total magnification will be 80 diameters.

I have been in the habit of using this plan myself, as it is so
simple and convenient, and can strongly recommend it to others.
It would be a great advantage if all opticians adopted it, and also
if they made their eye-pieces so as to give whole instead of frac-
tional multipliers. Mr. Zeiss's new eye-pieces are numbered 1, 2,
4, 8, 12, 18, and I think there is one of 27. They are so made
that the length of tube is not altered in changing them, which is a
great improvement, as objectives are corrected for a certain length
of tube. They also can be used for ordinary medium-angled
lenses, but are not recommended for extreme angles. Now that
so much attention has been drawn to eye-pieces, it is to be hoped

6 PRESIDENTIAL ADDRESS.

that the bad ones will be driveii out of the market, as a good
eye-piece is necessary to do justice to an objective. Another
advantage of the abolition of the secondary spectrum is that the
lenses so constructed can be used for photography without the
guess-work of altering the adjustment so as to bring the chemical
rays into focus. Mr. Zeiss has brought out a projection eye-piece
to be used in this work, but I have not tried it yet, so cannot give
any opinion about it. This art of photo-micrography is one which
has lately made rapid advances, but is still in its infant stage. To
those of our members who want employment for long winter
evenings I can highly recommend this branch of microscope work,
especially as certain improvements in photography have made it
more satisfactory. Everyone knows the advantage of a photo-
graph, as it keeps a permanent record of one's work, which is free
from the suspicion of being largely dependent on the imagination
(a suspicion to which drawings are always liable). Most observers
draw what they Avish to see rather than what is actually seen.
Besides having once got the negative, it is an easy matter to get
any number of copies from it.

To glance at the technical part of photo-micrography, good
rapid dry-plates are generally considered the best to use, and from
these copies and enlargements can always be made. Jiowever, I
am inclined to think that paper will be the coming thing for
microscopists, and the following method might be made practic-
able, as the camera would not get rough usage : — Attach a simple
and light roller-slide of small proportions to a very light conical
camera, carrying at the end opposite the roller-slide either a pro-
jection eye-piece or else a simple tube, so marked that the image
would be always properly focussed on the sensitive surface, and
if this camera was so arranged as to take the place of the eye-
piece when required, the niicroscopist could keep it near him
while at work, and in a few minutes could shift it for the eye-piece,
and take a photograph of any interesting object, developing the
image at his leisure. He would thus soon acquire an interesting
and valuable set of photographs. Now, if paper was used, there
would be often no need for printing at all, as the negative could
be placed in his album. The printing is often a most important
point, and if the negative is large enough to be satisfactory and

PRESIDENTIAL ADDRESS. 7

the microscopist has time to print by daylight, the ordinary
printing processes, albuminised silver paper, platinotype, and
carbon printing are available for him ; if he wants to print at
night, Eastman's bromide paper and many other rapid printing
papers are now procurable, giving excellent results.

If the negative is not large enough, he can enlarge either with
a camera or with one of the lanterns made for the purpose, or else
a home-made one, or by means of one of the magic-lanterns now
sold. Thus he can get a direct positive on one of the rapid
printing papers. For educational purposes an ordinary magic-
lantern is . excellent, and magic-lantern slides can easily be made
from photo-micrographs, which are sure to give satisfaction if well
managed. Another use of the optical lantern is to attach a
lantern microscope to it, and in that way ordinary slides may be
magnified and thrown on a screen. The ordinary objectives are
used with this instrument, and as long as high powers are not
used it is fairly satisfactory, though of course inferior to the
microscope itself.

I must not, after all, exclude the ordinary mode of draw-
ing by hand and the camera lucida, or else with a net micro-
meter, which is often more convenient. By this means those
who have artistic tastes are able to produce very pretty pictures,
which are certainly not less interesting because they show
animals and forms of life which are unknown to people in general.
This drawing by hand must always hold its place, as there are very
many objects which it is almost impossible to photograph satisfac-
torily, besides which the camera takes everything in, as it has
naturally no power of selection, and it often happens that only a
small part of an object is required, and also that that part is
partly concealed by other parts, which makes it unfit for photo-
graphy, added to which it is no easy matter to make artistic pho-
tographs. The chief results of the last year seem to me to be the
development of photography both in itself and in its reference to
microscope work, and also in the interest taken in it by photogra-
phers who any way know what a photograph ought to be like, and
who are thus able to give us most valuable help. Also, in this
important discovery of extra dense glass by Messrs. Schott and
Co., after long and laborious experiments, this glass must give us

8 PRESIDENTIAL ADDBESS.

a new weapon wherewith we can force Nature to surrender more
of her secrets to us, as it must be of great advantage in the manu-
facture of lenses, since it is ahvays easier to make a low power
than a high one. No doubt, lenses will be cut on more perfect
curves now that the index of refraction is increased.

In the practical use of a lens, a low power is always more
readily used and corrected, besides being considered more satis-
factory. Then it has the great advantage of not being so easily
damaged. It is for us to make the best use we can of these new
powers placed in our hands, and thus to help forward the science
of microscopy. We ought not to despise the old methods and pro-
cesses, but we ought to improve on them by grafting the new on
the old, and bind them into a homogeneous mass by the use of
our brains.

Microscopical study has the advantage of suiting every calibre
of mind and taste, and to all it offers fresh knowledge and nume-
rous untrodden paths, which are open to any student who feels a
desire to enter into original research on his own account, and thus
we can all make our lives useful and assist to build up the scienti-
fic knowledge of the world, and act up to the motto printed on
the cover of our Journal, that " knowledge is not given us to keep,
but to impart. Its worth is lost in concealment."

Formation of Pearls. — In oysters aged four years — which
are judged by the shells, weight, and appearance — the best pearls
are found. The shell, like the pearl, is formed by the secretion
of the animal, and is composed of animal matter and lime. The
iridescent hues on the inside of the shell are occasioned by the
edges of the thin, wavy, concentric layers overlapping one
another and reflecting the light. The minute furrows, containing
translucent carbonate of lime, produce a series of more or less
brilliant colours, according to the angle at which the light falls
upon them. Occasionally, some of the finest pearls are found
loose in the shell. As many as one hundred pearls have been
found in one oyster, but are of litde or no value. The pearls of
the young oyster are yellow, and in the older oyster are of a
pinkish hue. — 7?u//. U.S. Fish Comni.

[ 9 ]

apocbroiuatic ©Djcctivcs.

By J. W. GiFFORD.

MUCH has of late been written about the new glass, and
while some have exaggerated its advantages, others
maintain that inasmuch as the secondary spectrum is
removed, some of the best rays have been taken away, and that
the image is therefore weaker than with ordinary achromatics.

Messrs. Powell and Lealand, having recently constructed a
i/ioth apochromatic of numerical aperture 1*5 for the writer, who
has also, through the kindness of Mr. Curties, of Messrs. Baker,
Holborn, been able to compare it with several apochromatics by
Zeiss, it occurred to him that a short description of the glasses
and an account of the conclusions drawn might be of interest.

The tests used were the Podura scale and the l^uberde Ba-
cillus^ the beaded appearance of the latter when spore-bearing
making an excellent test object.

The Apochromatics tried were : —

(i) i/io in. oil immersion, N.A. i'5.

(2) 2'5 mm. water immersion, N.A. \'2^.

(3) 6'o mm. dry immersion, N.A. 0-95.

No. I by Powell and Lealand, Nos. 2 and 3 by Zeiss.
These were compared w'ith the following ordinary Achro-
matics : —

(i) 1/25 in., N.A. 1-38 \

(2) 1/20 in., N.A. I "5 >oil immersions.

(3) 1/12 in., N.A. 1-43 )

(4) 1/8 in., N.A. 1-26, water immersion.

(5) 1/4 in., N.A. of 100° dry.

Nos. I, 2, 3, and 4 by Powell and Lealand; No. 5 by Swift
and Son.

The new compensating eye-pieces were used throughout,
those by Zeiss magnifying 4, 8, 12, and 18 diameters, those by
Powell and Lealand, 10 and 20.

The stands used were Swift's Challenge, with dry achromatic
condenser, of aperture 180^, and Nelson-Curties's new Student's
stand, as made by Messrs. Baker.

]0 APOCHROMATIC OBJECTIVES.

The results given by Powell and Lealand's i/io in. apo-
chromatic eye-piece, x 20, and their 1/20 in. achromatic
X 10 were almost indistinguishable. There was a little less
colour with the i/io in., but the 1/20 in. gave, if anything,
sharper definition.

Powell and Lealand's 1/25 achromatic of N.A. i'38 and eye-
pieced X 8 gave as little colour as the i/io in. apochromatic
X 20, but the definition was not quite so crisp, doubtless on
account of its smaller aperture. The same might be said of the
1/12 in. of N.A. i'43 x 18.

Zeiss's water immersion apochromatic of N.A. i"25 and 2-5
millimetres focal length, and Powell and Lealand's new formula
1/8 in. water immersion achromatic were then tested with these
eye-pieces in the same way. The corrections for spherical aber-
rations with both these glasses were equally good, but the apo-
chromatic by Zeiss gave an image almost entirely free from colour
even with the highest-power eye-pieces.

Zeiss's dry apochromatic of "95 aperture and 6 mm. focal
length gave an absolutely water-white image even when used
X 20, and was otherwise superior to 1/4 in. of loo'' by
Swift and Son, with which it was compared, but it did not give
so flat a field of view. The 1/4 in. of loo*^ by Swift is the
best 1/4 in. of the ordinary achromatic type the writer has
seen ; the Zeiss dry apochromatic had, however, the advantage in
point of aperture.

The results obtained with Powell and Lealand's i/io in.
apochromatic and their 1/20 achromatic, and also with Zeiss's,
and Powell and Lealand's water immersions seemed rather to
lean towards the view that by eliminating the secondary spectrum
some of the resolving power is lost. On the other hand, the
apochromatics are more pleasant to work with and better adapted
for photo-micrography, though a projection eye-piece does much
in this respect for the ordinary glasses.

On the whole, the advantage to be derived from apochromatic
lenses seems smaller than has been anticipated. As has already
been noticed by Dr. Dallinger, the compensating eye-pieces are
perhaps the more important factor in the advance made.

Ordinary achromatics have been brought to such a state of

APOCHEOMATIC OBJECTIVES. 11

perfection as to leave little to be gained until some method of
further increasing the aperture has been worked out.

It has occurred to the writer that media having a higher
refracting index than cedar-oil, might be used with advantage
with immersion objectives constructed for the purpose.

It is a fact well known to opticians that the extreme marginal
rays with glasses of wide aperture give no image ; experience
proves, however, that there is a decided gain in increasing the
aperture even up to N.A. 1*5.

Is not this due to the fact that the last "i or more of aperture
is never utilised, and although we may get no more light through
the lens than would give an aperture of i"52, by using an immer-
sion medium of i'6 or more, might we not so compress the cone
of rays passing through as to make the marginal rays up to the
extreme limit of i"52 enter the front at a sufficiently favourable
point to be effective ?

The Tarantula at Home. — Herr von Bergso, in a recent work
has given some interesting data respecting the habits of the Taran-
tula, Lycosa tiireiitiiia, whose nests he has traced and examined
on the Roman Campagna. He found that the nest, which was
well rounded and smooth, was approached by a tunnel which,
after running about a foot straight down below the surface of the
ground, made a sudden short turn before it finally descended for
about another foot into the spider's abode. The entrance to the
tunnel is concealed by an arched covering made by the interlacing
of grasses and leaves. The eggs are enclosed in a spun bag, and
the young appear in the autumn, when they immediately seat
themselves on the body of the mother where they remain till
about April, neither parent nor offspring seeking food during their
hybernation. As many as 291 individuals were on one occasion
removed in February from the body of an emaciated tarantula.
The superstitious error of assuming that the bite of the animal
induces an irresistible desire of dancing is due to the fact that
dancing having been originally employed as a remedy against the
poison, which is believed to be eliminated by profuse perspiration,
the action of the poison was confounded with the means of its
eradication.

[ 12 ]

Ebe 1bc66ian f{^

By " Entomologist." *

THE British farmer has been talking of the Hessian fly ever
since the period of the American Revolution in the days
of good King George, and it is hard upon him that the
insect should actually appear on these shores now, at a time when
the agricultural interest is so depressed, though it is Queen Vic-
toria's Jubilee year. But it was observed to occur in more than
one locality last year, though some entomologists had a doubt
whether another species had not been mistaken for this notable
fly ; for in the same group of insects are several, also foes of the
cereal crops, and in appearance, or even in habits, not unlike the
much-dreaded pest. We may accept it, however, as an incon-
trovertible fact, that up to the year 1886 none but straggling
specimens occurred in England (if any), though the insect has
been known as one of the most destructive amongst the " blights
of the wheat " for just a century. It should be stated, perhaps,
that the appellation of the " Hessian fly " arose from a notion that
tlie German mercenaries brought the plague into the United
States, but this was proved to have been impossible. Erom 1 786 on-
ward, however, the Hessian fly has caused enormous destruction of
corn in the American Continent, and extended itself over a great
part of those regions where grain is an important crop. It has
been conjectured that the primitive habitat of the fly is on the
borders of Europe and Asia — i.e., about the shores of the Medi-
terranean, but this appears to me very unlikely, seeing that it was
first found to be doing mischief in America, and I would rather
assign it to that country. In Europe there is no record of its
occurrence until 1834, in Minorca, or possibly 1883, in Hungary;
it is reported from France, Austria, and other countries now, the
south of Russia being the last where if has caused alarm, but in
the Old World as yet the injury done is trifling compared with the
New, and all the researches of the American scientists and the
persevering efforts of growers have failed to put an eftectual check
on its yearly propagation and ravages.

* From TAe Journal of Hoiiuullurc,

THE HESSIAN FLY.

IS

Having thus touched briefly upon its general history, I pro-
ceed to describe the structure and habits of this fly, called in
science, very aptly, Cecidomyia destructor, and we have the advan-
tage of Mr. Meade's examination of British- bred specimens, as
recorded in the ''Entomologist." The perfect insect has the
head and eyes black and hairy, the antennse are rather long and

brownish, the proboscis small and pink, the
thorax black, with two red streaks running
from the neck to the base of the wings, the

IV-r^^'^j^'^'^^F-^ abdomen reddish brown, with regular black
J / H 1 \ spots, which coalesce m some specimens,
the legs pink, sprinkled with blackish hairs,
the wings, transparent as usual, are also
hairy. In the male flies the wings are
.longer and appear of a reddish tinge, and
the legs are paler, but the females, on the
whole, are the larger, and they seem to be
more abundant than the males. The number
of eggs laid by each female has been vari-
ously stated between ten and fifty ; probably
the smaller estimate is nearer to the average, if the size of the egg is
correctly reported. Like the larva of all flies, the maggot of the
Hessian fly is legless, but it has just below the head a curious
process or appendage, which the American observers call the
" breastbone." It is found in several species of Cecidomyia ; the
use is not known positively, but no doubt this in some way aids
the larva in acquiring its food, the mouth-organs being somewhat
feeble. This maggot is oval and glossy, with the head not very
discernible ; its skin dotted over by a number of tiny tubercles, in
colour white or greyish. To the chrysalis or pupa the name of
flax-seed is familiarly applied, from its likeness to that object.
This, however, is really the cast-off integument of the maggot,
forming a puparium, in which the true pupa lies to await its
transformation to a fly. This puparium is brown, spindle-shaped,
flattened, and each end is bluntly pointed. This pupa stage is of
special importance, for the puparia are hidden in the stalks of the
cereal, solitary often, sometimes two or three together, and it is by
this agency the species travel from one district or country to
another, as the flies themselves do not take long journeys.

14

THE HESSIAN FLY,

In most places where the Hessian fly has been under notice
two broods occur yearly, and the economy of the species is as
follows, it being premised that the second brood is that of which

we know more from the obvious results of its attacks : The

autumn flies emerge in August or September from the pupge, which
are almost invariably found above the second joint of the straw
from below, and seek out the young wheat or barley (it is one of

Fig. 2.

these the fly chiefly attacks) ; placing eggs on the sheath or young
leaves, the larvae work their way gradually into the plants, which
die off about the time the insects turn to pupre, in which state the
winter is passed. Emerging about April, the next brood of flies
finds the crop in an advanced stage of growth, and the larvae pro-
duced in May feed in, or between the sheath and the stem.
Here they lie in small parties of six or eight (Fig i), and the stem,
when they are increasing in size, bends at an angle and not
unfrequently breaks at the point where the attack has been made,
the ear, if formed, containing but a few dwarfed grains. By the
time the corn is cut, or soon after, the insect has completed its
larval existence and is ready to journey elsewhere in its form of
" flax-seed " during the autumn, for it does not seem probable that
the pupae or " flax-seed " which are produced from the spring
wheat scatter to any distance.

THE HESSIAN FLY. 13

As full particulars concerning last year's visitation of the
Hessian fly have appeared in many journals, it is only needful to
say that the first specimens noted in 1886 were forwarded to Miss
Omerod from barley-fields near Hertford. Subsequent reports of
its occurrence came from three other places in Hertfordshire,
from Romford, Essex, and Luton, Bedfordshire. Later in the
season the fly was found north of the Tweed near Inverness, and
near Crieff, localities where its appearance is certainly singular.
Though no complaints that I am aware of were made with
reference to the spring brood on the early corn, it must have bred
to some extent, for early in the summer of this year wheat and
barley were found to be infected in several of the places which
had produced the insect last year, and by degrees intelligence has
been received of a number of fresh attacks, the districts being often
wide apart, and as before both in England and Scotland. Mostly
they are not spread over a wide area, I believe, except in South
Lincolnshire, which has suffered considerably. It is not suppos-
able that all these localities have been infected by the progeny of
the flies noticed last year ; we must conclude there have been new
importations of the enemy. " Where has the attack come from?"
asks Miss Omerod, and Echo answers, "Where ? " It is mysterious,
but there can be no dispute that in the " flax-seed '' or pupa state
the insect must have come to us from the Continent or from
America. Probability points to the former. That we should
have escaped hitherto may be deemed an encouraging circumstance
for the future, as we may hope the climate of Britain is not
particularly favourable for this fly, or it would have got a lodgment
before, since the pupse must have been brought over by accident.
It is considered as proved they do not come in grain ; they must
therefore travel in the straw, either when that article is imported
as cargo, or when it is used for packing. An examination of what
is called " corn rubbish " has yielded " flax-seeds," so that this
medium may convey the insect from one locality to another in
Britain. As yet, however, I cannot say it is clearly made out how
pupae contained in foreign straw can be distributed over our corn-
fields. One way that has been suggested is this — To London, and
to some other towns, quantities of goods are sent from various
countries of Europe packed in straw ; the surplus of this is sold off

16 THE HESSIAN FLY.

by wholesale houses, and next reaches stables, where it is finally
converted into manure, and then is made use of by farmers or
market-gardeners. If so, we ought to have the Hessian fly about
Kent, especially near the Thames and the Medway, for we receive
much London manure. We are also in frequent communication
with the Continent, but I have no report of it at present. Possibly
the Kentish soil does not produce a growth of wheat and barley
agreeable to the insect, owing to its being generally chalky, and it
may thrive best where the plants are on clayey or loamy soil.
And it has been surmised that the Hessian fly is a lover of
moisture; if such be the case, then we may presume that had 1887
been a wet instead of a dry summer, we should have found a
greater abundance of the insect.

To the above interesting account of this destructive enemy to
important crops we append illustrations, representing its various
forms, with explanatory notes, for which we are indebted to
Messrs. E. Webb and Sons, Wordsley, Stourbridge, in whose farm-
seed catalogue the figures appear with a history of the enemy, and
suggested methods for preventing its attacks : — •

" In the illustration (Fig. 2) we have shown natural size of A, b,
c, and D, the eggs, maggots, chrysalids, and perfect insect belong-
ing to the Hessian fly. Underneath at e, f, g, and h, the same
stages of growth are shown enlarged five diameters. The eggs are
shown at a, at the base of a wheat leaf; at b the maggots, often
six or eight in number, have emerged from the eggs, and are
shown as grown to fully mature examples ; at c the maggots have
fixed themselves close to the stem, and after a lapse of five or six
weeks have taken on the brown chrysalis or ' flax-seed ' condition ;
at D the perfect Hessian fly is shown as it emerges from the
chrysalis — i.e., when the latter is about ten days old. The mis-
chief is caused by the maggots, which fix themselves on the young
corn, or when the corn is older, near the three lowest joints of the
stem or close to the root, and there suck the juices of the plant.
The effect of this injury is that young plants are killed, and the
stems of older plants are so greatly weakened that the ears only
produce a icw grains at most, and the corn stem itself commonly
bends abruptly down to the ground, either from the root or from
one of the joints a little above it."

[ 17 ]
By Mrs. Alice Eodington.

N a scientific journal an apology is hardly needed
for introducing this most interesting subject to the
reader, though the field which it covers is so vast
that only a small portion of it can be treated in one
paper. All who have followed, however imper"
fectly, the patient and laborious researches of the
great scientists, who have given up their lives to
the study of micro-organisms in disease, all such
students know how fascinating it has been to watch
the flood of light which has been poured over some of the darkest
secrets of medicine. It is, perhaps, not too much to say, that these
researches into the part played by micro-organisms in disease have
laid the very foundations for a science as distinguished from the art
of medicine. Formerly, when men spoke of infection, they spoke of
they knew not what, they combated they knew not what, and often,
as in the exhaustive bleedings practised in fevers, they actively aided
the enemy they sought to destroy. Now, the microscopically minute
foe is being hunted out, his whole life-history in many cases made
known, and the most efficient means devised for expelling and
exterminating him. Medicine has no longer to grapple with an
unknown and invisible foe.

I will now attempt to give a brief history of a few pathogenic
micro-organisms, and of the diseases to which they give rise. I
propose to divide these micro-organisms into two classes : first,
those which having entered the human body are ineradicable, and
the only end to whose ravages is death ; secondly, those which
keep up a warfare in our systems, and either destroy or are destroyed.
Foremost in the first class, both with regard to its historical im-
portance and the extent of its ravages, stands Bacillus Leprae.

Of all the terrible diseases which have afflicted mankind, no
one has been so universally dreaded as leprosy. Though the con-
tagiousness of this disease has lately been considered doubtful, yet
its horrible and incurable charactermade the possibility of contagion
New Series. Vol. I. c

1888.

18 MICRO-ORGANISMS AS PARASITES.

a subject of unutterable dread in earlier ages. The Mosaic law-
abounds with the severest enactments for the banishment of the
leper from the society of his fellow men, and for the destruction
of all his goods. He was to rend his clothes and to bare his head
as he cried, "unclean, unclean," and he was to "dwell alone,
without the camp."

The original habitat of leprosy seems to have been Egypt,
and it was brought thence into Europe by the victorious Romans.
By the first century after Christ it was established in Italy, and
from there spread to all the western countries under Roman rule — •
Spain, Gaul, and Britain. By the 7th century it was established
in Germany and Switzerland. Leper-houses existed at Verdun
Metz, and Maestricht in the yih century, and at St. Gall in the
8th, and Pepin and his great son, Charlemagne, made laws
regulating the mode of life of lepers. But it was amidst the stir
and movement of the Crusades that the ravages of leprosy
became frightful and almost incredible. In Western Europe alone
it was estimated that 19,000 leper-houses existed, most of them
being religious and dedicated to St. Lazarus ; in France, there
were at least 2,000 ; and in England, with its scanty population,
there were " 95 houses of the first class."

The isolation of lepers was most strictly enforced both by law
and by popular sentiment. The greatest or the meanest of
mankind smitten by leprosy was driven from the society of his
fellow creatures for ever. Alms and food were left where he
could fetch them, but his presence, being felt as a deadly danger,
he was provided with a large wooden clapper, by which he was
bound to give warning of his approach, that all might flee from
him. A poet monk of the middle ages, whose songs all Germany
was singing, was nevertheless one of these pitiable outcasts ; he
is described as " Aussatzt " — thrust out from amongst the people
(der ward von den Leuten aussatzig). Cruel as this life-long
banishment was for the victims of leprosy, the stern policy
adopted seems to have been successful in its aim, for in the T5th
century the disease had already declined, and in the 17th had
mostly disappeared. It survived in a sporadic form in a few
isolated places, and it is not yet extinct at Bergen in Norway, where
all its characteristics may be studied, unchanged by the lapse of

MICRO-ORGANISMS AS PARASITES. 19

thousands of years. This terrible disease, whose history I have
imperfectly described, is now known to be caused by a bacillus
which takes up its abode chiefly in the lymphatic vessels and the
deep tissues of the dermis. Not only is it never found in the
epidermis, but, as MM. Cornil et Suchard say, " the epidermal
covering forms a varnish impenetrable to the special parasite
of leprosy." Fortunately for us, the same may be said of the
epidermis, ivhen imi7ijicred, with regard to many other diseases.

The anaesthesia characteristic of leprosy is found to arise from
enormous groups of cells, containing bacilli, which lie amongst the
peripheral nerve-endings. The bacilli also invade the epiglottis
and the thyroid cartilage, thus accounting for the peculiar
hoarseness of the voice in leprosy. The bacillus leprce, one of the
oldest and most fatal enemies of the human race, is an extremely
faint, slender rod about half the length of a human blood-corpuscle.
It closely resembles bacilhis tuberculosis, except in being slightly
wider in comparison to its length. Without staining, the bacilli
are so small and faint as to be unrecognisable. What incalculable
pains have been taken in discovering the properties of aniline
and other dyes in staining (and thereby revealing the existence of)
micro-organisms, can best be realised by those who have read
Koch's description of his discovery of the bacillus of Septiaxmia
in the mouse, an organism so small that it can swarm inside the
red blood-corpuscles of mice. By numberless patient and most
delicate experiments, it was found out that organisms otherwise
too small, colourless, and delicate to be visible by the strongest
powers of the microscope, became easily recognisable when
suitably stained ; each micro-organism having an affinity for
some particular dye. Moreover, the protoplasm of cells takes one
colour, the nucleus another, the cell-wall (in vegetable cells) a
third, and the bacilli, when present in the cells, a fourth. In
Neisser's experiments on the lepra bacillus, the ordinary cell
protoplasm was stained rose-eosin ; the nuclei were found to be
blue, whilst the protoplasm of cells which contained bacilli was
coloured a bright orange ; the bacilli, being less deeply stained,
were visible with a comparatively low magnifying power.

With regard to the question of the contagiousness of leprosy,
I will quote the concluding words of MM. Cornil et Suchard,

20 MICRO-ORGANISMS AS PARASITES.

who have made the subject their special study : — " The tubercles
of leprosy, formed by a solid, dense, dermic tissue, are made of
large cells filled with bacteria. Tlic layers of the epidermis are free
from parasites, but are (from pressure) becoming constantly
thinned. So long as it is preserved, the layer of epidermis opposes
the diffusion of the parasite outwards, and constitutes a barrier
to its progress. It renders contagion very difficult." When, how-
ever, the thinned epidermis gives way, and an open ulcer is
formed, it is easy to see how readily fatal contagion might arise if
there were the slightest cut or other injury to the epidermis of a
person coming in contact with a leper.

The bacillus of leprosy has not yet been cultivated outside the
human body, nor is it communicable to the lower animals. It
has taken possession of its human host so long, that it is
apparently not to be found in a wild state (if I may be allowed
the expression). Many of the larger parasites of man and the
lower animals pass their whole cycle of existence in or on their
host, so the lepra bacillus forms no exception in nature.

In spite of all evidence existing to the contrary, many persons
will doubtless continue to refer leprosy to some unknown cause,
rather than believe it owes its origin to a bacillus universally
found in this disease and in no other, from Norway to China, and
from Honolulu to San Francisco, in cold climates and in hot, in
wet soils and in dry. I am tempted to say with rj)ante, " Non
ragionam di lor, ma guarda e passa." I am not aware that any
other strictly human parasite is invariably fatal to life ; glanders
is always, and anthrax usually, fatal to life, but the micro-organisms
of these diseases reside normally in animal hosts, and only by
accidental contagion prove fatal to man.

I come now to a disease which, terrible as have been its ravages,
experience proves can be guarded against with extraordinary
success. I speak of Asiatic cholera. When it first came with giant
strides from the east, thousands upon thousands of human beings
were its helpless victims. The resources of medical skill seemed
exhausted ; the most apposite remedies were tried, and all failed
alike. Men knew not how to grapple with the terrible new foe.
Amongst the simple and superstitious peasants of Brittany, the
cholera was thought to be brought by demons, which the

MICKO-ORGANISMS AS PARASITES. 21

terrified people actually believed they saw. M. Emile Souvestre
asked the cure of a country village, in the Lyonnais (Brittany),
what precautions his flock had taken against cholera. Slowly and
silently the poor priest led his friend into the churchyard, and
there showed him twelve open graves. That was the only
preparation of which these poor creatures could think, and so
terrible was the pestilence when it came, that carts and horses
failed to convey the number of victims, and wives and mothers
were to be seen bearing their beloved dead to their last resting-
place. Gradually it came to be recognised amongst the educated
classes that cleanliness was a deadly foe to cholera; that where the
drainage of a place was good, and above all where the water
supply was pure, safety might reasonably be expected. We can
hardly assert that it has been the superior piety and virtue of the
Enghsh which kept our country free from cholera during the late
fierce outbreak (1886) in France, Italy, and Spain. Our drainage
and our water supply leave much to be desired, but they are
incomparably better than the drainage and water supply of most
continental towns and villages, more especially those of Southern
Europe.

The patient and prolonged investigations of Koch have
satisfied many minds as to the fact that cholera is caused by the
presence of a specific micro-organism in the intestines, the
SpiriUiiiii Cholerce Asiatiav, popularly known as the Comma
Bacillus. In the very latest scientific journals (August, 1887),
and those of the highest character, the fact is assumed as proved.
New particulars are given as to the life history and peculiarities
of S. Cholerce Asiatiae, but no one thinks of disputing the right
of this spirillum to its distinguishing name. Of the difficulty of
the task undertaken by Koch, he speaks thus : — " When I
undertook this commission (from the German Government) I was
well aware of the difficulty of the task before me. Absolutely
nothing was known with regard to the virus of cholera, and I was
at a loss where to seek for it, whether in the intestinal canal,
or in the blood, or in some other place. Further, one did not know
whether bacteria would have to be dealt with, or some kind of
fungus, or an animal parasite, such as an amoeba. Even the
description of post-mortem appearances given in the text-books

22 MICRO-ORGANISMS AS PARASITES.

proved utterly erroneous and misleading." Suffice it to say that
Koch went out to Egypt and to India, that he examined nearly a
hundred specimens of choleraic infection, and likewise examined,
with the minutest care, cases of typhoid and typhus fever,
dysentery, and intestinal catarrli. In all the former cases the
comma bacilli were present ; in all the latter they were absent,
although i\\e post-?/iorte/n appearances in typhus resembled those
of cholera in a marked degree. Koch, therefore, came to the
conclusion that the bacillus found in cases of cholera, and of
cholera alone, were the exciting cause of that disease, hitherto
supposed to be due to an " organic poison," which had a
preference for living in the earth. (See Quain, " Dictionary of
Medicine.")

Nothing could be more strange than the way in which the
merest novices in microscopical work rushed into print to say
that Koch was mistaken. An experienced biologist would weigh
his evidence anxiously before venturing to break a lance with one
of the greatest scientists on his own ground, but as the homely
proverb says, "Fools rush in where angels fear to tread." Dabblers
with the microscope found a comma-shaped bacillus in the mouths
of healthy persons, and rushed to the medical journals to announce
the discovery, and to say that Koch's comma bacillus could be
found everywhere and every day. Had they merely read his
paper once, and remembered what they had read, they would
have known that one bacillus being often much like another, its
life-history must be patiently studied before its identity can be
proved. The comma bacillus of cholera, sown in a flask of
gelatine, behaves in a manner peculiar to itself. As the colony
of bacilli grow, they liquify the gelatine on which they rest, and
sink further down into it, causing "^fuiind-sliaped depression.

Nothing can be stranger than to read the peculiarities of
constitution of each kind of micro-organism, when its life-history
is studied. The comma bacilli prefer a temperature of from 30*^
to 40° C, but they are not extremely particular in this respect. They
"do quite well," as Koch says, at a temperature of 17° C., though
under 16° C. their growth stops altogether. They bear freezing
perfectly well. As food they enjoy strong soups, nourishing
jellies, and milk; in weak broth they do not thrive at all. Though

MICRO-ORGANISMS AS PARASITES. 23

they easily accommodate themselves to extremes of temperature,
and are with difficulty killed by either heat or cold ; they are
peculiarly sensitive to other influences. They will not grow
without air or in an atmosphere of carbonic acid, but they are not
destroyed. But one thing is fatal to comma bacilli, and that is to
be dried. This peculiarity was found out accidentally. Droplets
of meat-infusion containing comma bacilli had been placed on
cover-glasses, and allowed to dry. On being examined, no growth
was found upon any cover-glass ; all the germs were dead. This
was the more surprising to Koch, because the bacillus of anthrax,
which in many respects resembles that of cholera, can be dried
with impunit)'. To be dried for two hours is fatal to most, and
for three hours is fatal to all cholera bacilli.

Their constitutional peculiarities also give a clue to the reason
of the recovery of cholera patients, even from the stage of
collapse. The bacilli grow with extraordinary rapidity; cultivated
with other bacteria they quickly outgrow them, and this rapid
growth lasts for about twenty-four hours. But in two, or at the
most three days, the comma bacilli die, and the other bacteria which
may be present survive them. If the patient, therefore, can survive
his internal enemies, he has a chance of recovery. This life-
history forms a strong contrast to that of the bacillus of leprosy,
which can live and ceaselessly multiply for eight or ten years, and
dies — if even then it dies, only with its human victim. The use
of disinfectants has also been placed on a scientific basis by the
study of the individual constitutions of micro-organisms. The
cholera bacillus, for instance, will not develop in infusions
containing alcohol, lo per cent. ; camphor, i part in 300 ;
carbolic acid, i part in 400 ; quinine, i part in 5,000 ; and
corrosive sublimate, i part in 100,000.

The inhibitory action of quinine upon micro-organisms gives
us a clue to the reason of its action as a specific in fevers. And
before leaving this subject, I should like to refer my readers to a
profoundly interesting paper on the action of quinine on the
hematozoa of malarial fever, by Dr. Osier, of the University of
Pennsylvania, which appeared in the British Medical Journal for
March, 1887.

I will now return to the comma bacillus, and the question of its

24 MICRO-ORGANISMS AS PARASITES.

native home. Notwithstanding the most patient researches, Koch
could not find the cholera bacillus in tanks which had been
polluted through the horrible disregard of all sanitary rules, shown
by the native Hindoos. On the bank of one such tank during an
outbreak of cholera, Koch found from 30 to 40 huts, containing
between 200 and 300 persons. The natives bathed daily in the
tank, drank of the water, and washed their clothes in it, and it
was the only receptacle for all drainage. The epidemic had
already reached its height when comma bacilli were found in the
tank, and their appearance in this case followed the epidemic.
Where, then, are we to look for the original source of these out-
breaks of disease? Koch says, "All authors are agreed that the
delta of the Ganges is the true home of cholera, and I have come
to the conclusion that this is the case. For the only district of
India where cholera prevails year after year is the delta of the
Ganges. In all other parts of India it shows marked variations,
and may even disappear altogether for a longer or shorter time."
On the map of the province of Bengal you can see this delta of
the Ganges, bordered on the west by the Hoghli river, and on the
east by the Brahmaputra. Over the whole of this district cholera
continually prevails. On closer examination of the map it must
strike one that the upper part of the delta is thickly covered with
towns, while the base of the triangle remains uninhabited. This
uninhabited stretch of land, called the Sunderbuns, embraces an
area of 7,500 square miles. Here the great rivers Ganges and
Brahmaputra break up hito a network of water-courses, in which
the sea-water, mingled with river-water, Hows hither and thither
with the tide, and at flood-time places large tracts of the
Sunderbuns under water. A luxurious vegetation, and an abundant
animal life, have developed in this uninhabited region, which
is inaccessible to man, not only on account of the floods and the
numerous tigers, but on account of the pernicious fever, which
attacks those who venture into this region even for a short time.
Here the cholera bacillus would find the most favourable
conditions possible for im])lanting itself, where all the drainage
from a thickly-populated country is washed down by the current
and mingles with the brackish water of the Sunderbuns, already
teeming with decaying matter. Jessore, from which the epidemic

MICRO-ORGANISMS AS PARASITES. "25

of 1S17 originated, lies on the borders of this vast, infectious
marsh, and Calcutta, which is now the fixed home of cholera, is
connected with the neighbouring Sunderbuns, by a marshy tract
of land.

From its original home the cholera is carried by the enormous
bands of pilgrims, who travel yearly to the sacred cities of India,
and by the Mahometan pilgrims it is carried to the sacred cities
of Arabia. Here the tide of pilgrims from India meets the tide
of yearly pilgrims from Egypt and other Mahometan countries,
and thus the infection reaches the Levant, and thence spreads to
every European seaport where it can find a congenial resting-
place. I was once in the midst of a severe epidemic of cholera
at Gibraltar, in 1865. We watched the advance of the disease ;
first it was heard of at Cairo, then at Alexandria, next it appeared
at Malta, and we felt the turn of Gibraltar would come next. A
regiment, apparently uninfected, came from Malta ; it camped on
the neutral ground, a narrow neck of land connecting the rock
with the Spanish mainland. In a fortnight the regiment embarked
for the Cape, and in ten days' time cholera broke out violently in
Gibraltar, and (as we afterwards heard) broke out on board ship in
the regiment which was on its way to the Cape. I was much
struck at the time with the fact that no officers, or their wives, or
their children were attacked, though the poor soldiers died like
flies. The food of all inhabitants of the rock came from the
same market ; whence then came the immunity of the officers
and their families ? Our loater supply was perfectly distinct ; we
drank rain-water collected in tanks, removed from all possible
contagion by drainage. It was impossible, even then, not to arrive
at the conclusion that an uncontaminated water supply was the
secret of our escape, though our knowledge at that date could
only be empirical.

To return for a moment to the Hindu pilgrims. They are
crowded for weeks together by thousands in the narrowest space ;
the same tanks serve for drinking, bathing, and washing clothes ;
and under these circumstances who can wonder that cholera,
when once developed amongst the pilgrims, travels quickly over
the whole of India ? This source of evil has of late years
been much diminished by the stringent sanitary regulations of the
Indian Government.

26 MICRO-ORGANISBIS AS PARASITES,

It is hardly necessary to say that cholera is one of those
diseases, where the conflict of the bacillus with the organism it
has invaded is swift and sharp, a pitched battle ending soon in
victory or death for one side or the other. The same may be
said of typhoid, scarlet, and yellow fever, measles, diphtheria, small-
pox, and pneumonia. Not only is the bacterium exterminated in
the system in cases of recovery in the latter diseases (with the
exception of pneumonia), but the field in which it grew seems
exhausted of the necessary nourishment required by the parasite,
and it is uncommon to see a person attacked a second time by
measles, scarlet fever, whooping-cough, and other zymotic diseases.
Of the manner in which the living tissues proceed to attack
the dangerous invaders of the body, Mr. Bland Sutton gives a
most interesting account, founded (as we may expect to find in
such researches) upon the most minute and patient investigations
on his own part, and on that of the foreign pathologists, on whose
authority Mr. Sutton says "The leucocytes (familiarly known as
white blood-corpuscles) may be likened to a defending army ; the
blood-vessels are their roads and lines of communication. Every
composite organism maintains a certain proportion of leucocytes,
as representing its standing army. When the body is invaded by
bacilli, bacteria, micrococci, chemical, or other irritants, information
of the aggression is conveyed by the vaso-motor nerves, and
leucocytes rush to the attack ; reinforcements and recruits are
quickly formed to increase the standing army, sometimes twenty,
thirty, or forty more than the normal standard. In the conflict,
cells die, and are often eaten by their companions ; frequently the
slaughter is so great that the tissue becomes hardened by the dead
cells, in the form of pus ; the recent activity of the cells being
testified by the fact that their protoplasm often contains bacilli, etc.,
in various stages of destruction. These dead cells, like the corpses
of soldiers who have fallen in battle, later become hurtful
to the organism which in their lifetime they strenuously en-
deavoured to protect from harm. They are fertile sources of
septicoemia and pycemia, the pestilence and scourge so much
dreaded by operative surgeons." The analogy may seem at first a
little romantic, but its correctness will be shown by the facts
which will be placed before the reader.

MICRO-OKGANISMS AS PARASITES. 27

The line of enquiry which has led up to the discovery of the
function of leucocytes as destroyers and devourers of foreign
particles, injurious or unnecessary to the body, was begun by
Haeckel, who watched the corpuscles of a naked sea-snail eating
up particles of indigo, in amoeba fashion. He subsequently
watched the same process in the colourless blood of other inverte-
brates. Many other observers continued this line of investigation,
the most eminent and successful being the Russian scientist,
Metschnikoff. He found that the white cells of numerous
invertebrate animals devoured finely divided particles of carmine,
also disintegrated bodies of entomostraca, human blood-corpuscles,
milk globules, starch granules, etc. But more extraordinary and
important discoveries were to come. I will give in detail his
experiments on DapJmia (the water-flea). He kept many of these
little creatures in a tank, and after a time he found them infected
with fungus spores, which germinated and were dispersed by the
blood-current over the body. They were deposited in those parts
where the blood-current is slowest, and in these places (the
cephalic and hinder portions of the mantle cavity) heaps of
conidia collected. In the meantime the leucocytes did not
remain idle during the invasion ; they attacked and devoured the
conidia, took them into their interior, and digested them. If a
conidium were too much for one cell, others joined it, and
fused to form a giant cell or plasmodium, the better to exterminate
the invader. Notice this especially, for farther experiments have
shown that the same rule holds good for every organism, whether
animal or vegetable. " If the leucocytes finally overpower the
spores, the Daphnia lives ; if not, the spores over-run the
crustacean, and death is the result.'"'

In the B. Medical Journal^ a house-surgeon described his
experience with one of the fresh-water Algae, C/iara, which with
other pond weeds he kept in a glass jar placed in a hospital ward.
Soon he saw the Chara begin to drop, and the other water-plants
died outright. After two or three days the Chara began to revive,
and resumed its bright-green colour. The surgeon then examined
the water of the jar, and the tissues of Chara. He found, as
usual, in water kept in a hospital ward, that it was full of septic
organisms. The dead plants swarmed with living bacteria, but

28 MICRO-OEGANISMS AS PARASITES,

the cells of C/iara were full of dead and dying bacteria ; the plant
had had a hard fight, but was victorious. To return to Metsch-
nikoff's experiments, this time with a vertebrate animal. The
leucocytes in the lymphatics of a frog not only devour anthrax bacilli,
but called in other leucocytes to their aid. Illustrations of the
whole process, which occupied 40 minutes, will be found in Mr.
Bland Sutton's Lectures on Patliology. In Botryllis Metschnikoff
found a spirochxta closely resembling that of relapsing fever,
and a small bacillus resembling the lepra bacillis. Both these
organisms were pursued by leucocytes, ingested and absorbed by
them. Some leucocytes perished in the attempt. In the same
way Koch found bacillus anl/iracis, and the bacillus of scpticoemia
in the mouse, enclosed by white blood-cells. Throughout the
whole animal kingdom these cells use their ingestive powers for
destroying bacteria and similar organisms.

These amoeboid cells exhibit a very curious power of throwing
out pseudopodia, which unite with similar protrusions from
neighbouring amoeboid cells, until a considerable mass of proto-
l^lasm is formed by their influence. Such a mass of fused cells is
known as a Plasmodium. Metschnikoff has watched their formation
in a transparent mollusc F/iyllirhde, around masses of carmine
granules. He writes : " The cells came one by one to each lump,
and flattened themselves upon it, fusing with neighbouring cells as
these arrived. In this way arose plasmodia of difterent sizes, some
even visible to the naked eye, wJiicJi might be compared to the
giant-cells of vertebrates." He adds, " In all cases in which I
have found giant-cells in invertebrates, they have arisen round
foreign bodies, and always by fusion of separate cells." Mr.
Bland Sutton remarks, " In such diseases as tubercle, leprosy,
and the tuberculosis of the fowl and ox, there is a peculiar cell
to be detected, the giant-cell ; and in cases where bacilli have been
discovered in the tissues, these micro organisms have been found
to occupy the interior of the giant-cells, sometimes in enormous
numbers."

This view is remarkably confirmed by Koch, who says, in his
paper on the Etiology of Tuberculosis — " Direct observation seems
to show that on their first entry into the system, the tubercle-bacilli
are seized upon and carried away by wandering cells. If an

MICRO-ORGANISMS AS PARASITES. 20

animal be killed soon after infection, the blood is already found to
contain numbers of white blood-corpuscles, enclosing one or more
of the tubercle bacilli. A wandering cell which has taken up a
tubercle bacillus has no such harmless burden as if it had devoured
a particle of vermilion or carbon. With the latter load it might
travel a long distance, but under the poisonous influence of the
bacillus, changes take place in the white corpuscle which soon
bring it to a standstill. It increases more and more in size by
continuous multiplication of its nuclei, and at length attains the
form and size of the well-known giant-cell. Specimens properly
prepared show all the intervening stages between simple epithelioid
cells, containing only one bacillus, and fully formed multi-
nucleated cells containing many bacilli."

The further fate of the giant-cell varies. When the course of the
disease is slow, the number of bacilli enclosed in the cell remains
small ; in the most favourable cases the giant-cell remains, and
the bacilli die out. But when the course of the disease is rapid
the bacilli multiply rapidly, push through the wall of nuclei, and
the giant-cell succumbs. The behaviour of the bacilli in the
giant-cells is also most curious. The " idea involuntarily arises in
the mind," says Koch, " that there is a kind of antagonism
between the giant-cell and the parasites it contains. Where one
bacillus only is present, we often find the nuclei of a giant cell
collected together at one end, and the bacillus generally in the
part of the cell free from nuclei, at the furthest point of the
unoccupied pole. But when the number of bacilli is increased,
their behaviour towards the nuclei becomes more actively hostile.
They crowd more and more towards the periphery of the cell, push
between the nuclei, and finally break through the wall formed by
them. A considerable increase like this in the number of bacilli
seems always followed by the degeneration of the giant-cells and
their disappearance, leaving only groups of radiating bacilli to show
where they once existed." These facts seem to show that the modern
treatment of consumption (though begun, perhaps, empirically) rests
on a true scientific basis. In the pure, cold air of mountain regions,
or in the equally pure air of the open ocean, the consumptive
patient has to grapple only with the bacilli contained in his own
system ; there are no fresh spores in the atmosphere ready to seize

30 MICRO-ORGANISMS AS PARASITES.

upon diseased lungs. The system is braced up with as much
nourishing food as the patient can digest, and the giant-cells are
strengthened as much as possible for their battle with the enemy.
Under the old system, the poor victim of phthisis breathed
constantly a warm, close, spore-laden air, whilst lowering medicines
were employed to help the progress of the disease as much as
possible. Yet, it is seriously asked whether medicine has made
any progress during the present century !

Not only do leucocytes attack and devour bacteria, but they
perform important duties in removing us.eless embryonic tissues.
In the process of absorption of the gills and tails of larval
Batrachians (frogs, newts, etc.), a large number of these cells are
present, the protoplasm of which is crowded with fibres and
fragments of muscle. The fraginents of muscle retain their
structure for some time after ingestion, but gradually break up
into rounded, strongly refracting globules. These experiments,
originally made by Metschnikoff, are confirmed by Mr. Bland
Sutton in every particular. We have ample proof, in even the
present state of our knowledge, that the air, the water, and the
earth, and also our own bodies, teem with micro-organisms. Of
these, however, comparatively few are pathogenic, and an immense
number are not only useful but necessary. Bacteria are very
quickly destroyed in the blood of warm-blooded animals (if not
pathogenic to the particular animal). Herr Wysskowitch has
found that in from 3 to 4I hours no traces were found of various
bacilli, and spores of fungi which had been ingested into the
blood ; these included the bacillus of typhus, the cholera bacillus,
and other pathogenic organisms. Herr Wysskowitch says,
" Between the endothelial cells and the bacteria there is a
constant warfare. Either the cells conquer and the bacteria
perish, or the cells are destroyed by the bacteria, which are of
course in this case pathogenic to the animal. Similar testimony
is given by Herr Ribhaet, in the Joiuiial of the R. Microscopical
Society for August.

As I remarked at the beginning of this paper, we need no
longer feel we combat we know not what, and consequently
run less risk of aiding the enemy we seek to destroy, as must
ha\e been the case when repeated bleeding and starvation were

MICRO-ORGANISMS AS PARASITES, 31

relied upon as remedies for fever, and calomel, with close
confinement to hot, airless rooms, was thought the best treatment
for consumption. By bleeding, the dauntless, active little soldiers,
which sought to save the organism of which they formed a part,
were ruthlessly drained away, and the weakened patient only
escaped death by a species of miracle ! In most of the intensely
infectious zymotic diseases, the contest is of the nature of a
pitched battle, and in the white races, with a fair chance of victory
on the part of the patient. Where, however, the micro-organism
finds itself in virgin soil, as amongst the natives of the South Seas
and the Red Indians of North America, its ravages resemble those
of the mediaeval plagues of Europe in deadliness. The terrible
ravages caused by the introduction of measles into the Fiji Islands,
a few years ago, will probably be fresh in the recollection of
most of us.

My aim and ambition in writing this paper has been to send
any readers, who have been interested, straight to the original
authorities I have consulted, with the hope that they may therein
find the information and the keen interest I have found. My
apology for venturing to deal with subjects of which I have no
experimental knowledge, must be made in Professor Huxley's
words, on quitting the chair of the Royal Society: — "The man
who works away at one corner of nature, shutting his eyes to all
the rest, diminishes his chance of seeing what is to be seen in that
corner. That zvhich the investigator perceives depends much more
on what lies behind his sense-organs, thaii on the object in front of
them." Here comes in the function of the person who assiduously
collects and arranges the facts discovered by others. The writer
of the "History of Astronomy in the XIX. Century " has probably
made no astronomical discoveries herself. But what services she has
rendered in her clear account of the enormous progress of
astronomical science ! Again, the world made little progress —
indeed, had a way of constantly going back — whilst the wise men
kept their wisdom to themselves, despising the vulgar herd of
mortals. Knowledge, if it is to be of real service in eradicating
ignorance and superstition, must be made clear and plain to the
many. Darwin had the extraordinary genius and patience, not
only to make more original observations than perhaps any other

32 MICR0-ORGA.NISMS AS PARASITES.

man has done, but also to make the result of his investigations
clear and plain to any person of ordinary intelligence.

But many original observers are unable to do this. Each
works at his speciality as Oliver Wendell Holmes' immortal
"Scarabee," worked at the ^^ larva of Meloce" and they are hardly
aware of the magnitude of the coral reef they have been building.
Hundreds and thousands of original workers are carrying on their
investigations, yet one may search the leading periodicals in vain
for any account of the results they have accomplished, probably
because some stigma is supposed to attach to the fact of writing
upon science without original investigation. Yet we do not say
that only generals who have won battles, and politicians who have
led senates, must write about history ; we own that the historian
has his special work, his peculiar talent. It is time, too, that
Natural Science should have her historians ; the glorious work
she has done and is doing for men, should be proclaimed, not
buried in the pages of scientific journals, to be read only by
specialists.

The Chameleon. — The colour of its skin is changed by virtue
of the action of the nervous system on certain little vesicles con-
taining pigment, which are in abundance on its surface. These
contract when the nerves are excited, and thus squeeze out into a
deeper portion of the skin the contained pigment.

The Nature of Diatoms. — These curiously beautiful micro-
scopic objects can be found in the mud at the bottom of all pools
of water. They were formerly regarded as animals, but are now
classed among plants. Professor W. Mattieu Williams discovered
their vegetable character thirty years ago by an observation which
amounted to a demonstration. The white quartz pebbles in his
aquarium became coated with a brown growth, caused by the
development of these organisms, and at the same time evolved
bubbles of gas. In the course of a few days, he found an inch of
the vertical space of the test-tube, which he fixed to catch it,
filled with the gas, and it was proved, by burning wood and other
expeciments, to be nearly all oxygen. Animals expire carbonic
acid, plants expire oxygen. Therefore, diatoms are plants.

[33]

Zbc Development anb Xife^lbietor^ of the

^abpole.

By J. W. Gatehouse, F.I.C.

Fart I.

Plates I and II.

FOR some few years past it has been my custom during the
spring time to devote a certain amount of attention to the
development of the frog, obtaining for this purpose the
spawn in as early a stage as possible, and keeping it under various
conditions, so as to watch, with the unaided eye, as well as by
means of the microscope and chemical balance, the various
changes which the animal undergoes during its metamorphoses.

Although most of our best physiologists have written on the
same subject, there seems on several points, and especially as to
the nature of the food of the tadpole, a great divergence of
opinion, some averring that it feeds on vegetable diet, whilst others
are equally certain that it eats animal food.

Buckland, in his " Curiosities of Natural History," states that
tadpoles eat both decaying animal and vegetable matters, in
addition to being cannibals and eating each other. His words are
well worth quoting :— " In the horse-pond were many tadpoles
hustling and squeezing each other in their anxiety to get a dead
kitten. And why should they not fight for good places? The
dead kitten is to them what a turtle dinner is to the city folks ;
each duly appreciated by the rightful customers. But supposing
there happen to be no dead kitten or decayed vegetable matter in
the pond, what will the poor things get to eat ? Why, they will
do what the New Zealanders have done before them — viz., ate up
every specimen of the Dinornis they could find on the islands,
and then they set to work and ate up each other ; so do the tad-
poles." There is this difference, however, between the New
Zealanders and the tadpole, that whereas the former killed his
brother previously to breakfasting off him, the tadpole waits till
he is dead before he commences to make his meal.

Hu.xley takes the opposite view. In the " Course of Practical

New Series. Vol. I. D

1888.

34 DEVELOPMENT AND LIFE-HISTORY

Biology," by Huxley and Martin, it is stated, p. 163, that "the
animal (tadpole) crops the aquatic plants on which it lives by
means of the horny plates with which its jaws are provided."
Again, p. 164 : — "The labial membrane and the horny armature
of the mouth disappear, while teeth are developed in the upper
jaw on the vomers ; the intestine becomes less and less coiled, as,
not growing at the same rate as the body, it becomes relatively
shorter, and the animal gradually changes its diet from vegetable
to animal matters, the perfect frog being insectivorous. This
statement appears to be that generally adopted as fact at the
present day, and it was in hopes of throwing some light on these
apparently contradictory statements that my observations and
experiments were first commenced.

The ova or frog-spawn is deposited in water early in the year.
From the first or second week in February to the second week in
March, according to the season, the male and female frogs repair
to any fairly shallow, stagnant, or semi-stagnant pool, and there
the spawn is deposited in large masses, fertilisation taking place as
the ova are being deposited in the water. When we consider the
immense numbers of ova deposited by one female, and that each
egg is surrounded by a membrane which rapidly swells when it
touches the water into a semi-gelatinous covering, it appears
astonishing that nearly every egg becomes fertilised. Out of a
mass which, when fully swollen by absorption of water, measures
from six to nine inches in diameter and contains hundreds of
eggs, not more than ten or twelve eggs will remain undeveloped.
The further development of the egg is, however, much dependent
on temperature. During the present season (1887), thousands
around Bath were killed by the severe cold, which occurred within
a few days of spawning.

The eggs were laid in some of the ponds this year about
February 27th. Cold weather set in within a day or two, and
from March 12th to March 21st intense frost and deep snow ])re-
vailed, so that after the snow had disappeared masses of dead
spawn were taken from the same pond as that from which some
hundreds of tadpoles had by this time developed from the spawn,
which had been kept in a room at a minimum temperature of
40° F. and a maximum of 55" I*'.

OF THE TADPOLE. 35

It is not my intention to give any account of the development
of the egg from its earHest stages, but thinking that a comparison
of its structure in a median stage with that when newly laid might
be interesting, a frog was killed in September, 1886, and sections
made of the ova then contained in the ovary. The ovum at this
date consisted of a nucleus surrounded by a thick follicle enclosed
in a layer of dark pigment (Plate I., Fig. i). The follicle con-
sists of masses of oval granules. The nucleus is pear-shaped, and
consists of an undifferentiated mass of protoplasm, which, under
the treatment employed to obtain sections, frequently had a semi-
granular appearance.

At this point it would seem well to mention that the whole of
the sections spoken of in these papers, and of which diagrams
will be given, were prepared by gradual hardening in successive
strengths of spirit of 10 degrees, commencing with 20 degrees
and ending with absolute alcohol, next immersion in oil of
lavender, and lastly digesting at a temperature of 40 degrees C. for
some hours in a bath of soft paraffin.

The nucleus at the date mentioned was not truly central, but
very nearly so, and the whole ovum, from pressure of neighbour-
ing ova, was distinctly angular, and indeed roughly triang'ilar or
pentagonal, no two having exactly a similar shape. Plate I., Fig.
I, A, B, c, gives an idea of their appearance, showing — (i) The
pigment layer, e\ (2) The thick layer, composed of oval granules,
g ; (3) the pear-shaped nucleus, ;/, which is nearly circular, as
seen in transverse section.

When the ovum is first deposited, it consists of a dark ball,
the embryo, about the i/i4th of an inch (2 millimeters) in dia-
meter, enclosed in a jelly-like envelope, whicli to the eye appears
perfectly homogeneous, but if placed in dilute acetic acid (2 per
cent.) is seen to divide into two concentric layers, the inner one
distinctly marked off from the outer by its pale yellowish tint and
an apparent investing membrane.

This is sometimes called the albuminous, but, more frequently,
the gelatinous envelope. An analysis of it made on March 7th,
just a week after deposition, showed that it was neither albumen
nor gelatine, but a substance which in its chemical characters par-
lakes rather of the nature of chondrin, differing, however, from

36 DEVELOPMENT AND LIFE-HISTORY

that substance in not being converted into gelatine upon pro-
longed boiling. That, as a whole, it is not albumen is shown by
its not being coagulated by heat nor precipitated by any of the
substances which react upon albumen. The only portion of the
capsule which corresponded in any of its reactions to albumen was
the investing membrane of the inner capsule, which was rendered
opaque, both by acetic acid and by mercuric chloride. The
transparent envelope may be completely evaporated to dryness
over a water-bath without coagulating, but is dehydrated and gra-
dually rendered opaque by 92 per cent, alcohol. Boiled with
caustic potash, a turbid solution is obtained which is rendered
perfectly clear on neutralisation with acetic acid. Tannin has no
action upon it, showing it not to be gelatine. Fehling's sugar-test
does not reduce it, which proves it not to be a glucoside.

Its specific gravity was identical with that of water, the
number actually obtained being 999'6 instead of 1000. It
appears to absorb water for a long time after deposition, but
at the period when analysed contained —

Water ... ... ... ... 99*49

Solids ... ... ... ... "51

lOO'OO

This solid matter was transparent and perfectly hard and
horny ; indeed, almost glassy. A further analysis showed that it
contained —

Mineral matter ... ... ... 24*50

Yellowish, oily fat, soluble in ether ... -07

Organic matter, insoluble in alcohol ... 75*43

lOO'OO

From its peculiar chemical composition, it would seem that
some special name ought to be given to this envelope, and I would
suggest Batrachiti as applicable, in order to distinguish it both
from gelatine and chondrin.

The ovum after fertilisation rapidly undergoes a series of divi-
sions, and after a short time is seen to consist of a somewhat
mulberry-shaped mass, dark on the upper and light on the under
side. A section of this — taken on February 28th, when probably

OF THE TADPOLE. 37

about one day old — is seen, in Plate I., Fig. 2, a and b, to consist
of an undifferentiated yelk mass forming the body of the egg,
surrounded by a dark layer of cells, the epiblast, under which we
have a layer of larger cells, called the hypoblast. From the epi-
blast it will be seen in future plates that the epidermis, the
nervous system, and most of the organs of special sense, are
produced, whilst the hypoblast forms the whole of the epithelial
lining of the alimentary canal, with its glands, excepting the lips
and anus, which, like the external skin, are formed from epiblast.
These two layers are well seen in Plate I., Fig. 3, where the epi-
blast is seen as a dark line of cells, the hypoblast consisting of a
looser texture below. At the light pole of this figure may be
seen a row of nucleated cells, which are well defined and marked
off from the great body of non-nucleated cells, at this time form-
ing the bulk of the yelk mass. It is from the different growth ot
the nucleus in the cells that the distinctive character of each kind
of tissue may be traced.

The epiblast soon spreads over the whole surface, with the
exception of a small hole called the blastopore, through which an
invagination of the epiblast occurs, and after this has gone on for
some time, a flattening of the dark pole takes place (Plate I., Figs.
4, 5, and 6), and a delicate layer of cells, called the mesoblast
(Plate II., Figs, i, 2, 3, 4, etc.) forms between the epiblast and
hypoblast. This mesoblast, although barely visible at first, is yet
an extremely important part of the structure, as in the course of
development it forms the bones, muscles, connective tissues, and
blood-vessels.

The flattening of the dark pole was first observed on March
2nd, the third or fourth day after deposition. This flat spot soon
deepened down into a curve, the outer rim at the same time rising
up, forming a decided ridge or cornua, the sides of which,
gradually approaching each other, produce a medullary groove,
below which the most interesting and extensive modifications
and re-arrangement of the three layers of hypoblast, mesoblast,
and epiblast are occurring. These will be treated in a future
paper.

[38]

EXPLANATION OF PLATES L & II.

Plate I.
Fig. 1. — A. — Unfertilised ova, Sept., 1880, nucleus extracted.
B. — Ditto, nucleus in nitu.
C. — Nucleus extracted from A.
€, dark external envelope ; g., granular mass ; n., nucleus.

,, 2.— A.— Fertilised ovum, Feb. 27, 1887, light pole.
B. — Ditto, ditto, dark pole.
C. — Nucleated cell, x 125.
D. — Non-nucleated cell, x 125.

„ 3. — Fertilised ovum, March 3, 1887, x 50 ; showing ep. , epiblast ;
hy. , hypoblast, forming under it.

,, 4. — Section from another egg, same date, x 25, showing c. , trans-
parent envelope formed of three layers ; hy., hypoblast ;
ep., epiblast; md.g., medullary groove.

,, 5 and 6. — Two sections taken from one egg, March 4, in which
the medullary plate and cornua are seen forming more com-
pletely ep. , epiblast ; liy. , hypoblast ; c. , cornua.

Plate II.
Figs. 1 — 13. — Thirteen sections cut from one egg, March 5, and follow
in rotation according to the numbers, ms. , mesenteron ;
nc, notochord ; ep., epiblast ; hy., hypoblast ; j/i., niesoblast;
y, yelk mass ; c. , body cavity.

The Use of Pearl-Shells. — The pearl-shells shipped from
Australia to the United States and Europe, are used principally
for the manufacture of knife-handles, shirt-buttons, etc. Con-
siderable quantities arc also used for papier-mache and other
ornamental work. The pearl buttons, shirt-studs, etc., now made
in the United States are said to be the best and cheapest in the
world, a fact due in great measure to the care in selecting the
material, and to the improved methods of cutting. — Bull., U.S.,
Fish. Comm.

The Manchester Microscopical Society. — In the report
of this Society, in our October issue, we should have stated that
Mr, J. L. W. Miles was President in i886, and that the President
for 1887 is Professor A. Milnes Marshall, M.D., M.A., D.Sc,
F.R.S., F.R.M.S., etc.

Journal o£ Microscopy N.S. Vol. PI 1.

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[39]

Zbc HDicroscopc an^ bow to use

By V. A. Latham, F.R.M.S.

Part XIII. — Cements and Useful Recipes.

THE chief cements in microscopical work are gold-size, seal-
ing-wax varnish, solution of shellac, solution of asphalt,
marine glue, and Canada balsam.

Gold-Size. — Prepared by melting together gum animi, boiled in
linseed oil, red lead, litharge, sulphate of zinc, and turpentine.
Take 25 parts of linseed oil, boil with one part of red lead, and a
third part as much umber, for three hours. The clear fluid is
poured off and mixed with equal parts of white lead and yellow
ochre, which have been previously well pounded. This is to be
added in small successive portions and well mixed. The whole is
then again to be well boiled, and the clear fluid poured off for use.
The o/der the cement the better it is. This cement may be
bought ready for use.

Sealing-Wax. — Prepare by dissolving the very best powdered
sealing-wax in fairly strong alcohol with a gentle heat. It is apt
to dry rather brittle, but forms a good varnish for the last coat.

Shellac is made by dissolving powdered shellac in spirit of
wine. Shake the bottle frequently until a thick solution is
obtained.

Bell's Cement. — I believe this was originally suggested by Mr.
Tomes. It is sold by Messrs. Bell, chemists, Oxford Street. I
do not know the composition, but think it contains shellac and
gold-size.

Brunswick Black.— -Take of india-rubber, cut into very small
pieces, i drachm; asphaltum, 4 oz. ; Mineral Naphtha, 10 oz.
Dissolve the india-rubber in the naphtha, then add the asphaltum ;
if necessary, heat must be employed. Some friends say they
cannot always succeed with this. I believe the faults are — either
the rubber or asphaltum has not been pure^ or that the naphtha
used has been wood instead of mineral.

Common Brunswick Black is made by melting one pound of
asphaltum ; then adding half a pound of linseed oil and a quart

40 THE MICROSCOPE

of oil of turpentine. The best black is made by boiling together
a quarter of a pound of foreign asphaltum and 4^ ozs. of linseed
oil, which has been previously boiled with h oz. of litharge until
quite stringy. The mass is then mixed with half a pint of oil of
turpentine, or as much as may be required to make it of a proper
consistency. It is often improved by being thickened with lamp-
black. Dr. Euienstein, of Stuttgart, finds that equal parts of
Brunswick black and gold-size, with a very little Canada balsam,
form a very lasting cement. I find a good substitute for Bruns-
wick black in the "liquid stove-polish."

Electrical Cement— Melt together five parts of resin, one of
bees'-wax, and one of red ochre. It must be used whilst hot, and
can be readily moulded into any form. It is often employed in
making shallow cells for liquid mounts.

Mask-Lac. — This is a very good quick-drying cement, espe-
cially for wet preparations, and also as a coating for specimens
mounted in Canada balsam or copal. The variety of lac is
designated as No. 3 at Beseler's lac factory in Berlin (Schiitzen
Strasse, No. 66).

Shellac and Aniline (Thiersch). — After the specimens have been
mounted in Canada balsam, surround with a border of Canada bal-
sam dissolved in chloroform. After the third or fourth day apply a
final coating, consisting of a thick varnish of shellac, coloured with a
filtered, concentrated solution of aniline blue or gamboge in abso-
lute alcohol. Finally, about a scruple of castor-oil is to be added
to each ounce of the mixture, and after some further evaporation
is to be preserved in a well-closed vessel. If after a time it
becomes too concentrated, a few drops of absolute alcohol may
be added. The varnish is to be applied to the border of the
balsam with a brush. It soon becomes hard and forms an elegant
and hermetic covering and finishing cement.

Dr. Bastian's Cement. — This is much used in Germany, and is
the best cement for liquid cells. It is made by adding a consider-
able quantity of nitrate of bismuth to a solution of gum-mastic in
chloroform. It may be procured at almost any optician's.

An Extra-Adhesive Gum. — Dissolve 2 drachms of isinglass in
4 oz. of distilled vinegar; add as much gum arable as will give it
the required consistency. This keeps well, but is apt to become

AND HOW TO USE IT. 41

thinner, when a Httle more gum may be added.

Marine Glue (Dr. Goadby). — Dissolve, separately, equal parts
of shellac and india-rubber in coal or mineral naphtha, and after-
wards mixing the solutions thoroughly with heat. Marine glue is
dissolved by naphtha, ether, or a solution of potash.

Cement for attaching Gutta Percha or India-rubber to Glass
Slides(Hartin). — One part of gutta percha is to be cut into very
small pieces, and stirred at a gentle heat with 15 parts of oil of
turpentine. The gritty, insoluble matter, which is always con-
tained, is to be separated by straining through a linen cloth, and
then one part of shellac is to be added to the solution, kept at a
gentle heat, and occasionally stirred. The mixture is to be kept
hot until a drop, when allowed to fall upon a cool surface,
becomes tolerably hard. When required for use, the mixture is to
be heated, and a small quantity placed upon the slide upon which
the cell is to be fixed. The slide itself is then to be heated.

Dammar.— A good ringing cement is dammar dissolved in
chloroform, because if inclined to run under the cover it will
readily mix with the mounting materials. In drying, the dammar
shrinks, and thus renders it necessary to apply another coat in a
few hours' time.

A good and inexpensive Cement for Glycerine Mounts, etc.—
Dissolve 10 grs. of gum-ammoniac in i oz. of acetic acid (No. 8) ;
then add to this solution 2 drachms of Cox's gelatine. It flows
easily from the brush, and is waterproof, though rendered more so
if subsequently brushed over with a solution of 10 grs. of bichro-
mate of potash in i oz. of water. This cement is especially
recommended on account of its power of adhesion to glass, even
should there be a little glycerine left behind on the cover. After
the gelatine ring is dry, any cement may be used.

Ground Borax, mixed with plaster of Paris, makes a good
cement for large cells, etc.

French Cement. — A quantity of india-rubber scraps are care-
fully melted over a clear fire in a covered iron pot, but they must
not be permitted to catch fire. When the mass is quite fluid,
lime in a perfectly fine powder, having been slacked by exposure
to the air, is to be added in small quantities at a time,
the mi.xture being well stirred. When moderately thick, it is

42 THE MICROSCOPE

removed from the fire and well beaten in a mortar and moulded
in the hands until of the consistence of putty. It may then be
coloured with vermilion or other colours. This cement is quite
safe for mounting large and thick objects in fluid, as it rarely gets
hard.

Caoutchouc Cement.— Caoutchouc, cut small, J oz. ; mineral
naphtha, i pint. Dissolve with heat, and add shellac, | oz. This
cement requires great care in making.

Resin and Balsam Cement. — Resin, 2h oz. ; bees'-wax, ^ oz. ;
Canada balsam, i drachm. Dissolve with heat and mix. When
wanted for use, it must be rendered mouldable by the action of
heat. It is a strong cement.

Good Black Varnish.— Mix well in a mortar some lamp-black
and gold-size. It makes a good tough finishing varnish. Gold-
size, when added to Brunswick black, renders it less liable to crack.
It is better to keep nearly all the cements some time before use.

Mastic and Bismuth. — Dissolve gum mastic in chloroform, and
thicken with nitrate of bismuth. The solution of mastic should
be nearly saturated.

Kitton's Cement* is made of equal parts of white lead, red
lead, and litharge, all in powder. Grind together with a little tur-
pentine until thoroughly incorporated, and then mix with gold-
size. The mixture should be thin enough to use with a brush.
In using, one coat should be allowed to dry before applying
another. No more cement should be mixed with the gold-size
than is required for immediate use, as it sets quickly and becomes
unworkable. For balsam or glycerine-jelly mounts almost any
varnish will do, but for fluids, glycerine, etc., it is necessary to
have one tough, which will prevent leakage.

Liquid Glue.— Dissolve shellac in wood naphtha at a very low
temperature, until the mixture is of the required consistency. It
makes a very brittle varnish, but is improved by the addition of a
little glycerine and makes very good cells.

Guaiacum Varnish.— Gum guaiacum, 2 ounces; shellac, 2
ounces ; methylated spirit, 10 ounces. Powder the guaiacum and
dissolve it in the spirit, filter and then add the shellac. Keep the

* Moiitldy Microscopical Journal, Oct., 1876.

AND HOW TO USE IT.

4a

whole in a jar, surrounded by warm water, until it dissolves.

Matt Varnish.— Take gum mastic, 40 grs. ; gum sandarac, 160
grs. ; methylated ether, 4 oz. ; benzole, i| oz. Dissolve the gums
in the fluids and triturate in a mortar.

Black Matt Varnish.— Gum mastic, 50 grs. ; gum sandarac,
200 grs. ; methylated ether, i^ oz. ; benzole, ^ oz. Dissolve the
gums in the fluids and triturate in a mortar, with sufficient lamp-
black of finest quality.

French Polish. — Shellac, 3 oz. ; gum sandarac, -| oz. ; methy-
lated spirit, I pint. French polish is sometimes coloured with
gum-dragon, etc.

Dammar and Benzole. — Gum dammar, i o;-. ; benzole, 2 oz.

Mastic and Benzole. — Gum mastic, 4 oz. ; benzole, 3 oz.

Canada Balsam Varnish (for rendering ground-glass transpa-
rent).— Take 4 oz. of Canada balsam and bake in a cool oven till
quite brittle. When cooled, dissolve this in 1 2 oz. of benzole, in
which \ oz. of mastic has been previously dissolved.

Brown Varnish.— Pure india-rubber, 20 grs. ; bisulphide of
carbon, q.s. ; shellac, 2 drachms ; methylated spirit, 8 oz. Dis-
solve the india-rubber in the smallest possible quantity of bisul-
phide of carbon, and add this to the alcohol in such a manner
that the whole is mixed without the formation of clots. Now add
the shellac, and place the jar containing the mixture in boiling
water, until the whole of the shellac is dissolved and the smell of
the bisulphide has disappeared.

Litharge and Glycerine.— If dry sifted litharge powder is
mixed with glycerine, it forms a cement which hardens rapidly in
air and water. It bears 275° C., is very resistant to re-agents,
and adhesive to all materials, articles to be cemented being pre-
viously moistened with glycerine. (J. C. Douglas.)

Copal Varnish (Winsor and Newton's) may be made as a sub-
stitute for Canada balsam by evaporating it gently over a spirit-
lamp in a suitable vessel until nearly all the solvent (turpentine) is
driven off and the residue becomes viscid. To this, while warm,
pure benzole may be added, until it is considered to be sufficiently
liquid. It may then be used like fluid balsam, with or without
heat. It is absolutely necessary to use pure benzole.

44. THE MICROSCOPE

American Cement (Dr. Hunt). — Take some zinc white, as sold
for painters' use, drain off the oil, and mix with Canada balsam,
dissolved very thin with chloroform. If it does not flow freely
from the brush, add a little turpentine. The mixture should be
about the thickness of cream and kept in a bottle with a glass
cap. Ring the slide with the cement, and paint on it with artists'
oil colours, thinned if necessary with turpentine, and when dry
varnish with very dilute balsam, to give it a gloss.

Liquid Cement. — Compound tragacanth powder and powdered
gum acacia from any chemist, and if these are well mixed in
equal parts and moistened according to requirements at the time
with dilute acetic acid, or, if the colour be not of any importance,
with ordinary vinegar, a strong and lasting cement will be
obtained.

"White Hard Varnish consists of gum sandarac dissolved in
spirits of wine, and mixed with turpentine varnish.

Zinc White is composed of benzole, 8 parts ; gum dammar, 8
parts ; oxide of zinc, i part. Mix the gum dammar and the
benzole, filter through cotton wadding, after which mix in the
oxide of zinc in a mortar, and again filter through the wadding.

Gelatine Cement.— For sections mounted in glycerine, undoubt-
edly the best method is Dr. Marsh's,* who suggests gelatine
solution as a cement for first fixing the slide. The reason for this
is that gelatine readily mixes with the glycerine in its immediate
neighbourhood. He prepares the solution by placing a small
quantity of gelatine in a narrow glass beaker, covering it with
water, and allowing the gelatine to take up as much of the water
as it will. Any superfluous water is poured off, mixture heated,
and three or four drops of creosote are added to each ounce of
the fluid. Keep in a small bottle, and each time that the mixture
is needed it is " rendered fluid by immersing the bottle containing
it in a cup of warm water." The slide must be perfectly freed
from glycerine by the aid of a camel-hair pencil and a damp
cloth. A ring of the gelatine fluid is painted round the edge of
the cover-glass. As soon as this is set, paint it over " with a solu-
tion of bichromate of potash, made by dissolving lo grs. of that

* Dr. S. Marsh's " Section-Cutting, etc.," 2nd edition.

AND HOW TO USE IT. 45

salt in I oz. of distilled water." He recommends that "this
application of potash should be made in the daytime, as the
action of daylight upon it, in conjunction with the gelatine, is to
render the latter insoluble in water." Wash well in methylated
spirit, to remove all the glycerine, and then run on a ring of zinc
white, which may be repeated until a good firm ring is made. To
keep the brushes clean, I always have a little phial of turpentine
or benzole for zinc white, and warm water for the size, glue, or
gelatine. When zinc white becomes too thick to run readily,
dilute with benzole, but only when absolutely necessary.

Dammar Cement — Dissolve gum dammar in benzole, and add
one-third gold-size. It dries quickly, and is preferably used as a
first coat for fixing the cover-glass when glycerine is used for
mounting. If the square covers are employed, they may be fixed
by a simple method, much in vogue in Germany. A thin wax
taper is to be lighted, and being partially inverted for a few
seconds, the wax surrounding the wick will become melted.
After the slide has been freed from excess of glycerine, a drop of
this heated wax is allowed to fall upon each corner of the cover,
and a line of the melted wax run along the margins of the cover
between these points so as to perfectly surround it. If a good
coat of white zinc cement be subsequently laid over the wax, a
very durable and not unornamental line of union will have been
formed.

Coloured Cement. — Carefully evaporate shellac- varnish to con-
sistence of thin mucilage, and colour with a filtered, concen-
trated solution of aniline blue or gamboge in absolute alcohol.
Finally, about a scruple of castor-oil is to be added to each ounce
of the mixture, and, after some further evaporation, it is to be
preserved in a w«ll-closed vessel. If necessary, it may after a
time be diluted by a few drops of absolute alcohol.

Gum-Water, thickened with gilder's whiting until as thick as
treacle ; to each quarter of an ounce add two drops of glycerine.

Cement for Fixing Metals to Glass or Earthenware.— Mix
alum and plaster of Paris (finest kind) with water to a liquid
state or to a convenient paste. It forms an excellent cement for
many purposes, and resists the action of water for a considerable
time.

46 THE MICROSCOPE AND HOW TO USE IT.

Certain precautions are necessary to be observed in using
varnishing fluid or glycerine preparations : — i. — Use no more
glycerine or fluid than is just necessary to fill up the space
beneath the cover. 2. — If the medium should escape beyond the
cover-glass, soak it up with a piece of blotting-paper, and be
careful not to press the cover, or the cement will run into the cell.

Many students find the white zinc has run under the covers in
course of time. The only remedy I believe is to wash off and
clean with benzole ; then slightly warm the slide and lift off the
cover-glass. I believe it results from not using a varnish previous
to the white zinc. A friend of mine recommends two coats of
" painters' knotting " before laying on the coloured rings, and has
seldom a slide spoiled.

Smith's New Cement. — This is especially adapted for slides
mounted in the stannous chloride mounting medium. It is made
by diluting a somewhat thick shellac cement with benzole, and
adding sufficient litharge to give a consistency about the same as
the white zinc cement. It dries very quickly, forms very hard
rings, and it becomes dark-brown on exposure. A thin coat
should first be applied, and when this is well dried add as many
more as required.

Strong Cements for attaching Brass Cells to Glass Slides.—

(1) Carbonate of lead, | oz. ; red oxide of lead, | oz. ; litharge,
1 1 oz. Grind thoroughly together in a mortar. Stir some of this
into enough gold-size to make it work stiffly. If too much
adheres to the work, turn it off on turn-table when a little set.

(2) Best quality gum-arabic. Dissolve in cider-vinegar; add a
little sugar.

Mucilage for Slide Labels. — Dissolve 2 oz. dextrine in i oz.
acetic acid, diluted with 5 oz. water; when dissolved, add i oz.
alcohol. This is the same as that used for postage-stamps.

Literary. — The Shell-collector's Handbook for the Field, by
J. W. Williams, M.A., D.Sc, Editor of The Naturalisfs Monthly,
giving directions as to the collecting and preserving of British
Land and Fresh-Water Shells, and describing the habitat of each.
This volume will be iniblished immediately by Messrs. Roper and
Drowley of Ludgate Hill, and will give full details of every genus,
species, and variety known to the Conchological Society up to
date of publication.

[47]

Ibalf^an^lbour at tbc fllMcroecopc,

Mitb mv, Uuffcn Mest, if.X.S., jf.lR./ID.S., etc.

Onosma tauricu? (Plate III., Figs, i, 2, 3). — I am much obliged
to our friend, J. Carpenter (p. 51), for his reference to the article
on stellate hairs in Science Gossip. His description of the plant
scarcely does justice to its merits. I call it a dainty little flower,
which must now possess special interest to us as microscopists.
It is scarcely necessary to apologise for introducing a figure from
The Botanic Garden, Vol. II., No. 234. The name comes from
the Greek oa^i] (psiue), smell or savour. " When the soil is very
dry, and the situation sufficiently warm and sheltered to support it
in health, this little plant (only three inches high) becomes desir-
able as an ornament to the fiower-border." The preparation
before us becomes an interesting companion to a specimen of
the leaf mounted as an opaque object by another member.
Examining the leaf with which we are now favoured, I should
prefer it mounted in a cell deep enough to prevent disarrangement
by pressure. We should then see its connection with Lycopsis
arvensis (Fig. 5). In the latter there are large hairs seated on an
expanded cellular base, having carbonate of lime in the cells.
Both plants belong to the same natural order (Boraginace^).
Now, if each of the basal cells were produced into a spine, the
conditions presented by Onosma would be found. Imagine the
basal cells to communicate with the central spine, and to secrete a
highly irritating fluid, and we should have what is found in the
stings of nettles (Fig. 4) and the loasas.

Scales from Bracken (Plate III., Figs. 6 and 7) form a charming
object. ''A thing of beauty is a joy for ever." With this grace-
ful fern growing in our hedges, and over acres of common around,
I yet was unaware of the beautiful scale it bears, the technical
name for which is ranienta (chaffy scales). I must ask on what
part of the plant they are situated. Seeking them lately, I could
only get on the young, still buried shoots, long jointed hairs (Fig.
7), which form a thick felted covering, which wraps it up like a
warm blanket against the frost.

Fern (oblique section), probably Bracken ; shows well the
structure of the "■' Scalar if arm vessels" so characteristic of ferns.
Henfrey says, " These, so-called from the ladder-like markings, are
a very regular form of the reticulated type" (of ducts); "this
regularity appearing to depend however upon the relation between
the markings of the adjacent organs. ... In the scalariform
ducts a spiral fibrous deposit is conjoined into a network by

48 HALF-AN-HOUR AT

vertical fibres placed opposite the intercellular passages or the
meeting angles of contiguous cells or ducts^ leaving regular slit-like
spaces opposite the cavities of the adjacent cells. This form is
especially characteristic of the Ferns ; but it occurs also commonly
in the Dicotyledons in a less regular form, passing quite insensibly
into Pitted Ducts, as in the wood of Eryngiian maritimufn ; the
scalariform vessels of Ferns are often slightly unroUable." — (Micro.
Diet, 2nd ed., p. 640).

Ducts very similar are found in the Wheat Root, in the stem
of Vegetable Marrow, and elsewhere; indeed, I have often been
struck with the close similarity in structure between the ducts of
some common plants and those generally considered peculiar to
ferns.

Sections of Sugar-Cane (Plate IV., Figs, i and 2). — The
transverse section is more satisfactory than the longitudinal, which
would have been better if put in glycerine. The type of struc-
ture is very interesting, as connecting our ordinary fistulose
grasses with the compound structure met with in palms. There
are in the sugar-cane smaller ducts having a structure I have not
met with elsewhere — viz., distant annuli with the walls of the
vessels closely porose. These should be exhibited, as well as the
ectoderm, the structure of which is highly characteristic. Pieces
of sugar-cane in the fresh state are not unfrequently to be met
with.

Periploca Graeca, tr. sec. (PI. V.). — The special feature of
interest consists in the dark masses of inspissated proper juice.
Lindley tells us that "the milk of Periploca Graca is very acrid,
and has been employed by Orientals as a wolf-poison " (Lindley's
" Vegetable Kingdom," p. 626). I do not know the plant, which
belongs to the Asclepiadacece. This order contains the beautiful
Hoya carnosa and the singular Stapelias, the odour of whose
flowers is so foetid that they are commonly known by the name of
" carrion-flowers." Longitudinal sections showing the laticiferous
vessels and the ducts are required to complete the information
partially afforded by this specimen. In sections of the stem of
white poppy, the dark inspissated juice (opium) may be seen, much
as in the present slide.

Rhubarb, long, sec (Plate IV., Fig. 3), showing spiral vessels
and raphides /// situ as an opaque object, was shown a short time
ago, and excited much interest in those who had the pleasure of
seeing it. Wishing to know more about it, I have ascertained
that it was a piece of one of the dead, decaying leaf-stalks, which
at the date of writing were to be obtained in plenty where the
plant is cultivated. These are to be cut in short lengths, then
made into thin slices, and slightly pressed. A slide so prepared
should be in every cabinet.

THE MICROSCOPE. 49

Calyx of Deutzia gracilis (PL VI., Figs, i, 2, and 3).— Sure,
never were more lovely stars presented to us than these. The
plant belongs to a very small natural order {Philadelphacece). Four
species are cultivated in this country, all characterised by these
lovely diamond-spangled stars. D. scahra is in common cultiva-
tion, "the rough leaves of which are used in Japan" (its native
country) " by polishers " (Lindley's " Vegetable Kingdom," p.
750), like the stems of the " Dutch Rush " i^Equisetum hyemale)
with us. A lovely companion to this slide may be obtained from
the young shoots of this plant {D. scabra), mounted just as they
are. Here the stars shine out from a pinky purple ground.

Pollen of Shamrock (PL VI., Figs. 4 and 5). — "What is the
shamrock ? the national badge of Ould Erin." This question
has given rise to much discussion. By my valued friend, the
late Robert Ball, of Trinity College, Dublin, I was informed that
the educated Irish consider Oxalis aceiosella to be the true plant,
whilst the common people take the hop-trefoil {lifedicago hipulind)
for it, and have curious superstitions connected with finding four-
leaved exam])les of it — perhaps on " St. Patrick's day in the
morning." The general conclusion is that St. Patrick pointed his
hearers for an illustration of the Trinity to the first trifoliate leaf
to hand. If preaching in a wood, this might likely be the grace-
ful sorrel ; if in the meadows, then the trefoil. As it would be
necessary to wait, at any rate, for flowers of O. acefosella, I have
examined the pollen of O. floril>u?ida, an almost perennially-bloom-
ing, indoor plant, with flowers of a most beautiful rose colour.
Finding the pollen in the plant, with its elliptic outline, three deep
longitudinal sulci, and punctato-reticulate surface, to agree with
that in the slide before us, I think we may conclude that the
pollen was from the wood-sorrel.

EggofBot-Fly (PL VL, Figs. 5— 11).— With reference to H.
E. Freeman's remarks (p. 51), the ai)parent "hole " in the egg of
bot-fly is really a deep-rounded hollow ; its use, I suspect, to be
for attachment of a ligament of union between the lid and the
body of the egg-shell. The presence of the basal membranous
wings on the shell previous to hatching is a highly curious and
suggestive fact. They are special modifications of the alae on
the eggs of the lesser house-fly {Miisca domestica).

Stomach of Bee (PL VI. , Fig. 12). — The distribution of the
tracheae to the stomach of bee depends for its value on the
number, situation, size, and mode of arborescence. There is no
spiral present in the very fine ramifications. A valuable paper on
the anatomy of tracheae in insects, by Sir John Lubbock, wiU be
found in "Transactions of the Linn.Ean Society," also some
useful notes by B. T. Lowne in his work on "The Blow-Fly."
New Series. Vol. I. E

50 HALF-AN-nOUR AT THE MICROSCOPE.

Small Fly from Greenhouse is a homopteron. If there be
four wings present, with two joints to each tarsus, it is a species of
Psylla; if two Avings, and one joint only in each tarsus, then it is
a Coccus. Systematic descriptions of the insects in these genera
are much required. Two species of Psylla may be readily pro-
cured for purposes of study in the summer : — One, Psylla huxi
(whose history is traced by Reaumur, " Memoires," Tom. III., PI.
XXIX., Fig. I — 1 6), causes the terminal shoots and young leaves
of the box tree to assume the appearance of buds. The other
inhabits the underside of leaves of the great nettle. Of the
CocctdcB, the most accessible example is the " scale-insect " infest-
ing leaves of the myrtle and oleander. Westwood (Intro. Mod.
Class. Insects, II., pp. 434 — 450) should be consulted for a
general view of the subject, and also from its giving references to
authorities who have written in detail, with figures.

Sponge, a piece of. — The following particulars are wanting to
make this specimen a satisfactory demonstration, or indeed of any
value ; it wants to be connected with other things of a similar
kind. We should also be told its scientific name ; in what
direction the section has been made ; and from what part, near
the base of attachment, or the distant part of the sponge ; its
size and habitat (as fresh-water or marine). These particulars, if
satisfactorily given, would impart real value to what otherwise is
almost valueless.

Sand-Blast Cells promise to be a valuable addition to the
means of the working microscopist. One of the most important
questions in mounting at the present time is. How to display
objects wit/iout crushing, readily, without loss of time involved in
making, or the extra heavy weight of glass or tin cells. Large
sizes will be required, and it will be an advantage to have the
hollow not rounded, but in every part even with the surfaces of
the slide.

Bacteria in Sea-Air. — Moureau and Miquel, as a result of
their microscopical analyses of sea-air at various places, state that
when the breezes come from the sea the air is almost free from
bacteria. When 100 kilometres out at sea, the breezes coming
from the shore are almost free from them, thus proving that the
sea is an insurmountable barrier to contagion.

Exchange. — Well -mounted Slides of Foraminifera, Echinodermata,
Polyzoa, Diatomaceae, Fish-Scales, Crystals, and Spicules ; in exchange for
other well-mounted Slides. Lists exchanged.— W. M. Ranson, The Cottage,
Priory Road, Anfield, Liverpool.

[51]

Selccteb 1MotC6 from tbe Society's
1Rotc^BooF^0.

Onosma Cuticle, prepared for the polariscope (PI. III., Figs.
I — 5), is a very pleasing object with a i-inch o.g., with blue sele-
nite or dark ground. The plant is not much grown, the flowers
being inconspicuous. A short account of the plant and stellate
hairs will be found in Science Gossip, 187 1, p. 83. If viewed as
an opaque object, fresh leaves should be used, as the hairs shrivel
to a certain extent, and most leaves deteriorate rapidly when
mounted dry. J. Carpenter,

Eggs of Bot-Fly.— I have obtained several species of gadfly
this summer, and especially Gasierophilus equi, the bot-fly of the
horse. I send some eggs of this fly taken from the body of the
5 , and these show the grooves and filaments for attachment to
the hairs of the host in the itfunature egg. The cover is also
remarkably distinct (Plate VI., Fig. 7), and there is a hole, per-
fectly distinct, well seen in some of those on the slide, into which
a point on the cover probably fits, but I fail to see any corres-
ponding projection on the cover. I have just succeeded in
mounting an egg on the hair, showing the larva just emerging.
The lines on the surface are much more distinct on deposited
eggs. H. E. Freeman.

Scales of Pteris aquilina are very similar to some of those so
numerous on the back of the frond of Ccterach officinarum, but the
latter fern has circular scales mixed with the ovate ones.

H. F. Parsons.

Section of Asparagus, to compare with section of sugar-cane
(Plate IV.). The asparagus is, so far as I know, the only British
plant, except the Butcher's Broom, whose stem exhibits the
typical endogenous pattern. H. F. Parsons.

Shamrock.— Although the Irish of the present day use the
varieties of trefoil as the national emblem, the Oxalis acetosella
agrees with the description of the plant mentioned by early
writers, who state that it was eaten by the Irish and that it had a
sour taste. The trefoils or clovers could not have been thus
designated, as they do not answer the description, not being sour.

S. A. Brenan.

Spinnerets of Spider to Mount.— Put the spider in liquor
potassae for one night, then cut off the spinnerets with sharp scis-
sors, put then again in liquor potassae, and they will come clean.
Put them in glycerine and mount in jelly in a cell. W. LococK,

52 SELECTED NOTES FROM

Sugar-Cane. — There are one or two points in Mr. West's des-
cription of the sugar-cane, upon which if I express a doubt, that
doubt probably arises more from my own ignorance of the subject
than from any inaccuracy on his part. On page 7 of an element-
ary treatise by Edward Smith, forming part of Orr's Circle of the
Sciences, there occurs a description of the tissue called " sclero-
gen," accompanied by a figure illustrating its presence in the pith
of the elder, from which, and indeed from the appearance of the
slide under examination, I should infer that the markings seen on
the cell-walls were rather the result of sclerogenous deposit than,
as Mr. West observes, in the explanation to his plate (page 48
and Plate IV.), indicative of the presence of pores. Again, I
have been hitherto under the impression that there was no such
thing as a cambium layer in endogenous stems, at least in the
situation where it is found in exogens, between the bark and the
wood. Smith, at p. 87, says that the bark of endogens "cannot,
in any normal instances, be readily separated from the stem, as
may be readily seen by attempting to peel a cane. It does not
naturally crack, as does the bark of our forest-trees, but is hard,
dense, smooth, (usually) non-corrugated, unelastic, but slighdy
extensible, and is a permanent, unchanging structure " ; and
again, on p. 88, he says : — " It is the fashion to state that endo-
gens have no bark, since 7i07ie is separable from the wood, and that
the cuticle is simply the hardened, exposed cells of the stem,
with the ends of bundles of woody fibres intermixed." All this
seems to me incompatible with the thick zone of bark represented
by Mr. West's plate ; still less do I understand the existence of an
outer zone of growth, or cambium, in plants, which, as their name
implies, increase from within — that is, by the passing down of new
bundles of woody fibres from the leaves through the cellular
matrix of the stem. A. Hammond.

Eggs of Bot-Fly (pp. 49 and 51). — May I suggest that the circu-
lar marks on this object, about which some discussion appears to
have arisen, may be the micropyle, whereby the spermatic fila-
ments gain access to the yolk. Notices of this micropyle appear
in an article by Jabez Hogg on insect eggs in the Intellectual
Observer for December, 1867; it is also mentioned in Lowne's
"Anatomy of the Blow-Fly," pp. 114, 115. The wavy lines or
ridges noticed by Mr. West I take to be indicative of a cellular
structure in the chorion or eggshell. Such structure may be
noticed in more insect-eggs, and is mentioned by both Hogg and
Lowne. I have myself found it to assume a very curious form in
the eggs of the great green grasshopper, Acrida viridissivia^ In
this egg there is a strong chitinous covering surrounding the yolk,
upon which, as upon a basement, an external layer of dumb-bell-

Jotirria] of Microscopy N. SA/ol P], 3.

Sccd^. fj'^OTTi J'ter-vs a/p^jlmuy.

Journ al of Microscopy N. S , Vol 1 . Pi. 4 .

r 1.

^^ie^-

I

e.c.a

X50

X50

Stem of Sitgica- Cane.

Spiral Vessels and IiUj.J(iJ(\S i7( Stem, of Rhuharh.

THE society's NOTE-BOOKS. 53

shaped cells is found (see Plate VI., Fig. 12), the ends of which
are hexagonal and fit closely together, forming two continuous
surfaces, separated from each other by an intervening space,
which is bridged over by the central narrow portions of the cells,
as by so many pillars, like the blocks of coal which are left at
intervals to support the roof of a coal-pit. A. Hammond.

Insect Dissections.— I have been asked by a friend to describe
the manner in which I dissected some insect mounts Avhich I
lately sent round the Society. Pro botio publico, I will state that
the apparatus I employ is of a very simple description, consisting
of a few straight and bent needles, mounted in penholders, two
pairs of curved forceps obtained at the opticians, and also two
pairs of fine scissors, one bent in the plane of the blades, and
another curved at right angles to it, an old plano-convex lens from
a telescope mounted on the end of an arm, which projects from a
sliding piece which slides on a wooden upright fixed on a stand,
in the same manner as a bull's-eye condenser slides up and down
on its perpendicular support ; the whole made by a joiner. I
employ a bull's-eye with the edge of the wick, and another con-
denser to collect the rays rendered parallel by the bull's-eye, thus
getting a strong light. Use an old sardine-box for a dissecting
trough, with a leaded cork to pin the subject to, the operation
being all performed under water, with just sufficient to cover
them ; a minute knife extemporised by grinding down a packing-
needle, and setting it in a penholder, is often convenient when a
lancet is too large. The insects examined are mostly such as I
have collected during the summer months and preserved in spirit.
When the integument is to be studied, tlie " innards " should be
dissolved out by soaking in potash and afterwards washed and
brushed out. A. Hammond.

EXPLANATION OF PLATES III., IV., V., VL

Plate III.

Fig. 1. — Oaosma tauricum. Drawn by Tuffen West.
,, 2. — Leaf of ditto, natural size.
,, 3. — Stellate hair from underside of leaf, seen as an opaque object,

X 90. Drawn by John Carpenter.
,, 4. — Diag-ramuiatic sketch of hair of Stinging Nettle.
,, 5. — Ditto hair of Lycopsis.
,, 6. — Scale from Bracken, Ptevls aqiiilina, x 50.
,, 7. — Scale from young shoot of Bracken. Drawn by Tuffen West.
,, 8. — ficale ivom Alyssum calyciiium. Drawn by W. H. Beeby.

Plate IV.
Fig. 1. — Portion of a transverse section of stem of Sugar-Cane, x 50.
ecd. , ectoderm, outer layer of cells having stomata or epider-
mis. Within this is the bark, between which and the woody

54 SELECTED NOTES FROM THE SOCIETY'S NOTE-BOOKS.

portion of the stem is the zone of growth — cambium — indi-
cated by cb. ; v.b., v.b., vascular bundles, porous and annular
vessels embedded in a mass of wood-cells ; c.t., cellular tissue.

Fig. 2. — Portion of a longitudinal section ; c.t., cellular tissue, the
elements of which are seen to be porous ; 2>-^-; porous vessels,
not very distinctly seen, owing to surrounding wood-cells.

,, 3. — Si^iral vessels and raphides from stem of rhubarb, x 100.

Plate V.

Transverse section of stem of Periploca Grceca, x 50, showing to a
certain extent the structure of the pith, ^5. ; wood, w. ; and bark, b.

The wood is seen to be lax, with very numerous large ducts, d.d. ;
from minute fragments to be seen here and there, these are evidently
porous ducts, cb. indicates the cambium layer, or common centre of
growth for wood and bark, equivalent to the basement membrane in
animal tissues; /i./i., bases of hairs arising from the ectoderm ; m,.r.,
m.r., medullary rays, very numerous and fine, whose purpose is to
keep up the vital connection between the central structures and the
seat of vital growth. These are seen to be continued, though in an
imperfect form, into the bark. The black patches, present through-
out, but most strikingly so in the bark, are of an inspissated resinoid
juice, and constitute the feature of sj^ecial interest in the specimen.

Plate VI.

Fig. 1. — Flower of Deutzia (jraciUs, natural size, to show the position
whence the figures have been taken.

,, 2. — Portion of the ovary, with stellate hairs, x 50.

,, 3. — Portion of the petal on which these hairs are also sparingly
present, x 50.

,, 4, 5. — Pollen of Oxalis acetosella, end and side views.

,, G. — Empty egg-shell of Bot-fly, seen in profile.

,, 7. — One of the lids.

,, 8. — Outline of another lid, curled during the process of prepara-
tion for mounting.

,, 9. — Part of one of the shells more enlarged, to show that the
apparent hole is but a deep depression. The scale-like reti-
culation near the upper edge of a specimen is also shown, as
well as the way in which this passes gradually into undulated
transverse lines.

,, 10. — Front view of the upper part of the opening, to show the

deep hollow, now looking much like a hole.
,, 11.— Edge of a part of a specimen, to show the wavy transverse

lines to be really projecting ridges.

,, 12. — Transverse section of egg-shell of Acrida viridlssima, drawn
by A. Hammond.

,, 13. — Stomach of Bee, showing the beautifully arborescent charac-
ter of tracheae supplied to that part of this insect.

Plates IV., v., and VI. drawn by Tuifen West except Fig. 12,
Plate VI.

Journal of Microscopy Vol.1 PI. 5.

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Joui-nal of MicroscpoyN. S.Yol. Pi. 6.

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[55]

i^ucric^ ant) IRcplics,

[As the Scientific Enquirer is now discontinued, we shall publish in each
issue of the Journal such Questions as we may receive, together with
Answers to the same contributed by some of our specialists. — Ed.]

I. — What is the best way to harden the Earth-worm, so that
sections may be cut from it ? R. S. P.

Alcohol, I think, is the best medium. I have never tried to
cut sections of earth-worms, but a few days ago I put a large slug
in alcohol, and it is now hard enough to allow transverse sections
to be cut from it with a razor. If the querist finds any difficulty
in cutting after the alcohol hardening, he can easily cut them with
a freezing microtome or by embedding in paraffin wax.

B.Sc, Plymouth.

2. — What is the best way to prepare and mount specimens of
Stigmas to show Pollen-tubes ? S. G.

The Antirrhinum pistil is a good one to show the pollen-tubes,
but it is not in the stigma where they are to be found, but in the
style. The greatest difficulty is not in the mounting, but in
getting the pistil at the exact time when the pollen is throwing out
the tubes. It is best mounted dry on one of the shdes where the
cell is made on the glass, or make a cell with a turn-table and
Bates' black varnish or brown cement. By dividing the pistil in
two halves, it is generally transparent enough to see through ; if
not, it can only be teazed out with needles or cut with a freezing
microtome. B.Sc, Plymouth.

3. — How are the Concentric Circles in a transverse section
of Beet-root (looking like annual markings in timber) to be
accounted for ? R. S. P.

The well-known concentric rings of wood, broken up by
medullary rays, which alternate regularly with the zones of bast,
and which number as many as six or more in a strong one-year-old
beet-root, are due to an anomalous secondary thickening or
growth of the root. This anomalous thickening, which is met
with in other plants besides beet, and the process which produces
the phenomena that so closely resembles the annual rings in
timber, cannot be fully exj:)lained without the use of many botani-
cal terms. In the root of the beet, as the growth proceeds, there
are differentiated in it strands of wood and of bast corresponding

56 KE VIEWS.

to them, and medullary rays, which are further developed after the
manner of normal secondary thickening. Later on, the growth of
this secondary thickening zone ceases, and it is replaced by a new
one similar to it, which had already begun to appear at the outer
limit of the second layer of bast, in the form of tangential divi-
sions, which arise at scattered points, and extend thence laterally
all round. And since the same process is repeated, there arise in
the beet-root the annular markings. This short explanation is
condensed from De Bary's work, to which reference should be
made for fuller details. H. Vv^ Lett, ]\LA.

The concentric circles in beet-root are to be accounted for by
the fact that the root is actually the stem of the plant, and the
circles are those common to stems of exogenous plants.

E.Sc, Plymouth.

IRcvicwe.

Fresh-AVater Alg^ of the United States (exclusive of

the Diatomacese), Complemental to Desmids of the United States ; with
2,300 ilhistiations, covering 157 coloured plates, including 9 additional plates
of Desmids. By the Rev. Francis Wolle, member of the American Society of
Microscopists. Royal Svo. Vol. I., text pp. 364; Vol. II., Plates Nos. LIV.
to CCX. Price $10.00. (London : Dulau and Co., 37 Soho Square.)

We have before us two magnificent volumes, containing a vast amount of
most valuable knowledge. In the introductory chapter the author discusses
the polymorphiim of the Algre and its bearing upon the system of classifica-
tion, and suggests that sooner or later the whole system of classification must
be changed.

In these volumes the Algae are arranged under three classes, viz. — Rhodo-
phycese, Chlorophycere, and Cyanophycese, and are subdivided in the following
manner : —

Class I. — Rhodgi'HYCe.^;.

Order I. — Flon'deic. Families: — I, Lemaneacere ; 2, Porphyraceae ;
3, Batrachospermacece ; 4, Hildebrandtiaceae.

Class II. — Chlorophyce^.

Order II. — Confervoidea:. Families: — 5, ColeochcetaceK ; 6, Gidogonia-
cere ; 7, SjihceropleaceEe ; 8, Confervacete ; 9, Pithopehraceas.

Order III. — SipIionCiC. Families: — 10, Vaucheriacea; ; 11, Botrydiaceae.

Order IV. — Protococcoidecv. Families: — 12, \'olvocacece ; 13, Protococca-
cene ; 14, Palmellaceas ; 15, Chytridiea;.

Order V. — Zygosporeic. Families: — 16, Conjugala: ; 17, Desmidiea;.

Class III. — Cyangphyce.^.

Order VI. — Schizosporeic. Families: — 18, Nostocaceas ; 19, Chroococca-
cese.

The descriptions, both of genera and species, are full and good ; the
measurements of the cells, spores, and filaments are given in micromillimetres.
The labour of producing these volumes must have been immense, and w^e are

REVIEWS. 5t

told it was performed by the author himself; and as doubtless a great majority
of the forms descrilied may be found in England, students will do well to secure a
copy. The price in the United vStates is $10.00, or perhaps a trifle over two
guineas, including postage.

Die Naturlichen Pflanzenfamilien nebst ihren Gattungen
und wichtigeren Arten inshe sondere den Nutzhflanzen bearebelit unter
Mitwirkung zahlreicher hei'vorragender Fachgelehrten, Von A. Engler und K.
Pranth. Royal 8vo. (Leipzig : Wilhelm Engelmann ; London : Williams
and Norgate. 1S87.)

We have received the first twelve parts of this very important work. Each
part consists' of 48 pages, and is sold to subscribers at Ml. 50 (about is. 6d.),
It is admirably illustrated with a great number of very fine wood engravings,
showing anatomy, structural detail, etc. The orders which already have been
treated of, either wholly or in part, are : — Palmace^, by O. Drude ; Junca-
cere, F. Buchenan ; Stemynacete and Liliacea;, A. Engler ; Cicadacece and
Coniferas, A. W. Eichler, A. Englar, and K. Pranth ; Cyclanthacea;, O.
Drude ; Htemodoracere, F. Pax ; Gramin.\?, E. Ilackel : GnetaceK, A. W.
Eichler ; Aracere, A. Engler ; AmaryllidaccDe, Volloziaceie, Taccaceee, Drosco-
raceae, and IridacK, F. Pax ; Flagellariaceae, A. Engler ; Restionaceas and
Centralepidacese, G. Hieronymus ; Mayacacese and Xyridacese, A. Engler ;
EriocaulaceK, G. Hieronymus ; Rapateacese, A. Engler ; Bromeliacese, L.
Wittmack. It will be seen from the above that the list of collaborators is very
large, and embraces the most eminent German botanists. Each order is
treated in a thoroughly comprehensive manner under the following subjects : —
Literature, Botanical Characteristics, Organs of Vegetation, Anatomy,
Arrangement of Flowers and their Growth, Pollination, Fruit and ijeeds.
Geographical Distribution, Affinities, and Classification. In the 12 parts
before us, no fewer than 1,950 illustrations have been given and described
under 421 figures. We notice that the price to non-subscribers is M.3 for each
part and to subscribers I\l.i.50 (is. 6d).

The Flora of Howth. By H. C. Hart, F.L.S. Post 8vo,

pp. 137. (Dublin : Hodges, Figgis, and Co. 1887.)

This book will prove interesting to the naturalist generally and to the
botanist in particular. The introduction, which occupies 10 pages, gives an
account of the geological and other features of the promontory. The village
of Howth is situated about nine miles from Dublin. The author enumerates
545 species of plants found in the parish. A map of Howth (scale, 6 inches
to the mile) will be found at the end of the book.

Journal of Morphology. Edited by C. O. Whitman, with
the co-operation of Edward Phelps Allis, Junior. Vol. I., No. i, Sept., 1887.
Crown 4to. (London : W. P. Collins, 157 Great Portland St. ; Boston,
U.S.A. : Ginn and Co.)

The first part of this nev/ and important work has come to hand and con-
tains several valuable papers: — I.- — Spliyraimra osleri, a contribution to Ameri-
can Helminthology, by Profs. R. Ramsay Wright and A. B. Macullum ; 2. — ■
Development of the Compound Eyes of Crangon, by Dr. J. S. Kingsley ; 3. —
Eyes of Molluscs and Arthropods, by William Patten ; 4. — On the Phyloge-
netic Arrangement of the Sauropsidje, by Dr. G. Baur ; 5. — A ccjntribution to
the History of the Cierm-Layers in Clepsine, by C. O. Whitman ; 6. — The
Germ-Bands in Lumbricus, by Prof. E. B. Wilson ;, 7. — Studies on the Eyes of
Arthropods and Development of the Eyes of Vespa, with Observations on the
ocelli of some insects, by Dr. Wm. Patten. There are seven folding and one
single plate. The whole work is handsomely got up on stout paper.

58 EEVIEWS.

The Naturalist's Diary : A Day-Book of Meteorology,
Phenology, and Rural Biology. Arranged and edited by Charles Roberts,
F.R.C.S., L.R.C.S. 8vo, pp. xlvi. — 368. (London : Swan Sonnenschein
and Co.) Price 2s.6d.

This book, which contains a coloured chart showing the blossoming of
spring flowers in Europe, and a lengthy introduction on natural periodic phe-
nomena, etc., should be the daily companion of every naturalist. It
consists of a page for every day in the year, with blank spaces for memoranda
on the following subjects : — Temperature, Barometer, Rainfall, Plants and
Trees Blooming, Trees and Shrubs Leafing, Insects, Larvae, etc., appearing,
Fish, Reptiles, Birds' migration, song, nesting, etc., Animals seen breeding,
etc., Shooting, Fishing, Sports, etc. This book is suitable for any year, and
should be filled by daily entries during the year.

A Manual of Elementary Microscopical Manipulation,

for the use of Amateurs. By T. Charters White, M.R.C.S., L.D.S.,
F.R.M.S., etc. i2mo, pp. 104. (London : Roper and Drowley. 1887.)
Price 2s. 6d.

This little work is designed with the aid of affording the youngest begin-
ner such directions for preparing objects of interest and instruction in an
elementary but at the same time such a complete manner that he may grasp
their details and work out his studies with the most satisfactory results. The
author is so well known as a microscopist, that it appears quite superfluous for
us to say anything further.

Unfinished Worlds : A Study in Astronomy. By S. H.
Parkes, F.R.A.S., F.L.S., etc. 8vo, pp. xii.— 230. (London: Ilodder and
Stoughton. 1887.) Price 5s.

In the work before us, we have a brief summary of the results of recent
scientific discovery regarding the present physical condition of those far-off
worlds which the telescope and the spectroscope have revealed to us. It
treats of Nebula, Coloured Stars, the Sun, the Earth, Jupiter, Mars, Comets,
etc. The book is intended for general readers, and is well illustrated with
lithographic plates.

Short Studies from Nature. By various Authors. Cr. 8vo,
pp.386. (London: Cassell and Co.)

This interesting book has some very instructive and popularly-written
chapters on Bats, Flame, Birds of Passage, Snow, Dragon Flies, Oak Apples,
Comets, Caves, the Glow-Worm, and Minute Organisms, written by W. S.
Dallas, F.L.S., Prof. F. R. Eaton-Lowe, Dr. Robt. Brown, F.L.S., and
others. The chapters are well illustrated, a pretty plate showing various
coloured flames forming the frontispiece. We notice that the wood engraving
on page 146, which represents the dragon-fly emerging from the pupa, is
reversed. We have read the book with much pleasure.

Living Lights : A Popular Account of Phosphorescent Ani-
mals and Vegetables. By Charles Frederick Holder. Foolscap 410, pp. xvi.-
187. (London : Sampson, Low, and Co. 1887.) Price 8s. 6d.

The object of this splendid volume is " to interest young people in natural
history by the presentation of an attractive— indeed, marvellous— phase of
nature, and to encourage healthful outdoor observation, as well as habits of
investigation." The descriptions of these wonderful animals and plants are so
charmingly written, that, with respect to a great majority of his readers, the
author cannot fail to attain his object. The illustrations are numerous and
well-executed.

REVIEWS.

59

Ants, Bees, Dragon Flies, Earwigs, Crickets, and Flies.

By W. Harcourt Bath. Cr. 8vo, pp. io8. (London : S. Sonnenschein and
Co. 1888.) Trice is.

We are pleased to welcome another of the Young Collector's valuable
little handbooks. The one now before us treats of the orders — Ilymenoptera,
Neuroptera, Orthoptera, Hemiptera, and Diptera, and we are glad to find Mr.
Bath endeavouring to encourage the study of these most interesting, though
much neglected, order of the class INSECTA. The space at his disposal in so
small a book is of course very limited. He has, however, done much by way
of illustrations, of which we find no fewer than 156, to show the extent of the
field open to the young collector.

Bird Stories, Old and New, told in Pictures and Prose. By
Harrison Weir. .Sm. 4to, pp. 63. (London : Society for Promoting Christian
Knowledge. )

Mr. Harrison Weir tells many interesting stories of birds in his own
peculiarly pleasant manner ; ever}' page of the book is beautifully illustrated
with a number of etchings. It is printed throughout in sepia-toned ink, on
stout antique paper, which has altogether a pleasing, though somewhat
unusual efiect.

Great Waterfalls, Cataracts, and Geysers, described
and illustrated. By John Gibson. Cr. 8vo, pp. 288. (London : T. Nelson
and Sons. 1887.)

Describing the Falls of Niagara ; of the Yosemite Valley ; of the Yellow-
stone Region ; Kaieteur Falls ; Falls of Tequendama ; Falls of Montmorency,
Chaudiere, and Lorette ; Cataracts of Orinoco and Parana : Falls of the
Zambesi ; Falls and Cataracts of the Nile ; Falls of the Senegal ; Cataracts
and Rapids of the Congo ; some Swiss Falls ; Falls of the Clyde and Foyers ;
Cascade of Gavarnie ; Geysers of the Yellowstone Region ; Geysers of Ice-
land ; and the Geysers of New Zealand. It is nicely illustrated with 32 plates.

The Constellations and how to find them. Thirteen
Maps showing the position of the Constellations in the Sky during each month
of any year. A popular and simple guide to a knowledge of the Starry
Heavens. With introduction, general explanations, and a separate descrip-
tion of each map. By William Peek, F.R.A.S. Third edition, 4to.
Price, 2s. 6d. (Edinburgh and London : Gall and Inglis. )

An Easy Guide to the Constellations, with a Miniature
Atlas of the Stars. By the Rev. James Gall. i6mo. (Edinburgh and
London : Gall and Inglis.)

Two most useful books, by studying which a very fair knowledge of the
constellations may be readily acquired. The star-maps in both books are
printed in white on a very deep blue ground. The constellations are very
distinctly shown.

History of the Pacific States of North America. By
Hubert Howe Bancroft. Central America. Vol. II., from 1530 — 1800.
(San Francisco : The History Pub. Co.)

We have here an account of the Conquest of Peru ; the Government of
Castilla del Oro ; the Colonisation of Veragua ; the Occupation of Guate-
mala, Honduras, Nicaragua, and Costa Rica ; Affairs in Chiapas, Belize, and
Panama ; and the deeds of the Buccaneers — the adventures of Morgan and
other piratical raids — among other matters of interest are here given. The
Revolt of the Natives, the Quarrels of the Spaniards among themselves, and the
position of the Clergy in the affairs of conquest and occupation, are likewise
clearly set forth. The volume is one of absorbing interest throughout,

60 REVIEWS.

Pictorial Geography of the British Isles. By Mary

E. Palgrave. Oblong 4to, pp. 102. (London : Society for Promoting Christian
Knowledge. 1887. Price 5s.

This beautifully illustrated book teaches the elements of Physical and
Political Geography by pictures as well as letterpress. Its various chapters
describe how our Scenery was made ; a Summary of the British Scenery ; the
Coasts, Mountains, and Hills ; Plains and Rivers ; Lakes and Islands ;
Historical Scenery ; and the Industrial Geography of the British Isles. The
pictures are numerous and effective.

Physical Geography prepared on a new and original plan.

By John D. Quackenbos, A.M., M.D., John S. Newberry, M.D., LL.D.,
Charles H. Hitchcock, Ph.D., W. Le Conte Stevens, Ph.D., Henry Gannett,
William H. Dall, C. Hart Merriam, M.D., Nathiel L. Britton, E.M., Ph.D.,
Geo. F. Kemtz, Lieut. George M. Stoney. Sq. 410. (New York : D. Apple-
ton and Co.)

With such an array of names we are naturally led to look for something
unusually good, and we unhesitatingly say we are by no means disappointed.
The work is illustrated with a great number of well executed engravings,
diagrams, and maps in colours. Each author takes up the special subject for
which he was most fitted, and, as a result, we have a work of uncommon
excellence. Several schoolmasters, to whom we have submitted the book,
speak of it in the highest terms. A chapter at the end of the book is devoted to
the Geological History of the Physical features of the United States.

A Dictionary of Place Names, giving the Derivations.

By C. Blackie, with an Introduction by John Stuart Blackie. Third edition,
revised. Cr. 8vo, pp. xl. — 243. (London : John Murray. 1887.)

Geographical Etymology is a subject which is not so often studied as
perhaps it might be. In this work the root words are arranged alphabetically,
and as the names of Foreign as well as of English places are explained, the
book will doubtless prove of special and peculiar interest to the tourist. It is
undoubtedly the result of much patient research and study.

Imperial Globe Atlas of Modern and Ancient Geography,
with Index of 20,coo Names. (London and Edinburgh : Gall and Inglis.)
Price 3s. 6d.

This capital atlas consists of 33 imperial 410 maps (size, 14^ by iij), nicely
coloured and well engraved, and not so overcrowded with names as to be
indistinct. The index to the 20,000 names occupy 32 very closely printed
pages. This atlas is certainly a marvel of cheapness.

The Creator, and what we may know of the Method of
Creation. By \V. H. Dallinger, LL.D., F.R.S., etc. Svo, pp. S^. (London:
T. Woolmer. 1887.) Price 2s. 6d.

This is the Fernley Lecture for 1887, and is, with the exception of some
additional passages, printed as it was delivered. It addresses "thoughtful and
earnest minds, not concerned specially with questions of philosophy, metaphy-
sics, and science, but alive to the advanced knowledge and thought of our
times, and anxious to know, so far as in such a form it could be expressed, how
the great foundation of religious belief, the existence of Deity, is affected by
the splendid advance of our knowledge of nature." It is a most carefully
written discourse, and will unquestionably be read with profit by the thought-
ful student.

REVIEWS. 61

Oxford, Cambridge, and College of Preceptors' Ex-
amination Papers. By Rev. George Litting, M.A. , LL.B., and George
Home. Cr. 8vo, pp. iSo. (London Educational Supply Association.)

These questions embrace the following subjects : — Old and New Testa-
ment, English, Latin, and French Grammar, English History, Geography,
Arithmetic, Algebra, Euclid, Mechanics and Hydrostatics, Botany, and
Zoology. It is not pretended that they are the exact questions which will be
set in any given subject in any of these exams, but are fairly representative,
and the student will do well to master them.

The Examination Papers issued at the Ninth Examination

held by the Intermediate Education Board, in June, 1887. 8vo, pp. 93.
(Dublin : Browne and Nolan.) Price is.

These papers are prepared for Junior, Middle, and Senior grades of
students, and embrace Greek, Latin, English, French, German, Italian, and
Celtic ; Arithmetic, Book-keeping, Euclid, and Algebra ; Natural Philosophy,
Chemistry, Botany, Drawing (Geometrical and Perspective), Music, and
Domestic Economy. We feel that we cannot too strongly impress on intend-
ing candidates the necessity of studying the last year's examination papers.

Stirring Adventures in African Travel. By Charles
Bruce. Cr. 8vo., pp. 256. (Edinburgh : W. P. Nimmo. 188S.)

An interesting account of some of our great explorers — Alongo Park,
Livingstone, Captain .Speke, .Sir Samuel Baker, Henry M. Stanley, and
others. Lion Adventures, Elephant, Buffalo, and Rhinoceros Hunting ;
Shipwreck, Captivity, and Bombardment. The book abounds in Natural
History incidents, and will be found both interesting and instructive. It is
well illustrated.

Facts and Fictions of Mental Healing. By Chas. M.
Barrows. Cr. 8vo, pp. 248. (Boston, U.S.A. : H. H. Carter and Karrich.
1887.)

The author tells us "he has not sought to compel the reader's assent, but
that it has been his aim to awaken thought, and deepen the reader's interest,
by fairly stating the evidence both for and against mental healing, and leave
him to decide for himself." He further says, " There are facts that prove the
possibility of such cures without a peradventure ; there are fictions, also,
which must be abandoned, if mental healing is to get and retain a hold upon
the popular attention."

Ten Great Events of History. Compiled and arranged
by James Johonnot. Cr. 8vo, pp. 264. (New York : D. Appleton and Co.
1887.)

The ten epochs here described are those that have been potential in
shaping subsequent events, and in which men have struck blows for human
liberty, against odds, and regardless of personal consequences. They are —
The Defence of Freedom by Greek Valour ; Crusades and the Crusaders ;
Defence of Freedom in Alpine Passes ; Bruce and Bannockljurn : Columbus
and the New World ; Defence of Freedom in Dutch Dikes ; The Invincible
Armada ; Freedom's Voyage to America ; Plassey, and how an Empire was
Won ; Lexington and Bunker's Hill. The book is nicely printed and illus-
trated, and the events are well described.

62 REVIEWS.

Factors of Life. Three Lectures on Health, Food, and

Education. By H. G. Seeley, F.R.S. Post Svo, pp. 191. (London : Society
for Promoting Christian Knowledge.)

This is a volume of the well-known " People's Library," and treats of the
three subjects in a plain and forcible manner, and will well repay thoughtful
reading.

Queer Chums : Being a narrative of a Midshipman's

Adventures and Escapes in Eighteen Hundred and War-time. By

Charles H. Eden. Illustrated by VV. H. Overend. Cr. Svo, pp. xii. — 312.
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This exceedingly interesting story is founded chiefly on facts that came
under the author's notice, and will be read with delight by many of our young
friends. It has several illustrations.

Practical Chemistry : a Course of Laboratory Work. By
M. M. Pattison Muir, M.A., and Douglass Carnegie, B.A. Cr. Svo, pp.
viii. — 224. Price 3s.

Elementary Chemistry. By M. M. Pattison Muir, M.A.,
and Charles Slater, M. A., M.B. Pp. viii, — 36S. Price 4s. 6d. (Cambridge
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These two books are intended to be used together, the one being comple-
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Science. The author's aim has been to arrange a progressive course of prac-
tical chemistry, in which as the experiments become more difficult, the reason-
ing becomes more close and accurate. Appendices are added, giving outlines
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entertain views rather different from those which generally prevail regarding
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endeavoured to make the teaching given in this book sound, so far as it goes ;
and have endeavoured to blend together the facts and principles of the science,
and at the same time to avoid speculation.

The Cremation of the Dead considered from an Esthetic,
Sanitary, Religious, Historical, Medico-Legal, and Economical Standpoint.
By Hugo Erichsen, M.D., with an Introductory Note by Sir T. Spencer
Wells, Bart., P'.R.S., late President of the Royal College of Surgeons of
England, Surgeon to the Queen's Household. Cr. Svo, pp. xiv. — 264.
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It is unnecessary to state that the writer of this book most unquestionably
believes in Cremation as the best mode of disposing of the dead; he tells us in
his preface that " for all who like cleanliness, for all who love true sentiment,
for all friends of economy, for all who venerate their dead, and for all who are
not afraid of reform, the book was written." We have read the book with
much interest, and can cordially recommend it to the notice of our many
readers. It is well illustrated.

Dainty Ditties ; or, Old Nursery Rhymes with New Tunes.
By Frank J. Allen. (London : Novello. Ewer, and Co.) Price is. 6d., or
bound in cloth, 2s. 6d.

The author of this cliarming little collection of melodies will be remem-
bered by many " Postal Microscopists " as a former member of the Society,
ftlany of the settings are very quaint and original.

REVIEWS. 63

A Manual of Buhl-Work and Marquetry, with Practical
Instructions for Learners, and 90 coloured designs. By William Bemrose.
Third edition, 4to, pp. 32. (London : Bemrose and Sons.) Price 6s.

This is published as a sequel to two other works — " Manual of Wood-
Carving " and " Fret-Cutting," and is written for the instruction of amateurs ;
the instructions being given in clear and simple language, free from all trade
technicalities, and accompanied by a series of progressive designs, which are
calculated to aid the student in the attainment of considerable excellence in
the art. In our estimation the professional wood-carver may study this book
to advantage. The coloured plates of designs are well executed.

Round Nature's Dial. By Helen Marion Burnside. Cr.
4to, pp.^ 180. (London : George Routledge and Sons.) Price 6s.

This splendid book for young people is divided into four sections — Spring,
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engraved and printed in colours by Edmund Evans.

Practical Guide to Photography. By Marion and Co.
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Marion and Co., Soho Square. 18S7.) Price 2s. 6d.

This very useful book, after commencing with a historical sketch of
Photography, gives thoroughly practical details of the process, and a chapter
on the Ferro-Prussiate process, enlarging, and lantern slides. There are a
number of illustrations.

A History of Photography, written as a Practical Guide
and an Introduction to its Latest Developments. By W. Jerome Harrison,
F.G.S. 8vo, pp. 136. (New York : Scoville Manufacturing Co. 1887.)

This nicely got up volume gives a History of Photography from its origin,
and describes the various methods that have been employed from the time of
Daguerre to the latest methods now in use. It contains also an Appendix by
Dr. Maddox, on the discovery of the Gelatino-Bromide Process, a Biographic
Sketch of the author, and a Portrait by the Moss-Type Engraving Co.

Principles of Education Practically Applied. By

J. M. Greenwood, A.M. Cr. 8vo, pp. 192. (New York : D. Appleton and
Co. 1887.) Price, §1.

The author tells us that his object is to impress upon the minds of
teachers the important question—" IIow shall I teach so as to have my pupils
become self-reliant, independent, manly men, and womanly women ? " And,
in plain language, he tells the teachers what to do as well as what to avoid.
His directions are simple, pointed, and emphatic.

Shore and Sea ; or, Stories of Great Vikings and Sea-
Captains. By W. Davenport Adams. Cr. 8vo, pp. vi.— 348. (London :
Hodder and Stoughton. 1S87.) Price 5s.

The first portion of this book deals with the adventures of the old Norse-
men, w^ho made their way to Iceland, Greenland, and Labrador. Then we
have the story of Sebastian Cabot, and of De Soto and his conquest of
Florida ; followed by an account of the early colonizers of Virginia ; the
Deeds and Sufferings of Henry Hudson, etc. The book is very interesting
and nicely illustrated.

64 REVIEWS.

Our Home. Our Friends. Our Pets. (London : Rout-
ledge and Sons.)

Three books of Original Verses, written by Airs. Sale Barker, editor of
" Little Wide- Awake," very beautifully illustrated by F. A. Fraser, Paul
Hardy, and A. W. Cooper. The verses are charming, and the illustrations
are uncommonly nice. We notice that " Our Home " is printed by Ernst
Haufmann, at Lahr, Baden, and "Our Friends," under the direction of Otto
Mayer, by Judd and Co., London.

Sandy Ross : A Tale of the Sea. i2mo, pp. 96.

Arctic Stories. i2mo, pp. 96. (London and Edinburgh:
Gall and Inglis. )

Two very interesting and nicely-illustrated tales for young people,
suitable as presents for them.

Every Band of Hope Boy's Reciter. Vols, i and 2, con-
taining Original Recitations and Dialogues. By S. Knowles. Royal i6nio,
pp. xiv. — 3S4. (Manchester : Brook and Chrystal ; London : National Tem-
perance Publication Depot, 337 Strand.) Price is. each.

A lot of good temperance recitations and dialogues in prose and verse.
suitable for young people's gatherings and Band of Hope meetings. Vol. L is
in its eighth and Vol. H. in its third edition.

The Silver Voice: A Fairy Tale. Post 8vo, pp. 57.
Price IS. 6d.

The Bairn's Annual. 8vo, pp. 192. (London : Field and
Tuer, The Leadenhall Press.) — Two exceedingly amusing books for the young.
The very comical illustrations in Tlie Silver Voice are hand-coloured.

The Journal of the Royal Microscopical Society for

October contains a Monograph of the Genus Lycoperdon, by G. Mason, with
2 plates.

Science Gossip for December has the continuation of an

article on Slug Gossip, and the continuation also of Notes on the Common
Frog in a state of Domestication ; and many other papers of general interest.

The World's Inhabitants ; or, Mankind, Animals, and

Plants. By G. T. Bettany. (London : Ward and Lock.) — Parts I and 2 are
occupied with the Inhabitants of Europe, commencing with the Early Inhab-
itants of the British Isles ; has reached (chap, xi.) The Belgians. These
numbers are well illustrated.

Amateur Work. (London : Ward and Lock.)— In the
December number of this useful work are instructions for making a very cheap
microscope, and a lot of other articles interesting to the amateur. The new
volume commenced in November. Each number contains a large plate of full-
sized working drawings for some useful articles of furniture.

Our Earth and its Story. Edited by Dr. Robert Brown.
(London: Cassell and Co.) — Part XI. (December) contains a coloured chart,
showing the Distribution of Saltness in the Ocean. The chapters in the
present part describe Valleys and Fjords, their nature and origin ; Marine
Denudation ; and the Formation of Coast Scenery. The illustrations are good.

Development of tF^e ^abpole.

By J. W. Gatehouse, F.I.C.

Part II.

Plates VII. and VII.

'^^^j>S=^"

SERIES of sections taken from a single egg on
March 5th is shown on Plate II., as stated in our
first article, p. 38. The form of this specimen had
by this time become considerably modified from
its original spherical shape, a portion represented
by Figs. 6 to 13 having become flattened and
elongated. The yelk mass also is penetrated by
two distinct cavities formed by the invagination of
the outer layers seen in Figs, i, 2, 10, 11, and 12.
These cavities form respectively the neural canal and the
mesenteron, which are connected behind, and together form an
external opening, termed the blastopore. This is the only
opening into the egg, the whole of the exterior, besides this
minute hole, being surrounded by the epiblast. This blastopore
appears ultimately to produce the anus, which in its early stage is
termed the proctodeum.

In the axial dorsal line, a portion of the mesoblast now sepa-
rates into a gelatinous-looking rod forming the notochord. This
notochord, though not permanent in the perfect animal, will be
found to exist throughout the greater part of the embryonic life,
and at once indicates a theoretical, developmental connection
between the frog and the amphioxus, in which the notochord is
permanent.

What the use of this notochord is would be very difficult to
say, as it appears to have no permanent connection with any of
the essential organs of animal life, and is not concerned in the
direct development of the vertebral column as might at first sight
be supposed. From this time the egg commences to flatten and
elongate, the whole of the internal organs appearing with great
rapidity. On March 7, the formation of a true skin or epidermis
from the epiblast was distinctly seen to have commenced, and at

New Series.

Vol. I.

66 DEVELOPMENT OF THE TADPOLE.

the same time the division of portions of the yelk mass into
segments or somites, together with decided indications of the for-
mation of the branchial arches, could be traced sections of the
animal at this period, as given in Plate VII.

Fig. I shows the general external appearance of the embryo at
this date, whilst Figs. 2 and 3 give vertical longitudinal sections,
and Figs. 4 and 5 oblique ones, passing through the frontal nasal
process from between the letters g.—fn., Fig. 2, upwards through
the neural and body cavities. We thus obtain sections of some of
the more important organs which are now forming. Especially,
we notice the brain, the notochord, and pro-renal ducts. These
pro-renal ducts will be much better made out in the longitudinal
sections taken on March 8th and following dates. The frontal
nasal process is a ridge or protuberance extending the whole
length of the body and terminating at the top of the head, not
abruptly, but gradually merging into the rest of the epidermis.
As the animal grows, it is gradually obliterated.

In Fig. I of this Plate attention should be drawn to the dark
mass on the lower portion of the head, which will be found in
future sections to consist of a muscular growth called the claspers,
whereby the animal, during a certain portion of its existence,
attaches itself to any neighbouring objects.

In Fig. 2, Plate VII., the dark portions marked s. indicate
the position of the somites, segments which ultimately enclose the
vertebral column, so that the indentation in this and the next
figure really represents the back or dorsal region, whilst the oppo-
site side, which has more the appearance of a back, is actually the
ventral portion. It is thus seen that the greater number of
organic changes occur in the head and dorsal regions, whilst the
ventral side is still filled with undifferentiated yelk mass, merely
surrounded by the three layers of epiblast, mesoblast, and
hypoblast.

Sections taken on the succeeding day (March 9th) showed an
immense advance in growth. All those organs which previously
were only indicated in jiosition by slight differentiation of the yelk
mass had now become more distinct, whilst other parts were
readily made out.

Fig. I, Plate VIII., shows a vertical, longitudinal section of this

DEVELOPMENT OF THE TADPOLE. 67

date, whilst Figs. 2 and 3 are vertical and horizontal longitudinal
sections two days later (March nth), and Fig. 4, a section of
March 12th. Here it will be observed that brain, somites, noto-
chord, and claspers have all undergone a continuous and marked
increase in development, and in addition we have a mouth-cavity
forming, together with the pericardium, and an immature heart
within it. The notochord is well seen in Fig. 2 embraced by a
number of the somites ; whilst in Figs. 3 and 4 there are distinct
indications of both cerebrum and cerebellum, together with some
of the organs of special sense, as the auditory and optic sacs.
The pro-renal ducts, commencing just under the gill-arches and
running down the whole length of the body, merging at last into a
thin line of mesoblast, are also well seen in Fig. 3.

Not less important than either are the distinct advances made
in the growth of the gills. In Figs. 3 and 4 we see the gill-arches,
with the gills within them, well protruding from the sides of the
head. In the living animal it was not possible at this date to
observe anything like a circulation or any special aeration of
blood-corpuscles occurring in these immature gills. Indeed, from
the extremely elementary condition of the heart, it is not probable
that blood had yet commenced to form from any of the nucleated
cells.

In order to see whether it were possible to throw any light
on the physical changes occurring during development, it was
attempted to take the specific gravity of the animals at various
stages of their progress. Peculiar difficulties presented themselves
during this part of the investigation owing to the enveloping
batrachin attaching itself with the greatest pertinacity to the
enclosed embryo. It has been previously mentioned that the
specific gravity of the envelope itself was as nearly as possible
that of water or very slightly less. Whilst this was the case, it
was found that the embryo had a specific gravity decidedly greater
than that of water, and varying also from day to day according to
the progress of the development. The first attempts at obtaining
the specific gravity were made by immersing the embryos, freed
as far as possible from their envelope, in solutions of salt of
various densities. This, of course, stopped all life ; therefore, in
the later stages, it was attempted to obtain correct results by

68 DEVELOPMENT OF THE TADPOLE.

resting the animal for a short time on absorbent tissue, such as
blotting-paper or linen, till the epidermis was nearly dry, and then
quickly weighing first in air and then in water, the specific gravity
being obtained in the usual way by dividing the loss of weight in
water by the weight in air. As of course it was quite impossible
to attach the embryo or animal to a hair or other non-absorbent
material without injuring it, a specific-gravity bottle, with wide
mouth and grooved stopper, was utilised for the purpose. The
animal could be thus twice weighed with a minimum of discom-
sort, no permanent injury having apparently been inflicted on a
single specimen during the process. A little difficulty, indeed,
was at times experienced during the weighing in air from the
lively nature of some of the specimens after their legs had
appeared and before the tail was entirely absorbed. These lively
individuals, by applying their moist though not wet bodies to the
sides of the dish, would rapidly crawl, or rather glide, to its edge,
and there remain perched generally a sufficiently long time for the
weighing to be accurately performed.

(letting a little older, and perhaps bolder, some of them would
with a bound spring from the bottom of the receptacle to the
edge, and from thence take a long leap into the outer world. Not
a very extensive world either, as far as they were concerned, for
the majority of these tiny creatures failed to jump farther than the
bounds of the balance case, whence they were soon restored to
their own element. One huge fellow, however, who had grown
and fattened on the best of the land, or rather water, after
having experienced this kind of treatment two or three times
on various days ; in his attempts to baffle any further experiment
on himself, took such a desperate leap just as the weighing was
finished as to alight on the floor, having fallen through the
enormous height of about four feet, or approximately from
seventy to eighty times his own height. There he lay, poor
wretch, apparently dead, but in reality only stunned, for on care-
fully picking him up in order not to lose the carcase altogether he
showed such renewed signs of animation as to lead me at once to
replace him in his tank, where he lived and grew many days after.
But more of this individual at a later stage of our history. The
results obtained by this process of taking specific gravities were
most interesting.

DEVELOPMENT OF THE TADPOLE. 09

The embryo in the stage represented by Plate II. had a spe-
cific gravity of 1-027, but owing to the absorption of the segmenta-
tion cavity, this had increased in five days to 1 '068, which was the
highest density observed, and from this time the density gradually
diminished. Thus, on March 7th, the density being i-o68, it was
I '06 1 2 on March loth, and 1-062 on the 12th of the same month.
These weighings were made on embryos developing from spawn
laid on March 2nd, 1885, and were in about the same stage of
development as those figured in Plate VIII., Vol. I., as they had
just emerged from their encircling envelope, and were able to
commence using their tails whilst, holding on by means of the
claspers, to the sides of the aquarium or to the envelope from
which they had escaped. The remainder of the specific-gravity
estimations were not undertaken till two years after — namely, in
the spring of 1887.

From the loth of March the specific gravity went on slowly
decreasing, till on June 22, when the tadpole was at its highest
stage of development as a tadpole, and before its legs had com-
menced to protrude, the specific gravity had sunk to -774. The
weight of the animal thus experimented on in air was 3-6 grains,
and the weight of water equal in bulk to itself was 4-65 grains,
thus giving its weight as -774 as compared with the weight of an
equal bulk of water.

We thus find that at this stage of its development the animal
is decidedly lighter than water, and this is apparently due to the
power of taking in considerable quantities of air, which may be
expelled after having been used for respiration ; and I believe,
though I am not positive on the point, when the animal wishes to
sink and remain at the bottom, a portion of this air is condensed
and its place supplied by water.

Continuing our investigations on these specific-gravity experi-
ments, we find that as the legs grow and the tadpole merges gra-
dually into the state of the perfect animal, it becomes again
comparatively heavier, its density becoming as nearly as possible
that of water. Thus, the same animal, with its hind legs just
appearing through the skin, weighed 4-1 grains, and had a density
of -752 ; with hind legs well developed, it weighed 5 grains; with
a density of -869 ; and when the forelegs had also protruded, the

irO DEVELOPMENT OF THE TADPOLE.

gravity was "900. The well-matured animal, with hind and fore-
legs well developed and tail nearly or quite absorbed, had in
every case in which an estimation was made, a density distinctly
higher than that of water, and approximating to the density of the
original embryo. In a series of determinations of the densities of
animals in various stages of development, from the time their hind
legs began to protrude to the time the tail had become completely
absorbed, the following numbers were obtained : — Tail, half
absorbed — Density, "956 ; still further absorbed, "962, I'oio, i"oii,
i'oi5, i*o2o, i'02i, i*o28, i'o33, 1*034, i"049, i "066.

In taking these specific gravities, it is most important that the
water remains at the same temperature throughout, and that its
weight be accurately known, for as the weight of the animal gene-
rally varies from i to 5 grains, a very slight variation in the weight
of the water in which the experiment is conducted may make a
very serious error in the apparent density of the creature. When,
however, all jDroper precautions are taken, it is evident, from the
figures obtained, that the estimation of the specific gravity of
animals in different stages of their development may prove of
great assistance in physiological investigations.

As a special case, may be mentioned its use as an aid in ano-
ther portion of the present investigation. Whilst the tadpoles
were losing their tails, it was observed that they did not apparently
eat, or at least they fed to a much less extent than previously.
The balance was called in as an adjunct, with the following
results : — The large specimen previously mentioned was weighed
almost daily from the time that the tail commenced to be
absorbed until the operation was complete, when it was turned
out into a field to shift for itself. This process of tail-absorption
was accomplished in five days, the weight on July 12, when the
absorption commenced, being io'6 grains, with a specific gravity
of I '029, and on July 17th, when the tail was entirely gone, the
animal weighed only 9*5 grains, with a density exacdy that of
water. We thus see that in this case the animal, during the last
stage of its metamorphosis from tadpole into frog, lost over 10
per cent, of its weight, and at the same time decreased in specific
gravity. The reason of these changes in the specific gravity of
these animals during different periods of their metamorphoses will

DEVELOPMENT OF THE TADPOLE. 71

be seen more clearly as we proceed with their life-history.

Having seen it stated that tadpoles would not develop if kept
in the dark, a few experiments were made on this point. Embryos
of the age shown in Plate VII. were placed in a perfectly dark jar
on March 7th, and kept side by side with those developing in the
ordinary glass tanks, so as to be exposed to the same external
conditions, with the exception of the exclusion of light.

At the same time, another batch from the same lot was placed
in a dark cupboard at the top of the house, where the temperature
was frequently below freezing and never above 40? F. These
were in a glass jar, and were, of course, under very different con-
ditions to those kept in a room where the maximum temperature
might sometimes be 55° to 60° F., but whose minimum never
went below 40°. On March i8th it was found that the develop-
ment of the animals kept in the jar had proceeded equally with
those kept in the glass tanks, the only appreciable difference being
that those kept in the dark were on the whole a shade lighter in
colour than those kept in the glass tanks. It was, however, very
different with those in the cupboa'-d, many of which were dead
and all much arrested in development. All were dead by March
28th : several others being transferred from the dark jar to the
cupboard, all died by April 5th. Suspicion was now cast on the
glass vessel in which the animals were kept being the real cause of
this wholesale destruction, so that another was substituted identical
in every respect with that kept in the warmer room in the light.

A number was then transferred from the dark jar to the new
glass vessel and removed to the cold dark cupboard. By April 1 1
five only remained, and by May 4th, barely a month after they
were placed in the cupboard, all had died. As there were no
apparent circumstances connected with the surroundings or atmo-
sphere of this cupboard to account for the death of all these
animals, the only conclusion to which I could arrive from this
series of experiments was that whereas development proceeded as
well in the dark as in the light, provided the temperature did not
fall below 40° F., yet on the removal of animals which were
l^reviously developing under these conditions to a lower tempera-
ture in darkness, development was arrested, and death invariably
ensued.

t2 DEVELOPMENT OF THE TADPOLE.

We must now retrace our steps somewhat, in order to study
the progress of those animals which were kept under what may be
termed normal conditions. On March nth some of them com-
menced to fall out of their investing capsules, and formed small
masses at the bottom of the jar ; and next day these were able to
move their tails slightly, so as to wriggle a little higher up the
glass. From March 12th to the 21st the weather was very cold,
and development was arrested to a very considerable extent ; but
by the latter date many had external gills well developed and
could swim easily, but preferred to remain close to the glass.
Whether attached or not by their claspers is very difficult to state,
as they could be removed with the slightest touch of a small
pencil-brush, so that the attachment, if existing, was of the very
slightest character. This, to me, seemed the more surprising, as
the microscopic preparations showed that the claspers at this
period were apparently powerful muscular appliances, capable of
producing a partial vacuum if applied to a smooth surface. I
therefore anticipated much greater difficulty than was really expe-
rienced in their removal.

The more prominent organs which had developed by this time,
although not yet arrived to perfection, were : — (i) Brain, with
cerebral vesicles, medulla oblongata, and medulla spinalis; (2)
Notochord, terminating a little behind the pituitary vesicle ; (3)
Branchial, hyoid, and mandibular arches ; (4) Pericardium, with
enclosed heart; (5) Claspers; (6) Mouth-cavity; (7) Pro-renal
ducts ; (8) Somites ; (9) Special-sense Capsules, as the auditory
and optic and olfactory capsules, from which we shall subsequently
find the ear, eye, and nasal organs to proceed.

[to be CONTINUED.]

EXPLANATION OF PLATES VII. AND YIII

Plate VII.
Fig. 1. — External appearance of the Tadpole, March 7, showing for-
mation of g. , gill arches.
,, 2, — Vertical longitudinal section of same, showing bnc, brain
with neural cavity; g., gill arclies ; no., notochord; fn.,
frontal nasal process ; 5., somites ; >j., yelk mass.

X

-.-•OD

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ace

4^ .-^^a«^^i^^^—

DeVelopTTLent of the Tad/Jol£^.

DEVELOrMENT OF THE TADPOLE. 73

Fig. 3. — Horizontal median section of same, same date : ep., epiblast ;
mf., mesoblast ; c, body cavity ; b., brain ; nc,, neural cavity.
,, 4, 5. — Oblique sections of same through the head portion taking
in part of the yelk mass ; mp , muscle plate ; no. , notochord ;
sno., sub-notochordal rod ; pr., pro-renal duct, other letters
as before.

Plate VIII.

Fig. 1. — Vertical longitudinal section, March 9 : 6r., brain ; tdc, noto-
. chord; c7., claspers ; s., somites; c, body cavity; y., yelk

mass.
,, 2. — Vertical longitudinal section, March 11. ^^rd. , pericardium,

with immature heart.
,, 3. — Longitudinal horizontal section of same; an., au. (marked

ace. on plate), auditory capsule; 2:)ni, pro-renal ducts;

g., gills ; hr., brain.
,, 4. — Longitudinal horizontal section through, nfc. , notochord,

March 12. Other letters the same.

The Phosphorescent Light of Glow-Worms. — From the
curious experiment mentioned in one of the late numbers of the
Alonitcur de la Photograplue, in which a glow-worm acted, by the
light emanating from its body, on a gelatine-bromide plate placed
at the bottom of a darkened box, this light appears to be about
uf tlie same actinic intensity as the phosphorescent light of sul-
phuret of calcium. It appears that the light of glow-worms and
of all phosphorescent animals is caused by a substance called
noctilucine, which is secreted by the animal as it is used, and that
the light is due to the slow oxidation of this substance. If some
of these insects have been seen to retain their luminosity in a
vacuum, or in hydrogen gas, it is because their tissue always
contains enough oxygen to allow the slow oxidation of the nocti-
lucine to continue under the circumstances for a certain length of
time.

Instinct of Birds. — It is reported in Peru and other parts of
South America, last year's fruit has been avoided by birds, while it
has caused the death of sheep and cattle when fed on them in
large quantities. These observations have been cited as tending
to show that the instinct of birds, with respect to the wholesome-
ness of fruits, is frequently a worthy guide for human beings to
follow. The possibility is suggested that the variation in the
fruit of different years may have something to do with the out-
break of cholera.

[ 74 ]

jEquiectacc^:
Xifcv1bi6toi\\ antiquity of Zwc, etc.

By W. G. Wheatcroft.

Plates IX., X., XL

THIS is the name of a natural order of cryptogamic plants,
which, whether regarded on account of their antiquity or
wide distribution over the face of the earth, are worthy of
careful consideration. This natural order contains only one
genus, Equisetum, or Horsetails. The generic name is derived
from eg'^^us, a horse, and sefa, a hair or bristle, in allusion to the
form of the stem. The Equisetum, Ephedron, and Anabasis of
Pliny are supposed to refer to one or other of the plants of this
genus. Equisda are found in most parts of the world, but there
are none in Australia or New Zealand. The tropics possess their
species as well as the more temperate climes. A few of the
species — as E. variegatum^ E. sylvaticum, etc. — have a very wide
distribution. E. variegatuni occurs as far north as Iceland. It is
also found in Quito, Bourbon, and Uitenhage ; whilst E. sylvati-
cum is found from the Arctic regions of North America to Simla.
E. giga7iteu}n, a Brazilian species, attains several feet in height,
and possesses a stout stem, three-quarters of an inch in diameter.
One species, on the contrary — E. debile — is so weak that it
requires the support of low bushes, up which it may be said to
climb, and Welwitsch describes E. dongatum as climbing up
Agave Americana at Lisbon.

The properties and uses of Equiseta are few, whilst E. arvense
is chiefly known as a troublesome weed to farmers, especially on
ground which has been reclaimed from rivers, and in fields where
water stagnates in winter. Almost the only useful purpose to
which these plants have been put by man is that of polishing hard
wood, iron, brass, etc. E. /lyanale, commonly known as Dutch
rushes, is chiefly employed for this purpose. Carpenter states
that in some species silex constitutes not less than 13 per cent, of
the whole solid matter and 50 per cent, of the inorganic ash. It
abounds especially in the cuticle, hence its use for polishing.

EQUISETACEiE. 75

Some of the siliceous particles are distributed in two lines parallel
to the axis ; others, however, are grouped into oval forms, con-
nected with each other, like the jewels of a necklace, by a chain
of particles forming a sort of curvilinear quadrangle ; and these
(which are, in fact, the particles occupying the cells of the sto-
mata) are arranged in pairs. Their form and arrangement are
peculiarly well seen under polarised light, for which the prepared
cuticle is a beautiful object.

Horsetails have been supposed to possess medicinal properties.
E. arvense, L., as an astringent, was formerly much used in
dysentery, ulcers of the lungs, phthisis, malignant fevers, etc.
Gerard thus describes its vulnerary properties : — " Dioscorides
saith that Horsetail being stamped and laid-to doth perfectly cure
wounds ; yea, although the sinues be cut asunder, as Galen
addeth. It is of so great and singular virtue in heahng wounds,
as that it is thought and reported for truth to cure wounds of the
bladder and other bowels, and helpeth ruptures and burstings." *
How far these ascribed virtues are apochryphal and how far real,
I leave for those who are learned in medicine and skilful in
surgery to decide. I do not presume even to hazard an opinion.

The British Flora, according to Sir Joseph Hooker, contains
eight species, viz. — E. arvense, \.., E. praiense, Ehrh., E. fiiaxi-
inu/n, Lam. (E. fluviatile, Sm., not L.), E. sylvaiiaim, L., E.
palustre, L., l>. polystachya, E. livwsum, L., b. fluviatile, L,, E.
hye?nale, b. E. Afoorei, Newm., E. variegaiuin, Schleich, b. E.
arenarium, Newm., c. E. JVilso/ii, Newm., d. E. trachyodon,
Braun. That eminent botanist, the late H. C. Watson, substan-
tially agreed with this arrangement, and it is given in the 7th edi-
tion of the London Catalogue. The editor of the 8th edition of
this very useful catalogue has, amongst many other changes which
he has effected, given specific rank to E. Moorei and E. trachy-
odon. He agrees with Sir J. Hooker in giving three varieties to
E. variegatum. Two of these he calls by the same names as Sir
Joseph and Mr. Watson, whilst to the third he gives the name
viajus, after Syme. I call attention to these changes, as well for
the purpose of identification as for showing how eminent botanists

* "Herbal," p. 1,116.

■^6 EQUISETACEiE.

differ as to what entitles a plant to specific rank, and how
unsatisfactory a condition classification is in this country at the
present time. I must likewise call attention to a discovery
recently made by a gentleman Avell known in the botanical world
for his work amongst Chara. I refer to Mr. W. H. Beeby. Mr.
Beeby seems to have found E. litorale in Surrey. He has pub-
lished a full account of the plant in the March, 1887, number of
i\\Q/ourfial of Botany. This plant is figured on the first page.
Mr. Beeby observes that " the most noteworthy features about
this plant are the abortive spores and the absence of elators."
Hence Dr. Milde calls it " one of the most remarkable of Crypto-
gams." By several authors it has been considered a hybrid
between E. arvcnse and E. Itinosum, but Dr. Milde concludes by
saying (" Die Hoheren Sporenpflanzen," p. 114) " that, consider-
ing the wide range of the plant, this supposition seems doubtful.
Hybrid cryptogams in other cases, always appear singly, and as
extraordinary rarities. The spores and sporangia are aborted in
all the stations. Nevertheless, solitary green normal spores may
always be found. At all events, I think, the life-history of this
plant is not yet complete. Duval-Jouve considers it a good
species, not a hybrid."

The Bath Flora contains five species of Equisetum, viz. — E.
arvetise^ L., E. maximum, Lam. {E Jinviaftle, S)m.), E. palusire, L.,
E. limosum, L., and E. hyeniale., L. " The largest Equisetum of the
present day," writes Berkeley, " is not to be compared with the
noble representatives, as Calamites, which occur in the Coal Mea-
sures and the New Red Sandstone. True Equiseta also occur in a
fossil state." But more on this subject hereafter.

I will now attempt to describe the form, structure, and habit of
a well-known representative of the genus, and then call your
attention to the life-history of the plant. Horsetails are vascular
cryptogams. They possess true vessels and are characterised by
the development from the spore of a leafless prothallium. This
prothallium is above ground and green. The aerial stem springs
from a creeping rhizome, which produces at its nodes a number of
adventitious roots. The stem is herbaceous, usually furrowed,
simple or branched, jointed, and provided at the joints or nodes
with toothed sheaths, formed by the coalescence of the leaves at

EQUISETACE^. 77

their base. The habit of the plant depends on this mode of
formation of the leaves, and on the verticillate arrangement of the
branches, which spring from buds in the cortex. The stem,
rhizome, and root are all derived from a single apical cell, which
divides into three series of segments. In the internal structure of
the stem the air-cavities are of great importance. Its centre is
occupied by a large central air-cavity (PI. IX., Fig. i, /'), and in
the surrounding ring of tissue, which is often rather narrow, there
is almost always a cortical air-cavity (Fig. i, /) between each pair
of vascular bundles. In addition, there often occur also the
so-called essential air-cavities (Fig. r, /") in the vascular bundles.
The stomata (Fig. i, sf.) are usually placed in a single or in
several rows between the elevated ridges of the stem. The
cortex consists of thin-walled or of only moderately thick-walled
parenchyma. It is separated on the inside from the vascular
bundles by a sheath, which sometimes encloses all the bundles
together (Fig. i, s.). The vascular bundles ascend in a vertical
direction and parallel to one another through the internodes, and
form annular coils in the nodes ; they are always "closed" bundles,
containing no cambium. Two other groups of vascular cells are
found on the cortical side of the bundle. The bast-portion
contains three elements : — parenchyma, bast-fibres, and sieve-
tubes ; it lies between the four groups of vascular cells and the
vascular bundle-sheath.

In the root is an axial bundle of vascular cells surrounded
by elongated parenchymatous cells, with which sieve-tubes and
bast-fibres are intermixed. The sporangia are capsules placed on
the under-side of scales belonging to the fructification (Fig. 2, /).
The fructification or receptacle is often placed on special shoots,
which are distinguished by their external form and by their brown
colour from the sterile green stems. The spores (S.S.) are pro-
vided with two hygroscopic bands or elators (Fig. 2, S.e.)^ only
loosely attached to them, formed by the splitting into narrow
strips and the partial detaching of the exospore or outermost of
the three coats of the spore, and serving, by their hygroscopic
properties, to assist in their dissemination. On germination, the
spore gives rise, first, to a flat prothallium, upon which are pro-
duced the antheridia and archegonia (PI. X., Figs, i, 2, 3). Most

78 EQUISETACEiE.

species of Equiseta are dioecious, the female prothallium being
larger than the male. In the antheridia are developed a very
large number of motile antherozoids ; in the archegonium is a
single central cell, containing an oosphere, which after impregna-
tion develops gradually into the young plant. The alternation of
generations is therefore precisely similar to that of ferns. The
Equisetacese are also propagated in a vegetative, non-sexual
manner, by means of subterranean stolons and tubers. "The
affinities of these plants," as Berkeley observes, " are quite clear
since the discovery of the extreme similarity of the mode of
development with that of ferns. The archegonia and spermato-
gonia, with their spermatozoids, are, in fact, almost identical.
The resemblance to Marchantiacece in the fruit is striking, but this
is rather one of analogy than of affinity, as the results of impreg-
nation are so different. In Marchantiacece the archegonia produce
merely a sporangium \ in Equisetacece, a new plant. The resem-
blance between these plants, again, and such Phsenogams as
Ephedra and Casuaritia is very striking, but it is, after all, merely
analogical. " The superior development of the cellular tissue
indicates a higher type than that of ferns, and if the nobler forms
of these are objected, we have but to point to extinct Eguisetacece.'"
A very interesting plant, which has no affinity with Equiseta,
although both its botanical and English name would seem to
point to a relationship, is Hipp^iris vulgaris, L., the Mare's Tail.
It grows frequently in close proximity to E. ntaxit?tum. I have
gathered specimens of both, growing within a foot or so of each
other, in the neighbourhood of this city (Bath). This plant seems
at one time to have been classed with Horsetails. This was
before compound microscopes were regarded as essential to the
study of botany. The application of the microscope to a trans-
verse section of the stem makes it manifest that the Mare's tail is
an exogenous plant. Further examination shows that it is not a
cryptogamic, but a flowering plant, for the flowers arise from the
axils of the leaves. I have made a sketch of a transverse
section of the plant, to enable you to compare it (PI. X., Fig. 4)
with one of E. arvense, L. (PI. X., Fig. 5). If I am open to
the charge of wandering away from the subject of my paper, I
must plead in extenuation that I have done so for the purpose of

EQUISETACEiE. 79

showing how effectually microscopic examination corrects some
botanical errors, and I trust that you, as microscopists, will
pardon the digression.

Let me now direct your attention to the subject of antiquity of
type as manifested in the EquiSETACEiE. I will then conclude
with a few parting words on permanency of type as shown in this
and some other portions of the vegetable kingdom. Although
one or two naturalists of some eminence have expressed a doubt
as to whether the Calamites of the Carboniferous period are true
Equiseta, there can, I think, be no doubt that representatives of
the order not only existed but occupied a prominent place in the
Flora of the Coal period.

Palaeontologists of no mean reputation give the primary repre-
sentatives of the Horsetail family a place amongst the earliest
traces of land vegetation yet discovered, namely — in the flora of
the Old Red Sandstone or Devonian period. PI. XL, Figs, i
and 2, represent stems of Calamites found in the coal-beds
of Europe. A careful examination of two slides I have lately
obtained from Mr. Spencer, of Halifax^one of which contains a
transverse and the other a longitudinal section of a species of
Calamite found in the Halifax coal strata, has enabled me to
form an opinion as to the vascular structure of these giants
of the forest and marsh of the Carboniferous era. Calamites had
peculiar roots. Fig. 3 is a representation of the radical termi-
nation of a Calamite. I think it is not improbable that the
transverse section under observation has been taken from some
part of the root of a Calamite. The dimensions of the section
and other indications seem to point to this conclusion. I once
possessed a fossil of a Calamite found in the coal-fields of Derby-
shire which measured more than five inches in diameter.

An eminent French botanist, Adolphe Brogniart, has called the
Carboniferous period " the age of Acrogens," so great appears to
have been the numerical proportion of flowerless plants of the
families of ferns, club-mosses, and horsetails. Brogniart reckoned
the known species in 1849 at 500, and the number has been
largely increased by recent research, in spite of reductions owing
to the discovery that different parts of even the same plants have
been taken for distinct species. " Brogniart's generalisation con-

80 EQUISETACE^.

cerning this flora," writes Sir Charles Lyell, "still holds true,
namely — that the state of the vegetable world was then extremely
different from that now prevailing, not only because the cryptoga-
mous plants constituted nearly the whole flora, but also because
they were, on the whole, more highly developed than any belong-
ing to the same class now existing, and united some forms now
only found separately and in distinct orders. The only ph?enoga-
mous plants which constitute any feature in the coal are the
coniferas; monocotyledonous angiosperms appear to have been
very rare, and the dicotyledonous, with one or two exceptions,
were wanting."

I will quote Sir Charles Lyell once more as to the Equisetacese
of the Coal period. This eminent geologist, referring to thfe
Horsetails, observes : — " To this family belong two fossil genera
of the Coal, Equisetites, and Calamites. The Calamites were
evidently closely related to the modern Horsetails {Eqiiiseia),
differing principally in their great size, the want of sheaths at the
joints, and some details of fructification. They grew in dense
brakes on sandy and muddy flats in the manner of modern
Equisetace^, and their remains are frequent in the coal. Seven
species of this plant occur in the great Nova Scotia section, where
stems of some of them, five inches in diameter and sometimes
eight feet high, may be seen terminating downwards in a tapering
root." The Brora coal, one of the most considerable Oolitic
seams in Europe, seems to have been formed almost exclusively of
an Equisetum, E. cohmmare. The Keuper beds in Wurtemberg
attain a thickness of about i,ooo feet. The plants of the Keuper
are generally analogous to those of the oolite and lias, consisting
of ferns, equisetaceous plants, cycads, and conifers, with a few
doubtful monocotyledons. " A few species," observes Lyell,
" such as Equisetites cohmmaris (Syn., Equisetum columnare, PI.
XL, Figs. 4, 5, and 6), are common to this group and the oolite."

Li the State of Virginia, some thirteen miles from Richmond,
there is a coal-field occurring in the depression of the granite
rocks, and occupying a geological position analogous to that of
the New Red Sandstone of the Connecticut valley. It extends
twenty-six miles from north to south and four to twelve miles from
east to west. The fossil plants found there consist chiefly of

EQUISETACE^. 81

zamites, calamites, equiseta, and ferns. The equiseta are very
commonly met with in a vertical position. " It is clear,"
observes Lyell, " that they grew in the places where they are now
buried in strata of hardened sand and mud. I found them main-
taining their erect attitude, at points many miles apart, in beds
both above and between the seams of coal." We have, I think,
ample proof of the existence of Equisetacese in the Carboniferous
measures, in the Upper Trias and the Oolite. I think, therefore,
that I have said enough in support of my claim to antiquity of
type on behalf of the Horsetails.

Observations on antiquity of type naturally lead to remarks on
permanency of type, a subject which, it seems to me, must strike
every observer of vegetable life more or less forcibly. Plants
constitutionally strong, like Horsetails, with something like armour
plating for their protection, and possessing more than one mode of
increasing their numbers, were admirably adapted to struggle
against the many vicissitudes of climate and other trying condi-
tions to which the early flora must have been subjected during the
countless ages which have elapsed since the coal-measures were
formed. The Glacial period, which must have sorely tried some
of the strong and destroyed many of the weakly-constituted
plants, seems to have worked little, if any, destruction upon Equi-
setaceous plants. They seem to stand in the foreground of
witnesses to the doctrine of permanency of type. But they are
not the only witnesses.

I must crave your attention for a few minutes longer, whilst I

refer to some remarkable observations which have been made by

Dr. Schweinfurth in the valley of the Nile. They are none the

less worthy of consideration because they refer to what, for want

of a better name, I v.-ill venture to designate the historic period.

The president of the Einnfean Society, Mr. W. Carruthers, F.R.S.,

in his address to the biological section of the British Association,

at their meeting held at Birmingham in 1886, after referring to

the result of an examination of certain gravel-beds in the north of

Eondon, which contained stems and leaves of Clematis vitalba, E.,

willow and birch, the foliage and fruit of Corylus Avella/m, E., and

Alnus ghifinosa, E., and the rhizomes of Osmiinda regalis, E. —

" none of which," as he remarked, " could be distinguished from

New .Series, Vol. I.

18S8. G

82 EQUISETACEiE.

the plants of our own day" — observed as follows: — "The most
important materials, however, for the comparison of former vege-
tation of a known age Avith that of our own day, have been
supplied by the specimens which have been obtained from the
tombs of the ancient Egyptians. Until recently, these consisted
mainly of fruits and seeds. These were all more or less carbon-
ised because the former rifling of the tombs had exposed them to
the air. . . . Tiie recent exploration of unopened tombs
belonging to an early period in the history of the Egyptian people
has permitted the examination of the plants in a condition which
could not have been anticipated. And happily the examination
of these materials has been made by a botanist who is thoroughly
acquainted with the existing flora of Egypt, for Dr. Schweinfurth
has for a quarter of a century been exploring the plants of the
Nile Valley. The plant-remains were included within the
mummy-wrappings, and being thus hermetically sealed have been
preserved with scarcely any change. By placing the plants in
water, Dr. Schweinfurth has succeeded in preparing a series of
specimens gathered four thousand years ago, which are as satis-
factory for the purposes of science as any collected at the present
day. These specimens consequently supply means for the closest
examination and comparison with their living representatives."

Mr. Carruthers states that Dr. Schweinfurth has determined no
less than fifty-nine species, some of which are represented by the
fruits employed as offerings to the dead ; others by the flowers
and leaves made into garlands ; and the remainder by branches on
which the body was placed, and which were enclosed within the
wrappings. Mr. Carruthers has enumerated the names of the
plants, fruits, and weeds found. These include the linseed still
grown in the Nile Valley {Liniim humile, Mill) and the berries of
Juniperus phccnicia, L. The pests of the Egyptian corn-fields are
not unknown to us, for Dr. Schweinfurth discovered Medicago
detiticulata, Willd., and Siiiapis arvensis, L., var. Allioni, a nearly-
related and equally objectionable weed with the well-known
Charlock of our corn-fields. The flax-crops in the days of
the Pharoahs seem to have been infested, as they are at the
present day, by this most troublesome weed. Mr. Carruthers,
after giving a very interesting account of the various plants found

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EQUISETACEiE. 83

in these mummy-wrappings, which time will not permit me to
refer to more fully, observes : — " In none of these species, except
the vine, to which I have referred, which Dr. Schweinfurth has
discovered, and of which he has made a careful study, has he been
able to detect any peculiarities in the living plants which are absent
in those obtained from the tombs." I venture to think that it would
be difficult to produce better evidence of permanency of type. It
is not my intention to base any theory on the facts I have called
attention to. I leave that to those who possess a more extensive
knowledge or a more lively imagination than I can lay claim to.

EXPLANATION OF PLATES IX., X., XL

Plate IX.

Eig. 1. — Transverse section throu'^h young stem of Epiisetum sylvatl-
cum, showing : — o., eiaidermis ; c, collencliyma, many of the
cells contaiiiing chlorophyll; s., vascular bundle sheath;
g, vascular bundle ; I, cortical air-cavity ; I', central air-
cavity ; r', air-cavity of the vascular bundles ; st., stomata.

After Thome, x 1.50.

>j 2. — A peltate scale, bearing the sporangia on its inner side facing

the stem, five being visible (highly magnified), s..s. , spores,

with the elaters unrolled ; c. , elaters. After Tliom^.

Plate X.

Fig. 1. — Prothallium of Eguisetum maximum, with eleven antheridia,
V, prothallium ; a. , antheridia.
-Prothallium (o), with archegonia («.), x 30.
-An antherozoid, x 500. After Thom^.

-Portion of transverse section of stem of Hippuris vulgaris
(Mare's Tail) ; natural order, Haloragete.

-Portion of transverse section of stem of Equlsetum arvenne,
showing : — u, central ; e, cortical air-cavities ; p, vascular
bundles ; ep. , epidermis ; s, air-cavities of vascular bundles,
X 50.

Plate XL
Fig. 1. — Stem of Calamite, one-tifth natural size. After Figuier.

,, 2. — Stem of Gulamites sucordii, Brong., as restored by Dr. Dawson.

After Lyell.
,, 3. — Radical termination of a Calamite from Nova Scotia.

After LyelL
,, 4. — Fragment of a stem of Eipiisetltea colnmnaris.

,, 5. — I'ortion of the same, magnified. After Lyell.

,, G. — EipusetiLmcolnmnare, natural size. After Hugh Miller.

All drawn by W. G. Wheatcroft.

>5

2.

))

3.

))

4,

5)

5.

[84]

By G. H. Bryan, B.A.

Plate XII., Fig. I.

IN the hotter parts of the earth, the threads spun by spiders are
often of considerable strength and toughness, and in some
cases are sufficiently strong to strike off the hats of passing
travellers or to be woven in looms like the fibres of the silkworm.

All the trap-door spiders are remarkable for the great strength
of their webs, which are used, not for the capture of prey, but for
the strengthening of their earthen homes. The silk is mostly
yellowish, and so tough that a nest may be removed without any
danger of damaging it, and the silk is so strong that, even when
the earth has been dried and wholly removed, it will bear a con-
siderable strain without breaking, and can be drawn over the
finger like a glove. Up to this point the burrow possesses no
advantage over that of the bird-spider, being a simple silk-lined
tube. But the spider now sets to work at the construction of a
door, by which the opening may be not only closed but concealed.

Guided by instinct, it weaves a circular web rather less than
the diameter of the burrow and works into it a quantity of earth.
This process is repeated until the spider has constructed a circular
plate of alternate layers of web and earth, nearly twice the thick-
ness of a penny and slightly conical. Eight or ten layers are
employed in the manufacture of the plate. A small portion of
this plate is attached to the lining of the burrow, the webs,
indeed, of the plate being woven into those of the lining and
being a continuation of them.

The plate, therefore, forms a door with a silken hinge, and so
accurately is it constructed that when it is closed the upper
surface is exactly level with the ground. It will be seen, therefore,
that the aperture is effectually closed ; but there are yet two
points in the structure of the trap-door which must be noticed.
In the first place, the spider takes care to cover tlie upper surface
with earth exactly resembling the soil in which the burrow is sunk,
even imitating the irregularity and roughness with astonishing
fidelity, and fixing lichens, moss, or even leaves, on it just as the

TRAI^-DOOtl SPIDERS. 85

chaffinch does on its nest. So perfectly is this done that to dis-
cover a trap-door is almost impossible.

Strangers, when sitting on a bank, are often astonished at
seeing a circular piece of earth lifted near them, the jaws and legs
of a spider partly protruded, and quickly withdrawn when the
intruder is seen. So rapidly does the spider pass back again into
its burrow and shut the door after it, that the movement has been
aptly compared to that of a cuckoo in a clock. Even when the
eye has been thus directed to the exact spot, it is not easy to find
the door. If, however, it be found, and an attempt be made to
open it, a tolerably strong resistance will be experienced. This is
caused by the inhabitant, which holds firmly with its forelegs to
the door and hind legs to the lining of its web, and resists as long
as it can. So firmly does it retain its hold, that when the nest has
been pulled out of the soil and torn asunder, the spider has come
away with the upper portion, still holding the door against the foe.
The marks thus made by the spider's claws may frequently be
seen, especially in the doors of old nests, as shown in the accom-
panying figure.

The second point of interest in the trap-door is the mode in
which it is fixed. The spider always chooses a sloping surface for
its burrow, and the hinge is always placed upon the highest point,
so that when the spider issues forth the door is self-acting and
shuts by its own weight.

For our knowledge of the European trap-door spiders, Ave are
mainly indebted to J. T. Moggridge, in whose work * the various
species and their nests will be found very completely described
and figured. He has roughly classified the nests of these spiders
under two headings — namely, the "cork" nests, so called from
their tight-fitting, cork-like lids ; and the " wafer " nests, in which
the lid laps loosely over the opening, and has been compared to a
wafer. Amongst the European species, Nemesia Moggridgii
(named after Mr. Moggridge), found at Mentone, N. aemcntaria,
and some others, construct nests with " cork " doors. These cork
nests all consist of a simple silk-lined tube, with the plug-like door
at the top, but many of the wafer nests are more complex.

The simplest form of wafer nest is that constructed by Neine-

* '• Harvesling Ants and Trap-door Spideiij." ( L, Reeve <^ Co.)

86 TRAP-DOOR SPIDERS

sia Siinoni, being a simple tube down to the very bottom, and
differing from the "cork" nests only in the structure of the door.
It is found at Bordeaux.

A Neapolitan species [Ncincsia ineridionalis) adds an upward
tube, branching from the main tube about half-way down, and
rising nearly to the surface of the earth. These nests may be
found very abundantly in some places on the hill of Posilipo, near
Naples, and also in the island of Ischia. Nciuesia sit/fiisa, from
Montpellier, builds an exactly similar nest.

Certain species found at JNIentone and other places on the
northern shores of the JNIediterranean add an inner door to their
nests. Thus, Ah'/nesiu Ehanora builds its nest with an em-
branched tube, and with a thick extra door of a circular form, but
straight along the hinge and with the upper side slightly concave.
This door is inserted somewhat above the middle of the tube, ami
opens inwards. It resembles cardboard in texture, and attached
to it are silken curtains or flaps, which cause it to close firmly,
while the tube is slightly widened below the door to permit of its
opening freely.

In digging out a very large nest of N. Elcanora at San Remo
in i8So, M. L. Faulder White discovered about an inch and a
half or two inches below the second door a very small cavity or
groove (about an inch long) in the wall of the tube, separated
partly from it by a silken fi'ament and completely filled with the
husks of small red ants. At the bottom of the nest was found
the spider, which was unusually large, but no remains of ants
(such as are often found) were there. Such a storehouse or larder
had never previously been noticed by anyone.

Another Mentone species, Nemesia Manderstjernce^ has a nest
with an upward branch, and the inner door, whose hinge is
attached to the point of junction, is so arranged that when open it
shuts up the branch ; when closed, it shuts off the whole lower
part of the nest. This door is oblong and channelled along its
outer surface, and the main tube frequently has an abrupt cavity
just opposite the door, so that when the latter is closed this cavity
looks very like the end of the tube.

Nemesia congener, found at Hyeres, has a nest somewhat
resembling this last, but the inner door is more circular. The

AND THEIR NESTS. 87

tube is curved while the branch is vertical, and there is never an
obtuse cavity half-way down.

The nest of a trap-door spider (Cteniza nidulans), found in
Jamaica, bears a curious resemblance to a very small yellow
stocking, and the likeness is increased by the fact that in most
cases the spider does not content itself with a single tube, but
makes the last inch or two of the end at an angle just like that of
a stocking-foot. The reason for choosing this form is rather
doubtful. At one time it was thought that the spider altered the
course of the burrow in consequence of coming across some
obstacle, such as a jDcbble or root ; but as the bend invariably
occurs at the same place, it is evidently intentional and not
accidental. This nest appears to be of the " cork " type.

In the British Museum there is a remarkable example of a
burrow with two trap-doors — one in the usual place at the entrance
and the other an inch or two below it. The reason for this dupli-
cate door was easily discovered. The nest had been made in
cultivated ground. Earth had been thrown over the mouth of the
burrow and buried it. The inmate had therefore burrowed
upwards until it had made its way into the open air and had then
constructed a second door.

This nest is essentially different from the double-door nests
above described, the inner door opening outwards instead of
inwards, and having exactly the same structure as the outer door.

It must be remembered that only the female spiders live in
these nests, the males being very rarely found. The young spider,
after quitting the nest of its mother, builds an exact copy of it in
miniature, and as it grows gradually enlarges its nest. In the
wafer-doors the layers of silk and earth, thus added, are visible,
but are better seen from the cork doors^ and in these they may
often be separated.

If the top part of the tube, with the lid, be removed, it will be
found, on returning to the same spot in a day or two, that the
spider has furnished a new door to the tube. The spiders are
nocturnal in their habits, frequently going out at night in search of
prey. It is stated that the Californian "cork" spider {Cteniza
Cali/ornica) fastens its door open with a silken thread before
leaving its nest, the door being so difficult to open from the

88 TRAP-DOOR SPIDERS.

outside. An interesting account of the habits of this species will
be found in the Scientific Enquirer for May, 1886. The tube of
its nest is far shorter than those of the European species, and it is
therefore well adapted for observation in captivity.

The greatest enemies of trap-door spiders in Europe are
lizards and centipedes, and the spiders are always on tlie alert to
guard against their attacks, so that if the outer door of a double-
door nest be opened, the spider immediately slams the inner door
to, for fear of its pursuers. If the latter be forced open or
removed, the spider will generally liee to the very bottom of her
nest, where she will be found crouched up in terror. Owing to
the complete concealment which the doors of the riests effect, the
only way of detecting them in countries where trap-door spiders
abound is to turn up all the likely-looking bits of earth until one
of the nests is found. Specimens of the top part of the nest,
showing the outer door, may be placed, with the surrounding
earth, in cardboard boxes of the proper size, and, alter filling the
tube with cotton wool, the best plan is to pour in plaster of Paris
to a certain height, fixing the portion of the nest and preventing
the earth from crumbling. Since the extension of the Parcels
Post to most parts of the Continent, a few of these curiosities
may occasionally find their way over to England.

The Hessian Fly and its Parasites. — Observations upon
the Hessian fly, Cccidomyia destructor, made in North Britain,
brought to light the fact that it has not reached our island without
bemg accompanied (or followed) by several of its minute parasitic
enemies. Probably, it is in some measure due to the i)roceedings
of these that it has not extended over a larger area in those dis-
tricts where it first appeared. One of the most curious facts is
that these parasites have been verified as occurring chiefly in
Russia — at least, four of the species ; the fifth has been recorded
in America and also in Ciermany. This rather supports the
theory that the recent visitation came to us through imports from
Km^idi.— Journal of Horticulture.

[80]

H ^l^ctho^ of prcparlno, for fllMcroscopical

Stu^v^ the IRabula: of Small Species

of (3a6te^opo^a/"

By Charles E. Beecher.

ONE of the early methods employed to obtain the lingual
membranes of Gasteropoda was by actual dissection.
This process, in many cases, is very laborious and the results
unsatisfactory. Advantage was next taken of the resistance of
the radulK to the action of ordinary chemical reagents. The
resistance to acids and alkalies induced the early belief in the
silicious composition of the teeth, and it is only quite recently that
the fallacy has been eradicated from text books on natural history,
and from special works on the moUusca. It is now known that
the teeth are composed of a substance closely related to chitine.
Its behaviour under the influence of the ordinary staining fluids
used in microscopical work is quite varied and interesting, and
affords some points of comparison with true chitine.

Another method, applied in the study of the extremely small
radulge of minute species of snails, was to crush the animal, and
examine the dentition through the translucent tissues. Of course,
this plan is in itself not altogether satisfactory, on account of the
difficulty of distinctly studying the characters of the lingual mem-
brane. Besides, it was not conducive to the production of clean,
beautiful, and permanent preparations, such as ought to be retained,
to serve as the types from which descriptions and illustrations have
been made, and from which important deductions have been
drawn.

When the characters of the odontophore came to be studied,
it was first thought that they would furnish a simple means of
classification, and an infallible method of determination. At the
present time, the best authorities have abandoned nearly all the
classifications of the Gasteropoda based upon the characters of
this member alone, and give to it an importance about equal in

* Frum The Journal of the Neiv York Microscopical Society.

90 THE RADULyE OF

value to that of the shell. Thus it will be seen that the radula
still holds an important position in the study of the moUusca, but
is not of the greatest value.

Several of the steps indicated in the following directions for
preparing the radulae of the Odontophora, for microscopical study,
and for permanent preservation, have been employed by previous
investigators in this department of research ; but it is believed
that some novel features are here described, and the entire se-
quence of processes is reduced to a system, which will be found to
produce uniform and satisfactory results. At first, I adopted the
methods in common use, and found that for the work which I had
undertaken — namely, the study of the lingual dentitions of the
American fresh-water species of Rissoidce — I could not attain the
desired degree of excellence in the preparation of the radute,
which would enable me to make a complete study of their various
features. This led to a long series of experiments, performed with
all the principal reagents used in microscopical investigation. An
enumeration of these experiments would add but little to our
knowledge, beyond the fact that most reagents are useless for this
work, and many are of but little value.

When manipulating with such small objects as the lingual rib-
bons of our Rissoidce, small species of Fianofbis, Goniobasis, Pi'J'o,
Vertigo, etc., simplicity is of the greatest moment, for in transfer-
ring the radula from one dish to another, and passing it through
successive reagents, it is very likely to be lost, or so mutilated in
handling as to be worthless. Therefore, a complicated or laborious
method is to be avoided if possible.

The transparency of the objects is also another obstacle to be
overcome, and while mounting media can be selected of a
different refractive index, yet the loss of absolute and reliable
differentiation, from the reflection of liglit from tlie polished
denticles, the interference of perspective in media of low refractive
indices, and tlie diffraction lines produced by the minute denticles,
render it extremely desirable to stain the specimens, and to mount
them in a highly refractive medium, or one that nearly agrees with
the refraction of the objects themselves.

MiiTHOD OF Preparation. ^The shells having first been
boiled or placed in alcohol to kill the organisms, the animals are

GASTEROrODA. 91

extracted from their shells by drawing them out with a mounted
needle or hook, and in the larger species the head is cut off, and
the remainder of the animal rejected. In the minute species, the
shell may be removed by hydrochloric acid. Either process may
be employed, to equal advantage, upon shells which contain the
dried remains of the animals.

The specimens are then placed in a small porcelain crucible
containing water, in a sand bath over a Bunsen burner. A little
boiling will soon render them in a condition for the rapid action
of a small piece of caustic potash, Avhich is next placed in the
crucible, and the whole allowed to boil until the tissues have
become disintegrated and partially combined with the potash.
I'he action of the potash should not be continued after it has
completed its work upon the tissues, as continued boiling will
attack the thin membrane, upon which are situated the lingual
teeth, and which holds them in position.

After removal from the burner, water is added and the undis-
solved material allowed to precipitate. With a pipette having a
rubber bulb, or by decanting, the fluid is nearly all removed, and
clean water again added. This is repeated, until the potash and
light flocculent matter are eliminated.

The residue is then washed into a flat-bottomed dish, or large
watch crystal, and the radulae, in the majority of cases, can be
perceived by the unassisted eye, and removed, by means of fine,
mounted needles, to another receptacle containing a very small
amount of water. In case the radul^e are very small, the material
is transferred drop by drop, with a pipette, and examined, under a
one inch or three-quarter inch objective, on the horizontal stage
of a microscope, preferably furnished with an erector. They can
then be removed from the mass of extraneous matter, and placed
in a separate receptacle, as in the former instance.

A drop of strong chromic acid is added to the specimens, and
in from one to two minutes the teeth on the radulre are stained a
light yellow or amber colour. After washing out the chromic acid,
the specimens are dehydrated in the usual way, and after removing
the alcohol with a pipette, absorbent paper, and partial evapo-
ration, oil of cloves is added, and the specimens are ready for
mounting in Canada balsam.

02 GASTEROPODA.

The lingual membranes will be found to be more or less
coiled, and usually attached to the jaws. It is desirable, in the
mounted specimen, to have the membrane flattened out, with the
dentiferous side uppermost, and dissociated from the jaw. Some
species have a large, strong jaw, which, if left with the lingual
membrane, will raise the cover-glass so far above the denticles as
to exclude the use of the higher powers of the microscope.
Therefore, some mechanical work is necessary to unfold the
radula, and remove the jaw. Having provided a clean glass slide
on the turn-table, the specimen is taken from the clove oil and
centered on the slide. Now placed under the microscope pro-
vided with an erector, and using mounted needles, the radula is
easily unrolled with the dentiferous side uppermost and the jaw
removed. Replaced upon the turn-table, a thin cover-glass is
superimposed and centered. The cover-glass should be put on
before the balsam is added, as it prevents the specimen from again
becoming coiled or displaced. A drop of balsam in benzole is
put adjacent to the edge of the cover, and the slide held an
instant over a gas-burner or alcohol-lamp, which will cause the
balsam to flow by capillarity under the cover-glass. A small
spring-clip is then used to press the cover down and hold it in
place. The slide is removed to a drying oven, and left until the
balsam has hardened, so that the portion outside the cover can be
scraped off. The slide is then cleaned by washing in strong
alcohol, using a piece of soft tissue paper to rub it dry. It is
quite essential to use cover-glasses of known thickness. Many
radulae require a one-tenth inch objective. The convexity of the
object, combined with the thickness of the cover, necessitates tiie
use of very thin glass. For the Rissoidc^, I have usually em-
ployed glass of "004 inch thickness.

Movement of the Earth's Surface.— At the equator, a
point on the earth's surface moves rather more than 1,000 miles
an hour; in latitude 45 deg., north or south, the rate of motion is
about 750 miles an hour. London is carried round the earth's
axis at the rate of more than ten miles per minute.

[93]

Smut of Mbcat, ®at5, an^ Badci?

Ustilaco carbo. Tul.

EVERY person, even the most unobservant, who has walked
through a field of wheat, oats, or barley, must have noticed
smutted ears. Instead of the healthy spike or panicle of
grain being presented, a sooty, ragged mass of black dust and
scales is seen surmounting the fruiting stems of the corn. In
some places the disease is called " chimney-sweeper," in others
" black ball," " dust-brand," or " smut." In certain districts it is
erroneously termed " bunt," which is a totally different disease of
corn. The black powder is produced in such profusion that it is
impossible to gather a few diseased ears without the hands being
soiled as if with soot. We have heard smutted ears called " the
male flowers of corn " by some country folk, the erroneous idea
being that these diseased ears are the male, or the black pollen-
bearing plant. Some districts are more liable to Smut than others,
although none are free. The disease is sometimes extremely
destructive, especially in oats. In some instances nearly the
whole crop becomes smutted, and in bad cases from one-sixth to
one-third of the crop is destroyed. When smutted wheat is
ground with sound grain, it not only seriously discolours the flour,
but it injures it as food. Straw infected with the black powder or
spores of the Smut fungus is disliked by cattle, and it is an offen-
sive adjunct to chaff when given in food to the animals of the farm.

The Smut disease of corn is caused by the presence of a
fungus which exists within the tissues of the plant, grows with the
growing stem, and at last bursts from the inside of the plant out-
wards at about the time when the corn is reaching maturity. The
name of the fungus is Ustilago carbo. The name is derived from
Ustio., which means a burning, and carbo., which means charcoal —
the compound name of the fungus having direct reference to the
burnt and sooty appearance of the parasite.

We will now make a close examination of the extremely
curious fungus which causes Smut, and show how it invades the

* We are indebted to Messrs. Webb and Sons, of Wordsley, for this
paper and for the excellent engravings with which it is illustrated.

94

SMUT OF WHEAT,

corn. If we take smutted ears of wheat, oats, and barley, and
examine them without a glass, we shall see them as at A, B, and C.

The first point to
be specially noted
in the field is
that every ear
which springs
from one root
will be smutted.
This fact indi-
cates that the
disease springs
from the base
and runs up every
stem from the
ground line. If
further proof of
this method of
growth is needed
it will be seen
that the lower-
most part of each
ear is the part
that first shows
the disease. It
is common to see
the bottom of an
ear of wheat or
barley, or a pani-
cle of oats, badly
smutted and the
top sound. The
disease in these
instances has not
yet reached the
top of the plant ; one never sees the top of an ear diseased and
the base sound. It is an undisputed fact that in Smut the disease
orows inside the stem from the bottom upwards.

The Smut Fungus. — Usfilago carbo, Tul., in
A, W/ieaf; B, Oats ; ami C, Barley.

OATS, AND BARLEY.

95

We will now take a dwarfed and diseased cluster of grains and
chaffy scales from a wheat-spike and magnify with a lens five
diameters. We now see it as at D. The chafty scales are rent
and torn, and from every fissure the fine sooty powder is seen
bursting out. If the cluster or spikelet is cut across as at E^ it
will be noticed that the whole farinaceous material of the interior
has been replaced by one compact mass of fine black dust. The
upper part of the stem of the corn^ and the scales and grains

Spikelet of Wheat (D) atid transz'efse section {E) ijivaded by the

Smut fungus^ enlarged 5 diameters. Disease pustules of

ditto, enlarged 25 diameters.

alike, are infested and choked by the sooty powder. If we take a
fragment of one of the chaff" scales, and magnify it with a micro-
scope 25 diameters, we shall see numerous cracks, some large,
others small, as at F, and from every crack the fine jet black
powder will be seen bursting out from the inside.

Every grain of this black powder is an inconceivably minute
spore or seed of the Smut fungus. In an early stage of the
disease, in a state seldom noticed by farmers, the fungus is colour-
less ; it grows within the stems of corn as fine transparent threads,
immeasurably finer than any spider's thread. These threads at
length reach the ears, the scales, and the infant grains. Here they
form within the substance of the plant a whitish viscous mass of

96

SMUT OF WHEAT,

threads and cells, and this mass at length gives rise to an im-
mensely large number of spores, which quickly become black in
colour, burst through the tissues, and so reach the outside air.
The fungus always grows so luxuriantly in the ears that nothing
is ultimately left of the part which should bear the grain but a
few dry vegetable threads, which are speedily torn apart, and this
wreck of what should be the ear is soon carried away by the
wind. As a rule, the ears, whether of wheat, oats, or barley, are
totally destroyed by the fungus.

(©

® ^ %^ (f*

X'400

T/ie spores or seeds of the Smut fuiigiis (G) enlarged 400 diameters ;

other fungus spores enlarged to the same scale at I and J ; and

Smut spores germinating, enlarged 1,000 diameters.

The particles of the black powder are excessively minute in
size. If they are magnified 400 diameters, they are seen as
at G. An idea of their extreme smallness may be gained by
comparin_^^ them with a seed or spore of the potato fungus, illus-
trated to the same scale at /, or with a seed or spore of the
putrefactive mildew of onions, shown to the same scale at J.
Two hundred of the spores of the Smut fungus could find ample
room inside a single spore of the onion fungus, y, named Perono-
spora Schkideniana. Owing to their extraordinary smallness, the
spores of the Smut fungus find their way everywhere ; they are

OATS, AND BARLEY. 97

also produced in such profusion that in a smutted district there is
not an inch of ground free from them.

The spores of the Smut fungus, on germination, of course
reproduce the disease in cereals. They do not germinate on dry
ground or in dry air, but will retain their vitality, if kept dry, for
at least a year. We have kept smutted ears in papers for a year
in a dry room, and at the end of this time the spores of the
fungus have been found to have suffered no injury. The spores,
like ordinary seeds, require moisture for germination, and if they
are put in a fihii of water they will germinate in from six to twelve
hours. The very highest powers of the microscope are required to
see this germination, and if objectives are used which magnify one
thousand diameters, germinating Smut-spores will be seen as at K,
L, and M. On germination, the outer coat of the spore bursts or
cracks, and out of the fissure a minute transparent bladder
emerges, which by budding soon gives rise to a second cell or
bladder, as at K. As growth is continued, further budding takes
place, at right and left, as well as at the top of the buds, as shown
at L and M. If the spores are grown in the juices from farmyard
manure diluted with water, the budding becomes much more
profuse, as at N. This bursting and budding of the minute
spores, which can be observed under the microscope, takes place
naturally in the ground in damp weather, and the purplish black
Smut-spores give place to innumerable quantities of these exces-
sively small, transparent, spore-like bladders.

It is a remarkable fact that these buds from Smut-spores
cannot be distinguished under the microscope from yeast. They
are capable of growing and multiplying for an indefinite period of
time in this yeast condition. Yeast is of course a fungus, and
observers are not wanting who say that germinated Smut-spores
are not only like a yeast, but they are positively yeast itself.
Whether this idea is a correct one is somewhat uncertain, but the
fact remains that yeast and germinated Smut appear to be identi-
cal. Both excite alcoholic fermentation. Smut-spores which have
germinated in our fields lead a non-parasitic life in and on the
ground. It is remarkable that the yeast-like buds from Smut-
spores are not only capable of producing a vast number of other
yeast-like bads, but some of these buds, probably influenced by

New Series, Vol. I.

1888. H

98 SMUT OF WHEAT, OATS AND BARLEY.

external dry or other conditions, produce, on germination,
extremely fine attenuated threads, as illustrated at O and F.
These attenuated threads are also produced on and in the ground,
and they secure access to cereals in the following manner : —

After the seeds of wheat, oats, and barley have been planted,
the first green leaf from the seed speedily appears above the
ground. In order to perform its vital functions, every leaf is fur-
nished on its under surface with an immense number of minute
orifices, which lead direct to the inner substance of the leaf.
Through these litde openings (termed stomata), the plant
parts with moisture in the form of fine vapour. In damp weather
every little opening or mouth stands naturally wide open. At the
same time, the yeast-like buds belonging to the Smut-fungus are
protruding their fine threads, as at O and F, upon the ground.
These threads come in contact with the first young leaves of
cereals, and enter amongst the tissues of the infant plants of
wheat, oats, and barley by the minute open mouths or organs of
transpiration belonging to the back of the leaves. When the
fine Smut-threads are once within the substance of the young
cereals, they are in their natural position. They speedily find
their way to the young stems, and, as the stems grow, the fungus
grows too, and is carried up by the growing stems. When
the ear or panicle is formed, all its parts, including the finest
stalks, are invaded by the fungus, and in these parts of the
plant it matures itself and produces its innumerable black seeds or
spores which burst through the plant from its apex, and from this
position once more reach the air and the ground.

It may be noted that the fungus can grow on no other plants
except cereals and grasses.

The Smut-fungus grows on a considerable number of wild
grasses, in waste places, such as darnel and the various wild oat,
barley, and rye grasses.

[99]

IRcw pboto^mMcroorapbic apparatus.

By C. Lees Curties.

THIS apparatus consists of a base-board of sufficient length to
take the camera when fully extended, the microscope, and
the lamp, and is an inexpensive form of camera, designed
by Mr. E. M. Nelson and myself, for use specially with Zeiss's new
projection eye-piece. No. 3 ; but can also be used with ordinary
eye-pieces, or where a long camera is required, without eye-piece.

The height of the camera above the base-board is the same as
the optic axis of the Nelson model microscope, but can be arranged
to the height of any microscope stand. The camera itself con-
sists of two millboard tubes, which are light but strong, the one
sliding into the other like the tube of a telescope ; the joint
between the two tubes is made light-tight by a velvet flap. Whe
the tubes are closed, the length of the camera is 2 feet, but it can
be used at any length up to 3 feet 6 inches. The outer tube is
fastened to an upright frame of wood, which is clamped to the
base-board by thumb-screws at any point of its extension ; this
tube is removed when the different sized diaphragms are put in
position.

The focussing screens of grey glass and plane glass, with finely
ruled diamond lines, slide in grooves at the back of the wood up-
right ; a double metal back is supplied which also slides easily in
the same grooves. The focussing is effected by a rod placed at
the right hand side of the camera, a string passes round this, and
over a wheel on the opposite side, taking a turn round the milled
head of the fine adjustment. This string is kept tight by a strong
elastic band. The feet of the microscope fit into blocks fastened
on the base-board.

The manner in which the apparatus is used is as follows : —
The- camera is closed up and pushed back as far as possible.
The microscope is then arranged in a horizontal position, with the
feet held firm under the blocks on the board. Sufficient room is
left between the eye-piece and the opening in the camera to allow
the eye of the operator to be placed to the eye-piece. The illumi-
nation is now centered and adjusted, and the image of the object

NEW PHOTO-MICROGRAPHIC APPAEATUS. 101

viewed with an ordinary eye-piece. Having completed the adjust-
ment, the eye-piece is removed and a projection eye-piece inserted.
The camera is now slid up to its place, but leaving enough room
for the fingers to adjust the eye-lens of the projection eye-piece.
This is moved until a sharp outline of the diaphragm in the eye-
piece is produced upon the grey glass screen or upon a piece of
white paper held near the end of the camera. The camera is now
pushed up until the front tube enters the light-excluding cap
fitted on the microscope tube, and then extended until the
desired size of the picture is obtained. The object should now
be accurately focussed upon the plate-glass screen, a good focus-
sing glass, of course, being used.

A very good method of judging exposure is given in Mr. E. C.
Bousfield's " Guide to the Science of Photo-Micrography," with
table for use in conjunction with Warnerke's sensitometer.

Artificial Serum. — An improved formula for artificial serum
may prove useful to those who make daily examinations of the
blood. Dr. Mayet, of Lyons, who is himself an expert microsco-
pist, recommends the following composition : — Distilled water, loo
grammes j anhydrous phosphate of sodium, 2 grammes ; sugar,
q.s., to bring the solution up to sp. gr., i"o85. This hquid
appears to be an excellent medium for preserving blood-cor-
puscles and other globular anatomical elements without alteration
for a considerable time, so that they may easily be counted and
examined under a high power in anaemia, leucocythsemia, etc.
Owing to the density and slight viscosity due to the sugar, and the
preserving action of the alkaline salt, the ditt'erent elements are
prevented from adhering together, and remain thus equally
distributed in the fluid.

Potassium Cyanide Vapour. — -It is a mistake to suppose,
says the Scientific Neivs, that the vapours given off by potassium
cyanide are deadly to all animals. We have seen several species
of beetles which, after prolonged imprisonment, along with abun-
dance of this chemical, came out quite safe and sound.

[ 102 ]

Zbc niMcroecopc anb 1bow to ITlee it.

By V. A. Latham, F.R.M.S.

Part XIV.

Practical Notes on Histology.
Special Methods for Examination of the Spinal CaRD,

Brain, etc.

THE great difficulties experienced by all investigators of the
nervous system have been chiefly fourfold : —

(a) That of becoming acquainted with the various methods
which lie so very scattered amongst the numerous scientific
periodicals.

{^) That of cutting sections of an entire human brain, or
large segments of it, of sufficient delicacy for microscopic purposes,
and with almost mathematical accuracy.

(t) That of retaining large masses of hardened nerve tissues
in absolutely the same condition as during life, without shrinking
or rendering the tissue friable.

(d) That of demonstrating the dark fibres with such clearness
that they can be traced throughout a great part of their course
with ease and certainty. All who have worked on the nervous
system know how great these difficulties arc, and how much we
need some process by which they can be overcome.

The great obscurity and errors which prevail in regard to the
normal and morbid anatomy of the nervous centre is, no doubt,
mainly due to these causes. The methods here given are those
which have proved of greatest use to me during the examination
of these organs, and I sincerely hope they will not be without
value to other experimenters.

General Method. — This investigation is a long and compli-
cated one, the tissues having to pass through the following stages
in the order given : —

I., Hardening ; H., Cutting ; HI., Staining ; IV., Mounting ;
each stage claiming its own special process.

I. Hardening the Tissues.-— Cut into small pieces, place them
in methylated si)irit, and let them stay for about two days

THE MICROSCOPE AND HOW TO USE IT. 103

(sometimes 24 hours will suffice), to ensure them against
subsequent decomposition. If the brain is the subject of research,
leave it for from four to six weeks to harden in the following
solution : — Chromic acid, i part ; bichromate of potash, 2 parts ;
water, 1,200 parts. If the spinal cord, then i part of the acid to
200 of water in the case of the human or large animal subject, or
I to 400 proportion in that of a small animal, will be sufficient to
induce the requisite induration. [Do not exceed the above-named
period of immersion, as the action may change and ruin the
specimen. Should you wish to defer your investigation, keep the
specimens in methylated spirit until ready to proceed with them.]

II. Cutting. — A mixture of i part of lard to 5 of paraffin,
having been heated in a water bath, is poured into a microtome
or a tin or paper box (see Jour fial of Microscopy, Vol. VI., p. 242).
Now, having first steeped your specimen some ten minutes in
absolute alcohol, hold in forceps and dip gently into the
embedding mixture for a moment, withdraw to prevent shrinkage,
and then replace and hold it until the mass begins to cool. Then,
with a razor, kept wet in methylated spirit, (or absolute alcohol if
you desire very fine sections) ; cut sections, sweeping obliquely
from right to left across the top of the microtome, taking care to
remove each slice in one sweep. Transfer sections seriatim to
water (or spirit), removing the adhering paraffin, if any, by
moving them circularly with a small-hair brush ; then pour off the
water or spirit. Having washed them, leave for some thirty
minutes in a solution of i part bichromate of potash to 100 of
water ; then proceed to stain and mount in the ordinary way.

Variation from above rules : —

Freezing has been successfully used in preparing brain, etc. ;
after staining in carmine mount in a mixture of hydrochloric
acid, 2 minims, or glacial acetic acid, 5 minims, added to
glycerine, i oz.

Sections of spinal cord should be taken from all the various
regions, and hardened in a solution of ammonia bichromate (2 or
5 per cent.) solution for from a week to a month, according to
what strength of solution was used ; transfer to spirit and cut.
Stain sections in eosin, carmine, hcematoxylin, lithium-carmine.
Anilin blue black, 1 7 per cent, solution stains the ganglion cells

104 The microscope

very well, and a double stain of eosin and hsematoxylin is
excellent.

Dog. — Some sections should be made as soon as the cord has
been hardened in the Erlicki's fluid, before placing the cord in
alcohol; in order that they may be stained in osmic acid ; others I
find give good results if the sections be placed in o'5 per cent,
methyl green for 1 2 hours ; wash well in distilled water, then place
in borax carmine. This shows the axis cylinder and ganglion
cells red, whilst the neuroglia comes out violet, the remainder green.
Erlicki washes his sections for two hours in distilled water before
staining in ammonia carmine.

Horse. — Get some short transverse sections and place for
forty-eight hours in Ranvier's alcohol. Then snip pieces out of
the anterior horn of grey matter, place in 2 per cent, solution
ot i)icro-carmine for twelve hours or so, then tease the
multipolar nerve-cells out with needles and mount in Farrant, in
a shallow cell.

To harden Spinal Cord and Brain in Erlicki's Fluid.—

It takes about ten days, but will do so in half the time if we care
to take the trouble to keep it at a temperature of about 40 deg.
C. or 104 deg. F. It must be fresh each time and filtered before
use. It must be changed daily or nearly so, and when the tissues
are hard enough the fluid is washed away with tap water and the
tissues finished in alcohol, commencing with 75 per cent.

Spinal Cord (Overlach's Method).— Place small pieces of the
spinal cord of a child in a 1 or 2 per cent, solution of ammonium
bichromate until hard (fifteen to twenty days) in a cool place.
Make sections, and place in a solution of chloride of gold, i part,
and potassium in 10,000 parts of water, which has been acidu-
lated by the addition of a few drops of hydrochloric acid. Then
wash in one part of hydrochloric acid in 2,000 — 3,000 parts of
water; then transfer for 10 minutes to a mixture of one part of
hydrochloric acid in 1,000 parts of ordinary alcohol ; then succes-
sively in absolute alcohol, oil of cloves, and Canada balsam.
After three or four hours the nerve network is visible.

Krause's Method.— Hang fresh cord in a cylinder full of
Mviller's fluid. Attach a small weight to the lower end to avoid
torsion. After twenty-four hours, change Miiller for i per cent, of

AND HOW TO USE IT. 105

chromic acid, which is changed for fresh on the fourth day. A
few days later (when the cord appears hard), the chromic acid is
removed by means of water and the cord put into spirit, followed
by absolute alcohol, which must be twice changed. Now imbed
in paraffin ; pass sections either (a) through alcohol, carmine, oil
of cloves, into Canada balsam ; or {d) simply through benzole or
Bromier's " Flochwasser " and Canada balsam. (" Flochwasser "
appears to me to be a preparation of xylol.*)

Bichromate and Silver Nitrate Process.— This is sometimes
spoken of as Golgi's method, and is taken from a paper of
Rezzonico, a pupil of Golgi.t

I. — Take pieces of perfectly fresh spinal cord and soak them
in a 2 per cent, solution of bichromate of potash for a varying
period, according to temperature. (In summer eight to fifteen
days may suffice ; in winter about a month is necessary.)

2. — Wash them, put in a 075 per cent, solution of nitrate of
silver. Time varies according to temperature. In summer the
reaction is complete throughout the tissues in two or three days ;
in winter, eight to ten days.

3.— Dehydrate small pieces in alcohol (make sections if neces-
sary), clear in oil of turpentine. Tease while in the turpentine
and mount in dammar.

4. — Leave preparations to themselves, in order that the
secondary impregnation may take place. In direct sunlight, eight
or ten days ; in diffused sunlight, twenty to forty days will be
required. Greater certainty is obtained by treating the fresh
tissues with osmic acid (by means of interstitial injection) before
putting into bichromate. In this case, a much shorter immersion
in bichromate will suffice (four to eight days).

By this method may be seen, in the medullated fibres of the
spinal cord, a chain of conical funnels, set one within another,
embracing the axis cylinder with their narrow aperture, etc.

Xylol for Central Nervous System (Merkel's Method.*) —
Dehydrate sections from system with 94 per cent, of alcohol, in
which they should remain ten minutes at least ; then clear with

*"Archiv. fiir .Mikros. Anatom." (1887).

t " Archivis par le Scienze Mediche."

106 OBITUARY.

xylol, in which they are examined. I think this method, perhaps,
the most superior of all for studying distribution of nerve-fibres.
Unfortunately, they are not quite permanent, though, if mounted
in Canada balsam, they last for some length of time. They may,
however, when they become so transparent as to be of no further
use, be re-prepaied by putting back into alcohol and thence in the
xylol.

OBITUARY.

^be late 2)i\ Bsa (5ra^.

DR. Asa Gray died at Boston, in Massachusetts, on the 31st
January last. By his death the world has been deprived
of one of its most able botanists. He was born in the
year 1810, and shortly alter taking his doctor's degree in Fairfield
College, he began those studies to which he has devoted the
remainder of his life. Dr. Asa Gray became known to European
botanists soon after the publication of his admirable " Text-Book
on the Structural and Morphological Botany of Ph?enogamous
Plants," in the year 1842. The fifth edition of this much-
esteemed work appeared in 1857, since which date the name of
Asa Gray has been on the lips of botanical students in almost
every country where the English language is spoken and the
science of botany taught. He was an occasional visitor at Kew,
where he is said to have profited by the study of the magnificent
Herbarium, which Sir Joseph Hooker has done so much to
enrich.

On one occasion he accompanied Sir Joseph Hooker on a
botanical trip across the American Continent. Dr. Asa Gray has
done excellent service to the botanical world in the preparation of
that great flora of the United States, which, we believe, is still
incomplete. In 1861 Dr. Asa Gray gave to the scientific world
another admirable work, in which he dealt fearlessly with the late
Charles Darwin's treatise on " The Origin of Species." He may
fairly be classed with Hooker, Lyell, and Huxley as one of the
chief English-speaking commentators on our great naturalist's

SELECTED NOTES. 107

best-known work. For at least half a century he has been the
highest authority, the practical dictator, of American botany.

Few men have left this world leaving more friends and less
enemies. Always genial and courteous, he possessed the happy
talent of expressing a difference of opinion without giving offence,
much less making an enemy of his opponent, and that in a
country where acrimonious disputes are at least quite as common
as in Europe. An excellent teacher and writer of text-books — ■
which are almost as much used in this country as on the other
side of the Atlantic— he was for many years on the professional
staff of Harvard College, at a time when such eminent teachers as
Agassiz, Wendell Holmes, Longfellow, and Lowell filled similar
positions in other departments. The Royal and Linnaean Societies
conferred on him the rare distinction of their Foreign Member-
ship. Few losses to science that have occurred within recent
years will be more felt than that of this truly excellent botanist.
His works will live in the recollection of many, and his indefati-
gable industry, ability, and generosity will, it is hoped, serve not
only to keep his memory " green," but to encourage others to
follow him in his peaceful and pleasant paths.

Sclccteb 1Rotc0 from tbe Society's
1Rote^Book0.

Plate XH.

Aspidiotus Nerii.— These insects are very interesting. I
believe these scale insects are Aphides. If so, their being vivi-
parous is no matter for surprise,* since it is the usual manner in
which the 7c>ingless form of insects is reproduced.

I have drawn one of the young specimens of Aspidiotus. All
its limbs are plainly seen — the antennae, the mouth, and the six

* The contributor of this slide says : — " I add a slide, Aspidiotus Nerii,
from oleander leaf, mainly interesting for containing a young specimen, born,
as far as I could discover, while mounting in l^alsam. The legs are clearly
discoverable in the young specimen, but difficult to trace in the mature insect.
I presume they are viviparous."

108 SELECTED NOTES FROM

legs. I can detect no separate head, nor any eyes. The mouth
is of the usual Aphis type. I would draw attention to the two
little tubes, or what appears to be the representatives of such,
situate at the end of the abdomen, which ants are in the habit of
" milking " in rose and other Aphides for honey-dew.

One of the most interesting features in these specimens is the
distinctness with which the trachial system can be seen. In the
specimen drawn, the air has been expelled from the main trunks,
and I cannot by any means see them, but they are visible in two
of the other specimens. I am uncertain whether three spiracles
on each side is the right number, but I cannot detect any more.

H. M. J, Underhill.

Rice-Paper. — Chinese rice-paper (so-called) is now known to
be prepared from the. pith of a shrubby tree, Aralia papyrifera,
which grows chiefly in the forests and on the hill-sides of For-
mosa, attaining a height of from 12 to 14 feet, and propagating
itself by suckers thrown up from the roots, like the bamboo.
The leaves are large, from one to two feet long, and even more in
their greatest width, palmate, with five to seven digitations, dark-
green on their upper surface and downy white below. Their foot-
stalks and the unexpanded leaf-buds are thickly covered with a
brownish down, which easily rubs off, and which consists of
stellate hairs. Large drooping panicles of greenish flowers rise
above tlie extremities of the stem and branches, giving the tree a
very handsome effect, and its general appearance is said somewhat
to resemble that of ihe castor-oil tree. The young suckers are
transplanted by the Chinese, lirst, into pots, and then into ground
prepared for them, where they are carefully tended till the plant
is fully grown. They are then cut down, the branches removed,
and the stems left to soak for some days in running water to
loosen the wood and facilitate the removal of the pith. This,
after being cleaned, is cut into cylinders of convenient length and
passed on to the paper-cutter, who, taking a sharp, broad-bladed
knife, makes a slight longitudinal incision in the cylinder, which
is then turned round gently and regularly on the edge of the knife
till the whole available material is planed off in thm, even slices.
Much care and dexterity are required to produce sheets of even
thickness. On these sheets, as is well known, the Chinese
execute admirable drawings and paintings. They are also exten-
sively used in the manufacture of artificial flowers, and are so
cheap that at some places 100 sheets — each about three inches
square — may be bought for three half-pence. The plant has been
introduced into New South Wales, where it thrives well, and pro-
pagates itself freely in the open air. It has also flowered ire-

THE society's NOTE-BOOKS, 109

quently (under glass, I presume) in the Royal Gardens at Kew.

J. H. Green.

Section Yellow Cam Wood is wood of Baphia nitida, a tree
growing in Sierra Leone to the height of forty or fifty feet.
About three or four hundred tons are annually imported. It is of
a deep red colour, and yields a brilliant but not permanent dye,
and dyers use it in the same way that they do the dye of another
species of the same genus, Brazil wood. There is a beautiful
plate of Baphia ?iitida in " Bot. Cat," Vol. IV., p. 367. The
flowers are yellow and somewhat similar to our yellow laburnum ;
hence its name (I suppose), Yellow Cam wood. The same wood
is sometimes called Bar-wood in commerce. E. E. Jarrett.

Aspidiotus Nerii.— If the scale is removed from the leaf when
it is just beginning to harden, it will be found to be full of eggs.
It is a very beautiful object to see something like 200 eggs of a
rich brown colour all closely packed together. At this point the
legs of the parent are still visible, and may be noticed slowly
moving backwards and forwards, while the whole of the internals
seem to have become eggs. A little older specimen of scale will
show the nest or back of the parent full of living young, whose
first business is to eat up the parent's legs, and then go off explor-
ing on their own account. There are, I think, always some few
eggs not hatched, which is probably owing to the loss of heat
through the final decease of the parent and the emptying of the
body caused by the roving of the rest of the family. If undis-
turbed, the young seem to stay about the old " home " for a day
or two, until they have lost all traces of the downy " packing,"
which always adheres to them at first.

If any member is troubled with his gardener's negligence
about cleaning off the scales, let him show the inside of a good
hard specimen, under a pocket-lens, to him. It will have more
effect than an hour's talk. (This recipe is recommended after
trial.) There are two red eye-spots on the young when hatched,
but I do not think they are of any practical use. The head is not
particularly marked off from the body, so far as I have been able
to make out. H. R. Boult.

Tingis hystricellus.— With this slide I enclose a cutting from
Science Gossip, 1869 : —

" This new and very interesting hemipterous insect, to which
I have given the name of Titigis hystricellus, was discovered in
Ceylon and collected from the Bringall plant by Mr. Staniforth
Green, a gentleman long resident in that island. All the species
of the genus to which it belongs are small, but the present species

110 SELECTED NOTES FROM

is exceedingly minute ; the largest of the specimens I have yet
seen scarcely attaining to one-eighth of an inch in length. When
examined, however, in the microscope, it is an elegant insect, and,
properly mounted as an opaque object, it makes a fine binocular
slide for the low powers. Very little appears at present to be
known with respect to its habits and economy.

" Mr. S. Green says : — ' It is common here, and hundreds of
examples may be found upon a single plant. Those I now
enclose were dried between the leaves of a book, and afterwards
exposed for a couple of hours to the direct rays of a hot sun. All
I can say of its habits is that it sticks close to the under side of
the Bringall leaf, and there undergoes all its changes, from the
larval to the perfect state. The larvne are black.

" Tingis is a genus of Fabricius, described in the ' Systema
Rhyngotorum ' (p. 124). Various species of Tiu^i's are found
nearly all over the world. In the cabinet of the British Museum
may be seen specimens from England and France, some of them
nearly as small as the species here figured ; as well as several from
Africa, North America, and the Philippine Islands. Other species
are found in Sweden^ and in fact all over Europe. A large
number inhabit South America, and four or five have been taken
in the island of Ceylon. The distribution of the genus may
therefore well be called 'world-wide.' The character which at
once distinguishes the Titigis hystricellus from all other known
species of the genus is the complete armature of spines, which
project from various parts of the head, thorax, and elytra. Each
of these spines, when examined by a somewhat higher power, is
found to have a sharp point or seta, ]^rojecting as from the open
end of an investing sheath. The integument of the elytra, as
well as that composing the dorsal surface of the thorax, appears
like a thin membrane nearly as transparent as glass, supported by
a strong reticulation bearing the spines, which radiate in every
direction. The metathorax extends far backwards, simulating, as
it does in many allied genera, a large-pointed scutellum. The
pupa is exceedingly interesting, being of a dark brown colour, and
covered with white spines ; those along the sides of the abdomen
are compound or branched, and each branch has a projecting seta.
These compound spines are not found on the imago insect.

" Some of the species in the cabinet of the British Museum are
very beautiful, not only in form, but in colour. They all show a
tendency to a reticulated structure of the elytra ; but the present
species differs from all of them in the quantity of spines bristling
over the dorsal surface. It is, in fact, a little insect porcupine,
and fully justifies the specific name of hystricellus."

This object should be viewed with the paraboloid.

Thos. Curties.

THE

society's note-books. Ill

English Tingis more resembles the American Tmgis ciliata
than the one described above. The open structure of the cephalo-
thorax appears to be very similar to the so-called " eyes " of
ixodes, but which in this case are certainly not organs of vision.
It would appear to be a provision of Nature for giving strength
and U^zhtiiess in structure. H. E. Freeman.

'<b'

Tingis.— Stephens, in his list of British insects, names no fewer
than 1 6 varieties. C. F. George.

Palatial Tooth of Fish (Fossil) probably belongs to the Stro-
phodus, a genus of shark frequent in the oolites. The tooth is a
flat plate adapted for crushing the shells of molluscs, on which the
fish probably feed. It is made up of a great number of minute
toothlets, welded together into a flat plate, in the same way that a
horse's hoof may be considered to be made up of a number of
hairs. The multiple pulp-cavities are seen in cross-section, each
surrounded by an area of clear material, and sending off" a cluster
of branched, dental tubules larger than those of mammalian teeth,
and not, like them, pursuing a parallel wave-course.

H. F. Parsons.

Section of Screw Pine (PI. XII, Figs. 3 and 4). — As Mr.

West has not figured this, I have tried to supply the deficiency.
The endogenous structure is very well seen, and I think that the
apparent increase and approximation of the woody bundles
towards the periphery {?iot seen in the drawing) is evidence of the
fact stated by Smith, p. 88, that these bundles, in the lower part
of their course, pass in curved lines outwards from the centre
towards the circumference of the stem. What is the colouring
matter with which so many of the cells are filled ? In the Intel-
lectual Observer for February, 1868, there is an article by John R.
Jackson, curator of the Museum, Kew Gardens, " On the
Fajidamis and its Allies," in which he points out that they
partake, on the one hand, somewhat of the habit of palms — viz.,
in their foliage ; while they incline to exogens in their manner of
branching. They are natives of the tropical regions of the Old
World, occurring but rarely in America. Some of them are
furnished with numerous aerial roots, as seen in Fig. 4 in the
Plate (from Smith, p. 61).

The following is Mr. Jackson's account of Pandatms odoratis-
simis, which I take to be synonymous with odourous. He says: —
" It is a plant some twelve or more feet in height, with spreading,
irregular branches and closely-imbricated leaves, arranged in three
spiral rows round the ends of the branches. It grows in the

112 SELECTED NOTES FROM

islands of the Pacific Ocean, China, and the East Indies, being
common along the banks of the canals and backwaters of Travan-
core, where it is planted for the purpose of binding the soil. The
long leaves are full of tough fibres, which are used for making
cordage of various thicknesses, as well as for making hunting-nets
and the drag-ropes of fishing-nets. Matting of all descriptions is
likewise made from them. Some of the sleeping-mats, which are
dyed or stained of various colours, are fine specimens of native
plaiting. The leaves are likewise used to make umbrellas, and
they are said to furnish excellent materials for paper-making.
The fibre from the leaves is commonly used in Tinnivelly when
mixed with flax for making ropes. The aerial roots are applied to
a variety of purposes in India. Manufactories exist in some
localities, where hats, baskets, mats, etc., are made from them.
On account of their light, spongy nature, they make excellent
stoppers for bottles in lieu of cork, and the more fibrous part,
when beaten out and the pulp removed, is used for brushes for
whitewashing, painting, etc. The roots are used medicinally by
the native practitioners, and an oil prepared from them has the
repute of being a cure for rheumatism. The flowers are odorifer-
ous, as the specific name indicates. Besides the numerous uses
already mentioned, the inner or pulpy part of the drupes is eaten
as an article of food in times of scarcity."

One can easily understand, on looking at the close texture of
the woody bundles, whose cut ends are seen in the slide, what
strong fibres they would make when ravelled out for the various
purposes enumerated. A. Hammond.

Section of Jaw of Mole affords a good example of mammalian
teeth. The fangs of the teeth are here seen in cross-section
embedded in the jaw-bone. In the centre of each is the pulp
cavity ; then the dentine with its radiating tubules ; external to
this the cement, filling up the interval between the tooth and its
bony socket. A set of ramifying canals is seen traversing the
bone to convey blood-vessels and nerves to the teeth. The bone
has, however, no Haversian canals to convey blood for its nutri-
tion, being so thin that suflicient nourishment can percolate into it
from the outer surface through the canaliculi. H. F. Parsons.

Foraminifera and Sea Soundings should not be mounted in
balsam. Opaque mounting is by far the best. The mounting as
transparencies destroys largely the power to clearly discriminate
the species, the whole appearance of the shell being so much
altered, and the examination as an " opaque " being all but
impossible. C. Elcock.

THE society's NOTE-BOOKS. 113

Spinnerets of Spider (PI. XII., Fig. 5).— These are from an
Epeira, most likely the common garden spider. It is with the
first pair of spinnerets, a, a (there is a slight depression in the
cushion of the spinning-tubes, giving each of the spinnerets the
appearance of being double), that the spider spins the radii of the
web, the threads of which are not sticky. The circular threads
which are not sticky are spun by the little pair of spinnerets in the
middle, which I call the second pair, b, b. These non-viscid cir-
cular (or, more properly speaking, "spiral") threads are not found
in a finished web, except in the litde patch in the middle. The
sticky circular threads are, I believe, spun by the third pair of
spinnerets, r, r, but this stickiness is not due to anything peculiar
in the construction of the spinnerets, which are identical in those
spiders which spin no sticky threads at all. I cannot say what
makes a spider's web sticky. My conjectures on this point will
be found in Science Gossip, 1874. H. j\I. J. Underhill.

Sectionof Tongue.— The papillae are of three kinds— ////^rw,
fungiform, and circumvallate. The latter are only found at the
root of the tongue. Tht filiform, as named from their shape, are
of small diameter in comparison with their length, and are sup-
posed to have to do with the tongue merely as an organ of touch.
The fungiform are much larger and fewer in number, and are
found chiefly on the sides and tip of the tongue ; they are con-
cerned (hypothetically) in the sense of taste, as are also the cir-
cumvallate papillae. E. C. Bousfield.

Onosma tauricus (see page 47), natural order, BoraginacecB. —
Thanks to a host of patient botanists, we have a wonderfully full
account from their general point of view; but it remains for micro,
workers to investigate thoroughly from theirs such micro, pecu-
liarities as the plant within its limits may possess. As yet, it
seems to me that they have only recognised that many plants of
this group have a central hair, at whose base lie certain cells, in
such prominence of development from their kindred contiguous
cells in the cuticle as to attract attention, and when these are dis-
posed in a stellate or rosulate group, and so form an object of
strikmg beauty, they pass into acceptance and record among what
are popularly called micro, objects. Such basal cells are certainly
a peculiarity to many plants of this natural order, although not
confined to it. The finest and most beautiful example of them I
ever saw was on a leaf of Borago verrucosa, a native of Arabia ;
and it is rather odd, that the finest specimens of oil-glands were
also on an Arabian plant, Origanum nervosum (a labiate), but I do
not know where to procure either plant.

Of Onosmas, besides the well-known 0. tauricum, there are in

New Series. Vol. I. i

1888.

114 SELECTED NOTES FROM

cultivation eleven hardy and three half-hardy species, all herba-
ceous perennials, with mostly yellow flowers. They are entirely
propagated by seed or division of root, and well able to take care
of themselves when once established in mixed border or on
rockwork. Raising this class of plant from seed is never desir-
able, unless delay is of no importance and great quantities
required. Any nurseryman who makes a speciality of supplying
perennials would probably send a rooted plant of O. tauricum
for about the ordinary price of a micro, slide, which would
at once furnish material for several slides, and be a permanent
plant for the garden as well, giving annual increase. I frequently
adopt this mode of acquisition, and call it " eating my cake and
having a bigger."

Among the Fulmonarias of this order, F. Siberica is a most
desirable one to cultivate and examine. The tuberculated appear-
ance (from which, according to the superstition of " Herbs and
Signatures," q.v.^ the lungworts, obtained their generic name) is
most strongly marked. W. Teasdale.

Hairs on Petal of Deutzia.— When hairs and scales are found
on the stem and leaves of a plant, it is not at all unusual for them
to extend over the calyx and petal of the flower also. Ordinary
examples of this may be seen in Rhododendron ferrugineiim and
most of the dwarf species and hybrids. These latter are now
very numerous, and their parentage uncertain, as florists give them
fancy names unknown to science. Incomparably the most beauti-
ful example I know is the flower of Correa ca?dinah's, when fresh
gathered. The calyx shows tawny rosettes on a lovely green
ground, the petal pearly stars on a crimson one. Even the foot-
stalk is indescribably beautiful. The plant blooms profusely
under glass most of the winter and spring months.

There are five deutzias in cultivation. D. gracilis is best
known and seen everywhere in its flowering season, early spring.
In D. scabra the hairs are larger and more developed, and to this
it owes its roughness and consequently its scientific name ; from
the use made of it, probably the hairs are siliceous, a sort of
exterior raphides. Both of these are natives of Japan, from which
country and from China most of our finest hardy plants of the
last thirty or forty years have come. D. corymbusa and D. sta-
minea are Himalayan species, also white-flowered. D. sanguinea
is a red-flowered species, of which I have no further information.

W. Teasdale.

Ramenta of Ferns.— Mr. West's suggestion (see p. 47) that the
office of these on the Bracken (?) is the protection of its young

THE society's NOTE-BOOKS. 115

fronds from frost has interested me, and prompts the further sugges-
tion that those so large and numerous on many tropical ferns may
possibly, to them, serve as a screen from heat, and tend to check
evaporation of moisture from the frond when the air is dry, and
possibly also to retain such moisture from dew or otherwise as might
from time to time come to refresh the plant.

As to the appearance and development of hairs, scales, etc.,
upon plants generally, it seems clear that in certain natural orders
certain forms are observed to be prevalent on many or most of the
plants belonging to them ; that in some species they are generally
more numerous and conspicuous than upon other species of the
same natural order; but when we come to the individual plants
themselves, there is in their hairs as much diversity of development
as there is in the hirsute adornment of the male of that noble
animal who subordinates all other created things to his own use
and pleasure, his female counterpart forming only occasionally a
rare exception to prove the rule.

That this animal developes differently under differing atmo-
spheric conditions may be seen by comparing a pretty-faced
specimen from a manufacturing town with a ruddy clodhopper
reared in the agricultural districts. The difference, however,
might not be so evident if the specimens were prepared for
examination by being soaked in potash for a week, squeezed flat
in a hydraulic press, and fixed in balsam between two slabs of
plate-glass. W. Teasdale.

Fern-Scales.— These occur more or less abundantly on all the
British ferns that I have examined. They vary very considerably
in general form as well as in shape and size of the cells. They
should be looked for, not on the back of the frond (except in
Ceterach), but on the stipe, the lower portion of which is usually
completely covered with them. Many of them polarise well.

W. H. Beeby.

Plant-Hairs.— Those interested in plant-hairs should get a
specimen of our native (?) plant, Alyssiim calycinum. Almost all
parts of the plant are covered with hairs of a very peculiar shape.
I give a rough sketch of one of these hairs on Plate III., Fig. 8.
Some examples are much simpler than this, while others are very
much more irregular. They polarise beautifully. W, H. Beeby.

Medicago.— Is Medicago ever found with quadrifid leaves ? I
have found four-leaved Oxalis, but never four-leaved Medicago.
The answer to this question might throw some light on which is
the true shamrock. W. H. Beeby.

Acidium compositarium.— These cluster-cups should be viewed

116 SELECTED NOTES.

with a Lieberkuhn. It is only when thus seen that the beautiful
pavement at the bottom of each well is effectively shown.

A. Nicholson.

Parasites to Mount— I first soak them in glycerine and water,
then place them on a slide, add warm jelly, put on cover, and
keep the jelly liquid for some time. To show the ramifications of
the minute tracheae, mounting in warm jelly without previous
soaking, and allowing them to cool rapidly, answers well.

D. Moore.

Spiral Fibre in Rhubarb.— This is a favourable opportunity to
draw the attention of members to a theory of their formation,
which was taught by Dr. Bristowe when I was student, and which
he elucidated in a paper in the St. Thomas's Hospital Reports a
few years ago. He supposes that the spiral dotted and pitted
appearance in cells is produced by the mechanical action of
growth acting on a sclerogenous layer (deposited in their interior)
when in a viscid state. He illustrates it by reference to the
parallelogram of forces. Thus the viscid layer of sclerogen is
stretched by the enlargement of the cell-wall in various degrees in
two or more directions, the result being a tendency to tear in a
direction representing the resultant of such forces.

I went into the subject some time ago, and came to the con-
clusion that the theory was probably right. A good illustration I
found in the common garden clematis. In a terminal joint where
there is a most rapid growth, and the forces of growth act most
evenly, spirals only are found in a second joint. All stages of the
tearing process may easily be observed in the newly-formed scle-
rogenous layer ; the original spirals formed when the now second
joint was the first, are only stretched open somewhat or increased
in size. He thus suggests that they are not deposited as spirals,
but as an homogeneous layer of sclerogen, which is made into a
spiral or other form by the enlargement and lengthening of the
cell-wall by the action of growth, the form being determined by
surrounding conditions influencing the amount of stretching force
exerted in various directions.

Spiral vessels are common in all quickly-growing portions of
plants, and this theory connects together the more rapid growth in
such parts with the presence of spiral fibres in certain cells, and is,
1 think, worth a hearing and further investigations. It is possible
that the same theory may account for the formation of the spiral
in the trachese of insects, but as yet known facts are too few to
admit of anything but conjecture. D. Moore.

[The above note should have appeared in our January issue,
but was pressed out. — Editor?^

Journal of Microscopy N. S. Vol.1. P1.12

2

1

'Vx-

m

an

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"I* ^^ .*

1.J' ^-*

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CORRESPONDENCE. Il7

Spiral Vessels to Mount.— Let them be soaked in dilute nitric
acid, in which a few grains of nitrate of potash is dissolved,
picking out the vessels carefully with a needle, and well wash in
water. They may then be mounted at once in glycerine jelly, or
further prepared for mounting in balsam. J. Carpenter.

Testacella. — This mollusc, according to Westwood, is carnivo-
rous, feeding on earth-worms, coming to the surface only at night.
Its dentition resembles the lanthincc. I am inclined to think they
are much more common than is supposed, but people do not
know where to search for them. H. E. Freeman.

EXPLANATION OF PLATE XIL

Fig. 1. — Entrance to the Nest of a Trap-door Spider, Cteniza Mog'
gridgii, with the door open. The small dots on the surface of
the door represent holes made by the claws of the spider in
holding down the door when alarmed.

Drawn by G. H. Bryan.

,, 2. — Aspidiotus, X 50, showing an., antennte ; m. , mouth; sp.,
spiracles. Drawn by H. M. J. Underhill.

,, 3. — Section of Screw Pine.

,, 4. — Rough sketch of tree. Drawn by A. Hammond.

,, 5. — Spinnerets of Spider, x 25. It has been attempted to give
a general view of the specimen, so far as could be done in so
small a figure, without attempting too much detail.

Drawn by Tuffen West.

Corrcspoubcncc,

[The Editor does not hold himself responsible for the opinions or statements of
his correspondents.]

[ To the Editor of ' ' The Journal of Microscopy and Natural Science. "]
Sir, —

The statement of "B.Sc, Plymouth," on p. 56
of your January number, is most misleading.

The root (so-called) of Beta is not a stem structure at all, as
a perusal of any modern text-book of Botany will show clearly.
The uppermost portion of it — i.e., the part which tapers downwards
to the ' shoulder ' — corresponds to the tigelhwi of the embryo,
this structure often forming a considerable part of the so-called
'root,' as_ in turnip, radish, cyclamen, etc., etc. All hehnu this
shoulder is root proper, and bears the well-known distinctive
characters of root-structure as opposed to stem-structure.

118 CORRESPONDENCE.

The root of Beta is anomalous in some respects, as are many
others, and for a detailed account of its special features I refer
your readers to De Bary's " Comparative Anatomy of the
Phanerogams and Ferns."

Yours faithfully,

H. W. S. Worsley-Benison.

[ To the Editor of " The Journal of Microscopy and Natural Science "\

Dear Sir, —

Kindly allow me space for a suggestion, which, if carried
out, would be, I think, of great service to the members of our
Postal Microscopical Society. ^Ve are even more isolated than
many other societies, but not less able and willing to help one
another, and a means of easily and quickly obtaining assistance of
our fellow-members would add much to the pleasure and success
of our work.

To obtain this without restricting or interfering with individual
tastes and pursuits, I propose that " circles " should be formed
among our members for work either of a general or of a specific
character; such as, for example, miscellaneous mounting, photo-
micrography, adulteration of food, pond-life, study of algse,
diatoms, desmids, mounting of whole insects, or any other subject
taken up as a pleasure for leisure time or for more serious and
scientific investigation.

We should require, first, a method of bringing into communi-
cation members pursuing the same or kindred branches of micro-
scopical work ; secondly, a method of electing a Correspondent
and homing some few rules for the greater convenience of all ;
thirdly, a means of easy and frequent communication between
members of each circle and between the different circles when
advantageous; and fourthly, a scheme by which the results
should be made useful and interesting to all the members of the
Society. This could all be done by the following regulations : —

(i) Let members of the Postal Microscopical Society seeking
to form or join such " circles " send a letter to our excellent
Secretary, giving their names and stating the subjects chosen.
Let each enclose six stamps for a " common fund " for the working
of each circle, if formed, or to be returned if the circle is not
formed. The Secretary would classify the names of applicants,
and when sufficient names were sent in to form one or more
circles — say, eight members in each — he would enter the names
in a " pass-book." This he would send to the member first on
the list, who would be " temporary correspondent." The common
fund would also be sent to the same.

CORRESPONDENCE. 119

(2) The "pass-book" should then be sent from member to
member in rotation. On its first round each member would
enter any suggestions he can offer, his acquirements, facilities, or
experience for the work in hand — viz., in mounting, drawing, pho-
tography, etc. etc. — and lastly stating whether he be willing or not
to undertake the light duties of "correspondent," which will be
seen in what follows.

(3) On the second round of the pass-book, each member
would vote for the correspondent, writing on one line the name
chosen from candidates and his own as voter. The temporary
correspondent, on the book reaching him, would add up the votes,
giving, if necessary, a casting-vote, and send on the pass-book to
the one who receives the majority of votes, with the common
fund, and send notice of election to the Secretary of the Society.

We should thus have been brought together for mutual help,
and have at hand an easy means of asking, giving, and obtaining
help by the continual rounds of the pass-book. If we have eight
members in each circle, and if one or two days are allowed for
the perusal of the pass-book, the book would come round to each
member either every eight or sixteen days. The postage would
not exceed one penny. The following might stand as preUminary
rules : —

{a) Members of the P. M.S. to be exclusively eligible as
members of " circle." Application to be made to the Secretary
of the Society as in No. i.

[b) Pass-books to be circulated as rapidly as possible in case
of voting, and at other times at such periods as may be settled
among members of each circle.

{c) Postage of "pass-books" and other articles sent round for
general use of the " circle " to be paid by each sender.

{d) Articles offered by any member for general inspection of
circle to be sent in first instance to " Correspondent."

((?) Each member to enter in " pass-book," diligently and con-
cisely, queries, answers, and results of work.

(_/) Correspondent to " summarise," each quarter, notes from
" pass-book " for publication in Journal of the Society — say,
under a heading, " News from the Circles."

{g) Boxes of slides to be formed as often as possible from the
work of members, and to be sent by " Correspondent " to our
Secretary for circulation through the Society. (The box should
first go the round of the circle sending it out for notes of general
interest.)

{h) The " common fund " would be used by Correspondent for
expenses incurred in postage, etc. A small levy now and then
would, perhaps, be necessary.

120 REVIEWS.

(/) Unanswered queries, etc., might be sent by " Correspond-
ent " to other circles or to the Scientific Enquire}:

{k) List of circles, with name and address of " Correspondent,"
at least, to appear in the Journal of our Society.

Thus, I think, we should work in better harmony, more
pleasantly and more usefully. In many cases of special difficulty
we should know where to seek information and to obtain it
quickly and cheaply from members of our own circle, or, if
necessary, from other circles.

Our very excellent Secretary, Mr. Allen, is, as usual with him,
quite ready to undertake the extra duties involved by this scheme.
If members will as soon as possible send in their names as I
propose in No. i, we could at once begin, and experience would
soon help us to form some good and permanent rules for the
better working of the circles.

A Member.

1Review6»

A Manual of British Discomycetes, with a Description of

all the Species of Fungi hitherto found in Britain, included in the family and
illustrations of the Genera. By William Phillips, F.L.S. Crown 8vo, pp.
xii. — 462. (London : Kegan Paul, Trench, and Co. 1888.)

This volume is the sixty-first of the International Scientific Series, and is
designed to provide the English student with the means of acquiring a know-
ledge of the Discomycetes of Britain. The author- evidently has spared no
pains in verifying and extending observations of the moriiliology, (or in no
instance where an authentic specimen was accessible has the opportunity of
examining it been neglected. The author divides the Discomycetes into the
following orders : —

I. — Helvellacece, containing 10 genera.

2.-

— PezizK,

12

3-

— Ascobolete,

6

4--

— Bulgarieae

5

5-

— Dermateae,

6

6.

— PatellariaceiE

3

7.

— StictcEe,

3

8.

— Phacidiacese,

3

9-

— Gymnoascete,

>)

I

genus.

At the end of the book are added an Addenda of certain species which have
been omitted from the body of the work, a Glossary of Terms, Description of
Plates, and General Index. We must not on\it to mention that there are
twelve excellent plates.

Die Natureichen Pflanzenfamilien nebst ihren Gattungen

und wichtigeren Arten insbesondere den Nulzpllanzcn bearbeitet unter Mitwir-
kung zahlreicher hervorragender Fachgelehrten von. A. Engler und K. Prantl.
Nos. 13, 14, 15.

Since our last notice we have received three parts of this fine work, con-

REVIEWS. 121

taining contributions from Messrs. A. Engler, H. Graf zu Solms, E. Hackel,
F. Pax, and K. Prantl. The illustrations number 97, consisting of upwards
of 500 figures. The subscription price to this work is about is. 6d. each part ;
price to non-subscribers, 3s.

A Manual OF North-American Birds. By Robert Ridge-
way. Royal 8vo, pp. xi. — 631, plates 124. (Philadelphia : J. B. Lippincott
and Co. 1SS7.)

This fine work was originally projected by the late Professor Spencer F.
Baird, and is based essentially upon the grand National Cabinet of American
Birds, which his energy, ability, and enthusiasm have developed from an
unpretentious nucleus to an unrivalled collection. It is intended to furnish a
convenient manual of North-American ornithology, reduced to the smallest
compass by the omission of everything that is not absolutely necessary for
determining the character of any given specimen, and including besides the
correct nomenclature of each species, a statement of its natural habitat, and
other concomitant data.

The 124 plates contain 464 finely-executed outline drawings of the generic
characters. A fine portrait of Prof. Baird forms a frontispiece to the volume.

Guide Pratique pour les Travaux de Micrographie, compre-
nant la Technique et les Applicationes du Microscope a I'Histologie Vegetale
et Animale, a la Bacteriologie, a la Clinique, a I'Hygiene. et a la Medicine
Legale. Par MM. Docteurs H. Beauregard et V. Galippe. Crown 8vo, pp.
vii. — 901. (Paris : G. Masson, 120 Boulevard Saint Germain. 1S88.)

The authors of this treatise have set before themselves a difficult task — to
produce a book that shall be a miniature library of all subjects connected with
microscopy ; and though, perhaps, it would be hardly correct to say that they
have achieved perfect success, yet they have produced a work of great value to
the student. The first few pages are devoted to the optical and mechanical
arrangements and to the preparation of microscopic objects. The main portion
of the work consists of, we might almost say, exhaustive treatises on Vegetable
and Animal Histology. We have a very instructive series of sub-chapters on
the Cell, its contents and changes. Then there is another series that deals
with the interesting question of Bacteria, pointing out the practical way of
studying this, in the present day, burning question. In the same way, when
we come to Animal Tissues, we have excellent treatises on Milk — its deriva-
tives and their adulteration, Blood-Parasites, Hairs, etc. There is also a
valuable chapter on the organisms that are found floating in the air. The
work is fully illustrated with wood engravings, which, judging from those that
come within the range of our own knowledge, we can pronounce to be true to
nature and very effective.

Practical Microscopy : A Course of Normal Histology for

Students and Practitioners of Medicine. By Maurice N. Miller, M.D. Royal
8vo, pp. XV.— 217. (New York : William Wood and Co. 1S87.)

This will be found a most useful work. It is divided into three parts : —
I •—Technology, in which the Microscope and Accessories are fully described,
with the method of preparing, cutting, staining, etc., tissues for microscopical
purposes; 2.— Structural Elements; and 3.— Organs, followed by Microscopi-
cal FormuLx. The illustrations— of which there are 126 — are photographical
reproductions of the author's own drawings and are very good.

Fossil Men and their Modern Representatives : An Attempt
to Illustrate the Characters and Condition of Pre- Historic Men in Europe by

122 REVIEWS.

those of the American Races. By J. W. Dawson, C.M.G., LL.D., F.R.S.,

F.G.S., etc. Crown 8vo, pp. viii. — 354. (London: Hodder and Stoughton.
1888.)

This work is intended as a popular exposition of some of those important
topics in which geologists, archseologists, historians, philologists, and anthro-
pologists are not always agreed. These the author treats from the point of
view of the geologist and naturalist, and on the principle of referring to
modern causes for the explanation of ancient effects. It contains 46 good
engravings.

A Popular Zoology. By J. Dorman Steele, Ph.D., and J.
W. p. Jenks, A.M. 8vo, pp. xiii. — 319. (New York and Chicago: A. S.
Barnes and Co. 1887.)

This work will prove a valuable one to the young student. Its principal
features are brevity, directness of statement, frequent foot-notes with anecdotes,
and a gradual introduction of scientific terms and language, so as to fit the
scholar to read zoological literature. It abounds with woodcuts, there being
no fewer than 481, each animal being figured. The text is largely occupied
with biography, telling us " how animals act, think, and are mutually related."
Every class of the animal kingdom is named, with most of its orders and
many of the principal genera. We note, too, that every scientific word is
czx^inWy pronounced. In the appendix will be found directions for collecting
and preserving specimens. At the end of the book a most useful table is given
of the systematic arrangement of the representative forms mentioned in the
book. It is a book with which we are much pleased.

Tenants of an Old Farm : Leaves from the Note-Book of a
Naturalist. By Henry M. C. McCook, D.D. With an Introduction by Sir
John Lubbock, M.P., F.R.S., etc. Crown 8vo, pp. 460. (London : Hodder
and Stoughton. 1888.)

This admirable work has, we believe, already found a very large sale in
America. In it the author gives, in a most pleasant, colloquial style, a
number of essays on his own peculiar specialities, more particularly ants and
spiders, although he tells us that, "like most naturalists, he thinks that the
truths of nature are attractive enough in themselves, and need not the season-
ing of fiction, even of so mild a flavour as offered by the "Tenants." He
assures us that most of the facts came under his own observation. By intro-
ducing the " tenants," more especially " Old Dan " and " Sary Ann," he is
able to add much folk-lore concerning insects, which perhaps would otherwise
either have been left out altogether, or certainly not told in so pleasant a
manner as we now have it.

We strongly advise our friends to get a copy of this book. It is a great
favourite with us. The illustrations are remarkably good.

Insect Ways on Summer Days in Garden, Forest, Field,
and Stream. By Jennett Humphreys. Crown 8vo, pp. 192. (London :
Blackie and Son. 1888.) Price 2s. 6d.

A series of instructive facts, very interestingly told, about many tiny
things by which we are surrounded. Each insect described is nicely illustrated
by an engraving. We cannot, however, help thinking that the fair authoress
has made one slight mistake when she says that the Water Boatman {Notonecia
glauca) feeds upon the Watermite and the Crab-Louse (! !), both of which are
represented in the illustrations.

A Student's Manual of Psychology, adapted from the
Katechisnms der Fsychologie of Friedrich Kirchner. By E. D. Drought.

REVIEWS. 123

Crown 8vo, pp. viii. — 344. (London: Swan Sonnenschien and Co. 1888.)
Price 4s. 6d.

The aim of the author of the work before us has been to make the reader
thoroughly acquainted, both with the present state of psychological investiga-
tion and with the difficulties of the individual problems. It presents psycho-
logy to educated persons — more particularly to students, examiners, and
teachers — in a popular though by no means superficial manner. The introduc-
tory portion of this manual is divided into four sections, and treats of — I, The
Meaning of Psychology ; 2, Its relation to other Sciences ; 3, History of Psy-
chology ; 4, Method of Psychology ; 5, Division of the subject. The body of
the work is divided into two parts : — Part I. treats of the Nature of the Soul ;
Part II., The Mental Faculties.

Discursive Essays on the Phenomena of the Heavens and

Physical History of the Earth. In two parts. Part I. By " Cosmopolitan."
8vo, pp. xxxii. — 330. (London : Literary Society, 376 Strand.) Price 6s.

This volume contains A New Theory in Astronomy, based on the Trans-
latory Motion of the Sun, and a New Theory on the Element of Cold in the
Universe, followed by a description of the Probable Origin of the Earth, For-
mation of its Ocean, Crust, Continents, and Islands, including a concise
review of the Evolution of the Organic Beings on its .Surface.

Chemical Lecture Notes. Taken from Prof. C. O. Curt-
man's Lectures at the St. Louis College of Pharmacy. By H. M. Whelpley,
Ph.G. Crown 8vo., pp. 143. (St. Louis, Mo., U.S.A.: The Author.)

The student in chemistry will find these notes helpful. They were origi-
nally published in the National Druggist, and treat of Chemical Phy-
sics, the Chemistry of Metalloids, the Chemistry of Metals, and Organic
Compounds.

The Medical Annual and Practitioner's Index. Crown 8vo,

pp. 568. (Bristol : J. Wright and Co. London : Hamilton, Adams, and Co,
1888.) Price 5s. 6d.

It is with much pleasure that we welcome to our editorial table this useful
work, and shall soon begin to regard it as an old friend. Since its commence-
ment we have noticed a continued yearly improvement, and congratulate the
editors on so successful a termination of another year of their labours. The
busy practitioner will, in many instances, find here the information he requires
put in very practical terms.

A summary of the year's work in Medicine, Surgery, and Therapeutics
has been placed before the reader. The arrangement is alphabetical, and the
directions are in clear and concise language. We have also a list of the prin-
cipal medical works published during the past year — Notes on New Inven-
tions, Improvements in Pharmacy, etc.. Lists of Private Asylums and Homes
for Inebriates, and of Hydropathic Establishments in Great Britain — and at
the end of the book are blank pages for notes. We cordially recommend it.

The Dictionary of New Treatment. Edited by Percy
Wilde, ^LD. (Medicine and Therapeutics), and W. H. Elam, F.R.C.S.
(Surgery). Crown 8vo, pp. 432. (Bristol: John Wright and Co. London:
Hamilton, Adams, and Co.)

" The Annual" for 1887 being out of print, it was decided to reprint this
portion of the work in a separate form. It contains a concise description of
the New Methods of Treatment, both medical and surgical, which have been
introduced during recent years, and may be considered as an appendix to the

124 REVIEWS.

systematic treatises on Medicine and Surgery. The Therapeutics of the New
Remedies are fully considered under the names of the diseases for which they
are especially employed. At the end of the book will be found an exhaustive
Index of Remedies and another of Diseases. Whilst this volume and " The
Medical Annual " for the current year are complete in themselves, each will
be found to be complemented by the other.

The Philosophy of Words : A Popular Introduction to the
Science of Language. By Frederico Garlanda, Fh.D. Crown 8vo, pp. 294.

The Fortunes of Words : Letters to a Lady. By Frederico
Garlanda, Ph.D. Crown 8vo, pp. 225.

(London : Trubner and Co. 18S8.)

In the two little books before us the aim of the author is to explain as
plainly as possible some of the most important results of the science of lan-
guage, whence our words come, what is their true meaning, and how is our
language connected with those of people around us. He thinks many people
speak too much as birds sing, without ever bringing our minds to reflect on
tlie nature of the sounds we utter.

The Philosophy of Words treats of Sounds and Language, the
English Language divided into Household Words, Church Words, Words of
Society, and Political Words ; Comparative Grammar ; Language and Rules ;
Local and Family Names, etc. etc.

The Fortunes of Words, which is written in the form of a series of
letters to a lady, treats very fully of the roots from which our words are
derived. Both books will well repay very careful study.

Durrant's Hand-Book for Essex. By Miller Christy.

Crown 8vo, pp. viii.- — 237. (Chelmsford : Edmund Durrant & Co. London :
Simpkin, Marshall, and Co. 1S87.) Price 2S. 6d.

This useful hand-book offers for the use of tourists and others a guide to
the principal buildings, places, and objects of interest in each parish of the
county. We have also a nice account of the History, Geology, Area, Popula-
tion, Literature, Antiquities, Worthies, and Natural History. It contains also
a map and two plans.

The Trade-Signs of Essex : A Popular Account of the

Origin and Meanings of the Public-House and other Signs now or formerly
found in the County of Essex. By Miller Christy. 8vo, pp. xii. — 184.
(Chelmsford : E. Durrant and Co. London : Grifliih, Farran, and Co. 1887.)
Price 7s. 6d.

Being for many years resident in Essex, it is with much interest that we
turn our attention to this and the preceding interesting books. The signs of
Essex are classified under the titles Heraldic, Mammalian, Ornithological,
Piscatorial, Insect, Reptilian, Botanical, Human, Nautical, and Miscellaneous.
Mr. Christy has performed his task in a thorough and masterly manner, and
gives his readers a large amount of valuable information on what at first sight
appears a somewhat unimportant subject. At the end is a Glossary of the
Heraldic Terms used in the book. The work is well illustrated, the frontis-
piece to the volume being a curious old engraving of Chelmsford High Street
in 1762.

Observations on Popular Antiquities, chiefly illustrating

the Origin of our Vulgar Customs, Ceremonies, and Superstitions. By John
Brand, with the additions of Sir Henry Ellis. Crown 8vo, pp. xvi. — 807.
(London : Chatto and Windus. 1888.) Price 7s. 6d.

REVIEWS. 126

Much light is thrown on many of our old-fashioned customs, such as
eating Pancakes on Shrove Tuesday, Cross-Buns on Good Friday, the Michael-
mas Goose, Mince-Pies at Christmas, etc., and on the forms and ceremonies
customary on many of the Saints' Days ; Marriage Customs and Ceremonies,
Customs at Deaths, Sports and Games, Omens, Charms, Divinations, and
very many other things too numerous to mention. The book is not only well
worth reading, but should be kept as a book of reference with respect to those
old wives' sayings that we so often meet with. It is capitally illustrated'.

Exercises in Arithmetic. By the Rev. T. Dalton, M.A.,
Assistant Master at Eton College. Crown 8vo, pp. 152. (London : John
Murray. 1888.)

This is one of the Eton Mathematical Series, and is designed to provide
exercises for work out of school. It is published without answers, but the
answers may be obtained from the publishers on the bonQ,-fide application of
any schoolmaster or teacher. Pages i to 130 each contain ten questions of a
miscellaneous character ; pages 131 to 140 are of a selected nature ; the rest
are selected questions from Cambridge, Oxford, and other examination papers.

The Diseases of the Bible. By Sir Risdon Bennett, M.D.,
LL.D., F.R.S. Crown 8vo, pp. 144. (London: Religious Tract Society.
1887.) Price 2s. 6d.

We are glad to find that learned men of the present day are doing much
to elucidate certain portions of Holy Writ, and to show that there is no real
antagonism between Biblical records and 19th century science. The region
into which the talented author conducts us is one to which the ordinary reader
is seldom admitted. The work before us is divided into seven chapters, and
treats of Leprosy ; Plague and Epidemic Diseases ; Ophthalmic Diseases and
Blindness ; Diseases of the Nervous System ; Diseases of Job, Herod, Ileze-
kiah, Jeroboam, and the Shunamite's Wife's Son ; Old Age ; and the Physical
Cause of the Death of Christ. In the Appendix Fiery Serpents are spoken of.

The Evangelisation of the World. Crown 8vo, pp. 242,

(London : Morgan and Scott.)

Shows what good work may be done by an earnest band of Christian
workers. The photographs and other illustrations (many of them being from
photographs) are exceedingly well executed. The book is full of interest.

Gospel Ethnology. By S. R. Pattison. Post 8vo, pp. viii,
— 226. (London : The Religious Tract Society.) Price 5s.

This little book, which contains upwards of thirty typical representations
of the human race, from as many different portions of the world, treats of the
Physical Unity of Man and the Spiritual Unity of Man ; then of the three
types of Black Races of Men accepting the Bible ; fifteen types of Yellow
Races ; and fourteen types of Jkown and White Races. The illustrations,
many of them full page, are very good.

The Gospel in Nature : Scripture Truths illustrated by

Facts from Nature. By Henry C. McCook, D.D., with an Introduction by
W. Carruthers, President of the Linn^ean Society, F.R.S., etc. Crown 8vo,
pp. xii. — 416. (London r Hodder and Stoughton. 188S.)

A very fresh volume of discourses, thoroughly evangelical in tone, in
which carefully-ascertained facts, gathered from a wide field of nature,
are used as illustrations of spiritual truths. The standpoint of the writer is

126 REVIEWS.

" Nature is God's great book of parables." Some of the lessons appear to us
far-fetched, but they are always such as do not depend for their force on the
strictness of the assumed analog)'. Dr. McCook is not only a diligent and
successful student of Nature, but is also one of the leaders of theological
thought in America.

Scripture Natural History, i. — Plants and Trees men-
tioned in the Bible. By William H. Groser, B.Sc. (Lond.). Crown 8vo, pp.
viii. — 235. (London : The Religious Tract Society. 18S8.) Price 3s.

This interesting work opens with a Sketch of the Vegetation of Palestine
and the Neighbouring Countries ; followed by an account of the Timber and
Forest Trees and Shrubs ; Fruit-Trees and Shrubs ; Grain and Vegetables ;
Herbs and Flowers ; Perfumes and Medicines ; and the Emblematic Use of
Plants in Scripture. It is illustrated with 14 well-executed plates.

Australian Ballads and Rhymes : Poems inspired by Life
and Scenery in Australia and New Zealand. Selected and edited by Douglas
B. W. Sladen, B.A. Square i6mo, pp. xxiv. — 301. (London : Walter Scott.
1888.)

A very nicely got-up volume of the "Canterbury Poets." Each volume
is neatly bound in cloth gilt, with red edges, and the pages throughout have a
red-line border. It is with pleasure that we notice this interesting little
volume, and congratulate editor and publisher on their success.

The Letters of Robert Burns, selected and arranged, with

an Introduction by J. Logie Robertson, M.A. (London : Walter Scott, 1887.)
A volume of the monthly " Camelot series," which, like the volume just
noticed, is also published at is.

Life of Oliver Goldsmith. By Austin Dobson. (London :
Walter Scott. 1888.)

This is one of the monthly shilling volumes of the "Great Writers' "
series, and is edited by Professor E. S. Robertson. It is very neatly bound in
cloth, contains a capital index, and an exhaustive bibliography of Goldsmith's
works by John P. Anderson, of the British Museum.

The Dawn of the Twentieth Century, ist of January,

1901. Crown 8vo., pp. 156. (London-.. Field and Tuer. 1888.)

This little brochure opens with an extract from " The Constitution " of the
1st of January, 1901. We find Edward \'II. on the throne, the Queen having
recently resigned. The love of her peoples — which never wavered during a
reign happily so lengthened — follows her Majesty as fervent and profound as
ever into the comparative retirement of Osborne and Balmoral. Then follows
the reports of the various secretaries, etc.

A Treatise on Photography. By Capt. W. de Wiveleslie

Abney, R.E., F. R.S. Fifth edition, revised and enlarged. Crown 8vo, pp.

xvi. 368. (London : Longmans, Green, and Co. 188S.) Price 3s. 6d.

The name of the author of this treatise is a sufficient guarantee that it,
like all the rest of the series ("Text-Books of Science"), contains a large
amount of valuable information. The edition has been, in a great measure,
re-written in certain portions, and a considerable quantity of new matter
added. The author's aim has been to give a rational explanation of most of
the different phenomena to be met with in Photography, and at the same time
to give sufficient practical directions to enable the student to produce a picture
which should be technically good, and also to show how photography may be
made an aid to research.

REVIEWS. 127

Wilson's Photographics : A Series of Lessons, accompanied

by Notes, on all Processes which are needful in the Art of Photography.
Fcap. 4to, pp. 336. (New York : E. L. Wilson.)

Dr. Wilson is undoul)tedly a master of the art he undertakes to teach in
the handsome book before us. He tells us that in writing it " I agreed in the
beginning that I would tell what I knew from experience in simple language —
this for the benefit and instruction of the beginner — at the heads of the pages,
in bold and honest type, and then, in the smaller and less dignified letter
following, elaborate, with the extended ideas of those who have accelerated
the advancement of our art by their discoveries, their practice, and the publi-
cation of their experience." This volume is very handsomely got up on fine
paper and illustrated with five phototypes, one being the portrait of the author,
and no photo engravings and woodcuts.

Photo-Engraving and Photo-Lithography in Line and in
Half-Tone ; also Collotype and Heliotype. By W. T. Wilkinson. Second
edition, revised and enlarged. Crown 8vo, pp. 200. (London : England
Bros., Charles St., Notting Hill. 1887.)

In the work before us the whole art of Photo-Lithography and of Photo-
Engraving is very thoroughly described. The method also of making relief
blocks from drawings, transferred to zinc without the intervention of photo-
graphy, and also the two processes of Collotype and Heliotype, have been
added. The author assures us that no formula or method has been given that
has not been tried. We may, therefore, look upon the book as being very
practical. We think it will prove very useful to those who wish to have their
books nicely illustrated, and more particularly so to those who wish to practice
the art.

The American Annual of Photography and Photographic
Times Annual for 1888. Edited by C. W. Caufield. 8vo, pp. 327. (New
York: Scovelle Manufacturing Co. 1888.)

The articles in this very useful annual have all been written expressly for
the work itself, and contain a vast amount of valuable information. The
illustrations — which consist of a Landscape by Obermetter's Photogravure
Process, an Eastman's Bromide Paper Print, a Zinc Etching by Stevens'
Process, a Portrait by the Ives Process, Landscape Photo-Lithograph, and
three Moss Type — are all excellent specimens of art. There are also
several wood engravings.

Electrical-Instrument Making for Amateurs. By S. R.
Bottom. Crown 8vo, pp. viii. — 175. (London: Whittaker and Co., Pater-
noster Square. 1888.)

The author, having felt the want, commonly experienced by most amateurs,
of a helping hand, gives in the nice little book before us such help as he believes
will assist the tyro in his attempts at the construction of the more useful pieces
of electrical apparatus, and shows how much trouble may be saved and
expense spared by the adoption of certain simple modes of procedure. He
makes no attempt at the expensive "brass and glass" work, as seen in the
opticians' windows, but promises that his instruments may be relied on to act
efficiently, which undoubtedly is the more desirable end to be aimed at. The
work is illustrated with about sixty very clear engravings. It is certainly a very
useful book.

The Journal of Indian Art. Nos. i to 21. Large folio

(about 15 inches by 11 inches). (London : W. Griggs, Hanover St., Peckham ;
Quarritch, Piccadilly.) Price 2s. each part.

These parts will form one of the most handsome books with which we

128 REVIEWS.

have for a long time been favoured. The most attractive feature of the work
is its very handsome and numerous plates, which are all executed in photo-
lithography by W. Griggs, of Peckham. Many of the plates are printed in a
number of colours. It would be impossible to describe the contents of each
number. We will take No. 12, which was published in June, 1887. It con-
tains a portrait of her Majesty the Queen-Empress; II. H. the Rlaharaja of
Jeypore ; H.H. the Maharaja of Ulwur ; Plan of the Indian Courts of the
Colonial and Indian Exhibition ; the Jeypore Pavilion and Screen ; Details of
Screens ; and many others. The letterpress accompanying each part is des-
criptive of the Arts and Industries of India.

Natural Philosophy for Beginners : Mechanics, Hydro-
statics, and Pneumatics. By William Nicolls, B.A. Third edition ; pp. 122.
(Dublin : E. Ponsonby. 1887.) Price 2s.

We are glad to see that this useful little work has reached its third edi-
tion. Although written in the first place for intermediate schools, it will be
found of much value for all students who are desirous of mastering the
elementary laws of matter and motion. The first part treats of the fundamen-
tal properties of solids, liquids, and gases, including an account of the metric
system of weights and measures, and descriptions of the various mechanical
powers. The second part forms a first step to the study of statics, pinetics,
and hydrostatics, Newton's laws of motion being, of course, taken as the fun-
damental basis on which the dynamical properties of matter depend. The
introduction of the conception of Veetors in treating pinematical propositions
is much to be commended, as giving the student an early notion of modern
dynamical views. Each chapter is illustrated by numerous examples and well-
selected questions, a set of miscellaneous examples being appended at the end
of the work. It is surprising what a large amount of information Mr. Nicolls
has condensed into this little book. Moreover, this has not been done at the
expense of clearness, for tlie explanations are remarkably lucid and easy of
comprehension.

The Divided Irish. By the Hon. Albert S. G. Canning,

author of " Revolting Ireland, 1798 and 1803," "Thoughts on Shakespere's
Historical Plays," etc. Crown 8vo, pp. 86. (Newry, Ireland ; ]. Warnock
and Co. 1888.) Price is.

In the little book before us Mr. Canning has collected his facts from a
great variety of sources, and assures us that he has endeavoured to treat
modern Irish history with thorough impartiality. It will donbtless be read
with much interest at the present time.

La Photographie Moderne : Pratique et Applications. Par

Albert Londe. Royal 8vo, pp. 312. (Paris: G. Masson, editeur, Libraire de
I'Academie de Medecine, 120 Boulevard St. Germain. 1888.)

Of the many useful treatises on photography that have come before us, we
think that we may fairly award to the present work the position of the first.
Not only is it a handsome volume, well printed, and well illustrated, but it
carries down the practice of the photographic art to its latest developments,
its application to astronomy, or, rather the charting of the stars and the repro-
duction of the lunar features, which are well illustrated and explained ; instan-
taneous photography, as a means of investigating the tiight of birds and the
actual movement of animals ; the use of the camera in the field, both for
peaceful and warlike purposes, are well brought out. We have no hesitation
in recommending this work to our readers as one of the best, if not the best,
of its kind.

^be IRomancc of 6ccb^Sowinci»

By H. W. S. Worsley-Benison, F.L.S.

VERY country child knows the appearance of a
' Dandelion-clock,' and has tried to " see what
o'clock it is " by the number of puffs needed to
blow away the round head of soft down at the
top of the flower-stalk in Autumn. Equally
<,^^)5^V familiar is the smaller tuft of grey down on
-^/A "5;^ Groundsel after flowering, although most people
T yK* y do not know that the botanical name of Ground-
sel is Se?iecio, from the Latin se?iex, ' an old man,'
given to it on account of the colour of this down. Most of
us can recollect the innumerable tufts of similar material
flying all over a thistle-field long after Butterfly and Bee have
done their work among the purple flowers. We have all seen
Sycamore ' keys ' strewing the ground in June and July, and
brown Ash ' keys ' persistent on the parent tree when October
winds have blown nearly every leaf from its hold. The bonnie
Autumn berries in our woods, and the fruits of Blackberry and
Strawberry have been gathered by children of younger and older
growth many a time and oft.

How many of us ever stay to inquire w/iy Groundsel and
Thistle possess their downy tufts, 7vhy Ash and Sycamore produce
their ' keys,' or 7c>hy many of the trees and plants are dressed in
fruiting time with crimson and scarlet, purple and olive? Not
only in order to the uses we make of them, we may be quite
sure. ' Dandelion-globes ' and ' Thistledown blows ' do not
exist only to tell the time of day to a four-year-old child, or " he
loves me — he loves me not " to the maiden of seventeen. Ash
and Sycamore have ' keys ' for some other purpose than to form
graceful, drooping clusters in June. The fruits and berries are
not solely for decoration and digestion by human gatherers.

Were these their only reasons for existence, that would soon
terminate, in all probability. All these and many others that we
could name gladden and delight us in various ways, as do the

New Series. Vol. I. K

1888.

130 THE ROMANCE OF SEED-SOWING.

flowers that come before each one of them ; but, as with the
flowers, so with down-tuft and 'key,' berry and fruit; they all
have their several missions to perform, in order to perpetuate the
very existence of their species, and to hold their own in the battle
of life.

Acknowledging that while they last, they are, in a thousand
forms and ways, beautiful and useful, I wish to try to show the
definite uses of these "common things," and of some curious and
wonderful contrivances to be found in plant-life all around us.
To come to the subject-matter of this lengthy introduction, let us
look for awhile at the various methods by which, either through
external agency or intrinsic power, trees and plants manage to
disperse their seeds, and to secure for their offspring a suitable
home, and a fit and proper environment.

The first question that naturally arises in many minds will
probably be, Why try to scatter or disperse them at all ? Why
not let them take their chance, and simply fall to the ground
immediately underneath the tree, shrub, or annual, as the case
may be, there to germinate and grow up into their parents' like-
ness ?

This is quite easily answered. In the case of trees, if all
the seeds fell round about the trunk, they would stand a poor
chance ; for if they ever germinated at all, the young seedlings
would get very little sun, and a great deal too much over-shadow,
and would be further harmed by the 'drip, drip,' from the
branches. In the cases of both trees and plants, moreover, the
large quantity of young plants would choke one another in the
struggle for life ; indeed, this not seldom occurs with some of our
garden annuals, as we can easily prove for ourselves. Again,
many plants soon exhaust the earth of certain mineral materials,
and if their seedlings attempted to grow in the same soil, they
would fail, the parent plant having used up the chief portion
of such substances.

A parallel to this is found in the fact that farmers
do not grow the same kind of plant for successive seasons in
the same field, but vary the sort from year to year, choosing
plants that draw different materials from the soil in consecutive
years. ' Rotation of crops ' we call it, but it is not our own

THE ROMANCE OF SEED-SOWING. 131

invention. We took centuries to find it out. The plants and
trees knew of it long ages ago, and so were led to develope the
various methods of ensuring a speedy and effectual transit of
their seeds to other and better soil, where they might find their
needed foods in rich abundance. Of course, in certain cases —
notably of some very small annuals, whose roots practically
exhaust the soil but little — their seedlings find a good position at
once, and manage to flourish ; those growing on sloping grassy
downs or cliffs, too, stand a better chance, inasmuch as their
seeds fall on ground at a lower level than that drawn on by the
parent plant. Examples of this are seen in our wild Snap-
drapons. Wall-flowers, and others, growing in such profusion on
railway-banks or on sloping limestone cliffs. For the most part,
however, those plants flourish best that develope tendencies that
tell in the direction of effectual dispersion of their seeds.

I must not omit mention of one thing, before detailing the
methods of dispersion. Seeds must not be scattered until they
are ' ripe,' and ready to set up their own independent existence.
Hence, we find all sorts of devices for protection of seeds during
their growth.

Some are enclosed in a thick, hard shell, such as Hazel-
nut, Beech-nut, Spanish Chestnut, Cocoa-nut, Monkey-pot, and
many others. Some are hidden away under overlapping wooden
scales, such as the cones of Firs and their allies. Some are sur-
rounded by thick fleshy coats, such as Horse-chestnut, Almond,
Apple, Cherry, and the like.

Walnut has a covering which is not only tough, but bitter
to the taste. Muaoia, one of the LegtanitioscE, has its pod
covered with stinging-hairs.

Some have the calyx closed over the ripening seeds, as
Winter Cherry, Strawberry-headed Trefoil, Herb Robert, and
some others of the same order. The wild Rose-fruits nestle
inside the hollowed-out flower-stalk which forms the Hip,
whose scarlet colour stands out in beautiful relief on the
bushes in September and October. Many Clovers have the
withered corolla for a covering to their seed-containing pod, and
perhaps no plant better knows how to protect its progeny than
Gorse, whose hair-covered pods defy wind, storm, and insect, until

132 THE ROMANCE OF SEED-SOWING.

the seeds are fully ripe, and ready to be scattered by the bursting
of the pods in the August sunshine.

Finally, there are some plants which by movement ensure
protection. The little Linaria of our rockeries and walls —
' Mother-of-Thousands,' as West-country folk call it, revels in
sunshine, but as soon as it is fertilized, it pushes itself into
some cranny or nook, hiding its seeds away until they are ripe.
Dandelion keeps its stalk bolt upright during the three or four
days of flower-expansion, but it bends down close to the earth, and
buries its flowers among the grass for ten or twelve days while the
seeds are getting ripe, afterwards becoming erect once more, for a
reason which we shall presently consider.

Now, let us see what are the agencies by which seeds are sent
or carried on their journeys. There are four chief ones, besides
one or two minor methods seen in only a few instances. We will
take the four principal ones first of all.

I. — Water. — Under this head I include the action of rivers
and ocean-currents.

Comparatively few seeds are carried by water, owing to
their being, as a rule, unable to withstand prolonged immer-
sion ; but it is still true, that the agency of water is a very
important one, especially in the form of marine currents.
Many seeds are small and light enough to need no further
adaptation ; but in the case of the larger kinds, they must not
only be able to answer to the law governing floating bodies, too
well known to quote here, but they must also be absolutely imper-
meable to water itself The Cocoa-nut rind is woody and fibrous.
Hence these fruits can easily withstand the action of sea-water
and protect the seed within. They may be carried for thousands
of miles over the sea, and yet when stranded, the seeds can readily
germinate. In this way we account for the wide range of this
Palm and its presence on the main coral islands of the Pacific.
Many seeds and fruits have thus been carried by the great
current of the Gulf Stream from Mexico, to the marshes on Ire-
land's western coast, to the lakes of the Hebrides, and to the
Norway coast. Others have gone by currents from Madeira
to the Canaries, and thence to the African borders.

Rivers, again, act in a similar manner. Seeds and fruits are

THE ROMANCE OF SEED-SOWING. 133

brought down from the mountainous districts, and deposited
among the level plains and grassy meadows, and thus we can
easily account for the presence of such species in what seem to
us strange habitats for them. Both in marine currents and in
rivers, the action of water in carrying seeds to a?iy purpose is most
effectual when the direction is from W. to E., or the opposite,
because then, the seeds are kept pretty much within the same lati-
tude and therefore in similar climates. Hence they will grow and
flourish where they eventually settle as well as they did in their
former home. Currents going from N. to S. or S. to N. take
them into unfavourable surroundings, and then they mostly perish.

Some seeds are specially fitted for water transit by the pre-
sence of air-bladders variously developed — e.g., those of Water-lily.
Others have a smooth rind with an oily juice, such as those of
Arrow-head {Sagittaria), of our water-ditches. This peculiarity is,
of course, of advantage in swampy and marshy districts, where the
water dries up in warm weather, and the courses of the current
vary so much,

II. — Winds. — In many ways we see the action of this second
agent. The simplest cases are those where the seeds (or their
equivalents) are infinitesimally small, and of exceeding lightness.
Thus, the spores of Fimgi, Lichens, Mosses, and Ferns are
easily carried by the wind to distant places ; and so the members
of some of the above-named Orders have an almost world-wide
range.

Some seeds of Flowering plants are also light enough to be
thus transported, or else they have some mechanical contrivance
to render them so. One of our little Corn-salads ( Valerianella
auricula), whose fruit contains three cells, developes only one
seed, the remaining two empty cells acting as a kind of balloon to
the fruit, and most likely facilitating their movement by the wind.
Then, again, there are seeds which are flat and very thin.
Those of Yellow-rattle, a parasite on meadow-grasses, afford an
example. The wind shakes them out of their bladder-like capsule
at ripening-time, and carries them to a distance, where they find a
congenial resting-place.

Coming to more familiar and more easily-seen contrivances,
we find the winged fruits and seeds, known to most of us.

134 THE ROMANCE OF SEED-SOWING.

Among winged fruits we Iiave the keys, or doubly-winged
fruits of Sycamore and Maple, the single one of Ash, and
the well-known winged nuts (so called) of Birch and Elm,
those of the latter covering the roads in April and early May.
When the winged fruit is detached from the tree, it falls slowly
with a rotatory motion, and the wind, if enough be present, is
sure to catch it and bear it away. Lime has no winged fruit,
but the long, narrow bract at the base of the bunch of fruits serves
the purpose. Watch a bunch of Lime-fruit falling, and note that
the fruits hang lowermost, the bract catching the wind and carry-
ing the whole mass away — very often to some distance. Among
plants also, we find instances of winged fruits, as in Dock,
Parsnip, and Penny Cress, the latter being, like others of its Order,
a winged pod, or pouch, containing the seeds.

In the case of Pine, it is the seed which is winged — i.e., it
carries with it a portion of the scale to which it was
formerly attached. So, if you examine the tiny seeds of Arbor
viicB and Cypress in our gardens, you will find these to be
surrounded by a thin membranous wing ; equally provided are
those of the beautiful Trumpet-creeper, while the seeds of some
Bignonias are so delicately winged that you can watch them
describing a series of circles in the air, hovering, so to speak,
before they finally settle.

There is one instance of a wind-wafted fruit which, although
not winged, I may name here. I refer to the ' Rose of Jericho,'
a pod-bearing annual found in Syria and Egypt. Its pods, when
dry, curl themselves up into a ball, and are driven, it may be, for
miles along the ground by the wind, until they happen on a damp
place ; there they stick, uncurl, open, and deposit their seeds.
There is another case : a kind of Grass, in which the whole inflo-
rescence, in the shape of a large round head, gets driven along the
sands of Australia, until it finds some moist spot where the
plant can again take root and let fall its seeds.

Still more complicated and beautiful than the wings already
seen are the tufts of down seen on many fruits and seeds, and
they serve a similar purpose. This down, which forms Dandelion
'clocks' and Thistle 'blows,' consists either of simple hairs, or
those provided with a feathery arrangement, It may be found

THE ROMANCE OF SEED-SOWING* 135

attached to either the fruit or the seed. In the latter it may cover
only a part of the surface, or it may entirely envelop the seed.

A tuft of hairs developed from the seed is usually called a
coma, from a Latin word signifying 'hair.' As one example of
such seeds, we may select Willow-herb, whose rosy flowers fringe
our river-banks and ditches— plants almost always found in wet or
marshy districts. Each seed is tufted with silky hairs, and the
opening pod, containing several of these, is a very beautiful
object. We are all familiar with the cotton-like hairs that show
the presence of the seeds on the numerous kinds of Willow trees
in early Spring or Summer. Here the seed nestles amid an almost
perfect envelope of hairs. The Asclepias, or American Milkweed,
has seeds tufted at one end, like those of our own Willow-herb.
The cotton of commerce consists of long, hair-like cells from the
seeds of Gossypmm, the Cotton-plant, one of the Malvacece, or
Mallow Order. Each thread is really a cylindrical cell, often very
long, which, when dried, flattens out and twists spirally. By this
pecuUar outline, cotton can always be detected under the
microscope.

A\'hen the hairs form a tuft on the fruit, we speak of them
collectively as d, pappus, from a classical word signifying 'an old
man,' in allusion to the grey colour.

The ripe carpels or fruits of Pasque-flower Anemone and
of wild Clematis are furnished with a feathery tail, which is in
reality the long style covered with silky hairs. The long,
feathered, graceful fruits of Clematis festoon our hedges in
Autumn, and are known popularly as Old-Man's Beard or
Traveller's Joy, and are among the most lovely of our country
sights. In the Red Valerian of our gardens, now wild in many
places, the calyx unrolls, after flowering, in the shape of a feathery
cap for the fruit, which can thus be easily carried about by the
wind. If you examine a single fruit from the thick, dark-brown
spike of Reed-mace or Bulrush {Typha), you will see that
it ends below in a very delicate stalk, around which, at three or
four different places, arise a series of circles of fine silvery hairs,
which support the tiny fruit in the air. The softness of the spike
is due to the presence of multitudes of fruits, each provided with
these hair circles.

136 THE ROMANCE OF SEED-SOWING.

The Cotton-grass of our moors is another example. It is not
a true Grass at all, but is the genus Eriophorum, belonging to
the Cyperacece, or Sedges. Its fruits have a tuft of long, silky hairs
springing from the base, and we often see a marshy landscape
white with thousands of these hair-covered fruits. You must not
confound this with the Cotton-plant above named.

The pappus, as an air-floating device, however, reaches the
climax of beauty and adaptation in the CompositcB, the Order
including Thistle, Dandelion, and very many other plants.
Examine a head of Dandelion early in its history, and you see
nothing of zx\y pappus ; but look at it later on, and you will see
in the place of the many florets that made up the so-called
' flower,' a spherical collection of beautiful hairs, which form the
' clock ' of the children. Each single fruit is prolonged above
into a long stalk or beak (very much longer than the fruit itself),
at the top of which is a close-set circle of delicate hairs arranged
laterally, so as to form a kind of parachute, concave above. This
parachute bears up the fruit and acts as a sail for it, and, being
by far the lighter end of the whole, causes the fruit to fldl to the
ground in the best position for its burial — namely, with the fruit
itself downward. Most assuredly, this wonderful contrivance for
dispersing the seeds is the reason why Dandelion is as common as
it is. " A common weed !" we say. Exactly ; and it is a common
weed because it is a highly-adapted type, as Grant Allen tells us.

In the Hawkweeds — relations of Dandelion — \.h.Q pappus is not
raised on a beak, but is close down on the fruit, and is not so
widely expanded, being more funnel-shaped. In Dandelion and
Hawk weed the hairs are simple ; but in the Thrincia of our lawns
(which some people will call Dandelion, but which is only a near
relative), they are every one feathered. This is carried to the
furthest point in Tragopogon, or Goat's-beard, called ' John Go-
to-bed-at-noon ' by country folk, because it closes at mid-day.
Here the hairs are not only feathery, but the feathery branches
interlace all round the circle, so as to form a very powerful pro-
peller under the influence of a breeze.

All these contrivances, whether found on fruit or seed, are
evidently developed by natural selection, in order to the better
dispersion of the life-containing germ.

THE ROMANCE OF SEED-SOWING. 137

One curious set of cases deserves a passing word while speak-
ing of hairs. Several seeds, and also some fruits ((?.§., some Sages
and Groundsels), are coated with short hairs containing spiral
threads coiled up inside them. The hairs are usually pressed
close to the seed or fruit, and kept down securely by a fibre of
mucilage. The wind carries these seeds to some favourable soil,
the dampness loosens the mucilage, the hairs spread out, are rup-
tured, and discharge the contained threads. These are highly
elastic, and on protrusion fix the seed in the soil quite securely.
Here, then, hairs serve to arrest the seeds or fruits, after disper-
sion. The mucilage present on the seeds of Flax and Cress
probably does similar duty when moistened by the damp soil.

III. — Animals. — Just as animals play a large and important
part in the fertilization of flowers, so we find them taking their
share in the dispersion of seeds and fruits. I cannot here give a
tithe of the instances in which this is seen. A few must suffice.
They perform their mission in different ways — some voluntarily,
some unconsciously. While Insects chiefly assist in fertilization.
Birds and Mammals are the principal agents in the work of
dispersion.

Fleshy fruits are attractive to animals, because they serve as
food. In these cases, therefore, the dispersion comes about by
voluntary action. Three characters come into prominence when
we consider this class of fruits— colour, fleshiness or juiciness,
and hardness.

Colour has long been recognised as operating largely in
the direction of dispersion of fruits and seeds. The aesthetic
side of a Bird's nature is by no means undeveloped, as we may
see in many ways, and we know that Birds are strongly attracted
by the beautiful and varied hues of a large number of our wild
berries and fruits. As we should expect, these colours are not
developed until the fruit is ripe, or nearly so. It would, of
course, operate injuriously, were it present at an immature
stage, and Nature always takes care that during the time when a
flower or a fruit needs protection, it shall be so clothed or enclosed
as to be inconspicuous and non-attractive. When, on the other
hand, fertilization is desired, colour and odour are laid under con-
tribution in order to induce Insects to visit ^^ flower ; when dis-

138

THE ROMANCE OF SEED-SOWING.

persion becomes necessary, colour and sweetness of taste in the
fruit come into play, to attract the animals of larger growth.

Again, colour, to be of service, must, as a rule, be distinguish-
able at a distance. Accordingly, we find that fruits develope tints
that are easily set off against the background of green leaves,
such as red, black, yellow, or white. Red is by far the
commonest colour, varying from pink to scarlet or deep crimson.
Between twenty and thirty of our native edible fruits have some
shade or other of red. Among these may be named Straw-
berry, Raspberry, Barberry, Rose, Rowan-tree, Dogwood,
Honeysuckle, Holly, Arum, Asparagus, Lily of the Valley, and
others. Next in frequency comes black, or hues closely ap-
proaching it — /.£'., dark green or dark purple. For instance.
Blackberry, Sloe, Alder, Bilberry, Elder, Plum, Ivy, Privet, and
Buckthorn. Of white fruits. Mistletoe, Myrtle, and Snowberry
furnish examples. I can only, for the moment, think of one
actually yellow native fruit — the Sea Buckthorn of our east
coasts : but we often find yellow blended with other tints on
the same fruits, as in Apple and Pear, and there are some
yellow seeds, as in Corn-flag, which are seen when the vessels
open and expose them to view. Yellow, although a showy colour,
would seem to lack the power to attract, and so is for the most
part absent.

Not only has colour in fruits gradually developed itself in
response to animal selection, but fieshiness or juiciness is trace-
able to the same cause. The soft, juicy pulp is both pleasant to
the taste (in most cases) and good for food. Accordingly, colour
having served to attract, juiciness, and in many instances s^cect-
fiess, steps in to satisfy. The Birds have found out that the two
pretty much go together, and they take care to use their know-
ledge. Colour is the sign-board hung out to give notice of the
delicious fare to be found inside.

Different parts of the plant share in the provision of the
dainty, tempting food. In Strawberry, where the tiny fruitlets
are gritty and inedible, the receptacle, or tip of the flower-stalk,
enlarges by degrees into the red, juicy, sweet mass known to us
all, and thus the fruits are devoured for the sake of the pulp in
which they arc embedded. In Raspberry and Blackberry, the

THE ROMANCE OF SEED-SOWING. 139

fruitlets themselves are juicy and sweet, and being thus better
fitted to attract, we find that these plants possess fewer seeds,
fewer being needed, since each one of the cluster can assert
itself by means of its rich pulpy envelope. In Rose, we find
fewer still ; the brightly-coloured hip — a development of the
receptacle, hollowed out to contain the fruits (not seeds, these
being inside the fruits) — presenting suftlcient attraction in itself,
both from its colour and composition. In Whitethorn, with
only two seeds, each well protected by its own bony covering,
we find perhaps the greatest attraction for Birds, especially
Robins. Here the calyx-tube forms part of the fruit. In Cherry,
the outer part of the single fruit becomes juicy, as also in Plum,
belonging to the same Genus.

Colour and juiciness having done their part, we next find that
hardness operates to prevent Birds from damaging the seed.
Nearly all the seeds of these fleshy fruits are protected by some
tough or stony covering, such as the outside layer of the minute
Strawberry fruits, or the stone of Cherry, Plum, or Hawthorn. In
other cases, the outer layer of the seed itself is sufficiently tough
to resist attack.

In cases where the seeds themselves are edible, we often find
them shut up within an envelope which is more or less bitter,
as in Walnut, Beech, and the two Chestnuts. These are refused
by Birds, and the edible part of the seed is stored away to form
food for the tiny embryo-plant. Even where these edible seeds
are sought for, as by Squirrels, dispersion is very often effected,
for many are dropped in transit, and others are forgotten and left
to germinate away from the parent-tree.

Birds disperse seeds in two ways. Either they carry off the
fruit and, devouring the juicy covering, drop the hard seed to
the earth ; or they swallow the fruits whole, as in Strawberry or
Raspberry, and the indigestible seeds are dropped in the ordinary
manner. We can easily see how powerful a method of dispersion
is afforded by Birds. Thrushes, going from North to South in
berry-time, must carry thousands of seeds to deposit them in the
warmer climate. The American Currant {Phytolacca) was long
ago introduced artificially into Bordeaux, its berries being used to
colour wines. It flourishes now all over Southern France and

140 THE ROMANCE OF SEED-SOWING.

Switzerland, and is by no means rare in the Tyrol, carried to
these districts by Birds.

Animals act as dispersers unconsciously, as I have already
said. Many fruits possess hooked processes in the shape of
curved hairs, or spines, or prickles. These become entangled in
the wool or fur of Sheep, Cows, and other animals, and are thus
effectually carried away. Of these, examples are seen in Wild
Carrot, Bur-parsley, Hedge-parsley, Burdock, Agrimony, Avens,
Enchanter's Nightshade, Hound's-tongue, Cleavers or Goose-grass
(familiar to everyone who has clambered through a hedge), and
some Forget-me-nots. In Burdock, the hooks are on the scales
of the involucre surrounding the flowers, so that one hook
being caught carries away several fruits, which further, each
possess a pappus. No wonder we find Burdock everywhere.
Some seeds themselves are similarly hooked — the large Stitch-
wort, for example, which decks nearly every hedge-bank in April.

Some foreign genera, such as the Mexican Alartynia, or
Devil's Claws, possess horns three or four inches long, and
Marty7iia well merits its name by the way in which it attaches
itself to horses' tails and irritates the innocent proprietors.
Others, like Pliwibago rosea, are viscid, and stick to animals by
this means. In Afyzodendron, a South American parasite, whose
brilliant flowers and fruits brighten the dark Patagonian forests,
the fruits are provided with three long, feathery, viscid appen-
dages, and, either carried by Birds, or wafted by breezes, to some
tree, they fasten themselves to a twig until germination ensues,
and then grow up into plants, feeding on the juices of the tree,
where they have taken lodging and board without so much as
" by your leave."

IV. — Rupture. — By this I mean the various methods by
which seed-vessels — i.e., fruits — dehisce, or open, of their own
accord, either in part, when the wind usually shakes the seeds out,
or through their entire length, in which cases the contained seeds
are more or less forcibly expelled. In this latter case, there is
complete self-dispersion, whereas in the former, the opening of the
vessel is the only part of the process entirely performed by the
plant. Let us first glance at a few cases of complete self-dis-
persion.

THE ROMANCE OF SEED-SOWING. 141

In Bitter-cress {Cardamine hirstita), a very common weed
on dry, open banks, the pod, at the proper moment, when the
seeds are ripe, suddenly rolls its two side-walls outwards and
upwards, and the seeds, lightly attached to a central delicate
membrane, are scattered six or seven feet away from the
plant. Even a puff of wind is sufficient to effect this purpose.
Wallflower acts similarly, but with less force, as may be seen
in any garden.

Among our wild Geraniums there are many interesting cases.
Herb Robert, which everyone knows, has five seed-vessels arrang-
ed around a central elongated column. Each vessel is prolonged
upwards into a thin rod, which is at first attached to the column,
but is slowly separated from it ; the flower, which after blossom-
ing turns downwards, now becomes erect, the rods become
highly elastic, and presently separate from the column with great
force, often scattering themselves and their attached vessels to
as great a distance as twenty feet. We may find scores of these
flowers in the woodlands, each of them with the erect central
column alone remaining, perfectly bare, and w^e must look for
some time to find the scattered seed-vessels far away.

In another. Geranium dissectiim, or Jagged Crane's-bill, the
rods remain clinging to the column together with the five vessels,
the seeds only being thrown off. Curiously enough, the vessels
split open on the side turned towards the central column, and it
would almost seem as if this were useless, but the plant has its
fashion of overcoming this difficulty. Just before the vessel
splits, the rod curls outwards, placing the vessel horizontally, and
so at right angles to the column. The vessel gradually opens as
the rod curls still more upwards, a delicate fringe of hairs keeping
the seed safely meantime, until, when the rod has gone far enough
to place the vessel nearly upside down, the hairs give way, and
the seed is ejected. In this species, therefore, we should find the
column, not bare, but surrounded at its top by the five curled-up
rods, each carrying its empty vessel with the inner face split and
looking upwards.

In Dog Violet ( Viola ca?iina), the capsule is raised on a
long stem, and at maturity opens by three valves, each holding a
row of four or five seeds. The walls of the open valves now

142 THE ROMANCE OF SEED-SOWING.

become dr}', and contract, the two edges approaching each other.
This, after a time, forces the seeds out with a jerk, throwing
them eight or ten feet off. In Sweet Violet and Hairy Violet
( V. odorata and hirsuta), the capsules are not so raised, the stem
being almost absent, and the leaves all springing from close to the
root. Here, we find that their capsules simply open as they he
on the ground, suffering the seeds to fall out among the grass
near by. Not being raised aloft, if the capsules shot their seeds,
the latter would probably strike against the surrounding grass and
fall back again, so the valves develope no contracting power, such
being useless, and they simply open quietly. Dog Violet has
found a better device for dispersion, and so in many generations
has gradually developed a tall stem, from the top of which its
elastic capsules can do their work with good effect.

In Common Balsam, or 'Touch-me-not,' the pod dehisces
through its whole length, and at maturity, if we gently press the
centre between the thumb and finger, it swells up under our touch,
parts suddenly, and away go the seeds. I have stood at one end
of a room twelve feet long, and by pressure caused a pod to throw
its seeds with force against the opposite wall. Again, go and look
at some of our Vetches, or at Broom in seed-time, and you will
find the pods split in two, with each half rolled or twisted on
itself, and the seeds gone. The pods possess a layer of woody
tissue at an acute angle to their axis. When this contracts, the
pod is, therefore, not curled up along its length, but twisted, like
a screw. Gorse, and some others of the Pea Order, open
with a sudden crackling noise, and shoot out the seeds. On a hot
August day you may stand by a clump of Gorse bushes and hear
a series of tiny reports, as one by one the pods burst.

Two singular instances are worth notice. The fruit of the
Sand-box tree {Hura crepitans) of America is about as large as
an orange, with a dozen or more deep furrows, which indicate
as many internal divisions into carpels. When ripe, and under a
hot sun, each separate carpel splits simultaneously, the whole
bursting with a loud explosion. From this fact, the plant has
earned the soubriquet of the ' Monkey's Dinner-bell ' !

Squirting Cucumber {Ecbaliuju elaterium) is one of the
Gourd Order, and when ripe is full to tension of a viscid fluid. A

THE ROMANCE OF SEED-SOWING. 143

very slight touch causes it to suddenly separate itself from its
stalk, the sides contract, and through the end where it was
attached, the whole contents, both fluid and seeds, are sent with a
whizzing sound some feet in the air. An unwary traveller,
touching Eibalium, may quite easily obtain a baptism not to his
liking. Intense heat causes spontaneous separation from the stalk
without any touch. These examples of complete self-dispersion
may suffice.

Of the cases where a partial dehiscence takes place, we may
name a few.

Mouse-ear Chickweed {Cerasiiinii), found in almost any
wild spot, has its capsule tilted laterally at the tip, and opens
by ten minute teeth. The seeds rest safely until a high wind
comes along, when they are shaken out and carried away.
This places it in a superior position to that of ordinary Chick-
weed {Stellaria media), which opens all the way down, the seeds
falling on the adjacent ground.

The beautiful Red Campion, with its bottle-shaped capsule,
also opens by ten teeth, and is admirably fitted for wind-disper-
sion. The Catch-fly of our corn-fields, Pink, and Primrose,
open in similar fashion.

Another method is that of pores, or tiny circular holes near
the top, through which the seeds escape under the action of wind
after the plant has opened its ' windows.' These may be seen in
Mignonette, Snapdragon, Toad-flax, Canterbury Bell, and notably
in Poppy, where the overhanging edges of the circle of stigmas
protect the openings. The pores themselves are said to close in
wet weather. This I have not, as yet, ascertained to be the fact
myself. In those Canterbury Bells whose fruits are pende/if, the
capsules open at the base, which is of course uppermost in these
cases. We see, therefore, that it is a useful provision that ensures
the capsules opening above, so that the seeds may remain prison-
ers until the wind acts on their capsules, and afterwards on them-
selves, to carry them far afield.

In Pimpernel and Plantain the capsules open by a circular
line entirely round the fruit, the top part coming off like a pill-box
cover. Here, again, the wind can act when the seeds are ready
for it.

144 THE ROMANCE OP SEED-SOWING.

Besides these four chief methods of dispersion, there is one
other occurring in a few cases and deserving of notice. I refer to
movemefits of the plafit itself — i.e., of some portion of it.

Dandelion, after lying horizontally among the grass while
ripening its seed, rises to an erect posture, thus enabling the wind
to act on the parachute-like pappus surmounting the fruit. On
the other hand, many plants, by their movements, provide not for
dispersion of seeds by wind, but for burial of them in the soil.
The small white Subterranean Clover [Trifolium subterraneii?n) of
our commons and downs is a good example. Here, instead of
the large number of florets seen in a head of purple Clover
and others, only about three of the bunch become well-developed
florets with pods ; the rest remain abortive in a sense — />., they
are developed into a number of short fibres, each having four
or five divisions like the fingers of a hand, but of course very
minute.

These palmate fibres together form a small green knob in the
centre of the flower-head. The whole plant lies close to the
ground, except that at blossoming-time the three florets stand
erect to secure fertilization by the Bees. This accomplished, the
stem lengthens and turns downwards, the palmate fibres are deve-
loped, and, being central, on touching the earth they bury them-
selves with a screwing sort of movement, thus working a hole,
into which the three pods (which have by this time bent
downwards) are drawn and effectually buried. Thus the plant
safely stores away its pods, full of seeds, which ripen under-
ground during Autumn and grow up in Spring. The plant,
growing only on ground quite closely cropped by animals, in this
way secures reproduction by burying the pods safely out of harm's
way. It sacrifices some of its flowers in order to make natural
gimlets, which can dig a grave for the three seed-bearing ones !

Many other plants, possessing the usual aerial pods, have also
some subterranean ones, usually shorter and with fewer seeds, the
smaller number being an advantage, as they the more easily
flourish when trying to germinate close to one another, while in
the aerial pods a larger number of seeds evidently secures a better
chance in the scattering process. Of these plants we find
examples in some species of Vetch, Vetchling, and Cress. In

THE ROMANCE OF SEED-SOWING. 145

American Eartli-nut {Arachis hypoc^ca), the ' nut,' so called — in
reality a pod — ^is buried while still unripe, and later on, under-
ground, developes its two seeds. If the burial for any reason be
not made, the pod withers, and no seeds are produced.

Some cases exist in wliich moviinent of the sted itself, after it
has left its capsule, either scatters or buries it. The seed of
\Vood-sorrel {Oxalis) ruptures its testa or coat, expelling the
body of the seed with violence. The Stork's-bills, belonging
to the Geranium Order, possess seeds which develope a
Iiairy, twisted ' awn,' which, under given conditions, principally of
moisture, unrolls and pushes the seed down into the ground, the
awn itself being kept fixed by surrounding herbage.

Stipa pennata, a pretty European Grass, has seeds with a
corkscrew rod and long feather springing from their apex ; the
whole arrangement is over a foot long, and in moist weather the
unrolling of the rod acts as in the Stork's-bill seeds, the feather
probably serving the purpose of carrying the seed, first of all, to
its resting-place.

The elaters, contractile filaments forming part of the spores
of the Horsetails, act in somewhat similar manner, by fixing the
spores to the earth, and in some water-weeds the spores are
furnished with vibratile cilia or fine hairs, enabling them to
move in the water spontaneously, and so disseminate them-
selves.

We have now seen the various agents and contrivances by
which seeds are placed in favourable situations for growth, and
we cannot fail to be struck with the wonderful adaptation and
ingenuity of many of them. That the wings, or the hooks, as the
case may be, are not mere accidents or ornaments, as some would
have us imagine, but exist for the purposes named, is, I think,
fixirly established by looking at the kinds of plants on which they
are found, and considering their stature. Sir John Lubbock, in a
most interesting paper in the Fortnightly for April, 1881, gives us
the two following statements (I quote them in outline only) : —

I.—" Roughly speaking, there are some 30 genera, belonging

to 21 different Orders, having seeds or fruits with wings. They

are all trees or climbing shrubs ; not one is a low herb. That

is, they all occur in situations where the wind has free access to

New Series, Vol. I. l

1888.

146 THE ROMANCE OF SEED-SOWING.

them. If the wings were merely accidental, why do we not find
them on low-growing shrubs and plants ? "

2. — " There are about 30 English species where dispersion is
effected by hooks, causing the fruits or seeds to adhere to the
coats of animals. If these hooks were simply ornamental, or
present by accident, why do we never see one such hooked fruit
on a water-plant or a tall tree ? What is the actual fact ? Out
of these 30, not one is aquatic ; not one is over 4 feet high ; not
one grows at a level belo7u that at which seeds would be likely
to get entangled in the fur of animals, having reference to the
usual size of British Mammals."

Thus approached, the ' keys ' of Ash and Sycamore
circling through the air, the silvery down of Thistle and Dan-
delion, the rich, deep crimsons and purples of our woodland
fruits all have meanings for us; we behold in all of them additional
evidences of the great truth of Natural Selection, by means of
which, through countless ages, the Great Designer has slowly and
certainly evolved the myriad forms and colours of fruits and seeds
that call for study and attention ; and we look with wonder and
delight on them all, as, with perfect adaptation of construction to
purpose, fruit and seed are sent forth far and wide, on their
beautiful mission of regeneration and abounding life.

The influence of the moon upon vegetation is an interesting
problem awaiting solution. A recent writer upon the subject
mentions that woodcutters in Cape Colony and in India insist that
timber is full of sap and unfit to be cut at full moon. Another
observation of lunar influence in Cape Colony is the rapid spoiling
of nuts and other provisions when exposed to moonlight, though
this may be due to the fact that the light serves as a guide to
insects. — [The editor, from many years' residence in Essex, is
well acquainted with the fact that no farmer's wife (of the old
school, at any rate) will pickle hams in a " waning " moon. The
days between new and full moon are chosen by the farmer to
kill hogs for home consumption, because, they say, the meat will
swell with the moon, but in a waning moon it will similarly
decrease. Is this custom noticed in other counties ? — Ed.] •

[147]

BcvclopiiKut of tbc ^abpole.

By J. W. Gatehouse, F.I.C.
Part III. Plate XIII.

N our last article mention was made of the various stages of
development occurring up to March 21st — that is, about
three weeks after the egg was deposited ; in the present
paper sections will be given of a single animal as it appeared on
March 17th. These are numbered in succession, i, 2, 3, 4, and
5, number 3 being as nearly as possible a median section, whilst
I, 2, and 4, 5 are two sections on each side of it respectively.

The first thing which strikes us on looking at these sections is
the enormous development of the brain and spinal cord in com-
parison with the size of the entire animal. The nervous system
fills up the whole upper portion of the cavity of the skull, extend-
ing down nearly to the cavity of the mouth, and behind stretching
out as a thick cord to the very extremity of the body. When we
compare this with the relative size of the brain and spinal cord as
existing in the adult frog, it will be at once seen that an immense
amount of both concentration and diffusion must occur between
the present and the adult stages — concentration in the approxima-
tion of the various portions of the nerve system to each other,
and a possible diffusion by portions of the nerve matter spreading
out so as to produce nerve-cords extending over the body.

Whether the whole of the nervous system is developed from
the nerve-matter at present formed, or whether fresh portions of
yelk assist in the formation of nerve substance will probably be
seen in our future sections. The length of the brain itself —
extending as it does from the very front portion of the head,
quite back to the segmented sheath surrounding both the spinal
cord and notochord — is much greater in proportion to the whole
nervous system in the embryo than it is in the adult. Thus, at
the present stage, the cerebral lobes, medulla oblongata, etc., are
at least as long as the remainder of the nerve-cord, but in the frog
the latter, within the vertebral column, must be quite three times
the length of the true brain, even if we include the olfactory lobes
as a portion of it.

148 DEVELOPMENT OF THE TADPOLE.

In our present sections it is easy to distinguish, not only the
cerebral hemisi)heres and the medulla oblongata, but also the
mid-brain, the optic, and olfactory lobes, as well as in section 2
what I believe to be the pineal gland. The whole of the brain
and spinal cord is bounded by a single layer of apparently epi-
blastic cells placed end to end, so as to form a delicate membrane
around it. The fore-brain, also, is at this period well marked oft
from the mid-brain by a slight depression and a hollow space
within the substance of the brain itself (Fig. 2,/;/.) It is here,
just above this depression, that a small oval body is situated, ter-
minating in front immediately over the hollow or ventricle above
mentioned, but extending backwards slightly over the mid-brain.
This oval body is in all probability the pineal gland. If this be
so, there is, however, no trace of the eye-structure recently found
in the pineal gland of some reptilia, unless, indeed, the very con-
siderable depression itself, which exists between the epidermis and
limiting membrane of the brain at this very spot, and which is
well seen in another section, of the same animal, not given in
these drawings, can be taken in connection with the small detached
mass of nerve matter as evidence of the existence of an unde-
veloped eye.

The membrane enveloping both brain and spinal cord at this
stage would appear to be the commencement of the pia mater.
All the organs are, however, surrounded by a similar, though in
some cases more delicate membrane. I'hus, the abdomen can
be distinctly seen to be bounded by three layers, the innermost of
which is bent round in the neighbourhood of the heart to form a
large closed chamber, corresponding to the pleuro-peritoneum of
the adult, the whole of the already-formed organs being on the
one side, and the undifferentiated yelk-mass on the other of this
membrane. From the lower side of the spinal cord, at intervals
along its length, small processes of nerve-matter can be seen to be
extending through the membranous wall; and beneath and around
these again cartilage can be perceived to be forming. The spinal
cord is at this period perfectly double throughout its wh6le length,
and rests upon the notochord, an elastic fibrous sheath, about
which more will be said hereafter, binding the two structures toge-
ther, although in some of my sections, from which the ligament

DEVELOPMENT OF THE TADPOLE. IJ-O

has been entirely removed, there appears a distinct Hne of separa-
tion between them. Balfour, in his embryology, tells us that the
posterior roots of the spinal nerves arise from the dorsal, and the
anterior roots of the same from the ventral side of the spinal
cord. These anterior and posterior roots, although at first sepa-
rate, ultimately coalesce to form the true nerve-cord.

In sections i, 2, and 3, we see one stage in the development of
the heart, lungs, kidney (or pronephros), and liver. The heart is
at this period peculiarly interesting, consisting, as it does, of a
pear-shaped sac, situated below, and a little to one side of the
mouth-cavity, within the pericardium. It is an open tube, bounded
by muscular walls, consisting distinctly of two rows of cells placed
end to end, so as to give somev/hat the appearance of transparent
rows of beads, threaded on an opaque, granular, and elastic
string, nearly the same size as the beads themselves. The inner
row represents the epithelial lining of the heart, whilst the outer
layer gives rise to its muscular wall. The interior of the sac
contains several round, granular cells, looking very like undiffer-
entiated yelk-cells, but very much smaller and quite round.
Attached to the upper portion of the sac, and towards the mouth-
cavity, one of the sections shows another sac, formed exactly on
the same principles, consisting, indeed, of a double tube, the wall
on one side conterminous with the wall of the heart, and the
inner tube filled with granular matter. The pear-shaped body
has exactly the shape of a ventricle, whilst the other fairly
well represents the position of the auricles, but as there is no
distinct connection to be traced between this structure and the
heart, besides their close approximation, it very probably represents
a young stage in the development of the lungs. The granules
within the pear-shaped body are distinctly arranged in the form of
two lines crossing each other, with little groups scattered about.
Between the heart and the undifferentiated yelk-mass lies the
liver. The rudiments of this organ make their appearance very
early ; indeed, traces of it are to be found in the animals whose
sections were given in the last article.

In sections 2, 3, 4, and 5, may be seen, just under the noto-
chord, an apparently granular structure, of which a much-enlarged
vertical section is seen in Fig. 8. This is the immature kidney, or

150 DEVELOPMENT OF THE TADPOLE.

pronephros. It consists of a convoluted tube, terminating in a
glandular hollow bulb. Further sections of this tube show its
structure to be more complicated than that given in the diagram,
as the lower sections proved the existence of several of these
bulbs, some round, whilst others were oval, and one or two pos-
sessed the appearance of a dumb-l)ell, with a very short, wide
handle between the knobs. The tube and its openings is entirely
surrounded by a membranous sheath, consisting of long, elliptical
cells. The convoluted tube or duct is itself composed of a large
number of flat, oval cells placed closely side by side, having much
the appearance of an immense number of tiny, flat pebbles,
arranged side by side, with their flat iaces touching each other and
their rounded edges pointing upwards. The internal portion of
the cells appear;; considerably darker than the external ; indeed,
the appearance is such as would be presented by a very minute
layer of epiblastic cells, surrounded by one of hypoblastic ; but
whether this is the case I have not been able to determine, as
there appears no definite line of demarcation between the dark
interior and lighter exterior of the tube-wall, such as should be
due to the approximation of these two difterent classes of cells.
This primitive kidney is the same structure, more fully developed,
which was shown in Fig 5, PI. ATI., and there called a pro-renal
duct.

Gotte states that the development of this duct commences
from a layer of the peritoneal epithelium, its front end being, as
here shown, immediately behind the branchial arches, and also
that it has free communication, by means of its openings, into the
body-cavity. DoubUess, this communication really exists, but at
the stage to which we have arrived it can only be through the
delicate membrane, if a single layer of cells is deserving this name,
which surrounds the whole organ, and separates it from the body-
cavity. Indeed, in a section four days older than the one drawn,
two of the openings are seen to lie directly against the mem-
brane, but the section does not enable me to make out whether
they are actually under it or o[)en up into it. These openings
have all the appearance of the end of a thickened tube, looking
like a thick, dark ring surrounding an opening of about the same
diameter as the thickness of the tube-walls.

Journal of Meroscopy I\F S. Vol.1. Pi 13

.«»"..';«''■•«*' /

prr

eb

eb

.0

TK.^

^•^T' '>' '^

'^^ sir •■ ^'''
-cl

■:Jip^J^«f^^^'^^*^''^"'^ '

■^&r^

prn sK'

DeVelcpme?'/^ uf' Tadpde^

DEVELOPMENT OF THE TADPOLE. 151

In the whole of our sections there will be seen, on the under
part of the head, a dark mass, cl. — called the claspers — an en-
larged horizontal section of which is given in Fig. 7. They are
hollow bodies, evidently outgrowths of the epidermis. The
central cavity is bounded internally by a row of very small, dark
cells, and radiating from these are larger, elongated, black cells,
■which stretch in fairly parallel masses nearly to the outside of the
structure, the whole being covered by the polygonal cells of the
epidermis. The two parts of which they are composed approxi-
mate very closely to each other, if they are not, indeed, in actual
organic connection, by means of the epidermis, but at a certain
period of their growth they are distinctly separate. Although these
commonly -called claspers are referred to by embryologists as suc-
torial discs, I cannot find any opening into the interior whereby
suction can be carried on by them. Nevertheless, that such an
opening exists would appear probable, unless, indeed, they are not
suctorial discs at all, but claspers in the true sense of the word.
From the yelk being situated in the abdominal region, combined
with the cavities in the head, the animal must necessarily take an
inclined position in the w-ater, head uppermost, whilst the compara-
tively great weight of the abdominal regions drags the animal down-
wards in the water. The claspers will now press laterally on any-
thing, as, e.g., parts of the gelatinous envelope or external objects,
which may mechanically find their way between them, the animal
being merely held in position by the combined effects of the
greater specific gravity of its lower parts and the slight adhesion
which takes place between the so-called suctorial discs.

EXPLANATION OF PLATE XIII.

Figs. 1 — 5. — Sections from one Tadpole, taken March 17tli.
,, G. — Mandible arches.
, , 7. — Claspers,
,, 8. — Pro-renal Ducts and Lungs.

Sp.c, spinal cord ; ?ic., notochord ; m.c, mouth-cavity ; h., heart ;
St., stomach ; al., alimentary tract ; ca. , cloaca ; cZ. , claspers ; I., liver ;
e.b., elastic band, surrounding notochord and spmal cord ; pni., pro-
neplnx>3, or immature kidney ; sh., sheath of ditto ; m.h., mandibular
and hyoid arches ; 0. , optic vesicle ; ati. , auditory capsule ; b. , brain ;
ep. , epidermis ; pn. , pineal gland ; ga. , ganglia.

[ 152 ]

prcparatioiie for Ibiob ipowcre.

By J. W. GiFFORD.

WITHIN the last few years, and especially since the Abbe-
Schott glass has come into requisition for the construc-
tion of lenses, the optical capabilities of the microscope
have been so much increased as to make microscopical research
rather a question of methods for the more careful and exact pre-
paration of the objects to be examined than of further advance
from an optical point of view.

Dr. Lionel Beale was, I believe, the first to point out tliat by
the ordinary method of fixing in spirit, staining, and mounting in
balsam, many points of minute structure are lost. His glycerine
carmine fluid for fixing and staining tissues at once has become
classic, and was composed as foUuws : —

Carmine ... ... lo grains.

Liquor ammonice ... ... o^ drachm.

Strong Glycerine ... ... 2 ounces.

Distilled Water ... ... 2

Alcohol .. ... oi ounce.

The carmine is dissolved in the ammonia by heat in a test-
tube, and then allowed to stand until the excess of ammonia has
escaped. The other ingredients are then added, and the whole
filtered. Perfectly fresh material is immersed in this for a period
of time varying from six to twenty-four hours, according to size
and temperature. The material is then washed in glycerine and
water, and placed in glycerine acidulated by acetic acid (ten drops
to the ounce) for several days. It may then be cut with \'alcn-
tin's knife, or teased out, and mounted in glycerine, with a trace
of acetic acid.

All things considered, there is no doubt that as a general
method this still stands second to none, especially where tissues,
such as a piece of mesentery or a minute ganglion, do not require
to l;e cut into sections, Init may be mounted as they are or teased
out with needles. But sections cut with Valentin's knife are
scarcely suitable for examination with high powers, and in order

PREPARATIONS FOR HIGH POWERS. 153

to enable thin sections to be cut with a modern microtome, the
material for cutting must be imbedded. This may, of course, be
accomplished by placing the material in gum solution and freezing
in the ordinary way, but, as Dr. Beale has pointed out, once allow
the tissues to leave glycerine or syrup, and change immediately
sets in, and the whole advantage of the process is lost. Besides,
the crystals formed by the freezing of pure gum solution more or
less break up all delicate structures. If, however, gum and syrup
be used as recommended by Mr. Cole, or a small quantity of
glycerine be added to plain gum, change is prevented and the
crystals are so finely granular as not perceptibly to injure the most
fragile tissues. I think the gum and glycerine is to be preferred.
Both syrup and glycerine retard freezing. Glycerine quite pre-
vents it, unless a small quantity only be used, and as the strength
of glycerine varies this must be ascertained by experiment.

Sections thus made are mounted in glycerine jelly, prepared
as follows : —

Glycerine ... ... 150 grammes.

Isinglass ... ... 30 „

Water ... ... ... q.s.

Dissolve the isinglass in as little water as possible, using gentle
heat, clarify with white of egg, strain through muslin, add the
glycerine, and keep the whole for some days at about 60" C. until
the greater part of the water has evaporated. In this way a very
highly refracting jelly may be made. Preparations mounted in
glycerine, as recommended by Dr. Beale, after a year or more
become exceedingly translucent, so that minute points of structure,
I'articularly intranuclear networks, can no longer be distinctly
made out. This is not tliC case with glycerine jelly. As little
heat as possible should be used in mounting, or the sections
shrink. After the cover-glass is put on, and all superfluous jelly
cleaned off, the mount may be ringed with gold size, which is, I
think, the most reliable of any cement for this purpose.

But where very faithful and instant fixing in statu quo is
required, I think a slight modification of Flemmings' chromo-
aceto-osmic acid is the best fixing agent, although on account of
its t'eeble powers of penetration it can only be employed where

154 PllEPARATIONS FOR HIGH POWERS.

the material is thin or can be cut into very small pieces. To a
watchglassful of ^^th per cent, chromic-acid solution, made with
distilled water, sufficient osmic acid is added to make it smell
distinctly, and finally one droj) of formic acid. The material — ■
immediately after death, in the case of an animal — is placed in
this for from half-an-hour to two hours, according to size ; that is
to say, for as short a time as will ensure thorough penetration of
the mixture, which may with advantage be slightly warmed. It is
then soaked in several changes of water, to which a little glycerine
has been added, and stained in a mixture of equal parts of
Kleinenberg's h^ematoxylin and glycerine. The formic acid may
be omitted, but delicate nerve-plexuses are not so sharply brought
out, and it is then far more difficult to stain. The material
should remain in the ha^matoxylin two days, and sliould then be
placed in a mixture of equal parts of glycerine and water, and
kept lukewarm for a week or longer, until most of the water has
evaporated. It may then be mounted whole, or frozen and cut
by the process before described, and finally mounted in glycerine
jelly. The nuclei amid the protoplasm lining the cells of Ana-
charis alsinasiruin may in this way be beautifully demonstrated
and compared with a living leaflet exhibiting cyclosis, where the
nuclei are indistinguishable from the protoplasm.

I have tried many methods of preparing delicate tissues for
examination with oil-immersion lenses of the highest aperture, but
have found these the only ones which give me certain results and
enable me to use these lenses with advantage. They are cer-
tainly troublesome, and have not the charm of novelty, but enable
an aperture of from i '3 to 1 '4 to be effectively employed, and I
think will be found successful in direct proportion to the care
used in carrying them out.

Fumigation is said to have originated with Acron, a physician
of Agrigentum, who is said to have caused great fires to be
lighted, and aromatics to be thrown into them to purify the air,
and thus to have stopped the plague of Athens and other places
in Greece about 473 b.c.

[ 155 ]

H^uincrical Bperturc.

By the Hon. J. G. P. Verekek

ALE TTER has appeared in the Scientific Enciuirer asking
for information on the connection between numerical and
angular aperture, and also for an ex[)lanation of the
maihematical terms used.

It would take too much space to write a reply to this query,
giving fully the proofs of the theorems, and also explaining all the
mathematical principles invoh ed ; but I shall endeavour to give
here a slight sketch of the various points.

First of all, the connection between angular aperture and
numerical aperture is very simple :

Let a - \ the angular aperture of a lens.

Let 111 = the refractive index of the medium between the
lens and the object.

Let A^=the numerical aperture.

Then N=m sin a.

Sin « is a contraction for the sine of the angle a, and if the
value of a is known in degrees the value of sin a will be found in
mathematical tables under the head of Natural Sines. I have,
however, appended a table of natural sines for every 5"^ of the
quadrant.

The value of m is only required for a few substances in micros-
copy, and I give them here : —

Air - I -ooo.

Water ------- 1-333.

Abbe's LBmersion Oil - i'52o.
Canada Balsam

Crown Glass ' ^ 53o-

It will be remarked that crown glass, of which the front lens
of an objective is usually made, and Abbe's immersion oil, have
about the same refractive index \ therefore an oil immersion lens
is also called a homogeneous immersion 1^ ns.

I'he next point is to explain the mathematical terms used, and
to give a slight sketch on refraction.

150

NUMERICAL APERTUEE.

Let FAX (Fig. i) be any angle, and let us call it A. From

Fig. I.

the point A, with any radius, describe a circle B H O, cutting A F
in B. From B let fall a per^jendicular B C, on the other leg of the
angle A, and produce B C to meet the circle in H. Then B C is
called the sine of the angle A to the radius A B, and is (Euclid
III. 3) half the length of the chord B H. With the centre A, and
another radius A F, describe any other circle ; through F draw F G
parallel to B H, and meeting A X in G ; then F G is also the sine
A to radius A F. But by Euclid VI., 4 :—

B C : F G : : A B : A F,
B C

therefore

A B

is a constant quantity for the same angle. Now

this fraction

B C
A B

turned into decimals is what is written down

in mathematical tables as the natural sine of the angle A, which
is itself given in degrees.

The angle A in the figure is less than a right angle, but it
might be greater. By a similar construction it will be seen that
sin A = sin (iSo"^ — A.) This is, however, unimportant for us, as in
objectives the semi-angle does not exceed 90''.

If through A, A Y is drawn perpendicular to A X, the angle
Y A F = 90*^ A, and is called the complement of the angle A
and is equal to the angle ABC (Euclid I., 23). Its sine, B D, is

NUMERICAL APERTURE. 15?

equal to A C, and is called the cosine (written cos :) of the angle

A.

AC ,

. • . = cos A.

A B

Through X, draw X K perpendicular to O X, and meeting A K
in K ; then the line K X touches the circle T F X, but does not cut
it, and is called a tangent. Now, X K is the tangent of the angle
A to the radius A F, which is equal to A X.

K X B C , .
•■• AX=XC -^"^^-

The cotangent, written cot., is the tangent of the complement
of A.

Therefore, if B A C is a right-angled triangle, having the right
angle at C,

BC . . AC . B C ^ .

-T— FT = sm A : = cos A ; — — = tan A.

A B ' A B AC

It IS evident also that tan A = -> and also that when A

cos A

is vtrrj' small the sine is almost equal to the arc subtending A.

For example, the length of the sine 3'' in a circle of 10 inches

radius is •523 inch, and tlie length of the arc is "524 inch. The

difference therefore is of an inch.

1000

We can now proceed to the chief law of refraction.

If a piece of string is made fast to a nail in the wall and held
loosely by the other end in the hand, and a slight up-and-down
motion given to the hand, the particles of the string are given
an up-and-down motion, and it is thrown into a series of elevations
and depressions, and the string apparetitly moves on, though, as a
matter of fact, it does not. This is called an undulatory, or wave
movement, from the familiar example of the waves of the sea.
Light is propagated in the same manner, but the movement is
believed to be a double one, at right angles to each other, as is
shown by experiments with polarised light. The propagation of
light takes place slower in a dense medium than in a rarer one.

Now let ISI N (Fig, 2) be the limiting surface between two
media of different densities, and let A O B C be a parallel beam
of light striking it obliquely, and let A O meet M N in O, and

158

NUMERICAL APERTURE,

B C meet it at C. From O draw O D perpendicular to B C, and
meeting it in D ; the line O D will represent the tangent to the
advancing waves. Now, when the wave advancing along B D has
reached C, the wave advancing along A O has entered a certain
distance into the second medium ; and this distance has the pro-
portionate length, to the length D C, that the speed of advance-
ment in the second medium has to that in the first : with the
centre O, and this multi|jle of the distance D C, describe, a semi-
circle, P H L. In Fig. 2, a, this distance is smaller thin D C,

Fig. 2, a.
and in Fig. 2, l>, is greater ; (in f^ict, the two figures are drawn to

Fig. 2, b.

NUMERICAL APERTURE. 159

cale, and represent the passage from air into glass and from glass
into air.) The wave advancing along A O must have got to some
point on this semi-circle by the time the wave along B D has
reached C : from C draw a tangent, C E, to the semi-circle, touching
it in E join O E. Then C E represents the tangent to the advanc-
ing waves in the new medium, for take any other wave direction in
the beam, represented by K L, and meeting M N in L ; draw L R
parallel to O E, meeting EC in R, and L Q parallel to O D,
meeting L C in Q, and L S parallel to C E, meeting O E in S.
(This is only drawn in Fig. 2, a, to avoid confusion of lines.)
Then

O L: LC :: O S : LR 1 T. ,. , ,„

\ Euclid VI., 4
OL:LC::KL:QC/

. • . O S : L R : : K L : Q C.

OS + LR:LR::KL + QC:QC.

OE:LR::DC:QC.

LR:QC::OE:DC.

Or, the distance L R is the right amount of advance in the new
medium for the wave along K L, whilst the wave along B C is
covering the distance Q C ; that is to say that C E represents the
tangent to the advancing waves in the new medium.

Through O draw G H perpendicular to ]\I N. Then the
angle A O G is called the angle of incidence, and the angle
HOE the angle of refraction.

Let angle A O G = /,
and angle H O E = ;-

Then, since A O D is a right angle, and G O C is a right angle,

take away the common angle GOD, then / = angle U O C. Also,

since angle HOC is a right angle, and angle E O C + angle

O C E are equal to a right angle ; take away the common angle

C O E J therefore, r =■ angle O C E.

..DC . . , O E

JNow, — -— = sm /, and -— -^ = sm ;-

DC sin /

O E sin r

D C

But — — - is the ratio expressing the speed of propagation of

light in the two mediums, and is constant ; there is, therefore, an

IGO NUMERICAL APERTURE.

invariable ratio bet>veen the sines of the angles of incidence and
refraction.

D C

The value of the fraction — — - when light passes from air into

O L

anotlier medium, is wliat is known as the refractive index of the

substance ; this makes the refractive index of air unity.

It is evident from the figures that rays perpendicular to the
surface M N suffer no deviation, but are only retarded.

If;;/ be taken as representing the refractive index of the i)as-
sage of light from air into another medium, the refractive
index of the passage of light from the other medium into air is

the reciprocal of ;;;, or — ; for the two parts of the refracted beam

are mutually dependent ; this is easily deduced from the figures.

Therefore, the passage of light from a medium into air is given by

^, ... sin r
the equation, sin i =

If r = 90*^, the radius is equal to the sine, and sin r = i ;
in this case the refracted ray lies along the surfice of the medium.
Take, for instance, the case of crown glass.

Then sin i = ^ =

m I "5 2

or /= 41* 8h' (nearly).

This angle is called the critical angle of glass, and a ray
having a larger angle of incidence cannot pass out, and is totally
reflected. The critical angle of water is 48*^ 35'.

From this it follows that an angle of

90^ (air) = 48° 35' (water) = 41^ 8h (glass)
in the amount of light-rays it contains ; so that the denser the
medium the more the rays of light are squeezed together.

Now let A B (Fig. 3) represent the section of a lens. This
may be either a single lens or the front lens of a system. Let
D C be drawn perpendicular to the lens, and passing through its
centre. Then D C represents the principal axis of the lens ; and
let F represent its focus, and A F and B F represent the extreme
boundaries of the cone of light-rays from F, passing into the lens.
Then the angle A F B is called the ''Angular Aperture'' of the
lens.

NUMERICAL APERTURE.

161

C ^7//;

7777^^-

A^^

7fm^3

Jit \.

C" ' "^"^ ~

J

/

/

Fig. 3.

Produce the lines A F and B F through the focus to F and K.
Draw M N through F, perpendicular to D C. Now, the angle
E F K is equal to the angle A F B, and if air is on both sides of
M N will represent the angular amount of light coming from air
into the lens, but if there is another mcdmm instead of air, the
angle E F K will not represent it.

In the case of the microscope, if a medium is placed between
the lens, it is always a denser one than air, and consequently angle
A F B represents a much larger angle in air, such as J F L.

For, let m = refractive index of the medium.
Let a = angle AFC = | A F B.
Let b =^ \ angle J F L.
Then sin b ^ ;;/ sin a.

Thus, it is necessary to take the angle J F L as the true angle
of aperture for the whole cone of rays, because if the cone of rays
represented by A F B are fully utilised, they are re-given out in
air.

The actual amount of light, of course, varies with the squares
of these quantities ; but, as in all microscopical work, it is found
more convenient to treat of linear equivalents.

Taking the same figure, suppose G H to be a lens of the same
diameter as A B, with a longer focus, but still at F, and G F H

New Series. Vol. I.
1888.

M

162 NUMERICAL APERTURE.

representing its angular aperture, it is evident that its angular

aperture is less than that of A B. This shows that focal length is

an element in the calculation of aperture.

If a lamp with a circular ground glass globe is looked at, the

part perpendicular to the eye is seen to be brighter than the edges ;

but if the sun or moon is looked at they seem equally bright all

over, and this in spite of the fact that equal visual angles take in

more of the surface radiating light at the edges than perpendicular

to the eye : the investigation of these phenomena, and of light

emitted from an infinitesimal bright surface element has given rise

to the Lambert law, which shows that the amount of light given

out does not depend on the ratios of the angles, but on the sines

of their inclination to the perpendicular. For exam]:)le, take an

angle of 60"^ and an angle of 120" round the perpendicular.

1 2 o *^ 2
Then-—- =— and the amount of light is not as 2= : i ^ 4 : i ;

but as -, = I -^ 4 = ^- , or light from 120'^ : light from

sm- 30 I

60^ :: 3 : I,

All these points show that the angle of aperture is insufficient
of itself to give a correct notion of the performance of a lens, but
that some function of this angle is required.

The word aperture simply means opening, and what we want
to get is the lineal opening of a lens, which lets the light through,
so as to be able to compare lenses together. The size of this
opening has already been shown to vary with the focal length; that
is to say, the longer the focal length the smaller the aperture for
the same diameter of lens, so that, if
0 = this opening,
/ = the focal length,
we want to find the ratio of 0 to/

The next question is. Where shall we measure this lineal
opening? If we measure the front lens, some of the light may
be cut off by diaphragms or in other ways ; that is to say, the
light might come in, but never get out again. The only useful
rays are those that get out, and as they get out into air we get rid
of refractive indexes. Therefore, the rays emerging from the
back lens are the ones to measure. There is another advantage,

NUMERICAL APERTURE.

1G3

that the rays emerge approximately parallel, so they give a clear
idea of an opening or aperture.

A convenient i)lace to choose for the proof I am giving is the
moment when they have just emerged.

Let G C and H D (Fig. 4) be the exterior and interior faces

iP^i^

a ^

Fig. 4.
of an aplanatic system on the plane of the paper and the line B A
represent the princi[)al axis of the system, meeting each face in
C and D. Let A and B be two conjugate foci, and A G any ray
of light which passes through the system, and is refracted along
H B to B ; then by the Abbe-Helmholz law of aplanatic con-
vergence,

Sin B

=a constant=r,

Sin A
as long as the same focus and system are considered. Let the
refractive index on the A side be in and on the B side unity,
that is, air ; then if a and b represent the ratio of the arc to the
radius of two very small conjugate angles lying close to the axis,
and E represent the magnification of the image at B by the
Lagrange Helmholz law,

a VI

^ ~ K
If the focal length of the objective be / and the image is pro-
jected to a distance, ^,

E= — (nearly)

a mf
' ' ' l^=~d;
but as the sines of very small angles are equal to the ratio of the
arc to the radius, and as tlie first equation holds good for all

angles,

mf

IG-t NUMERICAL APERTURE.

From B, and with a distance, ^^B D, describe an arc cutting
B H in F. The waves of light must touch this circle simul-
taneously to arrive along the equal radii at B together. From F
let fall F E perpendicular to B D, and meeting it in E, then F E
will represent the linear semi-opening =« and B F=B D=^.

_=sm B =c sui A^= -^ sm A,
d a

a^mf sin A,

^ ■ A

- ^ =w sm A.

Now, if the ray A G F B represents the most oblique ray
which passes in and out of the system,

a 0

^= -,^w sin \ angular aperture ;

or the ratio of the linear semi-aperture of any system to the focal
length of that system is equal to the sine of 1 angular aperture
multiplied by the refractive index of the medium between the
object and the lens. This is the numerical aperture.

As the angle B, in the case of the microscope, is always very
small if the arc F D or the tangent to H D was taken, the differ-
ence between their ratios to the distance B D and that of the sine
F E would be inappreciable, so this aperture is half the clear
opening of the back lens.

. • . If half the angle of aperture is represented by (T, and N
is the numerical aperture,

N = w sin a

In the case of a dry lens rii is of course unity.

There may be a slight feeling of dissatisfaction at taking

E = the magnifying power = — ;

but as a matter of fact this exactly expresses what we mean by an
objective of a certain focus.

For instance, take a ^ objective. We know this objective does
not focus a y% inch away from the object. We mean, however
that its magnifying power is that of a lens whose focus is in a cer-
tain ratio to the distance of distinct vision, which is always taken

NUMERICAL APERTURE. 165

as lo inches, and the magnifying power of this lens is supposed

to be 80, that is to say,

10 ,' I • 1

^- = 80 or /= ^ inch.

/ ^

This number, 80, multipHed by an ocular magnifying

5 times (A ocular) gives the magnifying power 400, and this holds

good for all the other powers.

The rule for the magnifying power of an objective is, divide 10
by the focal length in inches, and multiply the quotient by the
power of the eyepiece.

In the case of minute objects, some of which are transparent
and some opaque, the waves of light pass round them, or through
them, or both together, and thus may cause a disturbance in their
undulations. In this case images known as Diffraction Images are
formed.

In viewing minute objects it is important to combine as many
as possible of these images ; but these images are dispersed at
various angles from the perpendicular to the surface, and in a
denser medium than air these angles are of course reduced
according to the index of refraction, whicli proportion is given in
the formula for numerical aperture. An immersion lens therefore can
take more of these images in, and thus has greater resolving power.

Take, for instance, a lens of 170'' angular aperture; this, if a
dry lens, has a numerical aperture of o"9962, but if oil immersion
of I "5 14224, or the oil lens has more than half as much again
resolving power as the dry lens, though the dry lens is working
almost at its maximum. This could never have been inferred
from the angular aperture alone.

If the wave-length of green light is taken as inch (this

50,000

is a point between E and F in the spectrum) the numerical aper-
ture, multiplied by 100,000, will give a theoretical resolving power
in lines to the inch, which is often very convenient, though of
course rather rough.

For example : required a lense to resolve Amphipleura Pellurida,
which contains about 90,000 lines to the inch. To 90,000 add a
tenth for errors, etc. ; this makes 99,000; divide by 100,000. This
gives N A = -99 ^ sin 82° for a dry lens, = m sin a = 48° for

1C6

NUMERICAL APERTURE.

water immersion. That is, the angular aperture ought to be 164^
for a dry lens, or 96" for a water lens. Now for the power. Say
the eye-piece magnifies 10 times, and you want it resolved 100
lines to the inch, divide by 1,000, and you get

=99 or — inch will answer.

/ 10

I trust the above will give sufficient of the information

required. I have dwelt at length on refraction, as it seems to me

that it is there that so much misconception has crept in : it being

so difficult to see why different angles in different media may mean

one and the same thing. Diffraction I have only mentioned, as

it would lengthen this article inordinately, and has also nothing to

say to the measurement of aperture.

Table of Natui^al Sines to every 5''.

Angle.

Sine.

Angle.

Sine.

Angle.

Sine.

5^

0-0872

35^

0-5736

65°

0-9063

lo'^

0-1736

40-

0-6428

70-

0-9397

15^'

0-2588

1

45^^

0-7071

75^'

i

0-9659

20°

0-3420

50^

0-7660

80^

0-984S

25^

0 4226

55^'

0-S192

85^

0-9962

30-

0-5000

60^

0-8660

yo'-'

I -0000

[ 107]

Zbc IDilli all^ BcaMno iDi6C0VClv^ on Butter**
tl^ anb ni^oth Scales.

By Dr. Royston-Pigott, M.A., F.R.S.
Plate XIV.

^T OW that glasses of great power can be cheaply obtained, a
^ completely new field of enjoyment is to be found in the
examination of the Villi and beading of these scales,
mounted dry.

In 1 88 1, a short notice on A^illi was published by the Royal
Society. Since that time, the writer, having mounted about 450
species and spent most of his leisure in their investigation, has the
pleasure of announcing about 1 2 varieties of these Villi at present.

In 1880 they were with much difficulty descried on the scales
of the /ic'd Admiral ; but recently much larger and prominent
Villi have fortunately been discovered. They may be classed as
internal^ lyhig between the two membranes forming a scale ;
external, sometimes penetrating the inner membrane from within,
attached to the ribs and peeping outwards in an extraordinary
variety of forms, generally tipped with brilliant heads ; superficial,
being distributed in most grotesque forms upon the surface of
the scales next the wings.

Some further description of scales is here required. They are
all ribbed on the outer or air surface and, excepting the Villi,
smooth where they rest upon adjacent scales. Another point
should not be omitted. They are all saturated with a peculiar
scale-oil, which may by pressure be made to play a prominent part
by developing structure as it flows to and fro within the sac. It
has a very strong preservative power, and refuses for an immense
time to evaporate.-

These little wonders are best seen when a small portion of the
scale adheres to the cover-glass and when the ribbing lies below.

A very exact vertically-measuring apparatus records some of the
Villi erected, i — 5000th of an inch, but generally they are only
from I — 1 0,000th to I — 8oooth aloft above the unribbed mem-
brane which lies compactly upon the wing.

* I have some I'odura scales, 60 years old, quite full of this oil still.

168 THE VILLI AND BEADING DISCOVERED

Manipulation. — I have long known that the apparent thickness
of the black margins of cyHnders and spherules depends upon
two factors — angular aperture of the objective and of the illumi-
nator.

The outlines are seen thinnest with a wide-angled condenser,
such as Abbe's, and seen very thick by a low-angled one, such as
a one-and-a-half-inch Ross's objective. Objectives of many kinds
have been successfully employed as condensers for many years ;
also an Iris diaphragm and Powell's stops. In practice, a touch
of the hand rapidly reveals the best apertures for superb
definition.

Battledore scales require magnificent glasses to display the
beading on their surfaces. But very ordinary ones show the well-
known circular dot ; better ones descry pillars with oddly-shaped
bases connected internally by filaments, and if the focal depth be
sufficiently delicate, single pillars, which indeed are huge villi,
may be traced within, downward from head to base. To show
what can be done by the best modern glasses, the other day,
examining the Battledores of Polyonunatus Bceticus, tlie quill or
stem was seen glittering with the most minute, diamond-like
beading, evidently intended to secure the quill safely in its place,
the wing pocket.* I have seen this in no other species.

The types of villi lately discovered are in themselves highly
interesting : — Batonettes, Venniforms, Confluents, and lofty Erectilcs.
Besides these, eight other kinds had been previously discovered : —
Beaded Villi, Embossed Villi, Ciliated Villi, Connected Villi, Banana
or hunched Villi, Spinous Villi, Tall Villi. There can be no doubt
that many other varieties exist, and perhaps, after another seven
years' search, new kinds may be discovered. By the permission
of the Editor, a few of these will be represented I)y drawings.
Mr. Watkins, King's Mill House, Painswick, supplies a list and
wings.

* I extract an entry from my catalogues : —
" Supplied by Mr. Curties, scales {a, l>, c, d, e). Nearly all the scales show
ribs and Villi downwards, but scale [a] shows the other surface beautifully
jewelled with beading, especially the quill. When the ribs are shown upwards,
the bosses appear and are prolonged inwards. A i-32nd was used at last to
differentiate the two membranes (Feb. 8th, iSSi.) I reckon this minute
beading at i- 150,000th of an inch in diameter."

Journal of Microscopy N. S. Vol.1 Pi. 14..

J Mi i.n Scales (f -LejJidcpfera.'.

ON BUTTERFLY AND MOTH SCALES. 1C)9

EXPLANATION OF TLATE XIV.

Figs. 1 and 2 represent the hraarl margins seen in s])ider lines and glass
threads under small apertures, which narrow as the apertures
are increased.

,, 3 ic- a very precise drawing of a burst-open scale in which the
minute beading is beautifully represented (after Nature), which
I here term embossed Villi, Ziigccna Trignnilla.

,, 4 shows the effect of pressure. The Villi, formerly erect outside
the scale, are here demonstrated as flattened down. Zijyitna.
TriyonilUi.

,, 5 displays a very rec/((?n:/(t'' definition of Molecular beading, about
1-90, 000th of an inch in diameter, under a power of 2,100
diameters, abounding in minute spherules defined by their
sharp outlines or test rings.

,, C. — A scale accidentally torn open by the process of mounting
dry. The ribs are revealed underneath, and the rent-piece,
still attached, shows villi adherent to the torn membrane and
visible both externally and internally under the microsco]3e.
This butterfly wing came without a name, and I call it "No
name." No. 102. It is a Zygccna.

,, 7 represents some of the infinite forms of erect Villi, power 2,000.

,, 8. — Most wonderful variations of the forms of lai'ge Villi are to
be seen on the under surfaces of the Battledores of Lyccena
Alstis. One only is selected.

Mr. Hinton, 11 Vorley Road, Upper Holloway, has mounted a
great number of Villi slides.

Drawn from Nature by Royston-Pigott.

Curious Deposits in the Cells of the Dahlia. — H.
Leitgeb has published in a botanical journal a curious account of
the Crystalline deposits in Dahha tubers, and these may possibly
be met with in other plants of the same group, many of which are
used in pharmacy. In order to exiiibit wliat he terms the " spsero-
crystals of inulin," sections of dahlia tubers are usually soaked in
alcohol. The author having allowed a tuber to soak for several
years in tliis liquid, finds the spheres of inulin with radial stripes
grouped in the peripheral region of the tuber. Besides these, he
has noticed spheres that are composed of an amorphous nucleus,
surrounded by an envelope formed of radiating needles. These
crystals, he tells us, abounded in the i)ith and inner portions of
the i)arenchyma. On being burnt they leave, after complete com-
bustion, a mineral residue of the same shape as the crystals, con-
sisting of phosphate of lime. The amorphous nucleus is not inulin,
nor fat, but some organic substance, the nature of which is unknown.

[ 170 I

lEmbr^o of a parasitic }£uto3oa from a

Ibinnan Zootb,

By Jabez Hogg, F.R.M.S., M.R.C.S., etc.

QUITE lately, a medical friend requested me to examine and
report on an interesting microscopical specimen, which it
appears had " puzzled " him a good deal, and he was
therefore the more anxious to learn something of its natural
history. The " worm," as he termed it, was removed from the
tooth of a domestic servant, who had suffered some time from
toothache and neuralgic pains of the face. The removal of a
molar tooth afforded only temporary relief At the end of three or
four months, and on finding medical remedies of no avail, she met
with a gipsy, who recommended her ■' to smoke the worm out of
the tooth with henbane seeds." She obtained the seeds, and having
placed them, as directed, on hot cinders, allowed the fumes to
pass into her mouth. In a very short time, " six or eight worms
dropped out of her teeth into a tumbler of water." This for a
time seems to have afforded her relief, but as the pain again
returned, and for which remedies proved unavailing, my friend,
on one of his visits, induced her to use the henbane fumigation
in his presence. In a very short time, "a minute v/orm " wriggled
from the mouth, and was caught in a tumbler of water. This he
carried away with him, and on his return home put it up in a
temporary cell, which was sent to me for examination. I may
first say that, so far as I know, no [jrecisely similar case has
been well enough authenticated to be placed on record.
Accounts have appeared, and to the effect that violent attacks of
toothache have been traced to a " worm " lodged in the cavity of
a decayed tooth. Furthermore, it has been said that the
" worm " has been " smoked out," as in the instance related, by
henbane seeds. Such statements have hitherto been regarded
wiUi a good deal of incredulity by the medical profession. I
may mention, however, that I have met with two or three well-
authenticated cases of " worms " lodged in the nasal cavities, and
there producing alarming symptoms, which have subsided after
the worms were dislodged by tobacco smoke.

PARASITIC ENTOZOA FROM A TOOTH. 171

It is no uncommon error, which my friend has fallen into, of
describing the specimen sent to me as " one of the worms."
It is, however, neither a worm nor a maggot, but a veritable
embryo of a parasitic entozoa. It belongs undoubtedly to the
Trematoda or fluke family, a class of animals well known to
infest mankind as well as the lower animals. The puzzle in this
case is. How did embryos of the fluke find their way into the
patient's decayed tooth ? Probably in one of two ways. In all
likelihood the ova of the fluke will have been conveyed into the
mouth and stomach by eating tainted or infected animal food, the
liver of a sheep suftering from fluke ; or the eggs may have been
taken in infected, j^olluted drinking water, more frequently,
however, in diseased meat, fish, or fowl, which during the
masticatory process is left behind and safely lodged in a hollow
tooth or an exposed portion of the alveolar process, there to be
retained until more fully developed into the wriggling embryo,
which was finally dislodged by the henbane fumigation. It is
quite witliin the bounds of possibility that the patient may have
unwittingly suffered from ascarides. In such a case, the ova or
embryos, during their ordinary larval wanderings in search of a
final resting place, which shall prove suitable for their adult
condition, might find their way back to the stomach, throat, and
mouth of the sufferer.

No fluke arrives at sexual maturity before passing through a
cercarian stage of existence, while its tailed or larval form is
usually acquired by passing through an intermediary host, a
molluscan, or water animal. It may be a fish. The little water-
snail, Limncza triincatula, is undoubtedly the host, in its transition
stage, of tlie liver fluke of the sheep, and the amount of these
snails, seen at certain periods of the year about marsh lands, in
river water, in cisterns, and ponds to which cattle and sheep
resort to allay their thirst, is enormous.

Altogether, five specimens of the dislodged larval flukes were
sent to me ; four of them, however, owing to the want of proper
precautions for their preservation, were spoilt, being completely
covered over by the mycelia of a minute fungus. The cover-
glass also of the mounted specimen was broken in the post, so
that I heartily wished my medical friend had been a member of

172 PARASITIC ENTOZUA FROM A TOOTH.

tlie Postal Microscopical Society. With a little difficulty I finally
succeeded in remounting the young cercaria in balsam, thus
rendering the body nearly transparent for microscopical examina-
tion. It measures nearly a sixth of an inch in length. Its head,
which is of a pale yellowish brown colour, is terminated by a
buccal opening of a contractile, sucker-like nature. The hyaline
integument of the body throughout is broken up by a series of
longitudinal and transverse markings, which presents an appear-
ance of irregularly shaped, tesselated cells. The ventral opening
is situated at the lower third, where a considerable cleft
occurs, and here is seen to be the termination of a narrow gut,
which runs from just below the buccal opening to this point,
and is then lost to view. The lower third of the body constitutes
what is nominally described as a tail-like appendage in the larval
stage, and which is either broken off or absorbed in the fully-
matured fluke.

Filaria have now been found in almost every cavity of the
body, either in man, or in the lower animals, and it is not difficult
to conceive how several of these minute embryos may have
become lodged in the cavity of a hollow tooth of one among a
class of persons who notoriously disregard the use of the tooth-
brush.

The insect world is vast almost beyond our concejition. The
President of the London Entomological Society states that while
Linnaeus knew only 3,000 species of insects 120 years ago, the
collections of the world probably include at present 200,000 or
250,000 species. Certain data lead to the inference that we do
not yet possess more than one-tenth of those existing, so that even
the jjrescnt rapid rate of discovery will not complete our collec-
tions of insects in less than 1,000 years. Before the end of that
period, many species of to-day will have become extinct, and the
President urges that those likely soon to disappear shoukl be
especially sought.

[ 173 ]

(The IPntholoo^ of pollen in HiEstivie, or

Iba^'^jfevcr.

By Prof. Samuel Lockwood, Ph.D.
Plate XV.

CERTAIN places in the White Mountains of New Hampshire
have become notable as summer resorts for sufferers from
^stivis, or Hay-Fever. A number of these sanitaria lie
more or less contiguous to the sources of the Saco river, on the
one side, and the sources of the Connecticut on the other.

When the South winds prevail in either of these long tracts,
there is a lowering of the barometer, and at the same time a
nervous depression of the subjects of Hay- Fever. There is also
another change in the atmosphere, which is then laden with the
dust-produce of these valleys. A marked element in this dust is
pollen, chiefly that of Rag-weed and Golden-rod, which, especially
the former, abounds in the South, in the months of August and
September. At such a time the suffering among the Hay-Fever
guests is severe and general. Happily it does not continue, but
passes off with the change of wind. On the theory of a ne?irosis
the cause seems plain to me. With the sudden humidity of the
atmosphere, and low barometer, the tonic of the mountain air is
dissipated, and nervous depression results. Then, since the air in
this condition is surcharged with pollen, and other impurities, the
nerve endings of the respiratory passages are irritated unto acute
inflammation.

At the closing session of the United States Hay-Fever Asso-
ciation, last September, at Bethlehem, N.H., a long-cherished
desire was revived to learn the relative hygienic quality of the
favoured sanitaria, and that of places where the malady prevails.
Owing to my official relation, it fell to me to state the factors in
such a determination.

The problem to be solved might be called the Hygiene of the
atmosphere. It would involve, all through, consideration based
upon instrumental work. This would need such records of the
winds, humidity, range of the barometer and thermometer, as fall
to the meteorologist. The impurities, organic and inorganic, of
the atmosphere must also be considered, which side of the work

174 THE PATHOLOGY OF POLLEN IN /ESTIVIS,

would fall to the microscopist. If density were added, this would
cover all.

A word as to the conveyability of material particles by the
atmosphere. There is something ad captanduiii in the splurge of
the lugubrious poet : —

" The dust we tread upon was once alive."
But, in the present tense, how true is this of the dust we breathe !
(.\an we not recall the painful interest excited by Tyndall's experi-
ments on the impurities of the atmosphere? And, for our
purpose, how easy to repeat some of them I Let a beam of sun-
light through a hole in the shutter enter a dark room. It ajipears
as a slanting, living column. I say living, for every particle seems
in motion, due to the incessant dancing movements of millions of
motes.

If now a small spirit-flame, yielding no smoke, be held under
this beam, there will soon be seen a dark hole right through the
column. Withdraw the flame, and soon the contiguous motes
dance into it ; it is again illumined, and the dark hole disappears.
If now we pass a red-hot bar through it, the beam will be divided
into two parts by a black space. The bar withdrawn, soon the
neighbouring motes dance into it, and the beam is all light

agam.

The deduction, for our purpose, is that the so-called impurities
present are chiefly organic, and the heat lun-ns them out. The
spores, infusoria, and microbic matter are thus destroyed — the air
literally being purified by fire.

All these things, even the mineral matter, constitute the aerial
dust so distressing to the sufferer from Hay-Fever. And I hold
that a prominent irritant in the air, during the Hay-Fever season,
is pollen.

But what is pollen ? It is the fertilizing granule produced by
the stamens of a flower. These granules vary greatly in size and
form in the different flowers. Some are smooth, others are angu-
lar, but those, with which this discussion wifl deal, are globular or
elliptical, spiny, and very minute. Not noticing the pollen of the
grasses, which particularly affect the early forms of the disease,
perhaps the most mischievous of the pollens are those of the Rag-
weed and the Golden-rods. I have here specimens of the plants :

OR HAY-FEVER. 175

Rag-weed, Ambrosia arUmiskefolia, T,., and the Golden-rods,
Solidai^-o allissima, L., ^. laiiccolafa, L., and S. sqiiarrosa, Mulil.,
which three forms are typical. I have here also, under these
microscopes, pollen of all these plants, mounted on slides ; also
here are enlarged drawings of the pollens.

Fresh Rag-weed pollen is very nearly spherical. The granule
measures in these specimens, which are a little distorted by long
drying, ^^^ inch in length by ^^ inch in width. In a fresh speci-
men, or such as floats in the summer air, so fine are the points of
the spines that they are to that of a cambric needle as it is to the
point of a marling-spike, or even a crowbar. And yet this object,
with its subtle armature, is literally invisible to the unaided sight.
See Plate XV., Fig. i.

The pollen-grains of the Golden-rods are sub-elliptical, both
ends being of the same size. They are very spiny, and the spines
are relatively longer than those on the pollen of the Rag-weed.
They are of two lengths on the same granule. The pollen of S.
altissima, the most abundant, in these parts, of the many species,
is in length -— inch, and in width j-^^,, inch. The flowers are in a
recurved panicle, not unlike the graceful spray of an ostrich plume.

An abundant species is the S. laiiccolafa, whose flowers are
borne in scattered corymbs, or flattish-topped clusters, something
in the manner of the Wild Carrot, which habit is in striking con-
trast with the Golden-rods generally. This pollen makes a
narrower ellipse than the one just mentioned, the two diameters
being ^ and ^ inch respectively.

S. sqiiarrosa is less common than the other two species. The
flowers are more conspicuous, and arranged in a showy wand, or
sceptre-like spike. Its pollen measures ^ by j^^ inch, hence it
is larger than that of S. altissima.

And exceedingly interesting is the end view, since it shows a
tripartite disposition, being as it were depressed at three points.
Now these depressions are simply the terminations of three longi-
tudinal canals on the sides. The end view is shown in Fig. 2 ;
and Fig. 3 shows one of the longitudinal grooyes. I find these
marks much fainter in S. altissima^ and barely discernable in S.
lanceolata.

176 THE PATHOLOGY OF POLLEN IN ^STIVIS,

We have now noticed three points which are pertinent to the
discussion, as will appear, namely : the minuteness of these
pollen-grains, their spiny armature, and the naked grooving at the
surface.

I. — The first effect noticeable of pollen then is due to its
presence in the air as an impurity. The granules are taken in at
breathing, as a foreign element. Except that it is more pungent,
their action is in common with that of other impurities— namely,
suffocating. " Advanced Hay-Fever is always more or less
asthmatic, and impurities in the air will cause spasms, and in some
instances even the odour of domestic animals will bring this
about.

2. — But pollen, taken into the respiratory tubes, is a mechanical
irritant. In severe Hay-Fever all the air passages are in a state of
inflammation. The starting spot is in the vicinity of the nares. At
first the patient does not dislike the tickling of the pungent grains
of titillating dust. But it very soon becomes serious, and nature
summons all the sternutatory forces to eject the intruders. So
violent does this sternutation become, and so long continuous,
that the blood is started from the nostrils. The mucous mem-
brane of the nose and the immediate air-passages become super-
sensitive. In fact, the entire mucous surface is soon in a scalded
state, and every nerve-ending is a participant of torture. Suppose
a person's back to be in that state of eczema, in which inflammation
has reached suppuration, and a thistle-bur to be put down the
back. The rest may be left to imagination. Now suppose that
a number of grains of pollen of Rag-weed, or Golden-rod, with
which the air is laden, to be inhaled, when the whole nasal region
and the ducts beyond are scalded with the incessant discharge of
acrid secretions. Is not ea jh one of these infinitesimal teasels a
lacerator of the tender and inflamed membrane } Hence, when
these enter in myriads, what a combination for exquisite torture !
I have been caught in a place where Rag-weed pollen was
prevalent in the air, and have been seized with sudden spasms, so
violent that I have had to cling to a fence for support under
suffering that was inexpressible.

3. — Besides being a mechanical irritant because of the spines,
I am persuaded that pollen has a toxic quality in Hay-Fever. In

oil HAY FEVER. 177

plainer words, it poisons the already inflamed tissues of the
respiratory passages. No one doubts that, to some persons, skin-
poisoning is a certainty, upon walking on the lee-side of the toxic
SuiP.ach, RJins venenata^ in its flowering time. Why not then a
toxic eff"ect of pollen upon the mucous linings already super-
sensitive, and even lacerated by their presence ?

In the old herbals the Solidago, as the word almost imj)lies,
had a reputation for vulnerable virtues, it bemg used in treating
wounds. One of the species, S. odorata, yields an aromatic oil
on distillation. It cannot, then, I think, be inert upon the surflice
of the inflamed and minutely lacerated mucous membrane.

The laceration facilitates the poisoning. But there is another
possibility in this matter. The copious nasal secretions, acrid and
warm — have they no power for extracting the toxic principle ?

4. — And, lastly, I am constrained to believe that pollen, in
ylCstivis, is a vital automaton — that it can, as a living organism,
perforate the mucous lining, actuated on the principle of a
pseudo-instinct ; not altogether unlike the Carrion-fly, when it
deposits its eggs, by mistake, on the decaying, nitrogenous fungus,
instead of putrid flesh. If we are to understand by instinct,
"inherited experience," it is to be found even in plants. It is true
that we are told how the Hop twines to the left, and the Scarlet-
runner to the right, but back of tlie "how" lies the "why?"
And occasionally we find a change of habit in an individual
plant, as left-handedness is found among rational beings.

I must be permitted now to deal with some elementary ideas
on the subject of fertilisation by the pollen-grain. In respect to
the several pollens herein described, each must be regarded as a
highly-organised cell, with a twofold shell — an outer rind, which is
thick, and carries the armature of spines ; and an inner one, which
is thin, in fact, a membrane, which is exposed at the surface in
grooves, spots, or pores, and these exposed places are always
smooth. In the Golden-rods, as shown in the figures, these
depressions are longitudinal grooves. The interior of the pollen
consists of a viscid life-stuff, or protoplasm, whose function is to
fertilise the ovule, at the base of the style in the pistillate flower.
To effect this, a curious play of the life-force sets in. The style is
composed in part of a loose, or more or less spongy tissue, while
New .Series. Vol. I. N

178 THE PATHOLOUY OF POLLEN IN .ESTIVLS,

the stigma at the top is charged with a saccharine, sticky mucilage.
A pollen-grain, borne by the wind, or an insect, usually, now falls
upon the stigma, and is anchored to it by the spines sinking into
the gum. The moisture causes the grain to swell. There is a
protrusion of the membrane at one or more of the thin places at
the surface, whence a tube, or root-like process, emerges, and
penetrates the stigma. It seems to be an extension in tubular
fwrm of the membrane, and is filled with the protoplasm of the cell.
If tlie kid-glove on a lady's hand could be pinched at the back,
and that nip of the glove pulled out or extended, and the flesh
could flow into this extemporised little pipe, it would roughly
represent the pollen tube. Having pierced the outer coat of the
stigma, this tubule, by a sort of growth, keeps on lengthening, and
pushing its way down through the loose tissue of the style, until it
has reached the ovule at the base, when its mission ends, and the
future seed of that flower is assured.

Now to return to my statement of mistaken instinct in the
insect. Pseudo -instinct is also found in plants, even in the initial
life-processes. The surcharged nectary of a flower may appear in
a place aoproachable to a pollen grain. Should the granule alight
upon that viscid spot, out would pop the pollen-tube, with the
usual effort to pierce the epidermis of the flower, but in vain.
Indeed, we can easily deceive the pollen-grain, by dropping it upon
moistened sugar, and even witness this out-put of the tubule.

The point I would now make is this — that a similar pseudo-
instinct prevails with the pollen-grain, when it is inhaled, and falls
upon the moist and tender tissues of the inflamed linings of the
respiratory passages. All the favouring conditions are there — mois-
ture, softness, and warmth. Hence results an instinctive protrusion
of the pollen-tube into the puffy, inflamed, and exquisitely sensitive
tissues. I think this parasitical action has to do with that acute
stinging sensation in the nostrils so frequent in ^^stivis.

Thus have been instanced four possible modes of action for
pollen in Hay-Fever.

I. — Its suffocating effect as an impurity of the atmosphere,
thus exciting asthma.

2. — As a mechanical irritant begetting inflammation, even to
excoriation of the mucous membrane.

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OR HAY FEVER. 179

3. — As a toxic agent, poisoning the tissues.

4. — As a pseudo-parasite, penetrating the soft and sensitive parts.

It should be added that these activities are here supposed to
operate upon the system while in an abnormal state. In a word,
behind all there is a Hay-Fever neurosis. As the nasal ducts are
the first to show suffering in Hay-Fever, and the malady thence
extends to all the respiratory organs, as well as other parts of the
system, I think it bodes good that in addition to the long-known
" Laryngological Association," the medical fraternity have effected
a new organisation under the name " Rhinological." This new
society is to concern itself with the ailments of the nose, hypothe-
cating the fact that diseases of the throat and larynx almost always
have their origin in the nasal region.

EXPLANATION OF PLATE XV.

Fig. 1. — Pollen of Rag-weed, Ainhrosia artemisicefolia , L. : size, 7^^ by
7^0 inch.
,, 2. — Pollen of Golden-rod, Solidago squarrosa, Muhl. : end view,
showing spines of two lengths, and trilobate depressions ; size,
-^ by j^ inch.

,, 3. — Pollen of <S. squarrosa : side view', showing one of the three
longitudinal grooves, which in Figure 2 are indicated by the
trilobes.
,, 4. — A diagram of a group of pollens of S. squarrosa. Two are
side views, and six are end views.
The figures are necessarily diagrammatic. For Figures 1, 2, and 3,
I am indebted to Dr. Alfred C. Stokes.

(From the Journal of the New York Microscopical Society.)

Mr. Fred. Enock, of 11 Parolles Road, Upper Holloway, Lon-
don, has sent us a number of his very excellent Lithographic sketches
by which his slides are accompanied. We have also received from
him slides of vertical section through the cephalothorax and abdo-
men of the Garden Spider, Epeira diadema, showing the brain, heart,
liver, spinnerets, silk glands, and other internal organs ; Head of
Devil's Coach-Horse Beetle, Ocypus olens, mounted without pres-
sure, showing organs of the mouth in the natural form and colour;
the Bed Bug, Cimex lecfularius, showing internal and muscular
structure; and the beautiful Fairy Fly, Camptoptera papaveris, one
of the smallest winged insects, being only about one-fiftieth of
an inch long from head to tail. Mr. Knock's slides are the perfec-
tion of mounting.

• [ ISO ]

1balf=='an^1boiir at tbc HDicroecopc,

limtb /Hbr. Uutfcn Meet, ^.X.S., jf.1R./in).S., etc.

Plates XVI., XVII, XVIII.

Marine Diatoms, in situ (Plate XVI., Figs, i — 5). — This slide
may be likened to a thoroughly good girl — homely at first sight,
but constantly revealing new beauties as you seek to study her
character. It shows some points in structure which I have never
seen so well displayed before, and is worth many times over the
fancy things got up as " Selected Diatoms " to show the skill of
the mounter. There are five species present, which are named.
It is interesting to reflect that all these thousands of Synedra and
Cocconeis may by gemmation have come from a single individual
in each case, united for a time by, and subsequently pushed apart
through, the development of a protoplasmic investment. As we
survey their countless numbers, we can only liken them to the
leaves on a tree. It has been well said that Nature does her
greatest works through the agency of the smallest instruments.
We have here an apt illustration of it.

Hairs of Viburnum Lantana (PI. XA^L, Fig. 7, Mealy
Guelder Rose) make a very interesting slide of a class which is,
so far, new to our circulating boxes. Stellate hairs are mostly
sessile. In the example before us, however, the stellulas are evi-
dently seated on low stalks I hope the owner of this slide will
pursue the study of " Plant-Hairs " systematically. It is one
which, worked out seriatm, will yield results both interesting and
valuable. I remember noticing with surprise hairs of not less
than five well-marked types on the flower of the Snapdragon,
Antirrhimun majus. A good summary of the subject will be
found in the " Micrographic Dictionary," and scattered notes on
it in various places in Science Gossip.

Caprella linearis (PI. XVI., Fig. 6) belongs to the Order
Lccviodipoda among the Crustacea. The specimen here is a male.
The abdominal leaflets, in the female, form a marsupium or pouch,
in which, as with many other Crustaceans, the ova are borne, and
to which the young retreat when alarmed till they are able to shift
for themselves. Rymer Jones ("Outlines," p. 388, ed. 1861)
instances this as one of the most completely annulose forms
amongst the Crustacea. In Routledge's " Popular Natural His-
tory " (p. 628), the editor, the Rev. J. G. Wood, gives the follow-
ing very interesting extract from Gosse, after remarking on
CaprcUa linearis, or the Mantis shrimp : — " There are several
species belonging to this genus, and all possess similar habits.
Their bodies are, indeed, skeleton-like in their bony lankness, but

HALF-AN-HOUK AT THE MICROSCOPE. 181

their appetites are by no means small in proportion to their size.
Indeed, as is often the case with peculiarly meagre human beings,
they are most voracious, preying incessantly on every small
creature that comes in their way. They are furnished with terrible
instruments of prehension, their first and second pairs of legs
being devoted wholly to this purpose. The last joint but one is
enormously large, and the last joint is thin, and shuts down like
the blade of a clasp-knife into its haft, the groove being repre-
sented by a double row of spines, between which the blade is
received. The blade itself is finely notched along the edge.
These claw-like terminations to the legs are used, not only for
seizing prey, but for grasping the branches and drawing the long,
attenuated body from one part to another."

Mr. Goss, who has paid much attention to these curious
beings, remarks that their movements among the marine vegeta-
tion are wonderfully like those of the spider-monkeys among the
branches, their long, thin bodies adding to the resemblance.
They run about with great agility, and are always to be found
among the branches of the Plumatella cristata* The same
writer has given a very interesting history of the Mantis-Shrimp : —
" Their manners are excessively amusing. The middle part of
their body is destitute of limbs, having, instead of legs, two pairs
of oval, clear vesicles ; but the hinder extremity is furnished with
three pairs of legs armed with spines, and a terminal hooked
blade like that already described. With these hindermost legs the
animal takes a firm grasp of the twigs of the polypidom, and
rears up into the free water its gaunt skeleton of a body, stretch-
ing wide its scythe-like arms, with which it keeps up a see-saw
motion, swaying its whole body to and fro. Ever and anon the
blade is shut forcibly upon the grooved haft, and woe be to the
unfortunate infusorium, or mite, or rotifer, that comes within that
grasp. The whole action, the posture, figure of the animal, and
the structure of the limbs, are so closely like those of the tropical
genus. Mantis^ among insects, which I have watched thus taking
its prey in the Southern United States and the West Indies, that I
have no doubt passing animals are caught by the crustacean also
in this way, though I have not seen any actually secured.

" The antennae, too — at least, the inferior pair — are certainly,
I should think, accessory weapons of the animal's predatory
warfare. They consist of four or five stout joints, each of which
is armed on its inferior edge with two rows of long, stiff, curved
spines, set as regularly as the teeth of a comb, the rows divaricat-

* Note by Tiiffen West : — " If there be no error in this description, it
must apply to a fresh-water species, as Plumatella cristata is a synonym of
Alcyonella stagttorum."

New Series. Vol. I. o

182 HALF-AN-HOUR AT THE MICROSCOPE.

ing at a rather wide angle. From the sudden clutching of these
organs, I have no doubt that they, too, are for seizing prey, and
very effective instruments they must be, for the joints bend down
towards each other, and the long rows of spines interlacing must
form a secure prison, like a wire cage, out of which the jaws pro-
bably take the victim, when the bending-in of the antennas has
delivered it to the mouth.

" But these well-furnished animals are not satisfied with fishing
merely at one station. As I have said above, they climb nimbly
and eagerly to and fro, insinuating themselves among the branches
and dragging themselves hither and thither by the twigs. On a
straight surface, as when marching (the motion is too free and
rapid to call it craic/iiig) along the stem of a zoophyte, the crea-
ture proceeds by loops, catching hold with the fore-limbs, and
then bringing up the hinder ones close, the intermediate segments
of the body forming an arch, exactly as the caterpillars of geome-
tric moths, such as those, for example, that we see on gooseberry
bushes do. But the action of the crustacean is much more ener-
getic than that of the caterpillar ; indeed, all its motions strike me
as full of vigour and energy.

" I have seen the large red species swim, throwing its body
into a double curve like the letter Sj with the head bent down
and the hind limbs turned back, the body being in an upright
position. It was a most awkward attempt, and though there was
much effort there was little effect."

I have no doubt members would be able to keep these crusta-
ceans in an aquarium, and would find very interesting material for
study in watching their life-habits and especially their develop-
ment. A member at Fareham tells me that specimens appeared
occasionally in water drawn by a fresh-water pump — an estuary of
the sea, perhaps— a quarter of a mile from the pump, but evi-
dently having underground communication with the basin whence
the soft water came. I have found C. linearis abundantly in tidal
pools at Ryde, Isle of Wight.

Haematopinus suis. — This specimen appears to have been
prepared by simply soaking for a time in turpentine and then
mounting in balsam. This plan was recommended long ago by
Cornelius Varley in the London Physiological Journal, Vol. I.,
184 1, p. 31. By adopting it, important details of internal struc-
ture, destroyed by the plans most in vogue now, of steeping in
liqzi07- pofassce, may be beautifully retained. I allude in the
present instance to the supra- and sub- oesophagal ganglia and
nerves proceeding thence to the eyes, the antennae, and the oral
organs. The female differs little outwardly from the male, except
for the cleft vulva.

CORRESPONDENCE. 183

[We much regret that we are unable to complete Mr. Tuffen West's
valuable Notes in the present issue. The remainder, with the
"Selected Notes from Note-Books " having reference thereto, with
the explanation of Plates XVI., XVII., and XVIIL, will be
given in our next. — Editor?^

Corrceponbcnce.

\The Editor does ?iot hold himself responsible for the opitiions or
statements of his co-respondents^

Sir,—

In the Journal of Microscopy, etc., for April, Mr. Wheatcroft
draws special attention to the fact that in studying the plant-
remains found in Egyptians tombs, Dr. Schweinforth has not
been " able to detect any peculiarities in the living plants which
are absent in those obtained from the tombs." Mr. Wheatcroft
says these specimens were gathered at least four thousand years
ago, and he thinks it " would be difficult to produce better
evidence of permanency of type." Precisely this argument was
used with reference to the theory of permanency of type in
animals. We v/ere told that the domestic cat, whether in the
mummical state or in its pictured representations, was just the
same in that remote Egyptian age as it is at the present day.
But we know now that instead of finding permanency of type as
the prevailing law amongst animals, we find species and orders
fading into one another like dissolving views as we penetrate
further back into the abyss of time. The changes are very
gradual ; to lose a tooth would be far too sudden a transition.
One cusp disappears, and then another ; then the tooth appears
later, grows smaller, decays early, and finally disappears altogether.
The same gradual changes occur in the modifications of the whole
skeleton, but most noticeably in the limbs. The cat, so " exactly
like " our cat of the present day, changes by almost imperceptible
degrees into an animal which is neither cat nor weasel, but the
progenitor of both ; the dog into an animal which is neither bear
nor dog, but which has some characteristics of the two modern
species.

It is difficult to imagine how any paleontologist of the present
day could expect that an animal would be likely to change
perceptibly in such a brief second of geological time as four
thousand years. The whole of the Tertiary period can only be

184 CORRESPONDENCE.

expressed as a fraction when compared with the vast ages which
must have elapsed wliilst the paleozoic and the mesozoic rocks
were laid down ; and the post-tertiary, when man (as we know
him) and the modern species of animals took their rise, is a mere
insignificant sediment compared even to the tertiary period.
How, then, shall we express the geological_insignificance of the
human historical period ?

Under domestication, it is true that the progress of evolution
is more rapid than under normal circumstances. Yet man, so far
as I am aware, has only succeeded in accelerating the evolution of
one new family, that of the domestic dog, which can be traced
through distinct lines of descent from the wolf and jackal. But
the domestic dog becomes a true dog long before the oldest
Egyptian mummy received its wrappings ; ^the cat, a far more
modern and highly specialized carnivore, has not had time to
change since it was first domesticated.

What has all this to do with plants ? may fairly be asked. I
do not pretend to any acquaintance with paleobotany, but I
cannot help thinking that the laws which govern one great branch
of living beings govern also the other, and that as animals vary by
slow degrees during the vast ages of geological time, so plants
must also change. We see cultivated plants alter just as rapidly
under the hand of man, as domesticated animals; we see the
forest tree of warm regions become the creeping shrub of Arctic
climes ; therefore, we know that vegetable forms vary with the
action of their environment as do animals. There is also the
same tendency to the late evolution of higher forms which we see
in animals, and a tendency in some of the lower forms to dwindle
away ; as witness the giant calamites of the coal forests^ as com-
pared with the pigmy horsetails of the present day. The Equiseta
are to the calamites much what the modern newt is as compared
with the ancient labyrinthodont. My contention is not as to any
point of paleobotany, of which I am certainly not qualified to
judge, but only as to the utter insufificiency of the^time which has
elapsed since Egypt was a civilised kingdom, to^ produce' new
species of either animals or plants.

Should anyone wish to see how almost imperceptibly, but how
surely, Nature works in altering " types," I would refer him to
some of the later lectures of Professor Cope, in his " Origin of
the Fittest." A more popular account is given by Oscar Schmidt
in "The Mammalia" International Scientific Series.

Yours faithfully,

Alice Bodington.

Vancouver.

[ 185 ]

1Rcvic\\)0»

Journal of Morphology. Edited by C. O. Whitman, with

the co-operation of Edward I'helps Allis, jun. No. 2 ; pp. 193. (London:
W. P. Collins, Great Portland Street. Boston, U.S.A. : Ginn and Co.)

The second part (completing Vol. I.), 419 pp., is just to hand. It contains
five valuable papers, which treat of the Kinetic Phenomena of the Egg during
-Maturation and Fecundation (Ookinesis), by the editor, C. O. Whitman ; The
Embryology of Petromyzon, by Dr. W. B. Scott, of Princeton College, N.J. ;
a contribution to the Embryology of the Lizard, by Dr. Henry Orr, of Prince-
ton, N.J. ; The Foetal Membranes of the Marsupials, by Dr. IL F. Osborn,
of Princeton, N.J. ; and Some Observations on the Mental Powers of Spiders,
by George W. and Elizabeth G. Peckham, of Milwaukee, Wis. There are 7
double and 3 single plates. Prof. C. O. Whitman has been for many years
editor of the microscopical section of the American Na/icralist. We feel that
we cannot say too much in praise of this work.

The Origin of Floral Structures through Insect and other
Agencies. By the Rev. George Henslow, ^LA., F.L.S., F.G.S., etc. Crown
8vo, pp. xix. — 349. (London : Kegan, Paul, Trench, and Co.) Price 5s.

This is the sixty-fourth volume of the Liternational Scientific Series. The
author thinks we must look to the environment as furnishing the influences
which induce plants to vary in response to them. His object has been to
endeavour to refer every part of the structures of flowers to some one or more
definite causes arising from the environment taken in its widest sense. The
book contains eighty-eight illustrations.

Nature's Fairyland ; or, Rambles by Woodland, Meadow,

Stream, and Shore. By H. W. S. Worsley-Benison, F.L.S., etc. Crown 8vo,
pp. viii.^232. (London : Elliott Stock. 1888.) Price 5s.

We have read few books which have afforded us greater pleasure than the
volume now before us. That Mr. Worsley-Benison is a thorough and "all-
round " naturalist is plainly shown in the twenty-one chapters of which the
book is composed. These treat of widely different subjects. For instance,
we find four or five chapters on Botanical subjects, two or three on Spiders,
others on Waves, Rambles on the Dorset Coast, Fishes, The House- Fly's
Story told by herself, etc. We would strongly urge any young person about to
commence the study of botany to read carefully the three chapters entitled
" From Root to Flower," " Out among the Gorse," and " Companions of the
Corn." These chapters give, in a peculiarly interesting manner, some import-
ant facts in plant anatomy, told in a style which will engrave itself on the
mind of the student. All lovers of Nature will do well to read this book.
Its subjects are well varied and most interesting.

Forms of Animal Life : A Manual of Comparative Ana-
tomy, with descriptions of Selected Types. By the late George RoUeston,
D.M., F.R.S. Second edition, revised and enlarged by W. Hatchett Jackson,
M.A. Royal 8vo, pp. xxxii. — 937. (Oxford: Clarendon Press. London:
Henry Frowde. 1888.)

This edition was taken in hand by the late Prof. Rolleston in the Long
Vacation of 1879, and was carried on by him until he left England in Dec,
18S0, by which time he had completed the descriptions of Preparations I — 9,
and 3 new plates had been engraved under his direction. The distinctive cha-
racter of this book, as described in the preface to the first edition, consists in

186 REVIEWS.

its attempting so to combine the concrete facts of Zootomy with the outlines of
systematic classification as to enable the student to put them for himself into
their natural relations of foundation and superstructure. The foundation may
be made wider, and the superstructure may have its outline not only filled up,
but even considerably altered by subsequent and more extensive labours ; but
the nuitual relations of the one as foundation and of the other as superstruc-
ture, which this book particularly aims at illustrating, must always remain the
same. There are 14 excellently engraved plates.

The Elements of Botany for Beginners and for Schools.
By Asa Gray. 8vo, pp. 226. (New York and Chicago : Ivison, Blakeman,
and Co. 1887.)

This work of the late well-known author is intended to ground beginners
in Structural Botany and the principles of Vegetable life, mainly as concerns
Flowering or Phanerogamous plants, and to be a companion and interpreter to
the Manuals and Floras by which the student threads his way to a clear know-
ledge of the surrounding vegetable creation. We have the greatest confidence
in recommending this book. The last thirty-four pages are occupied by a
valuable glossary.

A History of Photography, written as a Practical Guide

and an Introduction to its Latest Developments. By W. Jerome Harrison,
F.G.S. ; with an Appendix by Dr. Maddox on the Discovery of the Gelatino-
Bromide Process. Svo, pp. 144. (Bradford : Percy Lund and Co. London :
Triibner and Co. 1SS8.)

The volume before us gives, as its title implies, a consecutive account of
the principal processes which have been employed in photography during the
brief half-century of its practical existence. In its 27 chapters we have an
account of the Origin of Photography, Some of its Pioneers, The Daguerreo-
type, The Callotype, and Collodion Processes, etc. The work is further illus-
trated with 12 photo-mechanical plates, portraits of some of the fathers of
photography, Short biographies of some are also given.

Photo-Engraving, Photo-Etching, and Photo-Lithography, in
Line and Half-Tone ; also. Collotype and Heliotype. By W. T. Wilkinson,
of London. Revised and enlarged by Edward L. Wilson. American (third)
edition. Crown 4to, pp. xvi. — 184. \New York : Edward L. Wilson. 1S88.)

In this handsomely got-up volume the author has made many additions to
his last English edition. Mr. Wilson has added further to the value of the
work by " boiling down " and incorporating the best points from current publi-
cations in France and Germany. Chapters and parts from the Handbnch der
Cheniigraphie titid Pliotochcmigraphie, bj' Mr. J. O. Morch, have also been
added, making the work complete up to date.

The volume is divided into six parts, viz. — Photo-Engraving in Line, in
Ilalf-Tone, and on Copper; Photo-Lithography in Line and in Half-Tone;
and Collographic Printing.

Familiar Animals and their 'Wild Kindred. By John Mon-
seith, ALA. Crown Svo, pp. 208. (Cincinnati and New York : Van Ant-
werp, Bragg, and Co.)

This is a school reading-book (third-reader grade). It conducts the reader
by a natural link of association from the more familiar to the less familiar facts
about animals. The publishers have evidently spared no expense in presenting
a large number of accurate pictures of the more prominent subjects of the text.

REVIEWS. 187

An Easy Guide to Scripture Animals, being a Description
of all the Animals mentioned in the Bible. J>y Vernon S. Morwood. Crown
8vo, pp. 184. (London: John Hogg.) Price is. 6d.

The animals are described in alphabetical order. After the description
will be found a series of questions which will assist the memory, Bible refer-
ences, and an anecdote. There are thirty fairly good illustrations and a
vocabulary explanatory of words used in the book. The book is designed and
very suitable for school and home use.

Sunlight. By the author of " The Interior of the Earth."
Second edition, with alterations and additions. Crown Svo, pp. xii. — ^180.
(London : Triibner and Co. 1887.)

Perhaps we cannot better describe this clever little work than by quoting
the concluding words of the author's preface : — " In the confusion now exist-
ing there is ample room for the serious consideration of my simple suggestion,
that light was the first cause of the creation of the earth, acting on a nebulous
mass that held in it gases or material sensitive to, absorptive and retentive of
that light."

Mechanics and Experimental Science, as required for the
Matriculation Examination of the University of London. By Edward Ave-
ling, D.Sc. Crown Svo, pp. viii. — 263. (London: Chapman and Hall.
1888.) Price 6s.

This is one of the series of Science volumes, which the author is bringing
out specially to meet the requirements of students practising for the London
Matriculation Examination under the new regulations which have just come
into force. The present work treats of mechanics, and a great feature of the
book is the very lucid explanations given to each branch of this, to many
young students, difficult study. It is divided into three sections, under the
titles of Kinematics, Dynamics, and Statics. The chapters on " Acceleration,"
"Falling Bodies," "Composition and Resolution of Velocities," for example,
are so carefully handled, and the specimen questions so fully worked out, that
we confidently recommend the book to private students, feeling assured that it
will help them. Besides numerous examples, a number of London, Cam-
bridge, and other examination papers are given at the end of the book.

Educational Topics of the Day : Chips from a Teacher's
Workshop. By L. R. Klemm, Ph.D. pp. 408. (Boston: Lee and She-
pard. 1888.)

Many of the articles in this book have appeared in some of the leading
educational journals in America. In them the author gives us his mode of
thinking and discussing and his manner of teaching. Those engaged in educa-
tion will doubtless consider some of these chips worth preserving. The book
is divided into ten chapters, among which we find " Some Principles and
Methods of Teaching," " The Art of Questioning," etc.

Notes on the Birds of Herefordshire. Contributed by
Members of the Woolhope Club. Collected and arranged by the late Henry
Graves Bull, M.D., etc. 8vo, pp. xxx. — 274. (London: Hamilton, Adams,
and Co. Hereford : Jakeman and Carver. 1888.)

These notes are not a formal treatise on the structure and classification of
the birds of Herefordshire, but rather familiar reminiscences of homely
favourites, notices of their every-day habits, and of the superstitions connected
with them, with many amusing anecdotes derived from personal observation.
Dr. Ball delighted in tracing out the allusions to birds which may be found in

188 REVIEWS.

our literature, especially in the poets, and very numerous quotations of this
kind are found in these pages. An excellent photographic portrait of Dr. Bull
forms a frontispiece to the vol.

A Catalogue of Canadian Birds, with Notes on the Distri-
bution of the Species. By Montague Chaml)erlain. Crown 4to, pp. v. — 143.
(St. John, N.B., Canada: J. & A. McMillan. 1SS7.)

This catalogue Ijrings together the names of all the birds that have been
discovered within the boundaries of the Dominion of Canada, from the Atlantic
Ocean to the Pacific, and North to the Arctic ; and presents these on the
system of nomenclature, and in the sequence now generally adopted by Ameri-
can Ornithologists, and gives the geographical distribution of each species.

Volcanoes and Earthquakes. By Samuel Kneeland, A.M.,

M.D. Crown 410, pp. 220. (Boston, U.S.A. : D. Lothrop Company. 1888.)
We have here a popular account of Earthquakes and Volcanoes, their
nature, causes, effects, and geographical distribution, from personal observa-
tion in the Hawaiian and Philippine Islands, Japan, Iceland, and the Mediter-
ranean Basin, Spain, and the United States.

Being for the most part the author's own observations in the countries
described, they of course partake largely of personal adventure, and are
exceedingly interesting. The illustrations are from photographs and drawings
made on the spot, and the whole work is handsomely got up.

Natural Resources of the United States. By Jacob
Harris Patton, M.A., Ph.D., etc. 8vo, pp. xvi. — 523. (London : W.
Allen and Co., Paternoster Square. New York : D. Apperton and Co. 1888.)

In the interesting volume before us, we have a concise narrative of the
natural resources of the United States in all their numerous forms — e.g.. Coal,
Petroleum, Natural Gas, Iron, Gold, Silver, Mercury, Copper, Lead, Zinc,
Tin, Precious Stones, Clays, Building Stone, Graphite, Salt, Mineral or
Medicinal Springs, Timbers, Grasses, Fruits, etc. etc. The author says : —
" These resources are remarkable for their vastness, but equally striking has
been the providential care which provided, under such peculiar circumstances,
a Christian people — lovers of liberty, civil and religious — to occupy the goodly
land, and by their energy and industry to bring into practical use these varied
treasures."

The Pleasures of Life. By Sir John Lubbock, Bart., M.P.,

F.R.S., D.C.L, LL.D., etc. Ninth edition. lamo, pp. viii. — 19S. (London:
Macmillan and Co. 1888.) Price is. 6d.

A series of interesting and instructive addresses delivered by the
author at special gatherings of schools and colleges. They embrace a variety
of subjects — The Duty of Happiness, The Happiness of Duty, A Song of
Books, The Choice of Books, The Blessing of Friends, The Value of Time,
and several others.

Year-Book of the Scientific and Learned Societies of

Great Britain and Ireland, comprising lists of the papers read during 1887.
8vo, pp. 256. (London: Charles Griftin and Co. 1888.) Price 7s. 6d.

This is the fifth annual issue of this very useful year-book, and contains
in addition to the names of the officers, and lists of the papers read during
1887, before Societies engaged in all departments of research, with the names
of their authors, an appendix comprising a list of the leading Scientific
Societies throughout tlie world, occupying some twenty-four pages. The Vear-
Book is a most valuable publication.

REVIEWS. 1 89

The Foundation of Death : A Study of the Drink Question.
By Axel Gustafson and Zadel Barnes Gustafson. Fifth edition revised, 8vo,
pp. xxxi. — 566. (London : Ilodder and Stoughton. 1888.)

The authors of the Iraok before us have treated the subject in a thoroughly
exhaustive manner. The work is divided into thirteen chapters, which treat of
Drinking among the Ancients, History of Distillation, Adulteration, The
Physiological, Pathological, and Moral Effects of Alcohol, etc. etc.

Pre-Glacian Man and the Aryan Race. By Lorenzo Burge.

Crown 8vo, pp. 272. (Boston, U.S.A. : Leeand Shepard. 1S87.) Price $1.50.

Perhaps we cannot better describe this book than by quoting its somewhat
quaint title more at length : —

" A History of Creation, and of the Birthplace and Wanderings of Man in
Central Asia, from B.C. 32,500 to B.C. 8,000, with a history of the Aryan race,
commencing B.C. 15,000, their rise and progress, and the promulgation of the
first revelation ; their spiritual decline, and the destruction of the Nation B.C.
4,705, the inroad of the Turanians, and the scattering of the remnant
of the race, B.C. 4,304, as deciphered from a very ancient document.
Also, an exposition of the law governing the formation and duration of the
great glacial period, and a record of its effects on Man, and on the configura-
tion of the globe ; a chapter on the Deluge : its cause, locality, and extent ;
and an account of the ' Cannes Myth.' "

Introduction to Physical Science. By A. P. Gage, Ph.D.

Post 8vo, pp. viii. — 353. (Boston : Ginn and Co. 1888.)

The author tells us it has been his aim to adapt the book to the require-
ments and facilities of the average high school, and he has endeavoured to
bring the subjects within the comprehension of the ordinary pupil, without
attem])ting to " popularise " them by the use of loose and unscientific language.

The work contains upwards of three hundred good illustrations.

Among the Cannibals of New Guinea, being the Story of

the New Guinea Mission of the London Missionary Society. By Rev. .S.
McFarlane, LL.D., F.R.C.S. Post 8vo, pp. 192. (London: London Mis-
sionary .^ociety. John Snow and Co. 1888.) Price 5s.

We have here most interesting accounts of the Home of the Cannibals,
How we get at them. Exploration and Opening up of the Country, Manners
and Customs of the Cannibals, etc. etc. The book is illustrated with a series
of original drawings by an artist who has visited the island ; it contains also
portraits of the author, and of two other pioneers of the New Guinea Mission.

The Works of Hubert Howe Bancroft : The Native
Races of the Pacific States. Vol. L, Wild Tribes. 8vo, pp. xlix. — 797.
(London: Triibner and Co. San Francisco : The History Publishing Co.)

This volume, which is the first of a long series of historical works, evinces
a vast amount of research, no fewer than twelve hundred authors, a list of
whose writings are given, having been consulted in writing " The Native
Races." In it are given the manners and customs, occupation, food, dress,
dwellings, social habits, etc., of all the ruder nations from Alaska to Panama.
The first chapter is an ethnological introduction, after which the author
describes the physical and mental characteristics of the Native Races of the
Pacific States under seven distinct groups : — i. Hyperboreans ; 2, Columbians;
3, Californians ; 4, New Mexicans; 5, Wild Tribes of Mexico ; 6, Wild
Tribes of Central America ; 7, Civilised Nations of Mexico and Central
America. The last are not alluded to in the present volume. Several good
maps are given, and the whole work will doubtless prove of great interest.

1 90 REVIEWS.

A Practical Treatise on the Diseases of the Hair and
Scalp. By George Thomas Jackson, M.D. 8vo, pp. 356. (New York : E.
B. Treat. 1887.) Price S2.45.

This work discusses the various phases pertaining to the care of the scalp

and hair, and to the treatment of its diseases, parasitic and non-parasitic. The

hygiene of the hair is fully described, and directions given for its care. It is
addressed to the Medical profession.

The Twelve Tissue Remedies of Schiissler, comprising the

Theory, Therapeutical Application, Materia Medica, and a Complete Reper-
tory of these Remedies. Arranged and compiled by William Boericke, M.D.,
and Willis A. Dewey, M.D. Royal Svo, pp. 303. (Philadelphia: F. E.
Boericke. 1888.)

We are told that the treatise before us contains all that Schiissler himself
wrote on the subject, and embodies as well the whole published experience of
the homoeopathic school in their use, besides much original matter from
homoeopathic practitioners published for the first time.

Ambulance Lectures, to which is added a Nursing Lecture
in accordance with the St. John Ambulance Association, for Male and Female
Classes. By John H. Martin, M.D. Second edition. Post Svo, pp. xii. — 136.
(London : J. and A. Churchill. 1888.) Price 2s.

The six lectures of which this little work is composed were delivered to
separate classes of both sexes during the winter of 1885 — 6. The subjects of
the different lectures are The Human Body and its (Construction, Haemorrhage,
Fractures, Shock or Collapse, Methods of Lifting and Carrying the Sick and
Injured, and Nursing. There are 59 illustrations.

First Principles of Modern History. i2mo, pp. 140.
Price IS.

How TO Spell AND Speak English. i2mo, pp. 32. Price is.

A Simple Catechism of the Animal, Vegetable, and Mineral
Kingdoms, pp. 72. Price gd.

English Grammar for Beginners. Part L, The Parts of
Speech. By John Hugh Hawley, M.C.P. Post Svo, pp. 29. Price 6d.

Dates made Easy : A Mnemonic Synopsis of the History of
England. By John Hugh Hawley, >LC.P. Post Svo, pp. 32. Price 6d.

Lesson-Pegs. Second edition. Small 4to. Price is.

A Geographical Text-Book for Beginners. By William B.
Irvine. Fifth edition. 4to. Price is.

(London : Relfe Bros., 6 Charterhouse Buildings.)

Messrs. Relfe Bros, have sent us a small library of useful little books, all
well suited for school use. The Modern History treats of Home, Imperial,
and Foreign Politics and Social Progress, and impresses on the youthful mind
something of the grandeur of the British Empire. How TO Spell AND
Speak English contains a sketch of the History of the Language, and as a
frontispiece a Tree representing the Indo-European or Aryan Family of Lan-
guages, containing 8 principal branches or groups. The Catechism of the
Animal, Vegetable, and Mineral Kingdoms is nicely adapted to the capacities
of young children, and has reached its 7th edition. The Geographical
Text-Book contains a large amount of useful information, concisely given,
and twelve nicely-coloured plates.

REVIEWS. 191

Manual of Pharmacy and Pharmaceutical Chemistry.
By Chas. F. Heebner, Ph.G. Crown 8vo, pp. 213. (New York : Published
by the Author, 5 Gold Street. 18S7.) Price §2.

This work, though intended for the American pharmacist, contains a good
deal of information likely to prove serviceable to the English student of phar-
macy. Metrology, Specific Gravity, and Volume receive careful notice, and
we think the Chemistry and Pharmacy are of high order. The articles on
Percolation and the Preparation of Fluid Extracts will also be found useful.

Talks with Young Men. By J. Thain Davidson, D.D.
Crown 8vo, pp. viii. — 286. (London: Hodder and Stoughton. 1888.)
Price 3s. 6d.

A series of twenty familiar addresses, delivered in one of our London
churches to young men at their monthly Sunday evening service. These
" Talks " are plain and homely, and each lecture is full of interest.

British Birds and their Nests and Eggs. By W. Harcourt-
Bath. With a Chapter on Collecting and Preserving Birds, by R, Bowdler-
Sharpe, F.L.S., F.Z.S., etc. Crown 8vo, pp. 112.

Silkworms. By Edward A. Buder, B.A., B.Sc. Crown 8vo,
pp. loo. (London: Swann Sonnenschein and Co. 1888.) Price is. each.

These are two of the useful series of little books known as " The Young
Collector Series." In the first of these, Mr. Bath describes a great number of
our British Birds ; he gives us also a classified list of upwards of 400 British
birds, with their scientific as well as common names. ]\Ir. Sharpe gives at the
end of the book some valuable hints on collecting and preserving birds.

In the volume on "Silkworms," we have a History of Silk-Culture, with
the Life-History of the Silkworm, its Internal Structure, its Rearing and
Management, and its Diseases. Both books are nicely illustrated.

Home Experiments in Science for Old and Young : A
repertory of simple experiments with home-made apparatus. By T. O'Conor
Sloane, E.M., A.M., Ph.D., etc. Crown 8vo, pp. 261. (London : Sampson,
Low and Co. 1888.) Price 6s.

The object of the author has been to show such experiments as can be per-
formed with home-made apparatus, or without any special apparatus at all. A
great number of interesting and instructive experiments are described in a plea-
ing manner — thus we have Experiments in Mechanics, in Gravitation, Hydrau-
lics and Pneumatics, in Molecular Physics, with Soap Bubbles, and in Heat,
Sound, and Light. There is also a chapter on Scientific Lecturing. The
illustrations, of which there are nearly 100, are good.

The Ready-Reference Dictionary, containing 35,000 words.
Edited by \V. R. Balch. Crown 8vo, pp. 344. (London : Griffith, Farran,
Okeden, and Co. 1888.) Price 3s. 6d.

The chief features about this Dictionary are — ist, the fronts of the pages are
cut index fashion, so that the book may always be opened at the required
initial letter ; 2nd, the common words understood by everybody are, as a rule,
omitted ; and 3rd, each word is carefully pronounced. The meanings given to
the different words-are short and to the purpose.

A very handy dictionary, and convenient for reference.

A Higher Arithmetic, and Elementary Mensuration for the
Senior Classes of Schools and Candidates preparing for Public Examinations.

192 REVIEWS.

By P. Goyen. Crown 8vo, pp. xv. — 360. (London : Macmillan and Co
1888.) Price 5s.

This book will, we think, prove of immense value to students working
without a master, to pupil teachers and senior pupils. No formal rules are given
in the arithmetical portion of the book, but the suliject is so presented that the
student can readily make them for himself. The worked-out examples are
considerable in number, and very varied in type, so that the student having
worked up these should tind no difficulty in solving the exercises. We are
much pleased with the style of reasoning employed, and feel that we can con-
fidently recommend the book.

Arithmetic for Beginners:' A School Class-Book of Com-
mercial Arithmetic. By the Rev. J. B. Lock, M.A. i2mo, pp. vi. — 200.
(London : Macmillan and Co. 1SS8.)

The problems here given are well varied, and the worked-out examples
are well and clearly explained. In writing the book, the author kept carefully
in view the requirements of the New Examination for Commercial Certificates.
A chapter on Exchange and Foreign Money has been introduced, and some
specimen examination papers are added.

A Manual of Phonography. By Isaac Pitman. Five hun-
dred and seventieth thousand. New edition, i2mo, pp. 87. (London and
Bath : Isaac Pitman and Sons. 1S88.) Price is. 6d.

This edition of the "Manual of Phonography" has been entirely re-cast.
About six months ago, over one thousand copies were sent out, in proof, to
expert phonographic teachers and reporters, for suggestions and improvements.
Their experience is embodied in the present edition. So great was the desire
of phonographers to make this book as perfect as possible, that many of the
returned proof copies had to be sent a second and a third time.

After these proofs had been returned, about one hundred more, as final
proofs, were examined by different phonographers. The book has been re-set
in new type, and increased by twenty-four pages, the price remaining the
same, namely, is. 6d. The foundation of the book is laid on the lines of the
new " Phonographic Teacher," which was received with much approval when
issued about twelve months ago.

It is with much pleasure that we recommend this book to the notice of our
readers. ■

Will-Making made Safe and Easy. By Ahiiaric Rumsey,
Barrister-at-Law, etc. i2mo, pp. 140. (London : John Hogg. 1888.)
Price IS.

We do not consider it a safe practice for persons to make their own wills,
but when they determine to do so, it is well for them to take as good a guide
as they can procure. The author hopes that the book before us may be of use —
(i) to persons who wish to prepare their own will ; (2) to clergymen and other
well-educated persons who assist their less erudite neighbours in Will-making;
and (3) to members of the legal profession. The instructions are given in plain
and homely language,

Through a Microscope Something of the Science, together

with many curious observations indoor and out, and directions for a Home-
made Microscope. By Samuel Wells, Mary Treat, and Frederick Leroy
Sargent. l2mo, pp. 126. (Chicago: The Interstate Publishing Co.)

Describes, in simple language, the construction and application of the
microscope, and instructions are given for viewing many of the fresh-water
organisms.

REVIEWS. 193

The Game of Draughts simplified and illustrated with

practical diagrams. By Andrew Anderson. Fifth edition. Revised and
extended by Robert IM'Cullock, Glasgow. 8vo, pp. xxii, — 136. (Glasgow :
Tames P. Forrester. 1SS7.) Price is.

Those who are not skilled players will do well to study this little book.
It contains Instructions, Names of the Games and How Formed, Standard
Laws, Theory of the Moves, and Series of Elementary Positions, and a large
numbers of played-out Games, Problems, and Solutions.

Guide to the Student in Botany.

Outline of the First-year Course in Natural Science.

By Edward S. Burgess.

Two little works intended to supply students in the Washington High
School, with outlines for their course of study in Botany and Natural Science.
AH students will find the outline instructions here given most useful.

Moffatt's Geography of the British Empire.
The Earth and Solar System.
Mountains and Rivers.

i2mo, pp. 89, 103, 78. (London: Moffatt and Paige.) Price is. each.
These three little books give a large amount of information in a condensed
form.

A Key to the Mysteries of Water, Electricity, and Heat. By

William Baggatt. Crown 8vo, pp. 70. (London : Triibner and Co. 18S8.)
Price IS.

In this little book the author submits to the judgment of Scientists who
can divest themselves of their preconceived ophn'ons, certain facts respecting
the nature and properties of Electricity, which have for some time occupied
his thoughts.

The Gardener's Receipt Book : a Treasury of Interesting

Facts and Practical Information useful in Horticulture. By William Jones.
Sixth edition. l2mo, pp. 122. (London : Groombridge and Sons. 1888.)
Price IS.

We are told here the most effectual method for the destruction or
removal of everything injurious to the garden ; with preventatives and cures
for the various diseases of plants, and directions for the preservation of trees,
fruits, and flowers.

Songs of a Parish Priest. By Rev. Basil Edwards, M.A.

l2mo, pp. xiii. — 141. (Orpington, Kent : George Allen. 1888.)

A little volume of poems, of which the author says in his preface — "The
quiet of a country charge has enabled the writer to endeavour to link together
many of the objects most prominently connected with sacred thought in a rural
parish, and to present the results to the reader in somewhat of a sequence,
leading step by step from the lych-gate to the altar."

The Divine Programme of the World's History. By
Mr. and Mrs. Grattan-Guinness. 8vo, pp. viii. — 455. (London : Hodder
and Stoughton. 1S88.) Price 7s. 6d.

The aim of this volume is apologetic. Its argument is based on the Old
Testament canon, " When the word of the prophet shall come to pass, then
shall the prophet be known that the Lord hath truly sent him." The subject

194 REVIEWS.

is treated in seven sections, which together embrace the whole scope of Bible
prophecy from Adam to Christ, the object of the writer in each division being
to show that predictions, d priori, the most improbable have literally and
invariably been fulfilled in the way indicated, and hence the conclusion that
the original word was inspired. Devout readers will find much in this work to
refresh their minds and strengthen their faith.

Illustrations : A Pictorial Review of Knowledge. Con-
ducted by Francis George Heath. Crown 4to. Nos. i — 8. 1887—8.
','i It is needless to say that illustrations form a somewhat prominent
feature of this magazine ; they form, however, by no means the all-important
part of it. The articles are numerous, carefully written, and well varied.
Perhaps the contents of the last number will fairly represent the whole.
These are : — A Study of May ; Michael Dickson's Wife, a Prize Story ; Those
Young People, a Serial Story ; Cycling ; Through the Opera Glass ; Prize
Drawing Competition ; Pen-and-Pencil Portraits; Home; Garden, Field, and
Farm ; Schools, Private and Public ; Inventions ; Funny Old Customs : May
Day ; The Great Auk. Elach article is profusely illustrated.

Gall and Inglis's School Atlas of Modern and Ancient

Geography. Imperial 4to. (London and Edinburgh : Gall and Inglis.)

This atlas contains thirty-three very distinctly-engraved maps, all of which
are nicely coloured. These maps are 14 in. by iii in., except one, which is
double that size. This atlas will be found exceedingly useful in schools.

First Steps to Scientific Knowledge, complete in Seven
Parts. By Paul Bert. Translated by Madame Paul Bert. Revised and
edited by NVm. H. Greene, M.D. Post Svo, pp. 374. (Philadelphia: J. B.
Lippincott and Co.)

This book has already enjoyed a very large circulation in France and in
our own country, and we make no doubt that it will also do so in America.
We know of no book covering so wide a field of scientific knowledge, all of
which is brought down to the capacity of children. It treats of Animals,
Plants, Stones, and Rocks ; Physics ; Chemistry ; and Animal and Vegetable
Physiology.

The Education of Man. By Friedrich Froebel. Trans-
lated from the German and annotated by W. N. Hailmann, A.M. Crown Svo,
pp. XXV. — 332. (New York : D. Appleton and Co. 1887.)

This is the fifth volume of the International Educational Series, and is a
faithful rendering of Froebel's important work, which, as Dr. Harris says in
his editorial preface, deserves a thorough annual study by every teacher's
reading-club in the land. The translator's explanatory notes contribute very
materially to the right understanding of some difiicult passages. The work is
divided into two parts. The first deals with general principles, and considers
the development of man during infancy and boyhood. The second discusses
the chief subjects of instruction, grouping them under (i) religion, (2) natural
science and mathematics, (3) language, (4) art.

The Laws of Every-Day Life, for the Use of Schools. By
H. O. .\rnold-Forster. Crown Svo, pp. 240. (London : Cassell and Co.)
Price IS. 6d.

This book, which contains many useful lessons, is intended for school use,
and is designed as an introduction to the study of elementary political science.
It is divided into four parts : — The Law of the Land, the Laws of Nature and
Reason, How to Live under the Law, and Work and Workers. It is written
in language suitable for young people.

REVIEWS. 1 95

1,000 Ways of Earning a Living, ismo, pp. viii. — 184.
(London : Tit-Bits Office and Carr and Co.) Price is.

A large amount of time and pains has been spent on the production of this
book. It treats of Employment for Girls, Youths, The Educated of both
sexes, The Middle- Aged of both sexes. Useful Hints and Suggestions to all
seeking Occupation, or Emigration.

The paragraphs are arranged in alphabetical order under their various
titles, commencing with Actors and concluding with IFooti-Carvi/i^ and Young
IVonieit's Help Societies. Persons driven by force of circumstances to seek
employment will do well to consult this book.

Birds'-Nesting and Bird-Skinning : A Complete Descrip-
tion of the Nests and Eggs of Birds which Breed in Britain. By Edward
Newman. Second edition. Revised and re-written, with directions for their
Collection and Preservation, and a chapter on Bird-Skinning by Miller Christy.
i2mo, pp. xii. — 138. (London : T. Fisher Unwin. 18S8. )

In this little book a careful description is given of the nests and eggs of all
the British birds. The eggs are very accurately described — usual number in a
clutch, maximum and minimum measurements of eggs to decimals of an inch,
colouring, and other particulars. Instructions in birds'-nesting with tools and
accessories necessar}', and in bird-skinning, are also given. This is a very
useful little book.

Natural Causation : An Essay, in Four Parts. By C. E,
Plumptre. 8vo, pp. 198. (London : T. Fisher Unwin. 1888.) Price 7s. 6d.

Under the title, " Natural Causation," we have grouped together the
following essays, viz. — The Doctrine of Design, viewed from the Standpoint of
Evolution ; Philosophical Necessity, a Defence ; Natural Growth in Ethics ;
and Natural Growth in Civilisation. In these essays the author sets himself to
prove that everything in our world has proceeded by natural laws and not by
arbitrary interference, but rather in spite of it. These essays are thoughtfully
written. At the end of the book is a lengthy index, which will prove of value
in referring to any special argument.

Natural Philosophy for Beginners. — We regret to notice

that in our review of this little book, p. 128, our compositor has made us use
the words " pinetics " and " pinematical " for " kinetics " and " kinematical,"
and " Vectors " for " Vectors."

Elementary Lessons in Astronomy. By J. Norman Lock-

yer, F.R.S. l2mo, pp. xvi. — 363. (London: Macmillan and Co. 1888.)
Price 5s. 6d.

This, although not so stated on the title-page, is a revised edition of Mr.
Norman Lockyer's " Elementary Lessons in Astronomy," and in the earlier
portions of the book references are made to the conclusions, having reference
to the heavenly bodies that the author has recently communicated to the Royal
Society.

The work is illustrated with sixteen fine steel plates, which have been
placed at the author's disposal by Mr. Warren de la Rue ; there are besides
nearly 100 smaller engravings.

The Mystery of the Ages, contained in the Secret Doctrine
of all Religions. Second edition. By Marie, Countess of Caithness, Duchess
de Pomar. 8vo, pp. xxxii. — 541. (London: C. L. H. Wallace, Oxford
Mansions. 1887.)

196 REVIEWS.

We have not seen this work before ; but from the appearance of the text
we suppose it was formerly published under the title of Universal Theo-
SOPHY, a title which will sufficiently explain the nature of the work.

Our English Shores, being Recollections of Watering-Places
on the Coasts of England. By William Miller, F.R.S.E. Crown Svo, pp.
xvi. — 234. (Edinburgh : Oliphant, Anderson, and Co. London : Hamilton,
Adams, and Co. 1888.) Price 6s.

This book, unlike a " Guide-Book," which generally gives stereotyped
descriptions of the various seaside resorts, consists of a congeries of little tours,
and recounts the results of visits paid by the author to seaside towns on the
coast of England. These sketches will be found to be most readable and
interesting. The illustrations are nearly all selected from the author's
sketches, and are reductions by photo-zincography from pen-and-ink copies.

A 1'reatise on Plane Trigonometry, containing an account

of nyperbolic Functions, with Numerous Examples. By John Casey, LL.D.,
F. R.S. Crown Svo, pp. xvi. — 271. (Dublin: Hodges, Figgis, and Co.
London : Longman, Green, and Co. 1888.) Price 7s. 6d.

This work contains not only everything that is usually given in books on
trigonometry, but also much that has hitherto appeared only in mathematical
periodicals. Its eight chapters treat of — First Notions on Trigonometric Func-
tions ; Trignometric Formula; ; Theory of Logarithms ; Trigonometric Tables ;
Formulre relative to Triangles ; Resolution of Triangles and Quadrilaterals ;
Continuation of the Theory of Circular Functions ; and Imaginary Angles.

In Touch with Nature : Tales and Sketches from the Life.

By Gordon Staples, CM., M.D., R.N., etc. Crown Svo, pp. 224. (London:
Society for Promoting Christian Knowledge. 1888.) Price 2s.

Nineteen most interesting chapters compose the Ijook before us, concerning
which the author tells us that the stories and the sketches were all Ijorn out of
doors, in his orchard wigwam, in his woodland study, in ships in Arctic seas,
and in the Tropics during his caravan wanderings for the past three years.
The book is nicely illustrated.

The Art of Preparing Vegetables for the Tables. By
Sutton and Sons, Reading. i2mo, pp. 68. (London : Hamilton, Adams,
and Co. 1888.) Price is.

Messrs. Sutton and Sons give us here what they describe in their introduc-
tion as an " elementary code of vegetable cookery that the cooks themselves
may not disdain, and that many who are not cooks, but desire to know some-
thing of the art of cookery, may give attention to as of direct, practical value
to them." Our lady friends to whom we have submitted this little book speak
of it in high praise.

An Examination of the Theory of Evolution and some

of its Implications. By George Gresswell. Svo, pp. xiv. — 155. (London :
Williams and Norgate. 188S. ) Price is.

The work before us is evidently the outcome of much serious thought.
It appears to have grown out of a lecture entitled " The Evolution Hypothe-
sis," published at Cape Town in 1S85, to which many new ideas have been
incorporated. The book is divided into 11 chapters.

Sand Blast Cells. — Referring to a note on this subject, which

appeared on p. 50 of the Journal of Microscopy (January), Mr. B. Piftbrd, of
Ilemel Hampstead, Herts, sends us specimens of his Countersunk Cells.

Zbc air BIa^bcr of jf iebce con0it)cre^ as a
Degenerate Xung.

By Mrs. Alice Bodington.

the result of numerous investigations as to the
condition of the air-bladder of fishes, Mr. Charles
Morris, of the Academy of Natural Sciences of
Philadelphia, has arrived at the conclusion that
this organ was not primarily evolved as an aid in
swimming, but was originally a lung.

As with most degenerating organs, the air-
bladder is found in all stages of arrested develop-
ment. In the most highly-specialised fish, the
Teleosteans, it exhibits an extraordinary variation in shape, size,
and relation to the body. With some Teleosteans the air-bladder
has an open pneumatic duct connecting with the oesophagus, and in
a few cases with the stomach. With others this duct exists, but its
cavity is closed. In some cases it is reduced to a fine ligament.
In many other Teleosteans no traces of it exist. T/iese variafiofu
have no appreciable effect upo?i the velocity and activity of the fish.
Those that have no air-bladder seem in no respect at a disadvan-
tage as compared with those that have one. These variations
remind one of the various stages of degeneration of the eye and
optic nerves in blind animals.

If the air-bladder is of absolute necessity to a fish as a gravi-
tating organ, why is it not necessary to all, and why has it not
developed into some shape and condition of greatest efificiency ?
No animal organ, whose function is of known importance, presents
such extraordinary modifications. In the heart, lungs, brain, etc.,
there is one shape, position, and condition of greatest efficiency,
and throughout the lower forms we find a steady advance towards
this condition. There is in all these organs a persistent movement
towards homogeneity — not towards heterogeneity, such as we find
in the air-bladder. The existence of the air-bladder is proof that
it has had, at some time, a function of considerable importance.
Its many variations go to prove that it has ceased to perform any

New Series. Vol. I.

1888. P

198 THE AIR-BLADDER OF FISHES

essential function, and is on the road towards extinction. On no
otlier theory can we explain its great diversity in nearly-related
species.

If, then, we may look upon the air-bladder as an organ which
has partly or wholly lost its original function, the question
follows, What was that function ? There are certain good reasons
for believing that the h-eathing of air was the original purpose of
this orgaji. In mature Teleosteans this is occasionally indicated
by the existence of a pneumatic duct connecting with the oeso-
phagus. This duct is usually of no functional use, and varies
from partial to complete disappearance. But all fishes with an
air-bladder possess a duct in the early stage of embryological develop-
ment. In the mature stage it is lost by all Teleosteans except the
Physostomes. The extraordinary development of retia mirabilia
in the inner tunic of many air-bladders, though now used only for
the secretion of gases, may be survivals of ancient pulmonary
capillaries, which have changed their character with their function.
And the apparatus for compressing and dilating the bladder may
have been originally developed purely for respiratory purposes, as
this embryological persistence of the pneumatic duct would lead
one to suppose.

From the evidence afforded by embryology, we proceed to
that given by paleontology. The ancestors of the modern Teleos-
teans, the Ganoids, all possess an air-bladder, which remains a
fully-developed air-duct in the mature stage. In the sub-order,
Dipnoi, the air-bladder is functionally developed as a lung, and as
counterparts of these fishes existed in the Devonian age, it is pro-
bable that they breathed air then as they do now.

In the higher animals the duct connects with the ventral side
of the oesophagus, whereas in most of the Ganoids the air-duct
opens into the dorsal side of the oesophagus. But Wilder shows
there is a series of forms, mostly Ganoids, leading from Amia and
Lepidosteus, with the air-duct entering the throat or the dorsal
side, to Lepidosirea, in which it enters on the ventral side, as in
the higher vertebrates. In all the fishes just named, the air-
bladder functions as a lung ; in Polypteros it has lateral divisions ;
in Lepidosteus, the American Gar-Pike, it is cellular and lung-
like. The fish keeps near the surface, and may be seen to emit

CONSIDERED AS A DEGENERATE LUNG. 199

air-bubbles. The American Bow-Fin or Mad Fish (Amia) has a
bladder of the same lung-like character, and has been seen by
Wilder to come to the surface, open its jaws widely, and appa-
rently swallow a large quantity of air. Wilder remarks that, " so
far as experiments go, it seems probable that with both Amia and
Lepidosteus, there occurs an inhalation and exhalation of air at
pretty regular intervals, the whole process resembling that of
Menobranchas and other salamanders."

The Dipnoi have the air-bladder developed into a true lung.
Of these the Australian lung-fish, Ceratodus, has but a single air-
bladder, but this is provided with breathing pouches, which have
a symmetrical-lateral arrangement. It has no pulmonary artery,
but receives branches from the Arteria caliaca. Finally, Lepidos-
teus and Protopterus have completely-formed lungs, divided into
two lateral chambers^ and provided with a pulmonary artery.
Their cellular structure nearly approaches that of the batrachian
lung.

Professor Giinther says that some " fishes breathing air are,
even when brought into pure water, obliged to rise to the surface
at frequent intervals to take in a quantity of air, and, if kept
beneath the surface by means of a gauze net, they perish by suffo-
cation." In carrying out researches as to the original condition
of any organ, we find it always necessary to begin with low forms.
For instance, in studying the history of mammalian dentition, we
do not take the cats, whether recent or extinct, as guides ; we
study the dentition of the early Eocene mammals, and even peer
back into deeper recesses of time to examine the teeth of Jurassic
mammals. And the same rule applies to researches as to the
development of the brains and limbs of animals. We go as far
back and as low down as possible. Therefore, we are only follow-
ing sound, scientific precedents, if, when wishing to understand
the original function of the air-bladder, we study this organ, not
amongst the highly-developed Teleosteans, but amongst the sur-
vivals of archaic forms. If in fishes whose prototypes are found
in the Devonian age, the air-bladder functions as a lung, we have
good reasons for assuming that this was the original function of
the organ. To study the air-bladder as it exists in Teleosteans
would be Uke studying the development of the fingers in horses

200 THE AIR-BLADDER OF FISHES

or the development of the hind Hmbs in whales. We should not
discover the original history of these organs, but only that of
their extreme modification, or gradual suppression.

Mr. Morris next asks us to imagine what were the conditions
of life under which this organ was developed, and what were the
later conditions which rendered it in great measure or entirely
useless. The question takes us back to Devonian and Silurian
geological periods. In this era the seas were thronged with fishes
of two distinct orders — the Elasmobranchs and the Ganoids, the
former without, the latter with, an air-bladder. This difference in
organisation was probably the result of some marked difference in
their life-habits. The Ganoids may have inhabited poorly aerated
waters, or waters otherwise ill-adapted to breathing, while the
Elasmobranchs may have had their primordial habitat in clearer
and purer waters.

But there were other conditions which may have been the main
influencing causes of the development of an air-breathing organ. We
know that the land was habitable for long ages ere it gained any
vertebrate inhabitants. The presence of insects in Devonian and
Silurian strata proves this. Long ages passed during which we have
no evidence of land animals higher than insects or snails, and the
earth must have possessed much food material, both vegetable and
animal, available for a larger population than it possessed. It is
hardly probable that the active fish of the early seas made no
effort to obtain a share of this food. As many fishes now leave
the water temporarily for the land, in search of food, notwithstand-
ing the many dangerous enemies which lie in wait for them, it is
only reasonable to suppose that many fishes may have done so in
remote ages, when no such redoubtable foes awaited them. Such
fishes as left the sea for the land would find their enterprise richly
repaid by ample food, and would therefore have had a powerful
inducement to continue the habit. Other influences may be
inferred to have been at work then, as they are now. Foul and
muddy water, and the drying-up of pools, which now cause fish to
breath atmospheric air, must have been causes as likely to be
active in Devonian times as now.

At the opening of the carboniferous era there may have been
many lung-and-gill breathing Dipnoi, finned Batrachians as we

CONSIDERED AS A DEGENERATE LUNG. 201

may call them, which spent much of their life on shore. And
their habits of land life would naturally be attended by a gradual
change of the fins into better walking organs, from which by a long
continued process of evolution, may have arisen the leg and foot
of the primordial batrachian. For this purpose, to become fully
developed, however, the development of an internal bony skeleton
was necessary, and with the completion of this step of evolution
the lung-breathing fish probably directly unfolded into the true
amphibian. Were we left to imagine what such a fish would be
like, could we draw any form which would differ much from the
existing Perennibranchiates ?

But with the existence on land of vertebrates with bony
skeletons, the dominion of the fish must have gradually decreased.
The formidable reptiles which for a time had the mastery of the
world, would make terra firma less and less of a desirable resort.
The fin, too, could not compete with the leg and foot as an organ of
land motion, and those Dipnoi which had remained mainly fish-like
were probably driven back to the water. As a result of this
change of conditions, a retrogressive change took place in the air-
breathing organ. Some fishes never cease to use it as a lung, as
modern Dipnoi. Yet, with the Ganoids, as a rule, it has been used
only temporarily for breathing purposes. But with their successors,
the Teleosteans, it has lost all air-breathing capabilities, and has
passed through every stage of degeneration, from a condition
closely resembling that of the Ganoids to complete extinction.
This theory is not vitiated by the fact that the organ has developed
secondary uses. Innumerable instances exist of secondary adapta-
tions of organs which embryology shows had once far different uses,
as in the transformations which the gill arches have undergone
in the higher vertebrates, and the still more extraordinary modifi-
cations of functions in the primitive kidneys. One remarkable
fact may be mentioned as showing that the air-bladder has
an important function in the aeration of the blood in deep-sea
fishes. In fresh-water forms the organ contains nearly pure
nitrogen, whilst in deep-swimming sea-fish oxygen forms its main
contents (Dr. Gunther states that the proportion is sometimes as
high as 87 per cent, of oxygen). This difference is not due to any
differences in the gases contained in water at various depths, for

202 THE AIR-BLADDER OF FISHES.

the percentage of nitrogen is closely the same at all depths, while
oxygen diminishes in quantity from the surface downwards. Thus,
if the contents of the air-bladder depended on the relative
quantity of gases present, nitrogen should predominate below as
well as above. Furthermore, as showing that the bladder still
functions as an aerating organ, Cuvier says that when a fish is
deprived of its swim-bladder, the product of carbonic acid by the
branchiae is trifling. We cannot imagine such a result unless the
air-bladder in some way supplies oxygen to the blood, and thus
continues to perform, in an indirect manner, its probable original
function of a breathing organ.

If the hypothesis offered be a well-founded one, an interesting
conclusion as to the process of organic evolution may be taken.
We should see the air-breathing function at first performed by the
unchanged walls of the oesophagus. Then this became pouched.
Then the pouch became constricted off, with a duct of connection.
Then, as the original function vanished, the duct disappeared, and
what was originally a portion of the wall of the intestinal canal
became a separate internal sac. Then this sac in many instances
decreased in size, until in some cases it became a closed internal
bladder of the size of a pea, far removed from and utterly
disconnected with its place of origin. Finally, it completely
vanished. This process, if correctly drawn, certainly forms a very
remarkable cycle of development and degeneration, which probably
has no counterpart (Mr. Morris thinks) of a similarly striking
character in the whole circle of organic life.

Finally, it may be remarked that though many fish use their
air-bladder in all probability for gravitative purposes, yet, as many
most active fishes have no air-bladder, this organ could not by
any known law of evolution have been elaborated for a purpose
which actively-swimming fish can so easily dispense with.

I will only say, in conclusion, that this paper consists of such
copious extracts from Mr. Morris, that I have thought it un-
necessary to use inverted commas when quoting from his article.
Had I done so, my paper would have been, as the old lady found
'' Macbeth," too " full of quotations."

[203]

Development of tbe Z^a^pole♦

By J. W. Gatehouse, F.LC.

Part IV.

Plates XIX., XX., XXI.

TRx\CING back the development of the claspers described on
p. 151 (July), we find that, like the rest of the organs, they
too have undergone most decided alterations both in form and
structure, appearing first as a mere thickening of the epiblast, as
seen in Fig. i, Plate VII., and Figs, i and 2, Plate VIII. We
next find them showing an apparent invagination, or rather per-
haps a ring of dark, elongated, epiblastic cells, converging towards
a central opening, and resting upon what appears to be a
modification of cartilage. The whole is bounded posteriorly,
that is, on the inner side, with a single layer of cells continuous
with the mesoblastic layer, and indeed forming an integral part
of it (Fig. 5, Plate XXL). A section made two days later shows
the appearance given in Fig. 3, the two points shown in
Fig. 4 having advanced outwards and become double, whilst the
structure as a whole has also suffered a more complete longitu-
dinal division. The growth of this organ, as a whole, is
therefore seen to proceed much on the same lines as that which
occurs in simple cell division. These points ultimately coalesce,
the central division remaining, so that in their most perfect
development we arrive at the structure already figured in Plate
XIII., Fig. 7.

In our last article some doubts were thrown out as to the true
function of this organ, and when we consider its epiblastic origin,
and also that muscles are produced from the mesoblast, we are
compelled to arrive at the conclusion that these so-called claspers
do not clasp, and also that they are not suctorial discs, for not
being muscular they cannot suck, and are therefore not homo-
logous with the suctorial mouth of the Cyclostomata, as seen in
the Lamprey. What, then, is this structure ? What are its
functions ? We have seen that at one period of its history it
certainly appears to partially support the animal in the water, but

204 DEVELOPMENT OF THE TADPOLE.

having regard to its minute structure, which bears no indistinct
resemblance to the brain at an early stage, as well as to its
epiblastic origin, we are forced to the conclusion that its real
function is to act as a special sense organ, enabling the animal,
before it possesses eyes or ears, to place itself by feeling in com-
munication with that small portion of the outer world which forms
its limited surroundings. When more specialised organs are pro-
duced, these primitive ones atrophy, as they are of no further use.

As, up to the period to which we have arrived, one of the
most prominent structures seen in all the sections has been the
notochord, we will trace its history in some detail. In Plate
XIX., Fig. 2, of the present number, will be found a diagram of
the anterior end of this structure, as it existed in an animal of
March 20, enlarged 100 diameters ; but more or less complete
indications of it may be found in all the previous plates, with the
exception of the first. Reference should be made to these, and
especially to Figs. 7 and 8, Plate II., of January, 1888, and also
to Plate XIII., of the July part, for various longitudinal sections.

Our previous observations led us to the conclusion that the
whole of the organs of the animal were produced from either the
epiblastic, hypoblastic, or mesoblastic layers. In Amp/iioxus,
the Ascidians, the Lamprey, and Lepidosteus, it has been
demonstrated by several observers that the notochord is derived
from the hypoblastic layer. Towards the anterior portion of the
embryo — that is, the portion which ultimately forms the head —
certain of the hypoblastic cells split into two, so that whereas the
hypoblast is formed of a single layer of cells in the greater portion
of the embryo, yet at this particular point it consists of two
layers, the under one of which becomes the notochord. This
double layer of hypoblastic cells extends from the front to the
hinder end of the embryo in an axial line, nearer to what will
ultimately be the dorsal than the ventral side. The distinct
formation of the lower layer of cells into the notochord occurs
first towards the front, and gradually extends towards the back.
Gotte has thrown grave doubts as to whether this is the mode of
formation of the notochord in the case of the frog and other
Anura. He states that the notochord is formed, not from the
hypoblast at all, but from the mesoblast. His statement,

DEVELOPMENT OF THE TADPOLE. 205

illustrated by sectional diagrams, is, that the mesoblast forms a
continuous sheet around the ovum, under the epiblast, and that
in the axial dorsal line a central chord becomes separated to form
the notochord. Calberta, however, states, that when the meso-
blast is fully formed, and separated from the hypoblast, it does
not form a continuous sheet, but that it is broken in the dorsal
axial line, and the two portions separated from each other by a
ridge of hypoblastic cells. It is this hypoblastic ridge, he says,
and not a layer of cells from the mesoblast, which becomes differ-
entiated into the notochord.

Balfour says that his own observations are in favour of the
latter statement, as the mesoblast never appears to form an abso-
lutely continuous sheet. When such eminent embryologists differ,
it would be the highest presumption on my part, with my very
limited number of sections, to offer a decided opinion on so
extremely delicate a matter ; but I may state that when cutting
my earlier sections many of them were rejected because the layer
of mesoblast was never found perfect, and as my time for mount-
ing is very limited, I was obliged to retain only those which, from
the observations of previous observers, were considered most nearly
accurate. As, however, in other types there appears to be no
doubt that the notochord is really derived from the hypoblast, it is
very probable that the same thing takes place in this. As no
invertebrate animal possesses a notochord, it will be seen that the
study of this structure is of the highest importance in an embryo-
logical sense.

It would appear, from the observations of Gotte, Schneider,
Balfour, and others, that the structure of the notochord in the
Teleostei, Elasmobranchii, etc., is distinctly different from that
of the Amphibians, the former possessing an elastic sheath, called
the membrana elastica externa, and the latter being devoid of this
structure. My own sections, at the date given, and as roughly
drawn in PI. XIX., Fig. 2, show that the notochord at this period
consists of three parts : — Firstly, a central cellular portion ;
secondly, a delicate layer of cells; thirdly, a strong, fibrous,
elastic sheath. These we will describe in detail.

The central cellular portion consists, at its very anterior
extremity, of what appears to be a two-celled layer. From a con-

206 DEVELOPMENT OF THE TADPOLE.

sideration of the history of this structure, these would appear not
to be true cells, but rather to represent vacuoles which have
become filled with gelatinous substance. As we proceed towards
the tail, we find other layers intercalated between these, so that a
longitudinal section shows from three to five or more of such
layers irregularly disposed. As shown in the diagram, the noto-
chord penetrates into the head beyond the auditory capsules,
which are seen on either side of it, and terminates almost close to
the mid-brain in the region of the pituitary body, with which,
however, it has no connection. The cellular portion is not a
straight rod, but is composed of a number of slight constrictions
and expansions, caused apparently by the pressure at intervals of
the fibrous sheath with which it is surrounded.

This sheath does not entirely envelope the central portion, for
it is attached, as shown in the diagram, to the first constriction
immediately behind the auditory capsules. In front of this the
cellular portion is surrounded only by the delicate second layer,
spoken of before. This layer, which envelopes the whole noto-
chord, is very similar to the membrane mentioned in the last
article as surrounding the pro-renal ducts and all other organs at
this period. It consists of a number of delicate, nucleated,
spindle-shaped cells, broad in the centre, and terminating in
points where they are attached to each other.

The external sheath consists of a number of parallel fibrous
bands, having much the appearance of muscular tissue. This
sheath, with the notochord proper within it, can be seen in the
majority of the sections already described. It contains not only
the gelatinous rod and its covering proper, but also the great
double nerve-cord, which ultimately forms the spinal cord. As
the anterior portion of the sheath certainly extends under that
portion of the spinal cord known as the medulla oblongata, whilst
it does not surround it, there would appear to be an opening on
the dorsal side of the sheath, whence the nerve-cord penetrates it
just at the point where the medulla oblongata narrows down into
the medulla spinalis. An external view of the sheath shows it to
be composed of a number of irregular, transparent ridges, con-
nected by depressions, so as to form what almost looks like a
series of waves (PI. XIX., Fig. 4).

DEVELOPMENT OF THE TADPOLE. 207

In this figure there will be observed six dark patches,
marked ga., which are also surrounded by the sheath. These are
six of the ten sympathetic ganglia, lying immediately below the
spinal cord proper, and not yet apparently connected by any
commissure. These ganglia are intimately connected with struc-
tures which have been called the supra-renal bodies, which Balfour
considers to be actually developed from them.

My sections of March roth, as drawn in Plate XXI., Figs, i,
2, and 3, give most interesting and instructive details of one stage
in the growth of the notochord and its sheath. From the peculiar
form of the embryo at this stage, these .sections show both
transverse and longitudinal strictures from the same animal. In
Fig. I we have a transverse section of the notochord {nc), toge-
ther with the terminal attachments of the fibrous sheath, both
anteriorly and posteriorly. In front, the origin of the fibrous
bands is seen to occur at the junction of the epiblast with the
brain, the fibrous bands rapidly narrowing down to a single line,
so that at these points on either side of the brain the three struc-
tures— epiblast, forebrain, and fibrous sheath— are so closely
connected and amalgamated, that no distinction can be perceived
between them, although they immediately separate from each
other and become most distinct structures. Posteriorly, these
bands, after closely surrounding the notochord, spread out dis-
tinctly, and then immediately commence to lose their fibrous
character by resolving themselves into a number of separate
roundish cells, arranged in about five rows, which gradually coa-
lesce and run between the epiblast and undifferentiated yelk-mass,
at first in two rows and ultimately in a single row of cells, forming
a line of mesoblast.

In the same figure as that giving a diagram of the notochord
(PI. XIX., Fig. 2) will be found a sketch of the auditory capsules
{au.) of the same date, together with indications of nerve-sub-
stance proceeding from the brain to them. These auditory
capsules on March 9th were distinctly seen to be formed by an
invagination of the epiblast. At that time they appeared to be
nothing more than a pear-shaped sac, having a very minute
opening on the exterior. As seen in Fig. 2, PI. XIX., they con-
sisted of a sac containing much detached granular matter, the

208 DEVELOPMENT OF THE TADPOLE.

walls of the sac being formed of a series of almost rectangular
cells, placed side by side, being transformed epiblastic cells.

In PI. XIX. and Figs. 3, 6, 7, 8, and 9, PI. XX., respectively, will
be found diagrams and sketches of the eye at various periods.
Figs. 6 and 7, PI. XX.^ are diagrammatic representations of the
evolution of the eye, as usually given in text-books on physiology,
the remaining figures being drawn from various sections of my
own to illustrate the appearances presented by this organ at
different dates.

Lankester, who first worked out the development of this organ,
states that it appears as an oval pit of the epiblast, the edge of
which is formed by a projecting rim. The edges of this pit gra.
dually approach each other, whilst the epiblast lining of the floor
thickens. The cavity thus formed is eventually converted into the
inner optic chamber. A layer of mesoblast next grows in between
the walls of the sac and the external epiblast. The iris and lens
arise nearly simultaneously, the latter appearing to proceed from
the epiblast. In Fig. 8, PL XX., and Fig. 3, PI. XIX. , this lens
may be seen situated between the horns of the invaginated epi-
blast, but, as shown in the latter figure, now covered completely
by an epiblastic layer, transformed into skin. In both these
figures the nerve-cords proceeding from the brain to the eye can
be distinctly traced, and in Fig. 5, PI. XIX., we have a represen-
tation of the roots of these nerves as they proceed from the brain
itself. The interior of the eye at this date is filled with a transpa-
rent substance radiating from the exterior to the interior, where
most, if not all, of these almost transparent fibres terminate in a
small knob quite as transparent as themselves.

In his article -on the " Development of the Cephalopoda,"
Lankester gives an account of the first formation of the lens of
the eye. He says : — " It is formed entirely within the primitive
optic chamber, and at first depends as a short, cylindrical rod
from the middle point of the anterior wall of that chamber — that
is to say, from the point at which the chamber is finally closed up.
It grows subsequently by the deposition of concentric layers of a
horny material round this cone. No cells appear to be imme-
diately concerned in effecting the deposition, and it must be
looked upon as an organic concretion, formed from the liquid

DEVELOPMENT OF THE TADPOLE. 209

contained in the primitive optic chamber." Ultimately the lens
assumes a nearly spherical form, being composed of concentrically
arranged layers.

In PI. XX., Fig. 9, we have a peculiar section of the eye,
which appears to show one stage in the formation of the retina
and its connection with the optic nerve ; but it possesses so many
points of resemblance to Lankester's description of the formation
of the lens (above quoted), that since reading this I am in grave
doubt as to whether it does not refer to the lens and surroundings.
Although not well shown in the diagram, the central, suspended
oval portion consists of two or three concentric, transparent layers,
and as shown is entirely unconnected from every other part except
by its point of attachment.

In the "Philosophical Transactions" for 187 1 may be found a
minute and interesting account of the development of the skull of
the frog, by Dr. Parker, together with splendid diagrams of various
stages in that development. Fig. i, PI. XIX., shows one stage in
this development, as seen in a section of March 18th. In this we
see the branchial arches on each side {br.), together with some
gills, the formation of these having well commenced as apparent
outgrowths of the epidermis. The growth of these gills reminds
me very closely of the manner of reproduction by budding which
occurs in the hydra. A knob first makes its appearance, the
epidermis having all the appearance of being stretched and
pushed outwards by some inward force, which, continually acting
outwards and forwards, converts the knob into a rounded
protuberance.

Two or three other smaller knobs form 013 this (Fig. 2, PI.
XX.), and when the original gill has thus increased considerably
in length, it buds laterally, forming a rake-like structure, through
which the blood courses bathed externally by the water. These
gills are perfectly transparent, the course of the blood-globules
being distinctly observed. The blood does not at first seem to
follow any definite course through the gill-substance, but for a
time appears to take the line of least resistance, soon, however, to
become imprisoned in definite channels, the globules following
each other in the most orderly progress.

I was once looking at a specimen in which the gills were about

210 DEVELOPMENT OF THE TADPOLE.

one-half or a little further grown in which no movement could be
detected, but the blood-globules were seen lying perfectly still here
and there in the tissue. Suddenly, one of these gave a convulsive
throb, moved onwards slightly, retreated a little, then with a final
start moved forwards on its course, the rest following. Was this,
I wonder, the effect of the first true heart-beat which I observed,
giving an impulse to the whole of the globules throughout the
body, destined henceforth to act as carriers of nourishment to the
whole system? Possibly, however, it may only have been the
commencement of renewed circulation, which had been tempo-
rarily suspended on account of my own rough handling.
Whatever may be the correct explanation, the phenomenon was
most interesting and curious, having all the appearance of dead
and inert matter waking suddenly into life and continuing in that
life.

To return to our diagram, we notice not only the branchial
arches with the gills, but also the hyoid {hy.), mandibular, and
trabecular arches. Another section of the mandibular arches is
shown in Fig. 6, Plate XIII., where they are seen supporting the
mouth cavity {m.c).

It will be remembered that these observations were primarily
undertaken to obtain if possible some definite information on the
food of the tadpole. Reference to Figs, i, 2, and 3, Plate XIII.,
as well as to Figs, i and 5, Plate XX., will show that, although up
to March 23rd, the date of these sections, the mouth cavity was
well formed, yet the animal could not possibly eat, as the mouth
was not only closed, but perfectly covered with the epidermis,
although the papillffi on the labials had commenced to form, as well
as the salivary glands at the sides of the mouth. Up to this date
it will, therefore, have been manifestly impossible for these embryos
to have obtained food through the mouth, as mouth there was
none. Nourishment, however, must have been obtained; for
during the month now elapsed, the eggs had increased both in
weight and bulk, and as we have seen, had become so wonderfully
altered in form that there was now no resemblance to the original
spherical contour. All nourishment would, therefore, up to this
date, appear to have been imbibed from the water through the
epidermis ; but in a few days — namely, by March 29th — the lips

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DEVELOPMENT OF THE TADPOLE. 211

were fully formed, the mouth had opened, and the gills, on the
right hand side, had commenced to atrophy.

On March 30th, as far as my observations went, these little
creatures took their first meal. In our next we shall see of what
this and future meals consisted.

EXPLANATION OF PLATES XIX., XX., XXI.

Plate XIX.

Fig. 1. — Longitudinal Section of Tadpole, March 18, showing the
attachment of the elastic band to the notochord,

,, 2. — Front portion of notochord and auditory capsules (same date),

,, 3. — Horizontal section of eye, with root of optic nerve pro-
ceeding from the brain.

,, 4. —Portion of notochord, with sympathetic ganglia.

,, 5. — Olfactoiy capsules, with portion of brain showing nerve roots
proceeding to the eye.

Plate XX.
Figs. 1 — 5. — Horizontal and longitudinal sections, taken March 23.
,, 6 — 7. — Diagrammatic sections of eye.
,, 8 — 9. — Sections of same, drawn from nature.

Plate XXI.

Figs. 1 — 3. — Oblique sections of tadpole, March 10th, showing
arrangement of elastic band and notochord.

4 — 5. — Claspers.

sp. c. , spinal cord ; e. 6. , elastic band surrounding noto,
chord ; g. , gills ; hy. , hyoid arch ; ol. , olfactory capsule ;
b. , brain ; nc. , notochord ; au. , auditory capsule ; n. b. ,
nerve-roots from brain ; ep. , epidermis ; en. , lens ; ga. ,
ganglia; m. , mouth; m.c, mouth cavity; I., liver; h.,
heart ; br., brain •,pr.d., pro-renal ducts : al., alimentary
tract; o.c, optic capsule; pd., proctodeum, changing
ultimately into cloaca; m.p., muscle plate ; s.n.c, sub-
noto-chordal rod.

5>

[ 212 ]

By Beatrice Taylor,

JOHN AiTKEN, of Edinburgh, seven years ago, proved experi-
mentally that the presence of dust was essential to the
formation of fog and cloud. More recently, it has been
shown that fog may be cleared by the discharge of electricity in a
fog-clouded atmosphere. This dispersion of fog by electricity is,
however, at present too expensive a process to be of practical
utility.

In order that the reader may understand how Mr. Aitken
came to the conclusion that dust was a necessary factor in the
production of fog, I will give the experiments that forced him to
adopt this view. I will also investigate the case of town fogs, and
show that, like the caterpillars of Microgaster glomerata * (often
abused by market gardeners), town fogs are blessings in disguise.

Here is the first experiment. Two receivers were connected
with a boiler. Into one the air of the room was allowed to pass ;
the other was filled with air filtered through cotton wool, a process
which completely frees it from dust. Steam from the boiler was
admitted to the receiver containing ordinary air, and immediately
a white fog appeared within the receiver. Next, steam was
admitted to the receiver containing filtered air. Not the slightest
cloudiness was produced, although this receiver was just as full of
water-vapour as the one first experimented with. Therefore, we
may draw this conclusion : that dusty air — ordinary air — gives a
white cloud of condensed vapour ; dustless air no fogging.

The question at once suggests itself, Why does not water-
vapour condense in its visible form in air free from dust ? It has
been found that particles of water-vapour do not combine with
each other to form a cloud-particle, but that vapour must have a
solid or liquid body — a " free surface "— on which to condense.
Vapour in pure air consequently remains uncondensed and super-

* The parasite on the larva of the White Cabbage Butterfly, a visitor that
should be welcomed by every gardener.

FOGS. 213

saturated, while in ordinary air dust-particles form the nuclei on
which the vapour condenses. Since every cloud-particle is repre-
sented by a dust-particle, the more abundant the dust the more
dense the cloud.

To return to the experiment. When steam was passed into
the receiver containing filtered air, no vapour condensed in its
visible form until circulation brought it into contact with the free
surfaces of the sides of the receiver, when it gradually condensed
on those free surfaces. The density of the fog in the receiver
containing ordinary air indicates what a large amount of dust is
present every day in the air around us. But the particles of fog
do not represent all the dust-particles in the air experimented
upon. They do not tell the whole truth. That the fog-particles
first produced on admission of the steam only represent a small
part of the dust-particles present may be demonstrated by the
following experiment : —

Let as much steam be blown into a receiver containing ordi-
nary air as will produce a dense fog. Allow the fog to settle, but
do not allow any dusty air to enter. After the fog has settled,
blow in more steam. Again you will find a dense fog condensed
on the dust that escaped the first condensation. Allow this to
settle, and repeat the process a number of times, and you will find
that there is still fog forming. But after each condensation the
fog becomes less and less dense, till at last it ceases to be seen,
although on closely looking into the receiver the condensed
vapour will be seen falling as rain.

When the steam was blown in the first time, the fog was very
fine-textured. Each particle was so small that it floated in the
air. After each condensation the fog became less and less dense.
It at the same time became more coarse-grained and heavier, and
was seen faUing slowly. Near the end no fog was visible ;
nothing but fine rain appeared to be falling. If the air was still
further purified, even the rain ceased. In fact, the conditions
that obtained in the receiver containing filtered air have been
brought about, — the air has become completely freed of dust.

At this point it will be interesting to consider the effect of

absence of dust. Every object on the face of the earth would,

like the sides of the receiver that contained only filtered air, act

New Series, Vol, I.

1888, Q

214 FOGS.

as a condenser. Every blade of grass and every branch of a tree
would drip with moisture deposited by the passing air; our
dresses would become wet and dripping and umbrellas useless.
Worse than this, the inside of our houses would become wet ; the
walls and every object in the room would run with moisture.

Before going further, I will state what conclusions we have
arrived at from the foregoing experiments : —

I. — That whenever vapour condenses in the atmosphere, it
always does so on some solid nucleus.

2, — That the dust-particles in the air form the nuclei on which
the vapour condenses.

3. — That where there are many dust-particles a cloud appears
because each nucleus only gets a small allowance of vapour, and
is not made much larger or heavier, so that it continues to float.

4. — That where there are few dust-nuclei, the amount of
vapour condensed on each particle increases, so that the size and
weight of the whole number of particles increases, producing in
them a tendency to settle down. Fogs, therefore, will only be
produced where dust-nuclei are abundant.

5. — That if there were no dust there would be no fogs, no
mists, and probably no rain, while the supersaturated air would
convert everything into a condenser, on which it would deposit
its moisture.

But it will be asked. Where does all this dust, so plentiful in
the air, come from ? And is it the dust we see in a sunbeam ?
Anticipating these questions, I will explain what the sources of
atmospheric dust are. Broadly speaking, anything that breaks up
matter into minute parts contributes a share to the general fund.
The spray of the ocean, when dried and converted into fine dust,
is an important source. Meteoric dust and volcanic dust form
probably another source of supply. But where populous districts
are concerned, combustion is certainly one of the most important
sources. Before, however, giving the experiment by which the
importance of combustion as a supplier of condensation nuclei
has been demonstrated by Mr. Aitken, it will be well to consider
what the fog-producing particles are.

On entering a dark room into which the sun is shining through
a small opening in the shutters, the sun's rays have the form of a

FOGS. 215

luminous bar, which, on looking more closely, we find, is pro-
duced by the dust-motes floating in the air of the room reflecting
the light and becoming visible as they pass through the path of
the beam. And here is the answer to the second question : Are
these the fog-producers ? No. When air containing this dust is
heated or passed through a flame, these motes disappear and the
path of the sun becomes invisible. From this we might conclude
that air which passes over or through a flame where combustion
was perfect ought to be nearly dustless, and therefore ought not to
be a good medium for fogs. But we find air that has passed through
a flame is a good medium. What really happens appears to be
this : — The heating of the air by the flame increases the number
of particles. The heat would seem to destroy the light-reflecting
power of dust by breaking the larger motes into smaller ones, and
by carbonising or in some way changing their colour, and thus
making them less light-reflecting.

The fact that the products of combustion are fog-producers
may be proved in the following way : — Light a gas-flame within a
glass tube, and allow the products of combustion to pass into a
vessel into which steam can be blown when required.

The result of an experiment on these lines is that the com-
bustion of filtered air and dustless gas gives an extremely fog-
producing atmosphere. That the fogging is, however, due to dust
cannot be doubted, from the fact that the products of combustion,
when ^Ifered, give no cloudiness on the admission of steam.

By further experiments, it has been shown that the products of
combustion from a clear or smoky fire give about equal fogging,
and that of all the substances experimented upon sulphur was the
most active fog-producer. In fact, sulphur vapour gives rise to a
fog so dense that it is impossible to see through a thickness of two
inches, a degree of opacity not yet reached by our London fogs.

From these results, we learn that it is hopeless to expect that
by the adoption of fires having a perfect combustion — such as the
gas-fires, now so much advocated — we should diminish the
frequency, persistency, or density of our town fogs. All fires,
however perfect the combustion, are fog-producers when accom-
panied by certain conditions of moisture and temperature. From
this it will be seen that it is not the visible dust-motes seen in the

216 ' FOGS.

air that form the nuclei of fog and cloud particles, as these are
destroyed by combustion, and yet the air remains fog-producing.
No doubt these motes also play their part in condensation, but
their number is too small to be of importance. The fog and
cloud nuclei are a much finer form of dust, are quite invisible,
and though always present in our atmosphere are almost
unobserved.

But more perfect combustion will remote the yellow character
from the fogs and make them purer and whiter by preventing the
production of smoke, which at present mixes with our town fogs
and aggravates their character. It is the smoke that prevents
them dissolving when they enter our rooms, like a well-conditioned
country fog does in a country house.

We all know the saying of the Londoner, " The smuts are
falling ; there'll be rain shortly." This is how the circumstance
comes about :— The smoke-particles are good radiators, are soon
cooled, and form nuclei on which the vapour condenses. The
smoke-particles loaded with moisture are prevented from rising,
and descend into the streets. Therefore, it is perfectly true that
the falling of smuts indicates a saturated condition of the air.

There is another point to consider with reference to our town
fogs — that is, the fact that sulphur, when burned, is an intensely
active fog-producer. Calculation shows that there are 200 tons of
sulphur burned with coal every winter's day in London. This,
together with the high fog-producing power of ammonia, accounts
for the density of London fogs.

Before, however, condemning smoke and sulphur, we must
look for their good points. Like the good points in character,
they do not lie on the surface and annoy us as the bad ones do.

Full consideration must be given to the value of smoke-
carbon, as a deodorizer ; so, too, to the powerful antiseptic pro-
perties of sulphurous acid, formed by the burning sulphur. The
air during fogs is still and stagnant. There is no current to clear
away the foul smells and noxious germs that float in the air, which
might be more noxious than they are, were it not for the suspended
soot and burned sulphur.

[ 217 ]

lEconomic lEntomoloo^.

Presidential Address to the Highbury Microscopical
Society, by James A. Forster.

I PROPOSE in the following paper to give, in the simplest
language, some few facts and observations illustrating what I
would venture to term " Economic Entomology," and which
I would describe as the natural history of the insect friends and
foes of the gardener and agriculturist.

The importance of the study of Economic Entomology is, I
think, very generally much underrated. The entomologist is too
often regarded with a sort of mild scorn as a man who pokes
about in odd places and who finds his pleasure in childish
pursuits, or as an enthusiast wasting his time over very insignifi-
cant things and claiming for them a preposterous importance — in
fact, as an example of the old adage that " Small things amuse
small minds." This, I hold, is not even just to the mere collector,
but when applied to a true student of insect life is simply an
opinion born of ignorance. Small in size, indeed, are the animals
he studies, but their importance in the economy of nature is very
great and the study of their lives a most difficult one, requiring a
highly-trained observation, unlimited patience, unflagging zeal,
and in addition to these, a humble reverence for Nature ; for to the
arrogant and careless she will never tell her tale or disclose her
secrets. To the insect world we owe our most beautiful dresses,
famous and much-esteemed food, and some of our loveliest
flowers. On the other hand, some of our direst misfortunes have
been occasioned by insects, countries have been devastated by
them, nations reduced to the verge of starvation, travelling ren-
dered impossible, flocks annihilated. Surely the study of
creatures capable of affording us such benefits and of inflicting
such miseries cannot in any sense be deemed futile, simply
because they are, for the most part, small in size and insignificant
in appearance. Insignificant are they only to our unaided human
eyesight. Bring the microscope to our aid, and away vanishes
their insignificance, and they stand out revealed in all their

218 ECONOMIC ENTOMOLOGY.

wonder as creatures endowed with a beauty and strength that
even the higher branches of the animal kingdom cannot rival.

That the microscope has so furthered our knowledge of, and
is so essential to, the study of insect life, I think sufficiently
justifies my choice of a subject. I believe the subject is no
unimportant factor in one of our greatest national problems — viz.,
the Agricultural question. For, as it is evident that the conditions
of agriculture in this country are undergoing and must undergo
great changes, to result, probably, in the giving-up of the old
methods and the old productions, and the development of dairy-
farming, and the cultivation, at present neglected, of fruit and other
products now largely imported from foreign countries — if this
comes about, a national knowledge of insect life as affecting agri-
culture will become of increasing necessity, for with every new
cultivation will come new dangers from our insect enemies. Many
an insect at present rare in this country, and of no general or
economic interest, may, through the introduction of some new
crop or some new method of working the land, suddenly become
a most formidable plague, placing the prosperity of the cultivator
in the utmost peril. Such dangers can only be met and com-
bated with success by a thorough knowledge of these minute
creatures : their lives and habits, their histories, and, above all,
their enemies themselves, for the most part insects. The majority
of farmers and gardeners regard all insects alike as things to be
killed wherever seen, and in carrying out this theory murder some
of their best friends, while many of their deadliest foes, from
their habit of closely concealing themselves or from their minute
size, escape detection.

An important element in the education of a farmer should
be the teaching the use of the magnifying lens and the natur-
alist's habit of close and minute examination and accurate
estimation of the facts he observes. Indeed, not only for the
farmer is this teaching necessary, but I would urge that it, with a
general teaching of zoology, ought to form a distinctive part of
every boy's education. I mean that Natural History should not (as
is now mostly the case where it is taught at all) be taught as an
extra subject, but it should have a prominent place in the curricu-
lum of every school, to be taught with as much regularity and

ECONOMIC ENTOMOLOGY. 219

earnestness as grammar or language. These, surely, cannot excel
it as a means whereby to train the youthful intellect to habits of
close, careful, and accurate reasoning, order, and patient attention.
The study, properly directed, of God's creatures can hardly be of
less value as a mental and moral training than that of a dead
language, and must necessarily bear much more nearly on our
daily life.

The insect kingdom — by far the most numerous in species of
any corresponding group throughout animal life — is, as you are
aware, classified into some twelve or thirteen principal families.
Each of these families sends its quota to the host of the insect
marauders of our gardens and fields. Happily for us, each group
also contains not only species, but entire families, whose object in
life is to prey upon these pests, to hunt them down, to devour
them in each stage of their life. Thus has Nature put a check
upon their increase, without which the human race would quickly
have been eaten out of the land. Without these natural allies,
we should have been powerless to overcome these deadly if
minute enemies — the more deadly, indeed, because of their minute
size, which renders it so difficult for us to discover them till the
mischief they cause is well-nigh irremediable.

It is, then, evidently of the first importance that we should
acquire that knowledge which shall enable us to recognise our
friends so as not to confound them in the wholesale destruction
we attempt to bring about of our pests. As a first step towards
this knowledge, it is to be observed that the Insecta — Uke the
higher animal kingdoms — comprises groups of vegetable-feeders
and of flesh-feeders. Now, it is amongst the former that are
found those insects that cause the most serious losses to our
various crops ; while it is to the latter — to the predaceous and
carnivorous class — that we are indebted for the keeping within
bounds, the enormous increase of the devourers of our fruit and
food that would otherwise take place by reason of the wonderful
powers possessed by them of reproduction. It is thus, as in so
many instances throughout life, that Nature provides, as it were, a
natural balance of forces, and I would ask. What can we do more
wisely than avail ourselves of Nature's own means of keeping
in check the myriads of foes that would, if left to themselves,

220 ECONOMIC ENTOMOLOGY.

turn our fields and our gardens into barren wildernesses ? Had
our hop-growers perceived the truth of this, and persistently
and patiently fostered by every means in their power the
settlement in their gardens, and the increase, of aphis-eating
insects, such as the Lady-birds {Coccinelltdce), they would have
largely mitigated, if not entirely prevented, the almost incal-
culable losses they have suffered from the so-called " black
blights," which, instead, have become of increasing frequency
during the past fifty years. The great loss caused by the ravages
of aphides alone to hop-planters and the whole community may
be well brought home to us by the following facts and figures : —

In 1882 a serious blight occurred throughout the hop-growing
districts of England, causing a reduction of the average produc-
tion from 7 cwts. per acre to less than if cwts. Now, as in that
year the hop acreage was about 65,600 acres, the total yield of
which was under 115,000 cwts. instead of 460,000 cwts., it follows
that the loss on the crop was about 345,000 cwts., which, taken at
the average price of hops for the preceding twenty years {;£'] 7s.
per cwt), amounts to over ^,^2, 500, 000 sterling loss in that year
to the cultivators alone. But it was not they alone who directly
suffered for it. It is estimated that not more than ;^i 50,000
was paid that season for the picking of the crop, while had it
been an average one, the cost of picking would have amounted
to nearly ^^400,000. So nearly a quarter of a million sterling
was lost to the labourers in that one season. What an amount
of misery is expressed in these figures !

A few facts concerning our apple-orchards may further serve to
justify my claim for the economic importance of my subject.
There are in England, according to recent agricultural statistics,
at least 250,000 acres under fruit cultivation, of which by far the
larger part is occupied by apple-orchards, forming a very important
item in the crops of many districts in Devon, Somerset, Hereford-
shire, and Kent. Now, the apple, amongst its many enemies,
suffers from the attacks of two little moths and their caterpillars —
the small Ermine moth ( Hyponomenta -badelld) and the Codlin
moth ( Corpocapsa po7no}idla). The former, in the years 1865 and
1887, entirely devastated whole orchards throughout Kent and
also the West of England. Hundreds of acres of orchards were

ECONOMIC ENTOMOLOGY. 221

to be seen in the month of July of those years without a leaf
upon them — as bare, in fact, as though in mid-winter. Every leaf,
every bud, every blossom, had been cleared off by innumerable
swarms of Ermine moth caterpillars, which had not only entirely
destroyed the crop for the season, but had so seriously injured
and weakened the trees that they produced but very small and
poor crops in subsequent seasons. Again, in 1880, much damage
was done by the same insect.

In 1877, the second of the above-named moths, the Codlin
moth, caused much mischief to the orchards of Kent, where, it
was estimated, about thirty per cent, of the apples fell immature
by reason of the maggot having penetrated to the core. And,
further, it was found that a large portion of the fruit that did
ripen would not keep from the same cause. As this moth spe-
cially attacks pippins and the choicest descriptions of dessert
apples, the pecuniary loss to the growers must have been very
large ; but as there are no official statistics it is not possible to
estimate the amount. In the cider-producing districts, the des-
truction of half the crop, which frequently takes place through the
ravages of these two insects, must represent a very heavy loss to
the farmers. Very frequently the above mischief is attributed
to the weather, to the east wind, to that all-embracing word when
used by the gardener, " Blight " ; but if the observers would look
closer and more accurately the true enemy might easily be dis-
covered. When a gardener, seeing one of his trees with all the
leaves shrivelled up, drawn together, and enveloped, as it were, in
cobweb, with the blossoms falling off before mature or not
opening at all, tells you in a mysterious manner that there is a
"blight in the air" or that the tree is "struck," he is only con-
fessing his ignorance and want of observation, and consequent
inability of taking such precautions as shall render a recurrence of
the misfortune unlikely or at any rate less severe.

The limits of this paper and my lack of knowledge alike
render it impossible for me to attempt more than to describe a
very few of our insect foes ; but these that I shall now men-
tion will serve as a sample of the rest, and the consideration of
their life-histories will, to some extent, indicate the methods of
observation necessary for their study. As I have already said,

222 ECONOMIC ENTOMOLOGY.

each of the great insect families contributes its quota to the
devastating army. Certain families — notably, the Beetles (Coleop-
tera), the Bees, Wasps, Ants, etc. (Hymenoptera), the Ephemeras,
Dragon-Flies, etc. (Neuroptera) — send us friends as well as foes ;
others — like the Aphides (Homoptera) are unmixed evils.
The Aphides are, perhaps, the most terrible and dangerous
of all our scourges, and one of the most difficult to overcome,
their amazing power of increase being unequalled throughout the
animal kingdom. There is scarcely a plant that is not attacked
by them, nor a locality where they are not to be found in numbers,
and, under their popular name of " blight," dreaded by all gar-
deners and cultivators. At first sight it would hardly seem that they
could be worthy of much attention. Their round, short bodies,
nearly all belly, are carried on the frailest of legs ; their habits are
so sedentary that they seem intended to remain stationary ; where
they are born, for the most part, there they live and die, without
giving any evidence of the instinct so frequently met with in
insects. Their lives might almost be described as vegetable.
Yet their organisation is most singular, and their fecundity in
certain seasons so prodigious as to make them a real scourge.
They infest every kind of tree, plant, or flower. The rarest
flowers in our hot-houses and the commonest flowers of the
hedgerows alike serve them for home and food ; in short, they are of
all climates and all seasons.

They are both oviparous and viviparous. Their eggs, fixed to
the plants by a viscid secretion, have the appearance of little,
black, oval, shiny grains, deposited irregularly in large numbers on
the sheltered side of branch or leaf. The young larva when extruded
from the egg is nearly of its full size, and presents but little differ-
ence in appearance to the perfect insect. It emerges from the
egg by a sort of trap or cover, and falls out backwards. Shortly
after their birth, the young aphides work tlieir way on to the tender-
est and greenest part of the plant on which they find themselves.
They crowd close together, their heads usually pointing to a
common centre, and fix themselves by means of the large beak
with which their mouth is furnished, and through which they
incessantly suck up the sap of the plant, exhausting it and causing
strange excrescences like galls, and in the end the plant becomes

ECONOMIC ENTOMOLGY. 223

deformed and ruined. When three days old, the larva changes
its skin ; this is repeated three times at similar intervals. For the
greater number, these metamorphoses produce but little change in
appearance beyond a small tail, which develops at the end of the
abdomen. When about nine days old, the female aphis (condi-
tions of food and temperature being favourable) begin propagating
their species by giving birth to living larvae without having had
any connection with the male. This has been described by
Professor Owen as follows : —

" This larva, if circumstances of food and warmth be favour-
able, will produce a brood — indeed, a succession of broods of larvse
— like itself without connection with the male. In fact, no winged
males will have appeared, [f the virgin progeny be also kept
from any access to the male, each will again produce a brood of
the same number of aphides, and carefully prosecuted experi-
ments have shown that this procreation from a virgin mother will
continue to the eleventh generation before the spermatic virtue of
the ancestral coitus has been exhausted."

In favourable seasons, a certain portion of the third and
fourth of these viviparous generations undergo special changes.
At the first moulting small processes are observed on the back
These at successive moultings become largely developed, and
after the fourth and last change of skin appear as large, fully-
formed, transparent wings, on which the insect can fly away to
fresh fields and pastures new. These winged aphides produced
during the summer are always females. When two or three days
old they take their flight to found new colonies. After the fourth
generation, no further winged females are produced.

Towards the end of autumn the generations, usually eleven in
number, approach their close, and the last brood produces a
certain number of winged males, who fly off in search of partners.
Reproduction then follows its normal course. The females, after
marriage, give birth to no more living larvae and produce only
eggs. These remain during the winter protected by impervious
shells from the cold, which would destroy the soft larvae. In the
spring these are hatched, producing larvae as already described,
who in their turn repeat the viviparous generations.

This is a brief outline of the life-history of the aphis family,

224 ECONOMIC ENTOMOLOGY.

which contains many species, many of them only too well known
to most of us, like the Hop-fly [Aphis hutnuli). There are various
species peculiar to certain fruits and plants. Indeed, each fruit
seems to have its special aphis. Thus, we have the Apple Aphis
{A. malt), the Plum Aphis {A. prttni), the Currant Aphis {Rhopa-
losiphiwi j-ibis), and many others. Mr. Whitehead writes of the
Apple Aphis : —

" The Apple Aphis, or Green Fly (by which appellation it is
better known), derives its food solely from the juice of the leaves
and blossoms. It makes its appearance as soon as the buds begin
to swell and the leaves show signs of coming forth, and it follows
up the blossoms from their earliest development. The aphis
attacks the blossoms, being specially attracted by their saccharine
qualities, and either prevents the process of fructification or so
besets the tiny fruits that, weakened by the extraction of their
juices and begummed with viscous honey-dew, they are unable to
set properly. The fruit that perchance survives rarely attains to
full size, shape, or quality. As the leaves come out, their under
surfaces are occupied by the aphis, and soon curl up, get black,
and fall off, leaving the trees bare, and emitting a sickly smell
from all sides."

The aphis is one of the main causes of apples falling imma-
ture from the trees, and also largely affects the quality of the cider
in certain seasons. This species is found all over the world.
The Americans, however, claim that the pest was introduced in
their orchards by trees brought from Europe. Another species
very injurious to orchards is known as the Woolly Aphis, or Ame-
rican blight {Schizonema lanigerd) Everyone who has closely
noticed apple-trees will have frequently remarked knots or bunches
of a downy or woolly substance on parts of the stems and in
interstices of the bark. This is very frequently supposed to be a
form of mildew, but if closely examined it will be found that this
woolly substance covers little groups of aphides, all actively
engaged in extracting the sap. This form is specially liable to
attack newly-pruned trees if the cutting has been done carelessly.
Old and neglected orchards, of which there are too many, are the
special home of this pest, the lichenous and moss-covered stems
exactly suiting it and enabling it to remain unsuspected, while the

ECONOMIC ENTOMOLOGY. 225

trees attacked become after a time covered with swellings,
checking leaf and blossom, and ultimately causing both stem and
twigs to decay. This state is frequently called canker, and is
attributed to any cause but the right one — the exhaustion brought
about by the persistent suckings of myriads of larv^.

I have dwelt much longer than I intended on the Aphis ; but
before I pass on to other of our insect troubles, I must say a word
or two about the Phylloxera {P. vastatrix), which, although not
occurring in this country, has produced such wholesale destruc-
tion in the French vineyards, that its name has become known
throughout the claret-drinking world. The Phylloxera is a species
of Aphis of very small size, and somewhat different in form from
the species known in this country. It first appeared in France
about the year 1863 or 1864, and is supposed to have been
brought from America. It attacked first the Gard district ; then
rapidly spread to the south and west. Its minute size renders it
almost indistinguishable without a glass, and its appearance is like
a little yellow powder adhering to the stem of the vine. It is
oval in form, is furnished with two vigorous antennae, and has an
articulated beak more than half the length of its body. This,
when not in use, is folded against the lower side of the thorax,
where it lies between the six little legs. Its body tapers some-
what towards the extremity. Their changes and metamorphoses
are very similar to those already described. Towards the twen-
tieth day of their life, on their attaining the adult stage, their
abdomen enlarges on the sides, and four mamelons appear, and
immediately after the insect lays a batch of eggs. Each female
lays about thirty eggs in each batch, and as there are eight gene-
rations each year, the six months between April and November
suffice to produce such a horde of the voracious creatures that
more than half the vineyards of France have been destroyed by
them. And even supposing means be found to extirpate them, it
will require ten years for the mischief to be made good and the
vineyards restored.

The evil caused to the vine by the Phylloxera is a complete
draining of the sap from the stems. They attack only the main
stems, which furnish them most abundantly with the nourishment
they require. In spite of the attack of these countless hving

226 ECONOMIC ENTOMOLOGY.

pumps, which work incessantly, the vine-stems continue a most
rapid growth, more so than if in their normal and healthy state ;
but they become yellow instead of white, then gradually pass to
brown, the shrivelled bark serving as a lair for the Phylloxera.
As the evil continues, the bark becomes more and more folded
and shrivelled, until at last it assumes a blackish tint and falls in a
state of decay. The insects then abandon it to make fresh
attacks on fresh vines. Failing fresh plants, they attack the prin-
cipal roots, destroying their outer coverings after penetrating well
below the bark. When one root is annihilated, they work under-
ground to another, occasionally coming on to the surface of the
ground to hunt for healthy vines.

If not easy of detection in the commencement, the Phylloxera
cannot be overlooked after a time. After a vineyard has been
infested for two or three years, the stems attacked underground
produce only a leaf here and there. These are small and mal-
formed, and after languishing for a time turn yellow and roll up.
The whole plant dwindles, the grapes, arrested in their develop-
ment, hardly form, the pips split up, all fructification disappears,
,the leaves get thinner and smaller than ever, and soon the vine-
yard presents the aspect of complete ruin. And ruin it is, for the
only cure is the thorough burning of the old vines.

Many remedies have been suggested, but I do not think any
have been attended with much success. M. Dumas proposed the
employment of a concentrated alkaline solution of sulphate of
potassium, or soda, and the ammoniacal sulphate produced in gas
works. It is believed that this, if carefully used, would be efficacious,
as the Phylloxera would be poisoned and the vines probably much
benefited and strengthened by this chemical manure, but one
important difficulty arose, viz., the question of expense, which is
prohibitory.

Monsieur Bazille, of Montpellier, is stated to have employed
with success, a dressing composed of cow's urine, an alkaline
sulphate, and Yio of oil or tar. I, however, think the true and
practicable preventive for the attacks of the Phylloxera has yet to
be discovered, and considering the immense interests at stake, such
a discovery would be well worth making, and the discoverer would
deserve well of France and the world.

ECONOMIC ENTOMOLOGY. 227

The chief natural enemies of the Aphis family are found among
the Beetles {Colcoptera), one family of which, the Lady birds
{Coccincllidcc), are the great destroyers of Aphides, on which these
beetles, both in their larval and perfect states, feed with the utmost
voracity, and no better precaution can be taken against the attacks
of " Blight " than the colonisation of Lady birds in our gardens.
Another most valuable insect ally for this purpose, is the common
gauze-wing fly, sometimes called the "Stink fly" {Chrysopa peria).
It is well known in gardens, is delicate green in colour, has a long,
thin body, four very delicate wings, and two exceedingly bright
golden eyes. When handled it imparts to the fingers a most
disgusting scent; hence its name of Stink fly. This fly in the
perfect state preys on the Aphis, hovering over the infested plants,
alighting from time to time to snatch up some of its living food ;
but it is in the larval state that it does the most execution.

Among beetles we have many enemies, notably among whom
may be mentioned the Skip Jacks {Elateridce), known in their
larval condition as Wire worms ; the May bugs and their allies
{Alelolonthidce) ; the Weevils {Curculionidce), attacking corn, etc.,
in store; the Corn Beetle {Trogosita Mauritanicd) ; the Meal
worm, another of the same family ; the Pea Beetles {Bnichidce) ;
the Pea Weevils {Sitonidce) ; the w ood.-honx\g H}'ksinid(2, of which
the Scolytus destructor, too well known in our parks, is a good
example ; the family of Lotigtcor/ies, deadly enemies of
forest trees ; and the Chryso7nelidce. or Golden Apple Beetles. It
is evident the limits of this paper would not permit me to give a
life history of each of these destroyers. They are, with a host of
others I have not enumerated, formidable destroyers, largely and
directly affecting the profits of the farmer, though very frequently
he has no idea of the cause of the failure of his crop, perhaps
does not even know of the existence of the tiny ravager who has
robbed him of the fruit of his toil. Take, for instance the Wire-
worm. This {Agriotes lineatus), in its perfect state, is a narrow
brown beetle about ^5 of an inch long, with long wing cases or ely-
tra covered with parallel lines. They present somewhat a flattened
appearance, and the thorax is produced into spines at the hinder
angles, and underneath, the breast plate is produced into a long
point. They are remarkable for their great power when placed on

228 ECONOMIC ENTOMOLOGY.

their back, of jumping or throwing themselves into the air
by means of a sudden jerk of the thorax, in effecting which the
thoracic prolongations come into their places with a sharp sound
like the shutting of a spring. Hence their popular name of Click
Beetles or Skip Jacks. In the perfect state it is probable the
beetle does little or no harm to the crops, but in the larval stage
it is most formidable. The larva is something like the meal worm,
but more slender and elongate ; it is yellow and exceedingly tough,
like wire, whence its familiar name of Wire worm. They have, I
believe, no eyes, but possess a short, four-jointed antennae, and are
furnished with short, robust legs set close together. The apical
segment, possessing an anal prolongation, is especially hard and
frequently toothed ; they are found everywhere at the roots of
plants.

The attacks of Wire worms are most serious to sainfoin and
clover crops, also to pasture lands, the finer grasses being invari-
ably chosen, and the frequent failure of the grass seeds results
probably more often from the work of the Wire worm than from
any other cause. It is throughout the United Kingdom a continual
source of harm and loss to every description of corn crops. The
Wire worms fix their heads into the soft part of the stems, and with
their hard, strong jaws gnaw away the tissues so as to entirely
arrest the circulation of the sap. The insect remains in the
larval state for several years (the limit generally accorded is five
years), but it is difficult to ascertain the exact period. It is this
long, larval stage that causes them to be specially dangerous to
those crops, such as sainfoin, that remain on the land two or three
years. When full grown the larva descends deep into the earth to
undergo its transformation. It remains for a fortnight in the pupa
condition, when the perfect insect emerges and comes to the surface
of the ground. Fortunately this pest may be got rid of. A field
that is infested with it should be thoroughly and deeply ploughed
and scarified, and all growth in the soil rigidly destroyed. It
should then lie fallow for a winter, and in the spring again carefully
gone over to stop all weed growth, then be sown with tares. After
this a crop of mustard should be put in, and the Wire worm will
be effectually starved out, for numerous experiments have proved
that it cannot eat either of these plants.

ECONOMIC ENTOMOLOGY. 229

Other classes of Insect Enemies are the Cecidomiters or
Midges, of which the Uttle Wheat Midge may be seen at most
seasons flying in swarms on the edge of wheat fields. These later
on deposit their eggs within the wheat ears. The eggs soon hatch
out little white maggots, which then bury themselves into the
stigmata of the flowers of the wheat plant, thus hindering the
development of the grain, and frequently reducing the crop by a
fifth or more. In some years the amount of destruction
occasioned by it is very great.

Another most mischievous insect and very troublesome to get
rid of is the well-known Daddy-long-legs {Tipula oleracea.) The
female fly is stated by Curtis to contain some 300 eggs, forming a
mass which fills nearly the whole of the abdomen. These she
deposits in the autumn on the grass, they hatch out in the early
spring, and burying themselves into the ground soon grow into
dirty-looking grubs, an inch long, having very tough skins. They
are destitute of legs, but still have the power of burrowing rapidly
in the ground. They make their burrows a little below the
surface of the ground and among the roots of the grass on which
they feed. So actively do they work and feed that they quickly
kill off a patch of grass, and their presence underground is then
made known by an ugly brown dead patch on lawn or field. The
best remedies we can avail ourselves of against these pests are the
birds, especially rooks and starhngs, and also the much slandered
moles, which, as devourers of grubs of all sorts, wire worms, etc.
are simply invaluable, and should be cherished instead of being
killed and trapped as noxious vermin.

The injury we suffer from the Caterpillars of Moths and

Butterflies is probably much better known than that caused by

other classes of insects ; still, the ignorance of gardeners and

cultivators regarding these creatures, which are comparatively so

easy of observation, is astounding Among the lesser known, but

not the less dangerous on that account, are the caterpillars feeding

in the interior of the stems of various plants and shrubs ; one of

these, the clear wing moth larva, will serve as an example. The

moth is small, having more the appearance of a fly than a moth,

its wings being almost destitute of scales ; it lays its eggs on the

bark of currant-bushes. The larva on emerging from the egg

New Series. Vol. I.

1888. R

230 ECONOMIC ENTOMOLOGY,

immediately eats into the middle of the stem and then continues
eating its way along the pith, always working upwards. It goes on
feeding the whole of the autumn and a good portion of the winter,
and emerges as a moth the next summer. When a bush is attacked
by this creature nothing can save it, and the only thing to be done
is at once to cut away right down to the ground all the doubtful
stems and carefully burn them. This should be done in the
winter.

I have now touched in the most superficial manner upon four
only out of the 13 orders of insects, but I have more than exhausted
my space and I fear my readers' patience. If, however, any remarks
of mine shall induce anyone to study and observe the lives of these
creatures that are competing with us for our food, I feel sure I
shall have done some good. The field of research into the lives
and habits of insects is open to all, and the knowledge to be
gained is probably of far more importance to the world and likely
to result in more direct gain to mankind than most of us
dream of

Finally, I would venture to suggest that the study of insect life
is just the work a society such as ours might most usefully follow
up. I have always considered that we, as a society, would be
likely to be more successful, if each season we set ourselves some
special task, some subject to be thoroughly worked out and
ventilated at our meetings. We should thus certainly secure new
interests and pleasures in helping each other in our common study,
and should further justify our existence as a scientific society.

The Discovery of boulders in coal-seams has raised a difficulty
concerning the usually-accepted doctrine that beds of coal have
for the most part been formed of the remains of trees and plants
that grew on the spots where coal exists. It is now thought that
the immense beds of vegetable matter could never have grown bi
situ, but that they have been carried down from mountain-sides
by avalanches. Examples of this kind may be seen in the lakes
of Ancient Tyrol, of which the Aachensee furnishes the most
striking. In its deep, clear water, hundreds of trees may be seen
in an upright position, which have become soddened with water
and then have sunk to the bottom. The fjords of Norway
also afford examples. If this theory be correct, the presence
of boulders can be easily accounted for.

[231]

®n the fIDale (Bcnerative ©rcjans of ^wo

Species of C^pris :

CvUHis cincrea auD Cypris mlnuta.

Plates XXII. and XXIII.

By T. B. Rosseter, F.R.M.S.

BRADY, in his excellent monograph on the " Recent British
Ostracoda," published in Vol. 26, Trans. Linnean Society,
p. 374, places in the sub-genus Cypridce (Zenkier) a new
species, and gives it the specific name of Cinerea — ash-grey. He
says:— "It is distinct from any other British Cypris, and that he
has not been able to identify it with any of the numerous species
described by continental authors." It is plain, from Brady's
description, that he had only the female under consideration, for
he is silent about the male, but so exact is his description of this
species, that anyone having made himself acquainted with the
results of his investigations could not fail to recognise it when
seen. He only found it in one locality, viz. — in a pool on the
summit of Mickel Fell, Yorkshire, at an elevation of 2,000 feet.
It was during the month of December, of last year, that in a
stock-bottle, containing both sexes of C. mimita, I found some
specimens of Cypris, unknown to me, but which proved after-
wards, on reference to Brady, to be females, and one solitary
male of C. cinerea.

During the month of June last, I found both males and
females of C. cinerea in a pond at Churchwood, at an elevation of
220 feet, the property of the Dean and Chapter of Canterbury
Cathedral. I have not found it to be common, and do not think
it is so. When I discovered it, I plumed my feathers and fancied
I had found a new species, not only of the female, but of the
male Cypris also. At this time, I was conversant only with
" Baird's British Entomostraca," and could find nothing there to
satisfy my mind in connection with it. Not being aware that
Brady had discovered and described it, I made some careful notes
of both sexes, and, although I must confess I was somewhat dis-

232

THE MALE GENERATIVE ORGANS

appointed to find subsequently that the female was known to Brady
and that I was only second in the field, still, it was a consolation
to know that my observations concurred with his, and what was
still more gratifying was, that he gave no account of the male, nor
did he figure the male genital organs. I came, consequently, to
the conclusion that he had not seen it, and determined to
continue my investigations in that direction.

The following is a comparative description of C. cinerea, male
and female : —

Cypris cinerea (male), Rosseter.

Shell, oval; colour, ash-grey;
second antenna bears five long
setoe, the rest short; its claws, and
those of first foot, are not serra-
ted. The second foot bears three
setEe, one extremely long, being
two-thirds the length of foot,
and two short setae of equal
length. Post abdominal-rami
as in female, second maxillae
chelate; length, one-fortieth of
an inch ; breadth, one-fifty"
seventh of an inch.

Male organs consist of Bursa-
copulatrix, with intromittent
organ, and a paired mucous
glandulosa testis. Locality,
Churchwood, Harbeldown, Can-
terbury.

Cypris cinerea (female), Brady.

Carapace, oval ; surface of
shell, finely and closely punc-
tate ; colour, ash-grey. The
second antenna has three setee,
very long, the rest short ; its
claws, as those of first foot are
long, slender, and destitute of
serratures. Terminal set^e of
second foot, very stout from
base to the middle, then con-
stricted, and tapering to the
points. Post-abdominal-rami,
stout ; claws, short and stout ;
the lateral sette, and those on
inner border of the ramus, very
short and slender. Length,
one thirty-fifth of an inch ;
breadth, one-fifty-fifth of an
inch.

On comparison, it will be seen that there are some particulars
in the description of the male which do not correspond with
Brady's description of the female, but these are comparatively
slight. I allude, in the first place, to the filaments of the second
antenna, to which I have given very careful consideration, and
find that the same number of filaments exist in both sexes. The
long filaments, as they approach their termination, give off very
fine branches. These might easily be overlooked, and only

OF TWO SPECIES OF CYPRIS. 233

revealed themselves to me under a one-eighth objective, and then
very faintly, but with a one-sixteenth immersion they were dis-
tinctly seen. I also found that one of the short setse was
distinctly plumose (PI. XXII. Fig. 5). This is situated on the
inner side of the antenna, and is not mentioned by Brady.
Again, although it is said the claws of the first feet and second
antenna are not serrated, still, near the apices on the inner border,
are to be seen some very fine, close-set setcC, which seem to stand
out boldly from the margin of the claws. The male is, as a rule,
a trifle smaller than the female.

Brady, in order that his new species may be recognised, gives
two drawings : one of the post-abdominal rami and the other of
the second foot of the female. If we compare the second foot of
the male (Fig. 6) and that of the female (Fig. 7) with Brady's
drawing of the second foot of the female,* we shall be convinced
that one is the counterpart of the other. The long seta of the
second foot seems to be an articulated organ, capable of being
bent back on itself The two short setae are of equal length and
rigid ; their length is the one-six-hundredth of an inch. This
close comparison of the second foot, I think, establishes its iden-
tity as the male of C. cmerea, for although in outline the bursa
somewhat resembles C. compressa, the second foot of the latter
gives a decided negative to its being that species.

Even to a practical observer, it would be difficult, from exter-
nal appearances, to distinguish the male from the female. Its
conformation is in every respect similar. The anterior portion of
the male may, perhaps, be a little more rounded than in the
female, but the difference is not very apparent.

The male organs consist of a paired mucous-gland, a paired
bursa copulatrix, and intromittent organs. The mucous glands
are situated in the posterior portion of the carapace in the dorsal
region. They are in apposition one with the other, and are
nearly vertical. They are cylindrical, and composed of seven
whorls or rings. The five intermediate whorls are beset with long
filaments. The anterior whorl appears, when seen hi situ, to be a
perfect circle ; the periphery projects from the axis of the body,

* See Plate XXXVI., Figs. 7 and 9, Brady's Monograph of British Ostra-
coda, Vol. 26, Trans. Linnaean Society.

234 THE MALE GENERATIVE ORGANS

and is armed with strong spines, which are thickened at the base
and tapering towards the end. The posterior is a fac-simile of the
anterior. On each end we get a protuberance or crown. When
the anterior crown is flattened by pressure — as, for example, by
the cover-glass — we find a circular orifice, or stoma, whose dia-
meter is the one-two-thousandth of an inch {Fig. 3). It is com-
posed of eleven segments or petals These petals, in their natural
position, seem to perform the office of valves. This orifice is the
commencement of the vas deferens, which lines the interior of the
mucous gland, and, passing out at the posterior of the same, con-
tinues its course for a short distance in a straight line, and then
takes on a spiral form,* whose end straightens out and enters the
bursa copulatrix by the ligamentous tissue that binds the bursse
together at their lower extremity.

The bursa copulatrix in Cypris cinerea is a clasper- or pincer-
like arrangement ; the chelate ends resemble the claws of the
first pair of the thoracic members of the lobster (Fig. i). It is
situated in front of the post-abdominal rami, and, like the mucous
glands, lies in apposition, with its chelate ends pointing towards
the posterior portion of the body of the creature. It is com-
posed of chitine, and resists the action of liquor potassse, yet the
alkali differentiates its structure and facilitates the tracino; of the
intromittent organ.

The spermatozoa, when it enters the bursa, does not go direct
to the intromittent organ, but ascends up the curved side of the
bursa, turns on itself, and passes through an arched, chitinous
canal, and then passes into the intromittent organ, so that when
conjugation takes place, which it does on the ventral side, the
male anchors itself by the hooked palpus of the second maxilla ;
then, bending its body down until the claws are close under the
vulva, in which position they take a firm hold of the female.
This act brings the double intromittent organ in close connection
with the double vagina of the female, and causes the emission of
the spermatozoa into the receptaculum of the female. The
length of the bursa from tip of chela to base is from the one-
hundred-and-sixtieth to the one-hundred-and-seventy-sixth of an
inch, its greatest width, the one-four-hundredth of an inch. By

* The homologue of this is the vasa efierentia in the female.

OF TWO SPECIES OF CYPRIS. 235

this it will be seen that the bursa copulatrix of Cypris is the
reverse of Cypridina Medi terra nea*

Intromittent organ (Fig. i, c). — This is a paired organ, and is.
situated nearly in the centre of the bursa, close under the arches,
which receive and carry the spermatozoa previous to its entrance
into this organ (Fig. i, l>). It is a dropsical-looking organ, and
may be divided into two parts : the posterior and the anterior
portions. The former is an ovoid body, its upper end being the
broadest, and receives the spermatozoa from the canals. Its
downward course is somewhat diagonal, tending towards the base
of the bursa. The lower end, where it joins the anterior portion,
forms a kind of elbow. There it makes a junction with the ante-
rior half, which continues its course in a transverse direction
towards the flattened edge of the bursa. The intromittent organ
has no nodule, but the termination is somewhat bulbous. Its
edges lap over and form a wide, circular orifice, through which the
spermatozoa passes. Its length is one-thousandth of an inch and
diameter one-two-thousandth of an inch.

The Spermatozoa. — With respect to the spermatozoa, Mr.
Hervey, F.C.S., and myself spent much time, and jointly made
some careful investigations in connection with it. It is but fair to
state that part of our time was spent in investigating that of C.
miniita, and as the histology of one, and more especially as touch-
ing the question of mobility, is but the counterpart of the other, I
prefer giving an account of our researches under this heading.
Professor Huxley, quoting Zenkier, says that " the spermatozoa is
totally deprived of mobility."t If by mobility we are to understand
active inoveinait, then we join issue and say that, according to our
investigations, this statement is incorrect. It is immaterial
whether we take the spermatozoa as it exists in the male, or after
its injection into the spermatheca of the female. The result is
the same — viz., that it possesses very active properties. In dis-
secting the animal I use a suture needle with a flat back, and with
this, under a dissecting microscope, I gently crush the Cypris just
enough to crack the shell. Then with fine pointed needles I tear

* See Clans. Ostracoda, p. 425, Fig. 336, Sedgwick's translation,
f "Anatomy of Invertebrata," page 252.

236 THE MALE GENERATIVE OEGANS

away the carapace, leaving the body of the creature as bare as it is
possible to be. I then tease out the spermathecce, but cannot
always succeed in extracting them whole. The spermathecae are
paired organs, somewhat pear-shaped, the membranous tunic
being capable of great distension, yet when empty, in consequence
of the spermatozoa being used up, become very atrophied — in
fact, almost obliterated. They are difficult to preserve. I have,
however, succeeded in mounting them in glycerine, after being
emptied of spermatozoa by pressure (Fig. 8). When the sperma-
theca is filled with spermatozoa, it resembles an old-fashioned ball
of cotton, the zooids crossing and re-crossing each other. If a
cover-glass be placed gently over them so as not to crush or
rupture the tunic, we are able, with a one-eighth inch, to see the
mass of spermatozoa in a state of agitation, writhing like innu-
merable microscopic worms. It was at this stage that we com-
menced jointly our investigations as to their mobility. As has
been remarked above, the spermatozoa within the spermatheca
was teeming with life, and those in the neighbourhood of the
spermathecal aperture exhibited the same vibratory motion.
Having satisfied ourselves of their vitality and activity e7i masse, it
became necessary to examine them externally and individually. I
gently rolled the cover-glass with a needle. This had the desired
effect, and the spermatozoa, starting out from the fissure like a
number of Gordiidce, kept up an active, wriggling, writhing
motion. One fine fellow pushed its way out like a gigantic loop,
and kept up a constant action of twisting and untwisting itself
This twining and untwining action cannot be otherwise than an
"active mobile existence." When a spermatozoon emerges intact,
I have invariably noticed that one end, which I called the poste-
rior end, was hooked ; the other has four or five turns, like a
drawn-out corkscrew, which I call the anterior end (Fig. 4, a^ b).*

* My reason for applying the terms anterior and posterior is because I
have extracted ova with the spermatozoa attached to the ovum. The cork-
screw end had entered the micropyle, leaving the hooked end protruding.
The zoon had emptied itself of the sperm, was transparent, markings of the
coat had faded, and air-globules had entered the empty sheath. These air-
globules may have entered the sheath after extraction of ovum from the ovary,
and as it lay in the fluid on the glass plate of the dissecting instrument.

OF TWO SPECIES OF CYPRIS. 237

Whilst intently regarding the agitated mass which had been set
free, we saw one of the hooked ends protrude and gradually draw
itself out from the rest with an extended spiral motion, such as 1 had
never witnessed before. This process was very gradual, and at
last stopped. It then began to withdraw itself, until, arrivmg at a
certain stage in its backward progress, it again stopped, paused,
and then began to move forwards again. I had been using a
quarter-inch. This I changed for a one-eighth, and again watched
its backward and forward movements, which kept on for twenty
minutes. The motion was in a spiral direction, and the hooked
end seemed to agitate the fluid in its neighbourhood. Previous to
this, it had been no uncommon thing to see portions of the cara-
pace drawn towards them. I am unable to say whether this
action w^as caused by capillary attraction, or by the presence of
ciliate processes at present unseen by us. These portions of the
carapace became impaled at the end, and were spun round with
great velocity. This is remarkable when we consider the dis-
parity of size.

We thought we should like to trace the spermatozoa down the
efferent ducts. I therefore extracted the spermatheca with the
duct attached. These zooids were a lively lot, and we had no
difficulty in tracing the vibratory motion to the base of the sper-
matheca— spermathecal-aperture — and a short way down the duct,
when it was lost to view. I then extracted some of the zooids from
the duct. We found that a bundle of zooids of various sizes passed
down the duct. I extracted two in their entirety — viz., with their
hooked and corkscrew terminations. These I covered with a
cover-glass, adding distilled water, and thus was enabled to time
the length of their vitality as one hour and ten minutes, after
which time all motion ceased.

The spermatozoons are the carriers of the sperm. In imma-
ture specimens the sperm can be seen within the sheath. The
length of a spermatozoon barely exceeds the one-fortieth of an
inch. If fresh, broken spermatozoa be examined with a one-
sixteenth immersion, it will be seen that sperm will escape by
emission, or it will protrude. If the former, it has a tendency to
run or frill off at the point where it is broken. If the latter, we
find a thin, membranous substance enclosing the sperm lining the

238 THE MALE GENERATIVE ORGANS

narrow circular tube within the hard coating of the zoon. I use
the expression, " hard coating of the zoon," because its power of
resistance to disintegrating influences is very great. It is only
amenable to liquor potass^ after long maceration, but its behav-
iour in the digestive organs of other aquatic animals is interest-
ing. I fed young newts with C. miniita and C. ctnerea, and after
a few days' feeding I killed the newts and extracted the viscera.
The shelly substance of some of the Cypris was unaffected, but
those which were near the rectum were soft and pulpy and the
viscera partially digested, but the spermatheca was intact and the
spermatozoa active. In other newts that I fed, some of the
Cypris were enabled to resist the gastric juices that are poured
into the alimentary canal and to pass, /(?/• anum, alive. I have
taken them out of the rectum of a newt, placed them in water in
a watch-glass, and they have been none the worse for their Jonah-
like experience. For four days I fed some Sticklebacks with C.
viinuta, and on the fourth day I opened them to see results. The
greater number of the Cypris were lying in the intestine, dead
but undigested. Those which were in the oesophagus, when
placed in water, recovered their vitality. I examined some of the
dead specimens. The spermatheca was intact, but the sperma-
tozoa, as a body, had lost their mobility, except in one case,
which was close to the pylorus. They had preserved their vitality,
although the Cypris was dead. I also found one specimen of
Cypris, whose viscera had been entirely absorbed, leaving the
spermatheca, filled with spermatozoa, intact in the interior of the
valves. The valves were in a very pulpy condition. These I
mounted in glycerine (Fig. ii), to show the density of their
structure and capability of resisting the absorbing and disintegrat-
ing influence of the gastric juices.

Cypris Minuta (Brady), Figs. 9 and 10.— In adding a draw-
ing of the bursa-copulatrix and second foot of C. viimtta, I do so
because Brady frankly admits that he has never seen a perfect
specimen of the male of this creature. This is, I presume,
because it is somewhat rare in English ponds. I found it to be
very plentiful in a low-lying pond in this district, which is full in
the winter, but quite dry in the summer (from the month o^
October last year to January of this year), after which time I

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Orgfans of Cyprus

OF TWO SPECIES OF CYPRIS. 239

failed to find it. I have come to the conclusion that this is the
copulatory season, as during this time the spermatophore is filled
with spermatozoa. My stock-bottle, which I filled last December,
still contains some male specimens of C. niinufa, but at those
intervals when the pond was frozen over, or during the summer
months when it was dry, I have drawn specimens from my stock-
bottle for investigation, and have found them not exactly destitute
of spermatozoa, but inert and in a very morbid condition.

What has been said above of C. cincrea with regard to the
position of the generative organs and the mucous glands applies
also to C. ininufa. It will be seen, on reference to Plates XXII.
and XXIII., Figs, i and 9, that the chelae are much broader and
more transparent in C. nwmta than in C. ciiierea. The bursce are
smaller, being about the one-two-hundred-and-eighty-sixth of an
inch long and the one-four-hundredth of an inch broad. The
intromittent organ is placed a little farther back and lower down
in the bursa. It is somewhat globular at the posterior end, but
has no elbow. As it descends, it takes a sharp curve round the
base of the bursa until its termination points towards the flat edge
of that organ. It terminates in a nodule, and has a fairly-wide
aperture. I have traced the spermatozoa from the arched canal
down the intromittent organ. Its length is one-eight-hundred-and-
thirtieth of an inch and diameter one-three-thousand-three-
hundredth of an inch. On the second foot we get a different
formation of the central seta2 to that given by Brady. That the
spur-like formation is the more accurate will be seen on reference
to Fig. 10. I have always found the carapace to be hispid and
the second maxilla chelate. It is twenty-three years since Brady
added C. cinerea as a new species to his monograph, and since
then until now it appears to have escaped detection.

EXPLANATION OF PLATES XXII. and XXIII.

Fig. 1. — Cijpris cinerea, bursa-copulatrix : — a, spermatozoa ; h, arched
canal ; c, intromittent organ ; x 595 diam.
,, 3. — Cypr is cinerea: — Stoma of same, x 2,000. diam.
,, 4. — Ditto, spermatozoa: — a, anterior; h, posterior; i/isth inch
immersion.

2-40 PSEUDO-HELMINTHS.

Fig. 5. — Cypris cinerea : — Plumose seta, second antenna, x 595 diam.

6. — Ditto, second foot male, ^th of an inch, Zeiss.

7. — Ditto, ,, ,, female, ,, ,,

8. — Ditto, female emjity receptaculum-semines, ^th inch, Zeiss.

9. — Cypris miituta, male, bursa copulatrix, letters same as in Fig,
1, X 595 diam.

10. — Cypris minuta, male, second foot, x 595 diam.

11. — Ditto, taken from intestine of a Stickleback after the viscera
has been digested, x 155 diam.

12. — Cypris cinerea: — Anterior end of mucous glandulosa, show-
ing stoma, X 595 diam.

pscubo^lbchninthci : points in tbc IHatural
Ibietor^ of a IReniatobc Mornu

By Jabez Hogg, F.R.M.S., M.R.C.S., etc.

IN my paper on " The Embryo of a Parasitic Entozoa," in the
Jownal of Microscopy and Natural Scte?ice, July, by a slip of
the pen, the measurement of the embryo, as given on page
172, is, I find, somewhat over-estimated. I had, in fact, forgotten
for the moment that I was viewing it under a somewhat low
magnifying power. A few lines further on 1 would also ask the
readers of the Journal to substitute the word " epithelial " for
" tesselated." I should be glad, at the same time, to avail myself
of the opportunity to offer a few remarks on several communica-
tions with which I have been favoured on the interesting question
of spurious parasites, or, as they are designated by writers on this
branch of natural history, " pseudo-helminths," the greater part of
which have no relation whatever to the animal kingdom.

First, let me say, once and for all, that with regard to henbane
seeds, as a remedy in toothache, I have had no personal expe-
rience of its efficacy, and can offer no opinion ; but more than one
of my correspondents furnish me with confirmatory evidence on
this point. Dr. Ringwood, for instance, says : — " I have known
cases where, though the teeth were bad, but free from pain,
henbane-seed inhalations have been followed by the expulsion of

PSEUDO-HELMINTHS. 241

several parasites." On the other hand, a dentist of considerable
experience writes me: — "I have seen parasites drop from the
mouths of patients on the bare application of hot water and by-
steaming the mouth." I need hardly say that such testimony
might have proved of more value had these bodies been exam-
ined under the microscope and classified.

I am well aware of the fact, however, that the seeds of the
henbane plant do furnish us at times with a spurious body which
may be mistaken for a " worm " or parasite. Those of my
readers curious in these matters may easily satisfy themselves of
this fact by taking the seeds and subjecting them to the action of
heat and moisture. The testa will be seen to swell out, force
open the micropyle, and the radicle, or embryo, with one end
charred by the heat, shoots out and completes the illusion. But
this spurious worm or maggot is large enough to be seen by the
naked eye, and is, I think, hardly likely to deceive a skilled
observer. There are, however, a very considerable number of
other bodies, which have been described as worms or parasites, as,
e.g., shreds of blood and tissue detached from the gums and
sides of the mouth by the hot fomentations ; small fragments of
vegetable, and even of mineral substances. A typical illustration
of the latter is furnished by one of my correspondents. " If," he
writes, " a tooth be broken on extraction after acute toothache, the
sphacelated pulp will often be seen to occupy the nerve-cavity and
root-canals. It forms an ashy grey, tapering, thread-like structure,
not unlike a worm in shape, and it is just possible that it may
assume the appearance of a worm and have been mistaken for
one."

Among vegetable matters, those more frequently mistaken for
worms or parasites are shreds of fibro-cellular tissue, awns of
grasses, pith, the carpellary segment of the orange, and, as Dr.
Fraser reminds me, " a cleverly-cut fragment of a sod of earth,
and small pieces of the vascular bundle of a fern." " I have
seen," he says, " these and other substances palmed off on my
patients by a notorious impostor, a reputed tooth-ache curer, who
trades upon the credulity of those who are ready to believe in
Faith-healing."

With regard to the specimen which I brought to the notice of

242 PSEUDO-HELMINTHS.

the readers of this Journal in July, I ought to say, perhaps, that
my task was a simple one — that of verification, or, more properly
speaking, classification. But a professional friend and naturalist
tempts me into a byepath of speculation. He insinuatingly
writes : — " Would it not find a more fitting place among Nema-
TODA, and probably be Filaria bronchialis ? " My reply is that it
certainly belongs to the Treisiatoda, although it bears a close
resemblance to the male Sderostoma syngatnus, a nematode ento-
zoon, better known under the name of the Gape-worm, a parasite
not only more widely distributed, but is invested with a special
general interest from the fact that it is the cause of the gape-
disease among chickens, pheasants, partridges, magpies, hooded
crows, starlings, swifts, and many other birds. There is an
undoubted family likeness, however, among the embryos of all
the genera of entozoa. The first stage of their existence and
development is passed in the water and as free swimmers, quite
irrespective of whether their final destination be Redice or
Cercarice.

In the cause of suffering humanity, it is quite worth while to
pursue the morphology of these pests somewhat further. There
is yet so much to learn regarding them and their several stages of
existence, the more intimate relations which obtain between their
embryos and their intermediary hosts, and the extent of the
pathological conditions to which they sooner or later give rise in
the animal body. We are quite unable to guess by what instinc-
tive agency they are enabled to discover and select the most
appropriate resting-place in the interior of this or that animal, and
whereby they are enabled to attain to a higher state of organisa-
tion. Nothing can strike us with more astonishment than that
the Gape-worm, Sderostoma synganms, should select and find its
way, not to the oesophagus, but to the windpipe of the chicken or
bird, and thus subject its host to a cruel death by suffocation. It
seems to be bent upon propagating its species at the cost of life
to the higher orders of creation. With reference to internal para-
sites as a whole, although certain districts are known to have
special attractions for many of them, yet none seem to have an
abiding resting-place. On the contrary, all have a disposition to
roam over a wide area, and it is in this way they so thoroughly

PSEUDO-HELMINTHS, 243

succeed in baffling the scientific acumen of the skilled Helmin-
thologist.

For the reasons stated, even small and apparently isolated
facts are often of some importance. Now, I have lately had the
advantage of making myself fully acquainted with the " Gape-
worm " by a careful examination, and after removal by my own
hand of innumerable specimens from the windpipe of the young
pheasant, and I trust the observations I am about to offer may
prove acceptable to the student of natural history. I may point
out, first, the great disparity observed in the size of the sexes.
The female of the genus Sderostoma syiigaiiius measures full six-
eighths of an inch in length, while the male scarcely exceeds the
one-eighth of an inch. On detaching the female from the trachea
of the bird, and of which she had still a very firm hold, she was
of a deep-red colour, at first sight very like the smaller blood-
worm of the Thames, Gordiiis aquaiicus, and for which, when
taken out of the windpipe, she might easily have been mistaken.
The male worm, from its minuteness and want of colour, was at
first quite overlooked by me, but on a more careful search, and
by the aid of a pocket-lens, was at length discovered attached to
the upper fourth of the body of the female. The remarkable
tenacity of life displayed by these parasites I must not pass over
without notice, as on the third day after the death of the bird I
found, on cutting open the windpipe, the whole of the females
alive and vigorous, and so they remained for twenty-four hours,
although immersed in water and exposed to the light.

With reference to their morphology, the integumentary cover-
ing of the body is uniformly smooth throughout, and about the
upper portion of the epidermis an irregular epithelial pigmentary
layer can be made out. Beneath this is the denser cutis, and
then a broad band of longitudinal and transverse muscular fibres,
which under a high power bear a striking resemblance to the
striped muscle of the Vertebrata. The most internal basement
membrane consists of a delicate mucous coat and a layer of
tesselated epithelium. The digestive and ccecal canal of
the female is seen to terminate in a sharply-pointed anal open-
ing, which also serves as an ovipositor. The terminal portion
of the male differs very considerably. It is truncated and

244 PSEUDO-HELMINTHS.

rounded off, turns sharply on itself to form a clift and an open-
ing, in which are placed the organs of generation.

The nervous system is quite of an elementary nature. So far
as I can discover, it consists of a single cephalic ganglion, which
sends off one or more minute branches to the proboscis or oral
opening. Organs of special sense are entirely wanting. There is
nothing remarkable about the mouth. It is formed for suctorial
purposes only. In form and structure it is perfectly circular, and
is divided into two or three rings, which are acted upon by
separate sets of circular and radial muscular fibres. The inner or
middle ring, when opened out, divides into six etjual parts, which
turn outwards upon the inner lip, somewhat like the petals of
certain flowers. The muscular layer is capable, when set in
action, of producing a considerable vacuum, while the radial set
will convert the innermost disc into a sphincter, closing up the
oesophageal opening. The oral arrangement of the male appears
to me to differ slightly. I make out a third inner divided disc,
with a series of equally disposed chitinous teeth.

Dr. Cobbold, in his valuable work on " Entozoa," in a wood-
cut drawing of the female, represents the disc I allude to, but this
is an error on his part, for this is only seen in the male. The
vulva and uterus of the female is located unusually high up in the
body, and here the male is securely attached. In this case it is
the female who shows herself an imperious monogamist, for
having selected a mate she compels him to cling to her body, and
thus carries him about with her for the rest of her natural life. It
has long been in dispute whether or not actual incorporation of
substances takes place between the sexes. Von Seibold taught
that there is actual incorporation, but I believe this is quite a
mistaken view, founded, of course, on the very intimate nature of
the connection, although the same kind of joining of the sexes is
seen to take place in certain of the Lepidoptera — the silkworm
moth, for instance.

The male organ of generation is of a very distinctive cha-
racter. It consists of a double set of trifurcate, finger-like series
of processes, and an intermediate tripartite penis. These several
parts, on passing through the vulva, have an antagonistic action to
the other. I have been unable to satisfy myself of the existence

PSEUDO-HELMINTHS. 245

of any cup-shaped appendage formed out of a folded extension of
the dermal covering, described by Dr. Cobbold, and which, he
says, consists of " a membranous bursa, strengthened internally
by a series of projecting rays, intended for the purpose of fixing
and supporting it in the same manner as we find the whalebone
rods employed to distend the hood of the umbrella."

The ova sac is tortuous and convoluted, and extends through-
out the length of the body. It is literally loaded with eggs in all
stages of development, and numbering from one to two or three
thousand. The egg, as first seen, is a mere globular speck of
protoplasm, but after fertilisation takes place the mass breaks up,
the nuclei enlarge, and segmentation of the whole quickly follows.
At the same time the egg becomes ovoid in shape, with a lid or
micropyle at one end, and through which the young worm emerges
at maturity. When first hatched, the embryo is without structure.
It is little more than a contractile integument, enclosing innumer-
able granular bodies, no distinctive or formed organs being visible.
Notwithstanding, it is quite equal to an active migration, and pro-
bably will next be met with in the body of one of the smaller
Pulmonata, or attached to a portion of decaying vegetable sub-
stance, and ultimately finding its way to a pond or stream of
water. Evidence is certainly wanting in confirmation of the
statement made that it enters the body of the common earthworm.
In what way it really gains access to its intermediary host remains
a mystery. There is, however, no doubt whatever of its extraor-
dinary breeding powers and great tenacity of life.

Should a single worm enter the windpipe of one of the
feathered tribe, it quickly proves itself a bloodthirsty foe. I have
seen the trachea of a young chicken swarming with Gape-worms,
and I have been led to wonder how breathing was sustained and
life prolonged.

I conclude with a word of warning, because I have been given
to understand that in some agricultural districts it is no uncom-
mon thing for the poor people to cook and eat poultry and game
dying or killed from gape-disease. The head and neck is perhaps
severed from the body and carelessly thrown out into the dust-
heap, to be pecked at and eaten, and so to infect other birds and
animals, a prolific source of spreading a loathsome and noxious

New Series. Vol. I.

1888. s

246 INSTANTANEOUS MOUNTING.

disease. It is, therefore, of the utmost importance that the
bodies of birds dying from " Gapes " should be burnt — cremated —
as soon as possible after death. By taking a precaution of this
kind, and by paying greater attention to the hygiene of the
poultry-yard, this terrible Strongnliis may be prevented from
slaying annually its thousands of victims.

3n0tantaneou0 riDountino in jfarrant'e (Bum
anb (Bl^ccrinc riDeMuni.

By R. H. Ward, M.D., Troy, New York.

TOO much can scarcely be said in favour of Farrant's Gum
and Glycerine Medium* for facility of use. It may be
inferior to glycerine jelly for mounting sections that are
large and not liable to be injured by heating, as both it and that
are doubtless inferior to Canada balsam for objects that are not
too transparent in the latter, or that can be rendered sufficiently
conspicuous by staining, and that can be dehydrated and trans-
ferred to the balsam without injurious modification of structure.
But it answers excellently for a very large variety of specimens,
both animal and vegetable, that can be studied to advantage in
water or in glycerine, and that, in the former case, can be trans-
ferred to a dense mucilaginous medium without detraction by
exosmose. For such objects it very nearly accomplishes the
paradox of enabling one to mount specimens without the trouble
of mounting them.

Those who prepare objects for the trade, and students who are
working in the laboratories as learners, make a business of the
hardening of objects, the cutting of sections, the handling of

* Farrant's medium is prepared as follows : —

Picked gum Arabic ... ... 4 parts by weight.

Distilled water (cold) ... ... 4 ,, ,,

Glycerine ... ... 2 ,, ,,

Keep in a glass-stoppered bottle, in which should be put a small piece of
camphor.

INSTANTANEOUS MOUNTING. 247

re-agents, the selection and manipulation of varnishes, etc. ; and
many amateurs and even professional admirers take pleasure in
imitating, and often excelling, them in this recreative work.

Many professional microscopists, however, find their time
filled with other engagements. Objects almost without number
are examined for purely scientific investigation, or for sanitary,
economic, medical, or legal purposes, and then are inevitably
thrown away for want of the time required, but not just then
available, for mounting them. Such objects are often examined in
glycerine ; and proving interesting, they are laid aside unsealed
only to be found spoiled when next seen, or are ringed with
varnish, without a cell, to make a mount that will be short-lived
by reason of the running-in or splitting-off of the cement. It is
no more trouble to place such objects, and cover them, in the
gum and glycerine medium at first, than in plain glycerine ; and
then they are already mounted to begin with, and they can, as
desired, be washed off the next day, or be neglected for years
without injury.

The following points may be of use to those not accustomed to
this instantaneous method of mounting : —

I. — Use only sufficient of the medium. By a little care a drop
of the right size can be employed, so that the cover-glass will be
supported to the edges, but without enough surplus material to
require the fussy procedure of cleaning off the excess. If any
should require removal, leave it to be scraped off with a knife
after drying for a few hours, instead of washing it off at once with
water.

2. — Breathe on the slide, and also on the cover-glass, just
before making contact with the medium, to moisten the surface,
and thereby prevent entanglement of air-bubbles.

3. — Plunge the object into the drop of medium by means of a
needle or of a flattened lifter, without entangfing air by unneces-
sary stirring, and remove with the needle point any bubbles that
may be seen. Do not discard the specimen if a few small bubbles
be included, as they may disappear in time.

4. — The object may be taken from glycerine, or from a watery
fluid, or even from diluted alcohol. Do not dry it enough to get
air into the tissues ; but be careful not to carry too much of the

248 INSTANTANEOUS MOUNTING.

medium with it, as it is easy to introduce, in this way, enough
water to make the medium too thin, or enough glycerine to
prevent its drying properly.

■ 5. — Keep, within reach, a bottle of carmine or haematoxylin
stain, the latter being capable, probably, of most general applica-
tion ; and try immersing in a drop of it, on a slide or in a watch-
glass, such objects as are likely to take the stain promptly. Many
delicate sections, or membranes, teased-out tissues or fibres, secre-
tions containing interesting physiological or pathological structures,
etc., will be stained exquisitely by being dipped in this a few
seconds, on the way to the mounting medium, or at most by lying
in it while the next object is being examined.

6. — If the object be thin, no care is required after covering; but
if thick, air may possibly enter at the side by shrinkage in drying,
which should be corrected by keeping the mounts in sight a few
days and applying, when required, a small drop of the medium,
not over but at one side of the incipient air-bubble, so that it will
run in in place of the air.

7. — If the object prove valuable, but not otherwise, label and
number it at once, and record in a systematic catalogue anything
important that may be known about it.

8. — If properly managed, the slide will need no cleaning after
the mounting and labelling are finished. It should only require to
lie untouched for a few days while the gum is drying at the edge
of the cover-glass.

9. — Any time, after a few weeks, months, or years, the slide
may be placed on a turn-table and a ring of shellac varnish or
Bell's cement added. This will give a neat amber finish, and
may keep the medium from distorting the object or the cover-
glass by shrinking too much or from becoming too hard and gra-
nular, in case it has been incorrectly prepared or used.

By adopting this method of preserving suitable objects that
may come under his examination, the busiest man may, in the
course of a few years, prepare a valuable collection, without
appreciable labour and almost without knowing that he is doing it.

[249]

Zbc niMcroscopc au^ Ibow to ITlec it

By V. A. Latham, F.R.M.S.

Part XV.

Practical Hints on Histology.

Special Methods for Examination of the Spinal Cord,

Brain, etc. (continued.)

Spinal Cord, Fibres of (SchiefFordecker's method).

PLACE a piece of fresh cord, with its membranes removed, foi
about a month in Miiller's solution ; then wash for about
twenty-four hours with water, and afterwards place in alcohol.
AVash the sections in water for one or two days, and stain with
palladium chloride or gold chloride. Wash with water, and pass
through absolute alcohol and oil of cloves into balsam.

Palladium Chloride. —This agent is used to demonstrate the
longitudinal fibres (therefore, longitudinal sections must be cut), a
solution of I — 10,000 strength is taken. The sections should
remain in it till light brown (about three hours).

Gold Chloride.— Used for transverse sections. Strength,
I to 5,000 or 10,000; time, i to 3 hours. Wash the sections well in
water, and place in acetic acid, h to i per cent., for twenty-four
hours. Then mount as described above.

Picro-Carminate of Soda and Palladium Chloride.— Place the
sections for one to three minutes in a i to 300 or 600 solution of
palladium ; rinse in water ; throw for eight to ten minutes into a
cold saturated solution of picro-carminate of soda. Mount in
dammar.

Staining Isolated Ganglion Cells.— Macerate small pieces in a
small quantity (just sufficient to cover them) of Ranvier's alcohol
for several days. Take some small fragments of grey matter, and
well shake them in a test-tube with a little water. Then add a
little glycerine and a few drops of the concentrated solution of
picro-carminate of soda, and set the whole aside for one or two
days. Decant, and to the red deposit, which is now composed of
stained ganglion-cells, add one or two drops of glycerine, and

250 THE MICROSCOPE AND

place the whole for two days in a dessicator, with sulphuric acid.
(This is best done in a watch-glass or flat-bottomed cell.) The
cells are best got on to the slide by pouring a drop of the dehy-
drated glycerine on to it.

Aniline Blue for Processes of Ganglion Cells.— Take sections
of cord or brain that have been hardened in bichromate ; wash
with acidulated water, stained, in the dark, in a slightly acidulated
hydrochloric or acetic acid solution of the soluble aniline blue of
commerce. Wash out with acidulated water, rinse quickly with
absolute alcohol, clear i7i the dark with creosote, and mount in
dammar. N.B. — Do not allow them to remain in the creosote
long, and they must be preserved permanently in the dark.

Carriere's Method* for Ganglion Cells. — Put fresh sections of
cord into the three following solutions : — {a) Bichromate of
potash, i:6oo; {b) bichromate of potash, 1:500; (r) chromate of
ammonia, i :6oo. After ten days remove sections from a and b,
wash with water, throw into barely transparent ammoniacal solu-
tion of carmine. Five days afterwards the sections from a were
easily teased out ; in seven to ten days those from b ; those from
c were removed after fourteen days into the carmine solution ; and
after three days tease them. By these solutions the anastomoses
between cells of anterior cornea may be demonstrated.

Weigert's Method for Central Nervous System t— Stain the
sections, hardened in Miiller's fluid or bichromate of potash, for
twenty-four hours in a concentrated watery solution of acid fuchsin
(soda-salt of rose-aniline sulphate). Wash in water, and transfer
to an alkaline solution of alcohol — viz., 100 cc. of absolute alco-
hol with 10 cc. of a solution, made by dissolving i gramme of
fused caustic potash in 100 cc. of absolute alcohol, and filtering
for a few seconds, until the first sign of the grey nerve tissue of
the section becomes visible. Wash in water, which must not be
acid, and dehydrate with absolute alcohol saturated with sodic
chloride, to preserve the colour of the section. Clear with oil of
cloves, and mount in Canada balsam. The blue tint may be
increased by putting the sections in a solution of i part of hydro-

* Arch, fiir Mikr. Anat., xiv. (1877), p. 126.
t Centralblatt f. D. Med. Wissenschaflen, 1884, pp. 42—46.

HOW TO USE IT. 251

chloric acid to 5 of water, then wash in water, dehydrate with
alcohol. I have found it useful in demonstrating the neuroglia
cells and processes to stain in carmine ; and instead of completely
clearing up, treat with methylated spirit instead of absolute
alcohol, leave long enough to drive out only part of the water ;
clear up partly in clove oil, mount in dammar, and examine at
once.

Weigert's Improved Method.*— If sections are to be stained
by this method, they should always be hardened by Mullers or
Erlitzki's fluids. The latter is made of bichromate of potash, 5
parts; sulphate of copper, i part; water, 200 parts; and the
time taken is about eight or ten days, and the hardening fluid
must not be washed out before placing the piece of tissue in the
freezing microtome. The sections should be cut before the
pieces have been soaked in water or placed in alcohol for perma-
nent preservation.

Staining. — Make some sections, and always examine them first
in a drop of glycerine before staining, if the ordinary stains are
desired. If Weigert's method is employed to harden tissue, do
not wash and imbed in celloidin. Moisten the blade of the knife
with alcohol, and place the sections as cut in that fluid. First,
immerse the sections in haematoxylin fluid, prepared as follows : —
Hsematoxylin, 075 to i part; alcohol, lo'o parts; water, 90*0
parts. Boil the mixture, and allow it to stand for some days to
" ripen" before being used. The dye may be rendered ready for
immediate use by the addition of i cc. of a cold, saturated solu-
tion of carbonate of lithium to 100 cc.'s of the hsematoxylin
fluid. Place a watch-glass with the sections and solution in a hot-
air bath, at a temperature of between 35*^ and 45 *? C. The time
varies. For spinal cord, one or two hours is sufficient, whilst
cerebral tissue often requires twenty-four hours. The tissue is
now of a blue or black colour ; transfer to the differentiating
fluid, which is prepared as follows : — Borax, 2 parts ; ferrocyanide
of potassium, 2\ parts; water, 100 parts. Soak for from half-an-
hour to an hour, or more. The grey substance is now pale yellow
or brown, whilst the white matter remains dark blue or black.

• " Fortschritte der Medicin," 1884, Bd. II., Nos. 60, 86, Bd. III., No. 8.

2o2 THE MICROSCOPE AND

Thoroughly wash in water, not in alcohol, which precipitates the
ferro-cyanide solution. Then dehydrate with absolute alcohol,
clear by means of xylol or origanum oil. These re-agents do not
affect the celloidin. Mount in Canada balsam or dammar.

A slight modification is as follows : — Harden the material in
bichromate of potash, follow by alcohol, embed in celloidin, cut
sections, and immerse them in a half-saturated acetate of copper
solution for twenty-four hours, and then in alcohol for a few
minutes. After this put the sections into a solution of hsematoxy-
lin for twenty-four hours, and wash in water for a few minutes.
Then transfer them to a solution of ferro-cyanide of potash till
the colour is washed out, except from the medullated fibres. I
find this very good for cord of Tabe's dorsalis and brain sections.
Some regard the acetate of copper as a hardening agent, which it
is not, and if used as such the tissue will be spoilt.

The only drawback to Weigert's method is that sections must
be cut and stained immediately after hardening and before trans-
ferring to alcohol. If pieces after hardening have been in alcohol
so long as to become green (a change which takes place in all
chromic acid specimens after being kept in alcohol), the staining
will fail. To obviate this, the tissue is subjected to the celloidin
process, and fixed on a piece of cork in the usual way. Then
place in a beaker, with the saturated acetate of copper solution (as
above), diluted with an equal quantity of water, and the whole
placed in a hot-air bath, and kept at between 35'' to 45*^ C. for
two days ; after which cut sections and stain as before. By this
method, heating hsematoxylin is unnecessary while staining, and
the differentiating fluid should be diluted with an equal volume of
water.

Chloral Hydrate Method.— Harden in Miiller, bichromate of
potash, or if a faster reaction is required, ammonium bichromate
may be used, or a 10 per cent, solution of chloral hydrate.
Change after twenty-four hours and again at the end of the third
day, and at the end of the first, second, and fourth weeks ; after
which the cord may be left in the fluid until it is transferred to the
gum and syrup solution before the sections are made. Stain and
mount as required.

HOW TO USE IT. 253

Debore's Method.*— Place in a 4 per cent, solution of bichro-
mate of ammonia for three weeks, then in a solution of phrenic
gum for three days, and for three days more in alcohol. Cut
sections and place in water to prevent curling ; immerse in a satu-
rated solution of picric acid for twenty-four hours, and colour with
carmine for about twenty minutes, the picric acid acting as a
mordant.

Double Stain for Nervous System-f— Sections — which should
not be in water for more than five to ten minutes after cutting —
should be placed for several hours in a concentrated watery solu-
tion of methylin-blue ; wash in water and transfer to a saturated
watery solution of acid fuchsin for about five minutes. Quickly
wash in water, and place for a few seconds in i per cent, alcoholic
solution of caustic potash, and wash in a large quantity of water.
Gerlach's network of delicate fibres stain blue or violet on red
ground.

Prof. Adamkiewicz's Method is to stain with saffranin and
methylin-blue when individual segments are to be differentiated
and mount as usual for anilins.

Staining Axis Cylinder of Medullated Nerve-Fibres. — Fix the

nerve on a cork, and place for two hours in a J per cent, solution
of osmic acid ; wash for two hours in distilled water ; stain for
twenty-four to twenty-eight hours in a saturated solution of acid
fuchsin ; wash for six to twelve hours in absolute alcohol, clarified
with oil of cloves, imbed in parafiin, and cut.

An excellent method, and one which gives very satisfactory
results, is that which is used by Dr. C. Robertson, Demonstrator
of Anatomy, Oxford. Place portions of ivarin cord, about i in.
long, in spirit (10 over proof) from four to five hours ; transfer to
a 6 per cent, solution of bichromate of potash for six days, care
being taken during the process of hardening to remove with a
razor thin sections from the ends to allow the solution to tho-
roughly penetrate to the interior of each piece. Transfer to weak
spirit for two days, then to strong for two or three more days, when

* "Archives de Neurolgie."
t " Zeitschr. f. Weis. Mikr.," Vol. II., 1885.

254 THE MICROSCOPE.

the cord may be kept till wanted for sections. Portions of cord
are stained before sections are made by soaking for twelve hours in
a solution of good picro-carmine. Wash in weak spirit, and soak
for a short time in absolute alcohol, which should be used to wet
the razor in cutting. Clear in clove oil, and mount in dammar or
Canada balsam dissolved in benzole. This way of staining in
picro carmine before cutting enables one to trace the processes,
cells, etc. The best picro carmine is made by MM. Rousseau
and Son, Paris, or Martindale. The only objection to the ammo-
nium-bichromate method is that the solution is liable to deposit
in the form of small specks amongst the nerve.

Spirit and Iodine Mixture and Ammonium Bichromate.—
Place the cord in a long glass tube of rectified or methylated
spirit, made slightly brownish with tincture of iodine for three or
four days, or until the iodine colour has vanished. Cut into
pieces about half-an-inch long, and place them in three times their
bulk of a 2 per cent, watery solution of ammonium bichromate
for four to five weeks, and transfer to spirit until required.

I have found Dr. H. Gibbe's Double Stain to show cells, nuclei,
etc., well, and it is pleasant to work with.

Beck's New "Purple" stains nuclei well, and brings out
minute vessels. It is a slow process, and requires a good deal of
washing in spirit, and is therefore not a very handy stain.

Coppock's Magenta and Aniline is a very ready stain, diffe-
rentiates the several structures, and is easily dehydrated with
clove oil.

Anilin Blue Black, according to the depth of tint employed, is
good for the differentiation of structure. It brings out well the
cells from the neuroglia. It, however, requires care in adjusting
the tint.

Judson's Cambridge Blue is a convenient form of stain.

Ink is a very good stain, more especially for the cells of
Purkinje in the brain.

[255 ]

1balf=*aiHI:)our at the riDicroscopc,

Mitb /IDc. Uxxttcn Wicst, if.X.S., jf.lR./ID.S., etc.

Phthirius ing-uinalis (PL XVII., upper portion). — The charac-
ters which separate Phthirius from Pcdiculus are — the fusion of
the thorax and abdomen, and the possession of two kinds of limbs,
ambulatory and scansorial. It is a very remarkable form of life;
the fusion of thorax and abdomen and corresponding union of
nerve-centres, would denote it the highest form known among the
anoplura; but on the other hand, by the possession of rudiment-
ary abdominal limbs (a characteristic unknown in any other
example of this natural order), it makes an approach to the
lowest form of Arthropoda — the Millipedes and Centipedes.

I know nothing in its way equal to the idea of huge, massive
power conveyed by an attentive study of one of the posterior
limbs in this creature. Time does not allow of entering fully into
it here, and it is the less needful, as the details are carefully given
in the Plate, with, for comparison, the corresponding limb from
the Hog-Louse, Hcemotopinus stiis.

As many of our members belong to the medical profession, I
-think it scarcely needful to apologise for quoting a highly-interest-
ing case of its occurrence in the upper eyelash, from a work to
which some of them may not have ready access. For the ability
to do this, I am indebted to the kind courtesy of J. F. Streatfield,
one of the surgeons to the Royal London Ophthalmic Hospital,
Moorfields, and editor (in 1859) of the "Reports." The case is
ably reported by Mr. W. W. Harkness : —

" The following case seems worthy of record, both on account
of its comparative rareness, and also because opportunity was
afforded of accurately determining the nature of the insect infest-
ing the eyelashes. For the very faithful drawings illustrating the
case, I am indebted to Mr. Streatfield, amongst whose out-patients
it occurred: —

" R. P., aet. 50, a German Jewess, residing in Houndsditch,
applied at the Moorfields Hospital, on account of a chronic
ophthalmia of the left eye. On examination, the lashes of the
right upper eyelid were found to be thickly studded with a
number of dark-brown, bud-like bodies, of about i — 48th inch in
length, and which microscopical examination proved to be the
eggs of the Phthirius, or Pediculus pubis. One or two Phthirii
were also found half-hidden among the lashes, which were spread
and seemed to be kept apart by the numerous ova attached to
them. The eyebrow, and when first seen the lower lids, were free

256 HALF-AN-HOUR AT

from eggs and insects. The left eyebrow and lashes were also
unaffected.

" The patient was not conscious of anything amiss with the
right eye, and did not appear to suffer any inconvenience from the
presence of the insects."

Dalrymple (" Pathology of the Human Eye") mentions his
having seen three cases of this complaint in children, and gives a
representation of the eyelashes, but not of the insect, although he
calls the disease Phthiriasis. Wedl (" Grundziige der Pathologis-
chen Histologie "), in describing the Fhthirius, says that it is met
with in the hair of the pubes, axilla, breast, and eyebrows. I
have been unable to find a representation of an insect actually
taken from the eyelashes.

" The insect represented in Plate IX., Fig. 2 (a most careful
figure, corresponding in every respect to the insect before us, and
perfect), was taken from the eyelashes and mounted in glycerine,
and will be seen to be a well-marked specimen of the Common
Crab-Louse, or Fhthirius. In Fig. 4 is seen the ordinary appear-
ance of the eggs as seen with a magnifying power of 80 diameters.
In Fig. 5 (our Fig. 5) the egg has been rendered transparent by
glycerine, and examined with a power of 130 ; in this the foetal
louse is distinctly seen. The lashes were found to have on them
from one to five eggs. The latter are pear-shaped and cemented
by their narrow ends to the shafts of the hairs with a transparent
cement. The broad end of the egg has a lip, to which is attached
a conical lid, studded with little nodular processes. This falls off
when the foetus is fully developed. The egg is lined throughout
with a membrane (chorion), which contains the foetus. The lice
were found adhering closely to the cuticle at the roots of the
lashes, and considerable force was required to dislodge them.

" On close investigation, the patient was found to have the
Fhthirius in the hair of the pubes, and of the axilla, and the
Fediculus capitis in that of the head. At a subsequent visit, an
egg, resembling those of the Fhthirius, was found in the right
eyebrows, as also a Fhthirius in the lashes of the right lower lid.

" The particulars of this case clearly illustrate the fact that the
louse which infests the eyelashes is the Fht/iirius, although the
Fediculus capitis may exist at the same time in the head.

"The treatment consisted in cutting off the eyelashes as
closely as possible and painting the edges of the lids with a
strong solution of bichloride of mercury. After two operations
the patient reported herself cured." To this the editor appends a
note, as follows : — " She only answered by her daughter, and as
she did not appear herself again at the hospital the ctire could not
be completed. It is the more unlikely that she will be free from
the complaint even in the eyelids, since it has been remarked that

THE MICROSCOPE. 257

these parasites progress from the pubes to the axilla, and then to
the eyelids, always upwards."

Parasite from Flying Fox (PI. XVIII., Figs, i and 2). — This
belongs to the Nycferibiid(C, the very lowest among the Dip-
tera. It is a most anomalous form. I append figures of male
and female, to facilitate comparison of the parts in the two sexes.
" The second general section of the Diptera is composed of small
groups of parasitic insects of very peculiar structure, forming the
Linnaean genus, Hippobosca, and differing from the flies compos-
ing the former section ( ffii-Zr/afe) in the structure of the mouth,
the insertion of the antennae within the head, and of the latter
within the front of the thorax, the denticulation of the tarsal
claws, and the nature of their transformations." — Westwood,
'■'■ Ititrodiictioti to Modern Classification of Insects" Vol. II., p. 580.

We owe much of our knowledge of these singular parasites to
Professor Westwood. As usual, he has paid great attention to the
parts comprising the mouth, and dismisses the subject as
follows : — An extract from Van der Hoeven (" Handbook of
Zoology," Vol. I., p. 311) will best precede: — "The bucal organs
pass into fine threads through a small opening ('Just like a thread
through the eye of a needle ' (Westwood)."

They are three in number. " Being of unequal size, and con-
sequently single organs, they cannot represent either mandibles or
maxillae, and must therefore be regarded as the analogues of the
labrum, lingua, and labium " (Westwood, loc. cit., p. 582). The
determination is, however, acknowledged to be one of extreme
difficulty, and there seem to be scarcely sufficient materials as yet
whereby to settle the knowledge with sufficient precision. I hope
members who may have opportunities of studying bats will pay
special attention to their parasites.

On a former occasion, the extraordinary way in which they
represent, with the Diptera, the Ixodidce amongst the acari, was
pointed out. The fusion in the $ of all the abnormal segments
beyond the first, to form a spider-hke body, strikes me as one of
the most singular points about it, the long hairs terminating it
even having their counterparts in those which guard the spinnerets
of spiders. In the male, as will be seen here, the abdominal
segments are as distinct and as moveable as in ordinary flies.
" The abdomen " (in Nycteribia) " is covered with a continuous
membrane, capable of great distension, which occurs in the
female, the larvae hatching and being nourished in that situation
until they have assumed the pupa state, when each is deposited in
the shape of a soft, white, roundish egg notched at one end,
without any trace of articulation, and nearly as large as the abdo-
men of the parent fly. Subsequently this puparium becomes

258 HALF-AN-HOUR AT

hard and dark-coloured, and within this puparium the real pupa is
found, and from which the fly escapes by scaling off the notched
extremity of the case. Although these insects are furnished with
a pair of remarkable ovaries, their progeny consists but of a single
pupa, after the exclusion of which the abdomen becomes shri-
velled and contracted " {Joe. cii., p. 584).

The "curious appendages at apex of thorax," referred toby
Dr. Rowe (p. 260), demand attentive consideration : — " They have
neither wings nor balancers," says the learned author we have so
frequently quoted, " but the intermediate legs are connected at
the base with a pair of strong, comb-like organs, which are the
probable representatives of wings." And such turns out to be the
case ! The scales to which these strong, abbreviated bristles are
attached are riidi??ientary wings! You will hardly wonder after
this to learn that rudimentary balancers are also present, or that
" Mr. McLeay has shown me" (Professor Westwood) "species
from the West Indies possessing short wings."

When all the forms we can obtain have been round the
Society, and the facts they present come to be grouped in series,
you will be perhaps better able than now to appreciate the delight
with which I studied these parasites of Flying Fox. I was eagerly
wishful to see specimens, and they came in answer to the unut-
tered wish. The " quaint zone of processes " is simply an
excessive development of strong hairs present at the free edge of
the first abdominal segment in ordinary flies. Another very
remarkable point is the division of the femur into two portions, of
the tibia into three, of the basal joint of the tarsus into numerous
articulations (twenty-five). This " vegetative repetition," as Pro-
fessor Owen has aptly termed similar conditions, is paralleled in
Phalangiuni, the long-limbed autumnal spider, or "Harvestman."
The form of the claws is, as the contributor has well expressed it,
wonderfully adapted for clinging to its victim. In thinking over
the claws of other clinging creatures by way of instituting a com-
parison, it occurred to me, " Why, that's wonderfully like the
claws of sloths, that spend all their lives hanging to the branches
of trees," and the claws of the flea, that hang on to our skin so
vivaciously, and the claws of Melophagus, and so on. But it
would take a long paper to describe all worthy of note in this
interesting creature.

Melophag^us ovinus, Sheep-Tick (PI. XVII., Fig. 6) will be fully
described in the explanation of that Plate.

Wing of House-Fly is from Mima domestica, the smaller
house-fly. It looks like the work of a beginner, who deserves
genuine praise for giving his attention to the natural objects
whereby he is surrounded. If we keep that steadily in view, we

THE MICROSCOPE.

259

shall be astonished to find how much may be learnt with little
trouble. Nay, I will put it more strongly, and say. How much is
constantly passing before us, calculated to make the most prosaic
life one of unceasing interest ! I have been running over the list
of natural orders of insects in Westwood, and find, as I thought,
that from the windows alone of my house in the country, examples
of every order, from the highest to the lowest, of very many
genera, and of a large number of species have been procured.

The e7iiire wing should always be mounted, which is best done
by cutting it out carefully with a handled needle (see PI. XVII.,
Fig. 7), ground down on a hone, to make a cutting-instrument.
The fly being held in the left hand, and a watchmaker's eye-glass
used, the work to be done may be clearly seen. There is attached
to the base of the wings, behind, a pair of small membranous
appendages, termed alulae, or winglets, of a whitish colour. And
they are best displayed when mounted dry, with the free end of
the wing pointing to the left hand, the direction whence the light
comes. The lovely iridescent hues thus obtained make it a
splendid object, and the " ridge and furrow " arrangement of the
membrane, to secure the utmost effect when beating the air in
flight, is very beautiful and deserving most thoughtful study.

Batrachospermum moniliforme (PI. XXIV., Figs, i, 2, 3) was
preserved in prime condition, and the different parts are well
and clearly seen.

Hairs on Frond of Elk's Horn Fern (PI. XXIV., Figs. 4, 5).
— Though the form of the hairs is stellate on both surfaces, a
marked distinction will be seen between those seated on the front
and back of the frond respectively. The former are few in
number, scattered, with mostly eight long-drawn-out rays. The
latter form a dense pile, packed as closely as they well can be.
The rays are more numerous, varying in number from ten to
thirteen, and are also shorter and stouter. There can be no
doubt these differences are connected with the relative amount of
exposure to light, heat, and moisture of the two surfaces. It will
be interesting to note the character of plant-hairs on the opposed
surfaces of leaves at every opportunity in this connection. Cor-
responding differences to those here observed are well marked in
Deutzia scabra and the ^Mealy Guelder Rose.

A Law to make the destruction of barberry bushes obligatory in
France, Spain, Italy, and Switzerland, except for ornamental pur-
poses in gardens and parks, on account of the cecidium promoting
the increase of wheat-rust, is being urged by the French National
Society of Agriculture.

[260]

Sclccteb IRotes from tbc Society's
1Rote*=Book0«

Parasite of Flying Fox. — This insect being supplied with such
claws, two to each foot, scarcely needs the adventitious aid of
either of the quaint zones of processes, or the equally curious
appendage at apex of thorax. The animal belongs to the Chirop-
tera, of the family Fteropodiz, or Rousettes. The term " Fox " is
in allusion to the dog-like form of head. The rough outlines (PI.
XVIII., Fig. lo) gives some idea of the head. They are native of
the eastern hemisphere, and are the largest of the bats. The
Kalong of Java, Pteropiis edulis, measures no less than five feet in
extent of wing and nearly two in length. They are nocturnal in
their habits, and are vegetable feeders. T. Smith-Rowe, M.D.

The Rousette. — In addition to Dr. Rowe's remarks, I have
added a rough sketch (PI. XVIII., Fig. ii) of the skull of the
Rousette. In the East Indies, the chase of Pteropi forms a fre-.
quent amusement of the colonists. The flight of these animals is
slow and steady, and capable of long continuance. Their ravages
among the delicate oriental fruits occasionally cause much annoy-
ance to the inhabitants of these islands. Bevan Lewis.

EXPLANATION OF PLATES XVL, XVIL, XVIIL, & XXIV.

Plate XVI.

Upper portion.

Diatoms in situ.
Fig. 1. — Cocconeis scutellum.

,, 2. — Synedra superba.

,, 3. — Podosphsenia Ehrenbergii.

,, 4. — Rhabdonema arcuatum.

,, 5. — Grammatophora marina.

s.v. (" side view " in the technical sense ; sometimes it would
be more expressive if called ' ' end view. ")

f.v., front view ; it is in this view that the cingulum ("con-
necting membrane ") is seen, centre portion ; all x 200.

Middle portion.

Several hairs from leaf of Vibermun lantana (Mealy
Guelder-rose), x 100.

Lower portion.
6. — Caprella linearis, <^ , x 8.

fv

. (■ \ . .
5 :, • ^ .

JauiTial of Microscopy N. S, Vol. 1 Pi. 16

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EXPLANATION OF PLATES. 261

Plate XVII.

Upper portion.
Fig. i. — Phthiritis inguinalis, ^ , 20.

ths., great thoracic spiracle — here apparently prothoracic.
1 a.s., 2 a.s., 3 a.s., 4rt.s. , 5 a.s., 6a.s., spiracles of the 1st to
the 6th abdominal segments, respectively, seen through the
body, rendered very transparent for the purpose.
r.L, r.l., r.l., r.l., rudimentary abdominal limbs, the true
limbs belonging exclusively to the thorax. The position of the
stomach, with partly digested food (blood), three immature
ova, etc., are also seen. The extremities of the anterior
limtjs will be seen to differ to a striking degree from those of
the posterior limbs.

,, 2. — Termination of second limb, left side, of Hcematopinus siiis,
posterior aspect, tb., tibia ; trs., tarsus, said to be composed
of one joint only ; pv., pulvillus, (pulvillus, a pillow or cush-
ion). The spongy bodies at the end of a fly's foot are
" pulvilli" ; p., a. soft papilla, bearing two or three hairs ;
probably a delicate organ of touch; ad.c, ac^.c, adductor
muscles of the claw ; s.b., " sesamoid bone " of the adductor
muscle.

,, 3. — Second limb of Phthirms inguinalis. The same letters
indicate corresponding parts. The dotted line indicates
point of fusion of tibia and tarsus.

4. — The eye in Mr. Harkness's case of Phthiriasis palpebrarum.

5. — Egg (containing a foetal louse) and an egg shell (with lid

detached, and puckered internal membrane) mounted in

glycerine, from the same.

J)

Lower portion.
,, 6. — Melophagus ovinus, sheep tick, 3' , seen in the ventral aspect,
X 10.

ee. , eyes (position of) ; at. , at. , position of antennae ; r. ,
rostrum ; pp. , palpi ; 1 ab, dorsal portion of first abdominal
segment ; 1 abx , ventral plate of same segment ; v. , vent
and orifice of external organs of generation; pt.s., protho-
racic spiracle (position of) ; mt.s., methoracic spiracle ; 1 a.s. ,
2 a.s., 3 a.s., 4 a.s., 5 a.s., position of the 1st to the 5th
abdominal spiracles, respectively ; 6 a.s., spiracle of 6th ab-
dominal segment.

,, 7. — Sketch, showing method of using a mounted needle in
dissecting a fly.

Plate XVIII.
Fig. 1. — Nyderibia, ^ , from Flying Fox.
g.s., genital segments, coalesced.

,, 2. — Outline view of ? , Nyderibia, from Flying Fox. The same
letters are used as in figure 6 of preceding plate (sheep tick)
to indicate corresponding parts.

New Series. Vol. L

i888. T

262 EXPLANATION OF PLATES.

a., ala (rudimentary wings); s.p. 1 «. 6., strongly developed
spines on posterior edge of dorsal plate, 1st abdominal seg-
ment ; s.p. X , three stout spines a little behind the latter ;/. ,
femur ; t., tibia ; trs., tarsus, divided into five joints.
Fig. 3.— Bones of left fore-limb of a clinging mammal, the two-toed
sloth (much reduced).

^j 4. — Second limb, left side, of a species of Phalangium (" Har-
vestman ") to show reticulation of tibia (t.), as in Nyderibia,
and " vegetative repetition " of tarsal segments, x 10.

,, 5. — Fore limb, left side, of flea {Pulex hominis), in further
illustration of curved clinging claws.

,, 6. — Rudimentary ala of Nyderibia, with spines.

,, 7. — Two of the dorsal spines of 1st abdominal segment, one in
outline only, the other showing fluting, x 75.

,, 7a. — Diagrammatic section of spine. (The structure of these
spines recalls that of the teeth in the Labyrinthodonts. )

,, 8. — Right prothoracic spiracle, x 50
,, 9. — First abdominal spiracle, x 50

,, 10.— Rough sketch of head of Flying Fox. Drawn by Dr. Rowe.
,, 11. — Sketch of Skull of Rousette. Drawn by Dr. Be van Lewis.

All the others drawn by Tuflen West.

Plate XXIV.

Fig. 1. — Specimen of Batrachospermum moniliforme, natural size.

,, 2. — Piece, x 20, to show general appearance.

,, 3. — Portion, x 150, to show details : — st.f., stem-fibres ; r.f.,
root-fibres, supposed by Berkeley to be analogous in fujiction
to the stomata of higher plants. The difterence may be
expressed as corresponding to that between external gills and
internal lungs ; br.f. , branch-fibres, curiously like the myce-
lium of fungi ; sp. , spore.

Lower portion of same plate.

Hairs on Upper or Anterior, and Lower or Posterior Surfaces
of Frond of Elk's Horn Fern :—

,, 4. — The upper surface, x 50.

,, 5. — The lower surface, x 50.

Drawn by Tuflen West.

Journal of Microscopy N. S. Vol.1, Pi. 24

,stf

rf--:^.i

--t'

.<^■■.■

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"mm

^' xl50

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-sp

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Lower surface

Upper surface

4

§tellai.e Fairs on Tron-d of JElks Horn Fgrri.

[263]

A New English Dictionary on Historical Principles,

founded mainly on the materials collected by the Philological Society, edited by
James A. H. Murray, LL. D., President of the Philological Society, with the
assistance of many scholars and men of science. Parts l to 4, royal 4to, pp.
Ixii., 1240+152. (Oxford: The Clarendon Press; London: Henry Frowde,
Amen Corner.)

Few books which we have noticed have afforded us greater pleasure than
has the fine work now before us. We are told that it has been in course of
preparation for upwards of a quarter of a century. Its aim is to furnish an
adequate account of the meaning, origin, and history of English words, now
in general use, or known to have been in use at any time during the last seven
hundred years. It endeavours (i) to show, with regard to each individual
word, when, how, in what shape, and with what significance, it became
English ; what development of form and meaning it has since received ; which
of its uses have in course of time become obsolete, and which still survive ;
whatever uses have since arisen, by what processes, and when ; (2) to illustrate
these facts by a series of quotations ranging from the first known occurrence of
the word to the latest or down to the present day, the word being thus made to
exhibit its own history and meaning ; (3) to treat the etymology of each word
on the basis of historical fact, and in accordance with the method and results
of modern philological science. Different forms, sizes, and styles of type have
been employed to facilitate reference, and an illustration with date is given of
the use of every word from the nth century.

The four parts before us cover the whole of A and B, and form Vol. I.
of the entire work, whilst the second section of part 4 commences the 2nd
Vol. with C to Cass. Each entire part is published at 12s. 6d.

The Oxford Bible for Teachers. (London : Henry

Frowde, Oxford University Press.)

These valuable Bibles and helps for teachers are issued in several sizes,
and at a great variety of prices from 3s. upwards. The one before us is Ruby
i6mo, No. 5a, on thin paper. The type is remarkably clear and distinct.
The Helps to the Study of the Bible occupy 472 pages, and will prove most
valuable to the teacher or Bible-student.

Johnston's Pictorial Astronomical and Geographical Dia-
grams. Size, 50x42 inches. Price, 12s. on cloth and roller, varnished.
(Edinburgh and London : W. and A. K. Johnston.)

This large wall-map contains a number of Astronomical Diagrams,
showing Orbits of the Earth and Superior Planets ; Day and Night, with the
Moon's Orbit ; Eclipses of the Sun and Moon ; the Tides, Seasons, etc. ;
several Geographical Diagrams, showing Parallels of Latitude, Meridians of
Longitude, Zones of the Earth, and Magnetic Compass ; a large coloured
view representing Natural Phenomena over the Globe, as well as man's
work on it, such as Railways, Bridges, Cities, Harbours, Ships, etc. ; and a
map representing and explaining Geographical terms as indicated on maps.
The Sheet is accompanied by an explanatory Handbook.

The Comprehensive Teachers' Bible, together with New

and Revised Helps to Bible Study, a New Concordance, and an Indexed Bible
Atlas. (London : S. Bagster and Sons.)

We have received specimen copies of the Comprehensive Teachers' Bible,

264 REVIEWS.

and find the Helps contain a large amount of very valuable information, as,
e.g., Chapters on the Historical Origin of the Bible, Revelation, and Inspira-
tion ; Ancient and Modern Versions of the Old and New Testaments ;
National History of Israel ; Jewish History between Old and New Testament
periods ; Natural History of the Bible ; Chronological Tables ; Index of
Proper Names ; Alphabetical Index to the Scriptures ; a Concordance ; and
14 coloured maps. These Bibles are handsomely bound, and prices vary from
4s. to 28s. 6d. The type of the Emerald 8vo (size Si in. x sg in. x if in,
thick) is beautifully clear and distinct.

The Difficulties of Algebra made Easy : A Book for
Beginners. By H. C. Tarn, Post Svo, pp. vii.-Qi. (London: MofFatt and
Paige. 1883.) Price is.

This is an excellent little work, dealing chiefly with " Results of Multipli-
cation " and " Resolution of Factors "—most important steps in Algebra, so
seldom intelligently taught in our schools. The explanations and the graduated
examples accompanying them are so good that we strongly recommend the
book to all who have failed to grasp the " first principles " of Algebra.

Matthews' Euclid Examination Papers, Crown Svo, pp.
191, (London: Moffat and Paige.) Price is.

These papers contain 400 Exercises on Euclid I, — IV., taken from the
Cambridge Mathematical Tripos, London Matriculation, Queen's Scholarship,
and Certificate Examinations, the whole forming an Appendix to Matthews'
•' Deductions from Euclid and how to work them." The " hints " for solution
of problems, etc., are very useful.

Mensuration made Easy, or the Decimal System for the
Million, with its application to the daily employments of the Artizan and
Mechanic. Eighteenth edition. Post Svo, pp. 84. (London : Effingham,
Wilson, and Co.) Price is.

This is specially written for those who have had deficient instruction in
decimal arithmetic and calculations of Simple Measurements. It will be found
to answer its purpose, but the most valuable pages are those on the decimal
system of coinage, weights, and measures.

An Elementary Treatise on Mensuration, containing

numerous Solutions and Examples. By E. J. Henchie. Crown Svo, pp. xii,-
224, (London : School Book Publishing Co., Red Lion Square.) Price 3s.

This supplies a long-felt want for a comprehensive work on Mensuration
at a moderate price, and although it is called "elementary," a great variety of
methods for the measurement of simple and complex figures are given. There
are separate chapters on Land-surveying and Guaging. The examples are
numerous and well arranged. Diagrams are freely introduced, and all referen-
ces to Trigonometry avoided.

The Book of Bee-Keeping : A Practical and Complete
Manual on the Proper Management of Bees. By W. B. Webster. Crown
Svo, pp. 103. (London: L. Upcott Gill. 18S8,)

A book which will doubtless prove very serviceable to the bee-keeper.
After treating of the Advantages of Bee-keeping, the Natural History of the
Honey Bee is somewhat fully dwelt on, more especially in describing the
different varieties of Bees, followed by chapters on the Products of Bees,
Appliances, Food, Swarming, Diseases, and Enemies of Bees, etc. There are
several illustrations showing Cells and various kinds of frame and other hives.

REVIEWS, 265

Bicycles and Tricycles of the Year 1888. By Harry
Hewitt Griffin. Crown 8vo, pp. io8. (London : L. Upcott Gill. l888.)
Price IS.

A chronicle of the new Inventions and Improvements introduced each
season, and a permanent record of the progress in the manufacture of Bicycles
and Tricycles ; designed also to assist intending purchasers in the choice of a
machine. This book is in the eleventh year of its publication and has a
number of illustrations.

The Mechanic's Workshop Handy Book : A Practical
Manual on Mechanical Manipulation. By Paul N. Hasluck, A.I.M.E.
Crown 8vo, pp. 136. (London : Crossby, Lockwood, and Son. 1888.)
Price 2s.

Being designed for the help and guidance of young mechanics and others
interested in the manipulation of metals, the little book commences with
some account of the constituents and characteristics of Metals and Alloys
familiar to the mechanic in his daily work. Special attention is given to the
handling of various tools. Its chapters treat of Metals and Alloys, Iron, Steel,
and Brass, and their Treatment ; Tool Grinding, etc. It will doubtless prove
useful to workers of all ages and degrees of experience.

Charles A. Gillig's Tours and Excursions in Great
Britain : A day, week, or month on rail, road, and water. By Stephen F.
Smart. Crown 8vo, pp. vii.-426. (London: The United States Exchange,
9 Strand.) Price 2s.

With the help of this book and an ample purse, the tourist may spend a
month very pleasantly. He is supposed to start from London, and is conducted
to a great number of places on the East Coast, round the South Coast, to
Berwick-on-Tweed, and from thence to various places in Scotland, and finally
on a series of Welsh tours.

A Year in the Fields. By John Watson. T2mo, pp. 118.

(Edinburgh: David Douglass. 1888.) Price is.

In writing a history of the months, the author has preferred to describe
them as they were at the time of writing (1886), and not according to precon-
ceived notions, or "as they ought to be." This book reached us early in July,
and we were surprised to find the present weather so accurately described.
He says : — " We have now come to the close of the seventh month, and July
has been as abnormal as the rest. Instead of the summer sun and glowing
heat, we have been beaten and blown about by the blasts of October."

A Practical Treatise on the Manufacture of Cheap Non-
Alcoholic Beverages, with Sketches of My Life as a Temperance Reformer.
By Robert Seager, Ipswich. i2mo, pp. 96. (London : National Temperance
Publication Depot, 337 Strand.) Price is.

The writer gives a detailed account of the manufacture of a variety of
temperance drinks for home use. He also assures us that the finest mineral
water can be produced at the amazingly low cost of id. per dozen bottles,
and that quart syphon bottles for table use may be filled at id. each.

The Handy Route-Book of England and Wales. Part II.,

Middle England, with Map. By Charles Howard. l2mo, pp. xvi.— 309.
(London : Mason and Payne. 1888.) Price 2s.

A very convenient work for the tourist, and especially so for the cyclist.

266 REVIEWS.

It gives the names of all Towns and Villages and places of interest passed on
the road, with their distances from each other, and from the starting point as
well as from the destination, the direction and distance of the nearest place on
all the branch roads ; a tariff of Hotel Charges, Railway Rates for Cycles, etc.

Illustrated Guide to Ilfracombe and North Devon.
Edited by W. WaUers. With Plans and Maps. Square i6mo, pp. x. — 205.
(Ilfracombe : Twiss and Son.) Price is.

The visitor to Ilfracombe and North Devon will find this a useful hand-
book. The topography has, we are told, been brought up to date of publica-
tion. A good description is given of all the places of interest in the neigh-
bourhood. There are about 30 illustrations.

The Household Handy Book : A Useful Manual for
Everyday Life. Compiled by Mrs. Valentine. Crown 8vo, pp. xi. — 308.
(London : Frederick Warne and Co.) Price 2s. 6d.

Mrs. Valentine's book is addressed to young women, and is intended to
give them information that may enable them to add a fresh amount of pleasure
and usefulness to their lives- Advice and instruction on a great variety of
subjects are given, ranging from Receipts for making Home Pretty ; Fancy
Work ; Dress ; Food and How to Cook it ; Domestic Pets ; to Geography,
Arithmetic, and Natural Science.

Choice British Ferns : Their Varieties and Culture. By
Charles T. Druery, F.L.S. With Illustrations of about 120 Select Ferns.
Crown 8vo, pp. iv. — 167. (London: L. Upcott Gill. 1888.)

A number of the most beautiful and striking forms of British Ferns are
described and illustrated in a very pleasing manner, the plates being printed
with a black ground on drab paper. The book is not overcrowded with scien-
tific terms, and the common forms are described and figured so as to be easily
recognised. The book is divided into two sections :— i. — The Collection and
Cultivation of British Ferns ; and 2. — The Fern Families of Britain.

Modern Engine-Making in Theory and Practice. By J.
Pocock. Cr. 8vo, pp. vi. — 178. (London : Swan Sonnenschein and Co.
1888.) Price 2s. 6d.

A series of papers, which will doubtless prove useful to a large body of
amateurs. Instructions are given for building model engines of all kinds and
patterns. There are 115 engravings.

A Text-Book of Physiology. By John Gray M'Kendrick,
M.D., LL.D., F.R.S., etc. Including Histology, by Philipp Stohr, M.D.
8vo, pp. XXV. — 516. (Glasgow : James Maclehose & Sons. 1888.) Price i6s.

This will be found an exhaustive treatise on the general physiology of the
tissues. The introductory section deals with general notions as to living
matter, more especially with reference to the doctrines regarding energy which
form the basis of modern science. The nature and properties of the chemical
substances found in the bodies, and the nature of the chemical reactions with
which the phenomena of life are associated, are then discussed. Then follows
chapters on the physiology of the tissues, in which their origin is discussed in
the light of recent investigations, and finally a section on the contractile
tissues. This volume will be shortly followed by another on the special phy-
siology of the organs. The work is illustrated with 318 engravings and a
coloured plate of the spectra.

REVIEWS. 267

The Beginnings in Pharmacy : An Introductory Treatise on

the Practical Manipulation of Drugs, and the Various Processes employed in
the Preparation of Medicines. By R. Rother. Second edition. 8vo, pp.
vii. — 342. (Detroit, Alich., U.S.A.: \Vm. Graham Printing Co. 1888.)

This book cannot fail to be very useful to the student in pharmacy. The
routine, as here presented, commences with the simpler object-lessons in the
calling, and gradually becomes more and more difficult, but correspondingly
important as the treatment progresses. We have been much pleased with the
perusal of the book.

Curious Creatures and their Ways, with Illustrations.
By Marianne Bell. Crown 8vo, pp. 265. (London : St. Anselm's Society, 5
Agar Street. 1888.)

A series of entertaining papers, nicely illustrated, on Ancient Dragons ;
Seals and Sea-Lions ; Mermaids and Sea-Cows ; The Warriors of the Sea ;
Otters, Wild and Tame ; Beavers and their Dwellings ; Frogs and Toads ;
Rats and their Devices ; Monkeys and their Faculties, etc. etc.

George Birkbeck, the Pioneer of Popular Education : A
Memoir and a Review. By John George Godard. Second edition. Crown
8vo, pp. xvi. — 248. (London : Bemrose and Sons. 1888.) Price 2s. 6d.

In preparing the work before us, the author tells us he has consulted some
300 volumes. He narrates the Ancestry, Birth, and Early Life of Dr. Birk-
beck ; his early educational labours ; formation of the London Mechanics'
Institution ; the Rapid Growth of the Popular Education Movement, etc. A
portrait of the doctor forms a pleasing frontispiece to the volume.

Flower-Gardening for Amateurs in Town, Suburban, and
Country Gardens, with a Chapter on the Greenhouse. By Lewis Castle.
Crown 8vo, pp. xii. — 236. (London : Swan Sonnenschein and Co. 1888.)
Price 2s. 6d.

The object of this treatise is to furnish amateurs with a few hints upon
subjects that are dealt with exhaustively in more elaborate works. It points
out methods of diversifying the charms of a garden, as well as indicating the
practical details of cultivation. It is nicely illustrated.

British Reptiles and Batrachians. By Catherine C.
Hopley. Crown 8vo, pp. 94. (London : Swan Sonnenschein and Co. 1888.)
Price IS.

Another of the " Young Collector Series " — a series of books we strongly
recommend all our young friends to become possessors of. This volume treats
of the Viper, the Ring Snake, the Smooth Snake, Frogs, Toads, Newts,
Lizards, etc.

Indigestion : Its Causes and Cure. By John H. Clarke,
M.D. i2mo, pp. viii. — 100. (London: James Epps and Co. 18S8.)
Price IS.

In these pages the author first treats of the normal process of digestion,
and then goes on to sketch the various deviations from the normal to which
the process is liable, and to show how they may be avoided and how cured.

Irish Minstrelsy, being a Selection of Irish Songs, Lyrics,
and Ballads, Original and Translated. Edited, with Notes and Introduction,

268 REVIEWS.

by H. Halliday Sparling. i6mo, pp. xviii. — 368. (London : Walter Scott.
1887.)

A volume of the "Canterbury Poets" series, in which the attempt has
been made of furnishing readers with an opportunity of judging Irish charac-
ter, and of providing Irish readers with a book that, in its scope and com-
pleteness, might find a place on their own bookshelves.

The Pocket Gazetteer of the World : A Dictionary of
General Geography. Edited by J. G. Bartholomew, P\R.S.E., F.R.G.S.,
etc. 32mo, pp. ix.— 630. (London: John Walker and Co., Warwick Lane.
1888.) Price 3s. 6d.

Here we have, in a small compass, a concise geographical description of
35,000 places, covering every place of importance in the world. In addition,
there are nine maps, showing Height of Land and Depth of Sea; Zones of
Temperature ; Mean Annual Rainfall ; Ocean Currents ; Land Surface
Features; Prevailing Winds; Density of Population^ Races of Mankind ;
The British Empire ; and Principal Routes of Commerce.

The Works of Hubert Howe Bancroft : Vol. H., Native
Races, Vol. II., 8vo, pp. xii.— 805, (London : Trubner and Co. San
Francisco : The History Publishing Co. 1886.)

Another of these important works is now before us. It continues the his-
tory of the Aborigines of the Pacific States, and describes in very readable
language the more advanced Nuhua and Maya races, including their govern-
ment, laws, courts of justice, land tenure, system of taxation, commerce, edu-
cation, arts, and literature. We have been much interested with Chapter III.,
describing the Government of the Nahua nations, the magnificence of their
Monarchs, the Ceremony of Anointment, Address of the High Priest to the
King, Homage of the Nobles, General Rejoicing throughout the Kingdom,
Ceremony of Coronation, with a description of the Crown, the Coronation
Speech of one of the Kings, etc. etc. The volume contains a map and several
good engravings, two representing Calendars of the Aztec Year and the Aztec
month, the year being divided into months, containing 20 days ; each
month and day is represented by its peculiar hieroglyphic ; these are specially
interesting.

The Photographic Colourist's Guide. By John L. Gihon.
Post 8vo, pp. 88. (New York : Edward L. Wilson. 1878.)

In the little work before us the author gives information with regard to all
classes of photographs. Its twelve chapters treat of India-ink work, the
Prniciples to be considered in the application of Colours, the production of
the picture originally known as Ivorytype, Crayon work, etc.

Hints for Yacht-Building for Amateurs. By Tyrrell E.
Biddle. 8vo, pp. 43. (London : George Wilson, 20 Glasshouse Street,
Piccadilly, and Simpkin and Marshall. 1888.) Price 2s.

These '' Hints " form a continuation of Mr. Biddle's Hints to Beginners in
Amateur Yacht Designing, and contain full instructions with drawings for
Building a Yacht.

The Nature and Constitution of the Ego. By Anna
Bonus Kingsford, M.D. Foolscap 4to. (London : Field and Tuer. 1SS8.)
Price IS.

A selection, being Lecture V., from "The Perfect Way,"

REVIEWS. iJ69

Britain's Salamis, or the Glorious Fight of 1588. By \V.

n. K. Wright, F.R.Hist.Soc. With an Introductory Poem by Lewis
Morris and other original poems and ballads. Foolscap 4to, pp. 71. (Ply-
mouth : W. Frank Westcott. 1888.) Price IS.

An Historical Lecture delivered at various places in the West of England
by Mr. W. H. K. Wright.

Warrior Kings from Charlemagne to Frederic the Great.
By Lady Lamb. 8vo, pp. 378. (London : George Routledge and .Sons.
1889.) Price 6s.

This handsomely bound book would be considered a very valuable present
by many boys of our acquaintance. Its subjects are Charlemagne, William
the Conqueror, Frederic Barbarossa, Richard Cceur de Lion, Edward I.,
Robert Bruce, Henry V., Frances I., Henry IV., Gustavus Adolphus, King of
Sweden, Charles XII. of Sweden, and Frederic the Great. It contains a
number of illustrations and twelve full-sized plates.

The Photographic Instructor for the Professional and
Amateur, being the comprehensive series of practical lessons issued to the
students of the Chautauqua School of Photography, revised and enlarged,
edited by W. I. Lincoln Adams, editor of the Photographic Times. With an
Appendix on the Nature and Uses of the various chemicals and substances
employed in Photographic Practice, by Professor Charles Ehrmann. 8vo, pp.
196. (New Vork : Scoville Manufacturing Co. 1888.)

Two years ago the authorities of the Chautauqua University recognised the
growing demand for photographic knowledge by establishing a school of photo-
graphy with Chautauqua ideas, and as an integral part of the great university ;
of this school Professor Ehrmann was chosen instructor. The introduction
tells us that "the series of lessons which follow this are written more especially
for those who know little or nothing of the charming art of photography, yet
who desire to be taught its mysteries by easy, simple methods, leaving for later
study the whys and the wherefores, the chemistry of the science."

We have gone carefully through the book and find that the subject has
been well treated. The book, like ail the rest of the Scoville Co.'s publica-
tions, is beautifully got up and well illustrated with wood engravings in the
text, in addition to which the frontispiece is a half-tone engraving direct from
the negative of a view at Chautauqua. There is also a photo of the Professor
in his studies.

The Photographic Negative, written as a Practical Guide

to the preparation of sensitive surfaces by the Calotype, Albumen, Collodion,
and Gelatine processes on glass and paper, with supplementary chapters on
development, etc. By the Rev. W. H. Burbank. 8vo, pp. 198. (New
York : Scoville Manufacturing Co. 1888.)

The author is so well known in the photographic world that we. are sure
to find instruction in whatever emanates from his pen. He tells us that he has
aimed to select only those methods known to have permanent value, and in
addition to those subjects mentioned in the title, as quoted above, the volume
treats of Methods of Stripping Films from Glass Plates, Colour-sensitive
Plates, Instantaneous Photography, Photo-Micrography, and Micro-Photo-
graphy, the Transformation of Negatives to Positives, etc. The book is well
illustrated.

270 REVIEWS.

T' Fisher Folk of Filey Bay : Poems chiefly in the
Yorkshire dialect. By the Rev. W. H. Oxley, M.A. 4to, pp. 46. (Scar-
borough : E. T. W. Dennis. 1888.)

A collection of interesting Poems, illustrated with etchings describing
"Our Parson," "The Widow's Tale," " T' Sunrise fre' t' Window, ov t' Auld
Cottage on t' Cliff Top," etc.

The Chess-Player's Manual, containing the Laws of the

Game, according to the revised code laid down by the British Chess Associa-
tion, 1862, by G. n. D. Gossip, revised and edited with an American Appen-
dix by S. Lipschlitz. 8vo, pp. xi.-884. Appendix, pp. v. -122. (London :
George Routledge and Sons. 1888.)

This work contains comprehensive and thorough analysis of all the
openings — both regular and irregular — with the most important discoveries that
have been made of late years by the leading authorities. The Appendix
contains Revisions, Amendments, Specimen Games, and a number of Problems
selected from recent first-prize compositions, thus bringing the entire work
fully up to date. It is a handsomely got up volume and well illustrated with
diagrams.

Modern Science in Bible Lands. By Sir J. WilHam
Dawson, C.M.G., LL.D., F.R.S., F.G.S., etc., with Maps and Illustrations.
Crown 8vo, pp. xii.-6o6. (London : Hodder and Stoughton. 1888.)
Price 9s.

The author of this exceedingly interesting book desires his reacjers to share
with him the pleasure of a tour in Italy, Egypt, and Syria, in which he studied
such points in the geology and physical features of those countries as might
throw light on their ancient history, and especially on the history of the Scrip-
tures. The chapters treat of the Firebelt of Southern Europe, the Haunts
and Habits of Primitive Man, Early Man in Genesis, Egyptian Stones and
Teaching, Egypt and Israel, The Topography of the Exodus, Palestine — its
Structure and History, Resources and Prospects of Bible Lands, etc. There
are numerous illustrations.

The Thermal Baths of Bath : Their History, Literature,
Medical and Surgical Uses and Effects, together with the Aix-Massage and
Natural Vapour Treatment. By Henry William Freeman, F. R. C.S.I. ,
M.R.C.S., L.C.P., etc. Crown 8vo, pp. xliv. — 379. (London: Hamilton,
Adams, and Co. Bath : Charles Hallett. 1888.) Price 5s.

Dr. Freeman gives, in the work before us, a capital history of these
world-famed baths, which, we feel sure, will be read with interest by many
who do not require the waters for their medicinal values. A sketch of the
lives of some of the most prominent Bath physicians of a former age is given,
with a list of their more important works. In the account of the springs,
comparisons, both quantitatively and qualitatively, are made with Continental
and other Foreign Spas. The subject of Massage is treated at considerable
length, the European and American systems being respectively described.
We notice also that the diseases in which the Waters are, and those in which
they are not found efficacious, are carefully described and classified. The book
is beautifully illustrated by a number of Woodburytype plates and large
folding maps of the ancient Roman, and modern baths.

Nature and the Bible : Illustrations of the Philosophy of
Universal Motion. Second edition, with an Appendix showing the Causes of

REVIEWS. 271

Earthquakes, Volcanic Eruptions, and Sliooting .Stars. By James Davis, C.E.
l2mo, pp. xi. — 246 + 36. (London: Houlston and Sons. 1887.) Price ^s.
Tliis little book is divided into two sections, the first being entitled the
Laws of Motion as defined in Mathematics, being the Philosophy of Time ;
and the second, the Philosophy of Motion applied to Universal Creation in
agreement with the Sacred Scriptures. There is also an Appendix on Evi-
dences Natural and Revealed concerning Earthquakes, Volcanic Eruptions,
and Meteors and Shooting Stars.

Kindergarten Education. By M. Stephens. Post 8vo,

pp. vii.— 63. (Dublin : Alex. Thom and Co. 1888.) Price 2s. 6d.

By the aid of this little book parents will have no difficulty in carrying on
the system of kindergarten education with their young children. The book is
really addressed to teachers and the whole system is thoroughly explained.
At the end are 26 well-engraved plates, showing the manner of using the
blocks, etc.

A Manual of the English Language. By John Gibson,
M.A. Crown Svo, pp. 88. (London : Cornish and Sons. 1888.)

Mr. Gibson's " Manuals and Guides" are well known. This one is quite
up to their usual standard of usefulness as a careful epitome of larger Gram-
mars. The Appendix contains test papers for Examination students.

Amateur Work. (London: Ward and Lock.) Price 6d.

The September part of this well-known publication contains, among other
things, a full-sized drawing of designs for an Occasional Chair, with Fret-work
Ornamentation, and a great variety of information specially valuable to the
amateur. The articles are well illustrated.

Our Earth and Its Story. Edited by Dr. Robert Brown,
M.A., F.R.G.S., F.L.S., etc. (London : Cassell & Co.) Price 6d. monthly.

Part 20 of this interesting work has reached us, and contains an account
of the Cainozoic Deposits ; the Pleistocene System ; the Quaternary Period ;
and Prehistoric Man and his Dwelling-Places. It contains a coloured map,
showing the Distribution of Vegetation and a number of excellent wood
engravings.

The World's Inhabitants ; or, Mankind, Animals, and
Plants. By G. T. Bettany, M.A., B.Sc, London: Ward and Lock.)
Price 6d. monthly.

We have before us the eleventh part of this work, in which are described
the Inhabitants of South Africa, the South Tropical Africans, the Malagasy,
the Distribution of the African Races, African Animals, and African Plants.
The illustrations are numerous and good.

The Prescription, Therapeutically, Pharmaceutically, and

Grammatically Considered. By Otta A. Wall, M.D., Ph. G., etc. 8vo, pp.
184. (St. Louis, Mo., U.S.A. : The Aug. Gast Bank Note Co. 1888.)

This work is intended for the use of American students, but there is much
in it likely to interest those engaged in medicine and pharmacy. The teaching
throughout is of a high order, and the different subjects are dealt with in a
conscientious manner.

%\Qt Of platee.

Aspidiotus nerii
Batrachospermum moniliforme
Bee, Stomach of
Bot-Fly, Eggs of
Caprella linearis
Cypris, Organs of
Deutzia, Hairs of
Elk's Horn Fern, Hairs of
Equisetacese
Flying-Fox Parasite
Marine Diatoms
Melophagus ovinus
Onosma tauricum
Periploca Graeca stem ...
Pollen in Hay-Fever
Pteris aquilina, Scales of
Phthirius inguinalis
Rhubarb, Spiral Vessels of
Screw Pine, Section
Spinnerets of Spider
Sugar-Cane, Stern
Tadpole, Development of

Ditto

Ditto

Ditto
Trap-door Spider's Nest
Viburnum lantana. Hairs of
Villi on Scales of Lepidoptera

Plate

Page

12

107

24

259

6

50

6

SO

16

180

22, 23

231

6

50

24

259

9, 10, II

74

18

257

16

180

17

257

3

47

5

49

15

173

3

47

17

255

4

48

12

107

12

107

4

48

I, 2

33

7,8

65

13

147

19, 20, 21

203

12

107

16

180

14

167

gn^cy IDoL E, 1Rew Serice.

Page
^cidium Compositarum ... 115

^stivis, The Pathology of Pollen

in ... ... ... 173

Adamkiewicz's Method .. 253

Air Bladder of Fishes considered

as a Degenerate Lung .. 197

American Cement ... ... 44

Ammonium Bichromate ... 254

Aniline, Blue Black ... ... 254

Aniline Blue for Ganglion Cells ... 250
Aperture, Numerical ... 155

Apochromatic Objectives ... 9

Asparagus, Sections of ... 51

Aspidiotus Nerii ... 107, 109

Bacteria in Sea Air ... ... 50

Bastian's Cement ... ... 40

Batrachospermum moniliforme ... 259
Beck's New Purple ... ... 254

Bee, .Stomach of ... ... 49

Beecher, C. E., on Preparing the
Radulse of Gasteropoda for
Micro-Study ... ... 89

Beetroot, Concentric Circles in

55. 56, "7
Bell's Cement ... ••■39

Benison, H. W. S. Worsley, on

the Romance of Seed Sowing 129
Benzole and Dammar ... 43

Benzole and Mastic ... 43

Bichromate of .Silver Process for

Spinal Cord ... ... 105

Birds, Instinct of ... •••73

Bismuth and Mastic ... ... 42

Black Matt Varnish ... ••■43

Blow Fly, Head of ... ... 260

Blue Black Aniline ... ... 254

Bodington, Mrs. A., on Micro-
organisms as Parasites ... 17
Bodington, Mrs. A., on the Air

Bladder of Fishes ... 197

Borax, Ground ... ... 41

Bot-Fly, Egg of ... 49.51.52

Bracken, Scales from ... 47

Brown Varnish ... ... 43

Brunswick Black ... ••• 39

Bryan, G. H., on Trapdoor Spiders
and their Nests ... 84

Calyx of Deutzia Gracilis
Cam wood. Section of
Canada Balsam Varnish
Caoutchouc Cement ...
Caprella linearis

Page

■ 49
. 109

• 43

• 42
. 180

Carriere's Method for Ganglion

Cells ... ... 250

Cells of Dahlia, Deposits in ... 169
Cells, Sand Blast ... ... 50

Cement, American ... ... 44

Cement, Dr. Bastian's ... 40

Cement, Bell's ... ... 39

Cement, Caoutchouc ... 42

Cement, Coloured ... ... 45

Cement, Dammar ... ... 45

Cement, Electrical ... ... 40

Cement for attaching Gutta Percha,

etc., to Glass ... ... 41

Cement for fixing Metals to Glass,

etc. ... ... ... 45

Cement, French ... ... 41

Cement, Gelatine ... ... 44

Cement, Good, for Glycerine ... 41
Cement, Kitton's ... ... 42

Cement, Liquid ... ... 44

Cement Resin and Balsam ... 42

Cement, Smith's New ... 46

Cement, Strong, for attaching Brass

Cells to Glass ... ... 46

Cement and Useful Recipes ... 39
Chameleon, The ... ... 32

Chloral Hydrate Method ... 252

Coloured Cement ... ... 45

Common Brunswick Black ... 39

Concentric Circles in Beetroot

55.56, 117
Copal Varnish ... • • • 43

Coppock's Magenta and Aniline 254
Correspondence ... 117, 183

Curties, C. L., on a new Photo-
Micro Apparatus ... 99
Cuticle of Onosma .. •••57
Cutting Tissues ... ... 103

Cypris, Male Organs of two Species

of ... ... ... 23j

Dahlia, Deposits in the Cells of ... 169
Dammar ... ... ... 41

Dammar and Benzole ... 43

L.4719

274

INDEX.

Page
Dammar and Cement ... 45

Debore's Method ... ... 253

Deutzia Gracilis, Calyx of ... 49

Deutzia, Hair on Petals of ... 1 14

Development and Life-History of

the Tadpole 33, 65, 147, 203

Diatoms, Marine ... ... l8o

Diatoms, The Nature of ... 32

Dissections of Insects ... 53

Dog, Spinal Cord of... ... 104

Double Stain for Nervous System 253
Double Stain, Gibbe's ... 254

Earth's Surface, Movement of ... 92

Earthworm, To Harden .. 55

Economic Entomology ... 217
EggofBot-Fly .. 49,51,52

Electrical Cement ... ... 40

Elk-Horn Fern, Hair from ... 259

English Tingis ... ... iii

Equisetaceffi, Life History of ... 74
Erlicki's Fluid for Hardening

Spinal Cord ... ... 104

Farrant's Gum and Glycerine,
Mounting in

Fern, Hair from

Fern, Oblique Section

Ferns, Ramenta of ...

Ferns, Scales of

Fish, Palatial Tooth of

Fishes, The Air Bladder of

Fly from Greenhouse

Fly, Wing of

Flying Fox, Parasite of

Fogs _ ...

Foraminifera from Sea Soundings

Forster, J. A., on Economic Ento-
mology

French Cement

French Polish

Freezing Tissues

Fumigation

246

259

47

114

"S
III

197

50

258

257, 260

... 212

112

217
41

43
103

154

Ganglion Cells, Aniline Blue for 250
Ganglion Cells, Carriere's method 250
Ganglion Cells, Staining ... 249

Gasteropoda, Method of Preparing

the Radula of ... ... 89

Gatehouse, J. \V., on the Develop-
ment and Life History of the
Tadpole 33, 65, 147, 203

Gelatine Cement ... •••44

Gibbe's Double Stain ... 254

Page
Gifford, J. W., on Apochromatic

Objectives ... ... 9

Giftbrd, J. W., on Preparations

for High Powers ... 152

Glass or Earthenware, Cement for 45
Glow-worm, Phosphoresent Light of 73
Glue, Liquid ... ... 42

Glue, Marine ... ... 41

Glycerine and Litharge ... 43

Glycerine Mounts, Cement for ... 41
Gold Chloride ... ... 249

Gold-size ... •••39

Good Black Varnish ... ... 32

Gray, Dr. Asa, the late ... 106

Greenhouse, Fly from ... 50

Guaiacum Varnish ... ... 42

Gum, extra adhesive... ... 40

Gum water ... ... 45

Hasmatopinus suis ... ... 182

Hair from Elk-horn Fern ... 259

Hairs on Petals of Deutzia ... 114

Hairs on Viburnum Lantana ... 180
Half-an-Hour at the Microscope
with Mr. Tuffen West

47, 180, 255
Hardening Tissues ... ... 102

Hay-fever, the Pathology of Pollen

in ... ... ... 173

Head of Blow Fly ... ... 260

Hessian Fly, The .. ... 12

Hessian Fly and its Parasites ... 88
High Powers. Preparations for ... 152
Histology, Practical Notes on 102, 249
Hogg, Dr. Jabez, on Pseudo-Hel-
minths ... ... 240

Hogg, Dr. Jabez, on Entozoa from

Human Tooth ... ... 170

Horse, Spinal Cord of ... 104

House-fly, Wing of .... ... 258

Ink ... ... ... 254

Insect Dissections ... •••53

Insect World, The ... ... 172

Instantaneous Mounting in Farrant's
Medium ... ... 246

Instinct of Birds ... •••73

Jaw of Mole, Section of
Judson's Cambridge Blue

112

254

Kitton's Cement ... ... 42

Krause's Method of Preparing

Spinal Cord ... ... 104

INDEX.

275

Page
Labels, Mucilage for ... 46

Latham, V. A., on the Microscope

and How to Use it 39, 102, 249
Liquid Cement ... ... 44

Liquid Glue ... ... 42

Litharge and Glycerine ... 43

Lock wood, Professor, on the

Pathology of Pollen in Hay
Fever ... ... 173

Magenta and Aniline, Coppock's 245
Manchester Microscopical Society,

The ... ... ... 38

Marine Diatoms ... ... 180

Marine Glue ... ... 41

Mask-Lac ... ... 40

Mastic and Benzole ... ... 43

Mastic and Bismuth ... ... 42

Matt Varnish ... •••43

Melophagus ovinus ... ... 258

Mendicago ... ... 115

Micro-Organisms as Parasites ... 17

Microscope and How to use it, The 39,

102, 249
Mole, Section of Jaw of ... 112
Moon, The Influence of, on Vege-
tation ... ... 146

Mounting Spinneret of Spider ... 51

Movement of the Earth's Surface 92

Mucilage for Slide-Labels ... 46

Nematode Worm, Points in the

Nature of ... ... 240

Nerve-Fibre, Staining ... 253

Nervous System, Double Stain for 253
Nervous System, Weigert's Method

for ... 250, 251

Nervous System, Xylol for ... 105

Numerical Aperture ... ... 155

Obituary ... ... ... 106

Objectives, Apochromatic ... 9

Onosma Cuticle ... .. 51

Onosma Tauricus ... 47, 113
Overlach's Method of Preparing

Spinal Cord ... ... 104

Palatial Tooth of Fish ... 11 1

Pallidium Chloride ... ... 249

Parasite from Flying Fox 257, 260

Parasites of the Hessian Fly ... 88

Parasites, Micro-organisms as ... 17

Parasites, To Mount ... ... 116

Parasitic Entozoa from Human

Tooth ... ... 170

Page
Pearl Shells, The Use of •..38

Pearls, Formation of ... 8

Periploca Graeca .. ..48

Phosphoresent Light of Glow-
worm ... •••73
Photo-Micro Apparatus, New ... 99
Phthirius Inguinalis ... ... 255

Picro Carminate of Soda and Palla-
dium Chloride ... ... 249

Pigott, Dr. Royston, on the Villi
and Beading found on Scales
of Lepidoptera ... ... 167

Plant Hairs ... ... 115

Pollen in Hay Fever ... 173

Pollen of Shamrock ... ... 49

Preparations for High Powers ... 152
Presidential Address ... ... i

Pseudo-Helminths ... ... 240

Pteris Aquilina, Scales of ... 51

Purple, Beck's New ... ... 254

Queries and Replies

55

Radulse of Gasteropoda, To Pre-
pare... ... ... 89

Ramenta of Ferns ... ... 114

Recipes and Cements, Useful ... 39
Resin and Balsam Cement ... 42

Reviews ... ... 56, 120, 185

Rhubarb, Long Section ... 48

Rhubarb, Spiral Fibre in ... 116

Rice Paper ... ... 108

Romance of Seed Sowing ... 129

Rossiter, T. B., on the Male
Organs of Two Species of
Cypris ... ... 231

Rousette, The ... ... 260

Sand-blast Cells
Scales from Bracken ...
Scales of Ferns
Scales of Pteris Aquilina
Schieffordecker's Method
Screw Pine, Section of
Sea Air, Bacteria in ...

SO

47

115

51

249
III

50

Sea Soundings, Foraminifera from 112
Sealing Wax ... •■•39

Section of Asparagus ... 51

Section of Fern ... •••47

Section of Jaw of Mole ... 112

Section of Tongue ... ••• 113

Section of Rhubarb ... ... 48

Section of Screw Pine ... 11 1

Section of Sugar Cane ... 48

Section of Yellow Cam Wood ... 109
Seed Sowing, The Romance of ... 129

276

INDEX.

Selected Notes from the Society's

51^

Page

Note-Books

Shamrock

Shamrock, Pollen of

Sheep Tick

Shellac ...

Shellac and Aniline ...

Slide Labels, Mucilage for

Smith's New Cement

Smut of Wheat, Oats, and Barley

Spider, Spinnerets of

Spinal Cord, Brain, etc., to exam-
ine ...

Spinal Cord, Fibre of

Spinal Cord of Dog ...

Spinal Cord of Horse

Spinal Cord, To Harden

Spinnerets of Spider

Spinnerets of Spider, To Mount

Spiral Fibre in Rhubarb

Spiral Vessels, To Mount

Spirit and Iodine Mixture

Sponge, a Piece of ...

Staining ...

Staining Medullated Nerve Fibre

Staining Isolated Ganglion Cells

Stigmas, To Prepare, to Show
Pollen Tubes

Stomach of Bee

Sugar Cane

Sugar Cane Sections

107
51

49
258

39
40
46
46
93
"3

102, 249
249
104
104
104
113
51
116

117

254

50

251

253
249

55
49
52

48

Tadpole, Development and Life
History of 33, 65, 147,

Tarantula at Home, The
Taylor, Miss B., on Fogs
Testacella

Tingis Hystricellus ...
Tingis, English

203
II
212
117
109
III

Tissues, To Cut

Tissues, Freezing

Tissues, Hardening ...

Tongue, Section of ...

Tooth, Parasitic Entozoa from ...

Trap-door Spiders and their Nests

Tuffen West, Half-an-Hour at the

Microscope with... 47, 180, 255

Page
103
103
102

"3

170

84

Varnish, Brown ... •••43

Varnish, Canada Balsam ... 43

Varnish, Copal ... •••43

Varnish, Good Black ... 42

Varnish, Guaiacum ... ... 42

Varnish, Matt ... ••■43

Vegetation, The Influence of the

Moon on ... . . 146

Vereker, Hon. J. G. P., on

Numerical Aperture .. 155

Vereker, Hon- J. G. P., Presiden-
tial Address ... ... i

Viburnum lantana, Hairs of ... 180
Villi and Beading on Scales of

Lepidoptera ... ... 167

Ward, Dr. R. H., On Mounting in

Farrant's Medium
Weigert's Method for Nervous

System
West, Mr. Tuffen,

with
Wheatcroft, W. J

History of Equisetacese
White, Hard Varnish
White Zinc
Wing of House-Fly ...

246

250, 251
Half-an-Hour

47, 180, 255
On Life-

• • 74
.. 44

• 44
.. 258

Xylol for Central Nervous System 105

Zinc, White

44

IRevtews.

Adventures in African Travel, Stirring 61

Algebra Made Easy

Amateur Work

Ambulance Lectures

Among the Cannibals of New

Guinea
Ants, Bees, Dragon-Flies, etc. ...

264

64, 271

190

189
59

Arctic Stories ... ... 64

Arithmetic, A Higher ... 191

Arithmetic, Exercises in ... 125

Arithmetic for Beginners ... 192

Art of Preparing Vegetables for

the Table ... ... 196

Astronomy, Elementary Lessons in 195

INDEX.

277

Page

Atlas, Gall and Inglis's School ... 194

Atlas, Imperial Globe ... 60

Australian Ballads and Rhymes ... 126

Bairns' Annual, The ... 64
Bancroft, Works of .. 189, 268

Band of Hope Reciter ... 64

Bath, The Thermal Baths of ... 270

Bee-keeping, Book of ... 264

Bible, Comprehensive Teacher's... 263

Bible, Diseases of the ... 125

Bible, Oxford, for Teachers ... 263

Bicycles and Tricycles of the Year 265

Bird Stories Old and New ... 59

Birds'-Nesting and Bird-Skinning. 195

Birds, Canadian ... ... 188

Birds of Herefordshire ... 187

Birkbeck, George ... ... 267

Botany, Elements of... ... 186

Botany, Guide to the Student in ... 193

Britain's Salamis .. ... 269

British Birds ... ... 191

British Isles, Pictorial Geography of 60

British Reptiles ... ... 267

Buhl Work, Manual of ... 63

Burns, Robert, Letters of ... 126

Canadian Birds, Catalogue of ... 188

Chemical Lecture Notes ... 123

Chemistry, Elementary ... 62

Chemistry, Practical ... ... 62

Chess- Players' Manual ... 270

Comprehensive Teacher's Bible ... 263
Constellations, A Guide to ■■•59
Constellations and How to Find

Them ... •••59

Creator, The ... ... 60

Cremation of the Dead ... 62

Curious Creatures and their Ways. 267

Dawn of the 20th Century ... 126

Dainty Ditties ... ... 62

Dates Made Easy ... 190

Dictionary, A New English ... 263

Dictionary of Plant Names ... 60

Dictionary, The Ready Reference. 191
Die Naturlichen Planzenfamilien

57, 120

Discomycetes, Manual of British 120

Discursive Essays ... .. 123

Divided Irish, The ... ... 128

Divine Programme of the World's

History ... ... 193

Draughts, The Game of ... 193

New Series. Vol. 1.
i:

Page

Earth and Solar System, The ... 193

Education of Man, The ... 194

Education, Principles of ... 63

Educational Topics of the Day ... 187
Electrical Instrument-Making for

Amateurs ... ... 127

Engine-Making ... ... 266

English Grammar for Beginners ... 190

English Language, A Manual of... 271

Essex, Durrant's Handbook of ... 124

Essex, Trade-Signs of ... 124

Euclid Examination Papers .. 264

Evangelisation of the World ... 125
Evolution, Examination of the

Theory of ... ... 196

Examination Papers, Board of Edu-
cation ... ... 61

Examination Papers, Oxford and

Cambridge ... ... 61

Factors of Life ... ... 62

Familiar Animals ... ... 186

Ferns, Choice British ... 266
First Steps in Scientific Knowledge 194

Flora of Howth, The ... 57

Floral Structures, Origin of ... 185

Flower Gardening for Amateurs ... 267

Forms of Animal Life ... 185

Fossil Men .. ... 121

Foundation of Death ... 189
Fresh-Water Algse of the United

States ... ..56

Gall and Inglis's School Atlas ... 191

Gardener's Receipt Book ... 193

Gazetteer, The Pocket ... 268

Geographical Text Book ... 190

Geography, Physical ... 60

Gillig's Tours and Excursions ... 265

Geography, Pictorial ... 60

Goldsmith, Life of ... ... 126

Gospel Ethnology ... ... 125

Gospel in Nature ... ... 125

Great Water- Falls, Cataracts, etc. 59
Guide Pratique pour les Travaux

de Micrographie... ... 121

Hair, Diseases of ... ... 190

Handy Route Book of England

and Wales ... ...265

Herefordshire, Birds of ... 187

History, Great Events of ... 61

Home Experiments in Science ... 191

Household Handy Book ... 266

u

278

INDEX.

Page
How to Spell and Speak English... 190

Ilfracombe Guide ... ... 266

Illustrations ... ... 194

In Touch with Nature ... 196

Indian Art, Journal of ... 127

Indigestion ... .. 267

Insect Ways in Summer Days ... 122

Irish Minstrelsy ... .. 267

Johnston's Pictoral Astronomical

and Geographical Diagrams ... 263
Journal of Indian Art ... 12S

Journal of Morphology 57, 185

Journal of Royal Micro. Society 64

Kindergarten Education ... 271

La Photographie Moderne ... 128

Laws of Everyday Life ... 194

Lesson Pegs ... ..190

Living Lights ... •••58

Matthew's Euclid Exam. Papers 264

Mechanics and Experimental Sci... 187

Mechanics' Workshop Handy-Book 265

Medical Annual, The ... 123
Mensuration, Elementary Treatise

on ... ... ... 264

Mensuration Made Easy . . . 264
Mental Healing, Facts and Fic-
tions of .. ... 61

Microscopie, Guide Pratique ... 121
Microscopical Manipulation, Manual

of Elementary ... ... 58

Microscopy, Practical . . 121

Modern History, First Principles of 190

Modern Science in Bible Lands ... 270
Moffatt's Geography of British

Empire ... ... 193

Morphology, Journal of 57, 185

Mountains and Rivers ... 193

Mystery of the Ages, The ... 195

Nature and Constitution of the Ego 268
Nature and the Bible ... 270

Nature, Short Studies from ... 58

Natural Causation ... ... 195

Natural Philosophy for Begin-
ners ... 128, 19s
Naturalist's Diary ... -.58
Nature's Fairyland ... ... 185

New Treatment, Dictionary of ... 123
Non- Alcoholic Beverages ... 265

North- American Birds, Manual of 121

Page
1,000 Ways of Earning a Living... 195
Our Earth and its Story 64, 271

Our English Shores .. . . 196

Our Home . . ... 64

Outlines of Course in Natural

Science ... ... 193

Oxford Bible for Teachers ... 263

Pacific States of North America,

History of ... ■••59

Pharmacy, Beginnings in ... 267

Pharmacy, Manual of .. igi

Phonography, Manual of ... 192

Photo-Engraving, etc. 127, 186

Photographic Colourist's Guide ... 268
Photographic Instructor ... 269

Photographic Negative ... 269

Photography, A Treatise on ... 126
Photography, American Manual of 127
Photography, History of 63, 1S6

Photography, Practical Guide to... 63
Photographies, Wilson's ... 127

Physical Science, Introduction to.. 189
Physiology, Text-Book of ... 266

Pictorial Geography of the British

Isles ,. . . 60

Place, Names, Dictionary of ... 60
Pleasures of Life ... ... 188

Popular Antiquities, Observations

on ... ... ... 124

Pre-Glacial Man ... ... 189

Prescription, The ... ... 271

Psychology, Students' Manual of... 122

Queer Chums

Round Nature's Dial..

62

63

Sand-Blast Cells ... ... 169

Sandy Ross ... ... 64

Science Gossip ... ... 64

Scripture Animals, Guide to ... 187

Scripture Natural History ... 126

Shore and Sea ... ... 63

Silkworms ... ... 191

Silver Voice, The ... ... 64

Simple Catechism of the Animal

and Vegetable Kingdoms ... 190

Songs of a Parish Priest ... 193

Sunlight ... ... ... 187

Talks with Young Men ... 191

Tenants of an Old Farm ... 122

T' Fisher Folk of Filey Bay ... 270

INDEX.

279

Through a Microscope
Trigonometry, Treatise on Plane
Twelve Tissue Remedies

Unfinished Worlds ...
United States, Natural Resources
of the

Volcanoes and Earthquakes

Page Page

. 192 Water, Electricity, and Heat, Key

196 to the Mysteries of ... 193

. 190 Will-Making made Safe and Easy 192

Words, Fortune of ... ..124

-g Words, Philosophy of ... 124

World's Inhabitants, The 64, 271

'^^ Yacht-Building, Hints for .. 268

_ Year-Book of Scientific Societies 188

■^^ Year in the Fields .. ... 265

Warrior Kings

269 Zoology, A Popular

122

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