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THE

C Y C L O P M D I A

ANATOMY and PHYSIOLOGY.

VOL. IV,— PART II.

S T A W R I

1849-1852

THE

CYCLOPAEDIA

OF

ANATOMY and PHYSIOLOGY.

EDITED BY

ROBERT B. TODD, M.D. F.R.S.

FELLOW OF THE ROYAL COLLEGE OF PHYSICIANS;

PHYSICIAN TO KING’S COLLEGE HOSPITAL; AND FORMERLY
PROFESSOR OF PHYSIOLOGY AND OF GENERAL AND MORBID ANATOMY IN KING’S COLLEGE,

LONDON, ETC. ETC.

YOL. IV. — PART II.

STA -WRI

1849—1852

15704

LONDON

LONGMAN, BROWN, GREEN, LONGMANS, & ROBERTS.

■ -Id

To Ad,

STATISTICS.

801

In such instances, there is little appearance
of any thing morbid beyond the increase of
size. The contained blood is usually very
dark, and the spleen shares the deepening of
colour. By long duration, the capsule of the
organ and the fibrous tissues generally, be-
come somewhat thickened, but in other re-
spects the texture is little altered. In the
second class, in which the swelling is pro-
bably produced by a peculiar state of the
blood ( dyscrasia ), and is certainly associated
with a class of blood diseases, the texture of
the organ is usually much altered. The size of
the spleen is often astonishingly increased, so
that it possesses a volume of from 100 to 300
cubic inches, and a weight of 10-20 lbs. The
increase includes, besides blood, a considerable
quantity of a fibrinous material, the nature of
which, and its relations to the healthy organ,
are at present little known. The colour and
consistence are of every possible gradation ;
from greyish to deep brownish red, or from
a soft, friable mass, to a dense, firm, and
almost fibrous texture. There is a general
relation of these changes to the date and
duration of the swelling ; thus in acute or
recent cases, the organ is usually soft and of
a dark colour, while by long continuance, or
in chronic diseases, its consistence is greatly
increased, and its colour, as well as that of
the contained blood, is much paler or greyer
than natural. Atrophy of the spleen, or slow
and permanent diminution of its size, is much
more infrequent than the preceding converse
condition. It is associated with similar
varieties of colour and consistence.

Inflammation of the spleen. — The peritoneal
surface of the organ shares in the diseases of
this structure generally, and an inflammation
of this part of the serous membrane not un-
frequently accompanies the enlargements pre-
viously mentioned. The exsudation and re-
sults are no way peculiar. Concerning in-
flammation of the parenchyma of the spleen
little can at present be said. The large and
numerous veins which it contains are liable
to inflammation, the secondary being the
more frequent form of phlebitis which affects
them.

As regards other morbid products, organ-
ised and unorganised, the spleen offers no-
thing deserving a special notice.

Bibliography. — M. Malpighi, De Liene, in
Exercitationibus de Yiscerum Structura, Loud.
1GS9. 12. F. Ruysch, De Glandulis, Fibris, Cellu-
lisque Lienalibus, Epist. Anat. Quart. Opera omnia.
A. V. Leeuwenhoek, Microscopical Observations on
the Structure of the Spleen, Phil. Transact. 1706,
p. 2305. T. Douglass, Observations on the Glands
in the Human Spleen, Phil. Transact. 1714, p. 499.
IV. Stuckeley, Of the Spleen, its Description and
History, Uses and Diseases, Lond. 1722. B. 8.
Albin us, De Liene, in Anotat. Academ. lib. vii.
cap. 14. p. 84. De Lasone, Histoire Anatomique de
la Rate, Memoires de l’Academ. de Paris, 1754. T.
Lieutaud, Observation sur la Grosseur Naturelle de
la Rate, Mem. de l’Acad. de Paris, 1788. W. IJew-
son, Experimental Inquiries, Lond. 1776 ; et Opus
Posthumum, Lugd. Bot., 1786. L. et T. P. Asso-
lanti, Reeherches sur la Rate, Paris, 1801. A. Morcs-
ehi, Del vero e priraario Uso della Milza nell ’homo

VOL. IV.

e in tutti gli Animali Vertebrati, Milano, 1803.
JBenj. Rush, An Inquiry into the Functions of the
Spleen, & c., Philadelphia, 1806. Everard Home,
On the Structure and. Uses of the Spleen, Philos.
Transact, for 1808, p. 45. ; further Experiments on
the Spleen, p. 133. ; Experiments, &c., ibid. 1811.
C. F. Heusinger, Ueber den Bau und die Verrichtung
der Milz, Eisenach, 1817. F. Tiedemann und L.
Gmelin, Versuche iiber die Wege, auf welchen Sub -
stanzen aus dem Magen und Darm ini Blut gelan-
gen, iiber die Verrichtung der Milz und die gehei-
men Hamwege, Heidelberg, 1820. T. Hodgkin, On
the Uses of the Spleen, Edinb. Med. and Surg.
Journ., 1822, p. 83. Dobson, Lond. Med. and Phys.
Journal, 1830, Oct. G. C. Holland, Physiology of
the Foetus, Liver, and Spleen, London, 1831. T.
Muller, Ueber die Structurder eigenthiimlichen Kiir-
perchen in der Milz einiger pflanzenfressender Sau-
gethiere, Miill. Arch., 1834. T. C. H. Giesher, Spleno-
logie, oder anatomisch-physiologische Untersuchun-
gen iiber die Milz, Zurich, 1835. M. T. Evans, Lond.
Edinb. and Dubl. Phil. Mag., 1833. FTov. Schwager-
Bardeleben, Observationes Microscopicse de Glandu-
larum Ductu Excretorio carentium Structura, &c.
Berol. 1841. Th. v. Hcssling, Untersuchungen iiber
die weissen Korperchen der menschlichen Milz,
Regenzburg, 1842. I. Reid, Lond. and Edinb.
Monthly Joum., 1843. Apr. Fr. Oesterlen, Beitrage
zur Physiologie des gesunden und kranken Orga-
nismus, Jena, 1843, pp. 41 — 52. E. Huschke, Lehre
von den Eingeweiden und Sinnesorganen, Leipzig,

1844. Schlemm, Berliner Worterbuch der medicin.
Wissenschaften, Band xxiii. Th. 435. Ch. Poelmann,
Memoire sur la Structure et les Fonctions de la Rate,
Annales et Bulletin de la Societe de Medeeine da
Gaud, 1846, Dec. C. Handfield Jones, On the Yel-
low Corpuscles of the Spleen, Lond. Med. Gazette,
1847, J an. John Simon, On the Thymus Gland, Lond.

1845. A. Kolliker, Ueber den Bau imd die Verrich-
tungen der Milz, in Mittheilungen der Ziiricher
naturforschenden Gesellschaft, 1847. A. Ecker,
Ueber die Veranderungen welche die Blutkorper-
chen in der Milz erleiden, in Zeitschrift fur rationelle
Medicin, Band vi. 1847. C. B. Heinrich, Die Krank-
heiten der Milz, Leipzig, 1847. T. Landis, Beitrage
zur Lehre iiber die Verrichtungen der Milz, Zurich,
1847. Gerlach, Ueber die Blutkorperchenhalten-
den Zellen der Milz, in Zeitschrift fur rationelle
Medicin, Band vii. 1848. T. Bedard, Reeherches
experimentales sur les Fonctions de la Rate et sur
celles de la Veine Porte, Archives Generates de Me-
dicine, Paris, 1848, Oct. Nov. Dec.

( Albert Kolliker.') *■

STATISTICS, MEDICAL. — The Sin-
tistical Method; the Numerical Method. La
Methode Numerique. — It is to be regretted
that the use of numbers in any branch of
scientific inquiry should have seemed to need
a special name ; for the name has given rise
to prejudices and misconceptions which could
never have attached to the thing signified.
There is no science which has not sooner or
later discovered the absolute necessity of re-
sorting to figures as measures and standards
of comparison ; nor is there any sufficient
reason why physiology and medicine should
claim an exemption denied to every other
branch of human knowledge. On the con-
trary, they belong in an especial manner to
the class of sciences which may hope to de-
rive the greatest benefit from the use of num-

* The Editor is indebted to his friend Dr. Brinton,
for the translation of the article on the normal
anatomy of the spleen from the German MSS. of
Professor Kolliker, and for the sketch of the abnor-
mal anatomy.

3 F

15704

602 STATISTICS.

bers ; and even those persons who are most
given to express doubts of the necessity or
expediency of resorting to them, find them-
selves constrained to sanction by their own
practice what they condemn in theory. This
is an all-sufficient answer to those who con-
tent themselves with objecting in general
terms to the employment of numbers in me-
dical investigations. As to more minute and
detailed objections, these will be found to be
anticipated and disarmed by the simple con-
sideration that they apply in reality not to
the use, but to the abuse of numbers. The
time has long gone by, when the absolute
dependence of all science on observation and
experiment could admit of question or dis-
pute ; and, as no one in the present day
claims for physiology and medicine any im-
munity from the severe conditions which the
very nature of things imposes, we are spared
those appeals to authority which might for-
merly have been required at our hands. The
absolute necessity of observation and experi-
ment towards the improvement of the science
and art of medicine, in the widest acceptation
of those terms, may, therefore, be safely taken
for granted. The only points upon which any
serious difference of opinion or divergence of
practice exists, are the degree of care and
accuracy which should be brought to bear on
individual observations and experiments, the
properties which fit single facts to be thrown
into groups or classes ; the language which
ought to be employed in expressing the ge-
neral results of such classifications ; and the
number of facts which, being so grouped or
classified, may be required to establish a ge-
neral proposition, or to furnish an accurate
test or trustworthy standard of comparison.

The human mind is so constituted, that it
looks forward to an occurrence with a con-
fidence proportioned to the number of times
that it has been previously known to happen.
Hence, the universal belief that all living
beings will die, and that the sun will rise and
set to-morrow ; hence, the somewhat less
sanguine expectation that quinine will cure
ague, and that vaccination will either pre-
vent or modify small-pox ; hence, the little
hope we have that a severe attack of Asiatic
cholera will terminate favourably, and our
absolute despair of the recovery of a patient
seized with hydrophobia. In these, and other
analogous cases, we have either the expe-
rience of all mankind in all times and places,
or that of large numbers of men in addition
to our own. We do not require that the in-
dividual occurrences which have created our
confidence, our misgiving, or our despair,
should be committed to paper, arranged in
columns, and embodied in sums or averages.
For practical purposes we are satisfied with
our own impressions. But should a doubt be
expressed, and supported by a show of reason
or experience, whether vaccination possess
the virtue generally attributed to it ; should
some new preventive measure or mode of
treatment be recommended in cholera, as su-
perior to other plans previously adopted ; we

ask for the specific facts which have seemed
to warrant the doubts of the one party, and
the recommendation of the other. If these
facts are few, we naturally view them with
mistrust, and are disposed to attribute them,
at the best, to some coincidence ; or if, being
more in number, their actual amount is stated
in vague and general terms, we as naturally
demand the precise figures. We feel instinc-
tively, that common and familiar words are
altogether wanting in precision ; that they
take their meaning from the character of
those who use them ; that, in a word, “ the
sometimes of the cautious is the often of the
sanguine, the always of the empiric, and the
never of the sceptic ; while the numbers,
1, 10, 100, 1000, have but one meaning for
all mankind.”

But this mistrust of vague generalities of
expression, is not the only form in which the
more cautious and logical spirit of modern
times embodies itself. The same misgivings
are felt and expressed as to the propriety of
committing the facts which are to serve as the
materials of our theories to the uncertain keep-
ing of the memory. We feel that a science
built up of such materials, bears to true science
the same sort of relation which tradition bears
to history. It may not be destitute of valu-
able truths and sound principles, but it must
fail in that precision and delicacy of discrimi-
nation which forms the peculiar attribute of
true science as of true history. The history
of medicine abounds with examples of impor-
tant principles of treatment, and valuable re-
medies discovered solely by the light of
experience, based upon the mere recollection
of a number of individual occurrences. In
this way the efficacy of bark and arsenic in
ague, of mercury in syphilis, and of iodide of
potassium in certain forms of secondary disease
was discovered. Indeed, it may be confidently
affirmed that all our knowledge of remedies is
traceable to this source ; and it is probable
that we shall continue to be indebted to it for
all future discoveries of importance. It is the
natural method of discovery, and, as such, will
necessarily maintain its ground. But a very
little reflection will convince us of the utter
inadequacy of this method to meet the strict
requirements of the science, and the ever-vary-
ing exigencies of the art of medicine. We
may be able by its aid to sketch the broad out-
lines, and mark the salient points of a science,
but we cannot hope to fill in the details with
all the lights and shadows which go to make
up the perfect landscape. Still less can we
satisfy ourselves or others as to the real merits
of disputed questions by an appeal to un-
written or loosely recorded experience. We
all feel that there is no solution for our doubts
short of an appeal to observations carefully
and faithfully recorded, and summed up in the
clear and simple language of figures. The use
of mercury in syphilis, supplies us with an apt
illustration of this truth. An experience,
founded upon unrecorded and unnumbered
occurrences, first recommended this remedy
for the treatment of that disease ; but it would

STATISTICS.

appear that a counter experience of the same
kind was continually leading to its disuse.
Thus Morgagni tells us that, when he was
quite a young man and went to Bologna, both
methods of using mercury, internal and ex-
ternal, were so far deserted, that he never saw
any physician make use of them, or ever
heard of his using them, for the whole space
of eight years, during which he studied there.* * * §
It would also appear that from the beginning
of the sixteenth century up to the present time,
there has always been a large number of sur-
geons, who have either abandoned the mer-
curial treatment altogether, or have restricted
the use of the mineral to certain exceptional
cases.f In the difference of opinion which
prevailed upon this subject, the necessity of
submitting the question at issue to the test of
figures made itself so strongly felt, that a series
of the most elaborate inquiries was undertaken
at the instigation of governments, or by private
individuals. These inquiries resulted in the
collection of nearly 80,000 facts, by means of
which the possibility of promptly healing ve-
nereal sores without mercury and with but
moderate risk of a relapse, or of the occurrence
of secondary symptoms, was conclusively esta-
blished. J To this same test of figures, all the
questions which arise from time to time, as to
the relative value of the several remedies recom-
mended in the treatment of syphilis are, by
common consent, submitted. A most con-
vincing proof that the numerical method is, in
all cases of doubt and difficulty, the means of
solution to which men naturally resort, is af-
forded by the treatise of Benjamin Bell, on this
very subject, published in the year 1793. §
Speaking of the treatment of incipient chancres
by caustic, he notices the very important ob-
jection, that the cure of the sores was often
succeeded by buboes ; and he adds, that for
a considerable time he was induced to suppose
that the swellings of the glands, which thus
take place after the cure of chancres, were
more the effect of accident than of the method
of treatment, and that they would have oc-
curred under whatever management the sores
might have been. The frequency, however,
of their appearance, led him at last to suspect
that he was mistaken, and further observation
made it obvious that this was the case. He
goes on to observe, “ As experiment alone
could determine the question, I was resolved
to employ this test. Of the first twenty
patients who occurred with incipient chancres,
in ten they were destroyed by an immediate
and effectual application of lunar caustic, the
remedy being employed, according to my usual
custom at that time, instantly on my being
called ; of the other ten, five were dressed with
blue mercurial ointment, and five with common
wax ointment. The sores to which caustic

* Morgagni’s 58tfi Epistle.

t See on this subject, the British and Foreign
Medical Beview, vol. v. p. 4.

+ British and Foreign Medical Beview, vol. v.
p. 7.

§ A Treatise on Gonorrhoea Virulenta, and Lues
Venerea. By Benjamin Bell, vol. ii. p. 322.

803

were applied healed much sooner than the
others, and next to them the sores that were
dressed with mercurial ointment. But of the
ten patients to whom caustic was applied, no
less than eight had buboes, whilst only one
bubo occurred in all the others; and it happened
in one of the patients whose chancres had
been dressed with mercury. I thought also
that buboes appeared to be less frequent from
the application of caustic, where mercury had
been previously given. This fell within my ob-
servation from time to time, with patients who
had taken mercury, either of their own'accord
or by the advice of others ; and appearing to be
of importance, I was resolved to bring it like-
wise to the test of experiment, and the result
was as follows : of forty-eight patients with
chancres in an incipient state, and exactly as
they occurred in practice, one half was treated
in the manner I have mentioned, by destroy-
ing the chancres with caustic immediately on
my being desired to see them, while all the
others were put under mercury for eight or
ten days before the application of caustic. In
every other circumstance the method of treat-
ment was the same. The difference, however,
surprised me exceedingly. Of the twenty-four
treated with the immediate application of
caustic, twenty were seized with buboes; while
only three buboes occurred in an equal number
to whom mercury had been previously admin-
istered.”

The subject of the treatment of syphilis
has been selected for illustration on account
of the large use which has been made of
figures in discussing the relative value of the
two modes of treatment; and the extract from
the works of Benjamin Bell as a proof that,
long anterior to any discussions among me-
dical men as to the value of the numerical
method and the extent to which it might be
applied in the solution of medical questions,
men of shrewd common sense were driven to
the use of numbers, as the natural and only
means of solving difficult questions, and set-
ting doubtful or disputed points at rest. Thus
much, by way of introduction, the difference
of opinion which prevails as to the value of
the numerical method seemed to demand.

The numerical or statistical method may be
defined as the science which prescribes rides
for the bringing together of scattered observ-
ations, arranging them in classes, testing their
sufficiency in point of number, and deducing
from them, when so arranged, average and
extreme results, fitted by their very condensa-
tion to become standards of comparison and
data for reasoning.

The numerical method*, so defined and

* The term, numerical method, will be used
throughout this article in preference to the word
statistics, or statistical method; for, properly speak-
ing, statistics means the science of states (from the
German word staat, a state), and is therefore syno-
nymous with the terms “ political economy,” “ po-
litical science,” “ social science.” The first use of
the term statistics has been traced to Achenwal,
Professor of History in Gottingen, who, in 174S,
published an historical work, in which the phrase
scientia statistica occurs for the first time. The use
3 F 2

80-4

STATISTICS.

understood, comprises two distinct inquiries,
the one relating to the individual facts which
form the materials for the calculation of aver-
age and extreme values, and the other re-
ferring to the averages and extremes them-
selves. This natural and convenient division
of the subject it is proposed now to adopt.

1 . Of facts considered as the elements of sta-
tistical inquiries. — Scientific inquiries are con-
versant with two orders of facts : — namely,
phenomena of varying intensity, and events
brought about by a multitude of causes. The
first class of facts enters very largely into the
science of physiology ; the last class consti-
tutes, though not to the exclusion of the first,
the mass of the materials by which the prac-
tical sciences of medicine and hygiene are
built up.

As examples of phenomena of varying inten-
sity may be cited the pulse and respiration,
the temperature of the body, the secretions of
the skin, kidneys, and lungs, the evacuations
of the bowels, the weight and stature of the
body at different ages, and the muscular de-
velopment and power of different nations and
classes of persons. These phenomena, care-
fully observed and recorded by the aid of the
watch, the thermometer, the measure, the
balance, and other instruments adapted to
special purposes, become so many numerical
values, having the same relation to the aver-
ages deduced from them, as the more simple
events expressed in units bear to the mean
results for which they furnish the materials.

As an example of an event brought about by
a multitude of causes may be mentioned the
event of death, governed, as to the age at
which it occurs, by original strength or pecu-
liarity of constitution, good or bad nursing
and management in infancy, sex, occupation
and habits of life, climate and place of abode,
skilful or unskilful treatment in sickness ; in
a word, by the varied influences which make
one man to differ physically from another.
This is an illustration taken from the science
of hygiene. The alternative of death or re-
covery from a disease induced by a cause or
causes of variable intensity in persons of
opposite sex and of different ages, with con-
stitutions modified by the several agencies
just specified, and submitted to different
modes of treatment, is an example from the
practice of medicine. Physiology furnishes
illustrations of the same kind in those func-
tions of the body (such as the cutting of the
teeth, and the first appearance and cessation
of the catamenia) which are dependent for

of numbers as a necessary means of comparison in
this work of Achemval, led men to confound the in-
strument with tiie science. Dufau, in his Traite de
Statistique, incorrectly derives the term statistics
from the Latin status.

The meaning attached to the words statism and
statist, in the writings of poets, essayists, and
dramatists, hears out the view just put forward of
the proper signification of the term statistics. Mil-
ton, for instance, speaks of “ statists and lawyers,”
and elsewhere uses the term in the sense of a man
haling political power and influence. Ford also
uses the word in this latter sense. Soutli speaks of
persons who called our religion statism.

the period of their occurrence on peculiarity
of constitution determined by the combined
action of the influences already adverted to.

Between these two orders of facts — phe-
nomena of varying intensity, and events
brought about by a multitude of causes —
there is no other difference but that which is
apparent on the face of each, namely, that
each individual fact, in the one case, is repre-
sented by a variable number, while in the
other it is a simple unit. If, for example, we
count the pulse of several men at the same
age, we shall find that each separate observa-
tion gives a different number; but, the event
of death or recovery in cases of typhus fever
will be recorded as a simple unit. In all other
respects the two classes of facts closely re-
semble each other; for the number of beats
peculiar to the pulse of each individual, is as
much the result of the concurrent action of
several causes, as the event of death or reco-
very from fever. The original and acquired
constitution, towards the formation of which
so many causes must have conspired, deter-
mines the number of the pulse in the one
case, and influences the event of the disease
in the other. The two classes of facts are
also equally fitted to supply the elements for
the determination of average and extreme
values ; for it is obvious that the mean and
extreme numbers of the pulse, in males and
females respectively, furnish as trustworthy
standards of comparison and data for reason-
ing, as the average number of men following
different occupations who die before any spe-
cified period of life, and the greatest age
which they respectively attain.

From what has been just stated, it will be
seen that all the facts which form the mate-
rials for our averages, are phenomena or events
brought about by the concurrent action of a
multitude of causes. The facts or events
with which the physiologist and physician
are conversant, are remarkable for the mul-
tiplicity of the causes which conspire to pro-
duce them. The subject of study is the hu-
man frame, with its differences of sex, age,
and inherited or acquired constitution, acted
upon by the variable influences of climate, oc-
cupation, and habits of life, and still further
modified in disease by the treatment and re-
gimen which may happen to be adopted. In
consequence of the number and diversity of
the influences brought to bear upon it, the
human frame presents an object of study only
less difficult than the human mind, affected
by a like number and variety of moral causes,
of which the true nature and force have to
be unravelled by multiplied observations on
the condition of mankind under different cir-
cumstances ; the aggregate of such observ-
ations constituting a great part of the science
of statistics properly so called, and bearing to
the practical science of government the same
relation which pathology and therapeutics,
based upon large collections of facts, do to
the practice of medicine.

Now this dependence of the individual facts
or events with which physiology and medicine
are conversant on the concurrent action of a

STATISTICS.

805

multitude of causes, lias been urged as an ob-
jection to the introduction of the numerical
method into the service of those sciences.
It is admitted, that the use of numbers and
averages by the astronomer who deals with
the more simple relations of matter, such as
magnitude and relative position, and by the
engineer who avails himself of its more simple
properties, such as its hardness, tenacity and
elasticity, have contributed to make the science
of the one perfect, and the art of the other
safe ; but it is contended that the use of num-
bers cannot be extended beyond such narrow
limits with safety or advantage, and that medi-
cine and political economy lie beyond these
limits. The actual practiceof mankind, founded
upon an instinctive perception of the necessity
of employing figures in the service of the phy-
sician and statesman, may be fairly alleged as
a sufficient answer to this objection ; but a
little consideration will serve to show its
futility.

In the first place, it is self-evident that the
exclusion of figures from the service of medi-
cine, does not bring about the disuse of those
very facts and events which are objected to as
unfit to be employed as statistical or numerical
elements. The physician will still persist in
stating and recording the results of his expe-
rience. He will still assert that he has sometimes
observed this symptom in a certain disease,
that he has often found that remedy beneficial,
that he has almost never known such and such
a mode of treatment to fail. Those who con-
tend for the use of numbers in medicine,
merely insist on the necessity of reducing the
sometimes, the often , and the almost never to a
more correct and intelligible form of expres-
sion ; and the}' argue that it is utterly incon-
sistent to object to the use of facts as mate-
rials or elements of numerical propositions,
and yet not to censure the use of these same
facts as foundations for loose and inaccurate
verbal statements. From this dilemma there
is obviously no escape. But, though the ob-
jection itself is futile, the misgiving of which
it is the exaggerated expression is natural and
well founded. It cannot excite surprise that
the individual facts or events which own so
many concurrent causes should be regarded
as requiring, on the part of the observer, a
greater degree of care in verifying, recording,
collecting, and arranging them than would be
necessary in the more simple cases already
adduced ; and that both the facts themselves,
and the numerical expressions in which they
are embodied, should be viewed with a pro-
portionate degree of distrust. From this mo-
derate and reasonable view of the case, no
advocate of the numerical method will be
found to dissent. On the contrary, he will
seek to strengthen it by giving due promi-
nence to each separate ground of misgiving,
and by laying down stringent rules for the
guidance and governance of the observer.
Before proceeding to detail some of these
rules, it may be well to advert to a probable,
and, indeed, obvious cause, of the distrust with
which numerical data are sometimes regarded.

Indiscreet advocates of the numerical method
have sought to apply the general results of
collections of cases expressed in the language
of figures to the treatment of individual cases
of the same disease, without making allowance
for those differences between case and case
which confessedly existed in the collections
themselves. They have used a general prin-
ciple, as if it had been a rigid and unbending
rule of action ; forgetting that though, as the
experience of assurance offices abundantly tes-
tifies, the general results obtained from a large
number of individual facts may be safely re-
applied to an aggregate of facts of the same
nature, they cannot be brought to bear on a
single case, or on a small number of cases,
without the greatest danger. Each case must
be viewed in practice, first as a generality
governed by some large law of prognosis,
diagnosis, and treatment ; and secondly, as a
specialty demanding a careful consideration of
all its peculiarities.

Among the rules which ought to govern the
observer in the collection of facts destined to
form the elements of averages, there are some
of so simple and obvious a nature as to re-
quire no discussion. Such are, the previous
preparation of some simple and available form
of register, by means of which the several facts
may be committed to paper at the very time
of observation, so that nothing maybe trusted
to the memory ; the careful selection of the
facts themselves ; the shaping of the inquiries
which may be necessary to elucidate those
facts as nearly as may be in the same terms ;
the avoidance as much as possible of such
leading questions as would be likely to bias the
respondent, when the facts in question, like
most of the particulars which make up the
history of diseases, are dependent upon testi-
mony ; and especially the purging of the ob-
server’s own mind of prejudices and precon-
ceptions in respect of the subject of inquiry.

The careful selection of the facts which are
to form the materials of our averages is by
far the most important of these rules, and
one which demands a little further consider-
ation. If we consider the facts we are ob-
serving in the light of phenomena, or events
brought about by a multitude of concurrent
causes, it will be obvious that care will re-
quire to be exercised, not so much in verify-
ing each phenomenon or event as that of
which we are in search, as in ascertaining that
all the concurrent causes or conditions are,
or have been, in operation to bring about that
phenomenon or event. The absence of a
single cause or condition will vitiate the in-
dividual fact, and impair or destroy the value
of our average results. A few illustrations
will suffice to show what is here intended.
We are anxious to determine the true average
frequency of the pulse in adult males, in a
state of rest, and as free as possible from the
influence of all disturbing causes ; but, either
from ignorance or oversight, we count it in-
differently in every position of the body, and
at all times of the day. In this case, our facts
cease to be comparable facts ; for it is well
3 r 3

806

STATISTICS.

known, that both posture and time of day
have a remarkable influence on the number of
the pulse. Or, to take another case, we wish
to ascertain the influence of some employment
upon health (say that of the letter-press
printer) ; but we overlook the important fact,
that in every printing office, two or three very
distinct occupations are carried on, of which
the most important are those of the com-
positor and pressman. Not being fully aware
of this fact, and of the wide difference exist-
ing between the two employments, we pro-
ceed to extract from some mortuary register
the ages at death of printers as a class, calcu-
late the average age at death, and then proceed
to group the whole class of printers with that
large class of occupations carried on in-doors,
with little bodily exertion, to which the com-
positor alone properly belongs, but from
which the pressman is, by the nature of his
employment, excluded. In this case, we
should have been misled by the common
name borne by men following two really dis-
tinct occupations, and our facts would again
cease to be comparable facts. A third and apt
illustration is afforded by the Asiatic cholera.
We wish to compare two different remedies
or plans of treatment ; but we administer the
one remedy, or adopt the one plan, at the
onset of the epidemic, and the other during
its decline. Here, again, our facts are not
comparable facts ; for it is one of the well-
known characteristics of this disease, that it
is more severe on its first occurrence than
during the period of its decline. The same
sort of error would be committed, if one
remedy were administered in an early, and
the other in an advanced, stage of the attacks
themselves. The principle which these illus-
trations are intended to enforce, is the ne-
cessity of selecting, as the elements of the
same average, facts strictly comparable, or, in
other words, brought about by the same com-
bination of causes. Over the intensity with
which each cause acts in individual instances,
the observer can exercise no control. His
province is to ascertain that the same com-
bination of causes is at work to bring about
each phenomenon or event. If from ignor-
ance or oversight he fails in this duty, he im-
pairs the value of his facts, and vitiates his
inferences in proportion to tiie number and
force of the conditions that he has overlooked
or omitted.

In the observation and collection, therefore,
of the individual phenomena or events which
are to serve as materials for our average re-
sults, the first precaution to be observed is,
that those phenomena or events should be
strictly comparable as regards the combination
of causes by which they are brought about;
or, as the French statists express it, we must
ensure “ I'invariabilite de I’ensemble des causes
jtossibles." The frequent omission of this most
necessary precaution has given birth to the
dogma of Morgagni — Non numerandee sed per-
•pendendee sunt obseivationes — and to the most
valid objections urged against the applica-
tion of the numerical method in medicine.

For the collection, arrangement, and classifi-
cation of the facts which are to form the ma-
terials of our averages, no concise rules can
be laid down. The tabular forms must adapt
themselves to the exigencies of each individual
inquiry ; and must be more or less complk
cated as the subjects of investigation con-
sist of few or many particulars. In reporting
cases, for instance, and in collecting and
analyzing those recorded by others, tabular
forms embracing many particulars are re-
quired ; and the preparation of such forms
demands unusual skill and care.'* The same
remarks apply to the collection and classifi-
cation of recorded experiences and opinions
bearing on particular subjects of inquiry j- ; a
numerical summary of authorities favourable
and adverse to particular doctrines, consti-
tuting what may be not inaptly termed the
statistics of opinion.

2. Of the average and extreme results de-
duced from observation. — The observer having
exercised all due care in the observation of
his facts, having grouped together only those
events which owned the same combination
of antecedents or causes ; and having further
correctly performed the work of enumeration,
has thus obtained certain average and extreme
results, which are to constitute standards of
comparison and data for reasoning ; the
question naturally arises — are these average
and extreme results sound and trustworthy
standards and data, or not ; and what are the
circumstances which render them the one or
the other ? Common sense and experience
combine to give an authoritative answer to
this question. Our average and extreme re-
sults are more or less sound and trustworthy,
as the individual facts from which they have
been calculated are more or less numerous.
Where the facts upon which it is attempted
to found a general principle, or to establish a
standard of comparison, are very few, we are at
once conscious of their insufficiency ; and the
more readily when an attempt is made to apply
the principle or standard in question to some
important practical purpose. A better illus-
tration of the futility of such an attempt can
scarcely be found than the well-known test of
Ploucquet. That author proposed to deter-
mine whether or not a child was still-born
by referring every doubtful case to a standard
of comparison, founded upon three observ-

* On this subject the late Dr. Todd, of Brighton,
has written a very able work, which may be safely
recommended to all who desire to enter upon such
complicated investigations. The title of this work
is : — The Book of Analysis, or a New Method of
Experience, whereby the Induction of the Novum
Organon is made easy of Application to Medicine,
Physiology, Meteorology, and Natural History ; to
Statistics, Political Economy, Metaphysics, and the
more complex Departments of Knowledge. By
Tweedy John Todd, M.D., of the Royal College of
Physicians of London, &c. &c. 1831.

f Reference may here be made to a paper pub-
lished in the 3rd volume of the Journal of the
Statistical Society of London, “ On the best Method
of Collecting and Arranging Facts, with a proposed
New Plan of Common- Place Book.” By the Author
of this Essay.

STATISTICS.

807

ations of the relative weight of the lungs and
body ; of which three observations, one was
made upon the body of an immature infant,
so that the subjects of the observations were
not strictly comparable. Though Ploucquet,
in this procedure, offended against two of the
most obvious statistical rules, his test con-
tinued to be treated with undeserved respect,
till comparatively recent investigations on a
larger scale had demonstrated the little re-
liance to be placed upon it.

The most common attention to the ordinary
daily occurrences of life would suffice to
caution us against such errors as that into
which Ploucquet fell. Coincidencesof the most
startling character are constantly happening
to put us on our guard against them. One
which occurred to the wrriter of this article
deserves to be put on record. Two cases of
congenital absence of the larger pectoral
muscle on the same side of the body, oc-
curred, on the same day, among the out-
patients of the King’s College Hospital,
This defect he has never happened to observe
within the wards of that Hospital or else-
where, either before or since. A similar
coincidence, though of a less striking cha-
racter, presented itself in the same institution
while the writer was noticing with some care
and interest the complexion and physiognomy
of patients suffering from pulmonary consump-
tion. His own previous experience, in con-
formity with the general opinion, had pointed
out the fair complexion as that of the great
majority of phthisical patients ; but the almost
exclusive occurrence for several days together
of the olive complexion, among patients
labouring under that disease, had almost led
him to discard his former opinion and that of
the best authorities, and to embrace one which,
as farther observation convinced him, would
have been erroneous.

Games of chance are constantly furnishing
striking examples of these coincidences, in
the shape of what is familiarly known as a run
of good or ill-luck ; the same event, favourable
or unfavourable, occurring many times in suc-
cession, contrary not only to reasonable ex-
pectation, but to the results of unerring cal-
culation. On the other hand, the success of
the bank, with only a slight calculated chance
in its favour, but with a capital sufficiently
large to await the inevitable change in the run
of luck, vindicates the sufficiency of large
numbers of facts. The great annual fluctu-
ations, too, which take place in the balance of
the receipts and expenditure of assurance
offices, but the ultimate safety of their trans-
actions, when extending over a long term of
years and embracing a large number of in-
surances, serve to enforce the same truth.

The sufficiency for all practical purposes
of large numbers of facts, may also be inferred
from the remarkable uniformity observed to
take place in the annual summaries of events
brought about by the continued operation of
the same combination of causes. The annual
reports of the Registrar-General supply many
illustrations of this principle. The illustration

best suited to our present purpose, is one
drawn from an event removed, by the very
nature of the case, beyond the reach of ex-
ternal influences, or only very remotely and
indirectly amenable to them ; namely, the
proportion of male and female births in suc-
cessive years. In the eighth annual report
of the Registrar-General (p. lxi.), a table is
given, in which the number of males and
females born, to every hundred living males
and females respectively, is recorded for the
seven years 1839-45. If we substitute
100,000 for 100, the table will read thus.

Year.

Males.

Females.

Excess of
Males.

1839

6,498

6,211

287

1840

6,539

6,250

289

1841

6,580

6,289

291

1842

6,564

6,273

291

1843

6,597

6,305

292

1844

6,676

6,381

295

1845

6,622

6,329

293

The largest excess of male over female
births, therefore, in these seven years is 295,
anti the least 287, the average being 291; so
that the extreme fluctuation amounts to only
8 births in about 6500, or considerably less
than 1 in 800 ; while the excess or defect above
or below the average of 291 is only 4 births,
or less than 1 in 1600. If the causes which
determine the births of males and females re-
spectively could be assumed to be constant
and uniform, these fractional fluctuations
would express the divergences due to the
insufficiency of the number of observations
to express an absolutely true result. The
close approximation actually obtained must
be held to prove the sufficiency for every prac-
tical purpose of results based upon large
numbers of observations.

Having thus shown, by two opposite ex-
amples, the total insufficiency of small num-
bers of facts, and the sufficiency, at least for
practical purposes, of large numbers of ob-
servations, it will be necessary to enter into a
more detailed examination of the relative
value of numbers of observations intermediate
between these two extremes.

From what has been already stated, it must
be obvious that the degree of confidence to
be reposed in results based upon different
collections of facts must vary with the num-
ber of those facts ; and that, other things
being equal, the value of the results must
increase with every addition made to that
number. But it is only by actual observation,
or by mathematical calculations based upon
indisputable data, that the precise value of
any particular number of facts can be deter-
mined. Observation, indeed, is altogether
unequal to give more than a vague and general
idea of the relative values of small and large
collections of facts ; so that we must ulti-
mately resort to the mathematics both for
authoritative decisions and safe guides. As,
however, the large majority of mankind is
destitute of that mathematical knowledge and
3 F 4

S03

STATISTICS.

training which is essential to the appreciation
of mathematical rules, it is desirable to show,
by an appeal to the results of actual observ-
ation, the increasing value of increasing col-
lections of facts, as well as the rate of that
increase. For this purpose, it is proposed to
make use of some observations collected by
the writer of this article. Having had occa-
sion, a few years since, to bring together, from
the pages of the Peerage and Baronetage, the
ages at death of the male members of the En-
glish aristocracy, dying 21 years and upwards,
to the number of several hundreds, it ap-
peared to be a favourable opportunity of test-
ing the relative values of large and small
numbers of facts, as well as of obtaining a
rude approximation to a rule or measure of
value. The ages at death, relating, as they do,
to members of the same class in society, and
taken without selection from the successive
obituaries of noble families, constitute a col-
lection of strictly comparable facts, well suited
to the purpose in view. The following table,
which embodies the results of these facts in
their bearing on the question before us, has
been formed in the following manner: — The
several facts were first arranged in groups of
2.3 each ; two successive groups of 25 were
then formed into groups of 30 ; the groups of
50, in like manner, into groups of 100, and so
on, till the last totals in the table were ob-
tained. The greatest and least averages ob-
tained from each group of facts were then
selected, and, with the range, or difference be-
tween them, thrown into a tabular form.

Number

Average Age at Death.

of Facts.

Max.

Min.

Range.

25

69-40

50-64

18-76

50

66-44

55-20

11-24

100

63-70

56-85

6-85

200

62-38

57-61

4-77

400

61-10

58-24

2-86

800

60-84

59-67

1-17

V,

J

1600

60-25

Now, if we assume the true average duration
of life among the members of the Peerage and
Baronetage, who have attained their 21st year
to extend to 60 years (being the mean of
I COO observations), and, for the sake of
simplicity, substitute for the decimals in the
table the whole numbers nearest to them in
magnitude, it will follow that, in making use
of the several groups of observations specified

Number of
Facts.

Error in Excess
or Defect.

25

9 ,

50

5i

100

34

200

2|

400

14

800

0-i

in the first column of the annexed table, we
may have the errors in excess or in defect
which are enumerated in the second column.

These figures, then, represent the extreme
error which could have been committed, in
this particular case, by relying on 25, 50, 100,
200, 400, and 800 facts respectively. But it
must be borne in mind, that this collection of
facts is one which, from the very nature of
the case, is likely to present a minimum of
divergence between the averages deduced
from the same number of facts ; for the several
obituaries, from which the ages at death are
taken, register the deaths of one and the same
class, inhabitants of the same country, and
split into family groups bearing a close re-
semblance to each other. If, instead of a
single class, exposed to similar influences, and
not admitting of subdivision into smaller
classes, we were to take the members of that
large section of the community which is ge-
nerally known as the upper and middle class,
with their numerous subdivisions of employ-
ment, and class them by fifties and hundreds,
we should encounter a much more consider-
able divergence. The results of such a com-
parison for the class in question are embodied
in the following table.

Number

Average Age at Death.

of Facts.

Max.

Min.

Range.

50

84-44

56-78

27-66

100

76-24

58-25

17-99

200

73-54

61-50

12-04

400

69-78

63-51

6-27

800

68-67

65-07

3-60

1600

67-93

64-84

3-09

3200

66-38

65-82

0-56

V

V

6400

66-10

If, as in the former case, we take 66 years
to be the true average age attained by the
entire middle class, reckoning from 21 years
of age, and reduce the range in each case to
the nearest whole number, we shall have the
following divergences.

Number of
Facts.

Error in Excess
or Defect.

50

14

100

9

200

6

400

3

800

2

1600

H

3200

o?

In this instance, therefore, though we begin
with 50 in place of 25 facts, we obtain a
possible error in excess or defect of 14 years
in place of 9| years. It must be obvious,
then, that the errors to which averages de-
duced from any given number of facts are
liable, will vary with the nature of those facts ;
and that the extent of possible error will bear

STATISTICS.

809

a certain proportion to the number of the
influences which are brought to bear on each
unit of each collection of facts.

It must not, however, be forgotten that the
figures in these several tables represent only
possible errors. It may happen that the first
25 observations brought together may yield
an average differing by less than a single unit

from the mean of thousands of observations ;
and there is always a balance of probability
in favour of the average even of a small num-
ber of facts approximating more closely to
the true average than to the extremes. That
this is the case will be evident on the most
cursory inspection of the following tables,
of which the first is founded upon the facts

Average Age
at Death.

25 Facts.
72 Groups.

50 Facts.
36 Groups.

100 Facts.
18 Groups.

200 Facts.
9 Groups.

400 Facts.
4 Groups.

800 Facts.
2 Groups.

69

1

G8

0

67

0

66

3

1

65

4

0

64

9

2

1

63

3

3

1

62

3

5

3

3

61

9

6

3

0

3

1

6®

9

4

3

2

0

1

59

8

5

3

3

0

58

6

5

1

1

1

57

5

i

3

56

6

3

55

1

1

54

3

53

1

52

0

51

1

Average Age
at Death.

50 Facts.
128 Groups.

100 Facts.
64 Groups.

200 Facts.
32 Groups.

400 Facts.
16 Groups.

800 Facts.
8 Groups.

1600 Facts.
4 Groups.

3200 Facts.
2 Groups.

84

1

83

0

82

0

81

0

80

0

79

0

78

0

77

0

76

1

1

75

1

0

74

4

1

1

73

2

1

0

72

2

1

0

71

5

0

0

70

4

4

0

1

69

7

3

2

0

1

68

13

5

3

1

0

1

67

17

9

4

4

1

0

<6 II

20

13

14

4

2

1

2

65

5

13

2

4

3

2

64

16

6

2

2

1

63

11

1

2

62

10

4

1

61

3

1

1

60

3

0

59

0

0

58

0

1

57

3

810

STATISTICS.

relating to the duration of life of the aristo-
cracy, and the second on the facts relating to
the duration of life of the combined upper
and middle classes. For the sake of per-
spicuity, the average of all the facts in either
table is distinguished by a larger type.

These tables speak for themselves. In the
first table, for instance, the small number of
25 facts is seen to yield the same average as
the total of 1800 facts in no less than 9 in-
stances, or one eighth of the whole number ;
while in 26 out of 72 instances, or more than
one third, the average of 25 facts exceeds or
falls short of the average of 1800 facts by
only a single unit. In like manner, it ap-
pears from the second table, that in 20 cases
out of 128, or little less than one sixth, the
average of 50 facts coincides with that of
6400 facts; and that in 42 out of 128, or
nearly one third, it differs from it only by a
single unit. Without entering into a minute
examination of the other columns of the two
tables, it will suffice to state that the proba-
bility in favour of an average of a given num-
ber of observations coinciding with the true
average increases with the number of observ-
ations ; so that we are again brought back to
the expediency of collecting large numbers
of observations wherever it is practicable so
to do. In using small numbers of facts to
establish data for reasoning or standards of
comparison, we are bound to speak with dif-
fidence of their sufficiency, and we ought to
regard them rather in the light of probabilities
requiring to be strengthened by other pro-
babilities, as weak arguments require to be
supported by additional reasons, than as, in
themselves, worthy of great reliance. Ac-
cording to this view of the case, we are not
precluded from the use of averages drawn
from small numbers of facts. The employ-
ment of such averages with this proviso is an
absolute scientific necessity ; for in many in-
stances we are prevented by causes too nu-
merous to specify from bringing together facts
by the hundred or the thousand, and yet,
were we to reject the smaller numbers as in-
admissible, we should be thrown back upon
the still more loose and less trustworthy
general statements from which it is the pro-
vince of statistics to rescue us.

An examination of the two foregoing tables,
as well as of those which display the extreme
variations between the averages derived from
the same numbers of facts, will serve to prove
the hopelessness of any attempt to establish
by observation rules for measuring the rela-
tive value of averages derived from different
numbers of facts. It must be equally evident
that no deductions drawn from observation
can enable us to state the actual liability to
error of any given number of facts, considered
as facts, without reference to their peculiar
nature. To determine this liability to error
belongs solely to the mathematics.

If, on the one hand, observation is unable
to supply us with the means of testing the
true liability to error of conclusions based on

a given number of facts, considered as facts,
without reference to their peculiar nature, it
must be evident, on the other hand, that ma-
thematical formulae deduced from abstract
reasoning can only supply us with the means
of measuring the value of a given number of
facts in this their abstract relation, without
taking into account the varying quality of the
facts themselves. But as it is of the utmost
importance to be able to test the abstract
sufficiency of a given number of facts to
establish a principle or to supply a sound
standard of comparison, it will be necessary
to enter at some length into this part of our
subject.

The facts already adduced, must have
abundantly shown that the limits of deviation
from a true average result are wider or nar-
rower as the number of facts from which the
average is drawn is smaller or greater. Many
eminent mathematicians, and M. Poisson
among the number, have laboured to convert
this general principle into an exact numerical
expression or formula, applicable as a test of
the true value of larger or smaller collections
of facts, and as an exact measure of the
limits of variation. M. Gavarret, in his work
on Medical Statistics, contends successfully
for the introduction of these formulae into
the service of the medical man ; and adopting
the sentiment of Laplace, “ Le systeme tout
entier des connaissances humaines se rattache
a la theorie des probabilities, ” he insists that
medical statistics, or, as we prefer to term
it, the Numerical Method, applied to medicine,
is nothing more nor less than a special appli-
cation of the Calculus of Probabilities, and
the Theory of large Numbers ; and that as
such it is the most indispensable complement
of the experimental method. In other words,
he deems it incumbent on the medical man to
apply to his numerical results the corrections
supplied by the formulae of the pure mathe-
matics ; and before he concludes that any
number actually obtained by observation is a
true representative of a fact or law, to deter-
mine whether that number may not be com-
prised within the limits of possible variation.
M. Gavarret illustrates the necessity of this
precaution by applying his mathematical for-
mulae to a great variety of results based upon
observation ; but he especially insists upon
bringing the alleged efficacy of certain modes
of treatment to this searching test. The most
convenient course to adopt, in reference to
these formulae, will be to present the calcula-
tions based upon them in tabular forms, and
then to apply these calculations to one or
two striking examples.

The following table presents at one view
the possible errors corresponding to average
mortalities deduced from different numbers
of observations. It is obvious that the table
is equally applicable to other contingencies
of the same kind, where one of twm events
is possible in every instance. The mode of
using it will be presently explained and illus-
trated.

STATISTICS. 811

Tabic of the possible Errors corresponding to Average Mortalities deduced from different Numbers

of Observations.*

Number
of Ob-
serva-
tions.

Average Mor-
tality by
Observation.

Number

of

Deaths.

Number
of Re-
coveries.

Possible Error.

Number
of Ob-
serva-
tions.

Average Mor-
tality by
Observation.

Number

of

Deaths.

Number
of Re-
coveries.

Possible Error.

25

0-200000

5

20

0-226274

500

0 300000

150

350

0-057965

50

OT 00000

5

45

0-120000

500

0-350000

175

325

0-060333

50

0-200000

10

40

0 160000

50

0-300000

15

35

0 183302

600

0100000

60

540

0 034641

600

0-150000

90

510

0-041231

100

0 '100000

10

90

0-084852

600

0 200000

120

480

0-046188

100

0-150000

15

85

0-100994

600

0-250000

150

450

0-050000

100

0-200000

20

80

0-113136

600

0-300000

180

420

0-052915

100

0-250000

25

75

0-122474

600

0-350000

210

390

0 055077

100

0-300000

30

70

0-129614

100

0-350000

35

65

0-134906

700

o-iocooo

70

630

0 032071

700

0-150000

105

595

0038173

200

o-iooooo

20

180

0 060000

700

0-200000

140

560

0-042762

200

0-150000

30

170

0-071414

700

0-250000

175

525

0-046291

200

0-200000

40

160

0-080000

700

0-300000

210

490

0 048990

200

0-250000

50

150

0 086602

700

0-350000

245

455

0-050990

200

0-300000

60

140

0-091650

200

0-350000

70

130

0-095392

800

0100000

80

720

0-030000

800

0 150000

120

680

0 035707

300

o-iooooo

30

270

0-048990

800

0-200000

160

640

0-040000

300

0-170000

45

255

0 058309

800

0-250000

200

600

0-043301

300

0-200000

60

240

0-065320

800

0-300000

240

560

0 045826

300

0-250000

75

225

0 070711

800

0 350000

280

520

0 047697

300

0 300000

90

210

0-074833

300

0-350000

105

195

0-077889

900

0 100000

90

810

0 028284

900

0-150000

135

7 65

0 033665

400

0-100000

40

360

0 042426

900

0 200000

180

720

0-037712

400

0-150000

60

340

0-050497

900

0-250000

225

675

0 040825

400

0-200000

80

320

0 056568

900

0-300000

270

630

0 043205

400

0-250000

100

300

0-061237

900

0-350000

315

585

0 044969

400

0-300000

120

280

0-064807

400

0 350000

140

260

0-067454

1000

o-iooooo

100

900

0 026833

1000

0 150000

150

850

0 031937

500

0-100000

50

450

0-037947

1000

0 200000

200

800

0-035777

500

01 50000

75

425

0 045167

1000

0-250000

250

750

0-038730

500

0-200000

100

400

0 050596

1000

0-300000

300

700

0 040988

500

0-250000

125

375

0 054772

1000

0-350000

350

650

0-042661

The use of this table will be best explained
by an example. Let us suppose that a me-
dical man, having, for a long time, adopted
a particular course of treatment in a certain
malady, has arrived at the following results :
1-20 deaths, 680 recoveries, 800 cases.

The average mortality in this case would

* This table is an abbreviation of one given at
p. 142. of Gavarret’s work, but with additional cal-
culations based on the same formula, for the numbers
from 25 to 200 inclusive. The formula from which
the figures in the column of possible errors have
been calculated is,

in which m represents the number of times that an
event a has happened, n the number of times that
an event b has happened, and /u the total number

of events : so that m + n = /*; — the average ffe-

quency of the events m,as obtained by observation ; and
m /2.m.nan( jA /2 .m.n

V 2V m W ~~P

the limits within which the true average, as corrected
by the formula, lies.

be or 0-150000 (see the second column
of the table for 800 facts and 120 deaths).
At first sight the medical observer would ap-
pear to be justified in asserting that under
li is method of treatment the mortality was at
the rate of only 150,000 in 1,000,000 patients,
or 15 per cent. But this assertion would be
immediately met by the objection that the
number of facts is not sufficient to justify this
statement, that an average deduced from so
small a number as 800 facts can only be re-
ceived as an approximation to the truth, and
that it requires to be corrected by the aid of
the figures in the table.

Accordingly, on referring to the column of
possible errors corresponding to 800 cases
and 120 deaths, we find that the error in ex-
cess and defect to which this number of facts
is liable, amounts to 0"035707, which error
must be added to and taken from the
O' 150000, the result of actual observation.
It follows, therefore, that the true result must
he somewhere between the numbers

0- 1 50000 added to 0-035707, or 0-185707,
and 0 150000 dim. by 0-035707, or 0-114293.

8)2

STATISTICS.

So that instead of asserting, as we should
seem justified in doing, that the mortality
under the influence of the treatment adopted
amounted to 15 per cent., we could only
claim a mortality comprised between the
numbers

185,707 and 1 Id, 293 in 1,000,000 cases:
or approximatively between the numbers, 19
and 1 1 per cent.

Uncorrected observation, therefore, would
give, as the result of the treatment adopted,
15 per cent., while corrected observation
would give some number between 19 and 11
per cent.

The application of the formula given in the
note to an actual case will be more instruc-
tive than an imaginary example.

M. Louis, in his Reclierches sur In Ficvre
Typhoide, has attempted to illustrate the treat-
ment of typhus fever, by minutely analysing
HO cases.' The result was as follows : —
Number of deaths (m) 52
Number of recoveries (n) 88
Total - (/a) HO.

The mortality in these cases was therefore
_y_, or 0 37143 ; and if we were to take this
mortality as the strict expression of the re-
sults of the treatment adopted, we should
shape our proposition as follows: — The mor-
tality of typhus fever, under the treatment
adopted by M. Louis, amounted to

37, H3 deaths in 100,000 patients ;
or, in round numbers,

37 deaths in 100 patients

If, now, vve proceed by means of the formula
referred to, to determine the possible error at-
taching to this proposition (i. <?. to the num-
ber of facts upon which it is made to rest),
we find it to be equal to

2 / 2 . m . n 2 / 2 . 52 . 88

V & = \/ (H0)J -0-H550.

This being the possible error in excess
and defect, the true influence of the treat-
ment will be comprised between the following
limits : —
in . 2 / 2 .m.n

+ , / — =0-37143 + 0-1 1550=0-48693

m V A

11550=0-25593.

and

m V ^

Thus all that we really learn from this re-
cord of experience is, that, under the treat-
ment adopted, the number of deaths may vary
between

48,693 and 25,593 in 100,000 patients,
or approximatively between 49 and 26 in 100

patients.

In other words, if we were to employ the
same mode of treatment in a great number
of cases of typhus fever, we might lose any
number between about a fourth and a half of
our patients.*

The same formula is equally applicable to
the solution of doubtful questions relative to
the results of two or more series of facts which

* Gavarret, Principes Gdneraux de Statistique
jMddicale, p. 284.

we are desirous of comparing. It may happen
that the difference between the average result
of one series of facts and that of a second
series, is so inconsiderable, as to leave us in
doubt w hether it may not be explained by a
reference to the limits of error to which the
number of facts in either return is liable.*

It often happens, that the average results
of two series of observations relating to two
alternative events (such as the events of
death or recovery in particular diseases, the
birth of a male or female child, &c.) approxi-
mate so closely, that we are at a loss whether
to attribute the slight difference existing be-
tween the two averages to coincidence, or to
the operation of certain efficient causes. If
the number of observed facts be small, the
difference between the averages derived from
the two series of facts may be so slight as to
fall short of the difference between the limits
of error in excess or defect. The same re-
sult may also happen with any number of
facts, however considerable. In order to
solve the doubts which necessarily attach
to such close approximations, a mathematical
formula has been brought into requisition,
and employed in the formation of tables ap-
plicable to this purpose. Such a table is
subjoined. The mode of applying it will be
presently explained.

The use of this table will be understood
from the following example : — In the six
years 1839-44 there occurred in England, on
the average of those years, 515,478 births, of
which 264,245 were males, and 251,233 fe-
males. As the difference between these two
numbers is not very considerable, a question
might arise, whether that difference- is not
compatible with the error in excess to which
half a million of facts is liable. The use of
the formula on which the foregoing table is
founded, would at once clear up this doubt.

264,245 male births in a total of 515,478,
is equal to

512,904 male births in 1,000,000 births.
But, on the supposition that the male and
female births are really equal in number, we
have the limits of variation equal to 500,000

+ A / and 500,000— A / — %—

/V 515478 /V 515478,

or 500,0004-000,624 and 500,000—000,624,
or a maximum of 500,624, and a minimum of
499,376. The difference by the formula is,
therefore, 1248 in the million, while the ob-
served difference between the highest and
lowest number of male births occurring in the
six years 1839-44, is 514,809 — 511,781, or
3,028. The inference, therefore, is irresist-
ible, that the excess of male births is due to
some efficient cause or causes, and that it is
not merely an error to which the number of
half a million of facts is inevitably exposed. j-

* For illustrations of this application of the fore-
going table, and of the formula from which the figures
are calculated, see Gavarret’s Statistique Medicale,
p. 80. et seq., and notes, p. 274.

f Several applications of this table and of the
formula from which the figures are derived, will be

STATISTICS.

813

Table of the Limits of Variation compatible
with an equal Chance relative to two observed
Events.*

Number
of Cases.

Limits of Variation.

100

0-641429

0-358571

150

0-615470

0-384530

200

0-600000

0-400000

250

0-589442

0-410558

300

0-581650

0-418350

350

0-575593

0-424407

400

0-570711

0-429289

450

0-566667

0-4S3333

500

0-563246

0-436754

550

0-560302

0-439698

600

0-557735

0-442265

650

0-555470

0-444530

700

0-553452

0-446548

750

0-551640

0-448360

800

0-550000

0 450000

850

0-548507

0-451493

900

0-547140

0-452860

950

0-545883

0-4541 17

1000

0-544721

0-455279

1100

0-542640

0-457360

1200

0-540825

0-459175

1300

0-539223

0-460777

1400

0-537796

0-462204

1500

0*536515

0-463485

1600

0*535355

0-464645

1700

0-534300

0-465700

1800

0-533S33

0-466667

1900

0-532444

0-467 556

2000

0-531623

0 468377

2500

0-528284

0-471716

3000

0-525820

0-474180

3500

0-523905

0-476095

4000

0-522361

0-477639

Provision having been thus made by the
two preceding tables for testing the suffi-
ciency of average results based upon different
numbers of facts relating to two alternatives,
and determining the possible variation or
limits of error to which the numbers of facts
in question, considered simply as facts, with-
out regard to their peculiar nature, are liable,
provision still remains to be made for testing
in like manner the value of those averages,
which belong especially to the domains of
physiology and hygiene, namely, the average
number of the pulse and respiration, the
average age at death of different classes of
the community, &c. In the absence of tables
specially adapted to this purpose, it must

found in the work of Gavarret, so often quoted,
from p. 143. onwards, and in the notes at p. 28G.
et seq.

* The formula employed in the construction of
this table is

c™ ±yi

where u, as before, represents the total of the ob-
served facts. The table will be found at greater
length at p. 230 of Gavarret’s work on Medical
Statistics.

suffice to state, in general terms, that the
averages derived from a given number of facts
are not to be regarded as strict expressions cf
the truth, but as approximations more or less
remote, as the number of facts is less or more
considerable.

But a very important question here arises :
— To what extent, and under what restric-
tions, do calculations based on mathematical
formulae and derived from abstract reasoning,
admit of application to the results of actual
observation ? Conceding, as we may safely
do, the soundness of the formulae, there is
yet great room to doubt the propriety of their
application to the average results of observa-
tion. For if we suppose a mathematical
formula to be applied successively to a long
series of averages derived from the same
number of facts, it must obviously administer
a similar correction to those averages which
happen to coincide with the true average, and
to those which lie at the two extremes. This
consideration is sufficient in itself to condemn
the use of mathematical formulae, except as
a means of exhibiting in a striking light the
possible error attaching to a small number of
facts, considered abstractedly as facts.

From the foregoing considerations, then, it
would seem to follow, that although averages
derived from small numbers of facts are sub-
ject to a considerable amount of possible
error, there is always such a probability of their
coinciding with, or not differing widely from,
the true averages, as to justify their employ-
ment as standards of comparison and data for
reasoning. At the same time it must he con-
ceded, that averages derived from small num-
bers of facts stand in need of a confirmation
which averages drawn from larger numbers ol
facts do not require, and that in using the
former we are bound to speak with a reserve
proportioned to the scantiness of our ma-
terials.

Of extreme values derived from observation.

■ — As averages founded upon large numbers
of facts are numerical expressions of true pro-
babilities, so extreme values are expressions,
in the same precise language, of possibilities.
Both orders of facts have their scientific and
practical applications ; but those applications
which belong to the extreme values have been
less attended to than those which pertain to
averages.

One obvious use of extreme values is to
confirm and strengthen the conclusions drawn
from averages. Thus, if we wish to ascertain
the relative duration of life of two classes of
persons, we may make use of the greatest
age attained by either class in confirmation of
the mean of all the observations ; and the
coincidence of the one with the other will
give increased confidence in the general result.

Another important use of extreme values is
as a test of numerical theories. Two apt il-
lustrations of this application of figures are
afforded by that practical science which deals
most lamely in possibilities — Forensic Medi-
cine. M. Orfila, in his “ Traite des Exhuma-
tions,” states that it is possible to determine

814 SUBCLAVIAN AllTERIES.

approxiinatively the stature of tiie skeleton
and of the body by measuring one of the cy-
lindrical bones; but instead of testing the
value of this conclusion by making use of the
extreme values, he contents himself with a
rough average. It appears, however, that if
we take several cylindrical bones having the
same length, and compare them with the cor-
responding ascertained stature of the skeleton,
the extreme statures are very wide apart.
Of seven ulnas, for instance, having each the
same length (viz. 10 inches, 8 lines), one cor-
responded to a stature of 6 feet 1J inch,
and another to a stature of only 5 feet 5
inches. The difference of 8J inches shows
the possible error which might be committed
by trusting to this standard of comparison,
and demonstrates its futility.

The other illustration is afforded by the
well-known test of the absolute weight of the
foetal lungs. It used to be laid down as a
rough average that in still-born mature chil-
dren the weight of the lungs was one ounce,
and in children that were born alive two
ounces. More accurate observation showed
that this rough guess was very far from the
truth. It was only, however, by the aid of
extreme values that the utter worthlessness
of this test could be proved. It resulted from
the collation of a moderate number of ob-
servations that the lowest weight before and
after respiration were the same to an unit,
while the greatest weight of the lungs of still-
born children, in two instances, surpassed the
greatest weight of the lungs of children born
alive. Nothing could more clearly demon-
strate the insufficiency and invalidity of this
test.

The same general principle which applies
to averages applies also to the extremes,
namely, that the value of the extremes in-
creases with the number of observations from
which they are selected. It is obvious, how-
ever, that a larger number of facts will be re-
quired to arrive at a true extreme value than
to obtain a close approximation to the true
mean : 10,000 facts, for instance, may give a
true mean duration of life for the inhabitants
of any country ; but as many millions may
not happen to embrace the greatest attainable
age.

The same principles, then, apply both to
the mean and to the extreme values derived
from observation. To obtain a correct mean
or a probable extreme, we must multiply our
facts.

Bibliography. — Gavarret, Jules, Principes G4-
n&aux de Statistique Medicate, ou Developpement
des Rfegles qui doivent prdsider h son Emploi. De
Morgan, Augustus, An Essay on Probabilities and
their Application to Life Contingencies and In-
surance Offices. Laplace, Essai Philosopliique sui-
tes Probability. Poisson, Recherches sur la Proba-
bility des Jugements. Todd, Tweedy John, The
Book of Analysis, or a new Method of Experience.
Quetelet M.A. Sur l’homme, et le Developpement de
ses Facultes.

( 'William A. Guy.')

STATISTICS, VITAL. See Vital
Statistics.

STOMACH and INTESTINAL CANAL.
See Supplement.

SUBCLAVIAN ARTERIES ( Arteries
subclavice, Lat. ; Arteres sous-clavieres, Fr. ;
die Schlusselbein Pulsadern, Germ.). — These
arteries, two in number, are the great vessels
destined to supply the upper extremities with
blood. Each passes to the corresponding ex-
tremity as a continuous trunk, which in its
course gives off numerous collateral branches to
the larynx, neck, nervous centres, thorax, &c.

The subclavian arteries on the right and
left sides respectively differ from each other
in their origin, length, direction, and in their
relations to surrounding parts, — differences,
however, which occur in the first stage of
these vessels only : thus, on the right side,
the subclavian artery is derived from the
Arteria innominata, and on the left from the
arch of the aorta ; but on both sides alike the
lower or outer margin of the first rib marks
the termination of each vessel, which, in its
further course towards the upper extremity,
is designated by the name of Axillary.

The course of each subclavian artery may,
in general terms, be described as representing
an arch, the convexity of which looks upwards
towards the neck, whilst the concavity has an
aspect downwards, and corresponds closely to
the apex of the lung. On the right side the
extremities of this arch are nearly on the same
level, the outer, however, passing a little lower
down than the inner; whilst on the left side
the reverse obtains, the inner (or cardiac)
extremity of the arch of the left subclavian
artery, which springs from the aorta, being on
a much lower level than the outer. Owing to
the difference in the origin of these vessels,
the left subclavian artery has a stage within
the thorax, which does not belong to the
artery of the right side.

The subclavian artery on each side is ac-
companied by a vein of large size; the direction
of the vein is much more transverse than that
of the artery, so as to resemble in some
respect, as Cruveilhier expresses it, “ the cord
of the arc which the artery describes:” the
subclavian vein is consequently the shorter
vessel of the two.

The course of each subclavian artery may
be divided into three stages, to which the ma-
jority of anatomists agree in assigning the
following limits : —

A first stage comprises that portion of the .
vessel, from its origin, to the inner, or
tracheal edge, of the scalenus anticus
muscle.

A second stage includes so much of the
artery as is contained between the sca-
leni muscles ; and the

Third stage extends from the acromial edge
of the scalenus anticus muscle to the
lower or outer margin of the first rib :
at this latter point the axillary artery
commences.

According to some anatomists (as Bichat),
the outer margin of the scaleni muscles is
the limit between the subclavian and axillary

SUBCLAVIAN

vessels; others (as Cruveilhier) insist upon
the clavicle as the line of demarcation between
these two great trunks ; but the stages above
assigned to the subclavian arteries are strictly
in accordance with the views of British ana-
tomical authorities.

The subclavian vein may be divided into
two stages, which correspond to the second
and third stages of the artery ; at the inner
edge of the scalenus anticus muscle on each
side of the neck, the subclavian joins the in-
ternal jugular vein to form the vena inno-
minata (of Meckel), which latter vein conse-
quently corresponds to the first stage 0/ the
subclavian artery.

As the right and left subclavian arteries
differ from each other essentially in their first
stage, it is necessary to describe them sepa-
rately in this portion of their course.

First stage of the right subclavian artery.

— This portion of the vessel varies from one
to two inches in length ; it extends from the
summit of the arteria innominata to the tra-
cheal edge of the anterior scalenus muscle, and
passes in a direction outwards, and slightly
upwards. At its commencement it lies to the
right of the trachea, and is concealed by the
sterno-clavicular articulation.

In this stage the artery is contained in the
antero-infeiior triangle of the neck. The fol-
lowing structures here constitute its anterior
relations, and are described in the order in
which they present themselves in dissection :

— The skin, and subcutaneous cellular stra-
tum, with one sheet of the cervical fascia,
being divided, the tendon of the sterno-mas-
toid muscle (sternal origin) is exposed : be-
hind it is a cellular interval of constant ex-
istence, though of variable extent, where
anastomosing veins and small arterial twigs
ramify. The outer edges of the sterno-hyoid
and of the sterno-thyroid muscles are more
deeply placed ; the latter extends much fur-
ther outwards than the former, and hence it
more directly overhangs and conceals the
subclavian artery. These muscles are con-
tained in distinct sheaths (furnished by the
deep cervical fascia), which isolate them, as
well from the superficial as from the deeper-
seated parts : the layer of fascia which forms
the back of the sheath of the sterno-thyroid
muscle is the deepest lamina of the cervical
aponeurosis ; towards the middle line it in-
vests the front of the trachea, and the deep
thyroid veins; externally, it covers the carotid
and subclavian arteries, with their accompany-
ing veins, and is connected to the scalenus
anticus muscle, whilst, inferiorly, it is attached
to the clavicle, to the sternum, and to the
“ thoracico-cervical septum,” through the in-
tervention of which it is connected with the
fibrous layer of the pericardium. On the
removal of this fascia from the region under
consideration, the immediate anterior relations
of the subclavian artery are exhibited ; they
are as follow : —

a. The right vena innominata, its satellite
vein, lies anterior to the artery in the first
stage of its course, but on a lower plane, and

ARTERIES. 815

separated from it by the phrenic and vagus
nerves, and by the internal mammary artery.

b. The internal jugular vein, which passes
downwards and outwards into the subclavian
vein, in order to form with it the right vena
innominata, crosses the front of the artery
nearly at right angles : an interval (the result
of the inclination outwards of the internal
jugular vein) occurs between this vein and
the common carotid artery ; and here

c. The vagus nerve passes over the sub-
clavian artery ; whilst internal to this point
the subclavian artery is enveloped in a nervous
sheath, formed of

d. The cardiac filaments of the sympathetic
nerve.*

e. Lastly, the phrenic nerve constitutes an
important anterior relation of the subclavian
artery, passing anterior to the very last por-
tion of the first stage of the vessel, though
not in contact with it. The trajet of the
nerve is external to that of the internal jugular
vein, which, as before mentioned, crosses the
same aspect of the artery. There is no actual
contact between the phrenic nerve and the
subclavian artery, because the nerve, as it
leaves the inner margin of the scalenus an-
ticus muscle, lies on and crosses the origin of
the mammary artery, which thus separates
the nerve in question from the trunk of the
subclavian. The relation of

f. The vertebral vein, to the subclavian ar-
tery, is subject to much variety. According
to the descriptions of most anatomists, it
passes posterior to the artery; but the writer
has found this vein nearly as often in front of
the artery as behind it ; and occasionally he
has seen the vertebral vein terminate in two
branches, of which one passed on the anterior,
and the other on the posterior aspect of the
subclavian artery, so as to encircle that vessel
before they opened into the vena innominata.
When the vertebral vein is single, and passes
over the front of the subclavian artery, it
usually lies internal and parallel to the in-
ternal jugular vein.

The anterior relations of the first stage of the
right subclavian artery, are, therefore, the fol-
lowing : —

1. Integument, subcutaneous areolar tissue,

fascia.

2. Sterno-mastoid muscle, sterno-clavi-

cular articulation.

3. Sterno-hyoid and thyroid muscles, iso-

lated from one another, and from the
last-named muscle, by layers of the
cervical fascia.

4. The deep layer ofthe cervical aponeurosis.

5. The phrenic and vagus nerves, and the

cardiac filaments of the sympathetic
nerve.

6. The right innominate, and internal jugu-

lar veins, and sometimes

7. The vertebral vein.

The remaining relations of the artery in its
first stage are the following: —

Inferiorly, it corresponds to the loop of the

* Vide art. Neck, vol. iii. note to p. 575.

SUBCLAVIAN ARTERIES.

810

recurrent nerve, which sometimes has an an-
terior relation to the artery also, in consequence
of its arising from the pneumogastric at an
unusual height in the neck.

Superiorly, it gives off’ the vertebral artery
opposite a triangular interval, between the
scalenus antieus anti longus colli muscles.

Posteriorly, it corresponds from within out-
wards, to the transverse process of the seventh
cervical vertebra, to the inferior cardiac fila-
ments and inferior cervical ganglion, of the
sympathetic nerve, to the recurrent nerve, and
finally, to the cone of the pleura.

Nearly the cuter half of the posterior sur-
face of this portion of the subclavian artery
is thus closely related to this serous sac, being
usually that part of the vessel which is ex-
ternal to the origin of the vertebral branch,
and covered on its anterior surface by the
internal jugular vein.

First stage of the left subclavian artery. —
The subclavian artery on the left side arises
within the thorax, from the termination of
the second stage of the arch of the aorta, at
the level of the second dorsal vertebra ; it
thence assumes a direction nearly vertically
upwards, to the inner margin of the scalenus
antieus muscle, and lies to the leftside of, and
anterior to, the two upper dorsal vertebrae,
from which it is but a short way distant.

Whilst in the cavity of the thorax, the left
subclavian artery corresponds, posteriorly, to
the inferior cervical ganglion, and cord of the
sympathetic nerve, to the thoracic duct, and
more remotely to the longus colli muscle and
spinal column. Anteriorly, it is in relation with
the pleura, and more immediately with the left
pneumogastric and phrenic nerves (the latter
descends parallel to the artery, but the former
crosses it very obliquely, from above down-
wards and inwards), with the vertebral vein,
the confluence of the internal jugular and
left subclavian veins, and the great venous
trunk which they form by their confluence,
viz. the left vena innominata. Internal and
posterior to the artery are placed the oesopha-
gus and the left recurrent nerve ; internal
and anterior to it, is the left common carotid
artery ; whilst external to the artery, through-
out the entire of its thoracic stage, are the
left lung and pleura.

After a course within the thorax of about
tw’o inches and a half, the left subclavian
artery pierces the “thoracico-cervical septum,”
inclines outwards and a little forwards, and
attains the tracheal edge of the scalenus anti-
ctis muscle, when it bends abruptly outwards ;
this terminating portion of the first stage of
the vessel (which alone belongs to the cervi-
cal region) has, anterior to it, the left internal
jugular vein, the vagus and phrenic nerves,
and the thoracic duct, just before its termina-
tion in the great subclavian vein ; in addition
to these relations, the left subclavian has the
same coverings as the corresponding portion
of the subclavian artery on the right side.

Differences between the right and the left
subclavian arteries, in their first stage. — Length.
rl he first stage of the left subclavian artery is

much longer than that of the right, which it
exceeds by about the length of the Arteria
innominata. In the old subject, however, the
difference is scarcely so great, for at this
period of life, the part of the arch of the aorta,
from which the left subclavian artery arises,
is higher than that portion of it from which
the innominata springs.

Position. — The left subclavian artery is
nearer to the spinal column, the right to the
clavicle and sternum ; consequently the depth
of the artery from the surface is considerably
greater on the left side than on the right, a
circumstance which adds greatly to the diffi-
culty of the operation for securing the left
subclavian artery in a ligature.

Direction. — On the left side, the artery in
its first stage runs almost vertically, but as it
approaches the scaleni, it inclines outwards
and forwards, in order to pass between these
muscles ; this latter part of the vessel is situ-
ated in the neck, and is the only portion of
its first stage found there. On the right side,
the subclavian artery runs nearly horizontally
outwards, and is placed throughout the whole
of its first stage within the limits of the antero-
inferior triangle of the neck ; for although
somewhat concealed at its origin by the sterno-
clavicular articulation, yet it may be removed
from under cover of that joint, by extending
the neck, and depressing forcibly the shoulder
and clavicle.

Relations. — a. Pleura. — The pleura is an
anterior relation of the commencement of the
left, but a posterior relation of the termina-
tion of the right subclavian artery.

b. Veins. — 1. The satellite vein of the right
subclavian artery, in its first stage (the right
vena innominata), is parallel to the artery,
though on a plane anterior and inferior to it,
whilst the corresponding vein on the left side
crosses the left subclavian at right angles.

2. The internal jugular vein runs parallel
to the left, but intersects at right angles the
front of the right subclavian artery.

3. The vertebral vein is usually anterior to
the artery of the left, but posterior to the
artery of the right side.

c. Nerves. — The phrenic , vagi, and sympa-
thetic nerves are necessarily parallel to the left
subclavian artery, in thefirst stage of its course,
in consequence of its vertical direction, whilst
they run at right angles to the corresponding
part of the right, by reason of its transverse
course ; in other respects, however, these
nerves hold the same relative position to the
subclavian arteries at either side, the phrenic
and vagus being anterior, and the sympathetic
posterior, to the right and left subclavians
respectively. Lastly, the recurrent laryngeal
nerve passes behind the right subclavian artery,
looping round its under surface, whilst the
nerve on the left side encircles the arch of the
aorta, internal to the origin of the left sub-
clavian artery ; the recurrent is consequently
related to the inner side of the left subclavian
artery, but at no part of its course does it lie
posterior to that vessel.

d. The thoracic duct and oesophagus are

SUBCLAVIAN ARTERIES.

817

connected with the artery of the left side,
exclusively. The former holds a double relation
to that vessel ; in the thorax it passes behind it,
in the neck it rises high above it, and then
bends downwards in front of it, to open into
the confluence of the great veins. The oeso-
phagus, as has been mentioned, lies to the
right of the artery.

The differences which have thus been
pointed out, are of material importance with
reference to the operations upon these two
arteries.

In the remainder of their course the sub-
clavian arteries are perfectly symmetrical,
and one and the same description will apply
to both.

Subclavian arteries in their second stage. —
In its second stage each subclavian artery lies
in a remarkable intermuscular space, bounded
by the scaleni muscles. These muscles (sca-
lenus anticus and scalenus posticus) areclosely
approximated to each other at their attach-
ment to the tubercles of the cervical trans-
verse processes ; but in descending to their
insertions they diverge, leaving between them
a space truly triangular, of which the base,
placed inferiorly, corresponds to the first rib,
and to a small portion of the second. In
this space the subclavian artery, the brachial
plexus of nerves, and the cone of the pleura,
are situated In front, the artery is in contact
with the anterior ivall of this triangle, consti-
tuted by the scalenus anticus muscle; behind,
it is separated from the posterior boundary of
the triangle by the summit of the cone of the
pleura, which ascends thus high into the
interval between the scaleni, interposing itself
between the scalenus posticus and the subcla-
vian artery. Towards the summit of this
11 scalene triangle” the nervous cords which
constitute the brachial plexus are placed
along the convexity of the artery, superior
and external to it.

A fleshy slip ( Scalenus minimus, Soemmering)
is often found to pass from the scalenus an-
ticus to the lower, or costal extremity, of the
scalenus posticus ; in this course it runs be-
tween the roots of the brachial plexus, and
consequently subdivides into two the scalene
space. The lower compartment contains the
subclavian artery, the cone of the pleura, and
the inferior portion of the brachial plexus,
constituted by the seventh cervical nerve, and
the cord resulting from the union of the eighth
cervical, with the first dorsal nerve ; whilst in
the upper compartment (corresponding to the
apex of the triangle), the fifth and sixth nerves
of the plexus are seen to unite into a single
trunk.

On the front of the scalenus anticus, and
separated by that muscle from the subclavian
artery, are found the following parts : — Most
inferiorly the subclavian vein, lying on the
tendinous insertion of the muscle, and under
cover of the clavicle ; above the vein the
transverse branches of the thyroid axis, viz.
the supra-scapular, and the transversalis colli
arteries, of which the former is the more
inferior, whilst the phrenic nerve descends

VOL. IV.

obliquely inwards towards the tracheal edge of
the muscle, and intersects these two trans-
verse arteries by passing behind them.

Superficial to all these important structures
is the clavicular origin of the sterno-eleido-
mastoid muscle. In size, shape, and direction,
this muscle accurately corresponds to the sca-
lenus anticus, which lies deeper than it, and
from which it is separated by the parts just
now stated, to lie on the front of that
muscle.

The separation of the subclavian vein from
the subclavian artery in their second stage,
“ constitutes one of the most remarkable fea-
tures in its (anatomical) history this con-
dition is not, however, constant, for the vein
has been found to lie with the artery between
the scaleni (Blandin), and, in a few other
equally rare instances, the artery has accom-
panied the vein superficial to both muscles
(Manec, Quain). Lastly, the artery lias been
seen to pass through the anterior scalenus,
and hence to lie in part behind and in part
in front of that muscle (Quain). It is to be
understood that these deviations from the
normal arrangement are remarkably infre-
quent.

The anterior relations of the subclavian ar-
tery in its second stage, may be arranged in
four orders of parts : —

1. Skin, platysma, fascia.

2. Sterno-cleido-mastoid muscle (its clavi-
cular origin).

3. Subclavian vein, supra-scapular and
transverse cervical arteries, phrenic nerve,

4. Scalenus anticus muscle.

Subclavian artery in its third stage. — -After
the subclavian artery emerges from beneath
the scalenus anticus muscle, it inclines down-
wards and outwards, 'and thus completes the
arch which its entire course represents. In
this stage its position is marked by precise
limits, which are always recognisable, even in
the living subject. The artery, with the vein
and brachial plexus of nerves, which still ac-
company it, is here contained in the postero-
inferior triangle of the neck ( O mo-clavicular
space, Velpeau), the several boundaries of
which are constituted by the clavicle, and by
the sterno-mastoid and omo-hyoid muscles.

Whilst traversing this region the subclavian
artery lies at first on the scalenus posticus, and
then passes on the upper surface of the first
rib. The subclavian vein lies inferior and in-
ternal to the artery, and on a more superficial
plane than it, throughout the entire of this
portion of its course; it also passes with the
artery over the first rib. Two superficial
grooves in the adult bone mark the trajet and
relative position of these great vessels ; a tu-
bercle, which gives insertion to the scalenus
anticus muscle, separates these grooves from
each other (that for the artery is the more
posterior of the two) ; it is constantly present,
and serves as a guide to point out with pre-
cision the situation of the artery, and so assist
the operator to distinguish that vessel from
the parts which surround it. Such a guide
to the artery is peculiarly valuable, because,

3 G

818 SUBCLAVIAN ARTERIES.

in operations upon the larger blood-vessels,
the touch often fails to discriminate the pro-
per object, the characteristic pulsation of a
large artery being, under such circumstances,
often wanting.

In the postero-inferior triangle of the neck
the artery is covered by the integument, su-
perficial fascia and platysma, descending su-
perficial ( supra-clavicular ) twigs of the cervical
plexus, and by the external jugular vein. The
situation of this vein in the supra-clavicular
space, is subject to much variety ; it most fre-
quently runs near to the inner boundary of
the triangle and parallel to the outer edge of
the sterno-mastoid muscle, but frequently de-
scends in the very centre of the space ; in the
latter case it much embarrasses the operator
in attempting to expose the subclavian artery.

Next in order, a number of conglobate
glands, and a plexus of anastomosing veins,
principally from the scapular region, come into
view; these latter usually communicate with
the external jugular, or with the subclavian
vein. Areolar tissue which presents a laminated
arrangement encloses these glands and super-
ficial vessels, and isolates them from the
deeper-seated parts.

These structures being removed, the sub-
clavian artery appears to lie within a second
triangle of smaller dimensions, bounded inter-
nally by the scalenus anticus muscle, externally
and superiorly by the omo-hyoid muscle, and
iiferiorly by the first rib; this bone represents
the base of the triangle, and over it the artery
is seen to pass. At this depth, two collateral
arterial branches of considerable size cross
the supra-clavicular space, the one, the trans-
versalis colli, above, the other, the supra-
scapular, below the level of this portion of the
subclavian artery ; the latter is placed under
cover of the clavicle, and in contact with the
front of the subclavian vein. As the supra-
scapular artery pursues its course towards the
shoulder, it crosses in front of the subclavian
artery and of the brachial plexus of nerves.
Here likewise the clavicle and the subclavius
muscle constitute additional anterior relations
of the subclavian artery, now near its termi-
nation.

The nervous bundle of the brachial plexus is
parallel to the subclavian artery in its third
stage, and lies superior and external to the
vessel ; in its descent the lower division of
the plexus overhangs the artery, and one or
two of the branches ( anterior thoracic') cross
the anterior surface of the artery, and some-
times even encircle it in a nervous loop.

The anterior relations of the third stage of
the subclavian artery may therefore be thus
arranged : —

1. Integument, superficial cutaneous nerves,
platysma, fascia.

2. Areolar tissue in layers, glands, external
jugular vein, an intricate plexus of smaller
veins.

3. Anterior thoracic branches of the bra-
chial plexus, the subclavian vein, supra-sca-
pular artery, clavicle, and subclavius muscle.

'Anomalies in the origin of the subclavian ar-

teries.— 1. The right subclavian artery some-
times arises separately from the arch of the
aorta, in which case there is no arteria inno-
minata ; the branches that arise from the arch
of the aorta are then four in number, but con-
siderable variety has been observed in the
relation which the right subclavian bears to
the other three branches ; thus,

a. It may occupy the usual position of the
innominate artery, being the first in order of
the branches of the arch of the aorta; its re-
lations within the thorax will then correspond
with those assigned to the vessel whose place
it comes to occupy.

b. It may be the second in numerical order
of the branches of the arch, arising after the
right carotid artery, behind which it subse-
quently passes to arrive at its proper position
in the neck.

c. It may arise after the two carotids as the
third branch of the arch ; or,

d. It may be the last branch of the aorta, and
occupy the usual situation of the left sub-
clavian artery. Of the varieties already men-
tioned, this is the most frequently met with,
and, according to the statistics of Pro-
fessor Quain, it occurs once in every 250
examinations.

e. Sometimes (but much more rarely) this
vessel arises below the arch, from the thoracic
aorta, and its position may be so low, that it
will furnish some of the upper intercostal
arteries.

The course of the artery, when it thus arises
from the left of the arch, is very remarkable ;
it crosses in front of the spinal column, either
behind the oesophagus, or between that tube
and the trachea, and necessarily passes across
the neck behind all the other branches given
off' from the arch of the aorta. When thus ab-
normally situated behind the oesophagus, it
has been accidentally wounded by a foreign
body which had first transfixed that tube. A
remarkable example of this occurrence is
mentioned by Mr. Kirby, in the 2d vol. of the
Dublin Hospital Reports.

The irregularity in question, of the right
subclavian artery, was regarded by Dr. Bay-
ford as the cause of difficult deglutition, in a
case which had been accurately observed for
many years, and this new disease, as he con-
sidered it, he quaintly termed “ Dysphagia
lusoria.” *

In those instances, where the right sub-
clavian artery has been found to deviate thus
strangely from its usual course, the inferior
laryngeal nerve presented a remarkable change
of direction, depending no doubt on the altered
course of the artery ; in all the instances
which were noted, the nerve was given off
from the pneumogastric, higher up than usual,
and passed directly to the larynx, so as not to
be entitled to the name of “recurrent.” Dr.
Hart, who first directed attention to this fact,
has thus clearly explained the connection be-
tween the unusual position of the artery and

* Memoirs of the Medical Society of London,
vol. ii. 1793.

SUBCLAVIAN ARTERIES,

810

the altered direction of the nerve : “ In the ear-
lier periods of the existence of the foetus, the
rudiment of the head appears as a small pro-
jection from the upper and anterior part of
the trunk, the neck not being yet developed.
The larynx at this time is placed behind the
ascending portion of the arch of the aorta ;
while the brain, as it then exists, is situated so
low, as to rest on the thymus gland and front
of that vessel. Hence it is that the inferior
laryngeal nerves pass back to the larynx, se-
parated by the ascending aorta, the left going
through its arch, while the right goes below
the arteria innominata.

“ As gestation advances, the head becomes
more distinct, and the neck begins to be
formed after the second month, which, as it
lengthens, has the effect of removing the
brain upwards to a greater distance, and of
drawing out the larynx from the chest, in
consequence of which the nerves of the par
vagum and their recurrents become elongated,
and hence the circuitous route the latter are
found to take afterwards, forming loops in
which the aorta and right subclavian artery
are, as it were, suspended.”*

2. The left subclavian artery is much less
liable to vary in the mode of its origin than
the right ; the varieties observed are also
fewer in number, a. The origin of the left sub-
clavian artery is sometimes more approximated
than usual to the origin of the left carotid, and
in a few instances, b. its origin is fused into
that of the latter, so that these two vessels
arise by a common trunk, which is a left
arteria innominata.

It has been observed in those instances
where the arch of the aorta is reversed, so as
to pass from left to right, that the same irre-
gularities affect the transposed branches which
then arise from it, as have been stated to
occur when the arch holds its more usual po-
sition.

Branches of the subclavian arteries. — In the
number and arrangement of the branches of
the subclavian artery so much variety occurs,
that no general description could, perhaps, be
given, which would accurately describe their
arrangement in any one instance, and hence,
in works on anatomy, much discrepancy exists
on this subject ; the following description
agrees with that of the best authorities in
this country, and is strictly in accordance
with the accurate statistical details of Professor
Quain.

In its first stage the subclavian artery usually
gives origin to the following branches — the
vertebral , internal mammary, and thyroid axis ;
the last, after a very short course, divides
in a radiating manner into the inferior thyroid,
the supra-scapular (transversalis humeri), and
the transverse cervical (transversalis colli)
arteries ; besides, in the majority of instances,
the left subclavian artery, in its first stage,
furnishes (in addition to the branches already

* Dr. Hart, in Edinb. Med. and Surg. Journal,

1826.

enumerated) the supeiior intercostal artery, a
branch which, on the right side, more fre-
quently arises under cover of the scalenus
anticus muscle. All these branches arise
nearer to the scaleni muscles, and are conse-
quently more immediately covered by the
internal jugular vein on the left side of the
neck than on the right.

The position of these branches of the sub-
clavian artery, especially on the right side,
is of much interest in a surgical point of view.
“ The situation in which the branches arise
from any large artery is an important con-
sideration in its history, because of the influ-
ence which their presence has on the result
of an operation for the cure of aneurism.
And, considering the shortness of the trunk,
the size of the offsets, and the manner of
their arrangement on the parent vessel, it may
be confidently stated that there is no artery
in which the influence alluded to is more
considerable than in the subclavian.”*

The following statistics, derived from the
author just quoted, are useful to show the
average length of the subclavian artery, from
its origin to the point where its first branch
arises; in other words, the extent of the
artery in its first stage, suitable for the appli-
cation of a ligature.

In sixty-five bodies examined, this distance
measured —

i inch and under - - - in 8

More than i inch and not exceed-
ing 1 inch - - - - „ 33

More than 1 inch and not exceed-
ing 1| inch - - - - „ 23

If inch (the extreme length) - „ 1

Occasionally, the vertebral, or inferior tig-
roid artery, has been seen to arise very close
to the arteria innominata.

In the second stage the subclavian artery
most frequently gives off but a single branch,
which soon subdivides into the cervicalis pro-
funda and superior intercostal arteries. It is
less usual for these two arteries to arise
separately; thus, in 285 examinations, this
occurred in the proportion of but 1 to 20i,
whereas the former arrangement existed in
266 out of the entire number.

In the majority of instances no branches
arise from the subclavian artery external to the
scaleni; but the posterior scapular artery (in
general the continued trunk of the transver-
salis colli) frequently arises from the third
stage of the subclavian, and so frequently,
indeed, that Cruveilhier regards it, not as a
variety, but as the normal arrangement. It
is computed by Professor Quain that this
occurs in the proportion of 1 in 2% cases.

I. Vertebral artery. — This artery, which is
the first and largest, is at the same time one
of the most regular of the branches of the
subclavian artery, from the upper and posterior

* Anatomy of the Arteries of the Human Body,
with its Applications to Pathology and Operative
Surgery (Plates). By Prof. Quain. Part VI.

3 a 2

820

SUBCLAVIAN

aspect of which it usually arises. There is
no example on record where this branch
arose either between or beneath the scaleni
muscles.

From its origin, the vertebral artery assumes
a direction upwards, backwards, and slightly
outwards to the foramen, in the transverse
process of the sixth cervical vertebra ; having
passed through this, it is transmitted from
vertebra to vertebra by the foramina which
their transverse processes present, until finally
it traverses the foramen magnum, where its
cerebral, or cranial, stage commences.

Relations. — From its origin until it enters
the transverse process of the sixth cervical
vertebra, the vertebral artery is placed in a
muscular interspace, between the longus colli
and the scalenus anticus muscles, where it is
related in front to the trunk of the subclavian
artery, to its own vein, and to the inferior
thyroid artery ; the last of these, as it passes
transversely inwards, is interposed between
the vertebra! vessels and the sheath of the carotid
artery (in the sheath, the internal jugular
vein exactly corresponds to the anterior sur-
face of the vertebral artery). By its posterior
surface , the vertebral artery is in relation with
the inferior cervical ganglion of the sympa-
thetic nerve.

From the sixth to the second cervical ver-
tebra inclusive, the vertebral artery is lodged
in the bony foramina of the transverse pro-
cesses ; in the spaces between these, it is
enclosed by the pairs of intertransverse muscles,
being in close contact with the anterior set,
whilst from the posterior it is separated
regularly by the spinal nerves in their trajet
outwards. In this part of its course the
artery is slightly tortuous, a provision, no
doubt, to guard it against injury in the free
and varied motions of this portion of the
spine. For a similar reason its tortuosity
increases remarkably in the subsequent stage.

Having passed through the transverse pro-
cess of the axis, the vertebral artery inclines
outwards and slightly upwards, to reach the
foramen in the transverse process of the atlas,
a deviation from the former vertical course
of the artery which is rendered necessary by
the superior breadth of the first vertebra.

Whilst engaged in the curved canal {not
foramen) of the transverse process of the atlas,
the artery bends abruptly backwards and
inwards, so that on emerging from this bone
it becomes horizontally placed on the upper
surface of the posterior arch of the atlas.
Between the occipital bone and the atlas
the artery describes a curve, of which the
concavity, looking forwards and inwards,
embraces the occipito-atlantal articulation,
whilst the convexity, directed backwards and
outwards, is contained in a triangular space,
circumscribed in the following manner by the
small rotator muscles of the head. The sides
of this triangle are constituted by the superior
and inferior oblique muscles respectively, the
apex is at the transverse process of the atlas,
where both these muscles are attached ; whilst
the rectus capitis posticus major (placed in-

ARTERIES.

ternally) represents the base. Deeply situated
in this triangular space, the vertebral artery is
covered by the splenius and coinplexus muscles,
and rests on the posterior arch of the atlas ;
the bone presents a groove for the reception
of the artery ; but the sub-occipital nerve,
which frequently forms its ganglion in this
situation, is interposed. The space which has
just been described is occupied by yellow,
granular-looking fatty matter, and the occi-
pital artery winds along its upper boundary,
freely anastomosing with the vertebral.

The vertebral artery next passes beneath
the lower edge of the posterior occipito-atlan-
tal ligament, then perforates the dura mater,
and, taking a direction upwards, forwards, and
inwards, enters the cranium through the
foramen magnum. The posterior occipito-
atlantal ligament, by arching over the groove
on the upper surface of the atlas, forms a
foramen for the transmission of the artery.

As the vertebral artery' advances through
the foramen magnum, it passes between the
first and second tooth-like insertions of the
ligamentum dentatum, and then ascends, lying
on the anterior surface of the first of these
processes, by which it is separated from the
spinal accessory nerve, which latter passes
upwards on the posterior surface of the liga-
ment ; here the lingual nerve passes outwards
to the anterior condyloid foramen, above the
level of the artery.

Within the cranium, the vertebral arteries,
corresponding at first to the lateral aspects
of the upper portion of the medulla oblongata,
approximate to each other more and more as
they ascend, and ultimately unite at an acute
angle, opposite the inferior edge of the pons
varolii ; in this manner the basilar trunk is
formed.

Basilar artery ( Artere meso-cephalique,
Chaussier). — This artery, larger than either
of the vertebral arteries, is yet much less capa-
cious than the two vessels conjointly which
unite to form it ; its length corresponds
accurately to the longitudinal measurement
of the pons varolii ; it runs along the median
depression of the pons, lodged between that
body and the upper surface of the basilar
process of the occipital bone, and preserved
from pressure by the double concavity of the
surfaces between which it is interposed.

At its commencement the basilar artery
separates from each other the sixth nerves of
the opposite sides ; the arachnoid membrane
and the dura muter, with the transverse sinus of
Haller, are interposed between the artery
and the bone, whilst the pia mater alone
intervenes between it and the pons. At the
antero-superior edge of the pons the basilar
artery usually terminates in four branches,
two for the cerebrum and two for the cere-
bellum.

Branches of the vertebral artery. — 1.
Branches to the praevertebral muscles, which
anastomose with the cervicalis accendens and
superficialis colli arteries.

2. Numerous small branches, which enter
the spinal canal through the intervertebral

SUBCLAVIAN ARTERIES. 821

foramina, and which are conducted by the
nerves to the spinal cord, where they join and
reinforce the proper spinal arteries.

3. In the space between the atlas and occi-
pital bone, the vertebral artery sends several
long branches down the neck, which are con-
cealed by the splenius and complexus muscles.
Accompanied by smaller branches of the occi-
pital, these arteries keep up an important
anastomosis on the back of the neck with the
cervicalis profunda.

4, .5. The proper spinal arteries. These
are two in number on each side, an anterior
and a posterior branch from each vertebral
trunk.

The posterior spinal arteries arise lower
down than the anterior, and pass downwards
and backwards to reach the posterior surface
of the medulla oblongata ; from this the
artery of each side descends parallel to its
fellow, to which it is connected by numerous
transverse branches. Opposite the second
lumbar vertebra, the posterior spinal arteries
cease to exist as distinct trunks.

The anterior spinal arteries are given off
from the vertebral near to its termination ;
these arteries in descending approximate to
each other, and at last unite opposite the
lower edge of the medulla oblongata ; the
single trunk thus formed ( anterior median artery
of the spinal cord ) descends tortuously in front
of the medulla spinalis, and, passing through
the very centre of the fibres of the cauda
equina, reaches the lowest portion of the
vertebral canal, when it anastomoses with
branches of the sacral arteries.

The anterior and posterior spinal arteries
are connected in every region of the spine
with branches of arteries which enter the
spinal canal through the “ foramina of con-
junction these reinforcing branches, as the}7
may be termed, of the spinal arteries (derived
from the cervicalis ascendens and vertebral
in the neck, from the intercostal in the back,
and from the lumbar and sacral arteries in
the lower portion of the spinal column),
cause these arteries which they join to pre-
serve a remarkable uniformity of size through-
out their entire course. Both the spinal
arteries furnish small branches to the dura
mater and to the spinal cord.

Branches of the basilar artery. — 1. The
inferior (or posterior') cerebellar artery. —
This artery seldom arises in precisely the
same manner at opposite sides of the same
subject. It most frequently springs on one
side from the vertebral, and on the other
from the basilar trunk. Inclining outwards
and backwards, in front of the pyramidal
body, the vessel in question passes (according
as its origin is from the basilar, or from the
vertebral artery) before or behind the sixth
nerve; it then runs through the filaments
going to form the ninth nerve, and between
the pneumogastric and spinal accessory divi-
sion of the eighth pair; it is ultimately dis-
tributed internally to the inferior vermiform
process and sides of the median fissure (a

branch or two may be traced into the choroid
plexus of the fourth ventricle), and externally
to the inferior surface and circumference of
the cerebellum, where it communicates with
the superior artery of the cerebellum.

2. The superior (or antei'ior) cerebellar
artery. — This artery arises near the antero-
superior edge of the pons varolii ; it passes in
a curved direction outwards and backwards,
around the line of junction of the pons with
the crus cerebri. It is at first parallel to the
posterior artery of the cerebrum, but separated
from it by the third nerve. The fourth nerve
in its trajet forwards is strictly parallel to the
artery as it runs backwards on the side of the
pons varolii ; the nerve, however, is contained
in a canal between the layers of the tentorium,
whilst the artery proceeds beneath that par-
tition, and in contact with the upper surface
of the cerebellum.

The branches of the superior cerebellar
artery are numerous ; they are distributed to
the upper surface and circumference of the
cerebellum, anastomosing with the inferior
cerebellar artery, and also to the pons varolii,
velum interpositum, superior vermiform pro-
cess, and valve of Vieussens. One small
branch of this artery accompanies and separates
the facial and auditory nerves, entering with
them into the internal auditory meatus.
Lastly', some of its branches pass on the upper
surface of the tentorium, and are distributed
to the inferior surface of the cerebrum.

3. Posterior artery of the cerebrum. — The
two posterior arteries of the cerebrum are
the terminating branches of the basilar trunk;
each artery passes at first forwards, then
backwards and outwards, following the course
of the great cerebral fissure, and partly en-
circling the crus cerebri. For a considerable
portion of its course the posterior artery of
the cerebrum is parallel to the posterior (or
inferior) cerebellar artery; the two arteries,
however, are separated from one another, at
first, by the third nerve (which latter, in its
further course, hooks round the posterior
artery of the cerebrum), and subsequently by
the tentorium. At the point where the
posterior artery of the cerebrum changes its
direction in order to pass backwards and
outwards, it is joined by the “ posterior com-
municating artery,” and by this means a com-
munication is established between the internal
carotid and basilar arteries.

The posterior artery of the cerebrum is
chiefly distributed by long slender branches
to the inferior surface of the posterior lobe of
the cerebrum, but it furnishes, in addition,
the following collateral branches:—!. Nume-
rous small twigs which enter the floor of the
third ventricle, through the apertures in the
locus perforatus meditis, or are distributed to
the crura cerebri, corpora albicantia, and
tuber cenereum ; and 2. a choroid branch, which
winds round the crus cerebri, enters the
cerebral fissure, and is lost in the velum inter-
positum, corpora quadrigemina, and choroid
plexuses.

3 g 3

SUBCLAVIAN ARTERIES.

822

Varieties occasionally observable in the verte-
bral arteries. — 1. Of origin. — a. It lias already
been mentioned that the vertebral artery
may arise from different portions of the first
stage of the subclavian artery being sometimes
nearer, and sometimes further removed, from
the innominata; but, independently of these
varieties, the vertebral artery on the right
side is

b. Sometimes furnished by the common
carotid artery. In all the cases where this
anomaly has been observed, the right subcla-
vian artery was given off directly as a branch
of the aorta. Again,

c. The vertebral artery sometimes comes
off' from the arch of the aorta. This irre-
gularity is as unfrequent on the right, as it is
common on the left side. When the left
vertebral artery springs from the arch of the
aorta, it usually arises between the left carotid
and the left subclavian arteries, though some-
times its origin has been found to the left of
all the other branches of the arch.

d. In a few instances, more than one vessel
has been found to constitute the origin of the
vertebral artery; thus, it may be formed by
the union of two roots , both arising from the
subclavian artery, or one from the subclavian
and the other from the aorta. In one exam-
ple, where it was formed by three roots, two of
these were derived from the subclavian, and
the third from the inferior thyroid artery.
These roots of the vertebral artery in some
instances united before the artery had become
engaged in the vertebral foramina, whilst in
others the union took place subsequently.

2. Of size. — There is often a considerable
difference in the size of the two vertebral arte-
ries, which is stated to be most frequently in
favour of that of the left side ; thus, in 98 ob-
servations made by Mr. Davy, the left verte-
bral artery was the larger in twenty-six, and
the right in eight instances only.

3. Of course and relations. — The vertebral
artery may enter the transverse process of the
last cervical vertebra (though the contrary has
been asserted), or it may enter one of the fo-
ramina higher than that in the transverse pro-
cess of the sixth, which latter it usually selects.
When the artery enters any vertebra higher
than the sixth cervical, it always occupies an
unusually superficial position in the neck,
lying external and parallel to the common
carotid artery, for which, consequently, it is
liable to be mistaken. ( Vide Carotid Ar-
tery.)

The vertebral vein corresponds to the cer-
vical stage only of the artery. Its origin is
found in some branches from the deep muscles
at the back of the neck, joined by one from
the occipital vein, and by another which
passes through the posterior condyloid fo-
ramen. The vertebral vein traverses the
canal in the transverse process of the atlas*
and descends through the same foramina by
which the artery ascends ; whilst here it lies in
front of the artery, and has the same relations
as that vessel. Emerging from the foramen in

the sixth vertebra, the vertebral vein (liable
to the varieties already specified) opens into
the vena innominata close to its junction with
the internal jugular.

II. Internal mammary artery. — This ar-
tery arises (more externally than the ver-
tebral) from the anterior surface of the sub-
clavian, and near to the inner margin of the
anterior scalenus muscle. From this origin it
runs, first forwards, then downwards and
inwards, and enters the thorax, lying between
the pleura and the internal layer of intercostal
muscles.

Previous to entering the thorax, the in-
ternal mammary artery is crossed anteriorly
by the vena innominata and by the phrenic
nerve : the latter intersects the artery ob-
liquely from above and without, downwards
and inwards. In the thorax, however, the
nerve attains a position much posterior to the
artery.

The mammary artery descends on the back
of the anterior parieties of the chest a little
external to the junction of the costal cartilages
with the sternum, and is covered posteriorly
by the pleura at the line of reflexion of that
membrane to form the side of the anterior
mediastinum. Arrived at the cartilage of
the third rib, the artery in its farther
descent inclines a little outwards, and be-
comes separated from the pleura by the
fibres of the triangularis sterni; the vessel is
now placed between that muscle, which lies
behind it, and the internal layer of intercostal
muscles and the cartilages of the lower true
ribs, which constitute its anterior relations.
Opposite the cartilage of the seventh rib the
mammary artery terminates by dividing into
two branches, an external and an internal.

Branches of the mammary artery. — I.
Mediastinal branches, which are distributed
to the thymus gland (thymic arteries), and
the cellular issue of the anterior mediasti-
num.

2. A descending muscular branch to the
diaphragm ( superior phrenic), also termed, from
its so constantly accompanying the phrenic
nerve, the comes nervi phrenici. This branch
accompanies the nerve in a tortuous manner,
between the pleura and the pericardium, to
reach the upper surface of the diaphragm,
where it anastomoses with the phrenic arte-
ries from the aorta.

3. The anterior intercostal arteries. — These
are distributed to the six upper intercostal
spaces; but their number is greater than that
of the spaces for which they are destined, as
two branches are frequently found between
adjacent ribs, and this arrangement may even
prevail in all of these intercostal spaces.

The anterior intercostal arteries pass out-
wards in the intervals between the two planes
of intercostal?, in which muscles some of their
branches terminate; others are lost in anasto-
mosing with the intercostal arteries from the
aorta, whilst many perforate the muscular
fibres, and, arriving on the external surface
of the thorax, dip into the pectoral muscles

SUBCLAVIAN ARTERIES.

anJ the mammary gland. In both these latter
situations the arteries in question communi-
cate freely with the external thoracic branches
of the axillary, thus forming an important
connection between the circulation of the in-
terior and that of the exterior of the thorax.

The terminal branches of the internal mam-
mary artery are two in number, viz. internal
terminal branch (Ramus abdominalis) and an
external (Arteria musculo-phrenica, Haller).

4. The internal, or the abdominal branch,
is the smaller of the two, yet in direction it
represents the parent trunk. Having communi-
cated with the artery of the opposite side be-
hind the xiphoid cartilage, it escapes from the
thorax through a small triangular interval
between the fibres of the diaphragm, and
then immediately enters the sheath of the
rectus abdominis, descending between the
muscle and the posterior lamina of the sheath.
Having arrived opposite the umbilicus, it be-
comes distinctly continuous with ascending
branches of the internal epigastric artery ; it
likewise furnishes many branches to the sub-
stance of the rectus muscle, and others which,
piercing the sheath, are widely distributed to
the broad muscles of the abdomen.

5. The external terminating branch (or the
arteria musculo-phrenica), is larger than the
internal, from which it separates nearly at
right angles, passing almost transversely out-
wards in a curved course along the superior
line of attachment of the diaphragm to the
false ribs. In this course the artery gives off,
a. numerous phrenic branches of large size,
which enters the diaphragm all along its cos-
tal attachment ; and b. anterior intercostal
branches, which supply the lower intercostal
spaces in precisely the same manner as those
from the mammary trunk supply the upper,
and which have been already described.

Varieties. — The mammary artery presents
but few varieties either of origin or position ;
in 290 out of 297 examinations, this artery
occupied its normal position. In one in-
stance it arose beneath, in six instances ex-
ternal to the scalenus muscle, and in one only
of the six was it derived from the axillary
artery (Quain).

Much more rarely still does the mammary
artery deviate in the opposite direction, i.e.
inwards ; it has, however, been seen to spring
from the arch of the aorta, and also from the
arteria innominata. Occasionally too it arises
in common with the thyroid axis.

Two veins (one on either side of it) accom-
pany each internal mammary artery ; they are
formed by branches corresponding to those
given off' by the artery, with the exception
(according to Cruveilhier) of the vein accom-
panying the arteria comes nervi phrenici,
which on both sides terminates separately.
On the right side the mammary veins open into
the commencement of the vena cava; on the
left side, they are connected with the corre-
sponding vena innominata. “ The mammary
arteries are remarkable for the number of
their inosculations, and for the distant parts
of the arterial system which they serve to

823

connect : they anastomose with each other,
and their inosculations with the thoracic aorta
encircle the thorax. On the parieties of this
cavity their branches connect the axillary
and subclavian arteries ; on the diaphragm
they form a link in the chain of inosculations
between the subclavian artery and abdominal
aorta ; and in the parieties of the abdomen
they form an anastomosis most remarkable for
the distance between those vessels which it
serves to connect, namely, the arteries of the
superior and inferior extremities.”*

III. Thyroid axis. — This artery springs
from the anterior aspect of the subclavian
trunk, close to the inner edge of the scalenus
anticus muscle, and consequently from the
very last portion of the artery in its first
stage.

The thyroid axis forms a trunk only a few
lines in length, which projects forwards and a
little upwards ; the phrenic nerve is applied
against the outer surface of this artery, and
still retains the same relation to it, even where
the artery arises more externally than usual,
as if in such cases the nerve were drawn
outwards by the artery. This arrangement
was observed where the thyroid axis arose
from the third stage of the subclavian. The
thyroid axis usually terminates in three
branches : —

1. Inferior thyroid artery. — From the thy-
roid axis, this branch passes a little upwards,
and then turns inwards and backwards, de-
scribing a curve, of which the concavity looks
forwards and downwards, corresponding to
the carotid sheath. The artery next descends,
but soon afterwards inclines upwards and in-
wards until it reaches the thyroid body, thus
forming a second curve the reverse of the
former one, for the concavity of this second
curve looks upwards and backwards, and is
crossed anteriorly by the recurrent nerve.

The antenor relations of this artery are the
following ; —

It is crossed in its first curve, opposite the
sixth cervical vertebra, by the sympathetic
nerve, which more frequently on the right
than on the left side however, joins the middle
cervical ganglion in this situation. The inter-
nal jugular vein, vagus nerve, and carotid
artery, contained in their common sheath, are
the next parts which cross the artery ; and
lastly, the recurrent nerve, sub-hyoid muscles,
and thyroid gland, lie in front of it.

The recurrent nerve lies in front of the
second curve of the artery.

The inferior thyroid artery is posteriorly
in relation with the vertebral artery, the longus
colli muscle, and the vertebral column ; and,
on the left side, with the oesophagus and tho-
racic duct.

The thoracic duct very frequently passes
up behind the inferior thyroid artery to the
level of the sixth cervical vertebra, where,
bending downwards and forwards, it arches
over that vessel and descends in front of it,
to terminate in the subclavian vein.

* Harrison’s Surgical Anatomy of the Arteries.
4th Edition, p. 141. Dublin.

3 g 4

821 SUBCLAVIAN ARTERIES.

Branches of the inferior thyroid artery. —

a. Arteria cervica/is ascendens. — This branch
(arising from the upper convexity of the thy-
roid, where that vessel changes its direction to
pass downwards and inwards beneath the
carotid sheath) passes upwards on the super-
ficial surface of the scalenus anticus, parallel
and internal to the phrenic nerve. The cer-
vicalis ascendens (frequently as large as the
thyroid itself) furnishes numerous muscular
branches to the levator anguli scapulte, longus
colli, rectus capitis anticus major, and to the
scaleni muscles, some of which anastomose
with branches of the occipital artery ; it like-
wise gives off spinal branches, which enter the
spinal canal along the cervical nerves, and
are distributed to the cord, anastomosing both
within and without the canal of the vertebra
with the vertebral artery.

By some anatomists the cervicalis ascen-
dens is regarded as a branch of the thyroid
axis, from which it not unfrequently arises ;
in some rare instances it has originated di-
rectly from the subclavian artery. Sometimes
it is of very large size, and takes the place of
the occipital artery or of the cervicalis pro-
funda.

b. The inferior thyroid artery furnishes se-
veral descending branches, which from their
destination may be termed (Esophageal, tra-
cheal, and bronchial.

c. Terminal or thyroid branches. — The
inferior thyroid artery becomes extremely
tortuous as it approaches the thyroid gland ;
at last it divides into two or three large
branches, which enter the gland by its deep
surface, and which, in the substance and around
the margin of the gland, communicate freely
with the corresponding artery from the oppo-
site side, and with the superior thyroids of
the external carotid.

The reader is now referred to the article
Scapulae Region, in which the remaining
branches of the thyroid axis, viz. the supra-
scapular and transverse cervical arteries, have
already been followed to their ultimate distri-
bution ; it will be only necessary in this place
to describe the cervical portions of these two
collateral branches.

2. Suprascapular artery ( Arteria transver-
sals humeri). — This artery is at first directed
downwards, but having reached the shelter of
the clavicle, it passes nearly horizontally out-
wards to the superior costa of the scapula. It
crosses over the phrenic nerve, the scalenus
anticus muscle, and the subclavian vein ; it
then runs outwards in contact with the vein,
and bound to it by cellular tissue ; it next
passes across the subclavian artery and bra-
chial plexus of nerves, and finally arrives atthe
supra-spinal fossa, which it enters by passing
over the superior ligament of the scapula.

The supra-scapular artery has, anterior to it,
the sterno-mastoid muscle, the clavicle, and the
omo-hyoid and trapezius muscles. It accu-
rately corresponds to the base of the supra-
clavicular space.

3. Arteria Transversalis Colli. — This artery
is larger than the preceding ; from its origin

it passes transversely outwards over the sca-
lenus anticus muscle and the phrenic nerve ;
at the outer edge of this muscle, it inclines
backwards and runs through the midst of the
branches of the brachial plexus. The artery
at this stage crosses the summit of the omo-
clavicular triangle, above the level of the
subclavian artery. In the space between the
sterno-mastoid and the trapezius, the trans-
verse cervical artery gives off a large branch,
the cervicalis superficialis , which is destined
for superficial structures, integuments, pla-
tysma, glands, and superficial layer of mus-
cles.

The cervicalis superficialis ascends in the
posterior superior triangle of the neck, through
a chain of conglobate glands, and through the
meshes of the cervical plexus of nerves, anas-
tomosing with branches of the occipital and
vertebral arteries, and passing finally under
cover of the trapezius, to which it distributes
numerous twigs, as also to the levator anguli
scapulae and splenius.

After this the continued trunk of the trans-
verse cervical artery is usually called jiosterior
scapular artery, which has elsewhere been
described.

The posterior scapular, and the cervicalis
superficialis arteries, very frequently arise se-
parately, instead of springing by a common
trunk from the thyroid axis; in such cases the
posterior scapular is usually given oft’ by the
subclavian artery external to the scaleni.

IV. Arteria Cervicalis profunda.) These ar-

V. Superior Intercostal Artery. J teries (as
has been already mentioned) generally arise
by a short trunk common to both, from the
subclavian in its second stage. An analogy
may thus be observed between this trunk and
the aortic intercostal arteries; for, like them,
it divides into an anterior or intercostal branch
(the superior intercostal artery), and a poste-
rior or muscular branch (the cervicalis pro-
funda). The cervicalis profunda passes from
its origin backwards and upwards, between
the transverse process of the last cervical ver-
tebra and the first rib. When a supernumerary
cervical rib exists, the artery then passes be-
tween this latter and the first dorsal rib. It
thus gains the posterior aspect of the neck,
and ascends between the spinous and trans-
verse processes of thevertebrae, separated from
the laminae by the deep layer of muscles, and
covered by the great complexus muscle.

In this course the cervicalis profunda anas-
tomoses with the large muscular branches
which descend from the occipital and verte-
bral arteries.

The deep cervical artery sometimes passes
backwards at a higher or lower level than that
above specified ; these deviations must be rare,
since none of them existed in 40 subjects ex-
amined specially with reference to this subject
by Cruveilhier. In the extensive tables col-
lected by Professor Quain, and which have
already been frequently alluded to in this ar-
ticle, seventeen instances are given where
this artery passed between the first and second
rib ; in a very few examples, it escaped from

SUBCLAVIAN ARTERIES. 825

the thorax through the second intercostal
space, and in some other equally rare cases,
it has been seen to penetrate between the
sixth and seventh cervical transverse pro-
cesses.

The superior intercostal artery passes
downwards in a tortuous manner into the
thorax, and gives off branches which run out-
wards and supply the two or three upper
intercostal spaces ; the artery of the right,
usually passes to one intercostal space lower
than that of the left side. The branch to the
first intercostal space is in general the small-
est.

The trunk of the superior intercostal artery,
as it descends, has the following relations: — in
front, it is covered by the pleura and lung;
internal to it are placed the first dorsal gan-
glion of the sympathetic nerve, and the longus
colli muscle ; whilst posteriorly, i t corresponds
to the first dorsal spinal nerve (in its ascent
to join the last cervical), and to the neck of
the first rib.

In addition to the branches furnished to the
intercostal spaces, and which are two or three
in number, the superior intercostal gives off
several small branches which enter the spinal
canal through its lateral foramina, and also a
branch which passes downwards and esta-
blishes a communication with the first aortic
intercostal artery.

It has been already stated that the superior
intercostal and the deep cervical arteries most
frequently arise by a common trunk ; when
they arise separately, the left superior inter-
costal artery is generally derived from the
first stage of the corresponding subclavian
artery.

Operative proceedings. — It is not intended
in this place to enter into all the details con-
nected with the surgical relations of the sub-
clavian artery, since in the article which treats
of the surgical anatomy of the neck will be
found clearly described the modes of pro-
cedure to be adopted by the surgeon in the
operations for the ligature of this artery in
different parts of its course ; the following
few observations, which may be regarded as
supplemental to those just alluded to, naturally
follow the description which has been given
of the subclavian artery in the preceding
pages.

First stage. — When the relations of the
subclavian artery on the right side, internal to
the scaleni muscles, are carefully reviewed, the
inner half of this stage of the vessel will
appear to be the most eligible for the applica-
tion of the ligature, and the object of the
operator should be to secure the artery on
the cardiac side of its vertebral branch, as in
that situation the pleura is comparatively
little exposed to injury ; the jugular vein
should lie to the outside, and the vagus nerve
to the inside of the ligature, and any undue
disturbance of these parts, especially of the
latter, ought to be most sedulously avoided.

The artery was tied, for the first time in
this situation, by Mr. Colies, in the year 1813.
In that instance, as in every subsequent one

where the operation has been repeated, the
result has proved unfavourable ; nevertheless,
success has been so nearly attained in some of
these cases, that few wall be found to agree
with Blandin in pronouncing this operation
“ tout a fait irrationnelle ; ” nor are we to view
with favour the alternative first suggested by
Mr. Shaw, and lately revived and recom-
mended to the profession in some recent
works on surgery, viz., to remove the arm at
the shoulder-joint, and to make pressure on
the aneurismal tumour.

In the majority of the cases in which
hitherto the subclavian artery has been tied
internal to the scaleni, the cause of death was
referable to secondary haemorrhage ; the un-
avoidable proximity of the ligature on the one
hand to the heart, on the other to the aneur-
ismal sac, and the small extent of this part of
the subclavian artery to which a ligature can
be applied, without interfering with the colla-
teral branches, are probably the chief circum-
stances -which determine this fatal accident.
If, in the desire to avoid the vertebral, thyroid,
and mammary branches, the ligature be ap-
plied too close to the mouth of the carotid
artery, the current of blood through the latter
vessel will then, with almost positive certainty,
disturb those sanative processes at the seat of
ligature, on which the ultimate success of the
operation depends ; and hence, doubtless, has
originated the proposal to secure at the
same time both branches of the innominata.
The incisions necessary to expose the one,
would amply suffice for the ligature of the
other ; the circulation through the head and
upper extremity might afterwards be carried
on without material injury, and the formation
of a coagulum, more lengthy than that afforded
by the operations hitherto performed, might
lead to a favourable result. This suggestion
is due to Dr. Hayden, and is mentioned in his
account of the case in which he tied this
artery in its first stage, so far back as the year
1835.

The following brief particulars of a case
which lately came under the writer’s notice,
may be adduced as furnishing an additional ar-
gument in favour of this proposal. A woman,
about 25 years of age, became the subject of
an aneurism, situated at the root of the neck,
which W'as regarded as originating from the
arteria innominata. The subclavian and
carotid arteries were tied at one and the same
time, on the principle of Brasdor: — “ On the
fourteenth day after the operation, the liga-
ture came away from the subclavian artery
without any haemorrhage, and every thing pro-
mised a favourable result, especially as the
pulsation in the tumour had quite disappeared.
On the sixteenth day, the patient, a woman of
violent temper, had a quarrel with the nurse,
when she jumped out of bed, seized a pillow
and some books, and threw them at her:
while making this exertion, haemorrhage set in
from the carotid.” A renewal of the hae-
morrhage proved fatal. On examination it
appeared that “ perfect union had taken place
where the ligature had been applied to the sub-

SUBCLAVIAN ARTERIES.

826

clavian artery , but a small opening was found
in the carotid from which the haemorrhage
had proceeded.”

In this instance theinnominata was healthy ;
but, a little to the left of the origin of that
vessel, the aneurismal tumour, which was of
a pyriform shape, sprung from the arch of the
aorta, and thence passed upwards into the
neck, in front of, and overlapping the arteria
innominata. It is an extremely interesting
circumstance connected with this case, “ that
the tumour was filled with a firm coagulum.”

This is the only instance, as far as the writer
knows, in which a ligature placed, on the sub-
clavian artery, in its first stage , became detached
without the supervention of secondary hcemor-
rhage. In none of the cases where this artery
alone was secured did this circumstance occur,
much less in any of these instances did “ per-
fect union,” the result of adhesive inflamma-
tion, follow the application of the ligature. *

Until very recently it was thought that the
ligature of the subclavian artery internal to
the scaleni was feasible on the right side only,
and this opinion of British surgeons originated
perhaps in Mr. Colles’ statement, that “ this
operation, difficult on the right, must be
deemed impracticable on the left subclavian
artery.” Dr. Rodgers, of New York, has,
however, lately succeeded in securing the left
subclavian artery in its first stage. The result
of this case does not verify the opinion of
Velpeau, that “ the operation would be much
less dangerous on the left side than on the
right,” as the patient died of secondary hae-
morrhage on the fifteenth day.

British anatomists will be little disposed to
agree with Velpeau in such a prediction, and
still less will they concur with him in thinking
that it would be easier to tie the left sub-
clavian artery than the right; on the contrary,
the great depth of the left subclavian trunk
from the surface, the short distance to which
it rises out of the thorax, and the close con-
nection of the veins and nerves with its anterior
surface, must entitle this operation to the
distinction of being one of the most difficult,
whilst the peculiar and unseen risk of wound-
ing the thoracic duct must ever render it one
of the most dangerous, in surgery.

Second stage. — The subclavian artery has
been tied between the scaleni muscles in a
few instances. This operation was first per-
formed by Dupuytren, in 1819, in a case of
traumatic axillary aneurism ; the result was
successful ; yet there is nothing in this opera-
tion to recommend it, provided there be the
option of tying the artery in the supra-clavi-
cular space. Dupuytren did not (as some
have supposed) intend it to supersede the
latter operation ; he advised it in those cases
only, where the depth of the vessel in its

* The full details of this interesting case, which
occurred in the practice of Dr. Hobart, of Cork, will
be found in the forthcoming edition of “ Flood’s Sur-
gical Anatomy of the Arteries,” edited by Dr. Power,
one of the lecturers at the Richmond Hospital
School, to whom the writer is indebted for the facts
already quoted.

third stage is unusually great, in consequence
of some peculiarity of development, or the
unnatural elevation of the clavicle produced
by an aneurismal tumour.

The anatomical objections to this innovation,
which is sanctioned by the authority of Dupuy-
tren, are the following, and they are suffi-
ciently important to justify the conclusion
that, where a choice exists, the third stage of
the artery should always be selected for the
application of a ligature.

1st That in order to expose the subclavian
artery in its second stage, the division of two
muscles is required, viz., the clavicular portion
of the sterno-mastoid,and the scalenus anticus.

2d. That considerable risk of injuring the
phrenic nerve is incurred.

.3d. That the ligature must be in close
proximity to the branches usually furnished
by the subclavian artery between the scaleni,
viz., the cervicalis profunda, and superior
intercostal; and,

4th. That from its close connection with
the artery, the cone of the pleura is en-
dangered.

These theoretical objections to the ligature
of the subclavian between the scaleni, are
not the less deserving of notice because they
were originally passed over in silence, and
they go far to disprove the “ innocuitc” of the
operation, an advantage which has been
claimed for it by Dupuytren.*

The objections which have just been enu-
merated, are not however of sufficient weight
to forbid a repetition of the operation in any
case where insuperable difficulties are en-
countered in attempting to tie the artery in
its third stage ; under such circumstances, the
surgeon would evince both skill and dexterity
by dividing, as far as necessary, the scalenus
anticus muscle, and thus accomplishing the
object of the operation ; and in so doing he
would follow the example of the late Mr.
Liston, who, in a parallel case, thus succeeded
in securing the artery between the scaleni.

Where the outer edge of the muscle alone
is divided, and where .proper caution is used,
the safety of the phrenic nerve is not neces-
sarily compromised ; but without very great
caution in passing the needle, the pleura
will suffer injury, as it is placed in close con-
tact with the back of the artery. It should
also be borne in mind, that the phrenic nerve
has in a few instances been seen to pass down
beneath the clavicle, lying on the outer edge of
the scalenus anticus muscle ; should such an
anomaly occur in a person subjected to Du-
puytren’s operation, the nerve could scarcely
escape from injury. This irregularity in the
cervical stage of the phrenic nerve, has usually
been seen in connection with a variety of
origin of the axis thyroideus, which has been
already adverted to.f

* Vide “ Lemons Oracles,” tom. iv. ; and M. Marx
account of the operation in the “ Repertoire Generate
d’Anatomie,” No. 2.

f It may be presumed that the phrenic nerve was
thus unusually placed in a case which occurred in
the practice of Mr. Bransby Cooper, and which he

SUPRA-RENAL CAPSULES.

827

In its third stage, the subclavian artery has
very frequently been the subject of operation,
and the ligature of the vessel in this situation,
in a large number of the cases recorded, has
been eminently successful. Mr. Ramsden, of
St. Bartholomew’s Hospital, in the year 1809,
was the first who secured the artery in its
third stage, and since then the operation has
been successfully repeated by many surgeons,
in this as well as in other countries.

Although the subclavian artery, above the
clavicle, is covered by no muscular fibres
except those of the platysma, yet it always
lies at a considerable depth, which varies
much in different persons ; the statement of
Dupuytren will generally be found correct,
viz., “ that the third part of the course of the
subclavian artery is placed more superficially
in those who have long, slender necks, with
lean and pendant shoulders, but is, on the
contrary, deeply hidden in persons who have
short, thick necks, and muscular shoulders.”*

It is an unfortunate circumstance that the
disease for which the operation is usually
undertaken, should so constantly be the
cause of great difficulty in its performance,
for an axillary aneurism of any considerable
size cannot fail to elevate the clavicle con-
siderably. This fact is well illustrated in the
embarrassments experienced in a case where
the subclavian artery was tied by the late
Professor Todd, one of the surgeons of the
Richmond Hospital, and which are recorded
in the third volume of the Dublin Hospital
Reports. So great have been the difficulties
experienced in the operation, that on one
occasion Sir A. Cooper was obliged to abandon
the attempt, and on another (already alluded
to) Mr. Liston was compelled to tie the
artery between the scaleni, finding it im-
practicable to expose the vessel in its third
stage.

(B. Geo. M'Do wel.)

SUPRA-RENAL CAPSULES. (Die
Nebenniere, Germ. Capsules suprarenales seu
atrabilarics, Lat. Capsules suprarenales, atra-
bilaires, Fr.) — In the bodies of Vertebrata
we find a series of organs, which possess a
great outward resemblance to the glands, but
distinguish themselves from these by the
constant absence of a duct. To this class
belong the spleen, the thymus, the thyroid,

thus narrates in his published lectures: “Some
years ago I performed this operation (ligature of the
subclavian artery in the supra-clavieular space) on
a clergyman, in the presence of the late Dr. Babing-
ton and Mr. Travers ; no difficulty whatever oc-
curred, but immediately after its completion the
patient was seized with a constant hacking cough,
as if resulting from convulsive motion of the
diaphragm. This scarcely ceased night or day until
the sixth day after the operation, when he died.
No post-mortem examination was permitted; but
there can he no doubt, in my mind, that the phrenic
nerve had been injured, although it could not
possibly have been included in the ligature.” — Vide
Med. Gazette. Lond. Vol. xlii. p. 94. July, 1848.

* Lei^ons Orales, tom. iv. p. 528.

and the supra-renal capsules. On account
of their great richness in blood-vessels, these
organs have been named “ blood-glands,” or
“glands of blood-vessels,” or “vascular gang-
lia.” At present we are tolerably acquainted
with the range of their distribution, and the
differences of their form in the animal king-
dom ; we have, also, some knowledge of their
minute structure ; but, on the other hand,
their physiological import remains just as ob-
scure to the inquirers of the present century
as it was to the physicians of ages long gone

by-

The supra-renal capsules, glandules supra-
renales sen renes succenturiati, seu capisulce
atrabilarics, form, in the higher Vertebrata, a
double organ, which is constantly placed in
the neighbourhood of the kidneys; and from
this situation they have received their name.
So, also, in the lower Vertebrata they of-en
occupy the same situation ; but, not unffe-
quently, they are broken up into a number of
small glandular bodies. In the Invertebrata
they are altogether absent.

We shall successively consider, 1. The
larger series constituted by the differences of
form of supra-renal capsules in the animal
kingdom. 2. Their structure. 3. Their de-
velopment. 4. Their physiological relations.

I. As already mentioned, supra-renal cap-
sules occur only in the Vertebrata. But we
cannot attribute them to all of these without
exception. In the lowest Amphibia and Fishes,
these organs have not yet been indubitably
recognised. Among the Mammalia, the supra-
renal capsules exhibit everywhere essentially
the same structure, in spite of many differ-
ences of form, size, and situation.

In Man they possess a half-moon shaped,
or triangular and flattened form, with an an-
tero-posterior slightly arched surface, and a
sharp convex margin. At their bases they
are deeply excavated, so that by this part
they rest on the upper end of the kidney like
a cap. The anterior part of the basis of the
supra-renal capsule extends for a considerable
distance further forwards on the kidney than
the hinder part. The w hole organ is included
in a covering which consists of closely woven
areolar tissue ; and inferiorly, it is attached
by a looser areolar tissue to the kidney. At
the base of the organ is also found a well-
marked fissure, from out of which passes the
supra-renal vein, according to Krause’s state-
ment.* The anterior and posterior surfaces
of the supra-renal capsules exhibit an irregu-
larly wrinkled appearance, caused by the nu-
merous furrows of the areolar tissue. The
size of the supra-renal capsules amounts in
the adult to 1 — If) inches (German) in height,
and somewhat less in breadth. The greatest
antero-posterior thickness occurs in its lowest
part, and amounts from 21 — 4 lines. In their
middle the supra-renal capsules are consider-
ably thinner, amounting only to l-§ — 2-1 lines.
Their absolute weight is estimated by Meckel

* Vide Krause’s Handbuch der Anatomie. 2.
Anflage, Hannover, 1841. Band 1. S. 668,

828

SUPRA-RENAL CAPSULES.

to be one drachm : according to Krause * it
is from 80 — 120 grains; according to Huschkef
from 80 — 180 grains. The anatomist last
named found that its specific weight in the
newly-born infant was P0333; but Krause
•states the supra-rcnal capsules of the adult
to be of the somewhat lower specific gravity of
1-0103.

The two supra-renal capsules of the same
individual are generally of different size.
Usually the right is of somewhat lesser height,
but greater breadth, than the left, which
has the contrary diameter the larger.

The so-called accessory supra-renal capsules
are often found in man. They are small
round corpuscles, which, in various numbers,
are attached loosely to the inner border of
the supra-renal gland, or are sometimes im-
bedded in an excavation on its surface.

The supra-renal capsules of the Mammalia
essentially correspond with this description.}
They are always situated on the upper part
of the kidneys ; sometimes towards the inner
part, sometimes on the upper part of their
border, as in man. Sometimes they are not
so closely attached to the urinary organs as
in man, but are somewhat more removed
from them. Thus, for instance, are arranged
the supra-renal capsules of the Elephant and
Seal. But, in opposition to this constancy
of situation of these organs, we find very
considerable differences in respect of their
size and form.

The supra-renal capsules of Monkeys closely
approach the shape seen in the human sub-
ject ; but, not unfrequently, their size seems
somewhat more considerable. Among the
Carnivora they are, in the Dog, of an elongated
cylindrical form, sometimes thicker at the
margin than in the middle, and of a dense
solid texture. So also in the Cat, in
whom they are roundish, and somewhat flat-
tened. Amongst Insectivora they have in the
Mole ( Ta/pa curopcea') the form of a three-
sided pyramid. In the Seal they appear very
small, and Cuvier found that their size was, to
that of the kidneys, as 1 — 150. In this latter
animal the whole surface of the supra-renal
capsules is divided into a multitude of lobules,
or acini. Amongst all the Mammalia, these
blood-glands are largest in the Rodcntia, their
ratio to the kidneys being as 1 to 4 and 5 :
this is the case, to wit, in Coslogenys Paca,
and in the Guinea-pig ( Cavia cobaia). They
are roundish, and somewhat flattened, in the
Rabbit and the Dipus. The supra-renal cap-
sules of the Mouse, the Rat, and the Myoxus
Glis, have a shorter form ; while, on the other
hand, in Hystrix they become more cylindrical.

* Loc. cit.

-j- Huschke, Lehre von der Eingeweiden und Sin-
ncsorganen des mensclilichen Korpers. Leipzig;,
1844, S. 357. 1 fa

J Concerning the differences of form of the supra-
renal capsules may be consulted the well-known
text-books on comparative anatomy of Cuvier and
Meckel ; and, especially, Nagel in Muller’s Arcliiv
for 1836, S. 365., and JEcker, Die feinere Bau der
Nebennieren, Braunschweig, 1846.

Amongst the Racl/ydermala they have, in the
Elephant, the form of an elongated cone, and
their base is divided into two lobes, and turned
backwards. In the Pig, their form is about
midway between the cylindrical and the pris-
matic. Besides this, the supra-renal capsules
of this animal possess a considerable size. In
the Horse they are flattened and triangular,
approaching the human form. Among the
Ruminanlia they are, in the Rein-deer, of an
oval form, which approximates to the sphe-
rical. They are elongated in the Sheep. In
the Ox, their shape in some degree resembles
that of the kidney. Here they are almost
crescentic, not unlike a horse-shoe, and their
upper extremity is three-sided. Finally, the
supra-renal capsules of Cetaceans are, like
those of the Seal, exceedingly small, and
broken up into a number of small lobes.

We find a similar correspondence in the
class of Birds. Their supra-renal capsules
are generally small in proportion to the size
of the body ; sometimes spherical, sometimes
oval ; and, in general, divided into lobules.
They lie at the inner extremity of the anterior
part of the kidney, often close to the inferior
vena cava ; and they are covered by the tes-
ticles, or ovaries.

In the Rcptilia these organs are much less
known, since only isolated (and not unfre-
quently contradictory) observations have been
made respecting them. Hitherto they have
not been found among the Derotremate, Pe-
rennibranchiate, and Ctecilian orders of this
class.

The supra-renal capsules of the Saurians
have been very eagerly examined, and most
exactly in the genus Laceria. In these ani-
mals Nagel found them along the upper ex-
tremity of the vas deferens, in the form of two
long, small, lobulated bodies. Nagel’s obser-
vations have been recently confirmed, and
added to, by Ecker. The supra-renal cap-
sules, possessing the form stated by Nagel,
have a length of ]i lines, with a breadth of
lL They lie closely on the vena rcnalis re-
vehens, or on the vena cava ascendens, which
is constituted by the two efferent renal veins.
Since the right supra-renal capsule is usually
of somewhat larger size, it is wont to lie on
the vena cava itself ; while the left organ is
placed upon the vena renalis revehens. In
the male lizard the supra-renal capsules are
placed between the vein and the vas deferens ;
in the female they are situated between that
vessel and the ovary. Numerous blood-ves-
sels convey the blood from it into the corre-
sponding veins. The blind worm ( Anguis
fragi/is) also possesses long, small, supra-renal
capsules ; and so, probably, do the Crocodilus
Lucius and Ameiva teguixin. Nevertheless,
both the latter animals are at present insuffi-
ciently examined.

The supra-renal capsules of the Ophidia ex-
hibit a similar condition, the more exact
knowledge of which we especially owe to
Retzius. They form two long and small
bodies, and in the Python binistatus they at-
tain a length of 8 lines. The supra-renal

SUPRA-IIENAL CAPSULES.

829

capsules of serpents are likewise distinctly
tabulated, and very vascular. In other re-
spects, too, the arrangement of the vascular
system exhibits much that is interesting ; but
to this we shall hereafter return. They
always lie closely on the venae renales abdu-
centes ; and, according to the course taken
by the vessels just named, they are sometimes
nearer, sometimes farther from, the testicles
and ovary.

Batrachia. Formerly many zootomists
regarded as supra-renal capsules those pecu-
liar yellow finger-shaped masses of fat, which,
in these animals, lie superficially to the kid-
neys, and possess a connection with the sexual
organs, in the periodical increase of which
they take a share. Only recently have the
true supra-renal capsules been recognised ;
and to these the fatty bodies just mentioned
have not the remotest resemblance. To
Rathke* * * §, Retziusf, Gruby J, and others, we
owe the discovery and description of these
organs ; the signification of which receives
an additional and complete confirmation from
minute anatomy, as will be hereafter shown.
Here the supra-renal capsules no longer form
an organ anatomically defined, but are imme-
diately deposited on the abdominal surface of
the substance of the kidneys.

Among the tailless Batrachia, they appear
in this situation as a golden-yellow streak,
which does not extend the whole length of
the kidney, but ceases at a distance of one
line from its upper, and of two lines from its
lower, end. These supra-renal organs also
allow a lobular composition to be very dis-
tinctly discerned ; and they do not extend
along the kidney in a straight line, but usually
digress into the arched form. They surround
the trunks of the efferent renal veins at their
exit from the substance of the kidney ; so
that they seem to be, as it were, perforated
by this vessel. By a more careful investiga-
tion one may satisfy one’s self that the glands
are really imbedded in the coats of these
vessels. In the tailed Batrachia, on the
other hand, we no longer find the supra-renal
capsules in the shape of this connected streak,
but broken up on all sides into from twenty
to thirty separate and irregular lobules. These
are seated, partly in the substance of the
kidney at its inner border, partly between
the kidney and the inferior cava ; while they
are also partly deposited on the coats of the
latter vessel, and the gland-lobules have the
same relation to the efferent renal veins as in
the tailless Batrachians.

Finally, amongst all the orders of Reptilia,
the supra-renal capsules are least recognised
in the Chelonia. The statements formerly
made by Bojanus §, that the supra-renal cap-

* Beitrage zur Geschichte der Tliierwelt, Dritto
Abtheilung, Halle, 1825, S. 34.

+ Vide the treatise of Nagel.

t Annales des Sciences Naturelles. Zoologie,
Seconde Serie, tom. xvii. p. 209.

§ Anatome Testudinis, Wilmc, 1819 — 21. Folio
cum tab.

stiles were two long bodies, situated at the
inner margin of the kidneys, and a similar
statement of Nagel *, have been lately cor-
rected by Eeker.j- According to the last in-
quirer, the supra-renal capsules of the Tes-
tudo graica altogether correspond, both as
regards form and situation, with the similar
organs of the Frog ; since they lie on the
abdominal surface of the kidney, imbedded in
its mass, and extend almost the whole length
of this organ.

In Fishes the supra-renal capsules again
appear ; but, as regards their situation, form,
and number, they are much more diverse than
in the other Vertebrata. The supra-renal
organs of the cartilaginous fishes were dis-
covered, a long time ago, by Retzius. j For
a knowledge of them in the osseous fishes, we
are especially indebted to Stannius and Ecker.

In the osseous fishes they appear as small,
whitish corpuscles, of the size of from a pin's
head to a pea. Their form is, in general,
roundish or oval ; their surface is sometimes
smooth, sometimes rugged, and broken up
into lobules, as is the case in the Pike. Ac-
cording to the observations of Stannius, they
have not unfrequently a kidney-shaped form
in the Haddock ; and, according to Ecker,
they are sometimes triangular in the Salmon.

The number and situation of the supra-
renal capsules varies greatly in this group of
fishes. The presence of two supra-renal
capsules ought to be regarded as the rule.
They usually lie symmetrically in both halves
of the body, as in the higher animals ; they
may also occur a-symmetrically, or only in one
half of the body, as in the genus Pleuro-
nectes ; or they may be behind each other, as
in the genus Scomber.

But frequently, the supra-renal capsules are
present in great number ; in which case their
position becomes altogether irregular. Thus
one meets with three, four, six, or even more
supra-renal organs ; and Ecker has observed
as many as six in the Salmon. In the Pike, in
which only two to three supra-renal capsules
are present in the adult animal, the inquirer
just mentioned found that, in a young animal
of one foot in length, the whole kidney w as
beset with a great number of very small supra-
renal organs. I have myself remarked the
same condition, and occurring exactly in the
manner described, in two Pikes of the same
size : but, on the other hand, in another in-
stance it was absent.

As to the situation of the supra-renal
organs in the bony fishes, this also is subject
to very great differences. Sometimes these
glands lie more on the abdominal, sometimes
on the spinal, surface of the kidneys. The
former seems more frequently to happen ; and
in this case they generally project at the
hinder end of the kidnejq from the anterior
margin of the haemal canal of the inferior

* Loc. cit.

f Loc. cit.

j Observationes in Anatomiam Chondroptery-
gyiorum. Lund. 1819, 4to.

830

SUPRA-RENAL CAPSULES.

vertebral arch : this occurs in the genera
Cyprinus, Tinea, Pleuronectes, Anarrhichas,
Scomber. Or they occupy more the middle
of the kidney, as in the Salmo Salar. On the
other hand, they are found on its abdominal
surface in the Eel and Pike. They lie in this
situation very anteriorly, occupying, in the
Eel, the place where the two crura of the
renal mass unite. In the Pike they are yet
more advanced forwards, so that they come
to lie in the middle point of the length of the
body.

Amongst the cartilaginous fishes, the supra-
renal capsules seem in the Squalidm to be
only present as a single mass. This, in the
shape of a small ochre-yellow stripe, oc-
cupies the dorsal surface of the kidnejs.
But in the Rays the supra-renal organs form
a curved cylinder, which is constricted at two
points, and iies on the ureters ; at least
Retzius formerly stated this to be its condi-
tion. Stannius sometimes found in this genus
a similar elongated body behind the kidneys :
or, in other instances, four or five small glan-
dular corpuscles were present in its place.
And the latter observer found that the supra-
renal glands of the Sturgeon* consisted of
similar corpuscles in much larger number.

The supra-renal capsules of the cartila-
ginous fishes have a yellow colour, and are
also plainly lobulated.

As has been previously remarked, in the
least developed fishes the supra-renal cap-
sules have not been discovered, at least not
with any certainty, so that their existence
must remain a matter of doubt. In the
Myxinnid fishes, J. M filler -f- found behind the
gills, and on each side of the cardia, a clus-
tered gland which was devoid of an excretory
duct. He interprets it as a supra-renal organ ;
and regards as analogous to it the white
specks with which the trunks of the posterior
veins of the body are beset in the Ammo-
cmtes.J But the minute structure of the
glands in question in the Myxinoid fishes,
which is also described by Miiller, seems ra-
ther to contradict the explanation attempted.
And Ecker discovered a gland in the Petro-
myzon between the aorta and the great vein
of the body, and partly lying in the coat of
the latter: but this also had not the struc-
ture of a supra-renal capsule.

II. We next proceed to the minute struc-
ture of the supra-renal capsules, concerning
which Ecker has given a very good and fun-
damental description, so that we shall here in
great degree follow him. In Man and all
the Mammalia, they exhibit two kinds of sub-
stance, which have been designated by the
names of cortical and medullary substance.
The first is clearer than the latter, being in
Man of a yellowish-brown colour ; while the

* Stannius, Lehrbuch del- Yergleichender Ana-
tomie der Wirbelthiere, Berlin, 1846, S. 118.

t Vergleichende Anatomie der Myxinoiden.
Schluss. In der Abhandlungen der Academie der
Wissenschaften zu Berlin, 1843, S. 118.

J Kathke, Beitrage zur Geschichte der Thienvclt,
4te Abtheilung, S. 99.

medullary substance possesses a reddish-
brown hue. In many instances, the two
kinds of substance are little distinguishable
by the naked eye, so that the supra-renal
capsules exhibit only a simple mass, such as
Cuvier has described that of the Elephant to
be. Besides this, the amount of the two
layers varies very considerably. The cortical
substance is of some solidity; while, on the
contrary, the medullary matter is very delicate
and flaky. This great delicacy, together with
its considerable richness in blood-vessels,
makes it very probable, that the medullary
substance of the supra-renal capsules is de-
composed very quickly after death. And this
gives rise to the formation of a cavity, con-
taining a brownish-red fluid, which is not un-
frequently found in the interior of the human
supra renal capsules. Formerly this cavity
was regarded as normal and occurring during
life. The name “ capsulae atrabilariae ” is
connected with this notion, since these cavi-
ties were described as real by the older ana-
tomists. And although decomposition is
regarded as the chief agent in the formation
of these cavities, yet pathological conditions
seem to be by no means without their influence
towards them. Thus Rayer tells us the de-
velopment of cavities may occur in conse-
quence of rupture of the venous coats, and
the effusion of blood in the medullary sub-
stance.* Nagel also remarks concerning it,
that the supra-renal vein alone, which courses
in the centre of the organ, may be instru-
mental to the production of such a cavity,
albeit a small one ; so that by injections
through this vein the whole medullary mass
may frequently be torn up, and converted into
a cavity. The covering of the supra-renal
capsules consists of areolar tissue. At many
points of this covering little processes of are-
olar tissue pass directly into the interior of the
medullary substance, and thus separate it into
portions or lobes of different form and size.
These masses of areolar tissue are finally lost
in fine bundles, which separate the elementary
parts of the gland from each other. We shall
return to this again.

The further composition of the organ which
we are now contemplating is better seen in
Man than in any others of the Mammalia.

Fig. 542.

(After Fetter.')

a, Nucleus of the contents of the supra-renal cap-
sule from an adult man ; b, Nucleus enwrapped in
a fine granular mass ; c, Cell ; d, Nuclear-vesicle
of an embryo ; e, two gland-vesicles with their
contents from an adult..

* Gazette Medicale, 1838, p. 57.

SUPRA-RENAL CAPSULES. 831

In man the cortical substance appears to
be composed of an innumerable quantity of
completely shut glandular vesicles, which are
united into a mass by the ensheathing coats
previously mentioned. At the first glance
one might easily imagine that they were not
gland-vesicles, but tubes which, lying close to
each other, take a radiating course from the
centre towards the periphery. It is only at
either margin of the cortical substance that
the individual small roundish vesicles can be
verified. By more careful examination, we
can assure ourselves (as was first stated by
Ecker) that this tubular appearance is only
apparent, and that it is caused by the glan-
dular vesicles being arranged in rows, so as to
cover each other like the tiles of a roof. In
this manner the vesicles of a row, especially
when they are filled with dark contents, appear
like a tube, with a blind termination at each
extremity. The observation just mentioned
can be best made if the preparation be treated
with a dilute solution of an alkali. It will be
thus seen that these vesicles of the supra-
renal capsules are surrounded by and con-
structed of a fine, structureless, transparent
membrane, to the thickness of which we are
unable to assign any measurement, and which,
even by the use of the highest magnifying
powers of the microscope, appears as only a
simple line. This structureless membrane,
which modern observers have shown to be
a constituent of all glands with the single
exception of the liver, we shall indicate by
the name of the “ membrana propria.” It is
especially distinguished by the fact, that it is
not attacked by the dilute alkalies, as caustic
potash, and ammonia, but preserves exactly
its original appearance ; while the contents of
the gland are in general completely dissolved
by these agents. The use of these applica-
tions cannot be too much recommended in
examining the glands, as for instance those of
the stomach, intestine, &c. — a fact which has
been taught me by repeated experiments.
The gland-vesicles of the human supra-renal
capsules exhibit considerable differences of
size; besides which, their form is wont to
vary in some degree. The smaller vesicles
are roundish, and have a diameter of 8 to
12-1000ths of a line; the larger of these,
which seem elongated, have a length of 18 to
25-1000ths of a line, with a breadth of 10 to
15-1000ths. The smallest of these vesicles
occur in the greatest numbers at the limits of
the medullary substance ; while, on the con-
trary, the larger and more elongated vesicles
generally occupy its middle. The glandular
contents, which are surrounded by the vesicles,
appear, by a low magnifying power, as a dense
pap-like mass, which seems to be white by
reflected, and dark by transmitted light, and
consist of granules. Nevertheless on the
application of a powerful lens four consti-
tuents may be distinguished ; namely, — ( 1 )
very fine molecules, (2) fatty granules, (3)
nuclei, and finally, (4) cells in different stages
of their development.

(1) The fine elementary granules constitute

by far the great mass of the contents. They
are dissolved by alkalies, but alcohol and
ether do not effect their solution, and they are
little dissolved by acetic acid ; so that they
would thus seem to consist of an albuminous
substance, or of a so-called protein-com-
pound. They are immeasurably minute,
and in this respect resemble the pulverulent
molecules which cause the white colour of
the chyle.* Their quantity in the gland-
vesicles is so large that they render viscous
their fluid contents. It is only on the appli-
cation of water, that they aggregate them-
selves into masses or flocculi : previously to
this they pervade the viscid fluid with the
greatest uniformity. We will select for them
the name of pulverulent molecules.

2. The fatty granules are usually met with
in considerable quantity, and sometimes they
are very numerous. As may readily be ima-
gined, they are of very different diameters, and
range gradually from the smallest granules,
through larger ones, to small drops of fat.
The yellow colour of the cortical substance is
due to this constituent.

3. The nuclear structures appear umted
into a granular mass. They have an average
size of 3 to 4-1000ths of a line, a form which
is usually roundish and less frequently oval,
and they belong to the variety of the so-called
“ granular ” nuclei ; i. e. to those which are
formed of a granular mass, and are not vesi-
cular. The substance of these nuclei is in-
soluble in dilute acids, but is completely dis-
solved by the application of potash. Ecker
has made the interesting observation, that in
the embryo the granular nuclei are no longer
to be met with, but that their nuclei are ra-
ther vesicles ; that is, that they possess a wall,
which encloses a more or less fluid mass, in
which are contained one or two small punc-
tiform nucleoli. The same condition also
obtains in the nuclei of other embryonal
tissues.

4. Part of these nuclei are experiencing a
transition to cell development, so as to form
a constituent of perfect cells. The metamor-
phosis to the cell-form begins by a part of
the finely granular mass arranging itself
around a nucleus. Little clusters are thus
formed, each of which contains a nucleus.
The outer surface of such a mass then
becomes hardened, so that the most super-
ficial molecules form a wall or shell, the
cell-membrane; thus the cluster becomes
a cell. So that from the fine pulverulent
molecules proceed both the cell and the
cell-membrane. In conformity with this state-
ment, a microscopic examination of the ex-
pressed contents of the gland-vesicles reveals
nuclei, surrounded by irregular flocculi of fine
granular substance (6, fig. 542.), and other
nuclei, around which this latter substance has
formed itself into a well-defined, round, or
oval mass of 6 to 9-1000ths of a line in dia-
meter (c,fig. 542.). Finally, other masses

* Compare with this the experiments of II. Mul-
ler, in Henle und Pfeuffer’s Zeitschrift fur ratio-
nelle Medizin, 1845, iii. S. 299.

832

SUPRA- RENAL CAPSULES.

may be seen, on which an enclosing mem-
brane plainly exists.

The cell development just described holds
good of the supra-renal capsules of all Ver-
tebrata. It is thus of very wide distribution.
These cells are designated by the name of
globules of circumposition ( umhullungslcugeln ).
The so-called granule-cells, or inflammatory
globules, belong to the same class ; as also do
the globules of fission which originate from
the breaking up of the yolk. And I have also
observed that the polyhedral pigment cells of
the choroid coat of the eye are formed in the
same way. Finally (and of immediate interest
in this place), L have found that the cells
of many other glands are similarly formed ;
namely, the cells of the tubular gastric
glands, the glands of Lieberkuhn and of the
large intestine, the glands of Brunner, and
probably also those which occur in the uri-
nary tubules of the kidney. It may also be
conjectured that the cells of other glands will
be found to originate in the same way.

By a gradual enlargement these cells of the
cortical substance are metamorphosed into
gland-vesicles (c, flg. 512.); so that while in
the large gland-vesicles cells and nuclei occur
in numbers, the smaller ones contain only a
solitary nucleus. These smallest gland-vesiclcs
are no way distinguishable from the larger cells;
they also are cells, and the glandular con-
tents are exactly those of the cell, and the
membrana propria is identical with the cell
membrane. The contrast between these
vesicles and cells — a contrast upon which
Ecker has laid particular stress — is of little
importance. According to this observer, the
membrana propria of the vesicle is unchanged
by solution of potash, while, on the contrary,
the membrane of the cell is dissolved by
it. But by a repetition of the experiment
one may be assured that it is only a dilute
solution which leaves the membrana propria
unaffected, and that by a more concentrated
solution it is dissolved just as much as the
cell-membrane. The difference is thus only
quantitative, and is in exact conformity with
the gradually increasing hardness of the mem-
brane.

When fine sections of the medullary sub-
stance of the human supra-renal capsule are
examined with the aid of the microscope, it
is seen to be considerably clearer and more
transparent than the cortical substance ; a
circumstance which essentially depends on
the fact, that the fatty granules occur more
sparingly in the former than in the latter. In
Man, and in most of the other Mammalia, it
is rendered very distinguishable from the cor-
tical substance by the absence of the gland-
vesicles. It is found to consist of a basis of
fibrous tissue, which is formed by processes
that come off from the sheath of the cortical
substance, and in which numerous blood-ves-
sels and nerves take their course. In the
mass of areolar tissue the pulverulent mole-
cules above described are also met with ; and
besides these, nuclei and cells in different
stages of development.

Where accessary supra-renal capsules oc-
cur, they contain, according to Ecker, the
same vesicles ; of which the larger occupy the
outside, and the smaller the inside. But the
two kinds of substance are not present ; the
whole tissue answers to the cortical substance
of the real supra-renal capsules, and it has a
sometimes clearer, sometimes darker, yellowish
appearance.

The structure just described obtains with
little modification in all the Mammalia. It
is true that, at present, only the Carnivora,
Ruminantia, Solipeda,and Pachydermata, have
been examined. Nevertheless, according to
these observations, it is tolerably allowable
to generalise concerning all the orders of
Mammalia.

In the Ox, the brown cortical substance is
divided by strong bundles of areolar tissue
into lobules. The gland-vesicles exhibit no-
thing extraordinary, but, amongst the different
constituents of their contents, the fatty gra-
nules are much more sparingly present than
in man. Gerlach* found the glandular vesicles
very distinct in the Sheep. The structure of
the supra-renal capsules of the Goat and Pig
is identical with that seen in the Ox.

In the Horse, the gland-vesicles of the
cortical substance altogether correspond with
those of the human subject. Here also the
smaller and more spherical lie on the ex-
terior, while the larger and more oval occupy
the interior, and offer the tubular disposition
already referred to. But their membrana
propria is more delicate than in man. In the
young Horse the fatty contents of the gland-
vesicles are in very small quantity; while, on
the other hand, in older animals, it predo-
minates so considerably that it quite conceals
all the other contents, and renders their exa-
mination very difficult.

But the medullary substance in the Horse
offers a remarkable distinction from that of
the other Mammalia : namely, that it, as well
as the cortical substance, contains gland-
vesicles. These have a variable shape and size;
and are round, oval, elongated, or sometimes
curved in the shape of a bow. The contents
are the same as usual, only it is much poorer
in fat than the cortical substance ; and, on
this account, appears much clearer.

The supra-renal capsules of the Rodentia
and Carnivora possess the greatest quantity
of fat, and are therefore the most difficult of
examination.

Notwithstanding this, the white cortical
substance of the Rabbit exhibits the usual ar-
rangement : and, besides this, the medullary
mass not unfrequently presents small circum-
scribed collections of fat.

Among the beasts of prey, the Dog and Cat
have been examined, and in these the nuclei
of the contents are with difficulty discover-
able, owing to the innumerable quantity of
the fatty molecules. The nuclei are here also
granular in the older, vesicular in the younger

* Ilandbuch der Gewebelehre des Menschlichen
Korpers, Mainz, 1849, 2tn Liefcrung.

SUPRA-RENAL CAPSULES.

833

animals. A portion of fat not unfrequently
surrounds the cells of the glandular contents ;
and in this manner large dark globuies ori-
ginate, which completely obscure the enclosed
cell. These may especially be seen in the Cat,
where they take a clustered arrangement and
occupy the limits of the medullary and cor-
tical substance. The medullary substance is
poor in fat. Hitherto the gland-vesicles have
not been made out with certainty in this fatty
cortical substance, but they are very distinct
in the Hedgehog.

It yet remains to us to consider the dispo-
sition of the blood-vessels, lymphatics, and
nerves in the supra-renal capsules of the
Mammalia. For this purpose we shall select
those of Man.

Vessels. — In the human subject, each
supra-renal capsule is supplied with arterial
blood by three trunks : — by an arteria supra-
renalis superior, which is usually present, and
comes off as a branch of the phrenica inferior;
an arteria supra-renalis media, which is usu-
ally double on each side, and arises from the
aorta ; and finally, an arteria supra-renalis in-
ferior, which is a branch of the renal artery.
The further arrangement of the vascular sys-
tem has been especially examined by J. Mid-
ler*, anil Nagel f, whose results have been
recently confirmed by Ecker.jl

The numerous small arterial trunks having
arrived at the outer surface of the supra-renal
capsules, take a different distribution. One
part of them immediately pierce the sheath of
the organ, and enter its substance; while an-
other portion of them courses for a consider-
able distance on the outer surface before be-
coming lost in the interior.

In the interior of the organ itself these
small arterial trunks still take a different
course. One of these sets of vessels can
only be followed for a very short extent
in the cortical substance. After a course of
scarcely half a line in length, they break up
into a capillary network, with long meshes,
which encircle the gland vesicles of the cor-
tical substance. The other arterial trunks,
without giving off any branches, plunge at
right angles through the cortical mass into
the medullary substance. Here they break
up into twigs which, by devious paths, return
again into the cortical mass, to end also in a
network of capillary vessels. Thus the cor-
tical substance possesses a closer capillary
network than the medullary mass, a fact which
is in conformity with the predominant glan-
dular activity of the former stratum. Nagel,
in his Essay, has illustrated this distribution
of the arterial vessels by beautiful drawings.

The veins begin at the common margin of
the cortex and medulla. They alone con-
stitute almost all the vessels of the latter por-
tion, since the smallest branches gradually
unite to form larger ones, and these finally
join to form the vena supra-renalis , which

* I-Iildebrandt’s Anatomie, herausgegeben von E.
H. Weber, 4ter Theil, S. 356.

Loc. cit.

Loc. cit.

VOL. IV.

occupies the middle of the supra-renal cap-
sule; and, as was stated above, is proportion-
ally very large. “ Were we able,” says Nagel,
“ to exhibit this venous texture isolated from
the cellular tissue which receives it, the indi-
vidual smaller veins opening into the venous
trunk on all sides, and at very acute angles,
would render it most suitably comparable to a
poplar tree.”

Usually there is a single vena supra-renalis
for each supra-renal capsule. The right supra-
renal vein passes immediately from the gland
into the vena cava ascendens ; but the left
one forms a longer trunk, which opens into
the renal vein. But these statements of
Nagel are contradicted by others; for instance,
by Krause, according to whom two or three
veins generally leave each supra-renal capsule.

As far as observations have hitherto gone,
this disposition of the vascular system appears
to be tolerably constant for all the Mam-
malia.

The lymphatics of the supra-renal capsules
are not yet sufficiently known. According to
Arnold, there are superficial and deep ones.
In animals slain during the digestive act,
Ecker could only find the superficial lym-
phatics, so that Arnold’s statements would
seem to be doubtful. The absorbent trunks
of the supra-renal capsules unite with those
of the kidneys and the internal sexual organs,
and they open into the thoracic duct.

The uncommonly rich supply of nerves
possessed by the supra-renal capsules consti-
tutes a very striking phenomenon, and one
which finds no parallel in any cognate organs.
In Man, these nerves arise from the caeliac
and renal plexuses in the form of numerous
and proportionally large trunks. It is chiefly
through Ecker that we have become ac-
quainted with the further course of the nerves
in the interior of the organ. Larger and
smaller branches of nerves perforate the cor-
tical substance, usually contained in the bun-
dles of its areolar tissue, or accompanying its
arterial vessels, but giving off' no primitive
fibres. Only in the medullary substance do
the trunks of nerves break up into bundles of
fibres. The neighbouring bundles often ex-
change their nerve-fibres with each other, so
that, in this way, they form a dense micro-
scopic nervous tissue. It would seem that,
in the human subject, no ganglion corpuscles
are present in this sympathetic nerve tissue ;
but, in the Horse, in whom the supra-renal
corpuscles are yet richer in nerves than they
are in man, some ganglion corpuscles may be
seen on the nervous trunks of the tissue.
But one must be especially careful against
confounding gland-cells of the organ with
these ganglion corpuscles, which they super-
ficially resemble. This rich supply of nerves
seems only to pertain to the supra-renal cap-
sules of the Mammalia; in all the other Ver-
tebrata, whose supra-renal capsules, as will be
forthwith stated, are very similarly constituted,
it is completely wanting. On this account, it
becomes exceedingly difficult to state what

3 11

SUPRA-RENAL CAPSULES.

834

object is fulfilled by this united condition of
the nerve fibres.

In Birds, the structure of these vascular
glands is even more uniform than in the pre-
ceding classes. No separation into cortical
and medullary substance appears to occur in
any bird. A single observation of Meckel’s
states that in the Cassowary the two kinds of
substance are to be distinguished ; but this
statement is contradicted by the numerous
negative observations of Cuvier, Ecker, Bar-
deleben, and Nagel, on all the animals of this
class which they have examined, and hence
it requires a confirmation. The supra-renal
capsules of birds appear of a darkish or clearer
yellow colour, which, by the varying amount
of blood they contain, tends more or less
towards red. They are also enclosed in a
sheath of areolar tissue, and exhibit a basis
which consists of fibrous tissue and blood-
vessels. In this matrix the gland-vesicles
lie imbedded throughout the whole thickness
of the organ, and they are devoid of any
regular arrangement. They are of roundish,
oval, pear-shaped, or irregular form. Their
size varies from 44 to 56-t000ths of a line,
and in the Falco tinnunculus some of them
even attain the size of 22-100ths of a line.
Their membrana propria is very delicate. The
structure here specified may be best wit-
nessed in the supra-renal capsules of large
birds ; nevertheless, with some care, we may
succeed in recognising the gland-vesicles in
the smaller members of the class, as, for
instance, in the Pigeon.

The contents of their gland-vesicles closely
resemble those of the Mammalia. There are
the same fine pulverulent molecules of a pro-
tein compound ; and fatty granules, which are
usually in very large quantity, have a yel-
lowish colour, and give rise to the tint pos-
sessed by the whole organ. Not unfrequently
larger yellow drops of fat are visible. Besides
these, we come upon the granular nuclei pre-
viously mentioned, possessing a size of 22 to
31-10, OOOths of a line. Some of these nuclei
are also enveloped in a fine granular mass,
and exhibit a transition to cells in the mode
which we witnessed in the Mammalia. Not
unfrequently the nuclei are completely buried
in fatty granules, through which they are only
visible as clear spots. In the golden Eagle
Ecker remarked complete cells filled with
fatty granules ; these were probably caused
by the usually finely granular cells becoming
gradually filled with fat. In many of the
gland-vesicles, on the contrary, the fat is re-
markably diminished in its proportion to the
finely granular substance ; and it has been
conjectured by Ecker, and with great pro-
bability, that this difference in the amount of
fat depends upon the different stages of deve-
lopment of the gland- vesicles. Tn a very
young Pigeon I have found scarcely any fat
molecules, a fact which has some connection
with this statement.

The minute anatomy of the supra-renal
capsules of the Tfeptilia is as yet insuffi-
ciently known.

In the supra-renal capsules of Lacerta agilis,
Ecker was with some difficulty able to re-
cognise the same condition as that seen in
the higher Vertebrata; but the presence of a
membrana propria around the gland-vesicles
was especially indistinct. lie only remarked
masses of a darkish substance. These masses
consisted of fatty granules of the nuclei al-
ready described, and of granulated globules,
which contained a nucleus, and possesseil a
size of 31 to 44-10, OOOths of a line.

In the Adder, the obscurity of the contents
uncommonly aggravates the difficulty of ex-
amining their lobulated supra-renal capsules ;
but in the foetal Adder of three inches length,
Ecker was able to verify the separate gland-
vesicles in the usual manner. Here also
nuclei were seen ; and, besides these, large
pale gland-cells, which could not long resist
the action of water. Other cells were com-
pletely buried in fatty masses, just as they
were seen to be in the carnivorous Mammalia.

The arrangement of the vessels of the
supra-renal capsules is peculiar in the Snakes,
inasmuch as the greater part of the blood is
not brought to the organ by means of ar-
teries, but by veins. In consequence of this,
the supra-renal capsules have a kind of portal
venous system, such as is possessed by the
kidneys of Reptilia and the liver of Verte-
brata. The afferent supra-renal veins arise
by two branches from the wall of the body,
and from the plexus venosus of the vertebral
canal ; and after a tolerably long and isolated
course they reach the supra-renal capsules.
On an average, the right supra-renal capsule
receives two or three branches ; but the left,
which is wont to be smaller, only one or two.
The arterial blood is brought to the supra-
renal capsule by one or two vessels which
are branches from the aorta.

Both kinds of vessels ramify in the sub-
stance of these organs, so as to form a fine
capillary network. The efferent supra-renal
veins arise from this network in the form of
numerous small trunks. They pass from the
right supra-renal capsule immediately into the
vena cava posterior; but from that of the left
side into the inferior cava, and also into the
efferent renal vein.

In his examinations of the Testudo grteca,
Ecker found certain bodies, which he regards
as the supra-renal capsules of the Chclonian
reptiles. By microscopic examination, they
appear as yellow granules which are grouped
together in heaps. Each of these is en-
closed in a membrana propria, and thus con-
stitutes a gland-vesicle. Their contents are
altogether identical with those of the Batra-
chia, to which we shall next apply ourselves.

In the tailless Batrachia, the yellow lobules
already described consist of groups of vesicles.
Their form varies ; sometimes it is round,
sometimes oval, sometimes elongated or irre-
gular. The vesicles are always closed, and it
is only when they are grouped together that
they appear at first sight like blind sacs.
Fatty granules constitute the greater part of
their contents ; but besides these, the fine

SUPRA-RENAL CAPSULES.

835

granular substance is also present. Clear spots
may also be seen glimmering from amidst
the contents of the gland, and isolation shows
these to be cells of 5 to 9-1000ths of a line
in diameter, with finely granular contents and
a nucleus. The application of water renders
this more visible. Part of these cells are de-
void of the cell membrane, but others of
them exhibit it very distinctly. Besides these,
free nuclei are found ; these are sometimes
vesicular and contain a nucleolus, sometimes
they appear to be granulated. The nuclei
which are included in cells are always of the
latter kind.

From these microscopic characters of their
contents exactly corresponding with those of
the higher Vertebrata, the import of these
organs as supra-renal capsules is placed be-
yond all doubt.

The same structure obtains in the tailed
Batrachians, only the nuclei and cells are
larger, while a part of the latter are com-
pletely enclosed in fat. Numerous branches
of the afferent renal veins break up anew in
the supra-renal capsules, in order to provide
it with venous blood, a condition which re-
minds us of that seen in the Snakes.

The minute anatomy of the supra-renal cap-
sules of Fishes is very similar. In the Salmon
Ecker found them consisting of separate lo-
bules, which are deposited in a loose areolar
tissue perforated by vessels, and which, in ad-
dition, receive a special covering of this areo-
lar tissue. Each lobule is composed of a
number of large gland-vesicles, from 5 to 11-
lOOths of a line in size, which are surrounded
by blood-vessels. Their membrana propria
is completely structureless. In their contents
we again recognise the pulverulent molecules,
separate fatty granules, and vesicular and gra-
nular nuclei of 2-1000ths of a line in size.
The granular substance is rolled around these
nuclei in the manner before described ; so that
part of them come to notice as spheres with-
out walls, while part are real cells, surrounded
by a membrane, and of 7 to 9-100ths of a line
in measurement. It is not unfrequent to find
two or three nuclei, instead of one, in their
interior. We have remarked an exactly si-
milar condition in the supra-renal capsules of
the young Pike ; there is the same fibrous
coat, giving off processes which pass into the
interior, and thus isolate the gland-vesicles,
but the supra-renal organs are less divided
into lobules than in the fish previously con-
templated. The contents of the gland-vesicles
vary according to their size.

In the supra-renal capsules which are
smallest of all, and measure under 9-100ths
of a line, there are no gland-vesicles to be
seen, but only nuclei : to these we shall im-
mediately return. But in supra-renal cap-
sules which are somewhat larger, the nuclei
are partly included in cells.

By a yet further enlargement of these or-
gans, the gland-vesicles also appear : they
contain fine molecules, fatty granules, and
nuclei. These are vesicular, flat, of circular
or irregular form, and vary in size from 22 to

30-10,000ths of a line. Each of these nuclei
contains a single or double nucleolus. Not
unfrequently forms appear which may be con-
nected with a division of the nucleus, where
it appears cut through the middle, or even
incompletely broken up into three parts.

Finally, the gland-vesicles also contain
cells. By enlarging, these cells experience a
gradual transition into new gland- vesicles,
which are contained within the larger ones ;
so that we may distinguish them into mother-
vesicles and endogenous daughter-vesicles,
just as often happens in other cells, to wit,
those of cartilage. The endogenous vesicles
occur in the older ones in variable numbers.
The smaller gland-cells contain only a single
nucleus; others possess two or three of them,
which sometimes lie closely packed on each
other. Finally, in other cells, three, four, five,
and more nuclei occur; and in this manner,
by an increase in the number of the enclosed
nuclei, and at the same time a continual fur-
ther extension of the cell membrane, the cells
experience a transition into glandular ve-
sicles.

These conditions, which wrere first observed
by Ecker, and which I can completely con-
firm from an examination of the same animal,
will quite permit us to conclude as follow's
regarding the development of the glandular
vesicles. In the smallest gland-vesicles a
multiplication of nuclei takes place, most pro-
bably from those already present, by the me-
thod of fission. This multiplication extends
itself to free nuclei, as well as to those which
are included in cells. In the latter case, the
cell-membrane must be more and more ex-
tended by the formation of the nuclei; and in
this manner the cells of a gland-vesicle them-
selves are changed into new endogenous ve-
sicles. By this process, the mother vesicle
itself is considerably extended ; so that, finally,
its membrane comes into contact with the
sheath of the supra-renal capsule. Finally,
after the membrane of the mother vesicle
is destroyed new areolar tissue seems to be
developed between the secondary vesicles. In
this way the small supra-renal capsules of the
Pike experience their growth.

In large old Pikes, the process of multipli-
cation and growth seems no longer to occur.
In their supra-renal capsules, the fibrous
foundation is more considerable in quantity,
so that by its means the gland-vesicles are
more separated from each other."

So also in the genus Cyprinus, where a pre-
cisely similar structure of the supra-renal cap-
sules may be observed, one lights upon con-
ditions of nuclei in the gland-vesicles which
suffice to prove the transition of gland-cells
into gland-vesicles. As to the problematical
organs of the Myxine and Petromyzon, the
glands which Muller discovered in the Myxi-
noid fishes consist of tufts of small elongated
lobules, which are clothed with a kind of cylin-
drical epithelium.* Concerning the glands in

* See the drawing of this glandular structure in
J. Muller’s Essay.

3 u 2

836

SUPRA-RENAL CAPSULES.

the Petromyzon, Ecker only remarks, that the
microscopic constituents do not afford any
foundation for the view that they are supra-
renal capsules.

III. Development. — The supra-renal cap-
sules begin at a very early date of fatal life.
In the human subject they appear simul-
taneously with the kidneys in the seventh
week. The mode of their commencement is
not yet understood with certainty. Never-
theless there is scarcely any doubt that the
statement of Arnold, according to which the
supra-renal capsules are formed by a projec-
tion of the Wolffian bodies, is erroneous.
Most embryologists, as Valentin*, Bischofff,
and others, find that another method of begin-
ning obtains, namely, that these organs are
developed from an independent blastema,
which certainly lies very close to the Wolffian
bodies, but has nothing at all to do with them.
According to Meckel’s observations, both
supra-renal capsules constitute at first only a
single mass ; and Valentin’s researches on
the embryo of the Dog and Sheep harmonise
with this statement. But, nevertheless, this
opinion may be founded on an error. Mliller
found that the supra-renal capsules of a large
human fetus at the eighth week were plainly
double, only they lay very closely together at
their inferior part. Bischoff’s extensive re-
searches on the embryo of Man and other
Mammalia, confirm this statement of Muller,
and explain the error of Valentin and Meckel.
The embryonal form of the supra-renal
capsules in man is distinguished from the
later condition by its being composed of
large lobes ; and thus, to a great extent, it
resembles its permanent condition in some
animals.

It is highly singular that the human supra-
renal capsule in the earlier period of fatal
life, is not only much larger in proportion to
the size of the body than it is at a later
stage, but that it also considerably exceeds the
kidney in size {Jig. 543.). This is shown by

Fig. 543.

From an embryo of 8 lines in length,
a, Supra-renal capsule ; b, Kidney; c. Sexual
gland ; d, Wolffian bodies.

numerous observations of Meckel, Muller, and
others. In a human embryo of the ninth
week, Ecker has recently made the same ob-
servation. In the embryo of the tenth to the
twelfth week, which measures about two
inches in length, the kidneys and supra-renal

* Handbucb der Entwieklungsgescbichte des
Menschen, Berlin, 1835.

f Entwicklungsgeschicbte der Saugethiere und
des Menscben, 1842, S. 291.

capsules are for the first time of pretty equal
size. While, on the other hand, in the sixth
month the kidneys are, as was found by Meckel,
already about double the size of the supra-
renal capsules, and their weight is to that of
these latter as five to two. And as this com-
parative diminution of the supra-renal cap-
sules proceeds further, the proportions by
weight are in the mature embryo as three to
one. And even beyond this time, they expe-
rience a continual diminution, so that finally,
in the adult, the supra-renal capsule is only
l-28th the size of the kidney.

Strange to say, this extraordinary size of
these organs during the fatal period, does not
obtain in the other Mammalia. In the earliest
period of their embryonal life, the kidneys
have always been found considerably larger
than the supra-renal capsules. In them both
organs appear to grow in precisely equal pro-
portion to each other, so that their (compa-
rative) weight remains the same in the adult
animal as in the fetus. According to Ecker,
the supra-renal glands of the new-born kitten
are l-56th to l-60th the size of the urinary
glands. So also the other classes of Vertebrata
seem to accord with the Mammalia in this re-
spect. At least Ecker observed, in the em-
bryo and adult animal of the Coluber natrix,
the same relative proportion of size between
the kidney and supra-renal capsule.

If we regard the situation of the supra-renal
capsules in the animal kingdom, we shall find
a different condition in the different classes.

It is well known that the Wolffian bodies
begin in the embryo at a very early period,
and that these, from their structure and func-
tion, must be regarded as the kidneys of the
embryo ; so that the name of “ primordial or
original kidneys,” may be applied to them with
all accuracy. Now these primordial kidneys
have a very different duration in the different
classes of Vertebrata. In Fishes they remain
as the urinary glands during the whole of life ;
since in them, as Baer and Rathke found, an
organ similar to the kidneys of the higher
Vertebrata is never developed.

The kidneys of Fishes are, therefore, pri-
mordial kidneys.

But in the three higher classes of Vertebrata
the fact is found to be otherwise. Here the
primordial kidneys pertain to only a part of the
fatal life, and then make way for the true
kidneys, which are situated beneath the supra-
renal capsules.

Therefore, the supra-renal capsules of fishes
are placed on the Wolffian bodies, while in
the other Vertebrata they are in connection
with the kidneys.

In Man, in whom the supra-renal capsules
are at first uncommonly large, the primordial
kidneys disappear remarkably early, so that in
the second month they have vanished even to
the smallest relics.

The development of the tissues of these
organs is as yet most incompletely known ; at
present we have only a single statement of
Eeker’s respecting it. In a human embryo of
twelve weeks; this anatomist found a very

SUPRA-RENAL CAPSULES. 837

distinct cortical and medullary substance.
Rut only part of the morphological consti-
tuents were present ; viz., the elementary
granules, fat, and nuclear structures. Cells,
with or without a membrane, were only
sparingly found ; and gland-vesicles were
altogether absent. The embryos ot other
Mammalia exhibited the same results. In the
foetus of an ox of 1| feet in length, the vesicles
were for the first time detected ; and in this
instance, as in those of the mature animals
previously described, the gland-vesicles were,
according to Ecker’s opinion, developed from
enlarged cells.

In any case it is exceedingly interesting to
observe, that in spite of the very early found-
ation of the supra-renal capsule, this organ
seems to rest for a considerable time ; since,
before their gland-vesicles are developed, we
cannot ascribe any activity to the supra-renal
capsules. But in man, these vesicles are
only developed when the period at which the
supra-renal capsules attain their greatest bulk
is long passed.

IV. Physiology. — Finally we apply our-
selves to the functional relations of the supra-
renal capsules. Unfortunately, as regards
the activity of the glands of blood-vessels,
they all veil themselves in an impenetrable ob-
scurity. The recent vast strides of Physiology
have passed over them without leaving any
traces ; the last ten years having only brought
some new hypotheses concerning the function
of these organs, and very doubtfully enriched
the already great number of older conjectures.

It is not the aim of this essay either to
answer or to enumerate all that physicians of
earlier and later times have imagined as the
possible function of the supra-renal capsules.
These conjectures, for the most part ephemeral,
may be properly left to the history of ana-
tomico-physiological science ; and since we
willingly disclaim the intention to come for-
ward with a new hypothesis, we will only
call attention to some points of this mass of
matter.

Now that the minute structure of the supra-
renal capsules is known, it becomes even more
important to dissent from the opinion of
Cuvier. He attributed to the supra-renal
capsules pretty much the same function as the
kidneys/* because these two organs have much
similarity with each other, both in their form,
and in the tissues of which they are com-
posed.” At present we know how great is
the diversity between the tissues of the two
organs. Besides, the want of an excretory
duct is another fact completely passed over
by Cuvier. The opinion of Meckel, that the
supra-renal capsules stand in dependance with
the sexual functions, rests on just as little
foundation, and has been already confuted at
length by Nagel in his work. So also the
conjecture of Bergmann* and others — accord-
ing to which the supra-renal capsules stand
in a very close relation to the nervous system

* Bergmann, Dissertatio cle glandulis supra-
renalibus, Gotting®, 1839.

of the foetus — is equally erroneous. We will
willingly admit the correctness of the observ-
ation, that in brainless monsters the supra-
renal capsules are generally deficient ; but we
are forced to add, that we cannot annex any
distinct notions to this close relation to the
nervous system. Besides, this would suppose
that the function of the supra-renal capsule
differed in the foetus and in the adult animal ;
since certainly no one would seriously defend
such a relation of their function in the latter
case. And the support which this view seems
to receive from the structure of the supra-renal
capsules, is likewise only a fallacious one. At
one time, attention was drawn to the great
richness of the supra-renal capsules in nerves,
without reflecting that this is the case in only
one out of the four classes of vertebrate ani-
mals : and in the same way, the superficial like-
ness possessed by the gland-cells and ganglion
corpuscles was adduced in order to make out
the supra-renal capsule as a kind of ganglion.
This hypothesis was put aside by the dis-
covery of the gland-vesicles. And especially we
would briefly remark, that all those theories
which ascribe to the supra-renal capsules a
special import during embryonal life, have ori-
ginated from contemplating them in the human
foetus, in whom they are exceedingly large. Had
the supra-renal capsules of other animals been
kept in view, those opinions could scarcely
have been taken up ; and the special size of
these organs in the human embryo would have
been recognised for that which it really is,
an anomalous, isolated condition, which pos-
sibly stands in a causal relation with the swift
disappearance of the Wolffian bodies. And,
as we have already remarked, even apart
from this, the absence of the gland-vesicles
from the supra-renal capsules of the small
embryo is a fact which must not pass un-
noticed.

We will, therefore, only attempt to answer
such physiological questions concerning the
supra-renal capsules which are possibly sus-
ceptible of solution, and defer their full under-
standing to the future.

We will see whether the supra-renal cap-
sules in general can be called glands, and how
far they correspond with the other glands of
blood-vessels, with the thyroid, thymus, and
spleen. And then we may answer the ques-
tion, “ whether the supra-renal capsules ge-
nerally eliminate a glandular secretion, and
whether this secretion is to be regarded as
similar or diverse in the whole of the vascular
glands ?”

Microscopic anatomy has taught us to re-
cognise three kinds of form under which
glands are developed in the higher animals.
The first is a fine tube or canal of different
length ; the second is a small globular or
elongated sac, which is open at one end ; and
the third form is that of a globular and com-
pletely closed vesicle. A very delicate struc-
tureless membrane, the membrana propria,
forms the frame-work of all these glands ; and
it is distinguished by its insolubility in dilute
alkalies. On its exterior, it is surrounded by
3 n 3

839

SUPRA-RENAL CAPSULES.

a network of capillaries, while it includes
within its interior, glandular contents in very
diverse forms. These contents consist, in
general, of elementary granules, of an albu-
minous material, of fatty granules and small
drops of fat, and of nuclei and cells in the
most variable quantities. Cells, which are
the highest development of glandular contents,
are not always found : more frequently only
nuclei are noticed. It will be recollected that
in speaking of the contents of the supra-renal
capsules, we have stated that the development
of cells occurs by the method of circumposition
of a globular membrane, and the same method
obtains in a number of the glands.

The first two of the three forms of glands
frequently occur isolated, and thus exhibit
microscopic glandules of the greatest sim-
plicity ; as for instance the stomach glands of
Mammalia, the glands of Lieberkuhn, the cu-
taneous glands of the Frog. In other instances,
glandular tubes or sacs are connected to each
other in very variable number, and thus form
the larger glands. In this way the kidneys
and testicles originate from tubes ; while from
sacculi are formed the multitude of clustered
glands, as those of Brunner, the salivary
glands, and the pancreas.

The first two forms of glandular structure
have no further interest as regards our present
object ; but the case is very different with re-
spect to the third or vesicular form.

The gland-vesicles have a very diverse size,
ranging from microscopic dimensions to a
quarter, a half, or even a whole line or more.
Their shape is always spherical, so that their
membrana propria encloses a globular cavity,
which contains, suspended in a fluid, all the
different constituents of gland-contents pre-
viously spoken of. In very numerous experi-
ments I have never found vesicles of this kind
further divided by ensheathing membranes.

Generally the united gland-vesicles are in-
laid in the fibrous tissue of the particular
mucous membrane of the body ; they are
sometimes in greater, sometimes in smaller
quantity, so that great differences, both in-
i',ividual and generic, may be noticed in this
respect. In many places they occur with
greater frequency, so as to constitute the rule,
and have therefore received a special name.
For instance, the glandulae solitariae of the
intestine, and the lenticular glands of the
mucous membrane of the stomach, belong to
this category ; while in other cases more
than one or even many vesicles of this kind
are grouped together to form a glandular body
of some extent. Amongst such aggregations
may here be enumerated the Peyerian vesicles,
which form a single layer of this kind in the
mucous membrane of the intestine. We find
the same grouping in the ovary, where these
vesicles are called “ Graafian,” in honour of
their discoverer. But here they are some-
what more widely separated from each other
by the thickness of a solid fibrous basis, or by
the so-called stroma ; and they enclose, beside
the usual glandular contents, a peculiar body,
the primitive egg or ovum.

The physiological relations of the gland-
vesicles, and especially their duration and
origin, are as yet little known. The facts
may probably be stated as follows. The
gland- vesicles arise from cells which enlarge,
so that the cell-membrane becomes the wall
of the vesicle, and its contents form those
of the vesicle also. At least I have ob-
served exactly this occurrence to take place
in formation of vesicles in a fish of very
lovv development which inhabits our brook
(Ammocoetes branchialis). In this fish a num-
ber of glands of this kind may be found at
the dilated part of the intestinal canal, on both
sides of it near the spiral fold : these remain
tolerably small, although they experience con-
siderable variations of diameter. They are
densely filled with large, pale, smooth nuclei,
of oval or roundish form, the number of which
is greater or smaller according to the size of
the vesicle. Beside these are seen in the tissue
of the wall of the intestine separate cells,
which enclose two nuclei in no way distin-
guishable from those of the gland-vesicles.
From these cells they pass, by all intermediate
gradations, to the large vesicles. If one may
generalise on this observation, it may be stated
therefrom, in accordance with the proposition
mentioned above, that the shut gland-vesicles
proceed from cells. The gland-vesicles in the
mucous membranes of the Mammalia are very
unfavourable objects for examination ; so that,
unfortunately, in spite of many attempts, I
have not been so lucky as to observe their de-
velopment. So also I am unable to state in
what way the multiplication of nuclei takes
place, whether by a fission of the nuclei already
present, or whether new nuclei arise inde-
pendently of the old ones in the fluid of the
gland. But I conjecture that the latter is
the case.

By their further increase of size, the gland-
vesicles come to lie more on the surface of
the substance in which they are imbedded.
But the membrana propria does not possess
an unlimited extensibility, so that a period
arrives when it can no longer withstand the
contents, and is burst by them. This rending
occurs at the place of least resistance, namely,
at the upper and most external part, and en-
gages not only the membrana propria of the
gland-vesicle, but also the thin layer of fibrous
tissue present superficially to this. By the
occurrence of this so-called dehiscence of
the gland-vesicles, its fluid contents become
effused amongst the other constituents. This
process has long been known to occur in the
Graafian follicle of the ovary ; but it may
also be seen with the greatest distinctness in
the vesicles of the mucous membranes, as well
in the separate as in the Peyerian glands.
The burst gland-vesicle is thus brought into
connection with the outer world, and now
resembles a wide-bellied and short-necked
flask : it has thus suddenly become converted
into a small sac, such as we have already
found as a constituent of the glands treated
of as belonging to the second variety.

After their dehiscence, the gland-vesicles

SUPRA-RENAL CAPSULES. 839

appear to behave differently. Part of them
by bursting arrive at the end of their career.
They do not become distended with secretion
a second time, but the gland-vesicles cease to
exist as such in consequence of further meta-
morphosis. The ovary, the vesicles of which
disappear by the formation of a corpus luteum,
affords a proof of the occurrence of this pro-
cess. While, on the contrary, other gland-
vesicles seem to close again, and to become
distended with new secretion, in order to their
going through the process for a second or
perhaps a third time. It is exceedingly diffi-
cult to come at the truth respecting this matter,
but an examination of the Peyerian glands may
afford us some help in the investigation.

Each Peyerian patch consists of but a single
layer of gland-vesicles, which in the adult ap-
pear all to be at pretty much the same stage
of development. No second row of unde-
veloped vesicles is ever found beneath this
layer, such as might be supposed to serve as
a compensation for those which have burst ;
so that a Peyerian patch of glands, after all
the vesicles had burst, would necessarily .dis-
appear, if no closure of the vesicles followed,
unless indeed a power existed to develop a
new group of vesicles at some other point.
Now although the Peyerian glands of Man and
Mammalia certainly show individual varieties
in number and extent, yet the«e appear too
small to prove a destruction of the Peyerian
vesicles after the manner of the Graafian fol-
licles of the ovary. Besides this, I have never
been able to remark the least appearance which
could lead me to imagine a new development
of the glandular patches. Moreover, it is a
well ascertained fact, that in many Mammalia
certain Peyerian gland-patches show a con-
stant position and size at all periods. To this
category belongs a very large Peyerian patch
which exists in the rabbit at the point where
the ileum opens into the large intestine.
Such structures will scarce admit of any other
conclusion than that the gland-vesicles re-
close themselves after their dehiscence.

From these observations, which in part de-
pend on researches not yet published, we
shall be able to come to a decision respecting
the glandular nature of the supra-renal cap-
sules.

In them the same gland-cells appear ; the
same membrana propria, capable of with-
standing alkalies. Exteriorly this issurrounded
by capillaries, and interiorly it contains the
same mass, consisting of molecules of a protein
substance, fatty granules, nuclei, and cells de-
veloped by circumposition of a membrane.
We also find a development of gland-vesicles
from cells identical with that which was met
with in the Ammoccetes. The multiplication of
the nuclei here occurs by the method of fission.
And since, in the supra-renal capsules, these
undeveloped gland-vesicles occur in predomi-
nant quantity, we may, therefore, well imagine
that the old gland-vesicles are destroyed in
these organs, in which they undergo dehis-
cence. But their contents are not extruded
outwardly, as are those of the gland-vesicles

previouslydescribed.but into the fibrous frame-
work of the organ, in which they exist in the
fluid form, and from which they are subse-
quently received into the vascular system
either by immediate or mediate resorption.

We are therefore correct in regarding the
supra-renal capsules as glandular organs, and
their function as secretory ; and any hypo-
thesis which ascribes to them a function other
than secretory, may be safely considered erro-
neous.

If we now address ourselves to a comparison
of the structure of the supra-renal capsules
with that of other vascular glands, we shall see
how great a resemblance obtains.

Unfortunately, we do not possess such ex-
perimental researches regarding all of them
as those which Ecker has published in his
work on the supra-renal capsules. Only the
thymus gland has found an accurate observer
in Simon.* Nevertheless, we already know
thus much, that in two of the three other
vascular glands, viz., in the thymus and thy-
roid glands, a similar structure obtains. Bar-
deleben f was the first to observe what
Ecker J, Gerlach§, Schafther||, and others
confirmed, that in the thyroid gland gland-
vesicles occur grouped in masses, imbedded
in a loose cellular tissue, and surrounded by
blood-vessels. In Man, they are seen with
some difficulty ; but are more easily made
out in most of the Mammalia, anti best in
Birds and Reptilia. These vesicles, which
attain a size varying from G-lOOOdis to
5-100ths of a line, begin as cells which mea-
sure 5 to KMOOOths of a line, and which
are connected with them by all the transi-
tional forms. Suspended in a fluid which
occupies their interior, are varying numbers
of elementary granules of an albuminous
material ; and besides these, fatty granules,
nuclei of 2 to 3000ths of a line, and finally,
cells with one or more nuclei. In the earlier
periods of foetal life the vesicles are not to
be met with ; but their place is entirely oc-
cupied by cells, — a condition exactly similar
to that which was met with in examining the
supra-renal capsules.

So also the gland-vesicles of the thyroid
appear after some time to be destroyed, and
their contents resorbed. This is shown by
the fact, that frequently only younger and
undeveloped forms of these are to be met
with in the adult animal ; while in other in-
stances, the fully developed vesicles occur in
excessive numbers. Some distinction between
the thyroid and supra-renal capsules, although
not an important one, may possibly be de-
duced from the fact, that in most of the Mam-
malia, the nuclei and cells are ranged as an
epithelial stratum on the inner surface of the
vesicles, so that the remainder of their cavity

* A Physiological Essay on the Thymus Gland,
London, 1845.

f Observationes de glandularum ductu excretorio
carentium structura, Berolini, 1841.

I Loc. cit.

§ Loc. cit.

|j Henle und Pfeuffer’s Zeitschrift fur rationelle
Medizin, 1849.

3 i i 4.

810

SUPRA-RENAL CAPSULES.

is filled with a more or less dear fluid. Never-
theless, in Man, the gland-vesicles are generally
completely filled with the morphological con-
stituents of their contents.

As regards the thymus, we have lately had
Simon’s researches extended by Ecker, Ger-
lach, and Schaffner. The gland-vesicles here
likewise enclose similar contents. The quan-
tity of the elementary granules seems to be
very variable, and nuclei form the greater part
of the contents. In general, cells occur but
very sparingly. According to Simon, their
number is increased by involution of the
organ, in which case, also, fat molecules are
wont to appear in place of the elementary
granules. As to the gland-vesicles, they
deviate from those of the vascular glands
hitherto described. In the embryo of the
Adder and of Birds, Ecker saw many completely
shut gland-vesicles, which everywhere passed
into sacculi by pouchings of their membrana
propria. In the human thymus, and that of
Mammalia generally, only a few vesicles of
this kind were found, and the tunics of these
exhibited the same condition. Thus the
thymus gland exhibits a similarity with the
clustered glands ; but is distinguished from
these by the want of an excretory duct. And
these differences of the gland-vesicles, toge-
ther with the great number of the nuclear
structures, somewhat distinguish the thymus
from the supra-renal and thyroid glands.

The structure of the spleen is even more
different, — if it be allowable to decide upon
this organ, which is so uncommonly diffi-
cult of examination, from a few observations
of a somewhat contradictory tendency. It is
only the well-known Malpighian corpuscles
which can be regarded as glandular struc-
tures. In fact, this opinion would seem to
be correct, since Ecker found a delicate mem-
brane enclosing the vesicles. Nevertheless,
lately, an opinion has been put forth on many
sides, and based on continuous research, that
the Malpighian corpuscles are not closed
vesicles, but stand in connection with the
lymphatics, so as to constitute only vesicular
dilatations of these vessels. This view, which
is maintained by Gerlach and Schaffner, is
especially corroborated by the fact, that the
contents of the splenic vesicles differ from
those of the other vascular glands, and closely
approximate to those of the lymphatic ves-
sels. Thus we remark in their contents, cell
nuclei in very predominant quantity, the dia-
meter of which amounts to 2-1000ths of a
line. These nuclei appear sometimes smooth,
sometimes granular ; they often exhibit one
or two nucleoli, while in other instances they
have none. Roundish cells of 4 to 5-1000ths
of a line, and closely surrounding a nucleus,
may also be remarked in sparing quantities.
The above-mentioned relation of the Malpi-
ghian corpuscles to the lymphatic vessels is
probably supported by another circumstance.
Another cell formation may be found in al-
most every spleen, and certainly in the splenic
vesicles also. They are large, globular cells,
measuring from 5 to 10-1000ths of a line,

and with contents of a very different kind ; so
that from this fact one might conjecture that
they form a number of very different struc-
tures, which, however, are connected with
each other by transitional forms. Thus a
part of these cells contain more or less dark
elementary granules ; another part enclose
larger yellowish, or yellowish brown and
tuberculated corpuscles ; while finally, other
cells contain, with the latter corpuscles, one
or many completely developed blood corpus-
cles. This group of cells is susceptible of a
double interpretation. In the first place,
effused blood corpuscles may be enclosed by
a cell membrane, and may be broken up into
elementary granules in its interior. This
view has been taken by Kolliker*, and is
supported by pathological appearances. But
the process may be exactly the reverse ; the
blood corpuscles may be developed in the
interior of the cells, and then, after the burst-
ing of the cell wall, become free. And should
this latter view, which is especially maintained
by Gerlach f, ultimately turn out to be correct,
then we shall have in the Malpighian vesicles
of the spleen a new development of blood
corpuscles, just such as occurs after another
scheme, in the other district of the lymph
and chyle system. So that the spleen would
be an organ especially serving for the develop-
ment of blood corpuscles, and the old ex-
planation set forth by Hewson would be the
correct one. But if the process be that which
Kolliker supposes, the spleen will exercise the
function of destroying the blood corpuscles.
In any case, it is worthy of notice, that no
such cells containing blood corpuscles occur
in the other vascular glands. Gerlach could not
discover them in the thymus gland, and they
would scarcely have escaped Ecker's careful
observations of the supra-renal capsules. So
likewise, in a number of examinations of
supra-renal capsules, it is impossible to find
the least trace of their presence. Therefore
by all this the spleen is greatly distinguished
from the other vascular glands. Such great
differences of structure and contents will not
allow us to attribute a like function and a like
secretion to all these organs. Certainly we
cannot at all state of what kind these differ-
ences of secretion are, since the materials
prepared by these vascular glands are, as far
as regards their composition, completely ne-
glected : but that such differences must
exist, I think microscopic research will quite
warrant us in saying. In this respect the
thyroid gland and supra-renal capsule agree
most nearly together, since in general terms,
there is a great correspondence in their struc-
ture. And, as the spleen is the widest se-
parated from them, so it is not unlikely
that future research may remove it from
amongst the vascular glands.

Since the chemical constitution of the se-
cretion is unknown to us, we are unable to

* Vide Landis’s Dissertation, apparently under
Kolliker’s direction, Beitrage zur Lehre tiber die
Verrichtungen der Milz, Zurich, 1847. See also the
article Spleen.

f Loc. cit.

SWEAT.

84]

state either the object of the vascular glands
in general, or that of the supra-renal capsules
in particular. Pathological study also has,
up to the present time, failed to afford any-
thing which would allow any safe conclu-
sion to be drawn concerning the function of
the supra-renal capsules. By their concealed
situation, they elude the experiments of the
physiologist ; besides this, they are so small,
that their secretion can scarcely have any very
sudden and visible influence on the vegetative
life of the body. So that even by such an
eager operative interference as the extirpation
of this gland, the wished-for result might
scarcely be obtained.

I therefore repeat, that at present we are
completely in the dark as to the function of
the supra-renal capsules ; we know not at all
in what way they operate, and on this account
all references of the supra-renal capsules to
this or that organ — such as have so often
been made — are altogether empty and worth-
less. We may see at a glance that it would
be just as correct to assign a relation of the
supra-renal capsules to the eye or ear, as to
the sexual or urinary organs.

Ecker, who, in opposition to our view, re-
gards the secretion of all the vascular glands
as one and the same, keeps its contents of fat
and protein compound especially in view, and
conjectures that all the vascular glands are
adapted to the formation from the blood of a
secretion which is rich in protein and fat, and
which being subsequently retaken into the
current of the blood, in this manner benefits
nutrition. But apart from the fact, that one
cannot see why such a fluid should take this
round-about way through the vascular glands ;
apart from this, the quantity of protein com-
pounds in the secretion of all the vascular
glands of the body, even if we take this at
the highest estimate, is far too small to render
any enrichment of albuminous materials which
the body could obtain in this way other than
a very inconsiderable one. The want of an
excretory duct affords certainly this informa-
tion, that the secretion prepared by the vesicles
of the vascular glands is again received into
the blood ; but even this notion has connected
with it much that is obscure and uncertain.

The difference of thefunction of the vascular
glands is yet further upheld by the circum-
stance that their vital duration and activity is
different. The function of the thymus is the
first to wane ; that of the supra-renal capsules
seems likewise much diminished in more
advanced age ; while, on the contrary, the
activity of the spleen endures for the whole
life. These organs experience an excessive
deposit of fat in their vesicles, and by this
means gradually disappear.

( Heinrich Fret/.') *

SWEAT. — The cutaneous secretion is
formed by the spiral sudoriferous canals dis-
covered by Breschet and Purkinge. In con-

* The Editor begs to make his acknowledgments
to his friend Dr. Brinton for this translation from
the German MS. of Professor Frey.

sidering this subject it is important to make
the distinction between sweat and that ex-
halation which is constantly, and at the same
time insensibly, excreting from the healthy
skin. The latter is the manifestation of a
function indispensably necessary for the con-
tinuance of life ; while sweat may be regarded
merely as an occasional result, and as pro-
ducing on the surface certain excretive pro-
ducts which under ordinary conditions only
appear in small proportion on the skin, and
find their more natural exit from the organism
through other channels. It is true that sweat
contains among its constituents the ordinary
products of the insensible perspiration, but it
also contains other matters of a solid kind
which do not appear in a fluid form unless
cutaneous excitement be brought about, and
which in cold weather and in the case of in-
dolent, inactive persons, adhere to the cuticle,
and are gradually rubbed or washed off.
These solid matters are not volatile at the
ordinary temperature of the skin, and there-
fore will not pass off from the body in mate-
rial quantity by any amount of perspiration.
They become constituents of sweat, however,
inasmuch as they dissolve in the water which,
under exercise or owing to excessive tempe-
rature, appears on the surface. Thus sweat
is constituted of the ordinary aqueous pro-
ducts of the natural perspiration, which ap-
pearing in large quantity ceases to be va-
porised, and in addition it contains those
cutaneous secretions which the water dis-
solves, but which, when an animal does not
sweat, appear in less quantity, and adhere
utidissolved to the surface. As the ordinary
cutaneous transpiration forms an important
part of sweat, I shall proceed to consider it
before entering on the more immediate subject
of the present article.

In the healthy human subject, a portion of
water is constantly finding its way to the
surface, and under ordinary conditions is va-
porised nearly as fast as it is secreted. Some
difference is observed in individuals in this
respect, however, so that we observe some
whose skins are constantly moist, while others,
though in perfect health, have the skin almost
always dry, yet doubtless performing its ordi-
nary function. Perhaps the most agreeable
proportion of perspiration, and that which we
should regard as approaching more nearly to
the normal quantity, is that which maintains
a certain moisture on the surface sufficient to
impart an agreeable softness to the touch, and
scarcely to convey the idea of moisture.
Many attempts have been made to determine
the quantity of the cutaneous transpiration,
and perhaps nothing has ever been attempted
so unpromising in result. It is almost certain,
indeed, that we do not transpire equally
during any two minutes of the day, and on no
two days alike.

Sanctorius, the Venetian physician, whose
aphorisms contain much valuable matter, too
much neglected by the physiologists of the
present day, made lengthened experiments on
perspiration. The insensible perspiration has,

812

SWEAT.

indeed, been termed “ Sanctorum” in honour
of him.

This subject, curiously enough, received
some attention from the merry monarch
Charles the Second, who instituted many ex-
periments on the subject. Among other less
exalted, hut probably more trustworthy ob-
servers, may be mentioned Dodart, Keil, Ro-
binson, Home, and Linings, and of later date
Lavoisier and Seguin. According to an ex-
periment of Home, the perspiration during the
twelve hours of night varies from 12 to 18 oz.,
and in 234 hours the discharge amounted to 3
lbs. 3j- oz. On another occasion, however, the
amount was only 2 lbs. 64 oz. Keil states the
medium quantity of perspiration to be 31 oz.
only. Robinson states the amount for summer
to be 27 oz., and in winter 30 oz. daily.
Hartmann, in Germany, makes the daily
amount of perspiration 45 to 46 oz. Dodart,
in France, gives 40 oz. 3 dr. 26gr. for summer,
and 26 oz. 46 gr. lor winter. Sanctorius found
that in the warm humid air ot Venice, having
taken 8 lbs. of ingesta, the perspiration in
the 24 hours amounted to 5 lbs., the feces
to 4 oz., and the urine to 69 oz.

The observations made by Linings, in the
climate of South Carolina, bear importantly
on this subject. He found that while perspir-
ation, as might be expected, was most abund-
ant in the warm weather of summer, the
urine diminished proportionally, and that the
converse pertained tor the winter. He ob-
served the perspiration to exceed the urine
during seven months, and the urine the pers-
piration during five months of the twelve.
The largest proportion of urine observed was
143 oz., which occurred in December. The
largest proportion of perspiration was 130 oz.,
and was observed in September. The ingesta
were to the perspiration as 2-18 to 1. The
perspiration of the whole year was to the urine
as 1 to 1*08. These experiments differ from
those of Sanctorius and Rye, in showing that
the urine exceeds the perspiration even in a
hot climate.

On reviewing all that has been done by
various experimenters, it appears doubtful
whether, even in warm climates, the cutaneous
exhalation exceeds that of the urine, and we
ought most probably to regard it as consider-
ably below the quantity stated by Sancto-
rius. It must be remembered that, as in
the experiments described above, the per-
spiration is estimated from the loss sustained
by the body during a given period, after
subtracting the weight of feces and urine
discharged ; we have the pulmonary exhalation
therefore included in the account, as well as
the cutaneous.

Mr. Cruikshank made experiments which
are free from this source of error. He placed
his hand in a glass jar, making it air-tight by
means of bladder fixed round bis wrist and
also bound tight to the mouth of the jar. He
assumed that his hand presented a surface
— th that of the whole surface of the body,
and from that datum arrived at the conclusion
that the exhalation from the skin was 7 lbs.

6 oz. in the 24 hours, which, under exercise,
would amount to 12 lbs.

Mr. Abernethy made an experiment very
similar to the above, but according to bis cal-
culation, the exhalation for 24 hours would
amount only to 24 lbs. This extraordinary
difference may perhaps be accounted for by
the fact that Mr. Abernethy continued his
experiment six hours, and Mr. Cruikshank
only one hour, and such being the case, the
exhalation may have nearly ceased some length
of time before six hours had elapsed, owing
to the extremely moist atmosphere in which
Mr. A.’s hand was placed. Cruikshank, it
will be seen, would have to multiply by 24,
and Abernethy by 4 only for the result of 24
hours. Thus the former would magnify the
excess (obtained by the first hour affording a
dryer atmosphere) into an important quan-
tity.

Lavoisier and Seguin have made excellent
experiments with a view of ascertaining the
amount of cutaneous exhalation. They en-
closed the whole body in a varnished silk
bag. There was a small opening to this, which
was carefully cemented around the mouth of
the subject of experiment. Thus all the mois-
ture from the lungs escaped, while the cuta-
neous exhalation was confined in the bag.
By weighing the body before and after leaving
the bag, the total loss from skin and lungs
was ascertained. The amount of loss by the
lungs was ascertained by weighing the person
before be got into the bag and immediately
before he left it. After a long series of ex-
periments conducted in this manner, Lavoi-
sier and Seguin found that the mean loss by
pulmonary and cutaneous exhalation amounted
to 18grs. per minute, or 2 lbs. 13 oz. in 24
hours. Of this the pulmonary discharge was
15 oz., and the cutaneous exhalation 1 lb.
14 oz. This they regard, then, as the mean
amount of daily perspiration. The greatest
quantity of matter perspired in a minute, was
26' 25 grs. troy, and the minimum 9 grs. Ex-
halation is increased by fluids, but not by solid
food. It is at its minimum during meals, and
at its maximum during digestion.

Under certain conditions vapour has been
observed to escape from the body in very
great quantity. Thus, Haller observed, when
in the subterraneous caverns of Clausthal and
Rammelsberg, that a distinct cloud or smoke
could be perceived rising from the naked
human figure.

Some "diversity of opinion has prevailed
among experimenters as to the gases which
pass off from the body in company with the
water, by the function of insensible perspira-
tion. Abernethy and Mackensie detected
carbonic acid, and Collard de Martigny found
nitrogen in addition. These gases appear in
variable quantity, and are sometimes alto-
gether absent. After muscular exertion, and
after meals, they appear in great abundance.
According to Trousset, Barruel, and Ingen-
houss, nitrogen is sometimes exhaled without
carbonic acid. Monsieur Collard found that
the cutaneous transpiration contained most

SWEAT.

843

nitrogen when an animal diet had been
used, while carbonic acid prevailed when vege-
table food was taken. This experimenter also
satisfied himself that carbonic acid was evolved
from the skin in a gaseous form, and need not
be the result of oxydation of carbon by con-
tact with air, as he was able to collect it over
water from the skin. The insensible cuta-
neous transpiration may be regarded then
as composed of aqueous vapour, carbonic
acid, and nitrogen gases ; the two latter not
only varying in proportion like the first, but
probably being sometimes absent, even in
health, according to conditions of the organ-
ism, which are not yet sufficiently investi-
gated in relation to this subject.

When, under the conditions referred to
at the commencement of this article, the sur-
face becomes covered with sweat, the various
matters passing away from the skin by exces-
sive secretion have been examined by che-
mists with the following results : —

The total solid matters passing away from
the unexcited skin have been calculated at
about 7 to 8 scruples in the 24 hours, but the
very nature of the inquiry prevents any great
reliance being placed in such results.

When sweat is collected, as was done by
Simon, from persons subjected to the vapour
bath, it appears as a turbid fluid, yielding a
deposit by standing. This deposit consists of
epithelium scales. The clear fluid was found
by Simon to possess a specific gravity of
1003 to 1004. This result, however, must be
modified continually by the water condensed
on the surface from the aqueous vapour of
the bath. The fluid was acid, but only very
slightly so, and in the course of twenty-four
hours it became neutral. The acidity of the
sweat was therefore dependent on the pre-
sence of carbonic acid. Ammonia was evolved
from it after exposure. Simon analysed his
own sweat. He found it to develop an odour
of ammonia, and could detect that gas by
testing with the vapour of hydrochloric acid.
On evaporation, the peculiar smell of animal
extractive matter was observed. When the
dry matter was triturated with potash, ammo-
nia came offi Sulphuric acid added to ano-
ther portion developed sulphurous acid at
first, and afterwards produced a strong odour
of acetic acid. In one instance observed by
Simon, the sweat gave oft’ the odour of
butyric acid so strongly as to leave no doubt
on his mind of the presence of that substance.
Front various experiments, Simon concludes
normal sweat to contain —

1. Matters soluble in ether: traces of fat,
sometimes including butyric acid.

2. Matters soluble in alcohol : alcoholic
extractive, free lactic or acetic acid, chloride
of sodium, lactates and acetates of potash and
soda, lactate or hydrochlorate of ammonia.

3. Matter soluble in water : aqueous ex-
tractive, phosphate of soda, and, occasionally,
alkaline sulphate.

4. Matters insoluble in water : desqua-
mated epithelium, phosphate of lime, and
peroxide of iron.

Berzelius examined and analysed sweat as
obtained from the forehead. He found it to
contain much the same substances that exist
in the acid juice of flesh. He states chloride
of sodium to be in excess, however. The
skin is certainly an active excreter of free
phosphoric and lactic acids, and assists the
urine in its important office of discharging
these acids from the system. Landerer has
lately shown the presence of urea in healthy
sweat, and it is probably by decomposition of
this substance that collected sweat becomes
ammoniacal. Thus, the skin would appear,
under varying conditions, to assume the excre-
tory duties of the lungs and kidneys, and we
are almost constrained to regard its function
as supplementary as well as complimentary
to that of respiration and the excretion of
urine.

Anselmino has, perhaps, made the best
analyses of the sweat. According to him
one hundred parts of the solid matters of
sweat contain —

1. Substances insoluble in water and

alcohol (chiefly calcareous salts) 2'0

2. Aqueous extractive matter (re-

garded as salivary matter by An-
selmino, according to Berzelius
without sufficient reason), and
sulphates - - - - 21'0

3. Spirituous extractive (chloride of

sodium and osmazome) - - 4S'0

4. Alcoholic extractive (osmazome,

lactic acid and its salts, regarded
by Anselmino as acetic acid and
acetates) - 20-0

In order to obtain the solid matters of the
sweat, Anselmino collected it in the vapour
bath by means of clean sponges. The fluid
so obtained was filtered, and the water dis-
tilled off. Acetate of ammonia was found in
the receiver. Simon considers acetic acid to
be a constant constituent of the sweat, and
with Berzelius considers hydrochlorate of am-
monia to be a normal component of the fluid.
Simon, though agreeing in the general with
the results of Anselmino, failed to detect
sulphates in freshly collected sweat. He
found it, however, in the incinerated residue,
from which he infers that some of the con-
stituents of sweat contain sulphur.

The following is Ansel mino’s analysis of
sweat in 1000 parts: —

Water ... 995-00
Epidermis and calca-

987-500

reous salts

Aqueous extractive

•10

•250

matter (sulphates)
Spirituous extractive,
chlorides of sodium

1-05

2-625

and potassium
Alcoholic extractive,
acetates,lactates,and

2-40

6-000

free acetic acid

1*45

3-625

In the ash of the dried

residue

of sweat,

Anselmino found carbonate, sulphate, and
phosphate of soda, chloride of sodium, phos-
phate and carbonate of lime, with traces of
iron. In every 100 parts of dry matter of

814 SWEAT.

sweat, he found [ 22'9 of these fixed saline
matters.

But little is known concerning the sweat of
the lower animals. Fourcroy analysed the
white powder which hangs to the coat of the
horse when sweat has dried upon it ; he de-
tected urea in that substance, but Anselmino
could not. According to the latter chemist,
the white matter is made up of the following
constituents : —

1. A substance of acid reaction, with an
alkaline lactate or acetate.

2. Extractive matter possessing the odour
of the animal ; and chloride of sodium.

3. A brown extractive matter soluble in
water and precipitable by infusion of
galls. Alkaline chloride and sulphate.

The ash consisted of alkaline sulphates
and chlorides, but no carbonates or phos-
phates ; phosphate of lime and magnesia,
with traces of oxide of iron.

Sweat in disease. — The sweat in disease
has been submitted to examination in a very
unsatisfactory manner, but few analyses
having been made. Dr. Piutti, of Elgersburg,
made analyses of the sweat obtained from
three patients who were undergoing the water
cure, and obtained the following results : —

1. Patient suffering from chronic gout,
sp. gravity of the sweat 1003-5.

Water -

- 995-5

Chloride of sodium -

3-0

Phosphate of ammonia

•5

Acetate of ammonia

•5

Hydrosulphate of ammonia

- a trace

Extractive matters

•5

1000-

2. Patient the subject of gout during six
years, sp. gravity of the sweat 1004-.

Water .... 993-0

Chloride of sodium - - 4--0

Phosphate of ammonia - - 0'8

Acetate of ammonia - - 0'6

Hydrosulphate of ammonia - a trace
Extractive matters - - P6

1000-

3. Patient suffering from paraplegia,
otherwise healthy, sp. gravity of

the sweat 1003.

Water .... 994-6

Chloride of sodium - - 3'3

Phosphate of ammonia - - PI

Acetate of ammonia - - 0'5

Hydrosulphate of ammonia - a trace
Extractive matters - - 0'5

1000-

The animal matter possessed a green co-
lour in this case. Soluble in ether, but not
in alcohol.

1 he perspiration in different forms of
disease possesses a peculiar odour, and many
very fanciful opinions have been given on this
point. Scabies is said to afford a mouldy
odour; jaundice is musky, and syphilis

sweet. In ague, the odour of fresh-baked
brown bread is said to pass from the skin.
Stark states that the quantity of lactic acid
is increased in the sweat in scrofula, rhachitis,
and some cutaneous eruptions.

Prout noticed an increase in the quantity
of salts in sweat in a case of dropsy. An
excess of salts has also been noticed by An-
selmino in a severe case of gout. It has been
said that in cases of gouty and urinary con-
cretions the quantity of phosphate of lime is
increased. As regards the latter form of dis-
ease, there is no good reason to believe the
opinion above stated to be true.

A great increase of lactic acid is observed
in cases of rheumatism and gout ; the sweat
in such cases is always extremely acid. An-
selmino, however, states, that lie has ob-
served the sweat after a gouty attack has
passed off, containing a large proportion of
ammonia. Anselmino and Stark state that
they have detected albumen in sweat ; the
former in rheumatic fever, the latter in gas-
tric, putrid, and hectic diseases, and in cases
generally immediately before death. Simon
could not detect it in sweat which he obtained
from the breast of a person suffering from
phthisis in the colliquative stage.

Fat is also said to be found in large quan-
tity in colliquative sweats. Bilin and biliary
colouring matter, or biliphaein, have been found
in the sweat of icteric persons. Berend says
he has observed it in bilious fevers.

Voigtel states, that he observed blood to
sweat from under the arm of a young man
after violent exertion. Such perspiration is
also said to have been observed in scurvy and
low typhus fever. Uric acid has been found
in the sweat of gouty patients, probably in
the form of urate of soda.

Landerer observed a red-coloured sweat
in a fever patient’s axilla, which he believes
to have contained the red colouring matter
of the urine (uroerythrin). Blue perspira-
tion has been noticed by several writers. Dr.
Bleifuss noticed it coming from the foot of a
patient suffering from abdominal disease.
Michel noticed it in hysteria and hypochon-
driasis. Sugar has been detected in the per-
spiration of persons affected with diabetes,
by Nasse. Various substances used internally
as medicines, as articles of diet, or taken for
the purpose of experiment, have been recog-
nised in the sweat. These are, according to
Stark, sulphur, mercury, iodine, iodide of po-
tassium, assafoetida, garlic, saffron, olive oil,
rhubarb, indigo, Prussian blue, and copper.

Landerer observed, that if he took quina
his sweat became bitter.

In cases of Morbus Brightii I have been
able more than once to detect urea in the
perspiration, and 1 am inclined to believe it
constantly present both in cases of suppres-
sion and retention of urine.

I have stated that experiments lately made
by Landerer, the Athenian chemist, have
proved urea to exist in the sweat in health.
If this be proved, we of course can no longer
regard it as an abnormal constituent of that

SYMMETRY.

fluid, but must look upon it merely as present
in excess in the diseases above alluded to.

(£r. Owen liees.')

SYMMETRY (aw—yeTpor). In its general
acceptation this word means a just and har-
monious proportionment of parts to one
another and to their whole ; in anatomy, how-
ever, it has a different and more restricted
meaning. With its anatomical signification
alone I have now to deal, and that may be
defined as follows: — Symmetry is a word
used to express an idea that would be more
correctly represented by a verb than a noun,
for it is the idea of not a thing but a fact —
the fact, namely, that one half of an animal is
usually an exact reversed copy of the other —
the right side is a reversed copy, or repetition,
of the left. To this there are numerous ex-
ceptions, even in the human subject ; of which
hereafter.

That unreversed serial copying or repetition
which is observable, for instance, between the
scapular and pelvic limbs, is enunciated by the
analogous expression serial homology. The
point on which a distinction may be made
between symmetry and homology, is that of
the reversing of the copy or repetition as
characteristic of the latter. This characteristic
seems to impress one with the notion that the
two halves are parts of a whole, whereas an
unreversed serial recurrence of similar parts
inclines one to accord a kind of separate in-
dividuality to each repetition. A clear dis-
tinction between these two styles of repetition
ought undoubtedly to be firmly impressed and
maintained on the mind. I have, however,
for want of a convenient inflection of the
word under consideration, at the risk of some
confusion, been long accustomed to use the
expression lateral homology in reference to
symmetrical repetition — and in that sensei
shall have to use it in this article.

Whether the word symmetry should be
applied to that antero-posterior repetition
which is met with in caudal vertebrae of fishes,
for instance, is not yet determined by usage,
and it will be sufficient for me hereafter simply
to make my remarks upon the apparent exist-
ence of it. In so doing I shall use the ex-
pression antero-posterior homology in a sense
precisely parallel to that of lateral homology.

Lateral Repetition. — That the right
hand and foot, and the right side of the head
and trunk, are the exact counterpart of the
left is a fact so obvious, that merely to assert
it seems an unnecessary truism. It should,
however, by no means be regarded as a matter
of course. It might have been otherwise.

The human skeleton is, normally, perfectly
symmetrical in all its details, and so are the
skeletons of all vertebrate animals, with the
exception of the Pleuronectidre, or flat fishes,
noticed hereafter. The archetype or abstract
ideal figure of an osseous vertebral segment, as
that of Prof. Owen, at vol. iii. p. 824., is a
symmetrical form. But it is doubtful whether
any single bone in the skeleton should be re-
garded as primordially mesial and symmetrical

845

— whether any ossific point is originally in
the middle line. The ideal archetype of the
above illustrious author contains three mesial
azygos elements, viz. the haemal and neural
spines and centrum ; but it has always ap-
peared to me that each of these elements
should be represented in the ideal by a pair
of pieces, because each of them is occasionally
represented in nature by a pair of bones :
Prof. Owen, for instance, regards the two
parietal bones as the neural spine of a ver-
tebra. Though there is no difficulty in con-
ceiving the coalescence of any number of
pieces into one, and though it is easy to con-
ceive that this coalescence may have occurred
before the commencement of ossification, so
that two or more of the points destined to be-
come the centres of the ossifying process may
be brought so close together as, when manifest
by the earthy deposit, to appear but as one, yet
it is not possible to conceive that two pieces can
be developed from one ossific point. The single
azygos condition may proceed from the double,
but the double cannot proceed from the single ;
therefore the double condition must be re-
garded as the primordial, and should hold place
in the abstract type. There are occasionally
met with certain monstrosities which seem to
show in a remarkable manner that a vertebra
is composed of two lateral halves that are
primordially separate. Thus, in double-headed
monsters, wherein there are two vertebral
columns above, which coalesce and form one
below, the half of each of the two columns
which is adjacent to the other seems to be
lost at the point of coalescence, and the single
column below this point seems to be com-
posed of the right half of the one and the left
half of the other of the two columns. In the
skeleton of the Boa Constrictor preserved in
the Hunterian Museum, there are two ver-
tebras that are double on the right side and
single on the left, bearing two ribs on the right
side and only one on the left ; or rather there
are two specimens of right halves of vertebras,
existing independently, which are anchylosed,
the one to the vertebra in advance of it, the
other to the one behind it. This anchylosis
alone justifies the expression “vertebras double
on the right side but in neither instance is it
so complete as by any means to mask the real
nature of the independent half vertebra. Such
facts as these, especially the existence of one
half of a vertebra without the other, even
seem, in contradiction to the impression stated
above, to claim for each half of a vertebral
segment the importance of a separate indi-
viduality, such as is accorded to each ver-
tebral segment itself. They seem to show
that a vertebra is as much a compound of two
lateral parts symmetrically repeating one an-
other, as the human spinal column is a com-
pound of thirty-three serial repetitions of ver-
tebrae. The fact of the lateral halves being
reversed copies of one another, I am disposed
to regard as proof of their being parts only of
a whole, and as disentitling them to an indi-
viduality like that which we are accustomed
to assign to unreversed serial repetitions ; it

S-iG

SYMMETRY.

may, however, be regarded as not sufficient
proof of this. The value to be given to such
facts depends, here as elsewhere, upon the
peculiar bias of different minds, and the asso-
ciations that pre-oeeupy them. It is not
necessary in the present state of our know-
ledge, nay, it is not expedient, to bind the
mind down to this or that view of the facts
that come before it.

A remark, en passant, is due to the considera-
tion that the corresponding organs and parts
of organs of the two sides are not only similar
in form and structure, but normally of exactly
the same age. The corresponding ossific points
of each side make their appearance at pre-
cisely the same time, and in all respects the
original development and subsequent evolu-
tion and maturation of the embryo proceed
exactly pari passu. The exceptions alone to
this rule of symmetry will chiefly occupy
our consideration.

In Man, except perhaps in the very early
stages of his existence, exceptions are offered
by the heart, great blood-vessels, lymphatics
of the trunk, lungs, bowels, liver, spleen, and
pancreas, with their appendages. All these
parts were in all probability, in the very earliest
stages of the embryo, symmetrical ; most of
them have been proved by actual observa-
tion to have been so ; it is, however, difficult
to conceive this to have been the case with
the following other instances of departure
from symmetry.

All decussations in the middle line are
a-symmetrical. Indeed, if a fibre crosses
the median line anyhow but at right angles,
there is a departure from symmetry. Con-
sequently, the decussation of the optic
nerves, the decussation of fibres in the me-
dulla oblongata, and the decussation of white
fibres at the linea alba, are instances of ex-
ceptions to symmetrical repetition. One is
tempted, in the last instance especially, to
believe that these decussations are not in the
original embryonic pattern or plan ; but that
they are developed subsequently, in obedience
to subsequent circumstances : the knowledge
of the power which circumstances, external
or internal, existing at any period of an
animal’s life, have in modifying the directions
of fibres of areolar tissue, and of affecting it in
other ways, aids one in this belief.

The most remarkable of the above instances,
and that in which the primordial symmetry is
most widely departed from, is the heart and
the great blood-vessels that are immediately
connected with it. The heart first makes its
appearance as a mass of cells posited in the
middle line, which soon becomes hollow and
divided into three compartments, the lower
one of which receives the embryonic veins,
and is therefore the auricle, whilst the upper
one is the commencement of the aorta, or
bulbus arteriosus. The middle cavity (the
ventricle) becomes bent into a horse-shoe
form, so as to bring the auricle and bulbus
into apposition. From the latter proceeds a
median artery, giving off' six arches on each
side that surround the space occupied by

the digestive canal and converge towards the
spine, where they are received by two sym-
metrical aortas. The vein that enters the
auricle is a canal or sinus, that intercom-
municates between two venous trunks sym-
metrically placed on each side of the spine,
called ductus Cuvieri, the posterior continua-
tion of which is the cardinal (future azygos
and hemi-azygos) veins ; and the anterior,
the jugular. One of these ductus is permanent
as the superior cava. The omphalo-mesenteric
vein, which empties into the auricle, is at
this time situated in the midtile line between
and in front of the cardinal veins, and into
it falls the single mesial vena cava descen-
dens. The precise periods at which these
parts are first discernible, and those at which
the changes about to be described take place,
will be given in the article Ovum. It is
the manner of their metamorphosis alone
that bears upon this present inquiry. So far
all is symmetrical ; now commence those
changes whereby the adult impar arrange-
ment is eventually effected. The fourth and
fifth (from the heart) pairs of aortic arches
(the two anterior pairs), and the right one of
the second pair, soon disappear. The left one
of the second pair is permanent as the arch of
the aorta, and the third pair persist as the
subclavian arteries. The first pair give off
branches to the nascent lungs. Meantime, the
lower (abdominal) parts of the aorta; have co-
alesced, and those parts of them which inter-
vene between the second arch on the left side
(the arch of the aorta) and the third (the left
subclavian), and between the first arch of the
right side(right pulmonary artery) and the third
(right subclavian), disappear. Now we have,
on the left side, the first two arches uniting
behind to form the left aorta. The first gives
oft" a branch to the lungs, and that portion of it
which is beyond this pulmonic branch remains,
as the ductus arteriosus, pervious till birth ;
whilst that portion which is nearest to the heart
remains, in connection with the pulmonic
branch, permanent for life as the left pulmonary
artery. On the right side the first arch alone,
the second havingpreviously disappeared, forms
the right aorta, which soon joins its fellow
with which it coalesces below. The proxi-
mal part of this arch is permanent, and re-
mains in connection with its pulmonic branch
as the right pulmonary artery, whilst the part
of it beyond the pulmonic branch, together
with its continuation, the right aorta, down
to its point of junction with its fellow, soon
disappears. A septum, meanwhile, has been
developed in the ventricle of the heart, divid-
ing it into right and left ventricles, and an
imperfect one in the auricle. The bulbus
arteriosus also has been divided by a sep-
tum, in such a manner that the first pair of
arches remains in connection with one division
of it, which communicates with one of the
ventricles, whilst the permanent left arch of
the second pair communicates with the other
division, and through it with the other ven-
tricle. It is most probable that these septa,
when first developed, extend from side to

SYMMETRY.

8-17

side, consequently that the systemic ventricle
and aorta are at first in front of the pulmo-
nary ventricle and artery, and that the heart
subsequently undergoes a twist towards the
right, carrying the systemic ventricle round
behind to its permanent position on the left.
In reptiles, in which a great many other of the
mammalian foetal characters are permanent, the
root of the systemic is in front of that of the
pulmonic artery, and there is not that twining
round one another of the great arterial trunks
which is met with in man. Thus, then, these,
the most unsymmetrical parts of the whole
body, can be proved by actual observation to
have been originally perfectly symmetrical,
and the manner of their attainment to their
ultimate unsymmetrical form can be accu-
rately traced.

The a-symmetry of the lungs is little more
than a trifling difference of size between the
two, dependent upon the encroachment of the
heart by its displacement towards the left.
And the a-symmetry of the great abdominal
viscera enumerated above, and of their appen-
dages, depends entirely upon lateral displace-
ment and excesses of growth of one side
over the other, having reference to conve-
nience of packing. This a-symmetry, greater
in mammalia than in reptiles and fishes, on
account of the presence of the diaphragm,
which, so to speak, thrusts the abdominal
viscera downwards, necessitating lateral dis-
placement, attains its acme in man, owing to
the great lateral measurement compared with
the antero-posterior distance which is so
conspicuous in his figure when contrasted
with that of other animals. The hepatic at-
tachments of the falciform ligament and
gastro-splenic omentum landmark the original
median line of the liver ; and that larger part
of it which is to the right of the ligament
and behind the omentum, is the right lateral
homologue of that lesser part which is to the
left of the ligament and in front of the omen-
tum. The gall-bladder appears to be an un-
symmetrical organ, situated to the right of the
median line. I am unable to state whether or
not a left gall bladder has once existed and
been suppressed, or whether it is a diverticu-
lar production of the gall-duct evolved subse-
quently to the first sketching of the embryo ;
or, lastly, whether it is originally median and
subsequently displaced. The anterior wall of
the stomach is the left lateral homologue of
.the posterior wall. The spleen is an ori-
ginally median organ, situated in the originally
median meso-gastrium. The great omentum
is a pouching out of the meso-gastrium to-
wards the left, consequently its outer surface
is the left lateral homologue of its inner sur-
face.* The pancreas is an originally median
organ, one end of which has been displaced
along with the pylorus towards the right, so
that its anterior aspect is the left lateral ho-
mologue of the posterior. The intestinal
canal can be witnessed in the embryo as
a straight, uniform, mesial, and symmetrical

tube, until its length having become greater
than that of the region which it is destined
to occupy, it is compelled to arrange itself in
gyrations and loops. The posterior and an-
terior walls of the stomach were originally, as
indicated above, its right and left halves ;
and as to the other parts of the alimentary
tube, whatever difficulty there is in recog-
nising the manner of their displacement
in the human subject, is at once dispelled
by examining their condition in the lower
animals. No difficulty whatever is encoun-
tered in respect of the small intestines, for
their mesentery is attached nearly in the
median line ; the bowels themselves, however,
are continually varying their position, relative
and positive, according to the manner of
packing most convenient for their variable
contents. Not so easy is it to understand the
kind of displacement which has taken place
in respect of the large intestines. The colon is
curled back, and crosses over the small intes-
tine from right to left, forming a loop. In the
human subject, the true relation of these
parts is further masked by the singular circum-
stance of this crossing over occurring just
at the point where the meso-gastrium, after
having descended as the great omental bag, is
returning to the spine, and the colon, finding
it there, so to speak, avails itself of it, and
uses it as a mesentery ; anatomists have
named this borrowed portion of the meso-
gastrium the transverse meso-colon. In Ru-
minants the colon, being exceedingly long,
avails itself also of the mesentery of the
small intestines, into which a loop of it is
thrust further and further until it makes three
turns ; so that in tracing the colon onwards
with the finger, you make three spiral turns
in the mesentery, and then double and return
by three spiral turns placed between the
former spirals.* On the other hand, in the
Carnivora, where the colon is very short, it
crosses over the lower end of the ileum so near
to its termination that it is evident that the
next degree of shortening must result in the
continuation of the small and large intestines
in a straight line. This actually takes place in
the Reptiliaf, and then there is no longer any
difficulty in recognising the original mesial
and symmetrical position of the intestinal
tube and its appendages, so displaced in the
human subject as to make this recognition so
extremely difficult.

It is by no means uncommon to meet
with instances where all the unsymmetri-
cal ly posited organs of the human body are
placed completely vice versa to their usual
situations; the heart pointing towards the
right ; its pulmonic to the left of its systemic
ventricle; the vena cava to the left of the
aorta ; the liver in the left, and the spleen in
the right hypochondrium; and the caecum in
the left iliac fossa. Almost every anatomical
museum contains an instance of this kind ; and
in all instances where the history of the case
before death was known, the average health

* See Rcminantia.

t See jig. 491. Vol. III. Peritoneum.

See Peritoneum.

818

SYMMETRY.

and ordinarily well-developed state of the
subject attested the insignificance of this trans-
position in respect to the well-being of the
individual. Such cases are most interesting
from this consideration, — that all the unsym-
metrical organs are transposed. There is, I
believe, no instance on record of one, or two,
or less than the whole of the unsymmetrieal
organs occupying the side which is not their
usual one. This prompts the belief that the
side which these organs shall respectively oc-
cupy is determined by a single impulse first
given to one of them.

Abnormal deviations from symmetry are of
extremely frequent occurrence. The blood-
vessels of the body are very rarely perfectly
symmetrical. In the adult subject the two
sides of the body rarely match exactly in ex-
ternal form. The right hand is usually larger
than the left. Accidental circumstances oc-
curring to an individual frequently disturb the
symmetry, but it is by no means uncommon
to meet with evidence of hereditary trans-
mission of aberrations from symmetry. Such
monstrosities as supernumerary fingers and
toes are sometimes symmetrical, but just as
frequently, perhaps more frequently, the mon-
strosity exists on one side alone.

Comparative Anatomy.— I pass on now
hastily to notice such deviations from sym-
metry as are met with in the normal conditions
of the lower animals belonging to the ver-
tebrate sub-kingdom, and to examine the
question of symmetry in the other sub-king-
doms.

In all Mammalia there is much the same
departure from symmetry in the viscera of the
chest and abdomen as is found in the human
subject ; but in no other mammal is the lateral
displacement so great as in man, for in all
others there is a greater proportionate antero-
posterior depth of chest and belly. The only
other notable instances of a-symmetry known
to exist in the mammalian class are the fol-
lowing: — In the male narwhal or sea-unicorn
the left front incisor tooth attains the enormous
length of eight or ten feet, while the right one
is found as a rudiment that never pierces the
gum. Spirals in the middle line are departures
from symmetry ; consequently the spiral penis
of the boar, &c. must be regarded as instances
of a-symmetry ; a slight excess in length of
one of the halves is sufficient to produce this
spiral form. The left nostril of most of the Ce-
tacea is constantly much larger than the right.

In Birds there is much the same want of
symmetry in the viscera of the trunk as is met
with in mammals. The right one of the se-
cond pair of embryonic aortic arches however
is retained instead of the left, so that the adult
aorta arches over the right bronchus. But
notwithstanding this, the left ventricle is the
systemic one, and presents the same excess
over the right, in the thickness of its walls, as
in Mammalia. Both of the ductus Cuvieri are
retained and form two superior vence cavce.
The liver is situated mesially, that is to say,
its great fissure and falciform ligament are in
the middle line ; but its left lobe is usually the

larger, and in the common fowl presents a
fissure which is not repeated in the right. The
(esophagus diverges slightly towards the right,
but the cardiac orifice of the stomach is to the
left of the pyloric. The long loop described
by the duodenum, and the pancreas which is
surrounded by it, are found extending diagon-
ally across the abdomen in front of the other
bowels, their extremity resting in the left iliac
fossa, but they are not fixed in this position.
The gall bladder is situated as in Mammalia.
There being no great omentum, the spleen
occupies its typical position behind the sto-
mach. There is usually a disparity in the
length of the pair of caeca met with in this
class.

But the most remarkable exception to sym-
metry in the class Aves is that which exists in
th e female generative organs. The left ovary and
oviduct alone are functionally evolved, whilst
the right, becoming atrophied at an early
period, are barely traceable in the adult ani-
mal. A few instances are on record where
these right lateral homologues of the ovary
and oviduct have been found evolved in func-
tional size as a testicle and vas deferens, thus
forming lateral hermapnrodism.

The male generative organs of birds are all
symmetrical except the penis, when it exists,
which is spiral.

Another instance of want of symmetry is
presented by the beak of some birds, as the
cross-bill, &c.

Reptiles. — The heart of reptiles is situ-
ated in the middle line, but it is not symme-
trical in form, nor do the great blood-vessels
enter and quit it in a perfectly symmetrical
manner ; they however approach more nearly
to symmetry in this class than in any of those
which have been previously considered. In
all reptiles there are at first two aortae, sym-
metrically disposed, arching over the right
and left bronchi respectively, and uniting with
one another to form one trunk on the spine.
The vessels given off from these are, however,
most generally not symmetrical, the head and
front limbs being supplied frequently from the
right arch alone, and the chylopoietic viscera
from the left alone. The pulmonary arteries
arise behind the origin of the aortae. The
lungs of reptiles are usually two symmetrical
organs, but in the Ophidia the left lung,
when it exists, is much shorter than the right,
and in some, as Coluber thiringicus, it is
wanting altogether, the only vestige of it
being a caecal depression on the left side of
the lower end of the trachea ; this absence of
the left lung entails, of course, the loss of the
left pulmonary vessels.

The stomach and bowels of the Chelonia,
owing to the flattened form of the animals,
are nearly as much laterally displaced as in
the human subject. In the other reptiles
they are not much out of symmetry, yet in
none are they exactly symmetrical. The car-
diac end of the stomach tends, though often
but a little, towards the left ; the pyloric is
free, and can be brought without violence to
the middle line, but yet it is always found

SYMMETRY.

849

leaning to the right. This renders the spleen
more conspicuous on the left. The liver of
reptiles extends from side to side, but the
right lobe is the largest.*

In the tadpoles of toads and frogs, I have
observed that there is no gill opening on the
right side. In the Lepido-siren the anus is
situated on the right side of the mesial ridge
of the tail.

Fishes. — The heart of fishes is posited
symmetrically, but the relative position of the
auricle and ventricle is usually unsymmetrical,
the former being behind and to the left side of
the latter. The single arterial trunk, with its
branchial arches and the coalescing aortas,
however, are precisely alike on both sides.
The intestinal canal, being generally much
longer than the abdomen of the fish, is neces-
sitated to throw itself into unsymmetrical
loops and convolutions.

There is a very remarkable departure from
symmetry in all the members of the group of
fishes called Vleuronectidce, or flat fishes, such
as the turbot, halibut, sole, and flounder.
These fishes lie at the bottom, and swim, on
one side ; and the side which they keep
uppermost is coloured dark like the back of
other fishes, whilst that which they keep
undermost is white like another fish’s belly.
The dark-coloured side is also somewhat
convex, whilst the white side is nearly flat.
The dorsal azygos fin is continued on to the
head, beyond the eyes, almost to the muzzle,
and, what is most remarkable of all, both the
eyes appear on the dark side, and are actually
both situated on one side of the dorsal azygos
fin. With the exception of the different co-
lour of the skin, the different degrees of con-
vexity of the two sides, and a slight distortion
of the mouth, the whole of these fishes are
symmetrical in all their parts, besides the eyes
and the structures immediately surrounding
them. The bones immediately contiguous to
the eyes suffer the following remarkable dis-
tortion : — The occipital bone is almost per-
fectly symmetrical, and its mesial crest is
continued far forward as a sagittal crest be-
tween the parietals in the real as well as the
apparent middle line, supporting the styliform
bones to which the rays of the dorsal azygos
fin are articulated. There is a slight dif-
ference in the size of the parietals, that of the
right or white side being the largest ; but it is
the frontal and pre-frontal bones that suffer the
greatest distortion. Arriving at the frontals,
the real or primordial middle line is suddenly
deflected towards the left or dark side, whilst
the sagittal crest, still supporting the azygos
fin, is continued straight on, on the right fron-
tal alone. The left frontal is less expanded,
but more clumsy than the right, and extends
forwards in a curved form between the eyes,
presenting a concavity towards the right. To
this concave curve is sutured a falciform pro-
cess produced from the left anterior corner of
the right frontal, which is quadrate. This
suture of course indicates the real middle line.
The eyes are situated on each side of the sep-
* Yol. IV. fig. 220. p. 304. art. Reptilia.

VOL. IV.

turn thus formed. The end of this compound
septum rests on the suture between the two
pre-frontals, and this suture, which again in-
dicates the real mesial line, presently regains
the apparent middle. The right pre-frontal is
much larger than the left, and comes again
into contact with the right frontal on the
outside of the right eye, which therefore oc-
cupies an orbit with a complete bony margin,
whilst, the same thing not occurring on the
left, the eye of that side has no orbit, but
seems to lie loose in the soft structures
of the cheek. The symmetry of the base
of the skull is disturbed but slightly, the
long sphenoid and vomer forming nearly a
straight line, and participating but slightly
in the abrupt deflection of the middle line
which takes place above. Not the least curi-
ous part of this history is the non-participa-
tion of the dorsal azygos fin in the deflection
of the mesial line ; it furnishes an additional
proof that its rays are not a part of the endo-
skeleton. The eyes of the pleuronects are of
different sizes ; the furthest from the dorsal
fin (the left, the one that has no orbit) being
the smallest, and the optic nerve and optic
lobes of the brain, which belong to it, are
smaller than their fellows.*

In using the terms right and left in the
above descriptions, I have constantly had in
view the turbot, which is coloured, and shows
its eyes on the left side ; but the sole, dab,
and flounder, are coloured on the right, and
therefore those terms must be reversed when
applied to them. It is extremely common to
meet with individual specimens of Pleuro-
nectidae coloured, so to speak, on the wrong
side, that is to say, not on that side which is
usual, and the rule for the species. Turbots
coloured,, and having their eyes on their right
sides, are frequently met with, and the flound-
ers brought to the London market are almost
as frequently coloured, and show their eyes,
on the left as on the right side. The un-
symmetricalLy posited intestines of these fishes
do not participate in this transposition, but
occupy, respectively, the same sides in the
monstrous as in the normal individuals.
The frequency of these monstrosities tempts
one to conjecture that external circumstances
may, perhaps, determine which side of the
pleuronect shall have the eyes and be coloured.

Articulata. — The animals composing this
sub-kingdom are bilateral and symmetrical.
The abstract pattern or type of an articulate
animal, like that of the Vertebrata, is a sym-
metrical figure.f From this primordial sym-
metry there are but few deviations, and those
exceedingly trifling in amount.

Amongst the Entozoa, the English tape-
worm ( Tcenia solium), if the flat sides be
taken as dorsal and ventral, presents an in-
stance of a-symmetry in the position of its
genital orifices, which are situated on the
edge of each joint, sometimes on one side,
sometimes on the other, indifferently.

In the Natural History series of the Mu-

* Sec fig. 409. Vol. III.

f Vol. I. Fig. 378. art. Crustacea.

3 i

850

SYMMETRY.

seum of the College of Surgeons (No. 205.),
there is a portion' of a taenia lata, which ex-
hibits a monstrosity very interesting in its
bearing on the question of the individuality
of half segments (p. 845.). On one side,
which for distinction we will call right, there
are three half segments, the middle one of
which unites with two half segments of the
left side, leaving the upper and lower of the
three right halves isolated and independent.
One of these contains a generative apparatus.

Mollusca. — In this sub-kingdom absence
of symmetry seems to be the rule — its pre-
sence the exception. There are great prac-
tical difficulties in the way of finding an ab-
stract notion or type of a mollusk such as
have been found for the Vertebrata and Arti-
culata. If, however, such type he symme-
trical, that symmetry is departed from much
oftener than it is preserved. There is no
appearance in any mollusk of a serial re-
petition of parts — nothing like serial ho-
mology, except in the Chitons, whose shell
consists of a number of similar symmetrical
transverse bands. The highest class of mol-
lusks, the Cephalopoda, are symmetrical, and
when they inhabit shells, as the Argonaut
and pearly Nautilus, their shells are symme-
trical. But the enormous number of species
comprised in the classes Gasteropoda and
Acephala are nearly all unsymmetrical. The
slugs are the most symmetrical of the Gaste-
ropoda in their external form, but here the
air-orifice, for instance, is on one side.

Radiata. — For convenience of illustration,
I select from among the animals composing
this sub-kingdom the common star-fish. (Figs.
16, 22, &c. Yol. I. Art. Eciiinodersiata.)
This animal presents to our view a flattened
form with five exactly similar rays or arms ra-
diating from the centre, where is posited the
mouth . Around the mouth is a nervous circle
consisting of a number of ganglia corresponding
to the arms, connected with each other by
intercommunicating cords. Each arm is
symmetrical in itself. Now this figure may
be divided into two symmetrical halves by a
line drawn across it in either of five different
diameters. What is to decide which of these
is to be regarded as the mesial line ? For-
tunately there is, on the side which is the
reverse to that on which the oral orifice is
placed, a peculiar spot, the remains of an
embryonic structure, which is not in the
centre, and will therefore serve for a datum.
In certain other echinoderms the anus is situ-
ated eccentrically, in which case it also may
be taken as a datum. But still a line drawn
through either of these, the number of the
arms not being an even number, will divide
one of them in its middle on one side, and
pass through the interspace between two of
them on the other. This, as the arms are
exact repetitions of one another, seems an
unnatural and arbitrary proceeding. Still,
though it possesses no natural middle line,
and consequently is not bilateral, yet is the
star-fish a symmetrical animal, for the idea
of bilateralism is by no means included in our
definition of symmetry.

Whenever a number of exactly similar parts
symmetrical in themselves arc arranged around
a centre, whether their number be two, as in
bilateral forms, or five, as in the star-fish, the
whole figure is symmetrical. Abandoning
then the idea of bilateralism, we may look
upon the star-fish as composed of five repe-
titions arranged around a centre. Regarding
it in this manner, we are able to institute- a
comparison between the form of the star-fish
and that of the segmented vertebrates and
articulates. The star-fish may be regarded as
analogous to one segment of a vertebrate or
articulate — an animal with one vertebra.

I use the term analogous,” and not
“ homologous,” because the relation called
special homology cannot be demonstrated, in
any instance, between animals belonging to
different sub-kingdoms. The head, the legs,
the brain of an articulate, are only function-
ally the head, legs, or brain. They perform
the same function as, but they cannot be shown
to be homologous with, the head, legs, or brain
of a vertebrate. Indeed I have long held that
the sub-kingdoms should be limited by refer-
ence to special homology : all animals among
which homologies can be pointed out — which
all conform to the same type — should be
grouped together to form a sub-kingdom.

The view of the analogy of a radiate animal
to a vertebrate or articulate animal just given,
is considerably strengthened by the manner of
development of the common medusa. The
larva of the medusa is a polypiform living
thing, anchored by one end and tentaculated
at the other. This, after a while, becomes
marked with numerous -constrictions, like a
segmented animal, which constrictions become
more and more deep until they completely
divide the quondam polypiform being into a
number of pieces, each of which becomes a
perfect medusa. Here is a segmented animal,
each of whose joints becomes an independent
radiate individual ; ergo, each individual is
analogous to one segment of a vertebrate or
articulate.

Towards a different view tends the fact, that
though five, or a multiple of five, is usually
the number of the rays of the star-fish, yet
there are some members of the same group
the number of whose arms are neither the one
nor the other; for instance, there are eleven
and twelve-armed asterias. Now there is such
perfect constancy in the number of the parts
of vertebrate and articulate segments, that that
constancy seems an integral element of the
idea of an archetype. There is, however, no
constancy in the number of the vertebrate or
articulate segments that go to constitute an
animal, and therefore some may regard each
arm of an asteria as analogous to a vertebra ; —
the common star-fish, as composed of five
analogues of vertebral archetypes arranged in
a circle, — as a segmented animal bent upon
itself, with its anteriorand posterior extremities
adherent to one another. Which of these two
views is the correct one — whether either is
correct — can be decided then only when the
true import of serial homology and of sym-

SYMMETRY

851

metry is definitely ascertained ; when it is de-
termined what is due to division, what to
radiation, or whether division and radiation,
one, or both, or neither, are concerned in their
causation.

The skeleton of the Velella presents an in-
stance of departure from symmetry, mainly in
the oblique set of its vertical plate. The
common medusa has a circular outline, and
exhibits four quarters, which repeat one
another exactly, so that it seems to be marked
with a right-angled cross. The horizontal
plate of the skeleton of Velella is distorted to
a sub-rhomboid form, and marked with two
diagonal seams that cross one another
obliquely. The longer one of these diagonals
is produced upwards so as to form the oblique
sail-supporting vertical plate, which also pre-
sents a seam continued up from the point of
crossing of the diagonals, indicating that it is
composed of two parts uniting at this central
point. This de facto unsymmetrical radiate
is therefore easily reduced in idea to its pri-
mordial symmetry.

Infusoria. — Out of the vast number of
various forms met wit h amongst these animal-
cules the greater number are symmetrical.
This symmetry is usually not bilateral, but that
of the star-fish. There are, however, some
forms which are quite irreconcilable with sym-
metry, which no line can divide into two
similar halves, which are one, and present no
repetitions of parts ; except, indeed, when
they are undergoing fissiparous generation.

Amtero-eosterior Symmetry. — By re-
ference to the diagram at page 824. Vol. ILL
Fig. 433., representing the abstract notion
or type of a vertebral segment, it will be seen
that the upper or posterior half is a reverse
of the lower or anterior. Referring to what
really exists in nature, we find, in the caudal
vertebrae of fish, that their dorsal and ven-
tral halves are counterparts tolerably' exact,
yet that exactness is not nearly what exists
between the lateral halves. If an antero-
posterior as well as a lateral symmetry be
admitted, then we have four repetitions ar-
ranged around a centre. At all events there
is here, in the Vertebrata, some amount of
evidence of radiation or divergence from a
central axis comparable in some degree to
what we see in the Radiata. The anterior
and posterior parts of vertebral segments,
as ! found in nature, are usually extremely
dissimilar. The rays of the dorsal and ab-
dominal (anal) azygos fins of fishes are an-
tero-posterior repetitions, but the fan-like
tad fin, which in most fishes seems to be
remarkably symmetrical antero - posteriorly,
half of it apparently belonging to the dorsal
and the other half to the abdominal moiety
of the fish, usually belongs, as I have ob-
served in the typical fishes, cyprinoid, &c.,
in reality, entirely to the abdominal or
under moiety. The embryo of these fishes
at first has a tail like an eel, into which
the spinal column is continued nearly to
its tip. A little way from the extremity of
this, on the abdominal aspect, a group of

fin rays are soon observed to sprout out
meanwhile that the end of the vertebral co-
lumn shrinks and turns up. The group of
fin rays grows, and the vertebral column
shrinks, so that in time the former is brought
to form the fan-like extremity of the animal ;
but even then the atrophied end of the verte-
bral column may be detected occupying the
upper edge of the fan. Even in the adult
fish some trace of this original relation of
the tail fin can be detected. If the tail of
an adult homocercal fish be macerated or
boiled, and all the pieces which are not an-
chylosed to it be removed, what remains will
not be symmetrical, but will terminate by
turning or cocking up. Even in the Pieuro-
nectidae, whose tails seem to be remarkably
symmetrical, and where the spinal column
seems to terminate in a flat triangular piece,
it will be found that the lower half of this
piece can be easily removed, whilst the upper
half forms one piece with the body of the last
vertebra, with which, in fact, it forms a
coccyx composed of numerous degenerated
and consolidated vertebrae.

Symmetry of Disease. — This subject has
been most ably treated by Dr. W. Budd *.
of Bristol. Those local diseases, the cause
of which is in the blood, usually affect the
solids of the body symmetrically. This can
be often well observed in lepra, psoriasis, se-
condary syphilis, gout, and rheumatism, and
in the eruption caused by taking the iodide
of potassium. It is due, no doubt, to the
symmetrical disposition of those tissues for
which the morbid poisons have a peculiar affi-
nity. It proves, moreover, that there is more
of peculiarity in certain parts of organs than
what meets the eye, which peculiarity is sym-
metrical. For, though the tissue of all parts
of a bone, for instance, shall be exactly the
same, it shall be diseased at a certain part
only, and the disease shall be repeated in ex-
actly the same part of the corresponding bone
of the opposite side. Connected with this is
the observation made above, that the corre-
sponding points of both sides of the body are
exactly of the same age — have reached a cer-
tain stage of development at exactly the same
time. But the force of this observation in
explaining the symmetry' of disease is consi-
derably weakened by another fact noticed by
Dr. W. Budd, namely, that the diseases above
named are apt also to localise themselves in
parts that are serially homologous, or corre-
sponding in the upper or lower limbs, as the
knee and elbow, wrist and ankle ; for these
parts, though homologous, are not of the same
age. It is well known that the development
of the upper and lower limbs does not pro-
ceed p an passu. There is here, at least, some
determining agency more mysterious than
mere age. Still more curious and mysterious
is the relation of the eruption called shingles
to the bilateralism of the body. It often ex-
tends zone-like around one half, stopping
exactly at the median line before and behind,

* Medico-Chirurgical Transactions for 1842.

3 I 2

852

SYMPATHY.

and thus seemingly affording evidence of that
individuality of one half of the body which
was spoken of as a feasible opinion above.

Plants. — The leaf of the higher plants,
«:hich is the unit or individual of botanists, is
bilateral and symmetrical — always in idea,
generally in fact. These leaves are associated
together to form buds, branches, flowers, or
fruits, in whorls. Symmetrical figures are
often produced by these associations, but yet
the pattern is spiral. In watching the develop-
ment of spores of conferva, they are seen, whilst
still but single cells, to shoot out in various
manners, the majority of which are quite irre-
concilable with symmetry, either bilateral or ra-
diating. Whatever may be its import,' it is
quite certain, from the very nature of symmetry,
that the cause of it must be internal, that is
to say, within the body in which it is mani-
fested. But it has been conclusively deter-
mined, by experiments, that external influences,
acting upon them in certain directions only,
such as light, heat, and gravitation, exert a
considerable power in determining the form
of vegetable productions. Animals, doubt-
less, are also greatly affected by these agencies,
yet, as they enjoy the faculty of locomotion
whereby all parts of them are successively
turned towards the directions from which
these forces emanate, the form impressed
upon them by internal causes, suffers little or
no distortion therefrom; but plants, being
destitute of locomotion, continually receive
these influences in a partial manner, and con-
sequently we the less expect to meet with
symmetry among them. Whenever their in-
ternal forces tend to make them symmetrical,
the partial action of external agents is apt to
disturb their symmetry. It is this, probably,
that renders the germinating conferva cell
unsymmetrical.

Crystals of unorganised matter are spoken
of as symmetrical. The symmetry, however,
which they exhibit is not a bilateral sym-
metry. It consists of the repetition of the
same angles and facets at the poles of an
axis, but the repetitions are not reverses.
The reader may illustrate my meaning by cut-
ting a rhomboid in paper, when he will observe
that each of its angles and sides are twice re-
peated, but he will find it impossible to fold it
so that one half shall coincide with the other.

The precise import of the symmetry of or-
ganised bodies is, as repeatedly indicated above,
as yet involved in mystery. Albeit a fact so
evident, so constantly obvious to our senses,
as often, like gravitation, to pass unheeded,
it is a great and an important fact, — a fact of
the same orJer with those which have already
led to the establishment and demonstration of
grand, comprehensive, and unassailable theo-
ries— the bright triumphs of the human intel-
lect, that have reduced to order, simplicity,
and connexion, what before was all confused,
complicated, and disjointed, — a fact, there-
fore, that inspires us with hope for our, as
yet, imperfect science of anatomy. Tt seems
to tell of radiant forces, of certain, definite,
mathematical, and inexorable laws, concerned
in the production of animals. Taken with

the other important fact — serial homology,
it seems to suggest for the development of
Vertebrata and Articulata the multiplica-
tion of centres in a serial line — of centres
of radiant force, that then proceed to in-
duce the surrounding particles to arrange
themselves in a symmetrical figure. In truth,
as the mind contemplates this fact, various
theories pass before it, yet shadow}', change-
able, and indistinct as a phantasmagoria. One
day, perhaps, some one of these shall meet
with definite enunciation and clear demon-
stration ; at present we must be content with
putting the fact of symmetry prominently
forward and exhibiting it in various points of
view, with declaring it an important fact,
and not a matter of course.

(S. R. Pittard.)

SYMPATHETIC NERVE.— (See Sup-
plement.)

SYMPATHY (avv-traBos). — Sympathy may
be defined as the assumption by different
individuals, or by different parts of the same
individual, of the same or an analogous physio-
logical or pathological state at the same time,
or in rapid succession. It is popularly known
that the act of yawning, performed by one
individual in a company, is apt to induce in
many of the others an irresistible tendency to
the same act. In a similar manner, the excite-
ment of certain emotions (mirth or sadness,
laughter or tears) is apt to spread through
an assemblage of persons with extraordinary
rapidity. The power of eloquence, of music, or
of spectacle, to produce such effects, is witnessed
every day in places of public resort, whether
for devotion, business, or amusement.

Many instances are known in which con-
vulsions have been excited in persons not
previously subject to them, by the sight of a
patient in an epileptic fit. And peculiar ner-
vous disorders, of a convulsive kind, have
been found to affect nearly all the members
of a community without the slightest evidence
of their being contagious or infectious. An
impression upon an organ of sense may pro-
duce effects very different in their nature to
any thing which could be anticipated ; and
these many be purely of a physical kind, or
they may act primarily upon the mind. Thus
certain odours will induce syncope in some
people ; and the smell of a savoury dish to a
hungry person, or even the mention or the
thought of a meal, will excite a flow of saliva.
The emotion of pity excited by the sight of
some object of compassion, or by a narrative
of a mournful kind, will produce a copious
flow of tears.

All such phenomena are said to result from
Sympathy. When one yawns, immediately
in consequence of another’s yawning, the
former evidently and truly sympathises with
the latter ; and the convulsions which are
induced by the sight of another in a fit, are
not less sympathetic. The individual in whom
the convulsions are induced, sympathises with
the other. Such obvious instances of sym-
pathy between different individuals led to the

SYMPATHY.

853

supposition of some such similar consent
between different or even distant parts in the
same person.

Motions or sensations caused in certain
parts, in consequence of a primary irritation
of other and distant parts, are of the sym-
pathetic kind. These motions or sensations
are produced in, as it were, an indirect or
circuitous manner, or one different from that
in which they are ordinarily excited.

Thus a stimulus to the olfactory membrane
causes a peculiar affection of the sense of
smell, and occasions that depression of the
heart’s action, from which results a state of
syncope. Or another affection of the same
sense causes a suddenly increased action of
the salivary glands.

If we analyse any one of these examples of
sympathetic actions, it will appear that three
circumstances may be noticed in the produc-
tion of the phenomena : 1st, the primary

exciting cause, which may be an object pre-
sented to the mind through one of the organs
of sense, or causing an impression upon any
sensitive nerve, and therefore upon some part
of the centre of sensation; 2ndly, the part
affected directly by this primary stimulus ;
and, 3rdly, the action or sensation resulting
from the affection of this part.

Many other sensations or motions may be
enumerated besides those above referred to,
whether occurring in health or in disease;
and we shall give examples of these before we
discuss this subject further.

The examples of sympathetic sensations
which may be adduced are chiefly of the mor-
bid kind. Pain is felt at a certain part, in
consequence of an irritation in another part
distant from it, and apparently altogether
unconnected with it. A familiar instance of
this is pain in the knee from disease of the
hip-joint. So marked in some instances is
the pain in the knee, and so much has it ab-
sorbed the patient’s attention, that the real
seat of the disease has been overlooked, and
the remedies been applied exclusively to the
knee. Pain in the right shoulder, from
disease of the liver, is a sympathetic sensa-
tion of similar kind; and sometimes the
hepatic irritation causes pain over a more
extensive surface. Whytt mentions, that, in
two cases of suppuration of the liver, he had
seen the patients “ affected with a numbness
and debility of the right arm, thigh, and leg.”
Sometimes both shoulders are the seat of
pain, from hepatic irritation.

The peculiar sensations felt in the teeth
from a noise which grates upon the ears, is
sympathetic of the irritation of the auditory
nerve. Practitioners are well aware how many
morbid sensations in parts remote from the
intestinal canal may be cured by the removal
of scybala o-r other accumulations from it.
Painful affections of the nerves of the face,
and of other parts, are often due to a cause
of this kind. The irritation of a stone in the
bladder gives rise to pains in the thighs, or
to itching at the end of the penis ; and
uterine irritation, whether from disease or

from the enlargement of that organ in con-
nection with the early stage of pregnancy,
causes similar pains in the nerves of the
thighs.

Headache and defective vision are fre-
quently produced by disordered stomach. A
draught of very cold water, or ice, taken
quickly into the stomach, may occasion acute
pain in the course of either frontal nerve.
This same nerve on one side is frequently the
seat of pain after the imprudent use of acid
wines or other fermented liquors.

Movements , excited by the operation of a
stimulus applied at a distance, form a large
proportion of the instances of sympathetic
phenomena. All the ordinary physical ner-
vous actions in which motions are excited by
stimulating a sentient surface, may be regarded
as examples of sympathetic actions.* The
contraction of the iris upon the application of
the stimulus of light to the retina, or of the
pharyngeal muscles by stimulating the mucous
membrane of the fauces, are instances in point
where the stimulus acts indirectly upon the
contracting fibre. Nothing is more sure than
that in these instances the change wrought by
the stimulus in certain sentient nerves, travels
by a circuitous route through a nervous centre
to the muscles which are called into action.
Akin to these actions are the forcible respira-
tory movements which may be excited by ir-
ritation of the tracheal membrane, as coughing ;
or sneezing, by stimulating the nasal mem-
brane ; or vomiting, by irritating the fauces.
Spasmodic affections are often instances of
morbid actions in sympathy with intestinal
irritation, or the irritation of teething in chil-
dren. Partial or general convulsions are very
frequently due to either or both these causes.
We have known the most violent opisthotonos
co-existing for a considerable time with the pre-
sence of lumbricoid ascarides in the intestine;
but ceasing immediately on the removal of the
worms. Vomiting is commonly sympathetic
of diseased kidney, or of the passage of a
calculus along the ureter ; or of the passage
of a gall-stone along the gall duct ; or it may
be induced by the introduction of a catheter
into the urethra.

The consentaneous action of symmetrical
parts is no doubt due to a similar cause to
that by which most of the sympathetic actions
are excited, and more especially in those parts
where symmetry of action is constant, al-
though liable to be interrupted by the influence
of the will.

A distinct class of sympathetic actions con-
sists of those in which certain parts enlarge
or become developed simultaneously with, and
to a certain extent in effect of, the increase

* It lias been remarked, that the term “ sympa-
thetic actions ” involves a contradiction. But it
may be observed, that the contraction of the mus-
cles, on which the action depends, is only the
natural mode in which that class of vital organs can
manifest their consent with certain states of nervous
centres, or of sensitive nerves. The action is the
result of the state which the muscle assumes in
sympathy with the stimulated nerve. The con-
tradiction is therefore apparent, not real.

3 i 3

854

SYMPATHY.

of others. The penis, the beard, the vocal
organs, experience a marked increase of de-
velopment at the adult period of life simul-
taneously with the enlargement of the testes;
and, it may be added, in effect of their increase,
because the early removal of these organs pre-
vents the growth of the others. And so like-
wise as the ovaria are developed, the uterus,
the vulva, the mammae, increase in size ; the
ovarian and uterine irritation which accom-
panies the menstrual flux causes enlargement
of the breasts, which subsides as soon as that
period has gone by.

The various examples enumerated in the
preceding paragraphs may be classed under
three heads : first, sympathies between dif-
ferent individuals ; secondly, those which affect
the mind, and, through it, the body; and,
thirdly, those which are strictly organic, and
therefore physical.

Of the first class of sympathies we can offer
no physical explanation. Whether the ner-
vous system of one individual can directly
affect that of another, or whether the effect
is produced on the imagination, and after-
wards on the nervous system, are questions
still sub judice. The serpent fascinates his
prey, apparently by the power of his eyes,
and it is well known that one man can exert
a marked control over another by a mere
look ; and in the same way man can control
other animals, even the fiercest carnivora, by
a firm and decided glance of the eyes. It is
no explanation of sympathetic phenomena of
this kind to ascribe them to the effect of a
tendency to imitation. Imitation is voluntary ;
these actions are involuntary, or take place
even in despite of the will.*

In the second class of sympathetic pheno-
mena, an affection of the mind is a necessary
link. J3ut why that affection of the mind
should produce its peculiar effect is a question
difficult to solve. Why should the perception
of certain odours produce in one case in-
creased action of the salivary glands, and in
the other case cause syncope ? The only reply
which can be made to this question is, that in
these instances the impression on the senso-
rititn causes a change there analogous to that
which an original affection of the mind of
similar kind would produce, and therefore
gives rise to effects of the same nature as
those resulting from that mental change.
Thus the smell of savoury food excites in the
mind the idea of food, which in a hungry man
would, if it occurred spontaneously, occasion
a flow of saliva. And the odour which oc-
casions syncope, creates in the mind an emo-
tion of disgust, which, if it arose independently
of the physical impression, would affect the
heart through the centre of emotion. It. is
plain, however, that that portion of the ner-
vous centre which is affected in such cases,
must have a direct influence upon the parts
in which the sympathetic phenomena appear ;
and this through commissural fibres, or the
continuity of its gray matter with that of the
centre from which its nerves immediately
spring ; thus, in the instances referred to, the
* Bostock’s Physiology, vol. iii. p. 227.

centre of sensation, which is first affected, is,
through the medulla oblongata, connected with
the salivary glands by the fifth nerve, and with
the heart by the vagus.

We derive an explanation of the third
class of sympathetic phenomena from the
known laws of sensitive and motor nerves.
It is known that stimulation of a sensitive
nerve at its origin, or in any part of its course,
will give rise to a sensation which will be re-
ferred to the peripheral extremity of the sti-
mulated fibres ; and that a stimulus applied to
a motor nerve causes a change in it which
spreads peripherad from the point stimulated,
and therefore affects the muscular parts with
which it is connected. It is known also, that
a sentient nerve may excite a motor or sensi-
tive nerve which is implanted near to it in
the nervous centre — doubtless through the
change which it produces in that centre ; nor
can it be doubted that a sensitive nerve may
receive such a powerful stimulus as to exalt
the polar force of a large portion of the
nervous centre in the neighbourhood of its
insertion, and thus to excite a similar change
in all the nerves, whether motor or sensitive,
which are connected with it. Thus, ac-
cording to the intensity of the original stimu-
lus, there will be a radiation of nervous force
from the centre, either in one or two motor
or sensitive nerves, or in several such ; and
the number and variety of the sympathetic
phenomena will thus depend on the intensity
and extent of the change in the nervous
centre excited by the primary stimulus.

To explain, then, the phenomena of sensa-
tion and motion under consideration, we
must determine the individual nerves affected
in each instance, and ascertain what con-
nexions they have with each other. We
learn from anatomical investigation, that, al-
though nerves anastomose with each other in
their distribution, this anastomosis is by no
means of that kind which would justify the
supposition that an irritation could be com-
municated from one to the other in their
course. The nerve-fibres only lie in juxta-
position, but do not communicate ; and there
is an evident provision in the tubular mem-
brane and white substance of Schwann for
the insulation of the central axis, which is
probably the effective substance in the nervous
action. We must seek, therefore, in the
nervous centres for such a communication be-
tween these nerves as may explain the excita-
bility of one by the other. In the present
state of our knowledge we can do' no more
than state it as in the highest degree pro-
bable that nerves implanted in the centre im-
mediately contiguous to each other can exert
an influence upon the vesicular matter of the
centre, and upon each other.

But there are certain faets which demon-
strate beyond all doubt, that, in such actions
as we refer to, the integrity of the centre
forms a necessary condition. First, in many
of the instances it is plain that there can be
no connexion between the affected nerves
elsewhere than in the centre, for they are so
distinct from each other that there is not even

SYMPATHY.

that apparent connexion which results from the
anastomosis of a fasciculus of fibres of the one
with a portion of the other. Secondly, the
removal of the portion of the nervous centre
with which any one of the nerves concerned
in the sympathetic action is connected, will
prevent the development of the phenomenon,
although the nerves themselves remain un-
injured in their peripheral distribution, or in
their connexion with each other. Thirdly, if
there were any peripheral communication be-
tween neryes, it would be most likely to take
place in the plexuses. Experiments, how-
ever, upon the nerves which lead to these
show that each nerve-tube, in its passage
through them, retains its isolation as dis-
tinctly as in any other part of its course.
The three nerves which supply the lower
extremity in the frog, says Muller, form a
plexus from which two nervous trunks issue :
if one of these latter be divided and isolated
from all its connexions with muscles, and the
portion of it connected with the plexus irri-
tated, the impression will be transmitted in
the centripetal direction by the sensitive fibres
of nerve; but the motor fibres of the. other
nerve arising from the plexus are not affected,
and excite no contractions in the muscles to
which they are distributed.*

In applying these principles to the expla-
nation of the instances which we have quoted,
we shall find it difficult to determine the cen-
tral connexion in some, although in others
such a connexion is highly probable. It re-
mains, therefore, for future anatomical re-
search to ascertain what that connexion is
which enables one nerye to sympathise with
another. In the instance of pain in the
shoulder in sympathy with irritation of the
liver, the hepatic irritation excites a change
in some sensitive nerves, which is propagated
to the centre, and there affects some of the
sentient fibres distributed in the region of the
shoulder. The phrenic and the external tho-
racic nerves are both or either of them, but
more especially the former, favourably situ-
ated to constitute the excitant of such a
sympathetic sensation. The phrenic nerve
of the right side is largely distributed upon
the peritoneal surface of the diaphragm, and
upon the inferior vena cava, and forms many
connexions with the hepatic plexus in the
substance of the liver. It may therefore
readily participate in any irritation of that
organ. Now, the phrenic nerve is implanted
in the spinal cord on a level with the third or
fourth cervical nerves ; and the nerves of the
shoulder form their connexion with this cen-
tral organ about the same level. The origins
of these nerves, therefore, are sufficiently
contiguous to each other to warrant the be-
lief that an irritated state of one may be pro-
pagated to the other through the vesicular
matter of the centre. But it may be inquired
why the irritation is limited to sensitive
nerves of the shoulder ; and why movements
are not excited by the stimulation of the
motor fibres of the phrenic itself, or of other
* Baly’s Muller, vol. i. p. 756.

855

nerves. The limitation of the irritation to
one or two nerves depends on the degree of
the stimulus, and the absence of any move-
ments is due to the disposition of the phrenic
nerve on the surface being unfavourable for
the excitation of motions by irritation of its
peripheral branches. And the experiment
cited from Muller, in the last paragraph,
shows that simple irritation of the trunk of a
compound nerve in connexion with the centre
is not sufficient to produce motion ; which
requires probably either a more prolonged
and violent irritation of the nerve, or a polar
state of the centre in which it is implanted.

Some of the instances of sympathetic sen-
sations, referred to above, do not admit of an
explanation so obvious. The pain over the
brow from ice or cold water in the stomach
may be referred to irritation of the gastric
branches of the vagus, communicated in the
medulla oblongata to the fifth ; but why the
irritation should be limited to the ophthalmic
division of the fifth cannot be accounted for
in the present state of our knowledge.

In those sympathetic movements which are
of ordinary and normal occurrence, two pro-
visions seem to be secured, namely, a certain
peripheral organisation of the excitor nerve,
and a certain central relation between it and
the motor nerve. But in those which are of
a morbid kind, it is necessary to suppose the
existence of a more or less exalted polarity
of the centre in order to explain the pheno-
mena fully. This polar state will continue in
many instances even after the primary peri-
pheral irritation has been removed, as in te-
tanus, or in the convulsions from intestinal
irritation ; and we learn from this fact the
importance in practice of attending to the
state of the nervous centre, as well as to the
removal of the irritating cause.

There are other sympathetic phenomena,
of the physical kind, in which, however, the
nervous system does not appear to take a
prominent part. Such are the changes which
occur in different and distant organs in con-
nexion with a particular period of life, or the
development of a particular function. Among
these are the phenomena of puberty in both
sexes ; the enlargement of the mammae in
pregnancy. Whatever part the nervous sys-
tem may take in such changes, it is impos-
sible to account for them by reference to that
system only ; they must rather be regarded
as phenomena of nutrition occurring in har-
mony with the laws of growth, and there-
fore affecting the vital fluid more particularly
than any part of the system of solid parts.

Continuity of texture disposes, as is well
known, to the extension of a diseased state
originating at some one point. So also does,
contiguity. Phlegmonous inflammation of the
areolar tissue, and erysipelas in the skin,
spread with great rapidity. Inflammation
arising in one of the opposed surfaces of a
serous membrane readily attacks the other.
These effects have been vaguely assigned to
sympathy (the continuous and contiguous sym-
pathy of Hunter). But it cannot be supposed

3 i 4

856 TASTE.

that the nervous system takes part in the pro-
duction of sucli phenomena, which ought ra-
ther to be ascribed, in the one case, to the
continuity of blood-vessels, and, in the other,
to contamination either by effused fluids or
by morbid blood. (/?. B. Todd.')

SYNOVIA is that fluid which exists within
the membrane lining joints, to assist motion
by lubrication ; as also in the bursae. The
membranes generally, which line the various
cavities of the body, are lubricated by fluid.
This varies in character according to circum-
stances; and among these perhaps none more
tend to the requirement of especial conditions
than that of active and frequent motion, in-
volving friction of the surfaces so lubricated.

Thus we find that the fluid of the peri-
cardium differs essentially from that of the
ventricles of the brain ; while again the synovia,
supplying moisture to the joints, varies greatly
from the fluid of the pericardium, probably in
order to assist the opposed surfaces in bearing
friction in an exaggerated degree. The word
attrition appears, indeed, the most appropriate
to the conditions relieved by the presence of
synovia, placed as it is between surfaces oc-
casionally strongly approximated either by
superincumbent weight or muscular contrac-
tion.

Synovia was chemically examined by Mar-
gueron.-* The specimen he analysed was
viscid, and became gelatinous soon after it
was obtained. It then deposited a fibrous
matter, and became clear above. Though the
analysis of Margueron was not conducted on
the more exact principles characterising those
of the present day, it still serves to show that
the specimen was peculiar as an animal fluid,
and differed in one respect from the fluids
generally, which lubricate surfaces. Thus it
appears that as much as 1 1 '86 per cent, was
composed of fibrinous matter (fibrin), which
coagulated, as stated before, soon after the
fluid was obtained.

Margueron’s analysis is as follows : —

Fibrin - 11-86

Albumen - 4'52

Chloride of Sodium - - 1’75

Soda - 0 71

Phosphate of Lime - - 0-70

Water - 80’46

100-

Synovia has of late years been examined by
John.-}- It is described as a viscid transparent
yellowish or reddish fluid, resembling in its
odour the serum of the blood. The analysis

is stated as follows : —

Water 92-80

Albumen - 6’40

Extractive Matter, Chloride of
Sodium, and Carbonate of
Soda ----- 0-60

Phosphate of Lime - 0-I5

* Ann, (le Chimie, xiv.

t Simon’s Animal Chemistry. Trans. Sydenham
Society.

It will be seen that these two analyses vary
greatly — they were not made, it must be
recollected, at the same date ; and the methods
of animal analysis are greatly improved since
Margueron published. There is, however, an
important point in which both analyses agree,
viz. in stating phosphate of lime among the
constituents of the fluid. John makes no
mention of the existence of acoagulable fibrin-
ous matter ; a fact of much importance, which
it appears desirable carefully to inquire into,
insomuch as it is very possible the analyst may
have extracted the synovia after coagulation
had occurred within the membrane, and so
obtained the clear fluid only ; while Mar-
gueron may have been fortunate enough to
secure it before such change had taken place,
and in its natural condition.

With regard to this subject, on which our
knowledge is but scanty, it appears still of
importance to reflect on the material before
us ; and it is matter of no small interest to
consider how far the results of peculiar me-
chanical conditions are modified by variations
in the character of lubricating fluids, know-
ing, as we do, that, while the ventricles of the
brain, subject to agitation only, contain no
albumen in their lubricating fluid, the liquor
of the pericardium contains that principle in
abundance ; and that in the synovial fluid
adapted to the lubrication of the joints, we
have, in addition to albumen, not only a con-
siderable proportion of phosphate of lime, but
probably fibrin also, as a necessary consti-
tuent. (G. Owen Rees.)

TASTE. — The sense by which we distin-
guish the sapid properties of bodies. The term,
as commonly understood, includes much more
than this ; being usually employed to desig-
nate the whole of that knowledge of the
qualities of a body (except such as is purely
tactile), which we derive through the sensory
apparatus situated within the mouth. But it
will be hereafter shown tnat a considerable
part of this is dependent upon the assist-
ance of the olfactive sense; which is affected,
through the posterior nares, by the odorous
emanations of all such bodies as are capable
of giving them off ; and the indications of
which are so combined with those of the true
gustative sense, as to make an apparently
single impression upon the sensorium. More-
over, there are certain sensorial impressions
received through the organ of taste, which are
so nearly allied in their character to those of
touch , as to render it difficult to specify any
fundamental difference between them : such
are the pungent sensations produced by mus-
tard, pepper, the essential oils, &c. ; all of
which substanees produce a sensation when
applied for a sufficient length of time to any
part of the cutaneous surface, which can
scarcely be distinguished from that excited
through the organ of taste, in any other way
than by its inferior intensity, and by the ab-
sence of the concurrent odorous emanations.
The taste of such substances might, perhaps,
be considered, therefore, as the composite re-

TASTE.

857

suit of the impressions made upon the senso-
rium through a refined and acute touch, and
by the effect of their odorous emanations upon
the organ of smell. After making full allow-
ance, however, for all such as can be thus ac-
counted for, there remains a large class of pure
sapors, of which we take cognizance without
the assistance of smell, and which are alto-
gether dissimilar to any tactile impressions :
such are the bitter of quinine, the sour of tar-
taric acid, the sweet of sugar, the saline of
common salt, &c. The smell can give us no
assistance in distinguishing small particles of
these bodies, since they are either entirely
inodorous, or so nearly so as only to be
recognizable through its means when in large
masses ; and the most refined touch cannot
afford any indication of that kind of difference
among them, of which we are at once rendered
cognizant by taste. Still the gustative sensa-
tions scarcely differ more from the tactile than
some of these last differ among each other, —
the sense of heat and cold, for example, from
the simple sense of contactor resistance ; and
we shall find that the analogy between these
two senses is so strong, both as to the con-
ditions under which they are respectively ex-
ercised, and the structure of the apparatus
through which the impressions are received,
that they must be regarded as much more
nearly related to each other than either of
them is to the other senses, or than the
latter are amongst themselves.

The seat of the sense of taste is always at
the entrance to the alimentary canal ; and its
purpose is obviously to afford a means of dis-
crimination among the substances introduced
into the mouth as food. The surface of the
tongue is undoubtedly the special organ of
taste in the higher animals ; but there is ade-
quate evidence that the sense is not entirely
restricted to that organ, even in man ; and it
would seem improbable, considering the ob-
vious purpose of the sense, that it should be
wanting in that very large proportion of the
animal kingdom in which no tongue exists,
or in which the surface of that organ is so
hard and horny as to forbid our attributing
to it the possession of gustative sensibility.
Without affirming (with Magendie) that the
specific gustative sensibility extends over the
teeth, the gums, the palate, and the pharynx,
we feel justified in stating that in most persons
it is distinctly present on the surface of the
soft palate, especially in the neighbourhood
of the uvula, and on that of the arches of the
palate and of the fauces; and in a less degree
on the surface of the anterior part of the soft
palate. In making experiments upon this
point, as well as upon many others connected
with the sense of taste, it is important to bear
in mind that if aromatic substances be em-
ployed, the impressions derived through the
sense of smell may confuse the result; and
also that if the sensory surface be too much
exposed to cold air, its sensibility will be
greatly diminished. Further, it should be
borne in mind that a considerable amount of
individual difference may not improbably

exist, both as to the extent of the gustative
surface, and the relative acuteness of the sense
in different parts.

Conditions of the Sense of Taste. — In order
that gustative impressions may be communi-
cated to the sensorium, the first requisite is
an afferent nerve, endowed with the power of
receiving and transmitting them. The gusta-
tive surface in man and the higher animals
being supplied by two afferent nerves,. — the
glosso-pharyngeal, and the lingual branch of
the fifth pair, — we shall have to inquire
whether both of these are subservient to the
sense of taste, as well as to that of touch ; or
whether, as in the case of the organs of smell,
sight, and hearing, there is one nerve of
sptecial and another of general sense. The
peripheral extremities of both these nerves
are in relation with a 'papillary apparatus, in
which they are elevated above the general
surface, and come into close proximity with
capillary loops ; and here, as elsewhere, it
appears certain that the neighbourhood of cir-
culating blood is an essential condition for the
reception of sensory impressions. For the
gustative nerve-fibres to be impressed by the
distinctive properties of sapid substances, it
would further seem requisite that these sub-
stances should be brought into immediate
relation with them, and that they should pene-
trate, in the state of solution, through the
investments of the papillae, into their sub-
stance. This would seem to be proved by
the two following facts ; first, that every sub-
stance which possesses a distinct taste is more
or less soluble in the fluids of the mouth,
whilst substances which are perfectly insoluble
do not make their presence known in any
other way than through the sense of touch ;
and, second, that if the most sapid substance
be applied in a dry state to the papillary sur-
face, and this be also dry, no sensation of
taste is excited. Hence it may be inferred
that, in the reception of gustative impressions,
a change is produced in the molecular condi-
tion of the nerve-fibres, or, to use the lan-
guage of Messrs. Todd and Bowman, their
polarity is excited, by the direct agency of the
sapid matter itself. This change may be in-
duced, however, both by electrical and mecha-
nical stimulation. If we make the tongue
form part of a galvanic circuit, a peculiar sen-
sation is excited, which is certainly allied
rather to the gustative than to the tactile, and
which does not seem to be due (as at one
time supposed) to the decomposition of the
salts of the saliva. And, as Dr. Baly has
pointed out*, “if the end of the finger be
made to strike quickly, but lightly, the surface
of the tongue at its tip, or its edge near the
tip, so as to affect not the substance of the
organ, but merely the papillae, a taste some-
times acid, sometimes saline, like the taste
produced by electricity, will be distinctly per-
ceived. The sensation of taste thus induced
will sometimes continue several seconds after
the application of the mechanical stimulus.”

* Translation of Muller’s Physiology, p. 1062,
note.

858

TASTE.

On the other hand, as Wagner has truly re-
marked, if the surface of the tongue near the
root be touched with a clean dry glass rod, or
a drop of distilled water be placed upon it, a
slightly bitterish sensation is produced ; and
this, if the pressure be continued, passes into
that of nausea, and if the pressure be increased
even excites vomiting. The feeling of nausea
may be excited by mechanical irritation of
any part of the surface of the fauces and soft
palate ; and this feeling is certainly much
more allied to that of taste than to that of
touch. Further, it has been observed by
Henle, that if a small current of air be di-
rected upon the tongue, it gives rise to a cool
saline taste like that of saltpetre. Thus
we find that the peculiar effects of sapid
substances upon the nerves of taste may be
imitated to a certain extent by other agencies .
and it also appears that the sensations excited
by these vary according to the part of the
gustative surface on which they operate; me-
chanical or electrical stimulation of the front
of the tongue giving rise to a kind of saline
taste, whilst mechanical stimulation applied
to the back of the tongue and fauces excites
the feelings of bitterness and nausea.

One of the conditions requisite for the due
exercise of the gustative sense, is a tempera-
ture not departing far on either side from
that which is natural to the body. It appears
from the recent experiments of Prof. fi. H.
Weber * * * §, that if the tongue be kept immersed
for nearly a minute in water of about 125°,
the taste of sugar brought in contact with it,
either in powder or solution, is no longer
perceived ; the sense of touch, usually so
delicate at the tip of the tongue, being also
rendered imperfect. A similar imperfection
of taste and touch was produced by immers-
ing the tongue for the same length of time in
a mixture of water and broken ice.

Nerves of Taste. — Much controversy has
taken place upon the question whether or not
there be a special nerve of taste ; and whether
the lingual branch of the fifth pair, or the
glosso-pharyngeal, possesses the best claim to
this title. The principal points of this con-
troversy have been already noticed [See
Fifth Pair and Glosso-Pharyngeal] ; a
short review of it, however, with a notice of
the most recent inquiries on the subject, will
be here desirable. That the glosso-pharyn-
geal is the special nerve of taste, and that its
complete section on both sides destroys the
sensibility to gustative impressions, was first
affirmed by Panizza ; and his conclusions,
adopted by Dr. M. Hall and Mr. Broughton f,
have been since, to a certain extent, sup-
ported by the experiments of Valentin J and
Bruns.$ The grounds on which this doc-
trine rests are briefly as follows: — After re-

* Muller’s Archiv. 1 847„ S. 342.

f Sixth Report of British Association ; p. 125 of
Transactions of Sections.

J De Functionibus Nervorum Cerebralinm, &c.,
1849, p. 41.

§ De Nervis Cetaceorum,, Tub. 1836 ; quoted by
Muller.

covering from the depression which is the
immediate consequence of the operation, a
dog whose glosso-pharyngeal nerves have been
divided is said to eat pieces of meat rendered
bitter with colocynth, and to drink milk and
water dosed with the same drug, without any
repugnance ; whereas if the lingual nerves
be divided and the glosso-pharyngeals left
entire, the bitter morsel is rejected as soon
as it reaches the back of the mouth, although
it may have been at first seized very hastily.
But, on the contrary, it has been affirmed by
Kornfeld *, with whom Miiller and Gurlt
were associated, by Dr. Alcock-f-, by Dr.
John Reid by Guyot and Cazalis $, by
Magendie||, by Longet^I, and by Volkmann
and Bidder *■*, that distinct indications may
be obtained of the persistence of the sense of
taste, after complete section of the glosso-
pharyngeal nerves on both sides. Of a dog
in which the nerve had been divided before
giving off a single filament, Dr. J. Reid
states : — “I have repeatedly fed that dog
with morsels of animal food from my hand ;
and after he had taken several morsels in this
way, which he readily swallowed, I then pre-
sented a morsel similar in size to the others,
and with the colocynth, concealed in a way
that he could not see it ; but no sooner was
it taken into the mouth than it was rejected
with evident symptoms of disgust. This w'as
repeated more than once.” Bidder found
that although two dogs whose glosso-pharyn-
gei had been divided, swallowed pieces of flesh
soaked in an infusion of colocynth, which
another dog whose nerves were uninjured at
once rejected, yet certain movements of the
lips and tongue were observed, which showed
that these were not altogether relished. It
is obvious that, in such an inquiry, positive
evidence of the continuance of the sense of
taste is more conclusive than the negative
evidence from which its absence may be in-
ferred. It is right to bear in mind that, as
Wagner has pointed out, dogs when they are
hungry will devour meat however strongly
seasoned with bitter drugs, though all their
nerves be entire. Dr. Reid makes the re-
mark, in explanation of the results of Panizza,
that one of the dogs on which he had divided
the glosso-pharyngeal nerves, would eat the
morsel of meat containing colocynth, rather
than lose it, when very hungry \ though he
refused it, if he saw any prospect of procuring
another free from the bitter. Wherever any
such evidence of the persistence of the sense
of taste was obtained, this appeared specially
to exist in the anterior portion of the mouth.

* De Functionibus Nervorum Linguas Experi-
nienta. Berol. 1836.

f Dublin Journal of Medical and Chemical Science,,
1836.

J Edinb. Med. and Surg. Journal, Jan. 1838.

§ Archives Gdnerales de Medecine, 1839.

|| Lemons sur les Fonctions du Systfeme Nerveux,,
1839, tom. ii.

If Anatomie et Physiologie du Systbme Nerveux,
1842, tom. ii. p. 225.

** Articles Nervenphysiologie and Sc/imeclten in
Wagner’s Ilandworterbuch der Physiologie.

TASTE.

859

On the other hand, it has been maintained
by some physiologists (especially Magendie,
Muller, Gurlt, and Kornfeld), that the Un-
gual branch of the fifth pair is the special nerve
of taste ; although Muller does not altogether
exclude the participation of the glosso-pha-
ryngeal as having a share in the transmission
of gustative impressions from the posterior
part of the tongue and the fauces. The ex-
periments of Dr. Alcock and others, however,
appear to show that very distinct indications
of gustative sensibility are presented by ani-
mals in which this nerve has been divided, the
sense being merely deficient in the anterior
part of the tongue.

On the whole, then, it may be concluded
from experiment, that the glosso-pharyngeal
nerve and the lingual branch of the fifth pair
minister alike to the sense of taste ; the for-
mer being concerned in the transmission of
gustative impressions from the fauces anil the
posterior part of the tongue, and the latter
from the anterior portion of the tongue ; and
the former being the special recipient of the
impressions which produce the sense of nau-
sea. This inference is so completely in har-
mony with the results of anatomical inquiry,
that it may be considered as having a very
strong claim to reception as a physiological
truth. The branches of the glosso-pharyn-
geal appear to constitute the sole nervous
supply of that region at the base of the
tongue, of which the circumvallate papillae
form the centre, and also of the sides of the
tongue near the base. As it is universally
admitted that these parts are acutely endowed
with gustative sensibility, we cannot help re-
garding the glosso-pharyngeal nerve as its
instrument. On the other hand, the middle
and anterior parts of the dorsum of the tongue
appear to be solely supplied from the fifth pair,

— the tip, however, receiving a branch from
the glosso-pharyngeal, which runs towards it,
along the under surface. It has been denied
by some physiologists that the central por-
tion of the upper surface possesses the proper
gustative sensibility ; but we fully coincide in
the statements of those who maintain the
affirmative : and although it must be admitted
that the sense is not so acute as it is at the
base, sides, and apex of the tongue ; yet this
may be fairly attributed to the greater thick-
ness of the epithelial investment, and to the
predominance of the conical papillae over the
fungiform in the central region.

On turning to the pathological evidence
which bears upon this question, we find an
apparent contradiction in the phenomena re-
corded by different observers ; but this is in a
great degree removed by a more careful ex-
amination; and the evidence on the whole
preponderates in favour of the preceding con-
clusions. We shall make use of the excellent
summary recently put forth by Dr. J. Reid* :

— “ In the single cases observed and recorded
by Mayo, Serres, Romberg, Mr. Bishop, and
Todd and Bowman, and in the two cases by

* Physiological, Pathological, and Anatomical
Researches, p. 268.

Mr. Dixon, both common sensation and (he
sense of taste were annihilated in those parts
of the tongue supplied by the fifth pair ; while
in one case related by Mr. Noble, and ano-
ther by Vogt, common sensation was lost in
the parts of the tongue supplied by the third
branch of the fifth pair, yet the sense of taste
remained in these parts; and in a second case
related by Mr. Noble, there was loss of taste
with maintenance of feeling.” In some of
these cases the loss of the sense of taste ap-
peared to extend to the base of the tongue ;
but there was evidence that in these the
glosso-pharyngeal nerve was also involved in
the paralysis. “ We have no proof,” con-
tinues Dr. Reid, “ that in the cases related by
Mr. Noble and Vogt, the whole of the fila-
ments of the fifth pair sent to the tongue
were affected ; and in the case of Vogt the
derangement of the nerve was only tempo-
rary, for the patient recovered the sensation
of the part paralysed after the end of six
weeks. We believe that these cases, when
examined more closely, will rather be regard-
ed as affording arguments in favour of the
opinion, that the same nervous filaments do
not convey inwards the impressions which
excite pain and touch and the impressions
which excite taste ; and that different fila-
ments for conveying inwards the impressions
that excite these sensations are bound up in
the lingual branch of the fifth pair.” There
is believed to be no case on record, in which
the whole of the fifth pair, or of the third
branch of it, was found to be diseased after
death, and in which, during life, the sense of
taste had been retained in the anterior and
middle parts of the tongue. The evidence of
pathology, therefore, is in favour of that con-
clusion, as to the participation of the fifth
pair with the glosso-pharyngeal in the sense
of taste, at which we had arrived on other
grounds.

The question still remains, however, as to
the speciality of the nervous fibres which con-
vey the gustative impressions ; that is, whether
they are the common sensory fibres, whose
peculiarity of function depends on the nature
of the papillary apparatus at their peripheral
origin ; or whether they are incapable, like
the fibres of the olfactive, optic, and auditory
nerves, of conveying impressions of the ordi-
nary sensorial kind, being adapted exclusively
to receive and transmit the peculiar impres-
sions made by sapid bodies. Now, in favour
of the first view, it may be urged, that the
conditions of the sense of taste are so nearly
allied to those required for the exercise of
touch, that the two can scarcely be dis-
tinguished on this ground, and that the fifth
pair and the glosso-pharyngeal are both nerves
of common as well as of gustative sensibility ;
neither of which can be affirmed in regard to
the three other senses, or of the nerves which
minister to them. But, on the other hand, it
must be remarked, that these nerves do not
seem to be endowed with gustative and com-
mon sensibility in equal proportions ; for the
glosso-pharyngeal, which is decidedly more

8G0

TASTE.

susceptible than the lingual to gustative im-
pressions, far less readily excites manifesta-
tions of pain when subjected to mechanical
irritation. Hence, it would seem not im-
probable, that there may be in each a mixture
of the fibres which minister to the sense of
taste with those of tactile sensibility ; and
that the former may be so far special in their
endowments, as to be capable of receiving
only the peculiar impressions made by sapid
bodies, to which the latter may be insensible.
Such a view would seem to be supported by
the cases of Vogt and Noble just referred to ;
and it is in harmony with the views to which
we are led from the consideration of the
diversities manifested between the sense of
heat and cold and that of simple contact. [See
Touch.]

Gustative Papilla:. — The tongue is copiously
furnished with a papillary structure, bearing
a close resemblance to that of the skin, but
in many respects more complicated. Re-
ferring to the article Tongue for a more par-
ticular anatomical description of these papillae,
we have now to inquire into their connexion
with the sense of taste. According to the
recent investigations of Messrs. Todd and
Bowman, the lingual papillae are either simple
or compound ; the former, which do not differ
from those of the cutaneous surface in any
other obvious character than the nature of
their epithelial investment, are scattered over
the whole surface of the tongue, in parts where
the others do not exist, but they also par-
ticipate in the formation of the compound
papillae ; the latter are of three kinds, the cir-
cumvallate or calj/ciform, the fungiform, and the
conical. — The circumvallate papillae, which are
only eight or ten in number, and are restricted
to a small space at the base of the tongue,
consist merely of groups of simple papillae,
arranged in a peculiar manner, and separated
from those of the adjacent mucous membrane
by a circular fissure. Into these simple papillae
it has not yet been found possible to trace
any distinct nerve-fibres, though there can be
little doubt that it is penetrated by at least
the essential part of them. — The fungiform
papilla; are scattered singly over the surface,
chiefly about the sides and apex, and but very
sparingly in the middle of the dorsal region,
though they are abundant in front of the cir-
cumvallate papillae. These are composed of
aggregations of simple papillae, which rise,
however, considerably above the surface, and
are covered with an epithelium so thin that
they are distinguished by their blood-red
colour. Fasciculi of nerve-tubes may be dis-
tinctly traced into them ; but of the nature
of their termination it would be unwise to
give a positive statement. Some of the ap-
pearances presented by them favour the idea
that they form loops at their peripheral ex-
tremities ; whilst, in other instances, the tu-
bular portion of the fibre, with the white
substance of Schwann, seems to terminate
somewhat abruptly, whilst the central axis is
continued onwards into the substance of the
enveloping t'ssue, in which it loses itself.

— The conical or filiform, which are the most
numerous of the compound papillae, are dif-
fused over the whole surface of the tongue,
though most largely and numerously de-
veloped in its central part. They consist of
clusters of simple papillae of a peculiarly
elongated form, containing tubular nerve-
fibres, which may frequently be seen to form
distinct loops in their interior ; but their chief
peculiarity consists in their epithelial invest-
ment, which forms about two-thirds of their
length, and gives to them their whitish tint.
Tliis investment consists of a tuft of long
pointed processes, some of which present a
near approach in their dense texture to hair ;
whilst others may be regarded as soft or un-
condensed hairs. These processes are sent off
from the sides and summits of the secondary
papillae, and are usually inclined backwards,
lying buried in the recesses of the mouth.
The foregoing description applies, however,
only to the conical papillae of the human
tongue ; and there is a considerable diversity
in their structure in other animals. Thus, in
the Ruminants, each conical papilla is ter-
minated by a long, slender, flexible, horny
filament, curving backwards ; and in the Fe-
lines some of them are furnished with a brush-
like tuft of slender horny filaments, like those
of man*, whilst others are encased by firm
horny sheaths, which are prolonged backwards
as stiff spines. It is to this arrangement that
the peculiar roughness of the tongue of the
cat is due ; the organ being thus enabled to
act as a flexible rasp, whereby the bones
which they lick may be effectually cleaned of
the smallest particles of flesh that may adhere
to them ; and a single stroke of the tongue of
a lion is said to be capable of abrading the
whole thickness of the human skin.

After what has been already said of the
conditions essential to the exercise of the
sense of taste, there is no occasion to do
more than point out the evident fact, that, if
some of the papillae be covered with an epi-
thelial investment so dense as to resemble
horn, and offering an effectual barrier to the
penetration of fluids, these cannot be sup-
posed to have much participation in the
sense, if they possess any. It is obvious that
in the Felines the function of the spiny pa-
pillae must be purely mechanical ; and it
seems probable that the brush-like papillae
which lie among them, in common with those of
man, possess simple tactile sensibility, serving
to direct those muscular actions of the organ,
which so remarkably adapt it to deal with
minute particles of food. On the other hand,
the thinness of the epithelial investment on the
simple papillae which are scattered over the
surface of the tongue, and which form the
circumvallate and fungiform papillae by their
aggregation, indicates their special adaptation
to receive gustative impressions ; and this must
be admitted to be more especially the case
with the fungiform papillae, which often

* By Cuvier these filaments are supposed to be
the ultimate fasciculi of the fibres of the gustative
nerve ; but this is certainly an error.

TASTE.

undergo a kind of erection when sapid sub-
stances are brought into contact with them.
This inference is in complete harmony with
the relative acuteness of the senses of taste
and touch, in the portions of the surface on
which the one or the other class of papillae
is most abundant ; thus the sides and back
part of the tongue are unquestionably the
parts where the gustative sensibility is the
greatest, and it is there that the fungiform,
circumvallate, and simple papillae are most
thickly set; whilst the apex and central part
of the dorsum, over which the tactile sensi-
bility is predominant, is that on which we
meet with the largest number of filiform
papillae. Whether there be any difference
among the simple isolated papillae, and among
those which are aggregated into the com-
posite bodies that are termed fungiform and
circumvallate, we are scarcely in a con-
dition even to form a guess, until it shall
have been determined whether the gustative
and tactile nerve-fibres are identical or diverse
in their endowments. If the former, it will
be reasonable to suppose that every papilla
through which a gustative impression can be
made in virtue of the penetration of sapid
matter into its tissue, may also be subservient
to the reception of tactile impressions from
mechanical stimulation. On the other hand,
if it should be proved that the gustative sense
depends on a special set of fibres, we should
still have to inquire whether the same papilla
may not contain fibres of both classes, so as to
minister to both functions ; or whether some
of the papillae are purely gustative, whilst
others are purely tactile.

At present there is no adequate reason to
suppose that there is any essential difference
of function among the papillae covered with a
soft thin epithelium, whether these be solitary
or aggregate. An attempt was made by
Horn * to establish some such diversity ; but
the results of his experiments would rather
lead to the supposition that there is a dif-
ference in the gustative sensations excited by
the same substance, according as it is applied
to different regions of the tongue, than to
different papillae. Thus he found that more
than three-iourths of the substances which he
applied to the circumvallate papilla; excited
a bitter taste, or one in which a bitter was
associated with some other flavour, especi-
ally an alkaline or saline ; whilst the majority
of the substances applied to the filiform
papillae tasted acid, or acid with a mixture of
bitter and sweet. But since, as we have
seen, mere mechanical stimulation produces
different gustative sensations according to the
part of the tongue to which it is applied, it is
probable that the difference in Horn’s results
is not to be set down to the account of the
papilla?, but rather to that of the nerves by
which they are respectively supplied.

Exercise of the Sense. — The simple appli-
cation of a sapid substance to the gustative
surface is usually sufficient to excite the sen-

* Ueber den Geschmacksinn des Mensehen. Hei-
delberg, 1825.

861

sation ; and if this application be restricted
to one particular spot, we are able to recog-
nise its place more or less distinctly. In tins
respect, then, the gustative impression resem-
bles the tactile ; for whilst we cannot, by our
own consciousness, distinguish the parts of
the retina or of the auditory apparatus on
which visual or auditory impressions are
made, we can make this distinction in regard
to the surface which is supplied by the
nerves of general sense. This determination
is most precise when the impression is made
on the parts of the tongue of which the gus-
tative sensibility is most acute ; namely, the
apex, sides, and posterior part of the dorsum;
being probably aided, however, near the tip,
by the acuteness of its tactile sensibility. The
impressibility of the middle portion of the
dorsum is greatly inferior ; but still, when
the gustative sensation has been excited
there, it is referred to the spot on which the
sapid substance was laid. The contact of
sapid substances much more readily excites a
gustative sensation, when it is made to press
upon the papillae, or to move over them.
Thus there are some substances whose taste
is not perceived when they are simply applied
to the central part of the dorsum of the
tongue, but of whose presence we are at once
rendered cognizant by pressing the tongue
against the roof of the mouth. The full
flavour of a sapid substance, again, is more
readily perceived when it is rubbed on any
part of the tongue, than when it is simply
brought in contact with it or pressed against
it. Even when liquids are taken into the
mouth, their taste is most completely discri-
minated by causing them to move over the
gustative surface : thus the “ wine-taster ”
takes a small quantity of the liquor into his
mouth, carries it rapidly over every part of
its lining membrane, and then ejects it. It is
not improbable that this exaltation of the
usual effects is simply due to mechanica
causes ; the sapid particles being brought by
the pressure or movement into more rapid
and complete operation on the nerve-fibres,
than they would be if simply placed in con-
tact with the papilla;.

As in the case of the other senses, so do
we find with regard to that of taste, that
continual attention to its indications greatly
increases its acuteness. Thus the “tasters”
of wine, tea, &c., acquire a power of discrimi-
nation which is truly wonderful to those who
have not exercised themselves in the same
manner. Thus we have been informed that
the “ taster ” to one of the extensive cellars
of sherry wines at Cadiz or Seville has not
the least difficulty in distinguishing the butt
from which a given sample may have been
drawn, although the number of different va-
rieties of the same kind of wine under his
keeping may not be less than five hundred.
So we are informed by Dr. Kitchener that
many London epicures are capable of saying
in what precise reach of the Thames the
salmon on the table has been caught; and the
Parisian gourmet is said to be able to distin-

8G2

TASTE.

guish by the taste, whether the birds on which
he is dining are domesticated or wild, male or
female, or to give an exact determination of
the spices, &c., that are combined in a parti-
cular sauce.

On the other hand, the power of distin-
guishing sapors is for a time suspended, when
several substances of very decided but dif-
ferent tastes are taken into the mouth in
quick succession : thus, if sweet, sour, salt, or
bitter substances be applied to the tongue, or
if different kinds of wine be taken, one after
another, the sense is so much blunted after a
short time, as to impair or destroy the power
of discrimination between them until after an
interval of rest. So, again, when two sub-
stances of very different flavours are mingled
together, the stronger will frequently mask
the presence of the weaker : thus we often
find it advantageous, in prescribing nauseous
medicines, to combine with them aromatics,
whose stronger impression shall take posses-
sion (so to speak) of the sense for a time ;
and the object may be still more completely
attained by giving the aromatic a moment or
two previously, instead of simultaneously
with the disagreeable substance.

The influence of habit in blunting the sen-
sibility to particular tastes, is as remarkable
as it is in the case of other sensations. Still
more extraordinary, however, is the degree in
which the taste may be educated to approve
savours which are in the first instance most
disgusting. “Thus,” says Dr. Dunglison*,
“ the Roman liquamen or garum, the most
celebrated sauce of antiquity, was prepared
from the half-putrid intestines of fish ; and
one of the varieties of the Ottos mXtptov, or
laserpitium , is supposed to have been the
assafcetida. Even at this time, certain of
the Orientals are fond of the flavour of this
nauseous substance. Putrid meat is the de-
light of some nations ; and a rotten egg, es-
pecially if accompanied with the chick, is
highly esteemed by the Siamese. In civilised
countries, we find game, in a putrescent state,
eaten as a luxury ; this, to those unaccus-
tomed to it, requires a true education. The
same may be said of the pickled olive, and of
several cheeses ; the fromage cle Gruy'ere, for
example, so much esteemed by the inhabitants
of continental Europe.” Very extraordinary
appetencies for particular flavours are some-
times morbidly developed ; as in the case of
chlorotic girls, pregnant women, and insane
patients. The latter will sometimes even
devour their own excrement.

Independently of the changes produced by
the education of the taste, we find great al-
terations in the likes and dislikes connected
with it, taking place in accordance with the
development of the body, or with other
changes in its physiological conditions. Thus
to the infant there is obviously nothing so
agreeable as milk ; in more advanced child-
hood there is almost invariably a fondness for
sweets ; whilst after adult age this is usually
in a great degree superseded by a preference
* Human Physiology, vol. i. p. 116.

for other savours. It sometimes happens that
articles of diet which were peculiarly agree-
able to us in childhood, become positively
disgusting to us in later life ; whilst, on the
contrary, many things to which we feel a
strong distaste in childhood, are relished when
we come to be men, and this by a sponta-
neous change in our own appetencies. We
fully believe with Wagner that these altera-
tions are in some way connected with the
physical condition of the nutritive functions ;
for we have other examples in which this
connexion is very evident. Thus, we may
continually remark that articles of food for
which we have the keenest relish when we
commence a meal with a good appetite, be-
come positively distasteful when we have al-
ready satisfied it. Again, we have known per-
sons who have a positive repugnance to fatty or
oleaginous matters of almost any description,
so long as they reside in temperate climates,
but who eat them with avidity when exposed
to the severe cold of the arctic winter. And
even in our own country we may frequently
remark that the taste for such articles varies
with the temperature ; a cup of sweet olea-
ginous cocoa, which would be almost loathed
on a hot summer day, being very palatable on
a cold winter night ; whilst ascescent drinks,
such as would be greatly relished in the
former season, are altogether discarded in the
latter, except when a heated atmosphere
brings back the physical condition of the
system which renders them palatable.

So, again, we often observe in illness that
an alteration in the physical conditions of the
system so far affects the sense of taste, as to
produce a great alteration in the usual appe-
tencies. These alterations may probably be
due in some instances to the depravation of
the buccal secretions, so that the gustative
papillae are constantly surrounded with a sub-
stance possessing a certain taste of its own,
which of course affects their impressibility by
other savours. But there can be little doubt
that they are more commonly occasioned by
alterations in the condition of the gustative
apparatus itself, which becomes the exponent
(so to speak) of the wants of the system, and
which may be trusted, to a very considerable
extent, as indicating what is really most de-
sirable for it. Thus Dr. Holland remarks * :
— “In the majority of instances of actual
illness, provided the real feelings of the pa-
tient can be safely ascertained, his desires as
to food and drink may be safely complied
with. But undoubtedly much care is need-
ful that we be not deceived as to the state
of the appetites by what is merely habit or
wrong impression on the part of the patient,
or the effect of the solicitation of others. This
class of sensations is more nurtured out of
the course of nature than are those which
relate to the temperature of the body. The
mind becomes much more deeply engaged
with them ; and though in acute illness they
are generally submitted again to the natural
law, there are many lesser cases where
* Medical Notes and Reflections, p. 85.

TASTE.

863

enough remains of the leaven of habit to
render every precaution needful. With such
precautions, however, which every physician
who can take schooling from experience will
employ, the stomach of the patient becomes a
valuable guide ; whether it dictate abstinence
from a recurrence to food ; whether much or
little in quantity; whether what is solid or
liquid; whether much drink or little; whe-
ther things warm or cold ; whether sweet,
acid, or saline ; whether bland or stimulating
to the taste.” Further, Dr. Holland remarks ;
“ It is not wholly paradoxical to say that we
are authorised to give greatest heed to the
stomach when it suggests some seeming ex-
travagance of diet. It may be that this is a
mere depravation of the sense of taste ; but
frequently it expresses an actual need of the
stomach either in aid of its own functions or
indirectly (under the mysterious law just re-
ferred to) for the effecting of changes in the
whole mass of blood. It is a good practical
rule in such cases to withhold assent till we
find after a certain lapse of time that the same
desire continues or strongly recurs ; in which
case it may generally be taken as the index of
the fitness of the thing desired for the actual
state of the organs. In the early stage of
recovery from long gastric fevers, I recollect
many curious instances of such contrariety to
all rule being acquiesced in, with manifest
good to the patient. Dietetics must become
a much more exact branch of knowledge,
before we can be justified in opposing its
maxims to the natural and repeated sugges-
tions of the stomach, in the state either of
health or disease.” In regard to the use of
wine in fever, it is universally admitted by prac-
tical physicians that very important indica-
tions may frequently be drawn from the appe-
tency or dislike manifested towards it by the
patient ; this being often exhibited when there
is an almost entire obtuseness of the mind in
regard to all other external impressions. In
such circumstances these dormant instincts
seem to manifest themselves, which are kept
under by the intelligence in the normal con-
dition; instincts akin to those which guide the
lower animals in then- choice of food. There
is probably not a plant, however poisonous to
most, which has not one or more species of
animal specially adapted to derive from it
wholesome nutriment, and which is obviously
drawn to it by its odour or savour ; 'whilst
the most omnivorous feeders, such as the
monkey, are usually restrained by dislikes,
excited through these same senses, from
touching fruits which would be noxious to
them.

It cannot be doubted that, in all persons
of ordinary aptitude for the discrimination of
flavours, there are certain natural harmonies
and discords among these, as among colours
and sounds ; so that particular substances of
very different flavours taste agreeably in com-
bination, whilst others are mutually repug-
nant. Thus every body likes sugar in combi-
nation with the acid of fruits ; and the sugar
is popularly believed to neutralise the acid,

which (as we need scarcely say) is not at all
the case. On the other hand, sugar and
oysters are said to form one of the most
nauseous combinations possible. So, again,
the flavour of many wines is improved by
being tasted simultaneously with cheese, whilst
it is injured by fruits. — The art of cookery is
founded upon a knowledge of these facts,
which have not yet perhaps received from the
scientific physiologist the systematic atten-
tion they deserve. Attempts have been made
by Linnaeus, Boerhaave, and others, to form
a classification of savours ; but no such clas-
sification has come into general use, although
there are certain savours which all agree to
consider ’primary ; such as the aromatic, the
sweet, the acid, the bitter, the saline , the
astringent, and the pungent. By the first of
these the sense of taste is connected with that
of smell ; by the last two with that of touch.

The impressions made upon the sense of
taste seem to remain longer after the with-
drawal of the body that excited them, than
those which are received through most of our
other senses. This is not surprising, when it
is considered that particles of the sapid sub-
stance, which have once penetrated the pa-
pill®, may linger there in contact with the
sentient extremities of the nerves, for some
little time after they have passed away from
the external surface. In many cases, how-
ever, the substance leaves an after-taste which
is different from that which it first excited.
It is difficult to say how much of this may be
due to the difference of the impression which
is made upon the sensory papillae at the front
of the tongue and upon those at its base, and
also to the admixture of the olfactive sense,
which will be most actively called into play as
the sapid body is passing the fauces; and how
much to the exhaustion of the nerves conse-
quent upon their previous stimulation, so that
the after-taste is complementary to that first
received. It certainly appears to confirm the
former explanation, that the after-taste is
generally of that bitterish character which we
have seen to be produced by the mere me-
chanical stimulation of the papillae at the base
of the tongue. On the other hand, the fact
that tannin, one of the bitterest substances
known, has a sweetish after-taste, seems to
favour the latter view. Probably both causes
may participate in the production of the re-
sult.

It is not very common to find the sense of
taste excited in a purely subjective manner ;
since many of the tastes which are experienced
in disease are probably due, as already re-
marked, to the depravation of the buccal
secretions. Nevertheless, we occasionally
meet with instances in which some peculiar
gustative sensation, usually of a disagreeable
nature, is constantly experienced without
being traceable to any such cause ; and in
which, therefore, we must seek for its occasion
in some disordered functional condition of the
sensorium.

The purpose of the sense of taste is obviously
to serve as the guide and attraction towards

864

TEETH.

wholesome food, and to afford pleasure in the
reception of it, whilst it deters from the use of
such as would be deleterious. This is more
obvious in the lower animals than it is in man,
who is frequently led by habit and fashion to
a preference for substances which are high-
flavoured over those which are most whole-
some, and who is still more frequently induced
to gratify his gustative sense by the reception
of an amount of food which appetite alone
would not incite him to take in. Of the
pernicious results of such excess, this is not
the place to speak.

The only ulterior purposes which the sense
of taste appears to perform in the economy,
are to aid in exciting the flow of saliva, and
in certain cases to excite the act of vomiting.
Although the secretion of saliva is greatly
affected by other causes, — as, for example, by
the movement of the jaws, tongue, &c., — yet
it is much influenced by the sapid qualities of
the food introduced into the mouth, being
greatly increased by the taste of savoury food.
It is also augmented by the sight or odour of
such food ; but it is probable that the latter
sensations influence it not so much directly
as indirectly, namely, through the ideas which
they call up, for the idea alone, if called up
with sufficient vividness, is sufficient to make
“ the mouth water.” The sense of nausea, as
already remarked, seems intermediate between
taste and touch ; but it is connected most
closely with the former. We experience more
or less of difficulty in swallowing all substances
whose taste is peculiarly repugnant to us, and
we find ourselves compelled to regurgitate
them when the impression becomes of a
certain intensity. This is one of the auto-
matic actions in which it appears requisite
that a sensation, not a mere impression, should
participate.

( William B. Carpenter.')

TEETH. — Comparative Anatomy. (Sing.
a tooth; Tunth, Teut. ; Dens, Lat. ; Dente, Ital. ;
Dent, Fr.; Tand, Dan. ; Tain, Old English ;
Zahn, Germ. ; Dant, Welsh ; Dend, Erse ;
oOovc-coovroc, Gr. ; Dantis, Lithuanic; Dantas,
Sanscrit.*) A tootli is a hard body attached to
the mouth or commencement of the alimentary
canal, always exposed, save where its develop-
ment is permanently arrested, as in the rudi-
mental tusk of the Narwhal; commonly cal-
cified, the exceptions being few, e. g., the
horny teeth of the Lamprey and Platypus.
Teeth vary not only in their tissue, but still
more in number, size, form, structure, position,
and mode of attachment, in different animals :
they are principally adapted for seizing, tear-
ing, dividing, pounding, or grinding the food ;
in some they are modified to serve as wea-
pons of offence and defence ; in others as aids
in locomotion, means of anchorage, instru-

* These synonyms are cited as illustrative of the
coincidence in one of the primary words of a natural
class of languages that prevails from the East Indies,
through the west of Asia and across Europe, and as
indicative of the unity of stock of the great Indo-
European family of mankind.

ments for uprooting or cutting down trees,
or for transport and working of building
materials ; they are characteristic of age and
sex ; and in man they have secondary rela-
tions subservient to beauty and to speech.

Teeth are always most intimately related to
the food and habits of the animal, and are
therefore highly interesting to the physiolo-
gist : they form for the same reason most
important guides to the naturalist in the
classification of animals ; and their value, as
zoological characters, is enhanced by the
facility with which, from their position, they
can be examined in living or recent animals ;
whilst the durability of their tissues renders
them not less available to the paleontologist
in the determination of the nature and affi-
nities of extinct species, of whose organisation
they are often the sole remains discoverable
in the deposits of former periods of the earth’s
history.

Although there are many analogous struc-
tures in the inverterbrate classes, true calcified
teeth are peculiar to the Vertebrata, and may
be defined as bodies primarily, if not perma-
nently, distinct from the skeleton, consisting
of a cellular and tubular basis of animal
matter containing earthy particles, a fluid, and
a vascular pulp.

In general, the earth is present in such
quantity as to render the tooth harder than
bone, in which case the animal basis is gela-
tinous, as in other hard parts where a great
proportion of earth is combined with animal
matter. In a very few instances among the
vertebrate animals, the hardening material
exists in a much smaller proportion, and the
animal basis is albuminous ; the teeth here
agree, in both chemical and physical qualities,
with horn.

True teeth consist commonly of two or
more tissues, characterised by the proportions
of their earthy and animal constituents, and
by the size, form, and direction of the cavities
in the animal basis which contain the earth,
the fluid, or the vascular pulp.

The tissue which forms the body of the
tooth is called “dentine,” (Dentinum, Lat.;
Zahnbein, Zalmsubstanz, Germ. ; I’lvoire*, Fr.)

The tissue which forms the outer crust
of the tooth is called “ cement ” ( ccementum ,
crusta pietrosa, Lat.).

* The learned author of the article “ Secretions,”
in the “ Dictionnaire Universel d’Histoire Naturelle,”
8vo, 1848, adopts the term “ Dentine ” in preference
to Cuvier’s name “ ivoire,” and after defining its
properties, observes, “ Sur ces divers rapports, le
mot dentine, par lequel M. R. Owen les ddsigne, me
parait trfes lieureux.” The term “ ivory ” unavoid-
ably recalls the idea of the peculiar modification of
“ dentine,” which characterises the tusks of the ele-
phant, mammoth, and mastodon; but, besides this
objection to its more general application, the word,
is used in a still wider sense in the “ Lemons d’Ana-
tomie Comparee : ” “ Les unes (dents), en effet, out
la partie enfonce'e dans l’alveole denue'e d’email ;
cette partie, ou la racine, ne se compose gene'ralement
que de V ivoire intdrieure, recouvert trds rarement
d 'ivoire exterieure (les dents de cachalot) ; ” tom. iv.
Ed. posth. 1836, p. 200. The example cited of the
tissue here denominated “ ivoire exterieure ” is the
“ cement.” See my “ Odontography,” p. 355, pi. 89.

TEETH.

865

The third tissue, when present, is situated
between the dentine and cement, and is called
“enamel” ( encaustum , adamas, Lat.).

“ Dentine ” consists of an organised animal
basis disposed in the form of extremely minute
tubes and cells, and of earthy particles : these
particles have a twofold arrangement, being
either blended with the animal matter of the
interspaces and parietes of the tubes and cells,
or contained in a minutely granular state in
their cavities. The density of the dentine
arises principally from the proportion of earth
in the first of these states of combination, the
tubes and cells contain, besides the granular
earth, a colourless fluid, probably transuded
“ plasma” or “ liquor sanguinis,” and thus re-
late not only to the mechanical conditions of
the tooth, but to the vitality and nutrition of
the dentine.

This typical structure of dentine is well
illustrated in the article Tooth : such “ true
dentine” has no canals large enough to ad-
mit capillary vessels with the red particles of
blood, and it has been therefore called “ un-
vascular dentine.”

The simplest modification of dentine is that
in which capillary tracts of the primitive vas-
cular pulp remain uncalcified, and permanently
carry red blood into the substance of the
tissue. These so-called “ medullary canals ”
or “ vascular canals ” present various disposi-
tions in the dentine which they modify, and
which I have proposed to call “ vaso-dentine.”
It is often combined with true dentine in the
same tooth ; e.g. in the scalpriform incisors
of certain Rodents*, the tusks of the Ele-
phant f , the molars of the extinct Iguanodon.J

A third modification of the fundamental
tissue of the tooth is where the cellular basis
of the dentine is arranged in concentric layers
around the vascular canals, and contains “ ra-
diated cells ” like those of the osseous tissue :
it is called “ osteo-dentine.” The transition
from dentine to vaso-dentine, and from this to
osteo-dentine, is gradual, and the resemblance
of osteo-dentine to true bone is very close.

“ Cement ” always closely corresponds in
texture with the osseous tissue of the same
animal ; and wherever it occurs of sufficient
thickness, as upon the teeth of the horse,
sloth, or ruminant, it is also traversed, like
bone, by vascular canals. In reptiles and
mammals, in which the animal basis of the
bones of the skeleton is excavated by minute
radiated cells, forming with their contents the
“ corpuscles of Purkinje,” these are likewise
present, of similar size and form, in the
“ cement,” and are its chief characteristic as a
constituent of the tooth. The hardening ma-
terial of the cement is partly segregated and
combined with the parietes of the radiated
cells and canals, and is partly contained in
disgregated granules in the cells, which are
thus rendered white and opaque, viewed by
reflected light. The relative density of the
dentine and cement varies according to the

* Odontography, 4to, p. 405.
t lb. p. 643.
t lb. p. 251.

VOL. IV.

proportion of the earthy material, and chiefly
of that part which is combined with the
animal matter in the walls of the cavities, as
compared with the size and number of the
cavities themselves. In the complex grinders
of the elephant, the masked boar, and the
capybara, the cement, which forms nearly half
the mass of the tooth, wears down sooner
than the dentine.

The “ enamel ” is the hardest constituent
of a tooth, and, consequently, the hardest of
animal tissues; but it consists, like the other
dental substances, of earthy matter arranged
by organic forces in an animal matrix. Here,
however, the earth is mainly contained in the
canals of the animal membrane ; and, in
mammals and reptiles, completely fills those
canals, which are comparatively wide, whilst
their parietes are of extreme tenuity. The
hardening salts of the enamel are not only
present in far greater proportion than in the
other dental tissues ; but, in some animals,
are peculiarly distinguished by the presence
of fluate of lime.

The following are characteristic examples
of the above-defined tissues, and their different
combinations, in different teeth.

The examples are extremely few, and, as
far as I know, are peculiar to the class Pisces,
of calcified teeth which consist of a single
tissue, and this is always a modification of
dentine. The large pharyngeal teeth of the
Wrasse ( Labrus ) consist of a very hard kind
of unvascular dentine. Fig. 544. shows a ver-

Fig. 544.

Section of pharyngeal tooth of Lahnis, magnified.

,( Owen’s Odontography .)]

tical section of one of these teeth, supported
upon the very vascular osseous tissue of the
pharyngeal bone : p is the pulp cavity'.

The next stage of complexity is where a
portion of the dentine is modified by vascular
canals. Teeth, thus composed of dentine
and vaso-dentine, are very common in fishes.
The hard dentine is always external, and
holds the place, and performs the office, of
enamel in the teeth of higher animals ; but it
is only analogous to enamel, not the same

3 IC

HGG

TEETH.

tissue.* Fig. 545. illustrates this structure in
a longitudinal section of a tooth of a shark of

Fig. 515.

Fig. 517.

Section of tooth of Lamna, magnified.

( Owen's Odontography .)

the genus Lamna : v is the vaso-dentine ; d
the hard dentine; the earthy constituent so

F/g. 516.

Section of tooth of Cachalot ( Physeter ).

predominates that the tissue
takes a polish like enamel, for
which it has commonly been
mistaken in the teeth of fishes :
I have called it “ vitro-den-
tine.”

The molars of the Dugong
are examples of teeth com-
posed of dentine and cement,
the latter tissue forming a
thick external layer. Fig.
54G. A. is a transverse section
of the crown of the second
molar, natural size ; and B.
a magnified view of a por-
tion of the section ; d the
dentine, remarkable for the
number of minute calcigerous
cells at its periphery ; and c
the cement.

In the great teeth of the
lower jaw of the Cachalot,
the pulp-cavity of the growing
tooth becomes filled up by
osteo-dentine, the result of a modified calci-
fication of the dentinal pulp ; and the full-
grown tooth presents three tissues, as shown

Section of tooth of Dugong ( Ilalicore ), magnified.
* Odontography, pp. 17. 37.

TEETH.

S67

in fig. 5-17., in which c is the thick external
cement, d the hard dentine, and o the osteo-
dentine ; sometimes developed in loose stalac-
titic-shaped nodules.

In the teeth of the Sloth, and its great
extinct congener, the Megatherium, the hard
dentine is reduced to a thin layer, and the
chief bulk of the tooth is made up of a
central body of vaso-dentine, anti a thick ex-
ternal crust of cement. Fig. 5-18. represents a

F/g. 518.

d d

Section of tooth of Megatherium.

longitudinal section of a lower molar of the
Megatherium, of half the natural size : v is
the vaso-dentine, d is the hard dentine, and c
is the cement ; p is the base of the wide per-
sistent pulp-cavitv.

The hard dentine is, of course, the firmest
tissue of a tooth so composed, and forms the
crest of the transverse ridges of the grinding
surface, like the enamel plates in the elephant’s
grinder. It has, consequently, been described
to be enamel*, but its relation to that tissue
is only one of analogy or function.

The human teeth, and those of the carni-
vorous mammals, appear at first sight to be
composed of dentine and enamel only, as they
were described to be by the Cuviers f , who

* Cuvier, Ossemens Fossiles, 4to, t. v., pt. 1.,
p. 172. ; and Clift, Transactions of the Geological
Society, 1835, p. 438.

t F. Cuvier, Dents de Mammifferes, p. 1. 8vo,
1825; G. Cuvier, Lecons d’Anat. Comp. iv. (1836),
p. 199.

called them, therefore, simple teeth ; but their
crowns are originally, and their fangs are
always, covered by a thin coat of cement.
There is also commonly a small central tract
of osteo-dentine in old teeth.

In fig. 7, pi. 122, of my Odontography is
given a longitudinal section of a human molar
tooth, in which d is the dentine, e the enamel,
and c the cement.

The teeth, called by Cuvier compound or
complex in Mammalia, differ, as regards their
composition, from the preceding, only by the
different proportion and disposition of the
constituent tissues. Fig. 549. is a longitudinal
section of the incisor of a horse ; d is the
dentine, e the enamel, and c the cement ; c is
the layer of cement reflected into the deep
central depression of the crown ; and s is the
coloured mass of tartar and particles of food
which fills up that cavity, forming the “ mark”
of the horse-dealer. The characteristic struc-
ture of the three tissues is shown in the
magnified part of the section, fig. 550.

Fig. 549.

Section of incisor of a Horse ( Equus ).

A very complex tooth may be formed out
of two tissues by the way in which these may
be interblended, as the result of an original
complex disposition of the constituents of the
dental matrix.

Certain fishes, and a singular family of
gigantic extinct Batrachians, which I have
called “ Labyrinthodonts,”* exhibit, as the
name implies, a remarkable instance of this
kind of complexity. Fig. 551. is a view of a
canine tooth of the Labyrinthodon salaman-
droides, of the natural size : and fig. 552. is a
slightly magnified view of a transverse section
across the part of the crown marked a. At
first view, the tooth appears to be of the simple
conical kind, with the exterior surface merely
striated longitudinally, but every streak is a
fissure into which the very thin external layer
of cement ( c ) is reflected into the body* of

* Proceedings of the Geological Society, Jan “20>
1841, p. 257.

3 K 2

868

TEETH.

Fig. 550.

Magnified portion of section of incisor of Horse ;
c cement, e enamel, d dentine.

the tooth, following the sinuous wavings of
the lobes of dentine (rf), which diverge from
the central pulp-cavity, a.

The inflected fold of cement c runs straight
for about half a line, and then becomes wavy,
the waves rapidly increasing in breadth as
they recede from the periphery of the tooth ;
the first two, three, or four undulations are
simple ; then their contour itself becomes
broken by smaller or secondary waves; these
become stronger as the fold approaches the
centre of the tooth, when it increases in
thickness, and finally terminates by a slight
dilatation or loop close to the pulp-cavity,
from which the free margin of the inflected
fold of cement is separated by an extremely
thin layer of dentine. The number of the
inflected converging folds of dentine is about
fifty at the middle of the crown of the tooth
figured, but is greater at the base. All the
inflected folds of cement at the base of the
tooth have the same complicated disposition
with increased extent; but, as they approach
their termination towards tfie upper part of
the tooth, they also gradually diminish in
breadth, and consequently penetrate to a less
distance into the substance of the tooth.
Hence, in such a section as is delineated
(fig. 552.), it will be observed that some of the
convoluted folds, as those marked cc, extend
near to the centre of the tooth ; others, as
those marked c , reach only about half-way
to the centre ; and those folds, c" , which, to
use a geological expression, are “ cropping

Tooth of a Labyrintliodon, natural size.

out,” penetrate to a very short distance into
the dentine, and resemble, in their extent and

Fig. 552.

Transverse section of tooth of Labyrintliodon.
(Magnified.')

simplicity, the converging folds of cement in
the fangs of the tooth of the Iehthyosnurus.

The disposition of the dentine is still more
complicated than that of the cement. It con-
sists of a slender, central, conical column,
excavated by a conical pulp-cavity for a cer-

TEETII.

8G9

tain distance from the base of the tooth ; and
this column sends radiating outwards, from
its circumference, a series of vertical plates,
which divide into two once or twice before
they terminate at the periphery of the tooth.

Each of these diverging and dichotomising
plates gives off throughout its course smaller
processes, which stand at right angles, or
nearly so, to the main plate ; they are gene-
rally opposite, but sometimes alternate ; many
of the secondary plates or processes, which
are given off near the centre of the tooth, also
divide into two before they terminate; and
their contour is seen, in the transverse section,
to partake of all the undulations of the folds
of cement which invest and divide the den-
tinal plates and processes from each other.

The dental pulp-cavity is reduced to a
mere line about the upper third of the tooth,
but throughout its whole extent fissures radiate
from it, corresponding in number with the
radiating plates of dentine. Each fissure is
continued along the middle of each plate,
dividing where this divides, and extending
along the middle of each bifurcation and pro-
cess to within a short distance of the line of
cement. The pulp-fissure commonly dilates
into a canal at the origin of the lateral pro-
cesses of the radiating plates, before it divides
to accompany and penetrate those processes.

The main fissures or radiations of the pulp-
cavity extend to within a line or half a line
of the periphery of the tooth, and suddenly
dilate at their terminations into spaces, which,
in transverse section, are subcircular, oval, or

rally smaller spaces. All these spaces, or
canals, in the living tooth, must have been
occupied by corresponding processes of the
vascular pulp : they constitute so many cen-
tres of radiation of the fine calcigerous tubes,
which, with their uniting clear substance,
constitute the dentine.*

An analogous complexity is produced by
numerous fissures radiating from a central
mass of vaso-dentine, which more or less fills
up the pulp-cavity of the seemingly simple
conical teeth of the extinct family of fishes
which I have called “ Dendrodonts.”f Fig.
553. is one of these fossil teeth, of the natu-

Fig. 553.

Tooth of a Dendrodus, natural size.

ral size ; a a transverse section ; and jig. 554 a
reduced view of a portion of the same section,
enlarged twenty diameters.

Thus magnified, a central pulp-cavity, of

pyriform, p : the branches of the radiating relatively small size, and of an irregular lobu-
lines, which are continued into the lateral lated form, is discerned, a portion of which
secondary plates or processes of the dentinal * Odontography, pp. 195 — 217, pi. 64^, 64b.
lamella, likewise dilate into similar, and gene- + H>. p. 171.

3 k 3

870

TEETH.

is shown at p; this is immediately surrounded
by the transverse sections of large cylindrical
medullary, or pulp-canals of different sizes;
and, beyond these, there are smaller and more
numerous medullary canals, which are pro-
cesses of the central pulp-cavity. In the
transverse section these processes are seen
to be connected together by a net-work of
smaller medullary canals belonging to a coarse
osseous texture into which the pulp has been
converted, and this structure occupies the
middle half of the section. All the medullary
canals were filled by the opaque matrix.
From the circumference of the central net-
work, straight medullary fissures radiate at
pretty regular intervals to the periphery of
the tooth : most of these canals divide once,
rarely twice, in their course ; the division
taking place sometimes at their origin, in
others at different distances from their termi-
nations, and the branches diverge slightly as
they proceed. Each of the above medullary
fissures is continued from a short process of
the central structure, which is connected by a
concave line with the adjoining process, so
that the whole periphery of the transverse
section of the central coarse reticulo-medul-
lary body of the tooth presents a crenate out-
line. From each ray and its primary dicho-
tomous divisions, short branches are sent off
at brief intervals, generally at right angles
with the trunk, or slightly inclined towards
the periphery of the tooth. These subdivide
into a few short ramifications, like the branches
of a shrub, and terminate in irregular and
somewhat angular dilatations, simulating leaves,
but which resolve themselves into radiating
fasciculi of calcigerous tubes. There are
from fifteen to twenty-five or thirty- six of
these short and small lateral branches on
each side of the medullary rays.

A third kind of complication is produced
by an aggregation of many simple teeth into
a single mass.

The examples of these truly compound
teeth* are most common in the class of
Fishes, but the illustration here selected is
from the Mammalian class. Each tooth of
the Cape Ant-eater ( Oryeteropus ) presents a
simple form, is deeply set in the jaw, but
without dividing into fangs; its broad and
fiat base is porous, like the section of a com-
mon cane. The canals to which these pores
lead contain processes of a vascular pulp, and
are the centres of radiation of as many indc-

* In the “ Lemons A’Anatomie Comparde ” of
Cuvier, the teeth, in which folds of enamel and
cement penetrate the entire substance of the crown,
are called “compound:” “Nous appellons ‘dent
composee ’ celle dont les differentes substances
forment des replis tellement profonds, que dans
quelque sens qu'on coupe la dent, on coupe plusieurs
fois chacune des substances qui la composent : telles
sont, les dents molaires de 1’ Elephant.” The teeth
of the “ Labyrinthodonts ” would come under this
definition more truly than those of the elephant,
although they differ from them in having no enamel ;
for a molar of an elephant might be bisected, verti-
cally and transversely, without cutting the tissues
across more than once.

pendent series of dentinal tubules. Each
tooth, in fact, consists of a congeries of long
and slender prismatic denticles of dentine,
which are cemented together by their ossified
capsules, the columnar denticles slightly de-
creasing in diameter and occasionally bifur-
cating as they approach the grinding surface
of the tooth.

A figure of a longitudinal section of the
molar teeth is given in PI. 70, fig. 10. of my
“ Odontography,” and a magnified view of a
similar section in PI. 77. ; fig. 555. gives a
magnified view of a portion of the transverse

Fig. 555.

Part of transverse section of the tooth of the Oryc-
teropus. ( Magnified .)

section of the fourth molar, showing c the
cement; d the dentine; p the pulp-cavity of
the denticles ; and d' a section of one of the
denticles just beyond its bifurcation.

The pectinated incisors of the flying Lemur
of the Indian Islands (G ale opith ecus) are ex-
amples of teeth, the crowns of which are
composed of denticles consisting of hard den-
tine, with a covering of true enamel. The
layer of cement over this is too thin to show
its characteristic structure, and does not fill
up the intervals of the denticles, which stand
out as free processes from the base of the
crown. Tubular prolongations of the pulp-
cavity are continued up the centre of each
denticle.

Fig. 556. exhibits a longitudinal section,
magnified, of this kind of compound tooth;
d is the dentine; e the enamel; p the pulp-
cavity. The originally detached summits of
the crown of the human incisor are homo-
logous with these columnar processes, or
denticles of the incisor of the Galeopithecus.

In the compound molars of the great Afri-
can wart-hogs ( Phacochcerus) the columnar
denticles are in three rows, and their inter-
spaces are filled up by cement : each denticle
consists of a slender column of hard dentine
inclosed in a thick sheet of enamel, the whole
being bound together by the cement ; and the

TEETH.

871

denticles, as in the Galeopithecus , blending
together into a common base in the fully-de-
veloped tooth.

Fig. 556.

Section of lower incisor of Galeopithecus
( Magnified .)

A figure is given of the grinding surface of
the third true molar of the Phacochcerus Pal-

long diameter of the tooth. When the tooth
is bisected vertically and lengthwise, the three
substances, d dentine, e enamel, and c cement,

Fig. 557.

are seen interblended as in Jig. 557., in which
p is the common pulp-cavity, and r one of
the roots of this complex tooth.

A still more complex grinding apparatus is
found in certain fishes. The lower pharyngeal
bone of the parrot-fish ( Scants *), for ex-
ample, supports a dental plate with a tri-

Fig. 558.

Two of the upper pharyngeal teeth, Scarus. ( Magnified .)

lasii, in PL 140,y?g. 4, of my “ Odontography.” titrating surface like that of the compound
In the elephant the denticles of the com- molars of the Phacochcerus. The interlocked
pound molars are in the form of plates, vertical upper pharyngeals {Jig. 565.) support dental
to the grinding surface and tranverse to the * Odontography, pi. 51., fig. 3.

3 k 4

872

TEETH.

masses with a grinding surface more like that
of the compound molars of the elephant.

When a vertical and longitudinal section
is made of one of these upper pharyngeal
compound teeth, each denticle is seen to be
composed, as in fig. 558., of a body of very
hard and unvascular dentine d, with a thick
sheath of enamel e, the denticles being united
together by the cement c, and supported and
further united together, and to the pharyngeal
bone, by a basal mass of vascular osteo-dentine.

Such are some of the prominent features
of a field of observation which comparative
anatomy opens out to our view ; — such the
varied nature, and such the gradation of
complexity of the dental tissues, which, up to
December 1839*, continued, notwithstanding
successive approximations to the truth, to be
described in systematic works as a “ pha-
neros,” or “ a dead part or product exhaled
from the surface of a formative bulb ! ” The
truth may be slowly but is surely established,
subject to the usual attempts to mask or
detract from the merit of the discovery. By
no systematic authors has the hypothesis of
the formation of dentine by transudation or
secretion been more frequently or more ex-
plicitly enunciated than by the Cuviers.
Baron Cuvier repeats, in both editions of his
elaborate work — the “ Ossemens Fossiles ”
— “ C’est dans ce vide conpevable que se de-
poseront les matieres qui doivent former la
dent, savoir : la substance vulgairement ap-
pelee osseuse, qui sera transudee par des pro-
ductions gelatineuses venant du fond de la
capsule, et l’email qui sera depose par les
cloisons membraneuses,” t.ii. p. 61., ed. 1812.;
t. i. p. 33., ed. 1821. See, also, M. F. Cuvier,
“ Dents de Mammiferes,” 8vo, 1825. “ L’ivoire
se depose par couches concentriqucs,” p.
xxvii. ; “ L’email se depose dans un sens
contraire a l’ivoire,” ib. p. xxviii. And Baron
Cuvier again, in the second edition of his
“Lecons d’Anatomie Comparee,” t. iv. 1836,
p. 214 : “L’ivoire se depose par couches, par
line sorte de transudation.” In the first
edition of this classical work, Cuvier had
illustrated the peculiarity of the teeth of
certain fishes, which are at first detached and
afterwards united to the jaw-bone, by com-
paring their growth to that of the epiphyses
of the long bones : “ Mais les dents qui ne
tiennent qu’a la gencive seulement, commc
eelle des Stjuales , croissent a la maniere des
epiphyses des os, c’est- a-dire que toute leur
substance osseuse est d’abord tendre et po-
reuse, et qu’elle se durcit uniformement, et
finit par devenir entierement dure eomme de
Fivoire,” t. iii. 1805, p. 112. Whether the
great anatomist meant to imply that the

* See the Fasciculus of M. de Blainville’s great
work, “ Ostdograpliie et Odontographie d’Animaux
Vertebre's,” which he submitted to the Academy of
Sciences of the Institute of France on the same day,
December 16th, 1839, on which I communicated, on
the occasion of my election as corresponding member
of that body, my “ Theory of the development of
dentine by centripetal calcification and conversion
of the cells of the pulp.”

osseous tissue of the epiphyses of bones was
developed differently from osseous tissue in
general, c. g. by the uniform and simultaneous
hardening or calcification, obscurely referred
to in the above ([notation, may be questioned,
for such is not the way in which the teeth of
the shark are calcified. But this is certain,
that the idea, whatever it might have been,
had no influence on the fixed belief of the
developement of the dental tissue by trans-
udation expressed in their later and more
elaborate works by Baron Cuvier and his ac-
complished brother ; and, in point of fact, the
passage which I have quoted is expunged from
the second edition of the “ Lecons d’ Anatomie
Comparee,” 1835 : the successive stages of
calcification in the different teeth of the same
vertical series in the jaw of the shark, having
probably been noticed in the interim by Cuvier.

The author of the article “ Secretions ” in
the “Dictionnaire Universel d’Histoire Na-
turelle,” has, however, reproduced Cuvier’s ob-
scure comparison of certain fishes’ teeth to
the epiphyses of bone, as evidence of the need-
lessness of any ulterior researches for the
demonstration of the theory of dental de-
velopement by conversion and calcification of
the pulp. The passage from the third vol.
of the old edition (1800) of the “ Lecons
d’Anat. Comp.,” p. 112, is cited to show that
it naturally conducts to the knowledge of
such mode of developement of dentine : “ En
1840 et 1841 (the ‘ Comptes Rendus del’ Acad,
des Sciences’ give the true date) l’etude des
dents dc Squale par M. R. Owen, lui a de-
montree leur accroisseinent par intussuscep-
tion, comme elle avait ete a G. Cuvier trente-
cinq annees auparavant.” How or why G. .
Cuvier came to abandon the theory so demon-
strated, and how it happened that none of his
contemporaries adopted it, M. Duvernoy does
not explain. He does give a reason for the
omission, in the second edition of the “ Lecons
d’Anat. Comp.” of the passage which he affirms
to contain the demonstration ; “ Malheureuse-
ment, le copiste de cet ancien texte pour la
2de edition a ontis ce passage, par oubli.” It
was natural to conclude that its obscurity
and seeming contradiction to the theory of
dental developement, formally propounded by
Cuvier, as well as to the facts shown by
nature in the sharks, had been the cause of
its omission ; but even had the misfortune
to which M. Duvernoy now attributes that
omission (for in the copious list of addenda
and corrigenda to the fifth, 1837, and final,
1846, volumes it is not noticed) not occurred,
the coincidence of such passages as the fol-
lowing would still have been inexplicable
and irreconcilable with the deductions that
M. Dumeril is now enabled to draw from the
comparison of the shark’s tooth with the
epiphyses of long bones. “ L’ivoire se depose
par couches, par une sorte de transudation.”
Lecons d’Anat. Comparee, t. iv., 1836, p. 214.
To which proposition Cuvier has himself
added a note : “ Je me suis assure recemment,
sur des gerines de dents d’elephant, que la
substance osseuse de la dent se forme comme

TEETH.

les coquilles.” And the editor (M. Duvernoy),
in order to obviate any possibility of miscon-
ception, has himself subjoined a note to that
passage, as follows : “ L 'ivoire a ete aussi
substance osseuse, a cause deson analogie
de composition chimique et de durete avec
les os. Mais la nature inerte et inorganique
de cette substance, mieux appreciee dans ces
derniers temps, surtout par les travaux de
M. Cuvier, ne perrnet plus de la designer, avec
justesse, par cette seconde expression. Du
moins est-il necessaire de premunir le lecteur
contre l'idee fausse qu’il pourrait en tirer,
qu’elle serait organisee, qu’elle se develop-
perait a la maniere des os.” — Tom. cit. p. 201,
(18.36). In the same spirit in which M. Du-
vernoy sees (in 1848) that a true idea, instead
of a false one, may be drawn from casual expres-
sions and similies loosely applied in the old Le-
cons of 1800 and 1805 ; others have sought to
depreciate the value of the establishment of the
truth by citing the doubts, or tentative approxi-
mations made by Purkinje and Schwann to
my theory, interpreting such approximations
by the light of the established truth. So far
from finding such a resting-place for doubt in
Cuvier’s early simile, cited by M. Duvernoy
in 1848, or in the interrogatories of Schwann,
nothing short of the investigation of the whole
of this vast subject, zootomically, develop-
mentally, and microscopically, as narrated in
my “ Odontography,” sufficed to settle my
own doubts ; and nothing short of the evidence
and illustrations given in that work appeared
to me adequate to convert anatomists from
the excretion-hypothesis to the intussuscep-
tion theory.

That the dentine is the ossified pulp is an
older notion than that it is an inorganic
secretion from such pulp. But an hypo-
thesis, to be of any value in science, must be
proved. Almost every true theory has been
indicated, with various degrees of approxi-
mation, before its final establishment : but he
has ever been held, in exact philosophy, to
be the author of a theory, by whom it has
been first rightly enunciated and satisfactorily
established. When time has dissipated the
mists of individual or national rivalries and
jealousies, the name of the true discoverer is
clearly seen by the inextinguishable light of
true and impartial history : and to that period
I look forward with calm and confident hope.

I proceed now to briefly point out the
leading characteristics of the teeth in the dif-
ferent classes of the vertebrate animals.

Dental System of Fishes.

The teeth of fishes, whether we study them
in regard to their number, form, substance,
structure, situation, or mode of attachment,
offer a greater and more striking series of
varieties than do those of any other class of
animals.

As to number, they range from zero to
countless quantities. The Lancelet, the Am-
mocete, the Sturgeon, the Paddle-fish, and
the whole order of Loyhobranchii, are eden-

tulous. The Myxinoids have a single pointed
tooth on the roof of the mouth (fig. 559., a),
and two serrated dental plates ( b ) on the

Fig. 559.

Myxine. ( Milller .)

tongue. The Tench (fig. 514. Vol. III. p. 979.
art. Pisces) * has a single grinding tooth
on the occiput (c), opposed to two denti-
gerous pharyngeal jaws below (i id). In the
Lepidosiren a single maxillary dental plate
(fig. 560., a) is opposed to a single mandibular

Fig. 560.

Lepidosiren.

one (b), and there are two small denticles on
the nasal bone (c). In the extinct Sharks
with crushing teeth, called Ceratodus and Cte-
nodus, the jaws were armed with four teeth,
two above and two below. f In the Chimcerce,
two mandibular teeth are opposed to four
maxillary teeth. J From this low point the
number in different fishes is progressively
multiplied until, in the Pike, the Siluroids
(fig. 561.), and many other fishes, the mouth
becomes crowded with countless teeth.

With respect to form, 1 may first observe,
that as organised beings withdraw themselves
more and more, in their ascent in the scale of
life, from the influence of the general polarising
forces, so their parts progressively deviate
from geometrical figures: it is only, therefore,
in the lowest vertebrated class that we find
teeth in the form of perfect cubes, and of
prisms or plates with three sides (Myletes),
four sides ( Scarus ), five or six sides, Mylio-
bates (fig. 562.). The cone is the most com-
mon form in fishes : such teeth may be slender,
sharp-pointed, and so minute, numerous, and
closely aggregated, as to resemble the plush
or pile of velvet; these are called “villiform
teeth” (dentes villiformes, dents en velours §) ;
ail the teeth of the Perch are of this kind :

* And Odontography, pi. 57. fig. 5.

t See Odontography, pi. 22, figs. 2. 6, 7.

t lb., pi. 28, figs. 1, 2. 4. 6.

§ The French terms are those used by Cuvier
and Valenciennes in their great “ Histoire des Pois-
sons,” 4to.

87-1

TEETH.

when the teeth are equally fine anJ numerous,
but longer, they are called “ ciliiforin ” ( dentes

Fig. 561.

Palatine bone and teeth ( Silurus ).

ciliiformes) : when the teeth are similar to,
but rather stronger than these, they are called

Fig. 562.

as the villiform teeth, but of larger size, are
called “ rasp-teeth” ( dentes rciduliformes, dents
cn rape or en cardes, fig. 561.) ; the Pike pre-
sents such teeth on the back part of the vomer :
the teeth of the Sheat-fish ( Silurus glanis )
present all the gradations between the villi-
form and raduliform types. Setiform teeth
are common in the fishes thence called Chae-
todonts* ; in the genus Citharina they bifur-
cate at their free extremities ; in the genus
Platax they end there in three diverging
points {fig. 563.), and the cone here merges
into the long and slender cylinder. Some-
times the cone is compressed into a slender
trenchant blade : and this may be pointed and

* bristle j obousj tootb.

recurved, as in the Murcena; or barbed, as in
Trichiurus, and some other Scomberoids ; or
it may be bent upon itself, like a tenterhook,
as in the fishes thence called (loniodonts.*
In the Bonito may be perceived a progressive
thickening of the base of the conical teeth :
and this being combined in other predatory

Fig. 56.3.

il Tandibular teeth, magnified (Platax').

fishes with increased size and recurved direc-
tion, they then resemble the laniary or canine
teeth of carnivorous quadrupeds, as we see in
the large teeth of the Pike, in the Lophiusf,
and in certain sharks. ;£

The anterior diverging grappling teeth of
the wolf-fish form stronger cones ; and by
progressive blunting, flattening, and expansion
of the apex, observable in different fishes, the
cone gradually changes to the thick and
short cylinder, such as is seen in the back

Fig. 56-1.

teeth of the wolf-fish, and in similar grinding
and crushing teeth in other genera, whether
feeders on sea-weeds, or crustaceous and testa-
ceous animals. The grinding surface of these
short cylindrical teeth may be convex, as in
the Sheep’s-head fish ( Sargus ) ; or flattened,
as in the pharyngeal teeth of the Wrasse ( La -
brus).§ Sometimes the hemispheric teeth are
so numerous, and spread over so broad a sur-
face, as to resemble a pavement, as in the
pharyngeal bones of the Wrasse or Rock-fish
{Labrus, fig. 564.) ; or they may be so small,
as well as numerous ( dentes graniformes ), as
to give a granulated surface to the part of the
mouth to which they are attached (premax-
illaries of Cossi/phus).\\ A progressive increase

* Tot, in, an angle ; ibabs, a tooth,
t Vol. in., fig. 512, p. 978. art. Pisces.

X lb. fig. 510, p. 976.

§ lb. fig. 513, p. 978.

|| Odontography, pi. 45 ,fig. 1.

TEETH.

875

of the transverse over the vertical diameter
may be traced in the molar teeth of different
fishes, and sometimes in those of the same
individual, as in Labrus {fig. 564.), until the
cylindrical form is exchanged for that of the
depressed plate. Such dental plates {dentes
lamelliformes ) may be found, not only circular,
but elliptical, oval, semilunar, sigmoid, oblong,
or even square, hexagonal, pentagonal, or tri-
angular ; and the grinding surface may present
various and beautiful kinds of sculpturing.
The broadest and thinnest lameHiform teeth
are those that form the complex grinding
tubercle of the Diodon.* The front teeth of
the Flounder and Sargus present the form of
compressed plates, at least in the crown, and
are true dentes incisivi. Numerous wedge-
shaped dental plates {dentes cuneati ) are set
vertically in the upper pharyngeal bones of
the Parrot-fish ( Scants , fig. 565.). A thin

Fig. 565.

Superior pharyngeal hones and teeth {Seams').

lamella, slightly curved like a finger-nail, is
the singular form of tooth in an extinct genus
of fishes, which I have thence called Peta/odus.
Sometimes the incisive form of tooth is notched
in the middle of the cutting edge, as in Sargus
unimaculatus. Sometimes the edge of the
crown is trilobate {Aplodactylus, fig. 566.).

Fig. 566.

Front teeth of Aplodactylus.

Sometimes it is made quinquelobate by a
double notch on each side of the large middle
lobe {Boops). In the formidable Sea-pike

t Odontography, pi. 38, fin. 2 ; and art. Pisces,
Vol. 111. p 980, _/!</. 517.

{Sphyreena Barracuda ) the crown of each
tooth, large and small, is produced into a
compressed and sharp point, and resembles a
lancet. Sometimes the edges of such lancet-
shaped teeth are finely serrated, as in Priodon,
and the great Sharks of the genus Carcharias,
the fossil teeth of which indicate a species
{Carch. Mega/odon) sixty or seventy feet in
length.

The lancetted form is exchanged for the
stronger spear-shaped tooth in the Sharks of
the genus Lanina; and in the allied great ex-
tinct Otodus, as in the small Porbeagle, simi-
larly shaped, but stronger, piercing and cut-
ting teeth were complicated by one or more
accessory compressed cusps on each side their
base, like the Malay crease.

With respect to situation, the teeth, in
Sharks and Rays, are limited to the bones
(maxillary and mandibular), which form the
anterior aperture of the mouth : in the Carp
and other Cyprinoids the teeth are confined
to the bones (pharyngeal and basi-occipital)
which circumscribe the posterior aperture of
the mouth. The Wrasses ( Labrus ) and the
Parrot-fishes {Scarus) have teeth on the
pre-maxillary and pre-mandibular, as well as
on the upper and lower pharyngeals ; both
the anterior and posterior apertures of the
mouth being thus provided with instruments
for seizing, dividing, or comminuting the
food, the grinders being situated at the pha-
rynx. In most fishes teeth are developed
also in the intermediate parts of the oral
cavity, as on the palatines, the vomer, the
hyoid bones, the branchial arches ; and,
though less commonly, on the pterygoids, the
entopterygoids, the sphenoids, and even on
the nasal bone {fig. 560, c.). It is very rare
to find teeth developed on the true superior
maxillary bones ; but the Herring and Salmon
tribes, some of the Ganoid Fishes, and the
great Sudis, are examples of this approach to
the higher Vertebrata. Among the anoma-
lous positions of teeth may be cited, besides
the occipital alveolus of the Carp*, the mar-
ginal alveoli of the prolonged, depressed, well
ossified rostrum of the Saw-fish, Pristis.
In the Lampreys and in He/ostomus (an os-
seous fish), most of the teeth are attached to
the lips. Lastly, it is peculiar to the class
Pisces, amongst Vertebrata, to offer examples
of teeth developed in the median line of the
mouth, as in the palate of the Myxines {fig.
559, a.) ; or crossing the symphysis of the jaw,
as in Notulanus, Scymnus, and Myliobates.

Nor is the mode less varied than the place
of attachment. The teeth of Lophius, Pce-
cilia, Anableps, are always moveable. In most
fishes they are anchylosed to the jaws by
continuous ossification from the base of the
dental pulp ; the histological transition being
more or less gradual from the structure of
the tooth to that of the bone. Sometimes
we find, not the base, but one side of the
tooth anchylosed to the alveolar border of the
jaw ; and the teeth oppose each other by

* Odontography, pi. 8 ; and art, Pisces, Vol. III.,
p. 980, fig. 518.

876

TEETH.

their sides instead of their summits [Scarus*)',
in Pimelodus, however, where the teeth are
thus attached, the crown is bent down in
the upper teeth, and bent up in the lower
ones, at right angles to the fang, so that they
oppose each other by the normal surfaces.
Certain teeth of recent and fossil cartilagi-
nous fishes have their base divided into
processes like fangs, but these serve for the
attachment of ligaments, and are not set in
bony sockets like the true fangs or roots of
the teeth of the Mammalia. Some Sharks
have two divaricating fangs ; some fossil teeth
referred to my genus Pclalndus by Agassiz,
with the specific name “ radicans,” have the
base divided into several fangs or processes,
indicating a generic distinction. The base
of anchylosed teeth is, at first, attached to
the jaw-bone by ligament ; and in the Cod-
fish, Wolf-fish, and some other species, as
calcification of the tooth progresses towards
its base, the subjacent portion of the jaw-
bone receives a stimulus, and developes a
process corresponding in size and form with
the base of the tooth : for some time a thin
layer of ligamentous substance intervenes, but
anchylosis usually takes place to a greater or
less extent before the tooth is shed. Most of
the teeth of the Lophius retain the primitive
ligamentous connection; the ligaments-)- of
the large internal or posterior teeth of the
upper and lower jaws, radiate on the corre-
sponding sides of the bone, the base of the
tooth resting on a conformable alveolar pro-
cess. The ligaments do not permit the tooth
to be bent outwards beyond the vertical posi-
tion, but yield to pressure in the contrary direc-
tion, by which the point of the tooth may be
directed towards the back of the mouth ; the
instant, however, that the pressure is remitted,
the tooth returns through the elasticity of
the bent ligaments, as by the action of a spring;
into its usual erect positions {fig- 512, c. c.
Yol. III. p. 978. art. Pisces) ; the deglutition
of the prey of this voracious fish is thus facili-
tated, and its escape prevented. J The broad
and generally bifurcate bony base of the teeth
of Sharks is attached by ligament to the semi-
ossified crust of the cartilaginous jaws $ ;
but they have no power of erecting or de-
pressing the teeth at will. The small and
closely crowded teeth of Rays are also con-
nected by ligaments to the subjacent maxillary
and mandibular membranes. The broad tes-
selated teeth of the Myliobates have their
attached surface longitudinally grooved to
afford them better hold-fast, and the sides of
the contiguous teeth are articulated together
by serrated or finely undulating sutures, a
structure unique in dental organisation. || The
teeth of the Sphyrcena are examples of the
ordinary implantation in sockets, with the
addition of a slight anchylosis of the base of
the fully-formed tooth with the alveolar pa-

* Odontography, pi. 49 ; and art. Pisces, Yol. III.
Jig. 51G, p. 979.

f See art. Pisces, Yol. III., j fig. 512 d, p. 978.

$ Odontography, p. 154.

§ Art. Pisces, Vol. III., Jig. 510, p. 976.

|| Odontography, p. 46. pi. 27 c.

rietes ; and the compressed rostral teeth of
the Saw-fish are deeply implanted in sockets.
In the latter the hind margin of their base is
grooved, and a corresponding ridge from the
back part of the socket fits into the groove, and
gives additional fixation to the tooth. Some
implanted teeth in the present class have their
hollow base further supported, like the claws
of the feline tribe, upon a bony process aris-
ing from the base of the socket ; the incisors
of the Balistes, e. g., afford an example of this
double or reciprocal gomphosis. In fact, the
whole of this part of the organisation of fishes
is replete with beautiful instances of design,
and instructive illustrations of animal me-
chanics. The vertical section of a pharyngeal
jaw and teeth of the Wrasse ( Labrus *) would
afford the architect a model of a dome of
unusual strength, and so supported as to re-
lieve from pressure the floor of a vaulted
chamber beneath. The base of the dome-
shaped tooth is slightly contracted, and is
implanted in a shallow circular cavity; the
rounded margin of which is adapted to a cir-
cular groove in the contracted part of the
base; the margin of the tooth which imme-
diately transmits the pressure of the bone, is
strengthened by an inwardly projecting con-
vex ridge. The masonry of this inner but-
tress, and of the dome itself, is composed of
hollow columns, every one of which is placed
so as best to resist or transmit in the due
direction the external pressure. The floor
of the alveolus is thus relieved from the office
of sustaining the tooth : it forms, in fact, the
roof of a lower vault, in which the germ of a
successional tooth is in course of develop-
ment ; had the crushing tooth in use, rested,
as in the Wolf-fish, by the whole of its base
upon the alveolus, the supporting plate, gra-
dually undermined by the growth of the new
tooth, must have given way, and been forced
upon the subjacent delicate and highly vas-
cular and sensitive matrix of the half-formed
tooth. But the superincumbent pressure
is exclusively sustained by the border of
the alveolus, whence it is transferred to the
walls dividing the vaulted cavities containing
the germs of the new teeth ; the roofs of
these cavities yield to the absorbent process
consequent on the growth of the new teeth
without materially weakening the attachment
of the old teeth, and without the new teeth
being subjected to any pressure until their
growth is sufficiently advanced to enable them
to bear it with safety ; by this time the sus-
taining borders of the old alveolus are under-
mined, and the old worn-down tooth is shed.

The singular and powerfully developed
dental system of the Wolf-fish (Anarrhi-
c/ias Lupus) has been a subject of interest
to many anatomists. The general character
and physiological relations of the teeth in this
species had not escaped the attention of
Hunter. In his paper on the Gillaroo trout,
read before the Royal Society in 1774, he ob-
serves that “ the teeth of fishes which subsist

* Fig. 544 ; and art. Pisces, Vol. 111., Jig. 513, p. 978.,

TEETH.

877

chiefly on animal matter must vary according
as their food may be common salt fish, or
shell-fish.” “ Such fish as live on the first kind
have, like the carnivorous quadrupeds and
birds, no apparatus for mastication, their teeth
being intended merely for catching the food
and fitting it to be swallowed. But the shells
of the second kind of food render some de-
gree of masticatory power necessary to fit it
for its passage either into the stomach or
through the intestines : and accordingly we
find in certain fish a structure suited to the
purpose. Thus the mouth of the Wolf-fish is
almost paved with teeth, by means of which
it can break shells to pieces, and fit them for
the (Esophagus of the fish, and so effectually
disengage the food from them, that though it
lives upon such hard food, the stomach does
not differ from that of other fish.”

But in order to secure the capture of the
shell-fish, the teeth of the Wolf-fish are not all
crushers ; some present the laniary type, with
the apices more or less recurved and blunted
by use, and consist of strong cones spread
abroad, like grappling hooks, at the anterior
part of the mouth.*

The premaxillary teeth are all conical, and
arranged in two rows ; there are two, three,
or four in the exterior row, at the mesial half
of the bone, which are the largest ; and from
six to eight smaller teeth are irregularly
arranged behind. There are three large,
strong, diverging laniaries at the anterior end
of each premandibular bone, and immediately
behind these an irregular number of shorter
and smaller conical teeth, which gradually
exchange this form for that of large obtuse
tubercles ; these extend backwards, in a double
alternate series, along a great part of the
alveolar border of the bone, and are termi-
nated by two or three smaller teeth in a single
row, the last of which again presents the
conical form. Each palatine bone supports
a double row of teeth, the outer ones being
conical and straight, and from four to six in
number ; the inner ones two, three, or four in
number, and tuberculate. I have seen a spe-
cimen where the inner row was wanting on
one side. The lower surface of the vomer is
covered by a double irregularly alternate
series of the same kind of large tuberculate
crushing teeth as those at the middle of the
premandibular. All the teeth are anchylosed
to more or less developed alveolar eminences,
like the anterior teeth of the Lophius. The
periphery of the expanded circular base of the
large anterior grappling teeth is divided into
processes indicative of the original ligamen-
tous fasciculi at the base of the pulp by the
ossification of which their anchy losis is ef-
fected.

When such anchylosed teeth and the sup-
porting bone are divided by a vertical sec-
tion, as in fig. 2, pi. 66, of my “ Odonto-
graphy,” there may be generally discerned a
faint transverse line indicating the original
separation between the tooth and the bone,

* Odontography, pi. CO, Gl.

and more clearly defining the dental from the
osseous structure, than in the anchylosed teeth
of other fishes. From the enormous develop-
mentof theinusclesof thejaws, andthestrength
of the shells of the whelks and other testacea
which are cracked and crushed by the teeth,
their fracture and displacement must obviously
be no unfrequent occurrence ; and most speci-
mens of thejaws of the Wolf-fish exhibit some
of the teeth either separated at this line of
imperfect anchylosis, or, more rarely, broken
off above the base, or, still more rarely, de-
tached by fracture of the supporting osseous
alveolar process.

With regard to the substance of the teeth
of fishes, the modifications of dentine, called
vaso-dentine and osteo-dentine *, predomi-
nate much more than in the higher Verte-
brata ; and they thus more closely resemble
the bones which support them. There is,
however, great diversity in respect of sub-
stance. The teeth of most of the Chceto-
donts are flexible, elastic, and composed of a
yellowish subtransparent albuminous tissue ;
such, likewise, are the labial teeth of the He-
lostome, the premaxillary and mandibular
teeth of the Goniodonts, and of that percoid
genus thence called Trichodon. In the Cy-
clostomes the teeth consist of a denser albu-
minous substance. The upper pharyngeal
molar of the Carp consists of a peculiar brown
and semitransparent tissue, hardened by salts
of lime and magnesia. The teeth of the Fly-
ing-fish ( Exoccetus ), and Sucking-fish (Re-
mora'), consist of osteo-dentine. In many
fishes, e.g. the Aeanthurus, Spliyrcena , and
certain Sharks ( Larnna , fg. 545.), a base, or
body of osteo-dentine is coated by a layer of
true dentine, but of unusual hardness, like
enamel : in Prionodon this hard tissue predo-
minates. In the Labrus the pharyngeal crush-
ing teeth consist w holly of hard or unvascular
dentine (fig. 544.). In most Pycnodonts and
Cestracionts, and many other fishes, the body
of the tooth consists of ordinary unvascular
dentine, covered by a modification of that
tissue which I have called “ vitro-dentine ” from
its clear, polished, enamel-like character: but
this is not enamel, nor the product of a dis-
tinct organ from the dentinal pulp : it differs
from ordinary dentine in the greater propor-
tion of the mineral particles, their more mi-
nute diffusion through the gelatinous basis, in
the straighter course and more minute size
of the calcigerous tribes ; it results from the
calcification of the external layer of the den-
tinal pulp, and is the first part of the tooth
which is formed. In Sargus and Batistes
the body of the tooth consists of true dentine,
and the crown is covered by a thick layer of
a denser tissue, developed by a distinct organ,
and differing from the “ enamel ” of higher
animals only in the more complicated and or-
ganised mode of deposition of the earthy salts.
The ossification of the capsule of the complex
matrix of these teeth covers the enamel with
a thin coating of “ cement.” In the pharyngeal

* Odontography, Introduction, p. Ixxii.

878

TEETH.

teeth of the Scarus a fourth substance is
added by the ossification of the base of the
pulp after its summit and periphery have been
converted into hard dentine ; and the teeth
{Jig. 558.), thus composed of cement (c),
enamel (e), dentine (<7), and osteo-dentine, are
the most complex in regard to their sub-
stance that have yet been discovered in the
animal kingdom.

The tubes which convey the capillary ves-
sels through the substance of the osteo- and
vaso-dentine of the teeth of fishes* were
early recognised, on account of their com-
paratively large size ; as by Andre, c.g. in the
teeth of Acantliurus, and by Cuvier and Von
Born in the teeth of the Wolf-fish and other
species. Leeuwenhoek had also detected the
much finer tubes of the peripheral dentine
of the teeth of the Haddock. These “ den-
tinal tubuli” are given off’ from the parietes
of the vascular canals, and bend, divide, and
subdivide rapidly in the hard basis-tissue of
the interspaces of those canals in osteo-den-
tine ; the dentinal tubuli alone are found in
true dentine, anil they have a straighter and
more parallel course, usually at right angles
to the outer surface of the dentine Those
conical teeth which, when fully formed, con-
sist wholly or in great part of osteo-den-
tine or vaso-dentine, always first appear with
an apex of hard or true dentine. In some
fishes the simple central basal pulp-cavity of
such teeth, instead of breaking up into irregu-
_ar or parallel canals, sends out a series of
vertical plates from its periphery, which, when
calcified, give a fluted character to the base
of the tooth, e. g. in Lcpidosteus oxyurns.\
Sometimes such radiating vertical basal plates
of dentine are wavy in their course, and send
off narrow processes from their sides; and,
as a thin layer of the outer capsule interdigi-
tates with the outstanding plates of the den-
tinal pulp, and becomes co-calcified with them,
a transverse section of such a tooth presents
a series of interblended wavy or labyrinthic
tracts of thick dentine radiating from the cen-
tre, and of thin cement converging towards the
centre of the tooth. J An analogous but more

* The vaso-dentine of Pristis and Myliobates is
like that of the teetli of the Cape Anteater ( Orycte -
ropus) : the vaso-dentine of the Psammodonts re-
sembles that which forms the base of the tooth of
the Sloth and Megatherium : the vaso-dentine of
Mammals differs from the osteo-dentine in the
absence of the radiated “ Purkinjian,” cells.

f Wyman, American Journal of Natural Sciences,
Oct. 1843. Cuvier has given an accurate view of the
plaited structure of the base of the Wolf-fish’s teeth in
pi. 32, Jig. 7. of his Lemons d’Anatomie Comparee,
1805 ; where it is described at the base of the
osseous tubercle, which supports the true tooth.

{ This remarkable structure attains its highest
complication and forms the largest proportion of the
tooth in the gigantic extinct labyrintliodont Batra-
cliia, and from which, therefore, I have taken the
illustrations of that complex modification of dental
structure (Jig. 552 .). I had discovered hi 1841 the
more simple modification of this structure “ at the
base of the tooth in a few fishes ” (Geol. Trans., 2d
series, vol. vi., p. 507), but had not then seen so
complex an example in that class as Dr. Wyman

complicated structure obtains wlien the ra-
diating, wavy, vertical plates of dentine dicho-
tomise, and give off from their sides, through-
out their course, numerous branch plates and
processes, which are traversed by medullary
sinuses and canals with their peripheral ter-
minations dilated, and becoming the centres
of lobes or columns of hard dentine. The
transverse section of such teeth gives the ap-
pearance of branches of a tree, with leaf-stalks
and leaves, radiating from the central pulp-
cavity to the circumference of the tooth ; and
I have called the fossil fish in which this
structure was first detected, Dendrodus.

Thus, with reference to the main and funda-
mental tissue of tooth, we find not fewer than
six leading modifications in fishes;- — hard or
true dentine ( Sparokls , Labroids , Lophius, Bn-
listes, Pycnodonts, Prionodon, Sphyreena , Mega-
liclPhys , Ilhizodus , Diodon, Seams') ; osteo-
dentine ( Cestracion , Acrodus, Lepidosiren ,
Ctenodus, Hybudus, Percoids, Scioenokls , Cot-
toids, Gobioids, and many others); vaso-den-
tine ( Psammodus , Chimccroids, Pristis, My/io-
bates ) ; plici-dentine ( Lophius , Holoptychius,
Lcpidosteus oxywus , at the base of the teeth) ;
labyrintho-dentine ( Lepidosteus p/atyrhinus,
Bothriolepis) ; and dendro-dentine ( Dendro-
dus); besides the compound teeth of the
Scarus and ldiodon.

One structural modification may prevail in
some teeth, another in other teeth of the same
fish ; and two or more modifications may be
present in the same tooth, arising from changes
in the process of calcification and a persis-
tency of portions or processes of the primitive
vascular pulp or matrix of the dentine.

The dense covering of the beak-like jaws
of the Parrot-fishes {Scan), consists of a
stratum of prismatic denticles, standing al-
most vertically to the external surface of the
jaw-bone. An account of the structure and
development of this peculiar armature of the
jaws is abridged from my “ Odontography ”
(pp. 1 12 — 1 16.), in the article Pisces (Vol. III.
p. 979.). It is peculiarly adapted to the ha-
bits and exigencies of a tribe of fishes which
browse upon the lithophytes that clothe, as
with a richly tinted carpet, the bottom of the
sea, just as the Ruminant quadrupeds crop
the herbage of the dry land.

The irritable bodies of the gelatinous
polypes which constitute the food of these
fishes retract, when touched, into their star-
shaped stony shells, and the Scari conse-
quently require a dental apparatus strong
enough to break off' or scoop out these cal-
careous recesses. The jaws are, therefore,
prominent, short, and stout, as shown in Jig.
515. p. 979. Vol. III. ; and the exposed portions
of the premaxilliaries and premandibulars are
encased by the complicated dental covering
represented in figs. 515 and 516. Vol. HI.

The polypes and their cells are reduced to
a pulp by the action of the pharyngeal jaws

and M. Agassiz (Recherches sur les Poissons Fos-
siles, “ Sauroides,” 1843) subsequently described
and figured, in teeth of the genus Lepidosteus.

879

TEETH.

and teeth, that close the posterior aperture of
the mouth.

The superior dentigerous pharyngeals (Jigs.
558. and 565.) present the form of an elon-
gated, vertical, inequilateral, triangular plate ;
the upper and posterior margin is sharp and
concave ; the upper and anterior margin forms
a thickened articular surface, convex from side
to side, and playing in a corresponding groove
or concavity upon the base of the skull ; the
inferior boundary of the triangle is the longest,
and also the broadest; it is convex in the
antero-posterior direction, and Hat from side
to side. It is on this surface that the teeth
are implanted, anil in most species they form
two rows ; the outer one consisting of very
small, the inner one of large dental plates,
which are set nearly transversely across the
lower surface of the pharyngeal bone, and are
in close apposition, one behind the other :
their internal angles are produced beyond the
margin of the bone, and interlock with those
of the adjoining bone when the pharyngeals
are in their natural position ; the smaller
denticles of the outer row are set in the ex-
ternal interspaces of those of the inner row.

The single inferior pharyngeal bone con-
sists principally of an oblong dentigerous
plate, of the form represented in Jig. 3, pi.
51, of my “Odontography;” its breadth
somewhat exceeds that of the conjoined
dentigerous surface of the pharyngeals above,
and it is excavated to correspond with their
convexity. This dentigerous plate is prin-
cipally supported by a strong, slightly curved,
transverse, osseous bar, the extremities of
which expand into thick obtuse processes
for the implantation of the triturating muscles.
A longitudinal crest is continued downwards
and forwards from the middle line of the
inferior pharyngeal plate, anterior to the
transverse bar, to which the protractor mus-
cles are attached.

A longitudinal row of small oval teeth
alternating with the large lamelliform teeth,
like those of the superior pharyngeals, bounds
the dentigerous [Hate on each side; the inter-
mediate space is occupied exclusively by the
larger lamelliform or wedge-shaped teeth, set
vertically in the bone, and arranged trans-
versely in alternate and pretty close set series.

The dental plates are developed in wide
and deep cavities in the substance of the
posterior part of the lower, and of the an-
terior part of the upper pharyngeal bones.
Each denticle is developed in its proper cap-
sule, which contains an enamel-forming pulp
and a dentinal pulp, in close cohesion with
each other anil with the thin external capsule.
The teeth exhibit progressive stages of form-
ation as they approach the posterior part of
the upper and the anterior part of the lower
pharyngeal bones : as their formation advances
to completion they become soldered together
by ossification of their respective capsules
into one compound tooth, which soon be-
comes anchylosed by ossification of the den-
tinal pulp to the pharyngeal bone itself.

The dentine of the pharyngeal teeth of the

Scarus consists of calcigerous tubes and a
clear intermediate substance. The calcigerous
tubes average a diameter of of an inch,

and are separated by interspaces equal to
twice their own diameter. The course of
these tubes is shown in Jig. 558, d., in which
they are exposed by a vertical section through
the middle of two of the superior denticles.
They all, on leaving the pulp-cavity, form a
curve with the convexity turned towards the
base of the tooth, and then bend slightly in
the opposite direction ; the sigmoid curve
being most marked in the calcigerous tubes
at the base of the denticles, whilst those to-
wards the apex become longer and straighter.
Besides the primary curvatures exemplified
in the figure, each calcigerous tube is minutely
undulated ; it dichotomises three or four
times near its termination, sends oft’ many
fine lateral branches into the clear uniting
substance, and finally terminates in a series
of minute cells and inosculating loops at the
line of junction with the enamel.

This substance (Jig. 558, e .) is as thick as the
dentine, and consists of a similar combination
of minute tubes and a clear connecting sub-
stance. The tubes may be described as com-
mencing from the pheripheral surface of the
tooth to which they stand at right angles,
and, having proceeded parallel to each other
halfway towards the dentine, they then begin
to divide and subdivide, the branches crossing
each other obliquely, and finally terminating
in the cellular boundary between the enamel
and dentine.

The teeth which present this complex
structure are successively developed at one
extremity of the bone, in proportion as they
are worn away at the other ; not, however,
as Cuvier describes, from behind forwards, in
both upper and lower pharyngeal bones, but
in opposite directions in the opposite bones,
the course of succession being from before
backwards in the upper, and from behind
forwards in the lower pharyngeal bones. In
the progress of the attrition to which they
are subjected, the thin coat of cement result-
ing from the ossification of the capsule is first
removed from the apex of the tooth, then the
enamel constituting that apex, next the den-
tine, and, finally, the coarse central cellular
bone, supporting the hollow wedge-shaped
tooth ; and thus is produced a triturating
surface of four different substances of different
degrees of density. The enamel, being the
densest element, appears in the form of ellip-
tical transverse ridges, inclosing the dentine
and central bone ; and external to the enamel
is the cement which binds together the dif-
ferent denticles.

There is a close analogy between the dental
mass of the Scarus and the complicated
grinders of the elephant, both in form, struc-
ture, and in the reproduction of the compo-
nent denticles in horizontal succession. But
in the fish, the complexity of the triturating
surface is greater than in the Mammal, since,
from the mode in which the wedge-shaped
denticles of the Scarus are implanted upon.

880

TEETH.

and anchylosed to, the processes of the sup-
porting bone, this likewise enters into the
formation of the masticatory surface when
the tooth is worn down to a certain point.

The proof of the efficacy of the complex
masticatory apparatus above described is
afforded by the contents of the alimentary
canal of the Scari. Mr. Charles Darwin,
the accomplished naturalist and geologist,
who accompanied Captain Fitzroy, R. N., in
the circumnavigatory voyage of the “ Beagle,”
dissected several Parrot-fishes soon after they
were caught, and found the intestines laden
with nearly pure chalk, such being the nature
of their excrements ; whence he ranks these
fishes among the geological agents to which
is assigned the office of converting the skeletons
of the Lithophytes into chalk.

Development. — As might have been antici-
pated from the discovery of the varied and pre-
dominating vascular organisation in the teeth
of fishes, and the passage from non-vascular
dentine to vascular dentine in the same tooth,
the true law of the development of dentine
“ by centripetal metamorphosis and calcifica-
tion of the cells of the pulp,” was first defi-
nitely enunciated and illustrated from observ-
ations made on the development of the teeth
of fishes.*

It is interesting to observe in this class the
process arrested at each of the well-marked
stages through which the development of a
mammalian tooth passes. In all fishes the
first step is the simple production of a soft
vascular papilla from the free surface of the
buccal membrane : in Sharks and Rays these
papillae do not proceed to sink into the sub-
stance of the gum, but are covered by caps of
an opposite free fold of the buccal membrane ;
these caps do not contract any organic con-
nection with the papilliform matrix, but, as
this is converted into dental tissue, the tooth
is gradually withdrawn from the extraneous
protecting cap, to take its place and assume
the erect position on the margin of the jaw
(Jig. 510, b, a, art. Pisces, Vol. III. p. 976.).
Here, therefore, is represented the first and
transitory “ papillary ” stage of dental develop-
ment in Mammals ; and the simple crescentic
cartilaginous maxillary plate, with the open
groove behind containing the germinal papillae
of the teeth, offers in the Shark a magnified
representation of the earliest condition of the
jaws and teeth in the human embryo.

In many fishes, e. g. Lophius, Esox , the
dental papillae become buried in the membrane
from which they rise, and the surface to which
their basis is attached becomes the bottom of
a closed sac : but this sac does not become
inclosed in the substance of the jaw ; so that
teeth at different stages of growth are brought
away with the thick and soft gum, when it is
stripped from the jaw-bone. The final fix-
ation of teeth, so formed, is effected by the

* In my Hunterian Lectures, delivered at the
Royal College of Surgeons, May, 1839. See also,
Compte Rendu de l’Academie des Sciences, Dec.
1839, p. 784. ; and Odontography, Introduction, and
part i. passim.

development of ligamentous fibres in the sub-
mucous tissue between the jaw and the base
of the tooth, which fibres become the medium
of connection between those parts, either as
elastic ligaments, or by continuous ossifi-
cation. Here, therefore, is represented the
“ follicular ” stage of the development of a
mammalian tooth ; but the “ eruptive ” stage
takes place without previous inclosure of the
follicle and matrix in the substance of the
jaw-bone.

In Batistes, Scarus, Sphyrcena, the Sparoids,
and many other fishes, the formation of the
teeth presents all the usual stages which have
been observed to succeed each other in the
dentition of the higher Vertebrata: the papilla
sinks into a follicle, becomes surrounded by a
capsule, and is then included within a closed
alveolus of the growing jaw (Jig. 516. c,
Vol. III. p. 979. art. Pisces), where the de-
velopement of the tooth takes place and is
followed by the usual eruptive stages. A
distinct enamel-pulp is developed from the
inner surface of the capsule in Batistes, Scarus,
Sargus, and Chrysuphrys.

The most formidable dentition exhibited in
the order of osseous fishes, is that which cha-
racterises the Sphyrcena, and some extinct
fishes allied to this predatory genus. In the
great Barracuda of the southern shores of the
United States (Sphyrcena Barracuda, Cuv.),
the lower jaw contains a single row of large,
compressed, conical, sharp-pointed, and sharp-
edged teeth, resembling the blades of lancets,
but stronger at the base. The two anterior
of these teeth are twice as long as the rest,
but the posterior and serial teeth gradually
increase in size towards the back part of the
jaw ; there are about twenty-four of these
piercing and cutting teeth in each preman-
dibular bone. They are opposed to a double
row of similar teeth in the upper jaw, and fit
into the interspace of these two rows when
the mouth is closed. The outermost row is
situated on the intermaxillary, the innermost
on the palatine bones ; there are no teeth on
the vomer or superior maxillary bones. The
two anterior teeth in each premaxillary bone
equal the opposite pair in the lower jaw in
size : the posterior teeth are serial, numerous,
and of small size ; the second of the two an-
terior large premaxillary teeth is placed on
the inner side of the commencement of the
row of small teeth, and is a little inclined
backwards. The retaining power of all the
large anterior teeth is increased by a slight
posterior projection, similar to the barb of a
fish-hook, but smaller. The palatine bones
contain each nine or ten lancet-shaped teeth,
somewhat larger than the posterior ones of
the lower jaw. All these teeth afford good
examples of the mode of attachment by im-
plantation in sockets, which has been denied
to exist in fishes.*

The loss or injury to which these destruc-
tive weapons arc liable in the conflict which
the Sphyrcena wages with its living and

* Cuvier, Histoire Naturelle des Poissons, tom. i.
p 492.

TEETH.

881

struggling prey, is repaired by an uninter-
rupted succession of new pulps and teeth.
The existence of these is indicated by the
foramina, which are situated immediately
posterior to, or on the inner margin of, the
sockets of the teeth in place ; these foramina
lead to alveoli of reserve, in which the crowns
of the new teeth in different stages of de-
velopment are loosely embedded. It is in
this position of the germs of the teeth that
the Sphyrasnoid fishes, both recent and fossil,
mainly differ, as to their dental characters,
from the rest of the Scomberoid family, and
proportionally approach the Sauroid type.
The base or fang of the fully-developed tooth
of the Sphyrcena is anchylosed to the parietes
of the socket in which it is inserted. The
pressure of the crown of the new tooth ex-
cites absorption of the inner side of the base
of the old, which thus finally loses the requi-
site strength of attachment ; and its loss is
followed by the absorption of the old socket,
as in the higher animals.

It is interesting to observe that the alter-
nate teeth are, in general, contemporaneously
shed ; so that the maxillary armour is always
preserved in an effective state. The relative
position of the new teeth to their predecessors,
and their influence upon them, resembles, in
the Sphyrcena, some of the phenomena which
will be described in the dentition of the cro-
codilian reptiles. To the crocodiles the pre-
sent voracious fish also approximates in the
alveolar lodgment of the teeth ; but it mani-
fests its ichthyic character in the anchylosis
of the fully-developed teeth to their sockets,
and still more strikingly in the intimate struc-
ture of the teeth.

In all fishes the teeth are shed and re-
newed, not once only, as in Mammals, but
frequently, during the whole course of their
lives. The maxillary dental plates of Lcpi-
dosiren, the cylindrical dental masses of the
Chimteroid and Edaphodont fishes, and the
rostral teeth of Pris/is (if these modified
dermal spines may be so called) are, perhaps,
the sole examples of “permanent teeth” to
be met with in the whole class.

When the teeth are developed in alveolar
cavities, they are usually succeeded by others
in the vertical direction, as in the pharyngeal
bones of the Labroids (Jig. 513., art. Pisces,
Vol. III. p.978.) ; but sometimes they follow
one after the other, side by side, as in the
Scaroids (Pisces, Jig. 516. c, p. S'?!).). The
successional teeth owe the origin of their
matrix to the budding out from the capsule of
their predecessors of a caecal process, in which
the papillary rudiment of the dentinal pulp is
developed according to the laws explained
in the Introduction to my “ Odontography,”
and the article Tooth. But, in the great
majority of fishes, the germs of the new teeth
are developed, like those of the old, from the
free surface of the buccal membrane through-
out the entire period of succession ; a cir-
cumstance peculiar to the present class. The
Angler, the Pike, and most of our common
fishes, illustrate this mode of dental repro-

VOL. IV.

duction ; it is very conspicuous in the carti-
laginous fishes, in which the whole phalanx
of their numerous teeth is ever marching
slowly forwards in rotatory progress over the
alveolar border of the jaw, the teeth being
successively cast off as they reach the outer
margin, and new teeth rising from the mucous
membrane behind the rear rank of the pha-
lanx.

This endless succession and decadence of
the teeth, together with the vast numbers in
which they often coexist in the same fish,
illustrate the law of Vegetative or Irrelative
Repetition, as it manifests itself on the first
introduction of new organs in the animal
kingdom, under which light we must view
the above-described organised and calcified
preparatory instruments of digestion in the
lowest class of the vertebrate series.

At the extreme limit of the class of fishes,
and connecting that class with the reptiles,
stands the very remarkable genus, the dental
system of which is figured in cut 560. This
consists of two small, slender, conical, sharp-
pointed, and slightly recurved teeth, which
project downwards from the nasal bone (c),
arid of strong trenchant dental plates anchy-
losed with the alveolar border of the upper
(a) and lower ( h ) jaws, in each of which the
plate is divided at the middle, or symphysial
line, so as to form two distinct lateral teeth.

The office of the two laniariform teeth is to
pierce and retain the nutritive substance or
prey which is afterwards divided and com-
minuted by the strong maxillary dental plates.

The upper pair of these plates is supported
by the anterior part of a strong arch of bone,
which combines the characters of the su-
perior maxillary, palatine, and pterygoid bones;
the superior maxillary is represented by the
median and anterior bar, passing in front of
the dental plate of the lower jaw when the
mouth is shut, terminating on each side in a
process which projects outwards and back-
wards, as in Jig. 560 , a., on each side of the an-
terior part of the arch ; the palatine portion
constitutes the median part of the roof of the
mouth behind the foregoing ; the pterygoid
portion is indicated by its fulfilling the usual
function of au abutment extended between the
palatine portion of the upper jaw and the ar-
ticular pedicle of the lower jaw ; the upper
dental plates are confined to the first two
parts of the arch (maxillary and palatine), and
do not extend upon the pterygoid portion ;
the lower dental plates ( b ) are anchylosed to
the premandibular bone. Viewing the upper
pair of plates as a single tooth, it may be
described as indented at its outer surface by
five vertical angular notches, penetrating in-
wards through half the breadth of the sup-
porting bone, and dividing the plate into six
angular processes, which, from the direction
and varying form and breadth of the entering
notches, radiate from the posterior part of
the median line or division of the tooth. The
inferior dental plate is similarly notched on
its outer side, but the proportions of the an-
gular indentations are such, that they receive

3 L

882

TEETH.

all the processes of the upper dental plate
when the mouth is shut, whilst only the four
anterior processes are reciprocally received
into the notches of the upper dental plate,
this, with the supporting arch, being anterior
to the lower plate, — a position which is deci-
sive in favour of its maxillary character, and
against its homology with the vomer.

The dental plate consists, as in the Cod
and Sphyreena, of a central mass of coarse
osseous substance, traversed by large and
nearly parallel medullary canals, and an ex-
ternal sheath of very hard “ vitro-dentine.”
The medullary canals are continued from a
coarse reticulation of similar but wider canals
in the substance of the supporting bone, and
advance forwards, nearly parallel with each
other and with the plane of the upper surface
of the tooth ; they anastomose together by
short, curved, transverse canals, which inter-
cept spaces increasing in length as the canals
recede from the osseous basis. The canals
themselves diminish in size in the same ratio ;
and when they have arrived near the dense
outer layer, their divisions and inosculations
become again more frequent, the peripheral
loops forming a well-marked line of demarca-
tion between the coarse-tubed and the fine-
tubed dentine. The interspaces of the
medullary canals are occupied by a clear sub-
stance, and by moss-like reticulations of fine
dentinal tubes, which appear to be more
sparing in number than in the teeth of the
Sphyrcena or Shark. The dentinal tubes of
the vitro-dentine run nearly parallel to each
other, and vertically to the external surface of
the dental plate through about two-thirds of
the thickness of that tissue; they then bend
and cross each other in a manner very similar
to those of the vitro-dentine in the teeth of
the Lepidotus, Phyllodus, ike.*

In the , process of attrition this external
dense substance is worn away from the upper
surface of the dental processes in the lower
jaw, exposing the softer vaso-dentinal sub-
stance of the tooth ; in this state the den-
tal plate offers an analogy to the incisors
of the Rodents, a posterior softer substance
being sheathed by an anterior denser layer ;
and ar) external sharp edge is similarly kept
up by the unequal wearing .away of the two
substances. The progressive waste at the
tipper surface of the dental plate would appear
to be met by a corresponding additon of new
material to its lower part.

In the structure here presented we have a
condition of the dentine which has hitherto
been met with only in the class of fishes.

The test of the affinities of the present
paradoxical genus, afforded by the micro-
scopic examination of the teeth, gives addi-
tional confirmation to the view to which I
have been led, from arguments drawn from
the rest of its organisation, that the Lepido-
siren is in every essential point a member of
the class of fishes, j-

* See Odontography, pp. 70. 166, pi. 59 ,fig. 4.

t Linnean Transactions, vol. xviii. 1839. p. 350.
That the large size, or elliptical form of its blood-

Dental System of Reptiles.

If we compare the dental system of the
foregoing Batrachoid fish with that in the
true Batracliia, it is only to the larval state
of the Anourans that an analogy can be
found ; the tadpole of the frog having its
maxilla and mandibula each sheathed with a
single and continuous horny dental trenchant
covering. Were this sheath actually dentinal
in tissue and united to the jaw-bone, the re-
semblance to the Lepidosiren would be closer ;
but in point of fact the analogy is very
remote ; the horny beak of the tadpole is
never calcified or anchylosed, Rut is shed
during the progress of the metamorphosis.#
The Siren alone, among the larval-like pe-
rennibranchiate reptiles, retains the sheath
upon the extremity of the upper and lower
jaws.; it consists of a firm albuminous tissue,
and becomes harder than horn. But these
trenchant mandibles, which play upon one
another like the blades of a pair of curved
scissors, are associated with numerous small
but distinct true teeth, which are grouped
together to form a rasp-like surface on each
half of the divided vomer, and which beset
the alveolar border of the splenial element of
the mandible below.

In the class Reptilia, the whole order of
Chelonia is edentulous, as well as the whole
family of Toads ( Bufonidce ) in the order
Batracliia; certain extinct genera of Sau-
rians were likewise edentulous, e.g. the re-
markable “ Mhynchosaurus” of the new red
sandstone of Shropshire, and some of the
extinct Saurians of South Africa.

In the tortoises and turtles the jaw's are
covered by a sheath of horn, which in some
species is of considerable thickness and very
dense ; its working surface is trenchant in the
carnivorous species, but variously sculptured,
and adapted for both cutting and bruising in
the vegetable feeders ; it may be said that the
transitory condition of the mandibles of the
Batrachian larvee is here persistent.

The development of the continuous horny
maxillary sheath commences, as in the parrot
tribe, from a series of distinct papillm, which
sink into alveolar cavities, regularly arranged
(in Trionyx ) along the margins of the upper
and lower jaw-bones : these alveoli are in-
dicated by the persistence of vascular canals
long after the originally separate tooth-like
cones have become confluent, and the horny
sheath completed.

The teeth of the dentigerous Saurian,

discs should outweigh the cumulative evidence 'esta-
blishing the piscine nature of the Lepidosiren could
only be surmised by those -who are ignorant of the
variation in size and shape which the blood-discs
present in the class of fishes, and the consequent
unimportance of those particles as a character of the
class. As well might the Petromyzon be deemed a
mammal because its blood-discs are circular and
comparatively small, as the Lepidosiren be held to
be a Batrachian because its blood-discs are elliptical
and comparatively large.

* The large dental plates of Lepidosiren have
their neai'est homologues in those of the extinct
fish called Ceratodus (Odontography, pi. 22, Jig. 2.).

TEETH.

883

Ophidian, and Batrachian reptiles, are, for the
most part, simple and adapted for seizing and
holding, but not for dividing or masticating
their food. The Siren alone combines true
teeth with a horny maxillary trenchant sheath,
like that of the Chelonian reptiles.

With respect to number, in no existing rep-
tile are the teeth reduced so low as in certain
mammals and fishes ; nor, on the other hand,
are they ever so multiplied as in many of
the latter class. The extinct Dicynodont
reptiles of South Africa had but two teeth,
which were long tusks implanted in the upper
jaw.* Some species of Amplmbcena (A. alba),
with fifteen teeth in the upper jaw and four-
teen in the lower jaw, and certain Monitors
( Varanus), with sixteen teeth in the upper and
fourteen in the lower jaw, afford examples of
the smallest number of teeth amongst existing
reptiles ; and certain Batrachians, with teeth
“ en eardes ” at the roof of the mouth, or
which have upwards of eighty teeth in each
lateral maxillary series, present the largest
number. It is rarely that the number of the
teeth is fixed and determinate in any reptile
so as to be characteristic of the species, and
still more rarely have the individual teeth
such characters as to be determined homo-
logically from one species to another.

With respect to situation, the teeth may be
present on the jaws only, i.e. the maxillary, pre-
maxillary, and mandibular bones, as in the croco-
diles and many lizards : or upon the jaws and
roof of the mouth ; and here either upon the
pterygoid bones, as in the Iguana and Mosa-
saur, or upon both palatine and pterygoid
bones, as in most serpents, or upon the
vomer, as in most Batrachians, or upon both
vomerine and pterygoid bones, as in the Axo-
lote ; or upon the vomerine and sphenoid
bones, as in the Salamandraglutinosa, Maclure.
With respect to the marginal or jaw teeth,
these may be absent in the intermaxillary
bones, as in many serpents ; or they may be
present in the upper and not in the lower
jaw, as in most frogs ; or in both upper and
lower jaws, as in the tailed Batrachians ; and
among these they may be supported, upon
the lower jaw, by the preman dibular or den-
tary piece, as in the Salamanders, Menopome,
Amphiume, Proteus ; or upon the splenial
piece, as in the Siren ; or upon both splenial
and premandibular bones, as in the Axolotl.
The palatine and pterygoid teeth may, in the
Batrachians, be arranged in several rows, like
the “ dents en eardes ” of fishes. The sphe-
noid and splenial teeth are always so ar-
ranged in the few species that possess them.
The intermaxillary, maxillary, and preman-
dibular teeth are uniserial, or in one row, with
the exception of the Caecilia and the extinct
Labyrinthodonts, which have a double row of
teeth at the anterior part of the lower jaw.

The teeth of reptiles, with few exceptions,
present a simple conical form, with the crown
more or less curved, and the apex more or

* Transactions of the Geological Society, 2d series,
vol. vii., 1845, p. 59.

less acute. The cone varies in length and
thickness ; its transverse section is sometimes
circular, but more commonly elliptical or oval,
and this modification of the cone may be
traced through every gradation, from the
thick, round, canine-like tooth of the croco-
dile, to the sabre-shaped fang of the Varanus,
the Megalosaur, and the Cladeiodon.* Some-
times, as in the fully formed teeth of the
Megalosaur, one of the margins of the com-
pressed crown of the tooth is trenchant,
sometimes both are so ; and these may be
simply sharp-edged, as in the Varanus of
Timor, or finely serrated, as in the great Va-
ranus, the Cladeiodon, and the Megalosaur. -}-

The outer surface of the crown of the
tooth is usually smooth ; it may be polished,
as in the Leiodon, or impressed with fine
lines, as in the Labyrinthodon (jig. 531.), or
raised into many narrow ridges, as in the
Pleiosaur and Polyptychodon, or broken by a
few broad ridges, as in the Iguanodon (Jig.
571.), or grooved by a single longitudinal
furrow, as in some serpents (fig. 569, a).±

The cone is longest and its summit sharpest
in the serpents : from these may be traced,
chiefly in the lizard tribe, a progressive short-
ening, expansion of the base, and blunting of
the apex of the tooth, until the cone is
reduced to a hemispherical tubercle, or plate,
as in the Thorictes and Cyclodus (fig. 570. ).

In the Pleiosaur the dental cone is three-
sided, with one of the angles rounded off.
The posterior subcompressed teeth of the
alligator (fig. 573.) present a new modification
of form ; here they terminate in a mammillate
summit, supported by a slightly constricted
neck. In the tooth of the Hylceosaur the
expanded summit is flattened, bent, and spear-
shaped, with the edges blunted. But the
expansion of the crown is greatest in the sub-
compressed teeth of the extinct Cardioclon and
the existing Iguanas, the teeth of which are
farther complicated by having the margins
notched. The great Iguanodon had the crown
of the tooth expanded both in length and
breadth, and combining marginal dentations
with longitudinal ridges : this tooth (fig. 571.)
presents the most complicated external form
as yet discovered in the class of reptiles.

In no reptiles does the base of the tooth
ever branch into fangs.

Attachment. — As a general rule, the teeth
of reptiles are anchylosed to the bone which
supports them. When they continue distinct,
they may be lodged either in a continuous
groove, as in the Ichthyosaurs), or in separate
sockets, as in the Plesiosaur and Crocodilians
(fig. 573.). The base of the tooth is anchy-
losed to the walls of a moderately deep socket
in the extinct Megalosaur and Theocodon.
In the Labyrinthodonts and Caeciliae, among
the Bratrachians ; in most Ophidians ; and
in the Geckos, Agamians, and Varanians,
among the Saurians, the base of the tooth is

* Odontography, pi. 62 A, Jig. 4.

f lb. Jig. 6 c.

J lb. pi. 65 ; vol. iv.,Jzgs. 209, 210.

§ lb. pi. 13, Jig. 9.

3 l 2

884

TEETH.

imbedded in a shallow socket, and is confluent
therewith.

In the Scincoidians, the Safeguards ( Tejus ),
in most Iguanians, in the Chameleons and
most other Lacertian reptiles, the tooth is
anchylosed by an oblique surface extending
from the base more or less upon the outer
side of the crown to an external alveolar plate
of bone* * * §, the inner alveolar plate not being
developed. In the frogs the teeth are simi-
larly but less firmly attached to an external
parapet of bone. The lizards which have
their teeth thus attached to the side of the
jaw are termed Pleurodonts. In a few Igua-
nians, as the Istiures, the teeth appear to be
soldered to the margins of the jaws, these
have been termed “ Acrodonts.” In some
large extinct Lacertians, c. g. the Mosasaur
and Leiodon, the tooth is fixed upon a raised
conical process of bone, as shown in my
“ Odontography,” Plate 68. Jig. 1., and Plate
72. fig. 2.

These modifications of the attachment of
the teeth of reptiles are closely adapted to the
destined application of those instruments, and
relate to the habits and food of the species ;
vve may likewise perceive that they offer a
close analogy to some of the transitory con-
ditions of the human teeth. There is a
period, for example f, when the primitive
dental papillae are not defended by either an
outer or an inner alveolar process, any more
than their calcified homologues which are
confluent with the margin of the jaw in the
Rhynchocephalus.\ There is another stagetji,
in which the groove containing the den-
tal germs is defended by a single external
cartilaginous alveolar ridge ; this condition is
permanently typified in the Cyclodus {fig. 570.)
and most existing lizards. Next there is
developed in the human embryo an internal
alveolar plate, and the sacs and pulps of the
teeth sink into a deep but continuous groove,
in which traces of transverse partitions soon
make their appearance ; in the ancient Ichthy-
osaur the relation of the jaws to the teeth
never advanced beyond this stage.

Finally, the dental groove is divided by
complete partitions ||, and a separate socket
is formed for each tooth ; and this stage of
developement is attained in the highest or-
ganised reptiles, e.g. the crocodiles (fig. 573.).

Substance. — This may be four-fold, and a
single tooth may be composed of dentine,
cement, enamel, and bone; but the dentine
and cement are present in the teeth of all
reptiles.

In the Batrachians and Ophidians a thin
layer of cement invests the central body
of dentine, and, as usual, follows any in-
flections or sinuosities that may characterise

* Odontography, pi. 67.

t At the sixth week of gestation : see Prof. Good-
sir, “ On the Development of the Pittman Teeth,”
Edinburgh Medical and Surgical Journal, No. 138.

% See Geological Transactions, 2d series, vol. vii.
pt. 2, pi. 6, figs. 5 & 6, p. 83.

§ At the seventh or eighth week : Ibid.

I) At the sixth month : Ibid.

the dentine. Besides the outer coat of cement,
which is thickest at the base of the teeth, a
generally thin coat of enamel defends the
crown of the tooth in most Saurians, and the
last remains of the pulp are not unfrequently
converted into a coarse bone, both in the
teeth which are anchylosed to the jaw, and
in some teeth, as those of the Ichthyosaur,
which remain free. The only modification of
the dentine, which could at all entitle it to be
regarded in the light of a new or distinct
substance, is that which is peculiar in the
present class to the teeth of the Tguanodon,
and which will be described in the following
section.

Structure. — The varieties of dental structure
are few in the reptiles as compared with
either fishes ora mammals, and its most com-
plicated condition arises from interblending of
the dentinal and other substances rather than
from modifications of the tissues themselves.
In the teeth of most reptiles the intimate
structure of the dentine corresponds with
that which has been described as the type of
the tissue, e.g. the hard or un vascular dentine,
and which is the prevailing modification in
Mammalia, viz., the radiation of a system of
minute plasmatic tubes from a single pulp-
cavity, at right angles to the external surface
of the tooth. The most essential modification
of this structure is the intermingling of cylin-
drical processes of the pulp-cavity in the form
of medullary canals, with the finer tubular
structure.* Another modification is that in
which the dentine maintains its normal struc-
ture, but is folded inwardly upon itself, so as
to produce a deep longitudinal indentation on
one side of the tooth ; it is the expansion of
the bottom of such a longitudinal deep fold
that forms the central canal of the venom-
fang of the serpent ; but a glance at fig. 568.
will show that, notwithstanding the singularly
modified disposition of the dentine (b), its
structure remains unaltered ; and although
the pulp-cavity (p) is reduced to the form of a
crescentic fissure, the dentinal tubes continue to
radiate from it according to the usual law. By
a similar inflection of many vertical longi-
tudinal folds of the external cement and ex-
ternal surface of the tooth at regular intervals
around the entire circumference of the tooth,
and byr a corresponding extension of radiated
processes of the pulp-cavity and dentine into
the interspaces of such inflected and con-
verging folds, a modification of dental struc-
ture is established in certain extinct reptiles,
which, by the various sinuosities of the inter-
blended folds of cement and processes of
dentine, with the partial dilatations of the
radiated pulp-cavity, produces the compli-
cated structure which is described at p. 868.
and figured in cut 552. But this compli-
cation is nevertheless referable to a modi-
fication of form or arrangement of the dental
tissues, rather than of the structure of the
tissues themselves : the calcigerous tubes in
each sinuous lobe of dentine, in the most

Odontography, pi. 71, Iguanodon.

TEETH.

complex tooth of the Labyrinthodon, exhibit
the same general disposition and course as in
the fang of the serpent and in the still more
simple tooth of the Saurian.

Development. — The teeth of reptiles are
never completed, as in certain fishes, at the
first or papillary stage ; but the pulp sinks
into a follicle, and becomes inclosed by a cap-
sule ; and in certain reptiles this becomes
more or less surrounded by bone ; but the
process of development never offers the erup-
tive stage, in the sense in which this is
usually understood, as signifying the extrica-
tion of the young tooth from a closed alveolus.

The completion of a tooth, with the extinct
exception of the Dicynodont Reptiles, is soon
followed by preparation for its removal and
succession : the faculty of developing new
tooth-germs seems to be unlimited in the pre-
sent class, and the phenomena of dental deca-
dence and replacement are manifested at every
period of life; the number of teeth is gene-
rally the same in each successive series, and
the difference of size presented by the teeth
of different and distant series is considerable.

The new germ is always developed, in the
first instance, at the side of the base of the
old tooth, never in the cavity of the base ; the
crocodiles form no exception to this rule.
The poison-fangs of serpents succeed each
other from behind forwards ; in almost every
other instance the germ of the successional
tooth is developed at the inner side of the
base of its predecessor. In the frog the
dental germ makes its appearance in the
form of a papilla developed from the bottom
and towards the outer side of a small fissure
in the mucous membrane or gum that fills up
the shallow groove at the inner side of the
alveolar parapet and its adherent teeth : the
papilla is soon enveloped by a capsular pro-
cess of the surrounding membrane : there is
a small enamel pulp developed from the cap-
sule opposite the apex of the tooth ; the de-
position of the earthy salts in this mould is
accompanied by ossification of the capsule,
which afterwards proceeds pari passu with
the calcification of the dentinal papilla or
pulp ; so that, with the exception of its base,
the surface of the uncalcified part of the pulp
alone remains normally unadherent to the cap-
sule.

As the tooth acquires hardness and size, it
presses against the base of the contiguous
attached tooth, causes a progressive absorp-
tion of that part, and finally undermines, dis-
places, and replaces its predecessor. The
number of nascent matrices of the successional
teeth is so great in the frog, and they are
crowded so close together, that it is not
unusual to find the capsules of contiguous
tooth-germs becoming adherent together, as
their ossification proceeds. After a brief ma-
ceration, the soft gum may be stripped from
the shallow alveolar depression, and the
younger tooth-germs in different stages of
growth are brought away with it.

The mode of development of the teeth of
serpents does not differ essentially from that

885

of the teeth of the Batraehian above described
except in the relation of the papillae of the
successional poison-fangs to the branch of the
poison-duct that traverses the cavity of the
loose mucous gum in which they are deve-
loped.

Batraehian modifications. — Some of the pe-
culiarities of the dentition of the Batrachians
have already been noticed, as in the compa-
rison of the Siren with the Lepidosiren , in
which the true amphibian was shown to have
numerous teeth on the palate and lower jaw.*

The piscine character of rasp-like teeth
aggregated in numerous series, is manifested
also in the Axolotl j-, upon the palatal region
of the mouth, and upon the splenial or oper-
cular element of the lower jaw ; but the
superior maxillary bones are here developed,
and also support teeth. The premandibular
and the premaxillary bones, instead of pre-
serving the larval condition of the horny
sheath, have their alveolar border armed with
a single row of small, equal, fine and sharp-
pointed denticles, which are continued above,
along the maxillaries; thus establishing the
commencement of the ordinary Batraehian
condition of the marginal teeth of the buccal
cavity. The dentigerous bones of the palate
consist of two plates on each side, as in the
Siren ; the anterior pair, or vomerine bones,
converge and meet at their anterior extre-
mities ; the minute denticles which they sup-
port are arranged quincuncially ; the posterior
pair of bones are continued backwards ac-
cording to the usual disposition of the ptery-
goids, to abut against the tympanic bones ;
the denticles are confined to the anterior part
of their oral surface, and resemble in their
arrangement and anchylosed attachment those
of the vomerine series, of which they form the
posterior termination.

The frogs ( Rana ) J have no teeth on the
lower jaw ; but in some species the alveolar
edge of this bone is finely notched or dentated,
as in the horned frogs ( Ceratophrys ). The in-
termaxillary and maxillary bones support a
long, close-set, single series of small, conical,
hollow teeth, of which the apices only project
beyond the external alveolar ridge to which
they are attached. A short transverse row
of similar but smaller teeth extends along the
posterior border of each vomer, except in the
slender-armed frogs ( Leptobrachium j, and in
some of the tree frogs (e. g. Euchnemis), in
which the roof of the mouth is edentulous.

Amongst the most extraordinary examples
of extinct reptiles are those which are charac-
terised by the labyrinthic modification of the
dental structure above described, and which
with some affinities to Saurians, combine
characters which are essentially those of the
order Batrachia. I have ascertained by fossil
portions of the upper jaw of the Labyrinthodon
leptognathus that the maxillary or facial divi-
sion of the skull was broad, much depressed,
and flattened, resembling the skull of the

* Odontography, pi. 62, figs. 5 & 6

t lb. pi. 62, fig. 4.

t lb. pi. 62, fig. 10.

3 l 3

886

TEETH.

gigantic Salamander and of the Alligator ; and
the outer surface of the bones was strongly
sculptured, as in the Crocodilian family, but
of a relatively larger and coarser pattern.
The upper jaw contains a single row of small
teeth, about sixty in number, anterior to which
are three or four large conical tusks. The
bases of the serial teeth project directly from
the outer wall of the shallow socket, there
being no alveolar ridge external to it. The
second large anterior tusk is three times the
size of the first of the serial teeth, and the
size of these teeth gradually diminishes as
they are placed further back ; the length of
the common-sized teeth being about two lines,
and the greatest breadth one-third of a line.
The apical two-thirds of each tooth is smooth,
but the basal third is fluted and anchylosed
to the outer wall of the socket. The osseous
roof of the mouth is principally composed of
a pair of broad and flat bones, homologous
with the divided vomer in Batrachia, but of
much greater relative extent, approaching, in
this respect, those of the Menopome, and de-
fending the mouth with a more extensive
roof of bone than exists in any Lacertian
reptile ; physiologically, therefore, the La-
byrinthodon, in this part of its structure,
comes nearest to the Crocodile ; but the
structure itself, morphologically, is essen-
tially Batrachian.* In the Menopome f and
gigantic Salamander, a row of small teeth ex-
tends transversely across the anterior extre-
mity of the vomerine bones; and the occur-
rence in the Labyrinthodon of a similar row,
consisting in each palatine bone of three
median small teeth and two outer larger ones,
marks most strongly its Batrachian nature ;
and from the outermost tooth a longitudinal
row of small and equal-sized teeth is con-
tinued backward along the exterior margin of
the palatine bone. The whole of this series
of palatal teeth is nearly concentric with the
maxillary teeth.

In Lacertine reptiles the examples of a
row of palatal teeth are rare, and, when pre-
sent, it is short, and situated towards the
back of the palate, upon the pterygoid bones,
as in the Iguana and Mosasaur.j: In Batra-

chians the most common disposition of the
palatal teeth is a transverse row placed at the
anterior part of the divided vomer, as in Frogs,
the Menopome and gigantic Salamander, and
at the posterior part in certain toads. In the
Amphiume, on the contrary, the palatal teeth
form a nearly longitudinal series along the
outer margin of the palatine bones. The
Labyrinthodon combines both these disposi-
tions of the palatal teeth. The lower jaw,
like the upper, contains a series of small
teeth, with a few larger tusks anterior to them,
the serial teeth are long and slender, gradually
diminishing in size towards the anterior por-
tion of the jaw ; the largest fossil portion
which I have obtained presents a linear series
of not less than fifty sockets, placed alter*

* Odontography, pi. 63. A, fig. 3.

f lb. pi. 62. figs. 1 & 2.

f lb. pi. 68.

nately, one nearer the inner, the next nearer
the outer side of the jaw. The sockets of
the teeth are shallower than in the upper
jaw ; the outer wall is more developed than
the inner, and the anchylosed bases of the
teeth more nearly resemble, in their oblique
position, those of existing Batrachia. With
regard to the modification of the microscopic
structure of the teeth, I may observe that,
between the apex and the part where the
inflected vertical folds of the cement com-
mence, the tooth resembles, in the sim-
plicity of its intimate structure, that of the
entire tooth of ordinary Batrachia and most
reptiles ; and in the lower or basal half of the
tooth the labyrinthic structure above de-
scribed commences, and gradually increases
in complexity.

In the genus Deirodon* , the teeth of the
ordinary bones of the mouth are so small
as to be scarcely perceptible ; and they appear
to be soon lost, so that it has been described
as edentulous, and bas been called “ Anodon.”
An acquaintance with the habits and food
of this species has shown how admirably
this apparent defect is adapted to its well-
being. Its business is to restrain the undue
increase of the smaller birds by devouring
their eggs. Now if the teeth had existed
of the ordinary form and proportions in the
maxillary and palatal regions, the egg would
have been broken as soon as it was
seized, and much of the nutritious contents
would have escaped from the lipless mouth
of the snake in the act of deglutition ; but,
owing to the almost edentulous state of the
jaws, the egg glides along the expanded
opening unbroken ; and it is not until it has
reached the gullet, and the closed mouth
prevents any escape of the nutritious matter,
that the egg becomes exposed to instruments
adapted for its perforation. These instruments
consist of the inferior spinous pocessess (hyp-
apophyses) of the seven or eight posterior cer-
vical vertebrae, the extremities of which are
capped by a layer of hard cement, and pene-
trate the dorsal parietes of the oesophagus.
They may be readily seen, even in very
small subjects, in the interior of that tube,
in which their points are directed backwards.
The shell being sawed open longitudinally
by these vertebral teeth, the egg is crushed
by the contractions of the gullet, and is
carried to the stomach, where the shell is
no doubt soon dissolved by the acid gastric
juice.

In the Boa Constrictor, the teeth are
slender, conical, suddenly bent backwards
and inwards above their base of attachment ;
the crown is straight or very slightly curved,
e. g. in the posterior teeth. The inter-
maxillary bone supports four small teeth ;
each maxillary bone has eight much larger
ones, which gradually decrease in size as they
are placed further back. There are eight
or nine teeth of similar size and proportions
in each premandibular bone. These teeth

* The Coluber scaber of Linnreus ; an arboreal
serpent of South Africa.

TEETH.

are separated by wide intervals, from which
other teeth, similar to those in place, have
been detached. The base of each of the
above teeth is extended transversely, com-
pressed antero-posteriorly, and anchylosed
to a shallow alveolus, extending obliquely
across the shallower alveolar groove. An
affinity to the lizard tribes is manifested by
the greater development of the outer, as
compared with the inner wall of the alveolar
furrow.

The palatine teeth, of which there are
three or four in each palatal bone, are as
large as the superior maxillary, and are
similarly attached. The pterygoid teeth,
five or six in number, which complete the
internal dental series on the roof of the
mouth, are of smaller size, and gradually
diminish as they recede backwards. In the
interspaces of the fixed teeth in both these
bones,, the places, of attachment of the shed
teeth are always visible ; so that the dental
formula, if it included the vacated with the
occupied sockets, would express a greater
number of teeth than are ever in place and
use at the same time.* In the smaller species
of Boa, the intermaxillary bone is edentulous.

The Colubers, like other true serpents, have
two longitudinal rows of teeth on the roof of
the mouth, extending along the palatines and
pterygoids. The genus U/igodon appears to
form the sole exception to this rule. In the
Dryinus nasutus, a few small teeth are present
on the ecto-pterygoid as well as on the
pterygoid.

In certain genera of non-poisonous ser-
pents, as Dryophis, Dipsas, and Bucephalus,
in which the superior maxillary teeth increase
in size towards the posterior part of the
bone, the large terminal teeth of the series
are traversed along their anterior and convex
side by a longitudinal groove. In the Bu-
cephalus capensis, the two or three poste-
rior maxillary teeth present this structure,
and are much larger than the anterior teeth,
or those of the palatine and premandibular
series. They add materially, therefore, to
the power of retaining the prey, and may
conduct into the wounds which they inflict
an acrid saliva ; but they are not in con-
nection with the duct of an express poison-
gland. The long-grooved fangs are either
firmly fixed to the maxillary bones, or are
slightly moveable, according to their period of
growth. They are concealed by a sheath of
thick and soft gum, and their points are
directed backwards. The sheath always
contains loose recumbent grooved teeth,
ready to succeed those in place.

In most of the Colubri, each maxillary and
premandibular bone includes from twenty to
twenty-five teeth. They are less numerous
in the genera Tortrix and Homalopsis, and are
reduced to a still smaller number in the
poisonous serpents, in the typical genera of
which the short maxillary bone supports only
a single perforated fang.

887

Poisonous Serpents. ■— The transition to
these serpents, which was begun in the
Bucephali and allied genera with grooved
maxillary teeth, is completed by the poisonous
serpents of the genera Pelamis, Hydrophis,
JE/aps, Bongarus, anil Hamadryas.

The superior maxillary bone diminishes in
length with the decreasing number of teeth
which it supports. The ecto-pterygoid bone
elongates in the same ratio, so as to retain its
position as an abutment against the shortened
maxillary, and the muscles implanted into this
external pterygoid bone communicate through
it to the maxillary bone the hinge-like
movements backwards and forwards upon
the ginglymoid articulations connecting that
bone with the prefrontal and palatine bones.
As the fully-developed poison-fangs are at-
tached by the same firm basal anchylosis to
maxillary sockets, which forms the charac-
teristic mode of attachment of the simple or
solid teeth, they necessarily follow all the
movements of the superior maxillary bone.
When the external pterygoid is retracted, the
superior maxillary rotates backwards, and the
poison-fang is concealed in. the lax mucous
gum, with its point turned backwards. When
the muscles draw forward the external ptery-
goid, the superior maxillary' bone is pushed
forwards, and the recumbent fang withdrawn
from its concealment and erected.

In this power of changing the direction of
a large tooth, so that it may not impede the
passage of food through the mouth, we may
perceive an analogy between the viper and
the Lophius; but in the fish the movement
is confined to the tooth alone, and is depen-
dent on the mere physical property of the
elastic medium of attachment; in the serpent
the tooth has no independent motion, but
rotates with the jaw, whose movements are
governed by muscular actions. In the fish
the great teeth are erect, except when pressed
down by some extraneous force. In the ser-
pent the habitual position of the fang is the
recumbent one, and its erection takes place
only when the envenomed blow is to be
struck.

A true idea of the structure of a poison-
fang will be formed by supposing the crown
of a simple tooth, as that of a boa, to be
pressed flat, and its edges to be then bent
towards each other, and soldered together so
as to form a hollow cylinder, or rather cone,
open at both ends. The flattening of the
fang and its inflection around the poison-duct
commences immediately above the base, and
the suture of the inflected margins runs along
the anterior and convex side of the recurved
fang, as shown in Jig. 567, a. : the poison-
canal is thus in front of the pulp-cavity, as
shown in the longitudinal section of the fang
b. The basal aperture of the poison-canal v
is oblique, and its opposite outlet v' is still
more so, presenting the form of a narrow
elliptical longitudinal fissure terminating at a
short distance from the apex of the fang.
The relative position of the two apertures
of the poison-canal is shown in the figure of

3l 1

Odontography, pi. 65, Jigs. 6 & 7.

888 TEETH.

the fang of the large Cobra in my “ Odonto-
graphy ” (pi. 65. fig. 9., and in Vol. IV. p. 290.
fig. 210., art. Reptilia), where a fine hair is
represented as passing through the poison-
canal.

The poison-glands occupy the sides of the
posterior half of the head ; each gland con-
sists of a number of elongated narrow lobes,
extending from the main duct, which runs
along the lower border of the gland upwards
and slightly backwards : each lobe gives off
lobules throughout its extent, thus presenting
a pinnatifid structure ; and each lobule is
subdivided into smaller secerning caeca, which
constitute the ultimate structure of the gland.
The whole gland is surrounded by a double
aponeurotic capsule, of which the outermost
and strongest layer is in connection with the
muscles by whose contraction the several caeca
and lobes of the gland are compressed and
emptied of their secretion. This is then con-
veyed by the duct (see Reptilia, Vol. IV.
p. 291. ,fig. 2 1 1. e) to the basal aperture of the
poison-canal of the fang f We may suppose,
that as the analogous lachrymal and salivary
glands in other animals are most active during
particular emotions, so the rage which stimu-
lates the venom-snake to use its deadly weapon
must be accompanied with an increased secre-
tion and great distension of the poison-glands ;
and as the action of the compressing muscles
is contemporaneous with the blow by which
the serpent inflicts the wound, the poison is
at the same moment injected with force into
the wound from the apical outlet of the per-
forated fang.

The duct which conveys the poison, al-
though it runs through the centre of a great
part of the tooth, is really on the outside of
the tooth, the canal in which it is lodged
and protected being formed by a longi-
tudinal inflection of the dentinal parietes
of the pulp-cavity. This inflection coni-

Fig. 567.

A B

mences a little beyond the base of the tooth,
where its nature is readily appreciated, as the
poison-duct there rests in a slight groove or

longitudinal indentation on the convex side
of the fang; as it proceeds it sinks deeper
into the substance of the tooth, and the sides
of the groove meet and seem to coalesce, so
that tlie trace of the inflected fold ceases,
in some species, to be perceptible to the
naked eye ; and the fang appears, as it is
commonly described, to be perforated by the
duct of the poison-gland. In the Hydrophis
the groove remains permanently open, as in
fig 567. c.

From the real nature of the poison-canal
it follows that the transverse section of the
tooth varies in form in different parts of the
tooth ; at the base it is oblong, with a large
pulp-cavity of a corresponding form, with an
entering notch at the anterior surface ; farther
on the transverse section presents the form
of a horse-shoe, and the pulp-cavity that of
a crescent, the horns of which extend into
the sides of the deep cavity of the poison-
fling : a little beyond this part the section of
the tooth itself is crescentic, with the horns
obtuse and in contact, so as to circumscribe
the poison-canal ; and along the whole of
the middle four-sixths of the tooth, the section,
of which a magnified view is given in fig. 568.,

Fig. 568.

Section of poison-fang of Serpent. ( Magnified .)

shows the dentine of the fang inclosing the
poison-canal, and having its own centre or
pulp-canal (p,p), in the form of a crescentic
fissure, situated close to the concave border of
the inflected surface of the tooth. The pulp-
cavity disappears, and the poison-canal again
resumes the form of a groove near the apex
of the fang, and terminates on the anterior
surface in an elongated fissure.

The venom-fangs of the viper, rattle-snake,
and the Fer-de-lance are coated only with a
thin layer of a subtransparent and minutely
cellular cement. The disposition of the den-
tinal tubes is obedient to the general law of
verticality to the external surface of the tooth ;
it is represented as seen in the transverse sec-
tion from the middle of the fang in fig. 568.
Since the inflected surface of the tooth can
be exposed to no other pressure than that of

TEETH.

889

the turgescent duct with which it is in con-
tact, the tubes which proceed to the surface
d, while maintaining their normal relation ot
the right angle to it, are extremely short ; and
the layer of dentine separating the poison-
tube from the pulp-cavity is proportionally
thin. The calcigerous tubes that radiate from
the opposite side of the pulp-cavity to the
exposed surface b of the tooth are dispropor-
tionally long.

The teeth of Ophidians are developed and
completed in that part which forms the ori-
ginal seat of the tooth-germs in all animals;
viz. the mucous membrane or gum covering,
the alveolar border of the dentigerous bones.
This germ presents the same lax tissue, and
is as abundantly developed, as in the Pike,
Lophius, and many other fishes ; in which it
likewise serves as the nidus and locality for
the complete development of the teeth. The
primitive dental papillae in the common harm-
less snake very soon sinks into the substance
of the gum, and becomes inclosed by a cap-
sule. As soon as the deposition of the cal-
careous salts commences in the apex of the
papilla the capsule covering that part becomes
ossified and adherent to the dentine, and the
tooth begins to pierce and emerge from the
gum before its mould, the pulp, is half com-
pleted. Fresh layers of cells are successively
added to the base of the pulp, and converted,
by their confluence and calcification, into the
tubular dentine, until the full size of the
tooth is attained, when its situation in the
gum is gradually changed, and its base becomes

Fig.

surface of the pulp ; and the base of the
groove of the loose, growing, poison-fang is
brought into the same relation with the duct
of the poison gland as the displaced fang,
which has been severed from the duct.

Saurians. — The existing species of lizards
differ from those of the crocodile in the anchy-
losed condition of the teeth, which present few
modifications of importance ; those that yield
most fruit to physiology, and which have most
expanded our ideas of the extent of the re-
sources of Nature and the exceptional devi-
ations from what was deemed the rule of
structure in the Saurian dentition, have been
discovered by the study of the fossil teeth of
extinct forms of the order. Amongst these the
most extraordinary in respect of their dental
system have been recently discovered in aform-
ation in South Africa, which seems nearly as
ancient as our own coal-seams. I have called
them “ Dicynodonts,”* from their dentition
being reduced to one long and large canine
tooth on each side of the upper jaw. As
these teeth give, at first sight, a character to
the jaws like that which the long poison-fangs
give, when erected, to the jaws of the rattle-
snake, I shall briefly notice their characters
before entering upon the description of the
more normal Saurian dentition.

Fig. 569. gives a reduced side view of the
skull of the species of Fieynodon called 1). / a -
certiceps. The cranial cavity (8, 8) is extremely
contracted, as in all the cold-blooded quad-
rupeds : it is bounded on each side by wide
and deep temporal fossae (t) indicating power-

569.

n

Shull of Dicynodon lacerticeps, one-third natural size.

anchylosed to the shallow cavity of the alve-
olar surface of the bone.

In the posterior part of the large mucous
sheath of the poison-fang, the successors of
this tooth are always to be found in different
stages of development ; the pulp is at first
a simple papilla, and when it has sunk into
the gum the succeeding portion presents a
depression along its inferior surface, as it lies
horizontally, with the apex directed back-
wards; the capsule adheres to this inflected

ful muscles for the action of the lower jaw.
The orbits (o) are large and round ; the nos-
trils (w) are divided by the junction of the
nasal bones (15) with the premaxillaries (22),
as in lizards ; there is not a single median
external nostril, as in Chelonian and Croco-
dilian reptiles. The alveolar border of the
lower jaw and of the premaxillary part of the

* From Si;, ttvo, and the name given by

Hippocrates to the canine teeth, and signifying the
same idea as their common English denomination.

890

TEETII.

upper jaw is trenchant, and seems to have
been sheathed with horn.

The maxillary bone (21) is excavated by a
wide and deep alveolus, with a circular area
of half an inch, and lodges a long and strong,
slightly curved, and sharp-pointed, canine tooth
or tusk, which projects about two-thirds of its
length from the open extremity of the socket.
The direction of the tusks is forwards, down-
wards, and very slightly inwards ; the two
converging, as they descend along the outer
side of the compressed symphysis of the
lower jaw (c). The tusk is principally
composed of a body of compact unvascular
dentine. The base is excavated by a wide
conical pulp-cavity (p) with the apex extend-
ing to about one-half of the implanted part
of the tusk, and a linear tract is continued
along the centre of the solid part of the
tusk. From this central line the dentinal tubes
radiate, with a gentle curve at the beginning,
convex towards the point of the tusk, and then
proceeding straight to the periphery of the
tooth, but inclining towards the apex. They
present parallel secondary curves, divide di-
chotomously twice or thrice near their begin-
ning, and send off numerous small lateral
branches, chiefly from the side next the apex.
At their primary curve the dentinal tubes are
—-■i^-th of an inch in diameter, and their
intervals are -g-g-^th of an inch across. The
dentinal cells are most conspicuous near the
periphery of the tooth, and vary in diameter
from ¥ jnfth to ToVoth of an inch.

The enamel, at least at the middle of the
tusk, is thinner than in the teeth of the cro-
codile. It presents only a finely lamellated
texture, the layers being parallel with the
surface of the dentine on which it rests.
There is only a fine linear trace of cement on
the exterior of the sections of the implanted
base of the tusks ; and here it is too thin to
allow of the development of the radiated cells
in its substance. There is no trace of teeth
or their sockets in the lower jaw (25, 23); so
much of the alveolar border as is exposed pre-
sents a smooth and even edge, which seems to
have played like a scissor-blade upon the inner
side of the corresponding edentulous border
of the upper jaw ; and it is most probable,
from the analogies of similarly-shaped jaws of
existing Reptilia, that the fore part of both
the upper and under jaws were sheathed with
horn.

Until the discovery of the Rhynchosaurus *,
this edentulous and horn-sheathed condition
of the jaws was supposed to be peculiar to
the Chelonian order among reptiles ; and it is
not one of the least interesting features of
the Dicynodonts of the African sandstones,
that they should repeat a Chelonian character,
hitherto peculiar, amongst Lacertians, to the
above-cited remarkable extinct edentulous
genus of the new red sandstone of Shrop-
shire : but our interest rises almost to as-
tonishment, when, in a Saurian skull, we
find, superadded to the horn-clad mandibles

* Transactions of the Cambridge Philosophical
Society, vol. vii. part iii.

of the Tortoise, a pair of tusks, borrowed as
it were from the mammalian class, or rather
foreshadowing a structure which, in the actual
creation, is peculiar to certain members of the
highest organised warm-blooded animals.

In the other Reptilia, recent or extinct,
which most nearly approach the Mammalia in
the structure of their teeth, the difference
characteristic of the inferior and cold-blooded
class is manifested in the shape, and in the
system of shedding and succession, of the
teeth ; the base of the implanted teeth seldom
becomes consolidated, never contracted to a
point, as in the fangs of the simple teeth of
Mammalia, and at all periods of growth one
or more germs of teeth are formed within or
near the base of the tooth in use, prepared to
succeed it, and progressing towards its dis-
placement. The dental armature of the jaws
is kept in serviceable order by uninterrupted
change and succession ; but the matrix of the
individual tooth is soon exhausted, and the
life of the tooth itself may be said to be com-
paratively short.

The Dicynodonts not only manifest the
higher type of free implantation of the base
of the tooth in a deep and complete socket,
common to Crocodilians, Megalosaurs, and
Thecodonts, but make an additional and much
more important step towards the mammalian
type of dentition, by maintaining the service-
able state of the tusk by virtue of constant
renovation of the substance of one and the
same matrix, accordingly to the principle
manifested in the long-lived and ever-growing
tusks of the Walrus, and the scalpriform in-
cisors of the Rodentia.

The genera of the typical family of the
squamate Lacertians are arranged in two
sub-families, the chief characteristics of which
are derived from the dental system.

In the first group, the teeth are solid, or
without any permanent internal cavity, and
are very firmly anchylosed by their base to
the alveolar groove upon the inner side of
the jaw ; so that the extremity of the tooth
is slightly directed outwards. The species
which present this character are called Pleo-
donts.

In the second group, the teeth are ex-
cavated, or retain the pulp-cavity, and are
less firmly fixed to the jaws, being applied
vertically, like piles or buttresses, against the
outer alveolar parapet, but not adhering by
their base. This group is called Ccelodonts.

The Monitor Lizard of S. America is an
example of the Pleodont group, in which the
premaxillary teeth are ten in number. The
maxillary teeth vary from ten to fifteen on
each side, and increase in size as they are
placed farther back : the hindmost teeth are
tricuspid in young individuals, and present
the form of simple tubercles in the old Mo-
nitors. The mandibular teeth, fifteen to
eighteen in number in each ramus, correspond
in size and form with those above. In the
Coelodont group, the “Swift lizards” ( Tacky -
dromus ) have the pterygoid bones armed with
minute teeth. The teeth on both upper and

TEETII.

891

lower jaws are of larger size, and the hinder
ones are tricuspid. The true lizards ( La -
certa) have two kinds of teeth quoad form ;
the anterior small, conical, and recurved ; the
posterior larger, and hi- or tri-cuspid. Some
species have also pterygoid teeth ; as the
common Lacerta agilis.

In the Gigantic fossil Monitor of Maes-
tricht, the teeth combine the Pleodont with
the Acrodont* characters.

The true affinities of the Mosasaur, which
was at least twenty-four feet in length, and
the remains of which characterise the chalk-
formations, were first determined by Cuvier,
who places it in the Lacertian group of
Saurians, between the Iguame and Monitors.
Its dentition exhibits in an eminent degree
the Acrodont character; the teeth being sup-
ported on expanded conical bases anchylosed
to the summit of the alveolar ridge of the
jaw : no existing Saurian exactly parallels
this mode of attachment of the teeth, either
in regard to the breadth of the alveolar
border, or in the relative size of the osseous
cones to the teeth which they support. A
shallow socket is left where the tooth and
its supporting base are shed. The form of
the teeth is likewise different from that
hitherto observed in any existing Saurian :
the crown is pyramidal, with the outer side
nearly plane, or slightly convex, and separated
by two sharp ridges from the remaining sur-
face, which forms a half-cone. All the teeth

account of the Mosasaurus, “ has no true
root, but it adheres strongly to that pulp
which has secreted it, and it is further held
in connection with it by the remains of the
capsule which has furnished the enamel, and
which, by becoming ossified also, and uniting
itself to the maxillary bone and the ossified
pulp, implants or rivets the tooth with addi-
tional force.”

The necessity under which Cuvier felt
himself compelled to regard the crown and
the base of the tooth of the Mosasaur as two
distinct parts, is at once banished by the
recognition of the principle, that the processes
of calcification are essentially the same at
every part of a tooth, whether it be free or
anchylosed ; and that they are modified only,
as I have shown in my Memoir on the
Formation of the Teeth of the Shark*, ac-
cording to the density of the part to be pro-
duced.

Scincoid Lizards. — Most of these smooth-
scaled lizards have small mouths and slender
sharp teeth, fitted best for insect food ; they
are usually confined to the upper and lower
jaws ; but the medicinal Scink of ancient
pharmacy (Soincus officinalis) has four or five
small obtuse teeth upon each pterygoid bone.
The chief exception to the typical dentition
of the present family is made by the large
scincoid lizards of Australia, which, on that
account, have received the generic name of
Cyelodus. f

Fig. 570.

Lower jaw and teeth of Cyelodus nigro/uteus.

are slightly recurved, and their peripheral
surface is smooth. The teeth are implanted
upon the premaxillary, maxillary, and pre-
mandibulary bones ; a series of similarly shaped
but much smaller teeth are placed upon the
pterygoid bones.

The gradual transition from the simple
structure of the compact dentine to theosteo-
dentine of the anchylosed base of the tooth was
not known to Cuvier; otherwise he could not
have supposed that the crown and the base
of the tooth of the Mosasaurus were formed by
vital processes of so dissimilar a nature as to
forbid him considering them as parts of one
and the same body. Cuvier had originally
described the expanded base of the tooth of
the Mosasaur as the root of the tooth ; but
afterwards, observing that the corresponding
base became anchylosed by ossification of the
remains of the pulp to the jaw, he conceived
it to be incorrect to regard it as a part of a
body which he believed to be an inorganic
product, and the result of excretion. “ The
tooth,” he observes, in correcting his first

* Odontography, pp. 241. 208.

The dentition of the Cycl. nigroluteus is
exemplified in the lower jaw, fig. 570. In the
upper jaw, the single premaxillary bone has
depressions for twelve teeth, of which only
the alternate ones are usually in place ; they
are of very small size, with the fang com-
pressed laterally, and the crown antero-
posteriorly, so as to resemble a true incisor
in form, the summit sloping to an edge from
behind forwards, with the middle of the cut-
ting surface a little produced. Each superior
maxillary bone has depressions for fourteen
teeth ; they quickly increase in size, and
exchange their conical for a sub-hemispherical
crown; the eighth to the thirteenth inclusive
are the largest teeth ; they are set obliquely,
and pretty close together. In the lower jaw
there are two small incisors, at the anterior
part of each premandibular bone correspond-
ing with those of the premaxillary ; these are
succeeded by five or six conical teeth, and
the rest correspond in size and form with the
tuberculate molars of the upper jaw.

* Compte Rendu de l’Academie des Sciences,
Decembre, 1839,

f Round-toothed : zvzAas-, round ; tooth.

892

TEETH.

AH the teeth are attached, after the Pleuro-
dont type, by their base and outer margin to
shallow depressions on the outer side of the
external alveolar parapet.

The germs of the successional teeth, c.
Jig. 570., are developed at the inner side of the
base of their predecessors, a, which they
excavate, undermine, and displace in the
usual manner.

Iguanas. — Certain genera of this family of
lizards, e. g. Istiurus, Lopliyrus , Calutes, and
Otocryptis, have the teeth soldered, like those
of Mosasaums , to the summit of the alveolar
ridge, and thence are called “ Acrodonts : ” in
all these lizards the maxillary and mandibular
teeth may be divided into anterior laniary,
and posterior molary teeth. In most of the
Iguanians the teeth are lodged in a common
shallow oblique alveolar groove, and are
soldered to excavations on the inner surface
of the outer wall of the groove : these are
called Pleurodonts. Most of them possess
pterygoid as well as maxillary teeth ; but
the following genera, Hyperanodon, Tropido-
lepis, Phrynosoma, and Callisaurus, are excep-
tions.

In the Pleurodont Iguanians, the teeth
never present the true laniary form ; and if
simply conical, as at the extremes of the
maxillary series, the cone is more or less
obtuse ; but, in general, it is expanded, more
or less trilobate, or dentated along the mar-
gin of the crown.

The Amblyrhynchus, a genus which is some-
what remarkable for the marine habits of at
least one of the species ( Ambbyrliynclius ater ),
whose diet is sea-weed*, has the tricuspid
structure well developed in the posterior
teeth.

The typical genus of the present family of
Saurians ( Iguana tubercnlala ), is characterised
by the crenate or dentated margin of the
crown of the maxillary and premandibular
teeth, a few of the anterior small ones ex-
cepted. The pterygoid teeth are arranged
in two or three irregular rows, resembling
somewhat the “ dents en cardes ” of fishes.
In the full-grown Iguana tuberculata there
are from forty-seven to forty-nine teeth in
both upper and lower jaws. The number
is less in young subjects. The double row
of pterygoid teeth are in close order on each
side.

In the horned Iguana ( Metapoceros cor-
nutns), there are about fifty-six teeth in the
upper and lower jaws, of which the four
first are conical and slightly recurved. The
twelve succeeding teeth are somewhat larger
in size, with more compressed and expanded
crowns ; the rest are triangular, compressed,
with dentated margins. The inner surface of
the crown of the tooth is simply convex and

* This species, and probably all the known Am-
Uyrhynchi, or blunt-nosed Iguana?, inhabit the
islands in the Galopagos group ; their habits have
been well elucidated by Mr. Darwin (Voyage of the
Beagle, vol. iii. p. 466.). In specimens which he
dissected, he found the stomach loaded with minced
sea-weed.

smooth ; the outer surface traversed by a me-
dian, longitudinal, broad, obtuse ridge. There
is a single row of small teeth implanted in
each pterygoid bone. No Iguanian lizard has
teeth on the palatine bones.

The teeth of the Iguanodon, though re-
sembling those of the Iguana, do not present
an exact magnified image of them, but differ
in the greater relative thickness of the crown,
its more complicated external surface, and,
still more essentially, in a modification of the
internal structure, by which the Iguanodon
equally deviates from every other known
reptile.

As in the Iguana, the base of the tooth
is elongated, contracted, and subcylindrical ;
the crown expanded, and smoothly convex on
the inner side. When first formed, it is acu-
minated, compressed, its sloping sides ser-
rated, and its external surface traversed by
a median longitudinal ridge, and coated by a
layer of enamel, but, beyond this point, the
description of the tooth of the Iguanodon
indicates characters peculiar to that genus.
In most of the teeth that have hitherto been

TJnworn tooth of Iguanodon.

found, three longitudinal ridges {Jig. 571.)
traverse the outer surface of the crown, one
on each side of the median primitive ridge ;
these are separated from each other, and from
the serrated margins of the crown, by four
wide and smooth longitudinal grooves. The
relative width of these grooves varies in
different teeth ; sometimes a fourth small lon-
gitudinal ridge is developed on the outer
side of the crown. The marginal serrations,
which, at first sight, appear to be simple
notches, as in the Iguana, present, under
a low magnifying power, the form of trans-
verse ridges, themselves notched, so as to
resemble the mammilated margins of the un-
worn plates of the elephant’s grinder : slight
grooves lead from the interspaces of these
notches upon the sides of the marginal ridges.
These ridges, or dentations, do not extend
beyond the expanded part of the crown :
the longitudinal ridges are continued further
down, especially the median ones, which do
not subside till the fang of the tooth begins
to assume its subcylindrical form. The tooth
at first increases both in breadth and thick-
ness ; it then diminishes in breadth, but
its thickness goes on increasing ; in the
larger and fully formed teeth, the fang de-

893

TEETIL

creases in every diameter, and sometimes
tapers almost to a point. The smooth un*
broken surface of such fangs indicates that
they did not adhere to the inner side of
the maxillae, as in the Iguana, but were
placed in separate alveoli, as in the Cro-
codile and Megalosaur; such support would
appear, indeed, to be indispensable to teeth
so worn by mastication as those of the Igu-
anodon. A fracture of this tooth shows that
the pulp was not entirely solidified, but that
its cavity had continued open at the thickest
part of the tooth.

The apex of the tooth soon begins to be
worn away, and it would appear, by many
specimens that have been found, that the teeth
were retained until nearly the whole of the
crown had yielded to the daily abrasion. In
these teeth, however, the deep excavation of
the remaining fang, represented in profile in
the figure fig. 57 1., plainly bespeaks the pro-
gress of the successional tooth prepared to
supply the place of the worn-out grinder.

At the earlier stages of abrasion, a sharp
edge is maintained at the external part of the
tooth by means of the enamel which covers
that surface of the crown. The prominent
ridges upon that surface give a sinuous
contour to the middle of the cutting edge,
whilst its sides are jagged by the lateral
serrations. The adaptation of this admirable
dental instrument to the cropping and com-
minution of such tough vegetable food as the
Clathrariee and similar plants, which are found
buried with the Iguanodon, is pointed out by
Dr. JBuckland, with his usual felicity of il-
lustration, in his “ Bridgewater Treatise,”
vol. i. p. 246.

When the crown is worn away beyond the
enamel, it presents a broad and nearly hori-
zontal grinding surface, and now another
dental substance is brought into use to give
an inequality to that surface ; this is the
ossified remnant of the pulp, which, being
firmer than the surrounding dentine, forms a
slight transverse ridge in the middle of the
grinding surface. The tooth in this stage has
exchanged the functions of an incisor for
that of a molar, and is prepared to give the
final compression, or comminution, to the
coarsely divided vegetable matters.

The marginal edge of the incisive condition
of the tooth and the median ridge of the
molar stage are more effectually established
by the introduction of a modification into the
texture of the dentine, by which it is rendered
softer than in the existing Iguanas and other
reptiles, and more easily worn away : this is
effected by an arrest of the calcifying process
along certain cylindrical tracts of the pulp,
which is thus continued, in the form of
medullary canals, analogous to those in the
soft dentine of the Megatherium’s grinder,
from the central cavity, at pretty regular
intervals, parallel witli the calcigerous tubes,
nearly to the surface of the tooth. The
medullary canals radiate from the internal
and lateral sides of the pulp-cavity, and are
confined to the dentine forming the corre-

sponding walls of the tooth ; their diameter is
-f^joth of an inch ; they are separated by
pretty regular intervals, equal to from six to
eight of their own diameters ; they some-
times divide once in their course. Each
medullary Canal is surrounded by a clear sub-
stance ; its cavity was occupied in the section
described by a substance of a deeper yellow
colour than the rest of the dentine.

The calcigerous tubes present a diameter of

SWooth an *nc'b interspaces equal to
about four of their diameters. At the first
part of their course, near the pulp-cavity,
they are bent in strong undulations, but after-
wards proceed in slight and regular primary
curves, or in nearly straight lines, to the
periphery of the tooth. When viewed in a
longitudinal section of the tooth, the concavity
of the primary curvature is turned towards
the base of the tooth ; the lowest tubes are
inclined towards the root, the rest have a
general direction at right angles to the axis of
the tooth ; the few calcigerous tubes, which
proceed vertically to the apex, are soon worn
away, and can be seen only in a section of
the apical part of the crown of an incompletely
developed tooth. The secondary undulations
of each tooth are regular and very minute.
The branches, both primary and secondary,
of the calcigerous tubes are sent off from the
concave side of the main inflections ; the
minute secondary branches are remarkable at
certain parts of the tooth for their flexuous
ramifications, anastomoses, and dilatations into
minute calcigerous cells, which take place
along nearly parallel lines for a limited extent
of the course of the main tubes. The ap-
pearance of interruption in the course of the
calcigerous tubes, occasioned by this modi-
fication of their secondary branches, is repre-
sented by the irregularly dotted tracts in the
figure of the dental structure of this ancient
reptile given in my “ Odontography.” This
modification must contribute, with the me-
dullary canals, though in a minor degree, in
producing that inequality of texture and of
density in the dentine, which renders the
broad and thick tooth of the Iguanodon more
efficient as a triturating instrument.

The enamel which invests the harder
dentine, forming the outer side of the tooth,
presents the same peculiar dirty brown colour,
when viewed by transmitted light, as in most
other teeth : very minute and scarcely per-
ceptible undulating fibres, running vertically
to the surface of the tooth, is the only struc-
ture I have been able to detect in it.

The cement is simply and minutely cellular
upon the crown of the tooth, but it exhibits
the radiated cells at the base of the tooth.

The remains of the pulp in the contracted
cavity of the completely formed tooth are
converted into a dense but true osseous
substance, characterised by minute elliptical
radiated cells, whose long axis is parallel with
the plane of the concentric lamellae, which
surround the few and contracted medullary
canals in this substance.

894

TEETH.

The microscopical examination of the struc-
ture of the Iguanodon’s teeth thus contributes
additional evidence of the perfection of their
adaptation to the offices to which their more
obvious characters had indicated them to
have been destined.

To preserve a trenchant edge, a partial
coating of enamel is applied ; and, that the
thick body of the tooth might be worn away
in a more regularly oblique plane, the dentine
is rendered softer as it recedes from the
enameled edge by the simple contrivance of
arresting the calcifying process along certain
tracts of the inner wall of the tooth. When
attrition has at length exhausted the enamel
and the tooth is limited to its functions as a
grinder, a third substance has been prepared
in the ossified remnant of the pulp to add to
the efficiency of the dental instrument in its
final capacity. And if the following reflections
were natural and just after a review of the
external characters of the dental organs of
the Iguanodon, their truth and beauty be-
come still more manifest as our knowledge
of their subject becomes more particular and
exact :

“ In this curious piece of animal mechanism
we find a varied adjustment of all parts and
proportions of the tooth, to the exercise of
peculiar functions, attended by compensations
adapted to shifting conditions of the in-
strument, during different stages of its con-
sumption. And we must estimate the works
of nature by a different standard from that
which we apply to the productions of human
art, if we can view such examples of me-
chanical contrivance, united with so much
economy of expenditure, and with such anti-
cipated adaptations to varying conditions in
their application, without feeling a profound
conviction that all this adjustment has re-
sulted from design and high intelligence.”#

Varnnians. — Tn the great Crocodilian Moni-
tor ( Varanus crocndi/inus), the large fixed com-
pressed teeth, of which there may be about
seven in each upper maxillary bone and six in
each premandibular, are anchylosed by the
whole of their base and by an oblique surface
leading upwards on the outer side of the
tooth to a slight depression on the oblique
alveolar surface, as in the Far. striatus.
The base of the tooth is finely striated, the
lines being produced by inflected folds of the
external cement, as in the Ichthyosaur and
Labyrinthodon, but they are short and straight,
as in those of the former genus. The alveolar
channel or groove has scarcely any depth ;
but the anchylosed base of the tooth is applied
to an oblique surface, terminating in a sharp
edge, from which the outer side of the free
crown of the tooth is directly continued.
The great Varanus, like the variegated species
manifests its affinity to the Croeodilians in
the number of successive teeth which are in
progress of growth to replace each other ; but
from the position in which the germs of the
successional teeth are developed, the more

* Buckland’s Bridgewater Treatise, vol. i. p. 249.

advanced teeth in this species, as in the Far.
variegatus, do not exhibit the excavations that
characterise the same parts of the teeth of
the Enaliosaurs and Crocodiles.

Thecodonts. — W e have seen that among the
inferior or squamate Saurians there are two
leading modifications in the mode of attach-
ment of the teeth, the base of which may be
either anchylosed to the summit of an alveolar
ridge, or to the bottom of an alveolar groove,
and supported by its lateral wall. These
modifications are indicated respectively by
the terms “ Aerodont ” and “ Pleurodont.”
A third mode of fixation is presented by some
extinct Saurians, which, in other parts of
their organisation, adhere to the squamate or
Lacertine division of the order, the teeth
being implanted in sockets, either loosely or
confluent with the bonv walls of the cavity ;
these I have termed the “ Thecodont”* La-
certians : the most ancient of all Saurians
belong to this group ; viz. the Thuringian
Monitor, or Protorosaurus, and the Palceo-
saurus of the dolomitic conglomerates near
Bristol. The compressed Varanian form of
tooth, with trenchant and finely dentated
margins, which characterised the ancient Pa-
loeosaur and Chadeiodon, is continued in the
comparatively more recent and gigantic species
of terrestrial lizard, of which the remains were
discovered by Dr. Buckland in the oolite of
Stonesfield, by whom the peculiarities of the
jaws and teeth have been accurately and gra-
phically described in the following words : —

“ From these remains we learn that the
animal was a reptile, closely allied to some of
our modern lizards; and viewing the teeth as
instruments for providing food to a carni-
vorous creature of enormous magnitude, they
appear to have been admirably adapted to the
destructive office for which they have been
designed. Their form and mechanism will be
best explained by reference to the figures.

“ The outer margin of the jaw rises nearly
an inch above its inner margin, forming a
continuous lateral parapet to support the
teeth on the exterior side, where the greatest
support was necessary, whilst the inner margin
throws up a series of triangular plates of
bone forming a zigzag buttress along the
interior of the alveoli. From the centre of
each triangular plate, a bony partition crosses
to the outer parapet, thus completing the
successive alveoli. The new teeth are seen
in the angle between each triangular plate,
rising in reserve to supply the loss of older
teeth, as often as progressive growth, or ac-
cidental fracture, may render such renewal
necessary, and thus affording an exuberant
provision for a rapid succession and resto-
ration of these most essential implements.
They were formed in distinct cavities, by the
side of the old teeth, towards the interior
surface of the jaw, and probably expelled
them by the usual process of pressure and
absorption, insinuating themselves into the
cavities thus left vacant. This contrivance

* Odontography, part ii. p. 266.

TEETH.

895

for the renewal of teeth is strictly analogous
to that which takes place in the dentition of
many species of existing lizards.

“ In the structure of these teeth we find a
combination of mechanical contrivances ana*
logous to those which are adopted in the
construction of the knife, the sabre, and the
saw. When first protruded above the gum,
the apex of each tooth presented a double
cutting edge of serrated enamel. In this stage,
its position and line of action were nearly
vertical, and its form, like that of the two-
edged point of a sabre, cutting equally on
each side. As the tooth advanced in growth
it became curved backwards in the form of a
pruning-knife, and the edge of serrated enamel
was continued downwards to the base of the
inner and cutting side of the tooth, whilst
on the outer side a similar edge descended
but a short distance from the point, and the
convex portion of the tooth became blunt
and thick, as the back of a knife is made
thick for the purpose of producing strength.
The strength of the tooth was further in-
creased by the expansion of its side. Had
the serrature continued along the whole of
the blunt and convex portion of the tooth, it
would in this position have possessed no
useful cutting power ; it ceased precisely at
the point beyond which it could no longer be
effective. In a tooth thus formed for cutting
along its concave edge, each movement of
the jaw combined the power of the knife
and saw ; whilst the apex, in making the
first incision, acted like the two-edged point
of a sabre. The backward curvature of the
full-grown teeth enabled them to retain, like
barbs, the prey which they had penetrated.
In these adaptations we see contrivances
which human ingenuity has also adopted in
the preparation of various instruments of
art.” *

The teeth of the Megalosaur consist of a
central body of dentine, with an investment
of enamel upon the crown, and of cement
over all, but thickest upon the fang. The
marginal serrations are formed almost entirely
by the enamel, and when slightly magnified
are seen to be rounded, and separated by
slight basal grooves ; the smooth and polished
enamel upon the sides of the crown presents
a finely wrinkled appearance; the remains of
the pulp are converted into a coarse bone in
the completely formed tooth.

Enaliosaurs. — The teeth of the Ichthyo-
sauri have a simple, more or less acutely
conical form, with a long and, usually, ex-
panded or ventricose base, or implanted fang.
They are confined to the intermaxillary, max-
illary, and preman dibular bones, in which
they are arranged in a pretty close and un-
interrupted series, and are of nearly equal
size. They consist of a body of unvascular
dentine, invested at the base by a thick layer
of cement, and at the crown by a layer of
enamel, which is itself covered by a very thin
coat of cement ; the pulp-cavity is more or

* Bridgewater Treatise, vol. i. p. 237.

less occupied in fully-formed teeth by a coarse
bone. The external surface of the tooth is
marked by the longitudinal impressions and
ridges, but the teeth vary both as to outward
sculpturing and general form in the different
species.*

The chief peculiarity of the dental system
of the Ichthyosaur is the mode of the im-
plantation of the teeth ; instead of being an-
chylosed to the bottom and side of a con-
tinuous shallow groove, as in most Lacertians,
or implanted in distinct sockets, as in the The-
codon, Megalosaur, or Pterodactyle, they are
lodged loosely in a long and deep continuous
furrow, and retained by slight ridges between
the teeth, along the sides and bottom of the
furrow, and by the gum and organised mem-
branes continued into the groove and upon
the base of the teeth.

The germs of the new teeth are developed
at the inner side of the base of the old ones.

Crocodilia. - — The best and most readily
recognisable characters by which the existing
Crocodilians are grouped in appropriate genera,
are derived from modifications of the dental
system.

In the Caimans (genus Alligator ) the teeth
18 — 18 ^ 22 — 22

vary in number from —— to — — — • ; the

J 18 — 18 22 — 22

fourth tooth of the lower jaw, or canine, is
received into a cavity of the palatal surface of
the tipper jaw, where it is concealed when
the mouth is shut. In old individuals the
upper jaw is perforated by these large in-
ferior canines, and the fossae are converted
into foramina.

In the Crocodiles (genus Crocodilus) the
first tooth in the lower jaw perforates the
palatal process of the premaxillary bone
when the mouth is closed ; the fourth tooth
in the lower jaw is received into a notch exca-
vated in the side of the alveolar border of
the upper jaw, and is visible externally when
the mouth is closed.

In the two preceding genera the alveolar
borders of the jaw have an uneven or wavy
contour, and the teeth are of an unequal size.

In the Gavials (genus Gavialis) the teeth
are nearly equal in size and similar in form in
both jaws, and the first as well as the fourth
tooth in the lower jaw, passes into a groove
in the margin of the Upper jaw when the
mouth is closed.

In the alligators and crocodiles the teeth
are more unequal in size, and less regular in
arrangement, and more diversified in form
than in the Gavials : witness the strong thick
conical laniary teeth as contrasted with the
blunt mammillate summits of the posterior
teeth in the alligator ( Jig . 573.); The teeth
of the Gavial are subequal, most of them pre-
sent the form of crown, shown in Jig. 572.,
long, slender, pointed, subcompressed from
before backwards, with a trenchant edge on
the right and left sides, between which a few
faint longitudinal ridges traverse the basal
part of the enamelled crown.

* Odontography, pi. 73;

896

TEETH.

'Teeth in different stages of formation from one
alveolus of the Gavial : a is the base partly
absorbed by the pressure of b, the successional
tooth ; below which is figured c, the germ of the
next tooth to follow.

Amongst the remains of Crocodilians which
are scattered through the Tilgate strata, the
most common ones are detached teeth, from
the difference observable in the form of which,
Dr. Mantell has observed, that “ they appear
referable to two kinds, the one belonging to
that division of crocodiles with long slender
muzzles, named Gavial, the other to a species
of Crocodile, properly so-called, and resembling
a fossil species found at Caen.”*

Dr. Mantell has obligingly communicated
to me figures of well-preserved specimens of
both the forms of teeth alluded to, the exact-
ness of which I have recognised by a com-
parison with the specimens themselves in the
British Museum.

The tooth which, from its more slender
and acuminated form, approaches nearest to
the character of those of the Gavial, presents
a marked difference, however, from the teeth
of any of the recent species of that sub-genus
of Crocodilians, as well as from those of the
long and slender-snouted extinct genera,
called Teleosaurus, Steneosaurus, &c. I have
described itf, therefore, as indicative of a
distinct species, under the name of Crocodilus
cultridens. The crown is laterally compressed,
submeurved, with two opposite trenchant
edges, one forming the concave, the other the
convex, outline of the tooth. In the Gavial,
the direction of the flattening of the crown
and the situation of the trenchant edges are
the reverse, the compression being from be-
fore backwards, and the edges being lateral. J

* Wonders of Geology, 1839, vol. i. p. 386.

+ Odontography, pi. lxii. A, figs. 9, 10.

J The tooth attributed by M. Deslongchamps
to the PoikUopleuron, agrees in form with those of

The tooth of the Crocodilus cultridens thus re-
sembles in form that of the Megalosaur, and
perhaps still more those of the Argenton
crocodile ; but I have not observed any spe-
cimens of the Wealden teeth in which the
edges of the crown were serrated, as in both
the reptiles just cited. The teeth of the Cro-
codilus cultridens also present a character
which does not exist in the teeth of the
Megalosaur, and is not attributed by Cu-
vier to those of the Crocodile cT Argenton.
The sides of the crown are traversed by a
few longitudinal parallel ridges, with regular
intervals of about one line, in a crown of a
tooth one inch and a half in length : these
ridges subside before they reach the apex of
the tooth, and more rapidly at the convex
than at the concave side of the crown.

Hitherto these teeth have not been found
so associated with any part of the skeleton
of the same species as to yield further cha-
racters of the present extinct Crocodilian ;
but from the above-mentioned well-marked
differences between these teeth and those of
all the existing species, it is most probable
that the extinct crocodile formed the type of
a distinct sub-genus, for which the term Su-
chosaurus has been proposed.

The second form of tooth having the gene-
ric characters of those of the crocodile, which
has been discovered in the Wealden and
approximate strata, is as remarkable for its
thick, rounded, and obtuse crown as the teeth
of the preceding species are for their slender,
compressed, acute, and trenchant character.
It consequently approaches more nearly to
the teeth which characterise the broad and
comparatively short-snouted crocodiles; but
it differs from these in one of the same cha-
racters by which the tooth of the Suckosaurus
cultridens differs from those of the Gavials,
viz., in the longitudinal ridges which traverse
the exterior of the crown. These are, how-
ever, more numerous, more close-set, and
more neatly defined than in the Suckosaurus
cultridens. Two of the ridges, larger and
sharper than the rest, traverse opposite sides
of the tooth, from the base to the apex of the
crown ; they are placed, as in the crocodile
and Gavial, at the sides of the crown, midway
between the convex and concave lines of the
curvature of the tooth. These ridges are
confined to the enamel ; the cement-covered
cylindrical base of the tooth is smooth. The
size of the teeth varies from a length of crown
of two inches, with a basal diameter of one
inch and a half to teeth of one-third of these
dimensions. I have proposed to call this
extinct crocodile, with biconcave vertebrae,
Goniopkotis cfassidens.

Development. — In the black alligator of
Guiana the first fourteen teeth of the lower
jaw are implanted in distinct sockets, the
remaining posterior teeth are lodged close
together in a continuous groove, in which the
divisions for sockets are faintly indicated by
vertical ridges, as in the jaws of the Ichthyo-

the Gavial, and differs in the characters cited in the
text from those of the Crocodilus cultridens.

TEETH.

897

saurs. A thin compact floor of bone separates
this groove, and the sockets anterior to it,
from the large cavity of the ramus of the jaw;
it is pierced by bloodvessels for the supply of
the pulps of the growing teeth and the vas-
cular dentiparous membrane which lines the
alveolar cavities.

The tooth-germ is developed from the
membrane covering the angle between the
floor and the inner wall of the socket. It
becomes in this situation completely enveloped
by its capsule, and an enamel-organ is formed
at the inner surface of the capsule before the
young tooth penetrates the interior of the
pulp-cavity of its predecessor.

The matrix of the young growing tooth
affects, by its pressure, the inner wall of the
socket, as shown in Jig. 573, and forms for

Fig. 573.

Section of lower jaw , with four alveoli and teeth, of
the black Alligator.

itself a shallow recess : at the same time it
attacks the side of the base of the contained
tooth ; then, gaining a more extensive attach-
ment by its basis and increased size, it pene-
trates the large pulp-cavity of the previously
formed tooth either by a circular or semi-
circular perforation. The size of the calcified
part of the tooth-matrix which has produced
the corresponding absorption of the previously-
formed tooth on the one side, and of the
alveolar process on the other, is represented
in the second exposed alveolus of Jig. 573., the
tooth a having been displaced and turned
round to show the effects of the stimulus of
the pressure. The size of the perforation in
the tooth, and of the depression in the jaw,
proves them to have been, in great part,
caused by the soft matrix, which must have
produced its effect by exciting vital action of
the absorbents, and not by mere mechanical
force. The resistance of the wall of the
pulp-cavity having been thus overcome, the
growing tooth and its matrix recede from the
temporary alveolar depression, and sink into
the substance of the pulp contained in the

VOL. IV.

cavity of the fully-formed tooth. As the new
tooth grows, the pulp of the old one is re-
moved ; the old tooth itself is next attacked,
and the crown being undermined by the ab-
sorption of the inner surface of its base, may
be broken off’ by a slight external force, when
the point of the new tooth is exposed, as in
the 'fig. 573. b.

The new tooth disembarrasses itself of the
cylindrical base of its predecessor, with which
it is sheathed, by maintaining the excitement
of the absorbent process so long as the cement
of the old fang retains any vital connection
with the periosteum of the socket ; but the
frail remains of the old cylinder, thus re-
duced, are sometimes lifted off1 the socket
upon the crown of the new tooth, as in Jig. 573.
b, when they are speedily removed by the
action of the jaws. This is, however, the
only part of the process which is immediately
produced by mechanical force : an attentive
observation of the more important previous
stages of growth, teaches that the pressure
of the growing tooth operates upon the one
to be displaced only through the medium
of the vital absorbent action which it has
excited.

Most of the stages in the development and
succession of the teeth of the crocodiles are
described by Cuvier with his wonted clearness
and accuracy ; but the mechanical explanation
of the expulsion of the old tooth, which
Cuvier adopts from M. Tenon, is opposed
by the disproportionate smallness of the hard
part of the new tooth to the vacuity in the
old one, and by the fact that the matter im-
pressing— viz. the uncalcified part of the
walls of the tooth-matrix — is less dense than
the part impressed.

No sooner has the young tooth penetrated
the interior of the old one, than another
germ begins to be developed from the angle
between the base of the young tooth and the
inner alveolar process, or in the same relative
position as that in which its immediate pre-
decessor began to rise, and the processes of
succession and displacement are carried on,
uninterruptedly, throughout the long life of
these cold-blooded carnivorous reptiles.

From the period of exclusion from the egg,
the teeth of the crocodile succeed each other
in the vertical direction ; none are added
from behind forwards, like the true molars in
Mammalia. It follows, therefore, that the
number of the teeth of the crocodile is as
great when it first sees the light as when it
has acquired its full size; and, owing to the
rapidity of the succession, the cavity at the
base of the fully-formed tooth is never con-
solidated.

The fossil jaws of the extinct Crocodilians
demonstrate that the same law regulated the
succession of the teeth, at the ancient epochs
when those highly organised reptiles prevailed
in greatest numbers, and under the most
varied generic and specific modifications, as
at the present period, when they are reduced
to a single family, composed of so few and
slightly varied species as to have constituted
3 M

898

TEETH.

in the system of Linnaeus a small fraction of
his genus Lacerta.

Dental System of Mammals.

The class Mammalia, like that of Reptilia
and Pisces, includes a few genera and species
that are devoid of teeth : the true ant-eaters
( Myrmecophaga ), the scaly ant-eaters or Pan-
golins (Mams), and the spiny monotrematous
ant-eater (Echidna) , are examples of strictly
edentulous Mammals. The Ornithorhynchus
has horny teeth, and the whales (Balccna and
Balccnoptcra) have transitory embryonic cal-
cified teeth*, succeeded by whalebone sub-
stitutes-)- in the upper jaw. Horny processes
analogous to, perhaps homologous with, the
lingual and palatal teeth in fishes, are present
in the Echidna.

The female Narwhal seems to be eden-
tulous, but has the germs of two tusks in the
substance of the upper jaw-bones ; one of
these becomes developed into a large and
conspicuous weapon in the male Narwhal,
and, accordingly, suggested to Linnaeus the
name, for its genus, of Monodon, meaning
single tooth : but the tusk is never median,
like the truly single tooth on the palate of
the Myxine ; and occasionally both tusks are
developed in the Narwhal. In another Ceta-
cean, the great Bottle-nose, or Hyperoodon,
the teeth are reduced in the adult to two in
number, whence the specific name II. bidens,
but they are confined to the lower jaw. The
sharp-nosed dolphin (Ziphius) has also but
two teeth, one in each ramus of the lower
jaw ; and this is, perhaps, a sexual character.
The Delphinus griseus has five teeth on each
side of the lower jaw ; but they soon become
reduced to two. Amongst the marsupial ani-
mals, the genus Tarsipes is remarkable for the
paucity as well as minuteness of its teeth.

The elephant has never more than one
entire molar, or parts of two, in use on each
side of the upper and lower jaws ; to which
are added two tusks, more or less developed,
in the upper jaw.

Some Rodents, as the Australian Water-
rats (Hydromys), have two grinders on each
side of both jaws ; which, added to the four
cutting teeth in front, make twelve in all :
the common number of teeth in this order is
twenty ; but the hares and rabbits have twenty-
eight teeth. The sloth has eighteen teeth.
The number of teeth, thirty-two, which cha-
racterises man, the apes of the old world,
and the true ruminants, is the average one of
the class Mammalia ; but the typical number
is forty-four.

The examples of excessive number of teeth
are presented, in the order Bruta, by the
Priodont Armadillo, which has ninety-eight
teeth ; and, in the cetaceous order, by the
Cachalot, which has upwards of sixty teeth,
though most of them are confined to the
lower jaw ; by the common porpoise, which
has between eighty and ninety teeth ; by the

* Odontography, pi. 87 a, figs. 1 — 6.

t lb. pi. 76, figs. 4. 6 ; art. Cetacea, Yol. I. p. 572,
fig. 259 b.

Gangetic dolphin, which has one hundred
and twenty teeth ; and by the true dolphins
( Delphinus), which have from one hundred to
one hundred and ninety teeth, yielding the
maximum number in the class Mammalia.

Form. — Where the teeth are in excessive
number, as in the species above cited, they
are small, equal, or subequal, and of a simple
conical form ; pointed, and slightly recurved
in the common dolphin ; with a broad and
flattened base in the gangetic dolphin (Inia) ;
with the crown compressed, and broadest in
the porpoise ; compressed but truncate, and
equal with the fang, in the Priodon. The
compressed triangular teeth become coarsely
notched or dentated, at the hinder part of
the series, in the great extinct cetaceous Zeu-
glodon. The simple dentition of the smaller
Armadillos, of the Orycterope, and of the
three-toed Sloth, presents a difference in the
size, but little variety in the shape of the
teeth, which are subcylindrical, with broad
triturating surfaces ; in the two-toed Sloth,
the two anterior teeth of the upper jaw are
longer and larger than the rest, and adapted
for piercing and tearing.

In almost all the other Mammalia, particular
teeth have special forms for special uses :
thus, the front teeth, from being commonly
adapted to effect the first coarse division of
the food, have been called cutters or incisors ;
and the back teeth, which complete its com-
minution, grinders or molars ; large conical
teeth, situated behind the incisors, and adapted
by being nearer the insertion of the biting
muscles, to act with greater force, are called
holders, fearers, laniaries, or more commonly
canine teeth, from being well developed in the
dog and other Carnivora, although they are
given, likewise, to many vegetable feeders
for defence or combat : e. g. Musk-deer (fig.
580, VII.). Molar teeth, which are adapted for
mastication, have either tuberculate, or ridged,
or flat, summits ; and usually are either sur-
rounded by a fence of enamel, or are tra-
versed by enamel plates arranged in various
patterns. Certain molars in the Dugong,
the Mylodon, and the Zeuglodon, are so
deeply indented laterally by opposite longi-
tudinal grooves, as to appear, when abraded,
to be composed of two cylindrical teeth ce-
mented together, and the transverse section
of the crown is bilobed. The teeth of the
Glyptodon were fluted by two analogous
grooves on each side. The large molars of
the Capybara and Elephant have the crown
cleft into a numerous series of compressed
transverse plates, cemented together side by
side.

The teeth of the Mammalia have usually
so much more definite and complex a form
than those of fishes and reptiles, that three
parts are recognised in them : viz. the “fang,”
the “neck,” and the “crown.” The fang or
root (radix) is the inserted part ; the crown
(corona) the exposed part ; and the construc-
tion which divides these is called the neck
(cervix). The term “ fang ” is properly given
only to the implanted part of a tooth of re-

TEETH.

899

stricted growth, which fang gradually tapers
to its extremity ; those teeth which grow un-
interruptedly have not their exposed part se-
parated by a neck from their implanted part,
and this generally maintains to its extremity
the same shape and size as the exposed
crown,

It is peculiar to the class Mammalia to have
teeth implanted in sockets by two or more
fangs ; but this can only happen to teeth of
limited growth, and generally characterises
the molars and premolars ; perpetually grow-
ing teeth require the base to be kept simple
and widely excavated for the persistent pulp.
In no mammiferous animal does anchylosis of
the tooth with the jaw constitute a normal
mode of attachment. Each tooth has its
particular socket, to which it firmly adheres
by the close co-adaptation of their opposed
surfaces, and by the firm adhesion of the
alveolar periosteum to the organised cement
which invests the fang or fangs of the tooth ;
but in some of the Cetacea, at the posterior
part of the dental series, the sockets are wide
and shallow, and the teeth adhere more
strongly to the gum than to the periosteum ;
in the Cachalot I have seen all the teeth
brought away with the ligamentous gum, when
it has been stript from the sockets of the
lower jaw.

Teeth are fixed as a general rule in all
Vertebrata, and the only known exceptions
are those presented by certain species of
fishes, e. g. the Sharks, Lophioids, Gonio-
donts. In the higher Vertebrata the move-
ments of the teeth depend on those of the
jaw-bones to which they are affixed, but appear
to be independent in the ratio of the size of
the tooth to the bone to which it is attached.
Thus the extent of rotatory movement to
which the large perforated poison fangs of
the rattle-snake are subject depends upon the
rotation of the small maxillary bone. So
likewise the seemingly individual movements
of divarication and approximation observable
in the large lower incisors of the Bathyergus
and Macropus *, are due entirely to the
yielding nature of the symphysis uniting the
two rami of the lower jaw in which those
incisors are deeply and firmly implanted. It
is no more a property of the teeth themselves
than is that alternate removal of the lower
teeth from, and bringing of them in contact
with, the upper teeth of the mouth, which
one sees or feels in the act of mastication.

True teeth implanted in sockets are con-
fined, in the Mammalian class, to the maxil-
lary, premaxillary, and mandibular, or lower
maxillary bones, and form a single row in
each. They may project only from the pre-
maxillary bones, as in the Narwhal, or only
from the lower maxillary bone, as in Ziphius ;
or be apparent only in the lower maxillary
bone, as in the Cachalot ; or be limited to the
superior and inferior maxillaries, and not pre-
sent in the premaxillaries, as in the true
Pecora, and most Bruta of Linnaeus ; in

* See Mason Good’s Book of Nature, vol. i. p. 285.
1826.

general, teeth are situated in all the bones
above mentioned. In Man, where the pre-
maxillaries early coalesce with the maxillary
bones, where the jaws are very short and the
crowns of the teeth are of equal length, there
is no interspace or “diastema” in the dental
series of either jaw, and the teeth derive
some additional fixity by their close apposi-
tion and mutual pressure. No inferior Mam-
mal now presents this character; but its im-
portance, as associated with the peculiar
attributes of the human organisation, has been
somewhat diminished by the discovery of a
like contiguous arrangement of the teeth in
the jaws of a few extinct quadrupeds : e. g.
Anoplotherium, Nesodon, and Dichodon*

The teeth of the Mammalia usually consist
of hard unvascular dentine, defended at the
crown by an investment of enamel, and every-
where surrounded by a coat of cement. The
coronal cement is of extreme tenuity in Man,
Quadrumana, and terrestrial Carnivora ; it is
thicker in the Herbivora, especially in the
complex grinders of the Elephant ; and is
thickest in the teeth of the Sloths, Mega-
therioids, Dugong, Walrus, and Cachalot.
Vertical folds of enamel and cement penetrate
the crown of the tooth in the Ruminants, and
in most Rodents and Pachyderms, charac-
terising by their various forms the genera of
the last two orders ; but these folds never
converge from equidistant points of the cir-
cumference of the crown towards its centre.
The teeth of the quadrupeds of the order
Bruta ( Edentata , Cuv.) have no true enamel ;
this is absent likewise in the molars of the
Dugong and the Cachalot.-f- The tusks of
the Narwhal, Walrus, Dinotherium, Masto-
don, and Elephant consist of modified den-
tine, which, in the last two great proboscidian
animals, is properly called “ ivory,” J and is
covered by cement.

In the subjoined magnified view of a section
of the molar of a Megatherium, t is the hard
dentine, v the vaso-dentine, and c the cement

{fig- 574)-

The teeth in the Mammalia, as in the fore-
going classes, are formed by superaddition of
the hardening salts to pre-existing moulds of
animal pulp or membrane, organised so as to
insure the arrangement of the earthy particles
according to that pattern which characterises
each constituent texture of the tooth.

The complexity of the primordial basis, or
matrix, corresponds, therefore, with that of
the fully-formed tooth, and is least remark-
able in those conical teeth which consist only

* Quarterly Journal of tke Geological Society,
Feb. 1848, p. 86, pi. iv.

f M. Fr. Cuvier divides the teeth of Mammalia,
according to their composition, into four classes :
the first consists of ivory (dentine), enamel, and
cement ; the second of ivory and enamel ; the third
of ivory and cement; the fourth of ivory only.
(Dents des Mammifferes, p. xxi.) I have met with
no Mammalian teeth in which cement is absent,
and believe that the second and fourth of the above-
cited classes of teeth have no existence in nature.

J “ Hoc solum est ebur.” Plinius, Hist. Nat. lib.
xi. c. 37.

3m2

soo

TEETH.

of dentine and cement. The primary pulp, of the same form and diameter throughout,
which first appears as a papilla rising from the except in the immature animal, when it widens

ree surface of the alveolar gum, is the part of
the matrix which by its calcification consti-
tutes the dentine ; it sinks into a cell and
becomes surrounded by a closed capsule in
every mammiferous species, at an early stage
of the formation of the tooth ; and, as the
cement is the result of the ossification of the
capsule, every tooth must be covered by a
layer of that substance. In those teeth which
possess enamel, the mould or pulp of that
constituent is developed from the capsule
covering the coronal part of the dentinal pulp.
In the simple teeth the secondary or enamel
pulp covers the crown like a cap ; in the
complex teeth it sends processes into depres-
sions of the crown, which vary in depth,
breadth, direction, and number in the nu-
merous groups of the herbivorous and om-
nivorous quadrupeds. The dentinal pulp,
thus penetrated, offers corresponding com-
plications of form ; and as the capsule follows
the enamel pulp in all its folds and processes,
the external cavities or interspaces of the
dentine become occupied by enamel and ce-
ment ; the cement, like the capsule which
formed it, being the outermost substance, and
the enamel being interposed between it and
the dentine. The dental matrix presents the
most extensive interdigitation of the dentinal
and enamel pulps in the Capybara and Ele-
phant. The processes of formation and cal-
cification of the several constituents of Mam-
malian teeth will be found described in the
Introduction to my “Odontography”* and
in the article Tooth.

The matrix of the Mammalian tooth sinks
into a furrow and soon becomes inclosed in a
cell in the substance of the jaw-bone, from
which the crown of the growing tooth extri-
cates itself by exciting the absorbent process,
whilst the cell is deepened by the same pro-
cess and by the growth of the jaw into an
alveolus for the root of tne tooth. Where
the formative parts of the tootn are repro-
duced indefinitely to repair by their progres-
sive calcification the waste to which the work-
ing surface of the crown of the tooth has been
subject, the alveolus is of unusual depth, and

to its bottom or base. In teeth of limited
growth, the dentinal pulp is reproduced in
progressively decreasing quantity after the
completion of the exterior wall of the crown,
and forms by its calcification one or more
roots or fangs, which taper more or less ra-
pidly to their free extremity. The alveolus is
closely moulded upon the implanted part of
the tooth ; and it is worthy of special remark
that the complicated form of socket which
results from the development of two or more
fangs is peculiar to animals of the class Mam-
malia.*

In the formation of a single fang the ac-
tivity of the reproductive process becomes
enfeebled at the circumference, and is pro-
gressively' contracted within narrower limits
in relation to a single centre, until it ceases
at the completion of the apex of the fang ;
which, though for a long time perforated for
the admission of the vessels and nerves to the
interior of the tooth, is, in many cases, finally
closed by the ossification of the remaining
part of the capsule.

When a tooth is destined to be implanted
by two or more fangs, the reproduction of
the pulp is restricted to two or more parts of
the base of the coronal portion of the pulp,
around the centre of which parts the sphere
of its reproductive activity is progressively
contracted. The intervening parts of the
base of the coronal pulp adhere to the cap-
sule, which is simultaneously calcified with
them, covering those parts of the base of the
crown of the tooth with a layer of cement.
The ossification of the surrounding jaw being
governed by the changes in the soft, but
highly organised, dental matrix, fills up the

* On the strength of this generalisation, I have
established the Mammalian nature of the huge
extinct animal called Basilosaurus by Dr. Harlan,
and have advocated the claims of the diminutive
Amphitherium and Phascolotherium of the oolitic
slate of Stonesfield to be admitted into the same
high class, against the objections raised by M. de
Blainville. See “ Comptes Rendus de l’Acad. des
Sciences,” Oct. 22, 1838. The bifid base of the
teeth of certain sharks not being implanted in a
socket, forms no true exception to the rule enunciated
in the text. See Geological Transactions, 2d series,
vol. vi. p. 66. ^

* P. xli.

TEETH.

901

spaces unoccupied by the contracted and
divided pulp, and affords, by its periosteum,
a surface for the adhesion of the cement or
ossified capsule covering the completed part
of the tooth.

The matrix of certain teeth does not give
rise during any period of their formation to
the germ of a second tooth, destined to suc-
ceed the first ; this, therefore, when com-
pleted and worn down, is not replaced: all
the true Cetacea are limited to this simple
provision of teeth. In the Armadillos, Me-
gatherioids, and Sloths, the want of germi-
native power, as it may be called, in the
matrix is compensated by the persistence of
the matrix, and by the uninterrupted growth
of the teeth.

In most other Mammalia, the matrix of
the first developed tooth gives origin to the
germ of a second tooth, which sometimes dis-
places, sometimes takes its place by the side
of, its predecessor and parent. All those
teeth which are displaced by their progeny
are called temporary, deciduous, or milk
teeth ; the mode and direction in which they
are displaced and succeeded, — viz., from
above downwards in the upper, from below
upwards in the lower, jaw ; in both jaws
vertically — are the same as in the Crocodile ;
but the process is never repeated more than
once in any mammiferous animal. A con-
siderable proportion of the dental series is
thus changed; the second, or permanent
teeth, having a size and form as suitable to
the jaws of the adult, as the displaced tem-
porary teeth were adapted to those of the
young, animal. The permanent teeth, which
assume places not previously occupied by
deciduous ones, are always the most poste-
rior in their position, and generally the most
complex in their form. The successors of
the deciduous incisors and canines differ
from them chiefly in size ; the successors of
the deciduous molars may differ likewise in
shape, in which case they have always less
complex crowns than their predecessors.*

The “ bicuspids,” in Human Anatomy,
and the corresponding teeth, called “ pre-
molars,” in the lower Mammals, illustrate
this law.

The first true molar owes the germ of its
matrix to a vegetation or bud, separated by
the fissiparous process from the matrix of
the last deciduous tooth ; but the backward
elongation of the jaw affords space for its
development by the side of its progenitor,
during which process it may in like manner
give origin to a second, and this to a third,
molar, succeeding each other from before
backwards or horizontally.

In this successive germ-production, we
find repeated the multiparous property of
the dental matrix of the crocodile; but the

* “ C’est une rfegle ge'nerale, que les molaires de
remplacement ont une couronne nioins compliquee
que celles auxquelles elles succfedent; mais cette
couronne compliqude se trouve reportee sur les mo-
laires permanentes qui viennent plus en arrifere.”
This generalisation was established by Cuvier, in
his Lecons d’Anat. Comp., ed. 1805. vol. iii. p. 135.

concomitant growth of the jaw allows the
second, third, and sometimes fourth genera-
tion of true molars to co-exist, and come
into place side by side. In the Unguiculate,
and most of the Ungulate, species of the
placental division of the Mammalian class,
the fissiparous reproduction of horizontally
succeeding teeth stops at the third genera-
tion ; in other words, they have not more
than three true molars on each side of the
upper and lower jaws. In the Marsupial
series, the same process extends to a fourth
generation of true or horizontally succeeding
molars* ; and in most of the species, the
four true molars are in use and place at the
same time ; but in certain Kangaroos, the
anterior ones are shed before the posterior
ones are developed. This successive de-
cadence is still more characteristic of the
grinding teeth of the Elephant, which are
finally reduced to a single molar tooth on
each side of both jaws.

Thus the class Mammalia, in regard to the
times of formation and the succession of
the teeth, may be divided into two groups :
— the “ Monophyodonts” \ or those that
generate a single set of teeth ; and the “ Di-
phyodonts,” J or those that generate two sets
of teeth.

The Monophyodonts include the orders
Monotremata, Bruta ( Edentata , Cuv.), and
Cetacea ( Cetacea vera, Cuv.) : all the rest of
the order are Diphyodonts. In these, the
first set of teeth are called the milk or de-
ciduous teeth : the second set, the adult or
permanent teeth ; although the teeth of this
set are for the most part, like those of the
first set, of limited growth, contracting to a
root or roots, and being shed in greater or
less proportion during the life-time of the
species ; which life-time, in wild Carnivora
and Herbivora, is dependent on, and would
seem, indeed, to be determined by, the dura-
tion of the adult teeth.

The particulars of the Monophyodont
dentition will be found under the Articles
Monotremata, Vol. III. p. 387.; Cetacea,
Vol. I. pp. 563. 571. 573. ; (see my Odonto-
graphy, p. 345. pis. 87 — 91.); and Eden-
tata, Vol. II. p.53. ; (see also Odontography,
p. 317. pis. 76 — 80.) Examples of some of the
striking modifications of dental structure pre-
sented by recent or extinct animals of the order
Bruta, are given in figs. 548. and 574. of the
present article. It will be observed that I
have qualified the generalisation as regards
the Monophyodont character of the Cetacea,
by citing only that part of Cuvier’s order
which he termed “ true or carnivorous Ce-
tacea.” The animals of the order Sirenia

* This characteristic extension of the reproductive
power of the matrices of the true molars in the
Marsupials, is an approximation to the peculiar
activity and persistence of the same power in the
vertically succeeding teeth of the cold-blooded Ovi-
para, and is associated with many other instances of
the same affinity in more important parts of the
organization of the implacental Mammals.

t fuvtf, once ; $iu, I generate ; oSms, tooth.

j Si's, twice ; <pOu and oSw;.

3 m 3

902

TEETH.

(herbivorous Cetacea of Cuvier) differ in has been called in question.* I have, how-
many organic particulars from the Cetacea ever, discovered in specimens of the Malayan

Fig. 575.

Dentition of the Dugong (Halicore indicus).

proper*, and in none, perhaps, more strikingly
than in having both deciduous and permanent
teeth ; this succession takes place, at least,
with regard to the upper incisors of the Du-
gong, fig. 575.

These teeth project from the gum in the
male sex ; but neither upper nor lower in-
cisors are visible in the female.f The supe-
rior incisors are but two in number, in both
sexes ; in the male, they are moderately
long, subtriedral, slightly and equally curved,
of the same diameter from the base, and
deeply excavated to near the apex, which is
obliquely bevelled off to a sharp edge, like
the scalpriform teeth of the Rodentia. The
form and extent of the persistent pulp-cavity
of this tooth are shown in the figure of its
longitudinal section, in my “ Odontography,”
pi. 93. fig. 4. ; it becomes longer and more
pointed than in the permanent incisor of the
younger male (fig. 575, i). When fully de-
veloped, only the extremity of this tusk pro-
jects from the jaw, at least seven-eighths of
its extent being lodged in the socket, the
parietes of which are entire ; and the exterior
of the great premaxillary bones presents an
unbroken surface. In the female Dugong,
the growth of the permanent incisive tusks of
the upper jaw is arrested before they cut the
gum, and they remain through life concealed
in the premaxillaries ; the tusk is solid, is
about an inch shorter and less bent than
that of the male ; it is also irregularly cylin-
drical, longitudinally indented, and it gradually
diminishes to an obtuse rugged point ; the
base is suddenly expanded, bent obliquely
outwards, and presents a shallow excavation.
These were conjectured by Home to be the
“milk-tusks they are, however, character-
istic of sex, not of age ; and the existence of
deciduous tusks at any period in the Dugong

Dugong which I have dissected at the
Zoological Society, the true deciduous in-
cisors of the upper jaw (fig. 575, d i ) co-
existing with the permanent ones (i). They
are much smaller than the permanent tusks
of the female, and are loosely inserted by one
extremity in conical sockets immediately an-
terior to' those of the permanent tusks, ad-
hering by their opposite ends to the thick
tegumentary gum, which presented no out-
ward indication of their presence.

When this gum was stripped off the bone,
the deciduous tusks came away with it ; and
this may account for their usual absence in
dried crania of immature Dugongs, in which,
nevertheless, their alveoli are generally suffi-
ciently conspicuous. True permanent in-
cisors are not developed in the lower jaw of
the Dugong ; those which are occasionally
found there are abortive remnants of the first
or deciduous series, which are not destined at
any time to rise above the gum (fig. 575,
d i 3.).

The molar teeth of the Dugong resemble
those of the order Brata in the total absence
of enamel, and of any constriction defining
the crown from the fangs. In the Malayan
species, only five molars (fig. 575, 1, 2, 3, 4,
5.) are developed on each side of both jaws :
in the Australian Dugong six are developed ;
i. e. the Halicore indicus is characterised by
£ £

the molar formula in. - — -=20, whilst the
o — o

q Q

Halicore australis has in. - — -=24.j' But in
C — 6

both species, the number is progressively re-
duced, by the shedding of the anterior and

2 2

smaller molars, to in. - — -=8. The struc-
ture of these molar teeth is illustrated in

* Proceedings of the Zoological Society of London,
1838, p. 40.

f Proceedings of the Zool. Society, 1838, p. 41.

* Dr. Knox, Edinburgh Philosophical Transac-
tions, tom. xi. p. 389.

f See my appendix to Juke’s “ Voyage of the Fly.’

TEETH.

Jig. 546. b, their form in Jig. 546. a; the last
molar, when it comes into use, presents a
bilobed form of grinding surface, as is shown
at b,Jig. 575.

Owing to there being but one set of molars
in the Dugong, those teeth cannot be divided
into true and false molars, any more than in
the Sloths or Armadillos. In the true Di-
phyodonts, in which each kind of teeth have
deciduous predecessors, those grinders which
succeed the deciduous ones vertically, and
displace them, are called “premolars,” or
“ false molars,” and those that come into
place behind these, without pushing out
vertically any predecessors, are the “molars
proper,” or “ true molars.” In this article,
as in my “ Odontography,” the two sorts of
grinders are called respectively “ premolars ”
and “molars.” In the Marsupial order the
normal number of molars is four in each

dental series, i.e. m. -; in the placental

4 — 4

Diphyodonts their normal number is three,

3 3

i. e. in. ; the normal number of nre-

3—3 1

3 3

molars in the Marsupialia is - — but in the
4 4

Placentalia, it is : in both the numerical

4 — 4

character of the canines is one, i, e. -I — j ; that

of the incisors three, i.e.

3—3

3—3'

As regards

the latter teeth, however, the number of
exceptions in the Marsupialia is considerable,
and the incisors are sometimes in excess ;
whilst in the placental Diphyodonts, the in-
cisors never exceed the typical number, but
frequently depart from it by suppression or
arrest of development.

In fishes and reptiles, certain teeth might be
called “ incisive,” “ laniary,” or “ molar” teeth,
in reference to the special adaptation of their
form for cutting, tearing, or bruising; but such
terms, in the cold-blooded classes, imply no-
thing more than those modifications of form ;
they are not significative of constant and well-
defined groups of teeth, and could not become
the names of definite parts or organs determin-
able and traceable from one species to another.
In the Mammalian orders, with two sets of
teeth, these organs acquire fixed individual
characters, receive special denominations, and
can be determined from species to species.
This individualisation of the teeth is emi-
nently significative of the high grade of organ-
isation of the animals manifesting it ; espe-
cially when we consider the great proportion
of mineral substance which enters into the
composition of those parts ; in the number
and nature of which the principle of vegetative
repetition, and the power of the general
polarising forces, have been most controlled
in the Mammalia.

Originally, indeed, the name “ incisors,”
“laniaries” or “canines,” and “molars”
were given to the teeth, in Man and certain
mammals, as in reptiles, in reference merely to

903

the shape and offices so indicated ; but they
are now used as arbitrary signs, in a more fixed
and determinate sense. In some Carnivora,
e.g., the front teeth have broad tuberculate
summits, adapted for nipping and bruising,
while the principal back teeth are shaped for
cutting, and work upon each other like the
blades of scissors. The front teeth in the
elephant project from the upper jaw, in the
form, size, and direction of long pointed
horns. In short, shape and size are the least
constant of dental characters in the Mam-
malia; and the homologous teeth are deter-
mined, like other parts, by their relative
position, by their connections, and by their
development.

Those teeth which are implanted in the
premaxillary bones, and in the corresponding
part of the lower jaw, are called “ incisors,”
whatever be their shape or size. The tooth in
the maxillary bone, which is situated at, or
near to, the suture with the premaxillary, is
the “ canine,” as is also that tooth in the
lower jaw which, in opposing it, passes in
front of its crown when the mouth is closed.
The other teeth of the first set are the “ de-
ciduous molars ; ” the teeth which displace
and succeed them vertically are the “ pre-
molars;” the more posterior teeth, which are
not displaced by vertical successors, are the
“molars ” properly so called.

When the premolars and the molars are
below their typical number, the absent teeth
are missing from the fore-part of the pre-
molar series and from the back part of the
molar series. The most constant teeth are
the fourth premolar and the first true molar ;
and, these being known by' their order and
mode of development, the homologies of the
remaining molars and premolars are deter-
mined by counting the molars from before
backwards, e.g. “one,” “ two,” “three;” and
the premolars from behind forwards, e. g.
“ four,” “ three,” “ two,” “ one.” The incisors
are counted from the median line, commonly
the foremost part of both upper and lower
jaws, outwards and backwards. The first in-
cisor of the right side is the homotype, trans-
versely, of the contiguous incisor of the left
side in the same jaw, and, vertically7, of its
opposing tooth in the opposite jaw ; and so
with regard to the canines, premolars, and
molars ; just as the right arm is the homo-
type of the left arm in its own segment, and
also of the right leg of a succeeding segment.
It suffices, therefore, to reckon and name the
teeth of one side of either jaw in a species
with the typical number and kinds of teeth ;
e.g. the first, second, and third incisors, —
the first, second, third, and fourth premolars,
— the first, second, and third molars; and of
one side of both jaws in any case.

The homologous teeth being thus deter-
minable, they may be severally signified by a
symbol as well as by a name. The incisors,
e.g., by their initial letter i., and indivi-
dually by an added number, i. 1, i. 2, and
i. 3 ; the canines by the letter c. ; the pre-
molars by the letter p. ; and the molars by
3 hi 4

904

TEETH.

the letter m. ; these also being differentiated
by added numerals. Thus, the number of
these teeth, on each side of both jaws, in any
given species, Man e.g., may be expressed

2 2

by the following brief formula : — i. -i

J ° 2 — 2

1 — 1 2—2 3—3 , , ,

c ■ P- y_^> m • g— ^=32; and the homo-

logies of the individual teeth, in relation to
the typical formula, may be signified by i. 1.,
i. 2. ; c. ; p. 3., p. 4. ; m. 1., m. 2., m. 3. : the
suppressed teeth being i. 3.*, p. 1 ., and p. 2.

Examples of the typical dentition are ex-
ceptions in the actual creation ; but it was the
rule in the forms of Mammalia first introduced
into this planet ; and that, too, whether the
teeth were modified for animal or vegetable
food. Fig. 576., e. g., shows the dental series

The true molars in the one are tuberculate,
indicating its tendency to vegetable diet; in
the other, they are carnassial, and betoken
a peculiarly destructive and bloodthirsty spe-
cies.

In the Quarterly Geological Journal, No.
13, 1848, p. 36. pi. iv., I have described
and figured the entire dental series of one
side of the lower jaw of an extinct hoofed
quadruped, the Dichodon cuspidatus, from
eocene or oldest tertiary strata, also mani-
festing the normal number and kinds of teeth,
but with such equalit}' of height of crown,
that no interspace is needed to lodge any of
the teeth when the jaws are closed, and the
series is as entire and uninterrupted as in the
human subject. A great proportion of the
upper jaw and teeth has been discovered, and

Fig. 576.

Dentition of the Amphicyon major. Upper jaw.

of the upper jaw of the Amphicyon major, a the marks of abrasion on the lower teeth
mixed-feeding ferine animal, allied to the prove the Series above to have been as entire
Bear. Fig. 577. shows the dental series of and continuous as that below. The Anoplo-
the under jaw of a more strictly carnivorous therium (“Odontography,” pi. 135. Jig. 1.),

Fig. 577.

Dentition of the Hycenodon. Lower jaw.

beast, the Hycenodon ; the fossil remains of a
species of which have been discovered in the
oldest tertiary deposits of Hampshire. The
symbols denote the homologies of the teeth.

* I have been guided by the analogy of the hare
(Odontography, p. 410, pi. 104, fig. 5.) in this de-
termination ; but a contradictor might indulge his
instinct without liability to disproof from actual
knowledge.

from the gypsum quarries of Montmartre,
geologically as ancient as the eocene clays of
this island, long ago presented to Cuvier the
same peculiar continuous dental series as is
shown in the Dichodon. In his original Me-
moir, Cuvier described the canines as a fourth
pair of incisors, on account of their small
size and their trenchant shape ; but he after-
wards recognised their true homology with

TEETH.

905

the larger and more laniariform canines of the
Pa/cEotherium (“ Odontography,” pi. 135.,
tig. 4.). The Chceropotamus* * * § , the Anthraco-
therium-f, the HyopotamusX, the Hyracothe-
riu m § , the Oplotherium, the Meiycopotamus,
the Hippohyus, and other ancient (eocene
and miocene) tertiary mammalian genera
presented the forty-four teeth, in number and
kind according to that which is here pro-
pounded as the typical or normal dentition
of the placental Mammalia. Amongst the
existing genera, the hog (Sits) is one of the
few that retain this type. Fig. 578. shows
the entire permanent series, exposed, in both

molar, in. 2, has just begun to cut the gum
p. 2, p. 3, and p. 4, together with in. 3, are
more or less incomplete and concealed in
their closed alveoli.

The premolars must displace deciduous
molars in order to rise into place ; the molars
have no such relations ; it will be observed,
that the last deciduous molar, d. 4, has the
same relative superiority of size to d. 3 and
d. 2 which m. 3 bears to in. 2 and m. 1 ;
and the crowns of p. 3 and p. 4 are of a
more simple form than those of the milk-
teeth which they are destined to succeed.

Teeth of each of the kinds above deter-

Fig. 5 78.

Dentition of the Hog (Sus).

jaws, and indicated individually by their mined, and arbitrarily named “ incisors,” “ ca-
symbols. Fig. 579. illustrates the phenomena nines,” “ premolars,” “ molars,” have received
of development which distinguish the pre- other special names in regard to certain pe-

Fig. 579.

Deciduous and permanent teeth (Sus). Lower jaw.

molars from the molars. The first premolar,
p. 1, and the first molar, in. 1, are in place
and use, together with the three deciduous
molars, d. 2, d. 3, and d. 4 ; the second

* History of British Fossil Mammalia, p. 416,
fig. 164.

f Jobert, Annales des Sciences, t. xvii. p. 139.

| Quarterly Journal of the Geological Society,
May, 1848, p. 103, pi. viii.

§ Geological Transactions, 2nd series, vol. vi.
p. 203.

culiarities of form or other property; and the
ablest comparative anatomists have been led
astray in determining their homologies when
they have suffered themselves to be guided
exclusively by morphological characters. The
premolars in the human subject have been
called “ bicuspids.” The last upper pre-
molar and the first lower true molar in the
Carnivora are termed, from their peculiar
form, “ sectorials,” or “ carnassial teeth,”
“ molaires carnassieres ” of Cuvier, Teeth

906

TEETH.

of an elongated conical form, pro-
jecting considerably beyond the rest,
and of uninterrupted growth, are
called “tusks ; ” such are the incisors
of the Elephant and Dugong, the
canines of the Boar and Walrus :
the long and large incisors of the
Rodents have been termed, from the
shape and structure of their cutting
edge, scalpriforrn or chisel-teeth,
“ dentes scalpra.ru .” The inferior in-
cisors of the flying Lemurs ( Galeo -
jnthecus ) have the crown deeply
notched like a comb, and are termed
“ dentes pectinati.” The canines of
the Baboons are deeply grooved in
front, like the poison-fangs, “ dentes
canaliculati ,” of some serpents. The
compressed conical crowns of the
molar teeth of the small clawed
seals ( Stenorliynchus ) are divided
either like a trident, into three sharp
points, or like a saw, into four or
five points ; the molars of the great
extinct Zeuglodon had a similar
form ; such teeth have been called
dentes serrati. But the philosophical
course of the knowledge of nature
tends to explode needless terms of
art, invented for unimportant vari-
eties, and to establish and fix the
meaning of those terms that are
the signs of determinate species of
things.

The Cuviers divided the molar
series of teeth, according to their
form, into three kinds: “false mo-
lars,” “ carnassials,” and “ tubercu-
lar molars ; ” and, in giving the ge-
neric characters of Mammalia, based
the dental formulae on this system :
thus the genus Fells is characterised

as having “ fausses molaires

2-2,

2—2

carnassieres

1—1,

1—1

tuberculeuses

. _ 8»*

0—0 ’ c

The uninterrupted line marked
“ Cuvier” in V. Felis of fig. 580.,
intersects the teeth in each jaw
called carnassieres ; those anterior
to them being the teeth called
“ fausses molaires the single tooth
behind in the upper jaw is the “ tu-
berculeuse.” Most Zoologists, both
at home and abroad, have adopted
the Cuvierian system of formalising
the molar teeth. It seems a very
natural one in the case of the Cat

* “Les Dents des Mammifferes consi-
dtfrdes comnie Caracteres zoologiques,”
8vo. p. 77. In the original the numbers
4 2 2

are given f. m. c. t. ", the teeth

of each side being clubbed together ;
they are distinguished into right and left
in the text, to facilitate the comparison
with the formulae used in this Article.

Fig. 580.

Homo.

Ursus.

Can is.

Mustela.

Felis.

Machairodus.

Moschus.

Homologies of the teeth in Dipliyodont Mammals.

TEETH.

907

genus ; the tooth p. 4 above plays upon that,
in. 1, below, which has a similar remarkable
earnassial modification of form ; they fit, in-
deed, almost as Cuvier describes, like the
blades of a pair of scissors ; the two teeth
in advance of the earnassial in the upper jaw
(p. 3, p. 2) in like manner are opposed to
the same number of “ fausses molaires ” (p. 4,
p. 3) in the under jaw, and the canine c.
above plays upon the canine below ; all seems
straightforward and symmetrical, save that
the little tubercular, m. 1, above has no op-
ponent in the lower jaw. And, perhaps, the
close observer might notice that, whilst the
upper canine, c., glides behind its homotype be-
low, the first upper false molar (p. 2) passes
anterior to the crown of the first false molar
(p. 3) below ; and that the second false
molar and earnassial of the upper jaw are also
a little in advance of those teeth in the under
jaw when the mouth is shut.

In passing to the dentition of the Dog
(Jig. 580, III. Canis), formulised by Cuvier as:
„ , - 3—3 1—1

“ fausses molaires carnassieres | y, tu-

2 2 12..

berculeuses ~ „ ; — vr>” it will be ob-

2 — 2 14

served that here the first upper false molar
(p. 1) differs from that in Fe/is, inasmuch as,
when the mouth is shut, it preserves the same
relative position to its opponent below (p. 1)
which the upper canine does to the lower
canine, and that the same may be said of the
second and the third false molars ; but that
with regard to the earnassial above (p. 4)
this tooth repeats the same relative position
in regard to the fourth false molar below
(p. 4), and not to that tooth, m. 1, which
Cuvier regarded as the lower homotype of
the earnassial ; and, indeed, the more back-
ward position of the lower earnassial is so
slight that its significance might well be over-
looked, more especially as the two succeed-
ing tubercular teeth above were opposed to
two similar tuberculars below. Cuvier there-
fore leaves us to conclude that the tooth
which had no homotype or answerable op-
ponent above was either the fourth “fausse
molaire ” below, or else the first. How un-
important size and shape are, and how sig-
nificant relative position is in the determina-
tion of the homologies of teeth as of other
parts, may be learnt before quitting the na-
tural order of Carnivora ; e. g. by the condi-
tion of the dental system in the Bear ( Jig.
580, II. Ursus). Here the lower tooth, m. 1,
instead of presenting the earnassial character,
and resembling in form the upper tooth (p. 4),
which is the homologue of the upper car-
nassial in the dog, has a tubercular crown, and
corresponds in size as well as shape with the
upper tooth in. 1, to which it is almost wholly
opposed, and with the same slight advance of
position which we observe in the lower canine
as compared with the upper one, and in the four
lower premolars (p. \,p.2, p. 3, p. 4) as com-
pared with their veritable homotypes above.
F. Cuvier divides the molar series of the

genus Ursus into “ fausses molaires ,

The tendency in every thinker to generalise
and to recognise Nature’s harmonies, has led
him here to use the term “ carnassiere ” in
an arbitrary sense, and to apply it to a tooth
above (p. 4), which he owns has such a shape
and diminished size as would have led him to
regard it as merely a false molar, but that the
upper earnassial would then have entirely dis-
appeared ; and it has also led him to give the
name “carnassiere” to a tooth below, m. 1,
which he, nevertheless, describes as having a
tubercular and not a trenchant crown. In so
natural a group as the true Carnivora it was
impossible to overlook the homologues of the
trenchant carnassials of the lion, even when
they had become tubercular in the omnivo-
rous bear ; and Cuvier therefore, having de-
termined and defined the teeth so called in
the feline genus, felt compelled to distinguish
them by the same names after they had lost
their specific formal character. And if, indeed,
he had succeeded in discovering the teeth which
were truly answerable or homotypal in the
upper and lower jaws, the term “ earnassial ”
might have been retained as an arbitrary one
for such teeth, and have been applied to their
homologues in Man, the Ruminant, or the
Pachyderm, where they are as certainly de-
terminable as in those aberrant Carnivores,
in which they have equally lost their sectorial
shape. But the inconvenience of names in-
dicative of such specialties of form will be very
obvious when the term “ tuberculeuses” comes
to be applied to the three hindmost teeth in
the Hycsnodon (Jig. 577.), which teeth answer
to the broad crushing teeth, m. 1, m. 2, and
rn. 3, in the bear and some other existing Car-
nivora. The analogous term “ molar,” having
a less direct or descriptive meaning, is there-
fore so much the better as the requisite arbi-
trary name of a determinate species of teeth.

Had Cuvier been guided in his determina-
tions of the teeth by their mutual opposition in
the closed mouth, and had studied them with
this view in the Carnivora, with the dentition
most nearly approaching to the typical formula,
viz. the bear, he could then have seen that the
three small and inconstant lower premolars
(p. 1, p. 2, p. 3) were the homotypes of the
three small and similarly inconstant premolars
above; that the fourth false molar (p. 4) below,
which, as he observes, “ alone has the normal
form,” * was truly the homotype of the tooth
above (p. 4), which he found himself com-
pelled to reject from the class of “ fausses
molaires,” notwithstanding it presented their
normal form ; that the tubercular tooth, m. i,
which he calls “ carnassiere ” in the lower
jaw, was the veritable homotype of his first
“ molaire tuberculeuse ” above (m. 1), and that
the tooth in the inferior series which had no
answerable one above was his second “ tuber-

* Dents des Mammifferes, p. 111.

908

TEETH.

culeuse ” (my m. 3), and not any of the
four false molars. The true second tuber-
cular above (in. 2) is, however, so much de-
veloped in the bear as to oppose both in. 2 and
m. 3 in the lower jaw, and it might seem to
include the homotypes of both those teeth
coalesced. One sees with an interest such as
only these homological researches could ex-
cite, that they were distinctly developed in
the ancient Amphicyon (Jig. 576.), which ac-
cordingly presents the typical formula. Thus,
I repeat, the study of the relative position of
the teeth of the bear might have led to the
recognition of their real nature and homolo-
gies, and have helped to raise the mask of their
extreme formal modifications, by which they
are adapted to the habits of the more blood-
thirsty Carnivora. But the truth is plainly
and satisfactorily revealed when we come to
trace the course of development and succes-
sion of these teeth. The weight which must
ever attach itself to an opinion sanctioned by
the authority of both the Cuviers, demands
that a conclusion contrary to theirs, and
which seems to be opposed by Nature herself
in certain instances, should be supported by
all the evidence of which such conclusion is
susceptible.

I proceed, therefore, to show how, in the
bear, my determinations of the teeth are es-
tablished by their development, as well as by
their relative position. As the question only
concerns the molar series, the remarks will be
confined to these. In the jaws of the young
bear, figured in cut 581., the first premolar, p. 1 ,
is the only one of the permanent series in place ;

similarity to p. 4 in the lower jaw (Jig. 581,
Ursus), to be veritably the last of the pre-
molar series, and to agree not in shape only,
but in every essential character, with the
three preceding teeth called by Cuvier
“fausses molaires.” So, likewise, in the lower
jaw, we see that the primitive deciduous
series, d. 1, d. 2, d. 3, and d. 4, will be displaced
by the corresponding premolars, p. 1 ,p. 2 ,p. 3,
and p. 4 ; and that the tooth in. 1, called car-
r.assiere by Cuvier, in the lower jaw, differs
essentially from that p. 4, so called in the
upper jaw by being developed without any
vertical predecessor or deciduous tooth.

The same law of development and succes-
sion prevails in the genus Canis (Jig. 582.).
Although the tooth m. 1 in the lower jaw has
exchanged the tubercular for the carnassial
form, it is still developed, as in the bear,
behind the deciduous series, and indepen-
dently of any vertical predecessor; and the
tooth p. 4 above, although acquiring a relative
superiority of size to its homologue in the
bear, and more decidedly a carnassial form,
is not the homotype of the permanent carnas-
sial below, but of that premolar (p. 4) which is
destined to displace the deciduous carnassial
d. 4. The symbols sufficiently indicate the
relations of the other teeth, and the conclu-
sions that are to be drawn from them as to
their homologies. It is interesting to observe
in the deciduous, as well as in the permanent
series, that the lower carnassial d. 4 is not the
homotype of the upper one d. 3, but of the
tooth which Cuvier calls the “ tuberculeuse
du lait,” d. 4 in the upper jaw.

Fig. 581.

Deciduous and permanent dentition of the Bear (Ursus).

the other grinders in use are the deciduous
molars, d. 2, d. 3, and d. 4; d. 2 will be displaced
by p. 2, d. 3 by p. 3, and d. 4 by the tooth p. 4,
which, notwithstanding its size and shape,
Cuvier felt himself compelled to discard from
the series of false molars, but which we now
see is proved by its developmental relations to
d. 4, as well as by its relative position and

In the genus Felis (Jig. 580.), the small per-
manent tubercular molar of the upper jaw, in. 1,
has cut the gum before its analogue d. 4 of
the deciduous series has been shed ; but
though analogous in function, this is not ho-
mologous with, or the precedent tooth to in. 1,
but, as in the dog, to the great carnassially
modified premolar, p. 4. In the lower jaw the

TEETH.

909

tooth (m. 1), which is functionally analogous to tition, are in. 2 in the upper jaw, m. 2 and m. 3
the carnassial above, is also, as in the dog, the in the lower jaw ; p. 1 in the upper jaw, p. 1

Fig. 582.

Deciduous and permanent teeth in the Dog (Cams).

first of the true molar series, and the homo- and p. 2 in the lower jaw ; thus illustrating the
type of the little tubercular tooth (m. 1) above, rule enuntiated above, that, when the molar
And the homologies of the permanent teeth series falls short of the typical number it is
p. 4 above and m. 1 below, with those so from the two extremes of such series that the

Fig. 583.

Deciduous and permanen t teeth in the Lion (Felis).

symbolised in the dog (Jig. 582.), teach us teeth are taken, and that so much of the
that the teeth which are wanting, in order to series as is retained is thus preserved unbroken,
equal the number of those in the canine den- In the great extinct sabre-toothed tiger (Ma-

910

TEETH.

chair odns, fig. 580, VI.*), the series is still fur-
ther reduced by the loss ofp. 2 in the upper jaw.

That the student may test for himself the
demonstration which the developmental cha-
racters above defined, yield of the true nature
and homologies of the feline dentition, — the
most modifiedof all in the terrestrial Carnivora,
he is recommended to compare with nature
the following details of the appearance and
formation of the teeth in the common cat.
In this species the deciduous incisors d.i. begin
to appear between two and three weeks old ;
the canines d. c. next, and then the molars d. m.
follow, the whole being in place before the
sixth week. After the seventh month they
begin to fall in the same order; but the lower
sectorial molar m. t, and its tubercular homo-
type above (?«. 1) appear before d.2,d. 3, andrf. 4
fall. The longitudinal grooves are very faintly
marked in the deciduous canines. The first
deciduous molar ( d . 2), in the upper jaw is
a very small and simple one-fanged tooth ; it
is succeeded by the corresponding tooth of the
permanent series, which answers to the second
premolar ( p. 2) of the hyaena and dog. The
second deciduous molar ( d . 3) is the sectorial
tooth; its blade is trilobate, but both the anterior
and posterior smaller lobes are notched, and
the internal tubercle, which is relatively larger
than in the permanent sectorial, is continued
from the base of the middle lobe, as in the
deciduous sectorial of the dog and hyaena;
it thus typifies the form of the upper sectorial,
which is retained in the permanent dentition
of several Viverrine and Musteline species.
The third or internal fang of the deciduous
sectorial is continued from the inner tubercle,
and is opposite the interspace of the two
outer fangs. The Musteline type is further
adhered to by the young Feline in the large
proportional size of its deciduous tubercular
tooth, d. 4. In the lower jaw, the first milk-
molar (d. 3) is succeeded by a tooth {p. 3) which
answers to the third lower premolar in the
dog and civet. The deciduous sectorial {d. 4),
which is succeeded by the premolar (p. 4), an-
swering to the fourth in the dog, has a smaller
proportional anterior lobe, and a larger pos-
terior talon, which is usually notched ; thereby
approaching the form of the permanent lower
sectorial tooth in the MusteVidce.

In the article Carnivora (vol. i. p. 478.),
the remarks on the teeth are limited chiefly to
their physiological adaptations. A description
of some of their more remarkable structures
will here be given, according to the idea of the
nature of the teeth above developed. The
dental formula of the dog, jackal, wolf, and
fox, is illustrated in Jig. 580, III. Canis.

* Machairodus, from a sabre ; and oSou?,

a tootli. This generic name was imposed by
Dr. Kaup on the extinct animal which was armed
with canine teeth, like that figured in fig. 580, VI.
Such teeth, long, compressed, falciform, sharp-
pointed, and with anterior and posterior finely-
serrated edges, were first discovered in tertiary
strata in Italy and Germany, and were referred by
Cuvier to a species of bear, under the name of Ursus
cultridens. Fossil canines of this genus have been
found in Kent’s Hole cave, Torquay.

In the Megalotis, or Long-eared Fox (Oto-
cyon , Licht.), the deviation from the typical
dentition of the Canidce is effected by excess
of development ; two additional true molars
being present on each side of the upper, and
one on each side of the lower jaw, in the
permanent series of teeth ; and an approach
is made by the modified form of the sectorial
molar and of some of the other teeth to the
dentition of the Viverridoc. This family of
Carnivora, which comprehends the Civets,
Genets, Ichneumons, Musangs, Surikates, and
Mangues, is characterised, with few exceptions,

3 3 j j

by the following formula : — i. - — - ; c. ^ | ;

4 — 4 2—2

p. ^ ^ ; m. gZIo : = ^ differs from that

of the genus Canis by the absence of a tubercu-
lar tooth (m. 3) on each side of the lower jaw ;
but, in thus making a nearer step to the
typical carnivorous dentition, the Viverridce,
on the other hand, recede from it by the less
trenchant and more tubercular character of
the sectorial teeth, as is shown in the figures
of the teeth of the Viverra indica, in my “ Odon-
tography,” pi. 126. figs. 1, 2, and 3.

The canines are more feeble, and their
crowns are almost smooth ; the premolars,
however, assume a formidable size and shape
in some aquatic species, as those of the sub-
genus Cynogale, in which their crowns are
large, compressed, triangular, sharp-pointed,
witli trenchant and serrated edges, like the
teeth of certain sharks, (whence the name
Squalodon, proposed for one of the species),
and well adapted to the exigencies of quad-
rupeds subsisting principally on fish : the op-
posite or obtuse, thick form of the premolars
is manifested by some of the Musangs, as
Paradoxurus auratus. The upper sectorial
tooth, p. 4, is characterised by having its inner
tubercle larger, the middle conical division of
the blade thicker, and the posterior one smaller
than in the genus Canis. This tooth advances
to beneath the ant-orbital foramen in the Mu-
sangs ( Paradoxurus ) : it is situated farther
back in the Civets and Genets, in which the
blade of the sectorial is sharper. This shows
that relative position to the zygomatic or molar
process of the maxillary is not a good cha-
racter.

In the lower jaw the sectorial tooth (m. 1)
manifests its true molar character by the pre-
sence of an additional pointed lobe on the
inner side of the two lobes forming the blade
at the fore-part of the crown : the posterior,
low, and large lobe of the tooth being also
tri-tuberculate, as in the dog. The last
molar {in. 2) has an oval crown with four small
tubercles, resembling the penultimate lower
molar in the dog, with which it corresponds.

The deciduous dentition consists, in the

Viverrine family, of ; incisors

3—3

- — - ; canines

1—1 , 3—3

-jy— p ; molars 3IZ3

28. If the first per-

manent premolar has any predecessor, it
must be rudimental and disappear early in

TEETH

911

both jaws ; the second premolar displaces
the first normally developed deciduous molar ;
the third upper premolar displaces and suc-
ceeds the deciduous sectorial, which has a
sharper and more compressed blade, and a
relatively smaller internal tubercle, than the
permanent sectorial. This tooth displaces
the last deciduous molar, which is a tubercular
tooth, resembling in form the first of the two
upper permanent tuberculars ; these coming
into place without pushing out any prede-
cessors, enter into the category of true molar
teeth. In the lower jaw the third premolar
displaces the deciduous sectorial, which has
three trenchant lobes and a relatively smaller
posterior talon than the permanent sectorial.
The fourth premolar displaces the third
or tubercular milk-molar. The permanent
sectorial and tubercular molars displace
no predecessors, and are therefore m. 1 and
in. 2.

The first premolar, p. 1, is not developed
at any period in the Mangues ( Crossarchus ),
the Suricates ( Ryzcena ), or the Mangusta
•paludinosa ; these Viverrines, therefore, retain
throughout life more of the immature cha-
racters of the family, and in the same degree
approach in the numerical characters of their
dentition to the more typical Carnivora.

The alternate interlocking of the crowns of
the teeth of the upper and lower jaws, which is
their general relative position in the Carnivora,
is well marked in regard to the premolars
of the Viverridce {Jig. 580, IV.) : as the lower
canine is in front of the upper, so the first
lower premolar rises into the space between
the upper canine and first upper premolar ;
the fourth lower premolar in like manner fills
the space between the third upper premolar
{p. 3) and the sectorial tooth {p. 4), playing
upon the anterior lobe of the blade of that
tooth which indicates by its position, as by
its mode of succession, that it is the fourth
premolar of the upper jaw. The first true
molar below, modified as usual in the Car-
nivora to form the lower sectorial, sends the
three tubercles of its anterior part to fill the
space between the sectorial ( p . 4) and the
first true molar (in. 1) above. In the Mu-
sangs the lower ^sectorial is in more direct
opposition to its true homotype, the first
tubercular molar in the upper jaw ; and these
Indian Viverridce ( Paracloxuri ) are the least
carnivorous of their family, their chief food
consisting of the fruit of palm .trees, whence
they have been called “ Palm-cats.”

Hycena. — The dentition of this genus pre-
sents a nearer approach to the strictly car-
nivorous type by the reduction of the tuber-
cular molars to a single minute tooth on each
side of the upper jaw, the inferior molars
being all conical or sectorial teeth : the molar
teeth in both jaws are larger and stronger,
and the canines smaller in proportion than in
the Feline species, from the formula of which
the dentition of the hyaena differs numerically
only in the retention of an additional pre-
molar tooth, p. 1 above and p. 2 below,
on each side of both jaws. The dental

formula of the genus Ih/cena is: — in.
1—1 4—4 1 — 1

c-t=i> pm • 3=3’ m • r=r: = 34-

3—3

3—3’

The

crowns of the incisors form almost a straight
tranverse line in both jaws, the exterior
ones, above, being much larger than the
four middle ones, and extending their long
and thick inserted base further back : the
crown of the upper and outer incisor ( i . 3.)
is strong, conical, recurved, like that of a
small canine, with an anterior and posterior
edge, and a slight ridge along the inner side
of the base. The four intermediate small
incisors have their crown divided by a trans-
verse cleft into a strong anterior, conical lobe,
and a posterior ridge, which is notched ver-
tically ; giving the crown the figure of a
trefoil. The lower incisors gradually increase
in size from the first to the third ; this and
the second have the crown indented ex-
ternally ; but they have not the posterior
notched ridge like the small upper incisors ;
the apex of their conical crown fits into the
interspace of the three lobes of the incisor
above. The canines have a smooth convex
exterior surface, divided by an anterior and
posterior edge from a less convex inner side :
this surface is almost flat and of less relative
extent in the inferior canines. The first
premolar above (p. 1) is very small, with a
low, thick, conical crown : the second presents
a sudden increase of size, and an addition of
a posterior and internal basal ridge to the
strong cone. The third premolar exhibits
the same form on a still larger scale, and is
remarkable for its great strength. The pos-
terior part of the cone of each of these
premolars is traversed by a longitudinal ridge.
The fourth premolar is the carnassial tooth,
and has its long blade divided by two notches
into three lobes, the first a small thick cone,
the second a long and compressed cone, the
third a horizontal sinuous trenchant plate : a
strong triedral tubercle is developed from the
inner side of the base of the anterior part of
the crown. The single true molar of the
upper jaw ( m . l) is a tubercular tooth of
small size : transversely oblong in the Hycena
vulgaris and H.fusca ; smaller and sub-cir-
cular in the Hycena crocuta ; still smaller and
implanted by a single fang in the Hycena
spelcea : in all the existing species of Hycena it
has two fangs. The first premolar of the lower
jaw (p. 2) fits into the interspace between the
first and second premolars above, and answers,
therefore, to the second lower premolar in
the Viverridce: it is accordingly much larger
than the first (p. 1) above ; it has a ridge in
the fore-part of its cone, and a broad basal
talon behind. The second (p. 3) is the
largest of the lower premolars, has an anterior
and a posterior basal ridge, with a vertical
ridge ascending upon the fore as well as the
back part of the strong rounded cone : the
third premolar (p. 4.) is proportionably less
in the Hycena crocuta than in the II. vulgaris:
its posterior ridge is developed into a small
cone; the last tooth (m. 1) is the sectorial.

912

TEETH.

mid consists almost entirely of a blade divided
by a vertical fissure into two sub-equal com-
pressed pointed lobes : the points are less
produced than in the Felines, but the lower
sectorial of the hyaena is better distinguished
by the small posterior basal talon, from which
a ridge is continued along the inner side of the
base, and is slightly thickened at the fore-part
of the crown. According to the relative po-
sition of the crowns of the premolars the third
below ought to be the last, being analogous
to the fourth in the Viverridce, and the sec-
torial should be first true molar : we shall find
this view confirmed by the test of the mode of
succession of the permanent teeth. But the
mode of implantation of the premolar and
molar teeth may first be noticed. The first
upper premolar has but one fang; the second
and third have each two ; the sectorial tooth
has three, the two anterior ones on the same
tranverse line, the inner one supporting the
tubercle. The lower premolars and sectorial
have each two fangs, there being none truly
answering to the first above : the anterior
root of the lower (jj. 1) sectorial tooth is
very strongly developed in the great extinct
Cave-Hyaena.

3—3

The deciduous teeth consist of: — i. y —

j i 3 3

c. — — r, m. r. — x, = 28. The figure of the

1 — 1’ 3 — 3’ b

skull of the young Hycena crocuta in the
posthumous edition of the “ Ossemens Fos-
siles,” 8vo. 1836, pi. 190, fig. 3, shows that
stage when the correspondence with the
formula of the genus Felis is completed by the
appearance, in the upper jaw, of a small pre-
molar in the interspace between the canine
and first molar of the deciduous series : but
this appearance is due to the apex of the
first permanent premolar which cuts the gum
before any of the normal deciduous teeth are
shed : whether it is preceded, as in the dog,
by a deciduous germ-tooth in the foetus, I
know not. The first normal deciduous molar
is two-fanged, and has a more compressed
and consequently more carnivorous crown
than that of the second permanent premolar
by which it is succeeded. The second deci-
duous molar is the sectorial tooth : the inner
tubercle is continued from the base of the
middle lobe, and thus resembles the permanent
sectorial of the Glutton ( Gulo ) and many
other MusteUdee ; the deciduous tubercular
molar is relatively larger than in the adult
Hycena , and offers another feature of resem-
blance to the permanent dentition of the
Glutton. It is also worthy of remark that
the exterior incisor of the upper jaw is not
only absolutely, but relatively smaller in the
immature than in the adult dentition of the
hyaena, and again illustrates the resemblance
to the more common type of dentition in the
Carnivora.

The first and second deciduous molars be-
low have more compressed conical crowns
than their successors : the third deciduous
molar is the sectorial tooth, and, again, as

in Gulo, has a better developed binder tu-
bercle than the permanent sectorial ; it is not
displaced by this tooth, but, as in other Car-
nivora, by a premolar of more simple cha-
racter. The permanent sectorial is deve-
loped posteriorly, and rises, like other true
molars, without displacing a deciduous pre-
decessor.

The permanent dentition of the llycena, as
of other genera or families of the Carnivora,
assumes those characteristics which adapt it
for the peculiar food and habits of the adult,
and mark the deviation from the common
type, which always accompanies the progress
to maturity. The most characteristic modifi-
cation of this dentition is the great size and
strength of the molars as compared with the
canines, and more especially the thick and
strong conical crowns of the second and third
premolars in both jaws, the base of the cone
being belted by a strong ridge which defends
the subjacent gum.* This form of tooth is
especially adapted for gnawing and breaking
bones, and the whole cranium has its shape
modified by the enormous development of the
muscles which work the jaws and teeth in
this operation.f Adapted to obtain its food
from the coarser parts of animals which are
left by the nobler beasts of prey, the hyaena
chiefly seeks the dead carcass, and bears the
same relation to the lion which the vulture
does to the eagle. In consequence of the
quantity of bones which enter into its food,
the excrements consist of solid balls of a
3'ellowish white colour, and of a compact
earthy fracture. Such specimens of the sub-
stance, known in the old Materia Meclica by
the name of “ album graecum,” were dis-
covered by Dr. Buckland in the celebrated
ossiferous cavern at Kirkdale. They were
recognised at first sight by the keeper of a
menagerie, to whom they were shown, as
resembling both in form and appearance the
foeces of the spotted Hyaena ; and, being
analysed by Dr. Wollaston, were found to be
composed of the ingredients that might be
expected in fcecal matter derived from bones,
viz. phosphate of lime, carbonate of lime,
and a very small proportion of the triple
phosphate of ammonia and magnesia. This
discovery of the coprolites of the hyaena
formed, perhaps, the strongest of the links in
that chain of evidence by which Dr. Buckland
proved that the cave at Kirkdale, in York-
shire, had been, during a long succession of
years, inhabited as a den by hyaenas, and
that they dragged into its recesses the other
animal bodies, whose remains, splintered and
bearing marks of the teeth of the hyaena,
were found mixed indiscriminately with their
own.

* An eminent civil engineer, to whom I showed
the jaw of a hyaena, observed that the strong conical
tooth, with its basal ridge, was a perfect model of a
hammer for breaking stones for roads.

t “ The strength of the hyaena’s jaw is such that,
in attacking a dog, he begins by biting off his leg
at a single snap.” Buckland, “Reliquiae Diluvianae,
p. 23.

TEETH.

913

The dentition of the Weasel tribe ( Muste -
tides ) is illustrated (in Jig. 580, IV.) by that of
the Otter, Mnstela Lutra of Linnaeus, and
which is essentially a great aquatic Weasel or

o g | j

Polecat; its dental formula is i. ^ , c. - — j,

4, 4 j ]

P-- — -, m. - — - : = 36. In the Martin cats

( Mustela martes, L.), the little homotype of
p. 1 above is present in the lower jaw ; in the
bloodthirsty stoats and weasels, p. 1 is absent in
both jaws ; as it is likewise in the great sea-
otter ( Enhydra ), in which also the two middle
incisors are wanting in the lower jaw. In this
animal the second premolar (p. 3) has a strong
obtuse conical crown, double the size of that
of;;. 2 ; the third premolar ( p . 4) is more than
twice the size of p. 3, and represents the
upper carnassial or sectorial strangely modi-
fied ; the two lobes of the blade being hemi-
spheric tubercles. The last tooth, m. 1, has
a larger crown than the sectorial, and is of a
similar broad crushing form. In the lower
jaw the molar series are not separated by any
interspace: the first and second premolars
have oblique obtuse conical crowns. The
third premolar (p. 4) is more than twice the
size of the second (p. 3) and supports a large
anterior hemispheric protuberance with a
small internal tubercle and a posterior basal
ridge. The first true molar has an oblong
quadrate crown with an anterior small tubercle,
a larger and more prominent inner one, and
the rest of the broad horizontal surface un-
dulating. The second true molar has a trans-
versely elliptical crown depressed in the
centre. When the teeth are in apposition,
the anterior third of the first true molar below
is applied to the inner tubercle of the last
premolar above ; the rest of its crown plays
upon that of its homotype, the first true molar
in the upper jaw, leaving a small part of that
tooth to receive the appulse of the second
true molar below, which has no corresponding
tooth in the upper jaw.

The Mustelidce present great constancy in
regard to the number of their true molar
teeth; with one exception, the Ratel ( Melli -
vora), in which m. 2 is absent below, they
have one true molar on each side of the
upper jaw, and two on each side of the lower
jaw ; the second of these has always a broad
tubercular crown, like the one above. The
upper true molar is supported by one inner,
and sometimes by one ( Putorius , Gulo ),
sometimes two ( Mustela , Lutra, Melphitis),
outer fangs. The second true molar below
is also tubercular, but has a single fang. The
crown of the first true molar below offers
many gradations from the sectorial type, as
manifested in Putorius and Gulo , to the tuber-
cular type, as in the Taira, Ratel, and sea-
otter. The principal varieties occur, as
usual, in the comparatively less important
premolars : in the Martins and Gluttons,
they are as numerous as in the dog ; the
first, in both jaws, being implanted by a single
fang ; the rest by two, with the exception of

VOL. IV.

the last above, which has three roots. In
the otter, we find the first premolar removed
from the lower jaw ; and the second (now
the first) shows its true homology by its
double implantation, as well as by the position
of its crown behind the first in the upper
jaw (p. 1). In the Stoats, Skunks, and
Ratels, the premolar series is further reduced
by the loss of the anterior tooth (p. 1) in
both jaws, and by the diminution of the size of
p. 2, which thus becomes the first in both jaws,
and which is also now implanted by a single
fang. In a South American Skunk, the second
premolar disappears in the upper jaw, leaving
there only the homologues of the third and
fourth of the typical formula, p. 4 being
always the sectorial in the Mustelidce, as in
other terrestrial Carnivora. This tooth,
under all its modifications, retains the blade
with the lobe, corresponding to the middle
one in the feline sectorial, generally well
developed and sharp-pointed ; the differences
are principally manifested by the proportions
of the inner tubercle, and the relative size of
the third root supporting it. But the upper
sectorial, being a premolar, and therefore
requiring less modification of the crown to
adapt it for its special functions, manifests a
more limited extent of variety than the lower
sectorial, which, being a true molar, requires
greater modification of the typical form of its
crown to fit it for playing upon the sectorial
blade of p. 4 above.

Melidce. — In this sub-family I comprise
the European Badger ( Meles ), the Indian
Badger (Arctony. v), and the American Badger
( Tax-idea ) ; which, with respect to their den-
tition, stand at the opposite extreme of the
Mustelidce to that occupied by the predaceous
Weasel, and manifest the most tuberculate
and omnivorous character of the teeth. The

- . . . 3—3 1—1 3—3

formula is: — ?. 5 — 5; c. ~ — r; p. - — ;

o — ~o 1 — I 4?- -T

1—1

m. g — q '■ — 30,

The canines are strongly developed, well
pointed, with a posterior trenchant edge ;
they are more compressed in Arctonyx than
in Meles. The first lower premolar ( p . 1 )
is very small, single-fanged, and, generally,
soon lost. The first above, corresponding
with the second in the dog, is also small, and
implanted by two connate fangs. The second
upper premolar (;j. 3) has a larger, but
simple, sub-compressed conical crown, and is
implanted by two fangs: the third ( p . 4) re-
peats the form of the second on a larger scale,
with a better developed posterior talon, and
with the addition of a tri-tubereulate low flat
lobe, which is supported by a third fang : the
outer pointed and more produced part of this
tooth represents the blade of the sectorial
tooth and the entire crown of the antecedent
premolars. The true molar in Meles (in. 1)
is of enormous size compared with that of
any of the preceding Carnivora : it has three
external tubercles, and an extensive horizontal
surface traversed longitudinally by a low

3 N

TEETII.

91 1

ridge, and bounded by an internal belt, the
cingulum of Illiger: this tooth has a similarly
shaped, but relatively smaller, crown in Arc-
tonyx * The second premolar below (jp. 2)
is commonly the first, through the early loss
of the minute one in front ; its fangs are
usually connate, as in its homotype above.
The third and fourth premolars slightly in-
crease in size, have simple compressed conical
crowns, and two fangs each. The first true
molar below (m. 1) now retains little of its
sectorial character, the blade being represented
only by the two anterior small, compressed
pointed lobes; behind these, the crown ex-
pands into an oval grinding surface, narrower
in Arctonyx than in Miles, supporting three
tubercles and a posterior tuberculate ridge:
it has generally two principal roots and a
small intermediate accessory fang, as in the
otter. The second molar ( m . 2), which ter-
minates the series below, is of small size, and
has a rounded flat crown, depressed in the
centre, and with two small external tubercles;
its two short fangs are connate. In the
Labrador Badger, the last premolar has a
larger relative size, the part corresponding
with the blade of the sectorial, is sharper
and more produced, and the internal tu-
bercle has two lobes; the succeeding molar
tooth is reduced in size, and its crown pre-
sents a triangular form. The first true molar
below has its sectorial lobes better developed :
these differences give the North American
badgers a more carnivorous character than is
manifested by the Indian or European species.

Sub- Ursidce. — In other allied genera, which,
like the badgers, have been grouped, on ac-
count of the plantigrade structure of their
feet, with the bears, a progressive approxi-
mation is made to the type of the dentition of
the Ursine species. The first true molar
below soon loses all its sectorial modification,
and acquires its true tubercular character :
and the last premolar above becomes more
directly and completely opposed to its homo-
type in the lower jaw. The Racoon ( Procyon j')
and the Coati ( Nasua ) present good examples
of these transitional modifications; they have
the complete number of premolar teeth, the
3—3 1 — 1 4—4

dental formula being, i. ^ c. V • y — y»

w-U:-40-

The development of the in-

ner part of the crown of the last upper pre-
molar, which constitutes the tubercle of the
sectorial tooth, now produces two tubercles on
a level with the outer ones which represent the
blade; and the opposite premolar below (p. 4),
which is the true homotype of the modified
sectorial above, begins to acquire a marked
increase of breadth and accessory basal tu-
bercles. All the lower premolars, as well as
the true molars, have two fangs; the three first
premolars above have two fangs, the fourth
has three, like the two true molars above.

The dental formula of the Indian Bentu-

* See Odontography, pi. 128, fig. 13, m. 1.
t lb. pi. 129, Jig. 7. I lb .Jigs. 8—13.

rong ( Arctictis ) and Kinkajou ( Cercoleptes ) is
. 3—3 1—1 3—3 2—2

3—3’

1-1’ 3-

-3’ m' 2-

= 36.

PliocidcB. — We have seen a tendency to
deviate from the ferine number of the incisors
in the most aquatic and piscivorous of the
Musteline quadrupeds, viz. the sea-otter
( Enhydra ), in which species the two midtile
incisors of the lower jaw are not developed in
the permanent dentition. In the family of
true seals, the incisive formula is further re-
duced, in some species even to zero in the

lower jaw, and it never exceeds ^ All

the Phocidcc possess powerful canines ; only in
the aberrant walrus ( Trichechus ) are they absent
in the lower jaw, but this is compensated by the
singular excess of development which they
manifest in the upper jaw. In the pinnigrade,
as in the plantigrade, family of Carnivores we
find the teeth which correspond to true mo-
lars more numerous than in the digitigrade
species, and even occasionally rising to the
typical number, three on each side ; but this,
in the seals, is manifested in the upper and
not, as in the bears, in the lower jaw. The
entire molar series usually includes five,
rarely six teeth on each s:de of the upper
jaw, and five on each side of the lower jaw,
with crowns, which vary little in size or form
in the same individual ; they are supported in
some genera, as the Eared Seals ( Olarice )
and Elephant Seals ( Cystophora *), by a single
fang ; in other genera f by two fangs, which
are usually connate in the first or second
teeth ; the fang or fangs of both incisors,
canines and molars, are always remarkable
for their thickness, which commonly sur-
passes the longest diameter of the crown.
The crowns are most commonly compressed,
conical, more or less pointed, with the “ cin-
gulum ” and the anterior and posterior basal
tubercles more or less developed; in a few of
the largest species they are simple and ob-
tuse, and particularly so in the walrus, in
which the molar teeth are reduced to a
smaller number than in the true seals. J In
these the line of demarcation between the
true and false molars is very indefinitely in-
dicated by characters of form or position ;
but, according to the instances in which a
deciduous dentition has been observed, the
first three permanent molars in both jaws
succeed and displace the same number of
milk molars, and are consequently premolars ;
occasionally, in the seals with two-rooted
molars, the more simple character of the
premolar teeth is manifested by their fangs
being connate, and in the Stenorliynchus serri-
dens the more complex character of the true
molars is manifested in the crown. There is
no special modification of the crown of any
tooth by which it can merit the name of a

* Odontography, pi. 132, fig. 7.
t lb- figs. 1—4.

j The relation of Triclieclius to the PhocicUc is
analogous to that of Machairodus to the Felidcc, and
also, in the simplification of the molars, to that of
Proteles to CanicUe.

TEETH.

915

“sectorial” or “ carnassial ; ” but we may
point with certainty to the third molar above
and the fourth below as answering to those
teeth which manifest the sectorial character
in the terrestrial Carnivora.

The coadaptation of the crowns of the
upper and lower teeth is more completely
alternate than in any of the terrestrial Car-
nivora, the lower tooth always passing into
the interspace anterior to its fellow in the
upper jaw. In the genus P/wca proper ( Ca -
locepha/us, Cuv.) typified by the common seal

3 3

(Ph. vitulina), the dental formula is, i. — ,

c.

1_1 3_3

1 — Vp- 3—3’ m‘

2—2

2^2

: - 34.

The forms

and proportions of these teeth are shown
in PI. 132, Jig. 1., of my “Odontography.”
The first tooth above and below presents a
complete confluence of the fangs ; they are
separated from the second above ; but be-
low they sometimes do not become free
before the fourth, and sometimes the two
roots are distinct in the third anJ second
molars. In the P/wca anellata Kills., the
principal cusp of the molar teeth is com-
plicated with anterior and posterior smaller
cusps, sometimes one in number in the upper
molars ; the anterior accessory cusp is some-
times wanting in the first, and is rudimentary
in the rest ; but usually there are two small
cusps behind the principal one, and in the
three or four posterior molars in the lower
jaw there are sometimes two small cusps be-
fore and two behind the principal one.*

In the P/ioca caspica the upper molars have
commonly one accessory cusp before and one
behind the principal lobe; the lower molars
have one accessory cusp before and two be-
hind.

In the P/wca grccnlandica the upper molars
have no anterior basal cusp and only one be-
hind ; the lower molars have two cusps behind
and one in front, except the first, which re-
sembles that above, and, like it, has connate
fangs.

The condition of the molar teeth is nearly
the same in the P/wca barbata, but the crowns
are rather thicker and stronger, and the three
middle ones above have two posterior basal
cusps feebly indicated, the same being more
strongly marked in the four last molars
below.

The following genera of seals with double-
rooted molars ( Pelagius and Stenorhynchus)
have four incisors above as well as below, i. e.

2 9

- — An upper view of the molar teeth in

the Hooded Seal of the Mediterranean ( Pcla -
gius monachus ) is given in my Odontography,
PI. 132. Jig. 3., as when they are worn down
in an old specimen ; the crowns are thick,
obtuse, sub-compressed, with a well developed

* Nillson, in Wiegmann’s Arcliiv. 1841, 313. I
notice these varieties of the crown, in connection
with analogous ones in the fangs of the teeth of the
same species, to show the inadequacy of such cha-
racters as marks of subgeneric distinction.

cingulum, a principal lobe and an anterior and
posterior accessory basal lobule ; the fangs
are connate in the first tooth both above and
below.

The allied sub-genus ( Ommatophoca ) of seals
of the southern hemisphere has six molar
teeth on each side of the upper, and five on
each side of the lower jaw, with the principal
lobe of the crown more incurved. The two
first molars above are closely approximated,
but this may prove to be a variety.

In the Stenorhynchus the jaws are more
slender and produced, and the molar teeth are
remarkable for the long and slender shape of
the principal lobe, and of the accessory basal
cusps. The incisors have sharp conical re-
curved crowns, like the canines, and the ex-
ternal ones in the upper jaw are intermediate
in size between the canines and the middle in-
cisors.

In the Stenorhynchus leptonyx each molar
tooth in both jaws is trilobed, the anterior
and posterior accessory curving towards the
principal one, which is bent slightly back-
wards ; all the divisions are sharp-pointed,
and the crown of each molar thus resembles
the trident or fishing-spear ; the two fangs of
the first molar in both jaws are connate. In
Stenorhynchus serridens the three anterior mo-
lars on each side of both jaws are four-lobed,
there being one anterior and two posterior
accessory lobes ; the remaining posterior
molars (true molars) are five-lobed, the prin-
cipal cusp having one small lobe in front, and
three developed from its posterior margin ;
the summits of the lobes are obtuse, and the
posterior ones are recurved like the prin-
cipal lobe. Sometimes the third molar be-
low has three instead of two posterior acces-
sory lobes. Occasionally, also, the second, as
well as the first molar above, has it fangs con-
nate ; but the essentially duplex nature of
the seemingly single fang, which is unfailingly
manifested within by the double pulp-cavity,
is always outwardly indicated by the median
longitudinal opposite indentations of the im-
planted base. These slight and unessential
varieties, presented by the specimens of the
Saw-toothed Sterrink ( Stenorhynchus serridens )
brought home by the enterprising Naturalist
of Sir J. lloss’s Antarctic expedition, accord
with the analogous varieties noticed by the
best observers of the seals of our neighbour-
ing seas, as, for example, Nillson.

The Grey Seal ( Halichcerus gryphus) of our
own seas begins, by the extension of the
connate condition of the two roots through a
greater proportion of the molar series, to
manifest a transition to the family of seals
with true single-rooted molars ; the formula

of this genus is, i. ^ c. - p. ^ ^

2—2’ 1—1 1 3—3

2—2

m' c n • — 34. The four middle upper in-
cisors are close set, with pointed recurved
crowns ; the lateral ones are much larger and
laniariform : the canines have moderate crowns,
with a sharp ridge before and behind. The’

3 n 2

91G

TEETH.

crowns of the molar teeth are conical, sub-
compressed longitudinally and finely grooved,
with an anterior and posterior edge ; those
below have generally a slight notch at the
fore and back part of the base. The first
molars, both above and below, are the smallest,
with a simple crown and a single ventricose
fang ; the second and third above, and the
second, third, and fourth below, have two
connate roots ; the two roots are commonly
distinct in the remaining posterior molars : all
the roots are very thick.

In the genus Otaria the dental formula is,

i.

3—3

2—2’

c.

1 — 1
1—1’

V-

3—3

3—3’

m.

3—3

2—2

= 36.

The

two middle upper incisors are small, sub-com-
pressed, with the crown transversely notched ;
the simple crowns of the four incisors below
fit into these notches : the outer incisors above
are much larger, with a long pointed conical
crown, like a small canine. The true canine
is twice as large as the adjoining incisor, and
is rather less recurved. The molars have
each a single fang ; the crown is conical, sub-
compressed, pointed ; in the two last recurved,
with a basal ridge or “ cingulum,” broadest
within : but, in the Otaria jubata, the molars
have a pointed cusp developed from the fore-
part, and in the last two molars also from the
back part of the crown. In some species, as
the Otaria lobata (Phoca lobata, Fischer), the
single molar is not developed in the upper jaw,
and the outer incisors above are not so large :
in this species a thick plicated cingulum belts
the base of each molar and developes a small tu-
bercle from its fore-part in the molars of the
lower jaw ; the crown of the last molar above
is notched.

In the great proboscidian and hooded
Seals ( Cystophora ), the incisors and canines
still more predominate in size over the molars ;
but the incisors are reduced in number, the

2 2 ] 1 3 3

formula here is: i. ~ y, c. ^ y, p. - —t

2 2

m. : = 30. All the molars are single-

2—2 °

rooted, and all the incisors are laniariform.
The two middle incisors above and the two
below are nearly equal ; the outer incisors
above are larger. The canines are still more
formidable, especially in the males ; the curved
root is thick and subquadrate. The crowns
of the molar teeth are short, sub-compressed,
obtuse ; sometimes terminated by a knob and
defined by a constriction or neck from the
fang ; the last is the smallest.

In the Walrus ( Tnchechus rosmarus'), the
normal incisive formula is transitorily re-
presented in the very young animal, which
has three teeth in each intermaxillary bone
and two on each side of the fore-part of the
lower jaw ; they soon disappear, except the
outer pair above, which remain close to the
intermaxillary suture, on the inner side of the
sockets of the enormous canines, and seem to
commence the series of small and simple
molars which they resemble in size and form.
In the adult there are usually three molars or

premolars on each side above, behind the per-
manent incisor, and four similar teeth on each
side of the lower jaw ; the anterior one passing
into the interspace between the upper incisor
and the first molar, and therefore being the
homotype of the molar. In a young walrus’s
skull with canine tusks eight inches long, I
have seen a fourth upper molar, (fifth includ-
ing the incisor), of very small size, about a line
in breadth, lodged in a shallow fossa of the
jaw, behind the three persistent molars. The
crowns of these teeth must be almost on a
level with the gums in the recent head; they
are very obtuse and worn obliquely from above
down to the inner border of their base. The
molars of the lower jaw are rather narrower
from side to side than those above, and are
convex or worn upon their outer side. Each
molar has a short, thick, simple and solid root.

The canines are developed only in the
upper jaw, but are of enormous size, de-
scending and projecting from the mouth, like
tusks, slightly inclined outwards and bent
backwards; they present an oval transverse
section, with a shallow longitudinal groove
along the inner side, and one or two narrower
longitudinal impressions upon the outer side;
the base of the canine is widely open, its
growth being uninterrupted.

The food of the walrus consists of sea-
weed and bivalves ; the molars are well
adapted to break and crush shells ; and
fragments of a species of Mya have been
found, with pounded sea-weed, in the stomach.
The canine tusks serve as weapons of offence
and defence, and to aid the animal in mounting
and clambering over blocks of ice. For their
composition and microscopic structure I must
refer to my “ Odontography,” p. 51 1. et scq.

The precise determination of the teeth in
the walrus and some other kinds of seals,
still awaits the opportunity of examining very
young specimens with the deciduous series,
which is very early lost. When the clew is
afforded by the opportunity of studying the
development and succession of the teeth, it
infallibly conducts us to the true knowledge
of the nature, both of the teeth which are
retained, and of those that are wanting to
complete the typical number. We have
availed ourselves of this in deciphering the
much modified dentition of the genus Felts ;
and the same clew will guide us to a similar
satisfactory knowledge of the nature and
homologies of the teeth in the human species.
The discovery, by the great poet Gothe, of
the limits of the premaxillary bone in man
leads to the determination of the incisors,
which are reduced to two on each side of
both jaws : the contiguous tooth shows by
its shape, as well as position, that it is the
canine, and the characters of size and shape
have also served to divide the remaining five
teeth in each lateral series into two bicuspids
and three molars. In this instance, as in the
dentition of the bear, the secondary characters
conform with the essential ones. But since
we have seen of how little value shape or
size are, in the order Carnivora, in the deter-

TEETH.

917

initiation of the exact homologies of the teeth,
it is satisfactory to know that the more
constant and important character of develop-
ment gives the requisite certitude as to the
nature of the so-called bicuspids in the human
subject. In fig. 584., the condition of the

Fig. 584,

Deciduous and permanent teeth of a Child (Homo).

teeth is shown in the jaws of a child of about
six years of age. The two incisors on each
side ( di .) are followed by a canine, dc., and this
by three teeth having crowns resembling
those of the three molar teeth of the adult.
In fact, the last of the three is the first of
the permanent molars ; it has pushed through
the gum, like the two molars which are in
advance of it, without displacing any previous
tooth, and the substance of the jaw contains
no germ of any tooth destined to displace it :
it is therefore, by this character of its de-
velopment, a true molar, and the germs of
the permanent teeth, which are exposed in
the substance of the jaw between the diverging
fangs of the molars, d. 3 and d. 4, prove those
molars to be temporal’)', destined to be replaced,
and prove also that the teeth about to displace
them are premolars. According, therefore,
to the rule previously laid down, we count
the permanent molar in place the first of its
series fit. 1), and the adjoining premolar as
the last of its series, and consequently the
fourth of the typical dentition, or p. 4.

We are thus enabled, with the same scien-
tific certainty as that whereby we recognise
in the middle toe of the foot the homologue
of that great digit which forms the whole
foot and is encased by the hoof in the horse,
to point to p. 4, or the second bicuspid
in the upper jaw, and to m. 1, or the first
molar in the lower jaw of man, as the homo-
logues of the great carnassial teeth of the lion
and tiger. We also conclude that the teeth
which are wanting in man to complete the
typical molar series, are the first and second

premolars, the homologues of those marked
p. 1 and p. 2 in the bear. The characteristic
shortening of the maxillary bones required
this diminution of the number of their teeth, as
well as of their size, and of the canines more
especially ; and the still greater curtailment
of the premaxillary bone is attended with a
diminished number and an altered position of
the incisors. One sees, indeed, in the car-
nivorous series, that a corresponding decrease
in the number of the premolars is concomitant
with the shortening of the jaws. Already in
the Mustelidce, (Jjg.o&O., IV), p. 1 below is
abrogated; in EV/walso above, with the further
loss of p. 2 in the lower jaw ; the true molars
being correspondingly reduced in these strictly
flesh-eating animals, but taken away from the
back part of their series.

If we were desirous of further testing the
soundness of the foregoing conclusions as to
the nature of the teeth absent in the reduced
dental formula of man, we ought to trace the
mode in which the type is progressively
resumed in descending from man through the
order most nearly allied to our own.

Through a considerable part of the Qua-
drttmanous series, e. g. in all the Old World
genera above the Lemurs, the same number
and kinds of teeth are present as in man ;
the first deviation being the disproportionate
size of the canines and the concomitant break
or “ diastema ” in the dental series for the
reception of their crowns when the mouth
is shut. This is manifested in both the
Chimpanzees and Orangs, together with a
sexual difference in the proportions of the
canine teeth.

As the precise characteristics of the human
dentition are best demonstrated by comparison
with that brute species which is most nearly
allied to Man, and makes the first step in the
descending scale, I here subjoin the details of
such a comparison, which is the more required
since it is not touched upon in the article
Quadrumana, and will be the more acceptable
as one of its subjects is a species of Chim-
panzee (Tioglodytes Gorilla)*, unknown to
science when that article was written, and
which, so far as its organisation is known, is
more anthropoid than even the docile and
smaller species of Chimpanzee ( Troglodytes
niger). A side view of the teeth of a male,
full-grown, but not aged, specimen of the
great Chimpanzee is given of the natural size
in fig. 585., and a view of the working surface
of the whole series of the upper jaw in fig. 586.
This dentition, though in all its principal
characters strictly quadrumanous, yet, in the

* Drs. Savage and Wyman, Boston Journal of
Natural History, 1847 ; Owen, Transactions of the
Zoological Society, vol. iii. p. 381 (February, 1848).
M. F. Cuvier has not given a figure of the dentition
of any species of Chimpanzee ( Troglodytes ). Be-
lieving with his brother, that the Orang ( Pithecus ,
Geoffr.) made the nearest approach to man, the
dentition of an immature Pithecus Wurmhii with
one of the characteristically large permanent molars
(m. 1) in place, immediately follows the plate of the
human dentition in the “ Dents des Mammifhres,”
8vo. pis. i. & ii.

3 n 3

TEETH.

Fig. 585.

Dentition of upper jaw, Troglodytes Gorilla, adult male. ( Natural size.)

TEETH.

919

minor particulars in which it differs from the
dentition of the Orang, approaches nearer the
human type. In the upper jaw the middle
incisors {Jig. 586, i. 1) are smaller, the lateral
ones (ib. i. 2) larger than those of the Orang*;
they are thus more nearly equal to each other;
nevertheless the proportional superiority of
the middle pair is much greater than in Man,
and the proportional size of the four incisors
both to the entire skull and to the other teeth
is greater. Each incisor has a prominent
posterior basal ridge, and the outer angle of
the lateral incisors, i. 2, is rounded off as in
the Orang. The incisors incline forwards
from the vertical line as much as in the
great Orang. Thus the characteristics of the
human incisors are, in addition to their true
incisive wedge-like form, their near equality

teeth ” *, when the mouth is closed, is appli-
cable only to the female, and does not distin-
guish the Chimpanzees from the Orangs. In
the male of the smaller Chimpanzee ( Troglody-
tes niger ) the upper canine is conical, pointed,
but more compressed than in the Orang, and
with a sharper posterior edge ; convex ante-
riorly, becoming flatter at the posterior half of
the outer surface, and concave on the corre-
sponding part of the inner surface, which is
traversed by a shallow longitudinal impres-
sion ; a feeble longitudinal rising and a second
linear impression divide this from the convex
anterior surface, which also bears a longitu-
dinal groove at the base of the crown. The
canine is rather more than twice the size of
that in the female. In the male Gorilla
{Jigs. 585, 586.), the crown of the canine is

Fig. 587.

Dentition of adult female, Troglodytes Gorilla. ( Natural size.')

of size, their vertical or nearly vertical posi-
tion, and small relative size to the other teeth
and to the entire skull. The diastema be-
tween the incisors and the canine on each
side is as well marked in the male Chim-
panzee as in the male Orang. f The crown
of the canine (ib. c.fi passing outside the in-
terspace between the lower canine and pre-
molar, extends in the male Troglodytes Gorilla
a little below the alveolar border of the under
jaw when the mouth is shut ; the upper ca-
nine of the male Troglodytes niger likewise
projects a little below that border ; the
seventh character, therefore, which I had
formerly assigned to the genus, “ apices of
canines lodged in intervals of the opposite

* Compare fig. 586. with pi. xxxii. ( Pithecus
Wurmbii) and pi. xxxiv. (Pith. Morio), in vol. ii.
Zool. Trans.

t Compare fig. 586. with pi. xxxii. (Pith. Wurrn-
hii) in vol. ii. Zool. Trans.

more inclined outwards : the anterior groove
on the inner surface of the crown is deeper ;
the posterior groove is continued lower dowm
upon the fang, and the ridge between the
two grooves is more prominent than in the
Troglodytes niger. Both premolars (Jig. 586.
p. 3 and p. 4) are bicuspid ; the outer cusp of
the first and the inner cusp of the second being
the largest, and the first premolar consequently
appearing the largest on an external view (Jig.
585.). The difference is well marked in the
female (Jig . 587, p. 3, p. 4). The anterior ex-
ternal angle of the first premolar is not pro-
duced as in the Orang, which in this respect
makes a marked approach to the lower Qua-
drumana. In Man, where the outer curve of
the premolar part of the dental series is greater
than the inner one, the outer cusps of both
premolars are the largest ; the alternating su-
periority of size in the Chimpanzee accords
* Zool. Trans, vol. i. pi 372.

3 n 4

920

TEETH.

with, and contributes to, the straight line
which the canine and premolars form with
the true molars.

The true molars (Jig. 586., m. 1, to. 2, in. 3) are
quadricuspid, relatively larger in comparison
with the bicuspids than in the Orang. In the
first and second molars of both species of
Chimpanzee a low ridge connects the antero-
internal with the postero-external cusp, cross-
ing the crown obliquely, as in Man. There
is a feeble indication of the same ridge in the
unworn molars of the Orang ; but the four
principal cusps are much less distinct, and
the whole grinding surface is flatter and more
wrinkled than in the Chimpanzee. In the
Troglodytes niger the last molar is the smallest,
owing to the inferior development of the two
hinder cusps, and the oblique connecting
ridge is feebly marked. In the Troglodytes
Gorilla this ridge is as well developed as in
the other molars, but is more transverse in
position ; and the crown of in. 3 is equal in
size to that of in. ] or m. 2, having the pos-
terior outer cusp, and particularly the pos-
terior inner cusp, more distinctly developed
than in the Troglodytes niger. The repe-
tition of the strong sigmoid curves which
the unworn prominences of the first and se-
cond true molars present in Man, is a very
significant indication of the near affinity of
the Chimpanzee as compared with the ap-
proach made by the Orangs or any of the
inferior Quadrumana, in which the four cusps
of the true molars rise distinct and indepen-
dently of each other. A low ridge girts the
base of the antero-internal cusp of each of
the upper true molars in the male Chimpan-
zee: it is less marked in the female. The
premolars as well as molars are severally im-
planted by one internal and two external fangs,
diverging but curving towards each other at
their ends as if grasping the substance of the
jaw. I have found the two outer fangs of
the second premolar connate in one female
specimen of the Troglodytes niger. In no
variety of the human species are the premo-
lars normally implanted by three fangs ; at
most the root is bifid, and the outer and inner
divisions of the root are commonly connate.
It is only in the black varieties, and more
particularly that race inhabiting Australia, that

I have found the wisdom tooth, to. 3, with
three fangs as a general rule ; anil the two
outer ones are more or less confluent.

In the lower jaw of the great Chimpanzee
the lateral incisors are broader than the
middle ones, although they are smaller rela-
tively than in the Troglodytes niger ; they are
larger and less vertically implanted than in
Man. The lower canines are two inches and
a half in length, including the root ; the
enamelled crown is an inch and a quarter in
length, and nearly an inch across the base; it
is conical and trihedral ; the outer and ante-
rior surface is convex, the other two surfaces
are flattened or subconcave, and converging
to an almost trenchant edge directed inwards
and backwards ; a ridge separates the convex
from the antero-internal fiat surface; both
this and the posterior surface show slight
traces of a longitudinal rising at their middle
part. The lower canine of the male shows
the same relative superiority of size as the
upper one compared with that in the female
in both species of Chimpanzee. The canine
almost touches the incisor, but is separated
by a diastema one line and a half broad from
the first premolar. This tooth ( p . 3) is
larger externally than the second premolar,
and is three times the size of the human first
premolar (p. 3) ; it has a subtrihedral crown,
with the anterior and outer angle produced
forwards, slightly indicating the peculiar fea-
ture of the same tooth in the Baboons, but in
a less degree than in the Orang. The summit
of the crown ot' p. 3 terminates in two sharp
trihedral cusps, the outer one rising highest,
and the second cusp being feebly indicated
on the ridge extending from the inner side
of the first ; the crown has, also, a thick ridge
at the inner and posterior part of its base.
The second premolar (p. 4) has a subquad-
rate crown, with the two cusps developed
from its anterior half, and a third smaller one
from the inner angle of the posterior ridge.
Each lower premolar is implanted by two
antero-posteriorly compressed divergent fangs,
one in front of the other, the anterior fang
being the largest. The three true molars are
equal in size in the Troglodytes Gorilla ; in the
Troglodytes niger (Jig. 588.) the first (to. 1) is a
little larger than the last (to. 3), which is the

Dental series, lower jaw, adult male, Troglodytes niger. ( Natural Size.')

TEETH.

921

only molar in the smaller Chimpanzee as
large as the corresponding tooth in the black
varieties of the human subject *, in most of
which, especially the Australians, the true
molars attain larger dimensions than in the
yellow or white races. The four principal
cusps, especially the two inner ones, of the
first molar of both species of Chimpanzee are
more pointed and prolonged than in Man; a
fifth small cusp is developed behind the outer
pair, as in the Orangs and the Gibbons, but is
less than that in Man. The same additional
cusp is present in the second molar, which is
seldom seen in Man. The crucial groove on
the grinding surface is much less distinct than
in Man, not being continued across the ridge
connecting the anterior pair of cusps in the
Chimpanzee. The crown of the third molar
is longer antero-posteriorly from the greater
development of the fifth posterior cusp, which,
however, is rudimental in comparison with
that in the Semnopitheques and Macaques.
All the three true molars are supported by
two distinct and well developed antero-pos-
teriorly compressed divergent fangs, longitu-
dinally excavated on the sides turned towards
each other ; in the white and yellow races of
the human subject these fangs are usually
connate in in. 3, and sometimes also in m. 2.
The molar series in both species of Chim-
panzee forms a straight line, with a slight ten-
dency in the upper jaw to bend in the opposite
direction to the well-marked curve which the
same series describes in the human subject.

This difference of arrangement, with the
more complex implantation of the premolars,
the proportionally larger size of the incisors
as compared with the molars ; the still greater
relative magnitude of the canines ; and, above
all, the sexual distinction in that respect, illus-
trated byjftgs. 585. 587., stamp the Chimpan-
zees most decisively with not merely specific
but generic distinctive characters as compared
with Man. For the teeth are fashioned in
their shape and proportions in the dark re-
cesses of their closed formative alveoli, and
do not come into the sphere of operation of
external modifying causes until the full size of
the crowns has been acquired. The formid-
able natural weapons, with which the Creator
has armed the powerful males of both species
of Chimpanzee, form the compensation for
the want of that psychical capacity to forge
destructive instruments which has been re-
served as the exclusive prerogative of Man.
Both Chimpanzees and Orangs differ from
the human subject in the order of the de-
velopment of the permanent series of teeth ;
the second molar ( m . 2) conies into place
before either of the premolars has cut the
gum, and the last molar (in. 3) is acquired
before the canine. We may well suppose
that the larger grinders are earlier required
by the frugivorous Chimpanzees and Orangs
than by the higher organised omnivorous spe-
cies with more numerous and varied resources,
and probably one main condition of the earlier

* See my Odontography, pi. 119, fy. 2, m.

development of the canines and premolars in
Man may be their smaller relative size.

In the South American Quadrumana, the
number of teeth is increased to thirty-six
(art. Quadrumana,Vo1. IV. p.210.; Cebhnx *),
by an addition of one tooth to the molar
series on each side of both jaws. It might be
concluded, a priori, that as three is the typical
number of true molars in the placental Mam-
malia with two sets of teeth, the additional
tooth in the Cebince would be a premolar, and
form one step to the resumption of the normal
number (four) of that kind of teeth. The proof
of the accuracy of this inference is given by
the state of the dentition in the young Cebus
in Jig. 589., which corresponds with that of the
human child in Jig. 584-., i. e. the whole of the

Fig. 589.

Deciduous and permanent teeth of Cebus.

deciduous dentition is retained, and the first
true molar (in. 1) is in place on each side of
both jaws. The germs of the other teeth of
the permanent series are exposed in the upper
jaw ; and the crown of a premolar is found
above the third molar in place, as well as
above the second and first. As regards number,
therefore, the molar series, in Cebus, is interme-
diate between that of Mustela (Jig. 580., IV.)
and Felis (ib. V.) ; the little premolarj9.fi in
Mustela tells plainly enough which of the four
is wanting to complete the typical number
in the South American Monkey, and which
is the additional premolar distinguishing its
dental formula from that of the Old World
monkeys and man. By reference to Prof. Vro-
lik’s article (Quadrumana) it will be seen
that the eighth genus, including the little
Marmoset monkeys (Hapale, Ouistiii ), “ have
only the same number of teeth as the monkeys

4 1 — 1

of the Old World, viz. 32, i. t, c. m.

-f 1 — i

5—5 „
5—5'

But the difference is much greater

than this numerical conformity would intimate.
In a young Jacchus penicillatus I find that
there are three deciduous molars displaced by
three premolars, as in the other South Ame-
rican Quadrumana, and that it is the last true
molar, m. 3, the development of which is sup-
pressed, not the premolar p. 2, and thus these
diminutive squirrel-like monkeys actually differ

* The dental series seems, unluckily, not to have
been complete in either of the skulls represented by
the distinguished author of that able article ( das.
132, 133).

922

TEETH.

from the Old World Quadrumana more than
th eCebidce do ; i.e. they differ not only in having

four teeth ( p . 2 | — j), which the monkeys of

the Old World do not possess, but also by

wanting four teeth (m. 3 . .), which those

monkeys, as well as the Cebidee, actually have.
It is thus that the investigation of the exact
homologies of parts leads to a recognition of
the true characters indicative of zoological
affinity.

3—3

Most of the Lemurina have p. ^ m.

3—3

3—3’

together with remarkable modifications

of their incisive and canine teeth, of which
an extreme example is shown in the pectinated
tooth (Jig. 556.) of the Galeopithecus. The
inferior incisors slope forwards in all, and
the canines also, which are contiguous to
them, and very similar in shape. In the
Chirogaleus these canines are entered as in-
cisors in the dental formula of the genus
( Vol. IV. p. 215), and the laniariform premolar
(p. 2) is entered as a canine : M. Vrolik also
describes four teeth on each side of the upper
jaw, and four on each side of the lower jaw,
as true tuberculated molars. They have tuber-
culated crowns, but the value of shape as a
character is too small to permit our accepting
•so great an anomaly without the requisite
proof of their order of development and suc-
cession.

Even in the hoofed quadrupeds with toes
in uneven number ( Perissodactyla ), whose
premolars, for the most part, repeat both the
form and the complex structure of the true
molars, such premolars are distinguished by
the same character of development as those
of the Artiodactyla, or Ungulates with toes in
even number ; although in these the premolars
are distinguished also by modifications of size
and shape. The complex ridged and tuber-
culate crowns of the second, third, and fourth
grinders of the Rhinoceros, Hyrax (Jig. 590.),

tooth be determined, and its proper symbol
applied to it.

In pi. 136, 5, of my Odontography, the

three posterior teeth of the almost uniform
grinding series of the horse’s dentition are
thus proved to be the only ones entitled to
the name of “ true molars and, if any one
should doubt the certainty of the rule of count-
ing, by which the symbols, p. 4, p. 3, and p. 2,
are applied to the three large anterior grinding
teeth (ib. Jig. 19), which are commonly the
only premolars present in each lateral series of
the horse’s jaws, yet the occasional retention
of the diminutive tooth,/;. 1 (ib.y%. 6). would
establish its accuracy, whether such tooth be
regarded as the first of the deciduous series
unusually long retained, or the unusually small
and speedily lost successor (/;. 1) of an abortive
d 1.

The law of development, so beautiful for
its instructiveness and constancy in the pla-
cental Dipliyodonts, is here illustrated in the
little Ilyra.v (Jig. 591.), in which the d. 1 is

Fig. 591.

Deciduous and permanent molars of the Hyrax.

normally developed and succeeded by a per-
manent p. 1, differing from the rest only by a
graduated inferiority of size, which, in regard
to the last premolar, ceases to be a distinction
between it and the first true molar.

The elephant, which by' its digital characters
belongs to the odd-toed, or perissodactyle,
group of Pachyderms, also resembles them in
the close agreement in form and structure of
the grinding teeth representing the premolars,

Fig. 590.

and horse, no more prove them to be true
molars, than the trenchant shape of the lower
carnassials of the lion proves them to be false
molars. It is by development alone that the
primary division of the series of grinding teeth
can be established, and by that character
only can the homologies of each individual

with those that answer to the true molars of
the Hyrax, Tapir, and Rhinoceros. The gi-
gantic Proboscidian Pachyderms of Asia and
Africa present, however, so many peculiarities
of structure, as to have led to their being
located in a particular family in the Systematic
Mammalogies. And this seems to be justified

TEETH.

293

by no character more than by the singular
seeming exception which they present to the
Diphyodont rule which governs the dentition
of other hoofed quadrupeds. In fact, the
elephant, like the Dugong, sheds and replaces
vertically only its incisors, which are also two
in number, very long, and of constant growth,
forming tusks, with an analogous sexual dif-
erence in this respect in the female of the
Asiatic species. The molars, also, are suc-
cessively lost, are not vertically replaced, and
are reduced finally to one on each side of
both jaws, which is larger than any of its pre-
decessors. These analogies are interesting
and suggestive in connection with the other
approximations in the “ Sirenia” to the pa-
chydermal type, which I have pointed out in
the “ Proceedings of the Zoological Society.” *

The dentition of the genus Elephas, the sole
existing modification of the once numerous
and varied Proboscidian family, includes two
long tusks {fig. 592.), one in each of the
Intermaxillary bones, and large and complex
molars (ib. m. 3, 4, and 5) in both jaws : of
the latter there is never more than one wholly,
or two partially, in place and use on each
side at any given time ; for, like the molars of
the Mastodons, the series is continually in
progress of formation and destruction, of
shedding and replacement ; and in the ele-
phants all the grinders succeed one another like
true molars horizontally, from behind forwards.

The total number of teeth developed in the
2—2 G— 6

elephant appears to be vi-qIIq = 28.

The two large permanent tusks being pre-
ceded by two small deciduous ones, and the
number of molar teeth which follow one
another on each side of both jaws being at

“ The socket of the permanent tusk in
a new-born elephant, is a round cell about
three lines in diameter, situated on the inner
and posterior side of the aperture of the
temporary socket. The permanent tusks cut
the gum when about an inch in length, a

Fig. 592.

Section of cranium and tusk of the Elephant

month or two, usually, after the milk-tusks are
shed. At this period, according to Mr. Corse *,
the permanent tusks are ‘ black and ragged at
the ends. When they become longer, and
project beyond the lip, they soon are worn
smooth bv the motion and friction of the
trunk.’ Their widely open base is fixed upon
a conical pulp, which, with the capsule sur-
rounding the base of the tusk and the socket,
continues to increase in size and depth, ob-
literating all vestiges of that of the deciduous
tusk, and finally extending its base close to
the nasal aperture (fig. 592.). The tusk is
formed by successive calcification of layers of
the pulp in contact with the inner surface of
the pulp cavity ; and, being subject to no
habitual attrition from an opposed tooth, but
being worn only by the occasional uses to
which it is applied, it arrives at an extraor-
dinary length, following the curve originally

* Loc. cit., p. 212.

least six, of which the last three may, by
analogy, be regarded as answering to the true
molars of other Pachyderms. I have shown
in my Odontography that : —

“ The deciduous tusk makes its appearance
beyond the gum between the fifth and seventh
month ; it rarely exceeds two inches in length,
and is about a third of an inch in diameter
at its thickest part, where it protrudes from
the socket ; the fang is solidified, and con-
tracts to its termination, which is commonly
a little bent, and is considerably absorbed by
the time the tooth is shed, which takes place
between the first and second year.f

* 1838, p. 40.

f See Mr. Corse’s “ Memoir on the Teeth of the
Elephant,” in Philosophical Transactions, 1799,
p. 211 : a good figure of the deciduous tusk is given
in plate 5.

TEETH.

92-1

impressed upon it by the form of the socket,
and gradually widening from the projecting
apex to that part which was formed when the
matrix and the socket had reached their full
size.

“ These incisive teeth of the elephant not
only surpass other teeth in size, as belonging
to a quadruped so enormous, hut they are the
largest of all teeth in proportion to the size
of the body ; representing in a natural state
those monstrous incisors of the Rodents,
which are the result of accidental suppression
of the wearing force of the opposite teeth.”

The tusks of the elephant, like those of
the Mastodon, consist chiefly of that modifi-
cation of dentine which is called “ ivory,” and
which shows, on transverse fractures or sec-
tions, striae proceeding in the arc of a circle
from the centre to the circumference, in op-
posite directions, and forming by their decus-
sations curvilinear lozenges. This character
is peculiar to the Proboscidian Pachyderms.

In the Indian elephant the tusks are
always short and straight in the female, and
less deeply implanted than in the male : she
thus retaining, as usual, more of the charac-
ters of the immature state. In the male they
have been known to acquire a length of nine
feet, with a basal diameter of eight inches,
and to weigh one hundred and fifty pounds ;
but these dimensions are rare in the Asiatic
species.

Mr. Corse, speaking of the variety of
Indian elephant, called “ Dauntelah ” from its
large tusks, which project almost horizontally
with a slight curve upwards and outwards,
says, “ The largest I have known in Bengal did
not exceed seventy-two pounds avoirdupois;
at Tiperah they seldom exceed fifty pounds.”
There are varieties of the Dauntelah in which
the large tusks of the male are nearly or quite
straight ; and in a more marked breed called
“ Mooknah,” the tusks are much smaller, are
straight, and point directly downwards. These
ascertained varieties in an existing species
ought to weigh with the observers of analo-
gous varieties in the teeth of fossil Probos-
cidians, before they pronounce definitely on
their value as characters of distinct species.
More anomalous varieties occasionally pre-
sent themselves in the Indian Elephant, as
when one tusk is horizontal, the other ver-
tical; or when, from some distortion of the
alveolus, a spiral direction is impressed upon
the growth of the tusk, as in that specimen
figured by Grew in the “ Rarities of Gresham
College,” Tab. 4., and which is now in the
Museum of the Royal College of Surgeons,
London. The tusk of the elephant is slightly
moveable in its socket, and readily receives a
new direction of growth from habitual pres-
sure ; this often causes distorted tusks in
captive elephants, and Cuvier * relates the
mode in which advantage was taken of the
same impressibility, in order to rectify the
growth of such tusks in an elephant kept at
the Garden of Plants.

The tusks of the extinct Eleplias primi-
* Ossemens Fossiles, 4to. 1821, tom. i. p. 47.

genius , or Mammoth, have a bolder and more
extensive curvature than those of the Eleplias
indicus: some have been found which describe
a circle ; but, the curve being oblique, they
thus clear the head, and point outwards,
downwards, and backwards. The numerous
fossil tusks of the Mammoth which have been
discovered and recorded, may be ranged
under two averages of size: the larger ones at
nine feet and a half, the smaller at five feet
and a half in length. 1 have elsewhere* as-
signed reasons for the probability of the latter
belonging to the female Mammoth, which
must accordingly have differed from the exist-
ing elephant of India, and more resembles
that of Africa in the development of her
tusks ; yet manifesting an intermediate cha-
racter by their smaller size. Of the tusks
which are referable to the male Mammoth,
one from the newer tertiary deposits in Essex,
measured nine feet ten inches along the outer
curve, and two feet five inches in circum-
ference at its thickest part ; another from
Eschscholtz Bay was nine feet two inches in
length, and two feet one and a half inches in
circumference, and weighed one hundred and
sixty pounds. A Mammoth’s tusk has been
dredged up off Dungeness which measured
eleven feet in length. In several of the in-
stances of Mammoth’s tusks from British
strata, the ivory has been so little altered as
to be fit for the purposes of manufacture ; and
the tusks of the Mammoth, which are still
better preserved in the frozen drift of Siberia,
have long been collected in great numbers as
articles of commerce.f

Cuvier J states that the elephant of Africa,
at least in certain localities, has large tusks
in both sexes, and that the female of this
species, which lived seventeen years in the
menagerie of Louis XIV., had larger tusks
than those in any Indian elephant, male or
female, of the same size which he had seen.
The ivory of the tusks of the African ele-
phant is most esteemed by the manufacturer
for its density and whiteness.

The molar teeth of the elephant are re-
markable for their great size, even in relation
to the bulk of the animal, and for the extreme
complexity of their structure. The crown,
of which a great proportion is buried in the
socket, and very little more than the grinding
surface appears above the gum, is deeply di-
vided into a number of transverse perpen-
dicular plates (Jig. 557), consisting each of a
body of dentine (cl), coated by a layer of enamel
(e), and this again by the less dense bone-like

* History of British Fossil Mammalia, 8vo. 1844,
p. 244.

j- In the account of the Mammoth’s bones and
teeth of Siberia, published in the “ Philosophical
Transactions ” for 1737 (No. 446), tusks are cited
which weighed two hundred pounds each, and “ are
used as ivory, to make combs, boxes, and such
other things; being but little more brittle, and
easily turning yellow by weather and heat.” From
that time to the present there has been no inter-
mission in the supply of ivory, furnished by the
tusks of the extinct elephants of a former world.

J Eoc. cit., p. 55.

TEETH.

925

substance (c) which fills the interspaces of the
enamelled plates, and here more especially
merits the name of “ cement,” since it binds
together the several divisions of the crown
before they are fully formed and united by
the confluence of their bases into a common
body of dentine. As the calcification of each
plate begins at the summit, they remain de-
tached from each other and like so many se-
parate teeth or denticules, until their base is
completed, when it becomes blended with the
bases of contiguous plates to form the common
body of the crown of the complex tooth from
which the roots are next developed.

The plates of the molar teeth of the Si-
berian Mammoth ( Elephas primigenius ) are
thinner in proportion to their breadth, and
are generally a little expanded at the middle ;
and they are more numerous in proportion to
the size of the crown than in the existing
species of Asiatic Elephant. In the African
Elephant, on the other hand, the lamellar
divisions of the crown are fewer and thicker,
and they expand more uniformly from the
margins to the centre, yielding a lozenge-form
when cut or worn transversely, as in masti-
cation.

The horizontal as well as vertical course
of development of the elephant’s grinder
is well illustrated by the Mammoth’s molar,
the last of the lower jaw. The separate
digital processes of the posterior plates are
still distinct, and adhere only by the re-
maining cement ; a little in advance we see
them united to form the transverse plate ;
and, at the opposite extremity of the tooth,
the common base of dentine is exposed by
which the plates are finally blended into
one individual complex grinder*; this never
takes place simultaneously along the whole
course of the tooth in the larger molars of
the existing Indian elephant, or its extinct
congener, the Mammoth. The African ele-
phant, and some of the extinct Indian species,
as the El. planifrons, manifest their affinity
to the Mastodon by the basal confluence of
the hindmost plates before the foremost ones
are worn out. The formation of each grinder
begins with the summits of the anterior plate,
and the rest are completed in succession ; the
tooth is gradually advanced in position as its
growth proceeds; and, in the existing Indian
elephant, the anterior plates are brought into
use before the posterior ones are formed.
When the complex molar cuts the gum the
cement is first rubbed off the digital summits:
then their enamel cap is worn away, and the

* Some anatomists describe the divisions of the
crown of the elephant’s grinder as so many “ distinct
teeth ; ” and Mr. Corse (loc. cit. p. 213.), who first
propounded this view, calls each complex grinder
“ a case of teeth,” and states “ that these teeth are
merely joined to each other by an intermediate
softer substance, acting like a cement.” But this
description applies only to the imperfectly-formed
tooth ; and the detached eminences of the crown of
any complex tooth, at that stage of growth when
they are held together only by the still uncalcified
supporting matrix, might with equal justice be
regarded as so many distinct teeth.

central dentine comes into play with a promi-
nent enamel ring ; the digital processes are
next ground down to their common uniting
base, and a transverse tract of dentine with
its wavy border of enamel is exposed ; finally,
the transverse plates themselves are abraded
to their common base of dentine, and a smooth
and polished tract of that substance is pro-
duced.* From this basis the roots of the
molar are developed, and increase in length
to keep the worn crown on the grinding level,
until the reproductive force is exhausted.
When the whole extent of a grinder has
successively come into play, its last part is
reduced to a long fang supporting a smooth
and polished field of dentine, with, perhaps,
a few remnants of the bottom of the enamel
folds at its hinder part. When the complex
molar has been thus worn down to a uni-
form surface it becomes useless as an instru-
ment for grinding the coarse vegetable sub-
stances on which the elephant subsists ; it is
attacked by the absorbent action, and the
wasted portion of the molar is finally shed.

The grinding teeth of the elephant pro-
gressively increase in size, and in the number
of lamellar divisions, from the first to the last;
and, as the rate of increase in both respects is
nearly identical in both jaws, I shall describe
them chiefly as they appear in the lower one.

The first molar, which cuts the gum in the
course of the second week after birth, has a
sub-compressed crown, nine lines in antero-
posterior diameter, divided by three trans-
verse clefts into four plates, the third being
the broadest, and the tooth here measuring
six lines across f ; the first and second plates
have two mammilloid summits ; the third and
fourth have three or four such ; there is a sin-
gle and sometimes a double mammilloid sum-
mit at the fore and back part of the crown :
the base slightly contracts, and forms a neck
as long as the enamelled crown, but of less
breadth, and this divides into two, an anterior
and posterior, long, sub-cylindrical, diverging,
but mutually incurved fangs ; the total length
of this tooth is one inch and a half. The
corresponding upper molar, which Mr. Corse
describes as cutting the gum a little earlier
than the lower one, has the anterior single
digital process or mammilla, and the pos-
terior talon developed into a fifth plate,
smaller than the fourth, with which it* middle
part is confluent ; the neck of this tooth is
shorter, and the two fangs are shorter, larger,
and more compressed than those of the lower
first molar. This tooth is the homologue of
the probably deciduous molar ( d . 2) in other

* In the fossil specimen figured in plate 147, of
my “ Odontography,” the left molar l, exhibits all
the above-descrilied gradations of use ; but the right
molar, r, through some accident to the opposing
tooth in the lower jaw, has not been so worn,
but projects beyond the level of the left molar,
with the mammillated margins of the plates en-
tire.

f These are also the dimensions of the first lower
molar figured by Mr. Corse, loc. cit. pi. \i.flg. 1, i>,
and,/?#. 3 ; but I have seen the first lower molar of
smaller dimensions.

926

TEETH.

Ungulates; it is not a mere miniature of the
great molars of the mature animal, but re-
tains, agreeably with the period of life at
which it is developed, a character much more
nearly approaching that of the ordinary Pa-
ehydermal molar, manifesting the adherence
to the more general type by the minor com-
plexity of the crown, and by the form and
relative size of the fangs. In the transverse
divisions of the crown we perceive the affinity
to the Tapiroid type, the different links con-
necting which with the typical elephants are
supplied by the extinct Lophiodons, Dino-
theriums, and Mastodons. The sub-division
of the summits of the primary plates recalls
the character of the molars, especially the
smaller ones, of the Phacochere in the Hog-
tribe. As the elephant advances in age the
molars rapidly acquire their more special and
complex character.

The first molars are completely in place,
and in full use at three months, and are shed
when the elephant is about two years old.

The sudden increase and rapid develop-
ment of the second molar may account for the
non-existence of any vertical successor to the
former tooth, or “premolar,” in the elephant.
The eight or nine plates of the crown are
formed in the closed alveolus, behind the
first molar by the time this cuts the gum, and
they are united with the body of the tooth,
and most of them in use, when the first
molar is shed.

The average length of the second molar is
two inches and a half; ranging from two
inches to two inches and nine lines. The
greatest breadth, which is behind the middle
of the tooth, is from one inch to one inch
three lines. There are two roots: the cavity
of the small anterior one expands in the
crown, and is continued into that of the three
anterior plates. The thicker root supports
the rest of the tooth. The second molar is
worn out and shed before the beginning of
the sixth year.

The third molar has the crown divided into
from eleven to thirteen plates ; it averages
four inches in length, and two inches in
breadth, and has a small anterior, and a very
large posterior root ; it begins to appear
above the gum about the end of the second
year, is in its most complete state and exten-
sive usg during the fifth year, and is worn out
and shed in the ninth year. The last rem-
nant of the third molar is shown at m. 3,
fig. 592.

It is probable that the three teeth above de-
scribed are homologous with the deciduous mo-
lars, d. 2, d. 3, and d. 4. in the Hyrax and horse.

The fourth molar presents a marked supe-
riority of size over the third, and a somewhat
different form : the anterior angle is more
obliquely abraded, giving a pentagonal figure
to the tooth in the upper jaw {fig. 592. m. 4).
The number of plates in the crown of this
tooth is fifteen or sixteen : its length between
seven and eight inches ; its breadth three
inches. It has an anterior simple and slender
root supporting the three first plates ; a

second of larger size and bifid, supporting the
four next plates ; and a large contracting base
for the remainder. The fore-part of the
grinding surface of this tooth begins to pro-
trude through the gum at the sixth year: the
tooth is worn away, and its last remnant shed,
about the twentieth or twenty-fifth year. It
may be regarded as the homologue of the first
true molar of ordinary Pachyderms (m. 1).

The fifth molar, with a crown of from
seventeen to twenty plates, measures between
nine and ten inches in length, and about
three inches and a half in breadth. The
second root is more distinctly separated from
the first simple root than from the large mass
behind. It begins to appear above the gum
about the twentieth year : its duration has
not been ascertained by observation ; but it
probably is not shed before the sixtieth y ear.

The sixth molar appears to be the last, and
has from twenty-two to twenty-seven plates ;
its length, or antero-posterior extent, following
the curvature, is from twelve to fifteen inches :
the breadth of the grinding surface rarely
exceeds three inches and a half.

The reproductive power of the matrix in
some cases surpasses that of the formative
development of the cavity for lodging the
tooth, and the last lamellae are obliged to be
folded from behind forwards upon the side of
the tooth. Fig. 99, p. 2.33. of my “ History of
British Fossil Mammals,” shows this condition
in the last lower molar of the Mammoth.

One may reasonably conjecture that the
sixth molar of the Indian elephant, if it make
its appearance about the fiftieth y'ear, would,
from its superior depth and length, continue
to do the work of mastication until the pon-
derous Pachyderm had passed the century of
its existence.

Mr. Corse has figured the sixth molar,
(which he calls the seventh or eighth,) with
twenty-three plates, in tab. x. of his Memoir,
and a small cavity, c, is marked as an in-
cipient alveolus for a succeeding grinder.
Had it actually been such, it might have been
expected to contain some calcified portions
of the anterior plates of such succeeding
grinder.

The molar teeth, in all the species of
elephant, succeed each other from behind
forwards, moving, not in a right line, but in
the arc of a circle, shown by the curved line
in fig. 592. The position of the growing
tooth in the closed alveolus {in. 5) is almost
at right angles with that in use, the grinding
surface being at first directed backwards in
the upper jaw, and forwards in the lower jaw,
and brought, by the revolving course, into a
horizontal line in both jaws, so that they
oppose each other, when developed for use.
The imaginary pivot on which the grinders
revolve is next their root in the upper jaw,
and is next the grinding surface in the lower
jaw ; in both, towards the frontal surface of
the skull. Viewing both upper and lower
molars as one complex whole, subject to the
same revolving movement, the section dividing
such whole into upper and lower portion runs

TEETH.

927

parallel to the curve described by that move-
ment, the upper being the central portion, or
that nearest the pivot, the lower, the pe-
ripheral portion : the grinding surface of the
upper molars is consequently convex from
behind forwards, and that of the lower molars
concave : the upper molars are always

broader than the lower ones. The bony
plate forming the sockets of the growing teeth
is more than usually distinct from the body
of the maxillary, and participates in this re-
volving course, advancing forwards with the
teeth. The partition between the tooth in
use and its successor is perforated near the
middle; and, in its progress forwards, that
part next the grinding surface is first absorbed ;
the rest disappearing with the absorption of
the roots of the preceding grinder.

There are few examples of organs that
manifest a more striking adaptation of a
highly complex and beautiful structure to the
exigencies of the animal endowed with it, than
the grinding teeth of the elephant. We per-
ceive, for example, that the jaw is not en-
cumbered with the whole weight of the mas-
sive tooth at once, but that it is formed by
degrees as it is required ; the division of the
crown into a number of successive plates, and
the subdivision of these into cylindrical pro-
cesses, presenting the conditions most favour-
able to progressive formation. But a more
important advantage is gained by this sub-
division of the tooth ; each part is formed
like a perfect simple tooth, having a body of
dentine, a coat of enamel, and an outer in-
vestment of cement : a single digital pro-
cess may be compared to the simple canine
of a Carnivore ; a transverse row of these,
therefore, when the work of mastication
has commenced, presents, by virtue of the
different densities of their constituent sub-
stances, a series of cylindrical ridges of ena-
mel, with as many depressions of dentine,
and deeper external valleys of cement : the
more advanced and more abraded part of
the crown is traversed by the transverse
ridges of the enamel inclosing the depressed
surface of the dentine, and separated by the
deeper channels of the cement : the fore-part
of the tooth exhibits its least efficient con-
dition for mastication ; the inequalities of the
grinding surface being reduced in proportion
as the enamel and cement which invested the
dentinal plates have been worn away. This
part of the tooth is, however, still fitted for
the first coarse crushing of the branches of a
tree : the transverse enamel ridges of the
succeeding part of the tooth divide it into
smaller fragments, and the posterior islands
and tubercles of enamel pound it to the pulp
fit for deglutition. The structure and pro-
gressive development of the tooth not only
give to the elephant’s grinder the advantage
of the uneven surface which adapts the mill-
stone for its office, but, at tbe same time,
secure the constant presence of the most
efficient arrangement for the finer comminu-
tion of the food, at the part of the mouth
which is nearest the fauces.

With regard to the microscopic structure of
the peculiar modification of dentine called
“ ivory,” this is characterised partly' by the
minute size of the tubes, which, at their
origin from the pulp cavity, do not exceed
-^i-j-th of an inch in diameter, in their close
arrangement at intervals scarcely exceeding
the breadth of a single tube, and, above all,
on their strong and almost angular gyrations,
which are much greater than the secondary
curvatures of the tubes of ordinary dentine.

The dentinal tubes of ivory, as they radiate
from the pulp-cavitv, incline obliquely towards
the pointed end of the tusk, and describe
two slight primary curves, the first convex
towards that end, the second and shorter one
concave ; these curves in narrow sections
from near the open base of the tusk are
almost obscured by the strong angular parallel
secondary gyrations. The tubes divide dieho-
tomously, at acute angles, and gradually de-
crease in size as they approach the periphery
of the tusk.

The characteristic appearance of decussating
curved striae, with oblique rhomboidal spaces,
so conspicuous on transverse sections or frac-
tures of ivory, is due to the refraction of light
caused by the parallel secondary gy rations of
the tubes above described. The strong con-
tour lines observed in longitudinal sections of
ivory, parallel with the cone of the pulp-cavity,
and which are circular and concentric when
viewed in transverse slices of the tusk, are
commonly caused by strata of minute opaque
cellules, which are unusually numerous in the
interspaces of the tubes throughout the sub-
stance of the ivory, and by their very great
abundance and larger size in the peripheral
layers of cement. The close-set lateral branches
of the calcigerous tubes unite with the tubuli
of the cells. The decomposition of the fossil
tusks into superimposed conical layers takes
place along the strata of the opaque cellules,
and directly across the course of the calci-
gerous gyrating tubes.

The radiated cells of the true cement are
larger and more uniform in size and shape ;
many of them approach nearer the circular
figure than in ordinary teeth ; the long axis
of the more elliptical ones is parallel with
the plane of the stratum of cement ; their
average diameter is Tj-gVo^1 of an inch, and
their interspaces sometimes do not exceed
that dimension. The cemental tubuli appear
from their course, and sometimes from the
overlapping of the substances in the sections
examined, to be directly continued from the
tubuli of the ivory ; but Retzius expressly
denies the continuation, and states that the
cemental tubes at both the outer and the
inner surface of the cement have terminations
of less diameter than their middle part. This
is exact with respect to the major part of the
cement. In that near the base of the tusk I
have seen a few vascular canals. The contour
lines of the cement are usually wavy, and not
parallel with the line of the outer surface of
the ivory.

In the tusks of the Mastodon gigantcus the

928

TEETII.

outer layer of cement is relatively thicker
than in the tusks of the Mammoth or in those
of the Indian elephant. The general cha-
racter of the microscopic structure of the
ivory of the Mastodon’s tusk is the same as
that of the elephant. The peripheral ex-
tremities of the dentinal tubes are, in some
parts of the tusk, straighter than in the rest
of their course; the straighter extremities
were those which were first formed in the
calcification of the peripheral part of the pulp,
and this first-formed ivory is accordingly, in
such parts, more like the ordinary dentine,
and is analogous to the thin peripheral cap of
such substance in the teeth of the Sloth and
of some fishes.

The pulp soon, however, becomes subject
to that modification of the calcifying processes
by which the more tortuous disposition of
the tubuli and the more frequent interposition
of opaque cellules are produced ; modifications
which, in establishing the characters of ivory,
present a step in the transition from true
dentine to osteo-dentine.

By the minuteness and close arrangement
of the tubes, and especially by their strongly
undulating secondary curves, a tougher and
more elastic tissue is produced than results
from their disposition in ordinary dentine ;
and the modification which distinguishes
“ ivory ” is doubtless essential to the due
degree of coherence of so large a mass as the
elephant’s tusk, projecting so far from the
supporting socket, and to be frequently applied
in dealing hard blows and thrusts.

The central part ol* the tusk, especially
near the base of such as have reached their
full size, is occupied by a slender cylindrical
tract of modified ivory, perforated by a few
vascular canals, which is continued to the
apex of the tusk. It is not uncommon to
find processes of osteo-dentine or imperfect
bone-like ivory, projecting in a stalactitic
form * into the interior of the pulp-cavity,
apparently the consequence of partial inflam-
mation or malformation of the vascular pulp.
The musket-balls and other foreign bodies
which are occasionally found in ivory, are
immediately surrounded by osteo-dentine in
greater or less quantity. It has long ceased
to be a matter of wonder how such bodies
should become completely imbedded in the
substance of the tusk, sometimes without any
visible aperture, or how a leaden bullet may
have become lodged in the solid centre of a
very large tusk without having been flattened.
Such a ball, aimed at the head of an elephant,
may penetrate the thin bony socket and the
thinner ivory parietes of the wide conical
pulp-cavity occupying the inserted base of the
tusk ; if the projectile force was there spent,
the ball would gravitate to the opposite and
lower side of the pulp-cavity, as indicated in
Jig. 592. j- The presence of the foreign body

* Haller seems to have been the first to notice
these irregular internal deposits in the pulp-cavity
of the elephant’s tusk. Elementa Physiologic,
tom. viii. p. 519.

f Camper, “ Description Anatomique d’un Ele'-

exciting inflammation of the pulp, an irregular
course of calcification ensues, which results
in the disposition around the ball of a certain
thickness of osteo-dentine. The pulp then
resuming its healthy state and functions, coats
the inner surface of the osteo-dentine in-
closing the ball, together with the rest of the
conical cavity into which that mass projects,
with layers of normal ivory.*

The portion of the cement-forming capsule
surrounding the base of the tusk, and the part
of the pulp, which were perforated by the
ball in its passage, are soon replaced by the
active reparative power of these highly vascular
bodies. The hole formed by the ball in the
base of the tusk is then more or less completely
filled up by a thick coat of cement from with-
out and of osteo-dentine from within. Traces
of such a cicatrix closing the entrance have
been more than once noticed : and Blumen-
bach deduced, therefrom, a property in the
elephant’s tusk to pour out bony matter in
order to heal such wounds. The reparation
is however effected by the calcification of the
reproduced parts of the capsule and pulp.

By the continued progress of growth, the
ball so inclosed is carried forwards, in the
course indicated by the arrow in Jig. 592., to
the middle of the solidified exserted part of
the tusk, as in the example in Blumenbach’s
collection which he considered so curious.
Should the ball have penetrated the base of
the tusk of a young elephant, it may be carried
forwards by the uninterrupted growth of the
tusk until that base has become the apex, and
be finally exposed and discharged by the con-
tinual abrasion to which the apex of the tusk
is subjected. Yet none of these phenomena
prove the absolute non-vascularity of the tusk,
but only the low degree of its vascularity.
Blood circulates, slowly no doubt, through
the minute vascular canals which are con-
tinued through the centre of the ivory to the
very apex of the tusk : and it is from this
source that the fine tubular structure of the
ivory obtains the plasmatic colourless fluid by
which its low vitality is maintained.

Development. — The matrix of the tusk con-
sists of a large conical pulp, which is renewed
quicker than it is converted, and thus is not
only preserved, but grows, up to a certain
period of the animal’s life : it is lodged in the
cavity at the base of the tusk ; this base is
surrounded by the remains of the capsule, a
soft vascular membrane of moderate thickness,
which is confluent with the border of the
base of the pulp, where it receives its principal
vessels.

phant Male,” fol. p. 54. Cuvier, Annales du Mu-
seum, tom. viii. (1806) p. 115.

* Cuvier, “Annales du Musdum,” tom. viii. p. 115,
1806, “ Sur les defenses des ^Hphans, la structure,
l’accroissement, les caracteres distinctifs de l’ivoire,
et sur les maladies,” first clearly stated that the ball
or foreign body in the tusk of the elephant was
immediately surrounded by a substance different
from the regular ivory. The great anatomist ob-
serves, “ Toute la portion d’ivoire en dehors de la
balle est semblable au reste ; il n’y a que ce qui
l’entoure immediatement qui soit irregulier.”

TEETII.

929

I had the tusk and pulp of the great ele-
phant at the Zoological Gardens longitudinally
divided, soon after the death of that animal
in the summer of 1847. Although the pulp
could be easily detached from the inner surface
of the pulp-cavity, it was not without a certain
resistance, and when the edges of the co-
adapted pulp and tooth were examined by a
strong lens, the filamentary processes from
the outer surface of the pulp could be seen
stretching, as they were withdrawn from the
dentinal tubes, before they broke. They are
so minute that, to the naked eye, the detached
surface of the pulp seems to be entire, and
Cuvier was thus deceived in concluding that
there was no organic connection between the
pulp and the ivory.* As the learned professor
who has contributed the article “ Paciiyder-
mata ” adopts Cuvier’s description of the
formation of the teeth of the elephant by
deposition and transudation of the tissues
from free surfaces of the formative organs, I
have the more valued the rare opportunity of
testing and confirming, by examination of the
recent animal, the account of the processes of
conversion of those organs into the dental
tissues, which I gave in my “ Odontography.”

Each molar of the elephant is formed in
the interior of a membranous sac — the capsule,
the form of which partakes of that of the
future tooth, being cubical in the first molar,
oblong in the last, and rhomboidal in most of
the intermediate teeth ; but always decreasing
in vertical extent towards its posterior end,
and closed at all points, save where it is
penetrated by vessels and nerves. It is lodged
in an osseous cavity of the same form as itself,
and usually in part suspended freely in the
maxillary bone ; the bony case being destined
to form part of the socket of the tooth. The
exterior of the membranous capsule is simple
and vascular, as shown at m. 5, fig. 592. ; its
internal surface gives attachment to numerous
folds or processes, as in most other Ungulate
animals.

The dentinal pulp rises from the bottom of
the capsule, or that part which lines the deepen
part of the alveolus, in the form of transverse
parallel plates extending towards that part of
the capsule ready to escape from the socket.
These plates adhere only to the bottom of
the capsule ; their opposite extremity is free
from all adhesion. This summit is thinner
than the base ; it might be termed the edge
of the plate: but it is notched, or divided
into many digital processes. The tissue of
these digitated plates is identical with that of
the dentinal pulp of simple Mammalian teeth ;
it becomes also highly vascular at the parts
where the formation of the dentine is in active
progress.

Processes of the capsule descend from its
summit into the interspaces of the dentinal
pulp-plates, and consequently resemble them
in form ; but they adhere not only by their

* Annalesdu Museum, tom. viii. (180G), p. 94.
Tim account is repeated verbatim in the posthumous
edition of the “Ossemens Fossiles,” 183G.

VOL. IV.

base to the surface of the capsule next the
mouth, but also by their lateral margins to
the sides of the capsule, and thus resemble
partition-walls, confining each plate of the
dentinal pulp to its proper chamber ; the
margin of the partition opposite its attached
base is free in the interspace of the origins of
the dentinal pulp plates. The enamel organ,
which Cuvier appears to have recognised
under the name of the internal layer of the
capsule, is distinguishable by its light blue
sub-transparent colour and usual microscopic
texture, adhering to the free surface of the
partitions formed by the true inner layer of
the capsule. Although the enamel-pulp be
in close contact with the dentinal pulp prior
to the commencement of the formation of the
tooth, one may readily conceive a vacuity
between them, which is continued uninter-
ruptedly, in many foldings, between all the
gelatinous plates of the dentinal pulp, and the
partitions formed by the combined enamel-
pulp and the folds of the capsule. According
to the excretion-view, this delicate apparatus
must have been immediately subjected to the
violence of being compressed in the unyielding
bony box, by the deposition of the dense
matters of the tooth in the hypothetical vacuity
between the enamel and dentinal pulps; a
process of absorption must have been con-
ceived to be set on foot immediately that the
altered condition of the gelatinous secreting
organs took place ; and, according to Cuvier’s
hypothesis, the secreting function must be
supposed to have proceeded, without any ir-
regularity or interruption, while the process
of absorption was superinduced in the same
part to relieve it from the effects of pressure
produced by its own secretion.

The formation of the dentine commences
immediately beneath the membrana propria of
the pulp: a part which Cuvier distinctly
recognised, and which he accurately traced
as preserving its relative situation between
the dentme ami enamel throughout the whole
formation of the dentine, and discernible in
the completed tooth “ as a very fine greyish
line, which separates the enamel from the in-
ternal substance ” or dentine.

The calcification and conversion of the
cells of the dentinal pulp commence as usual
at the peripheral parts of the lamelliform pro-
cesses furthest from the attached base. It
may readily be conceived, therefore, that, at
the commencement, there is formed a little
cap upon each of the processes into which
the edges of the pulp-plates are divided. As
the centripetal calcification proceeds the caps
are converted into horn-shaped cones ; when
it has reached the bottom of the notches of
the edge of the pulp-plate all the cones be-
come united together into a single transverse
plate ; and, the process of conversion having
reached the base of the pulp-plate, these plates
coalesce to form a common base to the crown
of the tooth, which would then present the
same eminences and notches that charac-
terised the gelatinous pulp, if, during the
period of conversion, other substances had

3 o

930

TEETH.

not been formed upon the surface and in the
interspaces of the pulp-plates.

Coincident, however, with the formation
of the dentine, is the deposition of the hard-
ening salts of the enamel in the extremely
slender prismatic cells, which are for the most
part vertical to the plane of the inner surface
of the folds of the capsule to which they are
attached ; these cells or moulds give a sub-
transparent bluish tint to the enamel pulp.
The true inner part of the capsule forms
those thick transverse folds or partitions which
support the enamel organ, and with it fill the
interspaces of the dentinal pulps. With re-
gard to the formation of the cement, Cuvier,
after citing the opinion of Tenon — that it
was the result of ossification of the internal
layer of the capsule, and that of Blake — that
it was a deposition from the opposite surface
of the capsule to that which had deposited
the enamel, states his own conviction to be
that the cement is produced by the same
layer and by the same surface as that which
has produced the enamel. The proof alleged
is, that so long as any space remains between
the cement and the externa! capsule, that
space is found to contain a soft internal layer
of the capsule with a free surface next the
cement. The phenomena could not, in fact,
be otherwise explained according to the “ ex-
cretion theory ” of dental development. To
the obvious objection that the same part is
made, in this explanation, to secrete two
different products, Cuvier replies, that it un-
dergoes a change of tissue : “ Whilst it yielded
enamel only it was thin and transparent ; to
give cement it becomes thick, spongy, and of
a reddish colour.” * The external characters
of the enamel organ and cement-forming cap-
sule are correctly defined ; only, the one, in-
stead of being converted into the other, is in
fact changed into its supposed transudation :
the enamel fibres being formed, and properly
disposed in the direction in which their chief
strength is to lie, by the assimilative proper-
ties of the pre-arranged elongated prismatic
lion-nucleated cells, which take from the sur-
rounding plasma the required salts and com-
pact them in their interior.

Whilst this process is on foot, and before
the enamel fibres are firm in their position,
the capsule begins to undergo that change
which results in the formation of the thick
cement ; the calcifying process commences
from several points, and proceeds centrifu-
gally, radiating therefrom, and differing from
the ossification of bone chiefly in the number
of these centres, which, though close to the
new-formed enamel, are in the substance of
the inner vascular surface of the capsular
folds. The cells arrange themselves in con-
centric layers around the vessels, and act

* “ Seulement elle change de tissue : tant qu’elle
ne donnait que de l’email, elle dtai t mince et tvans-
parente ; pour donner du cortical elle devient epaisse,
spongieuse, opaque et rougeatre.” — Annales du
Musduni, tom. viii. p. 99; Ossemens Fossiles, ed.
1834, 8vo. tom. i p. 514. Art. Paciiydermata,
p. 8G9.

like those of the enamel pulp in receiving into
their interior the bone-salts in a clear and
compact state; during this process they be-
come confluent with each other, their piimi-
tive distinctness being indicated only by their
persistent granular nuclei, which now form
the radiated Parkin jian corpuscles. The in-
terspaces of the concentric series of confluent
cells become filled with the calcareous salts
in a rather more opaque state, and the con-
version of the capsule into cement goes on,
according to the processes more particularly
described in the Introduction to my “ Odon-
tography,” until a continuous stratum is formed
in close connection with the layer of enamel.

The uncalcified part of the capsule, always
much softer than cartilage, is very readily
detached from the calcified part, and to the
naked eye the separated surface seems entire,
and might readily pass, as with Cuvier, for
a secreting surface. But the fine vascular
processes which have been torn from the
medullary canals of the calcified part are
conspicuous, and resemble villi, when the
detached surface is examined, even with a
moderate magnifying power, under water.

Calcification extending from the numerous
centres, the different portions coalesce and
progressively add to the thickness of the ce-
ment until all the interspaces of the coronal
plates and the whole exterior of the crown is
covered with the bone-like substance. The
enamel-pulp ceases to be developed at the
base of the crown, but the capsule continues
to be formed pari passu with the partial
formation of the pulp, as this continues, pro-
gressively contracting, from the base of the
crown, to form by its calcification the roots.
The calcification of the capsule going on at
the same time, a layer of cement is formed in
immediate connection with the dentine. The
circumscribed spaces at the bottom of the
socket to which the capsule and dentinal pulp
adhere, where they receive their vessels and
nerves, and which are the seat of the progres-
sive formation of these respective moulds of
the two dental tissues, become gradually con-
tracted, and subdivided by the further localis-
ation of the reproductive forces to particular
spots, whence the subdivision of the base into
roots. The surrounding bone undergoes cor-
responding modifications, growing and filling
up the interspaces left by the dividing and
contracting points of attachment of the re-
siduary matrix. All is subordinated to one
harmonious law of growth by vascular action
and cell-formation, and of molecular decre-
ment modifying form by absorption. Me-
chanical squeezing or drawing out have no
share in these changes of the pulp or capsule;
pressure at most exercises only a gentle
stimulus to the vital processes. Cuvier be-
lieved that there were places where the den-
tinal pulp and the capsule were separate from
each other. I have never found such except
where the enamel-pulp was interposed be-
tween them in the crown of the tooth, or
where both pulp and capsule adhered to the
periosteum of the socket, below the crown.

TEETH.

031

Cuvier affirms that the number of fangs of an
elephant’s molar depends upon the number
of points at which the base of the gelatinous
(dentinal) pulp is attached to the bottom of
the capsule; and that the interspaces of these
attachments constitute the under part of the
crown or body of the tooth, the attachments
themselves forming the first beginnings of the
fangs. True to his hypothesis of the forma-
tion of the dental tissues by excretion, he
says * that the elongation of the fangs is pro-
duced by two circumstances : first, the pro-
gressive elongation of the layers of osseous
substance (dentine) which force the tooth to
rise and emerge from its socket; secondly,
the thickening of the body of the tooth by the
addition of successive layers to its inner sur-
face, which, filling up the interior cavity, leaves
scarcely room for the gelatinous pulp, and
forces it down into the interior of the roots.

This pulling up of the fang on the one hand,
and squeezing down the pulp on the other, are
forces too gross and mechanical to be admitted
in actual physiology to explain the growth of
the root of a tooth or of any other organised
product ; such modes of explanation were,
however, inevitable in adopting the excretion
theory of dental development.

With regard to the homologies of the com-
plex molars of the Proboscidian quadrupeds,
a species of insight which may come to be
deemed, in the course of anatomical science,
as of equal import to the knowledge of the
formative processes of parts, I must admit
that the mere fact of the marked and dispro-
portionate increase of size of the first of the
three last molars over its predecessor — the last
of the first three that are developed — may
appear but a feeble support to the analogical
evidence on which, chiefly, I have classed the
three last developed molars of the elephant, in
a category distinct from that of their smaller
predecessors. But the value of such indica-
tion and analogy will begin to be apparent
when we examine the condition of dental
development in the primeval forms of Pro-
boscidians. I have already shown that the
typical character of the Diphyodont dentition
was more closely and generally adhered to in
the genera that existed during the oldest ter-
tiary periods in geology than in their actual
successors : it became of course highly inter-
esting to inquire whether the miocene Mas-
todons, the earliest of the great Proboscidian
quadrupeds of which we have any cognizance,
manifested any analogous closer adhesion to
type than their elephantine successors, and
whether they would afford any actual proof
of the true deciduous nature of the first,

* “ Ces racines et les pddicules qui leur servent de
noyaux s’alongent ensuite par deux raisons : d’abord
les progrfes des lames de substance osseuse qui, s’alon-
geant toujours, forcent la dent h s’elever et a sortir
de l’alveole ; ensuite l’epaississement du corps de la
dent par la formation des couches successives qui,
en remplissant le vide inte'rieur, n’y laissent presque
plus de place pour le noyau gelatineux, et le refoulent
vers l’interieur des tubes des racines.” Annales du
Museum, viii. 1807, p. 108; Ossem. Fossiles, 1834,
p. 527.

second, or third molars, by the development
of a vertical successor or premolar. Cuvier
first ascertained the fact, though without ap-
preciating its full significance, in a specimen
of the upper jaw of the Mastodon angustidens
from Dax, in which the second six-lobed
deciduous molar was displaced by a four-
lobed or quadricuspid premolar developed
above it and succeeding it vertically.* The
same important fact was subsequently con-
firmed by Dr. Kaup in observations of the
Mastodon longirostris of the miocene tertiary
deposits of Eppelsheim.f

This satisfactorily' proves the true deci-
duous character of the first and second molars ;
and that the third molar in order of appear-
ance J, is also one (the last) of the de-
ciduous series, is indicated by the contrasted
superiority of size of the ante-penultimate
tooth, which I regard as the first of the true
molar series.

The great extent and activity of the pro-
cesses of dental development required for the
preparation of the large and complex true
molar teeth would seem to exhaust the power,
which, in ordinary Pachyderms, is expended in
developing the vertical successors of the deci-
duous teeth. In the primeval Mastodons above
cited, this normal exercise of the reproductive
force was not, however, wholly exhausted, and
one premolar, of more simple form than its
deciduous predecessor, was developed on each
side of both jaws. But even this trace of ad-
herence to the archetypal dentition is lost in
the more modified Proboscidians of the pre-
sent day.

Another and very interesting mark of adhe-
sion to the archetype is shown by the deve-
lopment of two incisors in the lower jaw in
the young of some of the Mastodons, by the
retention and development of one of these
inferior tusks in the male of the Mastodon
giganteus of North America, and by the reten-
tion of both in the European Mastodon longi-
rostris. No trace of these inferior homotypes
of the great premaxillary tusks have been
detected in the foetus or young of the existing
elephants.

In the gigantic Dinotherium the upper in-
cisors were suppressed, and the two lower
incisors were developed into huge tusks,
which curved down from the symphysis of
the massive under jaw. Most of the grinders
had two transverse ridges on the crown, as in
the Tapir ; two deciduous molars, if not three,
were succeeded vertically by two premolars,
the second of which (p. 4 of the typical series)
closely resembles the true molars, as in other
Perissodactyles.

The typical dentition is departed from in
the existing Hippopotamus by the early loss
of p. 1, and the reduction of the incisors to

2—2

2—2

in both jaws : in the extinct Hippopota'

mus of India p. 1 was longer retained, and the

* Ossemens Fossiles, 4to. ; Divers Mastodontes,
pi. iii. Jig. 2.

f Ossemens Fossiles de Darmstadt, 1835, pi. 1.

% Odontography, pi. 144 ,fig. 11, d. 3

3 o 2

932

TEETIT.

incisors were in normal number

3—3.

3—3’

whence

the term Hexaprolodun proposed for this inter-
esting restoration by its discoverers, Cantley
and Falconer.

I have before remarked that the even-toed
or artiodactyle Ungulata superadd the cha-
racters of simplified form and diminished size
to the more important and constant one of
vertical succession in their premolars. These
teeth in the Ruminants, c. g. (Jig. 580., VJL,
Moscnus./j. 2, 3, 4), represent only the moiety
of the true molars, oroneof the two semi-cylin-
drical lobes of which those teeth consist, with
at most a rudiment of the second lobe, as
Cuvier very accurately describes*, and F.
Cuvier figures in pi. 94. of his useful work,
“ Dents des Mammiferes.” An analogous
morphological character of the premolars will
be found to distinguish them in the dentition of
the genus Sus (figured in my “Odontography,”
pi. 140.,yfgi. 1 and 2), in the Hippopotamus (ib.
pi. 143.), and in the Phacochosrus (ib. pi. 141.),
where the premolar series is greatly reduced
in number : yet this instance of a natural
affinity manifested in so many other parts of
the organisation of the artiodactyle genera has
been overlooked in F. Cuvier’s work above
cited, although it is expressly designed to
show bow such zoological relations are illus-
trated by the teeth. Confiding in the accuracy
of the Baron Cuvier’s division of the hoofed
quadrupeds into “ Pachyderms ” and “ Rumi-
nants,” M. F. Cuvier separates the non ru-
minant Artiodactyles from the ruminant ge-
nera of the same natural division by interposing
the Tapir, Hyrax, Rhinoceros and Elephant ;
whilst the horse, which, in the size and com-
plexity of its premolars, as well as in many
other characters, agrees closely with the other
perissodactyle Pachyderms, is placed in close
juxtaposition with the Ruminants. f

Most of the deciduous molars of the Rumi-
nants resemble in form the true molars ; the
last, e.g. (Jig. 593., d. 4), has three lobes in the
owerjaw J likethelast true molar (?h. 3.). They

Permanent and deciduous teeth, Sheep (Ovis).
(Lower jaw.')

are three in number on each side, and, being
succeeded by as many premolars, the ordinary

, r , - 3—3 3—3

permanent molar formula is p. - — m. - — ^ :

* Ossemens Fossiles, 4to, tom. iv. p. 6.

f See my “ Remarks on the Classification of the
Hoofed Quadrupeds ” in “ Quarterly Journal of the
Geological Society,” May, 1848.

} When, therefore, the third grinder of the lower
jaw of any new or rare Ruminant shows three lobes,
the crowns of the premolars should be sought for
in the substance of the jaw below these, and above

but there is a rudiment of d. I in the embryo
fallow-deer, and in one of the most ancient of
the extinct Ruminants (Dorcatherium, Kaup)
the normal number of premolars was fully de-
veloped.

Sufficient, it is hoped, has been adduced to
prove that the molar scries of the Diphyo-
donts is naturally divisible into only two
groups, premolars and molars ; that the ty-
4 4 3 3

pical number of these is — - - — - ; and that
1 4 — 4’ 3 — 3

each individual tooth may be determined and
symbolised throughout the series, as is shown
in the instances under cut 580. If anything
were wanting to prove the artificial character
of a three-fold division of these teeth, and the
futility of any other classification than that
founded upon development, it would be af-
forded by the attempt to determine the homo-
logous teeth which is exemplified by the
dotted line which traverses the series, and
which crosses the teeth distinguished by the
name “ principales” in the great “ Osteo-
graphie and Odontographie ” nowin course
of publication by Prof, de Blainville.

This author abandons the classification of
the molar series adopted by the Cuviers,
without assigning his objections to it ; and
proposes another, in which he divides the
series into “ avant-molaires, principales, and
arriere-molaires;” he exemplifies this division
by the human dentition, in which the five
grinders on each side of both jaws are for-
mulised as “ deux avant-molaires, une princi-
pale, et deux arriere-molaires.”*

With regard to the characters of these
kinds of teeth, the avant-molaires are “simple
or complex,” the principals is “ trenchant,”
and the arriere-molaires are “ tuberculous.” f
But as shape is not a constant character,
especially in the “ principale,” the author pro-
poses another from its position, describing
it as “ being implanted below the root of
the zygomatic process of the maxillary bone ”
in the upper jaw ; and stating that the tooth
which opposes it below, and is in advance
of it, or crosses in front of it, is the lower
“ principale.”

In defining the dentition of the genus Felis% ,
M. de Blainville accordingly assigns I “avant-
molaire,” I “ principale,” and 2 “ arriere-
molaires ” in the upper jaw ; and 1 “ avant-
molaire,” 1 “ principale,” and 1 “ arriere-mo-
laire ” in the lower jaw. In another part of
the same work $, he, however, proposes another
formula, viz., 2 “ avant-molaires,” 1 “ princi-
pale,” and 1 “ arriere-molaire ” above ; 1

“ avant-molaire,” 1 “ principale,” and 1 “ar-
riere-molaire ” below ; but, taking either of
these determinations, or the dental formulae
which he assigns to other carnivorous genera,
and comparing them with his formula of the

their opponents in the upper jaw, and thus the
true characters of the permanent dentition may be
ascertained.

* Osteographie, tom. i. p. 43.

t Ib. p. 43.

t Osteographie des Carnivores, p. 69.

§ Osteographie des Felis, p. 55.

TEETH.

933

molar series in the Quadrumana and Man, we
find that a tooth which displaces and succeeds
a milk-tooth in one species is made the homo-
logue of a tooth, which, in Man and Quadru-
mana, rises above the gum without displacing
any predecessor : in other words, the “ prin-
cipal ” is a premolar in certain genera, and a
true molar in other genera. I may refer to
my Paper on the Classification of the Molar
Teeth in the “ Annales des Sciences,”* and to
the concluding pages of the chapter on the
teeth of the Carnivora in my “ Odontography ”
(p. 514), in proof that a “ molaire principale ”
does not exist in nature ; that the characters
by which it is defined by M. de Blainviile are
artificial ; and that they fail in their application
to determine the teeth in the series of pla-
cental Mammalia with deciduous and perma-
nent teeth.

In the series of figures, Jig. 580., the
continuous line traverses the tooth or its
homologue, in Man and the Ruminant, which
Cuvier distinguished as the “ molaire carnas-
siere:” the dotted line traverses that tooth
which M. de Blainviile distinguishes as the
“ molaire principale : ” the letters and numbers
symbolise the teeth and indicate their indi-
vidual homologies, and the binary division of
the molar series, which it has been one object
of the present Article to illustrate. I shall
conclude it by showing how these symbols
may be applied to the exposition of facts in
the comparative anatomy of the teeth, and for
that purpose select the complex and intricate
subject of the succession of the teeth in the
kangaroo.

The chief modifications of the marsupial
dentition are described and illustrated in the
article Marsupiali a ( Vol. III.pp. 258 — 298.).
When that volume was published I had not
had the means of tracing the period and order
of the development and succession of the
entire series of teeth in any of the marsupial
genera. The first of the five grinding teeth
on each side of the jaws of the wombat had
shown, by its displacing a milk-tooth vertically,
that it was a premolar ; and the adjoining
molar, by its earlier development and use, was
plainly the first of the four true molar teeth.
In the carnivorous and insectivorous families,
the marked difference of form and size of the
last four teeth from those intervening between
them and the canines, had also induced me to
class them as true molars, although I had not
got the developmental evidence of the fact,
except in the case of the Kangaroos and
Potoroos ( Mao-opus and Hypsiprymnus) .
The analogy, however, seemed to be sufficient
to justify the generalisation that the Marsupial
differed from the Placental Diphyodont raam-

4 4

mats in having four true molars, i , c., m. r

° ’ 4 — 4

3 3

instead of m. - — - ; and also that they differed

in

having only three premolars, i. e. p.

3—3

3—3

instead of }>,

4—4

grinding series,

-4 ’
7—7

the typical number of the
being the same. The

genus Myrmccobius offered the most remark-
able exception here, as the Manatee had done
in the placental series, in the increased number

. , . , 8—8 9—9

of the grinding teeth, e. g. to or — -,

which, according to the shape of the crowns,
were divided, in the Myrmecobius , into p.

g I;, in. — jj ; but the order of development

and succession may show that the number of
premolars is greater, and that of the true
molars less. The probably marsupial T/iy/a-
cotherium or Amphitherium from the Oxford
oolites — the most ancient of all known mam-
mals— had as many as twelve teeth in each
molar series, besides a canine and three
incisors, and by their form I have grouped

. 3—3 1 — 1 6—6 6—6

them as: «. c. p. m.

An interesting field of observation still re-
mains open in regard to the period and order of
developement of the deciduous and permanent
teeth, in the different carnivorous, omnivorous,
insectivorous, and frugivorous Marsupials. At
present I have ascertained the required facts
only in the herbivorous family ( Poephaga ).

The permanent dental formula of both the

3—3

Macropodida; and Hypsiprymnidce is, ;

1_] 1 — 1 4—4

c. — — - , p. - r, in. = 30. 4 he canines,

U — II 1 — 1 4 — 4

which are confined to the upper jaw, are
small or minute when retained ; and disappear
after being represented “ en germe” in most
of the true kangaroos.

The deciduous dentition of the great Kan-

, lr ■ v • • 3—3 1 — 1

garoo ( Macropus major) is, i. ^ yi c. ^ -

2 2

- — -^=18. The canines are rudimental,

and are absorbed rather than shed. The
deciduous incisors are shed before the young
animal finally quits the pouch : when this
takes place, the dentition is : —

1 — 1 2 — 2

12;

the upper incisors being i. I, the molars </. 3
and d. 4 of the typical dentition. This stage
is exemplified in the lower jaw at a, Jig. 594.
The next stage shows the acquisition of i. 2
in the upper jaw, and m. 1 in both jaws, and
the formula is : —

2—2 , 2—2
l^l’^"-2-2’

, Til. —

1 — 1

1 — 1

= 18. (B,/g. 594.)

At one year old, the dentition is : —

• 3—3 , 2—2 2—2 _ .

i. , d.m. , m. - — - — 24 ;

1—1 2—2 2—2

the additional teeth being i. 3 and m. 2 (c,
Jig. 594. : in which the demonstration of the
true deciduous character of d. 4 and d. 3 is
shown by the germ of their vertical successor,

* Tom. iii. (1845), p. 116.

Odontography, p. 376, pi. 99.

3 o 3

934

TEETH.

Fig.. 594.

Progress and change of dentition, Kangaroo (Macropus^.

TEMPERAMENT.

935

p. 4, which is exposed in the substance of
the jaw). The next stage is the shedding of
d. 3, and the acquisition of m. 3 (d , Jig. 594.).
Then d. 4 is shed by the ascent of p. 4 into
its place (e, Jig. 594.). Afterwards in. 4 is
acquired, and, in the Mr; cr opus gigas, p. 4 is
simultaneously pushed out (f ,Jig. 594.).

Thus, four individuals of this species may
be found to have the same number of molars,
q q

i.e. - ; two of these may seem, on a cur-
4 — 4 J

sory comparison, to have them of the same
shape, e. g., like c and e, Jig. 594. ; or like
d and f. In fact, to determine the identity
or difference in such instances, it requires
that the substance of the jaws be examined
to see if the germs of successional teeth he
present, as at p. 4, c and d, or at in. 4, f..

The result of such examination may be to
show that not one of the four kangaroos with

the in. - — -
4—4

had the same or homologous

teeth. The four grinders, c.g., may be —
d. 3, d. 4, in. 1, in. 2 ; as in c : or,
d. 4, in. 1 , m. 2, in. 3 ; as in d : or,
p. 4, in. 1, m. 2, in. 3 ; as in e : or,
vi. I, vi. 2, m. 3, and in. 4 ; as in f.

But the change does not stop here : as age
advances, in. 1 is shed, and the molar series
is reduced numerically to the condition of b ;
but, instead of in. 1, d. 4, and d. 3, it consists
of in. 2, in. 3, in. 4.

Finally, in. 2 is shed, and the dentition is re-
duced to the same numerical state as at a ,Jig.
594. : the teeth, however, being m. 3 and in. 4.

The order here described is not precisely
that which is followed in some of the smaller
species of kangaroo. In Macropus Benettii,
e.g., the acquisition of in. 3 is not accom-
panied by the shedding of d. 3, but the molar

^ j

series is numerically - — - : so, likewise, in

this species, the acquisition of in. 4 is not
accompanied by the displacement of p. 4 ;

5 5

and a molar series of is long retained ;

5 — 5

but, at the earlier period cited, the teeth
are : —

d. 3, d. 4, m. ], in. 2, and in. 4 :
and, at the lacer period, they are : —
p. 4, in. 1, in. 2, m. 3, and m. 4.

These symbols, it is hoped, are so plain and
simple as to have formed no obstacle to the
full and easy comprehension of the facts
explained bv means of them. Had those
facts been described in the ordinary way, by
means of verbal phrases or definitions of the
teeth, — e.g., “the second deciduous molar,
representing the fourth in the typical den-
tition,” instead of d. 4, and so on, — the de-
scription would have occupied much more
space, and have levied such a tax upon the
attention and memory, as must have tended
to enfeeble the judgment, and impair the
power of seizing and appreciating the results
of the comparisons.

Each year’s experience strengthens my
conviction that the rapid and successful pro-

gress of the knowledge of animal struc-
tures, and of the generalisations deducible
therefrom, will be mainly influenced by the
determination of the nature or homology
of the parts, and by the concomitant power
of condensing the propositions relating to
them, and of attaching to them signs or sym-
bols, equivalent to their single substantive
names. In my work on the “ Archetype of
the Skeleton,” I have denoted most of the
bones by simple numerals, which, if generally
adopted, might take the place of names; and
all the propositions respecting the centrum of
the occipital vertebra might be predicated of
I as intelligibly as of “ basioccipital.”

The symbols of the teeth are fewer, are
easily understood and remembered, render
unnecessary the endless repetition of the ver-
bal definition of the parts, harmonize con-
flicting synonyms, serve as a universal language,
and express the author’s meaning in the
fewest and clearest terms. The entomologist
has long found the advantage of such signs as
J and £ , signifying male and female, and the
like ; and it is time that the anatomist should
avail himself of this powerful instrument of
thought, instruction, and discovery, from
which the chemist, the astronomer, and the
mathematician have obtained such important
results.

(R. Owen.)

TEMPERAMENT. Although all indivi-
duals of the same species are composed of the
same tissues, consisting of the same elements
both proximate and ultimate, and agreeing in
all essential points of chemical constitution,
yet there exist between certain groups of
them, sometimes in the most striking degree,
differences not only in the physical powers
and actions of their frames, but also in their
mental qualities. These differences are refer-
rihle only to peculiarities in the constitution
of an individual, or in other words, to pecu-
liarities in the quality of his solids and fluids,
which are of a nature so recondite that we
cannot detect them by any chemical or ana-
tomical means, and we appreciate them only
by the character with which they impress the
physical and, to a certain extent, mental actions
of the individual in which they exist. To ex-
press this character in one word physiologists
employ the term temperament.

The use of this word is of very ancient
date. We trace it as far back as the time of
Galen, who broached the doctrine that the
blood consisted of four humours, correspond-
ing to the four elements ; these were respec-
tively designated bills, sanguis , atra bills,
phlegma. Nunc, says Haller, ex ejusmodi
quatuor humoribus sanguinem aiebant tempe-
rari, justamque omnium principiorum eommis-
tionem perfectissimum temperamentum efficere;
si vero aut sanguis supra legitimam suam
quasi dosin abundaret, sive bilis, sive terra
atrave bilis, sive phlegma, quatuor tunc sim-
plicia et praecipua teniperamenta aiebant oriri,
a bilis abundantia cholericum, ab aqute uber-
tate phlegmaticum, a sanguinis aucta portione
3 o 4

936

TEMPERAMENT.

sanguineum, et denique a copia atrae bilis vie-
lancholicum.*

This view of the doctrine of temperaments
prevailed in the schools down to the time of
Cullen, and we find that able and thoughtful
physician thus expressing himself upon the
subject : “ The ancients very early established
a distinction of temperaments which the
schools of physic have almost universally
adopted ever since, and appears to me to be
founded on observation. I am very much of
opinion, that we can perceive a combination
of a particular state of the chief circumstances
of the economy to take place very steadily in
certain persons, and thereby to form at least
two of the temperaments assigned by the an-
cients.” f

The temperaments, the existence of which
seems most consistent with observation, are
those admitted by Cullen, namely, the sangui-
ncous and the melancholic, the phlegmatic being
a degree or modification of the sanguineous,
and the choleric of the melancholic.

It is reasonable to expect an infinite variety
as regards the extent to which the character-
istic marks of the temperaments are manifested
in \arious individuals. Taking examples which
afford good indications, the two temperaments
above referred to may be described as follows,
after Cullen.

Individuals of the sanguine temperament
have the quantity of fluids in the body large
in proportion to the solids, the habit of body
soft and plump, after the period of manhood
disposed to obesity, and at all times, readily
sweating upon exercise, the skin smooth and
white, the hair soft, generally of a pale colour
or from thence passing through different shades
to a red ; the complexion ruddy, the eyes com-
monly blue; the strength of the whole body
is moderate, and the mind sensible, irritable,
cheerful, and unsteady. The most exquisite
examples of this temperament are found in
men from the time of puberty to that of man-
hood, and in women. In both sexes the cha-
racteristics of the temperaments are far less
manifest in old age.

In persons of the melancholic temperament
the habit of the body is rather hard and mea-
gre, the quantity of fluids in the whole system
moderate in proportion to the solids, the sim-
ple solids firm and dense, the hair hard, black,
with a tendency to curl, the skin coarse, of a
dun colour, with a corresponding complexion,
the eyes very constantly black, the strength
considerable, the mind slow, disposed to gra-
vity, caution and timidity, with little sensibi-
lity or irritability, but tenacious of all emotions
once excited, and therefore of great steadiness.
This temperament is most completely formed
in advanced life, but the characters of it ap-
pear often very early. j;

By some writers a nervous temperament is
admitted, the prominent characteristic of
which consists in a great excitability of
the nervous system, and a predominance of

* Haller, El. Physiolog. lib. v. sect. 4.

t Mat. Med.

j Cullen, loc. cit.

emotional impulses over the influence of the
will. Individuals of this temperament are
generally fidgetty and restless, take but little
sleep, and are anxious about rrifles ; they are
called “ creatures of impulse their emotions
are easily excited, and often not readily sub-
dued. In persons of this temperament, when
labouring under disease, phenomena referrible
to the nervous system are very apt to compli-
cate and often to obscure the morbid actions.
This temperament, however, cannot be said
to exist apart from the sanguineous or me-
lancholic : it always accompanies either one
or the other, most frequently the former, and
the most exquisite examples of it are found in
the female sex.

In looking at the physical conditions of
the best-marked examples of the sanguine
and melancholic temperaments, it is im-
portant to ascertain whether any one pro-
perty or quality stands out more prominently
than the rest, which might seem to give to
the whole economy of the individuals its
peculiar cast. It appears to me that there is
no single physical property which is so closely
associated with difference of temperament as
variety in the quantity, and perhaps also in the
kind, of colouring matter or pigment, evinced
by the colour of the hair and skin, and influ-
encing also the colour of the eyes, and of the
blood, anti of the nervous centres.

Individuals of the melancholic temperament
exhibit in their various tissues a considerable
amount of pigment, as shown by the dark co-
lour, generally black, of the hair and eyes,
while on the other hand those of the san-
guine temperament are deficient in colour,
having light hair, blue or grey eyes, and fair or
white skins. Observations are yet wanting,
in sufficient number, to determine the relative
amount of colouring matter in the blood of
individuals of each of these temperaments, or
to ascertain whether it is characterised by
any peculiar chemical qualities. It seems
highly probable that the amount and kind of
colouring nutter in the skin, hair, and eyes,
as well as of that in some of the secretions, as
bile, urine, &c. is influenced by the amount
and kind of the haematine.

The xanthous and leucous races of man in-
habiting for the most part cold or temperate
climates, afford the most numerous examples
of the sanguine temperament, while the me-
lano-contous or dark races found chiefly in
warm climates are mostly of the melancholic
temperament. And those individuals of the
xanthous and leucous races, which in physical
characters approach most nearly to the dark
races, as by the existence of a large quantity
of dark pigment in their tegumentary tissues,
are of the melancholic temperament, whilst
the light-coloured members of the xanthous
races are prone to exhibit the characters of
the sanguine temperament.

If it be admitted that a constant connection
exists between colour and temperament, as I
think is sufficiently obvious, it would follow
that the nature of the temperament is deter-
mined by certain peculiarities in the physical

TEMPORO-MAXILLARY ARTICULATION.

condition of the frame. These peculiarities
react to a certain extent upon the mind, and
more or less aid or clog its workings, but cer-
tain powers and modes of action of the mind
are by no means so constantly associated with
certain states of body, as to connect the men-
tal and bodily states as cause and effect. It
is true that the sanguine temperament is ge-
nerally accompanied by a mind exhibiting
certain characters, but the exceptions to this
are so numerous that we cannot assign the
corporeal state as the cause of the mental —
nor vice versa. Bodily peculiarities are in-
finitely more frequently inherited than mental,
— the powers and activity of the mind are
greatly determined by education and training ;
but those qualities of body which give a cha-
racter to its temperament are born with it ;
and although they may be modified by exter-
nal influences, they are yet at all times suf-
ficiently distinct to prove them to be inherent
physical properties of the entire organism.

At the same time it seems reasonable to
admit that the mind has its temperaments, as
the body has, and in a great measure inde-
pendently, and the terms, sanguine, melan-
cholic, phlegmatic, and choleric, may be
severally applied to them, according as the
emotions and feelings, and the intellectual
actions vary in their modes and degrees of
developement, and in their rate of working.

(R. B. Todd.)

TEMPORO-MAXILLARY ARTICU-
LATION.— Under this heading I propose to
give a brief account of the jointing of the
lower maxilla to the cranium. This joint can-
not, of course, be identified out of the verte-
brata. The mandibles and maxillae of the ar-
ticulata are not homologous with the jaws of
vertebrate animals, and the slit of their mouths
is placed vertically not horizontally.

In the human subject , as in all mammalia, this
articulation takes place between the squamous
portion of the temporal ( squamosal ) and the
inferior maxillary bones. The description of
the anatomy of the human temporo-maxillary
joint comprises, therefore, that of the diarthro-
dial articular surfaces of those bones, and also
ol the following parts : viz., the interarticuiar
fibro-cartilage, the two synovial sacs, the ex-
ternal and internal lateral and other liga-
ments, and part of the insertion of the external
pterygoid muscle.

Bones. — The articular condyle of the lower
jaw is sub-cylindroid in form, its length from
side to side being greater than its antero-pos-
terior measurement. The axis of this c 3 lin Jer,
however, is set neither directly from side to
side, nor yet exactly level, its inner part being
posterior to and below its outer; so that if
the axes of the two condyles were produced
inwards tiil they met, they would form an
angle in doing so, which would point down-
wards and backwards, — reaching the anterior
margin of the foramen magnum. The carti-
lage that encrusts this condyle extends further
down behind than in front.

The surface to which this condyle is

937

(mediately) articulated forms a part of the
glenoid fossa, and is situated just below the
base of the zygomatic process of the temporal
bone, between its roots. It has such form
as, in respect of the set of its axis, and its
tranverse measurement, pretty accurately fits
the condyle. It has, however, a greater
antero-posterior extent, in accordance with
the capability which this joint normally pos-
sesses, in addition to the usual ginglymoid
motion, of an antero-posterior gliding" to and
fro of the condyle — a kind of normal disloca-
tion. The glenoid fossa of the temporal bone
contains a portion of the parotid gland, as
well as the condyle of the inferior maxilla ; the
former occupies that portion of it which is
posterior to the glasserian fissure, whilst that
part which is anterior to the glasserian fissure,
is lined with cartilage for the articulation of
the latter. In man there is usually no bony
ridge bounding this articular surface pos-
teriorly, such as is generally found in the
lower mammalia.

The ridge that bounds it anteriorly is formed
by the inferior root of the zygoma, and the
cartilage is continued some way on to this
ridge. Externally it is limited by a tubercle
on the zygoma, which serves for the attach-
ment of the external lateral ligament of the
joint.

Interarticuiar fibro cartilage. — This is a
thin disc or meniscus, oval or sub-oblong in
form, concave below and convex above, thus
capping the condyle, thicker at the edges than
in the middle, where it is not unfrequently
thinned away even to perforation. It differs
from all the other fibro-cartilages in having
muscular fibres inserted into it; namely, a
portion of those of the external pterygoid.
This insertion takes place along its anterior
border, and by it the fibro-cartilage is made to
join in that normal amount of dislocation for-
wards, which as above stated, the condyle of
the lower maxilla is capable of, as well as in
the abnormal accidental dislocation of the
jaw. It is further held in its place by the
fibres of the external lateral ligament, and by
the synovial bursae of the joint.

Si/novial Bursce. — These are two in num-
ber, one above the interarticuiar fibro-carti-
lage and the other below it. The upper one
is the larger and slacker, for it alone is con-
cerned in the antero-posterior gliding of the
joint. The two sacs, ol course, communicate
and are reduced to one when the interarti-
cuiar fibro-cartilage is perforated in the
centre.

Ligaments. — There is only one ligament in
immediate relation with the temporo-maxil-
lary joint, namely, the external lateral. This
is a small ligament, broader above than below,
situated at the outside of the joint; attached
above to the tubercle situated at the point
of divergence of the roots of the zygoma; and
directed downwards and backwards to the
outside of the neck that supports the condyle
of the lower jaw. Midway in its passage from
the one to the other it is attached by its inner
aspect to the interarticuiar fibro-cartilage.

938

TEMPORO-MAXILLARY ARTICULATION.

The internal lateral ligament is a long thin
slip extending from the spinous process of the
sphenoid, and the neighbouring parts of the
temporal bone to the fore part of the lip of
the inferior dental canal. It lies behind the
external pterygoid muscle, by the origin of
which its cranial attachment is concealed, and
it is separated from the temporo-maxillary joint
by a considerable space through which pass
the internal maxillary artery and vein, giving
ofF their middle meningeal and inferior dental
branches, which indeed are conducted, the
former to the foramen spinosum of the sphe-
noid, the latter to the inferior dental canal, by
the ligament in question.

Numerous stray fibres of ligamentous tissue
strengthen the synovial sacs of the temporo-
maxillary joint, forming a kind of capsular
ligament.

That process of the cervical fascia, which
is called the stylo-maxillary ligament, is gene-
rally enumerated as one of the ligaments of
this joint. It extends from the styloid process
to the lower part of the ramus of the jaw,
separating the parotid from the submaxillary
gland, and affording attachment to the stylo-
glossus muscle. The condyle of the lower
jaw depends for the maintenance of its normal
apposition to the temporal bone much more
upon the masseter, temporal and pterygoid
muscles than upon these small ligaments ; by
these, however, its astero-posterior gliding is
indifferently tethered.

Muscles. — The external pterygoid-muscle,
proceeding backwards and outwards from its
origin, is mainly inserted into the front of the
neck that supports the maxillary condyle, the
upper part of it, however, is inserted into the
interarticular fibro-cartilage, which thereby is
drawn forward along with the condyle when
this muscle acts. This insertion is tendinous.

Motions of the j pint. — The temporo-maxil-
lary joint admits of a ginglymoid motion in the
vertical direction, by which the mouth is
opened and shut. This motion must of ne-
cessity always take place in the joints of both
sides at the same instant. It also admits of a
horizontal antero-posterior gliding motion, in
which the joint of one side only may be mainly
concerned. In the human subject the front
teeth of the lower jaw, in most cases, are not ex-
actly opposed to those of the upper jaw — that
is, the summits of the one set are not applied
to the summits of the other — in the ordinary
position of the mouth, either when at rest or
engaged in mastication. The lower incisor
teeth are usually posterior to the upper. But
when we bite with the front teeth we bring
the upper and lower set into apposition by
thrusting forward the lower jaw : in this act
both joints are similarly concerned. We can
also execute a grinding motion from side to
side, and this is done by thrusting forward one
condyle whilst the other merely revolves on
the axis of its neck.

The jaw is elevated or closed by the tem-
poral, masseter, and pterygoid muscles. The
pterygoid, chiefly the external, are the agents
in protruding it. These latter are antagonised

by the elevating and also by the depressing
muscles. The chief depressor of the lower
jaw is the digastric, as is clearly shown by its
comparative anatomy, but all those which ex-
tend from the chin to the hyoid bone are
capable of, and occasionally do assist in per-
forming this act.

The majority of the muscular fibres that
elevate the jaw arrive at their insertion into
it from before backwards ; thus the masseter
has a kind of twist in the arrangement of
its fibres, so that those which arise most
anteriorly are inserted very conspicuously
furthest back, whilst the remainder proceed
directly downwards or slightly forwards ; a
considerable portion of those of the temporal,
namely, those which arise from the anterior
part of the temporal fossa, run backwards to
their insertion into the coronoid process.
The use of this arrangement seems, upon a
careful consideration of the mechanics of the
question, to be the application of the elevating
or closing force in a more favourable direc-
tion, not, as might seem at first sight, the
protrusion of the lower jaw — that is amply
effected by the pterygoidcus externus.

Abnormal conditions of the temporo-
maxillary joint. — Accidents. — The condyle
of the lower jaw can only be dislocated in one
direction, namely forwards. In this accident
the condyle slips forward over the inferior root
of the zygoma, and is then drawn somewhat
upwards within the zygomatic arch. The inter-
articular cartilage is carried with it, Thisusually
happens to the joints of both sides, but occa-
sionally one condyle only is dislocated. It is
usually produced by the action of the muscles
when the mouth is very widely opened, as in
yawning, or more especially in biting a very
large object, such as a large apple.

When both the condyles are dislocated , the
lower jaw is thrust forwards and cannot be re-
tracted. The mouth is widely open and the
patient is unable to close it. The power of
swallowing is lost, and the saliva, the secretion
of which is probably increased, flotvs from the
mouth involuntarily. Articulation is difficult,
owing to the impossibility of making the labial
sounds. There is a conspicuous depression
beneath the zygoma just in front of the ear,
and a flatness in the masseteric region. The
coronoid process is much depressed, and forms
a visible protuberance beneath the zygoma,
and, as first observed by Mr. Adams of Dub-
lin, there is a prominence in the temporal re-
gion between the eyebrow and the ear, pro-
duced by the posterior fibres of the temporal
muscle being pushed up by the condyle in its
new position.

If this dislocation remains unreduced, the
parts, as in most other dislocations, gradually
accommodate themselves to their new position,
so that the power of articulation and deglu-
tition is re-acquired, the mouth can be closed,
and a considerable amount of motion is re-
gained, but the chin remains abnormally thrust
forwards, and there is always a depression in
the position normally occupied by the con-
dyle.

TEMPORO-MAXILLARY ARTICULATION.

When one condyle only is dislocated, the
chin is thrust forwards and towards one side
— that, namely, on which the condyle remains
in place. The coronoid process of the dis-
located side forms a prominence even more
conspicuous than when both condyles are
displaced, but the mouth is not so wide open.
There is, of course, the same depression in
front of the ear, and the same flatness of the
masseteric region.

Congenital malformation. Dr. R. W. Smith
of Dublin, in his Treatise on Fractures and
Dislocations,* gives a detailed account of the
dissection of a highly interesting case of “ Con-
genital luxation of the inferior maxilla.” The
malformation affected one side only, — the
right, — and consisted mainly of an absence,
or arrest of development of the condyle, the
only vestige of which was a small process
hooked inwards at its apex. This process did
not touch the temporal bone by a quarter of
an inch, and neither it nor the surface oppo-
site to it presented any articular cartilage, but
were both simply invested with periosteum.
There was no trace of an interarticular fibro-
cartilage, nor of a synovial sac, and the ex-
ternal lateral ligament sloped downwards and
forwards instead of downwards and backwards.
The glenoid cavity did not exist, or rather
the inferior root of the zygoma, which really
forms the glenoid cavity, was not developed.
There was conspicuous atrophy of the whole
of this side of the face in respect of the bones
— temporal, right half of the body and right
ramus of the inferior maxilla, malar, su-
perior maxillary, and even the right half of
the sphenoid, — and muscles, but the nerves
were as large as their fellows. The most re-
markable of the peculiarities of the surround-
ing parts, and that which clearly demonstrated
the abnormal condition not to be the result of
injury or disease, was an extreme shortness
of the zygomatic process of the the temporal
and a compensatory unusual length of that of
the malar bone. The former was only half an
inch long, whilst the latter was nearly twice
as long as that of the other side. During the
lifetime of this patient, who was an idiot, it
was observed that one side of his countenance
did not match the other, and that the dis-
parity was much increased when he opened
his mouth. He was often observed to have
spasmodic twitching of the abnormal side of
his face.

Disease. — Chronic rheumatic arthritis occa-
sionally affects this articulation. Both joints are
usually affected by it, but sometimes it attacks
the joint of one side only. It is most common
in elderly subjects. When it attacks the young
or middle aged, it is more rapid, accompanied
with more pain, and more likely to involve the
neck of the condyle and the ramus of the jaw.
The pain is often very severe but varia-
ble, apparently influenced by meteorological
changes. The lymphatic glands in the neigh-
bourhood of the diseased joint are much prone

* A Treatise on Fractures in the Vicinity of Joints
and on Certain Forms of accidental and congenital
Dislocations. Dublin, 1847. 8vo.

939

to enlargement; and sometimes the enlarged
condyle can be felt as a bony tumour just in
front of the ear. The chin is thrust forward,
mesially when both joints are affected, and
towards the healthy side, as well as forwards,
when only one is diseased. The motion of the
jaw is considerably impaired. On dissection,
the condyle, in cases of this affection, is gen-
erally found to be large and broad, but some-
times conical, rough, and devoid of cartilage.
Ivory or porcellanous deposit, so common in
other joints when affected with chronic rheu-
matic arthritis, is but rarely met with in this;
those abnormal ossific concretions in and
around the joints, which are so constantly
met with in the disease in question in other
situations, have also never been found in the
temporo-maxillary joint. The interarticular
fibro-cartilage had disappeared in every case
of this affection which has been dissected and
published. The glenoid cavity is enlarged,
divested of its articular cartilage, and presents
a roughened, abnormal surface. All indica-
tion of the disease stops suddenly at the glas-
serian fissure, and at the spheno-temporal
suture, and the enlargement of the glenoid
cavity takes place at the expense of the lower
root of the zygoma which generally becomes
entirely absorbed.

In the report of the proceedings of the
Pathological Socety of London in the Medical
Gazette of November .30. 1849, there is an
account of a highly interesting case of necrosis
of the condyle, back part of the ramus, and
angle of the lower jaw in a scrofulous boy.
The portion of necrosed bone, which was ex-
hibited to the society, was removed many
years before, by Mr. Keate, who also had
examined the patient, grown to a healthy
man, two years before the date of the com-
munication. As far as could be ascertained
by external investigation, the lost portion of
bone had been perfectly restored. There was
no deformity, and no impairment of motion.
There are two other similar cases on record ;
one by Desault, in which the whole ramus,
with the condyle and coronoid process, were
removed, the other by Mr. Syme, in which
the condyle and ramus were necrosed. In
both these cases, also, the lost bone was per-
fectly restored to all external appearance, but
there is no record of a dissection of such a
case. In some cases which are on record,
where the whole of the lower jaw, with both
its condyles, has been removed, its place has
been supplied by condensed fibrous tissue,
but there has been no reproduction of bone.

Anchylosis of the temporo-maxillary joint is
a very rare occurrence. There is, however,
one specimen of it in the Pathological series
of the Museum of the London College of
Surgeons. The fusion of the two bones is
complete, as is shown in the preparation by
a vertical, side to side, section through the
situation of the quondam joint. This section
shows that a perfectly normal-looking cancel-
lous structure, shelled over by a layer of dense
osseous tissue, is continued from the temporal
to the inferior maxillary bone, and exhibits no

940

TEMPORO-MAXILLARY ARTICULATION.

manner of trace to indicate where the joint
once was. In fact this anchylosis had existed
for fifty years before the death of the patient.
No record is preserved of the cause of it.
The joint of one side only is anchylosed, but
that of the other side is much altered in form.
An abnormal tubercle of bone projects down-
wards from the middle of the glenoid cavity
and is received into an abnormal excavation
or alveolus in the middle of the condyle. The
lower jaw is much wasted in size, and has lost
all its teeth save the two front incisors. The
upper jaw bones are thin and light.

The motion of the lower jaw is often lost
owing to an affection not immediately con-
nected with the joint itself. When, as often
happens in scarlatina, cancrum oris, &c. there
is extensive sloughing of the inside of the
cheeks, the cicatrices resulting from the heal-
ing of the great wounds contract, and form
bands, extending from the upper to the lower
jaw, so strong and unyielding that the muscles
which open the mouth are unable to antago-
nise them.

Comparative Anatomy.— If a palaeonto-
logist were asked what fragment of a verte-
brate skeleton, speaking generally' for all ver-
tebrata, would give him most information as
to the status and affinities of the animal to
which it belonged, he would most probably
answer — the articular portion of the lower
jaw or the articulation that receives it. Of
the convex anti concave surfaces which go to
form this articulation, in all the mammalia
the convexity is on the inferior maxilla, and
the concavity on the squamosal bone, whilst
in the three other vertebrate classes the re-
verse is invariably the case — the concavity is
on the inferior maxilla, the convexity on the
bone that articulates with it.

The under jaw does not articulate with the
same, or to speak more accurately, with the
homologous bone in all vertebrate animals.
In all the mammalia it articulates, as in man,
with the squamous element of the temporal
— the squamosal bone. In birds, reptiles, and
osseous fishes it articulates with bones which
are clearly the special homologues of the tym-
panic ring of the human subject. In cartila-
ginous fishes its articulation is with the ptery-
goid bone, the homologue of the human
internal pterygoid plate. The Lepidosiren,
in which so many other characters of the
osseous and cartilaginous fishes are so curi-
ously blended together, in strict accord with
this circumstance, presents an instance of the
pterygoid and tympanic bones contributing
each a part — the former the inner, the latter
the outer part, of the articular surface for the
reception of the lower jaw.*

It is well worth while to stop here and
review what is stated in the two preceding
paragraphs. What is said is, really, this ; —
every animal that suckles its young has a convex
articular surface to its lower jaw, whilst every
vertebrate that lays eggs has a concave sur-
face. Or this — every vertebrate animal that

has hair upon it, that has a diaphragm, or an
epiglottis, has a convex articular surface to
its lower maxilla, whilst all vertebrates that
are destitute of these have a concave surface.
Or, again, all animals that suckle their young,
and have diaphragms, hair, and epiglottides,
present their squamosal bones for the articu-
lation of their inferior maxillae, whilst all in
which the possession of these characters is
negatived present for this articulation their
tympanic, or, rarely, their pterygoid bones.
Can any physiological reason be assigned for
this? Can any final purpose, holding good in
all, or in the majority of, instances, be shown
to be served by this difference ? I think none
can. One cannot conceive but that it is a
matter of perfect indifference whether the
convexity is on this bone or that. Let us look
once more to the facts. The bat that flies,
but not the swallow, the whale that swims
but not the cod-fish, the camel that walks the
desert, but not the ostrich, the carnivorous
lion, seal, and weasel, but not the eagle,
penguin, crocodile, and shark, have convex
articulations to their lower jaw and present
to them their squamosal bones. Here then
is a caveat for the physiologist. A character
found in an animal may have no physiological
signification, — no relation to external circum-
stances, nor even a functional connexion with,
or dependence on other characters wherewith
it coexists, perhaps invariably. It may be due
to the status only of the animal. Physiolo-
gically independent it may exist in an animal
only because other independent characters
co-exist. It may be a Syneilogy, not a Teleo-
lo8U-

That certain independent characters in-
variably go together, which was so elaborately
illustrated by Cuvier, is a fact of a high order,
perhaps the twilight of some great truth. If
future investigations should prove that truth
to be progressive developement, towards which
hypothesis the inquirer is, even now, tempted
by so many striking facts, as well as by the
admirable use that can be made of it as a
scaffold theory, then we should say, and as
making use of a scaffolding we may say it now,
that certain characters are attained to at a cer-
tain stage in the chain of development, and,
therefore, those are found coexisting which are
proper to the degree of development to which
the animal has arrived. Such characters I
have been accustomed to call Syneilogies *, a
word which at all events has the merit of re-
ferring only to a well known fact, without in-
volving any hypothesis. To the palaeontologist
this “ correlation of independent characters ” j-
is, of course, invaluable, and for the purpose of
arranging natural groups in the animal kingdom,
these, so to speak, useless,or Syneilogical, cha-
racters are immeasurably more valuable than
those modifications to meet special exigencies
which are called teleologies.

Mammalia. — In all mammalia, except man,
the articular surface on the squamosal bone is
bounded posteriorly, or, in the rodents, inter-
* cruv, slfxi , Xoyog.

I Cuvier.

* Owen.

TEMPORO-MAXILLARY ARTICULATION. 911

nally, by a prominent ridge or process. This
is the case in the higher Quadrumana, and
there is an indication of it even in the lower
races of mankind. In the Carnivora the con-
dyle is in general extremely long, cylindroid,
and its length is set, almost or quite directly
from side to side, whilst the surface to which
it is opposed is bounded by a very salient
ridge fore and aft. This condition attains its
acme in the Badger, where the salient ridges,
especially the posterior, even arch over and
surround the cylindroid condyle so much, that
in the dry skull the lower jaw remains at-
tached to the cranium without any artificial
contrivance, and can be removed only by
slipping each half out sideways when the sym-
physis has been disjoined. With such a joint
there cannot, of course, be the usual lateral
motion of the jaw. In the Rodentia, on
the contrary, the long diameter of the con-
dyle is directed antero-posteriorly, and is ad-
apted to an antero-posterior groove, mostly
bounded, internally and externally, by salient
ridges. Hence that nibbling, antero-posterior
motion of the jaw, which is so conspicuous
in these animals, and with which their teeth
and masticatory muscles are in such admirable
relation. This only holds good in respect ot
the placental rodents. In that great marsupial
rodent, the Wombat, the salientiy arched,
cylindroid condyles have the usual side to
si le and converging-behind set of their long
diameters. The articular surface which is
opposed to this condyle is placed, as in the
placental rodents, on the zygomatic process,
which in both runs almost directly outwards;
instead, however, of being an antero-posterior
groove it is a transverse convex cylindroid,
describing a retreating curve ; so that in the
temporo-maxillary joint of the wombat a cylin-
droid ridge is opposed to another cylindroid
ridge, the one describing a salient, the other a
retreating arch.* The articular facets of the
temporo-maxillary joint in the Ruminantia
approach more nearly to plane surfaces than
in any other animals. The squamosal facet
is bounded by a ridge posteriorly, but bas
no bony limitation in front. This is in re-
lation with the extensive lateral movement
of the jaw which these animals use in chew-
ing the cud, and with the limited power of
gaping which they possess. The rest of the
mammalia present varieties in this joint which
are extremely interesting, but an account of
them would occupy more space than the limits
of this work permit.

Aves. — In birds, as above stated, the arti-
cular surface of the lower mandible is con-
cave, and is adapted to the tympanic bone, or,
as the older ornithologists called it, the os
quadratum.f The articular surface of the
lower jaw presents two concave depressions.
The tympanic bone is itself moveable, being
articulated to the cranium by two diarthrodial
joints, so that a bird’s lower jaw is swung to
the head by two moveable jointings.

* See Art. Marsuplalia, tig. 94.

t See Art. Aves.

Rcptilia. — The evenly concave articular
surface of a reptile’s lower jaw is often con-
tributed to by more than one of the osseous
pieces which compose the inferior maxilla of
the oviparous vertebrates. In the crocodile
by two, in some chelonia by three of these
pieces. The tympanic bone is articulated
with the other cranial bones by suture, and
is therefore immoveable, in the Crocodilia and
Chelonia, but it is articulated with them by
diarthrosis, and therefore moveable, in the
Lacertia, Ophidia, and Batraehia. In some
ophidia, as the Python, there being, properly
speaking, no symphysis of the lower jaw, but
instead of it an elastic ligament, holding the
two halves together at the chin, one temporo-
maxillary joint is capable of movement inde-
pendently of the other. In the Batraehia,
among their many fish-like characters is that
of a dismemberment of the tympanic bone,
which consists of an upper and a lower piece.

Pisces. — In the majority of fishes, the
tympanic bone is represented by four separate
pieces called epi-, hypo-, meso-, and prae-
tympanic bones. These, further, bear upon
their posterior edge three opercular bones,
which were considered by Geoffroy St. Hilaire
to be the homologues of the osstcula auditus,
but are regarded by Prof. Owen as append-
ages, serially homologous with the costal
appendages. The uppermost piece, the epi-
tympanic, articulates by a diarthrodial joint
with the mastoid, and the lowermost, hypo-
tympanic, presents a diarthrodial convexity to
the lower jaw. The four tympanic pieces arti-
culate with one another, and with the oper-
cular bones by the interposition of ligament,
or rather membrane, connecting their thin ad-
jacent edges together, so that the whole appa-
ratus is capable of bilging outwards in the
movements of respiration. In the eel tribe
( Mur anid as) the number of tympanic bones
is reduced to three, which is obviously an
approach towards the two tympanic pieces of
the Batraehia. The formation of the cranial
part of the joint in question by the pterygoid
and tympanic bones conjointly, in the Lepido-
siren has been mentioned above. In the Sharks
and Rays the tympanic pedicle descends upon
that part of the pterygoid which forms the
joint, but does not actually reach the articula-
tion, the pterygoid being interposed. In these
fishes, the super-maxillary and pterygoid pieces
being confluent, and both bearing teeth, it ap-
pears at first sight that the whole upper jaw is
formed by the former alone, consequently that
the inferior maxilla is articulated directly with
the super-maxillary ; such an articulation,
however, never takes place in any animal.

The inlerarticular fibro- cartilage is con-
stantly met with in Mammalia, but in neither
of the other vertebrate classes.

Homology of the joint. — The joint in ques-
tion is the articulation between the pleura-
pophysis and the hcemapoph ysis of the frontal
vertebra. It is therefore serially homologous
with the joint between the rib and the costal
cartilage of mammalia, or the vertebral and
sternal ribs of birds anti reptiles.

TERATOLOGY.

The joints connected with the maxillary
apparatus of some of the animals belonging
to the three lower sub-kingdoms are, as was
stated in the beginning, not homologous with
this joint, although identical in function. For
description of these parts see the articles
Annelida, Arachnida, Cephalopoda, Cir-
riiopeda, Crustacea, Echinodermata,
Entozoa, Insecta, Myriapoda, and Roti-

FEKA.

(S. R. Pittard.)

TERATOLOGY. — Under this name,
which vve owe to GeofFroy St. Hilaire, we un-
derstand the doctrine of congenital deformi-
ties * In a scientific sense, it constitutes a
part of Pathological Anatomy, and demands
our interest as much as the knowledge of
those other deviations from the normal state,
which is ordinarily regarded as constituting
that science. In fact, pathological anatomy
comprises all the anomalies of the organiza-
tion ; those which occur during intra-uterine
life are called congenital, and those which
arise during extra-uterine life acquired. We
refer to the former the imperfections of the
primitive formation, or what we call mon-
strosities. They are those deviations of the
organism which can be formed only in the
earliest periods of gestation, or, at least, pre-
viously to the termination of the fcetal con-
dition.

The opinions now held with respect to
these malformations differ widely from the
absurd notions which influence the descrip-
tions given of them by Aldrovandi, Ambrose
Pare, Licetus, Palfin, and Rueff. Formerly,
indeed, each monstrosity was considered as
the presage of some misfortune, the warrant
of divine vengeance, the effect of witchcraft,
&c. Lycosthenes used to go so far as to
add to the description of each monster the
picture of some calamity which was to be its
sequel. To that opinion they owe their name,
derived from the Latin verb monstrare.

Their aetiology was not less strange and in-
correct. Rueff) in 1580, devoted a whole
chapter to the inquiry, “ An homines ex dae-
monibus et rursus daemones ex hominibus in-
fantes concipere possunt?” and Casparus
Schottus treated the subject in about the
same style.')'

They both give negative answers to the ques-
tion, trusting to have proved by this means
that, monsters are not procreated by sexual
J intercourse of women with the devil. Other
wri'ers have endeavoured to explain the cause
from copulation with brute animals, or with
pregnant or menstruating women. Notwith-
standing our more enlightened modern ideas
on this subject, the origin of monstrous births
remains still very mysterious. The opinions
concerning it may be reduced to two main

points: 1. To the original malformation of
the germ ; 2. To the subsequent deformation
of the embryo by causes operating on its
development.

I. Original malformation of the germ. — If,
according to the opinions generally adopted at
the present time, the germ may be considered
as a product of secretion by the female organ-
ism, upon which the male sperm acts with its
material and vital influence, we may suppose
that this germ may be originally malformed,
owing to some influence proceeding either from
the female or from the male sex.

1. Such a primitive malformation of the
germ seems to exist in those cases in which
the same kind of monstrosity is repeatedly
procreated by the same parents. The cause
may be ascribed : —

a. To the mother. — It is a very important
fact that, in such cases, various degrees
of the same species of deformity are fre-
quently produced in successive progression,
so that the first born child is the most de-
formed; and in the following children the
deformity progressively decreases, ,and finally
disappears in the last born (G. Vrolik, Vering).
Sometimes a deformity of the mother is com-
municated to her offspring ; for instance, con-
genital luxation of the femur.

h. To the father. — Experience proves that
a well-formed man may procreate with dif-
ferent women children with the same mal-
formation (Meckel, Luber), anil that a de-
formity of the father may be transmitted to
the child (Burdach, Osiander). The last is
however rare.

2. A second proof in support of the pro-
bability of an original malformation of the
germ is found in hereditary deformities ex-
tending over more than one generation, viz.
hare-lip, excessive number of fingers, hypo-
spadias, &c.

3. A third proof may be deduced from the
possibility that the ovarian ova in man and
in the lower animals may be already mal-
formed (Bischoft).

II. Deformation of the originally well-formed
germ. — I . It is said that this may be produced
by mental impression of the pregnant woman,
or what the German authors call das Versehen.
But for this opinion no positive proof can be
afforded. According to the observations pub-
lished thereupon, and of which a great deal may
be found in the learned article Generation
of this Cyclopaedia, all the supposed mental
impressions, which have been considered as
the cause of malformations, took place, with
few exceptions, in the last stage of preg-
nancy.* And even in those cases in which an
earlier period may be certified, we could object
that the post hoc must not always lead to the
conclusion ergo propter hoc. It is of some im-
portance to appreciate the correctness of this

* From monster ; and science. _ _ * See my publications in Tijdschrift v. Natuur-

f I. Rueffus de Conceptu et Generatione Homims. ]yke gescliiedenis en Physiofogie, d. iv. bl. 221, en
Francof ad M. 1580. P. Casparus Schottus e tolgy. en Ilandb. d. Ziektch. Ontlurli. d. i. bl.
Societate Jesu, Physica curiosa, aucta et correcta, ggy.
sive Mirabilia Naturae et Artis. Lib. i. § xxii.

TERATOLOGY.

913

reasoning, for the theory of the mental im-
pressions, which was so readily adopted in the
barbarous middle ages, as a mode of saving
poor and innocent women from torture and
stake, finds even in the present day more ad-
vocates than might have been expected. Of
this I was convinced at the Congress of
Naturalists at Aix-la-Chapelle in 1847, and in
the Report of the Transactions of the Schweiz
zemchen Naturf Gesellschaft zu Chur, 29, 30,
31 Juli, 1844, in which the affected mind of
the pregnant woman is said to produce a
mysterious effect on the foetus, and that the
medium by which this influence is com-
municated may be the hearing as well as the
sight ! To crown all these absurdities, we see
mentioned in Rust, Magasin, B. xxi. S. 261.,
that a woman gave birth to a child with im-
perfect bones, which is attributed to her
having been present, before her pregnancy, at
the execution of a criminal by breaking on
the wheel. To all these fantastical considera-
tions I oppose the following arguments : —

a. That malformations seldom, or perhaps
never, agree with apprehensions or fears
a priori of pregnant women (G. Vrolik,
T. Zimmer, J. J. Plenck, and Burdach). On
the contrary, it often happens that a woman
who has once procreated a malformation, and
is continually troubled by the fear of another
similar sad occurrence, may become the happy
mother of a second well-formed child.

b. That the foetus, even when a germ, is
quite independent ; transferred from the ovary
into the uterus, it needs for its developement
a material intercourse with the maternal body,
but no organic connection ; for which reason
it can be formed as well without as within the
uterus, as in extra-uterine pregnancy ; that it
stands in no connection, either vascidar or
nervous, with the body of the mother, and
that therefore it is improbable that her mental
condition can have any influence whatever
upon the form of the foetus.

c. That malformations occur likewise among
the inferior animals, — insects, testaceous ani-
mals, echinodermata, — in which the develope-
ment of psychical life is very imperfect, and
the oviparous generation of which must pre-
serve the young from the influence of dis-
ordered maternal imagination.

cl. That in the case of twins, as the ace-
phali specially show, one child may he inal-
J formed and the other in perfect condition,
notwithstanding they were both exposed to
the same influences.

e. That more deeply situated organs, the
very existence of which may be unknown to
the pregnant woman, may be malformed ; as
for instance, the heart, the intestinal tube, ike.

If now, on all these grounds, I exclude the
mental impressions of pregnant women from
the retiology of malformations, I do not mean
to deny the influence which by her somatic
condition the mother may exercise upon the
feetus. Thus, if in consequence of mental
agitation, her body were to suffer a violent
shock, this might have a prejudicial influence
on the material transmission which takes place

between her and the foetus, and the latter might
thereby become morbidly affected. There are
instances ofits being the subject of intermittent
fever (P. Russell) ; of sudden death occa-
sioned by frightful agitation of the mother
(Wienholdt) ; of jaundice communicated by
the mother (Kerckring) ; of small-pox (Jen-
ner, Montgomery, Friedlander) ; of syphilis
and scarlet fever (R. Lee), all derived from
the mother. But all this is entirely different
from the effect of mental impressions. It is a
material result, easily conceived, and of which
physiologists need no further explanation.

2. A second cause of malformation of the
foetus is sought in external injury suffered by
women during their pregnancy. Meckel goes
so far as to reject this entirely. In some de-
formities, for instance, in hydrops ventriculo-
rum cerebri, the effect of external injury is
easily proved.

3. A third cause is attributed to diseases
of the ovum and of the feetus. Simpson
(Edinburgh Med. and Surg. Journal, No.
127., April, 1836, and Gazette Medicale de
Paris, Nov. 1836, p. 393.) has described an
acute and chronic form of placentitis, to which
ought to be ascribed all those singular ex-
udations which attach themselves to the feetus
as pseudo-membranes. Fig. 595, gives a spe-
cimen of adhesion of the placenta to the head
of a foetus deformed by urania.

Fig. 595.

In fig. 596. a pseudo-membrane passes to

TERATOLOGY.

944

the forehead, round which is twisted the um-
bilical cord.

Fig. 5 96.

In some, but very rare, cases, the coats of
the ovum are destroyed, and the foetus is im-
mediately attached to the inner surface of the
uterus ( Steinmetz). It is not to be denied, that
through these pseudo-membranes some mal-
formations of the foetus may be occasioned, as
Montgomery has proved, such as the truncation
of the extremities, which he names self-ampu-
tation. Further than this, however, we may
not go, for the brides placenlaires of Professor
St. Hilaire are certainly not a universal cause
of monstrosity. They are too accidental and
unstable to be such. The existence of mal-
formations in eggs which Geoffroy St. Hilaire
coated over with varnish or wax, affords no
proof of the possibility of a mechanical origin
of monstrosities. The exclusion of the air pre-
vents, in such a case, the necessary material
change in the ovum, in consequence of which
the perfect developement of the foetus is im-
paired.

The morbid state of the coats of the ovum
may likewise cause the so-called molce, which,
according to their consistency, are divided
into moke fungoscc, carnosce , cruentee, and
tendinoses. Valentin* distinguishes in the san-
guineous mass of mo/a carnosa a net of vessels,
from which the blood issues. It is the vas-
cular net of the chorion, in which the mass of
blood has been collected, in consequence of
too great a supply from the uterus. By these
means the villi are distended and removed.
The ovum being thus degenerated, occasions
defective respiration and nutrition of the
feetus, which in consequence soon dies. The
ovum, however, may still continue to grow,
and is finally expelled. In this manner these
molce are frequently the cause of miscarriage.

* Report. Anat. u. Physiol., Berlin, 1837, B. i.
S. 127.

Kerckring* inveighed in a spirited and in-
genious manner against the strange accounts
which were formerly given of these molce.

To the diseases of the placenta are referred
enlargement (Kyll, Pierrard, Devilliers), con-
gestion and apoplexy (J. Clarke, Darigan),
calcareous concretions (Hannover). For the
aetiology of malformations, this pathological
anatomy of the placenta is, however, very un-
productive. None of these can be explained
by it, nor were any accompanied by these pla-
cental diseases.

Nor does the nosology of the feetus afford
us much more information, notwithstanding
the monograph given by J. Gmesser.f It
cannot, however, be denied, that some of its
diseases may give rise to deformities ; for in-
stance, chronic inflammation of the brain to
hydrops ventriculorum cerebri, and this again
to Acrania.

Perhaps also, as Rokitansky states, a morbid
condition of the valves may be the cause of
some congenital abnormities of the heart.
Yet, notwithstanding all this, the diseases of
the foetus can only, in a very limited sense,
be assigned as the cause of its malformation ;
and hence the opinion of Otto, who ascribes
to this source a great many malformations,
ought to be rejected.

4. A fourth, and assuredly very general,
cause of malformation, consists in impeded de-
velopement of the foetus by some remote and un-
known cause. It is matter of dispute whether
this deforming cause operates on the foetus in
its totality, or whether it affects originally
only one system, which spreads its deforming
influence over all the others This last idea
was embraced by Tiedemann, who at first de-
duced all monstrosities from some det'ectof the
vascular, and later from the nervous system.
In opposition to this hypothesis, I suggest the
following considerations.

a. It is opposed to anatomical evidence.
The cyclopia , whose nature consists in a more
or less simplified eye ami a displaced or
absent external nose, is attributed by Tiede-
mann to the original absence of olfactory
nerves, producing the deformation of the
nasal cavity, and the original fusion of the
optic nerves, and of the thalami nervorum
opticorum effecting the simplification of the
eye. I have found, however, in cyclopes,
more than once, olfactory nerves, and have
likewise seen that there was no constant con-
currence between the simplified form of the
eye and of the optic nerve. A double optic
nerve may be found with a single eye-ball
(Eller, Henermann). With complete dupli-
cation of the internal parts of the eye, and
even with two separate eyes, I found a single
optic nerve, and likewise a double, though
not complete, as well as a single eye-ball,
notwithstanding the entire absence of the
optic nerve. Similar facts are quoted by
Ilaller and G. F. Wolff. Hare-lip with cleft

* Specil. Anat. Amstelodami, 1G70, Observ. 08
et 95.

f Die Iirankheiten des Foetus. Breslau, 1827. 8vo

TERATOLOGY.

palate is attributed by Tiedemann to the
original absence of olfactory nerves. G.
Vrolik found them, however, in children with
hare-lip. The nerves of organs may exist,
although the organs themselves may be ab-
sent (Seiler, W. Vrolik); and inversely, the
nerves may be wanting, while the organs are
present (C. G. Euttner). In anencephali the
body is very massive, notwithstanding the
imperfect condition of the nervous centres.
In double monsters there is no definite corre-
spondence between the condition of the nerv-
ous system and the duplication of the body
(W. Vrolik).*

b. Embryogenesis teaches that the forma-
tion of the several parts of the body is not
essentially the result of that of the nervous
system, but that, on the contrary, each part
is formed and developed independently. I
refer to what I have already said, in 1836 (in
my treatise on Cyclopia), and am happy to
find J. Muller, Rathke, Bischoff, Burdach,
and Stannius, with me on this subject.

What is now proved for the nervous system,
may equally be applied to the system of blood-
vessels; and hence I presume to conclude,
that no malformation whatever proceeds from
a central system, but is occasioned merely by
impeded developement, the cause of which
remains concealed. This impediment may be
confined to one part, or may be extended
over more. This extension may sometimes
stand either in causal connexion with an
original malformation, as for instance the dis-
placing of the nose in Cyclopes ; or may take
place in an entirely independent manner.
In the latter case, it is a complication of mal-
formation, which proves that it may extend
itself to more than one region of the body,
and to more than one apparatus. I have
met with an instance of this, in which to
acrania, cyclopia, and absence of the lower
jaw, was added ectopia of the intestines. If
the origin of the malformation is derived from
impeded developement, the so-called monstra
per defectum are the result, and from excessive
formation arise the monstra per excessum.

The malformations occasioned by impeded
developement may, for the most part, be com-
pared with the natural forms through which
the foetus passes in its normal developement.
On this is founded the ingenious idea of
Meckel, previously suggested by Wolff, that
most malformations are caused by arrest of
developement ( bildungshemmung ), for which
reason they must be said, according to
Bischoff, to be formed through arrested de-
velopement (heminungsbildungen) . They, how-
ever, never give 11s a perfect representation
of the form at which the foetus has been
arrested in its developement, because the in-
creased growth and the progressive nutrition
of the foetus cannot but make an important

* On this subject I have given copious elucida-
tion in the Treatise on Cyclopia in Transactions of
the First Class of the Royal Netherland Institute,
1836, vol. v. p. 25. ; on Double Monsters, ibid. 1840,
vol. ix. ; and Handbuch, vol. i. 1840.

VOL. IV.

945

modification therein. As the transient forms
of the human foetus are for the most part
comparable to the persistent forms of the
lower animals, the malformations occasioned
by impeded developement often acquire a
brute appearance ; and thus a reason is at
the same time given why they exhibit, in dif-
ferent animals, the form of the lower, but not
of the higher classes.

A consequence of this mode of origin is,
that they never deviate so much from the
normal form as would exclude them from the
rank of organized beings; and that the devia-
tions from the natural form are confined
within definite limits, so that they always re-
remind us more or less of the regular form.
Fixed laws of organization prevail in them,
by which they exhibit a certain fitness of
organization, and a tendency to render the
capacity for life as great as possible, not-
withstanding the malformation. Peculiar vi-
tal relations are hereby produced adapting
them for uterine life, and many are brought
forth well nourished and at full time. Most,
however, are unfit for life after birth, though
for very different reasons.

The following remarks may serve for the
elucidation of these peculiar vital accommo-
dations : —

1. We never see in malformed births, dis-
similar parts fused or united with each other,
such as the intestinal tube with the aorta,
the arteries with the nerves, &c. Each
part, therefore, retains, to a certain degree, its
own independence, according to what Fleisch-
mann denominates lex proprietors. The gullet
sometimes coalesces with the larynx, and the
bladder with the rectum ; but these parts are
not originally dissimilar, being developed from
a common mass.

2. The malformed parts are restricted to
their determinate place, according to what
Fleischmann denominates lex topicorum.

3. No malformed organ loses entirely its
own character, and no malformed animal loses
its generic distinction. It is, therefore, justly
observed by Soemmering, that nature does not
deviate ad infinitum, and that even in mon-
strosities a distinct gradation and natural or-
der are observable.

An immediate consequence of this must be,
that in one and the same sort of monstrosity,
there are different degrees of malformation,
varying from the greatest possible degree to
the very least. We might thus consider the
different monstrosities as so many genera, and
their varieties as so many species, where-
by, according to J. T. Meckel, a new or-
ganic kingdom is constituted, differing only
from the others by less constancy of form.
Consequently a definite type prevails in the
generation of monstrosities, and they are
subjected to fixed organic laws. This order
appears even — 1. In the number in which
they occur within a certain space of time. In
3000 births in Paris, there occurs about one
monster (J. Geoffroy St. Hilaire). 2. In
the sex. In impeded developement, the mal-
formed children are more frequently female,

3 p

916

TERATOLOGY.

in some sorts of double monsters, male. 3.

In a definite proportion between the species of
the animals, and the most frequent monstrosities
in them. Cyclopes, for instance, especially with
a snout, occur most frequently in swine ; double
monsters in man. 4. In the constant form
of monsters, even amongst the most heteroge-
neous animals. Cyclopia, double monsters,
acrania, have in Birds precisely the same cha-
racters as in the Mammalia. 5. In the greater
predisposition to monstrosity among some animals.
This is greater among domestic than among
wild animals; greater among the more perfect,
than among the less perfect ; three-fourths of
the monstrosities occur among Mammalia, one-
fourth among Birds (J. Geoffroy St. Hi-
laire). They happen seldom among Reptilia,
still less frequently among Fishes, Mollusca,
Articulata, and Radiata.

From these premises the consequence is
easily derived, that monstrosities do not take
place by chance, and therefore do not by any
means deserve the so very general appellation
of caprices of nature ( hums natures). The
result of this is, that they often present a
quantitative antithesis, according to what
Geoffroy St. Hilaire denominates loi de ba-
lancement. According to this law, the ex-
cessive developement of one part of the body
is often connected with checked formation of
another. To anenccphalia, cyclopia, spina
bifida, are often joined fingers and toes in ex-
cessive number ; to sireno-melia superfluous
vertebrae and ribs ; and frequently there occur
in double monsters malformations of the head.
Meckel saw, in one single instance, this an-
tithesis extend itself over different children
of one and the same mother. A girl had
on each extremity a superfluous digit, and
one hand of her sister wanted four fingers,
being the number of digits which her sister
had in excess, reckoning the four extremities
together.

1 have now arrived to the classification of
monstrosities ; but in order to prevent all
unnecessary waste of time, I shall avoid
entering into a full critical examination of
the systems propounded by Licetus, Huber,
Wigtel, Malacarne, Buffon.BIumenbach, Bres-
chet, Geoffroy St. Hilaire, Gurlt, Otto, and
Bischoff. Concerning these I refer to Bis-
choff*, from whom Rokitansky has chiefly
borrowed what he gives in his manual. Ac-
cording to my conviction, no suitable clas-
sification of monstrosities can be given, and
the efforts employed to this end may be re-
garded as failures. I confine myself, therefore,
to a simple grouping, taking embryogenesis
as my basis, without presuming on any further
classification, and I thus avoid a barbarous
nomenclature, which, in my opinion, is at-
tended with no advantage. My object is
simply to make the doctrine of malformations
useful for physiology and for medical practice,
nearly in the same manner as was done, almost

* Entwickelungs Gescliiehte mit besondere Be-
TUcksiclitigung der Missbildungen, in R. Wagner
Handworterbuch d. Physiologic, B. i. S. 887.

simultaneously with me, by the excellent F. A.
von Ammon.*

Malforbiations of the Ovum.

1 . Mola botryoides or hydatica, — Hydromelra
aquation, — is a degeneration of the chorion into
vesicles of different sizes, filled with a serous
liquor, which were erroneously taken for hy-
datids. They cover the surface of the en-
larged ovum, and are the villi of the chorion,
which, as no formation of vessels took place,
retained their original vesicular form (Ruysch,
Albinus, Sandifort, Cruveilhier, Velpeau).
Sometimes a foetus is found in it, which, how-
ever, in relation to the ovum may be said
to be small.

The small embryo most probably dies
in the early period of pregnancy, and the
degenerated ovum continues to grow till
a later period, when it is evacuated. In
most cases abortion is the consequence of
this condition of the ovum. Sometimes,
nevertheless, the pregnancy lasts till the full
time (Gregorini), or sometimes longer, as
happened in a case observed by Lossius, in
which it lasted six years. Sometimes the
foetus disappears, and then this degenerated
vesicular mass is evacuated alone, with ex-
cessive haemorrhage and great pain. This
is the last period of what is called false preg-
nancy.

The vesicles are inclosed in a kind of de-
cidua ; they are fixed on pedicles, from which
arise other vesicles with smaller stems, so as
to give to the whole the appearance of the
chorion, in an earlier period of its existence,
when the villi still preserve their original
vesicular form. The accurate observations of
Boeck show that, in most cases, these vesicles
contain blood, which sometimes can be dis-
placed by pressure from the one to the other
vesicle, or is coagulated. The internal sur-
face of the membrane which forms the vesicle
is smooth, the external interwoven with fibres.
A thus degenerated ovum has not the power
of bringing the foetus to a state of perfect
maturity. The death of the foetus and mis-
carriage are its consequences. Sometimes the
Mola botryoides is accompanied by malfor-
mation of the foetus (Valisnieri).

From this degeneration ought to be distin-
guished : 1st. The vesicular degeneration of
the placenta, when retained after a natural
parturition in the womb (Gregorini) ; 2nd.
The Polypi fugaces or vesiculares evacuated in
the anni climacterici by elderly women (Lev-
ret) ; 3rd. Those after suppressed menstrua-
tion in unpregnant women (Schleierbach,
Watson, Sporing, Lisfranc). As I have no ob-
servations of my own of any of these cases,
1 dare not pronounce any opinion about the
affinity of these vesicles to the Mola botryoides.

2. Separation of the placenta into lobes or
cotyledons. — This is without doubt to be
attributed to an arrest at a lower degree of
developement, and it offers some resemblance

* Die angeborenen Chirurgischen Krankheiten
ties Menschen. Berlin, 1842.

TERATOLOGY. 947

to the placenta of the Ruminants. The
smallest amount of deviation is a division
into two coherent lobes, which are separated
only by a small constriction (J. F. Meckel,
Ebert). Such a placenta has an oblong form.
Sometimes there is a single lobe adjoined to
the placenta ( placenta succenturiata ) ; it is of
much smaller dimensions than the placenta
itself, and united to it by vessels, without a
cord. The placenta may also be divided into
three (Rohault, Schwencke), four (Hoboken),
five (Meckel), or seven lobes (Kerckring,
Wrisberg). In the observation of Kerckring,
the arrest at a lower stage of development is
clearly shown by the presence of the Vena
omphalo-mescnterica.

3. The vessels of the umbilical cord are sepa-
rated near the placenta, and meet at a con-
siderable distance from it(Sandifort, Wrisberg,
Adolph). In one of the published cases, this
disposition of the vessels was the cause of
their rupture, which produced the child’s death
by haemorrhage. Sometimes they were ob-
served to run separately from the placenta to

Fig. 597.

the abdomen of the fetus, into which they
penetrated through separate openings. In
most cases they meet each other just at the
umbilicus (Gavel, Van Solingen).

4. The umbilical cord too long. — The com-
mon length of the cord is twenty inches
(Roederer, Wrisberg), but it may be forty-
eight inches (Wrisberg), sometimes even five
feet (Morlanne). The usual effect of such an
abnormal length of the cord is a circumvolu-
tion of it round the body of the fetus. An
example of it is given in a very misformed
fetus in fig. 597.

A circumvolution of this kind may some-
times become dangerous : 1. By acting as a
ligature round the neck, and producing stran-
gulation of the fetus (Buchanan, Hebenstreit) ;

2. By constricting one of the extremities,
and producing the spontaneous amputation of
Montgomery (Art. Fcetus,^. 157. Vol. II.)

3. By forming single or compound knots.
Although these are in general not dangerous,
while the vessels are sufficiently protected
against pressure by the Whartonian gelatine,
they may nevertheless in some cases be drawn
so tight as to obstruct the communication
between mother and child (Sandifort, Irvets,
D. W. II. Busch) ; and sometimes the um-
bilical cord breaks off near the knot when the
vessels have become obliterated by the pres-
sure. Fig. 598. gives an example of this in
an acephalus.

Fig. 598.

5. The umbilical cord too short. — Wrisberg
gives as a minimum a measure of seven inches.
It may, however, be much less. This short-
ness of the cord is in general accompanied by
a deformity of the fetus, usually by ectopia
of the abdominal viscera, by which it indi-
dicntes an arrest of developement at an earlier
period of embryogenesis. In this way we
should interpret the accounts of absence of
the umbilical cord.

6. Absence of one of the umbilical arteries,
is even observed in double monsters, but
occurs principally in ectopia viscerum abdomi-

3 P 2

948 TERATOLOGY.

nalium, and in defective formation of the infe-
rior part of the body. Serres hence derived the
conclusion, that this malformation is the con-
sequence of the want of one of the umbi-
lical arteries ; which is however wrong, as the
evolution of the whole body may be complete,
even when one of the umbilical arteries is
wanting. Fig. .599. represents a specimen of
this kind.

Fig. 599.

a, aorta ; b, b, spermatic arteries ; e, superior mesen-
teric ; d, d, common iiiacs ; e, the single umbilical
artery ; f, vena cava.

Mende even observed in a very well formed
child absence of one of the umbilical arteries,
together with an unusual course of the umbi-
lical vein, which, instead of communicating
with the vena porta;, opened immediately into
the right auricle of the heart.

7. Increased number of the vessels of the
cord. — A double umbilical vein is constantly
to be found in the Quadrumana of the New
World (Rudolphi). In Man the unusual
plurality of the umbilical vessels is but ap-
parent, as it is produced by the persistence of
the vasa omphalo-mesenterica.

8. Persistence of the umbilical vesicle, is a
natural condition in the Ouistiti (Rudolphi),
and occurs as a deviation in Man. Sometimes
it is only its duct that remains united with
the small intestine, forming what we call a
diverticulum.

9. Constriction of the umbilical cord occurs
at the point where the cord penetrates into
the abdomen. In the constricted part the
vessels, although remarkably narrowed, still
allow in some measure the circulation of the
blood. The cord is thereby contorted into a
spiral. The death of the foetus is its usual
effect (Landsberger). Fig. 147. of the second
volume of this Cyclopaedia gives a represent-
ation of this constriction of the umbilical
cord.

10. The umbilical cord too thick. — Its dia-
meter varies from 1J — 2£ inches. This is,
in general, the consequence of an uncommon
accumulation of the Whartonian gelatine, or
of an cedematous conditon. In one of the

recorded cases, the superior extremities were
wanting, and the anus was closed. In other
cases it is occasioned by an enormous quan-
tity of the liquor amnii, which is usually
accompanied with an abnormal developement
or impeded grow th of the foetus.

Malformations of the Foetus.

It is impossible to give in a concise article,
such as is suited to a cyclopaedia, a complete
description of all the various malformations of
the foetus. I must refer to my manual,
published in Dutch, under the title De mens-
chelyke Vrucht beschouwd in hare regelmatige
en onregelmatige ontwi/ckeling, Amsterdam,
1840 en 1842, and to my Tabulae ad illustran-
dam Embryo -ge?iesin Hominis et Mammalium,
where a more fidl and accurate description
of the various kinds of malformations of the
feetus is to be found. I can give here only a
short description of the principal groups, as
an introduction to the doctrine of the malfor-
mations of the foetus.

A. Monstrosities produced by an
Arrest of Developement.

I. Non-closure of the anterior Part of the
Body.

Embryogenesis teaches us, that the tho-
racic and abdominal cavities are originally
open, and close themselves by degrees at a
later period of uterine life. The late ossifica-
tion of the sternum and of the pubic bones is
the result of this original disposition. The
points of ossification are not formed in the
broad cartilaginous basis of the sternum be-
fore the fourth or fifth month of pregnancy ;
they are in the beginning widely separated
from each other by broad intervals in the
middle, and approach later to fuse into one
central osseous piece. This mode of formation
explains some of the original malformations
of the sternum; namely, its abnormal breadth,
the openings which are found in it, and its
separation into two parts. These two last
conditions denote, that the sternum is the
compound of two lateral halves fused together
(Rathke). The separation of the sternum
into two parts usually accompanies ectopia of
the thoracic and abdominal viscera.

Sometimes, although the thoracic viscera
are enclosed in their cavity, the original divi-
sion of the sternum remains, and is covered
up by the skin (Ficker, Serres, Winslow). In
some rare cases, the whole or the largest part
of the sternum is absent in individuals with no
other deformity (Von Ammon). In most of
these cases the manubrium alone is present
(Wiedemann). In some, but very rare, cases
the anterior wall of the thoracic and abdomi-
nal cavity is only closed by the skin, and its
osseous and fleshy parts are completely defi-
cient (R. G. Mayne). The linea alba is, as
well as the sternum, the cicatrix of a cleft
existing at an earlier period. This explains
its abnormal breadth, obvious in those cases
in which the wall of the abdomen has been

TERATOLOGY.

closed at a later period than usual. An ex-
ample of it is given in my Tabula XXIV.
jig. 4. Sometimes the muscles of the anterior
abdominal wall are wanting, in which case the
convolutions of the intestines may be seen and
felt through the skin (Von Ammon). The
thoracic and abdominal cavities being open
in the first periods of embryogenesis, if this
condition persists abnormally, it produces
ectopia of the thoracic and abdominal viscera.
The aperture through which the ectopia takes
place has a constant tendency to close ; it
shrinks therefore sometimes to a very small
opening (Hammer). Sometimes it is closed
in the middle, by a band which separates the
uncovered viscera into two portions (Hiihner,
Wolff).

Its principal forms are : —

1. Fissure of the whole anterior Wall of the
Body.

a. Complete ectopia of the thoracic and abdo-
minal viscera, which lie bare upon the anterior
surface of the body, to which is generally
added a cloaca. {Fig. 600.)

Fig. COO.

Child with ectopia viscerum.

a, liver ; b, heart ; c, c, lung ; d, stomach ; e, spleen ;
fif, intestinal canal ; g, kidney ; h, chorion ; i, am-
nion ; k, umbilical cord ; m, placenta.

The skeleton is very imperfect, in this com-
plete ectopia ; the thorax open, and the ver-
tebral column misformed by scoliosis. — This
may produce, as often met with in calves, a
complete inversion of the body, so that
through distortion of the spine, the head is

919

placed between the hind feet. This is what
Guilt calls sehistozomus rejlexus, and what I
represent in jig. 601.

Fig. 601.

Sehistozomus reflexus (Gurlt).

2. Fissure of the Thorax.

Ectopia of the heart. — In the regular evo-
lution of the foetus, the opening on the
anterior wall of the body closes itself, first at
its superior part, so as to cover the thoracic
viscera, while a part of the abdominal intes-
tines still remain out of their cavity and in
the sheath of the umbilical cord. Thus the
thoracic cavity is in general already closed,
whilst the abdominal is yet open. Neverthe-
less, it sometimes happens that the abdominal
cavity is completed, and that its viscera are
perfectly enclosed, whilst the thorax remains
open, and the heart is placed on its anterior
surface. In this malformation, called ectopia
cordis, the heart has no pericardium, and is
situated on the median line of the anterior
wall of the thorax ; it is more or less rounded,
and in general well formed, as may be seen in
jig. 595. The sternum is wanting (Tournelle,
Norand, Sandifort) ; divided into two parts
(Buttner, Martinez) ; or formed only by the
manubrium (Manchardt). It is rarely com-
plete ; but this is often the case when the
heart protrudes at the neck (Muse, Bubon-
nais, Breschet), or in the epigastric region
(Wilson).

During foetal life, the ectopia of the heart
is immaterial, but soon after birth it causes
the death of the child. Cruveilhier published
some interesting observations on the move-
ments of the heart in a case in which life was
protracted for a longer time than usual.*

* British and Foreign Review', No. XXVI.
October, 1841* p. 533.

3 ? 3

950

TERATOLOGY.

3. Fissure of the anterior abdominal Wall.

a. Complete ectopia of the abdominal viscera,

■ — The abdominal cavity is in general the last
closed. When it alone remains open, the
abdominal viscera only lie out of the body.
The fissure is mostly extended from the ensi-
form process of the sternum to the pubic
bones. One of the umbilical arteries is in ge-
neral wanting. Commonly this malformation is
complicated with adhesion of the membranes
of the ovu.m or of the placenta to the divided
integuments of the abdomen, with a cloaca,
with defective generative or uropoietic organs,
and with an incomplete pubic articulation.

b. Congenital umbilical hernia. — In a less
degree of deformity, the fissure is limited to
the epigastric region, above the insertion of
the umbilical cord, because this part of the
abdomen remains longest open. This gives
origin to congenital umbilical hernia. — The
umbilical cord passes under the viscera, which
lie exposed, or are only covered by the peri-
toneum. In the last case a sort of hernial
sac is formed, which has a cylindrical or glo-
bular form, and is produced by the two coats
of the ovum.

The external coat is that part of the amnion
which is the covering of the umbilical cord;
the internal, the peritoneum, which is con-
sidered by Meckel as a continuation of the
chorion from the umbilical cord. All these
facts [trove that congenital umbilical hernia is
caused by an arrest of developement at that
stage, in which a part of the abdominal viscera
are contained in the sheath of the umbilical cord.
The size of the tumor is variously modified
by the number and by the volume of the
viscera contained in it. When it contains
the liver, it is of a bluish colour. The viscera
lying in it, are always in an imperfect con-
dition. Only four cases are known, in which
the life of the malformed child lasted for any
time after birth (Meckel, Cruveilhier, Ilibke,
Van der Voort) ; in the case of Van der
Voort for eight, in that of Ilibke for twelve
months. In all these cases the external coat
of the hernial sac has mortified, and the tu-
mor has become gradually covered by the skin.
An accurate diagnosis of this malformation is
of great value. In two cases, in which it was
rot accurately recognised, a ligature was put
round the tumor, and it was cut off’. One of
these cases was the subject of an interesting
law proceeding.

c. Congenital ventral hernia. — The abdo-
minal cavity may also remain open, below the
umbilical cord (Fried, Hasenest, Bouchard).
This produces congenital ventral hernia. The
viscera lie exposed, or are covered by the
peritoneum.

d. Acquired umbilical hernia. — Hernia in the
umbilical cicatrix ought to be distinguished
from all these forms of ectopia. It is not
a congenital deformity, but is produced after
birth by an expansion of the umbilical cicatrix
to a globular, a cylindrical, or a conical tumor.
It is often observed in adults. If we adopt
for these the name of acquired, and for those

of new-born children that of congenital hernia,
it would be better to give to the true con-
genital umbilical hernia the name of hernia
funiculi umbilicalis (Seiler).

4. Fissure of the pubic and hypogastric Regions.

It sometimes happens that the pubic region
alone remains open. For a correct idea of the
malformations produced by it, it should be
borne in mind that in the Mammalia, and, as re-
cent observations teach, also in Man (Bischoff,
Wagner, A. Thompson, Coste, Sevres, Ar-
nold), the urinary bladder is formed by the
allantois. This is originally in communication
with the inferior part of the intestinal canal,
so as to form for both a common outlet, called
a cloaca, from which are evolved at a later
period the peripheral openings of the in-
testinal tube, and of the uropoietic and ge-
nerative organs. The pubic bones are formed
later than the iliac (Meckel) and the pre-
viously existing ischiatic bones. Their forma-
tion proceeds from the outside to the inside ;
therefore they are at first separated from each
other by a large interval, and subsequently ap-
proach each other, in a gradual manner, for the
formation of an amphiarthrosis. The foetus may
be arrested at this period of incomplete pubic
articulation. In an observation of Walter,
there was a fissure in the pubic region, though
the genital and uropoietic organs were not
malformed. This is the normal condition of
some mammalia, and of the majority of birds.
An arrest of developement may also take
place at the period when there exists a fusion
between the rectum and the allantois. Of
this various forms occur.

a. Formation of a cloaca. — A cloaca is said to
exist, when the generative and urinary organs
and the rectum have a common outlet. This
is often complicated with ectopia of the tho-
racic and abdominal viscera. The cloaca may
also exist alone. In its highest degree, the
ureters, the imperfect organs of generation,
and the opening of the rectum, are situated
close to each other in a circular depression
(Petit). In other cases, which approach
more to the natural condition, there is a
primordial urinary bladder, formed of two se-
parate parts (Mery), or merely constituted
by its bare posterior wall. Fig. 602. shows
how the fissured urinary bladder may be
complicated with the formation of a cloaca.

In most of the cases which I have pub-
lished, the opening through which the faeces
are evacuated, is formed by the ileum, and
the rectum is closed or wanting. This con-
firms the original formation of the intestinal
tube by a mouth- and anus-gut. In a case men-
tioned by Jung these two portions are quite
separate, and have each its separate open-
ing on the prolapsed posterior wall of the
urinary bladder. When these two openings
are fused, the cloaca persists, but approaches
more to the natural condition. This may take
place in different ways: — 1. The orifices of the
ureters only may be found on the posterior
wall of the bladder, or in the so-called in-
verted bladder, while the rectum still coheres

TERATOLOGY.

951

with the genital organs, just as in the cases
of imperforate anus just mentioned (Meckel,
Burns), or with an open anus, as in the cases
of Zhryham, Oliver, and Bonnet; this condi-
tion approaches the nearest to the natural state,

Fig. 602.

Hypogastric region o f a Child, which lived twenty-two
days , with vesica inversa, 8fc.

a, a, congenital umbilical hernia ; b, umbilical cord ;
c, c, the separated halves of the vesica urinaria,
with the urethral orifices ; d, anus ; e, e, penis epi-
spadiacus ; f frenulum ; g, cutaneous appendage
to the closed anus.

if the urinary bladder is complete (Martin) ;
2. The rectum may be separate, while the uri-
nary bladder remains fissured and fused with
the genital organs (Meckel, Gross); 3. The
fissured urinary bladder maybe separated from
the anus, without taking up the ureters, which
then open themselves into the rectum (Meckel,
Oberteuffer). In some cases the outlets of
these three apparatus are found not on a flat
surface, but in a cavity. The cloaca, existing
previously on the surface of the body, is then
removed from it and folded in, so as to form
a cavity.

In another degree of malformation the cavity
is formed, and the uropoietic and generative
organs are completely separated from each
other; but the rectum, being a distinct organ,
is nevertheless in connection with one of the
said parts, by means of a sort of canal. In
the female sex this communication is found
between the rectum and vagina (fistula ani
vaginalis congenita ) ; in the male sex between
the rectum and urinary bladder (fistula ani
vesicalis congenita'). The transition towards
the natural state is nearest when the rectum
opens into the urethra ; to this condition,
when it is complicated with an imperforate
anus, Papendorp has given the name of atresia
ani urethralis.

b. Congenital fissure of the urinary bladder. —
Without a cloaca, and with a perforate anus,
the interior surface of the posterior part of
the bladder may lie exposed on the hypogas-
tric region (prolapsus, inversio, fissio vesica:).

It then forms a red, spongy tumor, situated
somewhat above the separated pubic bones,
and involving the umbilicus, so as to give
the appearance of a deficiency of the um-
bilical cicatrix. In male children the ori-
fices of the vasa deferentia are to be found
on the inferior part of the tumor. The ure-
thral orifices are papillary eminences on the
naked internal surface of the bladder. The
urine drops continually out of them, but may
sometimes be seen to issue in a small stream.
The pubic bones are widely apart, sometimes
with an interspace of four inches. They have
no intermediate cartilage, but are merely
united together by a ligament, without form-
ing a synchondrosis. The consequence of
this is a very peculiar reeling in the walk of
the malformed subject, and a great disposition
to inguinal hernia, due to the absence of suf-
ficient support at the interior surface of the
body. The penis is fissured on its superior
surface (epispadias). The testes are, even in
adults, very small, and often retained in the
abdomen or in the inguinal canals. The
seminal vesicles, the prostate and the vasa
deferentia, offer various deviations. In the
female sex the labia majora and minora are
separated and without a commissure at their
upper part. The vagina is often closed or
very narrow. The anus is more protruded
than in the natural condition.

Sometimes the penis is epispadiac, with
a well-formed urinary bladder. In such a
case, Bonn found, nevertheless, the pubic
bones apart, but united by a ligamentous
texture. Although the continual dropping of
the urine is a very annoying disturbance,
which I contrived to remove by the means
illustrated in figs. 603 and 604 , and although
the generative organs are very incomplete,
this malformation is not dangerous to life,
which in several cases has been remarkably
protracted.

Fig. 603.

Hypogastric Region of a living Child, with vesica
inversa.

a, internal surface of the urinary bladder ; b, um-
bilical cicatrix ; c, c, urethral orifices ; d, epispa-
diac penis ; f, e, scrotum.

3 p 4

952

TERATOLOGY.

Fig. 604.

The same Region armed with an Apparatus for the
reception and evacuation of Urine.

c. Ectopia vesicce urinaria;. — The smallest
degree of deformity is when the urinary blad-
der remains intact, but lies in an opening in
the wall of the hypogastric region. It is ecto-
pia vesicce urinaria;, of which a representation
is given in fig. 605.; and for more details I
refer to my “ Tabulae ad illustrandum embryo-
genesin,"’ etc., Tab. xxx.

Fig. 605.

Hypogastric Region of a Child, which lived six years,
with ectopia vesicce urinarice.
a, part of the bladder lying on the surface of the ab-
domen; b, umbilical cicatrix ; c, penis; d,d, pre-
puce; h, urethral orifice; f, scrotum; g,g, testes,
lying at the inguinal region.

d. Inversio vesicce uninarice. Prolapsus ve-
sicce urinaria; inversce. — If the urachus re-
mains open after birth, the urinary bladder
may be expelled, anil thereby inverted through
it. R. Froriep ( Chirurg. Kupfertafeln, Heft 67.
Taf. cccxl.) has given an example of this
malformation. It ought to be distinguished
from the inversion of the bladder through the
urethra, which is possible even in adult women
( Voigtel).

If we take a general survey of all these cases
of non-closure of the hypogastric region, it

is evident that they are intimately connected
with one another.

The cloacal disposition is the highest, the
ectopia of the urinary bladder the lowest, de-
gree of malformation, and therefore the latter
is a distinct transition towards the natural con-
dition. The inversion of the urinary bladder
observed by Froriep has, as to its origin, no
direct relation to the other forms. It is but an
accidental effect of the remaining open of the
urachus, through which the bladder chanced
to become inverted, and the urine flowed away
through the urethra if the child was held up-
right. From the gradual transition of one form
into the other, I conclude that the origin of
this malformation cannot well be attributed to
a mechanical cause, as Duncan and Bonn
have asserted nearly at the same time. They
both consider it the effect of a preternatural
accumulation of urine, causing a violent dis-
tension, and later a rupture of the bladder, of
the urethra, of the hypogastric region, and
of the pubic articulation. This theory had
already, in the year 1816, a very strong oppo-
nent in my father (Verb. d. lc kl. van het
Koninkl. Nederl. Instit. D. II. B. 88). Ilis
chief arguments against it, to which I add
my own, are :

1. That, if the urinary bladder bursts, as may
happen in adults, the urine will be evacuated
into the abdominal cavity, without Assuring the
anterior wall. 2. That it is improbable that
in some cases such an accumulation should
fissure the whole apparatus, and in others re-
strict its effect to the corpora cavernosa,
penis, and the urethra, as may be seen in
simple epispadias (W. Vrolik, Bosson, Sals-
niann, Morgagni, and Oberteuffer). 3. That
by an observation of Baillie is proved, that in
fissureof the urinary bladder the posterior part
of the urethra may remain intact and closed,
while the corpora cavernosa are fissured at
the anterior part of the penis. 4. That I have
often found in the feetus atresia urethree com-
plicated with an unusual expansion of the
urinary bladder and of the ureters, but with-
out the least sign of bursting or of producing
the malformation in question. 5. That ectopia
of the urinary bladder demonstrates that the
anterior wall of the abdomen may be open, the
urinary bladder remaining intact ; or the sup-
posed effect may exist, when the cause is
absent. From all these and other remarks
and observations I conclude that the origin
of this malformation is not to he found in a
mechanical cause, neither internal nor external
(Roose). I am much more inclined to ascribe
all its different forms to arrest of develope-
ment. My chief grounds for this opinion are
the frequent coexistence of: — 1. The want
of arterice hypogastricce (G. Vrolik); 2. Ab-
normal condition of the kidneys and the ure-
ters (Pinel, Cooper, Isenflamm); 3. Fis-
sured dorsal vertebra (Littre, Revolat, Delfin,
G. Vrolik) ; and many other malformations, as
labium leporinum (Dupuytren, Meckel), con-
fluent toes (Saxtorph). The only question
which remains is, what is the cause of this
imperfect developement ? As to the cloacal

TERATOLOGY. 953

formation, it is certain that it may he said
to be an arrest at an earlier period of evolu-
tion ; but this is not certain with regard to
the vesica Jissa. The origin of this can only
be explained by an imperfect developement of
the urinary bladder from the allantois. It is
not improbable, as my drawing of the cloacal
formation shows also, that the urinary bladder
is formed by two half-parts, which approach
each other anteriorly and posteriorly on the
mesial line. If this junction does not occur,
the different forms of vesica inversa will be
formed. Atresia ani is, in the cloacal dis-
position, without doubt, an arrest of deve-
lopement at an early period of embryoge-
nesis ; for previously the anus is closed. And
epispadias shows that the penis is formed
by two parts, which may remain separated
from each other on the superior surface. Con-
sequently it appears, that the name of vesica
inversa is as improper as that of vesica Jissa.
But I shall propose no other name, because
we know sufficiently the meaning of it.

5. Cervical Fissure ( Fistula colli congenita).

Recent observations teach us that the ori-
ginal branchial fissures may persist in the
neck even in adults. Hyrtl mentioned this
malformation in a man of twenty, in whom the
external cervical opening was small and com-
municated with the pharynx close to the epi-
glottis. Among 34,000 young men, Riecke
found a fistula colli congenita twice.

6. Fissure of the Face.

In order to obtain a correct notion of
the different forms under which fissure of
the face may occur, it will be necessary to
know the gradual metamorphoses of the face
during its developement. Originally there
is a common oral and nasal cavity. The place
of the nose is occupied by two fissures, which
extend from the internal angles of the eyes
to the superior margin of the oral cavity.
There is at this period not the least indication
of a palate, so that the mouth and the nose
form one common cavity. In a human foetus
of less than an inchin length, Meckel found
the first rudiment of a palate, in the form
of an arc or a horse-shoe shape. On each
side this are is gradually completed, so as to
be at first open at its posterior part, but closed
afterwards, and forming a complete trans-
verse plate, separating the nasal from the oral
cavity. Rathke examined this more in de-
tail, in foetuses of the sheep : —

1. He learned that the supermaxillary ca-
vity is formed on each side from the lateral
wails of the cranium.

2. That between those two parts grows
out of the frontal wall of the skull a third
eminence, which forms the basis for the sep-
tum of the nose, that is, for the formation of
the vomer, of the septum of the ethmoid bone,
and of the intermaxillary bones.

3. That the two p?rts, quoted under No. ].,
are bent inwards, and coalesce with the mesial
part.

4. That the nasal cavity is at first a groove,

and has originally a form which persists
through their whole life in fishes.

5. That the oral and the nasal cavity form
originally a common cavity.

6. That the palate is originally a fissure.
By arrest of developement in these different
stages of embryogenesis, are formed the dif-
ferent species of facial fissure.

a. Complete fissure of the face. — The high-
est degree of malformation is, when the fissure
is extended from the angle of the mouth to
the internal angle of the eye, the orbits, the
nose, and the mouth forming but one cavity.
J. S. Meckel, Van Doeveren, and myself have
published examples of this malformation com-
plicated with acrania. The fissure sometimes
extends only over one lateral part of the face
(Leuckart), and in the greatest transition to
the natural condition it is but a shallow groove,
as is represented in Jig. 596.

A fissure sometimes extends in a transverse
direction over the head. C. Meyer observed
this twice in new-born sheep. In both the
palate had a double fissure, and the normal
opening of the mouth reached as far as the ear,
which in one of these lambs presented a trans-
verse fissure.

b. Double labium leporinum. — A transition
to the normal condition, yet a very imper-
fect one, is when the fissure is not extended
over the whole surface of the face, but is re-
stricted to the upper jaw. The highest de-
gree of deformity is double hare-lip ivith fissured
palate ( Labium leporinum duplex cum palato
Jisso). On each side of the upper lip a fis-
sure extends from the angles of the mouth
to the alee nasi. Between these is a protube-
rant tubercle, covered by a separate part of the
upper lip, and consequently by the external skin
and the gums. The tubercle is connected
with the septum of the nose, generally
obliquely distorted, and is filled up with the
germs of the incisors. By the confusion ot
the oral and nasal cavities, the true nasal ori-
fices are wanting, the osseous palate is defec-
tive, the soft palate and the uvula are fissured,
and the vomer united anteriorly with the pro-
tuberance, hangs in the midst of the fissure.
In a lesser degree of malformation, the alveolar
margin of the upper jaw is alone fissured, and
in the least degree the palate is complete.

c. Single hare-lip. — This name is adopted
for the malformation when it is limited to one
lateral part of the face. It may be complicated
with fissured palate. The lip is then, on one
side, fissured to the nostril, so as to form there
an immediate communication between the
oral and nasal cavity. The direction of the
fissure is seldom accurately in the mesial line.
If this occurs, it is the result of defective in-
termaxillary bones. The palate offers either a
simple or a double fissure. In a less degree
of malformation only the alveolar ridge is cleft,
and, in the least, the palate is complete. In
such a case the fissure of the upper lip is
merely a small incision.

d . Fissure of the palate without a hare-lip.
— The alveolar margin is in this case quite
complete, but the palatine and the supermaxil-

954

TERATOLOGY.

lary bones are largely separated from each
other posteriorly, so as to form a fissure, more
or less extensive, of the bony and of the soft
palate. Sometimes there is only a fissure of
the uvula (Yon Ammon). The nearest ap-
proach to the natural state is, when the planes
of the palatine bones form with each other an
acute angle rising high upwards in the nasal
cavity (Himly, W. Vrolik). In some cases,
the palate is fissured at its anterior part, close
to the foramen pa/atinum anticum (Jiiatus fora-
minis palatini antici, Von Ammon). En re-
sume, it appears that fissure of the palate and
hare-lip are independent of each other. But
it may happen that, originally, the fissure of
the palate coexists with the hare-lip and closes
itself later. The indentation which is ob-
served in hare-lip without fissure of the palate,
between the external incisive and the canine
tooth, makes it probable that nature proceeds
in this manner. It is also not improbable that
hare-lip may sometimes be cured spontane-
ously in the womb. The gradual transition of
the various forms of this malformation into each
other, shows that its cause is not external and
accidental, and that it is produced, neither by
blows which the child inflicts upon itself with
its fists (Jourdain), nor by a mechanical im-
pediment preventing the union of the palatine
laminae (Pinnder). Complete fissure of the
face and the palate is rather to be considered
as an arrest of developement at an early
period of formation. Hare-lip conforms with
the foetal condition in that period of develope-
ment which I have called the third. If the
original intermediate protuberance does not
unite itself with the lateral parts, double hare-
lip is formed. The protuberance obvious in
it is formed by the intermaxillary bone either
in its totality, or only by a part of it. If
it unites itself with only one lateral part,
single hare-lip is formed. The intermaxillary
bone is composed of four separate parts, of
which each contains an alveolus. The result
of this is, that each of these parts may be
united, separately, with the supermaxillary
bones ; which fact explains clearly why only
three or two incisive teeth are sometimes to
be found in the protuberance. The fissure
of the upper lip sometimes occupies the mesial
line, passing through the middle of the inter-
maxillary bone. This is also the case when the
intermaxillary bone is wanting.

In this way, all the various forms of fis-
sure of the face can be reduced to an arrest
of developement, which explains in the mean-
time the constant tendency of the fissure to
close itself, as may be observed in children
having this malformation. Fissure of the palate
and lip does not endanger the life of children,
and union of the separated parts in hare-lip
and cleft palate can be obtained by a surgical
operation.

e. Fissure of the under lip. — The under lip
is very seldom cleft (J. F. Meckel, Von
Ammon, Nicati, Bonisson). It is equally
rare for the under jaw to remain after birth
separated into two parts.

II. Fissure of the Skull ( Acrania ).

Many forms of this monstrosity are known,
to which different names have been given, as
acephalia spuria, microcephalia, anencephalia,
hemicephalia. But, for its shortness and ety-
mological sense, I prefer the name of acrania,
which was introduced by J. F. Meckel. Un-
der this name I comprehend all the different
forms in which this malformation occurs, and
also, with Himly, the hernia cerebri. Accord-
ing to my opinion, the division into different
families and genera, and the nomenclature of
J. Geoffroy St. Hilaire, ought to be rejected.
I, for my part, am always inclined to simplify
science as much as possible, and to be succinct
in its exposition; and I propose, therefore, the
following types.

First Type. — Want of the brain, and ex-
posure of the ivhole basis of the skull. — The
superior surface of the cranium is flat, and not
formed by the bones of the skull, but only by
a membrane, of which the margin is very un-
equal, hard, and formed by bones. The
external integuments extend over this margin,
and terminate there in an unequal line,
which is distinctly circumscribed by the thick
hair of the head. With this cutaneous border
is connected the slightly vaulted membrane, of
a red, somewhat bloody colour, which imme-
diately covers the periosteum that invests the
more or less convex surface of the basis of the
skull. The brain is wanting, but the central
terminations of the cerebral nerves are in most
cases present, yet sometimes these also are
wanting (J. F. Meckel). The forehead is flat,
and directed forwards in an oblique direction.
The eyes protrude on its anterior or orbital
margin, covered with swollen superior eyelids,
and directed more or less upwards. The face
is flat, and nearly horizontal ; the upper, and
still more so the under jaw are comparatively
longer than those of a well-formed subject ;
the tongue is in general prominent, because
the mouth cannot be shut on account of the

Fig. 006.

TERATOLOGY.

955

length of the under jaw. These distortions
give to such monstrosities a certain brute-like
aspect which induced the Germans to call them
Katzenlcopfe and the French teles de crapaud.
If the cervical part of the spinal column is in
the meantime cleft, the cervix is so shortened,
that the head seems to be fixed on the shoul-
ders, and the chin rests on the breast, as is
represented in fig. 606.

The malformation of the bones of the skull
and of the face is very great ; but as its de-
scription would take too much room here, I
refer the reader to my handbook and my plates,
and also to fig. 607., which will give a clear
idea of it.

Fig. 607.

Shill of a new born Child with Acrania.

a, a, frontals ; b, nasals ; e, c, very convex zygoma-
tic bones ; d, small ensiform processes ; e, sella
turcica ; f, f ate majores ossis sphenoidei ; g, g,
petrous bones; h, basal part of the sphenoid
bone; i, i, condyloid parts of the occipital bone;

l, l, depressed squamous parts of the occipital bone ;

m, small osseous laminae, representing the parietal
bones.

Second Type. — The denuded surface of the
basis cranii occupied bp a spongy substance,
instead of brain. — In most cases vesicles,
filled with a serous liquor, were observed to
occur in this spongy substance, and with
these occasionally also medullary corpuscles,
which may be considered as rudiments of
brain. There is sometimes a rudiment of
the cerebellum, together with a rudiment which
is continued into the spinal medulla, as though
it were a medulla oblongata. The cerebral
nerves are sometimes quite separated from,
sometimes united with, the spongy substance.
Sometimes they have the form of complete
or lacerated bags, which extend along the
superior surface of the skull and the posterior
surface of the spinal column. The spinal co-

lumn is either perfect, or partially, and some-
times entirely, cleft. The last of these con-
ditions is represented in fig. 608.

Fig. 608.

To this form of monstrosity Geoffroy St.
Hilaire gives the name of anencephalus. Spe-
cimens of it were found amongst the Egvptian
mummies in the sacred sepulchres of the Cy-
nocephali and Ibis, which is a very interesting
fact as regards monstrous births in those
times.

Third Type. — The surface of the basis
cranii only partially denuded, — a spongy
tumour occupying the place of the brain. The
skull may be closed at its posterior part,
and remain open at its summit. A more
or less malformed cerebral substance appears
on the summit of the skull, just as if it were

Fig. 609.

Section of the Head of a Child with Acrania, to show
the union of the malformed brain with the spinal
cord.

a, b, cellular sacs, taking the place of the brain ; c,
occipital bone ; d, spinal cord.

956

TERATOLOGY.

a hernia. The parietal bones are sometimes
present, together with flat frontal bones, and
a perpendicular occipital bone, so that the
summit of the skull is quite closed, with the
exception of a small opening. Fig. 609.
shows how the malformed cerebral substance
is applied to the medulla spinalis. All the
cerebral nerves are present.

This form of monstrosity has in general a
less brute-like aspect ; the trunk is more
evolved, and the whole body in general very
heavy.

Fourth Type. — The skull flat , more evolved,
but having an opening, through which the brain
protrudes as a hernia. — This is what we call a
cerebral hernia ( hernia cerebri, encephalocele) ,
viz. a tumour covered with the external integu-
ments arising from some part of the surface
of the skull, and containing a part of the
brain. It has commonly the form of a bag,
appended to the posterior part of the skull,
and resting on the neck. The head is never
turned with the face upwards ; the ears do
not rest on the shoulders ; the neck is not
wanting. The summit of the skull is flat and
closed, and its cavity is too small to include
the brain, which for this reason is placed on
its outside, and backwards. The occipital
bone has the form of a vertebral arc, which
surrounds the brain, lying at the outside.
Fig. 610. shows the external appearance of

Fig. 610.

this monstrosity, fig. 611. the structure of
the skull.

Fig. 611.

In many of the published observations, a
collection of serous fluid accompanied the
hernia cerebri, by which a hydro-encephalocele
was formed.

The situation of the cerebral hernia is
in general on the occiput, but sometimes
on both sides of the root of the nose ( VV.
Lyon, Kelch) ; above the eye (Adams); on
the forehead (Beclard, Saxtorph, Niemeyen,
Bredon, Guyenot) ; on the fontanella magna
(Held) ; in the parietal bone (Le Dran, Stein,
Tren) ; on the glabella, between the orbits
(Otto).

On a survey of these various types, it ap-
pears that they all belong to the same class of
monstrosities. The nature of the malform-
ation is in all the same, namely a defective de-
velopement of the skull and of the brain.
This takes place in different degrees, so as
to convey us gradually from the complete
want of brain to those cases in which it is
nearly perfect, and differing from the natural
condition only in situation. The constancy
of form is very interesting in this monstrosity,
so that the malformed children resemble each
other nearly in every museum, and the pub-
lished observations are quite accordant with
the cases now occasionally occurring. This
proves that the origin of the malformation
cannot be accidental. The want of the neck,
which is the reason why the ears rest on the
shoulders and the chin on the breast, and which
gives to this form of monstrosity such a pecu-
liar character, is often the consequence of the
want of some of the cervical vertebrae (Rathke,
Haller, Otto), or of their mutual coalition
(Rathke, W. Vrolik), or of their shortness
(Sandifort.) As a transition to the brute
form, this shortness of the neck is interest-
ing, reminding us of the condition of the
Cetacea. The prominence of the eyes is oc-
casioned by the flatness of the orbits, and
by the backward direction of their superior
margin. It differs from the manner in which
the eyes are prominent in children with internal
hydrocephalus. A rich growth of hair is
common to all the forms of acrania. Is
not this, and likewise the abundance of
areolar tissue, to be attributed to a vicarious
nutritive function ? The frequent absence
of the suprarenal glands (Otto), or at least
their imperfection and smallness (Morgagni,
Hewson, F. Meckel, Soemmering, W. Vrolik)
in all acranial foetuses is remarkable. The
capacity for persistent life after birth differs
according to the different forms of this
monstrosity. Acrania does not seem to in-
terfere with uterine life. The children who
are affected with it are all well nourished, and
some of them even very large, at the moment
of their birth. Nevertheless, they rarely live
longer than a few hours. During this short
life they offer some symptoms which are
attributable to the reflex action of the
nervous system ; such as, for instance, mus-
cular contractions when the skin is touched,
rejection by the mouth of the recently ex-
pressed juice of Pelargonium tomentosum, and
the attempt to suck a finger introduced into

TERATOLOGY.

957

the mouth. In cerebral hernia the chance
for the prolongation of life is greater. Some
cases are known in which life lasted 20,
30, and even 60 years. When complicated
with hydrocephalus, puncture has sometimes
been instituted, but without success (Earle).
Extirpation produced, in another case, in-
stantaneous death.

What are the causes of acrania ? From
some of its forms, it is clear that there has
been hydrocephalus followed by disruption
(Morgagni, Penada, Sandifort, Klein, Otto).
In an embryo figured by M. Schroeder Van
der Kolk, the summit of the head is extended
by hydrocephalus, and has on its superior
surface a black gangrenous spot which seems
to prognosticate a rupture.

In another foetus I observed a fissure in
the midst of an analogous spot. According
to my opinion, the lacerated bags, which are
sometimes found on or in the summit of the
naked internal surface of the basis cranii, or
at the back part of the more developed skull,
are caused by such ruptures. Tiedemann
gives a description of such a bag, filled with
serous fluid, but not yet burst, and situated
upon the head of a foetus, which has the ex-
ternal appearance of acrania. {Fig. 612.)

Fig. 612.

But in those cases in which the flat basis
of the skull is only covered with a membrane
and with cerebral nerves, in those in which
there is a spongy substance upon it, and in
those in which the skull, although flat, is
otherwise complete, not the least probability
exists of the rupture of a cerebral vesicle at
an early period of formation. I am able to
prove this, I think, by a small foetus of two
months, in which the superior part of the
skull is wanting, and in which a spongy mass
occupies the place of the brain.

it shows that acrania may also be a pri-
mitive malformation, occasioned by the simul-

taneous malformation of the brain and of the
skull. Why I do not impute these malforma-
tions to external injury, such as the leaping of
a monkey on the belly of a pregnant woman
(Sandifort), to a fall down stairs (Pauli), or
to the influence of imagination, needs not be
demonstrated.

III. Fissure of the Bach Part of the Body.

Hydrorachis and Spina bifda. — Fissure of
the spinal column (spina bifida), and dropsy
of the spinal medulla, occur each separately, or
connected together. In the highest degree
of fissure, the vertebral bodies even are cleft
(J. T. Meckel, Tulp, Fleischmann). Fig. 613.
represents such a case, after Cruveilhier.

Fig. 613.

In a less degree, the vertebral bodies are
complete, but their arcs very defective, being
completely wanting, or laterally incurved and
fused together. In the lowest degree, the two
halves of the vertebral arcs are completed, but
not united together, so that posteriorly an
open space remains between them, and a fis-
sure occupies the place of the processus spinosi,
which are separated into two lateral and
equally incurved parts.

When this form of fissure of the spinal
column is not accompanied by hydrorachis,
both parts of the vertebral arcs are not
bent laterally, but meet each other so ex-
actly, that no open space remains between
them. Sometimes the fissure is extended
over the whole vertebral column (spina bifida
totalis ), sometimes it is but partially cleft
(spina bifida partialis). The partial fissure
occurs more frequently in the lumbar than
in the cervical region of the column. The
cause of the greater frequency of the partial
fissure in the lumbar region is to be im-
puted to the termination of the spinal me-
dulla in this region ; to its expansion there

J

958 TERATOLOGY.

under the form of cauda equina; to the larger
sheath formed there by the dura mater ; and
to the very limited tendency which the osse-
ous nuclei of the lumbar and sacral vertebra
show to unite themselves into an arc, which
therefore remains always open at the inferior
part of the sacrum. Although it occurs some-
times alone, this sort of fissure is generally
accompanied with dropsy of the spinal medulla
( 'hydrorachis ), that is to say, with a sac of a red-
dish-violet colour, in which fluctuation is easily
discerned. Its external covering is sometimes
formed by the skin, and then it has the usual
colour of the body ; the skin, however, does
not in most cases cover the whole surface of
the tumour, hut ceases at its circumference,
and the rest of its surface is only covered with
the dura mater. When the child lives, the
dura mater becomes, after some time, thicker,
harder, and more solid. When the tumour
is covered with the skin, the dura mater is to
be found under it. These membranes become
often so thick, and so intimately united to-
gether, that it is nearly impossible to separate
them from each other. The serum contained
in the tumour is of a very variable quality,
principally composed of albumen, mucus, ge-
latin, and muriate of soda (Bostock). It is
effused between the pia mater and the arach-
noidea, or between this and the dura mater,
or in the primitive canal of the spinal me-
dulla. If this canal remains open, the hydro-
rachis is in general accompanied with hydro-
cephalus interims. Sometimes these sacs are
found on more than one spot of the spinal
medulla, or divided into two by a septum.
The size of the sac varies, and the complication
with hydrocephalus is very dangerous. If this
is the case, the artificial opening of the sac has
a very injurious effect. Convulsions and exu-
dative inflammation are in most of the cases
excited by it. In some very rare cases the
operation was attended with success. Sir
Astley Cooper healed hydrorachis by reiterated
puncturing with a thin needle and by com-
pression of the tumour. Dubourg is said to
have treated it with success by means of ex-
cision of the tumour and bringing together the
lipsof the wound with needles, in the same man-
ner as in the operation for hare-lip. Beynard
tied a ligature round the sac. E. de Thine-
court compressed the tumour, after having
opened it, with two small rods, which he
connected and pulled together by means of
ribbons. The noxious effects of hydrorachis
after the child’s birth make it necessary to
try an operation. Before birth this mal-
formation seems not to have the least in-
fill' nee upon the health of the child : it is
well nourished and duly constituted. After
birth the noxious effect is modified by the
different seat of the tumour. When seated
in the lumbar and sacral region, it is the
least dangerous. It is known that some indi-
viduals have lived with it twenty-eight y ears.
In most cases, however, paralysis of the in-
ferior part of the body is its consequence.
Hydrorachis in the cervical region is much
more dangerous. One case of this is men-

tioned in my “ Tabulae,” in which death sud-
denly occurred on opening the tumour.

Besides hydrorachis, some other malforma-
tions of the spinal medulla are observed some-
times to accompany fissure of the spinal column :

1. Complete want of the spinal medulla, com-
monly connected with acrania ; 2. Its appear-
ance under a cylindrical form, with persistance
of the primitive medullary canal (Morgagni,
Santorini), which is sometimes double (Gall,
Yon Ammon) ; 3. Fissure of the spinal me-
dulla into two juxtaposed cords; so that it
seems to be double, which is occasioned by
an arrest of developement at that period of
its evolution in which the two halves, of which
it is formed, are as yet separate ; 4. The pre-
sence of a simple nervous expansion instead
of spinal medulla; 5. The lamellar form of
the medulla ; 6. A too great length.

By all this it is proved, that fissure of
the spinal column may be accompanied with
hydrorachis, and with an imperfect deve-
lopement of the medulla. They are totally
independent of each other, and each is pro-
duced by its own cause. It is, however, not
very' improbable that a voluminous sac on
the medulla may prevent the union of the
points of ossification, by which the vertebral
arcs are to be formed ; but we are not, I think,
justified in concluding from this that hydro-
rachis is the cause of the fissure of the
vertebral column. For it may exist without
fissure of the spinal column, if it has not
acquired the form of a bag ; and the spinal
column may be cleft although the spinal me-
dulla is intact. This leads me to the con-
clusion, that malformation of the spinal me-
dulla, hydrorachis, and fissured spinal column,
do not essentially go together.

IV. Hydrocephalus congenitus.

Congenital dropsy of the brain. — Under this
name we understand such a great volume of
the head in a full-grown foetus that it opposes
in general a mechanical impediment to partu-
rition, which can only be removed by an arti-
ficial diminution of the volume of the head.
Its forms are — 1. Hydrocephalus interims ;

2. Hydrocephalus externus.

1. Hydrocephalus interims is said to exist
when the abnormal serous secretion occurs in
the ventricles of the brain, wherefore it has
also acquired the very rational name of
hydrops ventriculorum cerebri. It may be an
altogether primitive malformation, when the
brain is arrested at that period of its de-
velopement in which it has the form of a
very thin vesicle, filled with a serous fluid.
I have observed this condition principally
in Cyclopes, and give an example of it in
Jig. 6 1 4.

In such case there is no indication of the
hemispheres, nor of the convolutions of the
brain, and, in general, no difference to be
seen between the white and the grey cerebral
substance. In small foetuses of two months,
in which the bones of the skull could not yet
be discerned, this form of hydrocephalus has

TERATOLOGY.

959

Fig. 614.

Brain of a new-born Lamb with Cyclopia,
a, a, medullary expansion filled -with serous fluid ;
b, optic nerve ; c, c, peduncles of the brain ; d, pons
varolii; e, medulla oblongata; ff cerebellum ;
y, spinal medulla ; 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, the
cerebral nerves, existing besides the optic nerve.

been observed (G. Vrolik, Rudolphi). See
fig. G15.

Fig. 615.

(Altered from Rudolphi by TV. Vrolik.)

Human Ovum, with an Embryo of two months, affected
with hydrocephalus.

Internal hydrocephalus is, however, not
always occasioned by arrest of develope-
ment in an early period of formation, but
may be produced by chronic inflammation,
(G. Vrolik), to which the child is, without
doubt, as much subject during uterine life
as after its birth. The principal causes of it
seem to be external injuries suffered by the
pregnant woman, and sometimes even reite-
rated contact by the act of copulation, if the
pelvis is large, and the womb seated very
low. Pseudo-membranes are on this ac-
count often found on the internal surface of
the expanded ventricles (G. Vrolik), by which
the deposition of the serous liquor may be
limited to one or more of the cerebral ven-
tricles, so as to produce an a-symmetrical
expansion of the head ; this is, on the con-
trary, symmetrical, if both the lateral with
the third and fourth ventricle are equally and
universally extended by the fluid. The head
acquires, in such case, an enormous, but sym-
metrical, volume (E. Sandifort, W. Vrolik).
The slower such a secretion of fluid takes
place, the slower the head increases in volume,
and the less it endangers life, and the less
the free evolution of the mental faculties
is interfered with. Some cases are men-
tioned, in which life lasted sixty years
(G. Vrolik), thirtyyears (Michaelis), and fifty-
four years (Gall). It is remarkable that in many
of these cases, neither the senses nor the
intellectual facidties were in the least im-
paired. This proves that the substance of
the brain is not altered by it, and that the
form only of the brain is changed by the
unfolding of its convolutions. This unfolding
is the consequence of the pressure which
the fluid exercises from the inside towards
the outside, and of the thereby augmented
volume of the ventricles (Hunauld, Gall).
Those who presume that through the influ-
ence of the serum exudated in the ven-
tricles the dissolution and even the total de-
struction of the cerebral substance may be
effected, go evidently too far (Cruveilhier).
However large may be the surface into which
the hemispheres of the brain have been un-
folded, the white medullary substance can
always be distinguished from the grey
(G. Vrolik). The parts contained in the
ventricles are sometimes intact (G. Vrolik),
but sometimes incompletely developed, and
what we should call depressed (Aurivillius,
Biittner, Malacarne, Klein). The corpus
callosum assumes a thin lamellar form; the
septum pellucidum and the fornix become
thinner ; the glandula pituitaria and pinealis
deviate in general from their natural condition
(Friend, Malacarne, Wrisberg). The cerebral
nerves are in general not changed, and the
cerebellum is in most cases natural. The
lumen of the cerebral arteries is commonly
very large (Biittner), and Friend saw two in-
ternal carotids passing through the carotid
canal of the right side. In a few cases there
was observed a degeneration of the cerebral
substance, which resulted in a deranged and
feeble state of the mental faculties (Biittner).

TERATOLOGY.

960

Internal hydrocephalus has always a pre-
judicial influence upon the condition of the
rest of the body, principally upon its nutrition
and upon the osseous system, which it pre-
disposes to emollition. It has a very great
influence on the bones of the skull. Its effects
are : —

a. A large expansion of the skull, whilst
the face preserves its common shape, and is
in great disproportion to the enormous cir-
cumference of the skull. This disproportion
is the most significant symptom of hydroce-
phalus, and distinguishes it from simple am-
plification of the head.

b. A protuberance of the frontal tubero-
sities, which is to be considered as an arrest
at an early period of developement, occasion-
ing an enormous augmentation of the facial
angle, which greatly exceeds a right angle.

c. A pushing downwards of the orbital
parts of the frontal bone, which makes the
superior orbital margins to disappear totally,
and to form a protuberance with the frontal
part of the frontal bone. The eyes thence
acquire a strange direction, their axes being
turned upwards.

d. A-symmetry of the hydrocephalous
head, which is always more or less oblique.
This is the effect of the unequal expansion of
the brain. To this may also be ascribed the
strange form which the skull acquires when
it is regularly extended and developed on its
fore and lateral parts, whilst the occiput has
a very singular prominence. Such a form
is, without doubt, occasioned by a regular
expansion of both the hemispheres of the
brain up- and sidewards, whilst their posterior
lobes and the cerebellum have preserved their
regular form. The parietal bones are thereby
expanded and augmented in circumference,
whilst the occipital bone, not participating in
the expansion, is disproportioned to the rest
of the skull. The parietal bones are removed
from it, so that, during the primitive ossifica-
tion, an interval is formed, which is after-
wards filled up with Wormian ossicles.

Not less singular is the form of the head
and skull, when, probably on account of the
position of the head in the womb (as is the
case in a partus pedibus proeviis), the pressure
of the fluid has been exercised principally
downwards, so as to extend chiefly the lateral
parts of the head.

e. An abnormal disposition of the cranial
bones. The fontanellse acquire, in the first
instance, a very large dimension, and some
parts of the cranial bones remain cartila-
ginous, which parts are, in a more advanced
period, filled up with Wormian ossicles.
Buillie asserts, that sometimes the already
formed sutures are opened by the serum
exuded in hydrocephalus interims. In other
cases, the want of closure of the sutures is to
be imputed to a too great thinness of the
bones.

2. Hydrocephalus extemus is by some (Monro,
Wrisberg, Kartell) erroneously considered as
the result of hydrocephalus interims, followed
by laceration of the cerebral hemispheres.

It is proved, by a great many observations,
that such a laceration occurs very seldom.
The fluid is, in most cases of hydrocephalus
extemus, exuded on the surface of the brain.
This may be the consequence of an arrest of
developement, as I observed in a cyclopic lamb,
but it may also be produced by inflamma-
tion. The serum is accumulated between the
dura mater and the skull, or between the two
layers of the arachnoid membrane, but in
most cases its situation is between the dura
mater and the arachnoid membrane. In all
these cases the brain is strongly compressed,
shrunken, and hard (Kaltschmidt). Dullness
and somnolence are, according to Frank, the
consequences of hydrocephalus extemus, and
convulsive affections those of hydrocephalus
internus.

V. Acepliali, or Foetus without a Head.

When we observe the foetus in its first
periods of developement, the head is not yet
clearly distinct from the trunk. From the
third to the fifth week of gestation, the head,
not previously discernible, grows so rapidly,
that it has in the fourth week acquired the
same volume as the trunk. Now the de-
velopement of the foetus is sometimes arrested
at that early stage when the head is not yet
distinguishable ; the result of such an arrest
must manifestly be an acephalus. This de-
nomination is, again, as erroneous as many
others ; for not only the head, but many
other parts, are wanting. The question re-
mains whether a more appropriate name could
be given. Gurlt tried to do so, but, I fear,
not with good success. He calls the lowest
form of acepliali amorphus globosus, which is a
true contradictio in adjeeto. I think it there-
fore proper to preserve the old name of
acepliali, to which I refer, as has been done
by Tiedemann and G. Vrolik, nine types, for
which I think it not necessary to give special
names.

First Type. — Acepliali in the form of a
rounded mass, without any indication of extre-
mities. — Examples have been given by G.
Vrolik, Bland, and W. Vrolik, all of twins.
The rounded mass is covered with the skin ; it
contains an intestinal fold, and receives the
insertion of the umbilical cord. In general
there is found in it the rudimental indication
of vertebrae and of spinal medulla.

Second Type. — Acepliali in the form of
a rounded mass, with indication of feet. — The
chief observations of this form have been
given by G. Vrolik and Clarke, in cases of
twins. They have an umbilical cord, rudi-
mental external genital parts, and an anal
orifice, with an imperfect abdominal cavity, in
which are contained an intestinal loop formed
by a colon and caecum, and kidneys. Conse-
quently all the thoracic viscera, the liver, the
spleen, pancreas, stomach, and the small in-
testines, are wanting ; but there is a rudiment
of a nervous system, a tolerably complete
right inferior extremity, a pelvis, and a left
separate foot, without femur and crus. {Figs.
GIG, G 17.)

TERATOLOGY.

961

Fig. 616.

Human Aceplialus, born along with a well-formed child.

a, the right foot with five; b, the left, with
three toes ; h, the female genitals ; i, the anus ;
c, tumor formed by the umbilical cord; d, e,fg,
eminences covered by the skin.

Fig. 017.

Hie same Aceplialus with dissection of the skeleton.

a, a, the only obvious inferior dorsal vertebra,
with a pair of ribs ; 1,2, 3, 4, 5, lumbar vertebra; ;
b, sacrum ; c, c, d, iliac bones ; e, femur ; f bones
of the foot.

Third Type. — Acephali in which the trunk
is more developed , without a head and thoracic
or superior extremities, but composed of an in-
complete trunk, ivith an imperfect inferior extre-
mity. — In the lowest grade of this monstrosity
may be ranked an aceplialus observed by
Ruysch, consisting only of a leg. Somewhat
more perfect is the acephalous inferior ex-
tremity of a goat, mentioned by Hayn. It
consisted of a pelvic bone, with the other bones
of the inferior extremity, some muscles, the
vessels and nerves of the femur, which were
probably connected with the umbilical cord
of the perfect goat born at the same time as
the aceplialus.

Fourth Type. — Acephali in which the
trunk is more developed, without a thorax and
without superior limbs, and composed of an ab-
domen, genital organs , and two inferior limbs.
— The hypogastrinm and the two inferior
limbs are, then, more or less completely
formed parts. With exception of one, all

VOL. IV.

the observations which we know of it are ot
twins, and in one case of three children born
at one birth. In many it is proved that the
mother of the aceplialus has been often fecun-
dated. They are rarely full-grown at birth,
and they have in most instances a placenta
common to them and the well-formed child,
but with a separate cord ; the foetal membranes
also appear to he common to both. The cord
of the aceplialus contains sometimes two,
sometimes three or four vessels (T. U. Kalck).
The integuments of the monster, truncated at
its upper part, are irregularly tumified, by a
large quantity of thick, pale, or yellowish
subcutaneous cellular tissue. Interiorly there
are lumbar vertebra, with a pelvis, and the
hones and muscles of inferior limbs, besides
the spinal marrow and its nerves; the lumbar
and sacral parts of the sympathetic nerve ;
blood-vessels without a heart, of which the
arteries are connected with the umbilical ar-
teries, and the veins with the umbilical vein ;
a loop of intestines ; uropoietie, and genital
parts. All the other parts are wanting.

Fifth Type. — Acephali in which the trunk
is much more developed, with an imperfect tho-
rax, composed of some dorsal vertebral and ribs.
Fhe superior limbs are wanting. — The only
difference between this and the preceding
type is in the more complete trunk, there
being a thorax superadded to the abdomen.
In all the other points the structure re-
sembles that of the fourth type ; they are

Fig. 618.

Human Aceplialus born along with a well-formed child,
a, cutaneous fissure in the lower part of the
thorax ; b, umbilical hernia, under which are the
male external genital parts.

3 Q

TERATOLOGY.

The skeleton of the foregoing Acephalus.
a, mobile bone connected with the single cervical
vertebra.

always twins, and not full grown. As far as
it lias been mentioned by different obser-
vers, there is either a common placenta, with
two cords (Ponjol), or with one cord split
into two (Mery) ; or there are two placenta?
connected together (Herholdt); or there
are two totally separate ova, with a double
placenta (Monro). The external appear-
ance differs from that of the fourth type, by
greater length, and less truncated upper part
of the body, in which a feeble indication
of head may sometimes be visible (Ponjol,
Prochaska). The integuments are as in
the fourth type ; the toes are generally mal-
formed ; the arms and the external genital
organs are often abnormal. To the lumbar
part of the spinal column is joined an imper-
fect osseous thorax, sometimes with cervical
vertebrae (Hevermann), but without thoracic
viscera. The diaphragm exists in most cases.
There are vessels without a heart, which
cohere with the umbilical vessels. The viscera
of the epigastric region are commonly want-
ing ; Atkinson mentions only a liver. In some
intestines can be recognised either as intestina
tenuia or crassa. The uropoietic organs, and
the internal parts of generation are commonly
present. There is in all a spinal marrow.
The observations as to the nervous system
are very incomplete. (See Jigs. 618, 619.)

Sixth Type. — Acepliali with a trunk com-
posed of a thorax and an abdomen, and with two
superior and two inferior limbs. — When the
trunk is more developed, the thorax becomes
more convex, is more dEtinct from the abdo-
men. and supports two superior limbs. These
acepliali, too, are twins, at least in the greater
number of the cases. They are often not
full-grown, and borne by women who have
frequently been pregnant. The placenta is in
general common to the two foetuses, but
with two cords. The thorax is more perfect
than in the fifth type ; the upper part of the
body terminates not in an obtuse end, but in a
broad and flat surface, havii g a fissure in the
midst, with an indication of a head. The
sternum is often rudimentary, and the osseous
frame of the superior limbs is very incom-
plete. To the spinal column are added cervical
vertebrae, and sometimes a confused indication
of cranial bones. There is usually a dia-
phragm, but neither heart nor lungs. There
are commonly two vascular trunks, an arte-
rial and a venous. With the venous is con-
nected the umbilical vein ; and from the in-
ternal iliac arteries arise the umbilical arteries.
There are uropoietic organs, and an intestinal
canal, with a ctecal termination ; and some-
times a liver. This latter is, however, some-
times wanting, together with the spleen and
the par creas. In the intestinal tube there is
no meconium, but only a mucous substance.
The nervous system is very incomplete; but
there is constantly a spinal marrow with the
abdominal part of the sympathetic. I have
observed distinct muscles, of which the pre-
sence has been denied by others.

Seventh Type. — Acepliali in which some
cranial bones are found. — This has been
observed by Herholdt, in a monster, born
twin with a well-formed child, of a mo-
ther who had five other children. There
was an amorphous head, with an indication
of eyes and nosp, but without ears and
mouth : the rest of the body was much de-
formed. Of the cranial bones, the condyloid
and vertical portions of the occipital only
could be distinguished. There was no trace
of facial bones. Analogous observations have
been made by Curtius and Otto.

Eighth Type. — Body and extremities per-
fectly well developed, and having a neck, which
is wanting in the other types. The neclc is sur-
mounted and terminated by the ears. — This is
the form to which Guilt gives the name of
perocephalus aprosopus. I have met with
it in the lower animals only. The body and
the limbs are perfectly well developed; on the
perfect neck are placed two coalesced ears,
behind which there is an imperfect cranium,
composed principally of the cranial, minus the
facial, bones. In all this the deformity makes
a transition towards an imperfect formation of
the face. (Figs. 620, 621.)

Ninth Type. — Acepliali which are composed
of the trunk only, without the least indication of
superior or inferior limbs. — Only one case of
this monstrosity is known, observed by Vallis-
neri. In a foetus of a very mature period of

TERATOLOGY. 963

Fig. G20.

The superior cervical part of a perocephalous lamb,
terminated by the ears which are coalesced with
each other.

The skeleton of the parts represented in fig. 620.,
with the trachea and the oesophagus,
a, squamous part, and b, condyloid part of the
occipital bone ; c, petrous ; d, squamous, part of
the temporal bone ; e, parietal bone ; f, auditory
bones.

evolution, the head, the superior and the infe-
rior limbs, were wanting. There existed only a
trunk, which contained a tolerably large heart,
imperfect lungs, a malformed liver, a stomach,
and an intestinal canal.

From this survey of the characteristics
which distinguish the acephali, we learn that
they are born with two, three, or four other foe-
tuses at one birth. Can this quantitative
multiplication of the children be the cause of the
qualitative malformation of one of them ?
This is probable by the great fertility of the
mothers of acephali, which also indicates

that these monsters are produced by an
arrest of developeinent. It is very easy to
reduce their external appearance to the early
periods of developement, in which the head is
not yet distinct from the trunk, and in which
the limbs are not yet protruded. It is worth
mentioning that the abdominal cavity, with
the kidneys and a part of the intestinal canal,
are the most constant organs, which is very
interesting with reference to the genesis of
the intestinal tract. In the monstrous births
of the second, third, and fourth type, there is
only a colon, while in those in which a tho-
rax is superadded (as in the fifth and sixth
types), there is also an intestinum tenue with
the caecum. I regard this as a confirmation
of the statement, that the formation of the
intestinal canal commences at the two ex-
tremes, and proceeds from these to the mid-
dle part.

In the same manner the uniformity of cir-
cumference of the whole intestinal tube is an
arrest of developement at an early period of
embryogenesis, to which may also he referred
the ctecal beginning, and in many cases even
thecaecal termination of the intestine. The fre-
quent deficiency of the liver is the consequence
of the absence of the stomach and duode-
num, and therefore a sign that the liver is a
protrusion of the muepus membrane of the in-
testinal tube. The connexion between the con-
taining and the contained parts is also very dis-
tinctly proved by the acephali. The very gene-
ral presence of the lumbar part of the spine
determines the existence of kidneys ; that of
the pelvis, the existence of the urinary-bladder
and of the genital organs. The very imper-
fect condition of the thorax is in relation
with the absence of the heart. The pre-
sence of vessels without a heart demonstrates
that the circulation of the blood can be car-
ried on by these alone, and that the forma-
tion of vessels is quite independent of that of
the heart. The profusion of cellular tissue,
by which the swollen appearance of the
acephali is produced, may be formative sub-
stance, which has not been employed in the
production of the other parts of the body, and
which has therefore grown rather abundant.
In this manner many of the peculiarities of the
acephali can be reduced to fixed principles.

VI. Want and defective Formation of the
Trunk* (Acormiajfi

The highest degree of this kind of mon-
strosity is where neither trunk nor limbs are
formed. Lycosthenes, Rudolphi, and Nichol-
son describe monstrous births, in which the
head is the only part formed.

a. Sometimes only a part of the head is
ormed, of which I saw an example in a mon-
strous foetus born with a well-formed calf.
The tongue was the only well-developed part
in it. Th is shows that in the absence of all
the central organs, heart, lungs, skeleton, and
brain, there may be a well-constituted skin

* The word trunk is here used to include the ex-
tremities.

f From a, privativuin, and Koofibs truncus.

3 u 2

TERATOLOGY.

964

surrounding an amorphous mass of cellular
tissue, and only a single well-formed organ.
1 have given a fuller account of this case in
my Tab. lxii. figs. 4, 5, 6. Therefore we may
conclude that each part is formed sponte sud,
and that it is in its evolution quite indepen-
dent of the rest of the body.

b. A less degree of malformation is when
the superior part of the body is formed without
the inferior limbs. Fig. 597. gives a represen-
tation of this monstrosity, of which a succinct
account is to be found in my Handbook, D. ii.
Bl. 100, and Tab. lxiii.

c. In a more perfect developement of the
trunk one of the extremities may be wanting.

We call this malformation monopodia ; in
it one of the inferior half-parts of the body
has not been formed. It makes a transition
to those monsters, in which the inferior ex-
tremity of the body tapers gradually into a
tail-like form, which has given to them the
name of monstra Sireniformia.

d. Sympodia or Siren -like form is the
fourth species of defective formation of the
trunk. The single inferior extremity is com-

ing. 622.

Fig. 623.

posed of the elements of two, and arti-
culates with a pelvis, which is not formed,
as in monopodia , by one bone, but by a
coalescence of two. In most of them the
partially double, partially single inferior ex-
tremity terminates in a caudal point ; on
account of which the name of Sirenes has
been adopted. To this imperfection are added
closed anus, defect of external genital parts,
and the existence of but one artery in the
umbilical cord. The malformed inferior ex-
tremity has not always the same form. There-
fore we admit three varieties: — 1. Without
a foot, Sirenomelia of J. G. St. Hilaire ; 2.
With a single foot, more or less complete,
Uromelia of J. G. St. Hilaire ; 3. With a double
foot. Fig. 622. represents the second, and
fig. 623. the third variety.

By this survey of the four types of de-
fective formation of the trunk is proved that
they form a very natural series, in which we
are gradually inducted, from the total want of
a trunk to monsters in which inversion of
the inferior extremities is the only deviation
from the natural form. The same regularity
is here to be observed as in every other
class of monstrosities. It is therefore impos-
sible to ascribe their origin to accidental ex-
ternal causes. Meckel has opposed his own

TERATOLOGY.

peculiar and sarcastic wit to this absurd
mtiology, and gives the very ludicrous ac-
count of a surgeon who supposed that the
Sireniform monster had been formed during
a very difficult delivery. If it is, on the
contrary, an original malformation, it may be
asked, what can be its remote cause ? Is it
the original want of one of the umbilical ar-
teries? I should not think so ; for one of these
arteries is also wanting in the variety in
which all the parts of the two extremities are
present, and we know that one of them may
he wanting in a completely well-formed child.
(See p.948.) Another question is, whether
sympodia can be attributed to the coalescence
of the inferior extremities (Meckel, Kamm,
Boerhave, and Cruveilhier). Neither am I in-
clined to adopt this cause.

1. I cannot imagine a coalesence of bones
so complete, that through these could be
formed one single extremity.

2. It is impossible to explain by it the im-
perfect condition of the leg and of the foot
in the majority of cases.

3. From such a fusion or coalescence can-
not be derived the imperfect state of the
rectum, and of the sexual and uropoietic or-
gans.

It seems to me more probable that sym-
podia is due to some original malformation
of the pelvis and its viscera, of which the
cause remains unknown. The formation of
a head solely, of an incomplete trunk without
the lower limbs, or of a single inferior ex-
tremity, is certainly to be attributed to nothing
else but impeded developement. It shows,
moreover, that the different parts of the body
are quite independent of each other in their
original formation.

e. Original defective formation of the pelvis.
In a well constituted body the pelvis may be
originally malformed, as is proved by the ob-
liquely narrow pelvis of Nazele, and by the
transversely narrow pelvis of Robert ; of which
malformation the cause is to be found in the
imperfect formation of the sacrum.

f. Defective developement of the spinal
column. This has been principally observed
in calves. It is too short, defective, more or
less ineurvated, and some of the vertebrae
fused together. The head is situated at a
short distance from the thorax ; the tail and
the anus are reflected to the dorsal surface ;
the pelvis is too narrow, and turned upwards
at its posterior part.

VII. Defective Formation of the Extremities.

The origin of many malformations of the
limbs may be referred to the early period-,
ol embryogenesis. But for some of them this
is impossible.

1. JVant of all the extremities is an arrest of
developement at that period, in which the
limbs are not yet formed, and in which small
tubercles occupy their places. Sometimes the
superior extremities only are wanting, which
urges the inferior extremities to acquire a sort
of dexterity by which they may in some mea-
sure supply the place of the superior limbs.

965

Of all the examples which are known of it,
that of Thomas Schweicker is the most me-
morable. The inferior limbs only are rarely

Fig. 624.

3 u 3

866 TERATOLOGY.

wanting, and the cases few in which there is
but one superior or inferior extremity.

2. Want of the intermediate parts in the
extremities, so that the hand is attached im-
mediately to the shoulder, and the foot to the
hip. — This may happen in one or in more
extremities. Of the last, a very interesting
example occurred in the person of a certain
Marco Catonze, of whom I represent the ex-
ternal appearance and the skeleton in figs.
624, 625., referring for more details to my
Tab. lxxvii.

3. Limbs too short. — All their parts exist
in such case, but are too short, as if they
were not full-grown. The malformation is
however not limited to the extremities, but
extends over the trunk and the head. The
head has in all the known case3 the aspect
of hydrocephalus. The neck is short and
broad, the trunk short and swollen, and the
limbs short, broad, and thick. Soemmering
and Otto ascribe this to congenital rachitis.
But according to my opinion it ought to be
attributed to defective developement, which
is confirmed by the dissection, performed by
C. Mayer, of such a monstrosity.

4. Limbs which seem to be truncated. — Some-
times the fore-arm and the leg terminate
abruptly like stumps, and present the appear-
ance of cicatrices. I saw this on the four
extremities of a calf, of which I have repre-
sented the external form and the dissection
in my Tabul® lxxviii. and lxxix. In many of
the known cases this defective condition of
the limbs seems to be the result of arrested
developement. In some others, however, it is
the effect of mutilation produced by the con-
striction of the umbilical cord, or by pseudo-
membranes. Montgomery has given many
examples of it in his article Fcetus in this
Cyclopaedia. It is an interesting fact that
from these stumps may grow rudiments of
fingers, as Dr. Simpson showed me during the
visit which I paid him at Edinburgh.

5. Diminished number of fingers and toes. —
The highest degree of this malformation is the
existence of but one finger or toe. Sometimes
there are onlj' the thumb and the little finger,
as may be seen in a preparation in the mu-
seum of Ilovius at Amsterdam. The greatest
transition towards the natural condition is the
presence of four fingers or four toes.

6. Coalesced fingers and toes. — In other-
wise perfect limbs it is possible that hands
and feet may be arrested at that inferior de-
gree of developement, in which they are not
yet separated into fingers and toes. The child
is then born with fingers or toes, which seem
to be coalesced ; but that is nothing more than
a fallacious appearance. The malformation con-
sists really in absence of fission. Of this there
are different degrees : a, complete absence
of fingers and toes, instead of which there
is a common mass ; b, connection of the
fingers and toes by means of a membrane ; c,
the adhesion limited to the posterior parts
of the fingers and the toes, while their anterior
parts are completely free. All this may be
seen in figs. 626, 627, 628

Fig. 626.

{After Otto.')

7. To all these malformations of the limbs
ought to be added the abnormal direction of
the foot; but this is fully considered in the

TERATOLOGY.

9G7

article Abnormal Conditions of the Foot
in this Cyclopaedia.

VIII. Cyclopia.

Upon this interesting malformation, which
for many years was the object of my own inves-
tigations, I should have much to say ; but my
friend Paget has already given a succinct
survey of its different forms in his learned
Article Nose, to which, therefore, I refer. I
beg leave here to add to the observations
which I have published in my former works
upon the origin of Cyclopia , a few additional
remarks on the subject. Is it an arrest of
developement ? It cannot be denied that many
deviations of the parts in Cyclopes may be
referred to a previous natural form. For
example, in one of my published cases the
optic lobe and the brain formed one continu-
ous part, which is certainly an early natu-
ral condition. It is also certain that the
disposition of the hemispheres of the brain
in Cyclopes, which appear to be a single
vesicle, accords with the vesicular state of
the brain in the first period of its develope-
ment, and that the unprotected situation of
the ganglia of the brain, of the cerebellum,
and of the medulla oblongata, may be con-
sidered as a foetal condition. But, as to the
eyes, it is not so certain that their single-
ness is the result of an arrest of develope-
ment. E. Huschke has, however, main-
tained the opinion, that the eyes are formed
by a single vesicle, which becomes sepa-
rated into two ; but from the more recent
and accurate investigations of BischofF, we
must conclude that the optic lobes are
from the beginning separated and double,
taking their origin from the anterior cerebral
vesicle, and that from an abnormal condition
of this last, by which the rudiments of the
eyes approach each other and fuse together,
may be derived the cause of Cyclopia. If
this observation is true, of which it is difficult
to retain the least doubt, Cyclopia really ap-
pertains to the Verschmelzungs Bi/dungen of
Meckel in an early period of developement.
Perhaps it may be compared with the meta-
morphosis of the eyes in Daphnia , Cypris,
Polyphemus, and Cyclops , in which there are
originally two vesicular bulbs, which subse-
quently coalesce into one. But however this
may be, it remains certain that the malforma-
tion of the cranial and facial bones in Cyclopes
is the consequence of the abnormal condition
of the brain and of the visual and olfactive
apparatus.

IX. Deficiency of the Underjaw (jMonotici).

Want of the under jaw often coexists with
Cyclopia. By this complication is formed a
peculiar series of monsters, which make a
gradual transition to those in which, notwith-
standing the presence of two eves, the under
jaw is absent. I refer to this the following
species.

1. Total defect of the opening of the mouth, —
as observed by me in a lamb, in which also

the ears were removed to the basis of the
head and coalesced. The under jaw was
totally absent ; and behind the coalescent ears
there was an osseous vesicular cavity, formed
by the bulbous tympanic cavities, united to-
gether.

2. The opening of the mouth represented by
a fissure at the inferior surfaee of the face. —
The rest of the external appearance is similar
to the first species. The under jaw is want-
ing, but there is a rudiment of a tongue.

3. Too short an under jaw. In man and
the lower animals the under jaw is sometimes
incompletely developed, and more depressed
posteriorly than it ought to be. This original
brevity of the under-jaw is the cause of a great
many ulterior deformities.

Without doubt, these three forms of mon-
strosity make a continuous series. They
consist, as BischofF says, in an imperfect
developement of the first visceral arc, by which
the under jaw and the bones connected there-
with are either wanting or defectively formed,
the result of which is, that the ears are re-
moved to the basis of the head, and there
become fused together. The total defect of
the opening of the mouth is the highest, the
too short under jaw the least degree of mal-
formation.

Herewith I conclude my brief account of
the monstrosities resulting from arrest of de-
velopement. The description of the congenital
abnormal condition of the different apparatus
would oblige me to surpass the due limits of
an Article for this Cyclopaedia, which already,
1 fear, may be considered rather too long ; and
I think this the less necessary, because a
great deal of information about them may be
found in the Articles Anus, Diaphragm,
Fcetus, Hermaphroditism. I therefore
pass on to a succinct description of a second
group of monstrosities.

B. Monstrosities produced by Excess
of Developement.

I. Foetus in Fcetu.

The human fcetus may be included in an-
other foetus, or adhere to its body. This
may happen in two different manners : —

1. A foetus more or less perfect contained
in the cavity of the body of its twin-brother
or sister.

a. In the uterus. — The fcetus would be
pregnant in such a case at the moment of its
birth. The observations given of it are,
however, somewhat apocryphal.

b. In the abdomen. — In a case recorded by
Fattow, there are, in a foetus of seven months,
two rudiments of foetuses contained in its
abdomen. Such observations are also given
by Reiter, Heminger, Pacini, and E. Philips.
In general, the rudiments of a second foetus
are very imperfect, and included in a sac.
Sometimes, however, they are more complete,
which was, for example, the case in an observ-
ation of Young, of which the preparation is

3 q I

908

TERATOLOGY.

preserved in the splendid Museum of the
London College of Surgeons.

c. In the anterior mediastinum. — As in a case
recorded by Gordon, in a female of twenty-
one years.

d. In the scrotum and the testes. — Such
cases have been noticed by Rosenberger,
Hartmann, D. S. J. Wendt, Velpeau. Some-
times the rudiments of a second foetus are
found in the interior of the testis, sometimes
at its exterior surface.

e. In the stomach.

f. In the intestinal canal. — Highmore has
given such a case in a youth of fifteen or six-
teen years, in the gut of whom an acephalus
was found.

g. In the orbit. — According to Barnes.

h. At the tentorium of the dura mater.

i. At the palate. — - It is then in the form
of a fungous excrescence, consisting of the
rudiments of a second foetus (Otto, Sandi-
fort, Ehrman, Stadenski).

2. The more or less developed rudiments of
a fvelus adhere, in the form of a tumour,
to the external surface of a second body,
and are covered by the external integu-
ments.

a. To the check. — G. Vrolik observed in a
new-born male child, a sac of large circum-
ference, covered by the external skin, and ad-
hering to the region of the left cheek, but
without communication with the mouth. In
this sac there were tuberculous cartilages, os-
seous nuclei, and organised parts of indefinite
form and composition.

b. To the neck. — According to Joube.

c. To the epigastric and umbilical region. —
As recorded by E. B. Gaither.

d. To the sacral and perineal region. — This
is the most frequent mode of adhesion, as is
proved by a great many observations, among
which those of Himly and of Fleischmann
deserve special mention. This adhesion takes
place in different manners : 1. by external
cellular tissue ; 2. by internal union with the
abdominal and pelvic cavity (Himly, Schau-
mann, and Stanley) ; 3. by communication
with the spinal canal. There is sometimes
no vascular communication between the foetus
and its appendix (W. Vrolik) ; and in other
cases there are large branches going from the
arteria sacra media of the fretus to the sac. In
general, the sac has its own integuments, over
which passes the skin of the foetus. The
genital parts and the anus are always quite
separate from the sac, which merely lies in
apposition with them. In the majority of
the known cases, the rudiments of a foetus
contained in the sac are but confused and
ill-determined organic substances, intermin-
gled with a few osseous and cartilaginous
nuclei. In one case it was possible to recog-
nise the cranium with the face and the naked
encephalous masses (Wedemeyer) ; Mayer
and Blizard found an intestinal loop : Himly
saw distinct super-maxillary bones, and ru-
diments of temporal, frontal, and sphenoid
bones, &c.

If we take a survey of all the cases which
are designated as foetus in feetu, it is clear that
some may be compared with parasitical dis-
eases formed in the interior of the body of
the foetus. 1 presume that this is the case,
when the mass which is found consists only
of hair, fat, teeth, and some osseous nuclei,
contained in a cystic tumour. In other cases
the rudiments of a foetus are included with a
more or less perfect indication of an ovum in
the body of a second foetus, or adhere exter-
nally to it. The large number of theories on
the origin of this monstrosity have been criti-
cised by Himly. It is certain that none of
them can be maintained. It is most pro-
bable that the foetus in feetu is an incomplete
effort to form a double monster. In this
sense, some cases of feetus in feetu make a
transition towards that form of double mon-
sters which is named heteradelph.

II. Double Monsters, in which one of the Foe-
tuses is more or less perfect and the other

merely an Appendix to it ( Hetcradelphi ).

Under this name of heteradelphs, which we
owe to Geoffroy St. Hilaire, we understand
that species of double monsters of which
one foetus is large and perfect, and another,
or part of another, adheres to it like a para-
site. They should be considered as twins, of
which one has been developed at the expense
of the other, which other sometimes becomes
partially included in its body. According to
the more or less perfect state of the appen-
dix, they are reduced to different species.

First Species. — The appendix consisting
of a head only. — This may be connected : —

1. With the epigastric region (Winslow,
Flesse),

2. With the cranium (E. Flome),

3. With the back (Chabelard),

4. With the palate (Hofmann), or

5. With the under-jaw of the perfect feetus
(Geoffroy St. Hilaire, G. Sandifort).

Second Species. — The appendix consists
of more or less developed extremities only. —
Supernumerary extremities, more or less deve-
loped, are connected with some part of the
body of a perfect foetus, as :

1. Pelvis and two inferior extremities con-
nected with the epigastric region of the per-
fect foetus (Serres, E. Sandifort, Trombelli,
Mayer, Winslow, Reschel, Buxtorff, Cantwell,
Lycosthenes).

The appendix is sometimes more, sometimes
less perfect ; sometimes connected with the
sternum, sometimes with the epigastric region
or in communication with them by a cylin-
drical cutaneous prolongation. In the appen-
dix are regularly formed organs of generation,
kidneys, an intestinal loop in communication
with the intestinal canal of the supporting
feetus, and vessels which anastomose with
those of the latter. The adhering parasite is
therefore one with its supporter.

2. Pelvis and the two inferior extremities
connected with the lateral w'all of the abdo-
men of the perfect foetus (W. Vrolik).

3. Pelvis and two inferior extremities con-

TERATOLOGY. 969

nected with the pelvis of the perfect foetus
(Nuinan, Osiander, Haller).

4. Separate anterior or posterior extremi-
ties connected with some part of the perfect
foetus (W. Vrolik, Yon Baer).

All these varieties are indicated under the
names of gastromele, pygomele, and melomele.

Third Species. — The appendix is an ace-
phalus with four extremities. — The union has
as yet been observed only at the epigastric re-
gion of the supporting foetus, through which
the abdominal cavity was common to the two
bodies. In the appendix the genital organs
existed, but the anus was closed. In many
cases, the evacuation of urine has been ob-
served; the appendix showed circulation of
blood ; it had its own temperature, and was
dependent for nutrition on the chief or perfect
body. In the interior were found uropoietic
organs, vessels connected with those of the
chief body, and an imperfect intestinal canal
(Otto, Serres). In the supporting foetus are
sometimes found traces of double organs
(Otto, Serres, Rosenstiel).

Fourth Species. — The appendix a com-
plete body with a head and four extremities
(Bartholinus). — This form of heteradelph
makes the transition to anterior duplicity.
The appendix has but to be more equally pro-
portioned to the chief body, and a completely
double monster is formed. The best ex-
ample of this occurred in the person of a cer-
tain Lazarus Colloredo, who lived for some
length of time. His portrait is given by Bar-
tholinus.

This very peculiar appendix never took
food, nor had it evacuations of feces. But
the organic and the animal life appeared to
be very well developed, as its cutaneous ex-
halation, its movements of different parts
of its body, and the fact of its sleeping,
showed.

The common character, by which this whole
class of heteradelphs is distinguished, consists
in the comparatively smaller size, and, in ge-
neral, the defective developement, of the part
which is termed the parasite. Imagine this
difference removed by the fuller developement
of the parasite, by its obtaining all its own
organic apparatus, and by its growing pari
passu with the other, and an exact idea of
complete duplicity will be formed. It will
be observed also, that in the several members
of this class there is a regularly graduated
series, from those in which the superfluous
part is only an ill-developed limb, to those in
which the parasite differs from the chief in
nothing but its inferior size and its depend-
ence for nutrition. The cases of the last kind
are, however, rare. I know but three, of
which that of the said Lazarus Colloredo, de-
scribed by Bartholinus, is the most remarkable.
Much more commonly the parasite, even when
it possesses its full numerical complement of
parts, bears many signs of defective develope-
ment ; it is hare-lipped, or a cyclops, or has
atresia ani, or some other malformation from
arrest of developement. All this seems to me
to prove, that in heteradelphs there are

always the rudiments of two bodies, though
one or both may be defective.

The beings thus formed have rarely lived
many years after birth, and the histories of
the few that have survived are, for the most
part, well known in the records of medicine.
Perhaps the most remarkable is that of the
Chinese A-ke, of whom and his parasite
little models are to be found in most of the
anatomical museums of Europe. The para-
site’s life is, in general, only vegetative. In
one of the three cases, indeed, in which it
possessed all the constituent parts of a body,
it moved its limbs, and appeared to have its
own sensations ; but in the others, less per-
fectly formed, even these signs of individual
life were absent ; and in only one, that of
the Chinese A-ke, had the man who bore
the parasite any voluntary power over its
limbs. The nutrition of the parasite appears
to depend entirely on the body to which it is
fixed, and through which it both receives its
nutritive materials and discharges its excre-
tions. The one increases and decreases in-
size with the other; and, of course, the para-
site dies with the individual to which it is
attached. The influence which, in its turn,
it exercises on its supporter is not always
important. In the heteradelphs that die
early, death commonly ensues from the mal-
formation of the main body ; if they survive,
the parasite seems to do harm only, as an
ordinary tumour would, by its weight, and by
abstracting a certain amount of nourishment,
so that those who, thus burdened, have grow n
up to childhood or manhood have usually
been thin and delicate, like men subject to
some unnatural waste. But, nevertheless, it
will always be better to tolerate this evil than
to risk an operation of removal, when the re-
sults of all the examinations yet made prove
that the parasite is deeply and by important
organs connected with its supporter. The only
exception which I know to the correctness of
my opinion is the case in which Mr. Blizard
removed, with complete success, from the
sacrum of a child, a congenital tumour, which
seems to have been a parasite.

III. Double Monsters.

1. Anterior duplicity.

It has been already said that some of
the rarer kinds of heterade/phia approximate
closely to the double monsters. In all the
cases that stand nearest to the transition, the
parasite has been found adherent to the epi-
gastric region ; and the kind of duplicity
which is most closely related to them, is
therefore that in which the two bodies adhere
by their anterior surfaces, or what we call
anterior duplicity.

The most complete examples of duplicity
yet known are found in this class, whose dis-
tinctive characters are, that two bodies, in a
state of nearly equal developement, are placed
exactly opposite to one another, with their
sterna connected together, and with their
abdominal cavities either partially or com-
pletely coalesced. Here, however, as in all

970

TERATOLOGY.

the other classes, examples are found of gra-
dations towards a state of singleness. For
instance, the upper parts of the body being
completely double, the lower are united, so
that there are but three limbs, or only two
lower or posterior limbs. And, in like manner,
although in many cases the bodies are alike in
size and other characters, yet there are many
more in which one has so far surpassed the
other, both in size and in stage of develope-
ment, as completely to fill up the series be-
tween this class and the decided heteradelphs.
Whilst in the latter case we find close approxi-
mations to duplicity, there are even among the
most perfect double monsters peculiarities
which constantly recall to mind the parasitic
attachment of the heteradelphs.

With this nearly perfect external duplicity
there sometimes, but not always, corresponds
an equal duplicity of organs. The umbilical
cord may be single (Parsons, Otto), notwith-
standing the heart is perfectly double. The
two umbilical arteries belong but to one child ;
the umbilical vein bifurcates and enters both
bodies. In another case (Cruveilhier), the
single umbilical cord had two veins and four
arteries, and the heart was externally single,
and in its internal parts imperfectly double.
In a third double monster (Otto), the umbili-
cal cord had five vessels, two umbilical veins,
and three arteries, and in this there were two
hearts. In a fourth double monster the heart
and umbilical cord were single. The bond of
union, as far as the skeleton is concerned, is
commonly a tough fibrous connection between
the lower extremities of the sterna and the
ensiform cartilages, which are set directly
opposite to one another.

The rest of the sterna and the ribs are usu-
ally distinct, and the thoracic cavities are
thereby separated. In this case there are
commonly two separate and perfect hearts ;
but in the cases in which the sterna are
more completely fused, or (as happened in
one case) entirely absent (Comm. Litt. No-
rhnberg.'), only a single heart, or one partially
double, with, for instance, two ventricles and
four auricles, or otherwise malformed, is found.
But it is particularly remarkable that in these,
as in all other kinds of double monsters, there
is no constant relation whatever between the
respective states of the external and the in-
ternal organs, for the condition of the two
digestive canals, even in those which are ex-
ternally almost alike, is subject to still greater
varieties than the condition of the heart. The
abdominal organs are always in some degree
connected ; — the two livers are usually con-
tinuous.

A spleen, pancreas, and stomach are com-
monly found in each body, and each stomach
has its own duodenum, which, after some
length (being continued into the jejunum) unites
with the other to form a single tract of small
intestine, which again divides into two canals,
leading respectively to the large intestine of
each body. The lungs, the urinary, and the
genital systems are always double. The most
remarkable example of this class was the well-

known Siamese twins. When exhibited, they
were not exactly opposite to each other, but
stood side by side, or, rather, obliquely one
by the other ; but this position, there can be
little doubt, was acquired by the attempts
which they had instinctively made to separate
from each other in walking, or in lying and
sitting down, and by the extension they had
thus effected in their bond of union, which
was considerably more slender than in any
other yet described. It was quite impossible
for them to remain always face to face; there-
fore their bodies acquired an oblique direction,
in which they also moved. The consequence
of this was, that the right limbs of the one and
the left of the other individual were the prin-
cipal organs of movement ; and that the inter-
mediate limbs, that is to say, the left of the one
and the right of the other, remained merely
passive (Dubois). The one individual was
stronger than the other, and seemed to over-
rule him. But, nevertheless, in organic and
animal relation of life they seemed to be inde-
pendent of each other. Each had his own
circulation of blood, his own respiration, and
digestive functions. There did not seem to
be a large anastomosis of vessels between the
two bodies. But, by analogy with the fore-
said cases, we may conclude that these twins
are connected by the ends of their sterna, and
by some of their abdominal organs. As a proof
of this connection, may be adduced the result
of the observations of Mr. Mayo, communicated
at the Conversazione of the College of Physicians
March Sth, 1831, that when either of the
youths coughed, the bond of union swelled
up in its whole length, proving that they had
but one peritoneal cavity, of which a trans-
verse prolongation passed through the con-
necting medium. And, therefore, I should
conclude, that an attempt at separation could
not be made with probability of success. The
probability of having to cut through a piece
of liver, or a peritoneal canal, must render an
operation unwarrantable, unless, indeed, after
the death of one of the bodies during the
healthy state of the other. The case reported
by Konig has scarcely authority enough to
support a contrary opinion.

2. Lateral duplicity.

The varieties of form in anteriorly duplex
monsters are closely limited by the partial
nature of the union of the sterna and the
nearly complete distinctness of the thoracic
cavities, and hence of the whole upper part of
the body. In the next class, which I call lateral
duplicity, there is no such limit ; and between
the highest degree of duplicity found in it
and the lowest, or that in which the duplicity
is most nearly reduced to singleness, there is
a far more numerous series of intermediate
forms than in any other of the types ot double
monsters. In lateral duplicity, the two bodies
are not set opposite to one another, but are
turned sideways from one another. They
have a common thoracic cavity, for the forma-
tion of which (at least, in the highest degree
of duplicity,) the right ribs of one body, and

TERATOLOGY.

971

the left of the other, proceed towards the an-
terior and posterior aspects, and are there
connected with an anterior and posterior
sternum. The best idea of the construction
of this osseous fabric may be formed by sup-
posing the two complete chests of two bodies
to be set one against the other, and that then
the anterior extremities of the right ribs of
the right body, and those of the left ribs of
the left body, unite with one sternum and
pull it forwards, while, in the same manner,
the left ribs of the right body, and the right
of the left, unite on the posterior aspect
with the other sternum, and carry it back-
wards. The consequence is, that the two
vertebral columns are turned away from one
another, and that the parts above and below
the thorax are double. By the formation of
this common thorax, the lateral is distin-
guished from the anterior duplicity, in which
the thoraces are commonly connected only
by the points of the sterna, and, as to their
cavities, are separate. And with these diffe-
rences of external construction, others not
less important, of internal arrangement, coin-
cide, which fully justify the separation of the
two forms, however similar the external ap-
pearances of many of the examples of either
may be.

The numerous varieties of lateral duplicity
may be divided into two principal sets. The
first begins with the complete duplicity of the
whole body, and ends with its perfect sin-
gleness ; in the second, the duplicity of the
body remains, but the head gradually becomes
single. The forms included herein, of which
1 have given ample accounts elsewhere, may
be briefly summed up as follows.

1. Complete duplicity: — all the external
parts and sometimes the abdominal and pelvic
viscera double, — one common double-sized
thoracic cavity, formed in the manner just
described, and containing four lungs, and (in
all cases with which I have been acquainted)
only one heart. The examples of this form
are very numerous, and are to be met with in
all the large museums of Europe.

2. In the examples of this second group,
which exhibits the first step towards single-
ness, one of the sterna may be traced in a
succession of specimens, becoming gradually
narrower, and permitting a closer approxima-
tion of the two corresponding upper extremi-
ties, till, in some examples, they are com-
pletely united, and there are found only three
limbs above, with three or four below. The
two juxtaposed scapulte, for example, are
merged into one, or they remain separate,
but have only one humerus between them,
and this splits below, to articulate with two
fore-arms ; or there is but one fore-arm,
and this bears supernumerary fingers. In
short by a great variety of modes there is a
general tendency towards union of two of the
upper extremities.

3. In the third group we have a repetition
of the same series of changes in the lower
limbs, as in the second was traced in the
upper ; here, as there, presenting numerous

varieties, in the last and lowest of which only
three lower limbs, and the third of these ill-
formed, are found.

4. The third limb has now gradually disap-
peared, and, with a complete duplicity above
the pelvis, there are but two limbs below it,
and these well formed. In this class is placed,
with many others, the Ritta-Christina monster,
described by Serres, which lived to eight
months, and the still more remarkable ex-
ample mentioned by Buchanan, of a two-
headed man, 28 years old, who lived in the
reign of James III. of Scotland.

5. The union proceeding, and this simpli-
city of the lower part of the body being re-
tained, examples come next in which the
upper parts also are united ; the two super-
fluous upper limbs being united into one, pre-
senting a single upper-arm, with a double
fore-arm and hand, or a single upper-arm,
fore-arm, and hand with ten fingers, or only a
mal-formed limb, or a mere projection, occu-
pying the place of the superfluous limbs.

6. Even this last indication of duplicity of
the upper parts ceases, a scapula only remains,
or this also is absent ; and next, one of the
sterna having disappeared, and the vertebral
columns having been connected on the corre-
sponding side by their respective ribs united
into single arches, these now become gradually
shorter, and the columns approach each other
more and more nearly, till they are connected
by only a cartilaginous substance in the place
of ribs, or are at some part fused together.

7. In this next group both the upper and
lower parts of the body are single ; the ver-
tebral column is single below the cervical
region, or exhibits only a trace of duplicity
(to which something similar is often presented
by the sternum), but at the cervical region
becomes double, arid on each portion bears a
head. Of this also I have published many
examples.

8. In the eighth group the extent of that
cervical part of the column which is double
becomes less and less.

9. In the ninth group, the two heads are
seated on an apparently single neck, in which
all the cervical vertebrae are single, or only
bear traces of duplicity, except the first two,
or the first alone.

10. Hitherto the duplicity of the head was
perfect ; in this group the two heads also
begin to coalesce, and, in a considerable num-
ber of cases, gradations are traced in which
the adjacent ears are very closely approxi-
mated, and the heads are united behind.
Then there are cases in which one ear only is
placed between the adjacent surfaces of the
two heads, and this disappears gradually, and
at last totally. Next in order are the cases in
which the adjacent ears being lost, the two
adjacent and middle eyes first become very
close, and then occupying one orbit finally
coalesce. Next come those cases in which
there is such a union of the heads, that the
two upper jaws are articulated with one lower
jaw; and, lastly, those in which the head is
doubled only in individual parts or in which

TERATOLOGY.

972

there is one perfect heart, with some imperfect
part or parts of another attached to it.

1 1. The eleventh group of this division
includes the cases of lateral duplicity, in
which the body is single in the middle, but
doubled above and below (or in brutes ante-
riorly and posteriorly). In these, which are
of rarer kinds, a single neck bears two more
or less completely separated heads. The
vertebral column is for a considerable length
single, but at its lower part again divides, and
bears two sets of lower extremities.

12. In the twelfth group the body is single
above and doubled below.

13. In this there is a tendency towards
singleness, or even complete singleness, of the
head, but all parts of the trunk and all the limbs
are doubled, an arrangement by which, as al-
ready stated, these form a series entirely dis-
tinct from the rest. In some of these cases
the two heads are found coalesced below ; in
others, to which the name of janiceps has
been given, one face is directed backwards
and the other forwards, the remainders of the
two heads being merged into one ; in others,
one face is perfectly , the other very deficiently,
developed ; in others there are only the indis-
tinct traces of a second head presented in the
existence of one or two ears on the posterior
aspect of the more perfect one ; in others,
this trace of duplicity is still less evident ;
and, lastly, in the remainder of the group, it is
entirely lost, and one head only, which may
be well or ill formed, is found upon the
double body.

3. Inferior duplicity.

My third division of double monsters in-
cludes the cases in which there are two com-
plete bodies with the lower portions of their
respective trunks united, so that there is a
head with upper extremities both above and
below (the bodies being placed in the same
straight line) and on either side of the part
at which they meet two lower limbs. One
may best conceive this arrangement by sup-
posing two children stuck together by their
buttocks, and so fixed with wide-spreading
lower limbs, as may be seen inyfg. 146. of the
second volume of this Cyclopaedia. A com-
mon body is thus formed with a head at each
end, with two upper limbs both above and
below, and with two lower limbs, one belong-
ing to each foetus on the right and two on the
left of the united portions. A few cases only
of this remarkable monstrosity are recorded ;
and in these the duplicity was not always
complete, but exhibited in some the same
tendency towards singleness as was noticed
in the others. Thus in some there were but
three lower extremities ; in others there were
but two, or two with a third ill-developed on
the other side: and, again, in other groups
there were those which have a perfect head at
one end of the trunk, but an imperfect one or
none at all at the other.

These monsters have been known to live a
considerable time, their capacity for life being
probably owing to the separation of the hearts
and the absence of malformation in the more

important organs of the body. The umbilical
cord is single, and never has a double set of
vessels ; an apparent proof (confirmed by si-
milar examples in other classes) that the one
body is not formed of the materials of two ; a
conclusion which is supported by the coinci-
dent singleness of the anus and urinary blad-
der, and the union of the intestinal canals.

4. Posterior duplicity.

The fourth chief form is j)osterior duplicity,
in which two bodies are united by their
backs, or a part of them. The union may be
at the pelvis (which is most common), and
occurred in the well-known Hungarian sisters,
who lived to their twenty-second year ; or at
the back of the vertebral column, or at the
back part of the heads.

5. Superior duplicity.

The fifth is the superior duplicity, in which
the two children are connected by their skulls,
the bones of which are united so as to form a
single skull. In these also the place of union
varies greatly. The frontal bone of one coa-
lesces with the parietal or the occipital of the
other, or the foreheads are attached to one
another, or the side of one head to the front
of the other. But all these are very rare, and
of each kind only one or two examples can
be found on record.

All these are true double monsters. Of
tripled-bodied monsters but one instance is
known in the human subject ( At ti dell’ Acade-
mia de Cattania, t. viii. p. 203., 1834).

To conclude the description of duplicity,
those which occur in individual parts of the
body, the rest being single, viz. in the head,
chest, abdomen, and limbs, ought to be re-
corded ; such as, for example, two mouths, su-
pernumerary teeth and horns, two oesophagi
or duodena, double hearts, or supernumerary
cavities in one heart otherwise well formed, a
double penis and urethra, a double clitoris,
supernumerary breasts, kidneys, vertebrae, ribs,
fingers, toes, or whole limbs. But for all
these I refer to my monograph.

At present I prefer to give all those con-
siderations upon the origin of double mon-
sters, of which this highly interesting subject is
capable. From all the facts I have published,
I point out the following generalisations : —

The double monsters form collectively one
class of organic beings, which, however dif-
ferent in their several degrees of malforma-
tion, may be arranged in one continued series.
As the lowest degree of duplicity, may be
mentioned that of a single part of the body;
for example, a double or supernumerary fin-
ger ; as the highest, a complete double mon-
ster with two heads, four upper and four
lower limbs, and two trunks, such as the
Siamese twins. And between these two ex-
tremes there are different forms of duplicity,
which gradually run one into the other.

There is no positive or constant relation
between the external and the internal organs
as to their degrees or modes of duplicity. In
the completest duplicity of the exterior, for

TERATOLOGY.

973

example, the heart is often single, or even
shows signs of having been arrested in its
developement ; and, on the other hand, in the
more nearly single forms, the heart is usually
either partially or completely double. The
histories of the cases of anterior and lateral
duplicity, which I have given in my mono-
graph, furnish abundant proofs of this. Nor
is there any closer relation between the con-
dition of any other internal organ and that of
the exterior, than there is between it and the
heart ; for in nearly complete external dupli-
city any of the internal organs may be single ;
when there are two trunks indeed, the urinary
and genital organs are commonly double ; but
as for the stomach, the liver, and the lungs,
the correspondence between them and exter-
nal duplicity follows no other rule than that
where there are two necks there are two
tracheae and two oesophagi, and as a con-
sequence the lungs and stomach are also dou-
bled. When in like manner the stomach is
double, each has its spleen and pancreas ; but
the state of the liver is very variable ; some-
times there are two, sometimes but one with
a single or double gall-bladder; and these
differences often occur in the same form of
external duplicity.

Parts placed on the surface of the body are
more liable to multiplication than the internal
organs, and duplicity of a single part is there-
fore much less rare than the formation of a
complete double body. The upper half of the
body is more frequently doubled than the
lower, probably in consequence of its earlier
developement and the admitted preponderance
of the upper parts of the body. The union
of the two bodies takes place only between
similar parts. The more each of the bodies
is developed, the less is the bond of union
between them, as the examples of the Siamese
twins and the Hungarian sisters sufficiently
prove. And with this law is connected an-
other, namely, that the probability of grow-
ing up is greater in the same proportion as
the bond of union is smaller, and the coin-
cident fusion of internal organs less, as these
two and other double monsters prove. So
also the further the several organs are
from the situation at which the bodies are
united, the more perfect they are, — one
body is almost always less developed than
the other: in the heteradelphs this is al-
ways the case, and in others the difference
between the two bodies, though less evident,
is scarcely less constant than in them. There
are not commonly any signs of a double
monster having been at first two individuals.
For except in the cases of posterior and supe-
rior duplicity, and some singular examples of
attachment of the umbilical cord of one fcetus
to the head or the body of the other, there is
never more than one placenta and one cord,
and the latter usually contains only a single
set of vessels, which divide when they reach
the abdomen. And even in the posterior and
superior varieties of duplicity it is not yet
certain that there are two placentas ; in some
cases the placenta was positively single, and

in the remainder it has very rarely been ex-
amined. A last general rule is that in double
monsters the twins are of the same sex.
There is no well proved exception to this
important rule.

What explanation can be given, after all
these facts, of the origin of double monsters ?
On this subject, three hypotheses ought to be
mentioned : 1. The double monster has been
supposed to have proceeded from two distinct
embryos, whicli have become united in the
course of development ; 2. It has been held to
have originated in a single germ, which has
become double, or has been subdivided ; and
3. The germ has been regarded as abnormally
compound from the first, implying that the
organs and parts composing the double mon-
ster are at once produced from this germ,
without either separation or coalition of its
parts other than belong to the natural process
of developement. On the comparative merits
of the first and second hypotheses, as parts
of the general doctrine of monsters, one of
the most interesting physiological discussions
extant is recorded in the Memoires de l’ Aca-
demic des Sciences de Paris, between 1724; and
1743. The chief disputants were Lernery
and Winslow ; the contest lasted nineteen
years ; it engaged the attention of all anato-
mists, ant! called forth writings by Haller and
a crowd of authors of less note, and was only
terminated by the death of Lemery. Every
argument that could be founded on the know-
ledge of those days was brought forward, and
the subject was, for the time, utterly exhausted ;
but the facts accumulated in later years have
furnished such volumes of additional evidence,
that the same question, between original and
acquired monstrosity, as far as it relates to
double monsters, may even now claim to be
discussed.

It is certain that two ova may be formed
in one Graafian vesicle (Von Baer, Bischoff,
Bidder). The equally well-known fact, that
the common fowl sometimes produces double-
yolked eggs, naturally led at one time to the
opinion that the formation of double monsters
might be attributed to the developement and
subsequent union of the embryo in each yolk ;
an opinion which has been adopted by some
on very insufficient grounds, as it does not
appear to be warranted by any direct observ-
ations made upon the result of the incubation
of double-yolked eggs, and is at variance with
much of wdiat is known of the structure and
mode of union of the two embryos composing
a double monster.*

* I have here made use of the words of Professor
Allen Thompson, who, in a remarkable memoir upon
double monsters, published July, 1844, in the London
and Edinburgh Monthly Journal, fully entered into
the topic, and illustrated the genesis of double mon-
sters by some very interesting observations. I
lament that he was not acquainted with my mono-
graph upon the same subject, nor with the succinct
account which Mr. Paget has given of it in the
British and Foreign Medical Review for October,
1841. He would have found in it a great deal in
corroboration of his own opinions, in which I uni-
versally agree with him.

97+ TERATOLOGY.

C. F. Wolff has distinctly affirmed, that a
double-yolked egg is equivalent to a double
ovum ; that the produce of its incubation
would be twins ; and that a double monster
can only proceed from a single yolk contain-
ing a double germ. Examples of double em-
bryos of birds sometimes occur at the full
period of incubation, in which both are com-
plete, and there is no union, excepting at the
umbilicus. It is barely possible that each of
these embryos may have been developed from
a separate yolk, and that in the course of
incubation the two yolks have come to coa-
lesce, in consequence of external pressure, or
other causes. Towards the conclusion of the
period of incubation, when the yolk usually
enters the abdomen of the foetus, we may
suppose, in the case before us, a partial en-
trance of the common yolk into the abdomen
of each embryo, and thus, upon the subse-
quent contraction of the umbilical aperture,
the union of the two embryos may be effected.
We learn, from the accurately-detailed ob-
servation of C. F. Wolff, previously referred
to in my monograph, that two completely
separate foetuses may be formed in the bird’s
egg upon a single yolk, and within a single
germinal and vascular area. The egg, in
this instance, had been incubated six days,
and both the embryos were at once so com-
plete and so distinct, that there is no reason
to believe they v?ould have been united till
the period when the entrance of the yolk into
the abdomen of both, and the contraction of
the umbilical apertures, had brought them
together.

In a dozen double-yolked eggs, which Prof.
Allen Thompson brought to incubation, he
never succeeded in obtaining a double mon-
ster, nor even two embryos, at the full period,
from any of them. In several instances he
found that one yolk only had been productive.

All this proves that such double-yolked
eggs may produce twins, but that the forma-
tion of a double monster is not dependent on
them. It is highly probable that in the same
manner, in Mammalia, the arrival in the
uterus of two impregnated ova, in close
proximity with one another, will be attended
with the production, not of a double monster,
but of twins.

The complete fusion of these twins seems
to me quite impossible. One of my chief
arguments against the hypothesis of fusion
of originally separate germs is the important
fact, which I derive from my own investi-
gations and from those of others, that double
monsters form one series, among whose seve-
ral members the degrees and modes of devia-
tion from singleness gradually increase, and
pass, without one abrupt step, from the ad-
dition of a single ill-developed limb to the
nearly complete formation of two perfect
beings. Now if this be true, no hypothesis
can be acceptable if it do not plausibly ex-
plain the origin of the whole series of double
monsters, or if, though it may suffice to ex-
plain the facts in one part of the series, those
in another part are opposed to it. And here

is a fair objection against the hypothesis of
fusion of two originally perfect and separate
embryos. Grant that we might explain by it
the formation of several of the more perfect
instances of duplicity; still, if the same hypo-
thesis is altogether opposed by the simpler
forms of duplicity, it is surely not tenable.
For example, it cannot account for the exist-
ence on a child’s sacrum of a shapeless mass,
containing an isolated portion of intestine, as
in Mr. Hanley’s case. And still less can it
explain the existence of a superfluous limb ;
for the limbs are mere off-shoots, and are
produced at so late a period, that if we could
imagine two embryos to come in contact by
their shoulders or pelvis, and a fusion of those
parts to take place, we should still have to
explain how one of them, leaving only an arm
or a leg behind him, could for the rest of his
substance, head, trunk, and all, wholly dis-
appear.

It was a main objection against the doctrine
of Lemery, that if two germs came in contact
by accident (as he supposed), they could not
exhibit any regularity in their mode of attach-
ment, but faces would be forced into chests,
abdomens into spines, and so on. The mo-
derns, who adopt the same hypothesis, sup-
pose that the ova come in contact not by ac-
cident, but by an attraction de soi pour soi, of
which the influence is, that the two ova being
by accident set face to face or back to back,
or in any other way similia sinrilibus, will be
drawn to each other, and will unite by similar
parts. But, with all respect for the authority
of M. Geoffroy St. Hilaire and his disciples
(as Mr. Paget elegantly said in his abstract
of my monograph upon double monsters),
who regard this as “ la regie supreme de
tous les arrangements et de toutes les mo-
difications organiques chez les etres com-
poses,” I confess that I can find no good
evidence that such an attraction exists. I
can see in it nothing more than a very happy
expression of a fact, which it in no wise ex-
plains. The extraordinary notion of MM.
Delpech and Coste, that such an attraction
may be the result of electric currents, is
certainly no evidence of its existence, this
being entirely imaginary. And the reasoning
in its favour seems no better than the facts,
for I can find nothing but this kind of circle:
monsters adhere by similar parts, therefore
there is an attraction de soi pour soi; there is
then such an attraction, and therefore double
monsters so adhere. I believe, therefore, that
such an attraction is hypothetical ; and if it
be so, surely the hypothesis which involves it
and an accident as essential elements is less
probable, as well as less sufficient, than that
which I maintain. It is scarcely better than
Lemery’s, of mere accident ; for it requires
not only the accident of a particular position
of the ova, but that of their being of the same
sex, which has been said previously to be
the general rule for double monsters. After
all this, we conclude with the words of the
learned Wolff, published in 1773 : — “ Patet,
igitur, monstra composita non sic oriri, ut

TERATOLOGY.

975

aliquando duo separati integri embryones fue-
rint, qui dein contingentes et compressi, par-
tibus eorum nonnullis deslructis, aliis coalitis
et commixtis, concrescerent in unum novum
compositum corpus ; ea vero, quae vel defectu
partium vel insolita structura monstra sunt,
non ita fieri lit prius integri et naturales em-
bryones fuerint, qui deinde per causas acci-
dentales ad generationem non pertinentes
niutilati vel transmutati fuerint; sed necesse
esse, ut utraque monstrorum genera a primis
suis initiis jam ejusmodi monstra fuerint.”

If we are right in not admitting the exist-
ence and the fusion of two distinct germs,
we necessarily adopt the opinion that only
one germ has been formed, and that in this
excess of formative power lies the cause and
origin of every monstrous duplicity. Mr.
Allan Thompson demonstrated, in coincidence
with Wolff, Von Baer, and Reichert, as may
be seen in the wood-cut (y%. 629.), that

Fig. 629.

From a fowl’s egg after sixteen or eighteen hours’ in-
cubation. Magnified four times,
a , the germinal area of the cicatricula ; b, the
transparent area, containing two primitive traces
of embryos ; c c, primitive grooves of the double
embryonic trace, on each side of which are seen
the laminae dorsales.

( After A. Thompson.')

upon one yolk, and in one germinal mem-
brane or blastodermatic vesicle, there may be
formed, in birds, two primitive grooves, which,
in their ulterior increment, shall probably form
a double monster, as may be seen in a goose’s
egg, after five days’ incubation, represented
after Allan Thompson, inyfg. 630. By the for-
mation of such a double primitive groove in a
single ovum, we may explain the origin of the
principal types of double monsters ; and on
this point a recent observation of Valentin
seems particularly worthy of notice, viz. that
in which an injury, inflicted on the caudal ex-
tremity of an embryo on the second day, was
found, on the fifth, to have produced the
rudiments of a double pelvis and four in-
ferior extremities. But if we admit this cause
for those large and principal types, we must
acknowledge that it is insufficient for the
heteradelphs, and for all those cases in which,
the body remaining single, some parts are

Fig. 630.

I z h k

Double embryo removed from a goose’s egg after Jive
days’ incubation. Magnified four times,
g, the common heart ; h, rudiments of the superior,
i, of the inferior extremities ; h, the common ce-
phalic fold of the amnios ; l, the caudal folds.

( After A. Thompson.)

double. For these the excess of formative
power is the only explanation we can give.
We understand, under this name, not the
nisus formativus of the ancient physiologists,
working as a Deus ex machine, but the physical
and vital metamorphoses materioe , to which the
formation of a new being ought to be attri-
buted. Those who are fond of the modern
nomenclature may name it, if it pleases them,
typical or organic power. But enough, we admit
such a power, of whatever name it may be,
and contend further, that different degrees or
quantities of excess lie at the origin of all the
cases of double monsters, the degree of excess
determining in each the degree of duplicity.
If a certain excess of power be admitted
capable of producing any one case of duplicity,
other amounts of excess may be believed
capable of producing all the other cases which
differ from it only in degree ; and I meant to
have proved, in my monograph, and in the
succinct survey I have given of double mon-
sters in this Article, that all double monsters
may be referred to differences in degree of
deviation from the normal singleness.

But in many double monsters we see excess
in one part and defect in another, so that we
must suppose, in our hypothesis, that in these
cases the power, more or less excessive in
quantity, is also wrongly distributed. Nor
is this inconceivable ; for since, in the normal
developemental power, we must imagine at
least two elements, quantity and distribution,
and must acknowledge that, for the attain-
ment of a perfect result, the quantity must be
distributed in definite proportions to each
part, so it is not improbable that, in certain
circumstances of fault in the ovum, a normal
or an excessive power may be distributed dis-
proportionately in the several parts.

To sum up, therefore, our reasons for re-
jecting the hypothesis of fusion of ova in

976 TESTICLE (NORMAL ANATOMY).

favour of that of excess or irregular distri-
bution of developemental power, for preferring
to regard them as examples rather of single-
ness tending to duplicity than of duplicity
tending to singleness, are briefly these : that
it is probable that the whole class of monsters
by excess owe their origin to different de-
grees of one common fault, and consequently
that the explanation of their origin ought to
be the same for all ; that no kind of fusion
can account for the production of super-
numerary individual organs, the rest of the
body being single ; but that it is not impos-
sible that excess of power in the ovum, which
all admit can alone explain the lower degrees
of duplicity, may, in proportionally higher
degrees, perhaps by the formation of two
primitive grooves, produce the more complete
double monsters, or even two such separate
individuals as are sometimes found within a
single amnion.

Bibliography. — On account of the length of
this Article, and the great number of books upon the
subject, I shall omit the Bibliography, and refer to the
foot-notes as well as to the manuals of Meckel, Ro-
kitansky, Geoffroy St. Hilaire, von Ammon, and my
own, in which the bibliography is duly noticed.

(W. Vrolilc.)

TESTICLE. — (Human Anatomy). Gr.
opx‘r ; Latin, Testis — Testiculus ; French,
Testicule ; German, Rode ; Italian, Testieolo.

The testicle is the gland by which the
semen or spermatic fluid is secreted. Two in
number, and contained within the scrotum,
these organs are suspended at a variable and
unequal distance from the abdominal rings,
one testicle, generally the left, hanging a little
lower than the other. This arrangement pre-
vents collision between these organs when the
thighs are suddenly approximated ; one tes-
ticle slipping above the other, and thus elud-
ing violence. In cases of transposition of the
viscera and blood-vessels, it has been observed
that the right testicle hangs lower than the
left.

The shape of the testicle of an adult is that
of an oval with flattened sides. The organ
has two extremities, an antero-superior, and
a postero-inferior ; and two lateral surfaces.
Its position in relation to the body is rather
oblique, its long axis or antero-posterior di-
ameter passing from above downwards and a
little inwards. Its edges and sides are convex.
Its upper extremity is rounded and capped by
the epididymis, which rises above the body
of the gland like the crest on a helmet. Ac-
cording to Cruveilhier the testicle measures
two inches in length, one inch in breadth, and
eieht lines in thickness. Sir Astley Cooper
makes its long diameter two inches ; its trans-
verse, an inch and a half ; and its lateral, one
inch and one eighth. I have found the mean
dimensions of the testicle to be one inch and
three quarters in length, one inch and a quarter
across or in breadth, and one inch in thick-
ness or from side to side. Meckel states its
average weight to be four drachms, and Sir
A. Cooper about an ounce. I have lound the

mean of these two estimates, viz. six drachms,
to be the ordinary weight of the sound testicle
of a healthy adult.* There are few organs
subject to greater variations in size and weight
than the testicle, even in men of the same age
and constitution. The testicles also of the
same individual rarely agree, the volume and
weight of the left being, in general, greater
than those of the right. I weighed the tes-
ticles of six men, two of whom were killed by
violence, and found the left gland heavier than
the right in five; in neither of these instances,
however, was the difference more than a
drachm. The organ feels tense, compact, and
slightly elastic. Its degree of consistence
depends more on the tension of the tunica
albuginea than on the proper substance of the
gland. It is a good deal influenced by the
quantity of seminal fluid contained in the
tubular structure, and its state of activity or
rest ; the gland being tense and tumid when
the organ is exercised and the tubuli are dis-
tended, and soft and flaccid, when they are
empty and the gland inactive. The parts
composing the testicle may be described under
four heads : — 1. The protective parts or
tunics ; 2. The proper glandular or secreting
structure ; 3. The excretory parts ; 4. The
vessels and nerves.

I. The Protective Parts or Tunics. — The
Tunica Vaginalis. — This is a delicate serous
membrane in the form of a shut sac, which
consists of two portions ; an outer one, the
parietal, which is free and loose ; and an
inner, reflected, visceral or testicular portion,
which closely invests the gland. The two
portions are connected ami continuous with
each other. The outer one loosely invests
the whole of the testicle except its posterior
edge and inferior extremity, parts where the
membrane becomes attached to the gland.
It is connected with the testicle at about five
lines from the lower extremity, and the junc-
tion of the two portions is marked by a white
and rather irregular line. The uncovered por-
tion of the organ corresponds to the original
attachment of the gubernaculum. On the
inner side of the gland the membrane, after
investing the lower part of the cord to a
greater or less extent, is reflected to the epi-
didymis just below its head, and to the pos-
terior edge of the body of the testis, being
there separated from the epididymis by the
vas deferens and blood-vessels of the gland.
On the outer side the membrane entirely
covers and closely invests the epididymis,
and forms a cul-de-sac, which isolates its mid-
dle from the posterior border of the testicle,
and in cases of hydrocele is often distended
into a pouch. At the bottom of this sac the
tunica vaginalis on the two sides comes into
close contact, and sometimes there is a com-
munication at this spot between the two. The
smooth and polished surface of the shut sac
thus formed by the tunica vaginalis is lubri-

* This nearly accords with Krause’s estimate
(Muller’s Archiv. 1837.) — who found the mean
weight in five instances to be 354-4 grains, or five
drachms, two scruples and fourteen grains.

977

TESTICLE (NORMAL ANATOMY).

cated by an albuminous fluid, having the
ordinary properties of the secretions of the
other serous membranes. The office of this
membrane is to facilitate the movements of
the gland, so as to enable it to elude pressure
and escape violence.

In some adult subjects the tunica vaginalis,
which was originally a process from the serous
lining of the abdomen, still retains its con-
nexion with that cavity. When the com-
munication is free, the sac is very liable to
receive a protrusion of some of the contents
of the abdomen, and become the seat of con-
genital hernia. Sometimes the communica-
tion continues through a contracted tubular
canal, which, though too narrow to admit the
transit of any of the viscera, is open to the
passage of fluid. In other cases the oblitera-
tion is partial, one or more isolated serous sacs
being left along the cord. It more often
happens, however, that after the upper aper-
ture of this process has closed a considerable
part of it below remains unobliterated, so that
the tunica vaginalis extends for some distance
upwards in front of the cord. Frequently,
also, although the obliteration is complete,
remains of the prolongation may still be found
in the form of a slender whitish filament, or
fibrous process, which is lost in the areolar
tissue in the anterior part of the cord, but
may sometimes be traced as far as the tunica
vaginalis.

A small body of an irregular shape and
variable size, and of a pale red or pinkish hue,
is commonly found attached, often by a thin
pedicle, either to the upper extremity of the
testicle, or at the angle where the tunica
vaginalis passes from the body of the gland to
the epididymis. It is composed of a dupli-
cature of this membrane, containing some fine
areolar tissue and a number of small vessels.
It occasionally contains a little fat. I have
seen this little body in the testicle of the
fcetus whilst in the abdomen, and, in early
life, it is often of proportionally larger size,
and of a deeper red colour than in the adult.
It is quite distinct from the pedunculated
cysts often found attached to the head of the
epididymis. This little appendage to the
tunica vaginalis seems to correspond with,
and to be a type of, the remarkable omental
process attached to the superior part of the
testicle in the Rodentia and other animals.
That it is an unimportant structure in the
adult, is shown by its being frequently want-
ing. It may be of use, however, by slightly
increasing the secernent serous surface.

The tunica Albuginea, or Tunica Propria, is
a dense, tough, inelastic membrane, composed
almost solely of white fibrous tissue, analogous
to the sclerotic coat of the eye. It completely
invests the body of the testicle, but not the
epididymis. Its external surface is covered
by the tunica vaginalis reflexa, to which it
intimately adheres. This tunic is divisible
into two layers, which can be separated only
by a tedious dissection, but which in certain
animals may be detached without difficulty.
The branches of the spermatic artery and

VOL. iv.

veins ramify in the substance of the tunica
albuginea, in canals bearing in their arrange-
ment some analogy to the sinuses of the dura
mater, which membrane the outer layer is
supposed to resemble. The smaller vessels
are chiefly distributed on the inner layer,
which owing to its vascularity has been com-
pared to the pia mater investing the brain.
At the postero-superior border of the testicle,
and a little to its outer side, the tunica albu-
ginea forms an internal projecting body or
process, which lodges the blood-vessels and a
portion of the glandular structure of the tes-
ticle, called the rete testis. This body is
named, after the anatomist who first described
it, the Corpus Highmoii. It has since, how-
ever, been called by Sir A. Cooper the medi-
astinum testis , and he describes it as being
formed by the tunica albuginea, which at that
part is divisible into three layers. The first
layer turns upon the spermatic cord, and
unites with the sheath which covers the ves-
sels. The second layer unites with a similar
layer on the opposite side, and forms a thick
substance, between the fibres of which inter-
stices are left for blood-vessels and absorbents,
whilst the internal layer, uniting with that on
the opposite side, as well as with the preced-
ing layer of the tunica albuginea, forms the
process called mediastinum, which projects
into the testicle between the tubuli, and it is
in this substance that the seminal canals of
the rete are placed. The mediastinum is
therefore composed of two bodies ; the upper
placed towards the spermatic cord, the lower
towards the centre of the testicle : in the
upper are placed the blood-vessels ; in the
lower, the canals of the rete. Its length
varies from six to eleven lines.

II. Glandular or Secreting Structure. — The
glandular part of the testicle is very simple,
and its tissue is more easily demonstrated
than the structure of most other glands. It
consists of numerous seminiferous vessels or
tubes, supplied with blood-vessels, lymphatics,
and nerves. Its colour is a greyish yellow or
brown, more or less tinged with blood, and is
paler in infants and old men than in adults.
The tubes are collected into numerous lobes
or lobules, invested by a fine areolar tissue,
which, detached from the interior of the tunica
albuginea, penetrates the gland, and sends out
lateral processes forming septa, which separate
and sustain the lobules. These septa at their
origin, partake of the fibrous character of the
tunica albuginea, but as they converge towards
the superior border of the testicle, occupied
by the corpus Highmori, they become finer,
and are gradually resolved into a delicate
areolar tissue. The septa are traversed by
numerous blood-vessels, which minutely divide
in them before being distributed on the semi-
niferous tubes. Sir A. Cooper states, that
the inverted portion of the tunica albuginea,
forming the mediastinum testis, sends forth
numerous ligamentous cords, some of which
pass to the anterior edge of the testis ; whilst
others form shorter processes to support and
invest the lobes, being met by similar liga-
3 R

978 TESTICLE (NORMAL ANATOMY).

mentous cords from the inner surface of the
tunica albuginea. I have not been able to
make out any such ligamentous processes
passing into the substance of the testis, as are
represented in Sir A. Cooper’s work (part i.
pi. 2. fig. 3), which I have no doubt is an ex-
aggerated view of the preparation from which
it was taken. The cords described appear to
me to consist chiefly of blood-vessels sup-
ported by slight fibrous processes from the
tunica albuginea and areolar tissue. In a well-
injected testicle very little tissue of the nature
of ligament can be found between the lobes.
The secreting structure of the testicle, like the
texture of many other glands does not possess
much common sensibility. When exposed in
disease it may be probed and injured with the
forceps without pain.

Tubuli Seminiferi. — These tubes, which
form by far the greatest part of the bulk
of the glandular structure of the testicle,
are very numerous, and radiate from all parts
of the circumference of the organ towards
the mediastinum, making numberless con-
volutions which progressively diminish as
they approach the rete testis. Two or
more of the tubuli, being collected together
and invested by a common tunic of con-
densed areolar tissue, form a lobe or lobule of
a conical form, its apex terminating at the
corpus Ilighmori. The lobes thus formed are

Fig. 631.

The lobes attached to the mediastinum, but artificially
separated from each other. ( From a preparation
in the Hunterian Museum, formerly in Sir A.
Cooper's collection.')

not entirely distinct, but communicate with
neighbouring lobes : the processes investing
them are therefore incomplete, and the lobes
cannot be separated from each other without
division of some of the seminiferous tubuli.
Krause estimates the number of the lobes as
varying from 404 to 484.* The tubuli are of
a white colour and uniform size, but their
calibre differs in different subjects, and varies
a good deal according to the age of the subject
and the state of activity of the testicles, being
larger in young adults and when distended
with semen, than in old persons and when the
gland is in a state of rest. The size of the
ducts also often differs in the two testicles of
the same subject. In general the calibre of
the tubuli corresponds to the size of the tes-

* Muller, Archiv. ftir Anatomie, 1837, s. 22.

tide. Observers do not exactly agree in
their estimates of the diameter of the tubuli.
The average diameter of the uninjected canal
is estimated by Muller at yL- of a line ; by
Lauth * at yiyof an inch. Krause found the
tubuli, when filled with semen, to measure
about T~ of a line, and in old men and youths
J5.. Huschkef estimated the ordinary thick-
ness of the whole tube from yiy to J^of a line,
and that of the walls from — (y to yyT. Owing
to the stoutness of the basement membrane,
the thickness of the walls of the tubes is con-
siderable as compared with the secreting ducts
of other glands, and this accounts for the
tubes being able to resist the pressure of a
column of mercury in injections. Monro
reckoned the number of the seminiferous
tubes at 300 ; Lauth made the average num-
ber 840, and he estimated the mean length of
all the ducts united at 1750 feet. He found
the individual ducts to vary in length, the
mean being 25 inches. Krause estimated
their entire length at 1015 feet. The mem-
brane composing the tubuli is continuous
with the mucous surface of the genito-urinary
system. It is lined with epithelium, and the
spermatozoa are developed from the epi-

Fig. 032.

Glandular structure of the testicle, displayed by mer-
curial injection. ( After Lauth.)

a a a, glandular substance of the testicle subdi-
vided into lobes, each lobe being composed of con-
voluted tubuli closely packed; b, rete testis; c, vasa
efferentia ; d, inflected part of the vasa efferentia
forming the coni vasculosi; e, dilatations of the
efferent vessels ; f, body of the epididymis ; g, tail
of the epididymis; h, vasculum aberrans; i, in-
flected part of the vas deferens ; It, straight part of
the duct.

* Mem. de la Socidte d’Hist. Nat. de Strasbourg,
t. i.

f Encyclopedic Anatomique, t. v. p. 347.

TESTICLE (NORMAL ANATOMY). 979

thelial cells. There is no appearance of an
intertubular substance ; the ducts are merely
connected by a loose network of vessels, and
consequently readily admit of being sepa-
rated and unravelled. The tubes, when suc-
cessfully injected with quicksilver, form a
beautiful anatomical preparation. Sir A.
Cooper succeeded in filling the tubes with size
injection ; but he has not described the mode
in which it was effected, and other anatomists
have failed in similar attempts.*

When the tubuli seminiferi are unravelled,
they are found to divide and form numerous
anastamoses, which increase in frequency to-
wards the circumference of the testicle. (See
diagram, fig. 633. a1 a1). The tubuli thus form
one vast network of communication, so that it
is impossible to isolate completely either a duct
or a lobule. The credit of making this interest-
ing discovery of the anastamoses of the se-
minal tubes is due to Lauth. In only one
instance did he succeed in finding a duct, ter-
minating in a blind pouch, and this he regarded
as exceptional. Blind ends have been found,
however, more frequently by Krause. The
anastamoses ol the tubules have been observed
in the rat and other animals as well as in man.
The convolutions of the seminal tubes di-
minish in number as they approach the me-
diastinum, and cease altogether at a distance
of from one to two lines, where two or more
unite to form a single straight duct, termed
vas rectum, which joins the rete testis at a
right angle (a2 a2). The vasa recta are very
slender, and easily give way when injected :
their calibre, which is greater than that of the
seminal tubes, is estimated by Lauth at j-g-g-th

Fig. C33.

Diagram of the testicle. ( After Lauth.)

a a a, tubuli ; a1 a1, subdivisions and anastamoses
of the tubuli ; a2 a-, vasa recta.

The other references are the same as in fig. G32.

* Sir A. Cooper’s beautiful preparations of the
testicle are preserved in the Museum of the Boyal
College of Surgeons of England.

of an inch. Haller reckoned their number at
twenty, which is, however, too few.

Rete Testis, as its name implies, consists of
a plexus of seminal tubes, which occupies the
corpus Highmori, or mediastinum testis. The
vasa recta, after penetrating the walls of this
body, terminate in from seven to thirteen ves-
sels which, running parallel to each other in
a waving course, and frequently dividing and
anastomosing, form the rete testis, (b). Lauth
found the mean diameter of the vessels of the
rete in injected preparations of an inch.
According to Prochaska, these vessels are
supplied with valves, but such is not the case.
Small dilatations, however, are often found in
different parts of the plexus.

III. The Excretory Parts.- — The epididymis,
a continuation of the testicle, is a body of a
crescentic form, divided into an anterior and
upper extremity, called head, or globus major,
which is firmly attached to the testicle ; a
middle part or body, which is less in size, and
separated from the gland by a pouch of the
tunica vaginalis ; and a tail or globus minor,
connected to the testicle by areolar tissue.
The volume and weight of the epididymis
vary in different subjects, but are proportionate
to the size of the testicle. It is longer than
the testicle, measuring about two inches in
length and four or five lines in width. Its
name (from £tt\ upon, and SiSugos testis,) indi-
cates its position, which is along the postero-
superior border of the gland. The epididy-
mis is chiefly made up of seminal canals
connected and supported by a firm resisting
areolar tissue. The ducts which spring from
the upper part of the rete testis to form the
epididymis are termed vasa efferentia. They
are usually about twelve or fourteen in num-
ber, but vary from nine to thirty. The inflec-
tions of each of these efferent ducts are so
arranged as to form in the head of the epidi-
dymis a series of elongated conical figures
called coni vasculosi. These ducts, at their
commencement, run straight for a distance of
about one or two lines, when they form con-
volutions which become more numerous and
close as the ducts recede from the testicle.
Their length varies, the upper being the
shortest. Lauth found their average length
to be seven inches four lines, and calculating
their number at thirteen, he makes the united
length of the vasa efferentia nearly eight feet.
He states that the efferent ducts diminish in
size from their commencement to their ter-
mination in the canal of the epididymis, where
they are less than the seminiferous ducts of
the testicle. (Fig. 634.) As in the rete,
round dilatations of variable size are often
met with in these ducts. (Fig. 632., e e.)
The efferent ducts, after forming the coni
vasculosi, successively join a single duct, the
canal of the epididymis, at irregular distances,
the intermediate portions of the duct varying
in length from half an inch to six inches.
The efferent ducts are more slender than the
canal of the epididymis, and frequently give
way under the pressure of the column of mer-
cury when injected. The body and tail of the
3 r 2

980 TESTICLE (NORMAL ANATOMY).

epididymis are entirely made up of the con- didymis or vas deferens. It is more com-
volutions of the single canal in which the monly attached at the angle formed by the

Fig. 634.

An efferent vessel and a portion of the head of the
epididymis magnified, to show the progressive dimi-
nution of the canal of the cone, and the calibre of
this vessel, in comparison with that of the canal of
the epididymis.

c, vas deferens ; d, inflected portion of the duct ;
e e, head of the epididymis. ( After Lauth.)

vasa efferentia terminate, closely connected
by areolar tissue. Monro described this canal
as gradually increasing in size from the head
to the tail, and he estimated its calibre about
its middle at of an inch. Lauth states
that its size is subject to great irregularities in
different parts and in different subjects. This
anatomist has particularly described the con-
volutions of this duct, and has shown that they
are regularly arranged in four series, which
successively increase in size ; the first being
the smallest, and the fourth the largest. The
arrangement will be understood by reference
to the subjoined figure. Monro estimated the
length of the canal at thirty feet eleven inches.
Lauth found its mean length to be nineteen
feet four inches eight lines. The parietes of
the canal are strong, and bear considerable
resistance. The canal of the epididymis ter-
minates in the excretory duct of the testicle,
the vas deferens, and is usually contracted at
the part where the two join, which accounts
for the mercury when forced into the vas de-
ferens being often arrested at this point. It
was calculated by Monro that the semen, be-
fore arriving at the vas deferens traverses a
tube forty-two feet in length. Lauth, how-
ever, makes the whole distance but little more
than twenty-two feet.

Vasculum aberram. — This name was given
by Haller to a blind duct or coecal appendage
often found connected either to the epi-

Fig. f>35.

Canal of the epididymis partly unravelled, to show the
four series of inflections which the duct undergoes
in the several divisions of the epididymis,
o, o, first series of inflections ; p, p, second series ;
q, q, third series; r, r, fourth series. {After Lauth).

termination of the former in the latter. (Figs.
632., and 633, h.) It forms a convoluted
duct as large as the canal of the epididymis,
which is contracted at its insertion, and ter-
minates in a blind and often dilated extremity.
Sometimes after being dilated for a certain
distance it diminishes, and becoming very
minute, is lost in the areolar tissue of the
cord. It usually passes up the cord for about
two or three inches, but has been found to
extend as far up as the brim of the pelvis.
The length of this appendage when unravelled
varies from one to twelve or fourteen inches.
The vasculum aberrans is not constantly pre-
sent ; indeed, Monro found it only four times
in sixteen ; but 1 believe, with Lauth, that it
exists more frequently. Occasionally there is
more than one, and as many as three have
been found both by Lauth and Sir A. Cooper.
Hunter regarded these ducts as supernumerary
vasa deferentia, of a nature similar to the
double ureters.* Muller states that their
office is evidently the secretion of a fluid
which they pour into the epididymis. f We
have no evidence, however, that the duct
serves any particular office.

Vas deferens, — the excretory duct of the
testicle, commences from the tail of the epidi-
dymis, and terminates in one of the ejacu-
latory canals behind the bladder, being in
length from fifteen to sixteen inches. Arising

* Works by Palmer, vol. iv. p. 24.
t Physiology, trans. by Baly, vol. i. p. 45

TESTICLE (NORMAL ANATOMY). 981

from the contracted part of the canal of the
epididymis at an acute angle, it ascends along
the inner side of this body, from which it is
separated by areolar tissue and the spermatic
arteries and veins. A right or left testicle may
thus always be distinguished by the circum-
stance that when the testicle is in position,
the vas deferens is situated on the inner or
mesial side of the organ. In this part of its
course, for the distance of about an inch and
a half, or more, the vas deferens forms numer-
ous convolutions, {Jigs. 632., and 633, i),
which gradually cease as the duct mounts
above the testicle. The inflected part of the
vas deferens, when unravelled, was found by
Lauth to measure six inches and a half. It
afterwards takes a direct course (£) up the
spermatic cord to the inguinal canal, passing
behind and at a short distance from the
spermatic arteries and veins. On entering the
abdomen at the internal ring, it quits the
spermatic vessels and descends into the pelvis,
passing at first by the side of, and afterwards
behind and below the bladder, on the inner
side of the corresponding vesicula seminalis,
the excretory duct of which it joins at an
acute angle, to form the ejaculatory canal.
The canal of the vas deferens is extremely
fine, and its walls are nearly uniform in thick-
ness until it reaches the vesicula seminalis.
It is lined by a fine membrane of a mucous
character, which is continuous with the
urethra. This membrane forms longitudinal
folds. The vas deferens is round and in-
durated,— harder than any other excretory
duct in the body, by which character it is
easily distinguished, when handled, from the
other parts constituting the spermatic cord.
Many anatomists have entertained the opinion
that the parietes of this duct are muscular.
It is distinctly so in the bear, bull, and other
animals. On careful examination, however,
of sections of the human vas deferens with the
microscope, I could discover nothing more
than simple fibrous tissue. Huschke makes
three layers of fibres ; two longitudinal, and
one circular, situated between them ; the
latter being the thickest. The duct has an
external investment of condensed areolar
tissue.

IV. The Vessels and Nerves. — Spermatic
Vessels. — The spermatic arteries, the chief
vessels supplying the testicles, arise in pairs,
at a very acute angle, from the fore-part of
the aorta, immediately below the renal ar-
teries. Their origin is subject to consider-
able varieties. The twro seldom arise at the
same level, and the right is often a branch of
the right renal artery. Sometimes one or
both come off from the superior mesenteric.
Occasionally there are two spermatic arteries
on one or both sides, arising in the regular
way. All these deviations are more frequently
met with on the left than on the right side of
the body. Each artery pursues a tortuous
course downwards and outwards, passing
behind the peritoneum obliquely across the
psoas muscle and ureter, to which, as well
as to the surrounding areolar tissue, it gives

off several branches. The artery then enters
the inguinal canal through the internal ring,
and emerging at the external, passes down
the cord, being surrounded in its course by
the spermatic veins. The further distribution
of the artery is thus correctly described by
Sir A. Cooper: “ When the artery reaches
from one to three inches from the epididymis,
varying in different subjects, it divides into
two branches, which descend to the testicle
on its inner side, opposite to that on which
the epididymis is placed ; one passing on the
anterior and upper, the other to the posterior
and lower part of the testis. From the anterior
branch the vessels of the epididymis arise:
first, one which passes to its caput; secondly,
another to its body, and, thirdly, one to its
cauda and the first convolutions of the vas
deferens, communicating freely with the de-
ferential artery. The spermatic artery, after
giving off branches to the epididymis, enters
the testis, by penetrating the outer layer of
the tunica albuginea ; and dividing upon its
vascular layer, they form an arch by their
junction at the lower part of the testis, from
which numerous vessels pass upwards ; and
then descending, they supply7 the lobes of the
tubuli seminiferi. Besides this lower arch,
there is another passing in the direction of
the rete, extremely convoluted in its course,
and forming an anastomosis between the prin-
cipal branches.” The testis receives a further
supply of blood from anothe" vessel, the ar-
tery of the vas deferens, or posterior spermatic
artery, which arises from one of the vesical
arteries, branches of the internal iliac. This
artery divides into two sets of branches, one
set descending to the vesicula seminalis and
to the termination of the vas deferens ; the
other, ascending upon the vas deferens, runs
in a serpentine direction upon the coat of that
vessel, passing through the whole length of
the spermatic cord ; and when it reaches the
cauda epididymis, it divides into two sets of
branches, one advancing to unite with the
spermatic artery to supply the testis and epi-
didymis, the other passing backwards to the
tunica vaginalis and cremaster.

The spermatic veins spring in three sets
from the testicle, one from the rete and tubuli,
and another from the vascular layer of the
tunica albuginea, and a third from the lower
extremity of the vas deferens. The veins of
the testicle pass in three courses into the
beginning of the spermatic cord ; two of these
quit the back of the testicle, one at its anterior
and upper part, and a second at its centre ;
and these, after passing from two or three
inches, become united into one. The other
column accompanies the vas deferens. There
is also a large vein, just above the testicle,
which crosses to join the three columns. The
veins of the epididymis are one from the
caput, another from its body ; one from its
cauda, and another from its junction with the
vas deferens, besides some small branches ;
they terminate in the veins of the spermatic
cord. The veins, after quitting the testicle,
become extremely tortuous, and frequently
o R 3

982 TESTICLE (NORMAL ANATOMY).

divide and inosculate in the cord, forming a
plexus termed vasa patnpiniformia. These
communications cease as the veins approach
the ring, which they enter, and ascending
along with the psoas muscle in company with
the spermatic artery, unite to form a single
vein which usually terminates on the right
side in the vena cava inferior, and on the left,
in the renal vein ; though this is subject to
some variety. The left spermatic veins pass
under the sigmoid flexure of the colon. Many
anatomists speak of the spermatic veins as
being destitute of valves, which they assign
as one of the reasons for the occurrence of
varicocele. I have several times injected these
veins with alcohol, and on laying them open
have observed valves in the larger vessels,
and I have also found injections thrown into
the veins arrested by the valves. They are
seldom seen, however, very near the testicle,
or in the smaller veins forming the plexus;
nor have 1 observed them within the ab-
domen.

Absorbents. — The absorbent vessels of the
testicle are very numerous, and arise from
every part of its internal structure and coats.
They unite to form four or five trunks, which
ascend along the cord, and traverse the in-
guinal canal, without communicating with the
glands in the groin, but pass upwards in front
of the psoas muscle, behind the peritoneum,
and terminate in the lumbar glands on the
side of the aorta.

Nerves. — The nerves of the testicle are
derived chiefly from the renal plexus, but
partly also from the superior mesenteric and
aortic plexuses. These nerves descend in
company with the spermatic artery to the
cord, where, being joined by branches from
the hypogastric plexus, which pass along the
vas deferens, they form together the spermatic
plexus, the branches of which are intermingled
with the vessels of the cord, and ultimately
terminate in the substance of the testicle.
A few twigs from the external spermatic
nerve may also be traced to the coverings of
the gland.

The Testicle in the Fcetus, and its Passage
into the Scrotum. — The testicles are first de-
veloped and situated in the abdomen. They
originate from the lower part of the corpora
Wolffiana, and may be detected at an early
period of foetal existence immediately below
the kidneys on the forepart of the psoas
muscles, to which they are attached by a
reflexion of peritoneum. This membrane
closely invests the testicles in the same man-
ner as it covers the other abdominal viscera.
The position of the testicle in the abdomen
is nearly the same as it maintains after .its
passage into the scrotum. The epididymis,
however, is relatively of a larger size than in
the adult, being about one-third that of the
body of the organ. Attached to each testicle
whilst in the abdomen is a peculiar body,
which was termed by Mr. Hunter, who first
described it, the gubernaculum, as it was sup-
posed to serve as a guide to the testicle in its
passage. It is a soft solid projecting body

of a conical form, which varies somewhat in
shape and size at different periods of transi-
tion of the testes, becoming shorter and
thicker as the gland approaches the abdo-
minal ring. It is situated in front of the psoas
muscle, to which it is connected by a reflexion
of peritoneum. Its upper part is attached
to the inferior extremity of the testicle, lower
end of the epididymis, and commencement
of the vas deferens. The lower part of this
process passes out of the abdomen at the
abdominal ring, and diminishing in substance
and spreading, terminates in three processes,
each of which has a distinct attachment. The
central part and bulk of the gubernaculum is
composed of a soft, transparent, gelatinous
substance, which, on examination by the mi-
croscope, is found to consist of nucleated
cells, the primitive areolar tissue : this central
mass is surrounded by a layer of well-deve-
loped muscular fibres, which may be distin-
guished by the naked eye, and which can be
very distinctly recognised in the microscope
to be composed of striped elementary fibres.
These muscular fibres, which may be traced
the whole way from the ring to the testicle,
are surrounded by a layer of the soft elements
of the areolar tissue, similar to that composing
the central mass ; and, in the same way as the
testicle, the whole process, except at its pos-
terior part, is invested with peritoneum. On
carefully laying open the inguinal canal, and
gently drawing up the gubernaculum, the
muscular fibres may be traced to the three
processes, which are attached as follows : the
external and broadest is connected to Pou-
part’s ligament in the inguinal canal ; the
middle forms a lengthened band which escapes
at the external abdominal ring, and passes to
the bottom of the scrotum, where it joins the
dartos ; the internal takes the direction in-
wards, and has a firm attachment to the os
pubis and sheath of the rectus muscle. Be-
sides these, a number of muscular fibres are
reflected from the internal oblique on the front
of the gubernaculum. It thus appears, that
the attachments of the muscle of the guber-
naculum, and those of the cremaster in the
adult are exactly similar. I have succeeded
in tracing out the former before the testicle
has moved from its original position, at dif-
ferent stages of the process of transition, and
immediately after its completion ; and of the
identity of the two muscles no doubt can be
entertained. Cams was of opinion that the
cremaster does not exist before the transition
of the testicle; but that it is formed mecha-
nically, by the testicle pushing before it the
lower fibres of the internal oblique, so as to
form the loops of this muscle.* This view
which has been adopted by M. Jules Cloquet,
and after him by many of the anatomists ot
this country, is erroneous and inaccurate.)-

The vessels of the testicle in the foetus

* Compartive Anatomy, by Gore, vol. 2. p. 347.

Vide Obervations on the Structure of the Gu-
bernaculum, and on the Descent of the Testis in
the Foetus, by the author, inLond. Medical Gazette,
April 10. 1841, or in the Lancet, of the same date.

TESTICLE (NORMAL ANATOMY). 983

arise from" the nearest largest trunks, and
enter the substance of the gland at its pos-
terior part. The artery of the vas deferens,
from which the gubernaculum is chiefly sup-
plied, is nearly as large as the spermatic. The
long course taken by the arteries and veins of
the testicle when in the scrotum is thus ex-
plained by the original site of the organ, to
which circumstance must also be ascribed the
sharp turn upwards of the vas deferens from
the epididymis, the two being continuous in a
direct line, whilst the testicle is in the ab-
domen.

Fig. 636.

Diagram of the gubernaculum and testicle previous to
its descent.

1, the kidney ; 2, the testicle ; 3, 3, the peritoneum ’
4, vas deferens passing down into the pelvis by the
side of the bladder; 5, the bladder; 6, the abdo-
minal ring ; 7, 7, Poupart’s ligament ; 8, pubic por-
tion of the cremaster; 9, fibres of the cremaster
arising from Poupart’s ligament ; 10, portion of the
gubernaculum attached to the bottom of the scro-
tum.

Between the fifth and sixth month of foetal
existence, sometimes later, the testicle begins
to move from its situation near the kidney
towards the ring, which it usually reaches
about tlie seventh month. During the eighth
month it generally traverses the inguinal
canal, and by the end of the ninth arrives at
the bottom of the scrotum, in which situation
it is commonly found at birth. The testicle,
both during its passage to the ring and
through the inguinal canal, carries along with
it its original peritoneal coat, adhering by the
reflexion of this membrane, during the whole
of its course to the parts behind, in the same
manner as whilst situated below the kidney.
The testicle therefore does not pass directly
and abruptly into a pouch prepared to receive
it, but carries the peritoneum with it, con-
tinuing to be connected to the parts behind
by the reflexion of the membrane, between
the folds of which the vessels and nerves join
the gland. In the passage of the testicle from
the abdomen to the bottom of the scrotum,
the gubernaculum, including its peritoneal
investment and muscular fibres, undergoes
the same change as that which takes place
in certain of the rodentia at the access of the
season of sexual excitement ; the muscle of
the testicle is gradually everted, until, when
the transition is completed, it forms a mus-
cular envelope external to the process of peri-
toneum, which surrounds the gland and front
of the cord. As the testicle approaches the
bottom of the scrotum, the gubernaculum di-

minishes in size, owing to a change in the dis-
position of its areolar elements ; the muscular
fibres, however, undergo little or no diminu-
tion, and are very distinct around the tunica
vaginalis in the recently descended testicle.
The mass composing the central part of the
gubernaculum which is so soft, lax, and yield-
ing, as in every way to facilitate these changes,
becomes gradually diffused, and after the
arrival of the testicle in the scrotum, contri-
butes to form the loose areolar tissue which
afterwards exists so abundantly in this part;
the middle attachment of the gubernaculum,
which may be traced to the dartos at the
bottom of the scrotum, gradually wastes away
and soon becomes indistinct, though slight
traces of this process often remain to the
latest period of life. Thus, after death, in
dragging the testicle of an adult out of the
scrotum by pulling the cord, the lower part
of the gland, which is uncovered by serous
membrane, is often found connected to the
bottom of the scrotum by a band of firm and
dense areolar tissue, which requires division
with the scalpel. This band is the remains
of the middle attachment of the gubernaculum.
In cases in which the testicle has been re-
tained in the groin, I have traced a cord of
dense tissue from the gland to the lower part
of the scrotum. After the arrival of the tes-
ticle in the scrotum, the peritoneum with
which it is closely invested, its original en-
velope, becomes the inner layer of the tunica
vaginalis ; whilst the pouch around, which is
continuous with it, forms the outer layer, or
vaginal sac. Immediately after the arrival of
the testicle in the scrotum, this bag commu-
nicates with the abdomen, and in quadrupeds
continues to do so during life ; but in the
human subject it soon begins to close, and
when the foetus is ushered into the world,
the abdominal orifice is often shut, and the
whole canal from the ring to the upper part
of the gland is, in general, completely obli-
terated in the course of the first month after
birth. The obliteration is effected by an
intimate union of the surfaces of the serous
membrane. It sometimes does not take place
at all*, or is delayed or only partially com-

Fig. 637.

Diagram of the testicle immediately after its arrival
in the scrotum, the cremaster being everted.

1, the testicle ; 2, the shortened gubernaculum ;
3, 3, the peritoneum ; 4 , portion of the cremaster
arising from Poupart’s ligament; 5 pubic portion
of the muscle.

* The communication constantly remains open in
quadrupeds, the chimpanzee, according to Professor
3 r 4

984 TESTICLE (NORMAL ANATOMY).

pleted. Congenital hernia, or hydrocele is
the result of a failure in this process ; and
other forms of hydrocele are occasioned by
imperfect obliteration of the canal.

Much difference of opinion exists as to the
immediate cause of the transition of the tes-
ticle. Hunter, Meckel, and others came to the
conclusion that the muscular fibres of the
cremaster are insufficient to bring the testicle
further than the abdominal ring and complete
the passage. They were not, however, ac-
quainted with the attachment of this muscle to
the pubis external to the ring, or it would be
difficult to understand why Mr. Hunter, after
arriving at the conviction that the cremaster
passes to the testicle whilst in the abdomen,
chiefly from analogy, was not induced by the
same process of reasoning to conclude, that a
muscle capable of changing the position of
the testicle in brute animals, would be ade-
quate to accomplish the same office in the
human foetus. The necessity for some active
agent to effect this change in the latter would
appear to be greater even than in the lower
animals, since, in the usual position of the
foetus in utero, the passage of the testicle
is contrary to gravitation, * and unaided by
the movements of respiration. Now, when
we consider the attachments and connec-
tions of this muscle in the foetus ; the per-
fect development of its fibres, as ascertained
by microscopical examination ; and the circum-
stance that there are no other means, no other
motive powers, by which this change can be
effected, or in any way promoted, 1 think there
is no reason to doubt that the cremaster ex-
ecutes the same office in the human embryo,
as that which it undoubtedly performs in cer-
tain brute animals at a particular season.
The fibres proceeding from Poupart’s liga-
ment, and the obliquus interims, tend to guide
the gland into the inguinal canal ; those at-
tached to the os pubis to draw it outside
the abdominal ring ; and the process extend-
ing to the bottom of the scrotum, to direct it
to its final destination. As the process ap-
proaches completion, the muscular fibres
which perform so important a part in it gra-
dually become everted, and acquire the new
functions of elevating, supporting, and com-
pressing the gland.

The Functions of the Testicle. — The sperm
or fluid secreted by the testicle has been con-
sidered in the article (Semen). On survey-
ing the structure of this gland, we cannot fail
to remark the great extent of secreting surface
afforded by the numerous, long, and tortuous
tubuli, and the length and complexity of the
excretory duct through which the seminal
fluid has to pass. The extent of this duct is,
indeed, so remarkable, that many physiologists
have been led to suppose that the semen is

Owen, being the only brute animal in which the
tunica vaginalis forms a shut sac.

* For this reason I have departed from the usual
custom of English anatomists, and avoided describ-
ing the change in the position of the testicle, as
the descent.

further elaborated or perfected in its passage
through the convolutions constituting the
epididymis. An examination of the spermatic
fluid taken from the testicle and its duct
both in man and in the lower animals, under
all circumstances and at all periods, and the
varying state of the discharge in cases of
spermatic fistula, leave little room to doubt
that secretion takes place actively only dur-
ing tlie periods of sexual excitement, or under
the influence of sexual feelings and desires.
From birth to the period of puberty the
testicles remain small, and grow but little
in proportion to other parts ; but as the
body, on the arrival of puberty, becomes
stamped with the characters of the male sex,
they rapidly enlarge, their glandular structure
becomes much more developed, and, being
excited, these organs begin to exercise the
office of secretion, no spermatozoa being found
in them until this period arrives. The age at
which the testicles thus become developed
varies in different climates, and in different
constitutions, and is influenced by the mode
of life and circumstances in which the indivi-
dual is placed. The inhabitants of warm
climates reach the age of puberty earlier
than those of cold countries. In this part of
Europe the change takes place from the age
of fourteen to seventeen years, according
to circumstances. Unlike the inferior ani-
mals, the testicles in man are ready at all
seasons to perform their office. The de-
sires subside, and the secretion of semen be-
comes languid as life advances, though they
seldom cease entirely till the age of sixty-five
or seventy. Indeed, I have several times dis-
covered spermatozoa in the testicles of men
upwards of seventy years of age, and once in
the testicle of a tailor who died at the age of
eighty-seven. There are instances on record
of persons retaining the procreative faculty to
the age of one hundred years ; but in these
cases, as in the well-known instance of old
Parr, the general bodily powers were also pre-
served in a very extraordinary degree.*

“ To the use of the sexual organs for the
continuance of his race man is prompted by a
powerful instinctive desire, which he shares
with the lower animals. This instinct is ex-
cited by sensations, and these may either ori-
ginate in the sexual organs themselves or may
be excited through the organs of special sen-
sation. Thus in man it is most powerfully
aroused by impressions conveyed through the
sight or the touch : in many other animals,
the auditory and olfactive organs communi-
cate impressions which have an equal power ;
and it is not improbable that in certain mor-
bidly excited states of feeling, the same may
be the case in ourselves. That local impres-

* Old Pari', who lived to the great age of 152,
was dissected by the celebrated Harvey, and it is
stated, “Genitalibus erat integris, neque retructo
pene neque extenuato, neque scroto distento ramice
aquoso ut in decrepitis solet, testiculis etiam inte-
gris et magnis.” Bettus de Ortu et Natura San-
guinis, p. 320.

TESTICLE GNOEMAL ANATOMY). 985

sions have also very powerful effect in excit-
ing sexual desire must have been within the
experience of almost every one ; the fact is
most remarkable, however, in cases of saty-
riasis ; which disease is generally found to be
connected with some obvious cause of irrita-
tion of the generative system, such as pruri-
tus, active congestion,” &c.*

The part of the brain which is the seat of the
sexual appetite is supposed by the phrenolo-
gists to be the cerebellum, between which and
the genital organs a close sympathy is said to
exist. The grounds for this assumption, and
the objections which have been fairly urged
against it by sound physiologists, have been
stated in a preceding article. (Nervous Sys-
tem, Physiology of, vol. iii. p. 782. s.) No
doubt, however, can be entertained that the
mind is intimately connected with the procre-
ative faculty, and that the brain controls and
animates the desire for sexual enjoyment. An
affection of the brain, or the mind, as sudden
disgust, arrests the secretion of the testicles
and extinguishes all desire as quickly and
effectually as a strong mental impression stops
the secretion of the gastric juice, and takes
away ail appetite for food. The influence of
the brain on the reproductive function is well
illustrated by the occasional effects of injuries
of the head. Iiildanus mentions the case of
a man accused of impotency by his wife, who
sued for a divorce. Nothing external was de-
fective ; but the man stated that eight years
previously he had received a blow on his head
by a stick. From that period, “ confitebatur
penem erigi non posse.” f Dr. Fisher relates
the case of a gentleman who, while looking
out of the window of a railway carriage,
which at that moment encountered a violent
collision, received a blow on the head and
neck, by which he was stunned. On the se-
cond day after the accident he complained of
a numbness in his right arm, and experienced
difficulty in passing his urine. In the course
of two weeks he was able to leave his bed,
and walk in the street ; but his vision was
defective. Between the fourth and fifth week
after his injury he made the discovery that he
had lost the desire and physical power for
sexual intercourse, and that no amorous
sentiment, or the approach of a female could
excite it. Under appropriate treatment the
bladder gradually recovered its power, anti his
vision became perfect ; but the numbness of
the right arm continued, and the generative
functions remained partially impaired. His
mental powers, particularly his memory of
events, were also for a time seriously affected. J
Dr. Gall mentions that at Vienna he was con-
sulted by two officers who had become im-
potent in consequence of blows from fire-arms
which had grazed the napes of their necks.
One of the officers recovered his powers by

* Dr. Carpenter’s Principles of Human Physio-
logy, p. 619.

f Opera Observationum et Curationum Medico-
Chirurgicarum, p. 574.

X Case by Dr. Fisher. American Journal of the
Medical Sciences, Feb. 1839. p. 357.

degrees, married, and became the father of
several children.*

When treating of Atrophy of these glands,
I shall have occasion to mention cases in
which the genital function has been perma-
nently annihilated, and complete wasting of
the testicles has resulted from injuries of the
head. In respect to the mode in which these
organs are called into action, they bear consi-
derable analogy to the lachrymal, salivary, and
mammary glands, in which secretion is excited
both by the influence of the mind and by me-
chanical contact or local irritation of the ex-
tremity of the excretory duct, the glans penis
holding the same relation to the testicle as the
mucous membrane of the mouth does to the
salivary glands, or as the nipple does to the
mamma.

The influence of the testicles and brain
upon each other appears, as has been already
observed, to be reciprocal ; for not only may
desire be aroused by local irritation and ex-
citing the testicles to secrete, but the passion
itself never arises when these glands are re-
moved before puberty and is extinguished by
their extirpation afterwards. Nothing, indeed,
illustrates more forcibly the intimate relation
which the functions of the testicles bear to
the mind and character of the individual, and
the general organisation of the body, than the
effects of castration. When it is performed
in early life, the changes characteristic of
puberty never ensue. There is a deficiency
of the beard ; the muscles do not acquire the
manly tone and vigour ; the areolar and
adipose tissues abound ; the voice retains the
high and clear tones of infancy ; and the mind
remains deficient in energy and strength.
When the testicles are removed after the
period of puberty, the eunuch loses in part,
though not entirely, his former masculine
character. His beard grows less abundantly ;
his voice becomes shrill ; and there is di-
minished energy and vigour in all his senti-
ments and actions. These changes in the con-
stitution, as well as the loss of the sexual
instinct which occur in men thus degraded, do
not immediately succeed the removal of the
testicles, but take place gradually ; and there
are well-attested cases in which desire has
been experienced, and connection with emis-
sion accomplished many months after the loss
of these organs. This shows that the passion
is not solely dependent on the secretion of
semen, though it invariably declines when the
powrer of procreation becomes lost. The emis-
sions in such cases are imperfect and fruitless,
consisting merely of the secretions of the
vesiculte seminales and prostrate. The testi-
cles not being parts essential to life, are sub-
ject to different laws from those which re-
gulate the actions of the vital organs. Their
functions may be suspended, or they may
remain in abeyance for an indefinite period
without injury to the glands or any material
effect on the constitution. In persons of

* On the Functions of the Cerebellum, tr. by
Combe, p. 46.

986 TESTICLE (ABNORMAL ANATOMY).

recluse and studious habits the functions of
these organs often continue dormant for
years. Like the mammae in the unmarried
female, though inactive, they remain sound
and competent for secretion when duly ex-
cited and called upon to exercise their func-
tions. It often happens that the passions are
excited without an opportunity being afforded
for their gratification. Under these circum-
stances the testicles become encumbered with
secretion which would prove injurious to
them were they not relieved by occasional
nocturnal emission, or ejaculations of the
semen under the influence of dreams during
sleep, which appear to be a salutary provision
to obviate the inconveniences which might
result as well from ungratified desires as from
an accumulation of semen in the ducts.

Envelopes of the testicle. — The scrotum, or
pouch of integument containing the testicles,
including the dartos, has already been de-
scribed. (Article Scrotum).

Superficial or external spermatic fascia. —
Beneath the loose areolar tissue of the scro-
tum is situated a delicate layer of fascia, which
is continuous with the superficial fascia of
the lower part of the abdominal parietes, and,
descending so as to form a sheath to the
spermatic cord and an envelope to the testicle,
becomes continuous behind with the super-
ficial fascia of the perineum. This fascia
is usually very thick and distinct in cases
of large and old scrotal hernia.

Cremaster muscle — Directly beneath the
superficial fascia is found the cremaster muscle
(so named from icpep.6. w to suspend), or, as it
has been appropriately termed by Mr. Hunter,
the musculus testis. (For description, vide,
Abdomen, vol.i. p.6.) The two attachments of
this muscle, the external to Poupart’s ligament,
and the internal to the os pubis, correspond,
as I have previously (p. 983.) shown, to those
of the muscle of the gubernaculum, being
indeed the same structure, with its relations
altered. The actions of the cremaster, which,
with a few exceptions, are involuntary, appear
to be those of giving a tonic support to the
testicles, retracting them to the abdominal
rings, and compressing them during the
sexual act. In some instances, in boys before
the approach of puberty, this muscle has been
capable of drawing the gland up into the in-
guinal canal. Persons are occasionally met
with who possess a voluntary power over its
actions in various degrees of perfection. Some
are able to elevate the testicle on one side but
not on the other, whilst others can retract
both testicles to the abdominal rings, and
retain them there at will. A very remarkable
instance of the cremaster muscle being com-
pletely under the influence of volition is
recorded by Mr. Hutchinson.#

Deep spermatic fascia. — The tunica vagi-
nalis and spermatic cord are invested by a
thin delicate fascia, which is situated beneath
the cremaster muscle, and forms a common

* Practical Observations in Surgery, second edit.

p. 186.

fibrous envelope to the testicle, and spermatic
cord. It is attached to the back part of the
gland. This membrane may be traced as a
prolongation of the fascia transversals, and is
probably formed in the process of transition
of the testicle from the abdomen to the
scrotum.

The spermatic cord. — The parts composing
the spermatic cord, are the vas deferens, the
artery of the duct, the spermatic artery and
veins, the lymphatic vessels, and the spermatic
nerves. These parts are connected by loose
areolar tissue. A fibro-cellular process, being
the remains of the process of serous membrane
originally connecting the tunica vaginalis with
the peritoneum, may sometimes be perceived
in the front part of the cord. The spermatic
cord extends from the internal abdominal
ring to the back part of the testicle. Its
upper portion, therefore, lies in the inguinal
canal. The coverings of the cord are the
same as those of the testicle : viz., the inte-
guments, superficial fascia, cremaster muscle,
and deep spermatic fascia.

For Comparative Anatomy, see the
article Organs of Generation.

Abnormal Anatomy of the Testicle. —
Congenital imperfections and malformations. —
Numerical excesses and defects. — Cases of su-
pernumerary testicles are mentioned in the
writings of the old authors, and persons have
been described with four or five of them, ac-
companied with a proportionate increase in the
venereal appetite. Nearly all these cases are of
a fabulous character. Such must be remarked
of the case of -navr ipxos, or man with five tes-
ticles, mentioned by Schaarf*, and with that
of a man with four testicles alluded to by
Blegny.-j- Blasius, an old writer not un-
worthy of credit, has, however, given an
account of the examination of a man, thirty
years of age, and otherwise well formed, who
had two testicles on the right side, of the
same size and shape as that on the left, which
is illustrated by a small engraved figure re-
presenting a distinct artery from the aorta,
and vein from the vena cava proceeding to
each of the two testicles on the right side.J
This is the only case of supernumerary testicle
recorded by the old authors, which has any
semblance of authenticity. Neither Morgagni,
Haller, nor Meckel met with a single exam-
ple, and they questioned the existence of
such a condition. Two cases have recently
been recorded as examples of triple testicle,
but they were not verified by examination
after death. One is related by Bliimener, an
army surgeon, in Rust’s Magazin fur die
Gesammte Heilkunde for 1821 : the other by
Dr. Macann, a British surgeon. $ An epi-
plocele, a fatty or fibrous tumour in the
scrotum, or an encysted hydrocele of the cord,

* Epli. Nat. Cur. Dec. 111. Ann. v. vi. Obs. 89.
p. 175.

•f Zodiaque Fran^ais, Ann. 11. Most of the re-
puted cases of Triorchides are quoted by Arnaud, in
his Memoires de Ohirurgie. Mem. iii. part i.

} Ger. Blasius, Obs. Med. Anat. Obs. 20. p. 60.

§ Provincial Medical Journal, Nov. 5. 1842, p. 113.

TESTICLE (ABNORMAL ANATOMY).

might readily be mistaken for an additional
testicle. Morgagni mentions that he was once
deceived by a portion of omentum. In the
pathological collection at St. Thomas’s Hos-
pital is preserved the testicle of the eccentric
Dr. Monsey, who appeared during life to be
supplied with three of these glands. The sup-
posed additional testicle consists of an in-
durated fibrous tumour attached apparently
to the tunica vaginalis.

Many instances of monorchid.es, or persons
having only a single testicle are also mentioned
by the old authors ; but as the data are very
imperfect, and as little was known respecting
the transition of the testicle at the time these
cases were recorded, they must be viewed
with great suspicion. They were most pro-
bably cases in which one of the glands was
either retained within the abdomen, or, from
some cause had been completely atrophied.
I know no satisfactory reason why a defici-
ency of one or both testicles should not
occasionally occur without any other mal-
formation ; but they are anomalies of which
there are few authentic examples in the
annals of medical science. Mr. Paget has
published the particulars of a case in which
he believes one testicle was deficient at birth.* * * §
No account of the man is attached to the
particulars of the dissection, and it is open to
question whether the deficiency of the gland
was not the result of atrophy. Dr. Fisher, of
Boston f , has recorded a more satisfactory
example of absence of both testicles. The de j
ficiency was remarked from birth, and the sub-
ject of the malformation was regarded as a na-
tural eunuch, and died at the age of forty-five.

Mr. Thurnham has published an account of
the dissection of an infant who died at the age
of four months. In addition to an atrophied
condition of the right kidney, and a remark-
able malformation of the ureters, it was found
that neither of the testicles had descended.
The right lay in the abdominal cavity, just
above the inguinal canal. On the left side no
testicle would appear to have been formed ;
the spermatic vessels on this side terminated
in a little mass of fat ; the vas deferens, how-
ever, was present, and was apparently as well
developed as that of the perfect testicle. J A
case of monstrosity is related by Dr. Friese in
Casper's Wochenschrift.tji The child lived
only half an hour : in addition to the absence
of the external genital organs, there were
neither testes, vasa deferentia, nor vesiculae
seminales. Cases, however, in which the
whole of the genital apparatus is deficient or
irregularly formed, do not come within the
scope of this article. Geoffroy St. Hilaire has
recorded a remarkable, and so far as I know,
unique case of union of the testicles in the
abdomen. ||

* London Medical Gazette, vol. xxviii. p. 817.

f American Journal of the American Sciences,
vol. xxiii. p. 352.

J London Medical Gazette, vol. xx. p. 717.

§ Dec. 25. 1841. Quoted in the British and Fo-
reign Medical Review for April 1842, p. 527.

11 Hist, des Anomal. de l’Organ. t. i. p. 542.

987

Deficiencies and imperfections of the vas
deferens. — In Mr. Paget’s case of supposed
absence of the testicle it is stated, that the
vas deferens terminated nearly opposite the
external ring in a rounded cul-de-sac; and in
Dr. Fisher’s case of deficiency of both testicles,
that the vasa deferentia, though properly
formed and nearly of natural size, terminated
in cul-de-sacs at the end of the cord. In the
museum of St. Bartholomew’s Hospital, there
is a preparation taken from a man fifty years
of age, who died of strangulated hernia. A
piece of intestine was strictured by a band of
adhesion connected with the mesentery, and
the testicle was detained in the upper open-
ing of the ring. On dissection of the parts,
the vas deferens was found to terminate near
the testicle in a cul-de-sac. The gland was
very small, and its structure appeared granular
like the undeveloped testicle of a youth. There
was no trace of the epididymis. Mr. Hunter
in dissecting a male subject found the vasa
deferentia not only deficient near the testicles,
but terminating below in a single irregularly
formed vesicula seminalis, and having no com-
munication with the urethra.* There are a
few other cases on record, in which the vas
deferens has been defective at the extremity
which joins the ejaculatory canal. Thus,
Tenon, in the dissection of an infant affected
with extraversion of the bladder, found that
the vasa deferentia terminated separately at
the bottom of the pelvis, in two white tuber-
cles : the scrotum, testes, and vesiculae semi-
nales were in a natural state, j But besides
these imperfections at its two extremities, this
duct has been found wanting throughout nearly
its whole extent. Brugnoni mentions, that
in dissecting the parts of generation in a robust
man, from twenty-six to twenty-seven years
of age, he found the right epididymis almost
entirely absent, the only part remaining being
the head, which formed nodules filled with
semen. The rest of the epididymis and the
vas deferens were wanting, without any mark
of disease. The testicle was perfectly sound,
and nearly of the same size as the left one.
On examining the corresponding vesicula
seminalis he found at its anterior extremity a
portion of the canal of the vas deferens about
an inch in length, and properly formed. The
vesicula seminalis itself was flaccid and quite
empty ; whilst the left was full of semen. He
remarks, that although this vicious conforma-
tion was according to all appearances con-
genital, nevertheless the vesicula seminalis and
ejaculatory canal had preserved their natural
cavities. J In a case related by Bosscha, the
left vas deferens of a robust man terminated in
a blind extremity near the testicle, the rest
of the canal being wanting. There was the
rudiment of a left vesicula seminalis in the

* Works by Palmer, vol iv. p. 23.

f Mem stir quelques Vices des Voies Urinaires, Sec.
n Mem. de l’Acad. Roy. des Sciences a Paris, 1761,
p. 115.

J Observ. Anat. sur les Yesicnles Seminales.
Mem de 1’Acad. Roy. des Sciences it Turin, 1786,
and 1787, p. 625.

98b TESTICLE (ABNORMAL ANATOMY).

form of a blindly-ending canal running tor-
tuously in the shape of the letter S. The left
testicle was sound.*

Mr. Paget has happily explained the origin
of these several defects in the vas deferens, by
reference to the mode of development of the
special organs of generation. He observes t,
after Miiller and Valentin, that, in the normal
course of human development the proper ge-
nital organs are in either sex developed in two
distinct pieces : namely, the part for the for-
mation of the generative substance, the testicle
or ovary, and the part for the conveyance of
that substance out of the body, the seminal duct
or ovi-duct. The testicle or ovary as the case
may be, (and in their earliest periods they
cannot be distinguished), is formed on the
inner concave side of the corpus Wolffianum,
and the seminal or ovi-duct, which is originally
an isolated tube closed at both extremities,
passes along the outer border of that body
from the level of the formative organ above to
the cloaca or common sinus of the urinary,
genital, and digestive systems below. The
perfection of development is attained only by
the conducting tube acquiring its just connec-
tions at once with the formative organ, and,
through the medium of the cloaca, with the
exterior of the body. The sexual character is
first established, when, in the male, the for-
mative and conducting organs become con-
nected by the development of intermediate
tubes which constitute the epididymis ; or
when in the female, a simple aperture is formed
at the upper extremity of the conducting tube,
and is placed closely adjacent to the formative
organ. In both sexes alike, the lower ex-
tremities of the conducting tubes first open into
the common cloaca, and subsequently, when
that cavity is partitioned into bladder and rec-
tum, or bladder, vagina, and rectum, they ac-
quirein each their just connections, and become
in the male the perfect vasa deferentia, and
in the female the Fallopian tubes and uterus.

The inquiry is not without interest, what
influence have these deficiencies and imperfec-
tions in the vas deferens on the evolution and
subsequent condition of the testicle ? In the
case of the adult which occurred at St. Bar-
tholomew’s Hospital, the testicle was small,
and its structure appeared granular, like the
undeveloped testicle of a youth, but as it had
not descended into the scrotum, and was com-
bined with hernia, there may have been other
causes impeding its due evolution. In Mr.
Hunter’s case, the testicles which were in the
scrotum were very sound. In the case of the
man related by Brugnone, the testicle on the
side corresponding to the defective vas de-
ferens was perfectly sound, and nearly of the
same size as the other. So also in Bosscha’s
case, it is stated, that the testicle was sound.
Although either of these defects in the vas
deferens renders the gland an useless organ,

* Diss. sistens Obs. de vesiculse seminalis sinis-
tra defeetu, integris testibus, vase vero deferente
clauso, quoted by Dr. Yrolik, Handboek der Ontleed-
kundige Ziektekunde, 1st Deel. p. 210.

| Loc. cit. p. 818.

and if it occurred on both sides of the body,
would necessarily cause impotency, these
cases, nevertheless, tend to shew that the
absence or imperfection of the excretory duct
does not prevent the development of the tes-
ticle at the proper period, and has no direct
influence in causing it to waste; and these
inferences are fully confirmed by experiments
on animals, performed by Sir A. Cooper and
by myself.* These cases and experiments
show, then, that the testicles maybe properly
developed, though a physical obstacle to the
elimination of their secretion is present from
birth ; and that so long as the testicles exist
entire, though to no purpose, the individual
acquires and preserves all the marks of the
male sex ; the secretory organ alone appear-
ing to be that upon which the sexual charac-
ters depend. The engorgement of the se-
minal ducts with sperm is liable, it is true, to
cause inflammation of the testicle, which may
end in atrophy, but this is only a secondary
and occasional effect of the interruption in
the excretory duct.

Imperfect transition. — It occasionally hap-
pens that at birth one or both testicles have
not passed into the scrotum, being detained
either in the abdomen near the groin, in the
inguinal canal, or in the groin, just outside the
external ring. In a table of one hundred and
three male infants, examined by Wrisbergat the
time of birth, it appears that seventy-three had
both testicles in the scrotum ; in twenty-one,
one or both were in the groin. Of these, five
had both, seven the right, and nine the left in
the groin; in twelve, four had both, three the
right, five the left, only in the abdomen. f
According to this table, the imperfection occurs
rather more frequently on the left side than on
the right, in the proportion of seven to five.
In twenty-five cases examined at different ages,
varying from five to sixty, — sixteen of which
came under my own observation, the remainder
being taken from the recorded experience of
others, — in thirteen the imperfection was on
the right side, and in twelve on the left. Dr.
Marshall states, that in the examination of
10,800 recruits, he had found five in whom
the right, and six in whom the left testicle
was not apparent. In two of these cases there
was inguinal hernia on the side where the tes-
ticle had not descended. % He met with but
one instance in which both testicles had not
appeared. $ The testicle sometimes remains
permanently fixed in the situation in which it
is placed at birth || ; but in some instances the
passage, though delayed, is completed at some
period previous to puberty, and often within
a few weeks after birth. Mr. Hunter was of
opinion that this completion most frequently

* Vide Sir A. Cooper on Anatomy of the Testis,
p. 51., and my Treatise on the Diseases of the Testis,
p. 64, and seq.

f Commentatio Soc. Reg. Scient. Goetting. 1778.

| Hints to Young Medical Officers in the Army,
p. 83.

§ Ibid. p. 207.

|| Persons whose testicles had not made their ap-
pearance were called or testicondi, by the

ancients.

TESTICLE (ABNORMAL ANATOMY). 989

happens between the years of two and ten.-*
Of the twelve cases mentioned by Wrisberg,
in which one or both testicles were retained
in the abdomen, in one the descent took place
the day of birth, in three on the day after, in
three others on the third day, in two instances
on the fifth day, and in one on the twenty-
first day : in the other cases, the testicles had
not appeared at the fourth or fifth week after
parturition, f My own observations lead me
to believe, that if the passage does not take
place within a twelvemonth after birth, it is
rarely fully and perfectly completed afterwards,
without being accompanied with rupture. For
the causes which operate at this late period
tend as much to promote the formation of
hernia as the transition of the testicle. In
cases where the testicle makes no appearance
before puberty, uneasiness is often experienced
at that period, owing to the enlargement of
the gland being restrained by the rings and
parts composing the inguinal canal. At the
same time also, it is often protruded outside
the external ring by the movements of the
abdomen in respiration.

The causes of a failure in the transition of
the testicle have not been much investigated,
and as considerable doubt has long prevailed
respecting the mode and agency by which
this change is effected, no satisfactory explana-
tion could 'be expected of the circumstances
interrupting or preventing it. When we re-
flect on the nature of that process, as my
researches have led me to describe it, it is
clear, that there must not only be a perfect
adaptation of parts, a due relation between
the body displaced and the structures which
it traverses, but also corresponding power in
the agent by which it is accomplished. There
are few muscles in the human body whose
development in different individuals varies in
a greater degree than that of the cremaster.
And if such be the case after birth, it is not
unreasonable to presume that similar differ-
ences exist in the foetus before the gland
changes its position, and that a failure in the
process may be the result of deficient power
in the musculus testis to accomplish the pas-
sage. It is not improbable that this muscle
is sometimes paralysed, and that the faulty
transition is owing to a want of a due supply
of the nervous energy, which we know is often
denied to other muscles during foetal exist-
ence, and is the cause of deformities in the
feet and other parts, with which infants are often
ushered into the world. I think, indeed, we
may fairly enumerate paralysis and defective
development of the cremaster amongst the
presumed causes of the imperfect transition
of the testicle. Peritonitis occasionally at-
tacks the foetus in uteroj, and produces ad-
hesions between thevarious abdominal viscera.
It is well known that in congenital hernia the
testicle is frequently united to a portion of

* Lib. cit. p. 15.

t Lib. cit. p. 203.

j Vide Contributions to Intra-uterine Pathology,
by Dr. Simpson, Edinb. Med. and Surg. Journal,
nos. cxxxvii. and cxl.

intestine or omentum, and that the formation
of these adhesions previous to the transition
of the testicle is sometimes the cause of the
displacement, the viscera being drawn, together
with the gland, into the scrotum. Many facts
seem to show that similar adhesions are, on
the other hand, an occasional cause of the
temporary and permanent retention of the
testicle, the cremaster being insufficient to
overcome this obstacle to its passage.

In the examination of a man, age sixty, I
found the right testicle just external to the
abdominal ring ; it was small in size, and
closely adherent to a portion of omentum.
A young man was under my care for many
months, on account of an imperfect transition
of the testicle on the left side. The gland
moved backwards and forwards through the
external abdominal ring. By pressure above,
it could be forced down sufficiently to admit
of being examined. This testicle was much
smaller than the right, which was in the
scrotum, and I could distinctly make out
a portion of intestine closely adherent, which
accompanied the organ in all its movements.
It is probable that the smallness of the
opening in the internal abdominal ring is
sometimes a cause of the detention of the
testicle, especially in those cases in which the
organ is retained within the inguinal canal.
Mr. Wilson, an accurate anatomist, was of
this opinion*, which is supported by the fact,
that the testicle is oftener found in the groin
than in the cavity of the abdomen. M. Dela-
siauve mentions a case, in which, he states,
the organ was retained by the border of the
outer column of the ring, f Mr. Hunter was
inclined to suspect that the fault originates in
the testicles themselves. It is difficult to un-
derstand how this can be, for as the gland is
passive in this process, it can offer no obstacle,
unless it grows too large to pass the opening
in the abdominal parietes ; whereas, it is ad-
mitted that the gland when retained is usually
below the natural size. Nor does it appear,
that the interruption is owing to any want of
proper length in the vas deferens, for in a case
of imperfect transition in a boy, whose body
I examined, I particularly noticed that this
duct was so long as to be doubled on itself,
and tortuous, a circumstance which has been
remarked in other cases by Mr. Mayo J, Rosen-
merhelj), and others. It may be concluded
then, that the causes of a failure in the pas-
sage of the testicle are various ; that this
imperfection may result from want of power,
or paralysis of the cremaster muscle; from
adhesions retaining the gland within the ab-
domen ; and from a contracted state of the
opening of the external abdominal ring.

Mr. Hunter states, that when one or both
testicles remain through life in the belly, he
believes that they are exceedingly imperfect,

* Lectures on the Urinary and Genital Organs,
p. 405.

t Revue Medicale, Mars, 1840, p. 363.

i Human Physiology, 3d edit. p. 411.

§ Ueber die Radicalcur desin der Weiche liegen-
den Testikels.

990

TESTICLE (ABNORMAL AN ATOMY).

and probably incapable of performing their
natural functions ; and that this imperfection
prevents the disposition for descent taking
place. That they are more defective even
than those which are late in passing to the
scrotum, he infers from the circumstance, that
in quadrupeds, the testicle that has reached
the scrotum is considerably larger than the
one which remains in the abdomen. Mr.
Hunter had seen only one case in the human
subject where both testicles continued in the
abdomen, but this proved an exception to the
above observation, since we are led to con-
clude that they were perfectly formed, as the
person had all the powers and passions of a
man.* Professor Owen in commenting upon
these observations, states, “ It seems remark-
able that with this experience Mr. Hunter
should have formed from inconclusive analogy,
and promulgated, an opinion tending to occa-
sion so much unhappiness as that which attri-
butes exceeding imperfection and probable
incapacity of performing their natural func-
tions to testes which in the human subject
are retained within the abdomen. That there
is -nothing in such a situation which neces-
sarily tends to impair their efficiency is evident,
from the number of animals in which they
constantly form part of the abdominal vis-
cera ; and in those in which the testes na-
turally pass into a scrotum, their continuance
in the abdomen, according to our author’s
own observation, is accompanied only with
a difference of size or shape ; now we may
readily suppose that this may influence the
quantity, but not necessarily the quality, of
the secretion.” There are very few accounts
on record of the dissection of undescended
testicles. In a case, in which M. Cloquet
found the left testicle situated within the
abdomen, the gland was well formed, and
of the same size as the right, which had de-
scended into the scrotum. The parts taken
from an apprentice of Sir A. Cooper, who
unfortunately committed suicide in conse-
quence of the infirmity, are preserved in the
Museum of Guy’s Hospital. I have ex-
amined the preparation ; and the testicles,
which are both within the abdomen, close to
the internal ring, appear to be nearly, if not
quite, the natural size, and it is stated that
the ducts contained semen. In a lad, aged
nineteen, whose left testicle was found, by
Ur. Bright, within the abdomen, near the brim
of the pelvis, the gland was considerably
smaller than natural, but the ducts and se-
creting structure were quite perfect.')' These
are the only cases of testicles situated within
the abdomen in which we have any account
of the anatomical condition of the gland. In
addition to the evidence they afford of the ca-
pability of testicles thus placed to exercise their
functions, may be adduced the case of Mr.
Hunter, just alluded to, in which a person,
both of whose testicles continued in the ab-
domen, had all the powers and passions of

* Works by Palmer, vol. iv. p. 18.

f Hospital Reports, vol. ii. p. 258.

a man ; and a case recorded by Mr. Poland,
of a man so formed, who was aged twenty-
nine. He had all the signs of virility, had
married twice, and was the father of two
children.* On the other hand, Mr. Wilson
mentions the case of a young man, twenty-five
years of age, whose testicles never descended.
He had some beard, and not an unmanly ap-
pearance ; but although an imprudent, and
in some things a dissipated person, he had
never shown the least desire for women, or
disposition for sexual intercourse, f John
West, a lad, aged sixteen, died in the London
Hospital, in a state of universal anasarca.
There was no appearance of beard, and only
a few hairs were scattered over the pubes.
My attention was particularly directed to the
state of the genital organs, by observing that
the scrotum, which was greatly distended with
serous effusion, was not fully developed on
the right side. I found the right testicle
within the abdomen, about an inch and a half
above the internal ring. It was very small,
not larger than that of a child two years of
age ; and on cutting into it, the gland pre-
sented the granular appearance usually re-
marked at that early period.

Passage of the Testicle into the Perineum. —
Mr. Hunter first observed that the testicle in
changing its situation does not always pre-
serve a proper course towards the scrotum,
there being instances of its taking another
direction and passing into the perineum. How
this is brought about, he remarks, it is difficult
to say : it may possibly be occasioned by
something unusual in the construction of the
scrotum, or more probably, by a peculiarity in
that of the perineum itself. For it is not easy
to imagine how the testicle could make its
way to the parts about the perineum, if
these were in a perfectly natural state. He
met with two instances of this imperfection.
Many years ago a little boy, one of whose
testicles had thus deviated from its proper
course was brought to the London Hospital.
The gland was lodged in the perineum at the
root of the scrotum. M. Ricord met with
this singular anomaly in two instances. M.
Vidal (de Cassis) observed it in two brothers :
their father was exempt from it. The testicle
abnormally placed was smaller than the other. J
The irregularity is exceedingly rare, and the
above cases are all with which I am acquainted.

Passage of the Testicle through the Crural
Ring.- — M. Vidal relates the case of a man,
one of whose testicles, instead of passing out
of the abdomen at the inguinal canal, made its
exit at the crural ring. The organ was
mounted upon the abdomen like a crural
hernia. A portion of intestine traversed the
inguinal canal, forming a rupture on that side. $
I know of only one other instance of this

* Guy’s Hospital Reports. Second series, vol. i.
pp. 162, 163.

f Lectures on the Urinary and Genital Organs,
p. 408.

t Traitd de Pathologie exteme, t. v. p. 432. 2etne,
edit.

§ Ibid p. 431.

TESTICLE (ABNORMAL ANATOMY). 991

anomaly, which is reported by Eckardt. In
this ease, the testicle passed out at first
through the inguinal canal, but having been
returned by the patient into the abdomen, it
subsequently escaped at the femoral ring.*
Inversion of the Testicle. — It sometimes
happens that the position of the testicle in
the scrotum is reversed, so that the free sur-
face presents posteriorly, and the epididymis
is attached to the anterior part of the gland,
instead of to the posterior. The first case
that I met with was that of a man who had a
swelling of the right testicle, which puzzled
his medical attendant. On examination 1
found this to be the epididymis thickened
from chronic inflammation. I was able clearly
to trace the vas deferens proceeding to it along
the front of the scrotum. The body of the
testicle was unaffected, and its posterior edge
was quite smooth and regular. The disposition
of the left testicle was normal. On visiting
the Hopital de Midi in Paris, in April, 1849,
M. Ricord showed me a case of epididymitis
on the left side, in which the gland was thus
inverted. He informed me that he had often
met with this arrangement. I have since had
two patients under my care, one of whose tes-
ticles was thus inverted. One was a lad in the
London Hospital affected with epididymitis.
The other was a gentleman who consulted me
for chronic orchitis confined to the body of the
testicle. The epididymis being unaffected, the
inversion was less perceptible than in the three
preceding cases. M. Maissonneuve, in a thesis
published in Paris in 1835, I believe first
called attention to this irregular disposition,
which he states that he had met with many
times upon the dead body, and upon the
living, and he mentions what I remarked
myself in the four cases just noticed, that the
inversion was confined to one side. Surgeons
should bear in mind the liability to”this dis-
position of the gland in making their diagnosis
of the diseases affecting it.

Atrophy of the Testicle. — The testicles, like
other organs formed for the exercise of tem-
porary functions, do not arrive at a perfect
state of development until a certain period of
life, after which their activity ceases, and
they become gradually and imperceptibly
diminished. Thus we find that in early life
they are small in proportion to the size of the
body as compared with their condition at
puberty, and that as old age advances and the
generative functions cease to be called into
action, they undergo a diminution in size,
their vessels grow less, the seminiferous tubes
become small and contracted, and partially ob-
literated. In the lower animals these changes
are far more remarkable than in man, for as
the functions of the testicle are exerted only at
stated periods of the year, as the rutting or
copulating season advances these organs
rapidly increase in bulk, and in its decline
undergo a proportionate degree of wasting.
In man, it sometimes happens that the tes-

* Loder’s Journal fur die Chirurg. ii. Bd. 1 Stff.
s. 187.

tides do not acquire their proper size at the
usual period, their development being from
some cause or other arrested ; and also, after
the organs have arrived at their full and perfect
growth, that occasionally one or both suffer
a premature decay. Under the head then
of Atrophy of the Testicle I shall consider :

1. Arrest of Development ; and 2. Wasting.

Arrest of Development. ■ — If the congenital
lesions to which the testicle is liable had not
been previously treated of, the cases of ab-
sence of the organ already described, might be
correctly referred to the present head, as the
deficiency in these cases was no doubt the
result of an arrest in the early development of
the organ. But the cases that 1 am now
about to consider are those in which the sub-
sequent evolution which the testicles undergo
at puberty is delayed beyond the usual period,
or never takes place at all. Mr. Wilson
relates a curious instance of his having been
consulted by a gentleman, twenty-six years of
age, on the propriety of entering the marriage
state, whose penis and testicles very little ex-
ceeded in size those of a boy of eight years
of age. He had never felt the desire for
sexual intercourse until he became acquainted
with his intended wife ; since that period he
had experienced repeated erections, attended
with nocturnal emissions. He married, be-
came the father of a family ; and these parts,
which at six and twenty years of age were so
much smaller than usual, at twenty-eight had
increased nearly to the usual size of those of
an adult man.* Mr. Wilson mentions this
singular case, as it will admit of questions
whether the parts alluded to became properly
formed as to size, and possessed of the power
of secretion, in consequence of being, although
so late in life, influenced by the passions
excited b}' attachment to a particular female ;
or whether the enlargement and proper action
of the parts beginning, occasioned such passion
first to exist. He thinks the probability in
favour of the former supposition, in which
opinion I certainly concur. Lallemand men-
tions having seen a man about thirty years of
age, extremely fat, and without a beard or hair
on the pubes, whose penis and testicle ap-
peared to belong to a child of from seven to
eight years : he had never experienced erec-
tions or venereal desires. f A young man
died in the London Hospital of disease of the
heart. He was seventeen years and nine
months old : the body measured five feet five
inches in height, and was plump and well
formed. There was no appearance ofbeard,
or whiskers, or of hair on the pubes. The
penis and testicles were very small, not larger
than they are usually found in boys of three
or four years of age. The testicles were about
equal in size, and one of them weighed only
two scruples and one grain. Both organs
were normal in structure, appearing like the
glands in early life, when the tubular structure

* Lectures on the Urinary and Genital Organs,
p. 424.

t Des Pertes Se'minales Involontaires, t. ii. p. 380.

992

TESTICLE (ABNORMAL ANATOMY).

is very indistinctly developed. No sperma-
tozoa could be detected. These were clearly
instances of arrest of development of the tes-
ticles. As these organs are chiefly excited to
action by an operation of the mind, it is easy
to understand that they may sometimes re-
main undeveloped owing to defective organi-
sation of the brain, an absence of sexual
desires being invariably remarked in these
cases. Cases of wasting of the testicles after
injuries of the head, and the frequent absence
of the venereal appetite in cretins and idiots,
tend to strengthen this opinion. The follow-
ing are marked examples of defective develop-
ment of the sexual organs, accompanied with
imperfection of the brain. An idiot, aged
nineteen, subject to epileptic fits, died of
typhus fever in the Hackney union. The
youth was of short stature, and the form of
the body was not indicative of either sex, but
the contour was rounded as in the female.
There was no appearance of hair about the
face or pubes. The abdomen and other parts
were covered with a thick layer of fat. The
penis and scrotum were remarkably small, not
larger than they are usually found in a child
two or three years of age. Both testicles
were in the scrotum, but they were of very
diminutive size ; the right weighed less than
a drachm, and the left not more than twenty
three grains. The right gland had descended
a very little way below the abdominal ring.
The glandular structure and epididymis of
both testicles were indistinct, and the vasa
deferentia also extremely small. Nothing re-
markable was observed in the structure of the
brain. Mr. Hovell, the surgeon of the union,
also showed me another inmate of the same
workhouse, a lad aged nineteen, and of weak
mind, whose penis and testicles did not exceed
in size those of a boy seven or eight years of
age, and who had only a few scattered hairs
on the pubes. In the museum at Fort Pitt,
Chatham, are preserved two undeveloped
testicles about the size of those of a child
six months old, but healthy in structure,
which were taken from a lunatic 58 years of
age. His penis was small and he had never
experienced any inclination for sexual inter-
course.

Wasting. — In investigating the alterations
in the nutritive condition of the testicle, it is
very desirable to fix, if possible, some standard
by which they may be estimated. The size of
the gland is neither uniform nor conveniently
appreciated. Its weight, likewise, varies so
much in different persons and in the same in-
dividual at different periods, according as it
has lately exercised its functions or remained
inactive, and as it is full of semen or empty,
that it is scarcely possible to determine on any
accurate standard of this kind. (See p. 976.)

I should consider the testicle of an adult
weighing less than three drachms as in a
state of atrophy. A testicle in an advaced
state of wasting, not arising from disease of
the gland, usually preserves its shape, but
feels soft, having lost its elasticity and firm-

ness. Its texture is pale and exhibits few
blood-vessels, the tubuli and septa dividing
the lobes are indistinct, and the former cannot
be so readily drawn out into shreds as before.
The epididymis does not usually waste so
soon nor in the same degree as the body of
the testicle. It sometimes however, loses its
characteristic appearance, ami I have even
found it reduced to a few fibrous threads.
The fluid pressed out of the wasted testicle
and epididymis is entirely destitute of sper-
matic granules anti spermatozoa. In many
instances adipose tissue is deposited behind
the tunica vaginalis, and encroaches on the
epididymis and posterior part of the testicle.
Fatty matter is also found in the glandular sub-
stance of atrophied testicles, as in one taken
from a man aged forty-six, who died of dropy
consequent on disease of the kidneys, which
was wasted to one fifth its natural size. In ad-
dition to the presence of adipose tissue be-
neath the visceral portion of the tunica vagin-
alis, I recognised a quantity of yellow matter
irregularly disposed amongst the wasted tu-
buli. This matter on examination in the mi-
croscope, proved to be oil globules, and readily
dissolved on the application of ether. The
structures composing the spermatic cord un-
dergo a corresponding diminution ; the cre-
master muscle disappears, the nerves shrink,
and the vessels are reduced in size and num-
ber. The vas deferens, though small, can ge-
nerally be injected with mercury as far as the
commencement of the epididymis. A testicle,
atrophied from disease, is not only of dimin-
ished size and weight, but is altered in shape,
being uneven and irregular, and sometimes of
an elongated form. The surfaces of the tunica
vaginalis are adherent and its cavity is partly
or entirely obliterated. There is no, or very
little, trace of the proper glandular structure,
the organ being converted into fibrous tissue
of a firm texture. It loses its peculiar sensi-
bility to pressure, but is sometimes the seat of
morbid sensibility.

All those causes which produce decay
in other parts likewise occasion wasting of
the testicle. Thus an impeded circulation,
pressure, want of exercise, and loss of nervous
influence, have been noticed as causes of
atrophy of this gland. To these must be
added certain causes which specially affect the
testicle. The following case, related by Mr.
Wal drop, is a good example of atrophy from
defective nutrition. A person, both of whose
testicles were completely absorbed, nothing
being felt in the scrotum but a loose vaginal
coat, died of an aneurism of the aorta, formed
at the origin of the spermatic arteries, both
of which were obliterated.* A ligature on
the spermatic artery is sufficient to cause
a total decay of the testicle, which induced
the celebrated Harvey f to propose its ap-

* Note to his edition of Baillie’s works, vol. ii.
p. 315.

j- Anatomical Exercitations concerning the
Generation of Living Creatures. Lond. 1653, pp.
113, 114.

TESTICLE (ABNORMAL ANATOMY). 993

plication for the removal of a certain form of
sarcocele ; a suggestion, the credit of which
has been improperly assumed in recent years
by C. J. Maunoir, of Geneva. The influ-
ence of pressure in causing partial atrophy
of the testicle, is somtimes remarked in old
cases of hydrocele and hoematocele, in which
the gland has been long subjected to com-
pression from the retained fluid.

It has been said that the testicles waste in
those persons who strictly adhere to their
monastic vows, but I am not aware that there
is sufficient authority for this remark. In
persons who marry, after many years of ab-
stinence from sexual intercourse, the testicles
undergo a certain degree of enlargement. It is
a great error to suppose that sexual connec-
tion in early life is essential for the preservation
of these organs. In cases of enlargement of
the prostate the ejaculatory canals sometimes
become completely obstructed. Under these
circumstances, the semen secreted under ex-
citement having no means of escape, encum-
bers the testicles for a time, but afterwards
becomes absorbed, and it is said that atrophy
of these glands sometimes follows ; but I
have never observed any instance of wasting
of the organs from this cause. As examples of
atrophy of the testicles from loss of nervous in-
fluence, may be adduced cases of paraplegia,
in which these organs have been known to
waste. Portal mentions the case of a robust
man, aged thirty-five, who was attacked with
painter’s colic, attended with great debility
of the lower extremities. The testicles dimin-
ished considerably ; and although he after-
wards recovered from the paralysis of his
limbs, these glands always remained wasted ;
and the man was incapable of the act of gene-
ration.* In the xxth volume of the “Medical
and Physical Journal,” there is an account of
a case of recovery after fracture, with partial
dislocation of the first and second lumbar
vertebrae, followed by paraplegia, in which,
three years afterwards, the testicles were
found entirely obliterated. It has been stated
that the testicles sometimes waste from in-
juries, or from compression of the spine at
the origin of the spermatic nerves. In a
man who had received a blow on the lum-
bar region, the testicles gradually wasted
away.f

The most common cause of atrophy of the
the testicle is the distuibance in its organisa-
tion consequent upon inflammation. As the
inflammatory process ceases, the enlarged
gland not only becomes reduced to its original
size, but it sometimes slowly but steadily
diminishes, till at length very iittle vestige of
it remains Mr. Hunter has related three
cases in which the testicle decayed in this
way.J 1 have met with several instances of
atrophy arising from this cause, and there are
few surgeons of experience who have not
witnessed cases of the kind. Wasting of the

* Ccmrs d'Anatomie Medicale, t. v. p. 434.

f Baillie’s Works, by Wardrop, vol ii. p. 315.

j Treatise on the Venereal Disease.

VOL. IV.

testicle has been observed to occur after an
attack of orchitis in mumps, arising as it is
supposed from the translation of inflamma-
tion from the parotid to the testicle. Two
cases of\cynanche parotidea in the adult, in
which atrophy took place in the gland chiefly
affected, are related by Dr. R. Hamilton.* I
have witnessed one case, in which the patient
attributed the loss of the gland to an attack
of mumps in his infancy. Wasting is more
liable to occur after inflammation of the body
of the gland than after consecutive inflamma-
tion in which the epididymis is the part
chiefly affected. One or both testicles have
been found to waste in persons who have
indulged too much in sexual intercourse or
been addicted to onanism. Baron Larrey met
with several cases of atrophy from excessive
venery and abuse of strong drinks amongst
the soldiers of the Imperial Guard. f Sir B.
Brodie has recorded two cases in which
wasting was occasioned by over-excitement ;
in one from onanism, in the other from
sexual intercourse. j: I have also witnessed an
instance of total atrophy of the left testicle in
a person addicted to excessive masturbation.
In this case, and probably in the others just
quoted, the wasting was preceded by an
attack of inflammation induced by inordinate
excitement.

It is a common belief that wasting of the
testicle is liable to be induced by the long-
continued use of iodine. I have not met with
any instance of it, and there are few cases in
which the evidence is such as to render it at
all clear that the decay of the gland was really
occasioned by the remedy. M. Cullerier has
published the case of a young man who took
from twenty-five to thirty drops of the tinc-
ture of iodine for a period of three months
for the cure of an obstinate gonorrhaea. This
was followed by a state of impotency and
partial wasting of the testicles, which lasted a
twelvemonth, and the organs never regained
their former size and vigour. M. Cullerier
mentions another case of temporary loss of
virile power occurring from the use of the
iodine of iron.§ I feel convinced, however,
that if iodine produces wasting of the testicle
at all, it does so so rarely, that the liability
cannot be regarded as any objection to the
free and long-continued use of this valuable
remedy. Atrophy of the testicle has been
remarked in elephantiasis of the Greeks, a
disease in which tubercles are developed in
various parts of the skin. Dr. Adams, in an
account of the cases of that disease observed
in Maderia, states that all those who were
attacked with it before the age of puberty
never acquired the distinguishing marks of
that change in the constitution, and their
testicles diminished in size, and that in those
affected later in life the testicles became

* Philos. Trans. Edinb. vol. ii. art. ix. p. 59.

f Mdmoires de Chirurgie Militaires, vol. ii. p. 66.

j London Medical and Physical Journal, vol. Ivi.
p. 297.

§ Memoires de la Socie'te' de Chirurgie de Paris,
t. i.

3 s

994

TESTICLE (ABNORMAL ANATOMY).

atrophied, and they lost the power of pro-
creation.* * * § Mr. Peacock also noticed a wasting
of the testicles in several cases of elephan-
tiasis in the Leper Hospital of Colombo, in
Ceylon. f A similar condition of these glands
was remarked in a case of this disease, so
rare in this country, narrated by Mr. Law-
rence and also in another case at the
London Hospital, which I recorded many
years ago.$ In a confirmed case however
of this disease, in a boy aged thirteen, who
was under my care in the year 1849, there
was no diminution in the size of these glands.
Wasting of the testicles is liable to occur
after injuries of the head.

Some years ago I saw a man who had met
with an injury of this description, which had
been followed by wasting of the testicles, and
the development of tumours on each side of the
chest, resembling mammae. He was about
fifty- nine years of age, a married man, and the
father of several children. He had belonged
to the legion in the Queen of Spain’s service.
About tvvoyears and a half previously, in an at-
tempt to jump over a trench, he fell backwards
and injured the posterior part of his head.
Whilst on the ground he received a bayonet
wound on the side, and a sabre cut on the fore-
head. He recovered from these injuries and
returned to England. Since the accident he
had completely lost his virility. lie had no
desire for sexual connection ; his penis had
dwindled in size ; his right testicle had gradu-
ally wasted, and was no larger than a horse
bean, and the left gland was also a good deal
diminished in bulk. The skull at the occiput
seemed somewhat flattened. Baron Larrey
records the case of a man who was wounded
in the back of the neck by a musket ball
which grazed the inferior occipital protuber-
ance. He recovered from the injury, but the
testicles were reduced to a state of atrophy,
and the penis shrunk and remained inactive.
He also relates the case of a man of strong
constitution and vigorous passions who re-
ceived a sabre wound which cut off all the
convex projecting part of the occipital bone,
and exposed the dura mater. The patient lost
the senses of sight and hearing on the right
side, and his testicles sensibly diminished,
and in fifteen days were reduced, especially
the left, to the size of a bean.|| Lallemaud
had under his care a man thirty years of age,
who, in the expedition to Algiers had received
a sabre wound at the nape of the neck. His
testicles were wasted, and venereal desire as
well as erections had entirely ceased. II We
cannot doubt that in these cases the loss of
sexual desire, and the wasting of the testicles
were the direct results of the injury to the
brain, and they go far to prove the essential
dependence of the functions of these glands

* On Morbid Poisons, p. 265.

j- Edinb. Medical and Surgical Journal, vol. liii.
p. 139.

1 Medico-Chirurgical Transactions, vol. vi. p. 214.

§ Vide Medical Gazette, vol. vii. p. 447.

|| Me'moires de Chirurgie Mililaire, p. 262.

if Pertes Semiuales Involontaires, t. ii. p. 41.

upon the cerebral organ. The physiologist
cannot fail to notice the rapidity with which
the atrophy is stated in some of the cases to
have succeeded the injury and the extent to
which it proceeded. The withering of the
testicles, was, indeed, so remarkable, that it
can only be attributed to the sudden and
complete extinction of the sexual instinct
resident in the brain, and (if I may so express
myself) to the immediate impression on the
system of the future uselessness of these
organs. In old age and in lingering diseases
the decay of the testicles is extremely slow
and gradual, and is never carried to the extent
observed in cases of injury to the brain. In
fact, men have survived the power or desire
of performing the sexual act many years
without the testicles being materially reduced
in size. We have seen, too, that in the lower
animals the testicles have been rendered use-
less by interrupting the vasa deferentia, with-
out any such striking effect being produced
on the glands as occurred in these cases of
cerebral injury.

Inflammation of the tunica vaginalis , or acute
hydrocele. — The inflammatory changes of the
tunica vaginalis resemble those of the other
serous membranes. M. Roux injected a
hydrocele in a middle-aged man : inflamma-
tion was developed, but on the fourth day,
gangrenous erysipelas attacked the scrotum,
and caused the patient’s death on the tenth
day after the operation. On examining the
tunica vaginalis, he found that it contained a
large quantity of whitish serum, in the midst
of which floated flakes of albumen ; other
flakes of the same kind formed a thick coating
over the testicle and internal surface of the
membranous pouch. The serous membrane
beneath appeared slightly thickened, and of
a deep red colour. The epididymis and the
lower part of the cord were swollen, and con-
stituted the more solid part of the tumour
produced by the inflammation. The body of
the testicle was not increased in bulk, and it
retained its natural consistence.* In the mu-
seum of the College of Surgeons, there is a
beautifully injected preparation of hydrocele,
showing the effects of inflammation after the
application of the caustic. It is represented
in the annexed wood-cut, which exhibits the
sac with part of it cut away to show the
swollen state of the epididymis, and the
aperture made by the caustic(l); the tunica
vaginalis is coated with flocculi of lymph.
The sac of an inguinal hernia is seen above
the hydrocele. The sound state of the body
of the testicle, though surrounded by an in-
flamed serous tunic, whilst the epididymis
partakes in the disease, has been accounted
for by Gendrin. He says, when the sub-
serous cellular tissue, which always partici-
pates in the inflammation of a serous mem-
brane penetrates into the interior of an organ,
it becomes a ready means of communicating

* Journal Gdndral de Me'dicine, &c. t. lviii. p. 25. ;
quoted from Gendrin, Ilistoire Anatomique des In-
flammations, t. i. p. 143.

TESTICLE (ABNORMAL ANATOMY). 995

the inflammatory action ; but when the con-
tiguous organ or subjacent part is of a dif-

Fig. 638.

ferent structure from that of the cellular
tissue, the extension of inflammation inwards
is checked. Thus, in the case of the inflamed
tunica vaginalis, the cellular tissue readily
transmitted the morbid action to the epididy-
mis, but the tunica albuginea arrested its
progress to the body of the testicle ; and this
explains the fact that after inflammation of
the tunica vaginalis, excited by injection, the
body of the gland is rarely found to suffer.
On the other hand, the epididymis is seldom
attacked with inflammation without the disease
being quickly propagated to the tunica vagi-
nalis.

The lymph effused in inflammation very
often forms adhesions between the opposed
serous surfaces, and these after some time are
rendered very firm and dense, and in old cases
are often converted into a fibro-cartilaginous
structure. In a testicle which I examined
some little while after an attack of acute in-
flammation, I found the lymph on both sur-
faces of the tunica vaginalis presenting a
honeycomb or lace-like appearance, similar to
that often met with on the pericardium. In-
flammation, if violent, may end in the forma-
tion of pus ; suppuration is, however, a rare
occurrence, unless artificially excited, for the
cure of hydrocele. Inflammation of the tunica
vaginalis is not only the most frequent disease
of the testicle, but it is also one of the most
common affections to which the body is liable.

In the different disorders of the gland this
membrane usually becomes inflamed at some
period or other, and adhesions between its
opposed surfaces are scarcely less common
than those of the pleura. In examining the
testicles of twenty- four adults, I found ad-
hesions of greater or less extent in one or
both glands in as many as nine instances.

Hydrocele of the tunica vaginalis. — The sac
of the tunica vaginalis, like other serous ca-
vities, is liable to dropsical effusion. The
fluid effused is usually transparent, and of
an amber, pale yellow, citron, or straw co-
lour, and resembles the serum of the blood,
but is occasionally thick. According to Dr.
Marcet’s analysis*, 1000 grains of this fluid
of the specific gravity 1024r3 contained 80
grains of solid matter, of which 71’5 con-
sisted of animal, and 8"5 of saline ingredients :
hence it appears that this fluid only differs
from the serum of the blood in possessing
rather less animal matter. In an analysis
of the fluid of hydrocele made by Dr. Bos-
tockj-, lOO'OO parts of the specific gravity
102-1 were found to contain

Water ...

91-25

Albumen -

6'85

Uncoagulable matter -

1-1

Salts -

•8

100-00

A quantity of flakey matter or flocculent
albumen is sometimes found floating in the
fluid ; and it frequently contains, especially
in old people, cholesterine in the form of a
multitude of minute shining particles. The
quantity of cholesterine contained in nine-
teen ounces of dark fluid full of these shining
particles, which I removed from an old hy-
drocele, amounted to nine grains. In the
examination of a testicle from a man of co-
lour who died at an advanced age, I found the
tunica vaginalis and its investing tissues very
thick and firm, and the seat of cartilaginous
and osseous deposits ; it contained about three
drachms of a thick brownish substance, which
was almost entirely composed of cholesterine.
This was no doubt a very old case of hydro-
cele, in which, the more fluid parts having
been absorbed, the cholesterine was left be-
hind within the indurated sac. The quantity
of serum which is suffered to accumulate
varies considerably. In this country it seldom
exceeds twenty ounces, though it has been
known to amount to several pints. The
largest quantity which I have met with is
forty-eight ounces. Mr. Cline is said to have
removed from Gibbon the historian as much
as six quarts. |

In simple hydrocele the testicle is usually
found at the posterior part, and rather below
the centre, of the sac : its situation however
is subject to variations. Before the occur-

* Medico-Chinu-g. Trans, vol. ii. p. 372.

f Ibid. vol. iv. p. 72.

j Sir A. Cooper’s Lectures, by Tyrrell, vol. ii.
p. 92.

3 s 2

990 TESTICLE (ABNORMAL ANATOMY).

rence of hydrocele the tunica vaginalis may
have been inflamed and contracted adhesions,
so that the testicle may be connected to the
membrane in front ; in which case the serum
accumulates on each side of or above and
below the organ. The position of the testicle
in front may also be owing to an original
inversion of the organ, in which the free sur-
face presenting backwards, the fluid collects
in that direction and presses the testicle to
the front of the sac. Sometimes there are
several adhesions producing a sacculated ar-
rangement and forming what is termed a
multilocular hydrocele. Occasionally the cysts
thus formed have no communication with
each other. In two instances I have seen
a membranous partition in the sac of a hydro-
cele, separating it into two distinct cavities,
formed by a layer of false membrane. There
is one kind of sac or pouch often met with
in hydroceles which is not commonly de-
scribed. It is situated on the inner side of
the testicle, but the opening into it is always
found on the outer side between the body of
the gland and the middle of the epididymis.
This sac, which varies very much in size, is
formed by the distention of the cul-de-sac
which I have described as existing naturally
at this part. Two examples of this kind of
pouch are contained in the Hunterian Mu-
seum. One of them is represented in the
accompanying figure. In large hydroceles

Fig. 639.

1, aperture of the poucli between the body of the
testicle and middle of the epididymis.

the epididymis is usually elongated and dis-
placed ; and instead of a pouch being formed,
the central part of the epididymis is drawn
to some distance from the body of the tes-
ticle. In old hydroceles the sac is often a
good deal thickened, the tissues enveloping it
being condensed and converted into layers of
dense fascia, such as are commonly observed

investing only hernial sacs. The fibres, also,
of the cremaster muscle, frequently become
remarkably developed. This, however, is not
constantly the case ; for in some instances of
hydrocele of large size I have found this
muscle atrophied. The thickened sac after
many years acquires a cartilaginous cha-
racter, and it sometimes even becomes os-
sified. In cases which have been frequently
tapped, the sac is often found closely ad-
herent to the skin of the scrotum at the
various points perforated by the trocar. In
the Hunterian Museum there is a prepar-
ation showing a long narrow band of ad-
hesion passing from the anterior part of
the testicle across the dilated sac of the
tunica vaginalis to the membrane in front,
which is supposed to have resulted from a
wound of the testicle in the operation of tap-
ping. In all large hydroceles the spermatic
vessels are separated and displaced. The
glandular structure of the testicle is sound,
and the organ capable of exercising its func-
tions. The disease is strictly confined to the
investing serous tunic. The testicle is, how-
ever, frequently somewhat altered in shape,
being flattened by the pressure of the confined
fluid ; and in some instances has been found
partially atrophied.

Hydrocele is generally single, but some-
times occurs on both sides. It is commonly
said to form more frequently on the left side
than on the right. During the last few years
I have registered the new cases of hydrocele
coming under my notice in public and private
practice. Of one hundred and ten cases of
simple hydrocele, one hundred and four were
single, and six double. Of the former sixty-
two occurred on the right side, and forty-two
on the left. This result, which gives a decided
predominance to the right side, does not agree
with the observations of Velpeau, Gerdy, and
Dujat, who found the disease to be more
frequent on the left side. Hydrocele in young
infants is usually single, and in my experience,
more common on the right side. I have seen,
however, a few cases of double hydrocele at
this early period. When the fluid collected
in the tunica vaginalis is attended with en-
largement of the testicle, the swelling is termed
a hydro-sarcocele. This affection is generally
consequent on chronic orchitis, but it is occa-
sioned by other morbid changes, malignant as
well as innocent. In these cases the disease
of the testicle is the original complaint and
source of the irritation that excites an undue
secretion from the tunica vaginalis.

Congenital hydrocele. — In simple hydrocele,
the original communication between the ca-
vities of the peritoneum and of the tunica
vaginalis is permanently obliterated ; but it
sometimes happens that fluid accumulates
around the testicle in cases in which the
obliteration has not been completed, consti-
tuting the variety termed congenital hydrocele.
The opening of communication between the
two cavities is usually small in size, about
sufficient to admit a crow’s or goose’s quill.
There is rather a rare variety of congenital

TESTICLE (ABNORMAL ANATOMY). 997

hydrocele, in which the testicle is retained
in the abdomen or inguinal canal, while the
peritoneum, prolonged for a short distance
into the scrotum, forms the cyst containing
the fluid which is covered only by the inte-
guments and superficial fascia.

Encysted hydrocele of the testicle. — In this
form of hydrocele, fluid is effused into an ad-
ventitious cyst or cysts distinct from the sac of
the tunica vaginalis. The cyst is composed of
a thin delicate serous membrane, and may be
developed in three situations: 1. beneath the
visceral portion of the tunica vaginalis in-
vesting the epididymis ; 2. between the testi-
cular portion of the tunica vaginalis and the
tunica albuginea, which are thus separated
from each other ; 3. between the layers of
the loose or reflected portion of the tunica
vaginalis. The first is by far the most com-
mon situation, the two latter being very rare.
These cysts are composed of a delicate serous
membrane lined with tesselated epithelium,
and the fluid contained in them differs from
that of simple hydrocele in being perfectly
limpid and colourless, and nearly free from
albumen. In the cysts formed on the epi-
didymis, the fluid, instead of being limpid,
often presents an opaline opacity arising from
the presence of spermatozoa.

1. Small cysts not larger than a pea, and even
smaller, may frequently be found beneath the
serous membrane covering the head of the
epididymis, in which they produce a slight
depression. In several instances I have seen
as many as five and six perfectly distinct
cysts connected with this part.

Sometimes one or two small cysts are so
embedded in the substance of the epididymis,
that they cannot be recognised without dis-
section. Though these minute cysts generally
contain a limpid fluid, I have sometimes found
them filled with fluid of a milky hue, and I
have even observed matter like pus tinged
with blood. These accidental cysts some-
times project the tunica vaginalis before them
until they become so far separated from the
epididymis, where they were originally deve-
loped, as to be attached only by a narrow
peduncle formed by a contraction of the con-
necting tunica vaginalis. Such is the mode
of development of those small pendulous pe-
dunculated cysts containing a limpid fluid
often found hanging from the head of the epi-
didymis, which were erroneously supposed
by Morgagni to be hydatids. I have on many
occasions observed them in the different
stages of their production. Thus I have
seen a pedunculated cyst attached at one
part, whilst close to it there was a cyst of
a similar nature embedded in the substance
of the epididymis. In other instances I have
found the cyst very prominent, but still con-
nected by a broad attachment to the tunica
vaginalis reflected over it, the membrane not
having as yet contracted to form the narrow
neck. In all these cases the prolongation of
the tunica vaginalis investing the cyst could
always be demonstrated by cautious dissec-
tion, and between the membrane and the cyst

some minute red bloodvessels were generally
seen ramifying. These pednuculated cysts
never acquire a large size : I have seldom
found them to exceed that of a currant.
From the exposed situation of the testicle
they are liable to be ruptured, the vestiges of
them consisting of fimbriated folds of mem-
brane ; but this is not a common occurrence.
I have seen the delicate peduncle by which
the cyst was attached to the epididymis as
long as three quarters of an inch. M. Gosselin
states that small cysts are sometimes deve-
loped in the little appendage to the tunica va-
ginalis so often found connected with the
upper part of the testicle.* This I have never
seen.

So common are small cysts connected with
the epididymis in the various states and stages
I have described, that it is impossible to
examine many testicles, especially of persons
beyond the age of puberty, without finding
them. According to M. Gosselin f, they are
liable to be developed from the period of
puberty to the age of thirty or thirty-five, but
are rare at this period. After the age of forty
they are very common, having been met with
by him in at least two thirds of the testicles
examined. Now when one or more of these
cysts, instead of becoming pedunculated, en-
large so as to form a tumour in the scrotum

Fig. C40.

* Archives Centrales des Medecine, 4e Serie,
t. xvi. p. 27.

f M. Gosselin has given an elaborate account of
the cysts connected with the epididymis, in two pa-
pers published in the 16th volume of the Archives
Ge'nerales de Me'dicine. He makes two varieties of
them, the small and large, and states that sperma-
tozoa are found only in the latter. This distinction
I consider to be unfounded, the smaller cysts being
simply the early stage of the larger. M. Gosselin
assumes the credit of being the first to describe the
small cysts. They were, however, minutely de-
scribed by me, and illustrated in my work on the
Diseases of the Testis, published in 1843, of which
M. Gosselin could scarcely have been ignorant, since
he refers to my account of this form of hjrdrocele.

3 s 3

TESTICLE (ABNORMAL ANATOMY).

they constitute the form of hydrocele, called
from its original seat, encysted hydrocele of the
epididymis. I have observed this description
of hydrocele in all its various modifications,
from the enlargement simply of a single cyst to
the complication occasioned by the varied de-
velopment of several. As a cyst enlarges the
epididymis becomes flattened, and displaced
to one side, whilst the testicle is found either
in front or at the bottom. It is sometimes at
the side, but rarely at the posterior part of the
swelling.

In the above woodcut (fig. 640.) of a spe-
cimen in the London Hospital Museum, the
cyst is above the testicle, which is so dis-
placed by it that its anterior edge is directed
downwards. The tumour is generally of
smaller size than a simple hydrocele, the fluid
commonly not exceeding three or four ounces
in quantity. I have, however, removed as
much as thirty-two ounces from a single cyst.
When the hydrocele is composed of several
cysts, they are seldom of large size, but form
a cluster more or less complicated and irre-
gular, according to their size and number.

A curious sacculated arrangement produced
by the development of numerous contiguous
cysts may be seen in the annexed figure, (Jig.
641.) taken from a preparation dissected by

Fig. 641.

myself : part of the walls of the cysts are cut
away to exhibit their interiors. The cysts are
liable to inflammation, which causes more or less
alteration in the quality and appearance of the
fluid contained in them. The fluid may become
albuminous and assume the straw or amber
colour of ordinary hydrocele ; and the cyst
may contain lymph, form adhesions, or be
lined with a false membrane, the fluid being
thick and turbid. The cysts sometimes also
become filled with blood, constituting a variety
of haematocele.

2. A cyst may form between the tunica
albuginea and the visceral layer of the tunica
vaginalis, separating the two membranes which

are naturally closely adherent to each other.
This is a very rare form of hydrocele. A spe-
cimen which I discovered accidentally in dis-
section, is represented in the annexed wood-
cut. (Jig. 642.) The cyst contained about two

Fig. 642.

drachmsof fluid, and is situated along thefront
of the testicle ; it is a little thickened. A sec-
tion of it is preserved in the Hunterian Museum.
Sir B. Brodie has described a very similar
specimen.* Tn the museum of St. Thomas’s
Hospital there is a specimen of a small cyst
apparently developed from the epididymis : in
its subsequent growth it had extended on the
fore-part of the testicle, separating the tunica
vaginalis from the tunica albuginea.
t 3. In examining a healthy testicle I once
found six or seven small cysts about the size
of currants, studding the surface of the loose
portion of the tunica vaginalis. Two of them
were situated in a part of the membrane ex-
tending up the cord. They projected in-
ternally, and contained a limpid fluid. I have
twice since seen a similar kind of cyst in the
same portion of the tunica vaginalis. Similar
adventitious cysts have also been observed on
the internal surface of the sac of a simple
hydrocele, and a preparation of the kind is
contained in the Hunterian Museum. If a
cyst developed in this membrane were to
increase to any size, it would constitute a
swelling which might be appropriately termed
an encysted hydrocole of the tunica vaginalis.

A circumstance of much interest in con-
nection with encysted hydrocele of the tes-
ticle, is the occurrence of spermotozoa in the
fluid contents of the cyst, a discovery made
by the late Mr. Liston in 1843. During the
last six years I have met with them in as
many as twenty cases of encysted hydrocele :
indeed, in the majority of instances in which

* Lond. Med. and Phys. Journal, vol. Ivi. p. 522.

TESTICLE (ABNORMAL ANATOMY). 999

I have searched for them. They were found in
subjects of various ages from 30 to 75, and in
cysts of all sizes from that of a filbert to the
largest which the hydrocele attains. The fluid
in some instances contained these bodies in
remarkable abundance ; in others they existed
sparingly. When very numerous, they give
to the fluid an opaline opacity, or an appear-
ance resembling cocoa-nut milk which is so
characteristic as to enable the surgeon to pre-
dicate their presence from the appearance of
the fluid alone without minute examination.
If the fluid be allowed to remain at rest in a
glass vessel, the spermatozoa subside to the
bottom, rendering the lower portion more
opaque than the upper. The fluid also ex-
hibits slight traces of albumen, when tested in
the usual way, which is not the case with the
ordinary pellucid colourless fluid of encysted
hydrocele. The spermatozoa were often as
lively as in fresh semen. They were observed
more frequently in the larger cysts than in the
smaller. I once found them in fluids removed
from two distinct cysts connected with the
epididymis of a man about sixty years of age.
1 have detected them in the fluid from en-
cysted hydroceles tapped for the first time,
and also in the examination of small cysts
connected with testicles removed after death.
I removed from an old man aged 75, who had
had encysted hydrocele for eight years, and
which had never been tapped before, as much
as thirty-two ounces of fluid, which contained
an abundance of spermatozoa. They were
also detected in fluid taken from a man aged
54*, who stated that the tumour had existed for
eight years, and had never been operated on.

Various opinions have been broached to
account for the existence of spermatozoa in
the encysted form of hydrocele of the testicle.
The explanation which seems to me the most
reasonable and probable, is that which I
offered shortly after the occurrence of sper-
matozoa in encysted hydroceles was first dis-
covered*, viz. that their presence is probably
owing to the accidental rupture of a seminal
canal, and the escape of its contents into the
cyst of an existing hydrocele. The close
proximity of the efferent tubes, the slight tex-
ture of the ducts and delicate walls of the
cyst, and the liability of the part to contusion
and injur}-, when a swelling even of moderate
size exists, seemed to me to favour this
view. The circumstance that spermatozoa are
never found in very small cysts show that
they are not originally formed there, but are
a subsequent addition to their contents. Since
my attention has been drawn to this subject
I have investigated the history of the cases of
encysted hydrocele containing spermatozoa,
which came under my notice. In nearly all
instances the patients assured me that the
swelling had gradually formed after an injury
to the tes-icle ; and in two cases it was clear
that a small cystic swelling had long existed
in a stationary state, but after a slight blow

* Practical Treatise on Diseases of the Testis.
Appendix, p. 541.

had begun to enlarge. I strongly suspect
that, in these cases, a duct had been ruptured
by the contusion, and that the irritation con-
sequent on the injury, and perhaps on the
addition of such lively bodies as spermatozoa
to the fluid contents of the cyst, had led to
its further development. I have, it is true,
failed in establishing the fact of a communica-
tion between the duct and the cyst by ana-
tomical examination. In two instances of
large encysted hydrocele containing sperma-
tozoa, which I had an opportunity of examin-
ing, I injected the vas deferens with coloured
size, but the duct was so clogged with semen
that the fluid could not be made to reach the
head of the epididymis, to which the cyst was
attached. In a preparation of large encysted
bilocular hydrocele containing spermatozoa,
shown me by Mr. Busk, the vas deferens had
been injected with mercury, but none of the
metal reached the upper part of the epididymis.
The cyst evidently arose from the head of the
epididymis, and was embedded a little in its
substance. In these cases no opening com-
municating with a duct could be discovered
on examination of the cysts, but this is not
surprising, since the communication must be
extremely minute, so as readily to escape
detection, or it may even have been obliter-
ated.

Spermatozoa are stated to have been found
in some two or three instances in fluid re-
moved from the tunica vaginalis. It is not
improbable that these cases may have been
encysted hydrocles mistaken for simple. The
diagnosis is sometimes very difficult, and in
the case of the cyst examined by Mr. Paget,*
this error was made before death by a hospital
surgeon. I have, however, found spermatozoa
in the sac of the tunica vaginalis, and the fol-
lowing case will account tor their presence.
A man aged fifty-four died in the London
Hospital of disease of the kidneys, of one of the
ureters, and of the bladder, which appeared to
be consequent on a severe blow on the loins
about six weeks before. The tunica vaginalis
of one of the testicles contained two ounces
and a half of slightly opaque fluid, in which a
few spermatozoa were found. There were
three small cysts containing fluid immediately
connected with the epididymis, and also atone
spot an irregular ragged membranous appear-
ance, evidently caused by the rupture of a
cyst. It is most probable that the spermatozoa
had escaped from this cyst, which may indeed
have been burst at the time of the injury. I
have examined the fluid from the tunica vagi-
nalis in a large number of instances without
finding these bodies, and I believe their occur-
rence in the common form of hydrocele to be
extremely rare.

Diffused Hydrocele of the Spermatic Cord. —
Mr. Pott has given an admirable account of
this affection, under the denomination of hy-
drocele of the cells of the tunica communis. f It
has likewise been particularly described by

* Medico-chirurgical Trans., vol. 27. p. 398.

j- Vide his Treatise on Hydrocele.

3 s 4

1000

TESTICLE (ABNORMAL ANATOMY).

Scarpa.* The disease is of the nature of
simple oedema, a watery fluid being diffused
throughout the areolar tissue connecting the
vessels of the spermatic cord, and enclosed in
a sheath, which is invested by the musculo-
aponeurotic structure of the cremaster muscle.
When the complaint has lasted some time,
the sheath is found more or less thickened.
The areolar tissue within is infiltrated with a
limpid albuminous serum of a white or yel-
lowish colour, which flows out in the course
of the dissection. The cells infiltrated with
serum are converted into large vesicles, some
of which are big enough to admit the tip of
the finger. These cells are larger and more
delicate towards the base of the swelling,
where they sometimes disappear altogether ;
so that there is only one considerable cavity
at the lowest and more depending part. The
base of the swelling corresponds to the point
at which the spermatic vessels join the testicle,
and at this part a dense septum cuts off all
communication with the tunica vaginalis. In
some instances the effusion extends along the
cord into the abdomen, as in a remarkable case
related by Mr. Pott. In the annexed figure of
this affection, ( fig . 043.), taken from Scarpa,

the envelope of the cremaster is laid open, ex-
posing the pyramidal swelling enclosed in its
sheath of condensed areolar tissue. The tes-

* Memoria sull’ Idrocele de Cordone Spermatico.
Bertrandi, an Italian surgeon, in a memoir pub-
lished by the French Academy of Surgery, in 1778,
has given an accurate description of this affection,
which, however, he did not sufficiently distinguish
from the encysted hydrocele of the cord. He dis-
sected on the dead body a diffused hydrocele, which
contained twenty ounces of fluid.

tide and tunica vaginalis are seen below it.
In general anasarca the areolar tissue of the
spermatic cord, as well as of the scrotum, is
frequently distended with serum ; but oedema
of the cord alone is a very rare affection. Sir
A. Cooper makes no allusion to it, and Mr.
Pott, to whom we are indebted for so good
and accurate a description of this species of
hydrocele, probably met with a greater num-
ber of cases of it than have occurred in the
practice of any surgeon since his day.

Encysted Hydrocele of the Spermatic Cord —
A cyst containing fluid may be developed in
the loose areolar tissue of the spermatic cord.
The cyst is formed of a thin transparent
membrane, possessing the ordinary characters
of a serous membrane, and contains generally
a limpid aqueous liquid, having little or no
albumen, but sometimes a straw-coloured
serum similar to the fluid of simple hydrocele.
It is of an oval form, and its size, though
variable, seldom exceeds that of a hen’s egg,
and is usually smaller. It is loosely attached
by areolar tissue to the vessels of the cord
which are situated at its back part, but be-
come separated and displaced by it. The cyst
is invested by the common integuments, super-
ficial fascia, musculo-aponeurotic sheath of the
cremaster muscle, and fascia transversalis. It
may occur either immediately above the tes-
ticle, in the middle of the cord, or just below
the abdominal ring, and even within the in-
guinal canal. Usually there is a single cyst,
but occasionally several are developed, and a
chain of them has been formed along the cord.
The cyst and its contents are liable to changes
consequent upon inflammation. Encysted
hydrocele of the cord appears to originate,
in general, in a partial or imperfect oblitera-
tion of the prolongation of peritoneum drawn
down at the period of the transition of the
testicle. I have already described the different
appearances presented by the remains of this
prolongation, which, it has been remarked,
sometimes consists of a single cyst, or of two
or more sacculi, moistened by a serous fluid.
When this fluid accumulates in any quantity,
an encysted hydrocele is the result. Such is
obviously the mode of origin of this affection
when occurring in infants, and no doubt in
adults it generally originates in the same way.
M. J. Cloquet has remarked that the remains
of the peritoneal process accompanying the
testicles in their descent were met with in
male subjects of all ages, and he mentions as a
singular circumstance, that they were nearly
as frequently found in the old as in the young
subjects.* My own dissections agree with the
observations of this accurate anatomist. In
the museum at the London Hospital there is
a preparation showing the tunica vaginalis
continued for about two inches up the cord,
and, immediately above it, an encysted hydro-
cele, which was taken from an adult subject.
In dissecting the body of a man, aged eighteen,
I found an encysted hydrocele of the cord

* Description of the parts concerned in Inguinal
and Femoral Hernia, tr. by McWhinnie, p. 25.

TESTICLE (ABNORMAL ANATOMY). 1001

above the testicle in close contact with the
tunica vaginalis. Immediately above this cyst,
but quite distinct from it, there was a narrow
and empty serous sac three inches in length,
with a contracted neck, and communicating
with the abdomen. They are figured in the
accompanying engraving, with the hernial sac

Fig. 644.

laid open, and part of the parietes of the
encysted hydrocele cut away to expose their
interiors. The position of the testicle is so
changed that its anterior border is directed
downwards. In the examination of the body
of a man who died of disease of the heart, I
found on the right side a thickened and empty
serous pouch, extending for about an inch
and a half below the external abdominal ring.
Directly below it was an independent cyst,
capable of containing a walnut, similar in
structure to the hernial sac, but lined by a
thin false membrane. The tunica vaginalis,
which was healthy in structure, extended up
the cord as far as the cyst, from which it was
separated by a thick and firm partition. In
opening the body of a sailor who died with
ascites, I noticed at the internal ring a small,
delicate, transparent, pedunculated cyst, not
larger than a nut, projecting into the cavity
of the abdomen. In the spermatic cord, there
was a large serous cyst, which extended into
the inguinal canal, and contained a small
quantity of transparent fluid. A small orifice
at its upper part opened into the peduncu-
lated cyst, which proved to be a process from
the cyst in the cord. In fig. 644., I have
given a representation of an inguinal hernia,
combined with an elongated encysted hydro-
cele of the cord; and in fig. 647 , a repre-
sentation of an encysted hasmatocele of the
cord, in which the tunica vaginalis remained

unobliterated as far up as the cyst, whilst a
hernial sac is situated immediately above it.
These dissections confirm the view taken by
Sir A. Cooper, and now commonly adopted,
of the mode of origin of encysted hydrocele
of the spermatic cord in the adult.

Complications of hydrocele. — The following
are the principal : 1. Simple hydrocele, com-
bined with encysted hydrocele of the testicle.

2. Simple hydrocele, combined with encysted
hydrocele of the spermatic cord. 3. Simple
hydrocele, combined with diffused hydrocele
of the spermatic cord. 4. Oscheo-hydrocele,
including both simple hydrocele and encysted
hydrocele, combined respectively with inguinal
hernia.

1. The first is not an uncommon compli-
cation. In the dissection of these parts, I
have often found the tunica vaginalis distended
with three or four drachms, and even an ounce
or two of serum, two or more small distinct
cysts being at the same time connected with
the upper part of the epididymis ; and I have
twice met with this complication in both sides
in the same individual. The small adventi-
tious cysts appear to be the original disease,
the irritation produced by them being in all
probability the cause of the increased quan-
tity of fluid in the tunica vaginalis.

2. The second complication is somewhat
rare. In the pathological collection at the
London Hospital, there are two specimens of a
collection of fluid in the tunica vaginalis as-
sociated with an encysted hydrocele of the
spermatic cord. In one of them the tunica
vaginalis is unobliterated for about two inches
along the spermatic cord, and the encysted
hydrocele is immediately above it. In the
other preparation it is apparent that both sacs
have been the seat of inflammation, false mem-
branes being contained within them. This
complication sometimes occurs in infants.

3. Simple hydrocele associated with dif-
fused hydrocele of the cord is also rare. A
good delineation of this complication is given
in Scarpa’s work.

4. Scrotal hernia may be combined with
hydrocele. A voluminous hydrocele, if un-

Fig. 645.

TESTICLE (ABNORMAL ANATOMY).

J002

supported, appears to be highly favourable
to the occurrence of hernia and the extension
of the sac, by dragging down the peritoneum.
Oscheo-hydrocele is not an uncommon
complication. In most of the cases which I
have met with, the hydrocele was placed be-
low and free of the rupture, and in a few only
in front of it. I have never found the hernial
sac covering the fore part of a hydrocele.
The ordinary relations of hydrocele and scro-
tal hernia may be seen in the accompanying
woodcut. In figure 638., the sac of an in-
guinal hernia is represented at some little
distance above a small hydrocele. Dupuytren
states that, when a hydrocele is placed in
front of a hernia, a part of the omentum or
intestine sometimes descends into a cyst,
which projects into the hydrocele, and is
formed of the hernial sac and serous fold
of the tunic of the testicle.* This complica-
tion is of the nature of the hernia infantilis,
described by Mr. Key, and called by Sir A,
Cooper encysted hernia of the tunica vaginalis.

Hcematocele. — This is a term applied to the
swelling occasioned by effusion of blood in the
sac of the tunica vaginalis, or in a cyst connected
with the testicle ; it is also applied to tumours
produced by extravasation, either in the sub-
stance of the spermatic cord, or in the sac of
an encysted hydrocele of this part. Hcema-
tocele of the testicle, in which blood is effused
into the tunica vaginalis, is by far the most
common form of this affection. The extra-
vasation may take place in a healthy state of
the parts, or it may succeed, or be combined
with hydrocele. The first variety occurs from
the accidental rupture of some blood-vessel,
probably one of the vessels ramifying between
the tunica albuginea and tunica vaginalis
testis, owing either to a blow or a violent
straining effort. The second variety, in which
the extravasation takes place in combination
with hydrocele, is of more frequent occur-
rence than the first. It may also be produced
by a blow, or by the wound of some vessel,
in the operation of tapping. A blow occa-
sions a slight rupture of the tunica vaginalis,
and of some of the enlarged vessels ramifying
outside it, and the blood which escapes passes
into the sac and mixes with the fluid of the
hydrocele, producing a sudden increase in the
size of the tumour. The liability to this ac-
cidental effusion of blood is increased by a
diseased condition of the arteries, such as is
commonly met with in old people. The quan-
tity of blood effused under these circum-
stances varies considerably. It may be merely
sufficient to impart a red tinge to the serum.
In general, however, it is greater in amount,
and coagula are formed, which remain undis-
solved in the fluid. A haematocele maybe
produced in the operation of tapping a hydro-
cele, in two ways. It may be occasioned by
the accidental wound of some vessel rami-
fying over the tunica vaginals, which, instead
of bleeding externally, or into the areolar
tissue of the scrotum, pours its blood into

* Leyons Orales. Brussels edit. t. iv. p. 233.

the sac of the hydrocele ; or it may be caused
by the trocar or lancet penetrating too far,
and wounding the testicle or spermatic
artery.

In haematoceles which have existed for a
long period, the blood becomes changed into
a substance resembling coffee grounds, of a
brownish-red, or chocolate colour, and more
or less fluid. The coagula sometimes present
a cellular or honeycomb appearance, the cells
being filled with a reddish serum. Occasion-
ally the blood is found converted into a solid
fibrinous substance, of a yellow or fawn colour,
arranged in firm layers, similar to the coagula
lining the sac of an aneurism. In many in-
stances the effused blood is felt as a foreign
body, and produces inflammation in the tunica
vaginalis, which becomes coated with lymph,
and this mixing with blood and serum modi-
fies the appearance of the contents of the
cyst, rendering it turbid and of a lighter
colour. Sometimes the inflammation goes on
to suppuration, in which case pus is also
found in the sac. The inflammation usually
extends from the tunica vaginalis to the areolar
tissue and fascia external to the sac, which in
recent cases are found infiltrated with serum
and lymph, and in cases of old standing be-
come greatly thickened, indurated, and com-
pacted. In a case of haematocele, occasioned
by the wound of a vessel in tapping a hydro-
cele in which I was consulted, the inflamma-
tion which ensued caused, in the course of a
fortnight, great thickening of the tissues ex-
ternal to the sac, and the formation of an
abscess in the scrotum on one side of the
hasmatocele. I have found the tunica vagin-
alis and tissues investing it as much as half
an inch in thickness, and very firm and dense.

These changes in the sac are produced by
a more chronic form of inflammation of the
fascia and areolar tissue investing the sac. In
these old cases, the internal surface of the
tunica vaginalis instead of presenting its na-
tural smooth and polished surface, is rough,
granular, and irregular, and feels as dense and
tough as a piece of leather, having lost all
the characters of a serous membrane. In
haematocele, the testicle preserves the same
relation to the remainder of the tumour as
in simple hydrocele, being situated at the
posterior part, and rather below the centre.
Its position, however, is liable to similar al-
terations as occur in hydrocele, and they are
dependent upon the same causes. A young
man had a hydrocele, which had succeeded to
an attack of secondary orchitis, occasioning
an adhesion of the gland to the front of the
sac at its lower part. The case became con-
verted into a hsematocele by the wound of a
vessel in the operation of tapping. Inflam-
mation ensued, and it became necessary to lay
open the sac. The surgeon, in carrying the
incision to the lower part of the tunica va-
ginalis, divided the vas deferens and severed
the sound testicle nearly in two with his bis-
toury, the thickening around the sac having
prevented him from detecting the gland in
its unusual situation. In hrematocele, the

TESTICLE (ABNORMAL ANATOMY). 1003

glandular structure of the testicle sometimes
disappears in the same manner as in old cases
of hydrocele, atrophy being occasioned by the
long continued pressure arising from the ex-
travasated blood. Sir B. Brodie has recorded
two cases of old haematocele, in which the
testicle was completely atrophied.* In the
examination of a large haematocele which had
existed for many years, and was removed by
operation, under the impression that it was a
solid enlargement of the testicle, I found the
tunica vaginalis nearly half an inch thick, and
full of a soft friable substance of a chocolate
colour ; the testicle, which was situated at
the posterior part of the cavity, was some-
what flattened, and partly imbedded in the
thickened cyst ; but the glandular structure
was perfectly healthy, and the bulk of the
organ scarcely less than natural The haema-
tocele, with the sac and testicle laid open, is
represented in the accompanying figure. The

Fig. GIG.

structure of the testicle is usually indeed sound
in haematocele, but its nutrition becomes im-
paired when the disease is of very old stand-
ing.

Encysted hcematocele of the testicle, or
effusion of blood in a cyst connected with the
testicle, is an extremely rare affection. The
following is the only case of the kind that I
have met with. I was requested by one of
my colleagues at the London Hospital to
examine a case of painful tumour connected
with the left testicle. The patient, aged
eighteen, had injured the part three months
before. The scrotum was much swollen at the
time of the accident, and the tumour formed
afterwards. It was about the size of a chesnut,

* Lond. Med. and Phr^s. Journal, vol. Ivin. p.
299.

quite moveable, but attached to the epididymis.
The cyst was opened with a lancet, and exit
given to a quantity of dark coagula lodged in
a thickened cyst, the interior of which was
lined by a rough false membrane. No doubt
the cyst existed before the injury, which
caused effusion of blood and inflammation,
and thickening of the cyst.

Hcematocele of the spermatic cord is an
affection which was first noticed by Mr. Pott.
It is generally produced by the accidental
rupture of a spermatic vein, during violent
and sudden exertion, as in straining to lift a
heavy weight, when blood immediately es-
capes into, and infiltrates the loose areolar
tissue along the cord, where it accumulates,
its further diffusion being prevented by the
fascious envelope of this part. Mr. Pott has
related three cases, all of which happened in
this way. I have met with this variety of
haematocele, coupled with extravasation in
the scrotum, in two or three instances of
contusion, of this part. In one case in which
the effusion in the cord was on the left side
the spermatic veins were varicose.

Encysted hcematocele of the spermatic cord
results from the effusion of blood into the
cyst of a hydrocele of this part. But it is an
affection only known to me from preparations.
In the Museum of St. Bartholomew’s Hos-
pital there is a specimen of the kind. The
cyst is empty : but it is described to have
contained blood, and its walls are deeply
stained with the colour of partially decom-
posed blood. Its lining membrane is wrinkled
and coarsely granular, and the tissues around

Fig. 617.

1, testicle ; 2, hernial sac ; 3, encysted haematocele.

1004

TESTICLE (ABNORMAL ANATOMY).

it are thickened, brawny, and adherent toge-
ther. In the Hunterian Museum there is a
specimen (No. 2460.) of old encysted haema-
tocele of the spermatic cord. A good-sized
cyst, lined by a membrane, polished and a
little wrinkled, is filled with a soft, tawny-
looking granular matter, resembling the altered
coagulum of blood observed in ordinary
haematocele after long maceration in spirit.
The tissues around the cyst are thickened
and indurated, just like those around an old
haematocele of the testicle. There is a hernial
sac immediately above it, and a hydrocele
below, with the sac open for some distance
tip the cord as far as the cyst of the haema-
tocele. The latter does not communicate
either with the tunica vaginalis, or the hernial
sac. In the Musee Dupuytren at Paris,
I also saw a preparation of this affection,
which occurred in the practice of the late M.
Blandin.

Orchitis. — Inflammation of the testicle
occurs in two forms, acute and chronic ; and
it may commence either in the body or secre-
ting part of the organ, or in the epididymis.
Inflammation beginning in the body of the
testicle may be idiopathic, or may be excited
by external violence : the disease is at first
confined to the interior of the organ, the
epididymis and tunica vaginalis being affected
only secondarily, and sometimes entirely es-
caping. Orchitis is far more frequently a
consecutive affection than a primary, the in-
flammation being transmitted from the urethra
along the vas deferens. In this latter form
of orchitis, which is familiarly known by the
term hernia humoralis, the epididymis is first
attacked, and the tunica vaginalis generally
participates in the disease.

Acute Orchitis. — Few pathologists have
examined a testicle in a state of acute inflam-
mation, and I am unacquainted with anj au-
thentic account of the alterations in structure
from inflammation originating in the body of
the gland. I have twice had the opportunity of
examining a testicle affected with acute se-
condary orchitis ; and the following description
of the pathological appearances is drawn up
from these investigations, and from the ac-
count of the dissection of two testicles affected
with gonorrhoeal inflammation recorded by
M. Gaussail.* The tunica vaginalis is more or
less distended with lymph or albuminous
matter, infiltrated with reddish serum, which
form loose adhesions between the opposed
surfaces of the membrane ; these adhesions
are so slight as easily to admit of being broken
down with the finger. The membrane is in-
jected with a multitude of minute red vessels
which ramify in various directions and form a
compact network. At a later period red ves-
vels may be traced proceeding from the free
surface of the tunica vaginalis to the false
membranes forming the adhesions. The vo-
lume of the testicle appears very little if at
all increased, the great bulk of the tumour

* Memoire sur 1’Orchite Blennorrhagique, Ar-
chives Generales de Me'decine, tom. xxvii. p. 210.

being occasioned by the swollen epididymis
and effusion into the serous sac. When cut
into, the gland appears somewhat darker than
natural, from a congested state of its vessels.
The epididymis, particularly the lower part,
is enlarged to twice and sometimes thrice its
natural size, and feels thick, firm, and in-
durated. This enlargement is produced by
the effusion of a brownish deposit in the
areolar tissue between the convolutions of
the duct. The coats of the vas deferens are
thickened, and the vessels ramifying near them
injected, sometimes along the whole extent of
the duct. Albuminous deposit is found in the
areolar tissue around the tortuous part of the
vas deferens and tail of the epididymis, which
frequently forms the bulk of the swelling ob-
served in these cases. Owing to the epidi-
dymis being the part chiefly and most con-
stantly affected in consecutive orchitis, some
of the modern French writers have denomin-
ated the disease epididymitis.

In treating of the acute inflammatory
changes in the tunica vaginalis, I particularly
remarked that the inflammatory action was very
liable to extend to the substance of the epidi-
dymis, but not to the body of the testicle, and
I noticed the pathological law enunciated by
Gendrin, by which the circumstance was ac-
counted for. We find, too, that inflammation
of the epididymis is much more readily pro-
pagated to the tunica vaginalis than inflam-
mation originating in the glandular structure
of the testicle. When inflammation com-
mences in the body of the gland, the enlarge-
ment takes place slowly, and is seldom con-
siderable until the disease has existed for
some length of time, which is easily explained
by the unyielding texture of the tunica albu-
ginea, and the circumstance of the tunica
vaginalis remaining unaffected. Suppuration
occasionally takes place in this form of orchitis,
whereas in consecutive inflammation the form-
ation of pus in the substance of the gland is
of rather rare occurrence. I do not mean,
however, to assert, that the glandular struc-
ture of the testicle never suffers in consecutive
orchitis, for I believe that it does so in some
instances ; but, according to my observations,
and I have paid some attention to the sub-
ject, it very commonly escapes, the inflamma-
tion not extending further than to the epidi-
dymis. When inflammation terminates in
suppuration, the matter is so slow in making
its way externally, owing to the density, thick-
ness, and low organisation of the tunica al-
buginea, that it generally burrows in vari-
ous directions, producing numerous sinuses
throughout the gland, and disorganising its
delicate structure. The matter sometimes be-
comes encysted, forming a separate abscess.

In these cases, when the matter effused is
small in quantity, after all inflammation has
subsided, the more fluid particles are absorbed,
and the pus remains for a considerable time
in the form of ar indolent concrete mass,
which has been mistaken, after death, for tu-
bercular deposit. The pus when found in
this concrete state appears at first sight very

TESTICLE (ABNORMAL ANATOMY). 1005

like crude tubercular deposit ; but on further
examination it will be found to be contained
in a distinct cyst, from which it may easily be
separated, and the structure of the testicle
will be perceived to be more or less altered
from its healthy state; whereas in tubercular
disease, the morbid deposit is in immediate
contact with the tubular structure, which,
though atrophied by pressure, is usually in
other respects sound. Concrete pus may
likewise be mistaken for the firm yellow mat-
ter effused in chronic inflammation. It differs
from it, however, in being friable and easily
broken up, and also in being enclosed in a
cyst, whereas the yellow fibrinous substance
is homogeneous and consistent, and almost
inseparably diffused amongst and connected
with the convoluted tubuli around it. The
distinctive characters just described will be
easily recognised on comparing the accom-
panying representation of concrete pus en-
cysted in the testicle withj%. 651.

Fig. 648.

I examined two enlarged testicles taken
from a man who died suddenly. Both
glands had formerly been attacked with
acute inflammation, and for some months
before death they had been the seat of
chronic pain. In the left testicle, which
was the larger of the two, from two to three
drachms of thick yellow inspissated pus were
contained in a distinct cyst, which occupied
the centre of the gland. There was no trace
of tubuli, but the remainder of the organ was
composed of a fibrous tissue : the sac of the
tunica vaginalis was obliterated by close ad-
hesions. The tunica vaginalis of the right
testicle contained about half an ounce of
yellowish serum and in the centre of the gland
there was a small concrete abscess, but the
tubular structure was apparent and very little
diseased. Pus existing in this concrete or in-
spissated state often keeps up pain and irrita-
tion for a long period, and renders the testicle
liable to repeated relapses of inflammation.

Suppuration occasionally takes place in the

epididymis. In several cases of consecutive
orchitis which have come under my care, at a
late period of the disease an abscess formed
in the areolar tissue around the termination
of the epididymis and inflected portion of the
vas deferens, and burst at the most depending
part of the scrotum. In many instances,
after acute orchitis has subsided, the testicle
is restored to its natural condition ; in other
cases, permanent changes of a serious nature
are the consequence. I have observed in
testicles that have been affected with inflam-
mation some time before, that the septa ap-
pear to be more distinct, and to enter more
largely into the composition of the gland than
is natural; that the small seminal tubes are
less numerous and apparent ; and that a great
part of the organ is converted into a dense
white fibrous tissue, without the presence of
tubuli. In these cases the fibrinous matter
effused in the areolar tissue connecting the
tubuli, not having been absorbed after the
cessation of inflammatory action, had occa-
sioned partial atrophy of the proper structure
of the organ, and been converted into the
dense tissuejust described. Complete atrophy
is one of the most serious results of acute
inflammation of the testicle. I have already
remarked that the disturbance in the organisa-
tion of the testicle consequent upon inflam-
mation is the most common cause of wasting.
Consecutive orchitis, if not checked in the
early stage, seldom subsides without leaving
behind distinct traces of its existence, which
never disappear entirely during the remainder
of the patient’s life. The epididymis fre-
quently remains enlarged, presenting an in-
durated irregular knotty swelling, seated
usually at its lower part, which is occasioned
by the presence of a dense hard deposit be-
tween the convolutions of the duct and
around the inflected portion of the vas de-
ferens. On making a section of the epidi-
dymis in this state, I have often observed not
only a highly thickened condition of its duct,
but also, in some instances, very considerable
dilatation ; so that the point of a fine probe
might be introduced into the canal without
difficulty, its area being increased four or five
times. These effusions about the duct rarely
if ever produce its obliteration, the yielding
nature of the tissues preventing this injurious
result. In old cases the epididymis acquires
the density and consistence of cartilage, and
sometimes even of bone. These changes are
rarely found without the presence of old ad-
hesions, obliterating partially or completely
the sac of the tunica vaginalis. The coats of
the vas deferens are also found for some ex-
tent thickened and indurated. The alterations
noticed in the body of the testicle have been
observed, in some instances, coexisting with
those in the epididymis ; but in by far the
majority of cases, the glandular structure is
unimpaired. In only two cases in which the
epididymis was thus diseased, have I remarked
a decidedly atrophied condition of the organ.
The absence of pressure, owing to the unre-
sisting nature of the membrane investing the

1006 TESTICLE (ABNORMAL ANATOMY).

epididymis, appears to prevent the oblitera-
tion of the duct of which it is composed, and
thus accounts for atrophy occurring much
more rarely after consecutive orchitis than
after inflammation originating in the body of
the gland, where the delicate seminal tubes
are enclosed in the firm unyielding tunica
albuginea.

Chronic orchitis. — The testicle is liable to
a form of inflammatory swelling of a distinct
and chronic character, which occasionally
succeeds acute orchitis but far more com-
monly arises spontaneously. The disease is
of importance ; for, if unchecked, it tends to
disorganise and destroy the gland. The chief
anatomical character of this form of inflam-
mation is the deposit of a peculiar yellow,
homogeneous, inorganic matter in the struc-
ture of the testicle. This substance when
first formed is of soft consistence, but after-
wards becomes firm and solid, and so closely
adherent and intimately blended with the
proper structure of the organ as not to admit
of separation without much difficulty. In
some instances there is a single deposit of
this substance in the centre of the glandular
structure, as in the preparation from which
the annexed woodcut was taken. In others

Fig. 649.

several are interspersed throughout the tes-
ticle, portions of sound gland intervening.
In a case of chronic enlargement of both
testicles taken from a patient who died of
ramollissement of the medulla spinalis, I
found six or seven separate deposits of this
yellow matter in the substance of the right
testicle, and a single one only in the body of
the left. The small masses as they enlarge
coalesce, or the single one increases, until
the whole testicle presents an uniform yel-
lowish-white appearance. The epididymis is
frequently invaded at the same time by a
similar kind of morbid deposit, which also
tends to obliterate its tubular structure. This,
however, is not, as some pathologists suppose,
a constant occurrence ; for in the majority of
testicles thus diseased that 1 have examined,
the epididymis had entirely escaped. I have

never succeeded in injecting this deposit, or
in tracing vessels into it. But the vessels of
the testicle generally are enlarged. Patholo-
gists have differed as to the particular tissue
in which this yellow matter is deposited. Sir
A. Cooper and Cruveilhier describes it to be
seated in the areolar tissue between the
tubuli; whilst Sir B. Brodie is of opinion,
that it is secreted from their inner surface,
as he discovered the yellow substance in the
canal of the epididymis and also in the vas
deferens which are continuous with the
tubuli. I have had the opportunity of in-
specting a testicle affected with this disease,
in what seems to me to be its early stage
from which examination I think I have been
able satisfactorily to confirm this opinion.
The testicle was injected with red size, and a
section then made of it. The surfaces of the
tunica vaginalis were partly adherent, and
about three drachms of serum were collected
in one part of the sac. The body of the tes-
ticle was not much enlarged : it contained,
however, an abundant deposit of a firm opaque
matter. Near the anterior edge of the testicle
this deposit appeared in the section like round
isolated yellowish-grey bodies, separated from
each other by portions of the sound structure
of the gland : about the centre of the organ it
assumed a beaded arrangement, and towards
the mediastinum formed a number of closely-
set yellow lines or processes, radiating towards
the posterior part of the testicle, where they
were amalgamated into one uniform mass.
Further examination perfectly satisfied me
that this matter was lymph deposited in the
tubuli seminiferi. The isolated and beaded
appearances in the section resulted from
breaks in the lymph thus deposited. The real
seat of the effusion was very evident, from the
arrangement described near the mediastinum.
With a good lens some of the convoluted
tubuli could be distinctly seen, filled with and
dilated by the morbid deposit. A portion
was carefully examined in the microscope
with a similar result. The epididymis was

Fig. 650.

1, fistulous sinus leading to the suppurating ca-
vity in the head of the epididymis ; 2, concrete ab-
scess in the tail of the epididymis.

TESTICLE (ABNORMAL ANATOMY). 1007

much enlarged ; its head was filled with soft
concrete matter, surrounding an irregular
cavity with which a fistulous sinus com-
municated ; its tail contained a similar sub-
stance without any external opening. The
various appearances described are depicted in
the adjoining figure, which was taken from
the recent specimen. Similar appearances to
those noticed in this case have been described
and figured by Cruveilhier, in his “ Anatomie
Pathologique.”* He considers that the dis-
ease proceeds from the head of the epidi-
dymis towards the tail, and that the body of
the testicle is affected only consecutively. I
believe, myself, that the yellow deposit is the
ordinary result of chronic inflammation of the
testicle in whatever way produced ; but that
the peculiar appearances noticed in the case
just related and likewise described by Cru-
veilhier, — I mean the small isolated masses
in the substance of the gland, and radiating
towards the mediastinum, — are only observed
in those cases in which the disease originates
in the epididymis, and thence spreads to the
body of the testicle, and in which the part is
examined before the organ has become ex-
tensively diseased. These appearances are
not often seen, because it is not often that it
becomes necessary to remove a testicle in
such a condition, which is indeed a curable
one unless complicated with suppuration.
Cruveilhier supposes that this matter is effu-
sed in the areolar tissue of the testicle, and
radiates along the fibrous prolongations from
the corpus Highmori. I feel satisfied, however,
from my own observations, that he is mis-
taken, and that the interior of the tubuli is the
original seat of the deposit. This yellow
substance has been called the yellow tubercle
of the testis ; but, as it differs from tubercular
deposit, the term is objectionable and liable
to lead to error. It is evidently coagulable
lymph, which becomes more solid in the
testicle than in most other parts, owing, per-
haps, to the condensation consequent on the
firm resistance offered to any enlargement of
the gland by the unyielding tunica albuginea.
This disease is often accompanied with effu-
sion of serum into the tunica vaginalis, seldom
amounting, however, to more than three or
four ounces. Lymph also is sometimes de-
posited, and the sac may become partially, or
totally obliterated by adhesions.

The peculiar matter effused in this disease
under appropriate treatment undergoes com-
plete absorption, the testicle being left in a
condition to perform its natural functions.
It sometimes happens, however, that ulcera-
tion ensues in its tunics and integuments, and
that a fungous-looking growth gradually pro-
trudes through the opening which is thus
formed. This fungous growth is sometimes
termed granular swelling ; it has also received
the name of hernia testis, being formed in a
manner very analogous to that of a hernia
cerebri, in which the substance of the brain is
protruded through an ulcerated opening in

* Liv. v. pi. b., and liv. ix. pi. i.

the dura mater. It appears that the yellow
deposit after some time excites ulceration in
some part of the tunica albuginea. The tunica
vaginalis, and afterwards the skin, become
adherent at this spot, and likewise inflame
and ulcerate. The resistance afforded by the
dense unyielding tunica albuginea being thus
removed, the adventitious deposit gradually
presses out the tubular structure, which forms
a projecting tumour consisting of the tubuli
mixed up with this yellow substance, and also
of ordinary granulations which spring up from
the seminiferous structure. This projecting
growth presents an ash or yellowish-white ap-
pearance, varied by irregular patches of a pale
red hue, and sometimes of black. It is closely
girt by the scrotum, the ulcerated edges of which
are often thickened and everted. (fig. 651.)

Fig. 651.

The mass often projects so much that scarcely
an)' part of the organ is contained within the
scrotum. Though this hernial growth occurs
most frequently in an advanced stage of the
chronic form of inflammation, it is developed
in other diseases of the organ which occasion
ulceration of the tunica albuginea, and thus
afford an opening for the escape of its con-
tents. It is occasionally the result of an
attack of acute inflammation supervening
upon the chronic disease, and terminating in
suppuration in the substance of the gland. In
a case of this kind, in addition to the glan-
dular swelling, there are sinuses more or less
numerous, which burrow in the interior of the
organ, and discharge pus mingled with the
yellow matter. An attack of orchitis, origin-
ally acute, going on to suppuration, is also
liable to be followed by a fungous protrusion
of the secreting structure of the gland. In
the latter case, the growth is not so exube-
rant, and the seminiferous structure is more
distinctly apparent, owing to the absence of
the yellow matter ; but there are generally
sinuses which furnish a purulent discharge,
sometimes mixed with semen. Tubercular
matter deposited in the testicle may also lead
to suppuration, and the formation of a granu-
lar swelling.

A testicle after becoming somewhat en-
larged from chronic inflammation, often con-
tinues indolent and stationary for years,
giving rise to very little inconvenience. On
examining the organ in this state, the yellow
adventitious deposit is found to possess con-

1008 TESTICLE (ABNORMAL ANATOMY).

siderable firmness and consistency ; the tunica
albuginea is thickened, and in some places as
dense and indurated as cartilage ; and the
surfaces of the tunica vaginalis are closely
connected by old adhesions. The glandular
structure is partly displaced and atrophied by
the pressure of the yellow matter ; and it
often happens after some time, that both
undergo a slow process of wasting, so that an
enlarged and indurated gland is progressively
reduced, until scarcely any thing remains
beyond a mere nodule of the size of a nut
at which the spermatic cord terminates. I
found, on examination of the body of a man
who some few years previously had suffered
from chronic inflammation of the testicles,
both glands much indurated, but about the
natural size. In both, the tubular structure
was very deficient, its place being supplied by
a dense fibrous tissue. At the upper part of
the right testicle there was a yellowish de-
posit almost as dense as cartilage, and ex-
hibiting very little trace of vascularity. In
these indurated testicles the epididymis often
escapes the morbid alteration affecting the
body of the gland ; in other cases, however,
the epididymis is also found nodose, irregular,
and hard. It will be perceived, from the pre-
ceding observations, that the tendency of
this chronic disease is gradually to destroy
the integrity of the testicle. If the inflamma-
tion be checked in an early stage, the gland is
left unimpaired ; if its course be not arrested
until a later period, the secreting structure is
partly disorganised and reduced in size ; but
if the disease be allowed to continue un-
checked by treatment, the organ is totally
destroyed, either by ulceration of its tunics
and the escape of the glandular structure in
the shape of a fungous growth, or by the
slower process of wasting and absorption.

Syphilitic orchitis is essentially of the same
nature as the chronic orchitis just described.
It commonly commences in the body of
the gland and rarely terminates in suppur-
ation, or in the production of a hernial
fungus. Sir A. Cooper states that in the
majority of cases the disease attacks both
testicles. The eight examples recorded in his
work do not, however, bear out this remark;
for in only two of them does it appear that
both organs were attacked. According to my
observation, the disease is more commonly
confined to a single gland, though it occasion-
ally affects both ; this appears to be the
opinion also of Ricord.* The appearances on
dissection correspond with those observed in
chronic inflammation.

Tubercular Disease. — In the testicle,' this
deposit is met with in the crude state, form-
ing a yellow caseous substance similar to the
tubercular matter occurring in the lymphatic
glands. It is sometimes developed in a single
mass ; at other times several distinct deposi-
tions are formed in different parts of the
organ : in both cases at the expense of its
glandular structure, which becomes atrophied

* Traite' Pratique des Maladies Ve'ndriennes, p. 640.

as the disease advances. The epididymis is
more frequently affected than the body of the
gland. In a specimen taken from a man who
died of phthisis, I found the whole of the
epididymis occupied by tubercular matter, with
scarcely any trace of tubuli; whilst the body
of the gland, though small, was perfectly
sound and unaffected, (fig. 652.) In some
Fig. 652.

cases I have seen two, three, or more distinct
tubercular deposits, separated by portions of
healthy gland. This was the case in both
testicles removed from a middle-aged man
who died of phthisis. In some instances
these isolated masses appeared to be con-
tained in cysts formed by the processes from
the tunica albuginea which separate and sup-
port the lobules. Sometimes the separate
deposits seemed to be coalescing and joining
together, so as to form one continuous mass ;
and I have found a single mass of tubercular
matter surrounded by glandular structure ex-
panded into a thin layer. In other specimens
the whole testicle was occupied by a homo-
geneous cheesy mass, without any trace re-
maining of the original structure of the gland.
In some instances in which the disease was
thus advanced, there was very little increase
in the size of the testicle ; it only felt heavier
and harder than in the natural state. In
others, again, there was either a general uni-
form enlargement, or an irregular swelling at
some part, commonly at the head of the epi-
didymis. Some of these testicles, in which
the disease was not much advanced, when
injected made beautiful preparations, the
yellow inorganic tubercular matter contrasting
in a marked degree with the vermilion hue of
the intervening sound portions of the organ.
On several occasions I found a small quantity
of serum in the tunica vaginalis, with partial
adhesions and depositions of lymph. In a
further stage of the disease, the characteristic
deposit becomes softened down, and converted
into a yellow pultaceous substance, evidently
tubercular matter mixed with pus. The ab-
scess extends to the scrotum ; and after it has
burst and the matter has escaped externally,
cavities and sinuses are left which may be said
to resemble the tubercular cavities in the
lungs. The course of the disease, however.

TESTICLE (ABNORMAL ANATOMY).

In the testicle, more nearly resembles the
changes which ensue in tubercle of the ab-
sorbent glands.

It has been a question whether the tuber-
cular matter is originally formed in the areolar
tissue connecting the tubuli, or in the tubuli
themselves. I have certainly seen this de-
posit in the vas deferens near the testicle, and
within the ducts of the epididymis. Dr.
Carswell has given a representation of a tes-
ticle containing a multitude of pale yellow-
coloured granular bodies of various sizes,
which, he says, were obviously formed by the
accumulation of tuberculous matter in the
tubuli seminiferi. The epididymis was as
thick as the little finger, and its convoluted
ducts were obviously filled with a similar
deposit. I believe that tubercle may be de-
posited in both situations, within as well as
between the tubuli. Earthy matter is some-
times found in the testicle, generally in the
epididymis, the part most frequently the seat
of tubercle. This substance is exactly si-
milar to the putty-looking chalky matter
often observed in the lungs and bronchial
glands. It is highly probable that, in these
cases, the gland had at some former period
been the seat of tubercular deposit, but I
have not yet been able to establish this point
satisfactorily.

Carcinoma. — This disease occurs in the
testicle under the four forms of Scirrhus, En-
cephaloid, Colloid, and Melanosis.

Carcinoma seldom occurs in the testicle in
the dense form which it commonly assumes
in the breast. Sir A. Cooper describes a
scirrhous disease of the testicle, in which the
gland is invaded by a large white mass in
lobes or tubercles. The spermatic cord is
affected with a similar disease, and the glands
of the abdomen become converted into a
white solid texture, very unlike that of the
fungoid disease. I have a man, 52 years
of age, under my care at the present time,
with this disease of the testicle. It forms
a tumour about three times the natural size,
and is almost of stony hardness, especially at
the back part. There is also a large indurated
tumour in the spermatic cord. This affection
of the testicle is very rare, and is charac-
terised by its slow progress as well as by its
great induration.

Encephaloid cancer is by far the most fre-
quent form of malignant disease to which the
testicle is liable. When first observed, it is
found in one or two masses amongst the
tubuli, which gradually become destroyed as
the morbid deposit accumulates. The matter
is very rarely infiltrated. The testicle at this
early period is extremely firm and hard,
owing, not to the solid nature of the sub-
stance effused, but to the excessive distention
of the unyielding tunica albuginea by the
morbid growth within. The glandular struct
ture soon entirely disappears, the whole organ
being occupied by the new growth, inter-
mixed with and sustained by the septa and
fibrous processes from the mediastinum and
tunica albuginea. In some instances a thin

VOL. tv.

1009

layer of the tubular structure is found ex-
panded around a mass of encephaloid matter.
At this stage the tunica vaginalis is often dis-
tended with serum ; not, however, in any
considerable quantity. The tunica albuginea
next gives way, and a portion of the morbid
growth protrudes, forming a mass projecting
from the body of the gland ; this sometimes
occurs in more places than one. The epi-
didymis remains for some time unaffected ;
but, as the disease increases, this part like-
wise becomes implicated and destroyed. In
one instance I found the tubes in the head of
the epididymis (the only part of the gland not
destroyed) filled with white matter which,
on microscopic examination, proved to be
carcinomatous. The scrotum in a short time
becomes fully distended by the diseased mass,
which presents the well-known appearance
of encephaloid cancer ; viz. a homogeneous
substance of the consistence of brain, and
easily broken down with the fingers, of an
opaque white colour, and variegated with
patches of a pinkish hue. It is sometimes
mixed with small cysts containing serum ; at
other times with yellow deposits of lymph,
resembling that effused in chronic orchitis.
These small depositions of yellow fibrine oc-
casionally interspersed amongst the carcino-
matous matter, are almost peculiar to this dis-
ease in the testicle. I have only' once observed
them in cancer of other parts, and that was
in the kidney. As the enlargement goes on,
the scrotum becomes adherent to the tumour
in one or more places, then ulcerates, and
allows the protrusion of the morbid mass,
which projects as an open fungus. The
scrotum admits however of great distention
before ulceration ensues. The mass then
becomes less firm, and its consistence varies
very much in different parts, the morbid
matter being in some a mere pulp, or re-
sembling a creamy fluid. It is interspersed
with round or irregular patches of dark look-
ing coagula, and, when incised, often presents
in different places dark minute spots of va-
rious sizes, produced by coagulation of blood
in the vascular network usually mixed up
with the morbid deposit. On macerating
these tumours, or on pouring a stream of
water on them for some time, a granular sub-
stance, the cancerous matter, is washed away,
leaving behind a filamentous shreddy tissue
or meshes of a delicate areolar texture, which
may often be found connected to a denser
fibrous substance, the remains of the tunica
albuginea. The spermatic cord is often in-
vaded by a similar substance; and in an ad-
vanced stage of the complaint, large bodies
of the same kind, originating in disease of
the lumbar glands, are found on the sides of
the vertebrae, reaching as high up as the dia-
phragm.

Masses of a similar kind are sometimes
also found in the lungs. The carcinoma-
tous matter is often deposited in such abun-
dance as to form a tumour of very con-
siderable size ; indeed, there is no other dis-
ease of the testicle which occasions solid en-

3 T

1010

TESTICLE (ABNORMAL ANATOMY).

largements of so great a magnitude as ence-
plialoid cancer. M. P. Boyer removed a
testicle converted into an encephaloid tumour
which weighed more than nine pounds.* The
vessels of the cord undergo great enlargement
in this disease. In one case which I examined,
the spermatic artery was found as large as
the radial artery at the wrist. Cancerous
germs have also been found in the blood
contained in the spermatic veins. Encepha-
loid cancer of the testicle occurs at all periods
of life: no age, indeed, can be said to be
exempt from it. There are examples on
record of operations for the removal of tes-
ticles thus affected, within a twelvemonth
after birth. On the other hand I have met
with the disease as late in life as the age of
sixty-four. It more commonly occurs, how-
ever, in the middle period of life, or between
the ages of twenty and thirty.

Carcinoma has, in some few instances,
been found to originate from the tunica va-
ginalis, the glandular part of the testicle re-
maining for some time unaffected. Cases of
the kind have been recorded by Sir E. ITomef
and Sir A. Cooper. The other two forms of
cancer, colloid and melanosis, have rarely been
observed in the testicle. A preparation of the
former disease is contained in the Museum
of Guy's Hospital. The organ is enlarged
to four or five times its natural size, but pre-
serves its oval form : there is scarcely any
trace of the natural structure remaining, its
place being supplied by colloid matter. Cru-
veilhier has related the case of a man who
died of melanosis affecting the hand, lungs,
heart, stomach, and other parts. There was
a deposit of the same character in each tes-
ticle.

Cystic Disease. — The cysts developed in
the substance of the testicle and constituting
this disease vary very much both in number
and size, and in the appearance of their con-
tents. They may be only two or three in
number, or they may exist in a countless
multitude and occasion considerable enlarge-
ment of the organ. They vary in size from
that of a millet seed to the dimensions of a
pigeon’s egg. At an early period they gene-
rally consist of smooth and slightly vascular
cysts, closely adherent, and containing a
transparent light-coloured fluid. In other
cases the fluid is thick, viscid, and highly
albuminous, and sometimes tinged with blood.

I have never succeeded in detecting sperma-
tozoa in the fluid. Sometimes a small lo-
ludated growth arises from the walis of the
cyst, and increases until it is partly or wholly
filled and obliterated. The cysts usually in-
crease at the expense of the secreting struc-
ture of the testicle, which disappears or be-
comes much displaced. In some instances
the tubular structure forms an expanded
layer over the morbid mass. When inflam-
mation takes place, fibrine is effused be-
tween as well as within the cysts, and be-

* Revue Medieale. Nov. 1839.

f Observations on Cancer, p. 125. Anatomic
Patliologique, liv. xix. pi. 3, 4.

comes organised ; so that the tumour is
partly solid and partly composed of cysts
containing fluid. After some time, the sur-
faces of the tunica vaginalis become more or
less adherent, and in old cases the tumour is
intersected with fibrous bands. In several
specimens of the disease I have noticed small
masses of enchondroma interspersed amongst
the cysts. In sections the little pearly-looking
masses appear as if contained within the cysts.
They are however developed between them,
and are closely connected with their walls.
The occurrence of enchondroma in these
cystic tumours has scarcely been noticed by
pathologists. There are several specimens
in the Museum of the College of Surgeons.

Fig. 0.5 3.

Portion o f the section of a testicle in the Museum of
the College of Surgeons, with numerous masses of
enchondroma between the cysts, of the exact size,
a. a. enchondroma.

One of the specimens of cystic disease in this
collection measures five inches in its largest
diameter, and three inches in its smallest.
Sometimes small lobulated growths arise
from a part of the walls of the cyst, and in-
crease until the cavity is partly or wholly
filled and obliterated by them, in the same
manner as in cystic disease of the mamma.
The mode of origin of these cysts has not
been satisfactorily made out. It has been
supposed that they are formed of dilated and
obstructed seminiferous tubes ; but as in cer-
tain cases the tubular structure exists in the
form of a layer spread over the morbid mass,
it is clear that the disease could not have
originated in this way. This morbid change
is evidently quite distinct from the little cysts
so commonly developed in the head of the
epididymis : indeed this part is rarely affected
in cystic affections of the testicle. The dis-
ease is considered by some pathologists to be
of a malignant character. After removal of
a testicle thus diseased, tumours of a carci-
nomatous character have afterwards appeared
in the lumbar glands and other parts. Mr.
Caesar Hawkins showed me several prepara-
tions of cystic sarcoma of the testicle which
had been removed by operation where this
happened, and it occurred also in a case
which came under my own observation. The
unexpected result in this instance led me to
pay attention to the matter, and I am now
quite satisfied that the cystic disease may be

1011

TESTICLE (ABNORMAL ANATOMY).

developed under two forms. In one, it occurs
in combination with carcinomatous deposit :

Fig. 654.

Section of a cystic tumour of the testicle, showing a
multitude of cysts of various shapes and sizes, with
solid matter interposed hetwen them. The natural
glandular structure is wholly destroyed.

in the other and more common form, the
tumour is of an innocent character, and free
from the risk of disease attacking other parts
after removal of the organ. In the former
the cysts are larger and less numerous than
in the latter. By careful examination and
with the aid of the microscope the coexist-
ence of the two diseases may generally be
made out.

Ossific deposits in the testicle. — Earthy
matter occurs in the testicle under two forms :
1. Laminated, and often mixed up with car-
tilage ; and 2., as an inorganic deposit. In
the first form it is usually deposited between
the tunica vaginalis and tunica albuginea, in
little bony or cartilaginous patches, in which
a fibrous arrangement may be recognised. I
have frequently found one or two irregularly-
shaped projecting ossific bodies scarcely larger
than a pin’s head attached to the upper part
of the testicle. Ossific matter occurs also on
the adherent surface of the tunica vaginalis
in old cases of hydrocele, where it has been
found so abundant as to form a complete
ossific capsule. It has been said that the
epididymis alone may be encased in bone, the
testicle being free ; this I have never seen.
Bony matter occurs, however, in the sub-
stance of the epididymis as the result of ossi-
fication of the product of inflammation.
Earthy matter in this form is not often ob-

served in the substance of the testicle. The
gland, however, when atrophied and reduced
to a mere fibrous tissue, occasionally under-
goes both the cartilaginous and osseous trans-
formation. The cysts developed in the tes-
ticle, as I have already shown, are liable to
similar changes.

In the second form the earthy matter is
deposited in an irregular mass, containing
very little animal matter ; in appearance re-
sembling mortar, and very similar to the
earthy substance found in the lungs and
bronchial glands. It is generally met with in
the head of the epididymis, and sometimes in
the lower part, and but very seldom in the
body of the testicle. As I have already
stated, it is most probable that this earthy
matter results from the transformation of
tubercular matter deposited in the testicle in
early life.

Loose bodies in the tunica vaginalis. — - Loose
bodies are occasionally found in the cavity of
the tunica vaginalis. They are small in size,
and of an oval flattened shape, and their sur-
face is smooth and polished. Their texture
is in most instances elastic and homogeneous,
resembling the unattached cartilages found in
joints, and points of ossification are often
contained in their interior. In some speci-
mens I have observed the cartilaginous matter
to be arranged in concentric laminae. The
loose body is sometimes entirely composed of
bony matter. On examining a thin lamina of
one in the microscope, I could distinctly see
small oval corpuscules with a number of lines
proceeding from them very similar to those
of bone. They seldom exceed three in number,
and they occur generally in combination with
hydrocele, the loose bodies being the original
disease.

Foetal remains in the testicle. — The remains
of a feetus have been found in some rare
instances, in the scrotum, in connection with
the testicle. Several examples of the kind
have been collected by Ollivier (D’ Angers).*
In all these cases it was evident that the scrotal
inclusion had succeeded to an inclusion origi-
nally abdominal ; that is to say, that the
organic debris were first situated in the ab-
domen in connection with the testicle, and
had accompaniad the gland in its passage out
of that cavity. In the cases in which the
particular testicle was indicated, the right
was the one affected.

Varicocele is a term applied to a morbid
dilatation of the spermatic veins. On dis-
section they are found dilated, elongated, anil
more tortuous than natural, and apparently
more numerous, owing to the enlargement
of the smaller vessels. In an advanced
stage of the disease, their coats are thick-
ened ; so that when divided the vessels re-
main patent, and thus present the appear-
ance of arteries. The enlarged veins hang
down below the testicle, and reach upwards
into the inguinal canal ; and when very volu-

* Memoire sur la Monstruositd par Inclusions
Archives Gdne'rale de Medicine, t. xv. p. 540.

3 t 2

1012

TESTICLE (ABNORMAL ANATOMY).

minous conceal the gland, encroach on the
septum, and extend to the other side of the
scrotum. In a specimen which I carefully
examined, the vessels were arranged in three
clusters ( fig . 655). One formed of the
larger vessels proceeded from the inferior ex-
tremity of the testicle ; the second, in which
the vessels were less in size, but more numer-
ous and tortuous, arose from the upper ex-

Fig. 655.

tremity of the testicle ; whilst the third and
smallest cluster surrounded and accompanied
the vas deferens ( 1). The dilatation is not con-
fined to the veins exterior to the gland : even
those in the organ itself are varicose, and
enlarged veins may often be distinctly seen
ramifying between the tunica vaginalis and
tunica albuginea. The veins occasionally con-
tain phlebolites which are lodged in dilatations
of the vessels. The veins of the left testicle
are more subject to varicocele than those of
the right. In upwards of 120 operations per-
formed by Breschet, in only one instance was
the varicocele on the right side.* Pott met
wi h this disease on both sides of the body in
only one instance. The disease, however, is
far from being so rare on the right side as is
generally supposed, and often exists on both
at the same time, although the varicose state
of the right spermatic veins is always much
less than that ot the left. Of the causes of
varicocele, some operate on both sides, others
only on one. The most influential of the
former is the hydrostatic pressure consequent

Lanilouzy, Du Varicocele, p. 24.

upon the depending position of these veins,
which have to support the weight of a column
of blood extending from the testicle to the
second dorsal vertebra. The absence of valves
is mentioned as a circumstance conducing to
this disease ; but this is an error, for the
larger spermatic veins are always furnished
with valves, though the dilatation which
takes place in varicocele prevents them per-
forming their office. There are several anato-
mical circumstances, which, taken together,
are sufficient to explain the frequency of vari-
cocele on the left side. On the right side the
spermatic vein joins the vena cava nearly
parallel to the axis of that vessel, so that the
blood enters in the course of the circulation ;
but on the left side the spermatic vein termi-
nates in the emulgent vein at a right angle,
and in a direction perpendicular to the venous
current from the kidney, which is less favour-
able to the return of blood from the testicle,
since the two currents pursue a different di-
rection. The left testicle hangs lower than
the right, consequently the veins must be
longer, and the pressure produced by the
column of blood greater on the left side than
on the other. The accumulation of the feces
in the sigmoid flexure of the colon previous
to an evacuation tends to produce pressure
on the spermatic vein, and impede the return
of blood from the left testicle, especially in
persons whose bowels are habitually con-
stipated. Some persons subject to varicocele
suffer from it only when the bowels are in this
condition. But even the natural daily accu-
mulation may be sufficient to produce ob-
struction. To this cause, we must chiefly
attribute the circumstance that a varicose di-
latation of the veins of the ovary in the
female is nearly always confined to the left
side.

In the slight degree and chronic state in
which we most frequently meet with this
affection, no injurious effect is produced on
the testicle; but when highly or rapidly de-
veloped, the dilatation of the veins interferes
so much with the nutrition of the gland as
to occasion wasting. A partial atrophy of the
gland, coexisting with varicocele has come
under my notice in more than twenty
instances ; indeed, in nearly all cases in
which there was a decided dilatation of the
spermatic veins on one side only, the testicle
of that side was the smaller of the two. In a
man, aged fifty-six, with a varicocele on the
left side, the testicle was so reduced that it
scarcely exceeded the usual size of the organ
in an infant. Some years ago, a tall sailor was
under my care on account of a varicose ulcer
on the left leg, who had a large varicocele on
the left side, and a testicle so wasted, that it
could scarcely be felt through the tunica
vaginalis, which was loosely distended with
fluid. The period of puberty is the time at
which varicocele most cemmonly occurs. I
have met with very few cases before that age.

Adipose tumours. — The spermatic cord
may be the seat of abnormal depositions of
fat. They occur at different parts, as high up

TESTICLE (ABNORMAL ANATOMY). 1013

ns the inguinal canal, and as low down as the
epididymis. In examining the testicles of a
young man who died of pleurisy, 1 found a
quantity of fat along the cord, and around the
epididymis, and some also beneath the tunica
vaginalis covering the posterior part of the
testicle. In another case I met with small
isolated masses of fat, coupled with a small
encysted hydrocele of the cord. When de-
veloped in considerable abundance this de-
posit sometimes forms a tumour either in the
groin or in the scrotum. A tumour of this
kind in the scrotum has been mistaken for
omental hernia. I once dissected a lobulated
fatty tumour, surrounded by the thickened
sheath of the spermatic cord, on the body of
a man upwards of eighty years of age, which
was very similar in appearance to a portion of
omentum contained in a hernial sac. A
mass of fat, however, in the cord may form a
more defined and distinct swelling. Such a
tumour is preserved in the Museum of the
College of Surgeons. (No. 2461.) It is em-
bedded about an inch above the testicle, in
the tissues of the spermatic cord and loosely
connected with them. Its shape is oval ; it
measures four inches in length, and consists
of numerous lobes of soft fat, closely held
together by their thin fibro-cellular par-
titions. An interesting case of large fatty
tumour in the scrotum, originating in the
spermatic cord, was seen by several surgeons,
in 1844, much difficulty having been ex-
perienced in making out the nature of the
swelling. The tumour, together with the
testicle, was excised by Mr. Lawrence.*
Another of the same character, but of smaller
size, subsequent^ formed in the remains of
the cord in the groin, and was excised by me
in May, IS49. Collections of fat in the
scrotum have been known from the time of
Galen by the term steatoce/e. I suspect that
they all originated from the spermatic cord.

Morbid anatomy of the scrotum. — The
morbid appearances presented by the scrotum,
when the seat of oedema, inflammation, and
mortification, so closely resemble those of
other parts where loose areolar tissue abound,
that they require no particular description.

Elephantiasis. — This disease of the scro-
tum is rarely seen in Europe, but is of very
common occurrence in many other parts of the
globe. It consists in a morbid thickening, or
hypertrophy of the tissues of which the scro-
tum is composed. The epidermis becomes
thickened, rough as in icthyosis, and inter-
sected with fissures, or chaps. The corium
is excessively consolidated, and often nearly
an inch in thickness, and very dense. The
chief bulk, however, of the tumour, is formed
by the conversion of the loose areolar tissue
of the scrotum into a large mass of fibrous
tissue, infiltrated with a thick jelly-like fluid,
evidently albumen, as it coagulates on the ap-

* Vide accounts of this case by Lawrence, Me-
dical Gazette, May 30. 1845 ; by Brodie, Lectures
on Pathology, p. 271. ; by Edwards, and myself, in
Provincial Med. and Surg. Journal, June 25l 1845.

plication of heat, acid, or alochol, and some-
times on cooling after its removal from the
body. The areolte of this tissue vary a good
deal in size, but some of them have been
found large enough to admit the extremity of
the little finger. Examined in the micro-
scope this structure exhibits the white and
yellow elements of the areolar tissue, in some
instances mixed with fat cells. When the
part is condensed by inflammation, there are
often hardened masses in the substance of the
tumour, which has a lardaceous appearance
when cut, or resembles cartilage ; they some-
times undergo conversion into bone. The
testicles are buried in the morbid mass to-
wards its posterior part, but they are usually
sound in structure. Occasionally there is a
small quantity of serum in the tunica vagi-
nalis. In a case operated on in Calcutta,
there was a hydrocele on both sides imbedded
in the diseased parts, the largest of which
contained between five and six flints of fluid.*
The spermatic cords are elongated several
inches, owing to the testicles being gradually
dragged downwards during the growth of the
tumour, but the cords are not otherwise
diseased. In the remarkable case of Idoo
Loo, a native of China, operated on by Mr.
Key, in Guy’s Hospital, the cremaster mus-
cles were nearly as thick as the finger. The
morbid growth is not very vascular. Its
arteries are derived chiefly from the external
pudic and perineal vessels ; but these, owing
to the magnitude of the tumour, become*
greatly increased in size. Tbe veins are
numerous, large, varicose, and very tortuous.

The integuments of the penis are often
affected with a similar disease, and enlarge in
the same ratio as the scrotum. In cases
where the disease is confined to the scrotum,
the penis becomes drawn in and ultimately
disappears, being completely imbedded in the
tumour ; whilst the prepuce being elongated,
opens by a navel-like aperture on the anterior
surface of the tumour, as may be seen in the
subjoined woodcut. In confirmed cases of
elephantiasis, the tumour increases until in the
course of years it attains an enormous magni-
tude. As this takes place, the skin is bor-
rowed from the lower part of the abdomen,
so that the hair on the pubes becomes thinly
scattered on the front and upper part of the
tumour. The tumour assumes an oval or
pyramidal form, the apex being superior, and
is attached to the body by a thick peduncle
extending from the pubes, occupying the
whole of the perineum, and terminating pos-
teriorly at the verge of the anus. There is
scarcely any limit to the size which the
tumour may attain. It has been known to
acquire such a magnitude as to weigh more
than two hundred pounds f, exceeding the
weight of the rest of the body. It has been
found to measure more than four feet in cir-

* Calcutta Quarterly Journal, No. 3.

f Case cited from Ephe'merides d’Allemagne, by
Larrey. Blemoires de Chirurgie Militaire, t. ii. p.

3 T 3

1014 TESTICLE (ABNORMAL ANATOMY).

cumference, and almost to reach the ground
when the patient is in the upright position.
In a case operated on by Clot Bey in Esjypt,
the morbid mass, which weighed one hundred
and ten pounds, kept the patient’s legs far
apart, and obliged him to remain constantly
on the ground ; it was so bulky that he could
even sit upon it. In the accompanying figure

Fig. 656.

of a black man, affected with elephantiasis,
taken from Dr. Titley’s work on “ Diseases
of the Genitals, in the Male,” the tumour de-
scended nearly to the ankles.

Elephantiasis of the scrotum is a morbid
affection of the integuments, analogous to the
enlargement of the extremities commonly
known by the name of Barbadoes leg ; with
which, indeed, in those countries where the
disease is prevalent, it is liable to be com-
bined. Elephantiasis of the scrotum, how-
ever, grows to a greater size and makes more
rapid progress than the same disease in the
leg, owing to the very loose texture and de-
pending state of the parts. The labia pudendi
of females in warm climates are subject to a
similar change, though not to the same extent
nor so frequently as the scrotum. This dis-
ease appears to he the result of a low form of
inflammation of the veins, and to be analogous
to the affection termed phlegmasia dolens. It
is preceded by febrile attacks, attended with
pain and heat in the part, and swelling and
tenderness of the glands in the groin. After
a time, the scrotum continues to enlarge, in-
dependently of febrile attacks. In December,
1847, I saw a gentleman, from Barbadoes,
who had this disease in the early stage. The
whole scrotum was considerably enlarged,

forming a doughy inelastic swelling, fissured
in two or three places. A portion of skin
at the root of the penis was a little red and
puffy as if affected in a slight degree. The
glands in the left groin were enlarged, but
those on the right side were unaffected. The
testicles were sound.

Hypertrophy of the scrotum is an affection
of the same nature as the knotty and lobulated
growth of the skin occasionally observed on
the nose and in other parts. In this disease
the integuments appear as if composed of
lobes divided by fissures. In the Museum of
St. Bartholomew’s Hospital there is a pre-
paration of this kind, but no history is at-
tached to it. The hypertrophied scrotum
appears to have been removed during life.
Many years ago I saw a case of the kind at
the hospital of La Charite in Paris. The
patient was a young man whose scrotum was
hypertrophied to about four times its natural
size. This disease is liable to be confounded
with elephantiasis, but differs from it in the
circumstance that the morbid enlargement is
entirely confined to the skin, the subcutane-
ous areolar tissue being unaffected.

Cancer Scroti, or, as it is commonly called,
chimney sweeper's cancer, is a disease of the
skin, which attacks the scrotum of persons
who have been exposed to the contact of soot.
It is originally developed in the form of a
small pimple or warty excrescence, termed soot-
wart, which often remains on the scrotum for
months or even years without undergoing any
change Usually, there is only a single wart
at the lower part of the scrotum ; sometimes
there are two or three of different sizes ; and
occasionally they are so numerous and so
abundantly and largely developed as to form
a considerable cauliflower excrescence. After
a time the wart becomes soft, excoriated and
red, and exudes a thin irritating discharge,
which becoming dry forms an incrustation
over the excrescence. After the scab has
been picked off, or rubbed off by friction against
the dress, ulceration ensues, destroys the wart
and produces a painful chronic sore, possess-
ing the ordinary characters of a carcinomatous
ulcer on the skin, — thick, indurated and
everted edges, and an irregular excavated base,
the surface of which discharges a thin sanious
fluid. The ulcer, if suffered to proceed, in-

Fig. 657.

1 small soot warts ; 2, cancerous ulcer succeeding
the wart.

1015

TESTICLE (ABNORMAL ANATOMY).

creases widely, invading the whole scrotum
to the perineum, and laying bare the crura
penis. At the same time it penetrates deeply
to the tunica vaginalis, which becomes firmly
connected to the morbid scrotum and ad-
herent to the testicle. This organ nnay also
become involved in the disease, and be the
seat of a deep excavated sore. The glands
in the groin often enlarge at an early period
from irritation ; but at length they become
indurated and diseased. The inguinal glands
sometimes suppurate, and form intractable
ulcers in the groin similar in character to the
sore on the scrotum. The ulcer spreads to-
wards its circumference widely and super-
ficially, whilst in the centre it burrows deeply
until in many instances it reaches the great
vessels of the thigh, destroys their coats, and
causes death by haemorrhage. In other cases
the glands remain unaffected, but ulceration
advances slowly in the direction of the cord,
and a frightful sore is produced.

The small excrescence in which cancer
scroti usually originates is soft, vascular, and
sensitive ; and in many respects similar to
the soft warts which occur on the internal
membrane of the prepuce and on the glans
penis. The soot-wart appears, in fact, to con-
sist of a congeries of morbidly enlarged papillae.
The Museum of the London Hospital contains
a remarkable specimen of chimney-sweeper’s
cancer, in which nearly the whole scrotum
is occupied by a cauliflower excrescence,
which exhibits these papillae in a very ad-
vanced state of developement. It was removed
from an old man, about sixty-four years of
age, who afterwards left the hospital cured.
The morbid growth is composed of a number
of projecting processes densely grouped to-
gether, of variable size, but many very large,
with their summits lobulated, expanded, and
elevated on narrowpeduncles, more orlessflat-
tened. They are represented in the subjoined
engraving. The soot-wart is sometimes co-
vered with a dense and thick concretion, formed

Fig. 658.

by successive layers of incrustation, the su-
perficial still remaining attached, so as to form
a projecting elongated conical process, which
is not unlike the spur of the cock, and when
very long is occasionally twisted like the horn
of a ram. Some curious excrescences of this
kind are represented in the clever etchings of
Mr. Wadd.* The subjoined figure taken

Fig. 659.

from one of them, exhibits the process of its
exact size.

Upon dissecting a portion of scrotum af-
fected with chimney-sweeper’s cancer, the part
is found to present very similar appearances
to those of carcinoma of the lip. The tissue
at the base of the ulcer is dense, indurated,
and distinctly laminated, and possesses very
little vascularity. On examining some matter
scraped from the base of a soot-wart shortly
after its removal from the body, I perceived
a number of caudate and spindle-shaped
nucleated cells. Epithelial cells have likewise
been observed in several cases, and the dis-
ease is regarded as belonging to the epithelial
form of cancer. On examining some diseased
glands in the groin in a case of scrotal cancer,
I found them enlarged and indurated, and
composed of a whitish brown or yellowish
white substance, mixed up in some places with
a soft curd-like matter, or greyish pus, con-
tained in thin white cysts.

Carcinoma scroti is, with few exceptions,
confined to chimney-sweepers ; and the irrit-
ating action of the soot on the skin of the
scrotum is no doubt its exciting cause. A
similar disease occasionally occurs in other
parts of the skin, but the scrotum being sel-
dom cleansed and well adapted to harboursoot

* Cases of Diseased Prepuce and Scrotum, pi. x.
xi. xii.

3 T 4

1016

TESTICLE (ABNORMAL ANATOMY).

seems more exposed to the disease. Sir James
Earls has related the case of a man who had
a large sore resembling chimney-sweeper’s
cancer which reached from the bend of the
wrist to the knuckles, occupying almost the
whole of i he back of the left hand. The man
was a gardener, and for several springs had
been in the habit of strewing soot on the
ground round the young plants to preserve
them from slugs. He carried the soot in
an old garden pot which hung on his left
hand, while he strewed the soot with his
right.

The predisposition to cancer scroti appears
in some instances to be hereditary. The late
Mr. Earle extirpated the testicle and diseased
integuments from a sweep aged thirty-five, a
patient in St. Bartholomew’s Hospital, whose
grandfather, father, and one brother had all
perished from the effects of the disease. A
father and son were once in St. George’s
Hospital at the same time on account of it.
Mr. Cusack mentions that he removed a
soot-wart from the hand of a female who
carried on the business of chimney-sweeping,
and that he had previously excised an ex-
crescence of the same nature from the ear of
her son.*

Cancer scroti occurs more commonly at
the middle period than at any other time of
life. In the majority of cases which I have
met with the disease occurred between the
ages of thirty and forty. Those exposed
however to the action of soot may become
affected at a much earlier period. Mr. Wadd
has figured a diseased prepuce and soot-wart
on the scrotum from a boy aged fifteen ; and
Sir J. Earle witnessed a case of the disease
as early as at eight years of age. It appears
that the seeds of this malady are sown in
early Lfe, but in general do not germinate
untd they have remained for some time dor-
mant in the system. What is the permanent
effect on the scrotum produced by soot, which
thus renders it in certain individuals so pecu-
liarly susceptible of a cancerous action at
some distant period, we cannot explain ; but
that the soot, though the exciting cause of
the disease, may in some instances be a remote
one, is shown by several striking facts. It is
known that persons who have been sweeps
when young, but have abandoned the occu-
pation, have afterwards been attacked with
chimney-sweeper’s cancer, although they have
long been removed from all contact with soot.
A sailor between forty and fifty years of age,
was admitted into the London Hospital, with
an ulcerated sore on the scrotum, presenting
all the characters of genuine chimney-sweeper’s
cancer. The inguinal glands were indurated
and enlarged, and subsequently ulcerated.
He had been brought up as a sweep ; but for
the last twenty-two years, during which period
he had served at sea, he had not been em-
ployed amongst soot in any way whatever.
The disease first appeared in the scrotum

* Dublin Journal of Medical Science, vol. xxi
p. 137.

about three years before. In this case, there-
fore, the injurious influence of soot must have
been exerted nineteen years before the ap-
pearance of disease, during which long period
lie was entirely removed from the effects of
its exciting cause. It has sometimes hap-
pened, after the morbid parts had been com-
pletely extirpated, and the wound healed,
the patient having avoided further contact
with soot, that the disease has re-appeared
as it were afresh, a second and even a third
time ; not, however, in the cicatrix of the
wound, but on a different part of the scrotum.
These, and similar facts, lead to the conclu-
sion that though abandonment of his occupa-
tion may render the adult chimney-sweeper
less liable to cancer, it by no means forms a
satisfactory security against its occurrence.

Cancer scroti chiefly extends its ravages by
affecting the contiguous tissues, and has little
disposition to contaminate the lymphatic
glands or distant parts. An instance is on
record of an old chimney-sweeper, who had
been subject to this disease for forty years,
and had undergone three operations for its
removal, yet even then the glands in the groin
were unaffected* A man aged fifty-one who
had been a chimney-sweeper ever since the
age of seven years, was a patient of mine on
account of this disease. He had been re-
peatedly attacked with it during a period of
twenty-twro years, and had submitted to no
less than five operations for its removal. The
glands in one groin became affected only a
few months previously. Ulceration took place,
and the patient died from its irritative effects
on the constitution. On a careful examina-
tion of the body, no trace of internal disease
could be detected; The cancer was strictly
limited to the groin and scrotum. Mr. B.
Cooper has likewise recorded a case of chim-
ney-sweeper’s cancer which ended fatally;
and on examination none of the glands or
viscera of the interior of the body were af-
fected.j- These cases show that, when the
inguinal glands are indurated, they may be
excised with a fair hope of a successful result.

Alelanosis.- — Notwithstanding the dark co-
lour of the skin of the scrotum, melanosis is
an exceedingly rare affection of this part.
Indeed, the only case of its occurrence there
with which I am acquainted, is one that hap-
pened in my own practice. The patient was
a cabinet-maker, aged thirty-two, and the
disease commenced as a small dark spot, ap-
parently produced by some black deposit be-
neath the epidermis, raising it a little above
the surrounding surface. This spot increased
until it formed a fungous growth. I excised
the part, but the disease re-appeared in the
scrotum and in the glands of the groin six
months afterwards. It made, however, very
slow progress, and did not destroy the patient
for six years. J

* Mr. Hawkin’s Lecture on Tumours. Lond.
Med. Gazette, vol. xxi. p. 842.

f Lond. Med. Gazette, vol. xliii. p. 532.

J Vide Report of the Case in Lond. Journal of
Medicine, vol. i. p. 220.

THORAX.

Fibrous tumours. — A small fibrous tumour
is occasionally developed in the areolar tissue
of the scrotum. It may acquire the size of the
testicle, and being firm and of an oval form,
resembles a supernumerary gland. 1 have
met with only one case of this form of tumour.
Dr. Mott, of the United States, excised an
enormous mass from the scrotum of a man
about seventy-three years of age. The scrotum
was twelve to fifteen times its ordinary bulk,
and was filled with tumours of a stony hard-
ness, from the size of a nutmeg to that of a
large pea. The tumours had all a very white
appearance, and the integuments over two
or three of the largest, having been ulcerated
for upwards of a year, poured forth a foetid
discharge, together with a white substance
resembling mortar. The disease was upwards
of twenty years’ duration. I have no doubt
this disease was originally of a fibrous cha-
racter. The calcareous matter and other
changes resemble those occasionally observed
in large fibrous tumours of the uterus. A
tumour of a similar character and of great
size was removed by operation from the
scrotum of a man in St. Vincent’s hospital,
Dublin, by Dr. O’Ferrall.*

Bibliography. — Anatomy. — De Graaf, De Vir.
Organ. Gener. Lugd. Bat. 1668. Monro, Essays and
Observations, vol. i. Edinb. 1754; also De Testibus
et de Semine in variis Animalibus. Diss. Inaug.
Smellie. Thes. Med. ii. 317. 1755. Hunter, W. Me-
dical Commentaries, 1762. Warner, An Account of
the Testicles, 1774. Palletta, Nova Gubernaculi
Testis Hunteriani et Tunicie Vaginalis Descriptio,
1777. Brugnoni, De Testium in Fcetu positu, &c.,
1785. John Hunter, A Description of the Situation
of the Testis in the Fcetus, with its Descent into the
Scrotum, (Animal CEconomy), 1786. Seiler, Observ.
de Testiculorum ex Abdomine in Scrotum descensu,
Lepsise, 1817. Wilson, Lectures on the Urinary and
Genital Organs, 1821. Sir Astley Cooper, Observa-
tions on the Structure of the Testis, 4to., 1830.
Lauth, Memoir de la Societe d’Hist. Nat. de Stras-
bourg, t. i. 1830. Krause, Muller, Archiv. fur An-
atomie, 1837. Gulliver, Proceedings of Zoological
Society, 1842. Curling, Treatise on the Testis, 1843.
E. Huschke, Encyclopedie Anatomique, t. v. Paris,
1845.

Morbid Anatomy of the Testicle. — Pott, On
Hydrocele and other Diseases of the Testicle, 1767.
Bell, B. On Hydrocele and other Diseases of the
Testis, Edinb. 1794. Wolf, L. De Sarcocele, Er-
lang. 1799. Sir Astley Cooper, Observations cn the
Diseases of the Testis, 1830. Baring, Ueber den
Markschwamm der Hoden, Gbtting. 1833. Russell,
Observations on the Testicles, 1833. Brodie, Lec-
tures on Diseases of the Testicle, Lond. Med. Ga-
zette, vol. xiii. 1834. Berard, Journal desConnaiss.
Medico-Chirurgic. pour l’annee 1835. Velpeau, Diet,
de Me'd. t. xv. Landouzy, Du Varicocele, Paris,
1838. Curling, Treatise on the Diseases of the
Testis, 1843. Maladies des Testicules — Biblio-
theque du Medicin Practicien, t. iv. Paris, 1846.
Vidal ( de Cassis ), Traite de Pathologic, t. v. 1846.

(T. B. Curling.)

THORAX (3<5p«£ from Sropsui to leap, be-
cause in it the heart beats). “ The habitation
of the breathing parts.” — That part of the
human body destined to contain the lungs

* Dublin Hospital Gazette. Feb. 1845

1016

and heart, and by its movements to maintain
the function of respiration.

Generally by the term thorax is understood
a cavity set apart for the respiratory organs.
Such a cavity, however, is not essential to
respiration : a respiratory surface only is es-
sential. This must exist in every animal,
whilst a separate thorax is found perfect only
in mammalia.

The development of the respiratory surface
may take place in three ways.

1st. Either towards the intenor of the
body, in the form of ramified or sacculated ca-
vities ; or,

Sndly. Towards the exterior, in the form of
lamellated, ramified, pectinated, tufted, cili-
ated, or pinnated processes called “ branchice ,”
in which Nature seems to have exhausted all
imaginable varieties of form ; and,

3rdly. By a system of tubes ramified to ex-
treme fineness, either in an especial cavity or
thorax, or in a cavity common to these
organs and to others destined for the diges-
tive function.

The movements necessary to respiration,
are modified according to the form of the re-
spiratory apparatus and the nature of the
medium to be respired, whether pure air or
air contained in water.

In some of the lowest animals, the respira-
tory movements are the same as those of loco-
motion, as in the monad and other infusorial
animalcules. In all animals, even when the
respiratory organs are contained in a true
thoracic cavity, the frame-work serves other
purposes besides that of drawing in and
throwing out air ; it gives attachment to the
largest muscles of the upper extremity, whe-
ther prehensile or locomotive. In man parti-
cularly, we find the respiratory muscles con-
tribute to such acts as coughing, sucking,
sneezing, yawning, sighing, singing, vomiting,
as well as the innumerable articulate sounds
of language.

Distinct respiratory movements, as depen-
dent upon alternate contractions and dilata-
tions of a thoracic cavity, are most regular, or
at least, they have been more noticed, in
mammiferous animals. The thoracic cavities
of mammiferous animals have much of the
mechanism of respiration in common. They
all possess a vertebral column or spine, and
that peculiar frame-work of ribs, together with
a sternum, so articulated together as to move
in breathing.

There is likewise a great similarity of mus-
cular arrangement around the thoracic cavity;
and consequently the respiratory movements
closely resemble each other.

Although the boundaries of the thorax are
generally the parts which move in respiration,
and these are generally composed of vertebrae
ribs and sternum, yet some animals may
have either all of these, or they may lack some
of them, or, if present, they may not move
in the breathing function. Frogs have a ster-
num, but no ribs ; serpents have ribs, but no
sternum ; tortoises have ribs, vertebras, and

1018

THORAX.

sternum in one mass, rigid and immoveable :
the crocodile and lizard have perfect ribs, but
their sternum is almost entirely cartilaginous ;
and, lastly, in man, the components of the
thoracic cavity may have a mobility to com-
mand or exceed a space equal to the whole
cavity allotted for the respiratory organs. The
relative quantity of air which he can respire
for the aeration of his blood is probably
greater than in any other animal, and his
movements are more under the control of his
will, and are greatly influenced by mental
emotions.

Classification of the Respiratory
Movements in Animals. — It is not easy
to name any particular part in the perfect
thorax of the higher vertebrata, which is
equally destined for respiratory motion
throughout the class. Commonly with ribs
and intercostal muscles, we connect the idea
of a thorax, or a breathing chamber for re-
spiration ; but a fish has ribs, and likewise
intercostal muscles, yet not for any of the
purposes of respiration, nor do we acknow-
ledge them to belong to its thorax. A frog
has a thorax for respiration with internal
lungs, but no ribs, nor, consequently, any
intercostal muscles. Nor is a diaphragm
necessary to thoracic respiration ; for it is
mostly absent in birds and reptiles, and quite
rudimentary in the few instances (such as the
ostrich, crocodile, and chelonial, in which it is
met with. In the chelonia neither ribs, spine,
nor sternum are concerned in the respiratory
movements.

The movements of respiration tend to bring
before some surface, air or air contained
in water ; or to bring a certain surface con-
tinually into a fresh medium, In whatever
way this may be accomplished, whether
by moving the whole body, or part of the
body to and fro, such movements, likewise,
are not uniformly for the mere purpose of re-
spiration, i. e. the mere purpose of aeration.
All reptiles take more air into their capacious
lungs than they require for oxygenating the
blood, particularly in the aquatic kinds (as in
the turtle), where the air serves to buoy up
their heavy and slow-moving bodies in the
dense element they inhabit. Serpents are
provided with numerous highly-moveable ribs
and powerful intercostal muscles, capable of
rapid and extensive inspiration and expiration.
Tney can perfectly distend their body with air.
The same may be observed in the chameleon.
These volumes of air cannot alone be subservient
to respiration, as it cannot all come into contact
with the simple undivided respiratory sacs.
We see, therefore, there is no necessary rela-
tion between the quantity of air an animal may
inspire and the extent of respiratory surface.
The long hissing sound which serpents pro-
duce to alarm their prey, is effected by the
expulsion of this great volume of air, by their
ribs, through the narrow passages of the nos-
trils.

In the higher mammiferous animals, we find
respiration more especially destined for the
chemical purpose of oxygenating the blood.

Hence a more limited quantity is taken in, and
it is speedily thrown out again. Large animals
make fewer respirations than small ones. Ac-
cording to Scoresby*, the whale breathes
four or five times a minute ; the dog, the cat,
and rabbit, from twenty to thirty in the same
period ; and in small birds the respirations
are remarkably rapid.

Whatever be the form of the aerating or-
gan, “breathing” is accomplished either by,
1st, the weight of the atmosphere rushing
into certain cavities, because certain parts of
these cavities dilate and threaten a vacuum ;
or, 2ndly, by the direct projectile or collapsing
force of an organ throwing the ambient ele-
ment onward. These two ways are generally
more or less combined in the same animal.
Nor does there appear to be any relation be-
tween the grade of the animal and the order
of respiratory movement obtained. We notice
in the respiration of man a regular inspiration
and expiration, two currents in different di-
rections ; and in the lowest animal, the
connecting link with the vegetable kingdom,
the porifera, or sponge tribe, there are like-
wise two respiratory currents by distinct
channels, which are as regular as the motion
of rivers from their source to the ocean, or
any other movement depending upon the
established order of things. In some spe-
cies of medusae, there are peculiar sacs on
the inferior surface of the body, which,
during the expansion of the body, admit
water through certain apertures, and again
expel it during the succeeding contraction, re-
presenting a perfect inspiratory and expi-
ratory action. The complexity, therefore, of
respiratory movements does not correspond
with the increasing development of the
breathing organs. Those animals which have
an internal sacculated lung, always retain a
certain quantity of the breathing element in
“ reserve ” within their system ; whereas those
animals which have external lungs, or gills,
have no “ reserve ” respirable medium. They
need none, because where there is an exter-
nal lung, the ambient element answers the
purpose of the “reserve”; it is always in
contact with the breathing surface. This
“ reserve,” in mammalia, 6tc., is not, pro-
bably, so necessary to aeration as for the
purpose of ejecting any matter which may
obstruct the air passages — or, in more po-
pular language, for “ coughing ” up any matter
out of the throat.

The different kinds of respiratory move-
ment may be arranged as follows ; —

1. Infusorial Animalcules By projectile force.

2. Insects - Uncertain.

3. Fishes - By vacuum & pro-

jectile force.

4. Amphibia - - do. do.

5. Birds - do. do.

6. Mammalia - - do. do.

Of the First Kind of Respiratory Movement.
Infusoria. — These animals breathe by a stream
propelled in one direction, produced by the ra-

El. Physiol. Wagner, 8vo. 1844, p. 670.

THORAX.

1019

picl vibration of hair-like organs — cilia. ( Vid.
Art. Cilia.)

Of the Second Species of Respiration. In-
sects.— The breathing apparatus in insects
generally reaches a high degree of develop-
ment. Sometimes respiratory tubes or tra-
cheae penetrate every part, in the form of mi-
nute ramifying vessels conveying the included
air to all tiie organs. The moving power or
means of the renewal of the air in these tubes
is at present little known. Some insects, al-
though they live in water (as, for instance, the
water beetles, and also water spiders), retain
a bubble of air around them ; and, according
to Nitzch*, they renew the air in the irtrachae
by alternately elevating and depressing the an-
tennae. Beetles, before flying, seem to inflate
themselves with air, so as to unfold their
wings, which, like other parts of their body,
are supplied with air tubes. In this case
an inspirative effort must be made by some
cavity. Under certain circumstances, bees
emit a voice, a shrill sound, which is indepen-
dent of the motion of the wings, and which
appears to be connected with the existence of
a current of air through the respiratory tubes
or tracheae ; at least, such has been observed
when the animal has been irritated and im-
mersed in water, the surface of which, where
it was in contact with the orifice of the stig-
mata at the root of the wing, evidently vibrated
at the moment the sound was produced.)"

In the orthoptera particularly, there are
distinct respiratory movements, alternate dila-
tations and contractions of the abdomen ; in
fact, respiratory motions are more distinctly
perceptible in this division than in any other in-
sects. In the locusta verrucivora particularly, it
is easy to distinguish how the abdominal rings,
which have smaller abdominal scuta between
them inferiorly, are alternately elevated and
depressed exactly like ribs. If we smear the
great thoracic stigmata with oil, we find that
numerous bubbles of air escape from it during
these motions.

The organs of respiratory motion, by means
of which the supply of air is renewed, present
many points of uncertainty. On the one
hand, where large stigmata are placed opposite
to each other, and connected by tracheae, it is
easy to see that alternate opening and shutting
of their valves may produce a current capable
of renewing the supply of air. It is conceiv-
able also, how, in the orthoptera, lepidoptera,
and others, the expansion and contraction of
the body, and the elasticity of the air-sacs
contained in it, may cause the ingress of air.
It is less obvious, however, how the same
effect is produced in caterpillars and the larvae
of beetles, where a current of air cannot very
easily arise from the opposite position of the
stigmata, on account of the minute ramifica-
tions of the tracheae ; and consequently we
must look for some peculiar mechanism, pro-
bably cilia, unless we are disposed to admit

* On tlie Respiration of the Hydropliilse, in Reil's
Archiv. B. x. S. 440.

t Hunter, Philosophical Transactions. 1702.

p. 182.

the stagnation of the air in its vessels. Hence
it has been conjectured that the dilatation and
contraction of the dorsal vessel contributes to
this purpose. This, however, appears to be
scarcely possible ; and it might be asked on
the contrary, if the vermicular motion of the
body itself, the sliding of its segments upon
each other, are not the means of keeping up
the constant ingress and egress of air.*

In the lowest of the molluscous class, the
external tunic with which they are covered
is generally so elastic, that it is capable of
dilating by its own properties, when it has
been greatly contracted by the muscular coat
that is within ; and in forcible expirations.
Dr. Grant has observed these animals to
contract their muscular coat, and to retract
the exterior covering, so as to propel, with
considerable impetuosity, and to a distance,
the water that fills their respiratory cavity.
The elasticity of the tunic tends to over-
come the resistance of the muscular coat,
and to expand, to a certain extent, the respi-
ratory cavity. Without, therefore, the existence
of elastic ligaments, such as we find in ccnchi-
fera, there is a partial means of enlarging the
respiratory cavity given to these tunicated
animals. This, however, is only in occa-
sional, forced, respiration ; constant and al-
ternate contraction and expansion of the ex-
terior tunic is not met with in any known tu-
nicated, nor in a conchiferous animal, f The
streams that enter the respiratory, and pass
out of the anal aperture, are smooth, regular,
and incessant, and are produced by ciliary
movement.

Of the Third Species of Respiration. Fishes.
— It may be said that the thorax of fishes
usually presents four elastic cartilaginous
arches, which approximate and separate , open
or close the gills, at the same time increasing
or diminishing the capacity of the so-formed
thorax. These ribs, or branchial arches, sup-
port the gills, which are covered by a great
flap (operculum) on each side of the base of
the skull.

The respiratory current enters at the
mouth, passes through the fissures on each
side of the fauces, and escapes through the
branchial openings, placed laterally, covered
by the moveable operculum. This stream is
uniformly in one direction, — from before,
backwards. It might be asked, why does not
the water rush in by the branchial opening
when the mouth “ threatens” a vacuum? It
will be observed that the margin of the oper-
culum, or great lateral flap, is edged with a
delicate membrane, which acts as a valve, this,
by the pressure of the water, is forced close
round the lateral openings : thus, the water,
upon the expansion of the jaws, is prevented
entering behind, and consequently rushes in
towards the gills by the mouth ; the jaws now
close, the operculum immediately opens by the

* Reimarcus, Ueber das Athmen. in Reil’s Archiv.
B. xi. S. 2. ; and Nitzseh, Comment, de Respirat. p.
39. et seq.

j Grant’s Lecture “ On the Respiratory Organs
of Invertebrata.” Lancet, 1833 — 4, vol. i. p. 964.

1020

THORAX.

force of the jaws contracting with the mouth
full of water, which contraction, or expiration,
forces the water through the branchial arches
and ultimately out by the lateral openings.

Thus the respiration is of a mixed order.
The first stage by atmospheric and hydraulic
pressure ; the second stage by direct muscular
force, similar to that of swallowing.

If we cut off the delicate fringe around the
operculum the fish is suffocated, the opera-
tion being analogous to puncturing the human
thorax.

Fishes also possess a power of regulating
their respiration. We have watched fishes
when in a quiescent state move their respi-
ratory organs so gently that the motion was
nearly imperceptible, and at times quite so ;
but if at such times you alarm the animal,
respiration becomes vigorous, and a compa-
ratively vast body of water rushes past their
respiratory organs. The same may be like-
wise observed when fishes have remained long
in a small quantity of water, as if the respira-
tory movements became more and more vigo-
rous with the deterioration of their element,
but give them a fresh supply of water and re-
spiration becomes quiescent again.

Of the Fourth Species of Respiration. Amphi-
bia.— In this class there is a gradual develop-
ment of the animal formation from an aquatic
to an aerial being ; so likewise is the aqueous
gradually converted into aerial respiration.

The respiration of some of these animals is
indeed most curious, — curious as to the very
limited quantity of air necessary for their well-
being, and curious as to whether they have
this limited quantity supplied regularly or
otherwise. For instance, you may keep an
aquatic turtle out of water for days, and it
will keep constantly respiring air ; immerse
it in water, and it will remain below the sur-
face for half an hour, or an hour, without any
inconvenience, and some of these animals
will breathe at the surface during the day, and
sleep at the bottom all night without once
rising for air, while during the day the same
animal cannot remain below above half an
hour without showing signs of discomfort.
And again, the common tortoise during hy-
bernation breathes so small a quantity of air,
that we have never been able to form any
calculation of the quantity then respired.

In frogs there are no ribs by which the
lungs may be moved ; consequently there
is no vacuum formed by their thorax dur-
ing respiration ; they fill the lungs like the
tortoise, the newt, the chameleon, &c., by the
working of their jaws ; or, in other words, they
swallow their air just as we swallow our food.
In this respect their respiratory movements
resemble those of fishes ; the first process being
through the agency of external pressure, by
making a vacuum with the mouth ; the se-
cond, that of forcing, by the operation of the
pharynx. They resemble mammalia in having
an internal lung, retaining the air for some
time, and in expelling it through the same
channel by which it entered. The respira-
tion of the frog has gained attention, and is

hence better understood than that of many
other animals of this class. The followingis the
mechanism of its respiration, as described
particularly by Townson*, though before no-
ticed by Swammerdam and Malpighi. When
the broad lingual bone which forms the floor
of the mouth is drawn down from the pa-
late by its muscles, the air of the mouth is
rarefied, and an additional quantity enters
by the nasal apertures, which admit of being
closed by valves. The lingual bone is then
raised, the nasal apertures are closed, and
the air is now forced, or rather swallowed,
through the rima glottidis into the pulmonary
sacs, and can also fill the laryngeal pouches
which open into the mouth. Expiration is
produced partly by the pressure of the abdo-
minal muscles, and partly by the peculiar mus-
cular power of the pulmonary parietes. To
the careless observer the frog does not appear
to breathe : it is never seen to open its mouth ;
there is no motion of its sides like breathing,
and when it is provoked (or rather through
fear), though it still keeps its mouth close shut,
its sides and back rise, and it blows itself up ap-
parently by some internal power. Upon observ-
ing it more narrowly, that skinny and bag-like
part of its mouth which is under the jaw, is seen
to be in constant motion. While this bag is
dilating and contracting, the mouth is never
opened to take in new air, but it seems to live
all the while on one mouthful of air, and seems
to be playing it backwards and forwards between
the mouth and lungs. If we now observe the
nostrils, a twirling motion, which lets in air
at each movement of the jaws, is apparent,
corresponding to the quantity of air inspired.
If we keep the mouth open we presently see
the animal struggle for breath, for we by this
means disable the forcing apparatus from pro-
pelling the required air into the lungs.

The newt breathes with the jaws and nos-
trils like the frog. It has, like the frog, a
constant motion, by short strokes of the bag
under the jaw. This bag is formed by
the membranes of the mouth, covered and
moved by the genio-hyoid and mylo-hyoid
muscles. Every minute, or less, it stops,
as if intending some particular motion ; then
gradually the bag swells out under the lower-
jaw to a great size; the contained air is then
pressed down into the lungs, and in propor-
tion as the jaws are emptied, the sides of the
animal are swelled up. The toad, the chame-
leon, and the green lizard breathe in the same
way, propelling mouthfuls of air down into
the lungs. The chameleon can force down a
greater or smaller quantity of air, as its needs
or fears prompt it. At times it seems to fill
its body almost to bursting with air. The
tortoise, like the frog, holds its jaws close,
and swallows the air ; alternately depressing
and elevating the hyoid bone. The first of
these motions permits the air to enter the
nostrils, when, the tongue immediately closing
their internal aperture, the second motion
forces the air into the lungs. It is not un-

* Tracts and Obs. on Nat. Hist., &c. London, 1799.

THORAX.

1021

common to notice tortoises yawn ; but how
different is their yawning from that of man,
who makes, at that time, a deep inspiration,
while, in the tortoise, respiration is impossible.
We are not prepared exactly to say how the
tortoise and turtle expire ; hut probably the
expiration is performed by the contraction of
fhe abdominal muscles between the lower
shield or plastron and the posterior extremi-
ties ; for either of these animals can at will,
when alarmed, forcibly expel air with a hiss-
ing sound, although its shell is unyielding.

The most remarkable respiratory move-
ment we have noticed, has been in the com-
mon turtle. Sometimes this animal will swell
out his hard case, the sternum or plastron
yielding to some internal force ; but it is diffi-
cult to say by what means this is distended
and kept distended.

It is clear this animal can gorge itself with
air until it cannot sink in water, and that at
pleasure it can disgorge itself and fall to the
bottom, where it lives upon only a fraction of
the quantity of air it had just previously ex-
pelled.

Of the Fifth Species of Respiration. Birds.
— Here we have a contracting and dilating
thorax, with ribs and sternum. The cavity of
the chest is not divided by a diaphragm, but
is common to the whole digestive organs as
well as the lungs; or, as is said, they are
“all chest and no beliy.” They differ from all
other animals in this respect, that the lungs
do not hang in the cavity of the trunk as unat-
tached sacs, but are attached in the form of
flattened masses, of' spongy, bright red, cellular
texture, to the posterior side of the thorax,
reaching to the pelvis. They have vesicles or
air bags extending through the whole body ;
and the cancellated structure of their bones is
connected with the true lungs; so that if we
tie the trachea and amputate the wing, leaving
the stump of the bone exposed, the bird can
inspire and expire through the humerus. In
the same manner that the diffusion of air
through all parts of the body in insects makes
the highest extentof respiration in invertebrata,
so also is it with birds among the vertebrata.

The sternum and ribs, together with the
immoveable range of dorsal vertebrae, all con-
tribute to dilate and narrow the thorax, after
the manner of a bellows movement. This di-
latation and contraction draws the air through
the true lungs, which never move, and imme-
diately the air cells are expanded. By this
means two conditions are obtained ; the air is
drawn through the lungs for aeration ; and
the air filling the cancellated structure, renders
the bird specifically lighter.

The high flying rapacious bird can thus by
a respiratory movement attenuate the air in
his body, when soaring in the atmosphere, and
again at pleasure condense it in every inter-
stice of his frame, when he drops like a can-
non ball, to pounce on his prey ; but imme-
diately before seizing it, again he attenu-
ates the air within him to break his fall ; other-
wise he would be dashed to pieces upon the
pointed crag, and die along with his victim.

This beautiful provision is wholly due to
his respiratory movement, at one time acting
as a condensing, and at another time as an
exhausting syringe.

Of the Sixth Species of Respiration. Mam-
malia.— In this class we first meet with a
perfect muscular septum (diaphragm) forming
the two cavities of the trunk ; the one for the
lungs, and the other for the abdominal viscera
All animals which have a diaphragm, maintain
respiration in a manner similar to each other ;
for, indeed, it appears that the ouly use of
this muscle is to maintain a movement of air
— that unceasing pumping to and fro of inspi-
ration and expiration. Their respiration, or
at least their inspiration, is purely of the
vacuum order.

The diaphragm is the chief muscle of ordi-
nary breathing. It can act with great power,
protruding the viscera, by its descent, at each
ordinary inspiration. This is strikingly seen
in animals recumbent and at rest, as in the
cow, horse, goat, dog, &c., when it ap-
pears as if the animal was breathing with its
abdomen. The ribs likewise in some degree
maintain respiration in the lower mammiferous
animals, particularly in disease. For instance,
the respiration of the horse or dog, when the
lung is emphysematous, or what is familiarly
termed “ broken-winded,” is costal , and at
such times the respiratory action of the ribs
may be beautifully seen.

It is most probable that in mammalian re-
spiration we have the highest order of accom-
modation for peculiar respiration, according to
the condition of the animal ; i.e. an instinc-
tive power to respire by different parts of the
thoracic cavity, according to the needs of the
animal, whether modified by health or disease.

Nearly two hundred years ago, Lower
changed the respiratory movements of the dog
from diaphragmatic to costal, by paralysing the
diaphragm through the medium of the phrenic
nerve. ( Phil. Tr. Abr., vol i. p. 179.)

The respiration of mammalia is the bellows
action — inflation of the lungs by expansion of
the thorax, or inspiration by vacuum, and ex-
piration by propulsion.

The projectile force in the respiration of
mammalia is nearly all due to mere elastic
contractility ; i. e. ordinary expirations are
produced by the elasticity of the lungs and
ribs, returning backwards, or collapsing, after
their distension by the inspiratory muscles.
This mere dead and involuntary force performs
one half of our respiration.

Man is not distinguished either by the force,
extent, or complexity of his respiratory move-
ments ; he is exceeded in all these particulars
by inferior animals. The roar of the lion
gives the idea of an overwhelming expiratory
power ; nor are his lungs less complicated ;
and the vibration of thousands of cilia, pro-
moting currents around the monad, is more
complex than the simple respiratory thoracic
action of mammalia. The most striking dif-
ference is that produced by mental influence,
which appears to command the most delicate
modifications of this movement, so indicative

1022

THORAX.

of the passions of his mind, while in the lower
animals we see none of these.

Of the Thorax in Man. Anatomy of the
framework of the Thorax. — A portion of the
spine, the ribs, the sternum, together with
numerous muscles, form the wall of the human
thorax. The framework of bones is so ar-
ranged as to admit of free mobility in various
directions, so as to increase or diminish the
cubic capacity of the thoracic cavity.

Of theDorsal Vertebra;. — -That portion of the
spine which enters into the composition of
the thorax consists of the dorsal vertebra,
which are 12 in number, intermediate in size
and position, between the cervical and the
lumbar vertebrae. They form the main pillar
of support for the whole respiratory apparatus
— the great fixed point for the chief respira-
tory muscles to act against or draw upon.
Their general appearance is that of increasing
in size from above downwards ; but when
carefully examined, they are as two cones, the
apices of which touch at about the fourth
or fifth vertebra, from which point, in either
direction, they increase in their dimensions ;
their breadth laterally exceeds their depth
from before backwards. Their bodies are large
and project deeply into the cavity of the tho-
rax, diminishing greatly the antero-posterior
diameter of the chest. Out of twenty cases,
the average projection is 2-f of an inch, leaving
little more than 4 inches for the heart and
great blood-vessels.

A deep sulcus is thus formed, which if
a cast be taken of the cavity of the thorax,
is very striking. In phthisis puhnonalis,
the space between the bodies of these verte-
bra and the sternum is sometimes less than one
inch ! When the thorax changes its form by
disease, this centre pillar is liable to wedge in
or jam up the thoracic organs against the walls
of the chest.

The vertebra are connected to each other
by ligaments, and jointed beautifully into each
other, so as collectively to admit of extensive
motion, while there is but little movement
between any two vertebra.

Of the bonds of union, the most remarkable
are the inter-vertebral disks ( ligamenta inter-
vertebralia — Weitbr.) — composed of fibro-car-
tilage, and placed between the bodies of the
vertebrae, each disk serving to unite two
vertebra, and yet to permit a motion in any
direction, yielding on that side towards which
the column inclines, while on the contrary side
it expands with the increasing intervertebral
space. This substance is to the brain what
the cushion or “ buffer ” between each railway
carriage is to the traveller; it breaks a sud-
den jar from being transmitted from carriage
to carriage. So does this intervertebral sub-
stance soften down any sudden jerk received
at the lower extremity of the spine, preventing
its being transmitted to the brain in the varied
actions of walking, running, and leaping.

Of the Sternum (os pectoris : Xiphoides ), so
named from orepvov, the breast ; is a kind of
flattened bone, symmetrical in shape, which
occupies the anterior and middle part of the

thorax. It is supported by the ribs on either
side ; it is broadest at its upper part, and
then narrowed ; it widens again, and finally
becomes compressed and narrow where it
joins the ensiform cartilage. (Fig. 660, e.)
Its direction is oblique from above down-
wards and forwards. This, with the curva-
ture backwards of the spine opposite to it,
increases the antero-posterior diameter of the
thorax, as may be seen in a lateral view of a
cast of the thoracic cavity.

The length of the sternum, which is pro-
portionably smaller in the female than the
male, varies from 5 to inches. At the
upper part its breadth is from to 2 inches.

Its thickness above is about 6 lines ; at its
lowest part it is much thinner, never exceed-
ing three lines. The ancients compared the
sternum to the sword of a gladiator ; and
hence have arisen the denominations given to
its various parts : as the handle ( manubrium ),
the body ( mucro ), the point, or xiphoid
appendix, ( ensiformis ) ; but the last mention-
ed part now only retains the designation
grounded on this circumstance. This division
of the bone into three parts has been retained
by some modern anatomists, who describe the
three pieces of the sternum separately, as so
many distinct bones ; we shall only adhere to
this in speaking of the development of the
bone.

In anatomical language it is said, the ster-
num presents two surfaces, two borders, and
two extremities.

Of the anterior or cutaneous surface of the
Sternum. — This is subcutaneous, slightly con-
vex and affords attachment to the aponeurosis
of the pectoralis major and the sterno-cleido-
mastoid muscles. It presents three orfourtrans-
verse projecting lines, which are traces of the
original division of the bone into five pieces.
The union between the 1st and 2nd pieces cor-
responds to the insertion of the 2nd costal car-
tilage, and is frequently cartilaginous even in
the adult age. The line which marks the union
of the first two pieces of the bone is the most
remarkable : it causes a projection of variable
size in different individuals, which has been
sometimes mistaken for a fracture or exos-
tosis. At the lower part we sometimes find a
foramen ; sometimes in place of the foramen
there is a considerable aperture, to which
much importance has been attached, as afford-
ing a proof of the primitive separation of the
bone in the median line. (Fig. 660. d.) The
existence of this opening explains how puru-
lent matter deposited behind the sternum
may, in certain cases, make its way outwards
without any absorption of the bone. This
bone is covered by a strong interlacement of
very numerous aponeurotic fibres.

Of the posterior (mediastinal or cardiac') sur-
face.— This is slightly concave, and parallel in
direction to the anterior surface. The con-
cavity is directed downwards and backwards,
towards the cavity of the thorax, and gives
attachment superiorly to the sterno-liyoideus
and sterno-thyroideus muscles, interiorly to the
triangularis sterni.

THORAX.

1023

Along the middle line, this concavity cor-
responds with the interval left by the diverg-
ence of the two pleurae (anterior mediasti-
num).

In the young subject, transverse lines are
seen corresponding to those which occupy
the anterior surface ; all of these, except the
two between the first and second pieces oi
the bone, are effaced at a more advanced age.
This surface is in relation with many organs
contained in the chest, and especially the
heart, in front of which the sternum forms
a kind of shield. This is exemplified, as al-
ready noticed, in the frog, which is provided
with a sternum, though it has no ribs. At the
lower part of the sternum are many nutritient
foramina.

Of the borders of the Sternum. — These are
thick and marked at each side by seven an-
gular depressions for the reception of the
cartilages of the first seven ribs, which gives
this bone a notched and serrated appear-
ance. These angular cavities are separated
from each other by semilunar notches, which
are longer above than below, where the facettes
closely approach each other. The uppermost
of these seven cavities is shallow, triangular,
and at an early age becomes ingrained with the
cartilage of the first rib ; those which follow
are deeper, angular, and situated at the ex-
tremities of each of the transverse lines.
When examined in the dried specimen, they
appear more angular and deeper in proportion
to the youth of the subject.

Of the clavicular extremity. — This is slightly
convex, and is the broadest and thickest part
of the whole bone. It is slightly excavated
from side to side, and presents at each corner
a depression for the reception of the sternal
end of the clavicle, which bears the name
fourchette; this is surrounded with irregula-
rities for the insertion of ligaments. It fre-
quently happens that the two clavicular arti-
culations are not at the same height ; a fact
which was noticed by Morgagni, and which
Cruveilhier attributes to the unequal wearing
of the two articular surfaces. We have once
seen the clavicular articulation so low as to
unite with the first costal cartilage.

Of the inferior extremity of the Sternum. —
This is formed by the xiphoid appendix ;
or ensiform cartilage, for it often remains
cartilaginous to adult age. In length,
shape, and direction, it presents nume-
rous varieties ; it is frequently bifid, some-
times pierced by a foramen, and is occasion-
ally bent forwards, or to one side, and in
certain cases much depressed : its summit
gives attachment to an aponeurotic structure,
called the linea alba; behind, it indirectly
corresponds with the stomach, which rests
upon it when the body is placed in a prone
position.

Connections. — The sternum articulates with
fourteen ribs through the medium of their
cartilages, and more directly with the two cla-
vicles.

Structure of the Sternum. — This bone con-
sists of two very thin compact laminae, with

an intervening cancellated structure, the cells
of which are very large and have very
delicate parietes. It is one of the most
spongy bones of the body, and it is more
than probable that to this circumstance the
frequency of disease in it may be attributed.
Absorption of this bone and great displace-
ment by bending inwards is very common,
particularly in women who wear tight stays.
Under such circumstances, or by disease, we
have witnessed the sternum so depressed in-
wards that the depth, including all the thoracic
integuments from the spinous processes of
the dorsal vertebrae to the anterior surface
of this bone, did not exceed three inches, in-
stead of from seven to nine inches.

Of the Development or Ossification of the
Sternum. — As far as the middle of foetal
life or a little later, the sternum is altogether
cartilaginous, as represented at a. Jig. 6G0. This

Fig. GGO.

bone is one of the slowest in its ossification ;
it exhibits no bony points or centres of os-
sification up to the sixth month of fetal
life. It is also of all bones the one in which
the phenomena of ossification proceed with
the least regularity. After the sixth month
of foetal life, ossification begins with the for-
mation of osseous granules in the middle of
the intervals between the points at which the
cartilages of the ribs are connected.

“ There are five of these granules for the
sternum, exclusive of the ensiform appendage,
and they form as many pieces (e, Jig. 660.).
The process of ossification makes its appear-
ance in the first between the fifth and sixth
months ; and, soon following in the second and
third, it reaches the fourth at the end of fetal
life- The osseous centre of the last varies
considerably in the time of its appearance.
It may be found soon after birth, and may
not be visible for a considerable time (one or
two years) after that period.”

“ In many cases, one or more of the divi-
sions of the sternum are formed from more
nuclei than one, and there are peculiarities
with respect to the number and position of
these additional granules which require notice.”
Ossification of the 1st piece. — This some-
times presents a single nucleus (Jig. 660, b I .),
rounded and transversely strong ; sometimes
it presents two nuclei, and in this case they

102-1

THORAX.

may he either placed one above the other,
or side by side. In the former case the up-
permost nucleus is the larger ; in the latter,
both may be symmetrical and of equal size, or
what is more common, they may be of un-
equal magnitude. It may occasionally present
more than two osseous points. Albinus
found three in one subject, and four in
another.* Mr.Quain has a preparation in Uni-
versity College, where the very unusual num-
ber of six {fig. 660. c. U.) are to be seen. In
this case, where there is a plurality of osseous
points, the largest are generally situated alone;
exceptions to this rule are very rare.

Ossification of the body, or the 2nd, 3rd, 4 th,
and 5th pieces. — The osseous nuclei which
enter into the composition of the body of the
sternum have generally a rounded form when
they are single, and are situated in the middle
line ; where they are in pairs or are placed
laterally, they are more elongated, but smaller,
and appear to represent only the half of one
of the single nodules. The second piece has
not often more than a single granule ( b . 2,
c. 2'.), but the rest are frequently formed from
two nuclei, which are placed laterally to one
another (c 3', 4'.), and not vertically as occurs
in the first piece.

These different osseous points are always
so arranged as to be situated between two
costo-sternal articulations, so that a portion
of the sternum is developed in each of the
intervals comprised between the ribs. The
last piece is the only exception, being com-
mon to the articulation of the 6th and 7th
ribs. There are, therefore, four primitive
pieces of the body of the sternum ( b . 1, 2, 3,
4.), and each of these is sometimes formed
by one point of ossification ; at other times
by two lateral points. The first piece may be
formed of one or many ossific points, which
may be arranged vertically as well as laterally
To the centres of ossification here described,
M. Brechet f has added two small epi-sternal
granules, whose position is sufficiently shown
by the indication of them, fig. 660. at d**.
They occur only at rather advanced periods
of life, but they do not appear to be constant.

Union of the points of ossification of the body
of the Sternum. — In considering the union of
the different parts which compose the body of
the sternum, it is necessary to make a distinc-
tion between the lateral conjunction — that is,
the union of the osseous points which are
situated on each side of the median line- —
and the vertical conjunction, or the union of
the pieces of the sternum properly so called.
The lateral conjunction, or the union of these
osseous germs, which form a pair in the same
interval, always precedes the vertical conjunc-
tion.

The vertical conjunction, or the union of
the different pieces of the body of the sternum

* Craveilhier, Descrip. Anat. 8vo. 1840. Lond.
p. 87.

f Recherches sur Diffe'rentes Pieces du Sque-.
lette des Animaux Vertebres, &c. in “Annalesdes
Sciences Naturelles.” 2de Serie, t. 10. (Zoologie)
p. 91.

together, commences with the two inferior
portions. After this union, the body of the
bone consists only of three parts. The 2nd
piece then unites with the lower: the sternal
foramen is formed sometimes at the junction
of these last mentioned parts, sometimes at
the place where the two lateral points of the
4th and of the 3rd portions of the body are
united. If the interruption to the progress
of ossification should occur at the point where
the lateral parts of two sternal pieces would
meet, the foramen is likely to have con-
siderable size ; for it ma}' be the result of an
“arrest of development” proceeding from
four centres each constituting a part. ( Fig. 660.
d.) The union of the divisions of the body
of the sternum takes place precisely in the
inverse order of their appearance In fact
the appearance of the osseous points proceeds
from above downwards, while their union
proceeds from below upwards : a fact which
verifies the assertion, that the order of
development of osseous points is not always
correlative to the order of junction.

The lowest or 5th piece is joined to the
4th soon after puberty ; the 4th and
the 3rd are united, between 20 and 30
years of age ; and the body of the sternum
is usually not completed by the junction
of the 3rd piece to the 2nd before 35 or 40
years. Lastly, the 1st division does not in
general join the rest of the sternum at any
period ; but should its union happen to take
place, it is only to be met with in advanced
age.

Of the ossification of the appendix.- — -This is
generally accomplished by one nodule. Some-
times there are two ; and then they are rarely
symmetrical. The process commences in the
upper part of the cartilage, and very rarely
extends through the whole. The time of ap-
pearance of the osseous point is extremely
variable. Sometimes it is visible towards the
3rd or 4th year; sometimes not until the
12th or even the 18th year; according to
the observation of Beclard, between the 2nd
and 18th years.

From the 40th to the 50th year, and some-
times later, the appendix becomes united to
the body of the sternum. From the varieties
of ossification or development of the sternum,
it will be evident that it is impossible to assign
to it a limited number of osseous points.

Of tur Ribs. — The ribs ( Costa: from cus-
todes *) extend from the dorsal portion of
the vertebral column to the sternum, form-
ing arches which correspond to the lateral
segments of the chest. About one sixth of
the ribs are cartilaginous, and the rest os-
seous. The osseous portion is the rib pro-
perly so called ; the cartilaginous portion is
named the costal cartilage.

The ribs are 24 in number, 12 on each
side ; but cases occasionally occur in which
this number is augmented by the addition

* As if they were guardians of those principal
organs of the animal machine, the heart and lungs.
— Munro : The Anatomy of the Human Bones,
p. 234. Edingb. 1726.

THORAX.

1025

of a pair of cervical or lumbar ribs : in this
case the supernumerary ribs are formed
from the anterior parts of the transverse
processes of either the seventh cervical or first
lumbar vertebra ; which affords a strong
proof of the analogy existing between a
transverse process and a rib. Sometimes
the usual number is diminished to 22 : this is
more rarely the case. When this occurs, we
sometimes find two adjacent ribs united
throughout their entire length. Sometimes
the first rib is in a rudimentary state, being
properly formed posteriorly, but having its an-
terior extremity lost among the muscles, or
united to the 2nd rib. Mr. Quain has lately
seen an instance in which this diminution of
the number of the ribs was accompanied with
the absence of a dorsal vertebra.*

Classification of the ribs. — The ribs are nu-
merically designated 1st, 2nd, 3rd, and so on,
counting from above downwards. In the
living or in the undissected subject it is easier
to count the ribs from below upwards.

The seven superior ribs are united by
means of their own cartilaginous prolongations
(Jig. 6G1. b, c, d, e,f g, and h ; and fig. 662.)

Fig. 661.

to the sternum, and are called true ribs or
sternal ribs, or vertebrosternal ribs ; the re-
maining five are not so immediately prolonged
to the sternum, and are denominated false ribs,
or asternal ribs, or vertebral ribs.

We think it would be more judicious to
classify them otherwise, and consider the five
superior ribs as sternal, true, or thoracic ribs ;
the jive next inferior, as diaphragmatic ribs ;
the two last, being floating or false ribs. Be-
cause, the first five especially encompass the
cavity of the thorax ; the five next a portion
only of this space, together with a large por-
tion of the abdominal viscera ; and, lastly, be-
cause the two last do not touch the sternum
through the medium of any cartilage. The
transverse shade (_/tg. 682.) represents the arch

* Elements of Anatomy by Mr. Quain and AY.
Sharpey, M. D. London, 8vo. 1843, p. 105.

VOL. IV.

of the diaphragm, or the floor of the thorax.
Every rib articulates with the dorsal vertebra; ;

Fig. 662.

Position of the ribs and spine after deep expiration.

the spine is their fixed point, or centre of
motion, — the main pillar upon which they
act. The superior ten ribs articulate through
the medium of cartilages, the first seven
through the medium of their own, the next
three through that of those of their superior
neighbours, (fig. 661.) with the sternum.

The ribs have certain general characters
which distinguish them from all other bones;
and likewise certain proper or special charac-
ters, by which one is known from another.

I. Of the general characters of the ribs. — The
ribs resemble flattened bony hoops, varying in
breadth from -4 to '7 of an inch, and from -1
to •4 of an inch in thickness ; they once at-
tain a maximum, and twice a minimum length
(fig. 662.)

Theyareof averyirregularshape. Their arch
or curve is neither uniform relatively to each
other, nor yet relatively to itself at different
parts of the bone ; moreover they are twisted
in different degrees upon themselves so that
the two extremities of the same bone point
in different directions, and cannot simulta-
neously touch an horizontal surface.

Surfaces. — These bones present two sur-
faces : an external or cutaneous surface, which
is convex and smooth ; and an internal or pul~
monary surface, which is concave and likewise
smooth. The anterior end is comparatively
flat, the posterior is more cylindrical and
truncated, and is rough, particularly at the
extremity.

Borders. ■ — The ribs have two borders,
the one superior, and the other inferior. The
superior border is smooth and rounded, and
gives attachment to the intercostal muscles ;

3 u

102G THORAX.

the inferior border is more thin and sharp,
particularly in the middle third, or body, of the
bone. This thin or blade-like appearance is
caused by a groove on its inner aspect termed
sulcus costalis, which is commonly said to be
for the lodgment of the intercostal vessels : this
border also gives attachment to the intercostal
muscles. The borders are irregular in their
direction corresponding with the shape of the
rib ; which we shall presently notice.

Fig. 663.

d

Extremities. — (a) Posterior or vertebral
extremity. {Jig. 663. c). — This is rougher and
somewhat thicker than the other parts of
the rib, and is hence denominated its head
{capitulum costa). It presents, except in in-
stances to be presently stated two articular
facets, a superior and an inferior one, sepa-
rated by a well-defined ridge. Each of these
facets articulates with a corresponding small
surface on the bodies of two vertebrae, the
ridge just mentioned corresponding with the
intervertebral substance.

The head of the rib is supported by a
narrow round part, somewhat constricted —
the neck {Jig. 663. /). This is flattened from
before backwards and is the weakest part of
the bone. Behind the neck there are some
inequalities, which correspond to the trans-
verse process of the dorsal vertebra below.
Externally to the neck is an eminence
known as the tubercle of the rib (tuberos-
ity, tuberculum costce , Jig. 663. g), which is
smooth in one part for its articulation with
the transverse process of the lower of the two
vertebrae to which the head is connected, and
rough in the other, which is posterior, and in
some ribs superior to the above, for the inser-
tion of the posterior costo-transverse liga-
ment. The tubercles are most prominent in
the four or five superior ribs. Anterior to
the tubercle the rib suddenly bends forwards,
leaving this part the most convex, making
what is termed its angle. {Jig. 663. //) The
interval which separates the tuberosity from
the angle, is the thickest, roundest, and
strongest part of the bone.

(b) Anterior, or sternal extremity (Jig. 663.
d). — The anterior extremity of the ribs is
broad, flat, and deeply hollow'ed out at its
tip into an oval pit, into which is implanted
the costal cartilage. This extremity of the

rib is broader and thicker than it is an inch
more posteriorly.

Body. — This may be described as that
part intervening between the angle and the
anterior extremity. We have stated that the
posterior end is more round than the anterior ;
the body, therefore, may be considered as of
a transition form, passing from the cylindrical
to the flat, blade-like, shape as it approaches
towards the sternum.

Curve. — The curve which the ribs follow
is very irregular, and therefore not easy to
describe. No doubt they are of the form
best adapted to admit of a great increase of
thoracic capacity at_the expense of a remark-
ably small movement. They appear to encom-
pass the thorax in a somewhat spiral manner
(see dark lines Jigs. 682 and 683.) ; to accom-
plish which they have three curves, one the
common general arch or bend of the bone ;
the others the twist of the edges near the
extremities termed the curve of torsion.

(A) Arch or general bend of the ribs. — This
is the most remarkable feature of a rib. What-
ever be the curve of the 1st rib, it may
be said that each inferior rib describes a
curve “one size” larger; so that one rib
can be laid close within the other, like hoops
of gradually increasing sizes. Two distinct
curves will then be seen. It will be ob-
served that the part extending between the
head and the angle describes a larger cir-
cle than the angle itself, which as the name im-
plies, is the most acute turn in the bone.
More anterior to this, the curve becomes
remarkably large ; which Haller has so ex-
pressively described as representing the tan-
gent to the posterior curve. In connexion
with the general curve of the rib should be
noticed two linear measurements, viz., the
chord and the versed sine. In Jig. 664. is given

Fig. 664.

T3 T> A

Second rib.

the 2nd rib ; the line a b is the chord, and
d c the versed sine, or a line extending from
the chord to the most prominent part of the
bend of the bone. The general curve regulates
the length of the versed sine.

This curve of the rib gives the sides of the
chest a power of enlarging, — a lateral mobility,
— according to the length of the versed sine,
and quite distinct from the antero-posterior
enlargement, which is according to the length
of the chord. The ribs do not increase the
lateral dimensions of the thorax by abduction,
but solely by their rotation upon the line a b
(B) Curves of torsion of the ribs. — If we take

thorax.

1027

the 7th rib and place it on a table it will be
observed that the extremities cannot simul-
taneously rest upon one plane, because it is
twisted upon itself. This is due to what is
called the curve of torsion. The rib is twisted
at each end ; hence a posterior and an ante-
rior torsion. The posterior torsion is most
conspicuous, and is therefore more commonly
noticed.

(a) Posterior torsion. — This torsion is
marked at the angle of the rib (h,fig. 663.),
particularly upon the convex surface, by an
oblique line or a series of faint lines directed
from above downwards and forwards. Like
other features of the ribs, it passes through
gradations, being scarcely perceptible in
the 2nd rib, more so in the 3rd, and in-
creasing to the maximum in the 8th, in the
9th and 10th it quickly decreases, until it is
lost in the 11th and 12th. The greater the
torsion the more distinct is the angle ; where
the angle is rudimentary the torsion is imper-
ceptible, as in the 11th and 12th ribs.

The degrees of this torsion as it passes
through the ribs are most distinctly seen by
having the ribs separate, and placing them on
a flat surface with their superior edge upper-
most, arranging them so that they do not quite
touch each other, when the heads of the dif-
ferent ribs will stand up at different heights
from the table, forming a somewhat regular
wave. This is solely produced by this posterior
torsion.

(b) Anterior torsion. — Rear the anterior
extremity, on the convex surface, in well-
developed ribs, we observe an oblique line
analogous to that at the angle of the rib, but
much less distinctly marked. This line may
be considered as forming the anterior angle
and corresponding torsion of the ribs, which,
like the posterior, is intended for more favour-
able muscular insertions. Although the
anterior angle is comparatively feebly marked,
the anterior torsion of the ribs is as well
defined as the posterior torsion. It will
be seen in fig. 667, that while the posterior
extremity of the rib curls upwards, the an-
terior extremity curls downwards. In like
manner as we notice the posterior torsion
by placing the separate ribs on a table,
so may the anterior torsion be as strikingly
seen, taking care to place the ribs upon their
superior edge so that the sharp inferior edge
is turned upwards. The anterior ends will
be seen to stand up in different degrees from
the table according to their torsion, commenc-
ing with the 3rd or 4th and terminating with
the 10th rib.

Articulations of the ribs. — The ribs are
articulated behind with the dorsal vertebrae,
and in front with the sternum through the
medium of the costal cartilages. This has
already been noticed under Extremities of
the ribs.

Position of the ribs. — The ribs are arranged
more or less obliquely, — about midway
between the perpendicular and horizontal
(. figs. 662. and 683.) ; — and they somewhat

diverge from each other as they approach the
sternum. (figs. 662. 680. and 681.) Not one
of them is horizontal, though commonly re-
presented as if they were. Their position is
given in fig. 662. This is important to remem-
ber, because we shall see that costal breathing
altogether depends upon their obliquity.

Structure. — The compact and spongy sub-
stances are so distributed throughout the
whole length of the ribs that they possess
a certain degree of flexibility, with great
power of resistance. In joung subjects the
compact substance is in excess ; in the aged,
and in certain diseases, the opposite is the
case ; hence the extreme fragility of these
bones, which are then broken by the least
effort.

Development. — The ribs are amongst the
earliest developed bones, ossification com-
mencing in them even somewhat before it
has made its appearance in the vertebra.
The deposition of osseous matter extends
rapidly throughout them. Each rib (with
exceptions to be noticed) is formed from
one principal piece ; and two epiphyses. Of
these two epiphyses, one forms the head of
the rib, and the other the tubercle : their
ossification commences between the sixteenth
and twentieth years of age ; and they are united
to the rest of the bone a few years after, —
about the twenty-fifth year.

II. Special characters of different ribs. — The
differential characters of the ribs, when mi-
nutely examined, are well marked ; for, strictly
speaking, no two ribs on the same side are of
the same shape and dimensions. Although
the difference is very small between two con-
tiguous ribs, as, for instance, between the cen-
tral ribs, i. e. between the 6th, 7th, and 8th,
yet it is very conspicuous between those of
the top compared with those of the bottom of
the thorax. Whatever be the peculiarity under
examination, we find it most developed in
the 6th or 7th rib ; and below this it
becomes less and less marked, until, in the
12th rib, it appears rudimentary. In fact, the
12th rib may be considered little more than a
prolonged transverse process ; but not so
with the 1st rib, which possesses all the marks
and uses necessary to the character of a rib.

The ribs differ in their length, and in their
chord and versed-sine measurements, and
consequently in the area of thorax which
they encompass. The thoracic dimensions
vary considerably in different men and in the
two sexes; yet the relative measurements and
weight of the ribs will be found useful to
our comprehending more perfectly the res-
piratory movements.

These relative measurememts are from a
well-formed male thorax. The area-measure-
ment is calculated from an internal cast of
the thorax, cut up slice by slice through
each intercostal space. These slices were
traced upon paper and measured, giving the
absolute area of thoracic cavity encompassed
by each pair of ribs, their cartilages, and the
sternum. (S eeflg. 668.)

3 u 2

1028

THORAX.

Table A. — Relative Lengths and Weight of, and
Area of Thoracic Space encompassed by, the
respective Ribs, including the Space made up
by the Sternum and Costal Cartilages.

Rib.

Absolute

Length.

Chord

Length.

Versed

Sine

Area
Sq. In.

Weight,

Grains.

i

5-25

2-00

1-75

10-

98

2

9-00

3-75

3-00

27-

134

3

11-00

5-10

3-40

40-

181

4

12-25

6-00

3-50

51-

255

5

12-50

6-90

3-50

57-

308

6

12-60

710

3-50

63-

317

7

12-25

7-50

3-30

58"5

391

8

12-10

7-90

3-25

43-

363

9

11-50

7-75

3-10

27-

280

10

10-50

7-00

2-90

20-

216

11

8-25

5-90

2-25

10-

145

12

4-50

3-75

1-00

7-5

60

Fig. G65. represents the above table by
curves. The perpendicular lines represent
the ribs ; and the curves the characters re-
ferred to. By a general view it will be seen
that all the lines curve upwards, and are at
their highest at about from the 5th to the 9th
rib. We shall not treat of particular ribs, but
of certain characteristics as they run through
the ribs. A knowledge of their shape is ne-
cessary to comprehending the respiratory
movements in diagnosing thoracic disease.

1. Length. — The length of a rib may be
taken in three ways, — its absolute length,
chord length, and versed-sine length.

(a) Absolute length . — In the length from the
anterior to the posterior extremity, (a c b,

fig. 664.) the 12th rib is the shortest. The
1 1th rib is nearly double the length of the 12th
rib ; likewise the 2nd rib is nearly double the
length of the 1st rib ; therefore the 1st and
2nd, and the 11th and 12th differ more re-
markably in their length than do any of the
other ribs. The length (curve a, fig. G65.)
suddenly increases up to the 4th rib ; and
then the difference is trifling to the 8th rib ;
after this the shortening is as rapid as in the
four superior ribs.

(b) Chord length. — The dotted line b,fig.
G65, represents this measurement. This length
from tip to tip (a b, fig. GG4.) of the rib is
the chief modifier of the different apparent
mobility of particular ribs. If we allow the
range of costal movement to be the same in
each rib, while each succeeding rib increases
in its chord length, the apparent mobility in
different ribs will increase exactly as their
chord measurement increases. If a rib be three
inches long, and if its free extremity by a
given movement passes through one inch of
space, the free extremity of a rib six inches
long will, with the same absolute movement,
pass through two inches. The chord length is
an important element in modifying thoracic
capacity. It is in this measurement that the
1st rib is the shortest and nearly one half the
length of the 2nd rib, — as 2- is to 3‘75.
(Table A.)

The chord length (line b, fig. 665, com-
pare with line a,) increases and decreases less
abruptly than that of the absolute length.

If we were to admit that all the ribs at
their fulcra possessed the same extent of mo-
tion, still the antero-posterior length of the
thorax would be unequally increased, and that
exactly in relation to the chord measurement ;

Fig. G65.

and hence the 7th, 8th, 9th, and 10th ribs advances most, somewhat representing the
would advance most. It is a fact that in deep curve line b,fig. G65.

inspiration the lower part of the sternum (c) Versed Sine Length (d c, fig. 664.) —

THORAX.

1029

As the chord length is to the antero-posterior
movement, so is this measurement to the
lateral movement of the thorax. This is the
most uniform measurement in the ribs. If the
1st rib be D75, the 2nd rib is to that as 3;
and from this rib to the 9th rib, the versed
sine never exceeds 3'5 ; hence the curve c.
Jig. 665. is more horizontal than any of the
other curves. So likewise it will be found
that the lateral enlargement of the thorax in
deep breathing is more uniform than the
antero-posterior enlargement. (See dotted
line, Jigs. 711, 712. compared with dotted line,
Jigs. 713, 714.) The space gained by the ribs
rotating must be strictly in relation to the
length between the deepest part of the arch
and the chord line, (d c,Jig. 664.) This mea-
surement is greatest relatively in the 2nd rib,
and absolutely smallest in the 12th rib, the
curve here being very small.

The versed sine of the ribs corresponds
with the great curve: if a rib were not curved
at all, there would be no versed sine. The
versed sine does not increase after the 4th
rib; and the curvature of the first four ribs
forms smaller circles than the rest. The 5th
and 6th ribs, although rapidly increasing in
absolute length (see Table A.), yet present
nearly the same versed sine; and while the
chord line increases up to the 9th rib, from
the 6th to the 9th the versed sine decreases,
showing that the circle or arch of the rib
becomes larger as we descend, until the
12th rib, which describes the greatest curve
and the shortest versed sine.

In fact there is little difference in the versed
sine length from the 3rd to the 10th rib, as
described by the double line c,Jig. 665. This
difference of arching of the ribs constitutes the
conical form of the thorax, the smaller circles
being at the apex, and the larger at the base
of the cavity.

(2) Weight. — The ribs increase not only in
their various measurements but also in their
weight up to the 7th or 8th where they attain
their maximum development. The faint con-
tinuous curve, e. Jig. 665. is the line of the
relative weight.

(3) Torsion of the ribs {special characters ).
— We have already mentioned that the
ribs have two torsions, an anterior and a pos-
rerior. No rib is entirely free from this twist.
It is incorrect to believe that the 1st rib is
without any torsion, and therefore that the
whole rib in its length can touch the same
plane. In fact the 1st rib may in one sense
be looked upon as the most twisted of all
the set, inasmuch as the flat sides which are
internal and external in other ribs are in this
rib inferior and superior.

Like other features, the degree of torsion
in the different ribs is progressive towards a
maximum, and then towards a minimum. The
2nd, 11th, and 12th ribs are most devoid of
torsion. In the last two ribs the torsion ap-
pears less than it really is, because of their
shortness and the large circle which they de-
scribe.

The two torsions in each rib are always in

contrary directions, except in the 2nd rib,
where they are both downwards, but the tor-
sion is here very slight. In the 1st rib, as in
the ten inferior ribs, they are in contrary di-
rections to each other, so that its two ends
cannot touch the same plane at the same time ;
but its anterior and posterior torsions are
respectively contrary to those of the ten in-
ferior ribs ; its posterior torsion being, like
that of the second rib, downwards, and its an-
terior upwards.

The relative torsion of the ribs maybe ex-
pressed by giving the respective elevations of
each extremity from the plane upon which
they rest. Thus the posterior torsion is seen
when the rib rests upon its inferior edge, and
the anterior torsion when it rests upon its su-
perior edge. In this way the following table
is calculated.

Table B. — Torsions of the Ribs.

Ribs.

Posterior End
Torsion Upwards.

Anterior End
Torsion Downwards.

i

6-0*

5‘Of

2

2-5*

3-0

a

3-0

3-0

4

12*5

4-25

5

13-0

12-0

6

12-25

21-5

7

18-00

29-5

8

21-25

28-0

9

21-25

25-0

10

9-50

17-5

1 1

1-50

5-5

12

2-00

4-5

If the posterior twist of the ribs upwards be
expressed conjointly as 114, the anterior tor-
sion downwards is 153 ; therefore the anterior
torsion is greater than the posterior. The
torsions in the 2nd, 3rd, 11th, and 12th
are the least; and they are the greatest in the
7th, 8th, and 9th ribs. Moreover as the tor-
sion increases at one extremity of the rib, for
the most part it increases at the other like-
wise.

The ribs of some persons are much less
twisted than those of others. This is parti-
cularly the case in young subjects before the
age of puberty. In infants the torsions are
imperceptible ; therefore they increase as we
advance to maturity. These torsions afford
more favourable traction for the muscles.
Where the respiratory movement is most ap-
parent, as from the 4th to the 9th rib, the
torsion is highest.

t The posterior torsion gives the ribs, when
placed in their natural position, a very oblique
direction with reference to the spine. This is
very important to remember; for the more
oblique, the more favourable are they for mo-
bility or for increasing the thoracic cavity.
For the same reason the anterior torsion, being
in a contrary direction to the posterior, increases
still more the obliquity of the rib with refer-
* Downwards. j- Upwards.

3 u 3

1030 THORAX.

ence to the spine. But the relation of these
torsions to the spine are different : the pos-
terior torsion is relative to the spine late-
rally, while the anterior torsion relates to
the spine more in the antero-posterior direc-
tion : they both conspire to increase the obli-
quity of the rib in one given direction, — from
above downwards.

The torsion of the 1st rib, we have noticed,
is directed in a contrary direction to that of
other ribs ; and we have observed that the
presence of torsion in general favours
muscular traction : but the 1st rib is an
exception to this ; here the torsion exists
only between its two chief articulating pro-
cesses, — the head and the tubercle : in the
other ribs the torsion is between the tu-
bercle and the body of the bone. The pos-
terior torsion of the 1st rib appears to be
merely destined to afford the head a more
complete attachment to the body of the one
vertebra (the 1st dorsal) to which that rib
is fixed. A posterior torsion, in this short
rib, is not needed for muscular traction, be-
cause here the scaleni are placed in the most
favourable position — nearly at an angle of
90° with reference to the body of the bone
in question, while their other insertion into
the cervical vertebras facilitates the most ex-
tensive and favourable means for its mobility,
independently of any favouring twist in the
lib for that purpose.

(4) Surfaces ( special differences). — The
thorax being conical, or somewhat barrel-
shaped, it follows that the surfaces of
the ribs, like the hoops of a very spherical
barrel, must gradually change their direc-
tion ; thus the surfaces of the 1st rib are
nearly superior and inferior, this bone forming
the lid to the thorax, while the surfaces of the
6th or 7th rib are external and internal, and as
we proceed downwards to the 10th, 11th, and
12th ribs, the surfaces are again slightly
tending towards a superior and inferior po-
sition, so that the internal surfaces of the 1st
and 12th ribs are directed somewhat towards
each other. The body of the rib, or that
part which covers the lung laterally, and the
anterior and posterior extremities, have also
their surfaces inclined in different directions.
Thus, take a perfect rib, say the 7th, laterally
to the thorax the two surfaces are internal
and external, while at the anterior end they
are directed — external surface, forwards and
downwards ; internal surface, upwards and
backwards ; — at the posterior end, — external
surface, upwards and backwards ; internal
surface, downwards and forwards. This is
produced b}' their respective torsions. In
some of the lower animals the ribs overlap
each other like the tiles of a house; this
sometimes threatens in man, particularly in
diseases of the spine (y?g. 666.), when they
closely approach each other.

(5) Specific differences of the extremities of
the ribs. — The greatest difference is in the
posterior end of the rib. The anterior pre-
senting little difference.

(a) Anterior extremity. — These are all hol-

lowed out for their cartilage. As the ribs
become more perfectly developed, for in-
stance, the 5th, 6th, 7th, and 8th, the an-
terior extremity is broader, but not more
deeply hollowed out than some of the other
ribs, which are less perfectly developed, as in
the 2nd and 3rd, or 11th ribs. This extremity
is most pointed in the 12th rib.

Fig. 666.

(b) Posterior extremity. — The posterior ex-
tremity of the rib is more complicated, and
has certain named parts, as the head, neck,
tubercle, and angle, all of which become modi-
fied as we pass from above downwards. Their
differences may briefly be noticed.

1st Of the head. — On the head of the rib,
articulating with the vertebrae, a surface or
facet is formed. The 1st, the 11th, and the
12th ribs articulate each with the body of one
vertebra, and therefore they have one arti-
culating surface. All the rest articulate each
with the bodies of two vertebrae, and they
consequently have two such articulating sur-
faces as already described. The head of the
1st rib is relatively larger than that of the
others. For the most part, as the ribs in-
crease in size, the head likewise increases,
so that in the best developed rib the head and
its surfaces are most perfectly formed, dege-
nerating again to the 12th rib.

2nd Of the neck. — The neck being that
part of the rib between the articulation of
the rib with the bodies of the vertebra, and
that with the transverse process, and these
points differing but little in their distance
from each other in the dorsal vertebra?, it
follows that the absolute length of the neck
of the different ribs is nearly the same. The
necks of the ribs differ in their thickness, ac-
cordingly as their respective ribs increase or
diminish in size ; therefore, in the middle

THORAX. 1031

set of ribs, the necks are the thickest and
strongest. In the 11th and 12th ribs, the neck,
according to our definition, does not exist.

3 rd Of the tubercle. — As the tubercle ar-
ticulates with transverse processes, those ribs
which have no such articulation have no tu-
bercle; this is the case in the 11th and 12th
ribs. The tubercles are most prominent in the
superior ribs, gradually degenerating, or be-
coming less apparent, down to the 10th,
where it is almost rudimentary.

\lli Of the angle. — In strict anatomical lan-
guage, the 1st rib has no angle, but the tu-
bercle is very prominent, and gives the bone a
very angular appearance, likewise in the 2nd,
3rd, 11th, and 12th ribs the angle is almost
imperceptible, whereas it is well marked in
the 4th, 5th, Oth, 7th, 8th and 9th ribs.

(6) Groove ( specific differences ). — The
groove is not perceptible in the 1st, 11th,
and 12th ribs, but distinct in all the inter-
vening ones.

The 1st rib has two depressions separated
by a tuberosity. The anterior corresponds to
the subclavian vein, and the posterior to the
artery of the same name.

Costal cartilages. — The flexibility and elas-
ticity of the ribs is partly owing to their struc-
ture, but more especially to the cartilages
which prolong them in front. (Jigs. 661, 662.)
There are twelve costal cartilages distinguished
numerically, as 1st, 2nd, 3rd, &c. ; they are
separated from each other by intervals which
are very considerable at the upper part of
the thorax, but gradually diminish as we
proceed downwards. It is not very un-
common to meet with thirteen cartilages on
one side, and at other times there are only
eleven. Sometimes two cartilages are joined,
and so aticulate with the sides of the ster-
num ; when there are thirteen cartilages,
the supernumerary one generally exists be-
tween the 3rd and 4th ribs ; it is thin, and as
it were rudimentary ; it does not form the
continuation of any rib, and terminates insen-
sibly in the muscles. The cartilages from the
1st to the 7th articulate immediately with the
sternum ; and hence the name of sternal
given to ribs with which they are connected.
Of the other five cartilages, the last two have
no connection with that preceding them ; and
from this circumstance, the name floating has
been given to the last two ribs.

General characters of the costal cartilages.
— All the costal cartilages are flattened like
the ribs, and precisely resemble in breadth
and thickness the bones to which they are
attached. The external end is received into
a cavity hollowed out in the anterior extre-
mity of the lib; their internal or sternal ex-
tremity, which is much narrower than the
external, is angular and articulates with the
corresponding angular surfaces of the ster-
num. ( fig. 661.) Their anterior or cutaneous
surfaces are slightly convex, and covered by
the muscles of the anterior region of the
trunk, to many of which they give attach-
ment. Their posterior or mediastinal surfaces
are slightly concave. Their superior and

inferior edges bound the intercostal spaces, and
give attachment to the intercostal muscles.
“ They are,” says Cruveilhier, “ altogether
distinct from articular cartilages, and have a
peculiar tendency to ossify, this process
taking place partly on the surface, and partly
from within outwards.”

Differential characters of the costal carti-
lages.— The costal cartilages, like the ribs,
increase in length, from the 1st to the 7th,
and sometimes the 8th, which in this case
articulates with the sternum ; from this they
diminish in length to the 12th rib When
we recollect the conical shape of the thorax
this difference is to be accounted for, and
moreover, the osseous parts of the upper ribs
terminate anteriorly in a line directed ob-
liquely from above downwards and outwards.
The sternum is only about half the length of
the lateral pectoral space, so that only the
first four or five cartilages could join this
bone, did not the others turn upwards to
reach its sides (fig. 661 .), by joining the lower
edge of the immediately superior cartilage.
The first three cartilages alone, therefore, fol-
low the same direction as the long rib to
which they articulate.

The first cartilage differs from all the others
by its shortness, its thickness, and breadth,
and its tendency to ossify ; it is often, but
not always, continuous with the sternum.

The 2nd and 3rd costal cartilages cannot
be distinguished from each other, but they
differ from the rest in being joined to the
sternum at right angles, in not being bent, and
in being as broad at their sternal as at their
costal extremities..

The 4th cartilage becomes bent upwards,
after having followed the direction of the rib
for a little way. (fig. 661. <?.) The length and
the curvature of the cartilages of the 5th,
6th, and 7th ribs progressively increase, and
across their intercartilaginous spaces they fre-
quently touch each other. Their inner ends
become successively narrowed so as to cor-
respond with the diminishing cavities on the
edges of the sternum. The borders of the
5th, 6th, 7th, and 8th costal cartilages ar-
ticulate together, and present for this pur-
pose articular facets supported by emi-
nences. The cartilages of the 8th, 9th, and
10th ribs gradually diminish in length. Ex-
ternally they have the same breadth as the
rib, and decrease as they pass inwards, so as
to terminate by a pointed extremity, which is
applied to the lower edge of the cartilage
above. The cartilages of the lith and 12th
ribs are extremely short, particularly that of
the 12th, which is only a mere tip to the
bone, and seldom exceeds four or five lines
in length ; their free extremity loses itself, so
to speak, in the substance of the abdominal
parietes ; so that they are altogether uncon-
nected with the other cartilages.

Liability of the costal cartilages to ossify. —
The 1st cartilage usually becomes more or
less ossified in adult age, and is often anchy-
losed to the sternum. After the middle period
of life, osseous matter is likewise deposited
3 u 4

1032

THORAX.

to a greater or less extent in the other car-
tilages, and it is apparent in those of the
false, later than in those of the true ribs.

These observations apply to the male body ;
for in the female the process of ossification
does not affect the cartilages until old age has
arrived, and it always affects a comparatively
small number of cartilages, even if it should
happen to extend beyond the 1st, which com-
monly is not the case.

Of the ligaments of the ribs. — The liga-
ments of the ribs may be divided into three
sets, those which connect them, 1st, with the
bodies of the vertebras; 2ndly, with the trans-
verse processes, and 3rdly, with the sternum.
The rib is connected with the bodies of two
vertebrae (excepting those specified above)
forming with each a joint lined with synovial
membrane, and held in place by the following
ligaments : —

1st. With the bodies of the vertebree. — Costo-
vertebral ligaments , ( lig . capitulorum costarum).
— These consist, 1st, of an anterior ligament
which connects the head of each rib with the
sides of the bodies of the vertebras. Its fibres,
flat and radiated, are divided into three bundles,
of which the middle one passes horizontallyifor-
wards upon the corresponding inter-vertebral
cartilage, whilst the superior ascends to the
body of the vertebra above it, and the inferior
descends to that below. From the divergence
of its fibres this is usually called the stellate
ligament. 2ndly, of an inter- articular ligament,
a thin and short band of fibres which passes
transversely from the ridge separating the two
articular surfaces on the head of the rib, to
the inter-vertebral substance, and divides the
articulation into two parts, each lined hy a
separate synovial membrane. This ligament
does not exist in the articulation of the 1st,
11th, and 12th ribs, and in consequence there
is in them but one synovial membrane.

2 ndly. With the transverse processes of turn
vertebree. — The rib at its tubercle forms a
joint, lined by synovial membrane, with one
transverse process ; and to another (being
separated from it by a considerable interval),
it is connected by ligamentous structure of
some length. The costo-transverse ligaments
connect the tubercle and neck of the rib with
the transverse processes of the vertebrae ; they
are named from their position, posterior, mid-
dle, and anterior.

a. The posterior costo-transverse ligament. —
(tig. transversum externum costarum , Weitbr.)
consists of a very short, thick fasciculus of
fibres, which passes from the posterior surface
of the summit of the transverse process, to
the rough, inarticular part of the tubercle of
the rib. Those of the superior rib ascend,
those of the inferior rib somewhat descend.

b. The middle, or interosseous costo-trans-
verse ligament — consists of a series of very
short parallel fibres, which unite the neck of
the rib to the anterio surface of the con-
tiguous transverse process. These fibres are
best seen by removing horizontally a portion
of the rib and transverse process, and for-
cibly drawing one from the other.

c. The anterior, or long costo-transverse
ligament — (lig. transversum internum seu cer-
vicis costce internum, Weitbr.), is usually di-
vided into two fasciculi of fibres nearly op-
posite to one another, and on the same plane.
They pass from the neck of the rib obliquely
upwards and outwards to the lower, margin
of the transverse process next above it.

Characters peculiar to certain costo-vertebral
articulations. — The articulations of the 1st,
11th, and 12th ribs alone present peculiarities.

a. Costo-vertebral articulation of the \st rib.
— The rounded head of the 1st rib is received
into a cavity on the side of the body of the
1st dorsal vertebra, the articulation is therefore
a species of enarthrosis ; there is neither a
costo-vertebral interosseous ligament, nor a
superior costo-transverse ligament ; the syno-
vial membrane is much looser than in the cor-
responding articulations of other ribs.

b. Costo-vertebral articulation of the 1 \th
and 12 th ribs. — These present the same cha-
racters as the preceding, in this respect, that
the anterior cavity for the head of the bone is
situated upon a single vertebra. The head of
the rib, however, is Hattened, or very slightly
convex. There is no interosseous costo-
vertebral ligament. The superior costo-trans-
verse ligament is much broader and stronger
than in the other articulations. As the 11th
and 12th ribs have no tubercles, and the
transverse processes of the corresponding
vertebra; are but little developed, it follows
that there is no costo-transverse articulation :
but yet there is a costo-transverse interos-
seous ligament. All these ligaments are much
more loose than in the other articulations.

Srdlij. With the sternum ( Chondro-sternal
articulation). — The costo-sternal articulation
is between the angular extremities of the car-
tilages of the ribs and the corresponding
fossa: in the margins of the sternum ; these ar-
ticulations are covered and supported by two
sets of ligaments. 1st, by an anterior set of
ligamentous fibres, thin, scattered, and radi-
ated ( ligamenta mdiatim disjecta Weitbr.),

passing from the extremity of the cartilage
to the anterior surface of the sternum,
where they interlace with those of the op-
posite side, and are blended with the apo-
neurosis of the pectoralis major muscle.
2ndly, by a posterior set of fibres similarly
disposed, but not so thick or numerous, con-
necting the thoracic surfaces of the same
parts ; together with some ligamentous fibres
placed above, and others below the joint.

A synovial membrane is interposed be-
tween the ends of each true rib, and the
sternum. These membranes can he demon-
strated by slicing off a little of the anterior
surface of the sternum and cartilages. Cruveil-
hier doubts the existence of such synovial
membranes ; we are inclined to differ from him
in this respect.

Characters peculiar to chondro- or costo-
sternal articulations. — The 1st, 2nd, 6th, and
7th chondro-sternal articulations present the
following peculiarities : —

1st, The cartilage of the 1st rib is some-

THORAX. 1033

times continuous with the sternum, and is
sometimes articulated like the cartilages of
the other ribs. Cruveilhier found in one sub-
ject the 1st rib excessively moveable, because
its cartilage, instead of being continuous with
the sternum, had its upper edge applied to the
side of that bone to which it was united by
ligaments, and was ultimately articulated by
a narrow extremity immediately above the
2nd rib.

2ndly. The second cartilage is much more
angular at its inner extremity than any of the
others : it is received into the retreating angle
formed by the union of the first two pieces of
the sternum. Sometimes there is an inter-
osseous ligament in this joint, running from
the angle of the cartilage to the bottom of the
cavity, and there are then two synovial cap-
sules; in other cases there is only one, but it
is always more marked than in the other
joints.

The articulations of the 6th and 7th carti-
lages, besides the anterior ligaments, have also
a chondro- or costo-xiphoid ligament, more or
less strong, which crosses with the ligament of
the opposite side in front of the ensiform car-
tilage, and the lower end of the sternum.
Sometimes this ligament only exists for the
7th cartilage ; it is intended not only to
strengthen the chondro-sternal articulation,
but also to maintain the xiphoid appendix in
its place.

Connection of the ribs with their cartilages.
— The cartilages are almost immoveably
united to the ribs, being received into rounded
depressions on the ends of the ribs, and their
union is maintained only by periosteum, which
may be considered to represent their liga-
ments.

Articulations of the costal cartilages one with
tJie other. — Some of the costal cartilages
articulate with each other by their edges.

The 1st, 2nd, 3rd, 4th, and 5th costal car-
tilages do not articulate together, unless the
aponeurotic lamellae, sometimes very strong,
which form the continuation of the external
intercostal muscles, and occupy the whole
length of the cartilages, be considered as
uniting media.

The Gth, 7th, and 8th cartilages, frequently
the 5th, and sometimes the 9th, present true
articulations with one another. Cartilaginous
processes arise from the neighbouring edges
and come in contact with each other : there
are sometimes two articular faces between the
Gth and 7th cartilages. The means of union
are some vertical fibres united in bundles, so
as to form two ligaments, the one anterior
and thicker, the other posterior and thinner.
The edges of the articulating surfaces, from
the Gth to the 8th or 9th, are lined by s}'-
novial membrane. The 7th, 8th, and 10th
cartilages have not always articular surfaces,
but are simply united by vertical ligaments.

Ligaments of the sternum ( Membranae sterni,
Weitbr.) — The pieces of the sternum are
connected by a layer of fibro-eartilage,
placed between their contiguous borders ; anil,
on the anterior and posterior surfaces, liga-

mentous fibres maybe observed running longi-
tudinally, which serve to strengthen their con-
nection. They are sometimes called the
anterior and posterior sternal ligaments. The
longitudinal fibres are mixed with those ra-
diating from the costal cartilages, especially
in front of the sternum, where likewise they
blend with the aponeurosis of the pectoral
muscles. The anterior portion has thus most
of the accessory fibres, and is rough and irre-
gular ; the posterior one is smooth and pearly
in its aspect.

The muscles of the thorax will be more con-
veniently noticed hereafter.

Of the Thorax in general. — The ster-
num, the ribs and their cartilages, together
with the dorsal vertebra, are so united to-
gether as to compose the frame-work of the
thorax, (fg. 662.) Their arrangement is such
as collectively to admit of great mobility, and
at the same time to protect completely the or-
gans of respiration and the heart. How well
adapted this mechanism is for protecting those
vital organs is well shown by the impunity
with which the prize-fighter receives for many
hours the trained blows of his antagonist.

Although the range of motion between each
vertebra and the ribs attached to it, is very
limited, yet the whole frame-work of the
chest enjoys such mobility, that, by a deep
inspiration, its capacity is sometimes more
than doubled. This bony frame-work is by
no means destined solely to cover the respira-
tory organs, for it extends considerably down-
wards, composing part of the abdominal walls
within which lie the liver, spleen, kidneys,
stomach, duodenum, and part of the colon ;
hence the distinction between thoracic and
diaphragmatic ribs. In fact it will be found
that about one half only of the costal surface
is destined to compose the thorax. The shade
running transversely across the ribs in fig. 632.
marks the bottom of the thoracic cavity.

In each individual the thoracic cavity cor-
responds exactly with the volume of the heart
and lungs. But there is no relation between
the volume of the lungs and the vigour of the
constitution — nor between the size of the ca-
vity of the thorax and the amount of air which
can be respired, as will be hereafter shown.
There is likewise no relation between the vo-
lume of the thorax and that of the abdominal
cavity. No doubt the vigour of aeration in the
lungs is at all times exactly commensurate with
the vigour of the alimentary canal, so that the
one harmonises with the other; but this vigour
bears no relation to space or size. A small
thorax may in some individuals admit of
the inspiration of a greater volume of air
than a larger thorax in others. In fact it
may be commonly noticed that where there
is a large abdomen there is generally a
small thorax, and that the volume of air
which can be expelled at one effort from the
lungs of those who have a large abdomen,
is less than from those with a small abdomen.
The alimentary canal receives at once a given
quantity of food, and there it remains for an
indefinite time, the thorax large o>‘ small, it

1031

THORAX.

matters not which, aerates the blood from this
food by movements, quick or slow, long or
short ; therefore the respiratory movements
only, need be relative to the abdominal cavity,
in the same way as the volume of the blast
from a pair of bellows is more dependent on
their mobility than on their absolute size. The
above remarks are applicable to the thorax
of either male or female.

I. Boundaries of the thoracic cavity. — The
thoracic cavity, situated between the shoul-
ders and below the neck, extends but a
short way downwards, in the male about seven
inches, and in the female about eight inches,
below the clavicle, so that a horizontal line
drawn about an inch below the axilla, corres-
ponds (roughly) with its floor. The floor of
the chest, therefore, is much higher up in the
trunk of the body than is commonly supposed.
The thorax is bounded anteriorly by the
sternum and costal cartilages ; laterally by the
bodies of the ribs and the intercostal muscles ;
posteriorly by the vertebrae and angles of
the ribs, and interiorly by a thin tendinous
and fleshy floor — the diaphragm. The su-
rior aperture of the chest is about sixteen
inches in circumference, this is the smaller
end, and thence called the apex of the tho-
rax. It is bounded laterally by the two 1st
ribs, anteriorly by the upper edge of the
sternum and inter-articular ligament, and
posteriorly by the last cervical and first dorsal
vertebrae. The inferior aperture is about
thirty or thirty-one inches in circumference,
and forms the base of the chest. Anatomists
describe this part as bounded in front by
the cartilaginous extremity of the sternum
or xiphoid cartilage, and the cartilaginous
extremities of the last true and false ribs, and
more laterally by the 1 1th and 12th ribs, pos-
teriorly by the last dorsal and first lumbar
vertebrae. But as they assume to themseives
the privilege of giving a bone a surgical neck as
well as an anatomical one, so may we take a
similar liberty in describing the thorax for
medical purposes. In the examination of the
chest during life, too exclusive attention to
anatomical boundary has probably led to the
error, of regarding the chest as much deeper
than it really is, and thence to examining for
disease of the lung where really little or no lung
exists. A sharp instrument, piercing the chest
laterally, at the cartilaginous extremities of
the last true ribs, would most probably pene-
trate no lung, for the liver, spleen, stomach, &c.
are contained within these points. The
bottom of the chest is so moveable and so
much arched (See art. Diaphragm, fig. 3.),
that in the different stages of inspiration, the
lung assumes different positions This may be
demonstrated by percussing over the 5th rib
at its junction with its cartilage, first after a
deep expiration and then after a deep inspira-
tion ; in the latter the sound is “ clear,” in
the former it is strikingly “ dull.” Therefore,
instead of taking the insertion of the dia-
phragm as the bottom of the thorax, it will be
found more convenient for examining the
chest to take the top of the arch of this muscle

as the lower thoracic boundary, or the shaded
line crossing the ribs in fig. 4., for the medical
base. This may be described as corres-
ponding in front with the xiphoid cartilage ;
laterally to different osseous portions of the 7th,
8th, 9th, 10th, 11th, and sometimes the 12th
rib (fg. 682.), and posteriorly to the 8th and
9th dorsal vertebrae. This will [dace the
bottom of the thorax in a very different posi-
tion from what is generally supposed ; for, if
we express the distance from the 1st rib, to
the lowest point of the 10th rib as 13’5, that
from the 1st rib to the arch of the diaphragm
or medical boundary will be only 6-25, less
than one half the depth of the thorax as ana-
tomically described. The medical base of the
thorax forms a nearly horizontal plane, which
extends between the sternum and the bo-
dies of the 9th or 10th dorsal vertebrae, its
posterior being somewhat higher than its an-
terior. But on each side of the bodies of the
vertebrae there is a deep groove formed by the
angles of the ribs. In that part of this groove
which extends below the above-mentioned in-
clined plane, a wedge-shaped process of lung
is lodged, which varies in size in different sub-
jects, and consequently will be found to ter-
minate at different points in the dorsal re-
gion, as already noticed, sometimes hanging
down like a broad, thick flap, and at other
times forming only an insignificant process.

In examining the chest, it is of paramount
importance that the student should familiarly
know this medical floor of the thorax. The
sign laid down by the late Dr. Edwyn Har-
rison, for marking this boundary, we have
found strictly correct in every normal-shaped
thorax. Namely, take the xiphoid cartilage as
a point to start from, anti pass the flat hand
horizontally from thence to the side of the
chest, the index finger, when horizontal, will
distinguish a slight depression or sulcus at the
maximum lateral bulge of the thorax, then
from this point slide the hand slightly upwards
(perpendicularly), and it will pass over a
bulge, about enough to fill the palm of the
hand, into another sulcus, better defined than
the former one ; this groove corresponds with
the medical base of the thorax, and a probe
passed in here would graze the arch of the
diaphragm after passing through the moveable
inferior edges of the lungs. It is necessary that
the hand be kept perfectly horizontal, or it
will fall into an intercostal space, which does
not correspond with the groove in question.
With practice, the hand falls at once into the
upper sulcus, without first searching for the
lower one; indeed, latterly, Dr. Harrison
allowed that the lower sulcus might be absent,
and yet the upper one present.

This groove is higher upon the right side
than upon the left, corresponding to the height
of the liver.

By external observation, the medical base of
the thorax may be known by the slight rota-
tory motion made upon the diaphragm when
a person is walking. A kind of great ball
and socket-joint may be conceived to exist
between the abdomen and thorax, and the

THORAX.

1035

outer garments even exhibit a correspondence
to this base of the thorax.

II. Contents of the thorax.- — -Not only does
the thorax contain organs proper to itself,
but it lodges and protects others passing
to the abdomen ; thus, the food we eat passes
through the thorax to enter the stomach,
while the eighth nerve both supplies the lungs
and then passes onwards to the stomach.
Like other cavities, the thorax is lined with a
serous membrane ( pleura costa/is), which like-
wise invests the lungs ( -pleura pulinonalis )
(See Pleura). The heart and its blood-
vessels, the trachea, and the lungs, almost
completely fill the thorax. The remaining
organs, viz., the origin of the sterno-hyoid
and -thyroid muscles, remains of the thymus
gland, lymphatic glands, mammary vessels,
triangulares sterni muscles, the phrenic, the
eighth pair, and the splanchnic nerves, the
oesophagus, thoracic duct, vena azygos, and
venae cavae, occupy very little space.

Thus the thorax is completely filled. The
older anatomists, however, even as late asBenj.
Headley’s time, considered that there was a
considerable space containing air, between the
lungs and the walls of the thorax. Now, we
know that any considerable accumulation of
air in this situation would be destructive sto
the respiratory function.

III. Shape of the thorax. — The shape of the
thorax is subject to many varieties which
may be conveniently studied under the fol-
lowing headings :

External thorax. — The thorax in the
perfect subject is somewhat conical, broader
above than it is below ; but when deprived
of the upper extremities and their appen-
dages, the contrary obtains, for it is nar-
rower above than it is below (see figs. 662.
and 630. et seq.). Therefore the notion we
commonly connect with broad shoulders or
broad back, has but a feeble relation with
the absolute breadth of the thorax. In
fact the diameter of the neck corresponds more
correctly with the diameter of the upper
part or true apex of the thorax. Freeman the
American giant measured 26 inches from tip to
tip of his shoulders, while the diameter at the
lower part of his neck, in the same direction,
was only 6 inches. In women the mammae
materially add to the dimensions of the chest
towards the apex. We have found the
measure of a female round the thorax over
the mammae 4* 5\ inches, while the root of
the neck was 15 inches. Allowing two inches
for muscle, &c., the true thoracic apex would
not exceed 13 inches, whilst 45^ inches was
the apparent circumference of the thorax.
The true apex of the thorax is loaded with
large muscles, sometimes a vast quantity
of fat, the upper extremities, and in the
female with large mammas besides. The true
baseof the chest is comparatively little covered,
particularly below the axilla, where the serrati
are seen. This is the weakest and thinnest
part of the thorax, but it is well protected by
the arms.

(a ) The anterior or sternal region of the tho-

rax.— In a well-developed thorax the sternum
appears to lie in a fossa formed by the pecto-
rales and mammae. This region assumes more
or less of the perpendicular, according to the
carriage of the person ; a perpendicular drawn
to the external plane of the sternum would,
however, be directed upwards. Laterally to
this, the costal cartilages articulate with the
sternum ; and, still more laterally, the ribs and
their cartilages unite, forming an oblique ridge
from above downwards. (See fgs. 680. and
681. the line on each side of the sternum.)
Still more externally, and parallel to this,
may be noticed the projections formed by the
anterior angles of the ribs, which bound the
anterior region.

(b) The posterior or vertebral region. — In the
well-developed thorax the spines of the dorsal
vertebrae lie in a deep groove formed by the
great mass of the erector spinas on either
side. These masses extend outwards to about
the posterior angles of the ribs, which are
nearly in a plane with the spinous processes
of the vertebrae, and may be easily distin-
guished, bounding the posterior region.

(c) The lateral or costal region is composed
of the bodies of the ribs and the intercostal
spaces. Much difference has prevailed
amongst writers upon various points con-
nected with the ribs, and the spaces be-
tween the ribs. Probably this may have
arisen from their having made their observa-
tions upon the dead subject, wherein the
ribs have collapsed to their minimum, or the
thorax of a thin subject with the ribs expanded
by, perhaps, 200 cubic inches of air, or the ribs
when artificially articulated in the clean skele-
ton, wherein they are generally arranged too
wide apart and too horizontal.

In the collapsed state of the ribs, i. e. after
the most ample expiration by death, we no-
tice

1st, That the intercostal spaces are not of a
uniform width from the vertebrae to the ster-
num. They are most narrow behind, and be-
come wider as they approach the sternum
{fig. 680.). The 1st, 2d, and 3rd spaces upon
tile whole are broader than the five next in-
ferior, and the 10th and 11th spaces are the
widest (fig. 682.).

2dly, Their length differs with the length
of the ribs ; thus the two first and two last
spaces are the shortest.

3dly, The position of the intercostal spaces
is very oblique (fig. 684.), roughly speaking,
about mid-way between the horizontal and
the perpendicular.

4thly, They are moveable, and in the dif-
ferent stages of respiration they can assume
different positions and different perpendicular
widths.

It has been found necessary for the con-
venience of auscultation, to subdivide the
thorax more minutely. The subdivision pro-
posed by Laennec has been generally adopted,
although some of the terms, like those of the
respiratory sounds, have been modified by
writers of later date.

The anterior and lateral superior division,

J036

THORAX.

Table C. — Thoracic Regions.

REGION.

Anterior :

Clavicular (subclavian of Laennec) -
Infra-clavian (anterior superior of Laennec)
Mammary ------

Infra-mammary (sub-mammary of Laennec)

Sternal — superior, middle, inferior -
Lateral:

Axillary ------

lnfra-axillary (lateral of Laennec)
Inferior-lateral -

Acromial ------

Posterior :

Scapular, upper and lower
Interscapular ------

Infra -scapular (inferior dorsal of Laennec)

SITUATION.

Portion covered by the clavicle.

Between the clavicle and 4th rib inclusive.
Between the 4th and 8th ribs.

From the 8th rib to the cartilaginous border
of false ribs.

Over the respective parts of the sternum.

All the axilla to the 4th rib inclusive.

Between the 4th and 8th ribs at the side.

Below the 8th to the false ribs inclusive.

Between the clavicle, neck of humerus, and
along the upper margin of scapula, includ-
ing the root of the neck.

Supra-spinous fossa and infra-spinous fossa.

Between the inner margin of scapulae.

Below inferior angle of scapula and border of
serrati to the level of I2th vertebra.

give the clearest sound upon percussion, and
the back the least clear. Below Harrison’s
line, there is little or no evidence, from
percussion, of the presence of lung, except in
deep inspiration, and then the sound on per-
cussion is mixed with other sounds from the
abdominal organs. Only a small part of the
mammary region covers lung, scarcely any
being subjacent to the anterior parts of the
Cth,n7th, and 8th ribs. (See .fig. 4, wherein
a transverse shading indicates the diaphragm. )

Internal conformation of the thorax. — To
comprehend clearly the internal shape of the
thorax, it is necessary to take a cast of this
cavity. This may be done by making an open-
ing in the sternal region, just large enough to
admit the hand to remove the heart and
lungs, filling up the whole of the cavity with
plaster of Paris and returning the sternum,
then opening the abdomen, cutting away the
diaphragm, and so removing the cast, which
wives us a clear knowledge of the internal
conformation, and every kind of measurement
correctly. ( Fig. 667. is a cast from the cavity
of figs. 680—685, — male subject.) We
have stated that the perfect thorax viewed
externally, and the same when the superficial
muscles and upper extremities are removed,
differ widely in their relative form. The tho-
racic cavity likewise differs remarkably from
either of these views. The general view is
that of a cone, but broader from side to side
than from before backwards : therefore the
cone is somewhat flattened.

(a) Anterior region. — This very closely re-
sembles the anterior region of the external
surface, being convex in its form, precisely
corresponding with the concave sternum. The
upper part, immediately behind the supqior
end of the sternum, is rather concave {fig.
667 ). At this part the cavity divides into
two small cones, for the reception of the

right and left apices of the lungs, which
ascend upwards to a variable height, —
an inch or an inch and a half. Both apices
of the lungs are directed from below, upwards

Fig. 667.

a

Cast of the cavity of the thorax represented in figs.

1, 2, 3, 4, 5, and 6.

and forwards ; it is incorrect to consider
them as directed backwards ( fig. 667. a,
which is the left apex seen above the 1st
rib.) In some cases, particularly where the
lung presents a puckered appearance, the
axis of the apex is inclined nearly to the
horizontal, and at all times it is about per-
pendicular to the sternum. These apices,
throughout advancing life, are tending to in-
cline forwards ; it is this portion above the 1st
rib (fig. 667.), which is so vulnerable in phthisis
pulmonalis. There is great difference in the
precise character of these apices in different
individuals ; in fact we have seen no two the
same ; some are remarkably truncated, and
broad from before backwards ; others are thin
in this direction, and pointed ; some obtuse
and low, others acute and high. They have the

THORAX. 1037

same characters in both sexes. There is little
difference in the height of the two apices. The
elevation of the liver on the right side does
not necessarily cause the right apex to be
the higher. The right lung is more shallow
than the left; but this is not because it is
“ pushed up,” but because, in order to ac-
commodate the liver, there is less lung-
substance on the right side. It the mean of a
series of observations represents the right
side of the thoracic cavity as equal to 151, the
left may be given as 182. The same may be
said of both sexes.

(Li) Posterior region. — If we examine this
region upon a cast of the thoracic cavity, we
observe in the middle line a deep fossa, formed
by the projection, to the very centre ot the
thoracic cavity, of the bodies of the dorsal
vertebra.

This fossa is wider towards the base of the
thorax, as may be seen by comparing the dif-
ferent sections of the cast (compare the
notches, 10, 11, and 12, with those of 3, 4, and
5 in Jig. 668.).

Fig. 669. ;

Sections of a cast of the thorax showing the space
encompassed by each pair of ribs respectively.

The bodies of the thoracic vertebrae, form
almost a complete septum ; they are certainly
a central column of support for the whole
trunk of the body, bearing an equal distri-
bution of the superincumbent weight in all

directions. There is no part of the skeleton
which more strikingly demonstrates that man
was destined for the erect posture, than this
central position, together with the increasing
dimensions from above downwards, of the
vertebral column. These conditions exist only
in the human subject. The groove in the cast
formed by the dorsal vertebrae is directed
upwards and forwards, so that at the apex of
the thoracic cavity it completely divides the
lungs, producing two little cones laterally for
the lungs, forming the right and left apex.

At the base of the thorax this perpendicular
column again completely divides the lower
lobes of the two lungs. The shape of the
posterior part of the cast is that of a curve
directed upwards, and sharply forwards, near
the apex (fig. 6 67.). This curve near the apex
is, like the form of the apices, very various.

An inflated lung assumes the same shape
as this cast, giving even the marks of the ribs.
The student, in order to have a correct idea of
the lungs, should remove them from the body
with the heart attached ; then inflate them to
their utmost, when their shape, their lobes,
and relative mass before and behind, are clearly
seen.

If now we inspect the cavity of the thorax
itself, we find that the bodies of the vertebrae
by their projection as above described, divide
the posterior portion of the chest into
two vast lateral grooves, which lodge the
posterior portions of the lungs; these two
grooves, partaking of the form of the thorax,
are consequently conical in their configuration.
They lodge fully one half of the entire lungs.
This is worthy of remembering in reference to
diagnosis, particularly when pneumonia is sus-
pected ; in such cases auscultation of the dorsal
region demands as much attention as that
of the anterior region. Though less vulnerable
to phthisis pulmonalis, yet it may lodge disease
in parts comparatively remote, and where in-
flammation may insidiously gain serious ground
upon the patient, particularly in children.

(c) Lateral region. — This precisely corre-
sponds with the external lateral view of the
thorax (compare fig. 667. with Jig. 680.); it
presents indentation of the ribs, resembling a
diagonal, curved, grate.

(d ) The base of the thoracic cavity has been
described above.

Conformation as affected by age and sex.
— Age alters the conformation of the chest.
In the earlier periods of existence the thorax
is the smallest of the three great cavities,
probably from the inactivity of the lungs.
In the foetal thorax the antero-posterior dia-
meter exceeds the transverse diameter, the
sternum projecting forwards, and the heart and
thymus gland filling up the middle of the cavity.
The ribs in foetal life are less curved, and conse-
quently those deep grooves, seen in the interior
of the chest on each side the spine, formed
by the angle of the ribs, so conspicuous in
after life, are almost wanting ; the vertical
depth also is much less at this period, because
the lungs are unexpanded and unemployed,
while the abdominal viscera, particularly the

1038

THORAX.

large liver, are in activity and pushing up the
diaphragm. The superior opening or true apex
is greater from before backwards than trans-
versely, which is the very contrary to the
adult conformation. The inferior or true
base of the thorax is extremely wide in every
direction, from the encroachment of the ab-
dominal viscera. At birth the thorax sud-
denly enlarges, by the air expanding the lungs
to two or three times their previous cubic
dimensions. As age increases, the curvatures
of the ribs increase, and, with the vertebrae,
running up through the very centre of the tho-
rax, form the two great lateral grooves, peculiar
to man, for lodging the chief bulk of the lungs.
The depth of the thorax is diminished, while
its breadth is increased, and this participates
in that more perfect development of the
system at the age of puberty. It is at this
time that malformation of the chest fre-
quently becomes obvious, particularly in
females. In the adult age the thorax still
grows, but in a degree less apparent, until it
assumes the form of what is termed an
open chest, capable of expanding in any di-
rection, supplying us with air under violent
exercise, and resisting severe blows. As age
advances, through the decline of life, the
thorax has a tendency to collapse ; the bony
framework threatens to unite into one rigid
cage, the true apex droops forward, the shoul-
ders appear higher, and the round back of old
age becomes apparent, so that we may make a
tolerable guess at the age of an individual by
the conformation of the back. The erect
thorax is absolutely necessary to healthy
vigour, while the drooping-forward chest is
always accompanied with proportionate feeble-
ness.

Sex. — The chief difference of external
conformation between the sexes is due to the
largeness of the mammae, and the less width
across the shoulders in women than in men.
There is no distinguishing the sexes by the
internal form of the thorax, they so perfectly
resemble each other. The chest of the
female is only absolutely smaller, but not al-
ways that, certainly not relatively so. The
nipples are not uniformly in the same posi-
tion ; those of the female are generally closer
together than those of the male.

Conformation of the thorax affected by
disease and occupation. — The conformation
of the thorax chiefly depends upon the healthy
condition of the main pillar of support, the
spine ; but not always so, for that deformity
called “ chicken breast ” appears to be inde-
pendent of the condition of the spine. And,
again, emphysema of the lungs tends to pro-
trude the ribs and advance the sternum.

Disease, as caries of the vertebrae, or an
atonic condition of the thoracic muscles, owing
to which the spinal column may yield, either
laterally, producing “ lateral curvature,” or an-
teriorly, giving “ angular curvature,” produces
the most marked distortion of this pillar of
support, and consequently of the whole thorax.
In youth, particularly in females, (from the pre-
sent system of education,) the spinal column,

which is at all times sufficiently flexible, bends
under the weight of the head and arms ; and
for want of proper exercise the muscles of the
back become enfeebled, and unable to restore it
to the erect position. When “ rickets” attack
the spine, it may curve in any direction, com-
pressing the ribs and projecting the sternum.
It is surprising to witness to what an extent
of deformity the thorax may attain, and yet
life still remain (see fig. 666., where costal
respiration could not exist ; and where all
the abdominal viscera must have been
forced up into the cavity of the thorax,
for the 10th rib is nearly touching the
crista of the ilium). We have noticed a case
where such was the effort of nature to pre-
serve the thoracic and spinal cavities, that life
was maintained in a boy 14 years of age,
though 7 bodies of dorsal vertebrae were com-
pletely absorbed.

In emphysema of the lungs, the sternum is
protruded, and the antero-posterior diameter
of the thorax is increased sometimes by an
inch, the shoulders are raised, and the person
assumes always the form of a man who has
made the deepest inspiration.

In phthisis pulmonalis, the thorax changes
its form, which is manifested by the shoulders
inclining forwards, the anterior and superior
parts bending in the same direction ; the
otherwise round full apex becomes flattened,
collapsing upon itself; and there is an in-
capacity to extend the apex ; this is a sure
and delicate test of that disease threatening,
before any symptoms can be detected by au-
scultation. In other stages there is a loss of
symmetry in the sides. In pleuritic effusion or
in empyema, one side may be full and immov-
able, whilst the other has to perform the
respiratory functions. In fact, disease of
the respiratory organs may produce a change
in the form of the thorax, either downwards,
upwards, or outwards, or by collapse of the
apex.

Frequently repeated or permanent compres-
sion, may produce many varieties of conforma-
tion of the thorax. Cruveilhier observes that
infants, in whom the thorax was perfectly well
formed at birth, have become deformed and
flattened on the sides of the thorax, by pres-
sure from the hands of the nurse. Slight ex-
ternal pressure in early life may be productive
of permanent deformity of the thorax, The
effect of strong and permanent constriction, as
from tight stays, occasions a distortion in
the form of the chest. This kind of com-
pression principally affects the lower part of
the thorax ; so that the 5th, 6th, 7th, 8th, 9th,
and 10th ribs are pressed forwards and in-
wards, because the length of their cartilages
allow them to yield readily : and the viscera
corresponding to these ribs, also undergo
alteration in their position and figure, en-
croaching upon the thoracic cavity, com-
pressing the lungs upwards, into the apices of
the chest. The imprudent custom of females
wearing a hard unyielding piece of wood, steel,
or whalebone up the front of their corset,
commonly produces a compression inwards of

THORAX.

1039

the sternum. We once noticed a case where
the sternum was forced inwards to such an ex-
tent, that the entire depth of the thorax, by
external measurement, from the middle of the
sternum to the corresponding part of the back,
only measured 2 inches instead of 8 or 9
inches !

Occupation likewise modifies the form
of -the thorax. The clerk who writes
many hours at the desk, carries himself dif-
ferently to the soldier. Coal-miners have
stooping chests when they work in districts
where the coal seam is thin, and the roof
consequently low, as in the north of Eng-
land. In fact, all trades or occupations
which require stooping for many hours to-
gether, tend to injure and malform the chest.

Pigeon- or chicken-breast. — This is a mal-
formation quite distinct from any of the
above mentioned, always affecting the sternal
region in particular. An explanation of this
curious disease has attracted the attention of
Mr. Shaw, to whom we are indebted for
the following remarks.* He noticed the
effects produced upon the thorax by violent
efforts of breathing in a child with croup.
If we watch, says Mr. Shaw, the motions
of the thorax in a young patient who is in
danger of suffocation from an obstruction in
the wind-pipe, we shall perceive that at each
inspiration, while the superior ribs and
sternum are raised and protruded as in com-
mon costal, breathing, the lower ribs are, at
first, flattened, and then drawn inwards, so as
to produce a deep indentation on both sides.
The depression is greatest in the line of
junction of the ribs with their cartilages ; it
is as if a band had been tied tightly round
the waist, or resembles the indentation near
the margin of the chest, often seen in women
from tight lacing. The constriction lasts
during inspiration ; in expiration, the ribs by
their elasticity flap out and recover their
form. That the lower ribs should be drawn
inwards in the act of inspiration, diminishing
the area of the chest at a time when their
natural motion should enlarge it, will be un-
derstood by considering the relative conditions
of the thorax and the lungs in the laboured
respiration which arises from obstruction in
the wind-pipe. Under the sense of impend-
ing suffocation, the young patient instinctively
struggles to enlarge the cavity of the chest to
its greatest capacity ; but, while that effort is
making, the quantity of air that passes into the
lungs is very small, because of the obstruction
in the larynx or trachea : a portion of air
may reach the air-cells at the apex where the
bronchial tubes are short, but little or none
penetrates so far as the base of the lungs ;
consequently the lungs are imperfectly dilated.
If the child succeed in enlarging the area of
the chest in proportion to its powerful efforts,
while the lungs were at the same time but
partially dilated, it would follow that a vacuum
would be produced in the space between the

* Deformity of the Chest from Dyspnoea, Oct.
1841. bond. Med. Gaz. New Series, vol. i. 1842.

parietes of the thorax and lungs. But owing
to the great flexibility of the ribs near the
lower margin of the thorax in childhood, the
atmospheric pressure overcomes the action
of the muscles, and thrusts in the sides so
as to preserve the balance of the air w'ithin
and that without : in common language, the
walls of the chest on each side are “ sucked ”
inwards, like the valve in a pair of bellows.

When we look at the general shape of the
chest during the continuation of the con-
striction, we perceive at once a resemblance to
the pigeon-breast deformity ; there is in both
the same protrusion of the sternum, and the
same depression of the cartilages on each
side.

The question therefore arises, can the de-
formity have a similar origin to the change in
the figure of the chest which is caused by
difficult respiration ? Dupuytren wrote a
memoir upon this form of distortion, and he
has shown that difficult respiration and pigeon-
breast deformity are frequently associated to-
gether, so that he has almost constantly found
that patients who are pigeon-breasted have at
the same time enlargement of the tonsils ;
but Dupuytren does not profess to explain
why the two complaints should go together.
Some years ago Mr. Shaw had under his
care a little boy with greatly enlarged tonsils,
which were very low down in the throat,
owing, as it appeared, to their having got
within the grasp of the constrictor muscles
of the pharynx. He had constant dyspnoea,
and occasional fits of suffocation, in one of
which Mr. Shaw performed laryngotomy:
on his admission into the hospital, and for
several weeks afterwards, it was observed that
he had the “pigeon-breast” form of chest;
but after his tonsils were excised, and his
breathing had been perfectly free for some
time, the sternum subsided to its proper level,
and the thorax recovered its natural shape.
These facts prove that a connection, like
cause and effect, exists between obstruction
of the air passages and pigeon-breast de-
formity. It is not necessary that such impe-
diments should be so great as to produce
strongly marked symptoms of dyspnoea ; for,
while the distortion is being produced the
child is growing, — both the size and shape
of the chest are undergoing a natural change.
Mr. Shaw justly considers it quite possible
that a cause which may have very slight in-
fluence in changing the figure of the thorax, if
operating only for a week or a month, will, if
continued longer, disturb and modify the pro-
cess of growth ; so that after intervals of half-
years or years, a decided effect will be exhibited
in the form of the chest. It is not impossible
that continued disease in the air passages of
children, which may fail to attract much at-
tention, or at least may not be thought capa-
ble of producing distortion, may nevertheless
gradually and insidiously give rise to the per-
manent deformity of “ pigeon-breast.” Mr.
Shaw particularly refers to enlargement of
the tonsils, attended even with slight incon-
venience; to enlargement of the lymphatic

low THORAX.

glands in the course of the trachea or bronchi ;
to pressure upon the trachea by the thymus
gland, when later than natural in being ab-
sorbed, or when hypertrophied ; and to mor-
bid thickening of the mucous membrane of
the larynx, or of the trachea and bronchi
succeeding croup or cynanche pharyngea.
We concur with these views upon this sub-
ject, the more so as we likewise have noticed
the pigeon-breast in children where enlarged
tonsils have been present. We must not
imagine from this that, where there is dyspnoea,
there we shall always find the deformity in
question ; for difficult breathing may be caused
by other circumstances than those which dis-
turb the counter-pressure of the atmosphere
in the thorax.

IV. Dimensions of the thorax. — The mea-
surement of the thorax may be considered
externally and internally; and, what is most
remarkable, the one class of measurements
may not have any relation to the other class.
Moreover, the external measurements bear a
certain proportion to the whole frame, whilst
the internal do not.

(a) External measurements of the thorax. —
The external dimensions of the thorax differ
much in different men ; this is obvious to
all. There is the broad-chested and the nar-
row-chested man. Mr. Brent has calculated,
from an extensive number of observations,
the following proportions, which we arrange
thus : —

Table D. — Relation of the External Chest to the Height, measured over the Nipples.

Minimum chest : £ of the stature — of the stature = circumference of chest.

Medium chest : of the stature + fg of the stature = circumference of chest.

Maximum chest : 4 of the stature = circumference of chest.

For example, let us suppose a height of Cl inches, as follows, —
Minimum chest : height 61 in., £ = 30‘5 in. — J, = 29-5 in. circumference of chest.

Medium chest: height Cl in., 4 = 30-5 in. +
Maximum chest : height 61 in., § = 40’7 in.

Thus, by taking the most perfectly propor-
tioned chests, either from living figures or from
the classical athletce of ancient sculptures,
the following is the result.

Table E. — External Thoracic Dimensions,
(in three classes according to weight) in rela-
tion to the height, obtained from calculation.

MALES :

CIRCUMFERENCE OF TIIORAX.

Height.

Minimum

Weight.

Medium

Weight.

Maximum

Weight.

Ft.

In.

Inches.

Inches.

Inches.

5

0

29f

34.

374

5

1

304

344

374

5

2

30J

354

38f

5

3

3H

354

39

5

4

31f

364

39f

5

5

324

37

404

5

6

32f

374

404

5

7

334

384

414

5

8

33 f

38f

424

5

9

344

394

42f

.5

10

34f

39^

434

5

11

354

404

44

6

0

35f

404

44|

From this the minimum chests increase on
an average nearly f (3'9), the medium chests
rather more than £ (4’2), and the maximum
a of an inch for every increasing inch of stature.
We have found from observation, upon 1276
cases of all various classes conjoined, a re-
gular arithmetical progression of the thoracic
circumference over the nipples in relation to
weight.

By the total mean of our observations the
chest increases exactly one inch for every
10 lbs. increase of weight, sinking the effect of
height, which, however, cannot well be omitted.

,V ( — 4 '07 ) = 34 '5 7 in. circumference of chest.
= circumference of chest.

because, as a general rule, the height increases
with the weight.

Mr. Brent has found that twice the breadth
of the shoulders equals the circumference
of the thorax over the nipples — i. e. from
point to point, or the caliber of the broadest
part of the shoulders. Thus, if the caliber
be 18 inches, the thorax will be 36 inches
in circumference. Four times the distance
between the nipples is equal to the circum-
ference. Four times the antero-posterior
diameter is equal to the circumference : there-
fore the distance between the nipples is equal
to the depth from before backwards of the ex-
ternal thorax. At the height of 5 feet 9 inches
this antero-posterior diameter varies from 71-
inch. to 124 inches.

(b) Internal measurement of the thoracic
cavity. — Before entering into details we may
observe, that the thoracic cavity is much
smaller than we might, perhaps, be led to
expect ; that the depth from above down-
wards is, when compared with the body, very
shallow. It is, however, capable of enormous
dilatation or mobility, even to 100 per cent ;
80 per cent is common.

The absolute dimensions of the thoracic ca-
vity of females are obviously smaller than those
of males, because they are altogether of smaller
conformation, both in stature and weight ;
but, relatively, the difference is probably little.
Although the proportion of some of the
diameters may differ, yet that of the total
cubic measurements appears not to do so.

A certain rude relation of necessity must
exist between the size of a man and the
dimensions of his thoracic cavity. A man
7 feet high will have a larger chest than
one 5 feet or 6 feet high. But there is no
constant and uniform relation of the size of
the chest, either to the height or weight of

THORAX.

1041

the body. The function of the chest, how-
ever, as indicated by the quantity of air which
we can expel, is in strict relation to the mi-
nute difference of a single inch of stature, or
to 10 lbs. of weight. It appears probable that
the function of an organ may be exactly re-
lative to the size of the body, increasing or
decreasing with it, while the organ itself bears
no visible relation of volume either to its own
activity or to the dimensions of the body.

The greatest perpendicular depth of the
thoracic cavity, nearly corresponds with the
greatest lateral measurement ; or if the depth
be 8'7 the breadth is 9'7, and allowing for the
mobility of the base of the thorax, the depth
may yet more closely correspond to the breadth.
The average perpendicular depth of the female
thorax exactly corresponds with the average

breadth, being 8-l inches in both measure-
ments. The greatest antero-posterior dia-
meter in both sexes, i. e. from the sternum to
the deepest part of the great lateral groove
at the angle of the rib, is always less than
the greatest lateral breadth, being as 6 to 9 in
the male, and as 6 to 8 in the female.

These diameters, however, in no way cor-
respond to the stature. A man, 5 feet 4
inches high, measured from the apex of the
chest to the base 104 inches, whilst' a man
of 5 feet 10 inches, only measured 7 a inches
in the same direction, or the shorter man
exceeded the taller by 3 inches in the per-
pendicular depth of his thoracic cavity: —
but the taller man could exceed the shorter
by a volume of 77 cubic inches of air at one
deep expiration. In fact, the whole of the

Table F. — Average Measurements of the Thorax.

(The mean of the measurements of fourteen males and six females, — given in detail in Med.
Chirurg. Trans. 1846. Vol. 29. p. 176.)

MALES.

FEMALES.

Age --------

51 years

40 years

Height --------

66 in.

62 in.

Weight (without clothes) -

110 lbs.

Weight of heart -------

13 oz.

Weight of right lung ------

so „

19 „

Weight of left lung -------

25 „

17 „

External circumference over nipples -

32 in.

30 in.

Internal circumference (maximum) -

32 „

24

Internal circumference of right half -

15 „

13 „

Internal circumference of left half -

15 „

1 3 ,

Greatest depth, from before backwards, of thorax -

6-5 „

6 „

Distance between sternum and bodies of dorsal vertebrae -

4 ,,

4 „

Projection of dorsal vertebras into thoracic cavity -

2'5 „

2-5 „

Greatest breadth of cavity of thorax -

9 „

8 „

Internal superficies of costal walls of thorax ...

258 sq. in.

212 sq. in.
35 „

Superficies of diaphragm ------

49 „

Superficies of entire boundaries (diaphragm and costal — ) -

307 „

247 „

Volume of right half of thorax -----

151 cub. in.

Volume of left half of thorax

182 „

141

Volume of entire cavity ------

333 „

250

Depth of right lung from apex to arch of diaphragm

7 in.

Depth of left lung from apex to arch of diaphragm

9 „

8 „

Depth from between apices to diaphragm -

8 „

7 „

Depth from before backwards — right lung (maximum)

6 „

5-5 „

Depth from before backwards — left lung (maximum)

6-5 „

5'5 „

Distance between centre of apices of lung ...

2-5 „

2-3 „

Vital capacity -------

205 cub. in.

187 cub. in.

In the males the left apex was highest in 6, the right in 6, and in 2 the summits of the apices
were on the same level ; in the females, the left apex was highest in 2, and the right in 4.

VOL. IV. q Y

1042

THORAX.

internal measurements (cubic or diameter)
clearly bear no relation to the height or weight
of the man, whilst vital capacity * does so in
an exact ratio.

If we take a cast of the thoracic cavity and
view the base, it presents the shape of the
figures in diagram fig. 669. which gives a mean
measurement, in the males of forty-six, and
in females of thirty-five, superficial inches
In the diagram (reduced by scale), we affix
the height of each case, and the area in su-
perficial inches of such section.

But the base of the thorax presents another
measurement, that of the absolute area of the
diaphragm. By the Jigs. 2. and 3., art. Dia-
phragm, this muscle will be noticed as a large
muscle of a vaulted form. C .Jig. 670. repre-
ents a section of a thorax, the measurement of

Fig. 670.

Sup. Squ. in.
133

Dimensions of the diaphragm m three stages.

C, ordinary stage. B, spread out A, completely
extended. I), relative difference between expiration
and inspiration.

which is forty superficial inches; the figure B,
next above, is the diaphragm of the same per-
son spread out, which is extended to 110
square inches, being nearly three times the
area of the former figure ; even in this con-
dition the centre is quite free, and not upon
the stretch, though the circumference is so.
The full measurement is nearly obtained, by
slitting up the sides, as shown in figure A.
and this condition gives it an increase of
twenty-two superficial inches, making alto-
gether 133 square inches ; but even in this con-
dition the entire arched muscle is not perfectly
spread out. This was the diaphragm of a man
five feet six inches high, with an exceedingly

* By “ vital capacity ” is meant the measure of
the mobility of the chest, as more fully explained
hereafter. (P. 1056.)

small chest, only twenty-nine inches in ex-
ternal circumference, and whose vital capacity
was 188 cubic inches. The section, therefore,
of the thorax to the area of the diaphragm is
as 40 to 133, or 1 to 3'3. This renders the
base of the thorax highly mobile.

There is, perhaps invariably, a difference in
the dimensions of the two sides of the thorax, in
favour of the left side. The least difference
which we observed was one cubic inch, but
we think there must have been some error in
this observation. Passing this over, we may
say that the difference between the two sides
varies from 10 to 77 cubic inches, and that, in
all cases examined by us, the left side was
larger than the right. This difference, also,
we have found not to bear any relation to sex
or stature. One female of 5 feet 4 inches in
height had a difference of 77 cubic inches,
which exceeds by 10 inches any of the males
which we examined, up to 5 feet 10 inches
high.

Of the Respiratory Muscles. — There
are certain muscles especially destined to expand
and contract the thoracic cavity, and there are
others which act in different degrees as ac-
cessories, they may be classed as direct and
indirect respiratory muscles.

-The direct respiratory muscles are, inter-
costales externi and interni, levatores costarum,
infra costales, triangularis sttrni, and the dia-
phragm. The indirect respiratory muscles are
all those which straighten the' spine or aid in
fixing the whole body for the thoracic mus-
cles to act from as a fixed point, whilst
by their other attachment they elevate or
depress the ribs ; these are particularly the
muscles of the neck and upper extremities,
and those composing the walls of the abdo-
men. More indirectly still, the muscles of
the limbs assist in respiration; — in difficult
respiration, the patient seizes hold of any
fixed object, whilst he employs his whole
muscular force to assist in inspiration, or, as
Boerhaave has expressed it, “ scarcely any
particle remains in the body which is not
more or less concerned in the business of
respiration.”* The indirect respiratory mus-
cles, in fact, comprise nearly all the muscles
of the body ; therefore we shall only no-
tice the direct respiratory muscles. The di-
aphragm has already been described (art.
Diaphragm).

1. The intercostal muscles are arranged as
two thin laminae between the ribs ; one lamella
is external to the other, hence they are named
external and internal. The fibres of each layer
are oblique in their direction in reference to
the ribs, and each layer has its fibres disposed
in a contrary direction to those of the other ;
thus they are said to decussate. The twelve
ribs form eleven intercostal spaces, conse-
quently there are eleven such decussating
lamellae on each side of the thorax, and twenty-
two in all. Their attachments are to the in-
ferior border of one rib, and to the superior

* Prselect. ad Instit. 601. Morgagni. By Alex-
ander, vol. i. p. 357.

THORAX.

1043

border of the next below. They do not ac-
company each other throughout the entire
intercostal space. These muscles, therefore,
differ from each other in two ways, in the
direction of their fibres, and in the extent of
their attachment, for neither set are prolonged
throughout the entire length of an intercostal
space.

(a) Intercostales extern i. — These have their
fibres running obliquely downwards and for-
wards ; they are continued throughout the
whole osseous intercostal space, i. e. from the
tubercles of the ribs, to where the cartilages
commence ; here they terminate. Haller
once noticed these fibres “continued without
interruption to the sternum, filling up the in-
tercartilaginous spaces.”* A thin aponeurosis
is prolonged from the free anterior margin of
this layer, up to the sternum. This muscular
layer is thicker than the internal layer. Fig.
671. represents the anterior extremity of this

Fig. 671.

Fig. 672.

External intercostals. — Posterior view.

in their degree of obliquity relatively to those of
other intercostal spaces Thus, broadly, it may

External intercostals. — Anterior view.

layer, where it terminates with the osseous
part of the rib, and Jig. 672. the posterior view,
commencing at the vertebrae.

(b) Intercostales interni. — These, as their
name implies, are internal to the above layer.
Their fibres are likewise oblique, and have a
contrary direction, downwards and backwards
crossing the former layer. They commence
at the sternum, fill up the intercartilaginous
spaces, and part of the interosseous spaces,
and terminate at the angles of the ribs.
Fig. 671. represents them commencing at the
sternum, and disappearing behind the ex-
ternal layer. Figs. 673. and 674. show them for
the remainder of their course ; in Jig. 673. they
will be seen to terminate short of the verte-
bral column. A thin aponeurosis is pro-
longed from their free margin backwards, to
the end of the intercostal spaces.

. All the intercostal fibres are oblique in their
direction, with reference to the spine and ster-
num. The fibres of one intercostal space differ

* El. Phys. tom. iii. p. 29.

Fig. 673.

Internal intercostals. — Posterior view.

be stated that the external intercostal fibres in-
crease in the degree of their obliquity as they

Fig. 674.

Internal intercostals. — Anterior view.

proceed from the first to the last intercostal
space ■, and that the internal intercostal fibres,

3x2

low

THORAX.

on the contrary, decrease in the degree of their dicular to the two bars ; now move the bars
obliquity as they proceed in the same direc- up to p 3, ‘also at an angle of 45° with e e,
tion. Moreover, for the most part the ex- and the fibre l k becomes more oblique than
ternal fibres increase in their obliquity in the at the position p 2. Therefore a tension
same intercostal space as you proceed from may change from the oblique to the perpen-
the vertebra; towards the sternum, and the dicular relatively to the ribs ; but it can
internal intercostal fibres, on the contrary, never so change its relation to the spine,
increase their obliquity from the sternum Thus h" k" and i/ k' between the bars
towards the vertebra;, therefore they seldom at p 3 cross each other, in the same direc -
decussate at right angles to each other, or tion, but in different degrees of obliquity;
form a perfect cross like the letter X. This is when the bars are at p 4., they decussate in
their general relative position at death, but, directions contrary with reference to the bars,
during life, in every stage of respiration, their but not with reference to the body e e. The
degree of obliquity varies. The obliquity of position of the ribs is similar to the bars at
the intercostal fibres should be viewed more P 4; therefore the decussation of the inter-
with reference to the spine than to the ribs, costal muscles must be viewed with reference
because we shall show that their action is to the spine. The intercostal fibres never
relative to the spine, and not to the ribs cross each other like the lines i/k' and
and that they may be perpendicular to two t,"n" {fig. 675.), nor can they, by any change
ribs, while they are oblique to the spine, Gf movement, ever assume thatposition ; i. e.
because the ribs are themselves oblique, if they do not decussate in a direction con-
We have never seen any of the external trary with relation to the spine, in no change
intercostal fibres perpendicular to a rib, but Qf position, throughout the range of a semi-
we may see that arrangement in the internal circle, can they ever become directly decus-
layer of the lower intercostal spaces {fig- sating fibres but when they directly cross
673.). The omission of the relative posi- each other as vd and v'u {fig- 676.) relative to
tion of the spine with reference to the ob- E E) ;n every other position to which the bars
liquity of these muscles has led to many false

conclusions as to their action in respiration. pig. <37(5.

Let e e {fig. 675.) represent a spine or a rigid

body, and a c, b d two levers representing can be moved, they will be seen still to main-
ribs, allowing of free rotation at their centres of tain the same decussation,
motion a and l). These two bars are per- Action of the intercostal muscles. — There
pendicular, or at 90°, with reference to the is, probably, no subject in the whole range of
body EE; let l k represent a connecting science which has excited more violent con-
tension or elastic fibre of any kind, this is tention and acrimonious dispute, than that
oblique with reference to the two bars ac of the action of the intercostal muscles. The
and bd, but move these bars down to the illustrious and learned Haller could not enter
position of p 4, at an angle of 45° to the this field of inquiry without pausing to ob-
body e e, and the fibre l k becomes perpen- serve : “ Let it be allowed me to deplore,

&

THORAX.

1045

among the miseries of human life, that such
anger and bitter quarrels should be forced
upon us on account of matters wherein we are
so little personally concerned.”* * * §

Yet, strange to say, Haller opposed with
extreme violence his contemporary Hamber-
ger, whose investigations on this subject,
though still extant, fell, consequently, into
oblivion.

We know not who discovered the two sets
of intercostals. There appears to be no ac-
count of them prior to Galen, a. d. 131. He
observes, “ the intercostal muscles help the
midriff, that they might draw the chest in-
ward.”f Albinus (a.d. 17701 considered that
both the internal and external layers “ raise
the ribs.” J H. Cooke, a learned compiler of
1651, believed, they “ constrained and dilated
the chest,” — “ that the external layers bear
down the ribs, and that the internal separate
the ribs, so enlarging the thoracic cavity.” $
Strange to say, after this Cooke divests these
muscles of all thoracic motion whatever.

In 1685 it was the received opinion that the
external layer dilated, and that the inter-
nal layer contracted the thorax. || John Al-
phonso Borelli led the way to. a different
opinion, which prevailed amongst most phy-
siological writers. He believed, from mathe-
matical reasoning, that “ the fibres crossing
each other produced only one effect, viz.,
the drawing of the ribs together,” — acting
in the diagonal of the decussation. It is
curious that he never considered the proba-
bility of the two forces acting separately, as
other antagonising muscles can do. IT w.
Cheselden believed that both these muscles
dilated the thorax, acting as elevators of the
ribs, when the 1st rib was fixed by the scaleni
and serratus posticus posterior. ** * * §§

Cooke follows the views of Cheselden and
Borelli. ff Benjamin Hoadly takes another
view ; and, in so doing, illustrates the subject
with diagrams, and comes to the conclusion
that the external layers elevate, and that the
internal depress the ribs ; and that their com-
bined action is to arrest the respiratory move-
ment at will. He also says, “ neither range
can by their action push the ribs asunder.
Winslow agrees with Borelli : presupposing,
as usual, that the first rib is fixed. §§

Still the subject continued to be warmly dis-
puted, when Haller published a controversial
paper in 1746. In his “Elements” he treats the

* El. Phys. vol. iii. p. 36.

t De Usu Resp., ch. 15., 5 lib., De Usu Partium.

t Tr., fol., ed. 1777. Tab. xvii. 9, 10, et seq.

§ Cooke’s Descrip. Anat., fol., 1651., p. 257.

|| Samuel Collins’s System of Anat., fob, 1685,
vol. ii. p. 825.

If De Motu Animalium, pars secunda. Lugduni
Batavorum, 1710, p. 106., Prop. 84., Tab. xviii.
Fig. 2.

** Anatomy of the Humane Body, 3rd ed. 8vo.,
Lond. 1726, p. 117.

. tt Cook’s Anat. and Mechanical Essays, Lond.
1730, vol. i. p. 282. et seq.

It Gulstonian Lect. on Resp. 4to., Lond. 1740,

p. 6.

§§ Anatomical Exposition, 4to,. Lond. 1749, vol.
i. p. 318.

subject at length, siding with those whom he
thinks are right, and confirming the same by
many direct experiments.* Haller's view is,
that the external layers elevate the ribs, be-
cause their superior attachment is nearer the
vertebrae than their inferior one. Franciscus
Boissier de Sauvages agrees with him ; and
the same is held by the majority, yet some
doubt it.

His opinion touching the internal layer is,
that they likewise act as associates and ele-
vators of the ribs with the external layer, be-
cause “ their superior attachment is nearer
the sternum, and further from that bone in
the lower ones likewise, that “ that por-
tion of the internal layer placed between the
bony parts of the ribs, cannot have a diffe-
rent action from that portion placed between
the cartilages.” Joh. Swammerdam, Francis
Bayle, J. Wilhelmus Pauli, Christianus Vater,
Francis Nicholls, J. Fredericus Schreiber,
differ from this, believing that the internal
layers draw down the ribs.

Now follows a sharp antagonist to Haller,
viz. Hamberger, whose disputes with Haller
we gather from Haller’s writings, and not
from Hamberger’s writings.

Hamberger breaks out with an entirely new
view, which excites Haller to controversy .j-

Hamberger, says Haller J, believes that the
external intercostal muscles have one action,
— that they would raise the sternum: “ that
the internal layer would depress it.” Ham-
berger makes a machine “ to demonstrate,
that when the ribs are raised by these muscles
their intervals are dilated ; when depressed,
on the contrary, they are diminished.” He
furthermore gives, as his own discovery, that
“ the internal intercostals conjoining the os-
seous portions of the ribs, and that portion
which is between the cartilages, will raise
them, and are therefore associated in action
with the external layer.” Hamberger was the
first to assign a double action to the same
class of muscles : he likewise believed that
the whole ribs were lifted simultaneously^
Haller disputes the validity of Hamberger’s
experiments, upon the ground of his not con-
sidering the relative mobility of the first and
second rib ; because, says Haller, if the de-
pressing power of the intercostal muscles is to
the first rib as 20, the elevating power on the
second rib, by reason of the difference of
length and mobility, is as 380, nearly nine-
teen times greater ; and the lower rib is to
each superior rib, as far as . the seventh,
more moveable, in the ratio of 109 to 79. ]|
We cannot see, with Haller, how the ten-

* Vide Elementa Physiol. Corporis Humani,
tom. iii., p. 28., et seq. Lausan. 4to., 1766.

f Hamberger was bom 1697, and died in 1755.
Haller’s first anatomical paper upon respiration
appeared in 1746, and his Elementa Physiol. Cor-
poris Humani, in 1757-66.

x El. Phys. ib. p. 37.

§ Hamberger’s writings on this subject were an
essay De Respirationis Mechanismo, J ense, 1727, and
also'Physiologia Medica, Jense, 1751. — Ed.

|| Loc. cit. p. 39. et seq.

3x3

1016

THORAX.

dencyof action of a muscle can be affected by
the degree of mobility of a joint ; for it is not
necessary to the direction of the action of a
muscle that a bone should move. Haller also
denies that the two crossing fibres lengthen and
shorten inversely to each other ; or that
the intercostal spaces widen by their action.
Haller performed many experiments ; he ap-
plied strings to the ribs of a wet preparation,
representing the muscles, and pulled the
strings, and the intercostal spaces diminished.
By vivisections he determined, that in inspir-
ation the internal intercostals, “ simultane-
ously with the external layer, contract, swell,
and wrinkle, become perpendicular and hard,
with united lifting of the ribs in rotation,
the turning of the lower border forwards,
the protrusion of the sternum, the descent of
the diaphragm,” &c. On the other hand, he
observed in “ expiration, relaxation of the
whole series of intercostal muscles, increased
length and obliquity, increased distance be-
tween the spaces, relaxation of the diaphragm,
repression of the sternum, the descent of the
ribs, narrowing of the chest,” &c.*

It is curious to see that he makes the cubic
space of the thorax diminish with the inter-
costal spaces widening. Nor do we wonder
at his observing, in his vivisections, a contrac-
tion of both sets of these muscles, for he not
only skinned his animals, but “ cut down and
destroyed the external layers of intercostals,
to lay bare the internal layer.’ “Besides lap-
plied (says Haller) pain and fear , being more
efficient than mere pain itself,” by puncturing
the diaphragm to cause dyspnoea! Under
such circumstances — an animal tied down,
divested of all superficial muscles, with a
pierced chest, — in pain and fear,” —
and writhing under the scalpel, — producing
tetanic convulsions, and then a death-like
relaxation from syncope, — surely in such
a condition the action of the respiratory
muscles, so sensitive to the least mental
emotion, could not well be determined.

Although Haller appears positive, yet he
concludes his controversy with a brilliant
question, — a vivid picture of his master mind,
— “ Why has nature made two, rather than
one set of intercostal muscles, if, indeed, the
function of each is the same?”-)- Haller’s
views have, however, prevailed to this day,
and are still taught in our schools. ~ Some
authors have assigned but little to these
muscles, counting them as mere associate
muscles; others, that they are “wholly and
solely ” to form the thoracic parietes ; others
that they are rather movers of the spine.

Dr. John Barclay, a standing authority,
observes, that the supposition of the two sets
being antagonists in their actionr “ is now ob-
solete,” and must “ have been formed by the
very witchcraft of imagination, in defiance of
all observation and experiment.” J

Lastly, Dr. Sibson has made a commu-

* El. Phys. ib. p. 43.

•f Ib. p. 44.

f Barclay “ On Muscular Motion,” 8vo. Ed. 1808,
pp. 533, 534.

nication upon this subject. He observes, that
“ the scaleni invariably act during the whole
time of inspiration and that the function of
the intercostal muscles is complicated ; thus,

“ th e external intercostals, between the thoracic
set of ribs, are throughout inspiratory ; those
portions between their cartilages are expiratory,
between the diaphragmatic set of ribs they are
inspiratory behind , expiratory to the side and
in front, and between their cartilages they are
inspiratory ; between the intermediate set of
ribs they are for the most part s/ight/y in-
spiratory between the ribs, and expiratory in
front between the cartilages.”

“ The internal intercostals of the thoracic
ribs are expiratory behind and inspiratory in
front, if the ribs approach there, and are in-
spiratory between the costal cartilages. Be-
tween the diaphragmatic and intermediate set
of ribs, and between the cartilages, they are
thought expiratory”* From this view of Dr.
Sibson’s, we venture to gather, that different
fibres of the same layer of intercostal muscle
have diametrically opposite actions. We do
not understand upon what ground it can be
demonstrated that one muscle having a given
action between two ribs, shall, between the
same ribs, and observing the same obliquity
and same attachments, present a directly con-
trary action ; the conditions are the same, and
therefore the action must be the same. These
views, however, of Dr. Sibson, in the paper
in question, are not borne out by the narra-
tion of any experimental facts. Insufflation
on the dead body is not the movement of
inspiration in the living subject. It is better
to assign to these muscles the terms of ele-
vators or depressors of the ribs, instead of
inspiratory and expiratory muscles.

All these observers, as far as we have seen,
pre-suppose that the 1st rib is fixed by the
scaleni (this is the view now taught) ; and
that according to the fixing of the 1st rib, all
the intercostal muscles are either elevators
or depressors of the ribs. It is curious to
contemplate that, out of elements so few, two
ribs and two muscles, opinions so contrary
should be held with regard to the action of
these muscles. They have nevertheless an
action as definite as any other muscle in the
body.

We may here observe, that, although the
chest is conical, the ribs segments of circles,
and the spine mobile, yet treating them as
planes and lines will not lead to error. Two
parallel bars, rotating on a centre, will increase
and decrease the perpendicular distance be-
tween them ; so they will, if curved like the
ribs. This we have determined by experiment.

Although the rib has two movements, ele-
vation and rotation, yet these are associates,
and do not obstruct each other. We shall
employ the same diagrams as used by Dr.
Barclay', when describing the same muscles.

The intercostal muscles act as a force be-
tween two moveable ribs or levers ; therefore
let us consider —

T* Phil., Pt. 4, 1846, pp. 543, 544.

thorax.

1047

1st. The movement of such levers, when
rotating.

2nd. The effect of forces, oblique, perpen-
dicular, and decussating, upon such levers.

1st. The movement of ’ the levers. — Let
fig. 677. a represent a series of parallel bars,

Fig. 677.

R A

allowing of free rotation upon a rigid per-
pendicular body a a ; let the free extremities
of these bars be kept apart, so that the bars
may at all times be parallel to each other.
In this condition a certain distance exists
between the bars, and a certain distance be-
tween their free extremities and the perpen-
dicular body a a. Let b represent the same
bars moved into another position, resembling
that of the ribs ; in this position, the
two conditions seen at A are altered. The
perpendicular distances between the bars
are diminished, and the distance between the
free extremities of the bars and the body b b
is likewise diminished. If the direction of
this motion were still continued, the bars
would ultimately touch each other, and their
free extremities would be still nearer to the
body b b. But let the bars be elevated, as
in c c, and the same condition obtains as in
the bars at b b, viz., they approximate each
other, and the free ends come nearer to
the body, c c. In this case the bars only
have moved ; but the same effect can be
obtained without moving the bars. Let a b
{fig. 678.) be two bars at their maximum
distance, while horizontal ; at a b, and a' b',
they have nearly attained their minimum
perpendicular distances, though still hori-
zontal, because the rigid bodies c c and c' o'
have been moved respectively. Now, if we
join these hree last figures into one, as in
fig. 67 9., an then move the bars simulta-
neously, some bars will approximate each
other, whilst others will recede. The superior
four are at their maximum perpendicular dis-
tance from each other ; while the 4th, 5th,
and 6th are at a medium perpendicular dis-
tance, and the 6th, 7th, and 8th bars at their
minimum distance.

The distances of these bars are regulated by
the position of the rigid body representing
the spine. If all of them were moved upwards

Fig. 678.

c (•

3J

Diagram representing the position of the ribs affected
by the position of the spine.

simultaneously, the first four would approxi-
mate, whilst all the rest would recede from
each other. Therefore the positions of the
different parts representing the spine in fig.
679. command and regulate these changes.

Fig. 679.

Diagram as in fig. 678. with the three portions conjoined #

From this we learn, that the bars cannot
rotate without changing their distances, and
that when they are at 90° with reference
to the body a a {fig. 677.), they are at their
maximum distance from each other, and as
they pass this position on either side, this dis-
tance diminishes.

In the human body the spine may represent
the body to which the bars are attached
{fig. 677.). The movement of the ribs will
obey the same law in receding or approaching
each other, and whether they increase or
diminish their intercostal spaces, will depend
upon the relation they bear to the spine.

Fig. 682. is a cast, from a dissection of the
thorax of a male subject, weight 1071bs., height
5ft. 4in. This correctly represents the natural
position of the ribs, when the thorax is in a
state of complete expiration, or with only the
residual air in the lungs. The position of the
3x4

1048 THORAX.

ribs is very oblique ; the spine is curved ;
therefore the relation of the ribs to the spine is
different according to the curve, as are the
bars to the body representing the spine
( Jig . 679.). It will be seen that the inferior six
or seven ribs are at a more oblique angle to
the spine than the superior ribs. The spine
does not curve sufficiently to bring the upper
ribs to an angle of 90° with the spine; there-
fore, if all the ribs were raised simultane-
ously, they would all increase the breadth of
their intercostal spaces, whilst their sternal
end would recede from the vertebras, and thus,
by their elevation, the thoracic cavity would
be enlarged, until they attained the angle of
90 ° to the spine. But if the elevation were
carried beyond this point, the intercostal
spaces would diminish, and thus the thoracic
cavity would decrease. Fig. 684. is a pos-
terior view showing the sloping position of
the ribs more clearly. Now, if the spine
were perfectly erect, the ribs would have a
greater range, and consequently the upper
ribs could be elevated higher, and thus still
more increase the thoracic cavity. A man

Fig. 680.

Thorax as at death.

can expire a greater volume of air when
perfectly erect, than in any other position.
On the other hand, if we curve the spine,
we limit the divergence of the ribs, because
then we bring the ribs more into the po-
sition of ah and a' b' { fig. 678.). Tlius,
in diseases of the spine, when angular cur-
vature is extensive, the ribs are materially
limited in their capability of increasing the
perpendicular depth of their intercostal spaces,
and consequently the perpendicular depth of
the thorax.

Fig. 666. is an instance of angular spine,
reducing the ribs to their minimum distances
without their moving. We have found by ex-
periment, that the greatest volume of air which
persons with angular spine can expire, is little
more than equal to the volume of air of an
ordinary respiration ; i. e. from 20 to 40 cubic
inches, instead of 180 to 200 cubic inches.

The following experiment proves that the

ribs are all elevated when the chest is inflated,
and that the spine is straightened. Into the
thorax {Jig. 680. et seq .) we insufflated, or
forced into the lungs 310 cubic inches of air,
and a second cast was taken. The changed
position of the ribs and spine is represented in
Jigs. 681. 683. and 685. where it will be seen
that all the ribs are raised ; their perpendicu-
lar distances or intercostal spaces are all
increased, and the spine is more erect.

This experiment, therefore, demonstrates
two things : 1st, that by artificially inflating
the chest, the intercostal spaces are widened,
and 2dly, that the spine becomes more
erect. It is an experiment most unfavour-
able for showing these two points, because
the altered shape of the thorax by insufflation
is not to be compared with the exceedingly
enlarged condition produced by vital inspira-
tion ; in which case the spine becomes more
erect, and the intercostal spaces consequently
wider. By placing the fingers in the inter-
costal spaces of a living subject during
deep inspiration and expiration, it may easily
be perceived that in the former they widen.

Fig. 681.

Thorax artificially inflated with air.

and in the latter they collapse. From 3000
observations we have found that, in deep in-
spiration, the body becomes more erect, and
less so in expiration.

Insufflation is not the same, in effect, as
inspiration. In the former we force air into
the chest, until the parts most yielding, as
the diaphragm and abdominal parietes, are
rendered so tense that their tension is suffi-
cient to overcome the elastic force of the ribs,
their cartilages, and the lungs ; then, and not
until then, do we move the costal part of
the thorax. On the other hand, in the living
and deep inspiration, we lift the ribs and
sternum, the most unyielding portions, first.
These solely produce the threatened vacuum
which inflates the lungs, whilst very little, if
any, is accomplished by the diaphragm.

The following table shows the measure-
ments of the thorax, when expanded by in-
spiration and insufflation.

THORAX,

1049

Fig. 682. Fin 683.

Thorax as at death. Thorax artificially inflated with air.

Thorax as at death.

Thorax artificially inflated with air.

Table G. — Table of the Dimensions of the Thorax and Abdomen, in the Dead and Living Sub-
ject, with the same Quantity of Air distending them.

Thorax.

Abdomen.

Conditions at the time of observation.

Circum

over

nipples.

Diam.

lateral.

Diam.
ant. .post.

Circum.

Diam.

lateral.

Diam.

ant.-post.

in.

in.

in.

in.

in.

in.

Dead — Natural collapse

29f

10

8

29 i

8*

n

Insufflated

31*

10*

8-3-

31*

10

9f

Alive — Expiration

32

11*

94

25

10*

7 3

' T

Inspiration

37

m

Hf

25*

11

8f

Difference —

By insufflation, dead

H

_i

3.

If

LJ

By inspiration , alive

5

1

i

93.
^ 8

1

T

3

3

¥

1050

THORAX.

These facts show that we should be guarded
in determining the living respiratory move-
ments by experiments upon the dead subject.

It should be constantly borne in mind, that
to increase or diminish an intercostal space is to
elevate or depress the ribs, and that to elevate
or depress the ribs is to increase or diminish
their intercostal spaces : the one cannot be
accomplished without the other. Some au-
thors have spoken of these as distinct ; thus,
that in inspiration the" superior ribs ap-
proximate each other, whilst they are raised,
or that their rising or falling does not neces-
sarily involve an increase or diminishing of
the intercostal spaces ; but these two changes
are simultaneous and cannot be done sepa-
rately.

2nd. The effect of tensions , oblique, perpen-
dicular, and decussating, between the moveable
levers or ribs. — We employ a strip of vul-
canised Indian-rubber for a force representing
muscular contraction. A strip of this sub-
stance, of uniform thickness, 4 of an inch
broad and 10 inches long, increased its length,
with an increasing weight, as follows : —

1

+ the pan holding the
weight = 850gr. =

runner,
gr. inches.
1287a A

2

do. =

1725

3

4

do. =

2600

1

8

do. =

4350

If

16

do. =

7850

4

32

do. —

14850

12a

64

do. =

28850

2&1

Fig. 680.

demonstrated by a model, using a spring or
Indian-rubber as the tension, and may be

Although not exactly in accordance with
the law of perfect elasticity, yet it is roughly
so and enough for our purpose, viz. the
tension is greatest when most stretched, and
weakest when least stretched, corresponding
with muscular contraction.

Let e e (fig. 686.) be fixed, a b and c d two
moveable bars as before, t an oblique tension ;
if t shortens, it has been supposed that the two
bars would assume the position of a b' and
c d ; but not so : they both rise like a b" and
C v>'' until the two bars touch each other.* If
we prevent this touching of the two bars by
a rigid link, like that on parallel rulers, placed
as at s fig. 687., then the tension will still
raise the bars to o o'. In this experiment
three circumstances may be noticed. 1st,
that the bars have been elevated ; 2dly, that
the perpendicular distance between them has
been diminished ; and 3dly, that the tension
t has been shortened in attaining the position
o o'. Place the tension in a contrary direc-
tion, as between the bars a' b' and c' o', and
the bars are brought into a contrary position,
— drawn downwards to o' o'". This can be

* This appears to have been known to Hamberger ;
but the author of this article was not aware of it
until four years after he first introduced this move-
ment to notice. (See Med. Chirurg. Trans, vol. 29,
p. 213.) It is certain that Hamberger’s views were
not taught in any physiological school in this coun-
try, Germany, or France, nor noticed in any of our
philosophical works.

Fig. 687.

explained as follows. Let a b ,fig. 688., repre-
sent one bar, c d the perpendicular fixed body;
b is the free extremity of the bar; k an
axis from which a parallel bar has been re-
moved. Let e, i, and o be other fixed points ;
connect e to b by an elastic tension, and the
bar b will be moved towards e. Let the ten-
sion be fixed at i or o, still the bar b will be
raised towards the respective points. Let
the tension be fixed at k (the centre of mo-
tion of the bar which we suppose is removed),
and still the bar a b will be raised upwards
towards k, and assume the position of a b,
ic l (fig. 689.) at M. But it is not necessary to
this that the elastic force should extend from

Fig. 688.

THORAX.

Fig. 690.

1051

k to l in order to produce this motion : half
of it might be wood, bone, or iron, provided
the other half retained its elastic power. The
effect would be the same, and the bar a b at N
would be elevated by the tension between t l.

Fig. 689.

connecting the fixed point k with L by the
rigid body k t. It is the omission of the
fulcrum k, in calculating such oblique forces,
which has hitherto obscured the explanation
of the intercostal muscles.

This may be illustrated in another way
( fig. 690.). Let a b and c o represent bars as
before upon a c ; t' the tension ; let c d and a
c be fixed ; withdraw the pin at a, and the bar
a b is drawn forwards into the position b', and
the tension t becomes perpendicular to the
two bars. On the other hand, reverse the
experiment, as in fig. 691.; supposing c d and
the perpendicular body c a fixed, withdraw the
pin at a, and the bar a b is drawn backwards
to b'. This presupposes the bars kept apart,

otherwise the free bar would approximate the
fixed bare d. Therefore, one fulcrum is pushed
upon by one bar, and pulled upon by the other.
If the bars were kept fixed, and the body re-
presenting the spine was left free , the tension
would draw this last mentioned body into the

Fig. 691.

position of c c and c c fig. 678. Therefore, the
element of the two fulcra is the chief agent for
directing their upward or downward move-
ment, under an oblique tension. If we arrange
two bars with one fulcrum {fig. 692.), and allow

Fig. 692.

the tension to act as before, then the effect
is only to draw the two bars together, as o b
and o' d {fig. 693.). If we have an arrange-
ment to substitute two fulcra at a a' fig. 692.
and withdraw the centre fulcrum, then the
two bars rise as before.

Fig. 693.

Now we shall suppose the bars at an
angle of 90° to the body representing the spine.

A perpendicular tension (l o , fig. 694.) ad-
mits, of course, of no variation ; oblique ten-
sions admit of two variations :

thorax.

a, obliquity in contrary directions.

b, degrees of obliquity in each direction.

Fig. 694.

The perpendicular tension (l o, Jig. 694.)
produces but one effect, that of approxi-
mating the two bars a c and b d, because the
force of l o is acting upon a l and b o, levers
of the same length, their movements being
the same they would meet in the middle dis-
tance at s. But if the bars are kept parallel by a
rigid link like s, fig. 687. the perpendicular ten-
sion would produce no apparent effect upon the
two bars. They might be rotated in any direc-
tion, and the tension would remain of the same
length ; for example, in fig. 695. let t 2 be the
perpendicular tension between the bars a b
c d, move the bars to s or s', and the ten-

Fig. 695.

sion is the same length, hick, &c., may
represent different places in the rotation,
at each of which the tension t or k is the
same length, although the bars at s, t 2, and
s' are at different perpendicular distances from
each other. A rigid connective, as wood or
wire, may be substituted for the tension, an-
this will equally allow of the bars being rod
tated, and consequently changing their per-
pendicular distances to each other. Hence it
will be seen, that each of the lines k k k, are
of the same length, although the two se-
micircular lines describing the revolution of
the bars are constantly changing in their re-
lative distance to each othe We then seer,
the possibility of having a rigid body connect-
ing two bars, which shall nevertheless recede
and approximate each other. From this we
may gather, that though the sternum is rigid,
and the cartilages, perhaps, ossified, the ribs
may nevertheless maintain the capability of
altering the breadth of their intercostal spaces.

Perpendicular tension, therefore, like l o,
(parallel to a b,) cannot rotate the bars, be-
cause they never change their length.

All tensions are oblique which have one
of their attachments nearer to the spine
than the other, therefore, in fig. 694., l ic
and l t are oblique tensions. An oblique
tension, hence, is acting on bars at dissimilar
distances from their fulcra ; thus in fig. 696.,

Fig. 696.

Diagram showing that perpendicular fibres neve?
alter their length.

tension t ' is oblique to the line a a, and
the points on the lines a b, ad, to which
the tension t' is attached, is represented by
the lines a m and A m. And the law of action
of such tension is, that it tends to move both
bars or ribs towards that fulcrum which is near-
est to one of its attachments. Therefore ten-
sion l k (fig. 694.) would rotate the bars
towards B, and tension L t towards a. The
force of a given oblique tension between such
bars is modified by two circumstances, — by
the degree of obliquity, and by the obliquity of
the bars in reference to the body which re-
presents the spine.

Of the degree of obliquity of a tension. — Let
fig. 697. a b, c d, represent bars as before, the
different connecting lines tensions of different
degrees of obliquity, but of the same power
of tension. L k is perpendicular, and has no
rotating power, l k1 possesses a certain
amount of power, l ks more power, and l a
the maximum power, or the power of rotating.

THORAX.

1053

Fig. 697.

the bars increases with the increasing obliquity
of these tensions. By experiment we found
that equal tensions at the following angles, pro-
duced the following difference of power in
rotating the bars : —

Table H. — Power gained by a given Tension,

as an intercostal Muscle,
Obliquity.

in relation to its

Angle of tension.

Tension.

Resistance.

At 90°

2-5

0

„ 75°

2-5

1-50

„ 46°

2-5

2-25

„ 15°

2-5

4-25

„ 7°

2-5

5-50

The power descreases as the tension ap-
proaches the perpendicular l k', and increases
as it approaches l a ; this is the maximum
point : if the tension be attached to the body
e e, either above A or below it, the system is
changed into that of a single lever. From this
we gather, that the power of an intercostal
muscle, as an elevator and depressor of the
ribs, increases with its obliquity ; and that
this movement entirely depends upon its
obliquity. This is the only instance in the
body where the power of a muscle increases
with its obliquity.

Of the obliquity of the ribs or bars with re-
ference to the spine. — A given tension, say
at the angle of 45°, will, when the lever is at
90° to the spine act more powerfully than
when the lever is at an angle similar to that
of the ribs. We found by experiment, that
the bars in the following positions required
an increased power to sustain them. The
tension being uniform, and the resistance to
be overcome acting from the same point.

This gain of power is dependent upon the
obliquity of the bars and change in the direc-
tion of the tension, for in each of these posi-
tions the tension was maintained the same.
But if the tension be not kept uniform, still
the resistance is increased as the bars rise ;
thus, if the bars are at the angle of 50°
{Jig. 699. m") somewhat similar to the
position of the ribs, and these under a
certain tension allowed to resist a power
of 4, when they are moved upwards to
90°, through which revolution the tension
has kept diminishing (because it has kept
shortening), it will resist a power of 5.
In this we see a beautiful compensation to
the muscular contraction, viz. that while an in-
tercostal muscle is losing power as it con-
tracts, this loss is made up by the change in
position of the ribs. We feel conscious that
we can exert a retaining power at the ter-
mination of a deep inspiration as great, if not

greater, than at any other intermediate posi-
tion of the ribs, at all of which the muscular
power actually exerted is greater. All these
remarks apply equally if the spine be curved ;
for change of obliquity of the ribs, or change
of curvature of the spine to the ribs, is the
same thing.

Table I. — Change of Power, from the Obli-
quity of Bars or Ribs to the Spine.

Angles of the Bars with the
Body representing the Spine.

Tension.

Resistance.

30°

2-5

4

60°

2-5

12

90°

2-5

22

120°

2-5

33

Of oblique tensions in contrary directions.
— We have shown that an oblique tension
between parallel levers moves them in a cer-
tain course. Now it is evident that tension
in a contrary direction (all other things remain-
ing the same) must likewise move such levers
in a contrary direction. This is so clear that
although Haller asserted absolutely that cross-
ing muscles have the same action, yet he was
not comfortable under such an opinion, “ for,’ ’
says he, “ why do they cross ?”

We have shown that a tension in the di-
rection of l t fg. 694., will raise the bars,
and one in the direction of l k will depress
them; they are, therefore, antagonistic forces,
and when the tensions are similar, they pro-
duce an equilibrium of contrary force. If
the bars a b, c d, {fig. 676.) be rotated, the
lines will have directions contrary to each
other, and will lengthen and shorten inversely
to each other. Thus of the crossing tensions
{fg. 676.) v d and v' b, t' b becomes short-
ened to n b', and v d, on the contrary, becomes
lengthened to n b' ; and on the other side
of 90°, v d is shortened to s d, and v' b
lengthened to s' b. Therefore muscles circum-
stanced like the intercostals and crossing each
other, or observing contrary directions to each
other, cannot be associates in action, for when
one contracts, the other must relax, as the ribs
move. We represent this more clearly in
Jig. 698. where a b and c d represent bars as
before, rotating upon e/ e, and t t' two ten-
sions in contrary directions. As the bars are
raised towards m, t' lengthens, and if depressed
towards in' it shortens, while t lengthens to-
wards n, and shortens towards n'. We re-
present the tensions t t, & c., and t' t', &c.,
by the white lines, in the different positions
they would assume if the two bars were
rotated to those places in the half cir-
cle. It will likewise be observed, that
while either tension gradually lengthens or
shortens, the two bars pass through their
maximum perpendicular distance from each
other at b d, on either side of which they
attain their minimum distance. Therefore,
if we examine tension t at n' , the bars would
there be closer to each other than they are at
b d ; nevertheless, this tension in ascending
must contract while the bars are increasing
their perpendicular distances as they move
to b d ; beyond which the tension still

1054

THORAX.

shortens, while the bars now decrease their
perpendicular distance. Therefore it is per-
fectly compatible for an intercostal fibre to
separate the two ribs, between which it is at-
tached, by its contracting ; and, if above a
certain point (90° to the spine), to approxi-
mate the same ribs by its further contraction.

Fig. 698.

In deep inspiration it will be found that the
ribs increase the breadth of their intercostal
spaces (as was mentioned years ago by Ham-
berger) ; and that by the contraction of an
intercostal fibre. The bars ( fig . 698.) in ro-
tating, twice attain a minimum, and once a
maximum, distance from each other; while
the oblique tension in that revolution once
attains its maximum, and once its minimum
length.

Of tensions at different parts of the bars or
ribs. — Parallel tensions of equal power pro-
duce the same effect, whether near the ful-
crum or more distant from it ; an intercostal
fibre near the vertebrae, has the same power
as a fibre near the anterior extremity of the
ribs.

Let Fig. 696. represent ribs as before, with
two parallel tensions at different distances
from the body, E e, then
t' + a m — t' -\-am—t' -\-x(am — am)—t'+ a o
t + a n — t+a n — t+(A N — (I»)=t + A0.
Therefore the tension l t ( fig . 694.) acts with

the same power as tensions p p', which is
much nearer to the fulcra a b.

Knowing now the effect of a single oblique
tension, it is easy to consider an indefinite
number of tensions, for they follow the same
law of action.

In Jig. 699. the tensions x acting on a c, lift
Fig. 699.

the bars to in', and, by the same reason, ten-
tions observing a contrary direction and acting
upon a' c' lift the bars to in'". Therefore
tensions, although observing contrary direc-
tions, may be made to conspire to the same
action, and may therefore be associates when
acting upon different fulcra. We have shown
that tensions in contrary directions, but acting
upon the same fulcra, are antagonists. If we
join the levers ( fig. 699.) and increase their
number, we may represent the thorax as in
Jig. 700., k/c representing the spine, bb the
sternum, the bars a a the ribs, and the bars
a' a' the costal cartilages united to the bars
representing ribs by a movable joint ; let r
represent the external intercostals, these, we
know, will act as elevators, while those at h,
representing the internal intercostals, are asso-
ciates in action, although they observe a con-
trary direction, because they act upon the
fulcra in b b ; in fact, they are elevators of
the levers representing the cartilages.

What now is the combined action of a
series of two such tensions ? The whole body
of levers will be raised, and the part b b re-
presenting the sternum will have two motions :
it will be raised and moved forwards into the
position of b'b'. This is precisely the mo-
tion of the sternum in deep inspiration.
In a model of this kind, certain means
must be used to limit the motion, or the
movement is continued until the tensions
are at rest. Or, if the bars representing the
ribs a a ( fig . 700.) be fixed, then the tensions
representing the internal intercostals h would
depress the short bars representing the car-
tilages, because b b is free, and k k is fixed.
And were either set of tensions continued
over the joints representing the union of the
cartilages with the ribs, such fibres would

THORAX. 1055

antagonise each other. In nature the external
intercostals are not continued over to the in-
tercartilaginous spaces.

Fig. 700.

In this model all the ribs are elevated with-
out the first bar being drawn up by any ten-
sion representing the scalenii muscles. In
fact the fulcra are the fixed points ; therefore
there are here six fixed points for the tensions
to act upon, and hence each row of oblique
tensions acts quite independently.

This application of force and disposition of
the bars representing the ribs is after the
manner of that great engine of power the
“genou lever.” (Vide Potter’s Mechanics.)

Tensions in the first space {Jig- 700.) act
with a greater power in pushing out the body
b than do the tensions in the 5th space ; but,
on the other hand, the motion is less in the
1st than in the 5th space. It will also be
seen that these six bars, though moving all
equally, will produce an unequal effect upon
the body b b, forcing out the lower end more
than the upper end. The ribs of man, in the
same manner, increase in their length from
the 1st to the 8th, and, therefore, by an equal
mobility, an unequal protrusion of the sternum
is produced, advancing the lower end more
than the upper end. We have reason to believe
that the mobility of all the ribs is the same,
and that it is by their different lengths that the
different degrees of protrusion of the anterior
part of the thorax may be accounted for.

Having investigated the effect of artificial
tensions acting on bars made to represent
the ribs, we can now return to the consider-
ation of the action of the direct respiratory
muscles.

Action of the intercostal muscles (resumed). —
The intercostales externi are all elevators of the
ribs. Inspiratory muscles. They separate the
ribs in the act, and they can do this indepen-
dently of any other muscle fixing the first rib.
The intercostales interni have a double action.
All those portions between the ribs depress
the ribs and are expiratory muscles ; they also
approximate the ribs and in every way an-
tagonise the external intercostal muscles.
Those portions between the costal cartilages

are elevators of the cartilages, and associates
with the external intercostals, and, thence, in-
spiratory muscles. These muscles also can
act independently of any other muscle fixing
the first or last rib.

The intercostal muscles being antagonists,
they yield to each other, the same as any
other flexor yields to an extensor muscle.
We possess a perfect and definite command
over the ribs, and can stop their respiratory
movements at any stage of breathing, more
readily than we can those of the diaphragm.

It is necessary to healthy breathing that
we should raise all the ribs ; they are there-
fore all mobile, and all their intercostal spaces
are increased in their perpendicular distance
during inspiration, and diminished during ex-
piration.

II. Levatores costar um (Levatores breviores
costarum. Alb.). — These are narrow, tendinous,
and fleshy fasciculi {Jig. 672.) covering the pos-
terior end of the rib, and extending obliquely
downwards and forwards, in the same di-
rection as the external intercostals. Their
superior attachment is to the extremities of
the transverse processes of the dorsal ver-
tebrae ; their inferior to the margins of the
ribs between their angles and tubercles.
These fibres spread out and become flat at
their insertion. Each rib receives one from
the vertebra next above ; there are therefore
twelve muscles on each side ; and that for
the first rib is derived from the last cervical
vertebra. The inferior muscles of this series
divide into two parts ; one of which is distri-
buted as above stated ; but the other, consist-
ing of longer fibres, passes over one rib and tc-r
ininates on the second below ; and thus each
of the lower ribs receives muscular fibres from
the transverse processes of two vertebrae. The
long bands have been described as separate
muscles under the name levatores longiores
costarum (Albinus).

Action. — The same as the external inter-
costals. Elevators of the ribs and inspi-
ratory muscles. Acting directly upon their
fulcra, the transverse processes of the ver-
tebras.

III. Triangularis sterni ( Sterno-costalis , Ver-
heyen). — A thin flat plane of muscular and
tendinous fibres (fig. 674.) placed within the
thorax, immediately behind the costal carti-
lages. This muscle is attached to the inner
surface of the ensiform cartilage, lower part of
the sternum, and the cartilages of the lower
true ribs. From these origins its fibres pass
laterally along the inner walls of the thorax,
diverging upwards, horizontally, and down-
wards, and are attached by digitations (which
give to the outer margin a serrated appear-
ance) into the cartilages, lower border, and
inner surface, of each of the true ribs, from the
5th to the 2nd inclusive.

Action. — This muscle varies considerably
in the extent and points of its attachment in
different bodies, and even in the opposite sides
of the same body. Hence, it aids in drawing
down and drawing up (according to the di-

1056

THORAX.

rection of its fibres) the ribs. It may be said
to be both inspiratory and expiratory.

IY. Infra-costales (Verheyen). — In connec-
tion-with the inner surface of the ribs {fig. 673.)
several small bundles of fleshy and tendinous
fibres, which are thus named, will be found ex-
tending over two, and in some instances over
three, intercostal spaces. They have the same
direction with the internal intercostals, and are
(properly) often described as parts of those
muscles. The fasciculi vary in size and number,
and may be found on any of the intercostal
spaces, except, perhaps, the first ; but they are
most constant on the lower ribs.

Action. — The same as the costal portion
of the internal intercostals, depressors of the
ribs and expiratory muscles.

Of the elasticity of the ribs. —
Elasticity depends upon reaction, and restores
in a contrary direction the force which have
been impressed ; the effect produced is com-
mensurate with the amount of the cause, and
the reaction can never take place so long as the
cause continues to be applied ; but immedi-
ately that cause ceases, the elasticity comes
into action.

Inspiration is performed by the true inspi-
ratory muscles, and expiration, by the expira-
tory muscles, and the elasticity of the ribs
and their cartilages, together with the elasticity
of the lungs. We find a broad difference
manifested between the inspiratory and ex-
piratory power (Table R.), the latter exceed-
ing former by about one third. This differ-
ence is due to the elasticity of the ribs and
lungs associating their power with the ex-
piratory muscles. The combined elastic power
is very great ; we have examined it in two fa-
vourable cases, an hour after death, when
the bodies had not fallen one degree in
temperature.

X. H., a young man, slightly built, erect
and well formed, eet. 22, weight 9ist., height
5ft. 10in., vital capacity 235 cubic inches.
The absolute capacity of his chest was 248
cubic inches ; internal area 256in.; circumfe-
rence of the chest, over the nipples, in the or-
dinary state, alive 33 inches, dead 30A inches.
After death we forced air into his lungs, whilst
the temperature of the body was still at 97°.
The force resisting the introduction of this air
must havebeen due to the elasticity of the ribs
and their cartilages, together with that of the
lungs. By an arrangement, we could force in
different quantities of air, and measure the
collapsing power of the elastic parts, through
the medium of the confined air pressing upon
a column of mercury : the following was the
result : —

Table K. — Costal elastic Collapse.

X H.

Inch of

cub. in. mercury.

Air forced in 70 Resisting elasticity T20

Ditto 90 ditto T25

Ditto 160 ditto 2’50

We could not force in more air, for with this

pressure it was impossible to prevent the air
escaping with great rapidity through the ne-
cessary wounds. This experiment was re-
peated three times with the same result. It
will be remembered that X. H. had drawn
into his lungs, when alive, 75 cubic inches
of air more than we could force in, after
death. If, therefore, 160 cubic inches pro-
duced a collapsing elastic force equal to 2-5
we may suppose that 235 cubic inches would
produce an elastic force equal to not less
than 3‘9 in. of mercury. This chest, mea-
suring 256 superficial square inches, it fol-
lows that X. H., in breathing out 235 cubic
inches of air, with no more sensible effort
than that of a mere sigh, had to overcome
with his inspiratory muscles a gross elas-
tic resistance of about 499lbs., and with a
force equal to this weight would the thoracic
walls recoil for expiration upon the air in his
lungs.

N. C., height 5ft. 8in., weight lOst. 10lb.,
aet. 21: vital capacity, 200 cubic inches; ab-
solute capacity, 245 cubic inches; superficial
measurement of the entire thoracic cavity,
256 square inches ; circumference of the chest,
alive, 33 inches, dead, 34^. Temperature of
the body, when examined, 97° F. Tempera-
ture of the air forced into the lungs, 63° F.
This man was what is termed “ thick set,”
firm, erect, and well built, a porter by trade, a
very different case from the former. The fol-
lowing was the elastic power of his ribs : —

Table L. — Costal Collapse in N. C.

Inch of

cub. in. mercury.

Air forced in 70 Resisting elasticity l'OO

Ditto

90

ditto

1-50

Ditto

180

ditto

3-25

Ditto

200

ditto

4-50

The first ninety inches of air introduced
ruptured the lungs ; therefore the elasticity of
the lungs did not interfere with our experi-
ments. In both cases this resistance must be
referred only to the ribs, their cartilages and
ligamentous attachments ; also, in both cases,
the bodies were kept erect, or in the sitting
posture ; this should be attended to, for the
mere weight of the body upon the ribs when
recumbent would increase their collapsing
power.

These tables express a dead power al-
ways in reserve, equally powerful whether
we are in robust health, or emaciated by
age or disease. Dead or alive, this is ready
to be put into force ; and, in fact, it is
never at rest, never at zero, until death ; we
may even go farther, and say, not until de-
composition has weakened the collapsing ten-
sion of these parts. Cut through a costal
cartilage, or take out a small portion of the
sternum, say corresponding to the 3rd, 4th,
and 5th intercostal spaces, and the opening by
the elasticity of parts will retract , and we
never can restore them again to their original
fit, because the thoracic parietes are still not
at rest. The bony cage-work of the chest is

THORAX.

1057

so tightly knitted together, that at its mini-
mum contraction there still remains an elastic
force in operation. In fact we might expect
this, because the respiratory movements are
so small that it is necessary that an extensive
elastic power should be ready at all the re-
spiratory stages ; and therefore the parts are
upon the stretch before we begin to inspire in
order to increase to the geometrical degree re-
quired, of two, three, or four pounds to the
inch, by a very limited movement, which
would not be the case did we begin to in-
spire when the thoracic boundaries were at
zero, at least, if it did, the walls, &c., would
have to be much stronger.

Supposing inspiration to be the result of
muscular force equally distributed over the
whole thorax, the inspiratory power is easily
calculated. Taking the walls of the chest at
206 superficial inches, and the area of the
diaphragm as 51 superficial inches, and placing
them separately, it would appear as follows: —

Table M. — Inspiratory Muscular Power re-
quired to overcome Costal Elasticity, mea-
sured by the Insufflation of 200 Cubic Inches
of Air. (Case, N. C.)

Air forced into the
Chest.

Resistance manifested by
Inches of Mercury.

The same reduced to
Ounces on the superficial
Inch over the Thorax.

The same, given as a
total Force in lbs.

Total Power required by
the Diaphragm to resist
the Collapse of the Ribs,
in lbs.

Total Powersof the Walls
and Diaphragm conjoin-
ed, in lbs.

70

1-00

7-8

1044

24-8

129-2

90

1-50

11-7

150-6

37-3

187-9

180

3-25

25-3

326-3

80-6

406-9

200

4"50

35" 1

451-9

111-8

563-7

At the same time it must be remembered
that this result is produced by insufflation
which would excite an undue elastic tension
in the diaphragm and abdominal muscles. Yet,
on the other hand, in life a greater expansion
would be produced by the ribs, and thence a
greater resistance.

It may be questioned how far we are
entitled to add a resistance as due to the dia-
phragm. But let us suppose a thoracic cavity
collapsed to rest, with a fleshy floor or dia-
phragm also quiescent; let us suppose the
ribs expanded by some power from without ;
the air within the chest would be attenuated,
and the diaphragm would be forced upwards,
by atmospheric pressure, with a force exactly
commensurate to the rarefaction of the air
within the chest (presupposing that no air is
allowed to enter the chest when we expand the
ribs). In this case the diaphragm is resisting
the same force per inch as the walls of the chest.
Or on the other hand, fill the chest with
air to perfect distension, allow the ribs to
collapse, the diaphragm would have to
resist this collapse with a power exactly
commensurate with the recoiling elasticity of

VOL. IV.

the ribs ; therefore the diaphragm participates,
in common, in such resistances in the tho-
racic cavity. But, as the question may be
open to objection, we shall chiefly notice that
power in reference to the parietes of the
chest, given in the 3d and 4th columns in the
last table. This table shows that the man,
when alive, exerted a muscular power with
the walls of the chest, when he inspired 200
cubic inches of air, equal to a total weight
of 451"9 lbs. avordupois. Independently of
the collapsing elasticity of the lungs, which
would be not less than 128 lbs. more (see
Table O), his inspiratory muscles lifted a
weight of 32 stones, — a weight which he
could not have lifted with his arms : and yet
the animal economy is not conscious of this
exertion. We have supposed a uniform mus-
cular traction, which is not the case, because
the distribution of muscular fibre and tho-
racic mobility, is not equally applied in ex-
panding the chest. In diagram fig. 670, d
represents a section of the thorax : the portion
shaded is the range of thoracic mobility be-
tween extreme inspiration and expiration. The
mobility is unequal ; more is on the anterior
than on the posterior part ; therefore w-e may
presume muscular traction to be more at
one part than at another. This man could
exhale 300 cubic inches of air ; and there is
every reason to think, from this extensive
mobility, according to our last estimate, that
the elastic collapse of his ribs, at the termina-
tion of deep inspiration, would be not less
than 1000 lbs.

In the superficial measurements of the
thorax we have included every part, even
that covering the vertebras. Now certainly
we cannot think the elastic collapse over the
vertebra equal to that from the sternum ;
therefore, if we allow one-third of the chest
to be inactive, and the remainder elevated by
the respiratory muscles (which we think is
within the mark, because every part of the
chest is mobile), then in the case of N. C. in
deep inspiration the muscles would have to
overcome 301 lbs., or 23 ounces on the super-
ficial square inch of the thorax.

The last act of life is a deep expiration.
During life the ribs are always kept under a
certain degree of distension, which is ready
to send out from 70 to 100 cubic inches of
air at any moment ( Reserve air, p. 1067).
Our inspiratory muscles, in fact, are always
antagonising an elastic thoracic collapse ; and
this is always increasing or decreasing, ac-
cording to the stage of respiration, as quiescent
or forced, &c. There are cases, as in hang-
ing, where a man may die, at the moment of
full inspiration, from fear, making an effort to
resist the dreaded shock which he is about to
receive. N. C. died thus in a state of inspira-
tion. Making allowance for unequal elasticity
of the boundaries of the thorax, of -J- as above
stated, it may be safely said that the dif-
ferent stages of respiration or breathing re-
quire the following muscular power to antago-
nise the elastic power of the ribs throughout
life.

3 Y

1058

THORAX.

Table N. — Inspiratory Muscular Power
(corrected).

Different stages of
inspiration.

Elastic resist-
ance in ounces
on the super-
ficial square
inch to be over-
come by the
respiratory
muscles.

Total re-
sistance of
the same in
lbs.

la 1

5* \

Reserve air

5-G

09-G

l

Breathing air

7*8

104-4

Qi .
o .

Vital capacity

23-9

301-0

Thus we see that in the mere act of or-
(Unary breathing there is an elastic resistance,
independently of the elastic force of the lungs,
equal to more than 100 lbs. This is to be
lilted 18 or 20 times every minute of our life.

Of tiie Elastic Power of the Lungs.
— Independently of the powerful collapse
ol the ribs and their cartilages, expiration
is greatly aided by the elasticity of the lungs
themselves, which at all times', and in all the
stages of respiration, are tending to collapse
upon themselves ; and hence, immediately
upon puncturing the thorax, the lungs col-
lapse to half their dimensions.

From the earliest period of physiological re-
search, as usual, totally opposite opinions have
alternately prevailed as to whether the lungs
themselves are active in the respiratory move-
ments. Averroes, Riolan, Planter, and Bre-
mond#, were in favour of their independent
action ; and Bartholin, Diemerhoeck, Mayow,
and Haller f, opposed to it. Their elastic con-
tractility can only have been lost sight of by
reason of their quick contractible power ; for
immediately the thorax is punctured, before
parts are cleared away sufficiently to give a view
of the contents of the thorax, the lungs have
collapsed to their minimum, and a vast space
is always presented between the lungs and the
thoracic walls, which, by the old anatomists,
even in the time of Hoadly (1740), was con-
sidered to contain air necessary for respiration.

Dr. Carson of Liverpool appears to have
first noticed this elastic power of the lungs.
He judiciously observes : “ Breathing is, in
a great measure, the effect of this intermin-
able contest between the elasticity of the
lungs and the irritability of the diaphragm.” +

In his experiments upon the lungs of some
lower animals (bullocks), he found a collapsing
power equal to a column of from 12 to 18
inches of water; in a calf about 18 inches;
and in a dog about 10 inches.

In these experiments, the lungs, when in
situ, were inflated to their maximum. Pro-
bably the ribs interfered by their resistance
in aiding the collapse of the lungs. Never-

* Mem. de l’Acad. des Sciences, Paris, 17S9 ;
Muller, p. 346.

t El. Phys. t. iii. 1. viii. p. 226.

| Phil. Tr. 1820, part i. pp. 42, 43.

theless, at all times of nidation, even when
the residual volume only was in the lungs,
there was an elastic power in operation. Mr.
Gulliver informs us, that from an examination
of the lungs of man and the lower mammalia
he has been led to infer that the elastic tissue
is an important agent in expiration. This
tissue, he says, may be seen to invest the
entire surface of the lungs, forming a strong,
elastic, though delicate, capsule to the organ.
This investment of the lungs in the horse,
he informs us, resembles the fibres of the
ligamentum nuehae and the fibrous coat of
the aorta of the ox, as depicted in Gerber’s
Anat. pp. 54, 55.

The longitudinal fibres which enter into the
structure of the air-tubes throughout their
entire extent are very elastic, like the coats
of the arteries, and these are justly supposed
to possess the power of contracting each mi-
nute ramification of the lungs. When this
elastic power is at rest, and the lungs are col-
lapsed to their minimum, no external pressure
can discharge the remaining volume of air,
because the very pressure, to accomplish this,
compresses the exit tube in some part of its
course. The elastic contraction of each tube
acts somewhat like the vermicular motion of
the intestines, causing a specific diminution
of calibre upon each part of the column of
air in a ramification, driving it forward. But
when the elasticity has arrived at its mini-
mum, and this tissue is quiescent, we cannot
extract any more air from the lungs, because
the vermicular expelling power derived from
this elastic tissue ceases to act. The col-
lapsing power of the lungs acts in the same di-
rection as that of the ribs, but with less force.

According to Tables O and P. the total elas-
tic collapse of the male lung was equal to about
4301 grs. or nearly 10 oz. avoirdupois (9-8)
upon the superficial square inch of that organ,
and in the female about 50G0 gr. or 1P3 oz.
upon the superficial square inch. We think,
taking all things into consideration, that it is
safe to say, in making a deep inspiration for the
vital capacity-volume, that we may estimate the
elastic collapsing power of the lungs at one half
lb. avoirdupois, per superficial square inch ;
therefore, allowing the mean superficial mea-
surement of the male lung to be 300 in. and the
female 247 in., that the grow resistance, by the
elasticity of the lungs against the inspiratory
muscles, would be in the male 150 lbs., and
in the female 123 lbs. This is to be added
to the elastic force of the ribs (Table N).
In the female an unknown portion of the
residual volume escaped before we could
connect the hsemadynamometer ; for the next
volume added, of 90 cubic inches in the man
with all his residual volume, the collapsing
power was 7*2 in., and in the female, with the
addition of 100 cubic inches, it was 5‘5 in.,
which about makes up the difference of 2
in. of collapsing power lost by the accidental
escape of the residual volume.

In the case of two healthy persons ex-
amined immediately after death, — E. F. M.,
male, height 5 ft. 9 in., weight 10 st. 10 lbs..

THORAX.

1059

circumference over the nipples, alive, 38 in. ;
dead, 36 in. — died with an expiration, — we,
by means of the hoemadynamometer, contain-
ing water, attached to the trachea, found,
with different volumes of air in the lungs,
the following elastic collapsing power (tem-
perature— of body 98‘5° Fahr. — of atmo-
sphere 59‘5°, barometer 29-753).

Table O. — Elasticity of the Lungs (male,
aat. 29.).

Elastic col-
lapsing power,

* Volumes of air. in. of water-

Residual vol. - 2‘5

Reserve vol. ( + 90 cubic inches) 7'2
Breathing vol. ( + 20 ditto) - 8‘2
Vital capacity (+ 25 ditto + 150

ditto) 17-0

M. M, female; sudden death; temperature
of body 97-5°Fahr. ; ast. 28; height 5 ft. 9 in.;
circumference of chest over nipples 37 in.;
below 32) ; lungs healthy.

Table P. — Elasticity of Lungs (fern., set. 28.).

Elastic col-
lapsing power,

Volumes of air. in. of water.

Residual vol. - 0-7

Reserve vol. (+ 100 cubic inches) 5 5
Breathing vol. (+100 ditto) - 10‘0
Vital capacity (+ 90 ditto) 20'0

At the commencement of “ordinary breath-
ing” the collapsing power of the lungs in
our experiment was 7-2 in., or nearly * of
a lb. per superficial square inch. This is a
very notable power, not less in the gross,
oftentimes, than 100 lbs. of dead uncounter-
balanced resistance to the respiratory mus-
cles. In the female, with nearly an arith-
metical increase of 100 cubic inches per vo-
lume, the collapsing power increases 5 to 10
and 20. The insufflated volume in the male
being less regular, the collapsing power ma-
nifested is also less regular. But, taking the
mean resistance of the reserve and breathing
volumes in the male combined (160 cub. in.),
the power of collapse was 7’7 inches. In the
female, the mean of nearly the same quantity
of air in the lungs (within 10 cubic inches)
allowing for little or no residual volume at the
starting point when we inflated, is likewise
7-7 inches. We believe that the elastic power
of the lungs in the two sexes is the same ; —
indeed why should it not be so? because
the office of the elastic tissue is to drive
out of the lungs volumes of air no longer
required ; and it is probable that the resistance
given by the air, against the sides of the air
tubes, in both sexes, is the same; and unless
the number and calibre of the air tubes are
different, the resistance, by friction, to the
elastic collapse of the lungs, from the trans-
mission of similar volumes of air in the two
sexes, must be the same.

In three experiments we found the elastic
collapse of the lungs cease at different degrees;
i. e. different volumes of residual air were
displaced when the elastic force had come to
its minimum.

* For definition of these terms see p. 1065.

Table Q — Volume of Residual Air displaced by
the Elastic Collapse of the Lungs when the
Thorax was opened, in three Males.

Height.

Weight.

Circum. of
chest.

Weight of
Lung6.

| Vital capa-
I city.

Volume dis-
placed.

Bronchial

expansion.

H.

ft, in.

5 10

St Il)S.

II 10

in.

30i

lbs

in-

240

in.

30

in.

7

C.

5 8

10 10

34*

16J

200

60

1-5

M.

5 9

11 0

36

36

238

45

12-5

There is no order in the numbers 30, 60, and
45, relative to the other measurements. We
do not know what quantity of air remained after
these volumes were displaced. When we ex-
hausted the remainder of the residual volume,
which is not affected by the elastic collapse of
the lungs, the sides of the air tubes themselves
collapsed by the atmospheric pressure. They
likevvise are elastic, but in a contrary direc-
tion ; an expanding elasticity keeping them
open. We found that the expanding elasticity
acted so as to draw or suck inwards the air
with the different powers represented by 7, T5
and 12'5 inches of water in the haemadynamo-
meter, when we attempted to withdraw out of
the lungs more air than the lungs themselves
naturally displace by their collapsing elasticity.
Therefore these figures may represent the ex-
panding elasticity of the air tubes. In these
cases there is no apparent order ; but we learn
the fact that such elasticity^ exists. In the
case C there was a tubercular condition of
lung, in the milliary form, in one apex ; in II
there wras extensive pleuritic adhesions ; but
in the case of M the lungs were remarkably
healthy. It is interesting to notice that there
are here two elasticities in contrary direc-
tions,— an elastic collapse which has its limit
at a certain point, and an elastic expansion
of the air tubes, which likewise have their
limit of expansion at the same point, protecting
the calibre of the air tubes from any further
collapse.

In the case of M the expansion of the air
tubes was equal to 12 '5 inches of water ; by
calculation it appears that the collapse of the
elastic tissue upon the vital capacity volume
would be about 14 inches. These antago-
nistic forces are quite independent of the will,
or any nervous stimuli : one is for maintain-
ing an expiratory current of air, and the other
for preserving an open channel in the lungs for
inspiration.

The lungs are very delicate organs, and can
resist but little artificial force ; for, if once
inflated to the ordinary state of either the
breathing volume or vital capacity volume,
they do not appear able to collapse again to
their original size ; — probably intra-lobular
emphysema is produced.

In our experiments we forced air into the
lungs; they were expanded because we inflated
them. We now think it would be better to

3 v 2

10G0

THORAX.

inflate them by expanding them (removing the
external atmospheric pressure), and allow the
air to drop into the air vesicles by its own
gravitation (as in living respiration), when
they would in all probability collapse freely
to their original position. When they are in-
flated by expansion (the natural way of life)
the delicate cells of the lungs can safely resist
a force of from 3 to 9 inches of mercury, or
from 40 to 121 inches of water (see next
column) ; but when expanded bp inflation ,
their collapsing power was damaged so that
it could sustain only 17 or 20 inches of water.
This is worthy of notice in resuscitating the
apparently asphyxiated person, at which times
we have long been of opinion that bellows
and pumps are highly dangerous instruments
to use for maintaining artificial respiration.

Of the muscular contractility of the lungs.

— In the trachea transverse muscular fibres
extend across posteriorly, connecting the tips
of the incomplete rings of cartilage. In the
smaller bronchi they encircle the whole tubes,
and there appears to be little doubt but that
these circular fibres are to be found in every
part of the air tubes as far as the terminal air
vesicles.

Physiologists have disputed whether these
fibres are muscular or not ; if muscular, they
are important agents in respiration, acting as
a series of little expiratory muscles.

Dr. C. J. B. Williams lately read a paper at
the meeting of Glasgow (September 1840),
upon the subject.* He experimented upon
the lungs of some of the lower animals, —
several dogs, a rabbit, a bullock, a horse, &c\,

— as soon as possible after death, submitting
their lungs to galvanic stimuli, and securing a
hmmadynamometer with a stop-cork to the
trachea. He found that, upon applying this
stimulus, the fluid in the bent tube rose from
1 to 2 inches, and it immediately fell on break-
ing contact. This effect could only be pro-
duced by muscular contraction.

Kdlliker, a very accurate observer, confirms
these views, j- He found in man, in the larger
and finer bronchial tubes, a coat formed
of annular fibres, in one or more layers
according to the size of the tube, consisting
of unstriped muscular fibres ; and over this
coat a thin layer of fibro-cellular tissue
with nucleus-fibres. He found no mus-
cular fibres directed longitudinally. He ob-
serves, “ In former observations I thought
I had convinced myself of the existence of
unstriped muscular fibres in the air-cells; but
in my resumed examination of the lungs of
man and mammalia, I can with certainty see
nothing distinctly characteristic as such mus-
cular tissue.” Our knowledge of these cir-
cular muscular fibres was first chiefly derived
from the researches of Reisseissen. Laennec
considered spasmodic asthma to be assignable

* The Pathology and Diagnosis of Diseases of
the Chest, 8vo. by Dr. C. J. B. Williams, 1840, Lon-
don, p. 320.

f Beitrage zur Kenntniss der glatten Muskeln
in the Zeitschrift fur Wissenschaftliche Zoologie.
H. i. S. 40. 8vo, 1848.

to a spasm of these circular fibres. We are as
yet ignorant of the possible extent of contrac-
tion of these fibres. The discharge of air is
paramount, and that from the most remote vesi-
cle ; and we know that by no mechanial means
can we obtain this, and therefore a molecular
power is necessary, which we readily imagine
can be obtained by these tissues acting so
as to give a peristaltic motion, and thus dis-
placing from every individual vesicle the de-
licate stream of air necessary to be dis-
charged. We do not need these tissues for
inspiration, because the atmosphere, by its
mere weight, can penetrate into the most
remote air-cell, overcoming all the friction
against the sides of the air-tubes. The in-
spiratory volumes of air are but for one pur-
pose, to aerate the blood ; but the expiratory
volumes are for the voice and other purposes
sometimes requiring great force to aid in cer-
tain expulsive efforts.

Of Respiratory Muscular Power. —
Young falls into an error in supposing “ that
in muscles of the same kind the strength
must be as the number of fibres, or as
the extent of the surface which would be
formed by cutting the muscle across ; and it
is not improbable that the contractile force
of the muscles of a healthy man is equivalent
to about 500 lbs. for every square inch of the
section.” * When we examine men we find
no such calculations are to be relied upon.
It is very common to find two men of cor-
responding dimensions produce very different
effects upon any dynamic instrument.

The respiratory power mayor may not cor-
respond with the general development of mus-
cular force.

We have submitted 1500 men of various
classes to an experiment upon the inspiratory
and expiratory power. The resistance to this
power was a column of mercury, — th ehcemady-
namometer, or bent tube, first used by Dr.
Hales. He observes, “ A man, by a peculiar
action of his mouth and tongue, may suck
mercury 22 inches, and some men 27 or 28
inches, high ; yet I have found by experience
that, by the bare inspiring action of the dia-
phragm and dilating thorax, I could scarcely
raise the mercury 2 inches.” f Hales appa-
rently never tested the expiratory power.

We connected the column of mercury with
the index on a dial plate, which represented the
inches and tenths of inches of mercury lifted.
A tube was adapted to fit the nostrils through
which the inspiratory or expiratory effort was
made. By the former the index was moved
in one direction, and by the latter in the con-
trary direction ; each half of the dial plate
representing, respectively, inspiratory and ex-
piratory power, with expressive words at-
tached, as follow: — (See top of next page.)

It will be observed that the figures on each
side of the same word differ in their value,
those of the expiratory side ranging about one-
third higher than those on the inspiratory side.

* See Nat. Phil. Loud. 8vo, 1845, p. 99.

f Stat., vol. i. p. 267.

THORAX.

1061

Power of
Inspiratory
Muscles.

Table R.

Power of
Expiratory
Muscles

1*5 in.

Weak -

- 2-0 in.

2-0 „

Ordinary

- 2 5 „

2 ’5 „

Strong

- 3-5 „

3‘5 ,,

Very strong

- 4’5„

4-5 „

Remarkable

- 5-8 „

5'5 „

Very remarkable

- 7-0 „

6-0 „

Extraordinary -

- 8’5 „

7-0 „

Very extraordinary

- io-o „

Indeed when these powers are the same, it
indicates disease. We subjoin the following
table of the result of these cases. (Table S.)

To illustrate one of the points so striking
in these experiments (viz., the difference be-
tween the inspiratory and expiratory power),
we refer to diagram 701., which represents by

curves their relative position. The upper
line is the expiratory power, and the double
line below, the inspiratory power. The per-
pendicular lines are the different heights of
the cases examined. The position of these
curved lines indicates the power they re-
present, — the higher the curve the greater
the power. The two rows of figures at the
bottom are the inches and tenths of inches of
mercury elevated. (I. for inspiration, and E.
for expiration.)

According to this, at the height of 5 feet 7
inches, and 5 feet 8 inches, the inspiratory power
is greatest, and thence the inspiratory power
gradually decreases as the stature increases.
The men of 5 feet 7 inches anil 8 inches
elevate a column of 3 inches of mercury :
this may be considered a healthy power ; and
the men of 6 feet high elevate about 2J inches
of mercury as their healthy power.

Fig. 701.

ft. in ft. in. ft. in. ft. in. ft. in. ft in. ft. in. ft. in. ft. in. ft. in. ft. in. ft. in. ft. in. ft. in.
5051525354555S5758595 10 5 11 606 +

Expiratory.

Inspiratory.

E. 3-28 3-36 3'23 3 15 4'32 4'33 3'37 4‘13 4'13 4'28 5'94 3 63 448 4'4l

I- 2-55 2'0 2-52 2'31 2'70 2'84 2'70 3-07 2‘96 2‘91 2‘83 2'77 265 2'67

Inspiratory and expiratory power in healthy cases.

It may be asked, why connect this with
the height? Because it was found in six
collateral observations that this was the only
physical condition which presented a relation
so as to throw the experiments into an or-
derly position.* By Table S we see that the
respiratory power varies in different classes.
The “gentlemen,” for instance, are below most
of the other classes : at the height of 5 feet 8
inches, they elevate by inspiration 2‘35 inches
of mercury. This may account for the fact
why Dr. Hales could only raise 2 inches of
mercury by this effort.

The expiratory power is normally more
irregular — more apt to vary — than the inspi-
ratory power. The expiratory muscles par-
ticipate in other duties besides that of mere
expiration ; the vocation of the glass-blower,
the trumpeter, the wrestler, the jeweller
(blow-pipe), and the sailor, especially call
these muscles into use, increasing their na-
tural power. They thus oftentimes become
excessively strong. The inspiratory muscles
are exclusively for supplying us with air, in
which act they have only to oppose the
uniform resistance of elasticity. The inspira-
tory power is therefore the best indication
of the “ health ” — the “ vis vitce.”

As an instance of the effect of vocation chang-

* For the other observations, see p. 1068, and
Med. Chir. Trans. 1846. Yol. 39. p. 143 et seq.

ing one of the respiratory powers and not the
other, we may notice the Metropolitan po-
lice and the Thames police. The inspiratory
power of these two classes is nearly equal,
whilst the expiratory power of the Thames
police exceeds that of the Metropolitan
police, — the former using their upper extre-
mities, whilst the latter use their lower ex-
tremities most : — the former chase the thief
by the use of the oar ; the latter by the
swiftness of their legs.

Compositors and pressmen stand low
the former are the lowest in their respiratory
power ; the pressmen are much higher. The
order in which some of these classes come is
as follows : — the most powerful are the
Thames police ; next, the sailors ; the pau-
pers and the gentlemen are nearly equal ;
and lastly, diseased cases. The two last lines
is the mean of the four healthiest classes, —
the seamen, firemen, Thames police, and
pugilists : their maximum is 3 inches ; the
mean of the whole classes together is little
more than 2£ inches. The measure of this
power when expressed by inches of mercury
appears small, yet, when hydrostatically con-
sidered, it is very great. Men have wondered
that they could not elevate more mercury in
the tube; but all surprise vanishes when it is
recollected, that, by the law of hydrostatics,
when a column of 3 inches height of mer-

3 y 3

TaSle S. — Inspiratory aild Expiratory Power in relation to the Stature.

1062

THORAX.

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THORAX.

1063

cury is sustained, the force exerted by the
diaphragm alone is equal to the weight of as
much mercury as it would take to cover a
space of the same area as the diaphragm,
three inches deep. The column of mercury
raised, therefore, will not safely serve to
compare the respiratory power of men of
different dimensions, for the area of the thorax
must also be considered. For instance, we
examined a man, 4 feet 7iinches high (circum-
ference of the chest 29 inches), who raised
3' 15 inches ; and another man, 7 feet high
(chest 50 inches in circumference), who could
only elevate 3 inches of mercury : but the
dissimilarity between the area of the dia-
phragm in the dwarf and giant was such,
that the latter in reality lifted about 500 lbs.,
and the former only about 39 lbs. Suppose
the base of his chest to be 57 superficial
square inches ; had this man raised 3 inches
of mercury by his inspiratory muscles, his
diaphragm alone must have opposed a resist-
ance ecjual to more than 23 oz. on every inch
of that muscle, and a total weight of more
than 83 lbs. Moreover, the sides of the
chest, by attenuating the air within, resist
an atmospheric pressure equal to the weight
of a covering of mercury 3 inches in thick-
ness, or more than 23 oz. upon every inch
surface, which, if we take at 318 square
inches, the chest would be found to resist
a pressure of 713 lbs. ; and, allowing the
elastic resistance of the ribs as 1| inch of
mercury, this will bring the weight resisted
by the inspiratory muscles of the thorax as
follows : —

Diaphragm -
Wails of the chest
Costal resistance (elastic)
Lung -

83 lbs.
73 1 „
232 „
100 „

1146 lbs.

Or, in round numbers, we may say, that the
inspiratory muscles of such a man of ordinary
dimensions resisted 1000 lbs. This is a re-
sistance not counterbalanced ; for were it
counterbalanced, it would only be mere dis-
placement. We have made a safe addition
for the elasticity of the lungs. We think it
may be confidently stated that nine-tenths
of the thoracic surface conspire to this act,
allowing the remainder to lie dormant.

Although the difference between the in-
spiratory and expiratory powers, when tested
to their utmost, is so great, yet it must not l>e
thought that these two powers aie in their
ordinary action so dissimilar; and indeed,
when all things are considered, the question
may still be asked, is the inspiratory or ex-
piratory act the strongest? In the last table
(Table S.) there is uniformly a difference,
because the two powers are unequally taxed
with resistance. All elastic force is co-ope-
rating with the expiratory power, whilst it
antagonises the inspiratory power; therefore all
the power manifested in inspiration is muscu-

lar ; but in expiration it is partly muscular and
partly elastic power. This probably causes
the great apparent difference between inspira-
tion and expiration ; at least, if we separate
the resistance we assign to the elasticity of the
ribs and lungs from the expiratory power, we
shall nearly equalise the two. This can beeasily
proved upon one’s own person : — partially
empty the chest of air ; then forcibly test your
expiration upon the haemadynamometer : pro-
bably you can only elevate the mercury ]a
inch; then inspire deeply, completely filling
the lungs, and now test your expiratory power,
— instead of If inch, it will probably be
5 inches. This difference appears due to
two causes. 1st. In the deep inspiration the
ribs are put more upon the stretch than in
the moderate inspiration. 2d. The chest, when
distended with air, presents points of attach-
ment for muscular traction, to a greater me-
chanical advantage.

The most remarkable respiratory power,
as tested by the haemadynamometer, was in
the case of a Chatham recruit, who was fre-
quently examined by Dr. Andrew Smith, on
whose accuracy we place implicit confidence.
The man’s age was 18; height, 5 feet 6 inches,
weight, 10 stones 5 lbs. ; circumference of his
chest, 35 inches ; vital capacity, 230; — his
inspiratory power was equal to 7 inches of
mercury, and his expiratory power to 9 inches !
The thoracic power of this man, according
to our last calculation, was equal to a gross
weight of 22CO lbs. This was the amount
manifested, and we may safely consider 50 per
cent, of muscular power to be lost by the
obliquity of the respiratory muscles ; so that
this man possessed a vital power equal to
nearly 2 tons! He exhibited in no other
respect any remarkable feature of strength.

A dynamic instrument like the haemady-
namometer would be useful to those whose
duty it is to examine men for certain public
services, as for the army, navy, police, fire-
brigade, &c. With care, it would often detect
disease. The efforts required to move the
mercury test the whole trunk of the body.
The inspiratory test produces a rarefaction of
the air within the thorax, causing an extra
(unbalanced) atmospheric pressure upon the
body from without. In this way we have de-
tected rupture of the membrana tympani; for
the air rushing in by this opening equalised
the difference otherwise produced. The ex~
piratory test is of a contrary order, increasing
the pressure from within ; in this way we
have detected hernia.

The difference between the healthy and dis-
eased respiratory powers is broadly marked. —
It is shown in the annexed diagram (Jig. 702.);
the lower curve is the power manifested by
diseased, and the upper curve that of healthy
persons. The difference is about 50 per cent.,
because weakness is the most prominent
symptom of disease. We do not compare
the expiratory power for the reason already
assigned. We affix at the bottom of the
diagram the relative powers in figures.

3 y 4

1064

THORAX.

Fig. 702.

Heights.

ft. in. ft.-in. ft. in. ft. in. ft. in. ft. in. ft. in. ft. in. ft. in. ]ft. in. ft. in. ft. in. ft. in. ft. in.
0 0 5051 5 2 5 3 5 4 5 5 5 6 57 58 5 9 ilO 511 GO

50 51525354555657 58 59 5 10 5 11 606 +

Healtliy. 2'55 2-00 2-52 2‘31 2'70 2'84 2'70 3'07 2'96 2 91 2+3 2’77 3'65 2 67

Diseased. .82 1‘30 1'16 l'OO 1'34 -74 L25 '79 L67 1'32 -93 -88 +0 1'65

Inspiratory power of the healthy and diseased compared.

Of the Respiratory Volumes. — For
1500 years, from the time of Galen to Robert
Boyle, naturalists, physicians, anti philoso-
phers disputed the simple operation of draw-
ing air into the thorax. There were three
explanations given : — First, “ That by the dila-
tations of the chest the contiguous air is thrust
away, and that, pressing upon the next air to
it, and so onwards, the propulsion is continued
till the air be driven into the lungs, and so
dilate them.”

Secondly , That the chest is like a pair of
common bellows, “ which comes therefore
to be filled because it was dilated.”

Thirdly, That the lungs are like a bladder
“ which is therefore dilated because it is filled.”

The great philosopher Boyle adopts the bel-
lows’ action viz., that the lungs are filled with
air, because the chest is dilated, and that with-
out the motions of the thorax they could not
be filled. “ Indeed,” says Boyle, “ the dia-
phragm forms the principal instrument of
ordinary and gentle respiration, although to
restrained respiration, if I may so call it, the
intercostal muscles, and perhaps some others,
may be allowed eminently to concur.” * Co-
temporary with Boyle, we find Richard
Lowerf (1667) correctly understanding the
respiratory action; he makes a dog breathe
like a broken-winded horse, by' dividing the
phrenic nerve. What Boyle and Lower demon-
strated, every one now believes without dispute;
yet it took 100 years’ disputation, through a
number of unfounded hypothetical and contra-
dictory speculations, before the truths which
Boyle and Lower promulgated were received.
As late as the eighteenth century, little more
than one hundred years ago (a. d. 1737),
it was stated in the Gulstonian Lectures
before the Royal College of Physicians that
there was air between the pleura? J, — a con-
dition which we now know is almost instant

* Boyle’s Life and Works, fol., Lond. 1744, vol. i.
p. 64.

f Phil. Tr. Abr., vol. i. p. 179.

1 Hoadly, Lee. on Kesp., 4to, 1740, Loud., p. 1 1,
et seep

death. The first great epoch in the history
of respiration was at the time of Harvey
(1628), when he published his first work on
the circulation of the blood, though at this
time he did not stand commended for his
discovery ; for most persons opposed it ;
others said it was old ; and the epithet “ cir-
culator,” in its Latin invidious signification,
was applied to him. We know respiration
depends upon the weight of the air; and
at a very remote period air was known to
possess the quality of weight. Aristotle and
other ancient philosophers expressly speak
of the weight of the air. The process of re-
spiration is attributed by an ancient writer to
the pressure of the atmosphere forcing air
into the lungs.* Galileo was therefore fully
aware that the atmosphere possessed this pro-
perty ; yet when his attention was so immedi-
ately directed to one of the most striking effects
of it, he did not see its connection with respira-
tion. It was reserved for his pupil, Torricelli,
to discover (1643) the true law of atmo-
spheric pressure ; and as we can find no phi-
losophical reason assigned, prior to this date,
why air enters the lungs in inspiration, we may
date this as a first step in the advance of
knowledge upon our subject. Nevertheless,
no less an authority than Swammerdam
adopted, for upwards of twenty years after
this, the unphilosophical reasoning of Des-
cartes, that the air was forced into the lungs
by its increased density around the breast, oc-
casioned by the dilatations of the thorax, in
consequence of the elevation of the ribs.

In 1667 some attention was paid to respira-
tion being maintained by distinct volumes of
air ; for Hook kept a dog alive with common
bellows by artificial respiration, f Fabricius,
in the beginning of the 17th century, cor-
rectly explained the action of the diaphragm. J
Boreili is the earliest physiologist (1679) who

* Lardner’s Cyelop. Nat. PhD. Hydr. and Pneum.
p. 247.

f Phil. Tr. Abr. vol. i. p. 194.

j De Heap. ii. c. viii.

THORAX.

1065

established an experimental inquiry into the
quantity of air received by a single inspiration.*
Jurin improves upon Borelli. About this
time (1708) Dr. James Keile made some
correct measurements of the volume ot air
breathed, j- Then followed Dr. Hales, who
threw more light upon the doctrine of air,
the power of respiration, and the power of the
heart, than all his predecessors ; yet he was
quite ignorant of the use of respiration ; and
at this period (1733) really very little was
known upon the subject. In 1757 and fol-
lowing years, Black, Rutherford, Lavoisier,
Priestley, and Scheele, the chemists of the
age, threw light upon the matter by discover-
ing the composition of the atmosphere, and
consequently the composition of respired air.
It is since the time of Black that the most
valuable mass of our knowledge upon respir-
ation has been discovered.

The functions of the thorax may be divided
into two great heads, — the chemical and the
physical ; for an account of the former see
Respiration.

Every point of the thorax can move for the
purpose of respiration ; and hence has followed
a division of these movements, nominated
after the parts which respectively carry on
their functions, viz. costal breathing, and ab-
dominal or diaphragmic breathing. These
motions are, in health, symmetrical, constant,
regular, sensitive, and precisely the same ;
otherwise disease must exist.

The breathing movements are also expres-
sive of mental emotions. The tragedian imi-
tates them to give force to the character
he represents, whether it be the stealthy
breathing of the Roman conspirator sharpen-
ing his knife, or the deep swelling inspiration
of Ajax defying the lightning ; these repre-
sentations, without such movements, would
be but dull pictures of the mind of the
authors who left such characters on record.
It is much easier to become delicately fa-
miliar with these movements and their cha-
racteristic differences, than it is to describe
them.

The latitude of movement, performed by the
walls and floor of the thorax, admits of three
common degrees of division : —

First, extreme expansion or enlargement.

Second, extreme contraction or diminution ;
and

Third, an intermediate condition, — an or-
dinary or quiescent state.

These three divisions necessarily displace
volumes of air of different magnitude.

Were the respiratory movements but two
in number, extreme expansion and extreme
contraction, the quantity of air moved, and the
character of the movement, would be easy of
calculation and expression ; but the interme-
diate breathing or quiescent movement being
so limited, so perfectly under the control of
the will, so readily affected by mental emo-
tions and by the animal functions, renders

* Do Motu Animalium, p. 2. prop 81.

t Tentara. Med. Phys. p. 80.

the calculation of the volume of air ordinarily
passing through the lungs a very difficult
question.

The quantity of air in the thorax, together
with those portions which can be added at will,
may be arranged and denominated thus : —

First, residual air.

Second, reserve air.

Third, breathing air.

Fourth, complemental air.

Fifth, vital capacity.

1st. Of residual air. — After death the
lungs contain air, which is not displaced
by the last expiration ; this quantity remains
in the thorax as long as the lungs maintain
their natural structure; therefore we have no
control over this volume of air : to it we
assign the term “ residual air."

2nd. Reserve air is that portion which re-
mains in the chest after the gentle ordinary
expiration, but which may be displaced at
will.

3rd. Breathing air is that volume which is
displaced by the constant gentle inspiration
and expiration.

4th. The complemental air is that volume
which can at will be drawn into the lungs by a
violent exertion above the moderate effort of
ordinary breathing, constituting the deepest
possible inspiration. It is only occasionally
demanded.

5th. The vital capacity is these last three
divisions combined, being the greatest vo-
luntary expiration, following the deepest inspi-
ration.*

This division of thoracic movements for
commanding these different volumes of air
may be more clearly illustrated by diagram 703.

Fig. 703.

Let that portion marked Id represent the resi-
dual volume, or air left in the lungs, after a
complete voluntary expiration ; the part next

* According to physiological nomenclature,
perhaps the term “ vital capacity ” may be objec-
tionable ; but we adopt it, for want of a better term,
to signify a capacity or volume of air which can
only be displaced by living movements, and may
therefore be termed a “living volume,” or “vital
capacity.”

1066

THORAX.

anteriorly, left white, — the reserve volume,
or latitude of movement appropriated for dis-
placing that air left in the lungs at the
end of an ordinary expiration ; the black
stripe next anteriorly represents the mobi-
lity for commanding the volume of breathing
air ; and lastly, beyond this another white
stripe shows the extreme limit of inspiration
or thoracic mobility commanding the com-
plemental volume of air. These last three —
viz. the complemental, breathing, and reserve
volumes conjointly — we style vital capacity.
The absolute capacity may be considered as all
the divisions combined in one.

Whatever limits the mobility of the thorax
must modify the volume of air respired.
This applies to any or all of the above
movements. Therefore the measure of the
volume of air displaced becomes a measure
of the thoracic mobility ; and as disease affects
the mobility of the chest, the measure of the
volume of respired air becomes a measure of
disease.

The residual volume is entirely independ-
ent of the will, and always present in the
chest. The reserve volume, to use a simile,
is a “ tenant at will.’’ The breathing volume
is constantly passing out and in, many times
a minute. The complemental volume is seldom
in the chest, and then only for a very brief
period.

Whatever be the breathing volume ne-
cessary for our well-being, the mobility
demanded to maintain it is an intermediate
mobility, just as the dark stripe in fig. 703. is
intermediate between the white stripes ; so
that at both ends of the ordinary breathing
mobility there exists a spare mobility, which
we can command into action according to the
necessities required. This reserve and com-
plemental mobility may be looked upon as
a broad, spare margin which encompasses
our breathing ; so that any sudden exertion
may not (as it otherwise would) produce
painful dyspnoea and premature death.

This spare mobility, therefore, is always
ready to admit of irregularities in the ordinary
breathing, such asfrequent or infrequent, quick
or slow, regular or irregular, great or small,
equal or unequal, easy or difficult, complete or
incomplete, long or short, abdominal or costal;
as in coughing, running, laughing, crying, sing-
ing, sighing, and vociferating, many of which
are but extensions or modifications of the or-
dinary mobility, infringing upon this margin
— the complemental or reserved mobility.

This spare mobility is not only ready for
such exigencies as above mentioned, but it
becomes a reservoir for “ times of need.”
Thus a man can take from 230 to 300 cubic
inches of fresh air into his lungs, and live upon
it without inconvenience for two minutes with-
out breathing. * The knowledge of this fact

* It is better to inspire and expire forcibly five
or six times, cleansing the lungs of the old air, and
then give one deep inspiration, and there hold.
For the first 15 seconds a giddiness will be ex-
perienced ; but when this leaves us, we feel not the

would be of much use towards rescuing
a fellow creature from suffering amidst dense
smoke or in an irrespirable atmosphere,
as is found sometimes in mines and wells.
A variation of this condition was once wit-
nessed when Mr. Brunei descended to ex-
amine the breach which the river had made
in the Thames Tunnel. Having lowered
the diving-bell nearly 30 feet to the mouth of
the opening, this was found too narrow to
admit the bell ; so that no further observation
could be made upon the workings, which were
about 8 feet or 10 feet deeper: Mr. Brunei,
therefore, laying hold of a rope, left the bell,
and dived himself down the opening. His
companions in the bell, being alarmed at the
length of his stay, now about two minutes,
gave the signal for pulling up ; and the diver,
unprepared for the signal, had hardly time to
catch the rope, which he had let go, and was
surprised to find, on coming into the bell,
that he had remained below so long. On
descending again, he found that he could with
ease remain fully two minutes under water. In
this case the atmosphere, under a pressure of
30 feet of water, charged the lungs with nearly
a double volume of air compressed into the
same bulk as one volume at the surface of
the water. Our ordinary breathing volume
can only supply us for from three to five
seconds ; for if we suddenly stop breathing
for that time, we experience a degree of
inconvenience.

Of the volumes of air expelled from the
lungs. — A knowledge of this is of incalcu-
lable value to the physician and to the surgeon ;
for disease cannot attack the lungs or the
thoracic boundaries, without diminishing the
respiratory volume, which change ultimately
leads to the variations of the respiratory
murmurs, first noticed as a diagnostic sign of
disease by Laennee. Many experimenters
have measured the different volumes of re-
spired air, not primarily in reference to
disease, but merely as collateral to the ob-
servations of the chemist : hence experiments
have been few, and deductions highly dis-
crepant.

(a) Residual volume. — Dr. Hales notices this
volume, but assigns no measure for it*;
Allen and Pepjs estimate it at 108 cubic
inches in stout men of 5 feet 10 inches')' ;
Davy at 41 cubic inches J ; Goodwyn, by
the mean of seven experiments, at 108 cubic
inches ; Kite, who writes expressly upon
submersion, is obscure upon this point $ ;
Dr. Bostock allows 120 cubic inches || ;
Dunglison gives Menzie’s estimate of 179
cubic inches ; Jurin estimates it at 220 cubic
inches ; Fontana at 40; and Cuvier at from

slightest inconvenience for want of air; and two
minutes of time can be passed through without
breathing. The most expert pearl-divers cannot re-
main under water for a longer time.

* Stat., vol. i., p. 239.

■j Phil. Tr., 1809., vol. xeix. pp. 404. 428.

% Chem. and Phil. Remarks, p. 410.

§ Essays and Obs. Physical and Med. 1795, p. 8.

|| E . Phvs. 3d. Ed. p. 318.

THORAX.

100 to 60; Mechli at 52 and 40* * * §; Dr.
Herbert, of Gottingen concludes this volume
to be “ very little.”')' We have found it to
vary from 75 to 100 cubic inches. It must
be relative to the absolute capacity of the
chest, which varies from 248 to 457 cubic
inches. The mean absolute capacity is 312
cubic inches. Allowing 100 cubic inches for
the heart and large blood vessels, and 100
cubic inches for the parenchymatic structure
of the lungs, will leave a little more than 100
cubic inches for the residual air ; therefore
Allen and Pepys’s opinion may be relied upon
as very near the truth.

(b) Reserve volume. — Goodwyn omits
this volume altogether ; and this omission
was pointed out forty years ago by a phy-
siologist who himself omitted any notice of
the complemented air. Kite estimates this
at 87 cubic inches; Davy, by an experiment
upon himself, at 77 cubic inches J ; Dr. Bos-
tock, from trials upon himself, at ICO or
170 Mechel at 1 10 cubic inches.|| It
averages about 100 cubic inches ; our obser-
vations range from 70 to 110 cubic inches.
It is regulated by the point at which the or-
dinary breathing movement commences.

(c) Breathing volume. — This has attracted
most attention ; but the discrepancies of
opinion are nearly commensurate with the
number of observations. It would require
years of labour to determine this volume by
direct experiment, in a manner to be avail-
able to the physician ; and it would re-
quire a long time to perfect the observation
of it upon a single patient, because these
movements are so delicately affected by the
mind, so perfectly uncontrollable, and the
volume is so small, that a little error would
seriously damage the value of the observation.
The volume assigned by observers, varying
from 3 to 100 cubic inches, is as follows : —

Abildgaard -

_

Cub. in.

- 3

Abernethy -

-

- 12

Keutsch

-

6 to 12

Goodwyn

-

3 and 14

Lavoisier and Segttin

- 13

Wurzer and Lametheria

8 or 10

Kite

-

- 17

Davy

-

- 13 and 17

Allen and Pepys

-

;i6'5

Herbst

-

16 to 25

Jurin

-

- 20

Borelli

-

15 to 40

Herdolt

-

25 to 29

Dalton

-

- - 30

Fontana

_

- 35

Richeraud, Foland,

Gordon, and Ca-

vallo

-

- 30 to 40

Hales, Jurin, Sauvages, Haller, Ellis,
Summering, Thomson, Sprengel,

* Mechli’s Manual Descrip, and Pathological
Anat., vol. ii. p. 448.

t Bostock, Op. Cit., p. 316 ; and Archives Ge'n.
de Med., t. xxi. p. 412. et seq.

X Op. Cit., pp. 47, 48.

§ Op. Cit. p. 316.

j| Manual of Descrip. Anat., vol. ii. p. 447.

1067

Cub. in.

Bostock, Chaptal, Bell, Monro, and
Blumenbach - - - 40

Menzies - - - 42 to 46

Reil - - - 40 to 100

upon an average, it varies from 16 to 20,
though we have occasionally found it vary
from 7 to 77 cubic inches. Though our ob-
servations upon this point are but scanty com-
pared with those we made on the vital capa-
city, yet from about 80 experiments we con-
clude that man in a perfectly quiet state, as
when sitting, reading, &c., breathes much less
than he does under the ordinary excitement of
moving about. We think the perfectly quiet
breathing, when we can scarcely perceive any
movement (which is by no means uncommon),
may be from 7 to 12 cubic inches, and when
under ordinary excitement and exercise, from
1 6 to 20 cubic inches ; we have known it in
one case as high as 77 cubic inches. It is
probable that the quantity is relative to the
volume of blood to be aerated. Herbert
found that adults of smaller stature breathed
less than those who were taller.* It is proba-
ble that phthisical patients breathe very little,
— from 2 to 4 cubic inches ; but the number of
their breathing movements is greater, which
compensates for this small quantity.

(d) Complemental volume. — Davy, from
a single experiment (upon himselfj, calcu-
lates this at 119 cubic inches f ; Kite, at
nearly 200 cubic inches.^ It is regulated
by the position of the ordinary breathing
movement, which is intermediate between
it and the reserve air. It averages, from
direct experiment, rather higher than the
reserve volume, — about 105 or 110 cubic
inches. Taking the mean height at 5 ft.
8 in. the vital capacity is 230 cubic inches,
that is to say —

Reserve air -

cub. in,

- 100

Ordinary breathing

20

Complemental

- 1 10

230

(<■) Vital capacity volume. — Jurin and
Hales correspond in stating this at 220 cubic
inches § ; Davy at 213 cubic inches || ; and
he remarks in a note, “ this capacity is pro-
bably below the medium. My chest is nar-
row, measuring in circumference but 29
inches, and my neck rather long and slender.”
It is probable the figures 29 are a misprint
for 2 feet 9 inches round the chest. Dr.
Thomson, from the mean of twelve experi-
ments, upon men from fourteen to thirty-
three years of age, states it at 186J cubic
inches. Dr. Thomson himself could expel
193 cubic inches. He mentions that this
volume is constant when once determined.

* Muller, El. Phys., 1st ed. 8vo., Lond, p. 294>
vol. i., 1847.

t Op. Cit. p. 410.

t Op. Cit. p. 47.

§ Hales’s Sat., 1732, vol. i. p. 239.

|| Op. Cit. p. 410.

1008

THORAX.

The temperature of the respired air is not
mentioned.* Goodwyn states it at 200 cubic
inches-)-; Kite, at 300 cubic inches."); ; Menzies
at 200 § ; Bostock||, corroborated by Dun-
glison^T, omitting the complemental volume,
at210cubic inches; lastly, Thackral, who takes
this volume as the measure of health ; ex-
amines some soldiers, who give the mean of
217 cubic inches, and some shoemakers,
who average 182 cubic inches ; and he re-
marks, “ a tall young cornet threw out 295
cubic inches ; this was the greatest quantity
1 ever witnessed.” **

According to this evidence, the respective

volumes are, —

Cub. in.

Residual

volume, from

40

to 200

Reserve

9 9 99

77

„ 170

Breathing

99 59

3

„ 100

Complemental

99 99

1 19

„ 200

Vital Capacity

99 99

100

„ 300

The apparent discrepancies of the breathing
volumes are entirely due to the want of col-
lateral observations; for there is no distinction
between the sexes, nor age, nor stature, nor
weight. We have determined the vital capa-
city in one man as 80 cubic inches, in another
46-1 cubic inches ; therefore we might say this
volume varies from 80 to 460 cubic inches ;
but this discrepancy is cleared up, when
we add that the height of the former was
3 feet 9 inches, and his weight 4 stone 9 lbs.,
while the latter measured 7 feet, with a weight
of 22 stone ; and that if we arithmetically
reduce the one to the other, the vital capa-
city of a dwarf is within half an inch of what it
actually was, viz. 79'56 cubic inches by cal-
culation, and 80 cubic inches by direct expe-
riment. Collateral observations clear up the
experiment ; thus Kite was probably a tall
man, and therefore he states the vital capacity
as 300 cubic inches; Davy at 213 cubic
inches, because he was of shorter stature,
probably about 5 feet 7 inches; Hales, Jurin,
and Goodwyn about 5 feet 8 inches. We come
to this conclusion, because we find this vo-
lume bear a strict relation to stature. There-
fore, probably, all the observations already
mentioned are correct, and only wanted an-
other combination to remove the apparent
discrepancies.

We have especially directed our attention
to one of these volumes of air, the vital
capacity.

Vital Capacity. — There are tw-o ways
of measuring the permeability of the lungs,
or the volumes of air which they can displace,
viz. by measuring the actual movement or
mobility of the thoracic boundaries, or by
directly measuring the absolute cubic inches
of the volume of air expired. The former
is open to an error, but the latter is not.

* Thomson’s Anim. Chem., 1843, p. 610. et seq.

| Op. Cit. p. 32. note.

J Op. Cit. p. 48.

| Mayo’s Outlines of Pliys., p. 76.

|| Op. Cit. p. 321,

4f Ibid. vol. ii. p. 91.

** Thackral on the Effects of Arts, Trades, &c.
upon Health, p. 21. et seq.

If we take the movement as an index to
the permeability of the lungs, we obtain an
evidence only of movement, and not of the
permeabdity of the lungs for air, for we may
move the thoracic boundaries, and yet not
breathe. But when we measure the volume
of air, it is self-evident that this must be the
measure of both the permeability of the
lungs and of mobility of the thoracic bound-
aries, because we cannot breathe without
moving. The classes of persons we examined
were as follow : —

Sailors (Merchant Service)

Fire Brigade of London
Metropolitan Police -
Thames Police -

Paupers -

Mixed Class (Artisans)

First Battalion Grenadier Guards -
Royal Horse Guards (Blue)
Chatham Recruits -
Woolwich Marines -
Pugilists and Wrestlers
Giants and Dwarfs -

Printers J Pressmen 30 1 _

\ Compositors 43 J
Draymen -
Girls -

Gentlemen - - - -

Diseased Cases -

No.
- 121
- 82

- 144

- 76

- 129

- 370

- 87

- 59

- 185

- 573

- 24

- 4

- 73

- 20
- 26

- 97

- 360

Total - - 2430

Each individual was subjected to the fol-
lowing observations : —

1st. The number of cubic inches given by
the deepest expiration, following the deepest
inspiration. This was taken three times, and
the highest observation was noticed.

2nd. The inspiratory power.

3rd. The expiratory power.

4th. Circumference of the chest over the
nipples.

5th. Mobility of the chest with a tape-
measure.

6th. The height.

7th. The weight.

8th. The pulse (sitting).

9th. The number of ordinary respirations

per minute (sitting).

10th. The age

1 1th. Temperature of the air expired.

To determine these points, we constructed
an air receiver, denominated “ Spirometer.”
We used a bent tube (hsemadynamometer) for
ascertaining the respiratory power, scales and
stand for the height and weight, and a com-
mon tape-measure for measuring the mobility
of the chest.

We rarely exceeded three consecutive ob-
servations with the spirometer, because after
this the volume of respired air diminishes
from mere fatigue.

To measure the vital capacity volume. —
The Spirometer (fig. 704. >, consists of a
vessel containing water, out of which a re-
ceiver is raised by breathing into it through a

THORAX. 1069

tube ; the height to which the receiver is
raised, indicates the volume of the vital capacity .

To Prepare the Spirometer fur Use : —

1st. Place the spirometer about three feet
from the ground, upon a firm, level table.
2nd. Turn off the water-tap 4, and open the
air-tap 1.

Fig. 704.

3rd. Pour into the spout, behind, clear cold
water, until it is seen to rise behind the
slip of glass 3 (above the air-tube).

4th. Slide the moveable index 2, opposite 0
on the graduated scale 13, and add more
water until it is exactly on a level with the
straight edge of this index ; if too much
water be poured in, draw off by the tap 4,

sufficient to bring the water down to the
edge of the index.

5th. Pour a little coloured spirit into the bent
tube 5, until it stands about 3£ inches, as
at 6.

6th. Turn off the air-tap 1, then suspend
the counterbalance weights, 1 1, 1 1, from the
cord over the pnllies.

The spirometer is now ready for an observa-
tion. The flexible tube, terminated with a glass
mouth-piece, is held by the person about to
be examined, and the tap 1 is to be kept
open by the operator while the deep expira-
tion is being made.

To discharge the air out of the receiver. —
It will be seen that if the tap 1 be opened,
the receiver will rise out of the reservoir by
the power of the counterbalance weights,
until it touches the cross-head 9. To return
the receiver into its original position, the con-
tained air must be discharged ; this can be
done by slowly depressing the receiver down
into the reservoir, and so pressing the air out
by the way it entered, — through the air-tube.
But, in order to do so more rapidly, a large
valve at 14 admits of an instantaneous escape
of the air. Therefore, to discharge the air,
remove the plug 15 out of the socket 14 with
one hand, while the other returns the receiver
into its original position.

- Let the person to be examined loose his vest,
and any other tight garment — for the least
pressure from dress affects the mobility — -
stand perfectly erect ( fg . 705.), with the head

Fig. 705.

thrown well back ; then slowly and effectually
fill his chest with air, or inspire as deeply as
possible, and then he must lift the mouth-
piece of the spirometer 12 to his lips, still
standing in the same erect position, and
place the glass mouth-piece between the lips,
holding it there sufficiently tight so as not
to allow any breath to escape, lie then slowly
makes the deepest expiration , displacing all
the air he can out of his lungs through the
mouth-piece into the spirometer, where it is
measured to cubic inches, and confined there
by a stop-cock, until examined. This ob-
servation should be taken three times. The
operator, while the experiment is going on
should place his left hand upon the shoulder
of the person being examined ; in this way he
can determine as to the perfect inflation of
the lungs and expulsion of air from them as
well as the character of the thoracic expansion.
The thumb of the operator should cross the
clavicle, while the fingers rest on the upper

1070

THORAX.

edge of the scapula, then he feels the expand-
ing effect of inspiration, the swelling up of
the apex of the thorax.

To determine the volume of air in the spi-
rometer. — The graduated scale 13 is attached
to the receiver, and made to extend down-
wards on the outside of the reservoir, so as
always to be in relation with the index 2.
On this scale 0 corresponds with the top of the
receiver, or rather with the highest point to
which the water can be made to rise within
it. The number of cubic inches is shown by
the degree upon the scale pointed to by the
index 2, which corresponds with the level
of the water in the receiver. But the
water in the reservoir seen behind the slip
of glass may not be level with the water
within the receiver, just as the level of
the water in a pneumatic trough may be
higher or lower than the level of the water
contained in a glass receiver standing upon
the shelf. To know when these are level,
depress the receiver until the coloured fluid
in one leg of the bent tube, or inverted
syphon, 5, stands level with that in the other
leg, as at 6 ; then the water contained in the
receiver, and that external to it, are level to
each other ; and the air within the receiver is
of the same density as that without.

Immediately the plug 15 is replaced, and
the hands withdrawn from the receiver, the
latter will be seen to ascend some half-inch,
the water behind the slip of glass to fall, and
the coloured fluid in the bent tube to be
unequal. This is caused by the excess of
weight in the counterbalance (11, II,), which
is what necessitates the observation of the
coloured fluid in the bent tubes and the cor-
rection above directed. The scale is gra-
duated to degrees, each of which measures
two cubic inches.

To correct the respired volume for tem-
perature. — The table of the vital capacity-
volume is calculated at G0° Fahr. The tempe-
rature of a volume of air displaced out of the
lungs into the spirometer is reduced at once to
the temperature of the water in the spiro-
meter. This, according to the season of the
year, may be 50° or 80°. Now 330 cubic
inches at 50° would occupy 337 cubic inches
at 00°, and 330 at 80°, would be 317 at 60°.
For eight months out of the year there needs
no correction. But a correction is necessary,
when a thermometer in the room stands
much above or below 00°. We may estimate
the change in the bulk of air as for every
degree (Fahr.) of variation of temperature ;
thus if a man breathe, in winter, 295 cubic
inches of air into the spirometer, when the
thermometer in the room stands at 55°, being
5 degrees below G0°, then = 2‘95, must
be added to the 295 cubic inches, making
297‘95, or, in round numbers, 298 cubic
inches. On the other hand, if the vital ca-
pacity be determined at 215 cubic inches,
when the thermometer stands at 72°, which is
1 2° above G0°, — 5 must be deducted ;

making the corrected observation 210, instead
of 215 cubic inches.

In the absence of the spirometer, the mea-
sure of the mobility of the ribs, by means
of a common tape measure is of much value *
To measure the mobility of the thorax with
a tape measure, pass the tape measure round
the chest under the waistcoat, over the region
of the nipples, request the person to in-
spire deeply, and note that circumference,
then to expire deeply, and again note the
circumference, the difference is what we
term the mobility. This is a rough measure-
ment, but of no little value in doubtful
cases of chest disease. This difference, or
mobility, in men of all statures should be
about 3 inches, if it is found only 2i inches
the examination should be carried further ;
sometimes the mobility extends to 5i inches,
but this is excessively rare. Asa general rule,
when we find the mobility three inches, we
find the vital capacity volume correspond with
our table. Sometimes the mobility may be
good, and the vital capacity bad, because, as
we have already noticed, we may move the
walls of the chest without breathing.

The vital capacity is a constant quantity ;
habit will not increase it. But this volume is
disturbed directly, and modified by five circum-
stances :

1st, by height ; 2nd, by position ; 3rd, by
weight ; 4th, by age ; 5th, by disease.

1st. Of the effect of height.

The vital capacity volume bears a striking
relation to the height of the individual exa-
mined ; so that, if we take a man’s height, we
can tell the volume of his vital capacity. We
show this by a curve in fig. 710., as before ; let
the perpendicular lines represent the heights
increasing inch by inch from the left towards
the right ; the single continuous line is the
curve of the vital capacity, which gradually
ascends as it passes over the perpendicular
lines. The heights extend from 5 feet to 6 feet ;
above six feet the observations are few. Whe-
ther the vital capacity volume maintains the
same regular progression beyond this point
remains to be determined. If we draw a line
in a perfect arithmetical ascent of eight units
for every increasing height, the line of vital
capacity will be observed to run nearly pa-
rallel with it; therefore this volume increases
with the increase of stature. The figures at
the bottom represent the vital capacity in
cubic inches, being the mean of the observa-
tions under each height. The following table
(Table T.) places the subject more in
detail : —

A cursory inspection of the table shows
that the vital capacity increases with the
height ; this is without any consideration as
to age, weight, or circumference of the chest.
For clearness, we arrange it in a more re-
duced form, as in Table U.

* Dr. Sibson and Dr. Quain have invented some
ingenious instruments for measuring the thoracic
movements externally.

Table T. — Mean Vital Capacity Volume, in relation to Stature, of Fifteen different Classes of Men, or 1923 Cases, considered healthy

THORAX.

1071

1072

THORAX.

Table U Progression of the Vital Capacity

Volume, with the Stature — from the above.

Height.

£>

5 10

6 0

°1 5

2

I}*

i}'

s}5

o}s

]5

5 11

Mean of all ")
heights - J

Series from
Observations on
1012 cases.

Series from
Observations on
1923 cases.

Series in
Arithmetical
Progression.

1st result.

2nd result.

175-0

1760

174-0

188-5

191-0

190-0

206-0

207-0

2060

222-0

228-0

222-0

237-5

241-0

238-0

254-5

258-0

254-0

214-0

217-0

214-0

Table V. — Vital Capacity Volume (temp. 60°
F. ) necessary to Health at the Middle Period
of Life.

The first column contains the heights be-
tween five and six feet, increasing arithmeti-
cally two inches at a time, as 1. 3. 5., &c. ;
the next two columns are the result of ex-
periment ; the first upon 1012 cases at an
earlier period of the investigation ; the next
at a later period, when the whole cases con-
joined amounted to 1923 cases. We found
that the men from 5 feet to 5 feet 2 in. gave a
mean vital capacity of 176 cub. in.; the men
two inches taller a mean of 191 cub. inches;
the next, 207 cub. in., and so on ; thus the
volume increases as we descend the column.
Finding the progression so regular, we arranged
a fourth column, containing a series of numbers
in perfect arithmetical progression, commencing
with 174, and increasing sixteen at every subse-
quent step, corresponding to the two inches of
height successively added. We found, upon
comparing the two columns of observations
with the column of calculation, that there was
a close resemblance. The increase of sixteen
for every two inches is of course the same
as eight for every single inch ; hence the
rule deduced upon nearly 2000 cases (and
subsequently confirmed by double that number)
viz. That for every inch of stature, from 5
feet to 6 feet, eight additional cubic inches of air,
at 60°, are given out by a forced expiration.
This brings the detailed matter of a series of
tables and calculations into a point, and easy
of remembrance, the more so as extended ob-
servations upon nearly 5000 men have brought
the column of observation so close to the
column of regular progression, that it is only
necessary now to take the column of regular
progression as a standard for examining the
condition of the lungs as to their perme-
ability for air, and the mobility of the tho-
racic boundaries.

If we recollect that at the height of 5 feet,

Height.

ft. in.

0

1

2

3

4

5

6

7

8
9

10

11

to

1

2

3

4

5

6

7

8
9

10

11

0

Vital

capacity.

174

182

190

198

206

214

222

230

238

246

254

262

8 in. the vital capacity is 230, we can recollect
the rest by adding or subtracting eight to or
from this number, for every inch of stature
above or below 5 feet 8 in., between 5 and 6 feet.
These numbers may be taken as expressions of
certain conditions of the thorax, an expression
of mobility relative to breathing, and conse-
quently an expression of the permeability of
the lung. It therefore follows that whatever
affects the mobility of the thoracic bound-
aries, or the permeability of the lungs, the
amount of that cause is expressed by the
volume of the vital capacity. Incipient disease
is quick in affecting the vital capacity ; the
amount of the injury therefore is readily
measured. We are at a loss to assign any
just reason why the vital capacity is rela-
tive to the height, which is regulated by the
length of the limbs, and not by the length of
the trunk of the body. We have found by
experiment, that whatever be the standing
height, the sitting height is nearly the same
in all persons of between 5ft. and 6ft., and
if not actually the same, yet it is not a rule
that the tallest men sit the highest ; for in-
stance, one man standing 6ft. 0£in. measured
from his seat 2ft. llfin., whlie another who
stood 5ft. 6in., sat 3ft. high ; therefore the
length of the trunk bears no constant propor-
tion to the length of the legs. And we found
that men who stood low, breathed less than
men who stood higher, but who sat the same
height. Thus Jig. 706. represents two men ;
A. stood 4ft. 4^in., B. 5ft. 9^in.; they were
of the same age and circumference of the
chest. The weight of the short man was 7st.
2^11)., that of the taller man lOst. 3lb. Yet
their sitting height was precisely the same, as
is shown in Jig. 707. Nevertheless, the vital
capacity volume of the shorter man was 152,
and that of the taller man 236 cubic inches;
so that the man who stood the shorter, hut
who sat as tall, if not taller, breathed eighty-
four cubic inches less than the man who stood
seventeen inches higher. The mobility of the
chest of the taller man w'as nearly four inches,
that of the shorter man three inches. We ex-
amined several such cases with similar results.
The average vital capacity volume at all heights
is about 230 cubic inches. The greatest

THORAX.

1073

we have examined was Randall’s ; height 7 ft.
weight 22 st. ; vital capacity 464 cubic inches.
The smallest was Don Francisco; height 29 in.,
weight about 401bs. ; vital capacity 46 cubic

Fig. 706.

inches. The highest vital capacity at the
height of 5ft. Sin. was 330 cubic inches.

A question arises, are the lungs and tho-
racic parietes at their maximum stretch when
they contain the appropriate vital capacity
volume? We believe not. The vital capa-
city of the person from whom the preparations
figured above (Jigs. 680. et seq.) were taken,
whose height was 5jft. 4 in., weight 1071b.,
was 198 cubic inches ; yet, after death, we
forced 300 cubic inches of air into his lungs
without rupturing them, being 102 cubic inches
more than he could expire during life. There-
fore there is still a spare mobility of parts,
probably in reserve, to be exercised when dis-
ease attacks the lungs.

2nd. Vital capacity affected by the posi-
tion of the body. — We have said a man must
hold himself erect to breathe out a good vo-
lume of air ; because the mobility of the ribs
is affected by the uprightness of the spine ;
and, more than this, whatever touches the
ribs affects their mobility, and consequently
the vital capacity. Thus, standing, we have
produced a vital capacity of 260 cubic inches ;
sitting erect 255 cubic inches ; recumbent —
supine 230, prone 220 cubic inches ; position
making a difference of 40 cubic inches. This
may explain why patients with emphysematous
lungs sit up in bed, and why for them to lie
recumbent, is “suffocating;” because they
thereby diminish the thoracic mobility. It
may be well to recollect this effect upon respi-
“ ration, in treatment of diseases of the spine,
particularly at the present time, when they are

Fig. 707.

The relative height of the same persons sitting.

treated by laying the patient on the anterior pacity from 260 to 220 cubic inches,
part of the chest for weeks and months to- 3rd. Vital capacity affected by weight. --
gether, which position reduced our vital ca- The weight affects the vital capacity ; but

VOL. IV. 3 z

thorax.

1074

as yet the relation does not appear so regular
as that of the height. We are scarcely in a
position, at present, safely to say much upon
this point. As a general rule we find the weight
increases with the height ; so that it is not easy
to separate the effect of one from that of the
other. Suppose we take two men of the same
stature, say 5 feet 8 inches, the one 10 stone,
the other 14 stone in weight; one of them
above par, the other may be either at, or below
par. If 10 stone be considered par, the 14 stone
man is 4 stone in excess, or corpulent to
40 per cent. This excess weight blocks up
the range of mobility, and thus, mechanically,
diminishes the vital capacity volume. But
let us suppose men of dissimilar heigths, one
5 feet 8 inches and the other 6 feet ; the 6 foot
man should be heavier than the shorter man ;
— say 3 stone heavier. This is not excess
weight with him, and does not interfere with
his thoracic mobility ; therefore there is an
inseparable relation between the height and
weight. If, in a series of experiments, we
sink the height entirely, and keep the mere
weight in view, we shall find that the result as
to the vital capacity volume is without order.

Table W. — Vital Capacity Volume in Relation
to Weight.

Weight.

Vital capacity.

Difference.

st. St.

cub. in.

7 to 8

ICO

8 to 9

187

21 +

9 to 10

199

12 +

10 to 11

222

23 +

1 1 to 12

233

11 +

12 to 13

238

5 +

13 to 14

237

1 —

14 to 15

278

41 +

From this there is seen to be a rude increase
of the vital capacity with the increase of the
weight, but it is quite irregular, as 21., 12., 23.,
&c. We have also found the mean vital capa-
city of 147 men of 1 1 stone as 225 cubic inches,
and that of 32 men of 14 stone, only 233 cubic
inches, an increase of 8 cubic inches for an
increase of 42 lbs., or 3 stone. The over-
whelming effect of height disturbs the above
observation ; therefore the height must be
kept in view. We have calculated the weights
in relation to height, with reference to the res-
piratory function, upon a number of men at the
middle period of life. Besides the three classes
mentioned above, we have included 1554 cases
of healthy men in the prime of life, oblig-
ingly furnished by Mr. Brent, viz. the Oxford
and Cambridge rowers, London watermen,
cricketers, pedestrians, and gentlemen (Table
X). The weight now appears more regular,
increasing with the height, as from 92 lbs. to
218 lbs. We may make this progression ap-
pear more regular, as in Table Y, which
is calculated by adding the mean weight,
from the last table, of the men from 5 feet to
5 feet 2 inches (the mean of which is of course
5 ft. 1 in.), together, and taking the mean of
that, which will be found 1 19 9 lbs.; and the

next from 5 feet 1 inch to 5 feet 3 inches,
taking their mean as 126T lbs., and so on.

Table X. — Weight to Height, upon 3000 eases.

Height.

No. of
Cases.

Gross
Weight
in lbs.

Mean Wt.
in lbs.

Ft.

4

In. Ft

6 to 5

III.

0

20

2,399

92-26

5

0 „

5

1

17

1,964

115-52

5

1 „

5

2

36

4,476

124-33

5

2 „

5

3

43

5,497

127-86

5

3 „

5

4

88

12,145

138-01

5

4 „

5

5

126

17,537

139-17

5

5 „

5

6

214

31,016

144-93

5

c „

5

7

316

45,598

144-29

5

7 „

5

8

379

57,822

152-59

5

8 „

5

9

468

73,835

157'76

5

9 „

5

10

368

61,238

166-40

5

10 „

5

11

348

59,400

1 70-86

5

11 „

6

0

245

43,475

177-45

6

0 „

6

+

326

71,283

218-66

Total

-

-

3000

487,745

147-86

It thence follows, the range of stature from
5 feet 1 inch to 5 feet 1 1 inches is 10 inches ;
and the weight rises from 119 9 lbs. to

Table Y. — Difference of Weight to Stature on
2648 males, from the last table.

Exact

Stature.

Weight

lbs.

Weight more
exactly, lbs.

Difference
of Weight
in lbs.

Ft.

In.

In.

5

i

or

61

120

119-9

+

6-2

5

2

62

126

126-1

+

6-8

5

3

63

133

132 9

+

5-7

5

4

64

139

138-6

+

35

5

5

65

142

142 1

+

2 5

5

6

66

145

144-6

+

3-8

5

7

67

148

148-4

+

6-8

5

8

68

155

155-2

+

6-9

5

9

69

162

102-1

+

6‘5

5

10

70

169

168-6

+

5-6

5

11

71

174

174-2

174"2 lbs., or 54‘3 lbs. ; or 5'43 lbs. with
every inch of stature. To subdivide the range
of height it may be said : —

lbs. ft. in. ft. in.

Their rise is 6"2 from 5 1 to 5 4

3-3 — 5 4 „ 5 7

6-5—5 7 „ 5 1 1

There is an inequality from 5 feet 4 inches
to 5 feet 7 inches in the weight ; but this
would in all probability disappear if the ob-
servations were more extended ; at present it
may be stated generally that the weight in-
creases 6-5 lbs. (or 6^ ibs.) for every inch of
stature from 5 feet 7 inches to 6 feet, and
6'2 lbs. for every inch of stature from 5 feet
1 inch to 5 feet 4 inches, and 3’3 Ibs. for every
inch from 5 feet 4 inches to 5 feet 7 inches.

At 5 feet 8 inches, or G8 inches of stature,
the weight is 155'2 lbs., or nearly 11 stone ;

THORAX.

1075

from this as a starting point the weight at
any height may (so far as our limited ob-
servations warrant) be readily calculated. For
instance, the weight is, at the height of 5 feet
155*2

8 inches, — — — 2-282 lbs. for every inch of

stature, or 27"38 lbs. for every foot of
stature. The bulk or weight of bodies
having the same relative proportions, is as
the third power (cubes) of either of their
diameters : thus, if a person 67 inches high
weighs 148*44 lbs., a person 69 inches high

should weigh

/69\ 3
\67/

X

148*44

69 X 69 X 69
67 X 67 X 67

X 148-44=3Q076aX 148-44= 162-14 lbs. The

weight at that height, from observation, was
162-08 lbs., a similarity too close to be acci-
dental.

The weights vary as the 2"75th power of the
height, and not as the 3rd power. The rela-
tion between the two is quite close enough
to show, that there is a very intimate connec-
tion between the height and the weight. The
observation is made upon 1276 men at the
middle period of life.

Taking the height from 67 to 71 inches,
we have as follows : —

Table Z The calculated Weight compared with

the observed Weight, according to the above
Form.

Height in
Inches.

Weight deter-
mined by Cal-
culation.

Weight deter-
mined by Ob-
servation.

in.

lbs.

lbs.

67

148-8

148-4

68

155-5

155-2

69

162-1

162-1

70

169-3

1686

71

176-6

174-2

We have found that the vital capacity in-
creases 42 cubic inches with the weight from
100 lbs. to 155lbs., and from 155 lbs. to 200 lbs.
the effect is balanced by minus 5 and plus 5
cubic inches. In the first division there is an
increase of 42 cubic inches ; the weight then
comes into power, and disturbs the regular
progression for the next division ; therefore we
may say there is in the second division a de-
crease of 42 cubic inches in the vital capacity
volume from the effect of weight. We repre-

Fig. 708.

The Effect of Weight on the Vital Capacity.

sent this by a curve, fig. 708. The continuous
curve is the line of vital capacity crossing the
perpendicular lines of progressive weights.
The curve of volume ascends, and attains its
highest at 160 lbs., and from thence it is
nearly horizontal to 200 lbs. According to
this, the vital capacity increases nearly in the
ratio of 1 cubic inch per lb. from 105 to 155 lbs.,
and from 155 to 200 lbs. there is no increase.
This illustration of the effect of weight is cal-
culated at one height, viz. 5 feet 6 inches ;
therefore to this height only these points of
weight (from lli to 14 stone) refer. We
have noticed that the weight increases in a
certain ratio with the height, and that the
weight at 5 feet 6 inches affects the vital
capacity in the relation just mentioned, com-
mencing when the weight exceeds 7 per cent
upon the average weight. We may, perhaps,
connect this same relation with the other
heights through the arithmetical progression
of inch by inch. For example : — the weight
of men of 5 feet 1 inch is 199"9 lbs. ; to this
add 7 per cent (8 395 lbs.), making 128"2 lbs. ;

again, the tallest men, 5 feet 11 inches, weigh
174-2 lbs. ; to this add 7 per cent (12‘2 lbs.),
making 186-4 lbs. : therefore, at the height
of 5 feet 1 inch a man must exceed 128 lbs.,
or 9 stone 2 lbs., and the 5 feet 1 1 inches’
man 186 lbs., or 13 stone 4 lbs., before weight
may be expected to diminish the vital capa-
city volume in the relation of 1 cubic inch
per lb. for the next 25 lbs., 2^ stone being
the limit of our calculation. When the man
exceeds the mean weight (at each height)
by 7 per cent, the vital capacity decreases 1
cubic inch per lb. for the next 35 lbs. above
this weight. Beyond this it is not improbable
but that the decrease of the vital capacity is in
some geometrical progression. Below the mean
weight we have never found by experiment,
that the vital capacity is affected by weight.

The cause of the difference of weight
between men is involved in much obscu-
rity.* We may in fact consider the usual
weight of a man as his mean weight and

* See Chambers, Gulstonian Lect. 1850.

*3 z 2

1070

THORAX.

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190

200!

c. in.

:

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00

Cd

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Cl

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237

263

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r-

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221

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lbs.

180

190

c. in.

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00

02

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02

Cd

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Cl

Cd

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Cd

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261

274

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160

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130

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Heights.

ft. in. ft. in.
5 0 to 5 1

5 1 to 5 2

5 2 to 5 3

5 3 to 5 4

5 4 to 5 5

5 5 to 5 6

5 6 to 5 7

5 7 to 5 8

02

>o

o

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to

5 9 to 5 10

5 10 to 5 11

O

CD

O

VO

+

CD

O

o

CD

Total mean...

the term “ gained weight” should be under-
stood as weight swperadded to his usual
weight, or mean weight in the above Table.
Thus, if a man may lose weight below his
usual weight, he should gain above his usual
weight before he can be said to have gained
weight.

The effect of weight in diminishing the re-
spiratory volume, need not in the least disturb
the observer, when testing the lungs through
the measurement of the vital capacity, with re-

ference to phthisis or any other chest disease.
For collateral observations and the history of
the case, will sufficiently protect him’from such
difficulty. We see that the weight increases
at so much per inch ; we have no doubt that
by extended observations it will be found
to be regular through the whole series of
heights, and that it will be found to increase
7 lbs. for every inch of stature. We know that
the respiratory power increases in a similar
arithmetical relation. We do not mean that

THORAX.

1077

the lb. will correspond to the inch, for that
is accidental, merely depending upon the
units employed, but that the increase of each
will be found in an arithmetical progression,
and hence, probably, the reason why tall men
breathe more than short men.

But the weight can never be the sure guide
that the height is, because the former varies
at any time in life, even in a few days ; where-
as the latter varies only at the extremes of life.

4th. Relation of vital capacity to the circum-
ference of the thorax. — We notice this here,
because the question is so natural, “ Has
the size of the chest no relation to the
vital capacity?” We do not find that there
exists any direct relation between the cir-
cumference of the chest and the vital capa-
city. We have found —

Hei

ght.

Circum.

Vital

Men.

ft.

in.

in.

capacity.

1 1

5

.8

35

235

10

5

8

38

226

Therefore, the men with chests 3 inches
larger, breathed 9 cubic inches less, or 21 men
of the same height, but of different-sized chests,
breathed a mean vital capacity of 230 (the
due quantity according to Table T). We
have consolidated the following result upon
994 cases, the height is kept in view, calcu-
lated at 5 feet 6£ inches.

Table B B. — Circumference of the Chest," in Re-
lation to the Vital Capacity Volume, in 994
cases (Males).

Circumference
of Chest.

Vital

Capacity.

Number
of Cases

Cubic In.

J Difference^

1

30 to 304

200

14

— 13

304 „ 31

187

20

+ 18

31 „ 31 l

206

21

— 10

31i „ 32

196

35

+ 1

32 „ 321

197

32

— 7

321 „ 33

204

50

— 2

33 „ 331

202

44

0

33i „ 34

202

63

+ 63

3i „ 341

213

70

+ 4

34i m 35

217

78

— 2

35 „ 351

215

71

+ 14

35i „ 36

229

74

— 10

36 „ 36i

219

59

+ 2

36i „ 37

221

97

+ 18

37 „ 37i

239

59

— 4

37i „ 38

235

57

— 13

38 ., 381

222

41

+ 8

38i „ 39

230

40

— 6

39 „ 391

224

18

+ 2

39i „ 40

228

37

— 11

40 „ 40i

217

14

0

There is nothing in this table to confirm
that which we had thought would be the main
guide to the vital capacity volume ; thus,
compare together the first and last 14 men
whose chests differ 10 inches, and their vital
capacity only 17 inches ; or compare together
the first and last columns, the one is perfectly
regular and the other most irregular. There
is a certain rude relation between the thoracic

dimensions and the vital capacity ; if, for in-
stance, one man has a chest 35 inches in cir-
cumference, and 3 inches mobility, and another
man has a chest 40 inches in circumference, and
4 inches mobility, then the latter will surely
displace a larger volume of air than the former,
but omitting this, we expect as large a vital
capacity from a man with a thin and narrow
thorax, as from a man with a broad and deep
thorax. In fact, aeration need have no re-
lation to the thoracic dimension ; and, for the
same reason, the size of the chest no relation
to the vigour of the whole man. Indeed we
incline to the contrary, viz. that it is most
likely the respiration is most vigorous in the
narrow-chested man, when the mobility is
greatest. The vigour of the lungs, like every
other organ in the body, we believe, has no
relation to the dimensions. One person may
have a brain 1 lb. lighter, or £ less than an-
other person, and yet their capacity and men-
tal qualities shall not appear different.

5th. Vital capacity affected by age, — Age
affects the breathing movements, but less re-
markably than the height and weight. Indeed
the influence of age was not apparent in the
first calculation upon 1012 cases, nor until we
took a basis of 1923 cases. Time affects life
in two ways, first bringing it to perfection,
and then determining that perfection.

Table C C. — Effect of Age, from Observations
on 1775 healthy Men. the Height being kept
in View.

O

C.

o

o©

,0 -J

c* >,

S

Age.

Cubic

Inches.

Cases.

£ Jj

O O)

— >
ei £*

0

1

Uo

k- © £

Q

15 to 20

220

283

34]

1

220

+ 5

20 „ 25

220

491

34

r

25 „ 30

222

347

34

225

— 19

30 „ 35

228

242

35

■

35 „ 40

212

171

34

L

206

— 11

40 „ 45

201

93

35

45 „ 50
50 „ 55

197

193

55

37

35 1

36

195

— 13

55 „ 60

182

30

361

182

60 „ 66

183

26

35 J

Mean of all

ages

205-8

1775

35

The column of “ difference ” exhibits the
effect of time upon the breathing volumes.

From 15 to 35 years of age the vital ca-
pacity is increased, and from 35 to 65 years
of age it is decreased in the progression of
19, 11, and 13 cubic inches. We illustrate
this by a curve in fig. 709. The curve of the
vital capacity will be seen to rise slightly as
it passes the perpendicular lines of years until
it comes to 35 years of age, after which it
keeps declining as it cuts all the succeeding
lines of quinquennial periods down to 65
years. We may say, therefore, that the
vital capacity increases with the age up to

1078

Years

Vi

THORAX.

Fig. 709.

25 30 35 40 45 50 55 60

30 35 40 45 50 55 60 65

Vital capacity.

The Effect of Age on the Vital Capacity.

30 years, and from 30 to 60 it decreases
43 cubic inches, or 1*43 (nearly 1 A- cubic
inches) per year, or 7 cubic inches in 5
years, or 14^- cubic inches in 10 years. Al-
though this appears by calculation, yet we do
not strictly follow this ratio, as we find by
experience that the effect of age may be more
diminished, as follows : —

Table D D. — Vital Capacity at three Periods of
Life, from 4800 cases (males).

Height.

Vital Capa-
city.

Age from
15 to 55.

Vital Capa-
city,

Age from
55 to 65.

Vital Capa-
city.

Age from
65 to 75.

ft.

in.

ft.

in.

5

0 to 5

1

174

163

161

5

1 ,

, 5

2

182

173

168

5

2

, 5

3

190

181

175

5

3

, 5

4

198

188

182

5

4

, 5

5

206

196

190

5

5

, 5

6

214

203

197

5

6

, 5

7

222

21 1

204

5

7

, 5

8

230

219

2)2

5

8

, 5

9

238

226

219

5

9

, 5

10

246

234

226

10

, 5

1 1

254

242

234

5

1 1

, 6

0

262

249

241

From 55 to 65 we have deducted 5 cubic
inches per cent, and from 65 to 75 years of

age 8 cubic inches per cent. We have not
brought in the effect of time before the age of
55 years. This is supposed to be at the mean
weight. The first column* is derived from
observation, the two second are derived from
calculation.

6th. Of the effect of disease upon the vital
capacity. — The effect of disease upon re-
spiration was well known to Boerhaave and
Morgagni, they considered that the disturb-
ance of any organ in the body would dis-
order the whole function of respiration.
Morgagni devotes more than one-sixth of his
celebrated work, the “ Seats and Causes of
Disease ,” “ to diseases which affect respiration .”
We may safely say all thoracic and abdominal
diseases, as tumours, abscesses, and acute in-
flammations, will affect the respiration. Of the
different respiratory volumes, we select that
one which requires the most extended mo-
bility, viz. the vital capacity, which becomes
altered to an extent commensurate with
that of any disease physically affecting our
respiration, it is therefore a test of the pre-
sence and extent of such diseases. Such
movements as command this volume, extend
from the neck to the plantar muscles of the
feet.

One condition which we have been accus-
tomed to look upon as affecting our breathing,
does not affect it, viz. old pleuritic adhesions.

Fig. 710.

Heij

ft. in. ft. in. ft. in. ft. in. ft. in. ft. in, ft. in. ft. in. ft. in ft. in. it, in. It. in. ft. in. ft. in

50 5 1 52 53 54 55 5 6 57 58595 10 5 11 60

’ lls‘ [5 0 51 52 53 54 55 56 57 58 595 10 5 11 606 +

Hta'thy. 143 175
Diseased. 69 100

177 189 193 201

101 102 105 78

214 229 223 2.37

120 g8 130 111

246 247 259 276

96 130 114 106

T ital Capacity of the healthy and diseased

Cases compared.

THORAX.

We met with a case in which the lungs
could not, in consequence of pleuritic adhe-
sions, be removed from out of the thorax; in-
deed there was not one square inch of pleura
which was not firmly adherent. The lungs
had to be torn out by little pieces, and so
strong was the adhesion to the diaphragm,
that in removing them this muscle was
ruptured, yet the living respiratory mobility
of the thoracic walls exceeded by three inches
the whole thoracic space allotted for the heart
and lungs, as measured after death. This
space to the mobility was as 248 to 251. In
other respects the lungs were healthy.

Of all diseases, phthisis pulmonalis most
readily affects the vital capacity, not only
when the lungs are beginning to be infiltrated
with tubercular matter, but probably before
this.

This is shown in fig. 710. Taking all the
cases together, the difference is about 50
per cent.

The effect of this disease upon the vital
capacity in the case of Freeman was very
remarkable. This man came from America
in 1842 “trained for a prize fight.” He was
examined when in his “ best condition,” and
bis vital capacity measured 434 cub. in. (temp.
60°) ; height, 6 ft. 1 If in. ; weight, 1 9 st. 5 lbs. ;
circumference of the chest, 47 in. ; inspiratory
power, 5-0 in. ; expiratory power, 6'5 in.
Freeman fought his battle, and for the sub-
sequent two years lived a rambling and
dissolute life. In November, 1844, exactlj'
two years afterwards, he came to town in ill
health. At this time there was no ausculta-
tory evidence of phthisis pulmonalis ; but the
following difference appeared in his vital
capacity-volume :

Vital

Capacity.

Weight.

Inspiratory

Power.

Expiratory

Power.

Nov. 1842 -
Nov. 1844 -
Dec. 1844 -

cub. in.

434

390

360

320

st. lbs.

J 9 5
17 5
16 0
15 5

5-0

4-0

3-5

6-5

5-0

4-0

In October, 1845, he died at the Winches-
ter hospital ; and Mr. Paul, surgeon to that
charity, stated that Freeman died of extreme
exhaustion and debility, expectorating pus ;
and that his lung was throughout studded with
tubercles ; his weight at death was 10 st.
1 lb.; height, 6 ft. 7^ in. Another remark-
able case was that of a man of perfectly
healthy appearance, and in whom there was
no auscultatory or general sign of organic
disease, but whose vital capacity was deficient
by 47 cub. in.; and it was found, within three
days of the time when he was examined, that the
left lung at the apex was studded with miliary
tubercles, the whole not extending beyond
a square inch.

In diseases of the spine, particularly in
angular curvature, the mobility is changed
sometimes to such a degree that the vital
capacity is diminished to 20 cub. in. A full

1079

meal will even make a difference in the thora-
cic mobility, of from 12 to 20 cubic inches. If
the vital capacity is deficient, there must be
some cause producing the effect. It may or
may not be in the thoracic cavity. Collateral
observations must point more definitely to
the diseased part. The spirometer is only a
gauge to measure the mobility and perme-
ability of the lung; other circumstances must
point out the cause of the mobility and per-
meability being affected. Taking the observa-
tions upon the diseased cases by calculation,
the vital capacity volume may be arranged for
all heights as follows : *

Table E E, — Effect of Phthisis Pulmonalis upon
the Vital Capacity.

Height.

Health.

, Suspicious
Cases, 16 per
Cent.

1st Stage.
33 per Cent.

2d Stage.

Mixed.

43 per Cent.

ft.

in.

ft.

in.;

5

0 to 5

i

174

146

117

82

99

5

1 „

5

2

183

153

122

86

102

5

2 „

5

3

190

160

T27

89

108

5

3 „

5

4

198

166

133

93

113

5

4 „

5

5

206

173

138

97

117

5

5 „

5

6

214

180

143

100

122

5

e „

5

7

222

187

149

104 127

5

7 „

5

8

2.30

193

154

108 131

5

8 „

5

9

238

200

159

112

136

5

9 „

5

10

246

207

165

116 140

5

10 „

5

11

254

213

170

119

, 145

5

11 „

6

0

262

220

176

123 149

The question naturally arises, How far defi-
cient of the standard may be the vital capacity
without indicating disease? It has been found
that ten cubic inches below the due quantity,
i:e. 220 instead of 230 inches, need not excite
alarm ; but there is a point of deficiency in the
breathing volume at which it is difficult to say
whether it is merely one of those physiological
differences dependent on a certain irregularity
in all such observations, or deficiency indicative
of disease. A deficiency of 16 per cent, is sus-
picious. A man below 55 years of age breath-
ing 193 cub. in. instead of 230 cub. in., unless
he is excessively fat, is probably the subject of
disease.

In phthisis pulmonalis the deficiency may
amount to 90 per cent., and yet life be main-
tained. The vital capacity volume is likewise
a measure of improvement. A phthisical
patient may improve so as to gain 40 upon
220 cub. in.

Of the Respiratory Movements. — The
breathing volumes have been divided into
three kinds ; so likewise the breathing move-
ments admit of a similar division, — one ordi-
nary and two extraordinary movements.

By the independent action of the intercostal
muscles, every intercostal lamella can act sepa-
rately, therefore we have the thorax furnished
with 22 spaces by wdiich it can enlarge ; and

* See “Spirometer Observations,” First Report
of the Hospital for Consumption, p. 23. et sea. Lond

10 4 0 1

3 7. 4

1080

THORAX.

the diaphragm acting as one muscle, makes 23
mobile regions for respiration.

The respiratory movements of health may
be classed as costal and abdominal. The cha-
racter should be established by the order in
which they follow each other. In health the
walls of the thorax and the floor do not
dilate simultaneously but consecutively. The
character of “ the breathing" cannot always be
told by the eye, but it can always be deter-
mined by the touch. If we stand behind a
patient, when seated and leaning against the
back of the chair or against our person, and
pass the right arm over the shoulder, extending
it over the anterior part of the chest, until
the hand rests upon the abdomen over the
umbilical region, we command a delicate index
of the breathing movements. It will then be
found, that in ordinary male breathing the ab-
domen first bulges outwards ; the ribs and
sternum nearest the abdomen gently follow
this movement, until the motion, like a wave,
is lost over the thoracic region- The undu-
lation commences at the abdomen. This is
aoaomina, or diaphragmatic respiration. We
here have costal motion, but as the ribs moved
second it is not called costal breathing.

In costal breathing the upper ribs move first,
and the abdomen second. This is the ordinary
breathing in women.

All difficult, sudden, and extraordinary
breathing is costal ; we at such times direct
all our power towards the apex of the thorax,
first expanding that region, and gradually those
below it.

When we determine the order of breathing
by the sight, we must be careful to take the
position of the body into account. If the pa-
tient be recumbent (supine), we may notice
extensive costal motion, and, indeed, it may
be true costal breathing ; but place the pa-
tient erect, and the breathing may be diaphrag-
matic. When recumbent, all the motion is
thrown forwards, the natural backward and
lateral motion of the ribs being prevented ;
and so sensitive are the breathing movements
to impediments, that they may either take a
reverse action, or all the motion being thrown
forwards, will give a preternatural movement
of the ribs, which may be mistaken for costal
respiration.

Profile view of the breathing movements —
(a) Ordinary breathing (Male). — Fig. 711 was
obtained by tracing the shadow of a man on
paper. The back was fixed, so as to throw
all the movement forwards. The anterior
black, continuous line represents the ordinary
breathing. This line is thicker over the ab-
domen than elsewhere. The anterior margin
of this line indicates the boundary of the ordi-
nary inspiration, and the posterior margin the
boundary of the ordinary expiration .

(Female). — This is represented by the
anterior continuous line in fig. 7 1 2., in the same
manner as shown in the male. This line in
the female is broadest over the sternum, anti
narrow over the abdomen. The movement
over the abdomen of the female is so small,
that the number of the respirations cannot

Fig. 711.

Respiratory Movements. Male.

Deep inspiration, dotted line; ordinary state,
continuous line; deep expiration, anterior margin
of the shade.

be counted by the hand resting on that region
as it can be on the male. The question of
why women breathe costal, and men abdo-
minal, we cannot pretend to answer. We
doubt its being caused by any tight costume,
for we found the same to exist in twenty-four
girls between the ages of eleven and four-
teen, none of whom had ever worn any tight
dress. This peculiarity may be a reservation

Fig. 712.

Inspiration, dotted line. Ordinary, continuous
line. Expiration, anterior margin.

THORAX.

1081

against the period of gestation, when the ab-
domen cannot allow of so free a descent of
the diaphragm.

Fig. 713.

Respiratory Movements. Male. Front view.

Inspiration, broken line. Ordinary, continuous
line. Expiration, dotted line.

The lateral movement of ordinary breathing
is too limited to be represented by a line of
varying thickness : the position is given by
the continuous line, Jigs. 713. and 714.

Fig. 714.

Respiratory Movements. Female. Front view.

Inspiration, broken line. Ordinary, continuous
line. Expiration, dotted line.

(b) Deep inspiratory . — In Jig. 711. the
dotted line shows this position, as when a
man is just ready to displace his vital ca-
pacity-volume. The sternum is protruded
and the abdomen is drawn in. This is the same
in the female (Jig. 712.), the dotted line is
most advanced over the sternum, while over
the abdomen it is drawn inwards.

So much is the abdomen drawn in-
wards by deep inspiration, that the portion of
the continuous line (Jigs. 711, and 712.),
representing theordinary breathing is (over the
abdominal region) external to the dotted line
of deep inspiration. Therefore the greatest

enlargement of the thoracic cavity in both
sexes is made by the ribs, and not by the
diaphragm, as is generally believed. It
appears very questionable whether the dia-
phragm is any thing more than flattened and
that without descending.

Of the position of the diaphragm. — It is
clear that all that space between the line
of ordinary breathing and deep inspiration
(fig. 711.), below the ensiform cartilage,
where the two lines cut each other, may be
considered as just so much space deducted
from the abdominal cavity ; and therefore
the abdominal cavity, by deep breathing, is
just so much less than it was in the posi-
tion of ordinary breathing. Now, if the dia-
phragm descends at this moment, whilst the
abdominal parietes are being constringed on
all sides, what becomes of the abdominal vis-
cera? We know that in ordinary breathing
the abdomen advances because the diaphragm
descends, and recedes because the diaphragm
ascends. We may suppose the same accom-
modating movement between the diaphragm
and abdominal parietes, to take place in deep
breathing. There can be no doubt that the cir-
cumference of the thorax is increased, as shown
inD.y%. 670., and that the diaphragm must
extend its borders, and consequently the arch
must be flattened ; but this may be without
descending. We see (fig. 670.) that the sec-
tion of the thorax to the area of the diaphragm
is as 40 to 133 — the concavity of the dia-
phragm is enough to admit of its circumfe-
rence expanding without its descending.

Fig. 715. is a diagram of sections of the base
of the living chest in three stages, b is the chest
in ordinary : a, as in extreme expiration ; c, as
in extreme inspiration. In this case the vital ca-
pacity was 305 cubic inches, and the mobility
of the chest was 5 inches, a range by no means
common. The area of the chest varied 27
superficial inches between extreme inspiration
and expiration.*

In the sitting posture the same relations

Sections of the base of thorax in the three stages of
respiration , in the living subject.

* This is the chest of jig. 711.

1082 THORAX.

exist in the breathing movements ; the only
difference being that these movements are
more limited.

(c) Of the deep expiratory position. — In
fgs. 711. and 712. the margin of the shade is
the position of the thoracic boundaries in
deep expiration.

We have supposed the figures above men-
tioned as standing with the back fixed, for
the purpose of making clearly manifest the
relative position of these several breathing
movements. In fig. 716. the body is quite free,
and wholly alters its position in performing
expiration and inspiration. This should al-
ways be considered in noticing the breathing
movements in diagnosis.

j Fig. 716.

Respiratory Movements. Male, standing.
Expiration, dotted line. Inspiration, continuous line.

( d ) Of the change of position by extreme
breathing. — In expiration the head is pro-
truded and lowered (see figs. 71.3. and 714.).
Therefore, by inspiration the body is raised,
and the more erect the more can be inspired ;
by expiration it is lowered, so much so that
we have seen men when displacing their vital
capacity volume stoop themselves to one-lialf
their natural height, to one-sixth frequently:
we speak from a large number of cases, —
nearly 4000. Physiologists have reasoned
that, as upon the principle of a bladder becom-
ing longer when empty than when inflated,
so the chest is shorter when inflated than
when empty. But this example in no way
corresponds. The bladder expands, because
it is inflated; the chest is inflated because
it expands.

We have given the position of the breath-
ing parts (the body fixed) : we shall describe

the movement of these parts relatively in
time and order to each other, and the
peculiar character of these movements in
health, and some of their modifications by
disease.

Ordinary breathing. — In men this is sym-
metrical, and very limited, and commences
with an advancing and receding of the abdo-
men at and above the umbilical region, accom-
panied with a slight lateral enlargement, and
immediately followed by a bulging outwards
at the cartilages of the 7th, 8th, 9th, and 10th
ribs, and that part of the abdomen contiguous
to them, with a slight advance of the lower
third of the sternum. This is abdominal
breathing, because the abdomen moves first ;
and is confined to motion of the base of the
thorax. In women it is likewise symmetrical,
commencing with a gentle heaving of the upper
part of the thorax, more or less apparent ac-
cording to the fulness of the mammae. This
expansion commences with the 1st and next
three ribs following each other in succession,
accompanied with a slight elevation of the
shoulders and a slight lateral enlargement of
the chest, which is immediately followed by a
bulging outwards of the abdomen. So quick
is this motion of the diaphragm after the mo-
tion of the ribs, that at times they appear to
be synchronous, especially when the individual
examined is conscious of the observation,
though it is only an accommodating movement
of the diaphragm. This is costal breathing,
because the ribs move first, and the motion is
chiefly confined to the apex of the thorax.
Therefore that which is a healthy respiratory
movement in women is pathological in men.

Of the extraordinary breathing in both sexes
( Inspiration ). — This, like ordinary breathing,
is symmetrical: the clavicles, shoulders, sca-
pula, and superior ribs are raised, the sternum
advances, the infra-clavicular region swells re-
markably upwards and outwards (particularly
in females) like a rolling wave, the supra-cla-
vicular region is raised but this sometimes ap-
pears comparatively deepened (merely by the
action of the sterno-cleido-mastoideus), the
whole apex of the thorax is rendered more ob-
tuse, particularly in the antero-posterior dia-
meter. The lower ribs, at their cartilaginous
extremities, spread outwards, increasing both
the lateral and the antero-posterior diameter
of the base of the thorax, the cartilaginous (go-
thic) arch formed by the junction of the 6th,
7th, 8th, 9th, and 10th ribs below the sternum,
becomes more obtuse by their lateral motion,
the abdominal space within this arch, down to
the umbilicus, sinks inwards. Therefore this
breathing is costal, commencing with the
superior ribs, and terminating over the ab-
domen. The peculiar character of healthy
breathing (and it is impossible to lay too much
stress upon the movements of deep inspira-
tion, because they are so indicative of thoracic
disease) is that the ribs expand in succession.
There is an indescribable undulating roll, pro-
duced by the consecutive action of the re-
spective ribs, which always commences with
a superior rib ; — in costal breathing, a lower

THORAX.

1083

rib never moves first. In fact when we inspire
deeply we feel as if we directed all onr
power to the four or five superior ribs, giving
the greatest expansion to the very apex of the
lungs, — that most vulnerable part in phthisis
pulmonalis. When we look at the thoracic
cavity we see why this great power and mo-
bility is given to the upper part of the chest.
We see that the six superior ribs encompass
more space than the six inferior ribs. (See
Jig. 668.) So that where we command most
movement, there is the greatest portion of lung
to be expanded. The hand can measure most
delicately this healthy characteristic swelling or
filling up of theapex better than any instrument,
because the hand covers a large field of the chest,
and can distinguish the undulating movement.
Standing behind the person to be examined,
the fingers of both hands should be placed
over the clavicles, so that the tips rest on
the infra-clavicular regions, and the thumbs
over the inner borders of the scapulae. When
►. a deep inspiration is taken the fingers and
thumb of each hand diverge from each other,
and we thus gain a perfect knowledge of the
healthy “swelling expansion.” If the deep
respiratory movement is good, the ordinary
movement is sure to be good likewise. The
mere flat hand on the anterior and upper part
of the chest (facing the patient) will likewise
give the character, though less delicately. This
movement or swelling of the apex by deep
inspiration, is more distinctly marked on the
female than on the male subject. If this fine
swelling motion in deep breathing is absent
disease is present.

Pathological respiratory movements. — We
now speak of another class of breathing move-
ments, which are peculiar in this respect,
that the “undulating swell” of the chest
is wanting. The twelve intercostal mus-
cles move in every combination, as if to
meet impending difficulties, — tenacious of
life, and yielding only by compulsion to the ad-
vance of disease. Throughout the long list
of diseases which attack man these instinctive
movements have to contend, — shifting about,
or growing less and less. We have noticed a
man with lung disease, commence with costal
respiration of the lower ribs, and, as disease
advanced, he breathed with ribs higher and
higher up, so that at last he said, “ I breathe
with my neck;” and in truth it appeared so.
His 1st, 2nd, and 3rd ribs only appeared to
move. He passed through almost every
variety of respiration before he died.

The breathing movements are quick to
change, and the inquiry is interesting, what
causes the change ? One great cause is the
existence of dyspnoea, a disproportion between
the air passages and the volume of air to be
displaced, which may be caused by an obli-
terated state of lung, by tubercles, fluid in
the pleurae, hypertrophy of the heart, aneu-
rism of the great blood vessels, tumours of
various kinds, the pain of local inflammation,
pressure from the abdomen, whether ascites,
obesity, distended stomach, gravid uterus, or
any morbid growth bordering on the thoracic

cavity, or lesion of nervous integrity "requisite
for maintaining the respiratory movements.

Such conditions of themselves would oc-
casion deranged breathing movements. But
again there are reasons for thinking that these
movements may be changed from other causes
not so purely physical ; because sometimes
no dyspnoea is to be perceived, and yet the
movements are deranged, or they may change
backwards and forwards as if aerating specific
portions of the lungs, acting as a curative re-
medy to some incipient form of lung disease.
In complicated diseases of the chest a know-
ledge of the breathing movements is highly
useful. There is one condition in the res-
piratory act, which is indicative of a certain
state of chest, which, if not useful as a po-
sitive, is at least so as a negative evidence of
some existing state of things in the lungs.

The condition we allude to is a sinking in
and bulging out of portions of integuments
which cover the thoracic cavity. If we close
both nostrils and make a violent inspiratory
effort, the integuments between the sterno-
cleido-mastoidei immediately above the ster-
num, will be seen to sink inward from atmo-
spheric pressure. If we open one nostril, the
same is less apparent. If both are open and
the passages are free, it is not perceptible.
In expiration (with the same obstruction)
there is a bulging outwards of these integu-
ments. Sometimes, particularly in thin per-
sons, this may be seen on the integuments
covering the intercostal spaces. This sinking
inwards is an evidence of attenuated air, and
the bulging outwards of condensed air in the
lungs, near to the part. It is therefore an evi-
dence of some obstruction in the air passage.

Difficult breathing may be attended with
this feature, or not ; therefore it is an evi-
dence of something existing in one state of
dyspnoea which does not exist in another.

Dyspnoea without this “ sinking or bulging”
is a proof that there is no obstruction between
the air cells and the external air. But, on the
contrary, dyspnoea with this “ sinking and
bulging,” is a proof that there exists some
obstruction either as a direct diminution in
caliber of the air tube, or that more air is
drawn through certain tubes than is natural;
that this obstruction must have air on both
sides of it, and that the air on one side
is more attenuated than on the other. For
instance, when an aneurism on one of the large
vessels of a well-developed chest is pressing
upon one of the large bronchi, the respira-
tory sounds, and those elicited by percussion,
may be good, but respiration becomes la-
boured,— the case is obscure, but if there is
alternate sinking and fulness of the lower part
of the throat, we may be sure that there is
some definite obstruction in the air passages.
This, in connection with the history of the
case, may lead to the detection of the cause and
seat of the disease ; but dyspnoea without this
feature could not be caused by an aneurism
or tumour.

In emphysema of the lung this sinking and
bulging is very manifest. This circumstance

1081

THORAX.

proves simply that there is air in the chest
of different density to the external air ; and
if so, there must be some impediment in the
air tubes, preventing the restoration of at-
mospheric equilibrium.

Disease of the thoracic viscera affects the
breathing movements, causing them to be
more limited, or non-symmetrical, reversed,
massive, interrupted, partial, quick, slow, ir-
regular, or double.

(a) Of limited breathing movement. —
The mobility of parts when disease attacks
the chest may be surprisingly drawn forth.
Haller allows scarcely any mobility to the first
rib; Magendie asserts that the lower ribs are
immovable, because they either reasoned
from the healthy body, or anatomically : but
it is not uncommon in phthisical patients to
see strong and well-marked respiration kept up
by the 1st, 2nd, and 3rd ribs, or by the 10th,
11th and 12th; — these ribs are movable,
but it requires disease to bring their mo-
bility forth. We are satisfied that there is a
latent respiratory mobility during health, which
is manifested only by disease.

In disease particular parts take up ex-
aggerated movements, but the sum of these
movements is more limited than in health.
In the earliest cognisable stage of phthisis
pulmonalis the expansion of the thoracic
apex is diminished ; the shoulders incline
forwards and inwards, and become rounded ;
the spine is less erect ; the apex cannot ex-
pand. The mobility of the inferior ribs does
not so diminish, but sometimes maintains
life to the last. With an exaggerated move-
ment, the respiration is frequently costal and
abdominal at the same time, as if no part
could afford to be unemployed.

In 233 cases of phthisis pulmonalis (males)
in the first stage we noticed that the breathing
of 40 was costal, of 96 abdominal, and of 91
costal anil abdominal. The mobility by tape
measure was, instead of 3 inches and upwards,
as follows: — -

Table F F. — Diminished Mobility over the
Nipples on 233 Phthisical Males.

Difference between Inspiration
and Expiration.

Number of cases.

4 in.

-

3

3

4

-

5

1

-

54

H

-

13

H

-

44

if

-

23

2

-

53

2\

-

12

2i

-

25

-

1

(b) Of non-symmetrical breathing move-
ments.— In advanced stages of phthisis pul-
monalis non-symmetrical movements are no-
ticed ; but this may exist without a cavity or
effusion of fluid in the lung ; or a cavity
may exist with symmetrical movements (but
a cavity never exists without extensive dimi-

nution of mobility). Generally a cavity is at-
tended with non-symmetrical movements, or
a dragging up of one side of the chest ; and
in extreme cases there is no movement at all
in the region of the cavity. That symmetrical
movements may coexist with extensive disor-
ganisation or solidification of one lung is con-
trary to the opinion of many persons. It may
be explained by the fact of our having so much
spare lung. It has been found by experiment
that 310 cubic inches of air could be forced
into the lungs taken from a man with a healthy
chest (height, 5 feet 4 inches ; weight, 107 lbs. ;
vital capacity, 198 cubic inches), the absolute
capacity of whose thorax at death, was 245
cubic inches : therefore there was spare lung
for more than 100 cubic inches — a space
which he could not command during life.
May it not be possible that when a part of
the lung is consolidated or disabled, this spare
portion may come more completely into use,
and allow of the symmetrical movement ?

(c) Of reversed breathing movements. — A
man’s breathing may be costal or abdominal
for a month, a week, a day, an hour, a minute,
and change again, — every possible alternation
may occur. This may take place with or
without a cavity in the lungs, with or without
phthisis pulmonalis, as if a specific motion
drew in air to certain parts of the lungs to
excite some local change of condition. Al-
though costal respiration is maintained at a
greater expense of vital force, yet we see
when the vital power is fast ebbing the re-
spiration is always costal, and the last breath
is a deep costal inspiration followed by the last
expiration.

(d) Of massive breathing movements. —
Massive breathing is a marked feature of the
presence of emphysema in the lungs. There
is a total absence of that undulating, rolling,
and consecutive motion of the ribs. The
breathing is always costal, though it may be
conjoined with abdominal breathing, and the
ribs are elevated in the mass, sometimes
together with the shoulders clavicle and sca-
pula. Massive costal breathing is indicative
of emphysema of the lungs or pneumo-
thorax. In all other forms of dyspnoea the
undulating movement is more or less pre-
sent, though limited.

(e) Of interrupted breathing movements.
— In those diseases termed “ nervous,” parti-
cularly in young women, the breathing, espe-
cially the expiration, is sometimes interrupted
and jerking. This appears to be merely a
functional derangement; it may sound to the
ear like deficient respiration, for the intensity
of the “ murmur” is generally diminished, as
if the jerking “eased away” the expiring
air. This is sometimes the case in men. It
is very seldom combined with organic disease
of the lungs.

(f) Of partial breathing movements. — By
this we mean independent movement of cer-
tain ribs, or of some two or three of the res-
piratory regions. All the ribs may move as in
emphysematous breathing, or none of them
may move, or the lower, the upper, or the

THORAX.

1085

intermediate set may maintain the respiratory
function.

Andral observes, “ The partial immobility
of the ribs is not without interest in a physio-
logical point of view. Does not this fact
prove that, in inspiration, the ribs can move
independently of each other, and that they
have not merely a common movement ? If,”
says he, “ as we have often seen in phthisical
patients, the lower ribs can still move when
the upper ones remain motionless, it proves
that independently of the action of the scaleni,
the intercostal muscles are capable of taking,
an active part in the act of respiration.”*
In this way respiration may be separately car-
ried on by any of the twelve costal regions.
We have seen a man ill of rheumatism, lying
on his back, breathe solely with the diaphragm,
and not present the slightest motion of any
one of the ribs. And we have seen the con-
trary, viz., costal breathing, without the
slightest movement of the diaphragm. They
can act quite independently of each other, '

(g) Of quick and slow breathing move-
ments. — Not only thoracic disease, but most
illnesses, particularly febrile conditions, quicken
the respiration. In health the number of respi-
rations average twenty per minute (Table
G G), and it has been found that in 244
phthisical cases (males), the average number
was from twenty-four to twenty-eight per
minute (sitting) (Table 1 1), the highest
number was forty-four per minute. There
is every reason to believe that the che-
mical quality of expired air is the same
whether we are in health or in advanced
disease, though our requirements at these two
times may be very different; just as the quality
of smoke from a fire is the same whether it
burns briskly or slowly. — The quality is con-
stant, and the required modifications are ob-
tained by the difference of quantity in a given
time. Quick breathing is short, and slow
breathing is long, respiration. The natural
time of breathing may change by habit. We
have seen a man in health, whose ordinary
respirations were six per minute. This extra-
ordinary slowness was induced by an attack
of asthma, during which attack (lasting about
six years), his character of breathing changed
from eighteen short, to six long and deep,
respirations per minute ; though the asthma
entirely left him the character of the re-
spiration remained as first changed by the
dyspnoea. In this case the return of eighteen
respirations per minute, would be to him the
rapid respiration of fever, although formerly
the respiration of health. Time and volume,
in respiration, are the great modifiers of the
energy of aeration.

(h) Irregular breathing. — Irregular breath-
ing movements are less common when organic
disease is present. A nervous person, as well
as a phthisical person, may have every form of
irregular breathing, but in the phthisical per-
son the change is less frequent, and is probably
due to some change in the disease ; in the

* Andral, Clinique Me'dicale, tom. iv. 3d ed. 8vo.
Paris, 1804.

nervous person the change is frequent, some-
times once or twice during an examination of
the chest, Nervous breathing is generally well
marked in hysteria.

(i) Double breathing. — By this is meant cos-
tal and diaphragmatic breathing synchronous
with each other ; this is not uncommon in
severe cases of emphysema, when the mobility
of the ribs is much diminished. It is fre-
quently met with in phthisis pulmonalis ; —
in ninety-one cases out of 233. We have
no voluntary power to command this form
of breathing in health. It is to be looked
upon as a serious modification of respira-
tion. All the modifications of the respira-
tory movements, induced by disease, may
return to healthy breathing again, if the
derangement has not been kept up too long.
As a general rule, the respiratory movements
become natural soon after restoration of the
diseased parts to health.

Of the number of respirations in a given
time. — The ordinary respirations should
be counted without the individual being con-
scious of the observation ; otherwise they be-
come disturbed in number, and sometimes in
character.

Table GG. — Number of Respirations per Minute
(sitting) in 1897 males.

Respirations per minute.

From 9 to 1G

Number of cases.

79

16

-

-

-

239

17

-

-

-

105

18

-

-

-

195

19

-

-

-

74

20

-

-

-

561

21

-

-

-

129

22

-

-

-

143

23

-

-

-

42

24

-

-

-

243

24 to 40

-

-

87

Out of 1897 cases, 1731 of them breathed
from sixteen to twenty-four times, and nearly
one-third of them twenty times a minute.

The mean relative velocity of the breathing
and the pulse is about one respiration to four
pulsations of the heart (twenty to eighty),
and the variation in health in the number of
respirations is from sixteen to twenty-four,
and of the pulse from sixty-four to eighty-
eight per minute.

Table H H. — Relation between the Respiration
and the Pulse (sitting) 1407 males.

Number of Respirations
per Minute.

Pulse.

Number of
Cases.

16 -

- 64 -

- 218

17 -

- 82 -

- 102

18 -

- 70 -

- 176

20 -

- 82 -

- 546

22 -

- 83 -

- 135

24 -

- 88 -

- 230

From Table I I, phthisis pulmonalis in-
creases the velocity of the breathing move-
ments from twenty (the healthy mean) to
twenty-eight, and cases are numerous up to
thirty-six respirations per minute.

1080

THORAX.

Table II. — Number of Respirations, of 255
Phthisical Patients, per Minute (sitting).

Respirations per Number of

Minute. Cases.

12 to

14

-

_

41

4, 1

4

11 „

16

-

-

o.

16 ,,

18

-

-

13

id

.

21

18 „

20

-

-

4.

20 „

99.

_

_

44'

22

24

-

-

I'

24 „

26

-

_

49 '

- -

.

1 10

26 „

28

-

6J

\ 65 J

28 „
30 „

30

32

-

47'

“1

l

32 „
34 „

34

36

"

;

39

- 42.

90

36 „
38 „

38

40

“

-

16

”1

1

40 „

42

-

-

r

\ 17'

34

42 „

44

-

_

17J

*

A sudden change in atmospheric pressure
affects the number of breathing movements
in a given time. We found the following
limited but sudden increase of atmospheric
pressure increase them as follows. In South-
Hetton coal-mine in the county of Durham,
• — Depth of the mine 1488 feet.

At the level of the sea
At the bottom of the mine

Barom.

28-72

30-26

Thermom

- - 39 c

- - 49 c

Difference

1-54

10c

The additional pressure of the of an
atmosphere increased the ordinary breathing
from one to three times per minute.

This difference was purely the effect of
pressure, and not that of fatigue or mental
emotion. It might only be temporary.
Aeronauts inform us that diminished pres-

Tahle KK. — Effect of increased Atmospheric
Pressure on the “ordinary” Respirations upon
six healthy men.

ON THE SURFACE.

IN THE MINE.

Respira
Pulse. tions.

Respira-

Pulse. tions.

M. P.

50

15

50 16

— S.

98

20

98

24

— II.

72

16

68

19

— L.

90

14

88

15

— W.

88

185

93

22

— T.

85

18

100

20

Mean -

83 1 6-9

84-3

19-3

sure increases the number of respirations ;
but with them there is this difference, that
with diminished pressure there is a sensation
of a want of air. When the barometer is low
we feel lassitude, and call the “ day heavy,”
when in truth the air is lighter, and we ourselves
are heavier ; when the barometer is high, we
generally experience an indescribable sensation

of pleasure — the vital energies seem doubled.
With a sudden and considerable fall of the
barometer there is a transient plethora. The
blood-vessels become distended, owing to
which, together with certain hygrometric
changes in the air, we feel listless, and the
least exertion produces perspiration. Du-
hamel observed that, in the month of De-
cember, 1747, the barometer in less than two
days fell 1-J- in., producing a change of pressure
on the body of a man, of 1400 lbs. ; this he ob-
serves was accompanied with many sudden
deaths. It is evident that with an increased
pressure we get more air into the lungs with a
given mobility; for, eastern paribus, air, with the
barometer at 30 in. must be more dense than
the same air with the barometer at 29 in. In
the mine in question, we experienced a sensa-
tion of lightness and vigour. The number of
respirations are always increased when there
is a preternatural increase in the temperature
of the body.

Of the Sounds of Respiration. — The
breaking up of the air into minute streams was
discovered by Laennec to produce certain
sounds, named “breathing sounds:” which
sounds are now made available in detecting
organic disease in the lungs. As the air
penetrates the lungs, it is divided and sub-
divided until it enters the minute air vesi-
cles. The air passes, 1st, through the trachea,
producing “ tracheal sounds,” — a hollow
rough blowing ; 2nd, through the next divi-
sion of vessels (bronchial), producing “ bron-
chial sounds,” less hollow and termed “whiff-
ing or tubular and, 3rd, into the air vesicles,
producing “ vesicular sound,” — a soft, silky
murmur like a gentle breeze among the
leaves of trees. Dr. Jackson discovered that
which Laennec overlooked : — this murmur
is not heard in expiration, while the other
two sounds are. Hence the expiratory
murmur is a morbid sign, and if heard on
the left side below the acromial end of the
clavicle, is a sure sign of some altered
condition of the air tubes, not compatible
with a healthy lung. This expiratory mur-
mur may sometimes be heard faintly on the
right side, and not be a morbid sound ; but if
strongly heard there, it is a morbid sign. A
question now arises : Why is there a murmur-
ing sound with inspiration and not with expira-
tion ? First, let us inquire what is the dif-
ference between the inspiratory and the
expiratory act ? They differ in two ways :

1st. In Inspiration the lungs are passive ;
the chest threatens a vacuum, and the air
enters a rarefied space. In Expiration the
lungs are active ; there is no rarefied space ;
the air is squeezed out into the atmosphere.
This does not affect our question.

2dly. In Inspiration a volume of air is
broken up into smaller and smaller streams.
In Expiration these small streams are collected
up into the original volume by larger and
larger streams. This answers the question.

The hollow blowing sound in the trachea is
caused by the friction of the air against the
sides of the tube. The relation of the friction

THORAX.

1087

to the stream is the same whether the air passes
into or out of the lungs, therefore the tra-
cheal sounds are equally heard in expiration
and in inspiration. But not so in the lungs ;
here, as the stream of air proceeds it is
subdivided, and with every subdivision the
friction is increased ; so that with every
advance of the stream into the substance of
the lung the sound is increased, and becom-
ing more and more buried in the substance of
the lung is heard as in a continual murmur.
In expiration the very contrary happens.
The friction is as quickly diminished, until
the substance of the lung entirely masks what
remains. In the larger vessels when the
volume of the returning air becomes great, and
the diameter of the tube more uniform, the
friction is the same whichever way the air
passes, and here tracheal and bronchial ex-
piration are audible, during inspiration as
well as expiration. If we take a sheep’s
lung and inflate it, we hear the inspiratory
murmur; let go the air and we do not hear
it ; but contract part of the lung, say with the
edge of a paper knife, and 3 0U hear the mur-

mur during the lung’s collapsing, showing that
by increasing the friction you produce the
expiratory murmur.

When any disease thickens or diminishes
the diameter of the air tubes, or when one
part of the lung is obliterated and another
part has to do double work, then the friction
is increased, and thus expiratory murmur is a
true sign of some change in the minute air
tubes of the lungs. Sometimes the breathing
murmur is so gentle and the thickness of the
muscles so great that we have even in health
known the inspiratory murmur quite inaudible.

In organic change of the lung these sounds
become changed in their intensity, rhythm, and
character. The cause of the change of sound
is yet involved in much obscurity ; hence some
persons have been said to have had tubercular
lungs, when such has not been the case; or even
extensive cavities, &c., yeftime has shown that
there never hail been cavities. All the morbid
true sounds yet require to be verified as to their
cause. As we have natural changes in the
character of breathing, so are there changes in
the sounds of breathing, as follows : —

I. In its Intensity

II. In its Rhythm

1. Frequency

2. Duration

III. In its Character

When there is fluid or disorganisation in the
substance of the lung, there are certain crack-
linos, crepitations, and gurglings, causing
certain other sounds not included in the above
list. Unfortunately authors differ in the ap-
plication of the names for these sounds.
They may be all classed under two heads,
the dry and the moist, whether the tubes
be large or small in which the sounds are pro-
duced.

For the Bibliography see that of art.
“ Respiration,” p. 366.

(./. Hutchinson.')

THYMUS GLAND.— (French, Be thymus;
Italian, Tinio; German, Die Brustdruse; Lat.,
Thymus; Greek, Bvyoe.) — It is proposed in
this article to adopt the following arrange-
ment : First, to treat of the gland as it exists
in the human subject, comprehending its ordi-
nary and structural anatomy, and its develop-
ment. Secondly, to give a sketch of the
comparative anatomical history of the organ.
Thirdly, to treat of its physiology. Fourthly,
to mention what has been observed of morbid
changes occurring in it.

Human Anatomy. — Sir A. Cooper’s de-
scription of the gland in the human subject is as

Strong or exaggerated.
Feeble.

Absent or suppressed,
f Quick.

\ Slow.

Jerking or interrupted,
f Long.

-I Short.

I Expiration prolonged.

t Harsh.

Bronchial or tubular.
Cavernous.

Amphoric.

follows: — “This gland is formed of a tho-
racic and cervical portion on each side. The
former is situated in the anterior mediastinum,
and the latter is placed in the neck, just above
the first bone of the sternum, and behind the
sterno-hyoidei and sterno-thyroidei muscles.”
“ Between two and three months of foetal life,
as will be seen in the plate (Jig. 717.), it is so

Fig. 717.

The thymus , heart, larynx, 8fc., of the human foetus at
rather more than two months. ( After Sir A. Cooper .)

small as to be but just perceptible. At three
months (Jig. 718.) its increase is in propor-
tion to the relative magnitude of the foetus, and
thus it continues to grow gradually and equally
(.fig. 719.) to the seventh month, when it en-
larges out of proportion to its former growth.
At eight months it is large, but at the ninth

1088

THYMUS GLAND.

Fig. 718.

Thymus, Sfc., of human foetus at third month. ( After
Sir A. Cooper .)

month {fig. 720.) has undergone a sudden
change, becomes of great size, and is said to
weigh half an ounce, from which circumstance,
however, on account of the cavities which it

Fig. 719.

Thymus, Sfc., of human foetus at fifth month. ( After
Sir A. Cooper .)

contains, and the varieties to which it is sub-
ject, no judgment of its bulk can be formed.
It increases after birth, and continues large to
the first year, when it slowly disappears to the
time of puberty ; and in after age it ceases to
have cavities, and becomes a body of very
small dimensions.”

He next notices the following varieties in
configuration : — “ Although the gland is usu-
ally double, and the one side united to the
other by cellular membrane only, yet it some-
times happens that a third thoracic lobe exists,
which appears to join one lobe with the other,
but which allows, under a careful dissection,
of their being separated. There are also two
other varieties I have seen ; the first is the
vena innominata passing through the gland,
and the second, the same vein placed anteriorly
to the cervical lobes. Indeed, I scarcely find
two organs alike in form ; sometimes they are
round, whilst others are of great length, and
are so thin that the serpentine disposition of
their lobes may be seen without dissection.
The left gland is often larger than the right ;
but even in this respect so much variety is
observable, that it appears if the bulk of the

Fig. 720.

Thymus, 8fC.,of human foetus at ninth month. ( After
Sir A. Cooper. )

whole be the same, that it is of little import-
ance which may be of the greater magnitude,
the right or left gland, as its secretion will be
equally abundant.”

The relative situation of the thymus gland
to the adjacent parts is described as follows :
— “In cutting through the sternum in its
long axis, and then separating its two lateral
portions, so as to give a good view of the
mediastinum, the thymus gland appears situ-
ated behind the first and part of the second
bone of the sternum ; and posteriorly to the
origins of the sterno-hyoidei and sterno-thy-
roidei muscles. It reaches more than half
way down the sternum at birth, viz. to the
fourth rib, and extends from thence into the
neck near to the thyroid gland. It is con-
nected to the sternum and origins of the
sterno-hyoidei and sterno-thyroidei muscles by
cellular tissue ; it adheres strongly, by a coarse
cellular membrane, to the pericardium ; an-
teriorly and laterally the internal mammary
arteries and veins take their course. The
reflection of the pleura descending from the
cartilages of the ribs on each side, and con-
tinued to the fore part of the pericardium
forming the anterior mediastinum, makes its
lateral boundaries, and separates it from the
lungs; posteriorly it rests upon the vena in-
nominata, and upon the fascia of the thorax,
which descends from the sternum and first rib
to the curvature of the aorta, and to the three
large vessels which spring from it.” “ Such,
then, is the relative situation of the gland in
the chest. In the dissection of the cervical

THYMUS GLAND.

1089

portion of the thymus, the platysma myoides
and external jugular vein are first turned
aside, and the origins of the sterno-mastoidei
muscles are raised; when this has been accom-
plished, the sterno-byoidei appear covering
and passing over the thymus gland. The
sterno-thyroidei muscles . . . cover this organ
anteriorly; but when they are removed, the
cervical portions of the thymus are seen on
the anterior and lateral parts of the trachea,
and just below the thyroid gland, where it
passes on the fascia on the fore part of the
air tube, and unites with the larynx by liga-
ment.”

“ The internal jugular veins are placed an-
teriorly and laterally to the cervical portion,
and the carotid arteries, with the par vagum,
appear more externally.”

“ The first bone of the sternum and sternal
ends of the clavicle cover the junction of the
cervical with the thoracic portion of this
gland.”

“ In many of the subjects which I have ex-
amined, the cervical portion of the thymus
passes higher upon the right than on the left
side, and I have generally seen it joined by a
ligament to the larynx, and by vessels to the
thyroid gland.”

In a human foetus, at about the fourth-and-
a-half month, I found the thymus consisting
of two lateral portions, of which the right was
the larger (in another of similar age the left
was) ; this portion extended downward, lying
upon the pericardium, as far as opposite the

Fig.

right auricular appendix, and reached upwards
only to the left brachio cephalic vein, which it
did not cross ; the left extended downwards,
over the pericardium, to a point opposite the
middle ot the trunk of the pulmonary artery,
and passed up, lying upon the vena transversa,
and afterwards upon the side of the trachea, be-
tween it anti the common carotid, till it arrived
at the level of the bifurcation of the arteria
innominata.

The appearance of the gland in the foetus
about the middle of utero-gestation is precisely
similar to that of the salivary gland in the
same ; it is beautifully lobulated, and sur-
rounded by an atmosphere of nascent areolar
tissue. In the more perfectly formed con-
dition it is surrounded by' an envelope of
coarse cellular membrane, which penetrates
the intervals of its larger divisions, unites the
right and left portions together, and forms a
general envelope, by which it is connected to
the surrounding parts.

In examining the structure of the thymus,
we are conducted by two eminent guides to
conclusions almost identical, though by dif-
ferent modes of proceeding. This coincidence
is of great value, and we can scarcely enter-
tain a moment’s doubt of its being founded on
real truth ; it may therefore be well to notice
separately the modes of investigation above
referred to.

Sir A. Cooper, by skilful manipulation, suc-
ceeded in unravelling the gland, and showed
each lateral part to be composed of a

721.

1090 THYMUS

rope, on which the lobes and lolnili are set
somewhat like the beads on the string of a
necklace (7%. 721.). By injecting also the
glandular cavities with some fluid, as alcohol,
capable of hardening the tissue, or with co-
loured gelatine, which sets and permanently
distends them, he demonstrated the existence
of a central cavity or reservoir, communicating
with the glandular cavities by orifices leading
into pouches situated at the roots of the
lobes (Jig- 722.). The central cavity forms a

Fig. 722.

Section of thymus showing the reservoir, cells, and
pouches. ( After Sir .1 . Cooper.)

general communication between the different
lobes ; it does not maintain a straight course,
but passes in a somewhat spiral manner, be-
ginning from the lower part of the thoracic
portion, and extending even into the extremity
of the cervical part of the gland : its size varies
in different parts, being largest near the centre
of the thoracic, and least at the communication
of the thoracic with the cervical, part of the
gland. Sir A. Cooper conceived the reservoirs
to be lined by a very vascular mucous mem-
brane of somewhat villous character, but this
does not appear in reality to exist.

Such were the principal results obtained by
a most skilful and eminent anatomist, with all
the appliances and aids that his science could
at that day supply ; they were truly valuable
facts, but not so “ luciferous,” not so exhibit-
ant of physiological meaning, as those ob-
tained bv a subsequent inquirer, who, availing
himself of the more penetrating ken of the
modern achromatic lens, and seeking rather to
learn from the instructive examples which
Nature herself sets forth, than from results of
his own devising and producing, has both
confirmed the conclusions drawn from a less
refined scrutiny, and invested them with a
more correct bearing and interpretation. I
refer, of course, to the admirable researches
of Mr. Simon, which I now proceed to detail,
respecting the structure of the thymus, as
illustrated by its developement.

Developement. — The first trace of the or-

GLAND.

gan which has been discovered is in the
form of an exceedingly delicate tube, lying
along the carotid vessels in the neck, not
straight, but wavy at one part, and termi-
nating by closed extremities at both ends
(Jig- 723.). Its wall is formed by a transpa-

Fig. 723.

Primary tube. ( After Simon.)

rent homogeneous tunic, marked at regu-
lar intervals with elongated thickenings (the
remnants probably of the nuclei of primor-
dial cells), and enclosing granular matter, but
no distinct corpuscles. There seems some
probability that this tubular form, though
found to prevail in very early embryos, may
not be the really primitive one, but that a
linear series of cells is first developed, which
are afterwards blended together by fusion, so
as to constitute a tube (see Jig. 724.); this opi-

Fig. 724.

Supposed origin of primary tube. ( After Simon.)

nion however, I suspect, will not be confirmed ;
the limitary membrane of glandular and other
structures has generally appeared to me to be
produced quite independently of cells, so far,
at least, as that it should be regarded identical
with their coalesced envelopes. In the next
stage of developement, the homogenous wall
of the tube begins to bulge, and swell out into
vesicular cavities, which at first have wide
communications with the central canal or
tube, and are quite sessile, but afterwards
become attached by short and rather narrow

THYMUS GLAND.

1091

pedicles ( Jigs. 725. and 726.). This budding

Fig. 725.

Fig. 726.

Second stage of developement of primary tube forming
follicles. ( After Simon.')

out of the primary tube does not occur simul-
taneously at every part, or uniformly, but
chiefly at those situations which are ulti-
mately to attain the largest size ; thus in the
fatal calf we find tolerably well developed
bulgings of the primary tube opposite the
angle of the jaw, the upper part of the trachea,
and the pericardium, while the intervening

portions have smooth and undulated margins ;
and it is just the parts of the gland corre-
sponding to the above points, which ulti-
mately attain the greatest magnitude. The
third stage of developement consists in the
ramification of the follicles which have budded
out from the central cavity; — they do not
usually elongate much, before they throw off
fresh offsets, and these are completely sessile,
so that they have the appearance of vesicles
or imperfect spheres grouped together : the
mode in which the primary offset divides is
either dichotomous or quaternary (Jigs. 727.
and 728.), probably also often with some
degree of irregularity and inequality in the
size of contiguous offsets. By the extension

Figs. 727, 728.

Third stage of developement.
Ramification of follicles by dichotomous and
quaternary division. ( After Simon.)

of this follicular growth to all parts of the
primary tube, and bv successive lateral rami-
fications, occurring, as we have seen, to a
greater extent in some parts than in others, the
gland attains its mature size and complex
structure. In this state however it consists,
in very great measure, of vesicular cavities,
which cluster around and completely obscure
the primary tube from which they have origi-
nated ; yet this primary tube or reservoir does
exist, and is capable, as we have seen, of
being demonstrated, so that the term which
Mr. Simon has proposed, as expressing the
type of the mature structure, viz. tubulo-
vescicular, is sufficiently correct (Jig. 729.).
Two varieties have been observed in the seeond
stage of the process ; one is, that “ the tube
sometimes bulges uniformly in its whole cir-
cumference for some extent, forming a very
distinct ampulla;” the other, “ that in parts
where there are yet no bulgings, it is some-
times flexuous, or even contorted.”

The observations now detailed respecting
the progressive developement of the thymus,
are so important in the elucidation of its
structure, that I thought it very desirable to
repeat them, if possible, and confirm their ac-
curacy by independent testimony. I have
not, however, been able to procure a fetus at
a sufficiently early period to discover the
primary tube of the thymus, with its smooth
4 a 2

1092

Fig. 729.

THYMUS GLAND.

Fig. 730.

Diagram of fully developed thymus.

Showing how the primary central tube is covered
and concealed by the lateral developements, each of
which constitutes a conical mass, a, b, c, d, with a
very wide base. ( After Simon.)

unbulging wall, but 1 have seen it distinctly at
a period somewhat later, when the process of
lateral extension had but recently commenced.
This was in the embryo of a sheep, not more
than two inches long, where the thymic cavi-
ties were bounded by a well-marked limitary
membrane, and filled with nuclei. At the
extremity of the cervical portion, thedevelope-
ment of bulging offsets was much less ad-
vanced than towards the middle of the gland,
so that here the central tube was very appa-
rent, terminating by a closed extremity, and
having its margins rendered irregular and
wavy by the vesicles which had begun to
rise from it (Jig. 730.). The developing or-
gan was formed in a nidus of homogeneo-
fibrous tissue, interspersed with nuclei, which
was seen stretching across between the promi-
nent convexities of the bulgings. At the end
of the cervical portion this tissue was more
abundant, and there was seen running into it
a prolongation of the central cavity, which
appeared exactly like a short tube, pushing
on in a straight direction, and not expanding
nto a vesicular cavity. In a young chicken
the condition of the thymus was very similar,
and the central cavity was larger than the
small lateral offsets. These details, though in-
complete, leave scarcely a shadow of doubt that
Mr. Simon’s account is perfectly correct, that
the central cavity is the primary part from which
the vesicular offsets successively develope
themselves. This central cavity may, I am
inclined to believe, in some cases disappear
more or less completely ; at least, in an em-
bryonic sheep, three inches long, it not only
bore a smaller proportion to the multiplied
offsets, but its wall no longer exhibited the
investing limitary tissue, and it seemed as if it

The end of the tube is closed, the central cavity
is larger, the walls present numerous follicular pro-
trusions of irregular size and form. Towards the
middle the follicles are very much more developed.

were in some measure diminishing, and losing
its original distinctness. From what I have
seen in the sheep, I should be led to think that
the cervical and thoracic portions of the thy-
mus had, in that animal at least, distinct pri-
mary tubes as centres of developement, so
completely independent have the two parts
seemed to be of each other.

Mature structure of the gland. — The results
of minute scrutiny into the structure of the
fully-developed thymus, accord well with
those arrived at by other modes of inquiry.
Its surface, when freed from investing areolar
tissue, exhibits, though in a rather coarser
manner, the minutely-divided appearance so
characteristic of the conglomerate glands, and
this is especially evident when fat cells have
formed in the interstices of the lobules, pat-
terning the surface over with a network of
white streaks. In a thin section taken from
the gland and prepared for the microscope,
the outlines of the vesicular cavities are rea-
dily seen ; they are much larger than those of
the salivary glands, and vary very much in
size ; in a human foetus, at about the mid-
period, they averaged Jg inch, in a calf about
Jg inch, in a young guinea-pig they varied
from to TJ¥ inch. Their form is oval or
spherical, their outline distinct for about two-
thirds of their circumference, but in the
remaining part blended with adjacent ones, so
that there is never seen any thing resembling

THYMUS GLAND.

1093

a detached and closed vesicle. The sharp
definition of the outline by a clear dark line,
gives full assurance of the presence of an in-
vesting limitary or basement membrane ; this
constitutes a general envelope, forming the
boundary of each of the glandular cavities,
surrounding, therefore, the whole mass, but no-
where prolonged into an efferent canal, through
which the contents might escape. In structure
it is truly homogeneous, that is, considered
per se, but as it is closely invested by a very
thin layer of areolar tissue on its exterior, it
has sometimes a kind of fibrous, striated, as-
pect. In all respects it closely resembles the
basement tissue of other glands, and, as in
them, I have never been able to perceive in it
anything corresponding to the germinal cen-
tres of Mr. Goodsir.

The contents of the thymic cavities next
demand our attention. They consist almost
entirely of corpuscles, very closely resembling
(in fact identical with) the nuclei of glandular
cells ; the only difference which the most
careful scrutiny can detect between them, I
believe, is this, that they present more nume-
rous nucleoli than the nuclei of gland cells
usually do. I doubt, however, whether even
this is constantly the case. Their form is, I
think, for the most part spherical ; Mr. Simon
speaks of them as generally flat and circular,
but I have never observed one, if this be their
real form, presenting its thin edge to the eye,
as blood-discs frequently do. They vary a
good deal as to the condition of their interior
spots or nucleoli, some contain two or three,
some as many as four or five, a few have one
only, and some of the smaller none at all, but
are filled with a dimly molecular substance.
Their surrounding envelope is strong and
well defined, as that of nuclei always is. The
extreme variations in size of these corpuscles,
according to Mr. Simon, are --£5-5 hich for the
largest, and l°r the smallest, probably a
correct average, for the generality is about
s=Tnoo 'nc'h. Mingled with these I have
found in the thymus of a calf, as well as
in that of a young guinea-pig, a few larger
corpuscles, about double the size of the
former, of spherical form, filled either with
granular matter alone, or containing also
a nucleus or larger vesicular body.. I am
by no means inclined to regard these as cells
formed upon the originally-existing nuclei of
the cavities, but rather as expansions of the
nuclei themselves, with formation of granular
matter in their interior.

It is well worthy of remark, that in the
fully developed organ, before any appearance
of atrophy has taken place, no other contents
than those now described are found in the
glandular cavities. There is none of the abun-
dant granular material which forms so large a
part of the epithelium of most glands, no dif-
fused oily matter, the nuclei aggregated to-
gether into dense masses seem to fill the
ultimate vesicles completely, and there is no
trace of any material which can justly be re-
garded as the product of secretion. * ' A

* The contrast in this respect between the thy-

strong’solution of bichloride of mercury, in-
deed, coagulates a small quantity of diffused
plasma (probably the liquor sanguinis of blood
remaining in the capillaries) which adheres
irregularly round the neuclei, but its effect on
the contents of the thymus is very different from
that which it has on the albuminoid epithe-
lium of the true glands. This is a remarkable
circumstance, anJ, as yet, has not, I think,
been sufficiently attended to. If we en-
deavour to interpret it, it would seem to im-
ply that the thymus is not truly a secreting
organ, that is, that it does not separate from
the blood or elaborate any special product, or
in fact any product at all ; but that its func-
tion is limited to the formation of an appa-
ratus, which conforming closely to the type of
secretory glands is yet not endowed with any
analogous property. * The centres around
which the material of the secretion should be
evolved are present in myriads, but no gran-
ular substance analogous to that of glandular
epithelium is formed around them. It seems,
therefore, that in the case of the thynnis, the
liquor sanguinis exuded from the vascular
plexus through the homogeneous tunic simply
solidifies into cytoblasts or nuclei, in most
other glands a part takes the same organic form,
— a certain number of nuclei are formed, —
but these then become the centres of a dif-
ferent and more complete action, or are en-
dued with peculiar attractive powers, in virtue
of which the materials of the several secretions
collect around them in their respective labo-
ratories. Such is the fact microscopic inquiry
adduces, and such theinterpretation which may
be offered of it; let us now turn to chemistry,
and inquire whether the view we have just
suggested is supported or negatived by the
result of analysis. Mr. Simon gives three
analyses of the thymus, which, as he states,
though performed on the tissue itself, and not
on its fluid contents, may fairly be depended
on for conveying a sufficiently correct idea of
tbe chemical constitution of the matters con-
tained in its cavities. Now in none of these
is there any mention of any special substance
which couid be regarded as characterizing the
secretion, on the contrary, the constituent
elements are mere fibrinous, albuminous, or
extractive matters and ordinary saline com-
pounds, and there is none of these which
might not exist in the blood, and be most
readily derived from it. This is, in fact, the con-
clusion which Mr. Simon adopts ; he believes
that we may express the nature of the secre-
tion of the thymus as nearly as may be by the
formula of Proteine, or denominate it, in
physiological language, as simply nutrient
matter.

nuis and the thyroid is very instructive, in both the
limitary membrane forms closed cavities, which in
the one are chiefly filled with secretion, in the other
with nuclei, the accredited agents of secretory action.

* Whatever may be the nature of the fluid said
to be contained in the thymic cavities in which the
nuclei float, it is too small in quantity, and too little
apparent, to make it necessary to take it into
account ; certainly it never collects after the man-
ner of a secretion.

4 a 3

1091

THYMUS GLAND.

Sir A. Cooper describes the vascular sup-
ply of the thymus as follows: — “With re-
spect to the arteries of this organ, they are
principally derived from two sources. Each
thoracic portion is supplied by a branch which
is sent off by the internal mammary. It
enters at the junction of the cervical with the
thoracic part, generally on their outer side,
but sometimes between the cervical portions,
and, descending upon the middle of the gland,
divides to supply the spirally disposed lobes.
The other principal artery of the thjmus is
sometimes derived from the superior thyroi-
deal, at others from the inferior thyroideal
artery, and, descending upon the lobes of the
cervical portion, passes into them, and ulti-
mately anastomoses with the branch from
the mammary artery. The thymic arteries
may also arise from the trunk of the subcla-
vian, the vertebral, or the carotid artery, or
even from the arch of the aorta. The ca-
pillary network in which the arteries termi-
nate, is stated by Mr. Simon to be of “the
completest description. It is so arranged as
to include each individual vesicle within a
vascular capsule ; the capillaries are closely
applied upon the transparent texture (limitary
membrane) which bounds the cavities, and so
exceedingly dense is their network that the
meshes are of even less diameter than the
vessels themselves. Every portion of the
glandular substance is thus exposed in the
completest manner, and at every point of its
surface, to the penetration of the fluid ingre-
dients of the blood.” “The venae thymicse” Sir
A. Cooper states “ have a different course to
the arteries ; for although the internal mam-
mary and thyroideal veins receive small
branches from the gland, yet the principal veins
are those which end in the vena innominata.
A considerable vein springs from each thoracic
portion, and passes from the posterior surface
of this part of the thymus into the vena inno-
minata; having received a branch from the cer-
vical portion, and vessels from the thoracic: it
is found near the centre of the gland. A very
small vein enters the thyroideal from the cer-
vical portion, and this vein anastomoses with
that of the thoracic part.”

Respecting the absorbent vessels of the
thymus very little seems to be known ; we
may, however, fairly conclude from the
analogy of other parts, that they commence
by a network of minute vessels, which have
no communication whatever with the glan-
dular cavities, and cannot, therefore, serve the
purpose of excretory ducts as has been sup-
posed : the glands to which they proceed are
those of the anterior mediastinum.

Mr. Simon describes the nervous supply of
the thymus “ as mainly derived from the
plexus which surrounds the first part of the
subclavian artery, and which has its chief
origin from the inferior and middle cervical
ganglia. A small twig detaches itself from
this sympathetic plexus, just opposite the
origin of the internal mammary artery, accom-
panies that vessel in its course, and, on
arriving at the point where the thymic branch

arises, sends filaments along it into the sub-
stance of the gland. A second source of
supply is the cardiac branch of the pneumogas-
tric, which gives on each side a minute fila-
ment to the superior part of the gland.” “ In
one instance I have seen a very minute fibril
of the descendens noni emerge from the sub-
stance of the sterno-thyroid muscle, and reach
the cellular investment of the thymus ; and I
have sometimes seen delicate twigs of the
phrenic also detached towards the gland ; but
in each case the nerve has appeared to restrict
its distribution to the surface and coverings
of the organ, and has not accompanied any of
its vessels.”

The exact arrangement of the nervous
fibrils, both tubular and sympathetic, in the
substance of the gland is yet unknown ; but
it seems tolerably certain that they accompany
the vessels, enlace them with their plexiform
divisions, and terminate, in part at least, in a
looping manner.

Early development. — The following quota-
tion from Professor Goodsir’s paper in the
Philos. Transactions, contains his view's re
specting the development of the thymus and
two others of the ductless glands; I am un-
able from my own observation to confirm or
dispute the accuracy of his opinion, but can-
not do otherwise than refer to the labours of
so distinguished a physiologist.

“ That portion of the membrana intermedia
which is separated from the rest of the mem-
brane, and included in the body of the embryo
by the umbilical constriction, and which has
not already been devoted to the formation of
the heart, liver, pancreas, and external portion
of the intestinal canal, is found massed along
the trunks of the primitive venous system, the
sides of the arches of the aorta, the terminal
portion of that vessel, and the origins of the
omphalo-mesenteric arteries. The portions of
the membrana intermedia which are last in
being converted into special organs, the Wolf-
fian bodies, are the parts which project one
on each side of the aorta along the posterior
part of the cardinal veins of Rathke, between
the intestinal plates and visceral laminae. The
portions of the membrana intermedia, which
remain between the upper extremities of the
Wolffian bodies and the heart and liver, and
which surround the origins of the omphalo-
mesenteric arteries, do not become converted
into organs of special structure, but retain
during life the original constitution of the
membrana intermedia of the blastoderma, and
increase rapidly in the embryo constituting
the supra-renal capsules. That portion of the
membrana intermedia which is situated be-
tween those two aortic arches the extremities
of which become the carotid and subclavian
arteries, remains during life as the thyroid
body. It receives its blood from the first and
second aortic arches by two large trunks on
each side, the superior and inferior thyroid
arteries. That portion of the membrane which
passes in two parts from near the base of the
cranium back as far as the ductus Cuvieri and
anterior portions of the veins of Rathke, and

THYMUS GLAND.

1095

which are united and concentrated in front of
the heart, by passing from behind forwards in
harmony with corresponding motions of the
neighbouring part, becomes the thymus. The
structure of these organs is identical with that
of the blastoderma (?). Their probable func-
tion, namely, to prepare by the action of their
nucleated cells, and to throw into the vascular
system a matter necessary for the nutrition of
the animal during the period of its active
growth, a function which the observations and
opinions of the majority of physiologists have
assigned to them, is also essentially the same
with that of the blastoderma.”

Development of Size. — Having now examined
the anatomy of the thymus, and traced its
development with a view to the exact elucida-
tion of its structure, we have next to follow
out the successive periods of its growth, in
order to determine whether it be an organ
having special relation to foetal or to extra-
uterine life. The former alternative was that
to which the older anatomists, and even Sir
Astley Cooper, inclined ; but the correctness
of the latter seems now abundantly established.
Meckel, Hewson, Cloquet, and Sir A. Cooper
himself, all concur in stating that it continues
to grow at least up to the end of the first year
after birth ; and more recently the evidence
accumulated by Mr. Simon from his own ob-
servations and those of Hangsted have quite
set this important point at rest.

The following details have been selected
from the copious table of instances contained
in Mr. Simon’s essay, they show conclusively
that the gland does not attain its greatest size
for some time after birth, and that after a va-
riable period it gradually again diminishes.
Thus in the dog, at birth the gland weighs 4'75
grs. ; from 3 4 months to H year after it varies
from 360 to 780 grs. ; from 3 to 4 years it varies
from 150 to 46 grs. In the cat, at birth its
weight=64 grs. ; from 19 to 37 days after it=
30 to44grs. ; 4 to 6 years after=20 to 3 grs. In
the human foetus of 7 months the gland
weighed 33 grs. ; at 8 months 40 grs. ; at birth
84to240 grs. ; 9 months after, 270 grs. ; at 21
years 40 grs. The weight of the thymus is
subject to considerable varieties, which pro-
bably depend, as Mr. Simon points out, partly
on original differences, some individuals hav-
ing naturally a larger proportion of thymic
structure than others ; partly also on tempo-
rary alterations in the activity of the nutrient
processes, as is well exhibited in the effect of
over-exertion on the thymus of lambs re-
marked by Mr. Gulliver ; the size of the gland
is known also to diminish when the develop-
ment of the muscular system is promoted, it
being found to waste away much more rapidly
in young oxen used for draught, than in others
not so employed.

The general conclusion, which the able
physiologist from whose work I have drawn
so largely adopts, is, I think, truly judicious
and accurate ; he estimates the period, during
which the thymus persists and is active, not
so much according to the space of time which
has elapsed, but according to the state of the

general functions of the frame : if the assimi-
lating processes are active and vigorous, and
the supply abundant, and the demand only mo-
derate, the gland will be large and will persist
longjif onthecontrary thefirst processesof nu-
trition are imperfectly supplied, or if great mus-
cular exertion creates a considerable demand,
then the thymus ceases earlier to discharge its
function and becomes atrophied, because the
conditions no longer exist which are favoura-
ble to its subsistence. Now it is obvious that
in almost every individual these circumstances
which so greatly affect the nutrition of the
thymus may vary exceedingly, and it is there-
fore impossible to state an exact numerical
age as the period of the highest development
of the gland ; a physiological age may how-
ever with much certainty be named, and it is,
as Mr. Simon states, “ the age of early growth.”
The date of the earliest appearance of the
thymus in the human foetus is still little more
than matter of conjecture, it has not been po-
sitively detected before about the 9th week,
when it is quite distinct to the naked eye,
consisting of two lateral elongated portions
lying parallel to each other on the upper part
of the pericardium. Its structure at this time
is distinctly tubulo-vesicular, but there is
doubtless an earlier stage, when it corres-
ponds exactly to the simple primary tube dis-
covered, as before mentioned, in very early
mammalian embryos. The epoch of its entirely
vanishing is very variable and uncertain
“ about puberty it seems in most cases to
suffer its chief loss of substance, and to be re-
duced to a vestigiary form but for several
years later, even up to 20 or 25, distinct rem-
nants may still be discovered of its structure
amid the areolar tissue of the mediastinum.

Comparative Anatomy. — In presenting a
sketch of the comparative anatomy of the
thymus, I can but follow the elaborate ac-
count given by Mr. Simon.

Mammalia. — Among the Quadrumana the
thymus has, in the more anthropoid Apes,
nearly the same general shape and relations
as in the human subject, the cervical portion
seems to be variously developed in different
genera.

Among Cheiroptera the gland seems to be
persistent in the genera Vespertilio and Ga-
leopithecus, at least so far as anatomical in-
quiry has yet proceeded ; it consists of a
thoracic portion embracing the base of the
heart, and two cornua ascending parallel to
each other on either side of the windpipe
In a Bat which I dissected on the 20th of
March, and which was then in a wakeful
state, I could find no organ which I could
positively conclude to be a thymus. On each
side, however, of the root of the neck there
existed a pretty large yellowish lobulated
mass, resembling a good deal the aspect of a
conglomerate gland. It consisted of conical
lobes which were bounded and defined by a
distinct homogeneous membrane exactly re-
sembling the limitary tissue ; this was I think
continued by reflection from one lobe to an-
other, so as to form a common envelope to
4 a 4

1096

THYMUS GLAND.

all the cavities {fig. 731.). The lobular ca- consisted chiefly of aggregations of oil drops
vities were completely filled by aggregations and molecules. Within the thorax at its
of celloid particles, which were not manifestly upper part there was a similar lobulated grey-
nucleated, nor provided with an envelope, but ish white mass, resting upon the lower part of

Fig. 731.

Convexity of lobe from oil gland of Bat. A homogeneous membrane encloses a multitude of celloid par
tides, — the exterior row of which alone is visible, the rest of the mass being quite opaque.

the trachea and the great vessels, and ex-
tending round so as to come in contact on
each side with the lung ; the structure of this
was precisely the same as that of the masses
at the root of the neck, with which however it
was not continuous. I am much inclined to
regard these organs as representatives of the
thymus, both from their structure and situa-
tion, and because I know not what else they
could be ; they are not for a moment to be
confounded with the ordinary adipose tissue.

Among Inseclivora the thymus forms two
nearly equal lobes, lying on the base of the
heart and origin of the large vessels, with
greater vertical than transverse dimensions.
In some individuals, at least, it is not persistent
throughout life, nor does it appear to be spe-
cially developed.

In two Hedgehogs which I dissected, one
of which had been in a state of torpor until
three days before death, and the other had
been active and wakeful for several weeks,
I found at either side of the root of the
neck two roundish masses almost precisely
similar in appearance to those existing in
the same situation in the bat, and also two
broader and thinner ones lying in the ax-
ill® ; but there was no trace of any such
tissue in the thorax. The celloid particles
were more loaded with oil than in the bat,
especially in the dormant one, and in some
parts they were more or less broken up and
the oily matter diffused in the cavity. Re-
specting the existence of a real thymus
distinct from these glandular masses I am in
doubt, it is not altogether easy to distinguish
the structure from that of lymphatic glands
several of which lie upon the great vessels at
their origin from the heart. However this be
it is well worth remarking, that in two hi-
bernating animals belonging to different orders,
peculiar organs of precisely similar structure
were found ; while, on the other hand, in a
mole (an animal which I believe does not
hibernate) I could find no unequivocal trace
of thymus, nor of the peculiar oil glands which
I have described as existing in the bat and
hedgehog. This would indicate the existence
of the oil gland to have reference to hiberna-
tion, but a more extended inquiry on this
head is of course necessary before this sug-
gestion could have much claim to be received.

Among Carnivora the thymus, except in
the cat tribe, where it seems generally to
vanish at an early period, is entirely thoracic,
resting upon the upper part of the pericar-
dium and the origin of the vessels. When
mature “it has considerable thickness and
substance in the direction from before back-
ward, and its right and left lobes irregularly
overlap each other, so as to render the sepa-
ration between them indistinct.” When the
gland becomes attenuated it assumes the
form of a triangle, with the apex much pro-
longed upwards.

The thymus has been found by Mr.
Simon in (young) seals, though other ana-
tomists, including Meckel, who, as he says,
was little likely to overlook its presence,
had not observed its existence ; from this
he concludes that it declines and disappears
in this family, as in most other mammalia.
Its form in the common seal, when pre-
sent, is nearly symmetrical, consisting of
two broad thickish lobes, which prolong
themselves upwards to the root of the neck,
and abruptly terminate by clubbed extremi-
ties, which are deeply grooved in front by the
left vena innominata.

In the order of Marsupialia, three most
eminent anatomists had failed to recognise
the existence of a thymus, Mr. Simon has,
however, discovered this gland in several in-
stances, it is mostly placed on the pericar-
dium, not reaching into the neck. In the
foetus of the Kangaroo it has a peculiar con-
formation, being provided with a third, me-
dian, lobe projecting outwards between the
two others.

Among Rodents the thymus differs in
shape in the various genera. It consists in the
rat of two elongated parallel lobes, reaching
from the base of the heart to the root of the
neck. In the hare it is much thicker, but still
only extends to the root of the neck. In the
hibernating rodents the thymus is believed
to undergo at the approach of winter a re-
markable alteration, apparently as a prepara-
tion for the long sleep of that season. Tie-
dentann describes in a Marmot, which he
examined in the month of November while
in a state of torpor, the gland as “ filling the
whole of the anterior and posterior medias-
tina, extending along the great vessels of the

THYMUS GLAND.

1097

neck to the vicinity of the lower jaw, spread-
ing itself out above the clavicles on each side
of the neck, and even passing behind the
clavicles and pectoral muscles into the axil-
lary spaces.” Mr. Simon in his dissections
of the same family finds the masses described
by Tiedemann, as existing in the anterior and
posterior mediastina, but not those in the
neck, and states from microscopic examination
the remarkable fact, that they all consisted
of aggregations of fat vesicles. I do not ga-
ther clearly from his description whether these
fat cells were surrounded by a limitary mem-
brane, preserving the form of the thymic
cavities, in all the situations where the fat
masses are mentioned as existing ; i. e. whe-
ther all this fatty tissue was actually deve-
loped from the thymus, or a mere accumula-
tion in the ordinary way : nor does Mr. Simon
state whether the specimens he examined were
in a state of torpor at the time of their death
or not. I confess I should wish to have fur-
ther evidence concerning the accumulations of
fat in the marmot’s thymus. — I have never seen
a really nucleated fat cell, nor have I ever ob-
served any approach to such a development
of nuclei. Tiedemann’s description indicates
so strongly a great difference between the
conditions of the masses in question at the
commencement of winter and in the summer,
that it seems to me quite necessary that a
comparative examination of their minute
structure at both periods should be under-
taken before the question of their relation to
the thymus can be decided.

In Edentata the thymus is principally
thoracic, the Sloth and Armadillo present
small cervical prolongations connected to the
larger mass by very slender strips.

In Monotremata a thymus is found resting
on the origin of the great vessels, and scarcely
extending into the neck.

Among Pachydemiata there are marked
differences in the form and development of
the thymus. A foetal Elephant presented a
flat mass resting on the upper two-thirds of
the pericardium, and sending upwards a short
prolongation from its right lobe. In a Peccary
the cervical portions were of great length,
not only reaching to the angle of the jaw, but
folded down again beside the trachea. So-
lipeds have a thymus either entirely thoracic
or reaching but a little way into the neck.

Among Ruminants, the Calf is usually re-
ferred to as exhibiting a thymus, which may
serve as a type for the family. The gland
presents cervical cornua which are highly
developed, reach within the angle of the jaw
on each side, and form large complicated
masses up to the base of the cranium ; below,
these prolongations are narrowed, and united
in close juxtaposition to form an isthmus,
which passes behind the first bone of the
sternum, inclines to the left side, and expands
into another considerable mass of glandular
substance situated on the upper part of the
pericardium and covered by the left pleura.
In the Reindeer the submaxillaryr enlargements
are absent, and the tracheal are of compen-

sative size. In the Fallow deer, again, the cer-
vical portions are more developed, extending
up to the cranium, but not reaching below
quite to the pericardium.

A thymus has been found in several Ce-
tacea. In the foetal Dolphin there are two
large median portions, pericardiac and tracheal,
with deep seated lateral connecting cornua :
in the Mysticete whale there were two peri-
cardiac lobes, from the right one of which a
prolongation extended backwards across the
arch of the aorta, between the art. innomin.
and left carotid till it reached the trachea,
and ascended a small distance in front of that
tube to terminate in two little cornua : the
left lobe was of much smaller size.

Aves. — In the class of birds no organ unequi-
vocally possessing the characteristic structure
of a thymus had until lately been shown to
exist. Meckel, indeed, described in diving birds
an organ which he supposed to be peculiar to
them, and which he considered to be the
thymus. The microscope, however, in Mr.
Simon’s hand has demonstrated this organ to
be merely a mass of fat, and that, too, even
in the youngest specimens ; the same observer
has succeeded in discovering a real thymus,
which corresponds closely in structure with
that of mammalia at an early period of deve-
lopment. It is found in the neck of very
young birds, lying along the outer side of the
superficial cervical vessels, extending from
within a line or two of the base of the cra-
nium to just above the inlet of the thorax. It
appears as a semi-transparent ampullated tube
closed at both extremities, and rather broader
at its upper than at its lower part. Under the
microscope it is seen to have walls formed by
a distinct limitary membrane, and contents
consisting of nuclei. The period of its dis-
appearance varies somewhat, being earliest in
the tribes of powerful and active flight, but
in all occurring very much sooner than in
mammalia.

This discovery of Mr. Simon’s appeared to
me of so much interest, both as regards the
existence of the organ in birds, and the fur-
ther elucidation of its structure which might
be expected from the examination of the or-
gan in a lower grade of organized beings, that
I was anxious to repeat the observation.

The result was entirely confirmatory of Mr.
Simon’s description. In a chick about one week
old I found on each side of the neck a tube,
which appeared ampullated to the naked eye,
and which under the microscope exhibited a
large central cavity with numerous irregular
and slight lateral bulgings {fig. 732.). It
was filled with imperfect nuclei, and with
granular globules, which last were more nu-
merous than usual ; there was also a quantity
of oily matter in the form of minute drops or
molecules. It was remarkable that on the
right side the tube was divided into a number
of separate portions, which seemed to have
become quite isolated from each other ;
this, I conceive, to have been the commence-
ment of a process of degeneration, an idea
which seems also favoured by the existence of

1098

THYMUS GLAND.

a quantity of oily matter as a deposit in the
glandular cavities.

Fig. 732.

Lower end of thymic tube from chick one week old.

Diameter at a l-lo in.

lieptilia. — In the class of reptiles much un-
certainty has prevailed respecting the existence
of a thymus gland ; it has by some been con-
founded with the thyroid, by others denied to
exist at all. The microscope has again in the
same skilful hand cleared away the doubt, and
rendered it certain that a true thymus is found
in almost all reptiles, distinct from, and inde-
pendent of, the thyroid. In young specimens
of Chelonia there is found, extending upwards
on each side along the carotid, or between it
and the subclavian, an elongated white or
yellowish mass, possessing the characteristic
thymic structure, and easily distinguishable by
this from the true thyroid, which lies in the
median line between the carotids, near their
origin. I have repeated Mr. Simon’s obser-
vation on a tortoise, said to be about a year
old, and found in the situation lie indicates an

organ, which, though having to the naked eye
somewhat the appearance of fat, is shown by
the microscope to have the characteristic
structure of a thymus. The lateral cavities
are considerably more developed than in the
brid, they are of very various size and some-
what irregular, bounded by a distinct limitary
membrane, and filled with well formed nu-
clei, together with a quantity of opaque gra-
nular-looking matter consisting of minute
oily molecules. In Emydosauria the thoracic
portions of the thymus are large and of pris-
matic shape, they meet on the base of the
heart, overlapping the thyroid, and thence ex-
tend upwards along the carotid vessels to the
base of the skull where they terminate ; in
the lower part of the neck they diminish
somewhat in size, but afterwards continue of
uniform diameter.

In several Saurians ( Lacerlidae , Geckos,
Chameleons ) the thymus resembles that
just described, save that the pericardiac por-
tion is absent ; in adult specimens of others,
as Isturius and Scincidae, no thymus has
been detected, but a mass of fat exists just
above the base of the heart, which may
perhaps result from a transformation of the
gland.

In Ophidia the thymus observes one un-
deviating type of arrangement, it is found
lying on each side along the carotid, often
not strictly symmetrical, its lobes elongated
and sometimes broken into two or more
pieces. Most serpents possess a peculiar mass
of fat which is developed in connection with
the thymus, and often obscures or conceals it ;
in two specimens of rattlesnakes Mr. Simon
found this fat body was absent, but is inclined
to believe it exists in those which inhabit the
temperate latitudes. The thymus of serpents
is supposed by Mr. Simon to be persistent, and
to undergo transformation into fat.

From the Batrachian reptiles it was natural
to expect, that in consequence of the remark-
able transformation which some of them un-
dergo, and the intermediate condition main-
tained by others between reptile and piscine
life, some important information would be
gained respecting the true relation and import
of the thymus. So it has proved ; for in the
Frog only a mass of fat is found existing in the
adult animal in the situation of a thoracic
thymus, the very young animal, however, pre-
sents, in the same situation, true thymic struc-
ture, and the evidence of a real transformation
of the gland, — not a mere replacement of
it by fat, — seems more perfect than in the case
of the hibernators before referred to. It was
now a point of much interest to determine
the condition of the thymus in the fish-like
batrachian larva before its transformation had
occurred ; in none of these was any trace of
thymus detected, while in the youngest indi-
viduals in whom pulmonary respiration had
commenced the “ commencement of the or-
gan” was always to be found. Mr. Simon
remarks ; “ The essential step in reptile me-
tamorphosis is a higher developement of the
respiratory system : as a part of this pro-

THYMUS GLAND.

1099

cess we here find occurring the superaddition
of a thymus gland, —its first appearance in
the ascending scale of organization.” Among
the Perennibranckiata it is very interesting to
observe, that the gland is gradually suppressed
in proportion as the respiration becomes more
completely aquatic, a thymus is found in the
Menopoma, Amphiuma, Axolotl, and Meno-
branchus, but not in the Siren or Proteus ; its
position is rather peculiar, it lies in the neck,
on each side, along the lateral aspect of the
spine, just behind that prolongation of mucous
membrane which unites the branchial cavity
to the pharynx.

Pisces ■ — In fishes Mr. Simon has been unable
to discover any trace of a thymus, after search-
ing, carefully, in more than twenty genera ;
this result accords well with the absence of
the gland in the fish-like batrachian larva, and
with its disappearance in the lowest Perenni-
branchiata.

The following are the conclusions which
the eminent physiologist, so often referred to,
deduces from a survey of his detailed and
elaborate investigation. (1.) The presence
of the thymus gland is co-extensive with pul-
monary respiration. (2.) Its shape and po-
sition are variable and unimportant. (3.) Its
size and duration are, generally speaking, in
proportion to the habitual or periodical inac-
tivity of the animal. (4.) Where it remains
as a persistent organ, it is usually but one of
several means for the accumulation of nutri-
tive material ; its continuance, under such
circumstances is generally accompanied —
though in some instances superseded — by a
peculiar accessory contrivance, the fat body.

Physiology. — The time is now past when
an eminent physiologist could declare of the
organs usually known as glands without ducts,
“that in regard of their intimate structure and
physiological meaning, they are all equally
and utterly unknown to us.” With respect
to their structure, it may, I think, be said, that
they are as well understood, or perhaps even
better than the true glands, being in fact less
complex, and their constituent parts less in-
dependent. Their physiological meaning, it
must be confessed, is still obscure ; yet even on
this dark part of the demesne of our science
light is beginning to break, which we may fairly
hope will continue to brighten.

The results afforded by examination of the
thymus in the lower animals seem certainly to
connect the gland most closely with pulmo-
nary organs of respiration, and it would,
therefore, seem a natural conclusion, that it
subserves some purpose which has to do with
the aeration of the blood. It is also found
that the size of the gland may vary in a short
space of time very considerably, that is, that
its contents are capable of being absorbed very
quickly, as proved by the fact mentioned by
Mr. Gulliver, that in over-driven lambs, the
thymus will soon shrink remarkably, and be
nearly drained of its contents, but will be-
come as quickly distended again during rest
and plentiful nourishment. This seems to

imply that the material necessary for the
supply of the respiratory process is furnished
by the thymus, which thus, in Mr. Simon’s
words “ fulfils its use as a sinking-fund in
the service of respiration.” The persistence
of the gland, moreover, is observed to vary
considerably according to the muscular ac-
tivity of the animal, thus it disappears quickly
in young oxen put to the plough, it endures
longer in animals of quiet habits than in the
restless and energetic beasts of prey, and
vanishes at a very early period in the class of
birds, while it persists long in that of reptiles.
From this it seems to follow, that the use
fulfilled by the gland in the service of res-
piration is more or less superseded when the
muscular system is called into a high state of
activity, i. e. when there is considerable waste
of tissue yielding fuel for respiration. In
the hibernating animal, where the gland, pre-
parative to the winter sleep, is transformed
into a mass of fat, its application to the de-
mands of the respirtory process seems
scarcely doubtful, as the chemical nature of
the contents of its cavities is then peculiarly'
appropriate to neutaralise theoxydising agency
of the air.

Probable, however, as these views may' ap-
pear, they have been confronted by the fol-
lowing weighty objections. An able physio-
logist, in the Brit, and Foreign Med. Re-
view', observes, that the condition of young,
rapidly growing animals, and that of hiber-
nating animals, are rather opposite than pa-
rellel, that whereas in the latter, the waste of
the tissues is reduced to a minimum, in the
former it is certainly greater than in the adult,
so that there can be no deficiency of effete
material to feed the respiratory furnace. The
demand in the young creature is for plastic
materials, out of which the rapidly growing
and rapidly changing structures may be built
up and renewed. “ On the other hand, in the
hibernating animals all the nutritive actions
are at zero, and the respiration for a long
period is entirely dependent on the stores of
fatty matter which have previously been set
apart from the food. The demand is here for
combustible materials

The writer then observes, that the che-
mical nature of the contents of the thymus
correspond so exactly at the two periods of
active growth and hibernation to the kind of
demand which must then exist in the system,
that he conceives it more probable that the
use of the gland at these times is different ;
in the one slowly yielding up its hydro-car-
bonous contents to supply fuel to the respi-
ratory process, in the other performing the
principal part in elaborating, by means of its
myriad nuclei, fibrine from albumen, the plastic
from the non-plastic element. “ As the de-
mand for plastic material becomes less ener-
getic the thymus diminishes in size and dis-
appears, the production of plastic matter
within the absorbent and sanguiferous vessels
being then sufficient for the wants of the sys-
tem. Or if the organ remains,” its struc-
ture “ and the nature of its function changes,

1100

THYMUS GLAND.

and it cannot be deemed unreasonable to sup-
pose that its use in the system should change
also. In fact, that its use should be the same
in the two cases, where its functions are so
different, appears to us a very improbable
supposition.” Consonant with the above
view is that of Mr. Paget, who remarks in
his Report, that the fatty transformation of
the thymus is an atrophy or degeneration of
the gland, “ analogous to that atrophy by di-
minution or total removal of substance, which
takes place once for all in the animals in
which the thymus is not persistent. In each
case the atrophy is an indication that the ne-
cessity for the ordinary acts of the thymus
has ceased ; but in the hibernants it is, for
new circumstances, made to minister to a new
purpose, till at the expiration of the winter
sleep, and the recommencement of new growth
it begins again to be truly developed, and to
form the more highly azotized organic com-
pounds which it may restore to the blood for
the nutrition of the fresh growing tissues.”

On a careful consideration of the theories
now noticed (and no other are worthy of any
examination), it seems to me, certainly, that
the latter is nearest the truth ; and that we
cannot regard the thymus in the young animal
as a mere preparer of material fitted to sup-
port the respiration. The following argu-
ments must be allowed to weigh strongly
against Mr. Simon’s view. (1.) The chemi-
cal constitution of the thymus, consisting
chiefly of proteine and not of fatty matters,
seems by no means to be such as would be
best adapted to sustain the supply of com-
bustible material required in respiration. (2.)
The office of serving as a reservoir for ma-
terial to be used in respiration may be attri-
buted with much more probability to the
liver*, the construction of which, as also in
some measure its position relative to the cir-
culatory system, point it out as peculiarly
adapted for the reception of superfluous re-
spirable material from the blood, and equally
so for rendering it up again, when the demand
again begins to be felt in the circulating cur-
rent. Of this, the condition of the liver in
fish, and generally in all animals, in whom the
respiration is of a low type, is sufficient
proof. Now as the liver is of greater relative
size in the young than in the adult animal, it
is not likely that this one of its functions is
in any measure discharged by the thymus.
(3.) The anatomical constitution of the thymus
is very unlike that of an organ which serves

* I may just briefly mention here the results to
which I have been led by a long and careful study
of the liver in vertebrata. Its lobvdes (if it is so
divided) are not penetrated by excretory ducts, nor
are the secreting cells contained as in most other-
glands in the cavities of ducts, they lie naked in the
interstices of a close plexus ot most deli cate- walled,
capacious, capillaries, from which they readily re-
ceive the materials they are intended to act on ; and
to which they as readily render up their elaborated
products when these are called for. The excretory
ducts, consisting at their origins almost solely of
nuclei, attract into their cavities the oleo-biliary
secretion with which they are bathed; probably,
however, in so doing altering it to some extent.

as a reservoir of respirable matter. For
this purpose we should expect to find a
fluid stored up in cavities, such as the oil of
the fat vesicles, or the oleo-biliary matter which
collects within the cells of the liver ; the ana-
tomical elements, however, of the thymus are
totally different, being mere nuclei, with no
trace even of commencing cell development,
in fact, just that part of a glandular appa-
ratus which is not the secretion, however im-
portant a part it may play in the elaboration
of it. (4.) The transformation of the thymus
into fat previous to the winter sleep, con-
currently with the formation of other fat
masses in the axilla;, indicates, as above shown,
very strongly that the gland in its natural
state fulfils some purpose different from that
to which it is subservient during hibernation.
But as there can be no doubt that it undergoes
this change for the sake of the respiratory
function, — to fit itself for supplying those de-
mands during the long period when the waste
of the tissues is reduced to a minimum, and
no ingesta are taken,— it seems tolerably cer-
tain that while the gland continues in its
normal unchanged state, its action must be of
a different kind, not having special reference to
the function to which during hibernation it un-
doubtedly ministers. The circumstance quoted
by Mr. Simon from the writings of Mr. Gulliver,
respecting the remarkable shrinking of the
thymus in over-driven lambs, cannot be re-
garded as proving that the contents of its cavi-
ties are thus absorbed solely for the use of re-
spiration. It is more probable that they are
resumed into the blood, which has begun to be
impoverished by fasting and exercise, in order
that they may go to supply the nutrition of all
parts indifferently. With regard to the argu-
ments adduced by Mr. Simon from Compara-
tive Anatomy, to the effect, that a thymus has
some essential connection with pulmonary
organs of respiration, I would remark that
though it is certainly of weight, yet it can-
not be regarded as proving absolutely that
the two organs are co-related in function.
It may be that they are only simultaneously
developed, — connected together in virtue of
some law of organized being which requires
their coeval appearance, and yet not intended
to minister to a common pupose.* I grant
that observing their consentaneous appear-
ance, one should inquire whether they be not
essentially linked together in function, but if
this be not proved by subsequent inquiry, or
a fortiori, if it be shown to be unlikely, then
the argument arising from their co-develop-
ment ceases to have much force.

But if we decline accepting the theory pro-
posed by Mr. Simon, are we to close, uncon-
ditionally, with the other which has been
above expounded, and which is but a modifi-

* This is perhaps the more probable, seeing that
the thymus does not assert its connection with
organs of respiration taken generally, but only with
a particular modification of them, so that its exist-
ence is determined not so much by the degree in
which the function is fulfilled as by the mode. Hence
it is absent in the higher fishes and in insects.

TIIYMUS GLAND.

1101

cation of a former opinion, that of Cowper
and Haller, who regarded the thymus as
belonging to the class of conglobate glands.

It appears on the whole more consistent with
the various facts bearing on the subject which
are in our possession, and yet it is by no
means proved, and is open to some objections.

In the first place, one is inclined to look sus-
piciously on any hypothesis, which assigns the
production of a material almost universally
diffused throughout the body to any separate
organ, it seems far more truth-like to regard
the manufacture of the plastic element
(ftbrine), as taking place in the blood itself by
the agency of the white corpuscles, as Drs.
Addison, Williams, and Carpenter, have well
nigh demonstrated to be the case. It their
view be correct, it becomes still more impro-
bable that the thymic nuclei should be the
producers of fibrine, seeing that they are al-
together dissimilar in appearance and struc-
ture from the white granular corpuscles.
Moreover the early disappearance of the
thymus in birds, long before the demand for
plastic material can have materially dimi-
nished, makes it unlikely that in them its
function is the elaboration of fibrine. The
same observation applies to mammalia though
in a less degree; and, generally, 1 think there
can be little doubt that the self-forming, self-
sustaining blood, while supplied with an ade-
quate quantity of proper nourishment, is fully
capable of evolving within itself all that is
requisite for the nutrition of any part of the
system.

It seems almost unwise to broach any
further speculations respecting this ignotum
quid, especially after stating objections to the
views of others ; and yet while ideas are ot-
tered as mere suggestions, to serve if they may
as aids to the discovery of truth, they are not
without utility, since none can say without
trial which of these “ scintillas” may kindle the
light of truth. From the careful investigations
which have been made respecting the age at
which the gland attains its highest develop-
ment, and the conditions which chiefly affect
its size and repletion, it certainly appears to
be a very exact exponent of the state of the nu-
trient processes generally, — a delicate barome-
ter of nutrition, as Mr. Simon terms it. More-
over its anatomical constitution, as 1 have
insisted, seems to show that it does not truly
secrete, i. e. elaborate and separate some pe-
culiar principle from the blood, but that it is
a congeries of (nuclear) particles, which can
only be regarded as solidified liquor sanguinis,
and not in anywise as a true secretion, espe-
cially when we remember that in every such
fluid the nuclei of the producing cells sooner
or later disappear. Chemical analysis, as we
have seen, confirms this position ; the formula
expressing the nature of the contents of the
thymic cavities being identical with that of
proteine.

Now if one of the organs which belong to
the class of ductless glands have for its func-
tion to act as a living attractive recipient or
reservoir for the blood en masse, may not an-

other fulfil its destined purpose by serving as
a reservoir for that part of the blood which
ministers to nutrition, perhaps for the plastic
element of the liquor sanguinis in particular?
When such plastic material is in superabund-
ance in the circulating current, a quantity of
it passes off, and solidifying in the thymic
cavities, assumes that most universal of all
organized forms, the form of nuclei.* When
there is again a demand for such material,
the solidified particles would again liquefy,
and re-enter the impoverished blood. It is
not difficult to understand that such a func-
tion may be most necessary during the pe-
riod when growth is most active, the sup-
plies of nourishment most frequent, and the
waste of the tissues most rapid, but that as
the several nutrient processes, both of the
assimilative and destructive kind, attain to
more steadiness and equilibrium, diminishing
somewhat in their intensity and rapidity, but
increasing in real strength, firmness, stability,
and perfection (one is obliged to use somewhat
metaphorical language), it may no longer be
requisite, and the organ will therefore undergo
a gradual atrophy.

This hypothesis, which is really little else
than an expression of the facts above noticed,
has been principally suggested by the con-
sideration of the nature of the secretion (so
called) of the thymus, wherein it differs ab-
solutely from all other glands, in as much as
the nuclei constantly remain in then- primitive
state, and are not even mingled with granular
matter ; while it agrees in this respect with
another organ of similar kind, the spleen,
whose parenchyma consists of similar bare
nuclei, which exert so far as we know no real
secretory action. It is however by no means
improbable, that, even if this guess at the use
of the thymus be correct, we are yet very far
from being fully acquainted with all the rea-
sons why it exists, and why in such a situa-
tion, and under such a form. If Mr. Goodsir’s
account of its origin, from a portion of the
blastoderma, with the suprarenal capsules
and thyroid, be correct, it is possible that its
formation may be demanded by some recon-
dite law of development, in virtue of which
the extraction of one organ out of the pri-
mitive blastema necessitates, by a kind of
compensating action, that another should arise
in some sense complementary to it. This
idea, originally stated by Treviranus, has been
developed very ably and pleasingly by Pro-
fessor Paget, to whose lectures I refer for a
full exposition of it.

Morbid Anatomy. — Not much is known,
and probably there is not much to be known,
respecting the morbid conditions of the

* I would here direct attention to the remarkable
fact, that in all glandular, and in fact in almost all,
organs, the nuclei are almost precisely similar in
size and appearance, and do not differ from each
other in different parts more than individual ones do
in the same. Does not this indicate strongly a
tendency of liquor sanguinis effused in conditions of
healthy nutrition, to assume the form of nuclei, irre-
spective of the situation or special endowment of the
part where it is effused ?

THYMUS GLAND.

1102

thymus. Absence of the gland has only been
observed in cases of acephalistn, where the
brain and many other parts are simultane-
ously deficient, while in cases of anence-
phalism, where the brain is also wanting
wholly, but the general development much
more complete, the thymus is present; no-
thing therefore can be concluded from its
absence in cases of extreme monstrosity as
Mr. Simon has well observed.

Inflammation of the gland, if it ever happens,
is of rare occurrence. Professor Hope, however,
refers to a case by Mason, in which an abscess
of the thymus is said to have opened into the
trachea.

The same author states that Becher and
Hangstadt have collected about fifteen ex-
amples of persons, of different ages, affected
with more or less general tubercular disease,
in whom the thymus was found involved.
“ It was for the most part considerably en-
larged, very firmly united with surrounding
parts, and either converted by tubercular in-
filtration into a hardened mass, or else par-
tially destroyed by tuberculous softening. In
three or four instances calcareous concretions,
probably resulting from the retrogression of
tubercle, were discovered in the gland.”

Haller speaks of the thymus as being fre-
quently affected with scirrhus along with the
conglobate glands ; but though Becher gives
an instance on his own authority, and refers
to others, there can be no doubt that true
malignant disease of the gland is extremely
rare. Sir A. Cooper gives a case, in which
death was produced by the pressure of an
enlarged thymus upon the vena transversa
and upon the trachea, probably also upon the
vagi nerves ; there was severe dyspnoea and
oedema of the lower extremities. He considers
the disease to have been of the fungoid kind,
i. e. encephaloid.

Atrophy of the thymus occurs as a normal
event ; if, however, it should take place long
before the usual period, determined, as we
have seen, not so much by the lapse of time
as by the condition of the system, it must be
regarded as morbid. Yet in every such case it
is almost certain that the atrophy of the thy-
mus would be but part of a general malady,
wherein the nutrition of every organ was
greatly impaired.

Hypertrophy of the thymus has attracted
more attention. Dr. Kopp having noticed
several cases of suddenly fatal dyspnoea oc-
curring in children, in whom the gland was
found of large size, concluded that there was
some essential connection between the glan-
dular enlargement and the suffocative pa-
roxysms. The fallacy of this opinion has been
well pointed out by Mr. Simon and others. I
must refer to his work, and that of Professor
Hope, for a full account of their arguments,
and will only mention two circumstances,
which seem to me conclusive upon the point.
The first is, that “thymic asthma” may occur
with an unnaturally small thymus ; the second,
that when a thymus, enlarged by malignant
disease, as in Sir A. Cooper’s case, does oc-

casion dyspnoea, it is not sudden and pa-
roxysmal, but constant and exhausting.

For the history of the thymus, and for a copioits
list of authors who have written upon it, I can do
no better than refer to the Historical Introduction to
Mr. Simon’s essay.

(C. Handfleld Jones.)

THYROID GLAND. (French, glande
thyroide ; German, Die Schilddruse ; Italian,
Tiroidea glandola ; Latin, Glandulathyroidcea.)
The organ which has received this name is a
bilobed glandular body, situated in the human
subject in close proximity to the larynx, from
the prominent cartilage of which it has pro-
bably derived its appellation.

Its size varies considerably in different in-
dividuals, according to unknown peculiarities.
In the female it is generally larger than in
man ; reversing thus the proportion which
obtains between the vocal apparatus in the
two sexes, and so far negativing the idea,
that the larynx and the thyroid gland are in
any wise intimately connected.

The normal weight of the thyroid is about
one ounce, according to Cruveilhier. Any
great excess above this must be regarded as
indicating a pathological condition.

Its form, as has been said, is bilobed ; the
lateral lobes being united by a thinner and
narrower portion termed the isthmus. It
would appear (from the circumstance that
variations of form are most frequent in the
isthmus, which sometimes is even wanting)
that the lateral lobes are the primary parts of
the gland, and, in fact, in one entire class
(that of birds) the lobes lie entirely separate,
one on each side of the trachea. In the human
subject they are large and solid, presenting an
anterior convex surface, a posterior concave,
an external and inferior border which is con-
vex, and runs up to join the superior interior
concave border in a pointed cornu, which
reaches as far as the origin of the inferior con-
strictor pharyngis from the ala of the thyroid
cartilage. From the upper border of the
isthmus, or from the adjacent part of one of
the lateral lobes, there stretches upwards a
narrow strip of glandular tissue, which has
been called the pyramid or mesian column,
and which may have been sometimes mis-
taken for a muscle, as Cruveilhier asserts ;
though it is distinguished perfectly from the
so called levator gland, thyroid, by Haller.
This prolongation sometimes extends to the
hyoid bone, but generally not so far, and is
subject to numerous modifications of shape
and structure. The following list of the
various forms which the thyroid may pre-
sent, is taken from the catalogue of the mu-
seum of Guy’s Hospital, which Dr. Birkett, the
curator, most kindly allowed me to inspect,
together with the preparations. 1. Thyroid
without an isthmus, but having two mesian
columns. 2. Thyroid almost without an
isthmus, and having one mesian column. 3.
Thyroid with broad isthmus and one mesian
column. 4*. Thyroid with no isthmus, but
having one large mesian column. 5. Thyroid

THYROID GLAND.

1103

without isthmus, having one column (right),
anti an isolated portion on the left. 6. Thy-
roid with one lobe only developed, and a
little glandular body below the middle of
thyroid cartilage. 7. Thyroid gland replaced
by a membranous substance, two small por-
tions only remaining. 8. The gland with
isthmus and two mesian columns.

It is important to ascertain accurately the
situations and relations of the thyroid. I give
them as they are stated by Cruveilhier, and
confirmed by my own observation. The
isthmus lies across the first four rings of the
trachea, the first not being completely co-
vered.*' Its upper margin is about half an inch
below the inferior border of the cricoid carti-
lage : from it the mesian column passes up-
ward, lying upon the crico-thyroid muscle,
the thyroid cartilage, and the thyro-hyoid
membrane. The lower border of the isthmus
is free, and occasionally descends so low, that
there is not space between it and the sternum
to perform the operation of tracheotomy.
Posteriorly, the isthmus is firmly attached to
the rings of the trachea by close and dense
areolar tissue. The sterno-hyoid and sterno-
thyroid muscles overlap the greater part of
the isthmus ; a small portion, however, in the
median line is covered only by deep cervical
fascia, and perhaps crossed by some branches
of origin or communication of the anterior
jugular veins. The lateral lobes, concave
posteriorly, embrace, and rest against the sides
of, the trachea, the cricoid cartilage, the in-
ferior and lateral parts of the thyroid car-
tilage, and the lower part of the pharynx
and upper part of the oesophagus. “ These
lobes form, with the connecting isthmus, a
half or sometimes three fourths of a canal,
which surrounds all these parts. This re-
lation, one of great importance, explains
how certain goitres flatten the trachea late-
rally, hinder deglutition, and finally bring
on a real asphyxia from strangulation. ”j~ The
posterior border of the lateral lobes corre-
sponds to the vertebral column, and rests
upon the carotid artery ; but, if enlarged, it
extends further outward, and lies upon the
jugular vein. Both recurrent nerves ascend
behind the lateral lobes, and are closely in
relation with them as they pass under the
lower edge of the inferior constrictor muscle.
Anteriorly, the sterno- and omo-hyoid muscles
pass in front of the lateral lobes, the sterno-
thyroid is stretched as a thin band over their
surface, and in cases of considerable hyper-
trophy may be seen sunk in a deep groove
formed in their substance, or, as Cruveilhier
states, expanded to a width double or treble
its natural size. These muscles separate the
thyroideal lobes from the sterno-cleido-mas-
toid, which, with the mastoid artery and the
superficialis descendens on its inner surface,
overlaps their greater extent, as it passes
backwards and upwards to its cranial attach-
ment. “ The superior extremity of each of

* There is probably some variation in this, ac-
cording to the varying depth of the isthmus.

t Cruveilhier, Anat. Descr.

the lateral lobes terminating in a point,
whence the bicorned form which has been
attributed to the thyroid body, corresponds
on the inside of the carotid artery to the
lateral and posterior part of the thyroid car-
tilage, and extends sometimes even to the
neighbourhood of its upper border. The
inferior extremity, thick ami rounded, descends
more or less low in different subjects, and
corresponds to the fifth, sixth, or even to the
seventh ring of the trachea; it is situated
between the trachea and the common carotid
artery. By the inferior extremity the inferior
thyroid artery reaches the gland.” “ The
superior border is concave, and skirted by the
superior thyroid arteries.” The inferior is
convex, and has branches of the inferior
thyroid running along it.

The thyroid gland is of a red or reddish
yellow colour, of tolerably firm consistence,
and gives to the touch the sensation of
granulations. Cruveilhier, thus describing,
proceeds as follows : “ This organ presents
all the anatomical characters of glands,
and, like them, is separated by dissection
into glandular grains ” (doubtless meaning
the acini of Malpighi) ; “but there is, be-
tween these glandular grains and those of
ordinary glands, this difference, that in the
thyroid gland the glandular grains communi-
cate with each other, while in the others they
are independent.” He then details the result
of mercurial injection, to show that the glan-
dular grains, or granulations, have a vesicular
structure, and communicate with each other ;
this latter statement, however, is certainlv
erroneous, as we learn from more accurate
modes of investigation. The presence of a
certain amount of secreted fluid, in the natural
condition of the tissue of the thyroid, and
the accumulation of a similar material in
larger quantities under certain morbid con-
ditions, the eminent French anatomist justly
regards as evidence of the thyroid possessing
a secreting apparatus ; but, at the same time,
faithful to the results of accurate dissection,
he acknowledges that no excretory duct can
be found leading either into the trachea, the
ventricles of the larynx, or the foramen
caecum of the tongue, whither earlier ob-
servers had, with too nice refinement, sought
to trace its course. Far truer and more phy-
siological than such straining after uniformity
is the conclusion he adopts : “ I think that
there exist, in the economy, glands without
excretory ducts, such as the thymus, the supra-
renal capsules, and the thyroid gland. The li-
quid produced in the gland is absorbed entirely,
and fulfils unknown uses.” I have thought it
worth while to follow this accurate and trust-
worthy anatomist through his account of the
structure of the thyroid", though it be some-
what antiquated, partly for the sake of the
confirmation it affords to the results of a
more recondite and powerful analysis, and
partly that we may observe how securely we
may trust Nature’s own teachings, even when
they may appear, for a time, contradictory to
established doctrines, as doubtless it must

1104

THYROID GLAND.

once have been considered that a gland should
exist unprovided with an efferent duct.

I now proceed to give a more detailed
account of the structure of the thyroid gland.
Its surface is somewhat uneven, — a natural
condition which is often greatly exagge-
rated in hypertrophy of the gland ; it is tra-
versed by several large branches of the
nutrient arteries, which ramify over it before
they plunge into its substance. A thin fibrous
expansion, continuous with the sheath of the
cervical vessels on each side, forms a capsule
which invests the gland, and from whose
inner surface septa dip into the interior,
dividing its substance into lobes and lobules
much after the manner of a conglomerate
gland ; these fibrous septa are often well seen
in sections of hypertrophied specimens. A
thin slice of the thyroid, examined under a
low power of the microscope, displays its con-
stitution very perfectly and readily (Jig. 733.)

It is seen to be made up of closed vesicles,
aggregated together in groups of various size
by the fibrous expansions just described. The
form of these vesicles is primarily spherical ;
but many, perhaps the majority, are more or
less affected by mutual pressure, being trian-
gular, elongated, ovoid, or oblong. They are
all perfectly closed, the wall being formed by
an homogeneous limitary membrane, which is
easily traced all round, and can never be seen
passing off into a neck, or blending with the
envelope of an adjacent vesicle. Where a
number of vesicles lie closely crowded to-
gether, the homogeneous envelopes are of
course in contact, or separated only by the
interjacent vascular plexus ; but those form-
ing the surface of a group are invested by
a thin expansion of fibrous tissue derived
from the general capsule. The diameter
of the vesicles of the human thyroid I have
found to range from inch to ^

Fig. 733.

inch ; in the bullock, from inch to

inch ; the greater number averaging
about -jvU. inch, in this animal as well as in
the pig. In the mesian column I found, at
least in one instance, that the structure was
essentially the same as that of the thyroid
itself, only that there was a much greater
amount of fibrous stroma, which resembled
more nearly ordinary areolar tissue, containing
both the white and yellow element.

The vesicles are lined internally by an epithe-
lial stratum, consisting usually of nuclei set
closely together in a scanty basis substance
(Jig. 734.), which is either feebly granular, or of
a somewhat oily aspect. The nuclei are at
once recognised by the practised eye as
exactly resembling those of the true glands.
Their nucleoli are not always visible, and vary

Fig. 735.

Epithelium from thyroid,
of bullock.

Epithelial particles fro
thyroid of rabbit

Diameter

1

2000

in.

very much in number — from one to four or
five. The nuclei are, however, always vesicu-
lar, bounded by a strongly marked envelope
and have a mean diameter of -a^i-yth inch.
It has been observed by Mr. Simon, and I
have occasionally had the opportunity of

THYROID GLAND.

1 105

confirming the remark, that the nuclei, instead
of remaining in their primitive condition, pro-
ceed to the further stage of cell development ;
this he has noticed both in man and in several
of the lower animals. I should say that it is
certainly a circumstance of rather rare oc-
currence ; but it is worth remarking, that it
may be artificially produced by adding to the
specimen some coagulating re-agent, which
speedily solidifies a film of albuminous plasma
around the nuclei, and thus produces very
good imitations of cells. The epithelium of
the thyroideal cavities often assumes the form
of small vesicles larger than the nuclei (see
figs. 736, 737, 738.), and easily distinguished

Fig. 736.

Vesicular epithelium
from Human thyroid.
Diameter of vesicles,

j in

3-2000

Fig. 737.

Persieidar epithelium
from thyroid - of Pig.
Diameter of vesicles,
2-Tooo in-

Fig. 738.

Vesicle from thyroid of Hedgehog, lined by an
epithelium consisting of a double row of pellucid
delicate vesicles, 55t_ in. diam.

from them.* The diameter of these in a hu-
man subject averaged inch; in a bullock,
about T7Vir inch They are, in their natural
state, perfectly spherical, but often somewhat
angular from mutual pressure. Their contents
are a very faintly granular or pellucid material,
which does not surround a nucleus except iu
some rare instances, where there may be seen
an imperfect trace of one. These vesicles,
which I thus name to distinguish them from
the nucleated cells occasionally met with, exist
in the glandular cavities, sometimes alone,
sometimes mingled with the ordinary form of
epithelium in varying proportion. I am in-
clined to believe that they originate in the
nuclei, which undergo a kind of expansion,
at the same time losing their nucleoli. This
opinion needs further confirmatory evidence;

* I am obliged to use tlie same word (vesicle)
in speaking of the large glandular cavities, and of
the epithelial particles which line them : the dis-
tinction between them should, however, be carefully
borne in mind.

VOL. IV.

it is, however, certain, that they are not de-
veloped upon pre-existing nuclei. The layer
of epithelium is generally of no great thick-
ness, not occupying more than one eighth or
one sixth of the distance from the envelope
to the centre of the cavity ; in the rabbit,
however, it appeared to be more abundant,
encroaching considerably on the interior,
which, in this instance, was not filled with the
characteristic glistening secretion. In a sec-
tion prepared in the ordinary way, a large
quantity of epithelium is broken up, and may
be seen strewn over the field. Not unfre-
quently, however, the nuclei adhere firmly
together; and sometimes, as in the pig, I have
seen the greater part of the lining of a cavity
detached entire.

The contents of the cavities are for the
most part a clear, somewhat refracting, homo-
genous material, which is manifestly the pro-
duct of secretion, and fills all the spaces not
occupied by the epithelium : this fluid is some-
times contained in small vesicles Ti-;r to
inch diam. {figs. 739. and 740.) which have a

Fig. 739.

o

Two vesicles containing a transparent matter and no
epithelium. From thyroid of Bullock; the larger
in., the smaller in. diam.

Fig. 740.

Two vesicles from thyroid of Bulloch, having a
thicker lining of epithelium than usual, and each
containing a single vesicle, whose wall, of homo-
geneous membrane, surrounds the central cavity of
the original vesicle.

well marked, structureless envelope, but are
destitute of any thing like epithelium. They
may be seen occasionally in the interior of the
glandular cavities, and also floating free in the
field of view, having been perhaps detached
from cavities opened by the section. The
exact import of this circumstance does not
appear ; for I cannot regard them as newly
formed glandular vesicles, developed within
the original ones in an endogenous manner.
Were this the case they would occur more
frequently, and w'ould exhibit some traces of
epithelial lining. Large crystals, sometimes

4 B

1 106

THYROID GLAND.

of well marked prismatic, sometimes of oeto-
hedral, form, are seen occasionally in the
glandular cavities. They are generally single in
each, and I have no other guide than their
form to lead me to any opinion respecting
their chemical constitution. I have seen, in
a human thyroid, some large oval or circular
corpuscles about inch diam., consisting

of coarse granular matter not surrounded
by any distinct envelope, and of an opaque
dead white colour. These were perhaps ab-
normal formations ; yet in a tortoise, where the
gland was quite healthy, similar corpuscles,
and more numerous, were observed. The
clear fluid material, contained within the
glandular cavities, is generally spoken of as of
an albuminous nature. This opinion seems con-
firmed by two analyses of the gland, made by
my friend Mr. Beale, which may be regarded
(after allowance is made for the areolar tissue,
vessels, envelopes, and epithelium) as express-
ing pretty correctly the chemical nature of the
secretion which forms so large a part of the
whole bulk. These analyses I will presently
quote, but will first detail a few observations
of my own, as to the effects of certain re-
agents on the fluid in question.

Liq. Potasses, added to a thin section pre-
pared for the microscope, rendered it much
more transparent, partially dissolving the epi-
thelium, and leaving a quantity of oily matter
diffused throughout it. Acetic acid now added
to the specimen pretty7 nearly restored it to
its former appearance, but did not bring into
view any precipitated protein. Acetic acid,
alone, dissolves in part the epithelium of the
vesicles, and renders the fibrous tissue more
transparent. Liq. Ammonia dissolves the
epithelium in great part, but does not alter
the transparent contents of the cavities ; nor
does liq. potass® or acetic acid. Solution of
iodine does not materially affect the epithe-
lium of the cavities, but renders it more
opaque. Strong nitric acid at first renders the
epithelium more opaque and granular, but does
not manifestly affect the contained secretion.
After a time it colours this material bright
green or yellowish green, and disengages a
great many bubbles of gas. A saturated
solution of bichloride of mercury , even after
long maceration, does not seem materially
to affect the secreted contents of the vesicles ;
it makes their peripheral stratum of epithelium
quite opaque ; but the interior still appears
transparent and glistening.

The chief conclusion deducible from the
above results is, that the secreted material of
the glandular cavities of the thyroid is not
ordinary fluid albumen ; as otherwise it would
certainly be coagulated by the agents em-
ployed. The effect produced by nitric acid is
also worthy of notice, though I cannot ex-
plain the meaning of it.

Analysis of thyroid gland.

Human. Ox.

Water ... 70-6 71-34

Solid matter - - 29-4 28'66

Solid matter.

Animal (fibrinous and

albuminous) matter,

Human.

Ox.

vessels and fat -

26-384

24-628

Extractive matter

1-7

Extractive matter with

gelatine

2-888

Alkaline salts

0-5

0-642

Earthy salts

0-816

0-502

29-400

28-660

The analyses given above testify to the
presence of a large quantity of fibrinous and
albuminous matters in the gland, and leave no
doubt that its secretion is a protein com-
pound ; it is, however, unfortunately impos-
sible to procure a sufficient quantity apart
from other substances to analyze correctly ;
and the exact nature of the thyroideal secre-
tion consequently still remains unknown.
Thus much, however, seems to be ascertained,
or rendered very probable. (1) That the
secreted material is of an albuminoid nature.
(2) That it is not in the state of ordinary fluid
albumen. (3) That gelatine is sometimes an
ingredient of the secretion; (it was found in the
gland of an ox, but not in that of the human
subject, and consequently could not have been
derived from the fibrous tissue). (4) That
though crystals of triple phosphate and of
oxalate of lime occur in the cavities, no urea
nor lithic acid, nor in fact any special organic
compound, can be detected.*

Vessels. — The vascular supply of the thy-
roid is very abundant, and completely justifies
Cruveilhier’s opinion, that more than a mere
process of nutrition is carried on in the gland.

The arteries which are distributed chiefly to
this organ are very constant in their number,
and tolerably so I think in their respective
dimensions, though in this respect they vary
inversely with regard to each other. They
ordinarily arise, as has been well remarked by
Mr. Simon, just beyond the points where the
arteries to the brain are given off from the
large trunks,- — a circumstance which he con-
ceives to be very significant of the function of
the gland which they supply; — the two
superior thyroideal arising one on each side
from the external carotids, almost immediately
after the bifurcation of the common carotids,
and the inferior thyroideals from the intra-
scalenal portion of the subclavian, almost
opposite the point where the vertebrals are
given off. A fifth thyroideal artery occa-
sionally exists, — that named after Venbauer;
taking its origin from the arch of the aorta or
th earter. innominata. The superior thyroid not
unfrequently takes origin a little lower down
from the division of the common carotid, or
even from its trunk ; or it may arise higher up
from a common trunk with the lingual. It
courses first forward and inward, when it is

* I would not omit to express here my obligations
to Mr. Beale for undertaking the analyses, and for
the care and skill with which he has performed
them.

100

100

1107

THYROID GLAND.

covered only by the deep fascia and platysma ;
but it soon turns vertically downwards, and
runs beneath the sub-hyoidean muscles to the
upper extremity of the gland, where it divides
into three branches; one of these runs be-
tween the thyroid gland and the trachea, a
second skirts the external border of the lateral
lobe, while the third, running along the inter-
nal border, forms an anastomosis with the cor-
responding branch of the opposite side.

The inferior thyroid is noticed by Cruveil-
hier as one of the arterial branches most
liable to vary in its origin, — an opinion which,
emanating from a less high authority, I should
have been inclined to question. It may arise,
acccording to him, from the common carotid,
the arch of the aorta, or the arleria innomin-
ata. (The supra-scapular often, less commonly
the posterior scapular, and sometimes even
the internal mammary, spring from the com-
mencement of the inferior thyroid, which is
therefore called the thyroid axis.) Its course
is peculiar ; it runs at first straight upwards,
then comes downward, and again ascends to
reach the inferior extremity of the lateral lobe
of the gland. It passes in front of the trachea,
and behind the great vessels and vagus nerve :
t he connecting cord ofthe sympathetic descends
behind it to the middle cervical ganglion when
it exists, which is then almost constantly
found, as it were, seated astride upon the
vessel, exactly on the convexity of its first
curve. Like the superior thyroid, it has three
terminal branches, one running along the in-
ferior border of the gland, another breaking up
over the posterior face of the lateral lobe, and
a third which penetrates between the gland
and the trachea, and anastomoses with the
one of the opposite side along the upper
border ofthe isthmus. (Cruveilhier).

The capillary plexus, in which the minute
branches of these arteries terminate, is dis-
posed in the form of hollow spheres around the
glandular cavities, closely applied upon the
limitary membrane and forming a continuous
network throughout the gland. It is tolera-
bly close-meshed, but not nearly so much so
as that of the liver or kidney. The diameter of
the capillaries, in a recent injected specimen,
varied from -g- .^Voo inch, and the interspaces
were, I think, two or three times as large.

There are corresponding vence comites to
the superior and inferior thyroideal arteries.
The superior thyroid or thyro-laryngeal returns
its blood either into the internal jugular vein,
or into the common trunk of the facial and
lingual, before it joins either of the jugulars.
The middle thyroideal runs down and turns
aside, crossing the common carotid to enter
the internal jugular. Besides these there exist
constantly another pair of veins, which run
down in front of the trachea involved in the
deepest layer of cervical fascia, and terminate
either by opening both into the vena transversa,
or the left into this trunk, and the right into the
junction of it with the right brachio-cephalic.
Ihese veins run down, gradually diverging
from each other ; so that, from being at their
origin no more than one third of an inch

apart, they are separated at the lower part of
their course by an interval of about an inch, or
rather more. In this situation they are often
united by a transverse branch, and are said, by
Cruveilhier, to form, with the tracheal and
laryngeal veins proceeding to unite with them,
a considerable plexus, which it is impossible
to avoid in the operation of tracheotomy.
These veins correspond in some measure with
the thyroideal artery of Venbauer, but are
much more constant, and are sometimes three
or four in number; so that the blood they re-
turn is not proportioned to that conveyed by
the artery.

The lymphatics, originating probably in a
closed network, proceed to enter the deep
cervical glands. They may sometimes be seen
filled with a concrete albuminous substance,
which they have probably taken up from the
glandular cavities.

Nerves. — The recurrent laryngeal, shortly
before it passes under the margin of the in-
ferior constrictor muscle of the pharynx, gives
off some filaments to the thyroid gland ; some
are also furnished by the external laryngeal ;
while a plexus, derived from the middle cervical
ganglion, proceeds along the inferior thyroid
artery, and is distributed to the gland along
with its branches, forming communications
with the preceding. In thin sections of the
thyroid treated with acetic acid, I have seen
the nucleated bands of the sympathetic, con-
taining one or two cselio-spinal tubules,
running for some distance in the interspaces
of the vesicles ; they probably terminate by
forming a looping plexus ; but I have not been
able to ascertain anything certain on this head
respecting either these or the tubular fibres.

Development. — The thyroid is said by
Cruveilhier to be developed by two lateral
halves, which are subsequently united by
means of the isthmus. This statement seems
to be confirmed by the condition ofthe gland
in several of the lower animals, where the
lateral lobes continue separate, lying on each
side of the trachea ; and is also supported by
the occasional occurrence of a similar dispo-
sition in the human subject.

In my own researches it has not occurred
to me to observe this mode of development,
perhaps because I have not examined spe-
cimens at a sufficiently early period ; however,
in an embryonic sheep only two inches long,
where the thyroid was distinctly visible, it
presented the usual appearance — the lateral
lobes being connected by a narrow isthmus ;
the same was the case in a human foetus of
4i months ; the isthmus, however, being
wider, and not appearing to be of at all more
recent development than the lateral lobes.
In the embryo of the sheep just mentioned,
the gland was of an opaque whitish aspect,
differing materially from its natural reddish
colour ; it consisted principally of nuclei,
with a small quantity of granular matter.
Scarce any trace of a vesicular arrangement
existed ; but the whole mass was surrounded
by an investing membrane very nearly homo-
geneous in texture. In another embryonic
4 b 2

1108

THYROID GLAND.

sheep, three inches long, the thyroid was
much more of its natural reddish, semi-trans-
lucent colour ; still there was scarcely any
vesicular arrangement, the mass consisting
almost entirely of nuclei aggregated together.
The thyroid of the human foetus just men-
tioned was of the same grayish aspect as that
of the smallest of the embryonic sheep. It
also consisted chiefly of nuclei, but these
were to some extent collected together so as
to form solid globular masses (Jig . I'll.), not

Fig. 741.

>©ee©ffi^o<a<4,

(WS!

Incipient vesicle from thyroid of human foetus, at
about mid-period. It is a solid mass of nuclei, not
enclosed in a distinct envelope.

yet, however, quite definitely isolated, nor
surrounded by homogeneous envelopes. This,
however, seems to be the way in which the
vesicular cavities are developed ; the limitary
envelopes being formed around the primitive
nuclei, which assume the arrangement of epi-
thelium. The thyroid is of larger relative
magnitude during intra-uterine existence and
infancy than in after life, — a fact which seems
rather opposed to the view which regards this
gland as alternating its action with that of the
brain.

Comparative anatomy of thyroid. — The
existence of a thyroid gland in all the Mam-
malian orders seems to be undoubted ; and
though it is probable that, by a close and ex-
tended survey of the various families, some
interesting and perhaps instructive peculiarities
might be detected, yet I have not the oppor-
tunities necessary for undertaking such an
inquiry, and can only record one observation
where some deviation from the ordinary con-
dition was discovered. This was in a Rabbit,
in which the organ presented the vesicular
arrangement much less manifestly than is
usually the case. The epithelium consisted of
small imperfect celloid particles, disposed so
as to form hollow spheres ; but there was
scarce any appearance of secretion in the
included cavities, which were small, and
might at first have escaped observation.

For the following summary of the compa-
rative anatomy of the thyroid in birds and rep-
tiles, I am principally indebted to Mr. Simon’s
paper in the Philosophical Transactions.

In Birds, there are found, in all the va-
rious orders, two glands, situated one on
each side of the trachea, very near the lower
larynx, and frequently attached to the jugular
veins. They possess the characteristic struc-
ture of the thyroid body, consisting of a
dense aggregation of closed vesicles, which
contain a kind of epithelium, and are invested
by a close capillary network applied over their

homogeneous envelope. The position of these
glands with respect to the larynx seems to be
neither essential nor constant ; it is however
stated by Mr. Simon, that it “ always corre-
sponds to a particular spot of the vascular
system, viz., that it lies on the cervical vessels,
and receives its supply of blood just opposite
to the point at which the vertebral or carotid
arteries diverge to their respective destina-
tions.”

The following are the details of a mi-
croscopic examination which I made of these
glands in a Pigeon. They consist of closed
vesicles about inch diameter, having

their homogeneous envelope lined by a rather
thick layer of epithelium, so that the cavity
is proportionably contracted, sometimes not
being more than ^-Jro inch diameter The
epithelium consists, for the most part, of nuclei
and granular matter. Some of the nuclei are
very perfect, and show a distinct vesicular struc-
ture, with a well marked peripheral nucleolus.
Others aremore like granules, solid and opaque,
and not above half the size. The nuclei are
imbedded in granular matter, which for the
most part is diffused freely about, but occa-
sionally, though very rarely, constitutes the
contents of a cell. In some cavities the epi-
thelium assumes the form of non-nucleated
delicate vesicles, of rather large size (Jig. 7^2. b.).
No secretion, capable of being recognised
by the eye, exists in the glandular cavities.

From the thyroid of a Pigeon.

a, 'h, Two vesicles. The epithelium of a consists
of nuclei and granular matter ; that of b of rather
large, delicate, pellucid vesicles. The central cavity
is small, especially in a.

c, The two varieties of nuclei, and —

d, A complete nucleated cell.

Reptiles. — In the order Chelonia the organ,
which is demonstrated by the microscope
to be really the thyroid, is found occu-
pying a definite and uniform position. It lies
in the median plane of the body, immediately
above the base of the heart, between the two
carotid arteries, a ndis overlapped and con-
cealed by the pericardial lobes of the thymus.
The structure of the gland in a young Tor-
toise I found extremely w ell marked ; the ve-

THYROID GLAND.

sides were large, to ^inch diameter, closely
aggregated together, and very variously altered
from the spherical form by mutual pressure.
There was very little investing areolar tissue.
The epithelium consisted of a single row of
nuclei imbedded in granular matter, which
was more abundant than usually is the case.
In some parts this had almost disappeared,
and was replaced by delicate vesicles larger
than the nuclei which lay closely together in
contact with each other. Whichever of these
forms the epithelium assumed, it did not en-
croach much on the cavities of the vesicles,
which were large and filled with some trans-
parent non-refracting fluid.

Most of the cavities also contained one to
three yellowish coarsely granular globules,
--i— to in. diameter ; these existed in va-
rious stages of development. A fine large
octohedral crystal was also seen in one of
the cavities ; but there were no prisms of
triple phosphate (fig. 743.).

Among the various families of the Saurians
the thyroid is found to occupy different posi-

Fig. 743.

One side of a vesicle from thyroid of Tortoise.

The epithelial stratum consists of a single row of
nuclei, imbedded in a more abundant quantity of
granular matter than usual.

tions ; in some being single and mesial, in
others double ; in some it lies high in the
neck, in others low. Even in the same family
its arrangement is not always uniform ; thus
among the Lacertidce the gland is single, and
of considerable breadth in the true lizards
while in the Monitor it is double. Among the
IguanidcB, likewise, a similar variety prevails.
The Gechotuloe, Chamceleonidce, and Scincidce
present the same general form as the true
lizard. In the Chamseleon it is rather higher
(nearer the os hyoides) than in the other
families, and is overhung by the sacciform
dilatation of the larynx.

In the Amphisbania and Ophidia “the gland
lies just above the base of the heart, between
the right and left carotid arteries. It is a little
hidden by the thymus of each side ; and in
those genera which possess a fat body this
large organ lies conspicuously in front of both
the thymus and thyroid.”

In the Batrachian order there has been
found, in the common Frog, on each side a
small glandular body, which Mr. Simon de-
clares is unquestionably possessed of true
thyroid structure. They are situated on the
carotid arteries, just beside the cornua of the
hyoid bone. Huschke conceived these bodies
to have their origin in the shrinking of the
branchiae, and endeavoured to establish that
the thyroid generally had its origin in the
transformation of the branchial arches in the
early embryo. This hypothesis, however,
Mr. Simon well remarks, appears refuted by the
existence of the gland in a perenni-branchiate

i 109

animal, the Menobranehus, where it consists of
two symmetrical portions connected with the
inferior border of the os hyoides, one on each
side.

In the class of Fishes there seems yet some
doubt whether a true thyroid gland really exists.
Mr. Simon believes that he has discovered the
organ in many fishes, enumerating the Carp
( Cyprinus ), Pike (Esox), Cod (Gadas), Had-
dock ( Morrhua ), Whiting ( Merlangus ), Eel
(Anguilla), Sturgeon (Accipenser), Shark
(Squalus), and Skate ( Raia ) ; — it seems also
to be present in the Anableps, Exocostus, Cal-
lorhynchus, and Lamprey (Petromyzon), but
the evidence for its existence is less conclusive.
It may occupy, he states, either of three posi-
tions ; (1) as a single organ situated in the
median line in connection with the basibran-
chials, and supplied with blood from the
first branchial vein while yet within the gills.
(2) “ In the Gadidae the gland is double.
One portion lies on each side, not, as in the
last case, at the anterior extremity of the first
branchial arch, but near its posterior or ver-
tebral end. Here it occupies part of a recess
which is bounded by the gill below, and above
by the outer extremity of that transverse fold
of mucous membrane which limits the extent
of the palate. It is merely covered by mucous
membrane, which leaves it apparent to the
eye without need of any express dissection.
Its vascular supply is reflected to it from the
ophthalmic artery, which arises before the
formation of the systemic aorta from the first
branchial vein close to the origin of the pro-
per encephalic artery.” (3) “ In the carp,
anableps, pike, and exocoetus, the gland is
placed at the inner extremity of the same
duplieature of mucous membrane, and more
toward the palate, so as to lie upon the fibres
of the pterygoid muscle.” Though there is
this variety of situation, yet Mr. Simon re-
gards these several organs as constantly agree-
ing in one point, viz., in deriving their vascular
supply from the first branchial vein, and thus
being brought into connection with the ence-
phalic nervous centre, by their nutrient streams
having origin from a common source. Pro-
fessor Owen dissents from the view that the
pseudobranchiae are the analogues of the thy-
roid gland. He states that in osseous fishes
they are not diverticular to the cerebral circu-
lation, but only to the ophthalmic, and in most
cases are subsidiary, in this respect, to the cho-
roid vaso-ganglion. The sublingual gland of
Retzius is the organ which Professor Owen
considers as most nearly representing the
thyroid, though he suggests a doubt as to
whether, by reason of its relations to the heart
and great vessels, it may not more properly be
regarded as the analogue of the thymus.

It is with some hesitation that I proceed
to mention the results of my own examination
of some specimens from the three classes
pointed out by Mr. Simon, in which he seems
to regard the presence of a thyroid as un-
doubtedly ascertained. I have, however, care-
fully examined the structure with the micro-
scope in every instance, and I believe I may
4b 3

1110 THYROID

refer to the observations, so far as they go, as
free from any material error. In the Sliate I
have found the organ described by Retzius as
a salivary gland, and by Mr. Simon as a thy-
roid, occupying the situation well described by
the latter, and lying exactly upon the terminal
division of the branchial aorta. It was of a
faint reddish gray tint, and presented to the
unaided eye the appearance of a conglomerate
gland. No excretory duct, however, was ob-
served proceeding from it. In structure it
consisted of numerous vesicles aggregated to-
gether. The form of these was mostly circular ;
some were elongated, and many variously
altered by mutual pressure. Their diameter
was about T|-a-to inch (fig. 744. A). The
limiting envelope of the vesicles presented a

Fig. 744.

From thyroid of Skate.

A. Vesicle, in. in diameter.

B. Several of the nuclei imbedded in diffused
mottled substance.

good example of homogeneous membrane. It
was lined internally by a pretty thick stratum of
epithelial substance, which in some instances
was so abundant as almost to fill up the cavity.
The epithelium consisted of nuclei and a very
large quantity of rather coarse granular ma-
terial, which quite obscured the nuclei them-
selves (fig. 744. B.) There were also a few
granular cells, and, in the interior of many of
the vesicles, imperfect prismatic or octohedral
crystals could be discerned. I could not
discover, among the glandular structure, any
tubes resembling excretory ducts ; so that I
am much inclined to believe it has no relation
to the salivary organs, but belongs to the
class of ductless glands. A gland, however, it
assuredly is, and not a mere vaso -ganglion.
Besides this body I discovered at some dis-
tance behind it, just at the junction of the
branchial arches anteriorly, a small light red-
dish mass, which was covered in by a thin
fascia, and by the mucous membrane, and
could not be seen till the latter was dissected
offl Its structure was almost exactly similar
to that of the organ just described, con-
sisting of vesicles about -j-ijj to inch

diameter {fig. 745.), with a thick interior
stratum of epithelium resting on a beautiful
homogeneous limitary membrane. The pscu-

GLAND.

Fig. 745.

A vesicle from sublingual gland of Skate, diam. ^ in.

It contains abundance of nuclei and granular
matter, with delicate vesicles.

dobranchia, situated on the anterior wall of
the spiracular canal, is manifestly of entirely
different structure to the organs described. It
consists of small plicae of mucous membrane,
covered by a kind of pavement epithelium.
In a Dog-fish ( Spinax ) the pseudobranchia
was very small, but distinct. 1 could discover
no trace of the sublingual gland, or of the small
one behind it which I found in the skate.

In the cod and whiting the pseudobranchia
is situated, as Mr. Simon has described it, near
the upper extremity of the first branchial
arch on each side. It lies in a recess which
is bounded by the gill below, and above by
the outer extremity of that transverse fold of
mucous membrane which limits the extent of
the palate. Its structure is peculiar; Mr.
Simon regards it as a thyroid ; but from this
opinion I feel obliged to differ. The following
description is taken from examination of the
organ in the Cod, but applies equally to that
in the Whiting. It is a body of light red
colour, semi-transparent aspect, flattened so
as to present two faces, about one line and a
half in thickness, and having two borders,
one convex and slightly notched, the other
somewhat concave. The surface is slightly
uneven or nodulated. It is enclosed in a cap-
sule, through which some large vessels are
seen ramifying. Its general aspect is that of
“glandular flesh,” and certainly not of a mere
congeries of vessels. In structure it appears
to consist of parallel folds of homogeneous
membrane, beneath which is spread a vascular
plexus, and which are covered by an unusually
developed epithelium. This epithelium appears
under the form of granular cells of an oval,
circular, or irregular form, not distinctly nu-
cleated, and having a diameter of _.. i1ij-,i-- inch.
These do not appear to constitute a mere in-
vestment, but to form a layer of some thick-
ness, filling up the intervals between the
adjacent processes or folds of homogeneous
membrane. These organs, manifestly con-
structed after the type of gills, evince thus a
tendency to assume a glandular structure ;
yet I can see no sufficient reason for sup-
posing them to represent the thyroid, from
which they differ so entirely in structural
characters. In the whiting I could detect no
trace of a sublingual gland, nor of the small
posterior one; but in the Eel, where the

THYROID GLAND. lilt

pseudobranchia was absent, I found, by the
aid of the microscope, between the first and
second basibranchials, a small mass, which
consisted in great part of fat, but contained
also some large vesicles closely resembling
those of a real thyroid. Their diameter
varied from Ti1T to ^ inch. They had an ho-
mogeneous envelope lined by an epithelium,
consisting of small non-nucleated pellucid cor-
puscles, and surrounding a cavity filled by a
transparent somewhat refracting fluid.

In a P/euronectid I found the pseudobranchia
quite free, uncovered by mucous membrane,
and projecting a series of small distinct leaf-
lets into the branchial cavity. It differs essen-
tially from that of the cod or whiting, and
showed no tendency to assume a solid glan-
dular form, but was manifestly a real though
minute gill.

In a Carp [ found the pseudobranchia with
some difficulty. It was situated very deeply
between the anterior part of the upper ex-
tremity of the first branchial arch, and the
posterior border of the pterygoid muscle. Its
structure was entirely that of a gill, consisting
of parallel folds of a membrane, arranged
transversely to a median axis, and overlaying
a vascular plexus. These folds were covered
with a kind of scaly epithelium, which was
often detached in large pieces, and mingled
with some circular cells, closely resembling
mucous globules. I could find no trace of the
sublingual nor of other adjacent gland.

From the few facts now detailed I think it
may be concluded, (1) That there is no evi-
dence from their structural characters to prove
that the pseudobranchiae are the representa-
tive of the thyroid. (2) That in some in-
stances organs which seem to be of a totally
different kind are found, which resemble
very closely the structure of the thyroid
when it unquestionably exists. Mr. Simon
lays stress upon the circumstance, that the
pseudobranchiae and the sublingual gland re-
ceive their vascular supply from the same
source, viz. the 1st branchial vein ; this, how-
ever, is not constantly the case, the pseudo-
branchiae in osseous fishes, according to Pro-
fessor Owen, serving only as diverticula to the
ophthalmic, and not to the cerebral circulation;
so that on this ground they cannot be sup-
posed to have similar functions. For a philo-
sophical discussion, however, of the analogy
and homology of the pseudobranchia to the
thyroid, I would refer to Professor Owen’s
Lectures, vol. ii. p. 270. note.

Morphology. — The preceding details are
abundantly sufficient to prove the glandular
nature of the thyroid. This truth, which elder
anatomists saw clearly, though rather afar off)
we, by more intimate and minute scrutiny, are
enabled to confirm and establish in every par-
ticular. Let us take in order the several parts
ot the secretory apparatus of the thyroid as
we have described them, and see whether they
do not exactly correspond to homologous
parts in any undoubted gland. The recep-
tacular cavities, enclosed by envelopes of
homogeneous membrane, manifestly represent

the tubes of the kidney or testis, or the ter-
minal vesicles of the salivary gland. The
limitary tissue is identical in appearance in
each ; but disposed in the one so as to form
shut sacs ; in the others to ensure a pervious
canal or outlet, for the secretion. In the
true glands the limitary tissue or basement
membrane supports, on its interior, a layer
of epithelium, essentially consisting of nuclei
and granular matter. The same tissue in
the thyroid is lined internally by a similar
layer, which differs only in the smaller quantity
of granular matter interposed among the
nuclei, and in both cases the formation of
perfect cells (i. e. with envelopes) is uncom-
mon. The exterior of the limitary tissue is in
contact, in all the true glands, with a capillary
plexus, from which the materials for the
nutrition and growth of the epithelium are
furnished. The same disposition exists in the
thyroid. A certain amount of fibrous tissue,
or some modification of it, penetrates more or
less extensively among the elementary parts
of the true glands, and serves to pack and
unite their component parts together ; this also
we have had occasion to describe in the
thyroid. With respect to a supply of lym-
phatic vessels and nerves, it is sufficient to
state, that as far as ordinary dissection can go,
the thyroid is similarly circumstanced with the
other glands ; and there is no reason to doubt
that the actual arrangement of these parts in
all is the same. The parallel, thus exactly
sustained in every particular, warrants us in
regarding the thyroid as the tt apaSei-ypa of
the class of ductless glands, and it may be not
without advantage, if we take occasion to note,
in the other organs belonging to the same
class, how gradually the strongly marked
characters are laid aside, till the glandiform
organ passes into a modification of vascular
structure. In the supra-renal capsules the
limitary membrane, though described by an
eminent anatomist as usually forming tubes of
various length, enclosing celloid epithelial
particles, is, according to my observation
(which is however but limited), very faint, or
entirely absent. I have never been able to
discover it in the human adult or foetal sub-
ject; and in the sheep the cortical structure has
seemed to consist simply of rows of celloid
nucleated particles, without any enclosing
membrane. Conceding, however, that in these
organs the limitary tissue does exist, there can
be no doubt that it is much more feebly de-
veloped than in the thyroid, while, as a set off)
the epithelial particles are more perfectly
formed. In the case of the thymus the
limitary tissue is well marked, and resembles
very much, in its arrangement, that of the con-
glomerate salivary gland ; but the epithelium
is remarkably modified. The nuclei exist, but
almost alone. No granular matter of any pecu-
liar properties is formed around them, prepa-
rative to, and evidencing the existence of,
secretory action. In the spleen both these
alterations coincide. The epithelium is reduced
to mere nuclei aggregated in masses round
prodigiously developed venous radicles, and
4 b 4

1 112

THYROID GLAND.

the limitary tissue is discoverable nowhere,
not even surrounding those curious spherical
masses of nuclei the white corpuscles of Mal-
pighi. The only circumstance I know of,
which seems to indicate that even in the spleen
a kind of secretory action does occasionally
take place, is, that there frequently occur, in
the parenchyma, some peculiar yellow cor-
puscles, which are most abundant in fishes,
and of which I gave a detailed account some
years ago. The very presence, however, of these
(for they are by no means constant), as well as
their condition, argue strongly that secretion is
not the appointed function of the splenic
parenchyma. From this, the last and lowest
of the ductless glands, we descend to erectile
tissue, in which the venous portion of the
sanguiferous system is even more highly de-
veloped than in the spleen, and where the
intervening parenchyma is still further reduced
in quantity; yet, from the phenomenon of
afflux of blood to the part, it must be regarded,
I think, as exerting an attractive force, as is
unquestionably the case in the spleen.*

Returning from this digression to the con-
sideration of the thyroid, we may lay it down
as fully established, that it is a gland whose
secretion is formed, and collects, in closed
cavities. Now from this fact we are able
easily to deduce another, viz., that the secre-
tion when formed is capable of being absorbed
from the receptacular cavities ; for otherwise
these would go on enlarging and distending
themselves indefinitely, as in fact they do
under certain morbid conditions. But, though
there may be various causes concerned in
the production of bronchocele, yet I think it
must be regarded as proved, by Mr. M'Clellan’s
inquiries, that certain waters are adequate of
themselves to produce this disease ; — it would
appear that when they are drunk, some in-
gredient or principle is supplied to the blood,
which, being in excess, is straightway elimi-
mated by the epithelium of the glandular
cavities of the thyroid, and thus collects in,
and distends them. If a patient in whom this
has occurred be removed from using this
unwholesome water, and if the natural ab-
sorbing power be aided by the influence of
iodine, then, the supply of the substance for
which the thyroid has a special attraction
being cut off, the excess collected in the
receptacular cavities returns speedily to the
circulating current, which now, being in a
minus condition as to this principle, readily
resumes it. In such cases there seems, in
fact, to take place a very analogous process
to that which occurs in ordinary fattening
and emaciation ; if an excess of oily matter
exist in the blood, old fat vesicles enlarge, and
new ones are formed ; if the reverse is the

* The well marked variation in size of the spleen
at different times proves, I think beyond doubt,
that it exerts an actively attracting force on the
blood which traverses it ; else what possible reason
can be given for its containing much more blood at
one time than at another ? No contractile tissue
exists here which can be supposed to obstruct the
returning current by the splenic vein.

case, the oil in the fat cells is readily absorbed
into the blood circulating in the capillary
loops around them.

The condition in which the epithelium of
the thyroideal cavities is usually found is
worth observing, and seems susceptible of a
probable interpretation. It may be stated as
a pretty well established fact, that the nucleus
of a cell is the essential part, that in it resides
that influence, or is developed that force, which
produces all the phenomena of growth and
assimilation ; that, so long as the nucleus
persists, the energy of the cell, if one has been
formed, continues to be manifested ; but, if it
has disappeared, the active life of the cell is
at an end. It is also certain that the comple-
tion of a cell, i.e. its being surrounded by an
envelope, is by no means an essential circum-
stance ; that all the purposes of cell life may
be effected by the mere aggregation of granular
matter around a nucleus ; that, in fact, the
cell wall or envelope is of no importance, or
but very little, in the metabolic changes which
are produced, and that its presence, when it
exists, seems merely to denote a certain per-
manence of duration in the particle. Many
examples of the correctness of these state-
ments, will occur to every one who is in the
habit of examining the glandular organs in
man or the lower animals. I believe we
may also advance a step beyond these doc-
trines, and regard it as very probable that,
when we find an epithelial structure con-
sisting principally of bare nuclei, with but
a scanty interposed quantity of granular
matter, the secreting action there effected is
of a rapid and simple kind ; the destined pro-
duct being quickly formed and thrown off, and
not slowly evolved within the chamber of
a cell. The following instances may be re-
ferred to, as illustrating the extreme varieties
of secretory action in reference to this par-
ticular. The cells in which the spermatozoa
are formed must be of considerable per-
manence, the development of the filaments
taking place gradually, and in one instance, as
Mr. Goodsir has shown, only being completed
in the spermatheca of the female. The biliary
cells of various annelida are at first filled with
pale granular contents ; but gradually these
are replaced by the characteristic molecules
with which the cell becomes at last distended,
and thus remains, often for a long time. The
cells of the kidney of the common snail,
which are very perfectly formed, enclose,
within a well marked envelope, an opaque
white mass of uric acid, which, after a long
time, may increase to such a degree as com-
pletely to fill the cell. These cells are very
permanent.*

In contrast to these instances, wherein
complex and elaborate products are formed in
complete cells by a secretory action of a slow
and deliberate character, we may refer to (1)

* I preserved some snails in a box for about a
year — they remained in a perfectly torpid state, and
took no food. The renal cells at the end of that time
were almost all fully distended with uric acid, while
usually they are not more than half full.

THYROID GLAND.

1113

the absorbent glands, which doubtless produce
some change in the fluid which traverses them ;
this, however, must necessarily be a rapid
process, and, accordingly, scarce any cells are
formed ; the mass of the glandular paren-
chyma consisting of very perfect nuclei; (2),
the terminal hepatic ducts, whose walls, as I
have shown, consist almost entirely of nuclei
set close together, and which, by means of
these effective agents, eliminate the actual
biliary secretion from the varying, partly
biliary, partly oily, fluid formed by' the hepatic
cells on their exterior ; this process of elimi-
nation is, I believe, continually going on, and
is not so much of a metabolic as of an ab-
sorbing nature ; the essential change being
probably effected by the hepatic cells of the
lobules; (3) the nucleated tissue forming the
principal part of the villi, which scarce ever
developes cells,* but is constantly attracting
the chylous fluid through the basement mem-
brane from the cavity of the gut, and permit-
ting it to pass off by the efferent lacteals
(here scarce any chemical change appears to
take place) ; (4) the cineritious matter of the
cerebral hemispheres, which, amid the rapid
alternations of sensation, thought, and volition,
must be undergoing incessant change, consists,
in by far the greater part, of nuclei and granular
matter, the fully formed vesicles being few and
far between.

Applying, now, these views to the case of
the thyroid, there seems reason to believe that
the ordinary condition of its epithelium is such
as to adapt it for rapid and transitory action ;
so that a large amount of secretion may be
quickly thrown into its cavities on any sudden
occasion ; which again would easily transude
through the thin epithelial layer and homo-
geneous tunic, when the time of action had
passed by.

It may also be remarked, as consonant
with the views above stated, that as respects
its chemical nature the secretion of the thy-
roideal cavities is of a simple kind, not appa-
rently requiring much elaboration. It seems,
in fact, to be a mere modification of albuminous
matter containing, it may be, some gelatine,
but strongly contrasting with the highly
wrought products of the renal and hepatic
laboratories. This implies that the change
effected by the thyroideal epithelium on the
liquor sanguinis supplied to it is by no means
considerable.

Use. — Cruveilhier, writing about fifteen
years ago, briefly says, “ the use of the secre-
tion of the thyroid is unknown ; ” nor can
the anatomist of the present day give a
much more satisfactory account. So en-
veloped in mystery the use of the gland seems
to have been always regarded, that inquirers
have been more willing simply to confess
their ignorance than is usually the case, and
fewer speculations and hypotheses have been
broached respecting this than regarding other
points which promised at first sight to be of
easier solution. It is scarcely worth while

* I venture herein to differ from Professor Good-
sir, not without repeated and careful observations.

to mention the opinion, which supposes the
thyroid to have any essential connexion with
the larynx, either as pouring into it, through
supposed ducts, a fluid fitted to lubricate the
lining membrane, or, as Sir A. Carlisle sup-
posed, forming a protection to the delicate
organs of the voice, against the variations
in temperature of the external air. There
seems no doubt that the relative position of
the thyroid to the larynx is quite unimportant,
so far as the function of the organ is con-
cerned. This is borne out by the variations of
its site which occur in birds, and by the results
of morbid action ; since prodigious goitre does
not induce disease of the larynx, except in a
mechanical way, i.e. by injurious pressure.

Passing over more crude conceptions, we
come to consider a theory which has been
propounded by Mr. Simon, and which has
certainly every claim to our careful attention,
both from the character of its author, and as
it is the only one yet promulgated which can
be said to be even probable. He considers
that the thyroid acts as a diverticulum to the
cerebral circulation ; exercising, at the same
time, its secretory function in an alternating
manner with the encephalic nervous mass.
His words are, “ What diversion is to the
stream of blood viewed quantitatively, alter-
native secretion would be to the composition
of blood viewed qualitatively ; and I should
conceive that the use of the thyroid gland, in
its highest development, may depend on the
joint exercise of these two analogous func-
tions. I should suspect not only that the
thyroid receives, under certain circumstances,
a large share of the blood which would other-
wise have supplied the brain, but also that the
secretion of the former organ bears some
essential relation (which chemistry may here-
after elucidate) to the specific nutrition of the
latter ; that the gland, — whether or not it
appropriates its elements in the same proxi-
mate combination as the brain does, — may, at
all events, affect, in a precisely similar degree,
the chemical constitution of the blood tra-
versing it ; so that the respective contents of
the thyroid and cerebral veins would present
exactly similar alterations from the characters
of aortic blood. Finally, I should suppose
that these actions occur only, or chiefly, during
the quiescence of the brain, and that when
this organ resumes its activity the thyroid may
probably render up again from its vesicles to
the blood, in a still applicable form, those
materials which it had previously diverted
from their destination.”

This theory mainly rests on the circum-
stance that the thyroideal arteries arise in
close proximity to the cerebral, and this is
I think sufficiently constantly the case to form
a strong argument in its favour. It must be
remembered, however, that variations in the
place of origin of the arteries both of the brain
and thyroid, do occur without, as far as we
know, any interference with the full discharge
of the functions of the gland ; and it may also
be considered probable that the purpose of a
diverticular stream would have been better

1 1 14 THYROID GLAND.

attained, if the origin of the vessels had been
below instead of above the point of giving off
of the arteries to the brain. Besides, however,
this argument, two others may be mentioned
which at least favour the same view. One is,
that no special characteristic principle appears
to exist in the secretion of the thyroid, but
that it is a mere modification of albuminous
matter,— this seeming to imply that no special
use is served by the secretion of the gland,
that it is not elaborated for the sake of pro-
ducing any peculiar effect on some other part,
but that it is simply secerned from the circu-
lating current for a time, to return and mingle
with it again in a condition but little altered
from its primitive one of blood-plasma. The
other argument is drawn from the con-
dition of the epithelium, which, as we have
before remarked, seems adapted for rapid and
transitory action, so that it might quickly
secrete a large amount of material on any
diminution of the nutrient processes in the
brain. These arguments may be allowed to
possess some weight. Before, however, this
theory can be regarded as at all established,
a more sure and discriminating chemistry must
prove some relation of composition to exist
between the secretion of the thyroid and the
grey nervous matter. Till this is done we can
but deal with the question afar off, without
bringing it to an exact issue.

Morbid Anatomy. — The following morbid
changes have been observed to occur in the
thyroid ; ( 1 ) It may be affected with com-
mon inflammation. (2) It may be variously
altered by unhealthy or perverted action of its
own glandular structure. (3) It may be the
seat of adventitious formations. (4) Its
vessels may become remarkably enlarged, as
in the so called aneurism by anastomosis.

Inflammation, — Professor Hasse gives the
following description of inflammation occur-
ring in the thyroid. “ It is rare, but may at-
tack the organ either when healthy, or when
enlarged by previous disease. Its course is
more frequently chronic than acute. Within
a very brief interval the gland often swells
considerably, becomes very bloodshot, tense,
and painful, its texture softened and friable,
assuming at first a brown red, and ultimately
a dingy gray colour. The morbid anatomy
of this grade of inflammation is but imper-
fectly known ; that of the suppurative stage
has been more frequently observed, and
more fully described. Either separate ab-
scesses form, or else the entire gland is
converted into pus. Under favourable cir-
cumstances the abscess opens externally
through the skin. There are, however, ex-
amples of its obtaining vent through the
oesophagus, and determining a protracted
fistula of the gullet,* or of its discharging
itself into the trachea, and producing death by
suffocation. j- After evacuation of the pus,
together with numerous shreds of dead cellular
tissue, the tumour collapses ; the gland on the

* Unger, Beitrage zur Klinik der Chirurg. vol. i.

t Meckel.

side affected shrivels into a hard, cellulo-
filamentous knot, which adheres firmly to the
skin and to the surrounding parts. Some-
times the shrivelling of the one gradually
brings on wasting of the other lobe.”

Alterations of Structure. — Under the se-
cond head may be included hypertrophy of
the thyroid, or some enlargement without
appreciable change of texture. “ This variety,”
Prof. Hasse states, “ is frequent, and for
the most part inconsiderable.” It probably
depends merely on distension of the glan-
dular cavities by their accumulated secre-
tion. This change is almost wholly “ confined
to youth, and is frequent about the age of
pubertv in both sexes, — more so, however, in
the female.” “ Alternatives of increase and
decrease are especially apparent in this kind
of bronchocele, enlargement being most con-
spicuous at the approach of the menstrual
period.” This form, though it may be called
hypertrophy, is not quite strictly so desig-
nated, as there is no formation of new glandu-
lar tissue, but only' distension of the original
cavities, by an increased quantity of secretion.

“ Mehcerous degeneration of the thyroid is
one of the most frequent forms. It occurs at
all ages, and is uniformly attended with intu-
mescence. It may involve the organ in whole
or in part. In the former case the component
granules (or vesicles) are found unusually and
unequally enlarged, and transformed into sepa-
rate cells filled with a tenacious, viscous, jelly -
like substance, of the colour of honey. The
entire part is hard, nearly bloodless, and but
loosely coherent with the surrounding parts.
Where, as frequently happens, only certain
portions are disorganized, these form spherical
tumours varying in size, and imbedded clearly
in the healthy structure. They present a
brownish or yellow colour, and the consistency
of jelly or of melted glue. Sometimes they
appear as an opaque, reddish, soft, or even
lardaceous, swelling. In general but few
blood vessels are visible in this goitre, although
it may now and then be associated with ex-
uberant vascular growth.”

The foregoing description is quoted from
the translation by the Sydenham Society of
Professor Hasse’ s w'ork. He does not, how -
ever, seem to notice sufficiently, under this
head, the variety of matters which are found
in the enlarged glandular cavities. Cretaceous
matter, either in a pulverulent state, or form-
ing hard ossiform masses, I believe often
occurs, and in Prep. 1498, of the Patholo-
gical collection in the Museum of the College
of Surgeons, there is seen a quantity of solid
white substance, either opaque and soft, or
transparent, firm and chondroid, which oc-
cupies the larger cavities, the majority being
filled with a transparent jelly-like material ;
some also with cretaceous matter. One in-
teresting instance, probably belonging to this
class, is quoted in the Cyclop, of Pract. Medi-
cine from De Htien : — “ In cadavere horren-
dam mole thyroideam nactus, publice dissecui.
Mecum auditores mirabantur, nullum fere genus
tumorum dari, quin in hac sola thyroidea in-

THYROID GLAND.

veniretur. Hie enitn steatoma, ibi atheroma,
alio in loco purulentus tumor, in alio hyda-
trius, in alio erat coagulatus sanguis, fluidus
fere in alio, imo hinc glutine loculus plenus
erat, alibi calce cum sebo mista.”

I may mention here the results of micro-
scopic examination of a specimen of this form
of enlarged thyroid, for the opportunity of
making which I am indebted to the kind-
ness of the medical officers of St. George’s
Hospital. The gland was greatly enlarged ;
its surface somewhat nodulated. A sec-
tion displayed a number of cavities visible to
the naked eye, some of which were circular,
others elongated, and as it were compressed.
Many of them were about the size of a large
pin’s head; some however, much more capa-
cious. The majority were filled with a slightly
opaque, firm, gelatinous material ; but some
(the larger) with cretaceous or ossiform matter,
and some also with a reddish material. The
intervening structure in several places appeared
tolerably natural ; but even in this, on close in-
spection, enlarged vesicles were perceptible.
The areolar tissue separating the lobes of the
gland was hypertrophied, and formed whitish
septal bands. Under the microscope it was
seen that the vesicles were generally enlarged.
They were found of all sizes, from those that
were distinctly visible to the naked eye, or still
larger, down to the natural size. Their walls
were somewhat but not uniformly or very
greatly thickened. The homogeneous envelopes
presented, generally, somewhat of a fibrous
appearance. The greater number of the
cavities were distended with a transparent,
feebly refracting, structureless, material, in
which were numerous small irregularly shaped
particles of higher refracting power. This
material resembled, almost exactly, the normal
secretion in appearance, and, like it, was free
in the cavity of the vesicles. In these vesicles
there was very little trace of epithelium, only
some small, and fevv,non-nucleated corpuscles ;
but in other vesicles the epithelium was so
abundant, that it completely occupied the
cavity. It was in no respect different, except as
to quantity, from its healthy condition, con-
sisting of mere nuclei and interposed granular
matter in no great abundance. In some of
the vesicles there were large and beautiful
crystals of more or less perfect octohedral form.
These were either oxalate of lime or triple
phosphate. One prodigiously enlarged vesi-
cle contained a mass of calcareous matter,
very firm and dense throughout, but most in
its central and peripheral parts. In the latter
s'tuution there were numerous masses of ossi-
form substance, of yellowish semi-transparent
aspect. On crushing these, no bone lacunae
could be discerned in the fragments. They dis-
solved freely with strong effervescence in
nitric acid, leaving an homogeneo-fibrous basis
substance, which often exhibited a greenish
yellow tint. The material, thus proved to be of
cretaceous nature, contained, mingled with it,
numerous tablets of cholesterine. One small
reddish mass, occupying the cavity of a vesicle,
was found to consist almost wholly of blood

1115

globules and their detritus, and thus seemed
to be the result of haemorrhage. Another
opaque whitish mass did not effervesce with
nitric acid, and was therefore not cretaceous ;
it consisted of epithelial nuclei mingled with
peculiar, and rather abundant, granular matter.
In the above account it is worth noticing that
no cells were found ; the epithelium retained its
natural appearance ; also the matter distend-
ing the greater number of the cavities resem-
bled exactly, so far as the eye could judge, the
natural secretion ; and lastly, that in some in-
stances there was an accumulation of unaltered
epithelium and not of the secretion. This
last fact is of some importance with respect
to the exact nature of the function discharged
by the epithelium.

Owing to the kindness of my friend, Mr.
H. Gray, 1 have recently had the opportunity
of examining a remarkable specimen of Bron-
ckocele. The gland was greatly enlarged,— to
five or six times its natural magnitude, — and
altered in form, one lateral lobe being raised
up higher than the other, and the surface
being somewhat uneven and nodulated. On
a section being made, the exposed surface
presented a reddish glossy aspect, somewhat
resembling that of certain forms of malignant
disease which are undergoing softening: there
was no appearance of distended cavities ; in
fact, the structure to the eye exhibited less of
the cellular arrangement than is usual. Micro-
scopic examination confirmed the impression
derived from simple inspection. — But little of
the natural secreting structure remained, the
vesicles being destroyed, and their secretion,
though still present in some quantity, being
certainly diminished. Some traces of the
epithelium of the cavities were perceptible;
but there was no special cell growth indicative
of any adventitious formation ; a few large
cells or globules only, varying in size from
znro t0 i SV o diameter, existed in some

of the remaining cavities : these evidently
consisted of aggregations of oily molecules
and drops not manifestly enclosed by any en-
velope. The blood-vessels were prodigiously
and universally enlarged ; some of those which
were capillaries in structure were from two to
three times their normal diameter, and irre-
gularly dilated and varicose; they were every
where clustered over with minute oil drops ;
which formed so thick a coating to many of
them, that they appeared as white cylinders
by direct light. Some parts of the gland pre-
sented to the naked eye a whiter aspect than
others ; and in them it was seen that the de-
posit of oily matter along the vessels, and the
destruction of the glandular tissue, had pro-
ceeded to the greatest extent. In some places
there were masses of ossiform deposit.

The morbid alteration now described ap-
proaches most nearly, I think, to the vascular
and aneurismatie bronchocele ; but the exten-
sive destruction of the glandular tissue, and
the copious deposit of oily matter, show that
there must have been some grave derangement
of the nutrition of the gland. The case oc-
curred in a female (tet. 75.), who died with

1116

THYROID GLAND.

cirrhosis of the liver and ascites ; the kidneys
contained numerous small cysts, and there
were two fibrinous blocks in the spleen.

Adventitious formations. — Cystic formation
within the thyroid is next described by Pro-
fessor Hasse ; and regarding it as depending
on the development of new cysts within
the gland, and not on the perverted or ex-
cessive action of its own natural vesicular
cavities, it will fall under our third head.

I am, however, rather in doubt whether
most cases of cystic formation in the thy-
roid do not belong to the second category,
and are not dependent on the development
of any adventitious structure. Prof. Plasse
says, “ cystic formation within the thyroid
gland is one of the most frequent causes of
goitre. It occurs both by itself, and in con-
junction with other kinds of degeneration,
and constitutes the largest and most unsightly
of all tumours. Cysts of every variety and
size, either solitary or in congeries, are en-
countered in every part of the thyroid gland ;
an entire lobe, nay, the greater portion of the
whole organ, being sometimes engaged in
cystic development. The surrounding tex-
ture is seldom healthy, being generally com-
pressed, flabby, and bloodless. The cysts are,
for the most part, isolated. Occasionally, how-
ever, they abut one upon another, so as to
form a single multilocular capsule. Here, as
elsewhere, they are composed of two mem-
branes ; namely, an external filamentous, and
an inner serous, one. The external membrane
is either smooth, or sends forth bands which
attach it closely to the rest of the texture;
in many instances it partially, if not wholly,
ossifies. The sac contains a limpid fluid, or
a number of secondary hydatids *, or, again,
a jelly-like substance, but more commonly a
yellowish or whitish crystalline pulp, consist-
ing almost wholly of cholesterine crystals
with phosphate and carbonate of lime. In
some instances the cyst accidentally inflames
and becomes atrophied ; in others it gradually
fills with earthy matter, and is transformed
into a hard calcareous nodule. Cysts occur
in the thyroid gland, in both sexes, and nearly
at all ages; more frequently, however, in
females after the prime of life.” A remarkable
case of cystic formation in the thyroid is
mentioned by Andral. He states that the whole
organ was converted into a cj;st with bony
walls filled with a honey-like fluid. He seems
to recognise both the cystic and melicerous
degeneration as further stages of the per-
verted or excessive action which occurs in
simple hypertrophy, and justly refers to the
case of the ovary as exactly analogous, the
cysts of which, filled with various products,
originate, in all probability, in Graafian vesicles,
which undergo an abnormal development.

Prof. Hasse has never met with tubercles
occurring in the thyroid. Prof. Louis makes
no mention of such an occurrence, nor does
M. Papavoine in a table which he gives of

* Lieutaud mentions a case where the trachea
was perforated by one of these acephalo-cysts.

the seat of tubercle in various degrees, drawn
up from the examination of the bodies of fifty
children.

Sauten has observed that persons affected
with extensive bronchocele seldom or never
become subjects of phthisis.

Carcinomatous growths rarely affect the thy-
roid. Eight cases in 8289 of deaths occur-
ring from cancer in Paris, are ascribed to this
part. * The disease is sometimes primary,
sometimes secondary, or the result of invasion
from some neighbouring affected part.

Encephaloid or scirrhus in several of
their varieties have been known to occur in
the organ, but no example of colloid in it has
yet been detected : of course cysts filled with
melicerous contents must not be confounded
with the loculi of real colloid, to which they
bear some resemblance. Primary cancer in
the thyroid usually exhibits the characters of
scirrhus, secondary those of encephaloid: in
the first case the disease is usually infiltrated,
in the second of the tuberous form. Ence-
phaloid here, as elsewhere, often grows rapidly,
and attains a large size. It seems to ob-
literate entirely the natural appearance of the
gland. It is often of the hcematoid variety, in
which there is sometimes softening in the
centre of the mass, causing rupture of vessels
and extravasation of blood. Occasionally
black pigment is accumulated within its texture
in varying amount, “ Medullary cancer of this
gland must not be confounded with that of the
lymphatic glands of the neck, which often
simulates goitre.”

Enlargement of the Vessels. — The last
kind of morbid degeneration, which the thy-
roid has been observed to undergo, is that
to which the term vascular or aneurismatic
bronchocele has been applied. It is de-
scribed as follows by Professor Hasse, — “ All
the blood vessels are much amplified, the veins
in particular forming very dense, capacious,
often knotted, plexuses, and the whole texture
consisting apparently of adense coil of vessels.
The substance of the gland has almost en-
tirely lost its granular character ; it is flabby
and dark red. After death the tumour col-
lapses considerably, and can only be restored
to its original size by artificial injection. The
walls of the arteries and veins are attenuated,
the dilated membranes of the vessels contain
considerable clots, and capacious cavities are
found filled with black coagulated blood.
Vascularfbronchocele affects the entire gland;
principally, however, one or other lobe. It
occurs most frequently in females after the
prime of life, and is, like simple hypertrophy,
marked by periodical augmentation and de-
crease. Thisgeneral dilatation ofblood-vessels
must not be confounded with the exuberant
vascular (malignant) growth termed fungus
hsematodes, to which the thyroid gland is also
subject.” In the foregoing description we
have clearly set forth the condition of an
organ, the walls of whose vessels have, from
loss of their natural tonicity, yielded to the

* Walshe on cancer.

THYROID GLAND. 1117

impetus of the current of blood, and being
thus enlarged and distended, have pressed
upon the essential structure of the gland, and
caused it to become atrophied.

It may not be amiss to observe, after this
review, that the disease of the thyroid, which
is of by far the most frequent occurrence, viz.
enlargement of its magnitude from excessive
or perverted secretory action, is just of the
kind we should, from our knowledge of its
actual structure, expect would be most liable
to occur. For when once the nicely arranged
balance of secretion and absorption, with its
moderate alternating oscillations in either
direction, is permanently deranged, the closed
cavities of the glandular vesicles afford no
exit to the accumulating matters. Thus does
minute anatomy explain, and thus is it con-
firmed by, the changes wrought by disease.

History of Investigations. — The fol-
lowing is not presented as a complete history
of the thyroid, but as a sketch which it is
hoped contains the principal facts relative to
the advance of our knowledge respecting it.

In examining the works of Aristotle, I find
he makes no mention of the thyroid in two
places, where he describes the organs situated
in the neck, and speaks especially of the
trachea. Galen does not give any very dis-
tinct account of the thyroid, so far as I have
been able to discover ; but certainly seems to
allude to it in a passage in his book “ On the
Use of the Parts of the Human Body,” where
he speaks of the glands of the larynx, “ which
are always found more loose and spongy than
others, and which, by the common consent of
anatomists have been created for the purpose
of moistening and bathing all the parts of the
larynx and the passage of the throat.” The
following passage, quoted also in a note by
Morgagni *, seems to prove that he was aware
of the main peculiarity of the thyroid.
“ Now the neck has two glands, in which a
moisture is generated. But from the two
glands which are in the neck there come forth
no vessels by which the moisture may flow
out, as those do from the glands of the tongue.”
Vesalius, who wrote about a.d. 1542, dis-
tinctly recognises the existence of the thyroid
in the following passage from his work, “ De
corporis humani fabrica.” -f “And this dissec-
tion also shows two glands, adhering one on
each side, to the root of the larynx, which are
of large size, and very fungous, and nearly of the
colour of flesh, but darker, and covered over
with very conspicuous vessels.” In the second
book he describes their appearance in oxen, in
whom they resemble muscular tissue, he says,
very much, while in man their aspect is more
truly glandular. Jacobus Sylvius, who wrote
a little later than Vesalius, enumerates, in his
list of glands, “ duse item ad laryngis radicem
asperoeque arteriae initium utrinque una quse
interdum ob magnitudinem in unam abire
videntur.” Wharton, in his Adenographia,
published about 1656, gives a very full and
good description of the thyroid ; he notices

its situation, figure, magnitude, texture (sub-
stantiam), and consistence (soliditatem) ; and
remarks “ that it is much more full of blood
than any other gland, also more viscid and solid,
and more resembling muscular flesh. This
is the only difference, that it is not of a fibrous
structure, but rather of a glutinous nature.”
He assigns four uses to the gland, which it
may be worth while to quote, as affording an
example of the speculations then in vogue,
the last perhaps being not the least real and
important of those he mentions ! “(1) The

first and principal use of these glands appears
to be to take up certain superfluous moistures
from the recurrent nerve, and to bring them
back again into the vascular system by their
own lymph channels. (2) To cherish the
cartilages to which it is fixed, which are rather
of a chilly nature, by its own heat , for it is
copiously supplied with arteries, and abounds
with blood, from whence it may conveniently
impart heat to the neighbouring parts. (3)
To conduce by its exhalations to the lubri-
cation of the larynx, and so to render the
voice smoother, more melodious, and sweeter.
(4) To contribute much to the rounded con-
tour and beauty of the neck ; for they fill up
the empty spaces about the larynx, and make
its protuberant parts almost to subside and
become smooth, especially in the female sex,
to whom on this account a larger gland has
been assigned, which renders their necks more
even and beautiful.”

Verheyen, writing about 1720, describes
the thyroid as deriving its name from the
cartilage so called, and states that it is con-
sidered by some as double, i.e. consisting of
two glands. He says, “this gland, beyond
doubt, serves also to moisten the neighbour-
ing parts ; but, because it is very large, there
is an apparent reason why it should have
rather large excretory ducts, or one at least
very conspicuous, which yet hitherto has not
been discovered.”

About 1708, Evertzen wrote an inaugural
dissertation on the thyroid gland, noticing its
structure, some diseases to which it is liable,
and their treatment.

Morgagni, in his Advers. Anat. (1723) dis-
cusses two questions respecting the thyroid;
one as to whether the gland is double or
single, i. e. whether the lobes are connected
by an isthmus or not ; this he decides, as re-
spects man, positively in the affirmative. The
other vexcita questio, as to whether the thyroid
be provided with a duct or not, he confesses
to be yet undetermined. He notices the ex-
istence of vesicular cavities in enlarged thy-
roids, which he justly supposes to be the
natural cavities (nativi acini) dilated by their
accumulated secretion. From his examina-
tion of the secretion of the thyroid, “ modern
quendam, et obliniendo lubricandoque ido-
neum, succum communi isti amygdalarum
oleo longe consimilem and from observing
the thyroid to be exposed to the pressure of
contracting muscles, as is the case with some
other undoubted glands, he inclines to con-
sider it probable that the gland has some duct

Advers. Anat. i. c. 26.

f Lib. vi. cap. 4.

THYROID GLAND.

1118

opening into the pharynx, the (esophagus, or
into the top of the trachea.

Santorini (Observ. Anat. 1754), recognizes
the thyroid as a single gland, and makes men-
tion of its median column as previously known
to Morgagni, though it was probably dis-
covered by Bidloo or Lalonette. He details
the failure of his efforts to discover a duct,
though he had several times detected an
orifice at the anterior angle of the glottis, into
which a bristle could be passed ; and yet re-
marks that the thyroid gland may be urged to
expel its secretion by the pressure of the
sub-hyoidean muscles, the throbbings of the
carotids, and the contractions of the ceso-
phagus.

Haller (Element. Physiolog. 1766), in his
account of the thyroid, gives a good descrip-
tion of the median column, and of the several
varieties which it presents ; four times only
has he found it absent ; most frequently
existing on the left side ; sometimes, however,
on the right. He relates some experiments
of Lalonette, in which it appeared as if the
glandular cavities had been distended by
inflation with air, and also the lymphatic vessels
proceeding from them. The result of this coarse
proceeding he explains, and probably cor-
rectly, by supposing that the distended cavities
were those of the areolar texture, and not the
secreting vesicles. He remarks that, even
according to Lalonette’s testimony, no secre-
tion can ever be pressed out of the thyroid
gland into the cavity of the larynx ; or if any
appear it seems to be nothing more than the
contents of some mucous follicles. After
detailing the struggles and efforts of various
anatomists to discover an efferent duct, he
states at last that several inquirers, among
whom he mentions Ruysch in particular, had
adopted the only possible remaining opinion,
that a peculiar fluid was elaborated in the
gland, which being received into the radicles
of the veins, was returned into the blood.
This view, which laborious, and thoughtful,
and sagacious men were then slow to entertain,
is now universally adopted ; and it seems cer-
tainly a matter of wonder that it was not
sooner arrived at. May we not, however,
question whether, in regard to other glands, a
process somewhat similar does not also occur,
— whether certain complementary products of
secretory action are not formed in the gland,
and afterwards absorbed and carried off by
venous and lymphatic radicles?

Meckel’s description of the thyroid is as
complete as could be accomplished by the
most consummate anatomical skill, while un-
aided by the achromatic lens. I need not
refer to his well known pages, further than to
notice a suggestion which he offers, viz., that
as the median column is much more deve-
loped in the infant than in the adult, the
excretory duct may exist at that period (in
the median column), and become obliterated
as age advances.

In proceeding beyond this period, we come
to the anatomists of our own day ; several of
whom have advanced our knowledge con-

siderably respecting the thyroid and other
ductless glands. To none, however, are we
more indebted than to Mr. Simon ; whose
masterly and philosophical Essay on the
Thymus contains the best account of the
anatomy and physiology of these organs that
has yet been given.

Bibliography. — Wharton , Adenographia. Mor-
gagni, Adversaria Anatomiea. Haller, Elementa
Physiologic;!. Meckel and Cruveilhier’s works on
Descriptive Anatomy. Quain and Sharpey’s Ana-
tomy. Todd and Bowman, Physiological Anatomy.
Simon’s paper in Philos. Transact. 1844, on Com-
parative Anatomy of Thyroid. Various parts of the
essay of the same author on the Thymus gland.
Hade, Allgemeine Anatomie. CEsterlen, Beitrage
zur Pliysiologie.

( C. Handheld Jones. )

TIBIO-FIBULAR ARTICULATIONS.

— The bones of the leg, throughout the
greater part of their length parallel and con-
tiguous to each other only, are in contact by
their extremities. At the points of contact the
two tibio-fibular articulations, a superior and
an inferior, are situated.

Superior Tibio-Fibular Articulation.

— l’he head of the fibula is in contact with
the external tuberosity of the tibia. The for-
mer is furnished with an articulating surface
which has an aspect upwards, forwards, and in-
wards, whilst the articular facet on the latter
is placed rather towards the posterior part of
the tuberosity of the tibia, and is directed
downwards, backwards, and outwards. Both
surfaces are almost perfectly plane, their form
is circular, and they are encrusted with arti-
cular cartilage ; hence this articulation is to be
referred to the class arthrodia.

a. The ligaments of this joint are two in
number, named, from their relative positions,
anterior and posterior ligaments.

1. The anterior ligament of the superior
tibio-fibular articulation, is composed of a fas-
ciculus of white fibrous bands, which are all
parallel to each other. It passes from the
tibia downwards and outwards to the head of
the fibula, running in front of the synovial
membrane of the articulation which it defends.
The extensor digitorum communis muscle
covers this ligament anteriorly.

2. The posterior ligament follows a similar
direction on the posterior aspect of the joint;
but the fibres which compose it are neither so
numerous nor so strong as those of the pre-
ceding; this ligament is covered posteriorly
by the poplitasus muscle.

Lastly, the tendon of the biceps ( flexor
cruris ), by its attachment to the head of the
fibula, contributes, in no inconsiderable de-
gree, to the security of the articulation.

b. Synovial membrane. — There is nothing, in
the anatomical disposition of the synovial
membrane of this articulation, which requires
any particular notice ; but the surgeon should
remember that it is always in close proximity
to the serous sac of the knee joint, and that
in many instances the two synovial membranes
communicate with each other. The synovial

TIBIO-FIBULAll ARTICULATIONS. II 19

membrane of the knee joint is brought into
this close relationship with that of the tibio-
fibular articulation, by means of a prolonga-
tion which passes downwards from the former
around the tendon of the poplitaeus muscle ;
and when a communication does exist between
the two articulations, it will therefore be found
at the posterior aspect of the head of the
fibula.

This anatomical arrangement has an import-
ant bearing on a disputed point of practice,
viz. the extirpation of the head of the fibula
in amputations of the leg near the knee joint.
This proceeding, recommended originally by
Larrey and Garriques, and subsequently re-
vived by Mr. Guthrie, has been opposed by
Mr. Adams of Dublin, who, appealing to the
anatomical peculiarities just described, makes
them the grounds for rejecting altogether the
innovation in question. ( Vide “Abnormal
Condition of tub Knee Joint,” vol. iii.
p. 50.)

Inferior Tirio-Fibular Articulation.
— This articulation is intimately connected
with that of the ankle, from which, although
anatomically distinct, it cannot virtually be
separated.

The tibia and the fibula, at the lower part of
the leg, are closely connected for a consider-
able portion of their extent. The tibia pre-
sents, on its external aspect and inferiorly, a
triangular-shaped surface, two inches in verti-
cal height, and concave from side to side :
superiorly, or towards the apex of this space,
it presents a rough and scabrous surface ; but
inferiorly it is smooth and encrusted, in the
recent state, with articular cartiiage. The
inner surface of the lower end of the fibula is
of similar shape, but convex ; it is rough su-
periorly, and smooth inferiorly. Here the two
bones form an arthrodial articulation.

a. The cartilage, which in this situation in-
vests the opposed surfaces of the tibia and
fibula, is continuous with that which covers
the inferior surface of the tibia. It is also lined
by — b. — synovial membrane prolonged upwards
from the ankle joint, and which forms a small
cul-de-sac in the tibio-fibular articulation.
The rough irregular surfaces, on the bones
above the line of reflexion of the synovial
membrane, have the fibres of a strong inter-
osseous ligament implanted into them.

c. The ligaments of the inferior tibio-fibular
articulation are three in number ; 1 .an ante-
rior, 2. a posterior, and 3. an interosseous.

1. Anterior tibio-fibular ligament. — The fibres
of this ligament pursue a direction downwards
and outwards, from the anterior margin of the
small articulating surface on the tibia to the
outer malleolus ; and as the lower margin of
this ligament projects below the level of the
tibia, it deepens somewhat the cavity for the
reception of the astragalus. The tendon of
the peronaeus tertius muscle covers this liga-
ment in front.

2. Posterior tibio-fibular ligament. — This is a
strong, round, fibro-cartilaginous cord, which
passes from one malleolus to the other in an
arched manner, having a concavity directed

downwards, and connected with the posterior
ligament of the ankle joint, and a convexity
which adheres uniformly to the posterior arti-
cular margins of the tibia and fibula. This
ligament not only connects the two bones to
each other, but it also, like circumferential
fibro-cartilages elsewhere, serves the purpose
of deepening the mortice-shaped cavity of the
ankle joint which it borders. It likewise pre-
vents the immediate contact of the osseous
surfaces in forced extension of the foot, being
interposed between the bones as an elastic
cushion.

3. Interosseous tibio-fibular ligament. — This
is composed of short transverse bands firmly
implanted, at right angles, into the opposed
rough surfaces on the bones already described.
Superiorly, the fibres of this ligament extend
nearly as far as the lower margin of the inter-
osseous membrane, (separated from it by a
small interval, through which passes a branch
of the fibular artery), whilst inferiorly they
are limited by the direct contact of the two
bones of the leg, which they serve to bind
firmly together. In order to exhibit this
structure, either of two methods may be
adopted ; the bones of the leg may be sawn
across about their centres, and then forcibly
torn asunder, (in this way the ligament may be
seen, and its powers of resistance appreciated),
or the ligament may be exhibited in situ, by
making a vertical, transverse, section of both
bones, traversing the two malleoli, and also
the joint of the ankle.*

Mechanism of the tibio-fibular articulations.
— The movements of the fibula on the tibia are
extremely limited ; this is in accordance with
the general plan on which the skeleton of the
lower extremity is formed, its use being to
serve as an organ of support, and of locomo-
tion, only. The bones of the leg are connected
together by the intervention of ligaments, (not
consolidated together as in the arrangement
met with in a few of the Mammalia), and thus
a greater degree of elasticity is obtained without
any sacrifice of strength ; and it may be pre-
sumed that the slight degree of yielding and of
gliding motion, which is permitted in the tibio-
fibular articulations, may occasionally serve to
diffuse, and to lessen the intensity of shocks
applied to the lower extremity, and may thus
diminish its liability to injury, especially to
fracture.

Dislocation of the fibula, at the upper
tibio-fibular articulation, has occasionally, but
rarely, been met with as the result of injury.
Sir A. Cooper mentions a case of compound
fracture of the tibia, where this complication
was observed ; but the rarity of dislocations
in this situation, is accounted for by the cir-
cumstance, that the fibula, owing to its com-
parative slightness, almost invariably breaks,
on the application of a force far short of what
suffices to rupture its ligamentous connections
with the tibia.

The mechanism of the inferior tibio-fibular
articulation is inseparably connected with

* See fig. Cl. p. 1C3. vol. i.

] 120

TONGUE.

that of the neighbouring articulation of the
ankle. In fact, on the perfect adaptation of the
bones of the leg, at their lower extremities,
essentially depends the integrity of the ankle
joint itself.

By the union of the tibia with the fibula
the “mortice shaped” cavity, which receives
the pulley of the astragalus, is formed, and
any injuries which disturb the natural rela-
tions of these two bones interfere propor-
tionally with the functions of the ankle, which
is a perfect angular ginglymus.

Hence it is, that in some cases of fracture
of the lower end of the fibula, a widening of
the mortice is produced, from which more or
less of permanent deformity and inconve-
nience results, abnormal lateral motion being
then permitted. The connecting media be-
tween the tibia and the fibula inferiorly are of
extreme strength ; so much so, that no ordinary
violence seems capable of rupturing them ; the
bones being bound together, not only by the
special ligaments of the inferior tibio-fibular
articulation already described, but by the
annular ligaments and fasciae of the leg also.
Hence, as we might infer, the separation of
these bones by injury has never been observed,
except when the fibula has first been broken.
In the “ complete dislocation of the ’foot up-
wards and outwards, we are furnished with an
illustration of the immense strength of the
interosseous ligament ; as it is found that even
in this severe injury the fibres of this ligament
are not usually torn ; but the rough surface of
the tibia into which they are implanted is
broken off, and carried upwards and outwards
with the lower end of the fibula, to which the
interosseous ligament still binds it.” (See b.
fig. 54. vol. i. page 157 ; article “ Abnormal
Conditions of the Ankle Joint.”)

(Ben. George M‘Dowel.)

TONGUE. (rXwiTcra, Gr. ; Lingua, Lat. ;
la Langue, Fr. ; Zunge, Germ. ; Lingua,
Ital.) The tongue is a symmetrical muscular
organ, situated in the middle line, at the ori-
fice of the gastric portion of the gastro-
pulmonary mucous membrane, invested with
the mucous surface, and subserving to the
earlv stages of the process of digestion.

Human Anatomy. —The human tongue
(in common with that of all mammalia)
consists of, first, an osseous basis, itself
movable, to which it is attached, and with
which and on which it moves ; secondly, a
muscular system, in part extrinsic, serving to
attach it to certain fixed points and to move
it on them, and in part intrinsic, constituting
the bulk of its substance and moving it on it-
self; thirdly, a mucous investment, variously
modified in different parts ; fourthly, a pro-
per system of mucous glands ; fifthly, a small
quantity of fibrous and areolar tissue ; sixthly,
a still smaller quantity of fat ; seventhly, a
large vascular supply ; and eighthly, an abun-
dant distribution of nerves from three separate
sources.

Size. — The size of the tongue is very va-
rious. I have examined some tongues of

adults that certainly were not more than half
the size of others, and there does not seem to
be any relation between the size of the tongue
and that of the individual; but between it
and the size of the alveolar arch there is a
close relation, and hence we see it generally
much smaller in women than in men. It has
been generally stated that certain obscurities
in speech are caused by too large a tongue,
but there do not seem to be any well authen-
ticated cases to prove that this supposition is
correct. It may in some degree be explained
by the fact, that paralysis, which would cause
a thickness of speech, would also cause a
flaccid half-protruded condition, and, there-
fore, an apparent increase of size, of the
tongue.

Direction. — In its anterior half it follows
pretty much the direction of the lower jaw,
that is, it tends forwards and a little down-
wards, but behind this it curves downwards
and backwards, and ere it reaches the os
hyoides has become quite vertical, so that the
average of its direction would be downwards
and backwards, and its posterior extremity
much lower than its anterior.

Shape. — The tongue is of an ovoidal shape,
the broad part being behind ; and the character
of the curvature in front is parabolic, coin-
ciding with the parabolic curve of the lower
jaw : it possesses an exact lateral symmetry,
and is flattened from above downwards, being
thickest towards its base, and thinnest in
front. When taken out of the body it seems
to be flat, and in the same plane longitudin-
ally, but when in situ it possesses a double
curvature; one longitudinal, the most consi-
derable, by which the upper surface is rendered
convex, and by which the posterior part of
the tongue is bent from a horizontal to a ver-
tical direction ; the other, less considerable,
affects the tongue transversely, and renders
its posterior part concave in that direction :
it is much increased by the contraction of the
genioglossi, which draw the centre of the
tongue down, or by that of the styloglossi,
which draw its sides up. The longitudinal
curvature, too, is very much affected by the
position of the tongue, for when it is thrust
forward, and the hyoid bone raised, the whole
organ is much more horizontal, and the cur-
vature almost effaced.

General description. — In consequence of
its possessing a long axis, and being vertically
flattened, the tongue presents for description
a superior and inferior surface, two lateral
borders, and an anterior and posterior extremity.

The superior surface, borders, anterior ex-
tremity, and anterior third of the inferior sur-
face are free ; the posterior extremity and
posterior two thirds of the inferior surface are
attached. Along the line where the free and
attached surfaces meet, we see the investing
membrane leaving the tongue, and passing off
to neighbouring structures, investing the loose
areolar tissue by which in these situations it
is underlaid, and forming a system of yielding
and movable attachments. Thus at the base
the mucous membrane passes off to the an-

TONGUE.

terior surface of the epiglottis, the sides of the
pharynx, and upwards to the soft palate and
posterior parts of the cheeks. As we proceed
forwards we find it investing the sides, and
gradually more and more of the under surface,
reflected thence over the hyoglossi and ge-
nioglossi muscles, the sublingual glands,
vessels, and nerves, and much areolar tissue,
which separate it from the mylohyoid muscle,
to the inner surface of the alveoli of the lower
jaw, where it becomes continuous with the
mucous membrane covering the gums.

At certain points where this membrane
leaves the tongue it forms distinct folds, which,
from their being constant, have received par-
ticular names, and which act to a certain ex-
tent as ligaments or frena of the tongue, not so
much by virtue of their being folds of mucous
membrane, as from their containing within
their reduplications a certain amount of a
more or less unyielding tissue ; in some this
tissue is a mixture of white and yellow fibre,
in others it is muscle.

Of the first sort are three folds, a middle
and two lateral, passing from the base of the
tongue to the epiglottis, called the g/osso-
epiglottid folds, of which the central, which is
always present, and has been called the pos-
terior franum of the tongue, and fr cerium epi-
glottidis, is much the most considerable (fig.
745. d.) : they serve rather to check the move-
ments of the epiglottis than as lingual liga-
ments. Front the sides of the base of the
tongue, passing thence to the soft palate, are
seen four more folds, two on each side, which,
from their position, have been called the
pillars of the fauces. They are formed by the
raising of the mucous membrane from the
general surface by two muscles: the posterior,
the least considerable, by the palato-pharyn-
geus ; the anterior, more marked, by the
palatoglossus. The interval between these
two is called the amygdaloid fossa, from its
being occupied by the amygdalae, or tonsils :
the anterior pair taken together constitute the
constrictor of the fauces, and the narrowing
caused by the whole apparatus has received
the name of the isthmus faucium. From the
basis of these folds being muscular their pro-
minence is liable to constant variety. But
the most considerable of these folds, which is
called, par excellence, the freeman of the tongue
(freenum, frenulum Ungues'), is placed beneath
the anterior free extremity, which it connects
with the lower jaw. It consists of a prolonga-
tion forwards, beyond the free border of the
genioglossi, of the median fibrous lamina, which
raises into a prominent fold the mucous
membrane passing from the under surface of
the anterior part of the tongue to the neigh-
bouring alveoli of the lower jaw : it forms
a strong ligament, and limits the backward
movement of the anterior extremity of the
tongue. Sometimes an extreme shortness
of this ligament is a congenital malformation,
preventing the free movement of the organ,
and so impairing speech, mastication, &c., as
to necessitate the operation known as cutting
the tongue.

VOL. IV.

1121

Before entering into the specialities of the
anatomy of the tongue, let us examine its

Fig. 745.

Human tongue viewed on the upper surface or
dorsum. (After Soemmering.)

general configuration and external characters,
taking its surfaces, extremities, &c., in the
order above enunciated.

Superior surface. — On regarding the upper
surface of the tongue, we see first that it is
divided into two symmetrical portions by a
median longitudinal furrow (fig. 745. c.), com-
mencing at the tip, and extending back about
two thirds the length of the organ. It is
superficial when present, but in many cases
does not exist : it is the representative, in this
part, of that median line which symmetrically
divides all those organs of animal life that are
situated in the middle vertical plane. It is
very generally, but very incorrectly, stated*
that this furrow terminates posteriorly in the
foramen caecum. The two have no relation ;
the one often exists without the other ; and
in every case that I have seen, the foramen
has been separated from the posterior ter-
mination of the furrow by the ridge of the
circumvallate papillae, sometimes by a long
interval. This median furrow seems partly
formed by the action of muscles, and partly
by a deficiency of papillae. Another con-
spicuous character of the upper surface is,
that the roughnesses with which it is covered
are arranged in lines (fig. 745.), with a
direction obliquely forwards and outwards, so

* Bichat, Traits d’Anatomie, t. ii. p. 594.

4 c

1122

TONGUE.

that there is formed in the median line a
series of angles pointing backwards. This
disposition is seen to affect, more or less, all
the structures with which the surface is
covered. Thirdly, the upper surface of the
tongue is seen to be divisible into a smooth
and a rough portion. The smooth, or non-
papillary portion, occupying nearly the pos-
terior third, is characterised by smooth nodular
rugosities (fig- 745. <?), formed by small mu-
ciparous glands, which are abundantly dis-
tributed beneath the surface, and occupy the
whole space between the papillae and epi-
glottis : they are smallest and most scattered
behind, where they are gradually lost ; larger
and more prominent in front, where, from
their being disposed in the direction already
indicated, they form a prominent V-shaped
ridge with the opening directed forwards.
Just in front of this, separated by a groove, is
another V-shaped ridge, more definite, but
less constant in shape, formed by two con-
verging lines of button-like eminences, each
surrounded by a circular raised border of
more or less regularity ; these compound
organs are the circumvallate papilla (fig. 745.
ff). At the angle formed by the convergence
of their two rows, generally a little behind
that angle, is situated a cul-de-sac of very
variable size, which has received the name of
foramen ccecum ( le trou borgne, lacune de la
langue ), and which was formerly regarded as
the orifice at which several convergent sali-
vary ducts terminated* ; these supposed sali-
vary ducts were afterwards shown by Duver-
noyf and Haller J to be merely small veins.
Meckel considered that this foramen caecum
was nothing but a largely developed calyx of
a caliciform papilla, of which the central
portion was small, or wanting, or misplaced ;
that if the central eminence was well de-
veloped and in its proper situation, the
foramen caecum was wanting, and that it only
existed from some of the irregularities above
mentioned; an opinion adopted by Cruveilhier,
and by Professors Todd and Bowman in this
country. Meckel states that he has seen two,
one a great way behind the other. I have
more than once met with the same appear-
ance. In these cases the anterior one has
always contained a well developed papilla.
It can evidently perform no essential office, as
it is so often wanting. The whole of the su-
perior surface of the tongue, in front of the
circumvallate papilla:, comprising its anterior
two thirds, is covered by an investment of
coriaceous or filamentous asperities, longest in
the central parts, and arranged with the most
regularity at the back, where they are dis-
tributed in lines of more or less distinctness,
with a direction obliquely forwards and out-
wards (fig. 745. ii.). These eminences are
seen to be of two sorts ; one of a spheroidal
shape, distinguished during life by their red

* Coschwitz, De Ductu salivali novo. Halle,
1724.

f Loc. cit.

i Exp. et Dub. circa Ductum Coscliw. Leyden,
1727.

colour, and scattered here and there at the
posterior part, edges and tip, — these are the
fungiform papilla (fig. 745. h.) ; the others,
occupying the whole of the rest of the sur-
face, are the conical and filiform. To the
minute consideration of these structures a
future part of this article will be devoted.

Inferior surface. — This surface is attached
in its posterior two thirds by the muscles
passing from it to the hyoid bone and lower
jaw. The most posterior part of this attach-
ment is as wide as the tongue itself, so that
there no portion of the inferior surface is
free ; but in front of this the attachment
narrows, so that the lateral portions become
increasingly free till they meet at the fraenum,
in front of which they involve the whole
surface. The longitudinal furrow is much
more distinctly marked here than above, and
is constant : it passes from the tip, on which
it is continued, to the fraenum. On each side
of the furrow the ranine veins are seen pass-
ing forwards, and immediately beneath the tip
is a little cluster of mucous glands first de-
scribed by Nuck*, and also by Nuhn.f The
mucous membrane here is quite smooth and
free from any visible papillae.

The edges of the tongue, which separate
its upper and under surface, are thick behind
and gradually become thinner in front; they
are marked by a series of vertical ridges,
separated by corresponding furrows, very dis-
tinct on the upper, and gradually becoming
lost as they approach the under, surface.
They are very conspicuous at the posterior
part, but disappear anteriorly, and they differ
very much in their development in different
subjects. They are, essentially, fused conical
papillae. At the upper and posterior part of
the edges are also a series of small mucous-
glands.

The anterior extremity, apex, or point (fig.
745. b.), is flattened or rounded, blunt or
pointed, according to the movements of the
tongue, and slightly impressed by the median
furrow which is continued on it : it is not
marked by any of those vertical ridges that
characterise the edges.

The posterior extremity, or base. — Ere the
tongue reaches the os hyoides it becomes very
flat and thin, and this from two causes — di-
minution in the quantity of the intrinsic mus-
cles, and the passing off' of the extrinsic in
other directions ; so that instead of being
very thick, as is generally described, the base
is in reality the thinnest part of the whole
organ. It is flattened antero-posteriorly and
much extended laterally, and by its attach-
ment to the hyoid bone is curved in a horse-
shoe shape, which, however, is much effaced by
the insertion ot the epiglottis in the area of
the curvature. It is constituted laterally by
the hyoglossi, centrally by the hyoglossal liga-
ment, anteriorly by some fibres of the genio-
glossus, and behind and above by the mu-
cous membrane passing from it over the

* Sialograpliia, Ductuum aquosorum anatome
nova. Leyden, 1690.

f See Art. Salivary Glands, p. 426.

TONGUE.

epiglottis. It contains less muscular and more
fibrous tissue than any other part of the
tongue.

Such, then, is a general description of the
tongue, — such are the appearances that pre-
sent themselves to the eye, on regarding its ex-
ternal surface and configuration. Let us now
examine these structures more minutely, and,
to facilitate that examination, arrange the parts
that contribute to the formation of the organ,
according to the office the}’ fulfil, or their
absolute nature.

Regarding the tongue in this light, we find
that it may be considered as consisting of
three systems , —

1 . A basis, or system of support.

2. A muscular system , or system of move-
ment.

3. A tegumentary investment, or system of
sensation and protection.

1. Basis, or framework of the tongue. — This
consists of the hyoid bone, the hyoglossal
membrane or ligament, the median fibrous
septum (the cartilaginous lamina of M. Blan-
din), and, fourthly, to these may perhaps be
added, on account of its density, and its giving
attachment to most of the intrinsic muscles,
the compact fibrous tissue, or cutis, beneath
the mucous membrane.

Hyoid hone. A. seen from above, and B. in profile.

(. Natural size').

a. The hyoid bone (os hyoides, — upsiloides,
— lingualis, — linguae), called also the lingual
or tongue bone, has received its name from its
resemblance to the Greek u ; it is the homo-
logue in man of a very complex mechanism
in the lower vertebrata, from which circum-
stance it is sometimes called the hyoid ap-
paratus. It consists of a bony arch, with a
curvature nearly approaching a parabola, the
convexity being in front ; — situated in an
almost horizontal position behind and rather
below the lower jaw. In the lower ver-
tebrata the hyoid bone is connected to the
rest of the skeleton by bony media ; in man,
by the substitution of a ligament (the stylo-
hyoid) for a part of this osseous connection ;
it is isolated, and disconnected from all

1123

the other bones.* It performs the triple
office of a basis of the tongue, a point of
support to the larynx, and a point d'appui or
fulcrum, by which the contractions of the
intrinsic muscles of the tongue and larynx
may be impressed on those organs : it may
also be looked upon as the first part of that
framework (afterwards generally continued
by cartilage) which secures the permanent
patulence of the respiratory passages. It is
retained in its place by muscles and ligaments,
which, converging to it from different direc-
tions, effectually prevent its displacement :
thus it is tied upwards and backwards by the
ligament and muscles from the styloid process,
in front by the muscles from the chin and
lower jaw, below by those from the thyroid
cartilage, sternum, and scapula. Placed be-
tween the tongue and larynx, it impresses on
each the movement of the other, and is the
medium by which the motions of these two
organs are so intimately associated.

Relations. — Its whole external surface is
devoted to muscular insertions, which separate
it, anteriorly and laterally, from the cutaneous
structures. Behind, it is in relation with the
epiglottis, from which it is separated by some
dense cellular tissue, and by the thyrohyoid
membrane, and with the mucous membrane of
the pharynx.

In man the hyoid bone consists of five
pieces, — the basis or body, two greater cornua
which project backwards from the sides of the
body in a direction nearly horizontal but a
little upwards, and two lesser cornua, sur-
mounting the body and greater cornua at the
point of their union.

The body is quadrilateral, compressed an-
tero-posteriorly, curved, and laterally ex-
tended. Its anterior surface looks upwards, is
convex, and intersected by two irregular ridges,
a vertical and horizontal, which at the point of
their union project in a prominent tubercle,
which is the analogue in man of an additional
element of the hyoid apparatus in the lower
animals — the true lingual bone ( glossohyal ) :
this tubercle is sometimes bifurcated. The
portion above the transverse ridge is directed
much more upwards than that below, so that
it has sometimes been called the upper sur-
face : in that case the portion below is de-
scribed as the whole anterior surface, a cir-
cumstance which has led to much confusion
with regard to the nomenclature of muscular
insertions into this bone. The posterior surface
is concave, and looks downwards ; it is marked
by many little foramina entering the cancellous
structure, and is sometimes covered by a syno-
vial membrane. The lateral surfaces, small and
articular, are connected to the anterior ex-
tremities of the greater cornua by a lamina of
temporary cartilage, which, however, is seldom
completely ossified, and which admits a certain
amount of movement between the different

* In some rare cases this ligament has been
ossified, and then the condition of the os hyoides is
the same as that found in most quadrupeds, fish,
and reptiles.

4 C 2

1124

TONGUE.

parts. The superior border presents a double
curvature, something like the upper lip of the
mouth, i. e., it curves downwards at its ex-
tremities, and has a little dip in the middle.
The inferior border, of less extent, is thinner,
horizontal, and placed on a plane anterior to
the upper.

The greater cornua are at least half as long
again as the body, from the sides of which
they project, at first a little outwards and
then backwards; they possess a shaft and two
extremities. The anterior extremity is large,
club-shaped, tuberculated, and curved in-
wards towards the body, for its attachment
with which it presents an articular facet ; the
shaft tapers gradually posteriorly, and is la-
terally flattened, so that it has an outer and
inner surface, and an upper and lower border.
Its outer surface, which is continuous with
the anterior surface of the body, looks a little
upwards ; its lower border is smooth and
rounded; its upper border sharp, and, from
the obliquity of the surfaces, of less extent
than the lower. The posterior extremity is
expanded into a little tubercle, sometimes sur-
mounted by an epiphysis.

The lesser cornua (ossa pisiformia lingualia,
of Soemmering) are two little pyramidal or
pisiform nodules, projecting upwards, out-
wards, and backwards, from the point of
union of the greater cornua and body : they
are seldom completely ossified. They are
the homologues in man of a very considerable
process ( the ceratohyal ) in the lower animals,
in some of whom the proportion between the
lesser and greater cornua is inverted.

Structure — Chiefly compact, but a little
cancellous in the body and large extremity of
the greater cornua.

Development. — From five points ; one for
each element. Vesalius saw a case in which
there were six, there being two for the body.
The ossification commences in the greater
cornua ; it then takes place in the body,
where it begins soon after birth ; and, finally,
in the lesser cornua, where it does not com-
mence till some months after. It proceeds
but slowly, and generally leaves a thin lamina
of cartilage unossified, so that complete an-
chylosis of the different parts into one bone is
comparatively rare.

The morphological value of this bone and
its homological relations, will be treated of
hereafter.

b. The hyoglossal membrane or ligament.
— This is a vertical transverse lamina of very
dense areolar tissue, containing a large pro-
portion of the yellow element, passing up-
wards from the upper border of the body of
the os hyoides to the tongue, between which
it constitutes a means of union. ri he mus-
cular connection of the tongue with the
hyoid bone by means of the hyoglossus is
deficient in the central part of the body of
that bone, and, consequently, this ligament is,
in that situation, the only direct bond of
connection. It is dense, yellow, and very
elastic, and has a little fat dispersed among it,
though this is denied by Bichat. It may be

traced upwards into the tongue, sometimes as
far as an inch. It receives on its anterior
face those fibres of the genioglossus that
lie immediately above those that are inserted
into the hyoid bone, and also some of the
intrinsic longitudinal fibres of the tongue that
terminate upon it ; posteriorly it is in relation
with the upper part of the epiglottis and the
mucous membrane reflected upon it from the
tongue ; in fact, it immediately underlays the
glosso-epiglottid folds. Above, it is gradually
lost in the muscles of the tongue; below, it in
part terminates in the upper lip of the body of
the os hyoides, and in part is continued on
behind this bone, constituting the yellow elas-
tic tissue already referred to as being inter-
posed between it and the epiglottis. This
ligament has been well described by Bichat.*

c. Median fibrous septum ( median carti-
laginous lamina, Blandin). — Springing from
the anterior surface of the last-mentioned
structure, interposed between the two ge-
nioglossi muscles, passing forwards between
these two muscles as far as their genial origin,
upwards to the dorsum of the tongue as far
forwards as its centre, and thence to the
anterior free border of the genioglossi, and
a little beyond that border, is a vertical
lamina of fibrous tissue. It is thick and dense
behind and below, but gradually becomes
thinned out as it spreads upwards and for-
wards; as it gets thinner it becomes cribriform,
like the septum of the corpora cavernosa
penis, the areolae giving transmission to the
transverse muscles of the tongue, which pass
through it from side to side. It varies much
in different individuals; in some it is tolerably
dense, in some it is merely a fine areolar web.
This structure M. Blandin has dignified with
the name of “ median cartilaginous lamina ,” and
has described it as consisting of a vertical
sheet of that substance of more or less extent.
I have, however, looked in vain for any thing
like cartilage or fibro-cartilage in any part of
it. It appears to me to he nothing more than
intermuscular areolar tissue in rather greater
amount and density than usual, which hap-
pens to be placed in the median plane. It
has been supposed by some to be the analogue
of the small fusiform slip of cartilage placed
beneath the extremity of the tongue in the
dog and wolf, with which, however, it has
no relation : that structure is essentially dis-
tinct. Others have found in it the analogue
of the lingual bone, a conception still more
far-fetched. It has been supposed to give
origin to muscular fibres by its two surfaces.
This I have failed in detecting; certainly it
does not give attachment to any of the trans-
verse fibres of the tongue, to which it might
be supposed it would, if to any ; for they
may be seen, by transverse sections viewed
with the microscope, to pass, without excep-
tion, from side to side of the tongue, without
any break in their median plane.

d. Lastly, the investments of the tongue, in-
cluding the papillary structures and the true

* Traite d’Anatomie, t. ii. p. 596.

TONGUE.

cutis underlaying them, may he looked upon,
in one light, as a part of the framework of the
organ. They form a dense and unyielding
envelope, tending to preserve its shape and
give it firmness and support, and at the same
time affording attachment to a great number
of its muscular fibres.

Such, then, is a concise description of the
framework of the tongue. The first and last-
mentioned elements of it are, doubtless, the
most important; but it will be seen, at a
future page, that the intrinsic arrangement of
the tongue’s muscular fibres is such that they
mutually support each other, and tend to keep
the organ firm and compact, which obviates
the necessity of any considerable structures
especially destined for that purpose.

2. The muscular system. — Constituting
the chief bulk of the tongue, imparting the
required consistence to it, performing the ma-
jority of its functions — prehension, mastica-
tion, deglutition, speech, — and necessary even
to the perfection of taste, the muscular sys-
tem of the tongue may be considered the most
important of all.

The muscles of the tongue are of three
sorts, and admit of the following arrange-
ment :

a. Intrinsic.

h. Extrinsic.

c. Accessory.

The intrinsic muscles are those which form
the substance of the organ, that pass from
part to part of it, and that move the tongue
on itself.

The extrinsic (proper') are those that, as
well as entering in some degree into the sub-
stance of the tongue, pass from it to neigh-
bouring fixed points, to which they? attach it,
and on which they move it.

The accessory are those which, though not
contributing in any degree to the formation
of the tongue, nor attached to it, are yet
engaged in all its extrinsic movements, acting
as coadjutors to those proper extrinsic mus-
cles whose direction coincides with theirs.

Of the two first I shall speak particularly :
little more than their enumeration will suffice
for the last.

a. Intrinsic muscles of the tongue. — There
are three methods of investigating the arrange-
ment of the tongue’s intrinsic muscular struc-
ture : first, by the ordinary method of dissec-
tion, or separation ; secondly, by making
sections in different planes, and examining
the appearance of the cut surfaces ; thirdly,
by the microscopic examination of thin sec-
tions. The first, which is the oldest, is that
by which we gain the least information ; and
to its adoption must be attributed the fact that
so many of the older anatomists were in the
dark on this subject. By it we merely learn
the following facts : that certain of the ex-
trinsic muscles pass into the substance of
the tongue and contribute to certain of
the intrinsic ; that the direction of most of
the superficial fibres is more or less longitu-
dinal ; that the direction of the more deep-

1125

seated fibres is not longitudinal; that it is
complex, and incapable of demonstration by
separation.

The second method furnishes much more
certain information. By making the sections
in different planes, we vary the point from
which we regard them ; and the section made
in one plane corrects, and supplies the defi-
ciencies of, the other. The transverse vertical
section is the most important ; and to this I
shall chiefly? refer.

On making a transverse vertical section of a
human tongue, at a point just behind the ante-
rior free margin of thegenioglossus {fig. 747.),
the following are the appearances. Imme-
diately within the cutis, w'hich is seen to be to-
lerably thick, especially at the centre of the dor-
sum ( fg . 747. a.), is seen a dark red stratum.

Fig. 747.

a

Transverse vertical section of human tongue just
behind the free portion.

a, upper surface, showing the thickness of the
cutis there ; b, cortical portion ; e, central portion,
where the vertical fibres are seen crossing the
transverse ; d, genioglossi muscles ; e e, sub-
lingual glands.

also thick in the last-mentioned situation,
thinner at the lateral regions, and again thicker
as it curves inwards on each side of the in-
ferior surface. This is very dense, and cuts
with a perfectly even surface. I shall call it
the cortical portion (fig. 747. h.). Within this
and surrounded by it as by a border, is an
area of a more or less oval form, of a paler
colour, less dense, and showing a distinctly
fibrous character. The fibres appear for the
most part transverse (fg. 747. c.), horizontal
in the centre, but curved up a little on each
side. They are bounded on all sides by the
cortical portion. Entering the centre of the
bottom of the section, passing vertically up-
wards, crossing the last-mentioned fibres at
right angles, and terminating in the superior
surface of the cortical portion, are seen the
two genioglossi muscles (fig. 747. d.). These,
therefore, constitute a vertical set of fibres ;
but they are not the only vertical fibres ; at
each side of them, especially at the inferior
portion of the section, other vertical fibres
are seen passing upwards and a little inwards,
and intersecting the more lateral portions of
4 c 3

1126

TONGUE.

the transverse at right angles.* Ctuveilhier
has erroneously described them as passing
downwards and inwards: their divergence as
they pass downwards is very conspicuous.
The central area — the lingual nucleus ( noyau
lingual) of Bauer, — is therefore constituted
of two sets of fibres, a ventrical and trans-
verse ; the transverse being entirely intrinsic,
and the vertical in part intrinsic and in part
derived from the genioglossus.

A section made anterior to the free margin
of this last-mentioned muscle, shows the cor-
tical portion continued completely round the
tongue, without the break on its inferior sur-
face, occasioned, in the previous section, by
the entrance of the genioglossi muscles ; it
is also of greater thickness in proportion to
the central part, which is comparatively small,
and the transverse fibres have a less marked
upward curvature at their extremities.

Thirdly, a section made near the base of the
tongue shows the cortical portion nearly lost
at the upper surface, greatly accumulated at
the sides, but not of so compact a nature as in
more anterior situations ; the obliquely ver-
tical fibres tolerably abundant, but the trans-
verse nearly lost, and the greater part of the
inferior surface occupied by the expanded
genioglossi.

Transverse vertical sections, therefore, dis-
play two sets of fibres, a vertical and a trans-
verse, and shew their situation and quantity;
let us now see what additional light will be fur-
nished by a longitudinal vertical section. It
shesvs that the cortical portion consists of lon-
gitudinal fibres, and thus supplies a third set.
If the section be made in the middle line, or
near it, the whole cut surface is occupied by
the vertical fibres of the geniohyoglossus, at
first directed backwards, but curving upwards
so as to enter the tongue vertically, in which
vertical direction they are continuedup through
its entire thickness, and are lost in the longi-
tudinal fibres of the cortical portion ; if the
section is made in the lateral portions, it shows
the vertical striation occasioned hy the in-
trinsic vertical fibres, and the cortical portion,
as in the other. Having ascertained the si-
tuation and direction of the three sorts of
fibres, we may, by making transverse sections
at all points from the apex to the base, and
longitudinal ones at various distances from the
vertical median plane, and also by tracing the
extrinsic longitudinal muscles into the intrinsic,
and seeing what part of the one the other fur-
nishes, get an exact interpretation of them.
We should then find the tongue to consist of
the following muscles.

a. A. transverse lingual f, altogether intrinsic,

* Theile denies the existence of the intrinsic
vertical fibres ; he says that those seen in longi-
tudinal section are the ascending fibres of the genio-
glossus, and those seen besides them in trans-
verse sections are the most oblique of the transverse ;
— a misconception of which the microscopical ex-
amination of sections at once shows the fallacy.

f The adoption of the word lingual for all the
intrinsic muscles of the tongue, from the French
writers on this subject, has no objection against it,
and lias the advantage of brevity.

inserted on each side into the submucous
fibrous tissue or cutis, continued from apex to
base, more abundant anteriorly, where it is
horizontal, becoming more curved upwards as
we proceed backwards, and being lost at the
base.

/3. A vertical lingual, in part intrinsic ; in part
the lingual portion of an extrinsic muscle,
the genioglossus, existing from apex to base,
in all parts vertical to the surface, and there-
fore, from the curved direction of the tongue,
arranged in a more or less radiating or fan-
like manner.

7. A superior lingual, longitudinal, in-
trinsic, thin behind, thicker in the middle,
and thinner again at the apex, arising from
the hyoglossal membrane and cutis at the
base of the tongue in a gradual way, and
having a similar cutaneous insertion on the
upper surface of the tip and neighbouring
parts.

5. A lateral lingual, longitudinal, altogether
extrinsic in its origin ; derived from two prin-
cipal sources ; one, its upper and most super-
ficial portion from the fibres of the stylo-
glossus, which pass forward on the side of the
tongue after the insertion of that muscle into
it, the other from the anterior fibres of the
hyoglossus which have a similar distribution :
to this may be added a slender fasciculus of
fibres interposed betvveen the styloglossus and
hyoglossus, which many modern anatomists *
have described as the lingual muscle. The
muscle thus formed constitutes the accumula-
tion of longitudinal fibres before referred to
as seen at the sides of a transverse vertical
section of the base ; passing forwards they
become fused together and spread out so as
to constitute a thin layer, merging above by
converging towards the medial plane of the
dorsum, in the superior lingual, below in that
next to be described, and forming with them
a sheath of longitudinal fibres, investing the
whole surface of the tongue.

6. An inferior lingual, a stout fasciculus of
longitudinal muscular fibres entirely intrinsic,
arising at the base of the tongue between
the hyoglossus and genioglossus, and passing
forwards between these two muscles to be
inserted gradually into the cutis of the tongue
on the inferior surface near the apex. This
is the true lingual muscle of Douglas and Al-
bums, and of anatomists of the present day.
I am doubtful whether or not the most an-
terior fibres of the genioglossus bend for-
wards so much as to become longitudinal, but
I think not (though Cruveilhier says they do):
if they do, the longitudinal sheath in front of
the free margin of the genioglossus would
consist of four sets, behind it of three.

Since the longitudinal fibres invest the
whole of the free surface as a sheath ; since
they are, most of them, not directly, but
obliquely, longitudinal ; and since many of the
central spread out to the sides, while the
lateral converge to the centre, the division of
the longitudinal linguals into superior, lateral,

* Bichat, Traite d’Anatomie, t. ii. p. 43.

TONGUE.

J 127

and inferior must be to some extent arbitrary :
however, most of those on the upper surface
are intrinsic in their origin, those at the sides
are extrinsic in their origin, while those on
the inferior surface are sufficiently individual
and distinct : some subdivision appears ne-
cessary, and the one adopted will at any rate
assist in remembering these facts.

The microscopical examination of thin sections.
On making a thin transverse vertical section
of the human tongue, and examining it with

the microscope*, we see that the appearances
indicated by a similar section, viewed with the
naked eye, are correct, namely, that the in-
trinsic muscular fibres assume three principal
directions, a vertical, a transverse, and a lon-
gitudinal ; and that the longitudinal are con-
fined to the neighbourhood of the surface.
But we see more; we see a very curious and
artificial arrangement of the fibres very much
contributing to facilitate their package, and by
which they mutually support one another

Fig. 748.

Transverse vertical section of the left half of the human tongue at the most posterior part of the free

portion. ( Magnified 10 diameters .)

a, a, cutis ; h, b, cortical portion, consisting of the three orders of fibres ; c, central portion, con-
sisting only of two ; c 1, discs of longitudinal fibres, seen in section ; /, horizontal median plane ;
g, line of emergence of the vertical from the transverse fibres ; i, i', the most superior and inferior
of the transverse curving up and down ; h, k, the most lateral of the vertical curving outwards.

* The best method to adopt in making these
investigations is to keep a fresh human tongue two
or three days in spirit, and then boil it about an
hour. On being first put into the boiling water it
contracts and becomes very hard. "W hen sufficiently
boiled, let it dry in the air for a day, and then make

the sections with some very thin flat knife. Place
the sections on a glass slide with a drop or two of
water, cover them wdth a piece of thin glass, and
view them with an inch, or, if a very large field
is wanted, a two-inch object-glass.

4 c 4

1128 TONGUE.

and act with the greatest advantage. This
arrangement I shall now proceed to describe.

Suppose the section made at a point just
in front of the anterior free border of the
genioglossi {Jig. 748.). Immediately beneath
the papillae (which may be very well dis-
played by this method), the condensed sulv
mucous areolar tissue or cutis of the tongue is
seen, of considerable thickness, being thickest
on the upper surface, especially towards the
middle(aa). Immediately beneath this, around
the whole circumference of the tongue, is seen
a very curious areolated or fenestrated ap-
pearance, consisting of cross bars, branching
and interlacing irregularly at various angles,
leaving interspaces that are filled up by groups
of discs (dd). The cross bars are at once seen
to be small fasciculi of the vertical or trans-
verse fibres, or both, according to the part
looked at, and the groups of discs are seen to
be transverse sections of the longitudinal
fibres passing through the meshes formed by
the vertical and transverse, which they more
or less completely fill, and with whose shape
they more or less exactly correspond {Jigs. 748.
and 751.). The fasciculi of the longitudinal
fibres are in most situations much larger than
those of the vertical and transverse, among
which they are contained ; indeed, the lon-
gitudinal being confined to the surface, it
would naturally be expected that they would
preponderate there. The vertical fibres are
most abundant in the vertical median plane
and the horizontal in the horizontal median
plane (f), the vertical not existing near the
lateral surfaces, nor the transverse near the
superior and inferior surface {Jigs. 749. a, a) ;
anti from this fact result almost all the pe-
culiarities of arrangement of the fibres that we
see.

In the first place it results from this, that
the vertical and horizontal fibres cross each
other in the centre, which they entirely occupy,
and therefore exclude the longitudinal ; ac-
cordingly no discs are seen in the central
part of the tongue. Secondly, that at a cer-
tain line {fig. 748. g.) the vertical emerge
from the transverse, and are continued up
or down, to the superior or inferior surface,
alone; and similarly at the lateral regions the
transverse emerge from the vertical, and are
continued on alone to the cutis at the
sides; hence the fibres near the middle of the
upper and under surface, and at the borders
of the tongue, do not interlace but pass to
the surface with something of parallelism ;
and hence the fasciculi of longitudinal fibres
here are arranged, not as in the mesh of a
network, but in parallel rows at right angles
to the surface ; an arrangement very charac-
teristic of these situations. Thirdly, it would
result from this absence of vertical fibres at
the sides, and of the transverse above and
below, that there would be four situations
( h , h, b, b, fig. 749. a .) in the neutral ground
between the upper and under surfaces and the
borders respectively, where there would be no
cross fibres of any sort, and where the lon-
gitudinal fibres would exist alone, unsupported

and unseparated. Moreover, the vertical fibres
at the upper and under surface, and the trans-

Fig. 749.

a

Plan of the intrinsic muscles of the tongue as seen in
transverse section.

a, a, a, a, Superior, inferior, right and left
lateral regions ; b, b, b, b, right and left supra and
sub-lateral regions. (Compare with fig. 4.).

verse at the sides, would be so dense and
numerous that they would hardly admit of any
longitudinal fibres in their interspaces. Now
the support and separation of the longitudinal
fasciculi, and the admission of a sufficient
number of them at all the superficial parts of
the tongue (especially the two surfaces and the
two edges, which may be called the cardinal
points of the tongue with regard to its move-
ments), are the two things that are especially
to be brought about. To achieve this double
object, the vertical and horizontal fibres, as
they approach their respective surfaces, spread
out in a sort of fan-like manner ; the most
lateral of the vertical fibres spreading out to-
wards the sides {fig. 748. k, lc), and the most
superior and inferior of the transverse spread-
ing up and down towards the surfaces {fig.HtS.
i, i,fig. 749. B.). The two sets thus cross each
other and fill the otherwise empty space with
a network of considerable regularity and beauty,
which is characteristic of these four situations,
as the parallel fasciculi at right angles to the
surface are characteristic of the four inter-
mediate ones. For the sake of convenience
I shall call the situations where the transverse
and vertical fibres approach the surface in pa-
rallel bundles, the superior, the inferior, and
the right and left lateral regions {fig. 749. a,b.
a, a, a, a) : those in which they decussate as
they approach the surface, I shall call the
right and left supra-lateral, and the right and
left sub-lateral {fig. 749. B.b,b, b,b.). Fourthly ,
the mesial vertical and mesial horizontal plane
are the situations where the vertical and hori-
zontal fibres respectively would act with the
greatest power on the form of the tongue, and
where also they would admit of being the

TONGUE. 1129

longest ; hence we see the fasciculi in these
situations much larger and more densely
packed than in the intermediate positions,
so that they more than equal the longi-
tudinal fibres that they transmit. The ex-
treme lateral fibres, on the other hand, that
spread out and interlace, having little more
for their office than to support the longitudi-
nal fibres, are very small and scanty, many ot
them consisting of only a single fibre, and
hence at these points the preponderance of
the longitudinal over the vertical and hori-
zontal fibres is the greatest. Fifthly, the most
deep-seated of the longitudinal fibres ot the
upper and under surface are underlaid by a
definite floor of transverse fibres, and simi-
larly the deepest of those at the side are under-
laid by a floor of vertical fibres; therefore in
these situations there is a strong line of de-
marcation, the discs are abundant down to the
bottom of the cortical layer, and there they
terminate suddenly {Jig. 751.); but in the in-
termediate positions there is no definite floor,
no line of demarcation, but the discs of lon-
gitudinal fibres dip down at irregular distances
{Jigs. 748, 749, 750.).

This is the general plan and rationale of the
arrangement, but it is rather an exposition
than a description, and it must be understood
as merely referring to a transverse vertical
section of the tongue, made at the most pos-
terior part of the free portion of the tongue :
there are often irregularities that make it
difficult to recognise the plan, and, in some
situations, certain disturbing forces, and su-
peradded parts that quite upset its symmetry.
For example, behind the anterior third of the
tongue, the genioglossus is seen entering
its inferior surface, and displacing all longi-
tudinal fibres (Jig- 747. d) ; further back,
this displacement is more considerable, and
we have similar infringements from other
muscles; and the intermixture of fat towards
the base of the tongue tends materially to
upset the regularity of the muscular arrange-
ment. Yet, in spite of this, it may always be
detected, and the average of appearances will
be such as I have described.

The muscular fibres are neither straight
nor parallel ; those of each system maintain
their general direction, but their course is
wavy and tortuous, and characterised by the
utmost irregularity ; as the fibres pass out-
wards they branch and sometimes re-unite
(Jigs. 750, 751.), though their branchings are
much more frequent than their re-unions,
and hence the fasciculi are smaller and more
numerous near the periphery than towards
the centre (Jig. 751.) ; by these branchings of
the fasciculi each set of fibres, the vertical
or transverse, possesses what may be called
an intrinsic network, imperfectly marked cer-
tainly, but sufficient in some parts to mask
their parallelism and to break up the rows of
longitudinal fibres that are packed between
them.

The number of fibres in each of the vertical
or transverse fasciculi, varies according to the
part of the section viewed, and the situation

in the tongue irom which it is taken ; some-
times one single fibre constitutes the fasci-
culus, if one may say so, sometimes many
dozen. Some of the largest are the most
superior of the horizontal,— those that curve
up on each side towards the upper surface
(Jig. 750.). The same variety of size exists in

Fig. 750.

Portion of cortical layer of the right supra-lateral
region of the tongue, showing the interlacement of
a, a, the horizontal with b, b, the vertical fibres, the
longitudinal fibres filling the intervals having been
removed. Magnified 30 diameters.

the discs of longitudinal fibres cut across; the
number of fibres in them may be counted,
from two or three to thirty or forty : those
nearest the surface are certainly the smallest,
and they do not completely fill the meshes of
the muscular network through which they pass
(Jig- 751.), but a certain quantity of fibrous
tissue dips down among them : this, however,
only for a little way. The shape of the longi-
tudinal bundles is as various as their size —
circular, polygonal, triangular, elliptical, in
fact, every conceivable shape (Jig. 751.); they
seem moulded by the fibres among which
they lie, or, more correctly, they and the
others among which they lie, mutually regu-
late each other’s shape and direction.

The peculiarity, then, of the arrangement of
the intrinsic muscles of the tongue is this ; —
that there are three sets of fibres passing
through the same area, and acting in three
different directions ; that these three direc-
tions are, in the main, at right angles the one
to the other, in fact, that they coincide with

TONGUE.

1130

the three axes of the cube ; that to facilitate
this arrangement, a beautiful system of pack-

Fig. 751.

a, vertical fibres; b, topmost stratum of the
horizontal ; e, longitudinal, in section, occupying
the interspaces between the vertical.

a"e is adopted, whereby each of these is
enabled to pass in a straight line to its destin-
ation without being interfered with by the
other two ; whereby the individual bundles
of each set are isolated from their fellows ;
whereby the whole of them are contained in
the smallest possible compass ; whereby they
not only admit the passage of, but mutually
support and conduct each other ; whereby, in
consequence of this, they are enabled to dis-
pense with the support of cellular tissue,
which accordingly we find absent ; whereby,
lastly, the tongue contains the greatest amount
of muscular tissue possible for its bulk. This
system of package consists of this — that the
crossing of the fibres of any two sets forms
a lattice work, or mesh, through which the
third shall pass, and that the successive layers
of the crossing fibres shall be so arranged
that the areolm shall form continuous channels
for the transmission of the perforating ones.
In whatever plane we look at the fibres, we
find that this is the case — that two sets are
crossing fibres and one set perforating — that
two are seen in profile, one in section ; but,
as we vary the plane, so do we vary the ap-
pearance of the fibres, one set alone remain-
ing the same and two interchanging. Thus,
in a transverse vertical section the transverse

and vertical fibres are seen in profile, and the
longitudinal in section ; in a longitudinal ver-
tical section the vertical and longitudinal are
in profile, and the transverse in section ; while
again, in the horizontal section, the trans-
verse and longitudinal are seen in profile, and
the vertical in section. So, no set can be
called a perforating set or a crossing set, —
they are all equally so.

Again, we see that the office of the longi-
tudinal fibres requires that they should have
that special superficial arrangement which is
the only one left them by the necessary dis-
position of the other two. The chief office of
the longitudinal fibres is to alter the direction
of the tongue longitudinally, to twist it from
side to side, or up and down ; any thing but
a superficial distribution would render them
powerless for this act. For if the longitu-
dinal fibres were placed in the centre, it is
evident that they could only shorten the
tongue; but, being arranged superficially, when
a portion of them contracts, that side of the
tongue on which the contracting ones are is
shortened more than the rest ; in other words,
the tongue is turned towards that side ; and
it is only when the whole sheath of longi-
tudinal fibres acts equally that the tongue is
contracted directly backwards.

Having premised this general description,
I shall now proceed to give a particular ac-
count of the microscopical appearances of
successive sections made in the three prin-
cipal planes — the transverse, the longitudinal,
and the horizontal. I shall begin with the
transverse as being the clearest and the most
illustrative.

The first transverse vertical sections, made
at the tip of the tongue, ^of course remove
successive portions of the papillary structure :
we next come to the cutis — the dense areolar
tissue subtending the papillae — and many
sections are made before the appearance of
any muscle ; we have in fact to get through
the thickness of the cutis. The first muscular
fibres that make their appearance are the
transverse, consisting of a single slender
bundle of fibres in that direction, occupying
nearly a middle plane between the upper and
under surfaces, lying horizontally, collected
into a single bundle in the centre, but breaking
up at each end into smaller fasciculi, which
diverge as they pass to their insertion into
the cutis at the sides of the tongue, so as to
gain a more extended attachment. The
sections following this display an increasing
quantity of this muscle, the diameter of the
unbroken bundle in the centre being greater,
and the fasciculi into which it divides at
the sides more numerous ; but as yet no
other system of fibres has appeared. The
next addition, as we proceed backwards, is
that of vertical fibres, which are at first very
few and scanty, and placed not in the centre,
but in two sets, one on each side of the
centre ; they converge a little as they pass
upwards, and are rather curved, presenting their
concavity outwards. The succeeding sections
show them increasing in numbers and spread-

TONGUE.

1 131

ing towards the centre, where they finally meet,
and then the central part of the tongue is con-
stituted in the same way as it is throughout
the whole succeeding length of the organ,
namely, by decussating vertical anti transverse
fibres ; but as yet no longitudinal fibres have
appeared, and they are not seen till after the
transverse area of the tongue has been
entirely occupied by the vertical and hori-
zontal fibres as above described. They first
appear at the inferior surface, then at the
sublateral and lateral regions ; next they are
seen at the centre of the upper surface in a
small definite cluster, from which they spread
out, and so complete the circumference of the
tongue.

We see from this that the fibres that occupy
the extreme point of the tongue are the
transverse ; that the next met with are the
vertical ; and that the longitudinal do not
extend so far forward as either of the other
two. This is what might be expected. The
chief muscular, requisition at the extremity
of the tongue is the power of pointing it :
the shape of a tactile part is eminently
subservient to its power of touch, because
exact localisation, which is a most impor-
tant element in touch (if it is not the very
essence of it), depends on the smallness
of the touching part. Now the extremity of
the tongue, of its ordinary broad, flat shape
when at rest, would be a very poor tactile
instrument, and very far removed from a form
that would capacitate it for the minute ap-
preciation of distance and form. In what
way, then, is the desired pointed shape of the
tip of the tongue to be produced ? Manifestly
by transverse contraction, for it is by the
spread of the tongue in this direction that it
departs from the pointed form ; and so we see
the transverse fibres continued beyond either
of the others, and occupying at the extreme
tip the whole of the space assigned to the
muscular structure. Furthermore, the longi-
tudinal fibres are not necessary at the extreme
point, either to flatten or shorten the tip,
which is brought about by its own elasticity
immediately on the cessation of the con-
traction of the transverse fibres, or to move it
in any direction, which is done rather by the
movements of the parts coming immediately
next the tip than of the tip itself. Thus, both
negatively and positively, we see a reason
for the continuation of the transverse fibres
further forwards than either of the other two
sets.

The section last described completes what
may be called the theoretical structure of the
tongue (it is shown in fig. 748., in one half of
its extent) : the next change is one of in-
fraction of that completeness of muscular
structure, occasioned by the entrance of the
genioglossi muscles on the inferior surface,
whereby the continuity of the cortical layer is
isolated, there being no discs in the space
occupied by the immergence of these two mus-
cles. The subsequent changes in the appear-
ance of successive sections, are just such as
might be expected from the description al-

ready given of such sections when viewed by
the naked eye ; therefore, for the sake of
brevity, I shall not here advert to them.

A longitudinal vertical section, of course,
displays a reversing of the position in which
the discs and profile interlacement are re-
spectively seen ; the discs are here in the
central part instead of in the cortical, being
the transverse fibres cut across ; the cortical
layer is free from discs (except where, from
the vertical and longitudinal fibres being ob-
lique, they are obliquely cut), and is occupied
by the longitudinal and vertical fibres, both
seen in profile.

A horizontal section displays very much the
same appearance as the last : the discs are in
the central part, and there is an absence of
them in the circumferential portion; but in
this case the discs are of the vertical fibres, in
the other they were of the transverse.

Superficial sections, or sections made ob-
liquely, I shall not attempt to describe ; by
such means the appearances might be in-
finitely varied, but their description would
merely tend to confusion.

From the above account it is seen that the
microscopical investigation of the subject not
only confirms and proves the conclusion ar-
rived at by other means, but adds many new
and interesting facts, and supplies us with one
more instance of that contrivance and adapta-
tion of means to end that meets us at every
point.

I have entered rather fully into the intrinsic
muscular arrangements of the tongue, because
there is no good account of the subject, that
I can find, in the English language, nor of the
appearances as seen by the microscope, in any
language ; and I considered such an account
a desideratum.

Mode of termination of the intrinsic fibres.
— All the intrinsic fibres of the tongue, and
indeed, it may be said, almost if not quite all
of the extrinsic too, terminate by becoming in-
serted into the cutis — the sub-mucous fibrous
tissue — which is extremely dense and thick,
particularly on the upper surface. The trans-
verse and vertical fibres pass direct to the
cutis ; the longitudinal all ultimately have a
similar insertion. In vertical sections the fibres
may be seen passing up or down to the sur-
face, and entering the cutis, which having
pierced for a certain extent, they terminate ; —
some of them end just as they enter the fibrous
tissue ; some of them may be traced quite up
to the papillae.

It might naturally be expected that the
muscular fibres of the tongue would, from
their isolation, present great facilities for see-
ing the mode of the termination of muscle in
fibrous tissue ; and indeed this is the case in
a remarkable degree ; they seem to furnish the
great desideratum of a natural isolation of the
individual fibres, at the point where you are
sure of seeing their union with the fibrous
tissue that forms their means of attachment.
As the opinions that I have come to from my
own observations differ from those that are
the result of some of the best researches on

1132

TONGUE.

the subject that have been made, namely those
of Mr. Bowman, as published in the “ Philo-
sophical Transactions,” and in the “ Physio-
logical Anatomy ” of himself and Dr. Todd, I
would advance them with diffidence, and some-
thing like hesitation. The appearances that I
have invariably seen, by daily examinations for
some time, of sections from many tongues, is
this: each fibre, before its termination, gradu-
ally tapers, in a fusiform manner, with more or
less of acuteness ; sometimes the tapering is
rather sudden, in other cases very much pro-
longed (Jig. 752. a) ; in all the tapering is con-

Fig. 752.

A. Fasciculus of the vertical, fibres of the tongue,
showing their fusiform extremities and the ter-
mination of each muscular fibre in a filament of
•white fibrous tissue. (Magnified 100 diameters.
B. Magnified 200 diameters).

tinued so far that the muscular tissue becomes
nearly as fine as the fibrous tissue in which it
terminates: from this fine extremity the fibre
passes off, and the appearances at the point of
transition are of two sorts ; the one as seen
at b, a, where the muscle passes smoothly
off in the fibrous tissue, and you cannot tell
where the one commences and the other ends ;
the other as seen at b, b , where the pointed
extremity of the muscle is a little rounded,
and its outline plainly visible ; but in this case,
also, the diameter of the extremity of the
muscle as nearly as possible coincides with
that of the fibre. It is possible that the dif-
ference of appearance may depend in some
degree upon difference of focus, but, certainly,
I have not been able, in some cases, by any
ad justment of focus, to get a clear definition of
the point where the muscular structure termi-
nated. In those cases where the outline of
the termination of the muscle is defined, the
transverse striation may be traced up to its
very extremity ; where the outline of the one
merges in that of the other, the striae seem also
gradually to be lost, becoming a linear series
of little dots, and so fading away (b, a).

The conclusion that the appearance at once
suggested to me was, that the sarcolemma,
condensed by the diminution of its contents,
passed off from the acuminated extremity
as a tendon of white fibrous tissue ; and
this opinion was confirmed when I thought
of the genesis of these structures. If, as
seems probable from the account given by
Schwann and other physiologists of the de-
velopment of muscle, the sarcolemma is
the persistent cell-wall of the original for-
mation-cells of the fibre, and if white fibrous
tissue is true zellenfasern — altered cell-wall
of cells that have become elongated at their
opposite nodes, and plicated as it were, —
then we reduce the sarcolemma and the
white fibrous tissue to the same category
— altered cell-wall. The function of the cell-
wall of the muscle-cell is to secrete that
peculiar matter within it which ultimately
becomes sarcous matter; the function of the
cell-wall of the fibre-cell is to become elon-
gated and plicated, or otherwise longitudinally
striated. To explain, therefore, the gradual
passage of one structure into the other, we
have merely to suppose, on the part of the cell-
wall, the gradual mergence of one function,
and taking on of the other. These considera-
tions at any rate tend to obviate any ante-
cedent objections to the opinions suggested by
the appearances, that would have arisen if
there had been any thing essentially heteroge-
neous in the nature of the structures con-
cerned. The fact, that Mr. Bowman’s obser-
vations were made on the lower animals —
fish, Crustacea, and insects — may perhaps
account for the difference of the appearances.
It is a subject that requires more investiga-
tion, and no structures seem to me so much
adapted for this purpose as the tongues of the
lower vertebrata.

b. Extrinsic muscles of the tongue. — These
are four in number, the palatoglossus, the stylo-
glossus, the hyog/ossus, and the genioglossus ; at-
taching the tongue to the soft palate, base of
the skull, hyoid bone, and lower jaw, and mov-
ing it nearly in the four cardinal directions, up-
wards, downwards, backwards, and forwards.
They are all more or less of a mixed nature,
being continued in some degree into the
tongue. They move the organ en masse, and
attach it to distant parts by virtue of their
extrinsic portion ; they contribute to the sub-
stance of the organ, and affect its form, by
virtue of their intrinsic portion. It is this
continuity of the substance of the tongue with
its means of connection to distant parts that
makes those connections so strong and safe;
it is this prolongation of the extrinsic muscles
into the tongue that renders the association
of the extrinsic and intrinsic movements so
intimate.

The palatoglossus (g/osso-stap/iy/inus'), the
smallest of these muscles, constitutes the
connection between the soft palate and the
sides of the tongue. At its origin in the soft
palate its fibres are mingled with those of
the palatopharyngeus ; as it descends to the
tongue it becomes much narrower, constitut-

TONGUE.

1133

ing the anterior pillar of the fauces ; and
arrived at the sides of the tongue, it again
spreads out, and its fibres mingle with those
of the styloglossus, some of them passing
transversely into the medullary structure. It
lies immediately beneath the mucous mem-
brane, and in front of the tonsil. Action : To
constrict the fauces (hence its name, con-
strictor isthmi faucium ) by depressing the soft
palate and raising the sides of the tongue.

The styloglossus. — A small slender muscle
arising by a pointed tendinous origin from the
inferior half of the styloid process of the tem-
poral bone, and also slightly from the stylo-
maxillary ligament. It passes downwards and
inwards to the base of the tongue, opposite to
which it expands and becomes flattened ; a
few of its fibres bend inwards, the majority
being continued longitudinally along the side
of the tongue, where they may be traced to
near the apex, contributing to the formation
of the lateral lingual muscle. As they pass
forward, they mingle with those fibres of the
hyoglossus that have a similar direction, and
with the inferior lingual. Relations: Ex-
ternally, with the parotid and submaxillary
glands, the external carotid artery, the facial
artery, the Whartonian duct, the lingual
branch of the fifth nerve, and the stylomax-
illary ligament ; internally, with the stylo-
hyoid ligament, internal carotid, superior
constrictor of the pharynx, the jugular vein,
and hyoglossus muscle. Action: To retract
the tongue, to raise and expand its base, and
to render it concave from side to side by rais-
ing its borders.

The hyoglossus. — Flat, thin, and ascending
nearly vertically, this muscle approaches a
quadrilateral form ; but, from the dorsum of
the tongue ascending as it passes forwards,
its anterior border is much larger than its
posterior. It arises from the posterior ex-
tremity, and from the superior border and
outer surface of the greater cornua of the os
hyoides, and from the body in their immediate
neighbourhood. From this double origin the
fibres ascend in two distinct sets. Those
from the greater cornua, passing up nearly
parallel to one another, are inserted into the
sides of the tongue; those from the body
expand as they ascend, arch forwards, and,
gaining the side of the tongue at a point su-
perior and anterior to the other, pass forward
along the border of the tongue, and unite with
the styloglossus to form the lateral lingual.
These two portions are separated below by a
cellular interval ; and above a few fibres of
the styloglossus pass in between them. Al-
bums has described these as three distinct
muscles: one, the cerato-glossus^ arising from
the greater cornua ; another, the basio-g/ossus,
from the body : and a third, intermediate, the
ckondro-glossus, taking its origin from the
lesser cornua. Relations : The external

relations of this muscle are, — from above
downwards, with the submaxillary gland, the
hypoglossal nerve, the mylohyoid, stylo-
hyoid, and digastric muscles ; internally, it
covers the glosso-pharyngeal nerve, the middle

constrictor of the pharynx, the lingual ar-
tery, the stylohyoid ligament, the geniohyo-
glossus, and, at its attachment to the tongue,
the inferior lingualis, which separates it from
the last mentioned. Bichat erroneously states
that the lingual artery ordinarily passes be-
tween its two origins. Action: To depress
the sides of the tongue and render its dorsum
convex ; to retract the tongue and draw it
downwards. It is more frequently associated
with other muscles than isolated in its action ;
and accordingly as it acts alone or together
with other muscles, either as concurring with
them or antagonising them, so its actions
vary.

The genioglossus, the largest of all the mus-
cles of the tongue, which it connects to the
lower jaw, is of a radiated or fan-shape, and is
placed vertically in immediate contact with its
fellow of the opposite side. It arises from
the superior genial tubercle of the lower jaw
by a tendinous tuft from which the muscular
fibres radiate to their different destinations.
The most anterior, the shortest, forming the
anterior free margin of the muscle, pass up-
wards and forwards to the tongue, having
reached the under surface of which, they are
continued, according to Cruveilhier, on that
surface to the tip ; but in all the specimens
that I have examined they appeared to con-
tinue an oblique course to the dorsum. The
succeeding fibres pass more and more back-
wards, and having reached the inferior surface
of the tongue, are directed vertically to the
dorsum, into the middle line of the whole of
which they are inserted, from apex to base.
The two muscles may be separated up to the
point of their immergence into the tongue,
but beyond that line their separation is no
longer possible ; for, having entered the
tongue, they come into relation with the
transverse intrinsic fibres, which they cut at
right angles, and interlacing with which they
pass to the cutis of the dorsum, forming
part of the vertical intrinsic muscle, from
the rest of which they are not to be dis-
tinguished except by their mesial situation.
The fibres do not curve outwards, as sup-
posed by Marjolin, to form part of the
transverse lingual ; nor do they expand at
all at their insertion, as stated by Cru-
veilhier ; there is no disposition to lateral
divergence in any part of their course ;
on the contrary, their direction is rather
upwards and inwards throughout, and their
insertion extremely narrow — a mere line
— as it might be imagined it would be, when
its great longitudinal extent is remembered.
The longitudinal furrow is, I think, mainly
produced by the traction of this muscle in the
median line. The most inferior fibres pass
backwards and downwards, and are inserted
into the hyoglossal ligament. Some of the
fibres immediately above pass backwards, ac-
cording to some authors, to the sides of the
pharynx, where, uniting with the middle con-
strictor, they form the genio-jjhaj'yjigiens of
Winslow. Relations : Internally with its fellow,
being separated merely by areolar tissue con-

V./

TONGUE.

1134

taining some fat, particularly at its inferior
part and the median fibrous lamina, when the in-
termuscular areolar tissue is sufficiently dense
to deserve that name ; anteriorly, with the frse-
num, to which it is subjacent; inferiorly, with
the geniohyoid; and externally, with the sub-
lingual gland, the mylohyoid, hyoglossus, and
inferior lingualis muscles, the ranine artery, and
the gustatory nerve. The hypoglossal nerve
threads its fibres, and passes forwards among
them. Action: To raise and draw forwards
the tongue ; to assist in constricting the
pharynx ; to protrude, retract, or depress the
tongue in the mouth, according as all or part
of the fibres are employed ; to depress the
centre of the tongue, and render it concave,
from side to side.

c. Accessory extrinsic muscles. — These
are, in short, all the muscles that move
the os hyoides without being attached to
the tongue, for whatever moves the hyoid
bone must move the tongue, which is fixed to
it. They are accessory to th e proper extrinsic
muscles in two ways, either by acting in con-
cert with them, or by facilitating their action
on the tongue by rendering the hyoid bone a
fixed point. Thus, in the first method, the
stylohyoid and posterior belly of the digas-
tricus concur with the styloglossus in draw-
ing the tongue upwards and backwards. In
the same way, the anterior belly of the digas-
tricus, the mylohyoid, and geniohyoid, con-
cur with the inferior portion of the genio-
glossus in raising and drawing forwards the
hyoid bone, and facilitating the protrusion of
the tongue from the mouth. By the second
method the muscles from the styloid process
to the hyoid bone assist the longitudinal in-
trinsic muscles of the tongue by rendering the
base a fixed point from which they can ad-
vantageously act on its length, and in the
same way the inferior set of hyoidean muscles
are accessory to the hyoglossus by fixing
the hyoid bone down. More might be said
on this subject, but enough has been stated
to indicate the important relation of these
muscles to the proper muscles of the tongue,
and for the sake of brevity that may suffice.

Movements of the tongue. — All the infinite
variety of movements by which the tongue is,
by virtue of its complex muscular organisa-
tion, susceptible, may be arranged under
two heads, — its extrinsic and intrinsic move-
ments ; sometimes dissociated, more fre-
quently concurrent : for the sake of clearness
I shall consider them separately, and then
group them.

First, the intrinsic movements of the tongue
are of two sorts ; those affecting its length,
and those affecting its direction.

a. As affecting its length. The elongation
of the tongue is provided for, like all in-
trinsic elongation, by diminution of calibre ;
in the tongue this is produced by transverse and
vertical contraction, especially the transverse,
whereby the tongue becomes at once elon-
gated and pointed ; by this means the tip of
the tongue can be protruded beyond the teeth
without any movement of the organ en masse.

or any assistance of the extrinsic muscles.
From this elongated state it is restored to its
original position and shape by the contraction
of all the longitudinal fibres composing the
cortical portion, which draw it directly back,
the transverse and vertical fibres at the same
time ceasing to act. Thus we see that the
central and cortical portions of the intrinsic
muscles are antagonistic ; but they are capable
of association : for instance, when the tongue
is to be flattened and its sides pressed against
the teeth without any elongation, an action
very frequent in mastication and in the pro-
nunciation of some letters, this is done by
the contraction of the vertical fibres associ-
ated with the longitudinal, the one diminishing
the vertical thickness, and so spreading the
tongue out, the other preventing the elonga-
tion which the diminution of vertical thick-
ness would otherwise be attended with.

b. As affecting its direction. The direction
of the tongue is entirely regulated, as far as
the intrinsic muscles go, by the longitudinal
fibres, and their power of modifying the direc-
tion of the tongue, as well as shortening it,
depends on their power of partial action :
thus the lateral lingual of one side can act,
or of the other ; the superior or the inferior,
and the point of the tongue is of course moved
to the side of the acting muscle. This modi-
fication of the direction of the tongue is, per-
haps, the most complete movement that it
possesses; it is certainly the most extensive :
by it the tip of the tongue may be depressed
deep below the incisor teeth, or reflected back
on the soft palate, so as nearly to touch the
uvula; or laterally, from the pillars of the
fauces on one side it may be carried round
the cheeks and alveolar arches to the same
position on the other side : these are the
cardinal points, up and down, right and left;
they may be united in any proportions, so as
to carry the extremity of the tongue to any
intermediate position.

Moreover, the movements affecting the
length of the tongue may concur with those
affecting its direction ; for instance, on apply-
ing the tip of the tongue to the root of a
canine tooth of the upper jaw, on the outer
surface of the alveolus, the tongue is elon-
gated, and vertico-laterally flexed ; on apply-
ing it to the last molar tooth of the lower jaw
it is laterally flexed and shortened.

Secondly, the extrinsic movements of the
tongue admit of the same division as the
intrinsic, into those regulating its length, and
those regulating its direction or shape.

a. Thus the tongue is carried upwards and
backwards by the styloglossus, assisted by
the other styloid muscles, downwards and
backwards by the hyoglossus, directly back-
wards when these both concur; and it is
carried forwards and protruded from the
mouth by the genioglossus. These move-
ments, en masse, almost always concur with
the intrinsic movements, the whole organ
following to a certain extent the direction
of the extremity.

b. But the extrinsic muscles affect very

TONGUE.

1133

materially the direction and shape of the
tongue: the styloglossi raise and expand the
sides, the palatoglossi raise and approximate
them, and the hyoglossi depress them ; the
one set makes the dorsum of the tongue
transversely concave, the other convex :
moreover, the posterior fibres of the genio-
glossus draw the centre of the tongue for-
wards and downwards, so that they also
render the tongue transversely concave.
The action of the genioglossus is peculiar ;
the most posterior fibres draw forwards
the base of the tongue, and are those chiefly
concerned in the protrusion of the organ ;
the most anterior concur in replacing the
tongue when thus protruded ; when the
whole muscle acts it compresses the tongue
into a sort of button, and carries it deep
down in the arch of the lower jaw. The
relations of the hyoglossus and genioglossus
are worthy of remark : they are congeners,
inasmuch as they both tend to draw the
tongue downwards ; they are antagonists,
inasmuch as the one tends to draw the tongue
principally forwards, the other principally
backwards ; when all four muscles act, the
tongue is depressed deep in the jaw, but
further back than when the genioglossi act
alone ; when the two muscles of one side
act, that side alone is depressed, and a certain
torsion is given to the tongue which enables it
to ‘apply the tip advantageously to parts that
it would otherwise be very difficult to reach.
]f the movement of the tongue in transferring
the tip from the last inferior molar tooth of
one side to that of the other be watched, with
the mouth open, at a glass, it will be seen to
be collected in a globe at the back of the
mouth, and to rotate horizontally, as it were
on a pivot. The only way in which I can
conceive this movement to be brought about,
is by the consentaneous action of the hyo-
glossus of the one side with the genioglossus
of the other, — the one right with the other
left, then the one left with the other right,
and so on, the styloglossi and palatoglossi
at the same time preventing the depression of
the tongue.

But it would be vain to attempt to describe
in words the endless variety of movements
of which the tongue is susceptible; and if it
were possible to give an idea of them, space
could not be afforded: so, dismissing this part
of my subject, I will proceed to the next.

3. Tegumentary system. — The tegumentary
system of the tongue is formed by the mucous
membrane of the mouth passing on to it from
neighbouring parts, and undergoing special
modifications according to the part that it
invests. A superficial glance shows it at
once to admit of a triple division, into, first,
a really or apparently plane portion, situated
in front of the epiglottis, beneath the borders,
and on the free portion of the under surface ;
secondly', a papillary portion, covering the
anterior two-thirds of the upper surface, the
free borders, and the tip ; and, thirdly, a
glandular portion, occupying the posterior
third of the upper surface, where it is folded

into little crypts and raised in nodules over
small mucous glands: these glands exist also
along the sides and beneath the tip : they will
be reserved for future description.

The mucous membrane here, as elsewhere,
consists of three portions, — a basement or
limitary membrane, underlaid by a submucous
areolar tissue, and surmounted by an epithe-
lium.

a. Cutis. — The sub-basement areolar tissue
of the tongue exists in sufficient quantity
and density to deserve the name of a true
chorion or cutis. It is thickest at the upper
surface, where it underlays the papillae, espe-
cially towards the median line; its density too
is the greatest here, sometimes amounting to
almost a cartilaginous hardness, and the pro-
portion of white fibrous tissue to the yellow
is the greatest; it is thinnest on the under
surface and edges, where it contains more ot
the elastic element, especially in the neigh-
bourhood of the epiglottis ; at the line where
the attached and free portions of the tongue
meet, it gradually merges off into the loose
elastic web that underlays the mucous surface
in these situations. Its inner surface receives
the insertion of all the intrinsic muscles of the
tongue, among which for a short distance it
dips, and it sends processes into the folds that
attach the tongue to neighbouring parts, as
the glosso-epiglottidean and fraenum. It is
the medium in which the nerves and vessels
destined to the surface break up previous to
their ultimate distribution : the vascular rami-
fications form a plane network, coincident with
the surface, from which, at regular intervals,
the papillary' vessels ascend.

b. The basement membrane is variously
modified in the three situations above indi-
cated; it is either continued plane, projected
into papillm, or folded into mucous cry'pts,
from which its further involution constitutes
the minute ducts and ultimate follicles of the
mucous glands opening into these crypts: its
description will be involved in the particular
consideration of these structures.

c. Epithelium. — This very nearly approaches
in character the cuticle of the skin, which it
resembles in being of the scaly variety, in the
amount to which it exists, and in its being
divisible into two layers, a deep one closely
adherent to the basement membrane, consist-
ing of more recent cells, retaining much of the
cellular form (fig. 753., c.), and a superficial
one, readily desquamating, the cells of which
are older and flattened into scales (fig. 753.. d.).
It exists in very different quantity in different
parts, being most abundant where it invests
the papillary structures. The shape of the in-
dividual cells is very various ; where they are
flattened their area is much extended (fi<*. 753.,
a.), and they look four or five times as large
as the deep-seated ones ; but probably there
is no increase in size, their lateral extension
resulting from their greater thinness: viewed
in profile they appear quite filamentary ; some
of them are not flattened but elongated, so
that they appear linear in all aspects, and are
really so. In spite of all these modifications

1136

TONGUE.

Fig. 753.

Epithelium of the tongue.

a, a single flattened superficial cell, viewed super-
ficially and edgewise ; b, from the horse, showing
the filamentary prolongation of a part only of each
cell ; d, superficial ; e, deep layer.

a small single circular nucleus may generally
be seen very plainly occupying a central posi-
tion in the cell, and unchanged in form and
size by any of the changes that the cell under-
goes. Certainly the epithelium, covering
most parts of the tongue, does not contain
any pigment ; but I think that covering the
filiform papillae in the centre of the dorsum
very frequently does ; and for these reasons, —
because, first, the growth of the epithelium
here is very abundant, and it seems a general
rule that pigment should be associated with
an abundantly nourished or rapidly developed
epidermis, as is seen in hair, in the colour of
those spots that are called moles, and the hair
that proceeds from them, which, instead of being
invisible, as in neighbouring parts, is dark and
rank, and in the change of colour which the
cuticle and hair covering the parts of genera-
tion undergo at the increase of the nutrition
of the parts that accompanies the accession
of the generative function ; secondly, because
we see that the epithelium does undergo
great changes of colour, being generally dark-
est when most abundant ; thirdly, because, in
two cases that I have seen, in which the only
diseased condition was an enormous develop-
ment of the filiform processes which the epi-
thelium forms in the centre of the tongue,
the colour of the fur was a dark sepia or
Vandyke brown, almost black, exactly that
of pigment in other situations : we see too,
when the epithelium has been rendered
opaque bv soaking the tongue in alcohol, that
all the other papillae are whiter than the fili-
form occupying the centre of the dorsum,
which retain their tawny colour. The epithe-
lium of the tongue differs from the dermic
cuticle chiefly in its moisture, and the delicacy
and softness of its structure.

Papillary structure of the tongue. — The pa-
pillae of the tongue are generally contrasted
with those of the skin, in that while the latter
are covered over with an even layer of epi-
dermis, and therefore not visible to the naked
eye, the latter stand out free from the surface
of the epithelium, dipping down between
them. But viewed by the light of recent
researches, this is seen to be only the appa-
rent difference, the real difference being that
while the papillae of the skin are sessile, the

papillae of the tongue are arranged in groups
on proper pedicles or supports, whose tops
and sides they cover, and which elevate them
above the general surface. For it has been
recently shown by Professors Todd and Bow-
man *, that the papillae, heretofore considered
simple, are really compound organs, and that
they are covered by other smaller papillae,
whose form and whose method of nervous
and vascular supply, show their true analogy
to the papillae of the skin. In physiological
exactness, and to carry out the analogy insti-
tuted by these anatomists, we may say that
these large papillae, so called, are no more true
papillae, than the long processes in the intes-
tine of the rhinoceros are true villi. Now,
these secondary, or true physiological papilla,
are covered in by an even layer of epithelium,
in just the same way as the papillae of the
skin ; hence we see that the distinction gene-
rally laid down ceases. It would, however,
be too great an innovation to reject the name
of papillae for those organs that have so long
possessed it, and as the value and office of
their different parts will be implied in their
description, no misconception can arise. I
shall, therefore, continue the old nomen-
clature.

There are three principal forms under
which the papillae, visible to the naked eye,
exist on the surface of the tongue. 1st. The
circumvallate (caliciform, Cuv.), the largest and
fewest in number, and the most conspicuous,
situated at the junction of the middle and
posterior third of the tongue, where, by their
arrangement in two lines, having a direction
backwards and inwards, which meet in the
centre, they form a V-shaped ridge, with the
base directed forwards ; 2nd. The fungiform,
more numerous than the last mentioned, and
smaller, irregularly scattered over the centre,
sides, and apex of the tongue ; and, 3rd, The
conical or filiform, by far the most numerous
and smallest, arranged in a dense pile over the
whole anterior two-thirds of the upper surface,
among which the last-mentioned are im-
planted. To these may be added a fourth
class of simple sessile papillae, first pointed out
by Professors Todd and Bowman as existing
on the apparently non-papillary surface im-
mediately behind the circumvallate papillae,
and which I have found also to exist on the
whole of the under surface of the free portion
of the tongue.

The circumvallate papillae are of the most
complex form, and may be considered as con-
sisting of two parts — a central, button-like
projection, flattened or truncated at its free
surface, and a raised border surrounding it in
the form of a ring, of nearly equal elevation
with the central part, the two portions being
separated by a circumvallation, or fossa (h).
When a vertical section is made of one of
these papillae (Jig. 754*.), the central portion is
seen to be in the form of an inverted cone,
and the surrounding fold is seen to constitute
a cup, at the bottom of which the apex of the

* Physiological Anatomy, vol. i. p. 435.

TONGUE.

1137

Fig. 754.

Circumvallate papilla seen in vertical section,
a, Truncated surface, or base of the cone ; b, cir-
cumvallation ; c, raised border. (Mag. 16 diam.)

cone is attached. At the attached portion the
nerves and vessels enter, and the free trun-
cated surface, or base, of the cone is covered
with small secondary papilla?, concealed by
the epithelium ( Jig. 754. a) ; the free border is
also surmounted by secondary papillae, so that
it is, in fact, a circular compound papilla (c).
The circumvallate papillae possess the utmost
irregularity as to size, number, shape, and
arrangement. Their number has been much
overstated by some anatomists ; Cruveilhier
gives it as from sixteen to twenty, Marjolin
from nine to fifteen, Soemmering from twelve
to fourteen, and Meckel from three to twenty.
I think the number given by Messrs. Todd
and Bowman, as from eight to ten, is much
nearer the truth ; eertaiply, if ten can be
counted, they must be considered well deve-
loped ; frequently the number is below this —
I have seen as few as five, or even four. In
size they vary from that of an ordinary fungi-
form papilla to upwards of ^th of an inch in
diameter. They always assume more or less
of the V-shaped arrangement, but the per-
fection with which the linear series is main-
tained, the straightness of the lines that form
the angle, and the size of the angle so formed,
all vary very much ; I have seen them stretch-
ing across from side to side of the tongue,
almost in a straight line, with a third arm
projecting back from the centre, something
like the form of a tripod ; it is not uncommon
to find a stray one or two scattered to a great
distance beyond the prescribed line; the cen-
tral one is frequently thrown back half an
inch, and sometimes a lateral one is found

Fig.

quite at the edge of the tongue. In shape, the
varieties are chiefly owing to the relative size
and development of the central tubercle and
the circular ridge surrounding it. Sometimes
one of these parts is suppressed, and then
you either get what appears to be a large
fungiform papilla, or a set of ridges having
something of a circular or quadrilateral ar-
rangement, not to be distinguished from the
fused rows of conical papillae which surround
the circumvallate on all sides, and which
are, in fact, continuations and prolongations
of their calices. Haller mentions having seen
the circumvallate papilla; in two rows on
each side ; I have met with a similar arrange-
ment on one side. This appearance may in
some degree be accounted for by the supposi-
tion that the rows of conical papilla;, among
which the large fungiform immediately in front
of the circumvallate are planted, have attained
a circular or calyx-like arrangement around
them ; for a large fungiform papillae, situated
in a calyx so formed, would produce a very
perfect papilla circumvallata. This change is
just the reverse of that which reduces a cir-
cumvallate papilla to a fungiform by the sup-
pression of its surrounding ridge, and both, no
doubt, are sources of irregularity. These
papillae are supplied by branches from the
glosso-pharyngeal nerve, which may be dis-
tinctly traced to them ; their vascular supply
is abundant, and their epithelium thin and
fine, so that during life, and when injected,
they appear very red.

The fungiform papillae, as their name indi-
cates, have more or less of the form of a
sphere supported on a pedicle ; this is their
typical form, but they often deviate from it ;
in size they vary from J^th to J^th of an inch.
They are scattered over the sides and tip
of the tongue, and on the dorsum in front
of the circumvallate. They may be dis-
tinguished from the filiform, among which
they are implanted, by their red colour,
in which, in the thinness and smooth-
ness of the epithelium investing them, and
in the abundance of their vascular and
nervous supply, they resemble those last de-
scribed. When examined microscopically,
they are seen to be covered on their sides and
summit with secondary papillae {Jig. 755. A), to
755.

A, Fungiform papilla, showing the secondary papilla; on its surface, and at a the epithelium covering
them over. (Mag. 35 diam.)

B, Another, with the capillary loops of its simple papillae injected, a, artery; v, vein. The groove
around the base of some of the fungiform papilla; is here represented, as well as the capillary loops, c c,
of some neighbouring simple papilla;. (Mag. 18 diam.) {After Todd and Bowman.')

4 D

1138

TONGUE.

which, in injected specimens, the individual
loops of capillaries may be seen projecting
with great regularity and beauty (B). The
fungiform papillae are largest about the centre
of the tongue, smallest along the edges, and
most numerous at the sides of the tip, but
they are liable to the greatest variety in their
size and distribution ; I have seen them so
large about the centre of the tongue, as almost
to equal in size the circumvallate ; I have seen
them so numerous at the tip, as nearly to
equal in number the filiform among which
they were scattered ; again, in the same
region, I have seen them so scanty, that they
could hardly be said to exist there.*

The conical or filiform papillae, the third
class, constitute the great mass of the papillary
structure; they cover, in a close-set pile, the
whole of the anterior two-thirds of the
tongue, being limited behind by the circum-
vallate, and having the fungiform scattered
among them : it is their structure that imparts
the rough coriaceous character to the papil-
lary surface, and they constitute the fur in the
centre. They are altogether smaller, but in
length they exceed, at least in the centre, the
other two forms, and they exhibit greater di-
versity of structure and a more complete ab-
sence of typical shape than either of the other
varieties. They affect in some situations a

Fig. 756.

a, imbricated scaly epithelium investing the cylin-
drical portion of the papilla ; b, the commence-
ment of its breaking up ; c, its separation into its
ultimate filamentary processes ; d, the deep layer
of epithelium exposed by the removal of the more
scaly superficial one.

* May not these varieties explain the correspond-
ing diversities hi the acuteness of the sense of taste,
which we so often find in different individuals ?

linear arrangement, principally at their con-
fines, that is, in front of and around the
caliciform papillae, where they are continuous
with the elevations that surround these pa-
pillae, of which they are the continuations
forwards and outwards, and along the whole
free margin of the tongue, except at the tip,
where the linear arrangement cannot be traced.
In the first-mentioned situation their rows
run forwards and outwards, coinciding with
the arms of the V-shaped figure that the cir-
cumvallate papillae assume ; in the last-men-
tioned, they are placed vertically along the
sides (fig- 745. i i) : they have been well de-
scribed and figured by Soemmering.* Along the
centre of the tongue, in the neighbourhood
of the median furrow, the conical papillae often
assume a cracked and fissured appearance ;
but the linear arrangement is less marked here,
and the fissures have no determinate direc-
tion, but can be made and effaced according
to the movements of the tongue. The conical
papillae are largest in the neighbourhood of
the circumvallate, where they are truncated,
and where some of them assume almost a
fungiform shape : they are longest about the
centre of the tongue, near the median line,
and smallest in the anterior part, near the side
and tip. The form of the projections of base-
ment membrane, on which the epithelium is

Fig. 757.

Vertical section of conical papillce. (Mag. 25 diam.')
a, basement surface ; b, conical papilla of ordinary
shape; c, more nearly approaching the simple
form ; g, one quite simple ; e, deep cellular layer
of epithelium ; f superficial scaly portion ; h h,
points from which the filamentary prolongations
would have passed up.

placed, constituting the monld of the true
papillary structure, is generally something of
a cylindrical shape, the top supporting second-
ary papillae, or it is conical, the secondary
papillae being continued more or less down the
sides : or the base is small, and supports a
more expanded portion, and thus the conical
is seen to pass into the fungiform shape. But
it is in the epithelium that the characteristic
difference between these and the other papillae
* leones Organorum humanorum gustus et vocis.
Francofurti, 1808.

TONGUE 1139

is to be found. In the other forms we saw it
continued over the whole compound organ as
a thin indusium, covering in and concealing
the secondary papillae under its smooth invest-
ment, the scales being arranged parallel to
the surface ; but in the conical and filiform
papillse we not only see the epithelium exist-
ing in much greater quantity, but over each
secondary papilla assuming a vertical arrange-
ment, and, after continuing compact for some
little distance, breaking up into a brush of
hair-like processes (/ ig . 756.), the number
coinciding with that of the secondary papillse.
Where the secondary papilla are few the hairs
are few, where they are many the hairs are
many, and each hair may be traced down, by
following the line in which the epithelium is
vertical, to each papilla. In fact, these pro-
cesses are true hairs, and only differ from other
hairs in being short, uncompact, imperfectly
elaborated, and in having the imbrication
retroverse instead of directed forwards; and
the secondary papillse from which they spring
are true hair papillse, differing only from ordi-
nary hair papillae in being raised and grouped
on a common pedicle instead of sunk in a
proper follicle. In some cases the resemblance
of these filaments to ordinary hair is very
close indeed, as seen in fig. 758. ; indeed in c

Fig. 758.

Hair-like processes of fili form papilla,
a, Mag. 150, b and e, 100 diameters.

the chief difference is in the direction of the
imbrication : in some morbid specimens I have
seen it even closer.

Now this difference in the arrangement of
the epithelium on the different papillae in-
dicates, I think, a very important physiolo-
gical distinction ; in one case we see the sen-
tient papillae covered by a thin layer of a fine
epithelium, thinner over them than in the in-
tervals between them ; in the other case we
see each secondary papilla the seat of a rapid
generation of epithelium that clothes the
whole compound organ with a dense impene-
trable brush of hairs : this latter arrangement

seems as inconsistent with the possession of
sensibility as the former seems adapted to it,
and the difference would suggest to me the
division of the papillse into “ sentient ” and
“ protective among the former I would class
the cireumvallate and the fungiform, among
the latter the filiform and, with a certain qua-
lification, the conical : but I shall return to
this presently in speaking of the functions of
these papillae. The great difference between
the filiform and conical forms is in the amount
of the epithelium : in the filiform it is such
as has just been described ; in the conical, the
hairs are very short and thick, and terminate
in an even plane almost as soon as they' be-
come separate, so that they have not at all
a filamentary character. This epithelium is
being constantly generated and as constantly
thrown off, as is shown by the variation in the
quantity of fur on the tongue from day to day.
It is in these papillse that the separation into
two layers is best seen (fig. 757. ef), and the
appearances of this separation are such as to
make me think that the method of desqua-
mation is not by the shedding of individual
scales, but by the throwing off of the upper
layer, the under layer taking its place, itself
to become divided into a deep-seated and su-
perficial portion, and to be in turn thrown off
as it grows older. The vascular supply of these
papillae is very abundant, as might be expected
from the rapid nutrition that is taking place
from their surface. The pigmentary character
of the epithelium, at least under some circum-
stances, has been already referred to.

The simple papillae are scattered beneath
the apparently non-papillary surface behind
the cireumvallate, beneath the edges of the
tongue, and on the under surface of its free
portion, also among the conical and filiform ;
in the former situation they resemble the
secondary papillse of the cireumvallate and
fungiform, in the epithelium being continued
smoothly over them ; in the latter, those of
the filiform, each being the base of a hair-
like process. The situation of these pa-
pillae, their number and arrangement, is very
well shown by injection, when the individual
loops of capillaries may be seen passing up
from the sub-mucous plexus at regular inter-
vals, one to each papilla. The method in
which the conical papillae of the upper sur-
face pass into the simple of the under, is this :
— the ridges on the side of the tongue, to
which reference has already been made, con-
sist of fused conical papillae arranged in linear
series vertical to the edge, and, like them,
crowned with secondary papillae ; as they pass
down the edge towards the under surface they
become shallower, so that by the time they
have reached that surface, the secondary pa-
pillae, instead of being elevated, are sessile,
and immediately subtended by the cutis. This
is the true nature of those vertical ridges on
the edge of the tongue described by Bichat,
Soemmering, and many other anatomists.

Structure of papilla; . — The nature of the
true papillary structure, i. e. the contents of
the projection of basement membrane, seems

1 D 2

1140 TONGUE.

to be partly fibrous, partly granular : cer-
tainly something like yellow fibrous tissue
can be detected, particularly on the addition
of acetic acid ; but those specimens that I
have examined have appeared to be more
granular than fibrous, and in some cases,
where there has been a fortuitous rupture of
the papilla, there has been an abundant escape
of a finely granular material : the exact na-
ture of this granular material I have not been
able to ascertain ; it is not fatty. The me-
thod of termination of vessels is sufficiently
conspicuous, and has been already indicated.
With regard to the termination of nerves I
must confess, that, after long-continued and
careful search, I have been unable to find any
thing I can construe into a looped termina-
tion. I have traced the nerve for some little
way into the simple papilla, and then, its out-
line becoming less and less definite, it has
ceased to be visible, apparently from the loss
of the strong refraction of the white substance
of Schwann. If I might hazard an opinion, I
should say that the axis was probably de-
nuded of this investment, and, thus laid bare,
underwent some specific peripheral modifi-
cation. In a paper by Dr. Waller, recently
published in the“ Philosophical Transactions
of the Royal Society,” a method of nervous
termination by open mouths is suggested : con-
sidering the solid nature of the nerve-axis, this
appears to be an opinion that requires either
some modification, or the confirmation of re-
peated and varied observations, before it can
be received as certain. At present our means
of examining the termination of nerves, either
in the organs of sense or elsewhere, are im-
perfect, and until they are less so we can hope
to make but little advance in this, at present,
obscure subject.

Functions of the different papillae. — Three
offices are to be discharged by the papillae —
they are to exercise the sense of taste, the
sense of touch, and to form a suitable cloth-
ing and protection to the tongue. The struc-
ture of the circumvallate and fungiform pa-
pillae, their shape, their position, the nature
of their epithelium, all point them out as the
organs that are to discharge the first-men-
tioned function, and their nervous supply,
which may be demonstrated with facility,
makes that probability a certainty. To detail
the evidence on which this conclusion is based
would merely be to repeat what the reader
will find given at length under the [articles
Fifth Nerve, Eighth Nerve, and Taste,
to which I therefore refer him. By what pa-
pilla:, then, is the sense of touch exercised? I
think by the conical, and by them in contradis-
tinction to their non-gustatory congeners, the
filiform. My reasons are, first, that the sense
of touch is only possessed in any perfection by
the papillae at. the tip of the tongue.* Now

* There can be no doubt about this fact ; and it
is what we might antecedently expect, because it
is the most movable part, and therefore has the
widest range of application ; because it is the most
capable of movement, and therefore the best adapted
for that which is an essential condition of touch ;

these are conical and of the form the’most re-
moved from the filiform type, that is, their
epithelium is the least abundant of all the non-
gustatory papillae. Secondly, because the struc-
ture of the filiform papillae is the most incompat-
ible that could be devised for the possession of a
sense of touch in any perfection. And, thirdly,
because we do find, in fact, that the centre of
the dorsum of the tongue, where the filiform
papillae exist in the greatest abundance, is the
least sensitive part of any. Therefore, unless
we assign the sense of touch to the gustatory
papillae, which the lowness of its conditional
the back of the tongue, where the gustatory
papillae are so abundantly developed, seems to
negative, we are driven to the conical as the
only ones that can possess it. The filiform
papillae remain for the third office — that of
clothing and protecting the exposed dorsum
of the tongue ; their pilose investment ad-
mirably adapts them for this, and at the same
time it imparts to the surface a certain pre-
hensile power, enabling it to take hold of
and move readily what is placed on it, while
the backward direction of the hairs adds yet
more a special facility for transmitting food
towards the pharynx.

Mucous glands. — These are largest and most
abundant at the base of the tongue, where
they occupy the space behind the circum-
vallate papillae, and lie immediately beneath
the surface, which they raise in nodular emi-
nences. The most anterior of them form a
Y-shaped ridge, the counterpart of that formed
by the circumvallate papillae, from which they
are separated by a corresponding furrow.
These structures, which are true mucous
glands, analogous to the buccal and labial,
are of an oval or roundish lenticular shape :
in front of the epiglottis they are gradually
lost. Each gland is surmounted by a distinct
orifice, most conspicuous in the most posterior
of them, opening into a little crypt, generally
closed and collapsed, but dilatable so as to
be large enough to contain a mustard-seed,
and into the bottom of these crypts the
minute ducts of the glands open. Some of
these crypts I have found extending into
long and capacious canals, branching in dif-
ferent directions, and undermining the surface.
I have traced some of them half or three-
quarters of an inch before they have termi-
nated in their blind extremities : their surface
is quite smooth, and the orifices of the ducts
of neighbouring glands might be seen termi-
nating in different, parts of it. They probably
act as reservoirs, and permit some accumula-
tion of the secretion, and also prevent the
orifices of the glands from infarction by the
matters passing over the surface. Similar
glands, but smaller, are seen along the sides
of the tongue, particularly near the base ; and
under the tip a small aggregation of them,

because we find it is the tip that rve do apply to
parts that we want to feel ; because the tip is capa-
ble of receiving a pointed form, and therefore loca-
lising the impression more perfectly ; and because
the tip receives the most abundant supply of twigs
from the fifth nerve.

TONGUE.

1141

first described by Nuck, may generally be de-
tected : they are about eight or ten in num-
ber, much smaller than those at the base,
situated on each side of the median furrow,
and each surmounted by a little orifice. The
true glandular nature of all these structures
is proved by microscopical examination : they
are seen to be true conglomerate glands, their
ultimate follicles filled with an abundant se-
creting epithelium.

Vessels of the tongue. — The vascular supply
of this organ, which is large in proportion to
its size, is derived mainly from its proper ar-
tery, the lingual, but it receives some small
branches at its sides and base from the inferior
pharyngeal and palatine. The lingual artery
arises from the external carotid, between the
inferior thyroid and the facial : it passes up-
wards and inwards, at first superficial, covered
only by the integument and fasciae, to reach
the posterior border of the hyoglossus muscle,
beneath which it passes to its anterior border,
where it breaks up into its terminal branches,
the sublingual and the ranine. In the first part
of its course it lies on the middle constrictor of
the pharynx ; in the second part it is covered
by the hyoglossus and mylohyoid muscles,
and lies on the middle constrictor and genio-
glossus. Previous to passing beneath the
posterior border of the hyoglossus the artery
is crossed by the hypoglossal nerve, which, at
first placed below it, now rises above it ; the
hyoglossus muscle then separates the two,
the nerve lying outside of it and the artery
beneath it, but at its anterior border they are
again in relation ; the nerve, however, is now
inferior, having crossed the course of the
artery while beneath the hyoglossus. Its
branches are, 1st, a hyoid branch, passing along
the upper margin of the hyoid bone, corre-
sponding to a branch of the superior thyroid
running along the under margin of the bone,
with which and with its fellow of the opposite
side it anastomoses ; 2dly, the dorsalis linguce
branch, ascending from the artery in the se-
cond part of its course, supplying the side and
dorsum of the tongue ; 3dly, the sublingual,
one of its two terminal branches, passing
downwards and outwards from the anterior
margin of the hyoglossus to be distributed to
the sublingual gland, cellular tissue, and mu-
cous membrane adjacent ; 4thly, the ranine ,
which may be regarded as its continuation,
passing upwards and inwards in immediate
relation with the genioglossus to the tip,
where it anastomoses with its fellow. That
the communication of the arteries of the
opposite sides of the tongue is not very free,
is shown by the imperfect injection of one side
when the injection is made into the carotid of
the opposite side : it is free enough, however,
to make the ligature of the artery of one side
of little service in stopping haemorrhage of
that side, the supply from the other being
sufficient to keep it up.

Nerves of the tongue. — The tongue is sup-
plied with nerves from three sources, two
sentient — the lingual branch of the fifth, and
the glosso-pharyngeal, and one motor — the

ninth or hypoglossal nerve. The lingual or gus-
tatory nerve, one of the three great branches
into which the sensory portion of the inferior
maxillary division of the fifth breaks up after
its emergence through the foramen ovale,
passes down, at first between the external
pterygoid muscle and the small muscles of the
palate, then between the two pterygoids, then
between the internal pterygoids and the jaw,
finally escaping from between these two at
the anterior border of the muscle ; it then
runs downwards and forwards, under the pro-
tection of the jaw, to the side of the tongue,
crosses the mylohyoid attachment of the
superior constrictor, then passes forwards
beneath the sublingual gland and to the outer
side of the ranine artery, to terminate at
the tip of the tongue. The numerous small
branches that are distributed to the conical
and fungiform papilla; may be seen ascending
from the nerve whilst beneath the tongue,
passing upwards and forwards through the
substance of the organ to the mucous surface.
The other nerve of sensation, the glosso-pha-
ryngeal, the smallest and most anterior di-
vision of the eighth pair, emerges from the
skull through the foramen lacerum jugulare
by a distinct fibrous canal ; it then descends
between the jugular vein and internal carotid,
passing forwards, in front of that artery and
beneath the styloid process and muscles aris-
ing from it, to the anterior border of the stylo-
pharyngeus, between that muscle and the
styloglossus ; it then passes under the hyo-
glossus, beneath which and below the tonsil
it divides into its branches for the supply of
the gland and the tongue : its arch across the
neck is below that of the lingual, and above
the hypoglossal, but deeper seated than either.
The branches to the tongue are distributed
to the circumvallate papilla, and the mucous
surface behind them. The ninth, or hypo-
glossal nerve, the motor nerve of the tongue,
after escaping from the skull through the an-
terior condyloid foramen, lies at first deep,
between the internal jugular vein and carotid
artery ; coming forward between them it be-
comes superficial, and forms an arch across
the neck below, and parallel to, the digastric
muscle, hooks round the occipital artery, and
passes beneath the mylohyoid muscle, but
superficial to the hyoglossus, at the anterior
border of which it pierces the fibres of the
genioglossus, and divides into its branches
for the supply of this and the other muscles
of the tongue : its relations to the lingual
artery have been mentioned. For a more
detailed account of these nerves, of their
relations, branches, and the experiments on
the results of which the present amount of
our knowledge as to their function is based,
the reader is referred to the articles Fifth
Nerve, Eighth Nerve, Ninth Nerve, and
Taste.

Comparative Anatomy. — The first in-
dication that we find of any thing that can
be construed into a tongue is met with in
the Articulata, and, among them, in Insects.
Its claim to the name is a matter of doubt
4 n 3

1142

TONGUE.

among naturalists * ; but since a certain oral
appendage, at least in some of the orders,
has received by common consent the name
of lingua, I shall briefly describe it. The
mouth of insects is furnished with two lips
— an upper lip, or labrum, and a lower lip
or labium ; besides four jaws — a mandible,’
or upper, and a maxilla, or lower jaw, on each
side. The labium, or lower lip, is divisible
into two parts — a mentum, or basal joint,
and a more flexible piece moving on this, the
ligula, or labium proper. On the inner sur-
face of this labium is developed a small pro-
cess having a certain resemblance to a tongue,
situated in front of the oesophageal orifice,
and generally anchylosed with the labium at
the front and sides of that opening ; in some
cases, however, as in the locusts and dragon-
flies, it is free. This process Cuvier con-
sidered merely as a part of the labium, and
accordingly called it labium ; Fabricius anti
Latreille gave it the name of ligula. In shape
it is generally short, but in bees it is long ; it
is frequently simple, but in the wasp its apex
is trifid, the same in Melolontha stigma ; in
Canabus it possesses three short teeth ; in
JElaphras it terminates in a single tooth or
point. In substance it generally approaches
to a cartilaginous consistence, but in the Ortho-
ptera and Libellulcs it is much more fleshy :
and in the predaceous beetles it is as hard
and horny as the integument. In some cases
it is immovable, in others projectile and re-
tractile within the mouth ; in some cases
smooth, in others covered with hairs, as is
the case in the common hive-bee ; in Melo-
lontha stigma the hairs are incurved- In the
hive-bee the upper part of the tongue is car-
tilaginous, and remarkable for a number of
transverse rings : below the middle it consists
of a membrane longitudinally folded in in-
action, but capable of being inflated to a con-
siderable size : this membranous bag receives
the honey which the tongue, as it were, laps
from the flowers, and conveys it to the
pharynx. f

Mollusca. — Gasteropoda. In the acephalous
mollusca there is, of course, no tongue. But
the Gasteropoda are provided with a very sin-
gular apparatus, which, since it is usually called
the tongue, cannot be allowed to pass obser-
vation here, though its right to such an ap-
pellation is somewhat questionable. Its form
is subject to much variation, but it may be
described generally as a thin membrane, long
and narrow, the greater extent of which is
rolled into a tube. This tubular part (fig. 759.
A, b), occupies the posterior portion of the
membrane, the end being closed, while its an-
terior extremity is open and in connection
with the oesophagus ; in front of the tubular
part of the tongue is a continuation of the
same membrane, which is here flat, and in many

* Ce qu’on a nomme langue dans les eoleoptferes
et les ortkopteres, ou l’extremite membraneuse de la
l&vre inferieure, en me'rite k peine le nom. Cuv.,
Lemons d’Anat. Comp., t. iii. p. 347.

t Kirby and Spence, vol. iii. p. 453.

species also, as in the common whelk (Buc-
cinum undatum), it is recurved (fig. 759. A, 2).

Fig. 759.
i A ->

A. 1. Vertical section of head of Li max maxhnus ,
snowing the relative position of the mouth, a;
tongue, b ; and oesophagus, c.

2. Retracted proboscis of Buccinum undatum, a,
mouth ; b, tongue ; c, oesophagus.

B, single row of tongue-teeth of B. undatum.

This membrane is covered on its upper sur-
face with transverse rows of minute teeth, or
rather plates with tubercular or toothlike pro-
cesses upon them. The number of rows is
considerable, and very variable, the terrestrial
species averaging, probably, about eighty, and
the marine possessing often many more; the
number of plates in each row is subject to
still greater variation : the common whelk
(Buccinum undalum) has but three (fig. 759.
B), the large garden slug (Limax maximus)
has 180. The shape of the plates in terres-
trial gasteropoda is usually irregularly qua-
drangular, slightly longer than broad, while in
some fluviatile and marine species they as-
sume most complicated and elegant forms
(fig- 759. B). The centre plate of the row is
always symmetrical, and its denticular projec-
tions point in the direction of the closed end,
i. e. backwards, and nearly horizontally. The
plates on either side of this central plate usu-
ally assume in terrestrial gasteropods much
the same form and direction, while some of
the fluviatile and most of the marine species
present such an endless variety of forms, that
the most that can be said of them, generally,
is that the dental processes point backwards.
Fig. 759. B represents a row of the denti-
gerous tongue-plates ol the Buccinum unda-
tum: there are seen to be only three ; the cen-
tral one symmetrical, the lateral ones of very
different form, individually non-symmetrical,
but having an exact correspondence to one
another. The tongue itself (fig. 759. A, 2) is
attached, as before stated, to "the oesophagus
near its anterior extremity, and lies beneath
it. In the Helices and Limaces it is enveloped
in the muscular head of the gasteropod (fig.
759. A, 1), its posterior blind end being just
visible at the back part of the head, some dis-
tance below the point where the oesophagus
leaves that part and passes into the abdominal
cavity. In the whelk tribe it lies beneath, and
parallel to, the oesophagus, and is free, though
surrounded by strong muscular bands, the
general direction of which is also parallel to
the tongue. It is in this tribe that the an-
terior end of the tongue is curved downward,

TONGUE.

1143

while its posterior extremity unlike terrestrial
species, is furnished with a strong retractile
muscle. In some other marine gasteropoda,
as the limpet, a very small portion only of
the tongue is included in the head, whilst
the rest of it lies folded up in the abdominal
cavity, between the intestines and the muscular
foot, but perfectly free ; and in some cases it is
nearly twice as long as the entire length of
the animal.

Of the uses of this curious apparatus it is
difficult to speak with certainty. The short
thick tube of the terrestrial gasteropods ap-
pears adapted for the trituration of food pre-
paratory to its passing into the oesophagus :
these species are furnished with a large, strong,
horny plate, fixed in the mouth at the upper
part of the head, and, consequently, the
flat end of the tongue acts as an under jaw
working against this horny plate. It is not
easy, however, to imagine that the long nar-
row tube of the whelk tribe can be used in
the same way for triturating food, though
the envelope of strong muscles would fa-
vour that idea, while the consideration of
the still longer and perfectly free tube of
the limpet renders this use of the tongue
among the marine gasteropoda still more
improbable. It is well known that the
Buccinum undatum and its allies use the flat-
tened portion of the tongue as a file, with
which they bore holes through the shells of
other species and then feed upon them, and
the muscular apparatus by which this is ef-
fected is an admirable piece of mechanism.
It consists of a protractor muscle, over the
anterior extremity of which the curved por-
tion of the tongue is flexed, which, by its
self-elongation, probably by intrinsic trans-
verse contraction, projects this recurved por-
tion of the tongue from the mouth, and
keeps it there ; when the tongue is thus pro-
truded, the retractor muscle, already alluded
to, attached to its posterior blind extremity,
contracts rhythmically, and so pulls the re-
curved portion with a sawing motion over
the extremity of the protractor muscle, which
acts as a pulley for it : thus the teeth which
cover the outer or free surface of this reflected
portion are brought into the relation, with the
objects on which they are to act, the most ad-
vantageous for filing them away. But this
gives us no clue to the determination of the
manner in which the tubular part of the
tongue is employed, nor am I aware of any
probable conjecture having been advanced
upon the subject.

Professor Loven, of Stockholm, has pro-
posed a system of classification of gasteropoda
founded upon the forms of the tongue-plates
and their arrangement ; and it is probable that
conchologists will find the suggestion a valu-
able one, not so much for the sole foundation
of an arrangement as for a check upon classi-
fication on other bases.*

* For much of the above detail I am indebted to
Mr. Thomson, of King’s College, as well as for the
specimens from which the drawings were made.

Cephalopoda. Hitherto, in the insects
among the Articulata, and the gasteropods
among the Mollusca, we have only seen in the
tongue an instrument for facilitating, mediately
or immediately, the prehension of food : in
the Cephalopoda we have the first structural
indication of the sense of taste, and apparently
in a perfection consistent with the high orga-
nisation of the animal in other particulars. In
both the tetrabranchiate and dibrancliiate or-
ders of cephalopods we meet with tongues of
very similar structure, possessing in both an
anterior and posterior soft papillose part, and
an intermediate portion invested with a horny
lamina, beset with rows of recurved spines. It
is hardly possible to help seeing in this dis-
tribution of parts the strong analogy it pre-
sents to the mammalian tongue, in which the
gustatory papillae are situated near the tip and
base, while the centre of the dorsum is occu-
pied by a rough indusium, subserving the
same double office as the spiny lamina of the
cephalopod, protecting the organ and facili-
tating deglutition. In the Nautilus the tongue
is supported by an oblong horny substance,
probably analogous to the basis of the hyoid
bone, free at its posterior extremity, but em-
braced anteriorly by two retrahent muscles
which arise from the posterior margins of the
lower mandible. The anterior free extremity
of the tongue itself is divided into three soft,
fleshy, papillar caruncles, of which the central
or anterior one is the largest. Behind them
the surface is invested with a thin horny
plate, on which are set four longitudinal rows
of recurved spines, twelve in each row, each
spine being about two lines in length. Be-
hind this the tongue is again soft and sensory,
but the papillae are coarser ; a fleshy fold pro-
jects forward from each side of the fauces,
likewise covered with papillae. In the di-
branchiate order the papillary structure is less
perfectly developed, and the central horny
lamina, instead of being in one plane, is bent
at right angles into a vertical and horizontal
portion, the incurved spines being set only on
the vertical part. The rows of spines are
seven throughout, but in the Onychoteutkis, as
they descend towards the base of the plate,
the outer rows merge in those next them to-
wards the centre till there are only three rows.
The method in which the cephalopods appro-
priate their food, by tearing off piecemeal, by
means of their strong and sharp mandibles,
portions of the prey they have seized and are
holding in contact with their mouth, renders
the possession of the sense of taste of high
importance to them, as the immediate contact
of their food prevents their testing its nature
by the sense of sight : at the same time, the
full enjoyment of this sense is permitted by
the nature of their food, its partially commi-
nuted condition, and their protracted method
of taking it.

Vertebrata. — In the Invertebrata the defini-
tion of a tongue depends, with few exceptions,
on little more than locality and function — the
requisitions of a tongue and the possession of
an organ of any sort that fulfils those requi-
4 n 4

1144

TONGUE.

sitions, constitute its possession, or any oral
process, to which no other name can be assigned,
is called a tongue. But when we enter the
Vertebrata we find an organ of characteristic
structure, conforming to a general type, pos-
sessing many common characters, of a form
whose varieties are not so great as to prevent
its being the name of a particular shape, and
always constituted of those three systems
previously enumerated as essential to the
tongue of Vertebrata. I shall first consider
the comparative anatomy of the bony system
of the tongue in all Vertebrata, and then briefly
refer to some of the principal characters of
the organ itself in the four classes into which
that subkingdom is divided.

Hyoid apparatus. — The comparative ana-
tomy of the hyoid apparatus is a subject of
high interest, as it enables us, by its reflected
light, to read successfully the true nature and
value of the different elements of the structure
as met with in man and other mammalia. It
shows us, with the certainty of a demonstra-
tion, and the contrariety almost of a paradox,
that the hyoid bone in man, which we are ac-
customed to look upon as a single bone whose
dismemberment depends merely on late ossi-
fication, is, in reality, a composite structure —
a contribution from two distinct systems of
bones ; that while the body and lesser cornua
form part of the true endoskeleton , and are
congeneric with the bony framework of the
trunk and limbs, the greater cornua form part
of the visceral or splanchno-slceleton, and are
congeneric with the maxilliform supports of
the teeth of the stomach of the lobster, or the
bony pieces situated in the auriculo-ventricular
ling, in the hearts of ruminants, or with other
similar structures ; and that, as we must look
upon these in regard to the function they sub-
serve, as respectively digestive and circulatory
bones, so we must regard the greater cornua
of the hyoid as respiratory.

To prove the truth of this proposition, it
will be necessary to examine the state of the
hyoid apparatus in water-breathing animals,
and to connect its condition as found in these
with what we find it in air-breathers, by tra-
cing the modifications which its different parts
undergo in those animals, part of whose ex-
istence is destined to the respiration of water,
and part to that of air ; we shall thus gain a
clear insight into their homologies, and be
able to refer part to part without the chance
of fallacy, inasmuch as the link of their con-
nection is lodged not in different individuals,
but in different parts of the life of one. I
shall describe it,

1st., in fish. Professor Owen has shown
that the different segments of the true hyoid
arch are so many elements of the inverted or
haemal arch of the third cranial vertebra.
The centre of this arch in fishes (fig. 760. A)
is formed by four small, subcubical bones, the
basi-hyals (6 7/) (two only are represented in
the figure, being seen in profile), from the
sides of which extend upwards, backwards,
and outwards, two long and stout cylindrical
pieces, the cerato-hya/s (c h) ; the summit of

each of these is surmounted by a small trian-
gular piece, the epi-hyal (ep It), and the arch
thus constituted is suspended on each side, to
the base of the skull, by a small, slender
ossicle, the stylo-hyal (st h), which may be
considered either as the entire proximal piece
of the hyoid arch, or a dismemberment of that
piece, according as the posterior division of
the epitympanie, to which it is attached,
is looked upon as the displaced proximal
piece of the next arch in advance, the tym-
pano-mandibular, or as itself the proximal
element of the hyoid. This completes the
hyoid arch: in most fishes, however, there are
two more bones attached to the centre of the
apparatus, one stiliform, projecting forwards,
appended to the anterior surface of the median
symphysis of the basi-hyals, the glosso-hyal
(g h), the true lingual or tongue-bone; the
other, the uro-hyal ( u h), a vertically-expanded,
triangular piece, extending backwards from
the posterior surface of the basi-hyals. There
are generally appended to the posterior and
lateral surface of the cerato-hyals and epihyals
a series of slender, slightly curved rays,
varying in number from three to thirty, but
generally about seven, as in the cod (Gadus
Morrhua) (fig. 760. A) ; their office is to sup-
port the membrane that covers in the branchial
chamber, whence they are called branchio-
stega/s (b,b).

Immediately behind the hyoidean arch, we
meet with a system of arches, the branchial,
whose office is to support the gills, and whose
structure, position, development, and con-
nections prove them to have no relation with
the true skeleton : they are generally five in
number ; the four anterior being branchial, the
last, which is dentigerous and guards the
gullet, pharyngeal. Each arch rises laterally
from a median chain of ossicles attached to
the basi-hyal, or uro-hyal when ossified, and
consists of a short inferior piece, the hypo-
branchial, surmounted by a long, curved piece,
the cerato-branchial, bending first outwards
and upwards, then forwards and inwards,
under the base of the cranium. Now, these
arches are what were just now stated to be
homologous with the posterior or greater
cornua of the hyoid apparatus, in all vertebrate
forms, whenever they exist ; that they are so,
will best be shown by tracing the modifica-
tions they undergo in the metamorphoses of
the anourous batrachians. Fig. 760. B, 1. re-
presents the hyoid and branchial apparatus in
the water-breathing tadpole; B, 2, where the
same animal has become the air-breathing
frog. In the full-gilled tadpole (B, 1), a simple
basi-hyal (b h) supports laterally two cerato-
hyals (c h), and posteriorly two short hypo-
branchials (h b), to each of which are attached
four cerato-branchials (c b). The second stage
is marked by the divergence and growth of the
extremities of the hypo-branchials and the pro-
gressive absorption of the cerato-branchials.
At the third stage, the cerato-branchials have
disappeared, and the hypo-branchials have
assumed the character of true greater hyoidean
cornua (B, 2, h b). In the fourth stage they

TONGUE.

1145

Fig. 760.

Comparative anatomy of the hyoid apparatus. ( After Geoffroy and Owen.)

A, Fish (Cod). B, Reptile {Frog : 1, tadpole ; 2, adult). C, D, Bird. (C, Crane; D, Woodpecker).

E, Mammal ( Horse ).

became ossified, and, together with the cerato-
hyal, coalesce with the basi-hyal. As in their
previous condition they subserved to respira-
tion, so now they do the same — as they
before supported the branchiae, so now they
support the trachea and larynx : they may be
always recognized by this relation, — they
a'ways embrace the commencement of the
air-passages in their fork, being especially
connected with the first segment of the carti-
laginous framework of those passages, namely,
the thyroid cartilage ; the universality of this
relation has induced Professor Owen to name
them, in air-breathing vertebrata, thyro-hyals
{fig. 760. C, D, E, h b, cb).

In birds {fig.'iQO. C and D), the elements of
the true hyoid arch are either rudimentary
or suppressed, while the hypo- and cerato-
branchials {h b, c b) are enormously deve-

loped. The basi-hyal ( b h) is generally
elongated proportionately to the shape of the
tongue, and to its anterior extremity is usually
attached a glosso-hyal ( g h), to its posterior a
stiliform uro-hyal {u h ) which is prolonged be-
neath the trachea. In C, which represents the
hyoid apparatus of the crane {Grus cinerea),
the glosso-hyal is seen to be wanting, and two
rudimentary cerato-hyals (c h), lesser cornua ,
to be attached to the anterior extremity of
the basi-hyal. In D is represented the hyoid
apparatus of the woodpecker {Picus); the
parts are seen to be very long and slender,
furnishing the means for the lengthened pro-
trusion of the tongue in pursuit of food. All
the bones are seen to be linear ; there is a
long basi-hyal (b h), surmounted by an arrow-
shaped glosso-hyal ( g h), while two slender
hypo-branchials {h b,) {greater cornua) are

1146 TONGUE.

surmounted by two cerato-branchials (c b) of
extreme length and tenuity, which, curving
round the bird’s occiput and vertex, are
inserted by their cartilaginous extremities into
a canal in the upper mandible, the orifice of
which is placed to the inside of the right nos-
tril ; the true hyoid arch is here entirely sup-
pressed. And, indeed, birds’ tongues are not
attached, they are slung ; now, tongues are
attached by the osseous or fibrous continuity
of the hyoid arch ; they are slung by the loose,
unattached hypo- and cerato-branchials ; and
accordingly as either of these methods of con-
nection with the body is most consistent
with the tongue’s functions, so the one or the
other of these systems of bones preponde-
rates.

In mammalia we find the hyoid apparatus
recurring in its original completeness ; the
three pieces, the stylo-hyal, epi-hyal, and
cerato-hyal, composing the lateral arms of the
arch in the fish, have each their representa-
tive : the proportion of these parts, the com-
pleteness of their ossification, and their anchy-
losis, or separateness one from another, are
liable to great variety, but either in the bony
or ligamentous condition, fused or separate,
the parts may be always traced. The cerato-
hyals are represented by the lesser cornua ; the
stylo-hyals have their homologue in the sty-
loid process of the temporal ; and the epi-
hyal, or intervening portion of bone, is a cylin-
drical ossicle connecting the two : these are
seen in their greatest completeness in the true
carnivora. In man the epi-hyal is not normally
ossified, but remains in a permanently liga-
mentous condition, as the stylo-hyoid liga-
ment. In some rare instances, this ligament
has been ossified, and then the typical condi-
tion of the hyoid arch is restored ; two or
three of these instances have been recorded
and figured by Geoffroy. In fig. 760. E is
shown the condition of the hyoid apparatus in
the horse ; the stylo-hyals are seen to be very
large, and approximate so nearly to the cerato-
hyals, that the intervening bone, corresponding
to the stylo-hyoid ligament in man, is seen to
be a mere pisiform nodule (ep h) ; the hypo-
branchials, or posterior cornua (h b), are of
much the same shape as in man, while the
basi-hyal projects forwards in a rostrum, to
which is attached a glosso-hyal in two pieces
(g h ). In the ox the condition is much the
same as in the horse, but the epi-hyals are
longer, and the stylo-hyals shorter.

I will now briefly advert to the general
characters of the tongue itself, as met with in
the four classes of Vertebrata, — Pisces, Rep-
tilia, Aves, and Mammalia.

Pisces. — The tongue in fish is very rudi-
mentary ; in some it cannot be said to exist at
all ; in others it is a thin, fleshy investment,
that barely covers the glosso-hyal bone pro-
jecting into the mouth. In the herring {Clupea
Harengus), it seems to be represented by a
small muscle passing along the floor of the
mouth to be inserted into the symphysis
of the lower jaw, to depress and open which
seems to be its function. In the cod it is

round and thick, and seems to act as a sort of
cushion. In the conger (Murcena Conger), in
which it is very large, it seems to possess a
hyo-glossus muscle, which, arising from the
inferior portion of the hyoid arch, passes for-
ward on either side of the tongue, which, by
the action of one of these muscles, can thus
have a lateral deflexion imparted to it. The
structure of the investments of the tongue is
not such as to imply the possession of taste in
any degree, or any thing but a very low sensi-
bility. In some species, as, for instance, in the
sole ( Solca vulgaris), the surface is regularly
rugose, and might, at first sight, appear to be
papillary, but no true papillae are to be met
with in any fish’s tongue ; their only repre-
sentatives are the calcigerous processes, or
teeth, with which the tongues of some species
are more or less densely set, and which assist
in prehension and deglutition. Whether the
vascular, erectile tissue, situated on the palate
of the Cijprinoids , has any connection with the
sense of taste, is doubtful — probably not.

Reptilia. — The tongues of Reptilia possess
a very wide diversity ; some are immovable,
others the most remarkable for their protrac-
tility that we find in any organism ; some are
long, some so short as to have been described
as wanting; some are broad and thick, some
slender ; some present the development of
papillae in great perfection, some are quite
smooth ; the extremes of all these charac-
ters we find in the reptiles, and their oppo-
site conditions in those the most closely
allied. For example, among the Saurians, the
tongue of the crocodile is so immovable, as
to have been described by Aristotle as want-
ing ; while the chameleon presents us with
the most complete protractility of the organ
that the animal kingdom furnishes. I think
the teleologists have not a greater strong hold
than that furnished them by the tongues of
reptilia. Almost the only thing in common
that can be assigned to them is this, that pre-
hension is their principal function, and that
the sense of taste is very subordinate.

a. Batrachia. — All the Batrachia, in their
perfect state, feed on living prey*, and in
many of them the arrangement of the tongue,
to enable them to secure it, is remarkably
curious. Iu the frog, which presents a good
example, we see the tongue reversed, as it
were, the base or attached end being in front,
the apex or free extremity behind : its mus-
cular constitution explains this arrangement.
It consists essentially of two muscles, a genio-
glossus and hyo-glossus, invested by the
mucous membrane. The genio-glossus arises
from the inferior maxillary symphysis, and,
directed backwards towards the throat, spreads
out, and, together with its fellow, constitutes
the upper of the two muscular strata. The
hyoglossi arise from the lower surface of the
posterior hyoid cornua, are directed forwards

* In speaking of the frog Roesel says, “ Prajdam
vix venatur eamdem potius prsestolans, nec ullum
unquam devorabit insectum motu destitutum.” Hist.
Ranar., p. 16.

TONGUE. 1147

under the flattened cartilaginous plate of the
body of the hyoid bone, over the anterior bor-
der of which they are reflected as over a pul-
ley, where, coming in contact with the under
surface of the last-mentioned muscles, they
curve backwards, radiate in a fan-like manner,
and form the under of the two muscular layers.
This is the position in a state of rest, the hyo-
glossus lying under the genioglossus, and the
extremity of the tongue pointing down the
throat in contact with the fauces, and forming
a plug with which to close the posterior nares,
and prevent the regress of air every time it is
swallowed. But when the animal would seize
its prey, the position of the tongue is sud-
denly reversed ; the genioglossus contracts,
and moving on its genial attachment as on a
centre, the tongue is thrown forwards, the ge-
nioglossus now being below, the hyogiossus
above. The apex of the tongue having come
in contact with the prey to be seized, and se-
cured it by its viscid secretion, the organ is
instantly retracted and restored to its original
position by the contraction of the hyogiossus.
In many of the batrachians (as in the Triton)
the tongue is fixed in its entire extent, and is
of very various shapes, oblong, rhomboidal,
heart-shaped, &c., affording generic and spe-
cific distinctions, of which zoologists have
availed themselves in classification. The
tongues of Batrachia are invariably soft, and,
in some of them, as the frog, covered with
well-developed papillae, containing all the es-
sential elements of organs of taste and touch ;
that they are the seat of an acute sense of
taste is, however, highly improbable, not from
any thing in their structure, but from the fact
that these animals swallow their prey whole,
without any subdivision, frequently alive, bolt-
ing it as soon as seized.

b. Ophidia. — In the ophidians the tongue is
very much elongated, straight, flat or cylin-
drical, fleshy, highly protractile, and deeply
cleft at the apex into two tapering points
which are in a state of constant vibration when
the tongue is protruded. Tiiese points are
the extremities of two muscular cylinders,
which form the substance of the tongue, and
by their close apposition constitute that part
of it that seems to be undivided : they may be
traced a long way down in front of the tra-
chea. When the mouth is opened the tongue
very frequently cannot be seen, from its being
drawn within a sheath which contains it, the
orifice of which is placed in front of the aper-
ture of the glottis. From this sheath, and
from the mouth, it is being constantly pro-
jected, with a sort of vibratile darting move-
ment, and, from a deficiency in the plates at
the symphysis of the jaws, it can be protruded
from the mouth without the jaws being sepa-
rated : the character of this movement, and
the pointed slender shape of the tongue, have
given rise to the vulgar belief that it is the
animal s weapon of offence, a sort of dart con-
taining the poison that it instils into the
wounds it inflicts. From the nature of the
food of this order, from the disposition of the
parts of the mouth, and from the short so-

journ that the food makes in it, the perception
of savours is probably very slight.

c. Chelonia. — In Chelonia the tongue is not
elongable, and its muscular structure is very
simple, consisting only of two pair of muscles,
the genioglossus and hyogiossus. In the tur-
tles the surface is smooth ; in most of the
tortoises it is clothed with very large and well-
developed papillae, long, soft, and flexible,
arranged with great regularity in a close pile :
the structure of these papillae, together with
the masticatory apparatus possessed by these
animals, would imply their possession of a true
sense of taste.

d. Sauria. — Among the saurians we find in
the Crocodile a fixed tongue projecting so
little from the floor of the mouth, that Aris-
totle, as has been stated, described it as want-
ing; it is covered with a coriaceous integu-
ment, and is remarkable chiefly for a valve-like
process at its base, formed by a reduplication
of the integument over the vertical ridge of
the body of the hyoid bone, which, at the will
of the animal, is capable of being applied to a
similar one descending from the palate, and
shutting off the mouth from the posterior nares
and larynx, so that the animal can breathe
when its mouth is under the water or engaged
with its prey, and its nostrils only above the
surface. In the Lizard we find a tongue, in
shape very much like that of the Ophidians.

In the Chameleon we find an apparatus which,
for its remarkable structure and powers, has
always excited the attention and curiosity of
zootomists : Perrault, Hunter, Cuvier, Vallis-
nieri, Vrolick, Houston, Milne Edwards,
Spittal, Duvernoy, have all given their con-
tributions to the subject ; the connection of
the mechanism with the resulting phenomena,
as given by these authors, has been very di-
verse, and all, in the opinion of Bibron, un-
satisfactory. “ It is easy,” says this author*,
“ to conceive and explain a part of these
movements, by the structure of this tongue in
the chameleons, because the hyoid bone and
the muscles have been perfectly described,
and because it is easy to isolate them by dis-
section ; yet, by the very aid of this anatomy
we perceive that the movements which this
mechanism should effect would not suffice for
the production of such an excessive elongation,
that the animal, without using any violent exer-
tion, can lance from its mouth, by a sort of ex-
puition, a fleshy pipe of a length nearly equal to
that of its whole trunk, and that it can retract it
again within its throat with the same swiftness,
and without one’s perceiving any apparent
movement in the rest of its body.” The dif-
ficulty that Bibron felt was that of accounting
for the very great intrinsic elongation of the
tongue, and it appears to me to be a difficulty
that exists ; various authors account for it
variously ; in my own dissections I have not
met clear evidence of anything that satisfac-
torily explains it to me. I shall first describe
the tongue itself, and then the hyoidean appa-

* Erpetologie Generale, ou Histoire Naturelle
complete des Reptiles, Paris, 1836, t. iii. p. 174.

1148 TONGUE,

mouth, it is seen to be a whitish, fleshy, ru-
ratus and muscles, and from the description of
the two deduce the most probable explanation
of the movements.

When a portion of the integument and
lower jaw on one side is removed, so as to
expose the tongue when retracted within the

gous mass, about an inch and a half long, fill-
ing the buccal cavity, so as to depress the
floor of the mouth and throat, in shape some-
thing of a cone with the base in front : the
posterior half, or smaller part, is seen to be
thrown into deep and numerous transverse
rugae (Jig. 761. A, b, and C.) which extend

Tongue of the Chameleon.

A, retracted. B, elongated. C, seen from beneath, in situ, by incision and separation of the integument.

quite up to the hyoid bone, and give to this
part the appearance of an earth-worm, a simile
suggested by Belon. When the tongue is
drawn out it is seen to be capable of great
extension (B), the extension taking place
in the posterior or rugose portion, and being
effected by the obliteration of the transverse
rugae, which one by one are smoothed or
flattened out as the extension is continued,
so that when it is stretched as far as it will go
by moderate traction, the tongue, instead of
being an inch and a half long, of which only half
is occupied by the extensible portion, is five
inches long, the extensible part occupying
about six-sevenths of the entire extent, and
being much attenuated (B, b), while the an-
terior portion retains its original size and
shape (a). The tongue is thus seen to be
composed of two parts, a club-shaped ex-
tremity and a highly extensible medium of
connection between this extremity and the
hyoid bone : these two parts I shall now
describe.

The anterior club-shaped extremity is about
three quarters of an inch long, and three lines
in diameter, and in shape reminds one of the
corolla of a labiate flower ; in fact it is bilabi-
ate: it has a sort of dome above (a), termi-
nated in front by an upper lip (c), which is
opposed by a more projecting lower lip ( d ),
and between them is situated a funnel-shaped
mouth, which, when closed, as in A, forms a
horizontal cleft, but is capable of being opened
as shown in B, (and to an extent greater than
that represented in the figure,) and closed on

any object at the will of the animal, so as to
assist in the prehension of food. These lips
are furnished with a sort of orbicularis, and,
no doubt, too, with muscles that shall raise
the upper and depress the lower ; but I have
been unable to detect any fibres going in such
a direction as to produce these movements.
This part, as well as the whole of the tongue,
is invested with the mucous membrane of the
mouth, and the upper surface of the dome and
lower lip, are covered with minute papillae,
invested with a fine epithelium, and disposed,
in the former situation, in rows, indicated by
the lines (A, «). The part which covers in
the infundibular cavity, and which, after the
analogous part in a labiate flower, I have called
the dome, Bibron has not ill compared to a
tongue reversed.

The second portion consists essentially of
a membranous tube, threaded, as it were, by
the long cartilaginous stilet, or tongue bone,
of the hyoid apparatus ( the glosso-hyal). This
cartilaginous stilet, which has been errone-
ously described as bony, is about an inch and
a half long, and consequently passes through
the entire length of the tongue when re-
tracted, its anterior extremity being received
into the lower lip of the club-shaped portion :
it threads the tongue much in the same way
as a bodkin threads a bag when furnishing it
with a running string, and it is by the pucker-
ing of the membranous portion upon this
basis that the transverse rugae are formed.
The membranous tube itself (which has been
compared to a pipe, a piece of intestine, a

TONGUE.

1149

worm, &c.) is very complex in its structure :
it consists, first, of an investment of mucous
membrane, very thin and extensible, covered,
apparently, by a single layer of epithelium,
and a good deal of bluish-grey pigment, and
underlaid by fibrous tissue disposed at right
angles, transversely and longitudinally. When
the sheath, thus composed, is cut open, it is
seen to contain another fibrous sheath, smooth,
dense, white, and shining, the proper sheath
of the stilet, which it closely invests, and which
smoothly glides in it. Between these two
sheaths is a cavity which is occupied, first, by
a longitudinal muscle on each side (essentially
a hyoglossus), a very fine and slender fascicle,
which runs the entire length of the tongue,
and retracts it when protruded ; secondly, by
a nerve on each side, disposed, when the
tongue is retracted, in regular sinuosities, and,
when drawn out, about five inches long ; it
does not appear to give off any branches to the
muscle, and does not diminish in size as it
advances, so that it is probably distributed to
the extremity, and is sensitive ; thirdly, by
some cellular tissue loosely connecting the
mucous investment with the fibrous sheath of
the stilet ; fourthly, no doubt, arteries and
veins. The proper sheath of the stilet does
not contain a canal, but is attached to the
surface of the stilet, which glides in it not by
its movement on the sheath, but by the move-
ment of the parts of the sheath on itself.
When tlie stilet is retracted it is seen to be
cylindrical throughout, but as it advances its
sheath accumulates on its anterior extremity,
and it seems gradually to become club-shaped,
so that when the tongue is completely re-
tracted the under lip is filled not only with
the extremity of the stilet, but with the sheath
accumulated on it. Cuvier has described an
annular muscle existing throughout the entire
length of the membranous portion, which he
describes as the proper muscle of the tongue,
and to which he attributes its self-elongation.
If such a muscle exists, which I w ill not posi-
tively deny, it would fulfil all the required
conditions, and leave nothing to be explained ;
but I confess that, after careful microscopical
research, I have been unable to find any mus-
cular fibres having a transverse or circular dis-
position, all being referable to the longitudinal
bundles already referred to. Hunter has de-
scribed what he considered to be two coils of
some firm substance, wound in opposite di-
rections, which by their approximation would
become straightened, and so lengthen the
tongue ; — this is an ingenious hj pothesis, but
no more : there is nothing that will bear such
an interpretation. Perrault, in speaking of
the lungs of chameleons*, expresses an opi-
nion that the tongue is driven, or, as it were,
coughed out by the sudden expulsion of the
air which the lungs contain.

The hyoid apparatus consists of the hori-
zontal projecting portion — the stilet already
referred to, and four cornua, two short ante-
rior ones, and two long vertical posterior ones
(fig- 761. A and B). These parts can move

freely on each other, the articulation between
the stilet and the greater cornua is particularly
free. These cornua ascend, and are suspended
loosely behind the jaws ; they are about three
quarters of an inch long, and are clothed with
the muscles that are attached to them. These
muscles are, 1st, the geniohyoid (e. A B and
C’.), arising from the inner surface of the
symphysis menti in contact with its fellow,
and inserted into the inferior extremity of the
vertical cornua, sending up a slip which is
attached to its whole anterior border. 2dly,
a distinct, small fasciculus, the cerato-maxillary
( f ), arising from the inner surface of the lower
jaw, and inserted into the apex of the vertical
cornua. 3dly, the sternohyoid (g), arising
from the inner surface of the sternal extremity
of the fourth and fifth rib, and inserted into
the junction of the cornua and glossal portion
of the hyoid, 4thly, the cerato-sternal (Ji),
more slender and flattened than the last, the
antagonist of the cerato-maxillary, arising from
the outer surface of the sternal extremity of
the second rib, and inserted, just opposite the
cerato-maxillary, into the apex of the greater
cornua. 5thly, the omo-hyoid ( i ), inserted with
the sterno-hyoid. This complicated arrange-
ment of muscles, which I have drawn from na-
ture* in fig. 761. A, is the mechanism for
the direction and extrinsic propulsion of the
tongue ; by it the lower extremities of the
greater cornua are drawn forward, and the
summits depressed, so that, instead of being
vertical, they are horizontal and advanced
(B). The advance of the whole tongue
thus gained is nearly an inch, and since
the muscles that principally effect it, the
genio-hyoid (e), are very strong, and the
movement quick and forcible, the question
may arise — Is this projectile movement suf-
ficient to send the rest of the tongue forward,
and effect its elongation, after the hyoid ap-
paratus has come to a stop, in the same
manner as the arrow flies from the string of
a bow, though the string itself is suddenly
arrested ? I think not. I think that some
such muscular arrangement as that described
by Cuvier must exist ; and possibly, some
transverse bundles of fibres of not very cha-
racteristic appearance, which, from the absence
of transverse striae, I rejected as muscle, might
have been of a muscular nature. The retrac-
tion of the tongue is easily accounted for; it
is simply drawn back on the stilet by the lon-
gitudinal muscles. The use of the stilet appears
to be, partly as a support to the tongue when in
a state of rest, and partly to direct its move-
ments ; for aim is seen to be taken while the
tongue is still retracted : the animal first places
itself in such a position that its head shall
be turned directly to the object to be seized;
it then fixes its head still more accurately, then
slowly opens its mouth to a sufficient distance
to allow the free egress of the tongue ; it then
seems to fix it with a sort of tremulous rigid

* It may be well to state that not only these, but
all the figures illustrating this article (with one or
two exceptions, which I have acknowledged), are
original, and have been drawn by myself from na-
ture, so that I can vouch for their correctness.

Essais de Physique, t, i ii

1150

TONGUE.

movement, and, in an instant, the tongue has
been shot out, has again disappeared, and
with it its prey has disappeared too, the
whole being performed with a velocity that
startles one afresh every time it is witnessed.

Aves. — The tongue of birds may be stated, in
general, to be, like that of reptiles, prehensile
and non-gustatory. Taste and mastication,
or, at any rate, taste and some delay of the
food in the mouth, always go together ; in
birds the food experiences no delay in the
mouth, but, in almost all cases, is bolted at
once. In most instances, true prehension, or
the seizing of the food, is performed by the
bill, in some few by the tongue ; in nearly all,
however, the securing of it when in the mouth
is effected by the tongue, which is armed near
the base with numerous spines, directed back-
wards (fig. 763. ABD), that prevent the
regress of the prey, whether alive or dead, and
w hich, with a similar structure at the roof of
mouth and throat, must greatly assist the first
stage of deglutition. The structure of the
tongue of birds is generally such as not to
admit of intrinsic elongation ; its protrusion
therefore can only be effected by the move-
ment of the organ en masse ; and this is pro-
duced to a surprising extent by a particular
arrangement of the hyoid bone and its muscles,
which I will now describe. The general cha-
racter of the hyoid bone of birds, as already
stated, is elongation — longitudinal extension,
and to this add the fact of the suppression,
entire or partial, of osseous or ligamentous
attachment of the hyoid elements to the skull,
such attachment being inconsistent with the
required free movements of the organ. From
the posterior part of the body of the hyoid
bone project back the slender posterior cor-
nua forming, by their divergence, an acute
angle, embracing in its apex the upper part of
the larynx : as they pass beneath the occiput
the}' curve upwards, and are surmounted by
slender pieces, frequently cartilaginous ( 'ceralo -
branchial), having a still greater curvature; so
that the whole greater cornua, as thus consti-
tuted, embrace the back of the skull, to the
shape of which their curve is moulded, and on
which they are made to glide backwards and
forwards by the muscles that regulate the
protrusion and retraction of the tongue. The
principal of these muscles are two pair ; the
first the analogue of the stylo hyoid, which
retracts the tongue, and the second pair
which Cuvier has called the analogue of the
genio hyoid — the conical muscle of Vicq
d'Azyr, — which draws the tongue forwards :
the obliquity and length of these muscles,
and the free unattached suspension of the
hyoid apparatus, render the movements of
the tongue very free, and their range exten-
sive. The retrahent muscle, the stylo-hyoid
(fig- 762. a.), arises from the posterior part of
the lower jaw, and passes forward to be in-
serted into the upper surface of the junction
of the cornua and body of the hyoid : in
some birds it is more voluminous than in the
species figured, and has a more extended
insertion ; it retracts the tongue. The pro -
trusor ( b), which Cuvier has named, with

apparently insufficient reason, the analogue
of the genio hyoid, arises from the inner

Fig. 762.

Musclesof the Tongue of the UfeM/are (Turdus pilaris).
a, retractor; b, protrusor; c, cerato-glossal.

side of the lower mandible, passes downwards
and a little backwards to the posterior cor-
nua, which it embraces in its fibres from the
point where it comes in contact with it to
its extremity : the fibres become increasingly
oblique as they pass back, and embrace the
cornua in a muscular cone, which, by its con-
traction, causes the cornua to slide forwards in
it, and so protrude the tongue . in the wood-
pecker, in which the hyoid cornua pass com-
pletely round the head and into the upper
mandible, this muscle is of proportionate
length. Besides these, there is a mylo hyoid, a
thin layer passing from the lower mandible to
a median fibrous line, and a cerato-hyoid pass-
ing from the posterior cornua to the uro-hyal,
approximating these, and so directing the apex
of the tongue to the opposite side. Fig. 762. c.
is a small muscle, which I cannot find de-
scribed ; it passes from the under surface of
the basi- or glosso-hyal to the greater cornua, .
into which it is inserted within the sheath of
the conical muscle. I would suggest the name
of cerato glossal for it ; its action is to in-
crease the curvature of the cornua, and there-
by draw the tongue back.

Fig. 763. represents some different forms of

i( m ii?

^ v4

TONGUE. 1151

the tongue in birds. A, is that of, the snipe
(Scollopax gallinago ), which is seen to be
linear; B, of the fieldfare (Turdus pilaris), the
epithelium breaking up into a leash of filaments
at its extremity ; C, that of the king-fisher (Al-
cedo ispida), so short that it hardly projects from
the surface at the bottom of its long bill ; D,
is the tongue of the common goose, furnished
with a linear series of spines on each side,
forming a serrate margin, which, with a corre-
sponding serration in the upper mandible, con-
stitutes a sort of sieve, through which the bird
sifts and strains, as it were, the mud and water
which it palpates in search of food. In the
back part of the tongue, both in this and in the
other figures, there is seen to be a peculiar
armature of recurved spines, whose arrange-
ment in the different species is constant and
characteristic. Some good representations of
different varieties of tongues are given in the
article Aves.

Mammalia. — The tongue of mammals differs
not in any material point from that of man.
The proportion of the different parts of its
muscular structure differ more or less widely
from the human type, and we find certain
muscles that have no place in the tongue of
man: to enter into the minutiae of these diver-
sities would not, however, comport with the
scope of the present article ; they must be
sought in monographs especially devoted to this
part of the subject. The coincidence of the
size and form of the tongue with that of the
inferior maxillary arch is very general ; in the
rodents this is very conspicuous, the tongue being
of the same wedge shape as their cuneiform
jaw. In some animals, as in the ant-eater and
giraffe, the tongue admits of great elongation,
and becomes an important organ of prehension.
The different elements of the tegumentary sys-
tem are merely modifications of those found
in man : the three orders of papillae are gene-
rally sufficiently conspicuous, and in most in-
stances they are more regularly arranged, and
their structure is more typical than in the
human subject ; for instance, the circumvallate
papillae are symmetrical, they present a greater
contrast to the rest in number, being fewer
than in man, and none of the fungiform ap-
proach them in form; the shape of the fungi-
form too is not liable to any variety, and they
are implanted with great regularity among the
conical. The conical papillae are generally
true cones, and are arranged with mathemati-
cal precision in lines in different directions,
accordingly as they are viewed. All these
papillae may be well seen in the dog. In the
felidce the conical papillae of the centre of the
dorsum are converted into recurved spines of
great size and strength, which the animal uses
in scraping the meat from the bones when
feeding, and in combing its fur.

Functions of the Tongue. — The phy-
siology of the tongue, like its organisation,
is double, all its functions being referable
either to those sensory or muscular endow-
ments which it possesses in so remarkable
a degree. Naturally, these are intimately
associated, its sensibility being necessary for

the direction of its muscular action, and its
movements necessary for the perfection of its
sensibility; a systematic consideration of them,
however, necessitates their separation, and
those functions that are referable to the
tongue as an organ of sensibility, have already
been treated of in the articles Taste and
Touch, to which the reader is referred ; it
only remains for me to consider those that it
possesses as an organ of motion.

These are prehension, mastication, insaliva-
tion, deglutition, speech, and one or two unim-
portant and non-essential offices in which it
is engaged, which may be called the accidents
of its physiology, as despuition or spitting,
whistling, &c. Of these the four first-men-
tioned belong to the tongue as an organ of
digestion ; they are, in fact, the first four stages
of that process; all four exist in all mammalia,
the first and the last in all vertebrata ; speech
and the other non-digestive motor functions
are peculiar to man.

Prehension. — The tongue is not, properly
speaking, in man, an organ for the prehension
of solid food, that office being performed by
the hand, for which the opponent arrange-
ment of thumb and fingers eminently fits it,
so that the human tongue has not those ad-
ditional qualifications which we find in other
animals to adapt it for an organ of pre-
hension. And this, I may remark, is an in-
stance of a very general law — that the ascent
in the animal scale is not a passage from
animals with simple organs to animals with
complex organs, but from simple individuals
with organs of complex function, to complex
individuals with organs of simple function, the
addition as we ascend being, not of functions,
but of parts to discharge those functions, and
the advantage gained, not another thing done,
but the same thing done better. Thus in man,
instead of having one office more, the tongue
has one office less than in many animals below
him ; and the delicate and extended prehen-
sion supplied by his hands, diminishes by one
item the complexity of function, and, there-
fore, of organisation of his tongue. So that
in judging of the elevation of animals by their
individual organs, supposing such a method
to be admissible, we must not look to complex-
ity of structure of those organs, but to the
perfection of the resulting function. But to
return.

In the prehension of liquids, or suction, the
tongue in man is engaged; constituting a
movable wall of the oral cavity, it acts as a
piston, and draws the liquid into the mouth
by the formation of a temporary vacuum.
Bichat enumerates three methods of the pre-
hension of liquids, by suction, by drinking
from a vessel, and by infusion into the throat;
in the first two the tongue is concerned ; in
the last, which seems to me hardly to deserve
the name of prehension, it is not. In suction,
which is peculiar to the infant, the nipple is
seized by the lips, which are compressed
around it by the orbicularis oris; the velum
palati is elevated so as to close the posterior
nares : the tongue forms, by the contraction

TONGUE.

1152

of the middle fibres of the genio-glossus, which
depress its centre, a longitudinal channel,
which receives the nipple, and transmits the
milk to the pharynx as long as a vacuum con-
tinues to be formed. In drinking liquids from
a vessel the tongue forms a channel for its
transmission, but it flows down to the pharynx
by its own proper gravity.

Mastication. — As far as relates to the tongue,
which here, however, is only subsidiary to the
teeth, the mechanism of mastication may be
divided into three stages: — first, that of
placing the food in an advantageous position
with regard to the teeth; secondly, affecting
the position of the food in a definite manner
when under the action of the teeth ; thirdly,
collecting the scattered portions of masticated
aliment prior to deglutition. Immediately on
the introduction of a morsel of food into the
mouth, either bitten by the incisors or other-
wise, it is at once transferred to the molars,
so that it shall project beyond them, outwards,
against the cheek ; the cheek is then pushed
against it by the action of the buccinator, and
the food is slowly driven across the teeth,
which are rhythmically opened and closed, the
tongue at the same time pushing moderately
against it on the inside and so regulating the
movement imparted to it by the cheek. Thus
we see that the food under mastication is sub-
jected to an equable and regulated motion ;
that it is placed, as it were, between two
movable walls, and that by the even lateral
movements of these walls, and the rhythmical
vertical action of the teeth, its perfect masti-
cation is secured. As soon as the cheek has
pushed it inwards as far as it can, an interval
in the rhythmical closure of the teeth takes
place, and the tongue restores it to its former
position, again to be pushed inwards, and so
on. The equable mastication of the food is
secured much in the same way as the even
motion of a rod of timber, under the blade of
a circular saw, secures the cutting off of pieces
of equal thickness. Any one who watches
himself whilst eating will at once observe the
sets of rhythmical action, interrupted by short
interval, in which the food is restored to its
necessary position between the teeth. The
third stage, that of collecting the food from
all parts of the mouth, admits of no particular
description.

Insalivation. — There is no separate or super-
added process for insalivation; it proceeds con-
temporaneously with mastication, the motions
which are necessary for the one supplying
equally the required conditions of the other ;
while the food is being comminuted by the
teeth, dispersed by their action to different
parts of the mouth, recollected by the tongue
to be again dispersed, and so on, the salivary
secretion is freely mixed with it, and reduces
it to a homogeneous pulp : thus mastication
facilitates insalivation by breaking up the food,
and insalivation facilitates mastication by
softening it. As one set of acts performs
the two processes, of course there are not
any additional movements of the tongue to
describe.

Deglutition. — When the food has attained a
sufficient moisture and softness, which is ap-
preciated by the tongue’s sense of touch, it
is collected into a mass, and the process of
deglutition commences. Physiologists have
divided this process, and the division is a good
one, into three stages, which may be distin-
guished respectively as the oral , th e pharyngeal,
and the oesophageal: the first conducts it past
the anterior pillars of the fauces, the second in-
cludes its transmission from that point through
the pharynx into the oesophagus, and the
third commences with its arrival at the oeso-
phagus, and terminates with its entrance into
the stomach. The first is entirely voluntary ;
the second is of a mixed nature, engaging
partly voluntary and partly involuntary muscles,
and, though practicable at will, is yet impres-
sible on the transference to the back part of the
tongue of the material to be swallowed ; the
third is wholly involuntary. With the two
first alone the tongue is engaged, and, there-
fore, of these alone I shall speak.

The first stage is merely the reference of
the ball of alimentary matter to a point on the
back of the tongue, posterior to the anterior
pillars of the fauces. This is effected by the
pressure of the tongue against the palate,
whereby the food is forced back between the
two.

The second stage is a much more complex
process, involving a more varied mechanism,
and engaging in it different parts, the tongue,
the pillars of the fauces, the soft palate, the
larynx, and all the muscles of the pharynx.
As soon as the food has passed the anterior
palatine arch, that arch contracts, and by its
constriction entirely prevents the regression
of the food into the mouth ; at the same time
the base of the tongue, and with it the food,
is carried further hack, and a second closure
takes place from the approximation of the
posterior pillars of the fauces, produced by the
contraction of the palato-pharyngeal muscles
that form them: this part of the mechanism
requires a little explanation. The contraction
of the anterior pillars of the fauces closes the
entrance into the mouth by a constriction or
sphincter-like action : this is due to the general
circular form of the constrictor isthmi fau-
cium occasioned by the inward curvature of the
upper and lower extremities of each palato-
glossus muscle. The contraction of the palato-
pharyngei is not of this nature; they have not
the same inward curvature above and below,
and their inferior attachments to the pos-
terior borders of the thyroid cartilage are
capable of very little approximation ; when,
therefore, they contract, the soft palate being
fixed, they approach one another laterally like
two curtains, leaving a narrow chink in the
middle, wider below than above. As soon as
the food has passed this point, this contraction
takes place, so that the two muscles of the
opposite sides almost touch, the chink between
them being occupied bv the relaxed uvula ;
the passage into the posterior nares and upper
part of the pharynx is thus cut off, which has
induced Dzondi to call the posterior palatine

TONGUE.

1153

arch the velum palati postering. At the same
time that this is taking place, the base of the
tongue is thrown hack upon the epiglottis*, the
larynx being drawn upwards and forwards
to meet it, so that the rima glottidis is com-
pletely closed, and the food glides safely down,
over the inclined plane thus formed, into the
pharynx raised and dilated to receive it :
the food then comes within the grip of the
constrictors of the pharynx, which successively
pass it downwards to the oesophagus. This
process takes place so rapidly that it is difficult
to trace its parts in succession, and indeed
some of them, which apparently succeed one
another, are in reality contemporaneous : thus,
the first stage — the raising of the dorsum of
the tongue to the palate — is that which mainly
contributes to the inclined plane of the second
stage ; and the raising and carrying forwards
of the larynx under the tongue is that which
principally dilates the pharynx.f

The third stage, or the oesophageal, conducts
the food to the stomach ; it is of that peri-
staltic or vermicular nature that characterises
all the succeeding movements of the alimentary
canal ; the muscles concerned are entirely
involuntary, and the nature of the act purely
reflex. The tongue is not concerned in it.

Speech. — The tongue is the instrument
principally engaged in those modifications of
the oral passages which give rise to articulate
sounds, which, definitely grouped and com-
bined by man, and taken as the representa-
tives of certain objects, actions, qualities, and
relations, constitute Language. The con-
sideration of this interesting subject, however,
will more appropriately fall under the article
Voice, to which the reader is referred.

Morbid Anatomy of the Tongue.
— The tongue is obnoxious to a variety of
morbid changes, which might naturally be
expected from the number and nature of
the elementary tissues which enter into its
formation, as well as from the diversity of the
functions it has to perform, and the exposure
to injury in which it is placed; — changes
which may consist either in some increase,
decrease, or disproportion of its normal ele-
ments, in some lesion or morbid change in
those elements, or else in the superaddition of
some adventitious growth.

The tongue may be affected with inflam-
mation, hypertrophy, atrophy, induration ;
with ulceration, numerous morbid changes in
the conditions of the papillae ; with tumours,
cancer, aphthae ; and the organ, moreover, is
subject to be displaced, — there is prolapsus
of the tongue, the tongue may be inverted

* It would seem that the epiglottis is not abso-
lutely necessary for the protection of the rima glot-
tidis, but that the pressure of the base of the tongue
over it is sufficient ; as there are authentic cases on
record, in which the epiglottis was quite destroyed
by syphilis, and yet deglutition was never attended
with any inconvenience.

t For a detailed account of this process, see
Dzondi, die Functionen des weichen Gaumens.
Hade, 1831.

VOL. IV.

and embraced by the pharynx — swallowed ;
and the tongue may be unnaturally fixed by
an unusual extent of frenum, the individual
thus circumstanced being tongue-tied.

Inflammation of the tongue. — The morbid
changes caused by inflammation of the tongue
are modified by the structure of the organ.
There is one form of this disease in which,
from the extreme vascularity of the tongue
and the distensibility of its covering, it swells
to an enormous size with great rapidity, and
subsequently recedes without suppuration :
this I have ventured to call erectile. In other
cases the tongue suppurates. The constitu-
tional action of mercury is another cause of
glossitis. I therefore divide glossitis, for its
more complete consideration, into — I. Idio-
pathic (1. Suppurative; 2. Erectile)-, and
II. Mercurial.

Suppurative glossitis. — This is an extremely
uncommon affection. It commences with
heat, swelling, induration, and some fever;
matter presents itself at various lengths of
time, forming a more or less circumscribed
abscess. It generally occurs on one side, and
points just beneath the edge of the tongue.
According to Dr. Moller, of Zealand, scrofu-
lous persons are most liable to this affection.
Instances are recorded by Mr. A. Smee, Dr.
Graves, Dr. Moller, and one example occurred
in the practice of the author’s father. This
latter patient was a lady, recovering from
an attack of influenza. Her tongue, which
was affected principally on one side, became
swollen, tender, hard, stiff, and incapable of
movement. She could not speak, and swal-
lowed with great difficulty. At length the
pus was evacuated, and the tongue healed,
and recovered all its functions immediately'.
This lady now possesses a remarkably good
use of the organ.

Erectile glossitis. — This malady, though
less rare than the preceding, is still quite un-
common. The morbid condition of the tongue
in this disease appears to consist in an enor-
mous and rapid distension of the organ by
blood, rendering it very large, hard, and stiff.
In the majority of cases it occurs in people in
perfect health, and seems to be a purely idio-
pathic inflammation : in some cases it seems
to have followed exposure to cold, and in
others it was associated with febrile disorders.
In this disease the first change which occurs
is a perceptible enlargement of the tongue,
which feels rather stiff, painful, and tender
with a little difficulty in speaking, the patient
being in other respects well. The case gene-
rally proceeds rapidly; in two or three hours
the tongue is much larger; there is a good
deal of distressing burning felt in it. Sy-
nocha, symptomatic of the local inflammation,
now occurs, and goes on increasing with the
glossitis, and the patient becomes anxious and
alarmed. The tongue occupies now the whole
cavity of the mouth, or even protrudes, and
the jaws are kept apart. Mr. Martin thus
describes the condition of the tongue at this
stage ; — “ On examining the tongue, I found
that it occupied a large proportion of the

4 E

1154

TONGUE.

cavity of the mouth ; and I could with diffi-
culty introduce my little finger between it and
the upper jaw. It felt smooth and hard to
the touch, and had a thick coating of viscid
mucus : from the high degree of tension,
the point presented a glistening appearance.”
( Edinburgh Med. and Surg. Journal, vol. xxviii.
p. 76.) As the case advances the tongue
increases still further in size, the patient can-
not perform the first part of the act of deglu-
tition, and the liquid food is obliged to be
conveyed by some mechanism into the pha-
rynx ; respiration through the mouth ceases,
and that through the nares is impeded : the
patient is now almost on the verge of suffoca-
tion, and his distress and anxiety become
extreme. Mr. Martin remarks : — “At this
period respiration through the mouth was
totally suspended ; and he could not breathe,
even through the nostrils, but with difficulty.
His countenance was flushed and anxious, the
pulse was fluttering, his breathing offensive :
in short, he was threatened with immediate
suffocation.'’ (Luc. cit., p. 77.) The condition
of the tongue sometimes approaches gangrene.
Mr. Hayes, in describing a similar case at an
advanced stage, observes: — “It now began
to look of a dark black colour, or rather as if
it had been broiled over a smoky fire; indeed,
I expected it would mortify.” ( Memoirs of the
Medical Society of London, vol. ii. p. 193.)

I am not aware that mortification has ever
resulted in these cases ; neither does abscess
appear to be thus produced,* which, however,
may be accounted for by the fact, that these
urgent cases almost always render it necessary
that the organ should be freely incised on the
dorsum to evacuate the distending blood, and
this would prevent the formation of abscess;
though in some very severe instances, where
incision has not been practised, no abscess
has resulted. When the inflammatory action
ceases, which is immediate when the before-
mentioned operation is performed, the tongue
rapidly recovers, and the fever vanishes.
When the tongue is incised, the quantity of
blood discharged is very great.

The morbid change in the tongue does not
always go to the extent above described, and
then milder symptoms are produced. Dr.
England mentions two mild cases, in both of
which the left half of the tongue alone was
affected. Dr. Graves relates a severe case,
also confined to the left side, in which he
says the part “ appeared on the verge of gan-
grene.” (Dublin Hospital Reports, vol. iv.
p. 43.) De Lamalle narrates an example, in
which the patient was almost suffocated in
five hours from the first appearance of the
malady. The tongue was more than three
times its natural size ; it filled the whole
mouth, and protruded between the teeth.
Free incisions saved the organ and the patient.
Trincavellius mentions a case where it oc-

* Since the above has been in type, a case occur-
ring to Dr. Schneider has been published, where
this form of inflammation terminated in abscess.
(Casper’s Woclienschrift. No. 23.)

curred in Variola ; Mr. Hayes an instance,
where an individual, licking an urticarious
eruption, had this effect produced to a slight
extent on her tongue ; and the same thing, to
a small degree, 1 have known occur from a
person eating mussels.

Collier, Taynton, Job a Mekren, Paletta,
Elbuig, Frank, and Orgill, also enumerate ex-
amples of this condition.

Dr. Craigie has described a peculiar form
of glossitis, under the name of Lingual
Quinsy, which is an extension of ordinary
quinsy, or tonsillitis. The portion of the
tongue involved is that bounded in front by
the circumvallate papillae, behind by the epi-
glottis, and at the sides by the mucous mem-
brane passing off upon the pharynx and rami
of the lower jaw. The inflammation extends
down the palato-glossus muscle from the ton-
sils to the base of the tongue, and seems to
involve the mucous, submucous, and muscular
tissues. The parts are swollen, infiltrated,
and stiff ; the lower jaw cannot be depressed,
and attempts at deglutition are not only diffi-
cult, but the completion of the act is impos-
sible. There is an abundant secretion of
ropy mucus. Dr. Craigie had one fatal case,
in which he found after death, that “ the base
of the tongue was tumid, hard, and much
distended with blood and serum infiltrated
into its cellular tissue, and the parts between
that and the angle of the jaw were in like
manner infiltrated.” (Edin. Med. and Surg.
Journal, vol. xlii. p. 26.)

Mercurial glossitis. — Inflammation of the
tongue, the result of the mercurial action, is
but one symptom of the constitutional influ-
ence of that drug. The tongue in this case
becomes large, soft, painful, white and furred,
and much indented by the teeth along its
edges : the epithelium is soft and readily re-
moved, and the surface is apt to ulcerate.
The swelling is sometimes very great and
rapid. Siegel and Trincavellius each mention
such a case. I believe it has never caused
suppuration of the organ ; but the discon-
tinuance of the mercury is followed by com-
plete resolution.

Ulceration of the tongue. — This is the most
frequent of the morbid changes occurring in
the tongue, and of it there are several species
and varieties. The different species may be
enumerated as, I. The Dyspeptic ulceration,
or that arising from disorder of the prim as
viae ; II. Indurated non-malignant ulceration;
III. Gangrenous ulceration ; and IV. Syphi-
litic ulceration.

Dyspeptic ulceration is met with in three
principal forms. I. Small circular ulcerations
at the tip and along the edge of the tongue;
2. Severe and deeper ulcerations of the body
of the tongue ; and, 3. Aphthous ulceration.

The small circular ulcers of the tongue are
extremely common, and have been personally
experienced by almost every individual. They
consist of small, circular, generally regular and
well defined ulcers, which are superficial and
look as if a piece of mucous membrane had
been punched out ; the edges are sharp and

TONGUE.

1155

well defined : these ulcers vary in size from
that of a pin’s head to that of a split-pea, or
larger ; they are almost constantly situated at
the tip, or edges of the tongue ; they are
sometimes grey, at others red ; when touched
against the teeth they are acutely painful, and
their presence causes an abundant and con-
stant secretion of saliva. In the commence-
ment, however, there is no ulceration, but
the malady begins by an affection of a papilla,
consisting in an effusion of lymph into a
fungiform papilla (hereafter to be described),
and this terminates in ulceration : the papilla
is at first large, yellow, and distended with
lymph ; in a few hours it has disappeared, and
its site is occupied by an ulcer, which after-
wards more or less spreads in a regular, cen-
trifugal manner. I believe this process has
never before been properly described, — per-
sons not being aware that any thing has hap-
pened until the ulcer exists, and consequently
never seeing or exhibiting the malady in the
first stage; but any one, subject to these little
infirmities, may satisfy himself of the truth of
what I have said by carefully watching the
state of his tongue from day to day.

The severe and deep-seated ulcerations of
the tongue, arising from mere disorder of the
alimentary canal, may consist of an extension
of the already-described variety, or it may
commence by a vesication, or an excoriation
of the surface ; it generally occurs in people
who are debilitated from some cause or
another. Mr. Lawrence relates the following
characteristic case : — “A lady, between fifty
and sixty, of unhealthy appearance, with a red
pimply face, who had often suffered from dis-
order of the digestive organs, consulted me
for a disease of the tongue of formidable ap-
pearance. The middle and upper part of the
organ was swollen, and occupied by a deep
ulcer ol irregular figure and foul aspect. It
was very painful, interfering with mastication
and articulation. The digestive organs were
much disturbed. The complaint yielded
speedily and effectually to simple measures —
regulation ot diet, and the digestive organs,
small doses of extract of henbane, and sooth-
ing local means,” (Clinical Lecture, Medical
Gazette, vol. xxxvi. p. 800.)

Mr. Lawrence mentions an instance in
which rawness and severe excoriation of the
tongue often repeated, the result of periodic
and long-continued dyspepsia, appear to have
induced true scirrhus of the organ.

Aphthous ulceration. — The ulceration is
merely one stage of a peculiar morbid change,
to which the tongue, in common with some
other portions of the gastro-intestinal mucous
membrane, is liable. The tongue, however,
suffers more severely than most other parts.
It is eminently the result of disordered diges-
tion, and is accompanied with more or less
fever of an atonic character. An aphthous
tongue is rather swollen, tender, and furred,
and has a sensation of burning heat : on its
surface, scattered about irregularly, are small
white bodies, resembling little masses of curd,
varying in size from a split pea to a pin’s-

head, attached pretty firmly ; these bodies, as
well as the swollen state of the tongue, cause
the subject of them pain and inconvenience :
after a variable time these little white masses
fall off', leaving the membrane on which they
rested in an altered condition, — it is either raw
and excoriated at these spots, the epithelium
being peeled off and leaving the papillae naked,
exposed, and red ; or else, the deeper ele-
ments of the membrane being affected, an
ulcer is formed. These ulcers are generally
more or less circular and superficial, and are in
no way to be distinguished, at this stage, from
the little circular ulcers already described, but
aphthae on the neighbouring portions of the
tongue disclose their true nature. The white
aphthous mass itself has been variously de-
scribed as a slough, concrete mucus, and alhu-
mino-Jibrin, but it consists in reality of a mi-
nute parasitic fungus, which attaches itself to
the mucous membrane and burrows among its
epithelial cells. Seen under the microscope,
it is found to be composed of threads matted
together like felt, and intertwining among the
epithelium. Accompanying aphthae are gene-
rally to be seen on the surface of the tongue,
small vesicoe, spots of epithelium raised with
a little serum underneath, and also some of
the papillae distended with fibrinous exuda-
tion — conditions to be described presently.

Indurated non-malignant ulceration, — Indu-
rated ulcers, which are neither syphilitic nor
malignant, but closely resembling scirrhus,
are occasionally met with, and their doubtful
character gives the surgeon not a little trouble.
Mr. Lane narrates the following formidable
example : — “ Mr. G. B., aged 33, came to
me in the month of June, 1813, with a very
foul ulcer beneath the tongue, and said that
he some time before had had one on the upper
part of it, which he said was healed ; but on
examination there was a deep irregular fissure,
with raised, jagged, hardened edges, commu-
nicating with the ulcer under the tongue,
which, on examining with a probe, I found not
only communicated with the fissure on the
upper surface, but the instrument passed
through the substance of the tongue, into a
deep seated ulcer at the root of it, and thence
into the throat. The general appearance of
the disease was most alarming, bearing a very
strong character of carcinoma. He experienced
great pain and difficulty in deglutition, and
complained that the pain had of late extended
behind the ears, to the back of the head and
neck,” ( Medico-Chirur . Trans., vol. viii.p. 202.)
The case, however, was not one of carcinoma,
for the patient completely recovered under
alterative treatment. About two years since
an instance came under my own notice. A
man of about 45, had been a sailor ; had never
had syphilis ; for about six years had been
labouring under a disease of the tongue, with
little improvement, or permanent change, in
its condition. When 1 saw him, the right half
of the tongue was enlarged and much indu-
rated ; the left was of natural size and soft, but
with few papillae ; on the right side no pa-
pillae were to be seen, and the surface was ex-
4 e 2

1150

TONGUE.

coriated, chapped, and in parts superficially
ulcerated. lie told me that at one time the
left side had been diseased in a similar way.
The lymphatic glands behind and beneath the
jaw and down the neck were enlarged and
indurated, and had been so from the first. The
free application of lunar caustic to the tongue
lessened the affection, and the lymphatic
glands became smaller and softer ; but the
other side became afterwards diseased, and
was relieved by the same treatment ; the
tongue was, however, never restored to a
healthy state, though, when I last saw him,
there was no ulceration. There was profuse
secretion of saliva ; but, with this exception,
the man was remarkably healthy.

Mr. Lawrence, in his Clinical Lecture, al-
ready referred to, describes this condition of
tongue. ( hoc . cit., p. 799, case ii.)

Gangrenous ulceration. — The tongue is liable
to a peculiar gangrenous ulceration, called
“ Glossanthrax ” or “ Malignant pustule.”
It commences as a vesicle containing bloody
serum ; it gradually becomes black and bursts,
and the lingual tissues beneath and around it
are seen to be gangrenous ; this may proceed
till the whole tongue is in a state of mortifi-
cation : when it exists to this degree, there is
fever of a profound typhoid character, with
delirium, and the patient soon dies. Audral
has given an account of this disease in his
Pathological Anatomy. Heyfelder narrates
the case of a Prussian butcher, who, when
slaughtering a diseased sheep, put the knife
and held it for some time between his teeth.
In two or three day's the margin of his tongue
was covered with black pustules. The part
swelled alarmingly, and most painfully ; vio-
lent fever set in, and the patient was carried
off in the course of sixty hours.

I once saw a patient in low fever, who had
enormous sloughing of the dorsum of the
tongue, which proceeded in successive por-
tions till a large deep excavation, that would
have received half a walnut, was produced.

Syphilitic ulceration. — Hunter* strangely fell
into the error of thinking that venereal ulcer-
ations of the tongue are uncommon, whereas
they are the most common to which the organ
is liable ; and the tongue, next to the tonsils,
is more frequently attacked, in the constitu-
tional forms of this disease, than any other
portion of the mucous surface.

A small, circular, superficial ulcer is the most
common syphilitic affection of the tongue ; it
begins exactly like the little ulcers of dyspep-
tics, from which it cannot be distinguished.
These ulcers are situated principally at the
tip and along the edges of the tongue. As
in almost all instances of ulceration of the
tongue, the ulcer is the second part of the
process, and follows the deposition of fibrinous
matter under the basement membrane ; in this
case in a single papilla, or a few contiguous
ones, as I have already described. These ul-

* Speaking of ulceration of the tongue, Hunter
observes, “ these are commonly supposed to be vene-
real ; but I believe they seldom are.” ( Hunter’s Trea-
tise on the Venereal Disease. Page 337. 2nd Ed. 4to.)

cers generally do not extend, but yield to the
most simple treatment ; sometimes, however,
they do extend, and form various sized un-
healthy ulcers, deep in proportion to their
extent, cupped and indurated at the base. At
other times they show a tendency to run in
one direction, and remain superficial : 1 saw
an example of this in a patient who had a
very narrow superficial ulcer an inch in length,
originating in a small circular ulcer, and ex-
tending along the under surface of the tongue,
on the left side, just at the point where the
mucous membrane is reflected from that organ
to the jaw : it was very superficial, and, as it
progressed, it attacked the healthy membrane
in its course.

Rhagades or fissures in the tongue are not
uncommon : they are ulcerated clefts, which
extend down, often to a considerable depth,
into the substance ofthe tongue. Mr. Lawrence
describes one three quarters of an inch deep ;
though sometimes they only form a chap in
the mucous membrane: he also describes one
extending the whole length of the tongue, just
in its centre, in the long axis ; this was deep,
and with irregular ulcerated edges. When
seen in the fore part of the organ, they are
generally in the middle line, or nearly so ; but
those further back are scattered about, and
just in front of the ciroumvallate papillae,
which is their most usual situation. They
are commonly associated with an indurated
and irregularly tuberculated surface of tongue
— these tubercular lumps being sometimes
like large fissured warts, at others glossy and
smooth. The rhagades are generally red,
while the surrounding tubercles are grey, or
whitish, or, at other times, red and excoriated.

The glossy tubercle, to which I have re-
ferred, is a remarkable disease : it often forms
with great rapidity, and as quickly disappears.
It seems to consist in an effusion of lymph
into the cellular tissue underlying the mucous
membrane ; this effusion is very dense, and
raises and distends the surface of the tongue
at the affected part above the surrounding por-
tions ; the effect is, that the complications of
the membrane, which constitute the papillae,
become unfolded, and the papillae are, as it
were, opened out, — they form now one smooth
extent, and stretch over a large surface, the
faintest indications only of the papillae being
apparent, and sometimes they are totally ob-
literated. That this is the true explanation
of these smooth tubercles is evident from the
fact, that as they form, and in proportion to
the distension of the membrane, the papilla
diminish and shorten ; and as, under the influ-
ence of medicines, the swelling decreases, they
reappear exactly in the same ratio. These
tubercles have little sensation or pain, unless
the surface be excoriated ; they are dense,
almost as hard as schirrus ; their base is felt
pretty deep in the substance of the tongue ;
their surface is polished, glossy, and whitish —
they remind me of the tongue of a fish ; they
are generally oval or round, when smallish and
single, and they are most frequently situated
on the dorsum of the tongue, about half an

TONGUE.

1157

inch or an inch in front of the circumvallate
papillae, and on one side of the mesial line.
Sometimes they form over the whole surface
of the tongue. I am acquainted with a gen-
tleman who, at the time he was suffering from
syphilitic psoriasis, got an attack of dyspepsia ;
in less than thirty-six hours the whole of his
tongue was one mass of these tubercles, and
not a papilla was to be seen ; in a few days
(under the influence of iodide of potassium)
every papilla had reappeared, and the tongue
was in every way natural. This influence of
disordered stomach being the immediate and
exciting cause of the manifestation of the
syphilitic poison on the tongue, I have fre-
quently noticed ; a person who has a taint of
lues venerea can scarcely sustain the least dis-
order of the stomach or bowels without its
showing itself upon the tongue. These tu-
bercles of the tongue, when left to themselves,
are very apt to become fissured and form
rhagades ; the space between two of them is
liable to be the seat of an ulcerated fissure.
Deep circular ulcers sometimes form on these
tubercles.

Phagedcenic syphilitic ulcers are seen occa-
sionally on the tongues of feeble debilitated
people.

All these forms occur as the result of
the constitutional taint of lues venerea, at
various periods after the primary symptoms.
I have known the glossy tubercle and
rhagades occur fifteen years after the primary
sore.

Cancer of the tongue. — The tongue is liable
to be affected with scirrhus, having all the
properties of genuine cancer. Mr. Travers
has given a very graphic description of cancer
of the tongue, which I shall take the liberty of
quoting in extenso. — “ This is not a smooth
and firm rounded tubercle, such as is often
met with in this organ, but an irregular rugged
knob in its first stage, generally situated in the
anterior third, and midway between the raphe
and one edge. It sometimes, but seldom,
extends across the middle line, although it
often extends alongside of it. The hardness
is unyielding, inelastic, and the mucous surface
puckered and rigid. It also gives to the finger
and thumb of the surgeon the sensation of
solidity, or of its penetrating the entire mus-
cular substance, being perceived equally on
either surface. Sharp shoots of pain are felt
through the side of the affected organ, towards
the angle of the jaw and ear. The disease
tends to run backwards towards the base or
posterior edge. It sometimes acquires great
hulk before ulceration takes place, so as to
project the tongue from the mouth. In this
state a female patient of mine was seen some
time ago in St. Thomas’s Hospital, in whom
the permanent projection of the diseased organ,
beyond the widely distended lips, was from
three to four inches. The ulceration often
extends from the edge of the tongue to the
membrane of the mouth and gums, when the
elevated and distended membrane at length
gives way, and ulceration is rapid. The sur-
face of the ulcer is very uneven ; clean and

bright granulations appearing in parts, and in
others deep and sloughy hollows. The dart-
ing pain is very acute, but only occasional.
There is a dull aching always present, and as
constant a spitting as in deep salivation. It
happens to strong and hitherto healthy per-
sons, for the most part males from the age of
forty onwards. There is generally an evening
paroxysm of pain, and the nights are much
disturbed by the secretion accumulating in
the throat, which excites cough. Often the
patient is roused by a painful compression of
the tongue falling between the jaws. Speech
is much affected and painful.

“ Towards the fatal termination of the dis-
ease, occasional profuse haemorrhages take
place at shortening intervals, and alarm and
weaken the patient, who ultimately dies tabid
and exhausted, generally with symptoms of
more extensive disease of the mucous mem-
brane in other parts.

“ The period at which the sublingual and
contiguous lymphatic glands become affected,
and the extent of their change, are very vari-
able. I have known them form the base of
the tumor, the cauliflower fungus occupying
half the tongue, i. e. two or three inches long
and one broad ; after death the jaw was found
covered with fungus.” ( Meclico-Chirurgical
Transactions, vol. xv. part i. p. 245.)

The scirrhus is not infrequently at the very
margin of the tongue. Louis mentions a case
where there was a little circumscribed tubercle
of scirrhus, about the size of a filbert, at the
edge of the tongue : it was ulcerated.

It occasionally shows itself early in life :
Arnott mentions a case where it was present
in a girl of fifteen.

In a subject who died of lingual cancer,
dissected by myself, I found that the whole
of the right side of the tongue, right tonsil,
the upper part of the pharynx on the right
side, and the mucous membrane, extending
from the tongue to the epiglottis on the
same side, were removed by ulceration, and
the inner surface of the lower maxilla laid
bare. The other half of the tongue was
healthy, and only the ulcerated edge was
scirrhous. The lymphatics were enlarged,
and of a greenish -yellow colour : they con-
amed pus.

Tumours of the tongue. — A variety of tu-
mours have been met with in the tongue.

Fatty tumours have been found by Mr. Lis-
ton on the under surface of the tongue. Mr.
Hale Thomson exhibited to the Westminster
Medical Society, in 1839, a fatty tumour
which he removed from the side of the tongue.
It consisted of fat contained in a cyst.

Encysted tumours. — Many of the so-called
instances of ranula* have been abundantly
proved by Dupuytren, Breschet, and Malgaine
to be simply serous cysts, and not obstructed
salivary ducts. They consist of dense mem-
branous cysts, containing a thick albuminous

* The consideration of rantila belongs to the mor-
bid anatomy of the salivary glands, and not of the
tongue.

4 e 3

1 15S

TONGUE.

fluid, and not inspissated saliva. They are
situated in the cellular tissue immediately
under the mucous membrane, where they
sometimes grow to an enormous size. Mr.
Earle has described curious little vesicular
tumours, which he found in the tongue of a
boy : — “ Clusters of very minute semitrans-
parent vesicles pervaded the whole thickness
of the tongue, occupying nearly one-half, and
projected considerably both above and below
that organ. The slightest injury caused these
to bleed profusely, and in some places the
clusters were separated by deep clefts, which
discharged a fetid, irritating sanies.” ( Medico -
Chirur. Trans., vol. xii. pt. ii.) The tongue
was quite restored by the use of internal
medicine.

A mulberry-like tumour has been described
by Mr. Probart. It formed on the tip of the
tongue of a boy four years of age. It was of
a peculiar granulated appearance, resembling
a half-ripe mulberry, feeling hard and free
from pain. It grew gradually : at two months
it was the size of a nutmeg; but after that, in
five weeks, it rapidly increased till it was of
the bigness of a hen’s egg, protruding nearly
two inches beyond the lips, which were sepa-
rated widely by it, preventing the little patient
taking any thing but spoon meat, and that
with difficulty. It was highly vascular, and
bled profusely from innumerable vessels, which
nothing but the cautery would arrest, when
amputated. There was no return of the
disease.

Polypus-like tumours have been met with
on the tongue, consisting of a fleshy mass,
like the rest of the organ, attached to it by a
pedicle. Louis mentions one of these about
the size of a nutmeg, which he removed from
the tongue of a young man eighteen years of
age: it was situated on the middle of the
dorsum of the tongue. A more remarkable
example is described by Dr. Huie. The case
was ffiat of an old maiden lady, in whom a
tumour formed, about three months after a
catarrh and inflammation of the fauces, upon
the root of the tongue, and gradually increased
for twelve months, when “ the smooth
rounded form of the tumour conveyed, at
first sight, the idea that it was of an encysted
kind ; but, upon examination with the finger,
it was found to be as hard and unyielding as
the substance of the tongue itself, and evi-
dently of the nature of polypus.” ( Edinb .
Med.-Chirur. Trans., vol. iii. p. 72.) It filled
nearly the whole pharynx, and moved with
the tongue, to which it was attached by a
pedicle. Ligature was subsequently applied,
by which it was removed. “ The tumour,
which is in the Museum of the Royal College
of Surgeons (of Edinburgh), was of an oval
form, weighed exactly an ounce, and mea-
sured five inches in its long, and four in its
short, circumference. It was broadest op-
posite the insertion of the pedicle, which
entered at the distance of an inch from the
upper part of the tumour. A longitudinal
incision, which has been made into it, displays
a firm cartilaginous nucleus, as large as a

chestnut, surrounded by a fibro-cartilaginous
structure, forming the rest of the tumour.”
( Loc . cit., p. 76.) I strongly suspect that all
these pedunculated tumours of the tongue
are hypertrophied fungiform or circumvallate
papillae.

Hypertrophy and prolapsus of the tongue. —
This is a singular affection, which usually
commences in infancy, and is sometimes con-
genital. It generally begins and progresses
slowly by an enlargement of the organ within
the mouth ; it afterwards projects perma-
nently between the lips, and then advances
more rapidly, and the tongue, which was
before of normal, though hypertrophied, struc-
ture, becomes parched and fissured on the
upper surface, and ulcerated beneath. Some-
times the amount of tongue that is protruded
is enormous. The os hyoides and larynx are
drawn up, whilst the jaw is depressed, and
the incisors are pushed out in a horizontal
direction.

Dr. Wells, of Columbia, has given a good
case, of which the following is a condensed
description. The patient was a little girl, six
years old, with an enormous enlargement of
the tongue; otherwise she was in good health,
and a fine robust girl. The following are the
dimensions and state of the tongue at the
time : — length, as it remained at rest and
hung down over the chin, from the superior
incisors to the apex, two and a half inches;
circumference just in front of the lips, six
inches ; breadth, from one angle of the mouth
to the other, a little more than two inches.
It had undergone a very considerable change
in structure, was much more dense than na-
tural, and not subject to change in its dimen-
sions by the action of its own muscles, or, if
at all, very slightly so. Its motions other-
wise were sufficiently free : upper surface
smooth ; inferior covered with the cicatrices
of old ulcers, several of which, where the
tongue rested upon the alveolar processes of
the lower jaw, were but imperfectly healed ;
colour darker than natural. Within the mouth
the tongue had undergone no apparent change
except a moderate increase in width and
thickness. The front teeth had been dis-
placed from the lower jaw by the long-con-
tinued pressure of the tongue. The lower
lip was folded downwards. The anterior por-
tion of the superior maxillary bone had under-
gone a slight curve upwards ; the inferior a
much greater curve downwards; so that when
the back teeth came in contact, the front were
an inch asunder, or, rather, the space between
the upper teeth and the corresponding alveolar
processes below was something more than an
inch. This condition of tongue commenced
by an attack of glossitis in infancy. A portion
of the organ was removed by ligature, and
she completely recovered.

Mr. Crosse mentions a girl of six years old,
in whom the tongue was prolapsed three or
four inches ; and this was completely reduced
by pressure and leeching.

Mr. Liston has described an instance in
which the tongue projected three or four

TONGUE.

1159

inches from the lips of a young man, nineteen
years of age, the disease having been con-
genital. It was of a brown and livid colour,
rough, granulated, and fissured, and beneath
the mucous membrane were abundant venous
plexuses. This tongue was liable to periodic
intumescence, when it became much larger,
was very painful, and bled profusely. Mr.
Liston has stated his belief, that, from the
periodical enlargement and diminution of the
tongue, and the erectile tissue being evident
in many parts of its surface, the mass was
partly composed of a structure resembling
aneurism by anastomosis.

These hypertrophied tongues, when cur-
tailed by the knife or ligature sufficiently
to be taken within the teeth, generally soon
accommodate themselves to the form and
dimensions of the oral cavity.

Professor Lassus has given instances, where
this has been accomplished by means of ban-
daging and compressing the tongue.

Atrophy of the tongue. — I am not ac-
quainted with any instance of atrophy of the
entire organ, nor with any unassociated with
paralysis. It generally shows itself in cases
of hemiplegia, when the tongue does not im-
mediately recover, and results from diminished
nutrition, the consequence of want of ex-
ercise, being confined to the paralysed half,
just as the arm and leg of the affected side
become atrophied under the like circum-
stances. It is more obvious, however, when
the hypoglossal nerve alone is the seat of
injury or disease. Professor Budd mentions,
in his lectures, an instance which fell under
the care of his brother, Dr. William Budd,
of a man who sustained a stab in the neck,
dividing the external carotid artery and hypo-
glossal nerve on the left side. The artery
was secured, and the man recovered with
palsy of the left side of the tongue. At the
end of some weeks that half of the tongue
was much wasted, and all the movements of
the organ were performed by the other half.
The atrophy was confined to the muscular
element of the organ : taste and touch re-
mained uninjured. — (MS. Notes of Lecture.')

Dupuytren mentions an example of atrophy
and paralysis* of the left half of the tongue
caused by the pressure, upon the hypoglossal
nerve, of an hydatid cyst in the anterior con-
dyloid foramen.

In this condition, as well as in hemiplegia,
the state of the tongue is remarkable from
one part of the organ being passive, while the
other is active. As long as it is at rest, the
diminished size of the affected side is all that
is observable. When the tongue is extruded,
it is thrust over towards the affected side, — it
emerges from the mouth obliquely, because
the extruding muscles of the sound side have
no antagonists. The paralysis of the intrinsic
transverse muscular fibres gives rise to another
phenomenon, which I have never seen de-

* In both these cases the muscular motion was the
only function implicated, which, as Dupuytren ob-
serves, is interesting physiologically ; taste and or-
dinary sensation not being in the least affected.

scribed, — it is the curved form of the tongue
itself ; the raphe in the middle of the tongue
is not straight, but curved, and the concavity
looks towards the affected side. These fibres,
whose function it is to make narrow, and, by
that, to lengthen the tongue, only act on one
side, and only half the tongue is thus elon-
gated ; and this, being adherent to the other
half which sustains no elongation, is thrown
into an arch, on the same principle as the
curving of the compound wire in a Breguet’s
thermometer.

Diseases of the papilla. — In considering the
diseases of the surface of the tongue, authors
have not taken sufficient care to consider the
true anatomy' of the papillary membrane, and
their descriptions are consequently loose and
ill-defined. It is of the utmost importance to
state where the morbid changes are situated ;
whether above or beneath the basement mem-
brane; whether it is the epithelium, or the
vessels and sub-basement areolar tissue that
have undergone the alteration.

The papillae are liable to hypertrophy, atro-
phy, effusion of blood or of fibrine into their
interior ; they' may be denuded of their epi-
thelium, or that covering may be stained or
rendered opaque, producing what is called fur.

Hypertrophy of papilla. — The circuinvallate
papillae are liable to be enlarged, the central
portion forming a little tumour, rising above
the surrounding ring of membrane. Dr. An-
drew Ferguson has described them as increas-
ing to the size of peas. There are generally'
several affected at once. I have seen them
increased to this size, as well as some of the
fungiform papilla; at the back of the tongue, in
an individual suffering from scrofulous enlarge-
ment of the tonsils. The polypoid tumours
(retaining the same form and proportions as
these papilla, though greatly enlarged), I
believe to be nothing more than hypertrophied
fungiform, or circumvallate papillae.

The conical or filiform papillae are liable
to a peculiar change, which has, to the best
of my knowledge, never been described. It
consists in an enormous increase in their
epithelial element, forming long cylindrical
rods ; in fact, hairs : the only apparent change
in these organs being superficial to the base-
ment membrane. I am in possession of the
notes of two examples of this malady. For
the first I am indebted to my brother, Dr.
James Salter. He observes, “ My patient;
was an old gentleman, impoverished by in-
temperance ; his general health was good, and
he was now temperate : for some years he
had suffered from the peculiar affection of the
tongue under which he now laboured. This
affection was a great elongation of the conical
and filiform papillae, in all parts of the tongue
where these abound : they were eight or ten
times their natural length, and over-lapped
each other, like the pile of plush, or long
velvet. The hypertrophy' appeared to be en-
tirely in the long axis ; there was no increase
in circumference, and they were little larger
at their base than the apex. They were soft,
and lay over lapping each other on the sur-
4 e 4

1160

TONGUE.

face ; and by smoothing the finger over the
tongue they could be brushed from one side
to the other. Their colour was deep Van-
dyke-brown, and they were most numerous in
the centre of the tongue. They looked ex-
actly like little brown hairs. Sensation and
taste were both a good deal damaged.” To
my friend, Dr. Joseph Bullar, I am indebted
for the other instance. His patient was an
old lady of sixty-five ; she had been subject to
constipation, for which she was in the habit of
taking strong purgatives. The tongue was
latge, vascular, and the papillae of all kinds
prominently marked. It looked in an irritable
condition, as if sympathising with a congested
mucous membrane. On the middle and back
of the dorsum was a patch of hypertrophied
filiform papilla;, of a dark sepia colour, or
rather of the brown colour of a dark typhoid
tongue. These filamentous growths were re-
moved by forceps, and some were sent to me,
from which I made the accompanying draw-
ings. The specimens that I received were
very dark, almost black : I have some of them
in my possession now, nearly or quite half an
inch long ; their texture was very compact,
and their shape cylindrical, with hardly any
trace of tapering. They all, as seen by the

Fig, 764,

and 80 diameters.

microscope, possessed a retrorse imbrication
of the same character as ordinary filiform pa-
pillae {fig. 764.). The epithelium did not con-
tain any granular pigment, but the colour
appeared to pervade the whole cell, which
was evenly stained and semi-transparent. In
fig. 764. is seen a papilla, or hair, at full length,
and in fig. 765. a portion of another, showing
the imbrication of the epithelium.

The Scarlatina tongue contrasts remarkably
with the preceding ; for here the deeper ele-
ments of the papilla; are principally the seat of
change. In scarlet fever the capillaries of the
papilla;, in common with the sub-basement
vascular system of so large a portion both of
the internal and external surfaces of the body,
become turgid, and the papillae themselves —
not so much their epithelium — become en-

' Fig. 765.

A portion of hypertrophied papilla, showing well
the retrorse imbrication of its epithelium. Mag.
200 diameters.

larged and red. In the early stages of the
fever this change is concealed by the fur
(which is a sodden and opaque condition of
epithelium), as it regards the filiform papilla;,
— fur being, in all cases I believe, confined to
these and the papillae conicae. Not so the
fungiform papillae ; for these are exaggerated
and bright red. The result is, that the surface
is a combination of thick white cream-like fur
and red projected spots, the former being
most conspicuous where the filiform papilla;
abound — the central portions of the tongue,
— and the latter in the regions of the papillae
fungiformae — the edges and tip of the tongue.
These fungiform papilla; look like the achaania
scattered on the surface of the fruit of the
strawberry. As the disease advances, the
epithelial covering is shed, and only a thin
transparent epithelium remains : the papilla;
are consequently red and bright all over the
surface, which is clean, rough, red, and raw-
looking in every part.

Atrophy of the papilla; is occasionally met
with. Mr. Lawrence mentions the case of a
person in whom, from habitual drinking, the
tongue was, for the greater part of its surface,

] 161

TONGUE.

destitute of papillae : it was white, smooth and sore when touched. I have lately seen a
opaque on the surface. I have already men- patch, the size of a shilling, thus denuded in
tioned the obliteration of the papillae in the a patient suffering from diarrhoea,
glossy tubercle of syphilis, and it also occa- Fur. — The fur of the tongue is the epithe-
sionally occurs in lues venerea, independent lium, principally of the conical and filiform
of the tubercle. papillae, variously altered. It is most abund-

I have seen the tongues of old people re- ant where these papillae are most plentiful,
markably bald, especially as it regards the and it will be found, by inspecting minutely a
filiform papillae: as a general rule, these pa- furred tongue, that the fungiform papillae have
piilse are less prominent in the aged. undergone very little, if any, change. I be-

Effusions into ‘papillae. — The fungiform pa- lieve, with M. Piorry, that the fur of the
pill® are liable to be the seat of little extrava- tongue is chiefly dependent upon the con-
sations of blood. I am acquainted with a medi- dition of the saliva and mucus of the mouth :
cal gentleman who has himself frequently had and, holding this view, it is easy to understand
this trivial affection. It has always occurred to how it is that the filiform and conical papillae

him in the night, and is indicated by a sharp
pain, as though the tongue were stabbed by a
red-hot needle, caused, doubtless, by the pres-
sure of the blood upon the nerves in the papilla.
Upon examining the tongue a papilla is seen
to be distended into a minute capsule of blood,
at first red, and afterwards black. The coagu-
lum is absorbed in a few days, and the papilla
resumes its former appearance.

Lymph of a grey or ash-colour is apt to be
deposited in and under the papillae, in the
tongues of persons tainted with syphilis.
When this occurs on the dorsum, it gives a
grey speckled appearance to the patch, some
of the papillae in the spot being unaffected. It
looks as though this circumscribed surface
had been rubbed with chalk. The patches
vary in size from a split pea to a fourpenny
piece. Occurring under the tip and along the
under edge of the tongue, the appearance is a
whitish even spot, of gristly texture, and not
presenting a speckled appearance, the papillae
here being invisible, and covered up uniformly
with epithelium. This is the most common
situation for these spots, which after a time
become fissured, and ulcerate.

Lymph, effused into a fungiform papilla, is
the commencement of the common little cir-
cular ulcer on the tip and edge of the tongue.
I have snipped off, and examined under the
microscope, one of these papillae. It was filled
with a yellow, opaque, granular, sub-fibrous
mass. The papilla is not only enlarged by
this effusion of lymph, but is altered in form ;
its pedicle is elongated, and its head flattened.
When the papilla does not ulcerate, but returns
to a healthy state, its contents are absorbed,
it diminishes in size, and the summit of the
papilla becomes pitted in the centre. It then
gradually assumes its natural size, shape, and
colour. This may be easily seen by watching,
every few hours, a patient’s tongue through
an ordinary pocket lens.

Denuded papillae. — The papillae are occa-
sionally denuded by the effusion of serum be-
tween the basement membrane and epithelium,
by which this latter is raised into a blister,
and is subsequently rubbed off by the motions
of the tongue, leaving the red naked papillae
beneath. This denuded surface is red as com-
pared with the surrounding, and smooth, but
when viewed through a magnifier the small
naked papillae are seen to be regular and per-
fect. This surface is not ulcerated, but feels

are principally affected ; they hang among the
fluids of the mouth, exposing a large super-
ficies in proportion to their bulk ; their sur-
face is uneven and broken, and this, with the
imbricated state of the epithelial particles,
make them quickly and thoroughly imbibe, and
become saturated with, any fluid into which
they are immersed. In all this they contrast
with the fungiform papillae, whose surface, in
proportion to bulk, is small, and whose epithe-
lium is spread in a thin, even sheet, smoothly
over their surface. It must have been ob-
served by every one, that the colour of the
papillae of a brown typhoid tongue is identical
with that of the sordes around the teeth, which
is nothing more than the saliva and mucus, in
which these papillae have been bathed, inspis-
sated, and is doubtless the source of their
colour. The white fur consists of a white,
opaque, soft, sodden epithelium, which, when
viewed under the microscope, differs from the
epithelium in its ordinary state, in no other
particular than its opacity. When the fur is
brown, the epithelium presents the appearance
of being simply and evenly stained. There
are no opaque pigmentary particles in the
cavity of the cell.

The various amounts and characters of the
fur ; the different arrangements of it in dif-
ferent diseases and at different stages ; the al-
terations, form, and size of the tongue, &c. ; all
symptomatic of morbid changes elsewhere,
and belonging rather to the physician than the
morbid anatomist, I shall not stop to describe.
But it must not be forgotten that, in health,
many of these conditions are natural to some
persons : in some, the tongue is habitually
furred, in others it is chapped, ragged, and
irregular.

The healing and reparation of the papillary
surface of the tongue is not a little remark-
able. I have known the surface of the tongue,
after it has been immensely disfigured, es-
pecially in syphilitic cases, by tubercles, and
rhagades, and ulcers, restored almost to its
former condition. After ulceration it would
seem that the cicatrix contracts to a mere
line, while the surrounding mucous membrane
becomes extended, and either fresh papilke
form, or else the minute simple papillae in-
crease in dimensions, and become complicated,
for the papillary surface is ultimately quite
restored.

I shall conclude these observations on the

1 162

TONGUE.

morbid anatomy of the tongue with some re-
marks on faulty positions which the organ oc-
casionally obtains. 1 have already spoken of
prolapsus of the tongue, and there now re-
main for consideration — tongue-tie, tongue-
swallowing, and adhesion of the tongue to ad-
jacent parts.

Tongue-tie. — This is a congenital malform-
ation, consisting in the fraenum extending too
far forwards and being short, thus tying down
the tongue behind the incisor teeth of the
lower jaw. This may occur to any degree,
from an amount that is scarcely observable,
to the complete tying down the tip of the
tongue behind the necks of the middle incisors
of the lower jaw. The fraenum generally con-
sists simply of a small amount of fibrous tissue
contained in the fold of mucous membrane;
but it sometimes contains fibres of the genio-
glossus, which occasionally extend a con-
siderable way forwards : in the former case
the fraenum is thin, in the latter it may be of
some thickness. When left to nature the tie
gradually lengthens, and, at the same time,
recedes, and any unusual thickness arising
from the presence of muscular fibres gra-
dually lessens. This condition, to a slight
extent, is very frequent, and appears to be
hereditary. The cases are, however, extremely
rare where the fraenum is so short as to inter-
fere with sucking, mastication, deglutition, or
articulation.

Tongue-swallowing. — This arises from the
opposite of the last condition : the move-
ments of the tongue are too free ; it can be
inverted, and its apex thrown back into the
pharynx, which embraces it, and thus closes
the aperture leading to the lungs, and symp-
toms of suffocation are the result. It most
frequently happens to infants. It is enume-
rated by writers on Medical Jurisprudence, as
one of the modes of suicide among negroes.
Dr. Gordon Smith, Majendie, and Beck refer
to cases of it. Mr. Crosse tells of an instance,
where it could be performed at pleasure with-
out the slightest inconvenience.

Adhesions of the tongue. — Bernard relates
an instance, in which adhesions, of the thick-
ness of two lines and a half, had agglutinated
the lateral parts of the tongue to the internal
surface of the cheeks, to the extent of more
than an inch on each side. These adhesions
had succeeded an inflammation in the inside
of the mouth and tongue, the circumference
of which had ulcerated ; they interrupted the
functions of speech and mastication. M. Ber-
nard divided them by a single clip of the
scissors.

Necrosis of the hyoid bone. — The only in-
stance of disease of the hyoid bone with which
I am acquainted, is one related by Mr. Spry.
The disease was necrosis, the result of ex-
tended ulceration, which commenced in the
throat, and continued till the bone was laid
bare and dead. It was then expectorated en-
tire. The patient died several weeks after-
wards. The bone was entirely deprived of
periosteum, irregular on its surface, and in a
perfect state of necrosis.

[Since this Article has been in the press I
have become acquainted with a discovery of
Prof. Kolliker’s, that the muscular fibres in
certain situations are bifurcated and branched.
In a letter to Prof. Bowman he says, that this
is brilliantly exhibited by the muscles of the
tongue, and he gives a pen and ink illustration
of the method of branching. There can be no
doubt about a fact so detailed by such an au-
thority, but I must confess that I have not
recognised the appearances described.]

Bibliography. — jtlbinus, De Periglottide et
Corpore reticulari Lingual ; in Annot. Acad. t. i.
Alcock, Med. Gazette, Nov. 1836. Andral, Anat.
Pathol, sect. ii. Arnott, Med. Gazette, vol. xxiii.
Beck, Medical Jurisprudence, 1842. Bellini, Gus-
tos Organon novissime detectum. Bologna, 1665.
Bibron, Erpetologie Ge'ndrale, ou IPistoire Naturelle
complete des Reptiles. Paris, 1844. Bichat, Traite
d’Anatomie Descrip, t. ii. Paris, 1802. Blandin,
Mem. sur la Structure de la Langue, Archives Gen.
de Me'd. t. i. Paris, 1823. Breidenstein, De Morbis
Linguae. Erlangen, 1791. Breschet, Repertoire
d’Anatomie ; Journ. Univers. des Sciences Medicales,
1817. Collier, Med. Gazette, vol. xii. Craigie, Edin.
Med. and Sur. J ourn. vol. xlii. Crosse, Trans. Prov.
Med. and Sur. Assoc. 1837. Cruveilhier, Anat. De-
scrip. Cuvier, Lemons d’Anat. Comp. t. iii. 1805.
Be Lamalte, Mdm. de l’Acad. de Chir. t. v. Bu-
puytren, Chirur. Clinique, t. iii. Bzondi, Die
Punctionen des weielien Gaumens. Halle, 1831.
Earle, Med. Chir. Transact, vol. xii. England,
Provincial Med. and Surg. Journal, 1846. Ferguson
(A.), Med. and Pliys. Journal, 1802. Frascati, De
Lingua. Bologna, 1665. Gerdy, Mem. sur la Struct,
de la Langue ; Archiv. Ge'n. de Mdd. t. vii. Paris,
1825. Idem. Discus, et Propos d’Anat. Paris, 1825.
Art. “ Glossite,” Diet, de Mdd. Graves, Med.
Gazette, 1841-2. Dublin Hosp. Rep. vol. iv. Hal-
ler, lib. ix. and xiii. Hayes, Mem. of Med. Soc. of
Lond. vol. ii. Heister, De Lingua sana et aagrota.
Altdorf. 1716. Heyfelder, Med. Vereins-Zeitung,
1834. Hildebrandt, Handbuch der Anatomie des
Menschen. Brunswick, 1832. Home ( Sir E.), On
the Structure of the Tongue and removal of Parts
by Ligature, in Phil. Trans. 1805. Pract. Obs. on
Cancer, 1805. Horn, Ueber den Geschmacksinn
des Menschen. Heidelberg, 1825. I-Iuie, Edin. Med.
Chir. Trans, vol. iii. Hunter, On Venereal. Lond.
1788. Isenflamm, De Motu Linguae. Erlangen,
1792. Kempelen, Mechanismus der Menschlichen
Sprache. Wien, 1791. Kirby and Spence, In-
troduction to Entomology, vol. iii. Louis, Mem.
Physiol, et Path, sur la Langue ; Mem. de l’Acad.
de Chir. t. v. Malpighi, De Lingua. Bologna,
1665. Marjolin, Manuel d’Anatomie, t. ii. Paris,
1815. Meckel ( J . Ft), Manuel d’Anatomie Ge-
nerale, t. iii. Paris, 1825. Muller, Physiology, by
Baily. Owen, Lectures on Comparative Anatomy,
vol. i. and ii. Archetype and Homologies of the Ver-
tebrate Skeleton. Dissection of the Pearly Nautilus,
4to. 1832. Paletta, Journal of Foreign Medicine,
No. xix. Panizza, in Edinb. Med. and Surg. Journ.
Jan. 1836, and Med. Gazette, Sep. 1835. Ridge,
Glossology. Lond. 1844. Binder, De Lingua; ln-
volucris. Strasb. 1778. Rowland, Aglossostomo-
grapliie, ou Description d’une Bouche sans Langue,
&c. Saumur, 1630. Royen, De Fabrica et Hsu
Lingua;. Leyden, 1742. Scemmerring, leones Organ-
orum Humanorum Gustus et Vocis. Frankf. 1808.
Todd and Bowman, Physiological Anatomy, vol. i.
Treviranus, Biologie, t. iv. Van Laer, De Struct.
Capillorum Humanorum. 1841. Waller, Philoso-
phical Transact. 1849, part 1. Walter ( A . F.), Da
Lingua Humana. Leipsig, 1724. Wells, American
Journ. of Med. Science, 1833. Willis, in Trans, of
Phil. Soc. of Cambridge, vol. iii.

(II. Hyde Salter.)

TOUCH.

1163

TOUCH. — The sense through which we
take cognisance of the palpable properties of
bodies. The term is used, however, in two
meanings, between which it is requisite to
maintain a due discrimination. In its ex-
tended acceptation, it implies our conscious-
ness of all those sensory impressions, which
are neither olfactive, visual, auditory, nor
gustative ; and it is therefore designated as
the general sense, in contradistinction to
those, which are considered as special senses.
In its most limited application, on the other
hand, it is used to designate that modification
of the general sensibility, which is restricted
to the tegumentary surface, or to some special
portion of it, and which serves to excite
definite ideas in our minds respecting the
form, size, number, configuration, weight, tem-
perature, hardness, softness, &c., of objects
brought within its cognisance. The use of
the sense of Touch, in the acquirement of
these ideas, is, as we shall see hereafter, a
very complex process ; involving not merely
the discriminating employment of the proper
organs of touch, but also the assistance of
muscular action, and of the information de-
rived from it by the “ muscular sense.”

General Sensibility. — The most universal
of all the qualities or properties of matter
(that, in fact, upon which our notion of
it is founded) is resistance ; and it is of
this quality that we find the power of cog-
nisance most extensively diffused through
the body, and most universally possessed by
all beings endowed with consciousness. It
would seem to require nothing else than the
presence of nerves connected (directly or
indirectly) with sensorial centres ; for there
does not appear to be a need of any special
organisation, surrounding the peripheral ex-
tremities of these nerves, in order that they
may receive and transmit impressions. Thus
any unusual pressure on a nerve in its course
is at once perceived by the mind, — not,
however, as pressure, but as a disagreeable or
painful sensation, which gives no indication
of the mode in which it was excited. The
nerves of smell, sight, and hearing, are not
thus affected by mechanical irritation, no
manifestations of pain being exhibited when
they are pinched, torn, lacerated, &c. ; and
the general sensibility which these organs of
sense possess is dependent upon other nerves.
The nerves of taste, however, exhibit the
same susceptibility to tactile impressions, as
do those of touch ; and hence we have an
additional proof of the very close affinity of
these two senses (See Taste).

The only condition requisite for the ex-
ercise of “ general sensibility,” beyond the
integrity of the nervous apparatus, is the
adequate supply of oxygenated blood. Wher-
ever sensory nerves exist, we find them ac-
companied by blood-vessels ; and no non-
vascular tissue possesses in itself the least
degree of sensibility. Thus, in the epidermis,
hair, nails, cartilage, and tooth-substance, nei-
ther nerves nor blood-vessels exist, and we
find these tissues completely insensible. In

tendons, ligaments, fibrous membranes, and
in other parts whose function is purely me-
chanical, we find very little vascularity, and
extremely little sensitiveness to ordinary im-
pressions ; it is remarkable, however, that
although the tissues, whose function it is to re-
sist tension, are scarcely impressible by cutting,
burning, &c., they cannot be unduly stretched
without considerable pain. So, also, the serous
and synovial membranes are not in the least
susceptible of ordinary tactile impressions in
their healthy state ; but they become acutely
sensitive when inflamed. It does not at ail
follow, however, that the sensibility of a part
should increase with its vascularity ; for we
find that some of the most vascular organs in
the body are the least sensitive, the supply of
blood which they receive having some pur-
pose entirely different. Thus the sensibility
of the muscles is by no means proportionate
to the large amount of blood which they re-
ceive ; and even the substance of the brain
(like that of the nerves of special sensation)
is destitute of this property. So, again, the
mucous membranes lining the interior of the
several viscera, though supplied with blood
even more copiously than the skin, are very
far inferior to it in sensibility. The depend-
ence of this endowment, however, wherever
it exists, upon the continued circulation of
the blood, is at once made apparent by the
results of its suspension ; thus, when the
main artery of a limb is tied, there is a dimi-
nution of the sensibility both of its surface
and of its substance, which is so exactly
proportioned to the degree in which the sup-
ply of blood is diminished, and the reco-
very from which takes place so precisely in
accordance with the establishment of the col-
lateral circulation, that we cannot doubt that,
if the supply of blood were completely cut
off', sensibility would be entirely suspended.
The numbness produced by cold, in like
manner, is partly due to the stagnation which
it occasions in the capillary circulation in the
skin ; though it is doubtless in part attributable
to the immediate depressing influence of the
cold upon the vital endowments of the ner-
vous apparatus itself.

The general sensibility of the body may be
called into activity by impressions received
from objects external to it, or by causes ori-
ginating in itself ; and the consequent sensa-
tions are sometimes distinguished as “ ex-
ternal” and “internal.” These designations
are by no means logically correct ; for all
sensations must originate in causes external
to the recipient mind; whilst, on the other
hand, in order that any sensation may be felt,
a certain condition of the corporeal organism
must first be produced ; and this condition
may be precisely the same, whether it be
immediately dependent upon changes ori-
ginating in the body itself, or upon changes
impressed upon it from some agency external
to it. Still, however, the terms “ external ”
and “ internal ” sensations are sufficiently con-
venient, and sufficiently free from the pro-
bability of misconception, to justify the phy-

llGd

TOUCH.

siologist in the employment of them ; and
they will be accordingly employed in our
present enquiry.

The external sensations received through
this medium all require the absolute contact*
of the body which excites them, with the im-
pressible part ; and in this respect, therefore,
there is an exact correspondence between
the general sensibility and the sense of taste.

The force with which the impression is
made, is judged of by the intensity of the sen-
sation and the depth to which it is felt; whilst
the size of the object is in some degree es-
timated by the extent of surface over which
its contact is perceived. Both these estimates,
however, are extremely vague, when they
depend only upon the general sensibility of the
body ; we shall hereafter see how much more
precise they become, when the impressions
are received through the skin, which is the
special organ of touch, and when they are
aided and corrected by the muscular sense.
Still we find that the different modes in
which external objects affect even the general
sensibility, produce a very marked diversity
in the character of the sensations. Thus the
feeling called forth by a prick is of a very
different kind from that which arises from a
blow ; both, again, are very distinct from that
produced by a steady uniform pressure; and
all these are very different from the sensation
of stretching or tearing. In the case of a
prick, we have an intense impression made
on the sensible part ; but this is limited to a
very small spot ; whilst the impression of a
blow is made with a like intensity over a
much larger area, j- In the case of steady
pressure, on the other hand, the impression
is made over a large surface, but is less in-
tense ; whilst in stretching and tearing, the
mechanical condition of the nerves of the
part operated on is affected in a manner pre-
cisely opposite to that in which it is acted on
by pressure. The sense of shock, derived
from a blow extending over a large surface,
is very distinct from that of the mere blow,
and may be experienced when little or no
pain is felt, as from the “wind” of a shot;
and nearly allied to this is the peculiar jar
which is experienced, when the shock is
transmitted in such a manner as especially
to affect the solid casing of the nervous
centres, — as when we jump from a height,
without sufficient care to alight in such a

* There might seem to be an exception to this
statement in regard to heat and cold, which are
perceived when their source is at any distance that
allows its radiations to affect the tempei'ature of the
body itself. But, as will presently be shown, it
does not appear that the sense of temperature forms
part of the general sensibility of the body; the
power of appreciating heat or cold, as such, being
limited to the special organs of touch.

f There can be no doubt that a multitude of
pricks made at the same moment, in sufficiently close
proximity to prevent them from being separately
distinguished, would be felt as a blow ; this being the
only sensation which is received from the numerous
incisions simul t aneously made by the scarificator used
in cupping, when it is applied to the parts of the
jkin endowed with the least discriminating power.

manner as to deaden the concussion by the
elasticity ot the feet, &c. A succession of
slight impulses rapidly following one another,
gives rise to the peculiar sensation of thrill ;
which, though most readily excited when the
impressions are made upon the skin, may be
received through the internal organs also
as when we hold a vibrating body between
the teeth.

These and other well-marked differences
in the kind of information received through
the general sensibility of the body, seem ob-
viously attributable rather to diversities in
the mode in which the impressions are made,
than to any differences in the nature of the
impressions themselves, the character of the
fibres receiving them, or the endowments of
the ganglionic centres in which these fibres
terminate. And hence we seem to have a
greater right to conclude, that the various
affections of general sensibility, which are
usually ranked under the common head of
internal sensations, however unlike they may
be one to another, are really derived from
impressions which do not mutually differ so
essentially as do those of the special senses
from each other and from the general sense.
Of this kind are the sensations of hunger and
thirst, the “besoin de respirer,” the genital
sense, the sensation which calls for the expul-
sion of the urine and faeces, nausea, the feelings
of oppression and of “ sinking” at the stomach,
burning, itching, tingling, formication, and’
others. However different these are from
each other, when but slightly or moderately
excited, they all merge, when more strongly
called forth, into the simple consciousness of
pain ; and it is further common to them all,
that the nerves through which they are ex-
cited are the same as those which commu-
nicate the impressions that excite tactile
sensations, and that mechanical irritation of
any of these nerves occasions pain. To the
foregoing may be added the “ muscular sense,”
whereby we are informed of the degree of
effort put forth by a muscle; and the sense
of “ fatigue,” which seems to be a modifica-
tion of this. We are not conscious either of
effort or fatigue in the actions of any of the
muscles over which the will has no control,
such as the heart, the muscular walls of the
intestinal canal, &c. ; nor in the case of those
whose actions are purely rhythmical, as those
of respiration. It is, in fact, only when the
will is exerted, either in increasing the force
of their contractions, or in antagonising them
by the operation of some other muscles, that
we become conscious of effort ; and we shall
hereafter see that this sense is most important,
in enabling us to proportion the amount of
force we exert to the resistance to be over-
come,_ and in guiding us with regard to the
direction in which exertion is required. A
sense of effort and of fatigue seems also to be
excited in the sensorium by the mental opera-
tions of which the cerebrum is the instrument;
especially when these mental operations are
no longer spontaneous, or carried on with
facility, but when they require a more or less

TOUCH.

1165

potent exertion of the will to keep them in
activity. As we have every reason to believe
that all mental exertion, like muscular force,
involves (in our present state of being) a dis-
integration of the substance of its instrument
— the brain, — there is no difficulty in under-
standing that this disintegration, when carried
beyond a certain point, may excite the sense
of fatigue (see Sleep), just as the “besoin
de respirer” is felt after we have withheld our
respiratory movements for a few seconds, or
hanger when there is a deficiency of nu-
tritious matter in the circulating current. It
has been said by Mr. Mayo, “ that the frame
is in the completest health and condition,
when the internal sensations are not excited ;
the healthiest self-feeling being an absence
of all inward sensation.” This, however, is
scarcely a sufficient account of the fact ; for,
in the highest condition of health, there is not
only an absence of all uneasy feeling, but a
general sense of buoyancy and resiliency, dif-
ficult to describe in words, which may be
characterised as the positive sense of well-
being. So, on the other hand, without any
positive or distinct sensation, there may be a
consciousness of general discomfort, which
has been expressively termed by the French
malaise. These two sensations may probably
be considered as originating in the condition
of the blood ; the first being an indication of
its purity, and of its perfect adaptation to the
wants of the system ; whilst the second would
seem to proceed from a slight depravation
of its quality, resulting not unfrequently from
the imperfect elimination of excretory matters,
such as is not sufficient in itself to constitute
an actual disease.

Having thus passed in review the principal
manifestations of the general sensibility of
the body, and the conditions under which
they occur, we have now to proceed to the
investigation of the sense of touch, as exer-
cised by the organs specially adapted for the
reception of tactile impressions.

Sense of Touch.

Special Organs of Touch. — The peculiar
endowments of the tegumentary surface,
which enable us to draw from the impres-
sions received through it, information of so
much more varied and definite a character
than we can derive through any of the struc-
tures which it invests, appear to consist prin-
cipally, so far as the organ itself is concerned,
in its greater sensibility (that is, in its greater
aptitude for being affected by slight impres-
sions), and in its greater power of commu-
nicating distinct impressions from points in
close proximity ; but a large part of our in-
formation is dependent upon our power of
giving motion to the tactile organ, and thus of
increasing the force and variety of the impres-
sions which we derive through its surface, as
well as of receiving impressions of an entirely
different kind, from the action of the muscles
by which that motion is given. Thus, if we
simply bring a solid body into contact with
the point of the finger, we gain but little

information of the nature of its surface,
whether rough, smooth, or polished ; and we
can judge nothing of its form, except in regard
to that part of it in actual contact with the
fingers ; and even this is but vaguely ap-
preciated. This information may be rendered
somewhat more precise by pressing the object
against the finger; as we shall then feel the
impression made by elevations, points, or
roughnesses, if they be sufficiently prominent
and wide apart from each other ; whilst from
the degree of muscular force we exert, and
from the amount of yielding of which we are
conscious in the object itself, we judge of its
hardness, softness, elasticity, &c. But our
power of discrimination is immensely in-
creased, when we move the tactile surface on
the body to be examined, or vice versa ; for,
from the succession of impressions then made,
we obtain our best idea of the character
of the surface of the object ; whilst by the
combination of the tactile impressions with
the muscular sense, we judge of the relative
positions and connections of its different
parts, and of the form of the whole. But
besides this, we find that impressions may be
derived through the skin, which are not re-
ferable to a mere exaltation of its common
sensibility, being apparently of a different cha-
racter from any of which we become con-
scious through other structures ; such, espe-
cially, are sensations of temperature. Still
there would seem no sufficient cause for rank-
ing even these in a distinct category from the
ordinary tactile impressions ; for the feeling
of heat or cold does not differ more from that
of roughness or smoothness, than does the
colour of the object, as seen by the eye, from
its form as distinguished by the same organ.

The different parts of the cutaneous sur-
face are endowed with tactile sensibility in
very different degrees ; and this variation
seems closely to correspond with the degree
of development of that papillary structure,
which may be regarded as the special organ
of touch, strictly so called. These papillce
are most elevated and numerous on the tip of
the tongue and the points of the fingers ; are
less so on the palms of the hands and the
soles of the feet; are comparatively small and
few on the integument of the limbs, and on
several parts of the trunk can scarcely be dis-
covered at all. They are described by Messrs.
Todd and Bowman* as having an average
length in man of x^-th °f an inch ; and a
diameter at their base, where they spring from
the cuticle, of about xioth of an inch. Their
form is somewhat conical, tapering off to a
slightly rounded point. Their surface (after
the removal of the epidermis) appears to be
composed of the basement membrane of the
cutis itself ; and their interior is composed of
fibrous tissue, vessels, and nerves. In each
papilla we find a small arterial twig, derived
from the arterial plexus of the cutis; this,
advancing towards the apex of the papilla,
subdivides into two or more capillary ves-

* Physiological Anatomy, vol. i. p. 410.

1106

TOUCH.

sels; and these, forming loops whose con-
vexity lies in the summit of the papilla, re-
unite into venous radicles, which discharge
their blood into the venous plexus of the
cutis. “ The vascularity of the papillae,” as
Messrs. Todd and Bowman correctly remark,
(loc. cit.), “ is such, that their presence and
relative size may be determined simply by the
depth of the colour imparted to the skin by
a good injection of its vessels ; the'vascularity
of the integument is, therefore, in general
terms, proportioned to its perfection as an
organ of touch.” With regard to the nervous
supply of these papillae, however, it is less
easy to speak with confidence. It is derived,
like the sanguiferous, from the plexus in the
substance of the cutis, lying parallel to the
surface ; the tubular fibres ascend, to all ap-
pearance singly, from this plexus into the
papillae ; but their mode of termination or
return are not distinguishable with certainty.
The following are the results of the in-
quiries of Messrs. Todd and Bowman on this
point. “ In regard to the presence of nerves
in the papillae themselves, we can affirm that
we have distinctly traced solitary tubules
ascending among the other tissues of the
papillae about half-way to their summits, but
then becoming lost to sight, either by simply
ending, or else by losing the white substance
of Schwann, which alone enables us to dis-
tinguish them in such situations from other
textures We have in numerous in-

stances failed to detect any nerves at all within
the papillae, when such were plainly visible at
their base, and when, consequently, the che-
mical agent employed could scarcely have
destroyed their characteristic structure had
they been present. We incline to the belief
that the tubules, either entirely or in great
measure, lose the white substance when
within the papillae.”* With these statements,
so far as they go, the writer’s own observa-
tions are in entire accordance ; but he thinks
that from the appearances presented by sec-
tions examined by reflected instead of by
transmitted light, it may be inferred that the
nervous tubules in the tactile papillae undergo
a change somewhat similar to that which is
said by Wagner to take place in the nervous
tubuli of muscle ; namely, that whilst the
white substance of Schwann is not traceable
beyond a certain point, the central axis is
continued further, and that this breaks up
into minuter fibrillae, which form loops, like
those of the capillary blood vessels, returning
into the tubular fibre itself.

In the lower animals, as in man, it may be
observed that the papillary structure is espe-
cially developed on those parts of the tegu-
mentary surface which are especially endowed
with tactile sensibility, anil the impressions
received through which are of important use
in finding the movements of the instruments
of locomotion. Thus in the quadrumana
generally, both the hands and feet are thickly
set with papillae ; and in those which have a

* Op. cit. p. 412.

prehensile tail, the surface of this organ pos-
sesses them in abundance. In the carnivorous
and herbivorous mammalia, whose extremi-
ties are furnished with claws or encased in
hoofs, we find the lips and the parts sur-
rounding the nostrils to be the chief seat
of tactile sensibility, and to be copiously
furnished with papillae ; this is especially the
case with those which have the lips or nos-
trils prolonged into a snout or proboscis, as
in the pig, the rhinoceros, the tapir, and the
elephant. In the mole, too, the papillary
structure is remarkably developed at the ex-
tremity ol the snout. The only part of the
skin of birds on which tactile papillae have
been discovered is on the under surface of
the toes, and on the web of the palmipedes,
where they obviously receive impressions,
which guide the prehensile and other move-
ments of the feet. It is probable, however,
that the very sensitive skin which covers the
greater part of the mandibles in the duck
tribe, is furnished with papillae ; the tactile
impressions received through this part, when
the bill is plunged into mud &c., being the
chief means by which the presence of food is
discovered. In many lizards a papillary struc-
ture is found on the under surface of the
toes ; and in the chameleon it exists, also, on
the integuments of its prehensile tail. In the
soft skinned batrachia, an imperfect papillary
structure is more extensively diffused over
the surface ; but on the thumb of the male
frog, and probably on that of other batrachia,
there is an extraordinary development of pa-
pillary tissue at the season of sexual excite-
ment, large papillae being formed all over it.
This organisation is obviously connected with
the extraordinary prehensile propensity which
is then displayed by the animal, and which
enables him to keep the female in his grasp
during the whole period of the discharge of
the ova, in a manner which no voluntary effort
could effect. In serpents and chelonians, no
papillary apparatus has yet been detected ;
and in fishes and invertebrata its presence has
not been ascertained, although it would ap-
pear that certain parts, especially the tenta-
cula around the oral orifice, are endowed with
a high degree of tactile sensibility*

But it is not only on the tegumentary sur-
face of the exterior of the body, that tactile
sensibility is particularly acute ; nor is the pa-
pillary apparatus restricted to it alone. In
the tongue of man, we find the sense of touch
remarkably developed, especially at its tip ;
and of the papillae with which its surface is
beset, it is probable that some are the instru-
ments of tactile sensibility ; whilst others
minister to the gustative sense. (See Taste.)
So it is probable that in all animals which
have a soft fleshy tongue, furnished with pa-
pillae, and serving as the organ of taste, this
organ is the instrument of tactile sensibility also.

* The movements of these organs, or such as are
excited through contact with them, can scarcely be
in themselves regarded as a sufficient indication of
their tactile sensibility, as they may be purely reflex,
without involving consciousness of the impression.

TOUCH.

Besides the papillary apparatus, however,
we find certain animals endowed with special
organs of touch, which are constructed upon
a very different plan ; consisting of a rod or
filament, which is in itself insensible, but
which is connected at its base with nervous
fibres, in such a manner that any motion
or vibration communicated to it must be
transmitted to them. Such are the long stiff
hairs which are known as the “ whiskers” of
the feline tribe, and which are so particularly
large in the seal ; these are also highly deve-
loped in many of the rodentia, such as the
hare and rabbit ; and it has been proved by
experiment, that if they be cut off, the animal
loses in great degree its power of guiding its
movements in the dark. Thus Mr. Broughton
found that whilst a kitten whose whiskers
were entire was capable of threading its way
blindfold out of a labyrinth in which it was
designedly placed, it was totally unable to do
so when its whiskers were cut off ; for it then
struck its head repeatedly against the sides,
ran against all the corners, and tumbled over
steps placed in its way, instead of avoiding
them as it did prior to the loss of its whis-
kers.* In animals whose hairs are their im-
portant instruments of touch, a true papilla,
copiously furnished with nerves and blood-
vessels, is found to project into the bulb of
each hair. The jointed appendages to the
head, known as antenna and palpi, which are
possessed by most articulated animals, are un-
doubtedly instruments of touch, whatever
sensory impressions they may receive in addi-
tion. The antenna?, when prolonged, serve
to guide the movements of the animal ; the
impressions which they receive at their ex-
tremities being communicated to the nerves
at their base, just as a blind man judges by
the stick held in his hand of the proximity of
obstacles to his progress, j- On the other hand,
the palpi appear to minister to the cognisance
of objects brought into the neighbourhood of
the mouth, and to have for their chief office
to guide in the selection of food. But while
there are many facts which seem to indicate
that the antennas minister to the sense of
hearing, there are others which appear to
point to the palpi as the special instruments
of that of smell.

Conditions of the Sense of Touch. — The
sense of touch, strictly so called, is exercised
under conditions essentially the same as those
through which the general sensibility of the

* London Medical and Physical Journal, 1823.

f The author is acquainted with a blind gentle-
man who exhibits a remarkable dexterity in the use
of his stick in guiding his movements ; and he has
been informed by him, that much of his power of
discrimination depends upon the flexibility, elasti-
city, &c. of this instrument, so that, when he has
chanced to lose or break the one to which he has
been accustomed, it is often long before he can ob-
tain another that shall suit him so well. This cir-
cumstance seems to throw some light upon the re-
makable varieties of conformation in the antennae
of inse'cts ; as it may well be imagined that each is
adapted to receive and to communicate impressions
of a particular class, adapted to the wants of the
species.

1167

body is affected. It is requisite, in the first
place, that the bodies, of whose presence it
takes cognisance, should be brought into
actual contact with the tactile surface ; the
only exception being in regard to the tempe-
rature of objects, the influence of which may
be communicated by radiations from a distance.
This difference, however, does not indicate
any fundamental diversity such as some have
imagined to exist, between the sense of tem-
perature and that of resistance ; for, in each
case, that which is perceived by the mind is
the impression made upon the sensory organ ;
and the change in this is excited in the one
case by pressure, and in the other by heat or
cold. The same organ appears to be adapted
to take cognisance of both classes of impres-
sions ; a feeling of one kind being excited,
when its condition is altered by pressure ; and
a feeling of a different kind, when its tempe-
rature has undergone a change under the in-
fluence of calorific radiations. And the dif-
ference between these classes of sensations is
not greater than that which exists among
others, — whether of a general or a special
kind, — which we know to be transmitted by
the same nerve-fibres. Yet it would seem
that, whilst there is no sufficient reason for
supposing impressions of contact and of tem-
perature to be transmitted by different nerve-
fibres, we must admit that some of these
fibres, either in virtue of their own constitu-
tion, of the locality of their central termina-
tion, or of the apparatus with which they are
furnished at their peripheral origin, are en-
dowed with a greater readiness to receive and
transmit one or the other class of impressions.
For we find that the parts whose tactile sen-
sibility is the most discriminating, are not
always those by which the keenest apprecia-
tion of changes of temperature is obtained.
And, in like manner, the occasional occur-
rence of cases of paralysis, in which there is a
total loss of one kind of sensation, whilst the
other is preserved, or in which one is di-
minished beyond all proportion to the other,
seems to show that such a change may take
place in the nerve-fibres, as may indispose
them to the reception and transmission of one
class of impressions, whilst they are still
capable of actively responding to the other.

After what has been said of the necessity of
the supply of blood, for the active exercise of
common or general sensibility, and of the vas-
cularity of the special tactile organs, it is not
requisite to lay any further stress on this
point, in relation to the sense of touch, strictly
so called. Another important condition, which
is probably common to the whole sensory
apparatus of the warm-blooded animal, and
which has been already noticed under the
head of Taste, is a temperature not too far
removed from that which is natural to the
body. It has been shown by Professor E. H.
Weber, that if the fingers or the lips be im-
mersed for half a minute or a minute in water
heated to 125°, or cooled to 32°, the power
of tactile discrimination is so much impaired,
that the power of distinguishing between a

1168

TOUCH.

hot or cold fluid or solid body is for the time
completely lost, a feeling of pain alone being
experienced, which is the same whether the
body be hot or cold. This, too, he found to
be the case, when, instead of applying the heat
or cold to the peripheral extremities of the
nerve, he acted on its trunk. For this ex-
periment the ulnar nerve was selected, as its
trunk, at the elbow, lies immediately beneath
the surface. After immersing the elbow in
a mixture of ice and water for about six-
teen seconds, Professor Weber observed that
a peculiar painful sensation was experienced
along the under side of the fore-arm, the
wrist, the little finger, and the inner side of
the ring-finger. This pain had no resemblance
to that of cold. On continuing the immersion,
the pain increased considerably, and eventu-
ally became almost intolerable ; then it gra-
dually diminished, and the middle and ring-
fingers became numb, as if “ asleep,” had no
longer the power of distinguishing between
heat and cold, and could only imperfectly per-
ceive the contact and pressure of bodies. *

The exercise of the sense of touch may be
first considered under its simplest mode,
namely, that in which the object is simply ap-
plied to the tactile organ ; and in this we
have specially to consider the power of Tactile
Discrimination, and the Sense of Temperature.

Tactile Discrimination. — A very ingenious
method was devised by Professor Weber j-, for
determining the relative power of tactile dis-
crimination in different parts of the skin, which
is by no means accordant with their general
sensibility. Plis mode of ascertaining this, was
to touch the surface with the points of a pair
of compasses, guarded by bits of cork or seal-
ing-wax ; the eyes being closed at the same
time, the legs of the compasses were approxi-
mated to each other; until they were brought
so near that the points could be no longer felt
to be distinct from each other. The smallest
distance at which this can be perceived (en-
titled “the limit of confusion,” by Dr. Graves),
is found to differ remarkably on different
parts of the cutaneous surface ,- and the com-
parison of these diversities affords us the
means of estimating, — not their relative tactile
sensibility (for this it cannot measure), —
but their relative discriminating power. The
figures in the first column ot the following
Table represent these distances, as determined
by Professor Weber on his own person, stated
in Paris tines. The inquiry has been more re-
cently pursued by Professor Valentin J, whose
results on the whole correspond very closely
with those of Weber. He found, however, a
considerable extent of individual variation ;
some persons being able to distinguish the
points at half, or even one-third of the'dis-
tances required by others. In the following
table, the second column expresses the maxima

* Muller’s Avcliiv. 1847, p. 342.

f De Pulsu, Respiratione, Auditu, et Tactu, An-
notationes Anatomicse et Physiological Auct. H. E.
Weber. Lipsise, 1834.

t Lekrbuch der Pliysiologie des Menschen, Band
ii. S.56G.

of the “limit of confusion,” the third column
the minima, and the fourth column the mean of
all the observations made by Professor Valen-
tin ; it will be observed that his maxima cor-
respond almost exactly with the measure-
ments of Professor Weber on his own person.
In the fifth and sixth columns are shown the
relative acuteness and relative obtuseness of
the discriminating sense in different parts,
calculated from the mean results ; “the limit
of confusion ” (0'483) at the tip of the tongue
being taken as l’OOO. Thus the co-efficient
of the acuteness of the discriminating sense in
the palm of the hand, calculated by this
standard, is O’ 126 ; that of its obtuseness is
7-930. The co-efficient of acuteness for the
crown of the head, is 0-050 ; that of obtuse-
ness, for the same part, is 19-827. The co-
efficient of acuteness for the middle of the
dorsal spine is 0’020 ; that of its obtuseness
is 50-08C. Or, in other words, its acuteness
is only T£a_ths that of the tip of the tongue ;
its obtuseness fifty times as great.

Similar experiments, with the like results,
have been made by M. H. Belfield-Lefevre* ;
and from all these, the following general pro-
positions may be laid down ; — 1. On almost
any part of the integument, the interval
between the two points is more clearly dis-
tinguished, when the line which joins them is
transverse (i. e. perpendicular to the axis of the
body or member), than when it is longitudinal,
or parallel to that axis. According to Weber,
however, the tips of the fingers and of the
tongue constitute an exception to this rule; the
discriminating power being greatest in them,
when the line joining the points of the com-
passes is longitudinally directed. 2. When
two points, applied simultaneously to any
part of the integument, are clearly distin-
guished, the distance which separates them
seems to be greater, in proportion to the acute-
ness of the discriminating sense in the part of
the surface which is the subject of examina-
tion. Thus, as Weber remarks, if the points
of the compasses, set at a distance of two or
three lines, be applied to the cheek just before
the ear, and be then moved gradually towards
the angle of the mouth, the points will seem
to recede from one another, in consequence of
the increase of the discriminating sense in the
parts to which they are applied. 3. When
the two points are successively brought into
contact with the skin, they seem to be at a
greater distance from each other than if they
are simultaneously applied ; and, in general,
the distance will seem greater in proportion to
the interval between their application. 4. Two
points applied on different sides of the median
line, seem more remote from one another
than two points equally distant, but applied on
one and the same side of the median line ; in
other words, the power of discrimination is
greater when the two points are applied on
the two sides of the median line, than when
they are both applied on the same side. 5.
If two parts of the tegumentary surface be

* Recherches sur l.a Nature, la Distribution, et
l’Organs du Sens Tactile. Paris, 1837.

TOUCH.

] 109

TABLE.

Part of Surface.

Weber’s mea-
surements.

Valenti

Max.

n’s Measu
Min.

rements.

Mean.

Rela-

tive

acute-

ness.

Rela-

tive

obtuse-

ness.

I.

II.

III.

IV.

V.

VI.

Tip of the Tongue -----

_

I

0-50

0-40

0-483

1-000

1-000

Palmar surface of 3rd phalanx of fore finger

-

i

1-00

0-50

0 603

0-802

1-248

Do. do. middle finger

-

1 -00

0-37

0706

0-685

1 -461

Do. do. ring-finger

-

1-00

0 60

0-723

0-669

1 -496

Do. do. thumb

_

1 -oo

0-50

0-725

0-667

1 -500

Do. do. little finger

_

1 -oo

0-50

0-733

0-659

1-517

Red surface of under lip -

_

2

2-00

0-50

1-500

0-322

3-130

Do. upper lip - - - -

-

2-00

0-50

1-520

0-318

3-145

Palmar surface of 2nd phalanges of the fingers

-

2

2-00

1 -25

1-558

0-310

3 -223

1st

-

1 '75

1-50

1 -650

0-293

3-414

Middle of the dorsum of the tongue -

-

4

4-00

1-50

1 -916

0-252

3-964

Dorsal surface of the 3rd phalanges of the fingers

3

3-00

1 '75

2-125

0-227

4-397

Portion of the lips not red ...

-

4

4-00

1 -50

2-208

0-219

4-568

Tip of the nose -----

-

3

3-00

0-50

2-250

0-215

4-655

Edge of the tongue an inch from the tip

-

4 00

1-50

2-478

0-195

5-127

Lateral surface of the dorsum of the tongue

_

4 00

1-50

2-500

0-193

5-172

Palmar surface of the metacarpus

-

3

3-00

1-75

2-625

0-184

5-431

End of the great toe - - - -

5

5-00

3 00

3-250

0-149

6-724

Metacarpal joint of the thumb - - -

-

4

4-50

2-00

3-333

0-145

6-896

External surface of the eyelids - - -

-

5

5-00

2-50

3-833

0-126

7-930

Palm of the hand -

..

5

5-00

3 00

3-833

0126

7-930

Dorsal surface of 2nd phalanx of thumb

-

5

5-50

2-75

3-893

0-124

8-054

Do. do. fore finger

-

5-50

2-75

3 893

0-124

8-054

Do. do. middle finger

_

5-50

2 75

3-900

0-124

8-069

Do. do. little finger

-

5-50

2-50

3-943

0-122

8-158

Do. do. ring-finger

_

5-50

2-75

3-971

0-121

8-216

Centre of the hard palate - - - -

-

6

6-00

2-00

4 042

0-120

8-363

Mucous membrane of lips close to the gum

-

9

9 00

2-00

4-125

0-117

8-535

Skin of cheek over buccinator -

-

5

5 00

3-25

4-541

0-106

9-395

Skin of cheek over anterior part of malar bone

-

7

7-00

3-00

4-620

0-105

9-559

Dorsal surface of the 1st phalanges of the fingers

7

7-00

4 00

4-917

0-098

10-173

Prepuce ------

-

6-00

4-00

5-100

0 095

10-552

Dorsal surface over the heads of metacarpal bones

8

8-00

3-25

5-250

0-092

10-862

Skin of cheek over posterior part of malar bone

-

10

10-00

3-00

5 286

0-091

10936

Plantar surface of metacarpal bone of great toe

-

7-00

5 00

5-875

0-082

12-155

Lower part of forehead -

-

10

10-00

4-00

6-000

0-081

12-414

Back of the hand -----

-

14

14-00

3-50

6-966

0-069

14-412

Lower part of hairy scalp in occipital region

-

12

12-00

6-00

8-292

0-058

17-156

Surface of the throat beneath lower jaw

-

15

15-00

3-00

8-292

0-058

17-156

Back of the heel -----

-

10

10 00

8 00

9-000

0-054

18-621

Pubes -------

14-00

3-00

9-200

0-052

19-035

Crown of the head -----

-

15

15-00

5-50

9-583

0-050

19-827

Patella and neighbouring part of thigh

-

16

16-00

6-00

10-208

0-047

21 -120

Areola around nipple -

-

20-00

9-50

12-066

0-040

24-964

Dorsum of foot near the toes -

-

IS

18-00

7-50

12-525

0-039

25-914

Axilla -------

_ 1

14-00

12-00

13-000

0 037

26-897

Upper and lower extremities of fore arm -

-

18

18-00

7-00

13-292

0-036

27-501

Back of the neck near the occiput

-

24

24-00

8-00

13-292

0-036

27 501

Upper and lower extremities of leg -

-

18

18-00

9-00

13-708

0 035

28-361

Penis - - -

-

18

18-00

10-00

13-850

0 034

28 -655

Acromion and upper part of arm

-

IS

18-00

6 00

13-866

0 034

28 688

Sacral region ------

18

18-00

7-50

14-958

0-032

30-948

Sternum ------

20

20-00

8-00

15-875

0 030

32-845

Gluteal region and neighbouring part of thigh

-

18

18-00

10-50

16-625

0-029

34-397

Middle of fore arm, where its circumference

IS 1

30

30-00

8-75

17-083

0’028

35-344

greatest - - -

-J

Middle of thigh, do. -

30

30-00

9 00

17-633

0-027

36-482

Middle of cervical vertebras -

-

30

30-00

7-00

18-542

0-026

38-362

Five upper dorsal vertebras -

-

24

24-00

11-00

19 000

0-025

39-310

Lower part of thorax, and over lumbar vertebras

24

24 -00

11-50

19-912

0-022

44-758

Middle of the dorsal vertebra - - -

-

30

30-00

11-00

24-208

0-020

50086

VOL. IV.

4 F

!

1170

TOUCH.

selected, whose relative position is subject to
variation (such as the two eyelids, the two
lips, &c.), and the two points of the pair of
compasses be applied respectively to these two
surfaces, the distance which separates them
will seem to be much greater than if the two
points rest at the same time on one or the
other surface. 6. The same holds good, ac-
cording to Weber, when the two points are
applied to parts of the surface, which, though
in continuity with each other, differ remark-
ably, either in structure, in function, or in the
use habitually made of them ; thus, the points
will be more clearly distinguishable, and will
therefore seem to be more distant from each
other, when one is applied to the inner surface
and the other to the red outer surface of the
lips, than when they are both applied to the
latter, although its discriminating power is
much greater than that of the former; and the
same holds good of the margin and dorsum of
the tongue, the palmar and dorsal surfaces of
the last phalanges of the fingers, & c. 7. The
discriminating sense is more acute in the in-
teguments of the head, than in those of the
trunk ; and on the face, its acuteness di-
minishes as the distance from the mouth in-
creases. 8. The tactile discrimination of the
integuments of the limbs augments with the
distance of the part from the axis of the
body ; it is less in the integuments of the
trunk, than in those of the members.

The power of tactile discrimination may be
conceived to depend in part upon the mode
in which the ultimate nerve-fibres are dis-
tributed in the skin, being greater in propor-
tion as contiguous parts are supplied from
distinct central sources, and less when the
central terminations of their nerve-tubes are
the same. Thus, if two impressions be made
along the course of the same nerve-tube, they
will not be felt as two, but as one , and this
probably holds good of the parts of the in-
tegument supplied with branches from the
central axis of any one tube. On the other
hand, whenever two impressions be made
upon two distinct nerve-tubes, or on the
branches proceeding from them, they will
probably be felt to be double ; and the dis-
tance at which these impressions seem to the
tactile sense to be, appears to have a relation
to the distinctness of the central connections
of these nerve-tubes, as appears from the
fact that the “ limit of confusion ” is less
across the median line than on either side of
it ; that it is less between two parts (such as
the lips and eyelids) whose nervous supply is
known to be distinct, than on either part
separately ; and that it is less between two
parts whose nervous supply may be presumed,
from their difference of function, to be' dis-
tinct (as the inner and outer surfaces of the
lips), than on either part separately. More-
ever, it would not seem to be improbable that
one use of the plexuses from which the limbs
are supplied, is to produce such an inter-
mingling of the fibres from different gan-
glionic centres, that contiguous portions of
the integument shall be connected with cen-

tres very remote from each other, and their
discriminating power thus augmented. No
such intermingling takes place in the nerves
which supply the trunk, and the tactile dis-
crimination of its integument is (as we have
seen) vastly inferior to that of the extremities.
Thus it may happen that the common sensi-
bility of two parts may be the same, whilst
their power of tactile discrimination may differ
considerablv ; and we may even have the
common sensibility greatest where the tactile
discrimination is least, — as we experience, for
example, on the integument of the face, which
is far more sensitive to a blow, and especially
to a “ fillip,” than is the integument of the
palmar surface of the fingers, although greatly
inferior to them in discriminating power.
The actual nervous supply, and the conse-
quent sensibility, of a part, may be greater in
such cases ; but the unity, or close approxi-
mation, of the source from which this pro-
ceeds, may prevent its discriminating power
from augmenting in the same proportion.

In like manner, we find that the tactile dis-
crimination of different parts bears no relation
whatever to that peculiar modification of
common sensibility (which yet appears the
exclusive attribute of the external integuments)
through which the feeling of “tickling” is
excited. For the parts which are most sus-
ceptible to this feeiing, such as the axillae and
the soles of the feet, are possessed of a very
low degree of discriminating power, and those
which possess this power in the highest
degree (such as the tips of the fingers) are
the least “ ticklish.” Further, it is worthy of
notice that the parts through which that
peculiar sensation, which we have termed the
genital sense, is specially excited, — namely, the
penis and the mammary areola, — are remark-
able rather for the obtuseness than for the
acuteness of their power of tactile discrimina-
tion.

That it is only through the skin and those
parts of its internal reflexions which are in
closest proximity with it (especially the lining
of the mouth and nostrils), that we can dis-
criminate tactile impressions, appears from
this ; that although the internal mucous and
serous surfaces, the fibrous membranes, and
the parenchyma of many organs, &c. &c.,
are all capable of becoming acutely sensible
to pain when irritated or inflamed, yet no
foreign substance is ever distinctly felt by the
touch through these parts. Thus, although a
sensation of a pleasing or a painful nature is
excited by certain substances immediately
upon being swallowed, all consciousness of
their presence (so far as it is dependent upon
the sense of touch) soon ceases, and cannot
be again recalled by the utmost exertion of the
will. Further, a foreign substance, lodged in
the alimentary canal, or in the trachea, may
give rise to the greatest possible distress,
through the irritation it produces ; but though
it thus acts upon the nerves of the parts im-
mediately in contact with it, these nerves
convey no idea to the sufferer of the shape
or size of the body, or of any other of its

TOUCH.

1171

physical qualities, concerning which we re-
ceive information through the sense of touch.

Sense of Temperature. — This sense is
called into action when there is a difference
between the temperature of the sensory organ
and that of the surrounding medium, or of
substances with which it is specially brought
into contact. It is one of which the intensity
is determined, more perhaps than that of any
other sensation, rather by the relative than by
the absolute condition of the body which
excites it. Thus, if one hand be immersed
for a time in hot water, and the other in cold,
and both then be plunged into tepid water,
this will seem cool to the former and warm to
the latter. So, again, a person coming out of
cold air into an atmosphere of moderate tem-
perature, derives from it the feeling of genial
warmth, whilst another, coming into the very
same atmosphere from one much hotter, com-
plains of its chillness. Again, when the tem-
perature of different substances is compared
by the hand, the sense is not so much influ-
enced by the absolute amount of caloric
possessed by each, as by their power of
imparting cold or heat to the sensory organ.
Hence substances which are good conductors
(such as metals or marble) are felt to be
colder than those which conduct heat badly
(such as wood), although really of the same
temperature, because they draw off the heat
of the sensory surface more rapidly ; whilst,
on the other hand, if both be warmer than
the sensory surface, the best conductors will
seem to be the hottest, because their caloric
is most readily imparted. Further, the sense
of temperature is influenced in a remarkable
degree by the extent of surface on which the
impression is made. Every one is familiar
with the fact that hot water in which a single
finger may be held without inconvenience,
will be felt intolerably scalding when the
whole hand is immersed in it. And it has
been shown by Professor Weber, that if one
vessel of water be heated to 98° and another
to 104°, and the whole of the hand be im-
mersed in the former, while the finger alone
is immersed in the latter, a wrong judgment
of their relative temperatures will be probably
given, that which is really the cooler being
pronounced the hotter, on account of the
larger extent of surface on which it acts.
This mistake was made in some of his experi-
ments, when the difference was as much as
eight degrees ; the cooler water being at 98°,
and the hotter at 106°, and yet the former
being esteemed the hotter. So, again, the
immersion of the entire hand enables minute
differences of temperature to be detected,
which could not be recognised by the immer-
sion of a single finger. By the former method,
a difference of only one-third of a degree may
be distinguished ; the entire hand being im-
mersed, repeatedly and successively, in two
vessels of water, differing only that much in
their relative warmth. But it is remarked by
Professor Weber, that these minute differ-
ences are best detected when the medium
examined does not fall short of, or exceed

very considerably, the usual temperature of
the body ; just as the ear can best perceive a
difference of tone in sounds which are neither
very acute or very grave.*

It is a remarkable fact, discovered by Pro-
fessor Weber, that the left hand is in most
persons more sensible to variations of tem-
perature than the right. Thus, when the
hands of a person lying in bed, and having
exactly the same temperature, are plunged
each in a separate vessel of hot water, the
left hand is believed to be in the hotter
medium, although the water in which it is
immersed is really one or two degrees colder
than the other. This difference is the more
remarkable, as the power of tactile discrimina-
tion is usually greater in the right hand ; and
it is attributed bv Professor Weber to a
difference in the thickness of the epidermis,
the left hand usually having a thinner epi-
dermis than the right, especially in the palm,
because it is less used. But this will only
apply to the hand ; and since (as will be
presently shown) we possess a greater power
of discriminating pressures through the entire
surface of the left side than through that
of the right, it would seem much more pro-
bable that there is an original difference in
the tactile endowments of the two sides
respectively. There is certainly a strongly
marked difference between different parts of
the trunk in regard to their sensibility to tem-
perature, as is experienced by those who
sponge themselves over with cold water im-
mediately on leaving their bed in the morning.
In the writer’s case, the parts most sensitive
to the cold are in the centre of the dorsal
region behind ; in front, between the lower
end of the sternum and the umbilicus ; and
the corresponding portions of the flanks.
These spots are among the parts of the in-
tegument least possessed of tactile discrimi-
nation ; and yet the cold sponge passing over
them seems to be much lower in temperature
than when it is applied to other parts.

Some further experiments have recently
been made by Professor Weber, to determine
whether the sense of temperature is received
through any other channel than the sensory
apparatus contained in the integuments.)-
The first means of which he availed himself
for deciding this question, was that afforded by
the results of accident or surgical operations,
in which a portion of skin has been left defi-
cient. Thus, in three cases in which a large
portion of the skin had been destroyed by a
burn, and in which healing had not advanced
so far as to renew the organ of touch, it was
found that no correct discrimination could be
made between two spatulas, one of them at a
temperature of from 48° to 54°, the other of
from 113° to 122°, which were brought into

* He further remarks, that the comparison be-
tween two temperatures can be best made when the
impressions are not simultaneously made upon two
different parts, but are made in quick succession upon
the same part ; as mentioned hereafter to be the case
in regard to weights.

f Muller’s Archiv. 1849. Heft, iv. s. 273— -283.

4 f 2

1172

TOUCH.

contact with the denuded surface ; so that one
of these patients thrice affirmed that he was
being touched with the cold body when it
was the warm, and the reverse. But when
the spatula was in one instance made some-
what warmer, and was brought into contact
with the unskinned surface, the patient felt,
not heat but pain. Another means of gaining
information on this (mint is afforded by the
ingestion or injection of a large quantity of
warm or cold fluid into the stomach or intes-
tinal canal. Thus Professor Weber states,
that after drinking a tumbler of water at 32°,
he felt the cold water in the mouth, in the
palate, and in the pharynx, as far as the limits
of the sense of touch ; but that the gradual
passage of the cold water into the stomach
could not be perceived. There was, it is
true, a slight sensation of cold in the gastric
region ; but as it only occupied the situation
of the anterior wall of the stomach, it was at-
tributable to the abstraction of heat from the
abdominal integuments in contact with this.
In an opposite experiment, the author drank
quickly three glasses of milk, the temperature
of the first of which was 158°, that of the
second 145°, whilst that of the third was in-
termediate between the two. The sensation of
heat could not be traced lower down than
that of the cold in the previous experiment.
At the moment when the fluid entered the
stomach, there was a feeling which remained
for some time, but which could not be dis-
tinguished as heat, being mistakeable for cold.
In order to ascertain the sensations produced
in the large intestine by cold water, an in-
jection of 14 ozs. of water of the temperature
of 65° was thrown up the rectum, but scarcely
any sensation of cold could be perceived from
it. In another instance, 21 ozs. of water at
the same temperature was thrown up, without
any resulting sensation of cold. In both these
cases, on the return of the enema a few mi-
nutes afterwards, a distinct feeling of cold was
experienced at the anus. When water of so
low a temperature as 45£° was injected, the
first feeling excited was a sensation of cold in
the immediate neighbourhood of the anus, and
then a feeble movement in the bowels ; but a
little time afterwards, there was a faint sensa-
tion of cold, especially in the anterior wall of
the abdomen. This sensation, however, re-
mained after the return of the water ; and
may hence be attributed to the abstraction
of warmth from the abdominal integuments,
which was proved to take place, the temper-
ature of the surface being lowered 3 degrees.
So, again, if the cavity of the nose be filled
with cold water, the coldness is only perceived
in the parts of the cavity which are most en-
dowed with the proper tactile sense, namely,
the neighbourhood of the nostrils and of the
pharynx ; and it is not at all discernible in
the higher part of the cavity, which is espe-
cially subservient to the olfactive sense. [ See
Smell.] But when the water injected is very
cold ( e . g. 41°), a peculiar pain is felt in the
upper part of the nasal fossae, extending to
the regions of the forehead and lachrymal

canals ; this pain, however, is altogether dif-
ferent from the sense of coldness.

From the foregoing experiments it appears
fair to conclude, that the sensory nerves have
no power of receiving impressions arising from
difference of temperature, unless those im-
pressions are communicated through a special
organ ; but they afford no adequate ground for
the supposition, that a set of nerve-fibres is
provided for their transmission, distinct from
those which minister to common sensation.
This conclusion is confirmed by the fact, that
we cannot excite impressions of heat or cold
by direct application to the trunks of nerves
which we know must conduct such impres-
sions. Thus the parts of the skin immediately
beneath which lie large nerve-trunks, are not
more sensitive to moderate heat or cold than
any other part ; whilst a greater degree of
either is felt as pain, not as a change of tem-
perature. Thus, as we have already seen, a
mixture of ice and water, applied over the
ulnar nerve, affects it in fifteen seconds, and
produces severe pain, having no resemblance
to cold, such as cannot be excited by the
same cold applied to any other region. So
the nerve of the tooth-pulp is equally and
similarly affected by water of 43° and of 1 12°;
either application causing a pain exactly
similar to that excited by the other, or that
produced by pressure.*'

We have now to consider those more com-
plex modes of exercise of the sense of touch
which require the conjoint exercise of the
“ muscular sense;” and as this is a modifi-
cation of the general sensibility, which may
perhaps be regarded as being as special or
peculiar in its relations to the muscular sys-
tem as the sense of touch (properly so called)
is to that of the skin,] it will be desirable to
examine, in the first instance, into its modus
operandi.

Muscular Sense. — It may be stated as a
general fact, that all voluntary muscular con-
traction must be guided and controlled by sen-
sation ; and in the majority of cases, the con-
trolling sensation is derived from the muscles
themselves, of whose condition we are ren-
dered cognisant by the sensory nerves with
which they are furnished. The proof of this
necessity is furnished by the entire want of
power to make or sustain voluntary efforts,
when the guiding sensation is deficient. Thus,
in complete anaesthesia of the lower extre-
mities, without loss of muscular power, the
patient is as completely unable to walk, as if
the motor nerves had also been paralysed,
unless the deficient sensorial guidance be re-
placed by some other ; and in similar affections
of the upper extremities, there is a like in-
ability to raise the limb or to sustain a weight.
But in such cases, the deficiency of the “ mus-

* It is remarkable that the same should be true
of the impressions received through the skin itself,
when they pass beyond certain limits of intensity ;
thus, the sensation produced by touching frozen
mercury is said to be not distinguishable from that
which results from touching a red-hot iron.

TOUCH.

1173

cular sense” may be made good by the visual;
thus, the patient who cannot walk, because he
cannot feel either the contact of his foot with
the ground, or the muscular effort he is mak-
ing, can do so if he looks at his limbs ; and the
woman who cannot feel the pressure of her
child upon her arms, can yet sustain it as long
as she keeps her eyes fixed upon it, but no
longer, — the muscles ceasing to contract, and
the limb dropping powerless, the moment that
the eyes are withdrawn from it. There are two
groups of muscular actions, however, which,
although as voluntary in their character as
the foregoing, are yet habitually guided by
other sensations than those derived from the
muscles themselves. These are, the move-
ments of the eyeball, and those of the vocal
apparatus. The former are directed (as Dr.
Alison has well shown*) by the visual sense,
by which the action of the muscles is guided
and controlled in the same manner as that of
other muscles is directed by their own “mus-
cular sense and hence it happens that, when
we close our eyes, we cannot move them in
any required direction, without an effort that
strongly calls forth the muscular sense, by
which the action is then guided. In persons
who have become blind after having once
enjoyed sight, an association is formed by
habit between the muscular sense and the con-
tractile action, that enables the former to
serve as the guide after the loss of the visual
sense ; but in those who are born perfectly
blind, or who have become so in early infancy,
this association is never formed, and the eyes
of such persons exhibit a continued indefinite
movement, and cannot by any amount of effort
be steadily fixed in one spot, or be turned in
any definite direction. A very small amount
of the visual sense, however, such as serves
merely to indicate the direction of light, is
sufficient for the government of the move-
ments of the eye-ball.

In the production of vocal sounds, again,
that nice adjustment of the muscles of the
larynx, which is requisite to give forth deter-
minate tones, is ordinarily directed by the
auditory sense ; being learned in the first
instance under the guidance of the sounds
actually produced ; but being subsequently
effected voluntarily, in accordance with the
mental conception (a sort of inward sensa-
tion) of the tone to be uttered, which concep-
tion cannot be formed, unless the sense of
hearing has previously brought similar tones
to the mind. Hence it is that persons who
are born deaf, are also dumb. They may
have no malformation of the organs of speech ;
but they are incapable of uttering distinct
vocal sounds or musical tones, because they
have not the guiding conception, or recalled
sensation, of the nature of these. By long
training, however, and by imitative efforts
directed by the muscular sense of the larynx
itself, some persons thus circumstanced have
acquired the power of speech ; but the want

* Anatomical and Physiological Inferences from
the Study of the Nerves of the Orbit, in Trans, of
Hoy. Soc. Edinb., vol. xv.

of a sufficiently definite control over the vocal
muscles is always very evident in their use of
the organ. It is very rarely that a person
who has once enjoyed the sense of hearing,
afterwards becomes so completely deaf, as to
lose all auditory control over his vocal organs.
An example of this kind, however, has been
made known to the public by a well known
author, as having occurred in himself; and
the record of his experiences* contains many
points of much interest. The deafness was
the result of an accident occurring in child-
hood, which left him for some time in a state
of extreme debility ; and when he made the
attempt to speak, it was with considerable
pain in the vocal organs. This pain probably
resulted from the unaccustomed effort which
it was necessary to make, when the usual
guidance was wanting ; being analogous to
the uneasiness which we experience when we
attempt to move our eyes with the lids closed.
His voice at that time is described as being
very similar to that of a person born deaf and
dumb, but who has been taught to speak.
With the uneasiness in the use of the vocal
organs was associated an extreme mental in-
disposition to their employment ; and thus,
for some years, the voice was very little ex-
ercised. Circumstances afterwards forced it,
however, into constant employment; and great
improvement has subsequently taken place in
the power of vocalisation, evidently by atten-
tion to the indications of the muscular sense.
It is a curious circumstance, fully confirming
this view, that the words which had been in
use previously to the supervention of the
deafness, are still pronounced (such of them,
at least, as are kept in employment) as they
were in childhood ; the muscular movements
concerned in their articulation being still
guided by the original auditory conception, in
spite of the knowledge derived from the in-
formation of others, that their pronunciation
is erroneous. On the other hand, all the
words subsequently learned are pronounced
according to their spelling; the acquired as-
sociations between the muscular sensations
and the written signs being in this case the
obvious guide.

The perception of “effort” which we
derive through the impressions made on the
muscular sense, is one which, as we shall
presently see, is of immense value, in com-
bination with simple tactile sensation, in
informing us of the sensible properties of
external objects. In its simplest exercise,
however, it enables us to appreciate the
degree of muscular force which is being
exerted ; and excites in our minds our most
definite idea of power. It is true that we
might, by the exercise of our other senses,
have arrived at the conception of a tendency
in bodies to attract one another, or to com-
municate motion one to another ; but the
notion of the force with which they do so is
entirely founded, directly or indirectly, upon

* See the “ Lost Senses,” by Dr. Kitto ; vol. i.
chapters 2 and 3.

4 f 3

1174

TOUCH.

the conception of the muscular exertion
which would be required to produce or to
antagonise the movement. Thus it is, too,
that when we are about to make a muscular-
effort, the amount of force which we put
forth is governed by the mental conception of
that which will be required, as indicated by
the experience of former sensations ; just as
the contractions of the muscles of vocalisa-
tion are regulated by the conception of the
sound to be produced. Hence if the weight
be unknown to us, and it prove either much
heavier or much lighter than was expected,
we find that we have put forth too little or
too great a muscular effort.

It is through the “ muscular sense,” in
combination with the visual and tactile, that
those movements are regulated, which are
concerned alike in ordinary progression, and
in the maintenance of the equilibrium of the
body. That the visual sense has, in most
persons, a large share in this regulation, is
evident from the simple fact that no one who
has not been accustomed [to the deprivation
of it can continue to walk straightforwards,
when blind-folded, or in absolute darkness,
towards any point in the direction of which
he may have been at first guided. But the
blind man, who has been accustomed to rely
exclusively upon his muscular sense, has no
difficulty in keeping to a straight path ; and
moves onwards with a confidence which is in
remarkable contrast with the gait of a man
who has been deprived of sight for the oc-
casion only. In fact, as Mr. Mayo has well
remarked *, in our ordinary movements, “ we
lean upon our eyesight as upon crutches.”
And when our vision, instead of aiding and
guiding us, brings to the mind sensations of
an antagonistic character, our movements
become uncertain, from the loss of that power
of guidance and control over them which the
harmony of the two sensations usually gives.
Thus a person unaccustomed to look down
heights feels insecure at the top of a tower
or a precipice, although he knows that his
body is properly supported ; for the void
which he sees below him contradicts (so to
speak) the tactile sensations by which he
is made conscious of the due equilibrium of
his body. So, again, any one can walk along
a narrow plank which forms part of the floor
of a room, or which is elevated but a little
above it, without the least difficulty, and even
without any consciousness of effort. But
let that plank extend across a chasm, the
bottom of which is so far removed from the
eye that the visual sense gives no assistance ;
and even those who have braced their nerves
against all emotional distraction feel that an
effort is requisite to maintain the equilibrium
during the passage over it; — that effort
being aided by the withdrawal of the eyes
from the abyss below, and the fixation of
them on a point beyond, which at the same
time helps to give steadiness to the move-
ments, and distracts the mind from the sense

of its danger. The degree in which the
muscular sense is alone sufficient for the
guidance of such movements, when the mind
has no consciousness of the danger, and
when the visual sense neither affords aid nor
contributes to distract the attention, is re-
markably illustrated by the phenomena of
Somnambulism; for the sleep-walker traverses,
without the least hesitation, the narrow para-
pet of a house, and crosses narrow and insecure
planks, chambers, roofs, &c., under circum-
stances that clearly indicate the nature of the
guidance by which they are directed (see
Sleep, p. 694). The dependence of our
ordinary power of maintaining our equili-
brium upon the combination of the guiding
sensations derived through the sight and
the touch, is further well illustrated, as Mr.
Mayo has pointed out *, by what happens to
a landsman on first going to sea. “ It is long
before the passenger acquires his * sea legs.’
At first, as the ship moves, he can hardly
keep his feet ; the shifting lines of the vessel
and surface of the water unsettle his visual
stability ; the different inclinations of the
planks he stands on, his muscular sense. In
a short time, he learns to disregard the shift-
ing images and changing motions, or acquires
facility in adapting himself (like one on
horseback) to the different alterations in the
line of direction in his frame.” Before this
power, however, has been gained, the pas-
senger has usually to experience most dis-
tressingly that peculiar feeling of want of
support , which is consequent upon the pitch-
ing and rolling of the ship, but more par-
ticularly upon the former. As the part of
the vessel on which he is standing, sitting, or
lying, rises beneath him, there is a comfortable
sense of support ; but as it sinks, the want of
support is most disagreeably felt ; and the
continual repetition of this sensation gives
rise to nausea and vomiting. The tendency is
increased by the sight of continually shifting
lines and surfaces, which of itself, with many
individuals, disposes to the same state ; and
hence it is that the sickness may often be kept
at bay by simply closing the eyes, so as to
exclude these objects ; whilst, on the other
hand, the effort to stand or walk only serves
to augment the distress, by increasing the
sense of instability. — The giddiness and
nausea produced by rapidly turning round,
are the results of the same sensations. They
are usually excited more through the visual
than through the tactile sense ; but that the
latter is of itself quite sufficient to produce
them, is obvious from the fact that they are
experienced when the eyes are closed, as well
as by blind persons. The feeling of disturbed
equilibrium is more persistent than most
other sensations ; thus when a person has
turned round quickly several times in suc-
cession, and then suddenly stops, he feels a
whirling sensation, which excites a disposition
to continued motion in his limbs, and the
surrounding objects appear to move before

Outlines of Physiology, p. 355.

* Loc. cit.

TOUCH. 117

his eyes. But if, as Mr. Wheatstone has
pointed out, the person who is turning round
holds a large sheet of paper before and near
his face, so as to exclude all sight of the
room, and fixes his eyes upon a point — a
letter, for instance, in the middle of the
paper, — when he stops, he finds his head
perfectly steady, and the surrounding objects
have no apparent motion ; but his legs feel
unsteady, as if they continued actually turn-
ing round. And it is thus clearly proved
that the cause of the giddiness lies in the
affection of the senses, and not (as is usually
imagined) in disturbed cerebral action.

Sense of Weight. — This is usually derived
from a double source ; namely, the impression
made upon the cutaneous surface by the sim-
ple pressure of the body: and the conscious-
ness of the muscular effort employed to re-
sist that pressure. The latter enables us to
compare the weights of different bodies much
more accurately than the former, which is li-
able to excite fallacious ideas. The extent of
surface, for example, which is in contact with
the skin, greatly modifies the estimate of the
pressure of a heavy body ; the body feeling
lightest when its pressure is distributed over a
larger surface, and vice versa. Thus, a trun-
cated cone seems heavier when it rests (with-
out any effort being made to raise or support
it) upon its small extremity, than when it rests
upon its large extremity on the same part of
the surface. At first sight this fact appears
altogether antagonistic to the one just stated
with regard to the sense of temperature, the
impressions on which are more powerful when
they are made over a large than over a small
surface. But it is to be borne in mind, that
in the latter case an absolutely larger amount
of calorific influence is exerted, when the large
surface is exposed to the action of heat;
whilst in the former, the amount of pressure
is really the same, whether it be distributed
over a larger or a smaller area. The experi-
ments of Weber on the relative information
derived from the mere sense of pressure, and
from the sense of muscular effort, in the ap-
preciation of weights, are very instructive.
He found that if the two hands of the same
individual be placed upon cushions, and un-
equal weights be placed upon the right and
left hands respectively, the eyes being kept
shut, it will not be possible to say on which
hand the heavier weight lies, unless the dif-
ference be very considerable ; but a compara-
tively small amount of difference is at once dis-
criminated, when a muscular effort is made to
lift the hands from the cushions. This power
of comparison is capable of being rendered
more exact by practice ; so that men accus-
tomed to estimate weights by poising them in
their hands, will readily distinguish between
two which differ only by one-thirtieth part.
It is found that the power of comparison is
much greater (as in the estimation of tempe-
rature) when the impressions are successively,
than when they are simultaneously made, pro-
vided that the interval be not too long. Thus
in the comparison of two weights, the greatest

nicety is attained by poising the one, and
immediately afterwards the other, in the same
hand ; but the intervention of a few seconds
between the poising of the first and that of the
second does not prevent their accurate com-
parison. The interval may amount to twenty
seconds, and yet a just estimate may still be
made ; but when it amounts to forty seconds
all accuracy is lost. Professor Weber has
further ascertained, that, in the estimation of
weights by their simple pressure on the sur-
face, the left side and extremities have usually
a more acute perception than the right ; for
out of fourteen individuals, he found this to
be the case in eleven ; in two, the contrary
was observed ; whilst in one, no difference
was perceptible.

Sense of Direction. — The combination of
the muscular with the simply tactile sense
enables us also to judge in some degree of the
direction of the pressure. Of this we gain no
information whatever from the tactile sense
alone, which always suggests the idea that the
pressure is made vertically to the surface,
when it is not corrected by the sense of mus-
cular effort called forth to antagonise it. The
following example, given by Weber, shows
how completely involuntary may be this effort,
yet how large a share it has in communicating
to us the information we derive from an im-
pression, of whose direction we are rendered
cognisant. When a hair of the head is pulled,
he remarks, we can judge perfectly well of
the direction of the traction ; this power of
discrimination is not, however, derived (as
might at first be supposed) through the sen-
sation originating in the bulb of the hair, but
from the sense of the muscular effort which is
called forth to antagonise the traction, and to
keep the head steady during its continuance.
If we prevent these muscles from being called
into play, by steadily holding between the
hands the head of the person operated on,
and if we also prevent the traction from call-
ing forth the muscular action of the scalp, by
surrounding the point from which the hair is
pulled with a firm pressure by the fingers,
we find that the discriminating power is
completely lost ; the subject of the experi-
ment being totally unable to distinguish the
direction from which the hair is pulled.

It is by this combination, too, that we judge
of the rate and direction of the passive motion
of our bodies, when we have no other means
of guidance. If, for example, a person be
seated in a carriage, with his eyes closed, and
the carriage be suddenly put in motion, the
inertia of his body causes it to be thrown in
the contrary direction ; and, in order to re-
cover and sustain its equilibrium, a muscular
effort is required, which is greater in propor-
tion to the rate of motion. If the motion
continue uniform, however, this effort becomes
so habitual that he ceases to be conscious of
it ; and he only becomes cognisant of the mo-
tion by its cessation, the equilibrium of the
body being then again disturbed by its inertia,
which tends to impel it in the direction in
which it was previously moving, so as to re-

1176

TOUCH.

quire the effort of a contrary set of muscles for
the maintenance.of the erect position.

Mental Phenomena connected with the Sense.
— The interpretation which the mind puts
upon the impressions made by external ob-
jects upon the tactile organs, is partly the re-
sult of intuition, partly of experience. Thus
we intuitively refer an impression made upon
any part of a sensory nerve in its course, to
the peripheral extremities of that nerve, or
(as in cases of amputation) to the part from
which they should normally arise. Bo, again,
if a part of the body be removed from its
usual position and connections (as in the
Taliacotian and various other operations of
plastic surgery), impressions made upon it
continue to be referred to its original seat, so
long as it retains any nervous connection with
it, and until new connections have been
formed with the nerves of the part to which it
has been transferred. So, again, when our
members are in an unaccustomed position,
we still, unless our attention be directed to
the fact, interpret impressions made upon
them as if they were in their ordinary relation
to each other, and may thus be altogether
misled : — as in the experiment mentioned by
Aristotle, of rolling a pea or other globular
body between two fingers of one hand, which
are crossed instead of lying parallel, so that
the surfaces that are usually most distant
are brought into proximity with each other ;
the sensation then received is that of a dis-
tinct convex body opposed to each of these
surfaces, so that the single body seems to be
double ; whereas, if the pea were rolled be-
tween the two surfaces which are usually and
normally approximated, it is felt but as a single
globe. This intuitive reference is obviously
analogous to that by which we judge of the
relative situations of visual objects, from the
direction in which their rays impinge upon the
retina, or from the muscular sensations re-
ceived from the muscles of the orbit.

In a large proportion of other cases, how-
ever, our interpretation of our tactile sensa-
tions, especially of all those which relate to
the configuration, densitjq &c. of external ob-
jects, is based on experience ; and those who
watch the eagerness with which the infant
grasps and examines by its touch every attrac-
tive object within its reach, are at no loss to
perceive how the experience thus early inter-
woven (as it were) with the mind, in combin-
ation with that derived through the visual
sense, comes to supply the place of the con-
genital intuitions of the lower animals, and
to cause the tactile and visual perceptions to be
henceforth so indelibly associated, that each
is continually suggesting the other. Thus,
the notion of projection, which we derive
through the sight, comes to be associated
with that of solidity, which we receive through
the touch ; and the visual notion of polish is
so closely connected with the tactile notion
of smoothness, that the one almost necessarily
suggests the other. There is abundant evi-
dence, howeyer, that there is no necessary or
intuitive connection between the ideas which

we derive through these two senses respec-
tively ; but that this connection is acquired
by the consentaneous exercise of them. Thus,
from observations made upon persons born
blind, when visual power has been first ob-
tained, it is certain that the notions of form
previously acquired by the touch do not aid
in the visual discrimination or recognition of
objects : so that, for example, if any such
person had previously learned to distinguish
a sphere, a cube, and a pyramid, by the touch,
he would not be able to say which was which
by looking at them, until he had learned by
experience to associate the two classes of per-
ceptions : and, conversely, we cannot but be-
lieve that the same result would occur, if a
person whose notions of the external world
were derived from the sight alone, were sud-
denly and for the first time to become en-
dowed with the sense of touch.

It is, in fact, no less clear in regard to the
sense of touch than it is in regard to vision,
that it is not the sentient organ (as we are
accustomed to term it), but the mind, which
really perceives ; and that all the notions
which we derive through this sense with re-
spect to external objects, whether they be of
the most general kind or of a more particular
nature, are altogether distinct from the sensa-
tions themselves. It has been well remarked
by Professor Alison, that “ one decisive proof
of this being the true representation of this
part of our mental constitution is obtained by
attending to the idea of extension or space,
which is undoubtedly formed during the exer-
cise of the sense of touch, but which is no
sooner formed than it ‘ swells in the human
mind to infinity,’ to which, certainly, no
human sensation can bear any resemblance.”*
So, again, the elementary notion of an ex-
ternal universe as something distinct from the
individual self is altogether distinct from the
sensations which excites it. All that the
mind is conscious of, is a change in the condi-
tion of the corporeal organism ; and the re-
ference of the source of this change to some
external agency is a mental process in which
the action of the purely sensorial apparatus
has no concern.

It has been thought by some that the notion
of an external world depends more upon the
sensations received through the touch, than
upon those of any other kind. But there
does not seem to the author to be any reason
for considering that simply tactile impressions
are more necessarily or intuitively recognised
as proceeding from an external source than
are the visual, olfactive, auditory, or gustative.
But, as already shown, it is from the muscular
sense that we derive the idea of force, involv-
ing resistance to our own voluntary efforts ;
and it would seem to the writer to be on this
notion that our belief in the existence of an
universe external to ourselves most securely
rests.

The active co-operation of the mind is re-
quired, not only for the formation of the

* Outlines of Physiology, 3rd ed. p. 290.

TOUCH.

1177

notions so immediately springing from sensa-
tions as to be often confounded with them, but
also for the reception of the sensory impres-
sions themselves. Until, in fact, the mind
has been affected by these impressions, no
sensation can be said to exist ; and that of
‘which the mind takes cognisance is not the
external object but the impression produced
by it, and not the direct or immediate impres-
sion produced by it upon the organ which
first receives it, but the change in the senso-
rium consequent upon this. (See Sensa-
tion.) That this is the true account of the
process is now universally admitted both by
the psychologist and the physiologist ; and it
is placed beyond all reasonable question by
the occurrence of those subjective sensations,
which, until their indications are corrected
by experience, may suggest the idea of an
external source, with such vividness and de-
finiteness, that the objective unreality can
scarcely be credited. In some instances the
excitement of these subjective sensations ap-
pears due to the occurrence of a change in
the part in which they are felt, which simu-
lates that which would be produced by an
external impression ; as in the case of the sen-
sation of extreme heat, which is often expe-
rienced in inflammation to a degree far beyond
that which the actual exaltation of tempera-
ture would account for ; and the pain, of va-
rious kinds, often resembling that inflicted by
external injuries, which is the result of morbid
changes- in the part to which it is referred.
But in other cases they are clearly referable to
changes taking place in the course of the
nerve-trunk to the sensorium, which simulate
those which would naturally occur in it when
it is the conductor of an external impression ;
of this several examples have already been
given. Or, again, they may be due to a change
purely sensorial ; as in the various cases of
“ radiation of sensations ” elsewhere alluded
to (see Sensation); or, as in the sensations
of nausea, of shuddering, of tickling, of pain,
&c., which are frequently excited by changes
purely mental. The degree of intensity,
again, with which actual sensations are felt,
depends as much upon the state of the mind
as upon that of the corporeal organism.
Thus, if we experience a slight itching in the
skin, and direct our thoughts to it, we are
speedily annoyed by its increase ; whilst, if
we steadily fix our thoughts upon some
other object, we are soon unconscious of the
irritation. On the other hand, the complete
absorption of the mind in some train of
thought which engrosses its attention, may
render the individual unconscious of impres-
sions that would ordinarily induce severe
pain. This is remarkably seen in cases of
natural and artificial somnambulism (see
Sleep) ; and it is probable that in many of
the cases in which insane patients have in-
flicted severe wounds upon themselves, with-
out appearing to feel pain, the cause of the
immunity from suffering is to be found in the
entire possession which some dominant feel-
ing or idea has of their consciousness, so that

they are not cognizant of an}7 external im-
pressions but such as harmonize with it.
Even in ordinary cases, it is well known that
a severe injury suddenly inflicted, is much
less felt at the moment than a far slighter
injury of which the mind has been in expec-
tation ; thus, a limb has been carried away by
a cannon-ball, or the chest traversed by a
bullet, with far less consciousness of pain than
is produced by the trivial incision made in
ordinary venesection.

Improve ability of the Sense of Touch. — The
mental participation in the phenomena of
tactile sensation is further rendered obvious
by the improvement in discriminating power
which results from continual attention to its
indications. Of this we have examples in the
case of certain artisans, whose employments re-
quire them to cultivate their tactile discrimina-
tion ; thus, the female silk-throwsters of Bengal
are said to be able to distinguish bv the touch
alone tiventy different degrees of fineness in
the unwound cocoons, which are sorted ac-
cordingly ; and the Indian muslin-weaver con-
trives, by the delicacy of his touch, to make
the finest cambric in a loom of such simple
construction, that European fingers could at
best propose to make a piece of canvas in it.
The improvement in tactile discrimination is
more especially seen, however, in those indi-
viduals whose dependence upon it is increased
by the loss or deficiency of other senses ; and
especially by blindness, congenital or ac-
quired. Whilst it is doubtless to be attri-
buted, in great part, to the concentration of
the attention and of the powers of recollec-
tion and comparison upon the sensations
which are brought (as it were) to the mind,
it may not seem altogether improbable that
the improvement may in part depend upon an
increased development of the tactile organs
themselves ; resulting from that augmented
nutrition which would be the natural con-
sequence of the frequent use of them, and of
the increased flow of blood that seems to take
place towards any part on which the attention
is continually fixed. Certain it is, that many
blind persons can not merely obtain as defi-
nite and accurate conceptions of the form,
surface, &c., of objects over which they ra-
pidly pass their hands, as others could only
derive from the long and painstaking examin-
ation of them by their tactile organs ; but they
can discriminate minute differences, of which
those who have not specially cultivated this
faculty remain quite unconscious, even when
their attention is pointedly directed to their
discovery. The process by which the blind
learn to read from books printed in an ele-
vated type for their special use, affords an
interesting illustration of the nature of the
improveability of the proper sense of touch.
On first making the attempt, the learner needs
to use a large type; and even although (to a
person who has previously enjoyed his sight),
the visual form of each letter may be well
known, yet considerable experience is required
for the ready recognition of the tactile form of
each separate letter. After this step has been

1 178 TOUCH.

gained, the individual becomes able, by a fur-
ther period of diligent application, to recog-
nise the combination of letters in syllables
and words, without forming a separate idea
of each letter, just as we see to take place in
the child learning to read by eyesight ; and
the pupil in time acquires the power of read-
ing line after line, by passing the point of the
finger consecutively over each, with consider-
able rapidity. Now when this power has
once been thoroughly acquired, it is found
that the size of the type may be gradually
diminished, so that at last it may be reduced
to one but little larger than that of an ordi-
nary folio Bible, which is read at least as
rapidly as the words can be spoken.# As an
instance of the readiness and nicety of dis-
crimination which is frequently acquired by
those who are chiefly dependent upon this
sense for their knowledge of the outward
world, we may advert to the well-known case
of Laura Bridgman ; who, though destitute of
sight, hearing, and smell, is able to recognise
individuals with whom she has once been
well acquainted, by feeling their hands, even
after a long distance of time. It is related of
Carolan.the celebrated blind Irish bard, that on
accidentally grasping, at an interval of some
years, the hand of a female to whom he had
been formerly attached, he at once exclaimed,
with strong emotion, “ This is the hand of
Bridget Cruise.” A lady, who became blind,
and soon afterwards deaf and dumb, in conse-
quence of an attack of confluent small-pox, and
whose case is recorded in the Annual Register
for 1758, seems to have very speedily acquired
a remarkable exaltation of the sensibility she
retained. Like James Mitchell (see Smell,
p. 702.), she could distinguish strangers from
acquaintance by the smell ; but she required
the further help of the touch to distinguish
one friend from another. “ When they came
in, they used to present their hands to her as
a means for making themselves known. The
form and the warmth of the hand generally
furnished the differences which she distin-
guished ; but sometimes she would span the
wrist and measure the fingers. A lady with
whom she was well acquainted, coming in upon
a very hot day after having walked a mile,
presented her hand as usual ; she examined it
longer than ordinary, and seemed to doubt to
whom it belonged ; but at length she said, —

‘ I think it is Mrs. M. ; but she is warmer
to-day than I ever felt her before.’ ”f

* It is worthy of remark, that, when the idea of
teaching the blind to read from raised characters
was first being carried into practice, it was thought
requisite by many to adopt a new alphabet of sim-
pler forms, instead of the ordinary letters, in order
that they might be more readily discriminated.
This plan, however-, was subject to the disadvantage
that the teacher as well as the pupil was compelled
to learn this new alphabet ; and as it was soon found
that the ordinary Roman capitals, reduced to their
simplest forms, could be discriminated by the blind
with very little more trouble than the best set of
new signs that could be devised, the idea of a spe-
cial alphabet for their use has been given up.

f “ Lost Senses,” vol. ii. p. 81.

Of this lady it is positively affirmed that
she was able to distinguish colours by the
touch. “ A lady, who was nearly related to
the sufferer, having an apron on, which ac-
cording to the fashion of the time, was em-
broidered with silk of different colours, asked
her if she could tell her what colour it was ;
and after applying her fingers attentively to
the figures of the embroidery, she replied that
it was red, blue, and green ; but whether
there were other colours in the apron, the
writer of the account does not remember.
The same lady having a pink ribbon on her
head, and being desirous still further to
satisfy her curiosity and her doubts, asked
her what colour that was ? After feeling it
for some time, her cousin answered that it
was a pink colour. This answer was the more
surprising, as it showed that she was not
only capable of distinguishing different colours,
but different shades of the same colour.”# It
is probable that in this and similar cases, the
difference of hue is indicated by some diffe-
rence of surface, which becomes appreciable
to a refined touch. Of course, it can only be
to a person who has once enjoyed sight, and
who can therefore form ideas of colour, that
such ideas could be suggested by the sense of
touch ; and a new set of associations must be
formed by habit between the tactile qualities
of the surface, and the visual conception
called up by its designation. Those who
have been born blind must be utterly incapable
of forming any such conceptions, and distinc-
tions of colour can be to them nothing more
than names ; yet even such have been able to
discriminate by the touch between stuffs of
different hues, which were similar in other
respects. That such a power should be
attained seems the less difficult of belief, when
it is , borne in mind that all colour depends
upon the molecular arrangement of the par-
ticles of the surfaces of bodies ; so that there
is no great improbability — much less an im-
possibility— in the asserted discrimination of
these by a touch rendered delicate by con-
stant practice, and by the habit of attending to
its minutest indications. It is well known
that Dr. Saunderson, the celebrated blind pro-
fessor of mathematics at Cambridge, not only
acquired a very accurate knowledge of medals,
but could even distinguish genuine medals
from imitations, more certainly than most
connoisseurs in full possession of their senses ;
and this power must have depended on pecu-
liarities of their surface, too minute to be ap-
preciated by an ordinary touch, and not dis-
tinguished by the sight.

Not only does the sense of touch, in its
simplest form, undergo this remarkable exalta-
tion, but also the muscular sense, which is em-
ployed in combination with it in the acquire-
ment of information respecting the forms, di-
mensions, distances, &c. of objects. Of this,
the case of the lady just cited affords an apt
illustration : “ To amuse herself in the mourn-
ful solitude and darkness to which she had

Op. cit. p. 79.

TOUCH.

1179

been reduced, the sufferer took to working
with her needle; and it is remarked that her
needlework was uncommonly neat and exact.
Among many other pieces of needlework pre-
served in her family, was a pincushion which
could scarcely be equalled. She used also
sometimes to write ; and her writing was
executed with the same neatness and precision
as her needlework ; the characters were very
pretty, the lines were all even, and the letters
placed at equal distances from each other : —
but the most extraordinary circumstance was,
that she could by some means discover where
a letter or a word had been omitted, and
would place the caret under and the word over,
in the right place.” * This fact is obviously
analogous to those formerly related, in refer-
ence to the exaltation of the muscular sense
in the state of somnambulism. (See Sleep,
p. 694.) It is by the accurate estimates which
they are thus enabled to form, that we find
the blind able to learn various handicraft arts,
performance on musical instruments, &c. &c.,
which they practice with great success ; cabi-
net-making, turning, and even watch-making,
seem to be within the capacity of such as have
a mechanical turn ; but the greatest perfec-
tion of this sense is shown by those who have
succeeded in modelling and sculpture. Of
these, Giovanni Gonelli, sometimes called
Gambasia, from the place of his birth, deserves
special mention. He lost his sight at the age
of twenty, and remained for ten years in that
state, ignorant of the very elements of sculp-
ture. But, on a sudden, the desire of making
a statue came upon him ; and having handled
in every way a marble figure representing
Cosmo de Medici, he formed one of clay so
extremely like, that it astonished all who saw
it. His talent for statuary soon developed
itself to such a degree, that the Grand Duke
Ferdinand of Tuscany sent him to Rome to
model a statue of Pope Urban VIII., which
he also rendered a very striking likeness of
the original. He afterwards executed many
others with equal success ; amongst these,
a marble statue of our Charles I. It is re-
lated that the Duke of Braeciano, who had
seen him at work, doubted much that he was
completely blind, — and in order to set the
matter at rest, he caused the artist to model
his head in a dark cellar. It proved a striking

* Op. cit. p. 81. It is worthy of remark, that in
consequence of the strangeness of these facts to those
who observed them, it was long doubted whether
some faint remains of sight or hearing did not exist.
Many experiments were tried to settle this matter ;
but in this great caution was necessary ; for some
of these being accidentally discovered, she fell
into violent convulsions, — these being appar-
ently induced by the mental agitation she expe-
rienced at the thought of being suspected of insin-
cerity, or of being supposed capable of acting so
wicked a part, as to feign such infirmities. Sir Hans
Sloane, who attended this patient, long entertained
doubts respecting the facts related of her; but
having been permitted to satisfy himself by what-
ever experiments he thought proper, he at length
declared his conviction that she was totally blind,
deaf, and dumb.

likeness. Some, however, objecting that the
duke’s beard, which was of patriarchal ampli-
tude, had made the operation of producing a
seeming likeness too easy, the artist offered to
model one of the duke’s daughters, which he
accordingly did ; and this also proved an ad-
mirable likeness. Dr. Guillee, who details
the preceding case in his “ Essai sur l’lnstruc-
tion des Aveugles,” mentions also the more
recent case of M. Buret, whom he calls ‘‘ one
of the most able sculptors of the academy; ”
who became blind at the age of twenty-five,
but was not thereby deterred from pursuing
with much success, the course of life which he
had previously chosen. It is easy to be con-
ceived that a blind man might thus model or
chisel accurately under the guidance of his
touch, so far as mere form is concerned ; but
it has been thought difficult to understand
how he could thus discriminate and embody
that expression, which has been supposed to
be intangible* When it is remembered, how-
ever, that expression must at last depend upon
niceties of form, and can only be imitated by
the sculptor who is under the guidance of his
sight, by a minute attention to these niceties,
the difficulty altogether disappears. The blind
sculptor cannot form an idea of the expres-
sion of his model, as seen by the eyes of others;
but he may reproduce that expression with
complete success, by perfectly imitating the
form which exhibits it ; just as he may study
and understand the laws of optics, without
having ever seen the faintest ray of light.
The study of natural history might have been
supposed to be beyond the reach of the blind,
in consequence of the difficulty of distinguish-
ing specimens by the touch alone ; yet there
have been examples of complete success in
this pursuit. Thus of John Gough it is re-
lated, that “ from an early age he showed a
very decided taste for zoology ; and in time
he began to enlarge his knowledge of organic
bodies by extending his researches from the
animal to the vegetable kingdom. To bo-
tanical pursuits all the time he could spare
from the necessary studies of the school was
most assiduously devoted ; and as his ardour
in cultivating this branch of science was never
relaxed, he soon conquered most of the dif-
ficulties which the want of sight opposed to
the gratification of this taste, and was even-
tually able to discriminate and arrange with
great accuracy the plants that came under his
notice. His usual method of examining a
plant was by applying the tip of his tongue to
its several parts. Ordinary plants he could
easily and readily distinguish by the touch of
his fingers. To evince the power of discri-
mination and strength of memory, which could
alone have enabled him to take an interest in
this pursuit, it is mentioned, that towards the
end of his life a rare plant was put into his
hands, which he very soon called’ by its name,
observing that he had never met with more
than one specimen of it, and that was fifty

* “ Lost Senses,” vol. ii. p. 224.

1180 TOUCH.

years ago.”* A case of the same kind has
been long under the writer’s observation ; the
subject of it being a gentleman who became
blind from amaurosis soon after the age of
twenty. His attention having been directed to
geology and conchology, he gradually acquired
a very complete knowledge of shells both
recent and fossil ; being not only able to re-
cognise every one of the numerous specimens
in his own cabinet, but also to mention the
nearest alliances of a shell previously unknown
to him. He has occupied himself, moreover,
in freeing his fossil shells from their matrix,
with a hammer and chisel, knife, &c. ; and
has frequently done this with a perfection that
could scarcely be surpassed, rarely injuring
the specimen with his tools, and generally
clearing it completely from its incrustation,
where this was practicable. In this way he
has succeeded in forming a very valuable col-
lection of the fossils of the interesting locality
in which he resides.

A similar exaltation may manifest itself,
under the like circumstances, in the general
tactile sensibility, both of the surface and in-
terior of the body, especially as affected by the
vibrations transmitted through solid sub-
stances ; whereby a deficiency in the sense of
hearing is in some degree supplied. Thus the
visitor to a school for the deaf and dumb
remarks with surprise that a slight rap given
by the master on the table or floor is sufficient
to excite the attention of the pupils ; and
finds on examination that this is not heard,
but is felt by them. A minute account of his
personal experience on this head is given by
Dr. Kitto ; and as it involves several interest-
ing physiological considerations, the principal
facts mentioned by him will be here brought
under the notice of the reader. — “ In the state
of entire deafness,” he remarks, “ a peculiar
susceptibility of the whole frame to tangible
percussions supplies the only intimations which
have the slightest approximation to those
which hearing affords. I was about to call
this a peculiar susceptibility of the sense of
touch ; but this would unduly limit a kind
of vibration, which, in certain of its develop-
ments, seems to pervade the whole frame, to
the very bones and marrow. I do not at all
imagine that there is in this anything essen-
tially different from that which is experienced
by those who are in possession of their hear-
ing ; but it would seem that the absence of
that sense concentrates the attention more
exclusively upon the sensation which is
through this medium obtained ; and the in-
timation of which, being no longer checked
and verified by the information of higher
organs, assume an importance which does not
naturally belong to them.” This sense of
percussion is but little excited in the human
body by the vibrations of air ; obviously be-
cause there is no expanded surface adapted
to receive their influence. Thus Dr. Kitto
mentions that the loudest thunder makes
no impression upon him, unless it shakes

* “ Lost Senses,” vol. ii. p. 215.

the house in which he is ; in which case
it communicates a sensation resembling that
produced by the removal of a piece of fur-
niture in an adjoining room.* In like man-
ner, he is utterly unconscious alike of the
sound of bells, and of the vibration produced
by their percussion, unless the latter be pro-
pagated through solid bodies, as when he places
himself in direct contact with a tower in
which a powerful peal is being rung. “ 1 re-
member,” he says, “ that once when I was
showing a young friend from the country over
St. Paul's, we happened to be up examining
the great clock, at the very time it began to
strike. The sensation which this occasioned
was that of very heavy blows upon the fabric
in which I stood, communicated to my feet
by contact with the floor, and by the feet
diffused over the whole body. So,” he con-
tinues, “ guns — even powerful cannon —
make no impression upon this sense, unless
I happen to be very near when they are fired ;
in that case, I can compare the effect to no-
thing better than the sensation produced by
a heavy blow upon the head from a fist co-
vered with a boxing glove. This effect could
only be produced by the tangible percussion
of the air, and by the percussion upon the
ground transmitted by the feet.” So, again,
Dr. Kitto states that he is not conscious of
even a very loud knock at the door of the
room in which he is, unless the door be in
such connection with the floor that the per-
cussion is communicated through the latter,
or unless he be himself in contact with some
part of the wall to which it is hung. But, on
the other hand, he states, — “The drawing
of furniture, as tables and sofas, over the
floor above or below me, the shutting of
doors, and the feet of children at play,
distress me far more than the same causes
would do if 1 were in actual possession of
my hearing. By being to me unattended by
any circumstances or preliminaries, they
startle dreadfully ; and by the vibration
being diffused from the feet over the whole
body, they shake the whole nervous system,
in a way which even long use has not enabled
me to bear. The moving of a table is to me
more than to the reader would be the com-
bined noise and vibration of a mail coach
drawn over a wooden floor ; the feet of
children, like the tramp of horses upon the
same floor ; and the shutting of a door like a
thunder-clap, shaking the very house. It is
by having once heard, that I am enabled to
make such comparisons as these, for the
illustration of a sensation which one who
has never heard, and one who is not deaf,
would be alike unable to describe.” The
fact that the shutting of a door is felt with
painful distinctness (as Dr. Kitto elsewhere
mentions), even when upon a different floor,
whilst the loudest ordinary knocking at the
same door is not perceived, very curiously

* The writer of this article, residing near a rail-
way tunnel, has frequently noticed that the emer-
gence of a train is indicated by the succussion of
the windows of his house, before it becomes audible.

TOUCH,

1 181

illustrates the necessity for the transmission
of the vibrations along a solid medium. “The
valve of the door on which the percussion
is made by knocking, is a detached frame of
wood hung upon hinges, and the vibration is
therefore comparatively isolated and not pro-
pagated throughout the frame of the house, as
is the case when, in shutting the door, the
valve itself strikes the door-post, which is
identified with the framework ot the build-
ing.” In illustration of the acuteness of
this sense in his own person, Dr. Kitto states
that the lightest footfall upon the same floor
is quite sufficient to attract his attention, or
even to arouse him from sleep. “ If any
small article,” he continues, “ such as a
thimble, a pencil, a penknife, or even a more
minute object, falls from the table to the
floor, I am often aware of it, even when
other persons sitting at the same table have
not been apprised of it by the ear. The
greater the number of my points of contact
with the floor, the stronger are the impres-
sions I receive : hence they are more vivid and
distinct when I sit than when I stand ; be-
cause, in the former case, not only my own
two legs, but the four legs of my chair, are
concerned in conveying the percussion to
my sensorium. And when the chair itself on
which I am seated has been subject to the
percussion, the sensation is such as baffles
description. For instance, a few days since,
when I was seated with the back of my
chair facing a chiffoniere, the door of this re-
ceptacle was opened by some one, and swung
back so as to touch my chair. The touch
could not but have been slight, but to me the
concussion was dreadful, and almost made me
scream with the surprise and pain, the sensa-
tion being very similar to that which a heavy
person feels on touching the ground, when he
has jumped from a higher place than he ought.
Even this concussion, to me so violent and
distressing, had not been noticed by any one
in the room but myself. * * * If these per-
ceptions are so acute in carpeted rooms, it
will be easily understood by how much more
intense they become upon a naked wooden
floor. The sensation then amounts to torture
— as every movement or concussion, in any
part of the room, then comes with an in-
tensity of effect, far more than proportioned
to the difference in the impression which
would, under the same circumstances, be pro-
duced upon the auditory sense.”

It is interesting to remark that, notwith-
standing this acuteness of the sense in ques-
tion, it does not seem to convey (in Dr. K.’s
case at least) any information of the direction
or distance of the percussions, except such as
is afforded by their relative intensity. Thus
he says ; — “I am unable to determine from
the information of the sensation itself, whether
it has occurred upon the floor above, or in
that below me, or in the passage or room ad-
joining that in which I may be at the time.
I am not aware that the impression is more
distinct from the floor above than from that

below ; but it certainly is more distinct in
another room of the same floor, than from
either the one above or below; whence I am
much in the habit of referring to the next
room the percussions which make the strongest
impression on me. In this I am not seldom
mistaken. * * * The information is

equally defective, even in the very room I
may happen to occupy. If a book or other
object falls in any part of the room, the sen-
sation is painfully distinct, the percussion
being upon the very boards on which I stand ;
but even in this case, 1 am at a loss for the
quarter in which the circumstance has oc-
curred, and generally look for it in the wrong
direction, and have to scan the whole room
with my eye before I can make it out.” It is
probable that the want of power to estimate
direction arises from the circumstance that
the communication of the percussions takes
place, in this and similar cases, through the
same channel (the floor) to the same parts of
the solid mass of the body, through which
the vibrations immediately spread in every
direction. It can easily be conceived that if
the percussions were transmitted through a
liquid medium, its vibrations, being propagated
in a more determinate direction, might affect
one or another part of the surface in such a
manner as to suggest the direction of their
source ; and that in this mode aquatic animals
endowed with a nervous apparatus at their
surface, specially adapted to be impressed by
such vibrations, might communicate with each
other through great distances. This appears
to be the case with regard to the Spermaceti
Whale, and probably others of the Cetacea.
It has been observed by the whale-fishers,
that when a straggler from a “ school ” is
attacked, even at a distance of several miles
from it, a number of its fellows bear down to
its assistance, in an almost incredibly short
space of time. It can scarcely be doubted
that this communication must be made through
the medium of the vibrations of the water,
excited by the struggles of the animal, or per-
haps by some peculiar instinctive movements
especially adapted for this purpose, and pro-
pagated through the liquid medium to the
large cutaneous surface of the distant whales.
And this idea is confirmed by the fact, that
the nerves which proceed to the surface of
the body pass through the layers of blubber
(which form the inner part of the true skin)
with scarcely any division, and then spread
out into a network of extreme minuteness as
soon as they approach the exterior of the in-
tegument. The expanse of such a network
over a thick layer of elastic tissue, whose
meshes are distended with oleaginous fluid,
obviously affords a condition peculiarly fa-
vourable to the reception of impressions ori-
ginating in percussion.

After the details which have been given in
proof of the degree of exaltation of which the
general tactile sensibility is capable in the
human subject, we shall have less difficulty in
understanding that even the vibrations of air,

1182

TOUCH.

excited by percussion, may become the chief
means of guidance to animals possessed of a
special apparatus for taking cognisance of
them. Such appears to be the case in the
Bat tribe, and especially in those species
whose habits are most exclusively nocturnal,
and whose dwellings admit the smallest quan-
tity of light. “ The whole surface of their
wings, on both sides, may be considered as an
enormously-expanded organ of touch, of the
most exquisite sensibility to the peculiar sen-
sation for which it is intended ; and it is,
therefore, by the varied modifications of the
impulsion of the atmosphere upon this sur-
face, that the knowledge of the propinquity of
foreign bodies is communicated.”* It would not
seem improbable, however, that the remarkable
cutaneous expansions with which the nose and
ear are furnished in many bats, are subservi-
ent to this function. The enormous exten-
sion of the external ear may doubtless aug-
ment the intensity of the sense of hearing ;
but it is scarcely accordant with our know-
ledge of the conditions under which the sense
of smell is exercised, to suppose that the
extraordinary “ nose-leaf” of the Bhinolophide
should be in any great degree subservient to
olfactive purposes. The bats of this group
(to which belong the greater and lesser horse-
shoe bats of our own country) “ are more
completely lucifugous and retired in their ha-
bits than any others ; they are found in the
darkest penetralia of caverns, and other
places where there is not even the imperfect
light which the other genera of bats enjoy.” f
Some approach to this power of guidance, de-
rived either from the impressions made by the
air upon the cutaneous surface, or from the
radiation of heat, is occasionally seen in blind
persons; who can thus distinguish 1 by the
hands, and even by the face, the proximity of
solid bodies (as in approaching a wall, a
door, or a piece of furniture) without actually
touching them.

The sense of temperature, also, appears to
be capable of considerable improvement, when
its indications are habitually and discrimi-
natingly attended to, or when the mind is
intensely and exclusively fixed upon them.
Thus it is related of Dr. Saunderson, that
when some of his pupils were taking the sun’s
altitude, he was able to tell, by the slight
alteration in the temperature of the air, when
very light clouds were passing over the sun’s
disk.

Morbid Conditions or the Sense of
Touch.

Like most other vital functions, the sense
of touch may become disordered in the waj'
of deficiency, excess, or depravation.

The state of complete deficiency is known
as Anesthesia; a term which, strictly speaking,
designates the absence of all sensation, but
which is more commonly employed as re-
ferring to the sense of touch alone. This

* See Cheiroptera, vol. i. p. 599.

( Loc. cit.

state, which may be either general or local,
may arise from an interruption in the func-
tional activity of any part of the nervous ap-
paratus concerned in the reception of sensory
impressions; and thus may be due to causes
acting either (1) at the peripheral origins of
the sensory nerves, or (2) on the nerves in
their course, or (3) on the sensorial centres ;
as well as to such as act on the whole nervous
system at once. The causes which act at the
peripheral origins of the nerves may be such
as affect either the nerves themselves, the
capillary circulation, or both. Of the first
we have a typical example in the “ anaesthetic
agents,” ether, chloroform, &c. ; the applica-
tion of whose vapour for any length of time
to the cutaneous surface, entirely suspends its
power of receiving sensory impressions ; and
that this results from the direct action of
the substances on the peripheral nervous ex-
pansion, appears from the fact of the suspen-
sion being precisely limited to the part to
which the vapour is applied. But anaesthesia
may be induced, also, by the stagnation of the
capillary circulation in a part, without any
more direct affection of its nervous endow-
ments ; as we see when the main artery of
a limb has been tied, previously to the re-
establishment of the supply of blood by the
collateral circulation, or when the flow of
blood through it has been impeded by tem-
porary pressure. It is probable that cold
operates in producing local anaesthesia in both
these modes ; namely, by its direct sedative
action upon the peripheral nerves ; and by the
stagnation which it produces in the capillary
circulation. That the local anaesthesia, which
is a not unfrequent result of the presence of
poisonous substances in the blood, is due to
the special action of these substances upon
the peripheral nerves of the particular locality,
would not seem an improbable supposition ;
when it is remembered how frequently poisons
of various kinds single out some particular
part of a structure apparently homogeneous,
for the production of their peculiar effects, — ■
lead, for example, in whatever way introduced
into the system, acting first on the muscular
fibres of the alimentary canal, and afterwards
most commonly on the extensor muscles of
the forearm, in which its presence has been
detected by chemical analysis.

Of the anaesthesia induced by causes acting
upon the sensory nerves in their course from
the periphery to the centre, our most frequent
examples are those in which it is produced by
pressure on these trunks, whereby the con-
veyance of the sensory impressions to the
encephalon is effectually checked. Anaesthesia
may also arise, however, from diseased con-
ditions of these trunks, brought about by
perverted nutrition ; and there is a form of
paraplegia, in which the lesion of sensibility
(which is more completely lost than the motor
power) appears to commence in the peripheral
expansions of the nerves, and to extend along
the trunks to the central organs.* This is
* Graves’s Clinical Medicine, vol. i. p. 503.

TOUCH.

usually referrible, in the first place, to the
influence of cold and damp; and it is especi-
ally liable to occur in persons of a rheumatic
or gouty diathesis. That even the sedative
influence of cold may be propagated along
the nerve-trunks, and that its anaesthetic
effect is not due to its peripheral influence
alone, appears from the circumstance remarked
by Dr. Graves (loc. cit.), that the paralysis
induced by handling snow, or by immersing
the hands in freezing mixtures for some little
time, is not confined to the hands and fingers,
but extends to the muscles and surface of the
fore-arms. And it was also remarked by the
same eminent physician, that in a case in
which the inside of the ring finger had been
wounded by a blunt needle, and a partial
anaesthesia induced, the same effect was per-
ceived in the little finger (alike supplied by the
ulnar nerve), obviously through the extension
of the paralysing influence towards the centre,
so as to affect the trunk higher up than the
point at which its branch to the little finger
was given off. Dr. Graves further cites, as
an example of anaesthesia having its seat in
disordered nutrition of the peripheral nerves,
and gradually advancing along their trunks
towards the centres, the curious Epidemic de
Paris, which occurred in the spring and sum-
mer of 1828. “ It began (frequently in per-
sons of good constitution) with sensations of
pricking and severe pain in the integuments
of the hands and feet, accompanied by so
acute a degree of sensibility, that the patients
could not bear these parts to be touched by
the bed-clothes. After some time, a few days,
or even a few hours, a diminution, or even
abolition of sensation took place in the affected
members ; they became incapable of distin-
guishing the shape, texture, or temperature of
bodies, the power of motion declined, and
finally they were observed to become al-
together paralytic. The injury was not con-
fined to the hands and feet alone, but, ad-
vancing with progressive pace, extended over
the whole of both extremities. Persons lay
in bed powerless and helpless, and continued
in this state for weeks and months. Every
remedy which the ingenuity of the French
practitioners could suggest was tried, and
proved ineffectual. In some, the stomach
and bowels were deranged, and this affection
terminated in a bad state of health, and even
in death ; in others, the vital organs, cerebral,
respiratory, and digestive, were in the same
state as before their illness, and their appetites
were good, but still they remained paralytics.
At last, at some period of the disease, motion
and sensation gradually returned, and a re-
covery generally took place, although, in some
instances, the paralysis was very capricious,
vanishing and again re-appearing. In the
fatal cases, no evidence could be obtained,
from the most diligent search, of any lesion,
functional or organic, in the brain, cerebellum,
or spinal marrow.”* These phenomena are

1183

scarcely explicable on any other hypothesis
than that of some general cause (probably a
morbid matter circulating in the blood) affect-
ing the nutrition and functional activity of the
nerve-trunks, rather than of their centres.

That anaesthesia may proceed from various
causes whose operation is limited to the sen-
sorial centres, is a matter of every-day ex-
perience. It is, however, where they have
suffered from some obvious lesion of a com-
paratively restricted character, that the proof
of this is most complete ; for although there
is strong ground for believing that the ordi-
nary operation of anaesthetic agents and nar-
cotic poisons is confined to the cerebrum and
sensorium, yet we could not positively affirm
such to be the case, since, when taken into
the blood, they may act not only on the sen-
sorial centres, but on the entire nervous
system. All the phemornena of narcoctic
poisoning, however, indicate that opium, al-
cohol, &c., single out the cerebrum and sen-
sory ganglia for their special action, just as
strychnia singles out the spinal cord ; the
suspension of the functional activity of the
former being usually complete, before there is
the slightest affection of the latter. That a
failure of the circulation in the encephalon
produces complete anil universal ancesthesia
while it lasts, was fully proved by Sir A.
Cooper’s well-known experiment; and it
seems probable that many of the structural
lesions which manifest themselves in paralysis
of motion and sensation produce this suspen-
sion of functional power in parts not them-
selves affected by disease, chiefly in virtue of
the derangement of the intra-cranial circula-
tion which they invole.

There is one of the phenomena of the ances-
thesia produced by the accidental or inten-
tional introduction of poisonous substances
into the blood, which seems deserving of more
special notice ; viz., the suspension of the
power of receiving painful impressions, with-
out the obliteration of the ordinary tactile
sensibility. This is a frequent result of the
exhibition of ether and chloroform ; and does
net seem to depend upon a mere blunting of
the ordinary sensibility. It has been especi-
ally noticed, also, in cases of lead poisoning,
in which state it seems to be more frequent
than complete ancesthesia. According to M.
Beau, the insensibility to pain, which he terms
analgesia, may be observed in a large propor-
tion of cases of “ saturnine intoxication.”
“ We must not confine ourselves,” he remarks,
“to asking the patient whether he feels, but
limit our question to the sensation of pain.
Parts which are thus insensible to pain are so
also to tickling. This form of ancesthesia may
affect the entire surface, being, however, most
remarkable in the extremities, and especially
the upper ones. It may extend even to the
mucous membranes, and especially those
which are normally endowed with great sen-
sibility, — as the uvula, isthmus faucium,
nares, or conjunctiva, — any of which parts
may be tickled without the usual conse-

Op. Cit. p. 504,

1 184

TOUCH.

quences, the patient still being quite con-
scious of the mere contact.”*

Reference has been already made to the
influence of the attention on the acuteness of
sensations ; and to the slight degree in which
they are felt, when the mind is completely
engrossed in some other feeling or idea This
is sometimes seen in spontaneous reverie ;
and there are individuals who can exert such
a power of mental abstraction, as voluntarily
to concentrate their attention on some ex-
ternal object, or internal idea, so as to escape
all suffering from a severe operation. This,
however, is much better seen in some of those
cases of somnambulism (see Sleep) in which
the mind is completely under the guidance of
the suggestions received from without, its
whole spontaneous directing power being
suspended. For it is frequently possible, in
such cases, to withdraw the patient’s atten-
tion from any part of the body, to such an
extent that the anesthesia is complete as
regards that part, whilst every other portion
enjoys the ordinary sensibility. Thus a tem-
porary loss of sensation on the whole of one
side may be induced, or a single limb may be
rendered anaesthetic ; and the sensibility of
the parts may be instantaneously restored,
merely by directing the patient’s attention
towards them.

With regard to hi/perccsthesia, or increased
sensibility, we have much less definite in-
formation. There can be no doubt, however,
that it, too, may proceed from changes either
in the periphery, or in the central organs, and
perhaps also from an alteration in the trunks
of the nerves in their course. The acute
sensibility of an inflamed or irritated part is
an example of the first of these conditions ;
and the extraordinary exaltation of sensibility
in the incipient stage of phrenitis may serve
as an illustration of the second. In some cases
the entire nervous system would seem to
partake of this undue excitability ; this we
especially see in hysterical subjects, in whom
the slightest contact frequently occasions in-
tense suffering, so that even the mere pointing
of a finger at any part of the body will cause
a scream of alarm. The sufferings of such
persons are not rightly designated as ima-
ginary; they are as real to them as are those
proceeding from far more serious causes to
persons of less excitable temperament. The
fault partly lies in the habitual attention
which they pay to the most trivial feelings ;
but in part also, it may be surmised, to an
abnormal state of nutrition of the entire
nervous system, — both centres and trunks, —
from depravation of the blood. This view
harmonizes well with the fact just now stated,
that in the Epidemie de Paris , a temporary
hypersesthesia (afterwards giving place to an-
aesthesia) was commonly among the earliest
symptoms. And it is not a little curious
that in the remarkable series of cases of lead-
poisoning which recently occurred in the ex-
royal family of France, during their residence

* Archives GenQrales, tom. xvi. pp. 5 — 24.

at Claremont, the same symptom presented
itself, and was in some instances the only
symptom which indicated the morbid con-
tamination of the blood.* In most cases of
this form of hypereesthesia, the exaltation
of sensibility seems confined to the surface,
being much more excited by a slight touch
than by hard pressure ; and this difference
will frequently serve to distinguish the “hys-
terical” tenderness from that of inflammation,
in which the pain is augmented the more
severe the pressure. The writer has had
opportunities of noticing an extreme sensi-
tiveness to changes of temperature in certain
cases of somnambulism, both natural and
artificial ; and he believes that this fact affords
a ready solution of various marvels which
have been narrated touching the power of
“mesmerized” subjects to distinguish a piece
of money which had been held in the mes-
merizer’s hands, or a glass of water in which
his finger had been immersed.

It has recently been proposed to apply
Prof. Weber’s method of estimating the re-
lative acuteness of the tactile sense in dif-
ferent parts of the body, to the determination
of the degree of anaesthesia or of hyper-
eesthesia, in patients affected with these dis-
orders. Thus it was found by M. llrown-
Sequard that in one case of nearly complete
anaesthesia of the lower extremities, the pa-
tient only felt a single impression on the
skin of his legs, -when the points of the com-
passes were from 10 to 20 centim. apart ; the
normal “limit of confusion” for this portion
of the surface being from 3 to 5 centim. In
another case of slighter anaesthesia, the “ limit
of confusion” in the same part was from 9
to 15 centim. And in a third case of very
slight anaesthesia, it was from 6 to 7 centim.
In a case of hyperaesthesia, on the other
hand, which accompanied paralysis of the
motor power, the patient could perceive the
distinctness of the two points on the foot,
when they were separated to the distance
of only 5 millim., although the normal “limit
of confusion ” in that part was from 25 to 30
millim. The sensibility to pain, in this case,
was as much exaggerated as was the tactile
sensibility.

Of the depravation of tactile sensibility,
manifested in a variety of morbid phenomena,
— such as the sense of heat or even of burning
(without any real elevation of temperature),
of formication, of tickling, of itching, &c., —
it must suffice here to remark, that this, like
the preceding affections, may be due to causes
acting on the peripheral nerves, or on the
nervous centres, or on the connecting trunks.
Of the latter we have a good example in the
formication which generally succeeds complete
anaesthesia, when a nerve has been pressed
upon for a time, and the pressure is then re-
moved.

W. B. Carpenter.

* See Dr. Gueneau de Mussy’s Cases of Poisoning
by Lead at Claremont, in Dublin Quarterly Medical
Journal, May, 1849.

TUNICATA. 1185

TUNICATA. ( Tuniciers , Fr.; Nacht-
Muscheler and See-Scheiden, Germ.) — The
Tunicuta are molluscous animals, having no
calcified shell, but a more or less coriaceous
envelope or tunic, whence their name. This
external coat or test is either bag-shaped and
provided with two apertures, or is tube-shaped
and open at the ends. They have no distinct
head, and no organs serving as arras or feet ;
they are provided with a muscular and a
nervous system ; and with well-defined or-
gans of respiration, digestion, circulation, and
generation.

They are exclusively marine, and are widely
spread from the arctic to the tropical seas.
Sessile or foot-stalked on the rock, or in-
crusting seaweed and other bodies, their
external form is seldom of graceful contour ;
yet the arrangement of the individuals in the
compound masses often exhibits curious and
elegant designs. The floating forms, however,
with their lengthened, sinuous chain, or
tapering tubes, pellucid, rainbow-tinted, or,
by night, brightly phosphorescent, are sur-
passed by no terrestrial object. The other,
fixed, forms, not altogether destitute of ele-
gance of colour in the northern seas, become
in warmer climates more and more rich in
variegated hues, and in the tropics are
amongst the most resplendent living gems of
ocean’s parterres.

The earliest notice of the tunicate animals
is made by Aristotle, who gives a very cor-
rect account of the anatomical and zoological
characters of a simple Ascidian, which he calls
TtQvov.* * * § They, however, attracted no further
notice until comparatively late times. Ron-
deletf gives indifferent figures and descriptions.
Gesner and Aldrovandus, uniting Rondelet’s
Tethya with those given by Belong, which are
Alcyonia , were among the first who gave rise
to the confusion that long existed in the
history of these animals. Xinntcus in the
4th edition of his Systema Naturae placed a
Tethyum in his system, under the appellation
of Tethys ; he pointed out at the same time
that the animal of bivalve Molluscs was a
Tethys, showing that he was aware of the
analogy of the Bivalves with the Tunicates.
In other respects, however, he added to
the confusion. After that Bohatsch and
Plancus || figured and described some species.
Basterlf describes a species, and gives it
the name of Ascidium (from cutkoc, a skin-
bottle), at the same time adding a very just
remark on the analogy of its internal struc-
ture with that of the oyster. This analogy
was noticed also by Pallas, who proposed
the union of the Tethyum and Ascidium ** *,
which Linnaeus carried out in the 12th edit,
ol his Systema Naturae, uniting the species,
noticed by Bohatsch and Kcenig, under the

* Hist. Anim. lib. iv. c. vi., and De Part. Anim.

lib. vi. c. v.

f De Piscibus, 1554. J De Aquat. 1553.

§ De quibusd. Anim. Marin. 1761.

|| Conchis minus notis, pi. v. & vii. 1739.

t Opusc. subseciv. ii. x. 5. 1764.

** Miscell. Zoolog. 74. 1767.

VOL. IV.

name of Ascidia, and confining the name Tethys
to the inhabitants of the Bivalves.

Subsequently, O. F. Miiller*, O.Fabrieius'j",
Dicquemare J, Pallas^, and others, described
and figured several Ascidicc, which Brugiere ||
and GmelinlT collected together in their re-
spective works, without adding much to the
knowledge of the group. Cuvier’s first ob-
servations on the simple Ascidians were begun
in 1797, and his memoir on their anatomy
was published in 1815.** About the same
time were published the researches of Schalkyf
on the anatomy, and of Carus jj on the
anatomy and development of the Ascidians.
The memoirs of Peron and Lesueur $$ on the
Pyrosnma, Desmarest and Lesueur || || on the
Botrylius, and particularly the elaborate work
of SavignyTT on the simple and compound
Ascidians, enabled naturalists to make rapid
advances in the knowledge of this family.
With respect to the Salpians, Brown***, For-
skahlj-f-f, and Tilesius J were the first to
figure and describe any forms of this group.
Considerable confusion with regard to these
forms existed in the classifications of Linnaeus,
Pallas, Brugiere, and Bose, and indeed in the
earlier writings of Lamarck and Cuvier,
until the latter had an opportunity of work-
ing out the anatomical characters of these
animals.

The earlier works on the various branches
of this subject have been succeeded by the
publication of the researches of many dis-
tinguished naturalists. We are chiefly in-
debted to the labours of Cuvier, Savigny,
Carus, MacLeay, and Van Beneden, for in-
formation on the structure and development
of the simple Ascidians ; to the researches of
Cuvier, Kuhl and Van Hasselt, Chamisso,
Eschricht, and Krohn, for the history of the
Salpians ; and to Lesueur, Desmarest, Sa-
vigny, Lister, Sars, Milne-Edwards, Audouin,
and Forbes, for our knowledge of the com-
pound ascidian forms.

And, indeed, since the commencement of the
present century, the organisation of this group
has been studied with great care, rewarding the
labours of naturalists with discoveries of the
highest interest. “ It was in the animal of the
Sa/pa,’’’ says Van Beneden, “that Van Hasselt
discovered a heart of such extraordinary
character, changing incessantly its auricle to
ventricle and its ventricle to auricle, its ar-

* Zool. Dan. Prodromus, 1766.
f Fauna Groenland, 1780.
j Journal de Physique, 1777.

§ Spicilegia Zoologica, 1774, and Mem. de Pe-
tersbourg.

|| Encyclopedic Methodique ; Vers Mollusques.

Systema Naturae, edit. 13.

** Memoires du Museum, tom. ii.

ft De Ascidiarum Structura, Halle, 1814.

| j Meckel’s Archiv, tom. ii. and Acta Cur. Nat.
Bonn, vol. x.

§§ Annales du Museum, tom. iv.

1111 Bull. Nouv. Soc. Philom. 1815, and Journal de
Physique, tom. lxxx.

Mem. Anim. sans Vertebres, 2* part.

*** Natural History of Jamaica,
tff Descript. Animalium, &c. 1776.
jj j Ann. Hist. Nat. Leipzig, 1802.

4 G

1186

TUNICATA.

teries to veins and its veins to arteries. The
Ascidians, too, furnish the first examples of
complete metamorphosis in the lower ranks
of the animal kingdom. The honour of this
discovery is due to MM. Audouin and
Milne-Edwards. From the late discoveries
of M. Sars, these metamorphoses increase in
interest, and appear tobe still more remarkable.
And, lastly, the Ascidians have contributed
very considerably to our knowledge of the cir-
culatory apparatus of the Mollusca generally.”

The term Tunicata was first used by La-
marck ; its synonyms are Tethya , Auct. ; Soft-
shelled Molluscs, Hunter ; les Acephales sans
coquilles, Cuvier ; Acephalophora heterobran -
chiata, Blainville ; Tunicaries , Kirby ; Gymna-
cephala, Bronn. The Class of animals to
which it is applied may be zoologically de-
fined as consisting of acephalous Molluscs ;
with a soft shell or test, organised, coriaceous
or gelatinous, frequently destitute of mineral
constituents, having a large proportion of
cellulose in its composition : animals single
or aggregate ; the test of each animal
provided with two apertures, one bran-
chial, the other anal ; the mantle forming
an interior coat ; the branchiae attached
wholly or in part to the internal surface of
the mantle ; the mouth, without labial ten-
tacles, placed below the branchial apparatus ;
animals hermaphrodite, undergoing metamor-
phosis in their young state.

The cavity, whether of single or compound
Tunicates, is occupied by a more or less
muscular sac, provided, like the external tunic,
with two orifices. This sac, identical with
the “ mantle ” of the Acephalans, is attached to
the inner surface of the test, generally only at
the orifices, and contains the viscera. The di-
gestive, reproductive, and circulatory organs are
disposed at the base of the sac, and its upper
and larger portion, lined with, or traversed by,
the branchiae, forms the branchial cavity. This
is placed at the commencement of the alimen-
tary canal, of which it forms as it were the
antechamber. The branchiae have generally
the form of ridges, more or less complicated,
and seldom symmetrical. The alimentary
canal is simple, and barely distinguishable into
gullet, stomach, and intestine. It is always
convoluted or folded once on itself. The
liver adheres to the stomach, and in many
species is divided into distinct lobes. The

Monochitonida, Fleming.

Inner sac adhering throughout
to the external tunic. Orifices
without tentacular fringes.

heart consists of a slightly bent, contractile
tube, and is situated near to or within the in-
testinal loop. The reproductive organs, con-
sisting of ovary and testicle, are often lodged
in the fold of the intestine.

The animal of these “soft-shelled” Mol-
luscs has very close affinities with that of the
other Acephalans, especially the lamellibran-
chiates. And “ were the test of an Ascidian
converted into a hard shell, symmetrically
divided into two plates, connected together
dorsally by cartilage, and capable of separation
so as to expose the mantle along a ventral
mesial line, whilst the orifices protruded at
one extremity, it would present the closest
similarity with many bivalve Molluscs.”#
(Forbes.)

All the Tunicata are free during the earlier
periods of their existence ; some remain per-
manently free, floating in the water ( Salpce ,
&c.), but the generality ( Botrylli, Ascidice, &c.)
become fixed to shells, seaweeds, and other
marine bodies. Some exist as distinct indivi-
duals (Ascidia r, Cynthia, &c.), whilst various
degrees of combination are affected by others
( Botryllus , Clavellina, Pyrosoma, &c.) ; and
some are simple in one generation and com-
bined in the next ( Salpa ).

From the above-mentioned various con-
ditions of individualism or aggregation under
which these animals exist, the family is
divisible into two groups — the simple and
the aggregate. Such forms of the latter
group as were known to the earlier natu-
ralists were, from a general similarity of
appearance, classed by them with Alcyonia.
In the former group have been placed, until
a late date, the numerous species of the Sal-
pi dee, which now however, like the above-
mentioned groups, have been separately treated
of and illustrated in memoirs and monographs
devoted to them. Indeed, although the ex-
pressions, simple and aggregate, as will be seen
hereafter, are very convenient in describing
the physiology of the Tunicata, yet late re-
searches have shown that the conditions to
which they refer have but a subordinate value
in reference to the natural grouping of the
class.

As may naturally be inferred from what is
stated above, the Tunicata have been sub-
divided in various manners. The arrangement
we are inclined to adopt is as follows : —

’ Dichitonida, Fleming.

Inner sac more or less detached
from the external tunic ;
united to it at the two ori-
fices. Branchiae, large, equal, J>
spread on the inner surface of
this sac. Branchial orifice
with an inner membranaceous
ring and circle of tentacles. J

Fixed. Branchial and anal 1
orifices not opposite to I
each other. Branchiae |
conjoined. J

Floating. Branchial and!
anal orifices opposite to I
each other. Branchiae [
disjoined. J

Branchial and anal orifices
opposite to each other. J
Branchial and anal orifices
not opposite to each
other.

We may particularly mention the Myce, Pholades, &c.

Ascidiadoe.

Clavellinidse.

Botryllidae.

Pyrosomidae.

Salpidoe.

Pelonaiadae.

TUNICATA.

1187

Dfchitonida. — Family Ascidiad^e, E.
Forbes. Synonyms: Tethyes simples, Savigny;
Ascidiilce , MacLeay ; Tuniciers libres ou As-
cidiens, Lamarck; Ascidiaria, Stark; “ les Iso-
lees,” Cuvier ; Asddiacea, pars, Blainville ;
Ascidiens simples , Milne- Edwards ; Ascidiens ,
Van Beneden.

Body simple, fixed ; animals isolated or
gregarious ; not united into groups by a com-
mon integument ; oviparous, not gemmipa-
rous. The following genera are members of
this family : —

Ascidiad^e,

vel

ASCIDI.E SIMPLICES

Branch i;e not plicated

Branchiae plicated -

{Sessile
Pedunculated

f Ascidia.*

( Molgula.

f Cynthia.

Dcndrodoa.

I Chelyosoma.

{Bo tenia.
Cystingia.
Bipapillaria.

Genus Ascidia, Baster and Linnaeus. — •
“ Rarely,” says Professor E. Forbes, “ is the
dredge drawn up from any sea bed at all pro-
lific in submarine creatures, without contain-
ing few or many irregularly shaped leathery
bodies, fixed to sea-weed, rock, or shell, by
one extremity or by one side, free at the
other, and presenting two more or less pro-
minent orifices, from which, on the slightest
pressure, the sea-water is ejected with great
force. On the sea shore, when the tide is
out, we find similar bodies attached to the
under surface of rough stones. They are
variously, often splendidly, coloured ; but
otherwise are unattractive, or even repulsive,

Fig. 7G6.

Ascidia mammillata. (Original.')
a, branchial orifice, open ; b, anal orifice, closed.

in aspect. These creatures are Ascidia;, pro-
perly so called. Numbers of them are often
found clustering among tangles, like bunches
of some strange semitransparent fruit.” Some
species (in France, vitlgo “ le vichet ”) on the

coasts of the Channel f and the Mediterra-
nean, and in the Chinese Seas, are valued as
articles of food In this genus (Jig. 766.)
the body is sessile ; test, coriaceous or gelati-
nous ; branchial orifice eight and six-lobed ;
branchial sac not plicated, surmounted by a
circle of simple tentacular filaments.

Genus Mu/gu/a, E. Forbes; synonym, As-
cidia, Auct. — Body more or less globular,
attached or free if ; test membranous, usually"
invested with extraneous matter ; orifices on
very contractile and naked tubes, the bran-
chial six-lobed, the anal four-lobed.

Genus Cynthia, Savigny ; synonym, Ascidia,
Auct. — Body sessile, fixed or unattached; test
coriaceous ; branchial and anal orifices open-
ing in four rays or lobes ; branchial sac lon-
gitudinally plicated, surmounted by a circle of
tentacular filaments.

Genus Dendrodoa, MacLeay7. — Body sub-
cylindrical, fixed, sessile; test coriaceous,
smooth ; orifices terminal, minute, indistinctly
quadrifid ; branchial sac plicated ; tentacula

* Some very good observations on the subdi-
visions of the Ascidice have been made by M. Sa-
vigny7, Dr. Fleming, and Mr. MacLeay. ' But we
must not here enter further into details. The fol-
lowing classification is that adopted wholly or in
part by7 the above authors respectively : —

| Pyrena.

Phallusias - - -J Phallusia.

(. Ciona.

Cynthia.
Cresira.
Styela.
Pandocia.
Dendrodoa.

+ “ At Cette,” says Van Beneden, “ Ascidia: are
taken regularly to market ; and Cynthia microscomus,
although so repulsive externally, furnishes a very
delicate morsel, much sought after by some.”

{ Individuals of several species of Ascidians, viz.
of the following genera, Molgula, Cynthia, Cystingia,
Bipapillaria, and Pelonaia, are found unattached.
These animals, however, cannot be said to have an
entirely free existence, their tests, whether pe-
duncled or otherwise, being usually more or less
imbedded in sand or mud, and frequently held to
their anchorage by the agglutination of the sur-
rounding sand-grains to their outer surface. But
from such a position they are easily disturbed,
unless when they are lodged within the mud-filled
cavities of old shells and of water-worn stones, as
is the case with the Pelonaia.

A5C1LU.1S

Cyntliiae

4 G 2

1188 TUNIC ATA.

simple (Jig. 778). Dendrodoa closely agrees
with Cynthia in its branchial reticulations and
its digestive apparatus ; but, as Mr. Mac Leay
has observed, of the two ovaries possessed by
Cynthia, only one, and that the left, is found
in Dendrodoa, whilst the right ovary alone is
present in Pandocia.

Genus Chelyosoma, Broderip and Sowerby.
— Body depressed, oblong, fixed, sessile ; test
coriaceous, its upper surface consisting of
eight somewhat horny, angular plates ; ori-
fices small, prominent, perforating the plated
surface, each surrounded by six triangular
valvules (Jig. 767.) ; branchiae plicated ; ten-
tacles simple.

Fig. 767.

Chelyosoma Macleayanum. ( After Broderip and

Sowerby.')

a, branchial orifice; b, anal orifice; c, coriaceous
envelope of the sides ; d, stone to which the animal
is fixed.

To the Ascidiadce we may provisionally join
the following obscure form, occurring on the
coasts of South America;

Genus Fodia, Bose. — Body oval, mammil-
lated, divided throughout its length by a vertical
partition, which contains the stomach, into two
unequal tubes open at each end by an orifice,
the superior aperture rather depressed and ir-
regularly toothed, the inferior bordered by a
circular collar forming a sucker, and serving
to attach the animal to extraneous objects.

Genus Boltenia, Savigny ; synonym, Ascidia,
Auct. — Body more or less globular, fixed, pe-
dunculated, attached sometimes to the stem
of another individual; test coriaceous; ori-
fices lateral, and each cleft into four rays ;
branchial sac longitudinally plicated ; sur-
mounted by a circle of compound tentacula.

Genus Cystingia, MacLeay. — Body glo-
bular, fixed, pedunculated ; test subcoriaceous;
branchial orifice quadrifid, lateral ; anal irre-
gular, terminal ; branchial sac plicated ; tenta-
cula compound.

Genus Bipapillaria, Lamarck. — Body more
or less globular, free, pedunculated ; test mem-
branous ; the extremity of the body opposite
to the attachment of the peduncle bearing two
equal, conical papillae, having their apices per-
forate ; each orifice furnished with three very
short, stiff, setaceous, retractile tentacles.*

* This obscure genus was established by Lamarck
from a description and figure in Peron’s MSS.

Family Clavellinid/E, E. Forbes. Syno-
nyms : Ascidia ?, Auct. ; Tethyes simples, pars,
Savigny ; Ascidiens sociales, Milne-Edwards ;
Perophoriens, Van Beneden.

Body compound, fixed ; animals connected
by creeping, tubular prolongations of the com-
mon tunic, through which the blood circu-
lates. This family comprises two genera: —
Genus Clavellma, Savigny ; synonym, As-
cidia, Auct. — Body elongated, erect, more or
less pedunculated ; test smooth and trans-
parent ; branchial and anal orifices without
rays ; thorax usually marked with coloured
lines (Jig. 768.).

Fig. 768.

Clavellina producta. Group of two adult and se-
veral young individuals, magnified about Jive times.

( After Milne-Edwards.)

c, branchial orifice ; e, branchiae ; H, cloaca; i, anal
orifice ; It, inner tunic or mantle ; l, stomach ; m,
intestine ; n, termination of the anus and oviduct in
the cloaca ; o, the heart ; p, ovary ; p", ova ready
to pass into the cloaca ; u, vj, u", reproductive buds,
in different degrees of development, springing from
the abdomen of the adults.

Genus Perophora , Wiegmann.* — Individuals
pedunculated, suborbicular, compressed; tho-
rax not lineated by granular bands.

* This curious little social Ascidian was first
described and illustrated by Mr. J. Lister, in a
paper “ On the Structure and Functions of tubular
and cellular Polypi and of the Ascidise,” Philos.
Trans. 1834. Lister gave no name to the animal,

TUNICATA,

1189

Family Botryllida:, MacLeay. Syno-
nyms : Alcyonia, Auct. prior. ; Tethyes com-
poses, Savigny ; les Reunis ou Botryllaires ,
Lamarck ; les Agreges, Cuvier ; Ascidiaeea,
pars, Blainville; Ascidies composees, Milne-
Edwards; Pulyascidiens, Van Beneden.

Body compound, fixed ; animals associated;
the tests fused together, forming a common
mass in which the animals are imbedded in
one or more groups or “systems the indi-
viduals not connected by any internal union ;
oviparous and gemmiparous.

“ If, when walking on the sea-shore, about
low-water mark,” says the distinguished na-
turalist previously quoted, “ we turn over
large stones, or look under projecting eaves
of rock, we are almost sure to see translucent
jelly-like masses of various hues of orange,
purple, yellow, blue, grey, and green, some-
times nearly uniform in tint, sometimes beau-
tifully variegated, and very frequently pen-
cilled as if with stars of gorgeous device ;
now encrusting the surface of the rock, now
descending from it in icicle-like projections.
These are compound Ascidians. A tangle
or broad-leaved fucus, torn from its rocky
bed, or gathered on the sand, where the waves
have cast it after storms, will show us similar

'Polyclinina

BoTRYLLIDiE,

vel <

ASCIDIJ2 composite

Didemnina

l_Botryllina

The tribe Polyclinina (Jes Polycliniens,
Milne-Edwards) is characterised principally
by the division of the body into three distinct
portions, viz. a thorax, a superior abdomen,
and a post-abdomen. It has, however, other
anatomical peculiarities, such as the great de-
velopment of the organs of generation, and the
position of the heart at the inferior extremity
ot the body. This group comprehends nu-
merous species, and is divisible into two
natural sections, recognised by the external
conformation of the anal orifice. In one di-
vision (P. bistellata ) this orifice is surrounded
with a regular circlet of rays or marginal
lobules, and is exactly similar to the branchial
orifice. In the other division ( P . unistellata )
the anal differs from the branchial orifice in
not being rayed, or at least in having merely
irregular marginal lobules.

Genus Sigillina, Savigny. — Common body
a solid, elongated, erect cone ; gelatinous,
pedunculated, isolated or attached to similar
cones, consisting of a single system of many

but Professor Wiegmann subsequently (Jahresbe-
rieht in Archiv. 1835) gave it the appellation of
Perophora Listen.

bodies, mostly those star-figured, investing its
stalks, winding among the intricacies of its
roots, or clothing with a glairy coat the ex-
panse of its foliated extremities. ... In
examining these bodies, we find that it is not
a single animal which lies before us, but a
commonwealth of beings, bound together by
common and vital ties. Each star is a family,
each group of stars a community. Individuals
are linked together in systems, systems com-
bined into masses. . . . Indeed, few bo-

dies among the forms of animal life exhibit
such exquisite and kaleidoscopic figures as
those which we see displayed in the combina-
tions of the compound Ascidians.”

Previous to the researches of Savigny, the
Botryllidce were regarded as Alcyonia ; Gaert-
ner (1774) and Renieri (1793) being the only
naturalists who had suspected their compound
nature and true affinities.* “ The Memoir of
Savigny, published in 1816, however, threw
entirely new and unanticipated light on their
nature. He showed that they were essentially
Ascidians, differing from the simple forms only
in being united into more or less complicated
systems.” f

In the arrangement of Professor Milne-
Edwards the family is subdivided as follows :

{Bistellata
Unistellata

r Bistellata
l- Unistellata -

- Sigillina.

' Polyclinum.
Aplidium.

-< Sidnyum.
Synoieum.

_ Amaroucium.f
f Distomus
* \ Diazona.
f Didemnum.

- -j Eucaelium.

( Leptoclinum.
f Botryllus.

” (Botrylloides.

individuals disposed one above another in
irregular circles ; branchial and anal orifices
each with six rays ; abdomen larger than
thorax ; post -abdomen long and slender
{fig- 769.).

Genus Polyclinum, Savigny. — Common body
gelatinous or cartilaginous, polymorphous,
sessile or slightly pedunculate ; systems nu-
merous, convex, somewhat stellate, with cen-
tral cloacal cavities ; individuals (10 to 150)
placed at very unequal distances from their
common centre ; the cavity in the common
tegument occupied by each animal is divided
into three chambers one above another by
contractions of its calibre ; abdomen much
smaller than the thorax ; post-abdomen pe-
dunculate.

Genus Aplidium, Savigny ; synonym, Al-
cyonium, Auct. — Common body gelatinous
or cartilaginous, sessile ; systems very nume-

* For the early history of this genus, consult the
Memoir on Botryllus stellatus by MM. Desmarest
and Lesueur, Journal de Physique, tom. lxxx. 1815.

t In the latest (“ commemorative ”) edition of
Cuvier’s Regne Animal, M. Milne-Edwards has
established a new subgenus, Parascidia, which has
eight marginal teeth on the buccal orifice.

4- G 3

TUNICATA.

1190

rous, slightly prominent, annular or subellip-
tical, without central cavities; the animals
(3 to 25) are placed in a single row, at

Fig. 769.

Sigillina australis. ( After Savigny.')

A. Vertical section of a cone, or “ system ,” showing
the distribution of the animals, magnified.
ii. Isolated individual, magnified.

C. Natural size of isolated individual,
a, test, or external envelope ; b, branchial orifice ;
c, anal orifice ; d, thorax; e, abdomen ; f oeso-
phagus ; g, stomach ; A, intestine ; j, thoracic sinus ;
It, intestinal loop ; I, ovary ; m, oviduct.

equal distances from their common centre ;
branchial orifice six-rayed ; division of the
thorax and abdomen not always distinctly
marked.

Genus Sidnyum, Savigny. — Common body
gelatinous, presenting a series of closely
grouped cones, truncated and starred at the
summit, rising from a common incrusting base ;
each cone composed of a fascicle of indi-
viduals, varying in number from five or six
to ten or twelve, and forming a margin around
a depressed centre. The animals partake
of the characters of those of Synoicum and
Ap/idium, resembling the former in the struc-
ture of their stomach, and the latter in their
branchial sac. Each has an eight-toothed
branchial orifice and a simple tubular vent

folded against the thorax. The ovary is pe-
duncled, and very conspicuous at the ex-
tremity of the animal. (Forbes.)

Genus Synoicum, Philips.* — Common body
semicartilaginous, cylindrical, peduncled, iso-
lated or attached to similar cylindrical bodies ;
system single, circular, comprising six to
nine animals, terminal ; branchial orifice six-
rayed; anal orifice having six very unequal
rays, the three largest forming the exterior
margin of the central star ; post-abdomen
sessile.

Genus Amaroucium, Milne-Edwards. — Com-
mon body fleshy or coriaceous, polymorphous,
subpedunculate or sessile, and incrusting ;
systems numerous ; individuals arranged irre-
gularly around common cloacal apertures ;
divisions of the thorax and abdomina faintly
marked. This genus resembles Aplidium and
Synoicum in the general form of the animal,
and Polyclinum in the presence of a central
common cavity to each system (fig. 782 ).

The tribe Didemnina (Us Didemniens, Milne-
Edwards) is formed of all the compound
Ascidians whose body is distinctly divided
into two parts, thorax and abdomen. These
closely approach the Clavcllmee, and are dis-
tinguished from the Polyclinina by the absence
of the post-abdomen and by the position of
the organs of generation and the hearr, which
are raised up by the side of the intestine.
This tribe, like the Polyclinina, is divided into
two groups, according to the presence or ab-
sence of marginal rays around the anai orifice.
M. Milne-Edwards observes that the bistellate
group ( Distonius and Diazona ) forms a con-
necting link between the ClavcllincB and the
Botryllidce.

Genus Distomus, Gaertnert ; synonyms,
Alcyonium, Auct., Polyzona, Fleming. — Com-
mon body semi-cartilaginous, polymorphous,
sessile ; systems numerous, usually circular ;
individuals placed in one or two ranks at un-
equal distances from their common centre.
Both orifices six-rayed.

Genus Diazona, Savigny. — Common body
gelatinous, orbicular, sessile or subpedunculate ;
system single, expanded into a disc, compara-
ble to that of a flower or of an Actinia;
animals very prominent, arranged in con-
centric circles (.fig. 770.) ; branchial and anal
orifices six-rayed ; abdomen peduncled ;
ovary enclosed in the intestinal loop.

Genus Didemnum, Savigny. — Common body
coriaceous, polymorphous, sessile and incrust-
ing ; systems numerous, compressed, without
central cavities or distinct circumscription ;
animals without any appreciable order of
arrangement; abdomen peduncled; ovary
placed by the side of the intestinal loop, in-
creasing in length when the eggs are fully
developed.

Genus Euccdiiivi, Savigny. Common body
gelatinous, sessile and incrusting ; systems
numerous, without central cavities or distinct

* Voyage towards the North Pole, 1773, p. 109,
pi. 13.

f Gaertner, apud Pallas, Spicilegia Zoologiea,
1774.

TUNIC AT A.

1191

Fig. 770.

Diazona violacea, magnified. ( After Saviyny.)

circumscription ; animals sometimes scat-
tered, sometimes arranged in a quincunx ;
branchial orifice circular, without distinct
rays ; anal orifice very minute and indistinct ;
abdominal viscera pushed up bv the side of
the thorax.

Genus Leptoclinuvi, Milne-Edwards. — Com-
mon body sometimes coriaceous, sometimes
gelatinous, thin, sessile and incrusting ; sys-
tems few ; individuals arranged irregularly
around common cloacal cavities ; abdomen
peduncled, short, smaller than the thorax.

The tribe Botryllina (/ es Botrylliens, Milne-
Edwards) comprises those compound Asci-
dians that are united in systems around common
excretory cavities or cloaca;, and whose bodies
are not divided into a distinct thorax and
abdomen, the viscera being pushed forward
on the side of the branchial cavity, and form-
ing with the thorax an ovoid mass.

Genus Butryllus, Gaertner ; synonyms, Al-
cyonium, Auct., Polycyclus, Lamarck. — Com-
mon body gelatinous or cartilaginous, sessile
and incrusting ; systems numerous, pro-
minent, round or star-shaped, with central
cavities; individuals, six to twenty in each
system, lying horizontally with the vent far
from the branchial orifice; branchial orifice
simple ( fig. 771.).

Genus Botrylloides, Milne-Edwards. — This
genus resembles the foregoing in most respects,
except that the stars formed by the systems
of animals are irregular and ramifying ; the
cloacae being prolonged into the common
mass as irregular internal channels, on each
side of which the individuals are placed in
linear series, instead of having a simple star-
like arrangement around the cloacae, as in
Bntryllus. The animals of Botrylloides, more-
over, have a nearly vertical position, and their
orifices are closely approximate (fig. 783.).

We should perhaps also refer to the group
of the Botryllidce , an obscure form, first no-

ticed by Molina*, and subsequently named
Pyura by Blainville, and considered by the
latter to form a link between the simple and
compound Ascidians. M. Blainville gives the
following characteristics.

Fig. 771.

Botryllus violaceus. Two of the star-like systems, mag-
nified. ( After Milne- Edwards.)

a, a, common test ; b, b, b, some of the branchial ori-
fices ; c, the common anal orifice of one of the systems.

Genus Pyura, Blainville. — A pyriform body,
with two small short tubes, occupying a cell
in the external envelope, and forming, by its
union with 10 to 12 individuals, a kind of poly-
morphous mass somewhat resembling honey-
comb, apparently without any external orifice.

* Saggio sulla Historia naturale del Chili. Bo-
logna, 1782, 4to.

4 g 4

1 192

TUNICATA.

Family PYROSOMiDiE. Synonyms : Lucies
composees, Savigny ; Tuniciers reunis, pars,
Lamarck ; “ les agreges ,” pars, Cuvier ; Sal-
piens agreges, Blainville; Lucidce, MacLeay;
Pyrosomiens, Milne-Eclwards and Van Bene-
den. ThePyrosomians are represented by three
or four species of the single genus Pyrosoma.

They inhabit the Mediterranean and the
warmer parts of the ocean ; in the former at
times their abundance is a source of dread to
the fishermen, sometimes even completely
clogging their nets ; and in certain oceanic
regions they are met with in almost incredible
profusion. Their delicate and transparent
forms, their elegant tints, and their unrivalled
phosphorescence render them the most beau-
tiful of Molluscs, and objects of admiration to
the naturalist and the voyager. Mr. Bennett
relates that, during a voyage to India, the
ship, proceeding at a rapid rate, continued
during an entire night to passthrough distinct
but extensive fields of these Molluscs, float-
ing, and glowing as they floated, on all sides
of her course. Enveloped in a flame of bright
phosphorescent light, and gleaming with a
greenish lustre, the Pyrosomes, seen at night,
in vast shoals upwards of a mile in breadth,
and stretching out till lost in the distance,
present a spectacle the glory of which may be
easily imagined. The vessel, as it cleaves the
gleaming mass, throws up strong flashes of
light, as if ploughing through liquid fire, which
illuminates the hull, the sails, and the ropes
with a strange unearthly radiance.

Genus Pyrosoma, Peron. — Common body
semi-cartilaginous, floating, cylindrical, 2 to 14
inches long, | to 3 inches in circumference ;
bearing externally numerous pointed pro-
cesses, hollow and mammillated within, and
open at one of its extremities only. Animals
associated in a verticillate arrangement, having
two orifices, one at each extremity ; elongated,
fusiform, tapering at the outer, and obtuse at
the inner extremity ; united at the circum-
ference of the middle portion, by the fusion
of the tests to one another into rings, more
or less regular, and varying in number accord-
ing to species, so that the whole forms the
long cylinder above described.

Monochitonida. — Family Salpid,e,
Forbes. Synonyms : Salpce, Auct. ; Thalides,
pars, and Lucies simples, Savigny ; Biphores,
Brugiere ; Biplioridce, MacLeay; Tuniciers
libres, pars, Lamarck ; “ les isolees,” pars, Cuvier;
Sa/pacea, pars, and Salpiens simples, Blainville ;
Salpiens, Van Beneden. The Salpians are free,
swimming in the ocean ; plentiful in the Me-
diterranean and the warm parts of the ocean ;
occurring also occasionally in the Norwegian
and North British seas. In shape they re-
semble a short and wide tube, sometimes oval
or cylindrical, sometimes more or less square
in its transverse section, and varying consi-
derably in size according to species, from half
an inch to 8 or 10 inches in length.

The test is thin and transparent, open at
the ends and often supplied with terminal and
lateral processes. The mantle lines the test,
and is more or less adherent throughout ; its

interior constitutes the branchial cavity ; it is
provided at one of the terminal openings with
a more or less perfect valvular apparatus; and
contains a branchial fold traversing it obliquely.
Near one extremity the chief viscera are
grouped together into a conspicuous mass
(the “ visceral nucleus” of authors), to which
the brilliant tints of the liver usually impart
an orange, brown, or reddish hue {fig. 772.).

Fig. 772.

Salpai, isolated and associated.

A. S. runcinata, solitary ; B. S. runcinata, asso-
ciated ; c. S. zonaria, aggregated.

This family is of considerable interest on
account of their singular mode of reproduc-
tion, discovered by Chamisso, and on account
of the philosophical generalisations partly
founded thereon by Steenstrup. These ani-
mals occur under two distinct conditions,
being at one time solitary, and at another as-
sociated into circular or lengthened groups —
termed garlands, cordons, ribands, and chains
{fig. 772. B and c). The Salpa-chains, vary-
ing in length from a few inches to many
feet, swim through the tranquil water with
a regular serpentine movement, and are often
regarded by sailors as sea-serpents ; but when
taken from the water the individuals of the
group are easily detached. Thus, in conse-
quence of accidents, separate members of these
chains are often met with in seas abounding
with these Molluscs ; but other, separate,
Salpce are also met with that have never been
united to others, and differ considerably in
form from the associated ones (fig. 772. a).

Chamisso, however, discovered that such
permanently solitary Salpce do not belong to
species distinct from those united in chains,
however dissimilar (and they are usually so
dissimilar as to appear even generically dis-
tinct), but are either the parents or the pro-
geny, as the case may be, of the aggregate
forms ; and that chained Salpce do not produce
chained Salpce, but solitary Salpce, which in
their turn do not produce solitary, but chained
Salpce. Consequently, as Chamisso graphi-
cally observed, “a iS'«//>a-mother is not like
its daughter or its own mother, but resembles
its sister, its grand- daughter, and its grand-
mother.”*

This family is mainly represented by the
* Forbes, British Molluscs, p. 48.

TUNICATA. 1193

genus Salpa, Forskabl ; synonyms Thalia,
Brown ; Holothuria, Linneand Pallas ; Dagysa,
Banks and Solander ; Biphora, Brugiere ;
Tethis, Tilesius ; Pegea and Iasis, Savigny.
The characteristic features of this genus are
detailed above.

Quoy and Gaimard * established for some
animals nearly allied to the Salpes and inha-
biting the coasts of Amboina, the genus Do-
liolium, the characters of which are, its having
the form of a little cask open at the ends;
from two to ten lines in length ; the anterior
extremity a little prominent ; marked with
circles in relief on the external surface; and
having internal branchia, divided into two
branches ; and a heart and a dorsal vessel, si-
tuated near the union of these branches. This
name had also been previously given by Otto j-
to a genus established by him on a Mediterra-
nean Salpa, mutilated by a crustacean of the
genus Phronyme, that had made it its habita-
tion. This form, like Salpa triangularis and 5.
polymorpha (by Quoy and Gaimard, and Bory
de Vincent), has been erroneously regarded as
belonging to the family of Diphydes. MM.
Lowig and Kolliker, however, who found the
tissue of Doliolium to be identical with the pe-
culiar substance of the test of other Tunicata,
have pointed out its true affinities, and placed
it with the Salpidce.

Family Pelonaiad^:, Forbes. — This fa-
mily is represented by two rare animals, both
inhabitants of the Scottish seas, constituting
two species of a single genus, Pelonaia, esta-
blished by Professor E. Forbes and Professor
Goodsir.J We have derived our description
of the general and anatomical characters of
these interesting Molluscs from the detailed
account given of them by the original dis-
coverers.

Genus Pelonaia, Forbes and Goodsir. —
Animal simple, unattached. Test more or
less cartilaginous, smooth or wrinkled, elon-
gated, and cylindrical ; anterior extremity
bearing two orifices, four-cleft, without ten-
tacles, and placed on the same plane, on two
equal, approximate, papillose eminences ;
posterior extremity ending in a blunt point ;
mantle adherent to the test. The Pelonaice
live buried in mud, quite unattached to any
other body, and are extremely apathetic ani-
mals, presenting scarcely any appearance of
motion.

Anatomy and Physiology of the Tuni-
cata.

It will be most convenient to describe
the test generally for the whole tunicate class,
and the rest of their anatomy under the
heading of each of the families.

Test or Shell. — The test or external enve-
lope of the Ascidiadee is subject to considerable
variation of shape ; from the bottle-like form
of the Ascidia { fig. 766.), to the flat, patella-
like form of Chelyosoma ( fig . 767.) ; it is elastic,

* Voyage de 1’ Astrolabe, Zoologie, tom. iii.

t Nova Acta Academ. Nat. Curios, t. xi.

I Jameson’s Edinb. New Philosoph. Journal,
vol. xxxi. 1841.

varying very much in its thickness and con-
sistence in different species. In colour it
varies considerably, being occasionally nearly
black, sometimes red, orange, yellow, or
milky white. Its surface is sometimes smooth,
often tuberculated, covered with hairs or
spines, or otherwise roughened. Sometimes
minute patches of horny tissue or hardened
epidermis rise up irregularly on the surface of
the test ; in other cases these are placed in a
tessellated arrangement. In the peculiar and
unique form, Chelyosoma, first noticed by
Messrs. Broderip and Sowerby, and since more
fully described by Professor Eschricht, the
upper surface of the test is occupied by eight
large, horny, polygonal plates arranged some-
what like the shell-plates of a tortoise, and by
several smaller triangular plates, which form
two circles, one around the branchial, and the
other round the anal aperture of the animal
(fig. 767.). The large plates are so disposed
that the branchial orifice is surrounded by
three plates, and the anal by four, besides that
which is intermediate and abuts upon both :
this latter plate is hexagonal, the sides in con-
tact with the orificial valvules are lunated.
The three plates near the branchial orifice are
much larger than the four which are near to
the anal orifice. Each of the plates is marked
with three or four elevated striae, which are
near to the edges of the plate, and parallel with
them, leaving an area in the centre, and giving
rise to a general resemblance to the external
plates of the shell of a land tortoise. The
orifices are very small, and are surrounded by
six triangular valvules, each transversely stri-
ated, and, when shut, rising from the sur-
rounding surface in the form of a cone. The
lower or adherent part of the test of Chely-
osoma is coriaceous, with occasional slight
traces of separation into plates.

The test of Ascidia; is frequently covered
with innumerable smaller animals and their
spawn. Modiolae and Annelids burrow in it;
Cirrhipeds, naked Molluscs, and Actiniae lodge
upon it ; and Corallines cover it sometimes
with a little forest ; a condition fully justify-
ing the denomination of “ microcosmus,” be-
stowed by Redi * on a Mediterranean species.
Occasionally, as in Ascidia concliilega and Mol-
gida oculata, the animal works up extraneous
matter, as gravel, fragmentary shells, &c., with
the external surface of the test. It is by this
shell or test that the animal fixes itself. In
the sessile species, the tissue of the base or
the side of the test interlaces with the stems
of sea weeds and corallines, or closely adheres
to the surface of another ascidian sac, or of a
stone, a shell, a crab, or other object. In the
peduncled forms this tunic is at one point pro-
longed into a tubular process or stem, the dis-
tal extremity of which is attached to marine
bodies in the same manner as the base of the
sessile tests. In Cystingia and BipupiUuria,
however, this process or stalk appears to be
less perfectly developed, and not to be al-

* Opuscula varia Physiologies, 3 vols. 12mo.
Lugd. ilatav. 1725.

TUNICATA.

1 194

together adapted to maintain a permanent
attachment to a fixed body.

The external envelope of the Ascidiadce is
always perforated hy the two apertures
characteristic of the Tunicata, and analogous
to the prolonged respiratory orifices of the
CardiacecB and other Acephala. One of these
apertures*, nearly always placed at the sum-
mit of the test, receives the sea-water, and
admits it into the branchial cavity. The
second aperture f is placed a little lower
than the first, and, is in communication with
the rectum and oviduct. In Boltenia the ori-
fices are lateral ; in Cystingia the branchial
orifice is lateral, and the anal terminal ; the oral
orifice being always the highest in relative
position, and nearest to the insertion of the
pedicle by which the animal is suspended. In
Chclyosoma and Dendrodoa the orifices are
placed on the same plane ; in the former, on
the nearly flat superior surface of the animal,
and in the latter they are terminal.

The edges of the orifices are more or less
crenulate or divided. The branchial orifice
is 8-9 rayed, and the anal 6 rayed, in Phal-
lusia ; boih orifices are 4-fid in Cynthia, Bol-
tenia, and Dendrodoa. When contracted, they
are thrown into longitudinal folds ; this is
the more observable when the orifices are
somewhat prolonged into tubes.

The test receives from the body blood-
vessels, which its semitransparency in some
species allows the eye to follow to the extreme
ramifications. In the thinner tests the vessels
are but few, anti sometimes altogether escape
observation; but in the thick pellucid test
of Ascidia mamviillata the eye can discern an
extensive network of vascular ramifications.
The bloodvessels enter the test near the base.
The internal surface of the test has often a
glistening and pearly appearance, and is always
lined with an epithelium. In Boltenia reni-
formis this is a loose tissue, and forms a slight
attachment to the external surface of the mus-
cular sac or mantle of the body.

In A. mammillata a thin vertical septum
traverses a part of the cavity of the test.

The test of the Clave/linidce is very similar
in consistence and general appearance to that
of some of the more delicate species of the
Ascidiadce, but differs materially in having tu-
bular prolongations running from its base,
which are traversed by vessels continuous from
one individual to another, and from which
root-like processes young individuals are
continually being produced by the process of
gemmiparous reproduction ( Jig . 768.).

The tube-like test of the Salpidce is “ semicar-
tilaginous, or gelatinous, seeming as if carved
in crystal,” its transparency rendering conspi-
cuous the brilliant hues of the liver of the
contained animal. It is usually more or less
angular, bearing elongated crests, denticles,
and other processes, by means of which the
cohesion of the aggregated individuals is
maintained (Jig. 772.).

* The first, oral, buccal, branchial, or respiratory.

I The second, anal, ventral, or the funnel.

The tests of the little animals of which the
cylindrical body of the Pyrosoma is composed,
are intimately connected by their lateral sur-
faces, leaving their terminal orifices free (Jig.
786. a). The tissue of the whole common
envelope is semicartilaginons, transparent,
tinted with azure and other colours.

In the Botryl/idcc the external tunic is re-
presented by the tegumentary tissue com-
mon to the whole association of animals,
and which may perhaps be compared to the
polypary of aggregated Polyps. The close
aggregation of the animals causes a fusion,
as it were, of the tests of the whole into
a coriaceous or gelatinous mass, coated with
a tough epidermic membrane, and more
or less regularly beset with individuals or
groups of individuals (systems) ; or, rather,
the soft test of the originally isolated indivi-
dual, or single system, increasing in bulk and
producing within itself more and more embryos
of individuals and systems, becomes an ex-
tended, homogeneous mass, in which nu-
merous individuals are lodged (Jig. 771.). This
mass is irregular, fungous, jelly-like, spongy,
or coriaceous, incrusting other sessile Tuni-
cates and a variety of marine bodies.

Structure and chemical composition of the test.
— We are indebted to the labours of MM. Lo-
wigand Kolliker* for considerable information
on the subject of the constituent elements
and the growth of the test of the simple and
the compound Ascidians. These researches
were undertaken with the view of examining
into Dr. Schmidt’s statement of the existence
of the vegetable element “ cellulose” in the
tissue of the ascidian envelope. This they
found to be correct (as the following state-
ments will show), and they have also offered
a lucid explanation of the fact, to which we
shall subsequently refer. Cellulose forms the
cell walls of vegetables, and is unaffected either
by soda or hydrochloric acid.

The cartilaginous envelope of Phallusia
mammillaris (Fam. Ascidiadce ), examined in
specimens preserved in spirit, is composed of
three layers of different thicknesses (Jig. 773.).
The internal layer, formed simply of polygonal,
nucleated, epithelial cells, measuring 0-005"',
covers all the interior surface of the test; at
the two external orifices, and at the points
where it receives the nutrient vessels of the
test, it is united with another epithelial tissue
covering the mantle. The second layer is con-
siderably thicker, and is composed of a homo-
geneous substance, containing crystals and
nuclei. The former are not present every-
where, and are, perhaps, quite absent in the
recent animals ; when present they are visible
to the naked eye, and appear like white striae;
seen under a moderately magnifying power,
they have the form of crystals united in the
form of a star, or of irregular and polymor-
phous concretions. The nuclei are present in
considerable numbers and under different
forms ; those situated towards the interior are
round, 0-0015'" — 0 002'", with one or two

* Annales des Sciences Natuielles, 3 ser. tom. vi. 184G.

TUNICATA. 1195

opaque nucleoli, similar to fat-granules. The
external nuclei are larger, round or more or
less produced, and contain clear or granular
substance, and usually some opaque granules.

Fig. 773.

A. Transverse section, magnified 30 times. 1, inter-
nal layer of epithelial cells ; 2, the second or inter-
mediate layer, consisting of a homogeneous mass,
thickly strewn with nuclei ; 3, the external layer,
composed of a fundamental mass and cells of cellu-
lose, with dispersed nuclei (c). and having pigment-
cells and acicular crystals in the upper part; 4,
vessels.

B. A portion of the same, magnified 350 times, a,
fundamental mass ; b, cellulose cells ; c, nuclei, some
round, others star-shaped; d, acicular crystals of
carbonate of lime ; e, the extremity of a vessel ; /,
pigment-cells.

The third layer forms the principal mass of
the test of this species. It is the seat of the
numerous and large arteries, which, arising
from the heart, traverse it in every direction,
having brush-like ramifications, that penetrate
almost to the exterior surface, and then ap-
pear to pass into other vessels that accom-
pany them in their course. This layer is
formed of large cells, besides a clear homo-
geneous substance, which is a continuation of
the principal substance of the second layer ;
besides these there are locally distributed crys-
tals, nuclei, and pigment-cells.

The large cells, which R. Wagner previously
thought to be cartilaginous, are of a peculiar
nature, and resemble no other animal cell
hitherto known, except perhaps those of the
chorda dorsalis of some animals. The most re-
markable character of these cells is their size,
which varies from G'008"' to 0'U5"', the aver-
age being 0-02,// to O'OS'". Their form is
spherical, pyriform, or elliptical ; their con-
tents diaphanous and quite destitute of nucleus
or granules : and their membrane delicate,
smooth, and of an equal thickness throughout.

The smallest cells are irregularly dispersed
in the homogeneous fundamental mass that is
common to the second and third layers. The
larger cells are arranged closely together to-
wards the exterior surface of the layer, pre-
senting a very regular cellular tissue with very
little intermediate substance; but, immediately
beneath the external surface of the envelope,
the cells are rather more distant one from
another, and the intermediate tissue more

visible. The crystals and pigment-cells before
mentioned, are present only in the outer part
of this third layer ; the former are acicular,
about O’OOlo'" in length, occupying in com-
pact masses the intercellular intervals ; the
latter are yellow, and filled with somewhat
large granules, and surround in particular the
extreme ramifications of the vessels. The
nuclei, lastly, are similar to the large nuclei
of the second or intermediate layer, and are
everywhere present between the large cells in
considerable numbers.

When slices of the test are treated with hy-
drochloric acid, the crystals of the second and
third layers quickly disappear; treated with
a solution of soda, the epithelial cells, the
nuclei, the pigment-cells, and the vessels are
dissolved. The fundamental homogeneous sub-
stance of the second and third layers and the
large cells are not dissolved, nor do they
suffer any modification.

In Pkallusia monachus the large cells mea-
sure from O’Ol"' to O’OS"', and are more dis-
tinctly separated from one another than in the
preceding example. The nuclei of the homo-
geneous substance are few, and generally fusi-
form or even ramified; at the external surface
of the envelope they are mixed up with a
great number of minute yellow pigment-cells
and pigmentary granules, as well as with acicu-
lar crystals and very minute crystalline concre-
tions ; all of these being in the greatest num-
bers in the neighbourhood of the extremities
of the vessels. In one specimen of this spe-
cies MM. Lowig and Kolhker observed, that
in the interior of the third layer no cells could
be distinguished ; ultimately, however, they
distinctly saw well defined cavities or lacunas,
which were evidently vestiges of cells that had
been more or less completely fused with the
intermediate homogeneous substance ; and the
traces of these lost cells were found to be
more and more distinct towards the band of
perfect cells in the surface of the test.

In Pkallusia sulcata the large round or ellip-
tical cells, without nuclei, have a diameter of
00 V"— 0-15"'.

In Pkallusia gelatinosa a ver}' peculiar forma-
tion was observed by the experimenters. In
one specimen the soft, gelatinous substance
of the envelope exhibited no trace of cells
throughout its thickness, but its mass was
principally composed of a homogeneous sub-
stance similar to, that of the other Ascidice. In
another individual they observed some few
and indefinite remains of cells. In both spe-
cimens they found, as in the other species,
vessels and nuclei, the latter for the most part
round and measuring (V002'", in the homo-
geneous substance. In the individual desti-
tute of cells, there was also in the exterior
part a very large quantity of acicular crystals
and yellow granules, the latter frequently re-
sembling the nuclei with large coloured nu-
cleoli. The tissue in all the Ascidice examined,
when chemically treated, behaved in a similar
manner to that of Pkallusia mammillaris.

We have observed that the test of Boltenia
renifur'nis (preserved in spirit^ presents a ho-

1196

TUNICATA.

mogeneous structure crowded with “nuclei”
and bloodvessels, and only occasionally does
any trace of cellular tissue present itself, in
which case the cells are very minute, poly-
gonal, and compressed. Mr. J. Quekett has
detected calcareous spiculae in the test of this
species. They are situated towards the ex-
terior, and are very numerous and excessively
minute. Their form is usually cylindrical,
with triradiate or 4-5-fid extremities.*

The composition of the test of Clavellina
lepadiformis corresponds in all respects to that
of the above mentioned Ascidue ; certain parts
in the same individual having a more particular
resemblance to one species, and others to
another. The test, however, is quite destitute
of bloodvessels. Transverse sections of the
stalk of the Clavellina and of the excrescences
that spring from it, exhibit a tissue composed
of round or elongated non-nucleated cells,
0'01,// — O'Oli"', almost destitute of inter-
mediate tissue, and arranged very close to one
another.

It is only towards the upper extremity of
the stalk that the cells become more and more
separate, and even disappear little by little, as
happens in some Ascidice, and give place to
an intermediate homogeneous substance, bear-
ing a quantity of nuclei. In the largest and
superior moiety of the test a peculiar structure
is found. Externally is a dense, but not thick,
layer of delicate cells, which are very difficult
to recognise, and measure about 0'02w. Be-
tween the cells, and immediately at the surface,
are crystals of carbonate of lime, scattered
nuclei (measuring O’OOS"'), and large round
fatty granules. Interiorly to this occurs a
still thinner lamina, composed of a trans-
parent, colourless, homogeneous substance,
with infinitely minute pale granules. Next,
there is a layer of round granules or vesicles.
These are spherical, measuring O'OOOS'",
0‘0004///, and even O' 00 5'" ; their surface is
smooth or granulated; the largest are placed
in the middle, the smallest at the exterior;
they appear opaque, and like starch or fat
granules. With solution of iodine, they be-
come yellowish, without presenting any trace
of blue, and are probably fat grains.

Succeeding to these, a thick layer presents
itself, homogeneous, diaphanous, with some
few minute spherical nuclei, which, the nearer
they approach towards the interior, contain
more and more colourless granules. Lastly,
quite at the interior surface, is a thinnish, com-
pletely diaphanous substance, of equal thick-
ness throughout, with spherical granular nuclei,
measuring about O’OOS"'.

Treated with soda and with hydrochloric
acid, the crystals, nuclei, and fat granules of
the test of the Clavellina disappear ; the large
cells, on the contrary, and the homogeneous
substance, with its scattered granules, remain
perfectly unaffected, proving the identity of
the chemical composition in Asculia and Cla-
vellina.

* Several specimens are figured by Mr. Quekett in
the Descript, and Illustr. Catal. of the Histological
Series in the Mus. Royal Coll. Surgeons, 1849, plate
xvii. fig. 13.

The Salpa maxima does not contain, in its
gelatinous envelope, any trace of cells similar
to those of the Phallusia and Clavellina. It is
for the most part composed of a homogeneous,
clear, diaphanous substance. Towards the
interior surface, the several elements are not
so clearly arranged as in the middle and
external layers. In the innermost layers, a
multitude of very minute granules are pre-
sent ; in the others there are little round
nuclei, nucleated cells, and spherical or star-
shaped crystalline concretions. These latter are
very regular, and formed of 3 — 7 straight rays,
springing from a centre {Jig. 774. c). They

Fig. 774.

A. In crusted cells of the fundamental mass of
Didemnum candidum. a, unaltered cells ; h, a cell
the lime of which has been nearly extracted by
means of hydrochloric acid. ( After Lowig and
Kolliker).

b. Incrusted cells of Botryllus violaceus. a, sphe-
rical cell : b, cell with two colourless prolongations ;
c, with three ; d, with four ; and e, with only one
such prolongation.

C. Siliceous concretions from the test of Salpa maxi-
ma, magnified 350 times, f After Lowig and Kolliker').

D. Calcareous concretion from test of Leptoclinium
maculosum. ( After Milne-Edwards.)

are composed of a single or manifold series of
granules, which, as they approach the exterior,
increase or lessen in number, but always di-
minish in size. These do not appear to be car-
bonate of lime, not being soluble in hydro-
chloric acid; and their behaviour with muriate
of barytes shows that they are not formed of
sulphate of lime ; probably they are siliceous.
The granules and nuclei are dissolved by boil-
ing in solution of soda; but the homogeneous
substance, composing the mass of the tunic,
remains unchanged.

The test of Salpa bicaudata is essentially the
same, in the nature of its composition, as that

TUNICATA.

1197

of the Salpa maxima, the fundamental mass of
the gelatinous envelope being composed of the
homogeneous substance. It differs, however,
in the elements contained in this tissue, and
by the presence of a simple layer of epithelial
cells, covering it on the interior surface of the
test. In the interior layer of the homoge-
neous substance there are granulated vesi-
cles, having a diameter of 0003"' to 0‘004"'',
sometimes having the appearance of nuclei,
and sometimes that of cells. In the middle
part, here and there, are scattered round or
fusiform nuclei ; and in the exterior layer
are little crystals, round nuclei, and peculiar
concretions, similar to those of Salpa maxima.
Some of these concretions are small, elegantly
ramified, and disposed horizontally ; others
are larger, ramified in a brush-like form, and
appearing to the naked eye as white tufts.
These latter commence at the surface, descend
vertically towards the interior, and ultimately
form a tuft of fine ramified rays (fig- 775. d).

Fig. 775.

Transverse section of the test of Salpa bicaudata,

magnified 30 times. ( After Lowig and Kolliker.')

1, epithelial layer; 2, homogeneous mass, with
nucleoli ; b, fusiform and ramified concretions ; c,
nuclei ; d, brush -like concretions.

Magnified 350 times, these two sorts of con-
cretions are seen to be composed of opaque
granules of different sizes. The chemical
composition of the test of this Salpa is iden-
tical with that of the preceding species.

In the Pyrosoma giganteum, the common en-
velope of the individuals is also formed of a
homogeneous and structureless substance. In
its interior are scattered here and there round
nuclei, and some ramified cells, similar to
those of the loose cellular tissue of the em-
bryos of Mammifers, for example, to that of
the gelatine of Wharton. Both of these
latter elements disappear when treated with
soda; but the homogeneous substance al-
together resists the action of the soda, and
remains intact.

The Diazona violacea (Fam. Potryllidaf)
possesses, in the gelatinous mass of the com-
mon test, a diaphanous, structureless sub-
stance, quite destitute of cells. In the ex-
terior layers are crystals and concretions of
carbonate of lime, vesicles with violet-coloured
granules, fat granules, and, particularly to-
wards the interior, a great quantity of minute
round vesicles (nuclei). Treated with hy-
drochloric acid and with soda, the crystals,
nuclei, and pigment-cells are dissolved, but
the homogeneous substance remains un-

changed. Moreover, after having been a long
time exposed to the influence of the alkali,
and although the pigment-cells have disap-
peared, some portions of the exterior parts
retain a pale violet tint, giving evidence of the
presence of undissolved colouring particles,
and of an amorphous colouring matter per-
vading the mass.

The structure of the test of Didemnum can-
didum (Fam. Botryllulce ) is quite different front
that met with in any of the Tunicates before
mentioned. The white substance in which
the individual animals are lodged, which has
been figured also by Savigny, apparently pre-
sents only some white star-shaped bodies
{Jig. 774. a), measuring 0-006"' to 0-015'",
similar to those found by M. Milne-Edwards,
in Leptoclinum stellatum and L. vtaculosum
(Jig. 774. d), except only that the former are
of a more rounded form, and are provided
with shorter and more numerous points.*
But, on being treated with hydrochloric acid,
this substance has quite another appearance.
The white colour quickly disappears, bubbles
of gas being freely given off ; and. on ex-
amination with the microscope, there is seen
in the yellowish, transparent membrane that
remains, a fundamental homogeneous sub-
stance, in which are scattered round and
elongated cells, of O’OOS"' — O'OIS'" in di-
ameter, and some minute granular masses.
At first sight these cells appear to be analo-
gous to the large cells found in the tests of
Ascidia and Clavellina, being, like those of the
latter, non-nucleated, indistinctly marked by a
pale, delicate contour, and having perfectly
liquid contents. But by boiling with soda
they are quite dissolved, whereas the homo-
geneous substance remains unchanged. MM.
Lowig and Kolliker found also, that under the
influence of hydrochloric acid each of the star-
like corpuscles showed itself not to be a
simple concretion, but, losing its rays little
by little, became a cell filled with lime, and
ultimately appeared as a colourless, empty
cell, quite similar to those above described.
They add that they could not discover how
these curious cells, filled with lime, and fur-
nished with calcareous rays externally, were
formed ; but they thought it probable that
they were originally large cells, full of liquid,
which became gradually occupied with lime,
until ultimately the membrane of the cell
became incrusted, and the lime deposited on
its external surface.

* We have been favoured by Mr. Bowerbank
with an opportunity of examining his valuable
series of microscopical preparations of ascidian tis-
sues, including several kinds of the spiculoe entering
into the composition of the tests. The spiculse of
Didemnum are spherical bodies, closely invested with
short, thick, blunt spines, and nearly resemble the
globular spiculse of Tethea, except that the invest-
ing spines of the latter are more numerous and
much finer. The tissue occupied by these closely
set spiculse in the Didemnum is seen in the trans-
parent portions of Mr. Bowerbank’s beautifully
mounted specimens to be composed of diaphanous,
contiguous, irregularly hexagonal cells, the measure-
ments of which we have not had time to effect.
Numerous nucleoli are disseminated throughout the
tissue.

1198

TUN1CATA.

The common test of Aplidium gibbulosuin
presents a homogeneous substance with some
scattered nuclei, and a great quantity of round
cells, with very delicate membranes, measur-
ing O'OOS'" to 0'013,//, and even to G'02"'.
Those in the interior contain only a liquid ;
but the nearer they approach the exterior, the
more are they found to contain calcareous
concretions; and, lastly, there are cells per-
fectly incrusted, but without appendages.
Acted upon by soda and by hydrochloric acid,
the homogeneous substance alone remains,
the rest is dissolved.

In the “ common body ” of Botryllus vio-
lacens are some remarkably incrusted cells,
similar in some respects to those of Didemnum.
Some of these are perfectly round, with a
diameter of 0 009"', and, as those of Aplidium,
are filled with calcareous concretions ; others,
for the most part pyriform or fusiform, have
one or two pointed, colourless prolongations,
O'OOG'" — 0-009/v in length, and are organic
in substance ; others, lastly, round or tetra-
hedral, have even three or four of these
prolongations, which are often of a similar
length, and are regularly disposed, but just as
often are of different sizes, and without sym-
metry (y?g.774. n).# These prolonged cells
are probably analogous to the round cells in
Didemnum, that have lime in their interior and
calcareous deposits externally, and may even
be compared with vegetable cells (pollen-
granules, spores, &c.), bearing external de-
posits. Were these cells incrusted, they would
form star-like bodies, similar to those of the
Didemnum.

Professor M. Edwards observes, that in Lcp-
toclinum the substance of the tissue is crowded
with calcareous granules, which, seen with an
ordinary lens, appear to belittle spherical con-
cretions, but which are aggregations of little
pyramidal crystals, united by their base, so as
to represent a many-rayed star, surmounted
on each of its faces by a group of other
similar, but smaller, rays (see fig. 774. d).

The structure of the common test of the
Botryllus polycyclus is peculiar and quite dif-
ferent from those described above. In the
exterior parts of the common mass the struc-
ture resembles that ordinarily found in com-
pound Ascidians, being of a clear and homo-
geneous substance, with some nuclei and crys-
tals ; but in the interior distinct fibres are
found, by the side of the nuclei. These fibres
are of two kinds ; some, the least numerous,
are long, extremely pale and delicate, too fine
to be measured, and, crossing one another in all
directions, form elegant sinuosities ; others, less
numerous, are short, 0‘01,/// toO-03'" in length,
larger, opaque, and variously curved ; in a
word, they resemble certain nuclei transformed
into fibres ( Kernfasern ). Like the homoge-
neous substance of the exterior and interior
parts, these fibres resist the action of hydro-
chloric acid and of soda ; and consequently,

* Specimens of these spicula in Mr. Bowerbank’s
histological collection exhibit much more coarsely
granulated centres than those here figured.

since they are incontestably organic, they are
composed of non-azotised substance.

There are also some round points, visible
to the naked eye, dispersed in the common in-
tegument of this Botryllus. Some are white,
generally situated towards the interior of the
test, and appear under the microscope as
groups of granules or spiculac ; they are in-
soluble in a solution of soda, or in hydro-
chloric acid, and are probably siliceous, like
the concretions in Sa/pa. The other spots are
violet-coloured, or reddish, and are most
abundant in the external layers near the
groups of individuals, yet sometimes also
they are present in the interior parts of the
common mass. Seen under the microscope,
they appear as pyriform, round, or elongated
vesicles, bearing a reddish colouring matter,
contained probably in the cells, and are at-
tached to the extremities of the ramifying
canals that traverse the mass in every direc-
tion. These vesicles are the germs of new
individuals.*

The coriaceous test of the Cyntlnce (Fam.
Ascidiadce ) presents a composition still more
remarkable than that of the Bolrylli. In Cynthia
papitlata , the fibres that constitute a large
proportion of the test, are in some parts so
much developed, that they may bear compari-
son with the fibrils of any fibrous tissue found
in vertebrate animals.

In examining the structure of the test, where
it is of no great thickness, we find a simple
lamina, quite on the interior surface, eonsist-
ingofan epithelium, with polygonal cells, which
is united to the mantle by scattered, crossing,
muscular fibres. A thick layer of fibres suc-
ceeds, having cells and nuclei disseminated in
it. The fibres themselves are colourless, un-
dulating, resembling the fibrils of the fibrous
tissue of vertebrate animals, but narrower ;
they measure 0‘0002/// — 0-0004w in thick-
ness; they are never ramified, nor united into
bundles. In their direction they are in part
parallel to the axis of the animal, as in the
interior laminae ; and in part differently in-
terlaced, so that some are disposed longi-
tudinally, and others transversely (circular
and longitudinal fibres) ; hence, from the
disposition of the two kinds of layers, the
test can very easily be split into, sometimes
very delicate, laminae. There is apparently no
intermediate substance accompanying the
fibres, but the laminae formed by their diver-
gences are occupied by a quantity of granules
and vesicles of different forms. Firstly, there
are minute colourless molecules, in some
parts so abundant as to render the fibres in-
distinct, and to give to some of the thicker
layers a finely granular aspect ; secondly,
crystals, which are present only in the ex-
terior layers ; thirdly, nuclei, measuring
0’001/// to 0 003'", often with large granules,
apparently of fat ; fourthly, cells of different
forms. Some of these cells, containing nuclei

* The epiderm covering the common gelatinous
test of Botryllus stellatus is very tough, closely ad-
herent, and presents distinct cellular structure.

TUNICATA.

1199

and brown pigment-granules, are round, having
a diameter of 0,005/,/ to O'Ol'", or elon-
gated, with a diameter of 0‘OOQ"' to O'OOS'" ;
others are of a pale colour, and, from the
double nuclei and the included cells (2 to 7)
seen in some of them, strongly resemble
the cartilage-cells of the superior animals.
This resemblance is rendered the more strik-
ing by the round or elongate form of these
cells, by the peculiar arrangement of the en-
closed cells, and by the union of some of
the mother-cells, in this case generally round
and smaller, into groups of two or four.
This resemblance, however, is only external,
and due only to the fact that the cells
increase by formation in the interior, as in
cartilage ; because more exact observations
show that these cells, by further transitions,
become identical with the simpler pigment-
cells described above, and are only the more
developed forms of the latter, the pigment
having disappeared by degrees on account of
the condition of their growth.

The third layer is formed of a yellowish,
horny epidermis. The thin hairs which cover
the surface of the Cynthia papillata are formed
by this and the exterior fibrous layer. At
certain spots a bundle of fibres springs up from
the plane surface of the latter, which, being
coated with the horny epidermis, rises on the
surface as small needle-shaped bodies.

Where the test of the Cynthia attains a thick-
ness of i to and more, its composition
often changes in a remarkable manner (fig.
776.). In this case the epithelium is succeeded

Fig. 776.

Transverse section of Cynthia papil/ata, magnified
100 times. (After Lowig and Kolliker.'j

1, Internal layer of epithelium; 2, second layer,
homogeneous, with pigment-cells; 3, third layer,
composed of alternate layers of radiating fibres and
fibres parallel to the surface of the test; 4, fourth
layer, fibres parallel to the surface of the test ;
5. spines ; a, the thin yellowish outer surface ; b,
fibrous nuclei.

by a clear, homogeneous, structureless mass, of
a moderate thickness, with scattered pigment-
cells and nuclei. Next is a fine fibrous tissue,
composed of a great number of thin layers of
circular fibres, without cells or nuclei, and of
radiating fibres that unite these layers ; this
parses externally into an irregular fibrous
tissue, covered with a horny epidermis. Where
this peculiar stratification of fibres exists, the
test is not separable into laminae, because the
radiating fibres firmly connect the thin layers
of circular fibres.

Treated with hydrochloric acid and with
soda, the test of Cynthia is rendered quite
white. The pigment-cells, the coloured epi-
dermis, the mother-cells, the crystals, the
epithelium, the nuclei, and the granules are
dissolved, and there remain only the fibres
and the homogeneous substance that exists
here and there. These two elements, then,
are composed of cellulose.

The structure of the thick test of the
Cynthia Canopus is very similar to the above.
Interiorly there is an epithelium, then a thick
layer of longitudinal and circular fibres, some-
what indistinctly stratified, in which, towards
the exterior, crystals and largish round bodies,
composed apparently of groups of cells, are
disseminated ; lastly', a thin layer of solid,
whitish epidermis, with little conical papillae,
usually accompanied by processes from the
fibrous layer. The thick fibrous layer, only,
resists the action of hydrochloric acid and of
soda ; all the rest is dissolved without any
residue.

Cynthia pomaria presents, as the chief ma-
terial of its test, a layer of fibres similar to
those previously described, having chiefly a
longitudinal direction. Between the fibres
are crystals, round pigment-cells, measuring
0'004/// to O'OOO'", and further, here and there,
peculiar elongated cells, filled with yellow
granules, measuring 0-008'" and more. In-
ternally, and adhering to the fibrous layer, is
a simple epithelium, with polygonal cells that
have diameters of 0'006w to 0'008w. This
adheres to the inner tunic by means of mus-
cular fibres. Externally the fibrous layer is
covered by a yellowish, solid layer of unde-
termined structure. In the interior parts of
the fibrous layer occurs a somewdiat large
number of peculiar cells, apparently not ana-
logous to any other of animal or vegetable
structure. These cells are primitively similar
to pigment-cells, and round, but possessing a
thicker membrane, and without any apparent
nucleus. Subsequently they grow, preserving
their shape, to the size of O'Ol"'. The mem-
brane at the same time continues to thicken,
so much so that the cavity of the cell increas-
ing but slightly, the membrane attains a thick-
ness of 0,004"/. Lastly, the size of the cell
increases to 0'02w and the thickness of the
membrane to 0'006'". Whilst this develop-
ment is going on, fine lines are observable in
the thickened cell-membrane, and ultimately
the membrane is transformed into fibres, so
that one may see the moderately sized cells
in their cavities, and yet occupied by pigment

1200

TUNICATA.

or by pale granules, enveloped with an elegant
skein of fine, cylindrical, opaque fibres, which
can be isolated by compression. Whether the
fibres have a spiral arrangement is uncertain.
MM. Lowig and Kolliker, who discovered these
remarkable fibre-coated cells, remark that, as
to the manner in which this curious trans-
formation of the pigment-cells is brought
about, the increase of thickness in the cell-
membrane would take place by growth, or by
a development similar to that which occurs
in many vegetable cells, the membrane of
which consists of several layers, or by the de-
position of a substance applied externally.
As there is no appearance of any internal or
external deposit, and as the cell-cavity is not
diminished during the thickening of its walls,
they consider the first to be the more likely
cause of the above conditions, but, neverthe-
less, not sufficient alone to account for the
circumstances. It is difficult, perhaps, to say
how these fibres are formed, but it may be
that the cell-walls, by partial solidification,
ultimately become separable into fibres.

The fibrous tissue of the Cynthia pomaria is
insoluble in hydrochloric acid, or in solution
of soda ; the other elements of the test, sub-
mitted to these agents, disappear.

The following clever abstract of the facts
connected with the subject has been drawn up
by Professor Edward Forbes : —

“ MM. Lowig and Kolliker found cellulose
undoubtedly present in the envelopes of many
Tunicata, both simple and compound, in-
cluding the genera Phallusia, Cynthia , Cla-
vellina, Diazona, Botryllus, Pyrosoma, and
Salpa ; but they sought in vain for cellulose
in animals of inferior organisation, although
in some of the above-named creatures it
formed a very considerable part of the animal
tissues.

“ The Memoir of MM. Lowig and Kolliker
was examined by a committee of the French
Institute, consisting ofDumas,Milne-Edwards,
Boussingault, and Payen ; the last-named
eminent philosopher drew up the report. In
it he gives the following formula of the com-
position of the envelopes of the Tunicata : —

Cellulose

-

CO-34

Azotised substance

-

27-00

Inorganic matter -

-

12-66

10000

Fie remarks that the

establishment

the existence of cellulose in the Tunicata is
a ‘ fait capital’ in science, very important in
its bearing on future researches into the com-
parative physiology of the two kingdoms.

“ The explanation offered by Lowig and
Kolliker of these very anomalous facts is ex-
tremely ingenious, and probably very near the
truth. It is to the following effect: — Tuni-
cata live entirely upon vegetable organisms.
The contents of the stomachs of the Phal-
lusia, Clavellina, and Diazona, examined, con-
sisted of particles of florideous algae, which
had probably found their way there by chance,
and a great quantity of microscopic plants of
low position in the series, species of Navicula,

Frustulia, Baccilaria, Closterium, Sic. These
minute vegetable organisms have been shown
by Nageli and Schmidt to contain cellulose.

“ This is probably dissolved by the gastric
juice, that is to say, changed into sugar or
gum, in which state it circulates with the
blood, and is afterwards introduced into the
tunics, either directly by the sanguiferous
canals (as in Phallusia ), or by their prolonga-
tions ramified in the walls of the common
body (as in Diazona and Botryllus), which
thus, as Milne Edwards has shown, contain
also blood in their cavity, probably pene-
trating by imbibition when the envelopes have
no bloodvessels. The presence of cellulose
in the tunics of the ascidian Molluscs, then,
cannot be taken as an evidence of an ap-
proach to a vegetable nature in those bodies.
It affords us, however, a wholesome warning
against the placing of confidence in asserted
chemical distinctions between the great king-
doms of Nature.” *

From the observations made by MM. Lowig
and Kolliker on the histological characters of
the embryos of certain compound Ascidians,
they arrived at two important results. Firstly,
that the external structureless envelope of the
embryos, which, apparently, is identical with the
external envelope of the adults, is, according
to their analysis, composed of cellulose ; that
this envelope is formed only when the division
of the yolk is accomplished, and even when
the exterior form of the embryo is indicated.
Secondly, that this envelope, subsequently
containing, as in Botryllus and in Aplidium,
another structureless substance, fibres, nuclei,
and crystals, is primitively altogether homo-
geneous and unorganised.

Hence it appears that the test of the Tuni-
cates is a product of the activity of cells formed
subsequently to the process of the division of
the vitellus, and that primitively it is only a
mass secreted by these cells. Its ulterior
organisation is not yet understood, but remains
an open field for much interesting and im-
portant research.

Anatomy of the Ascidiad®. — We have
already referred to the external envelope of
the Tunicates as being analogous to the cal-
ciferous shells or tests of the other Acephalans;
and the muscular sac enclosed within it, as the
analogue of the mantle; and the membranous
sac lining the mantle as analogous to the
branchiae of the Acephalans. f

The rest of the viscera of the Ascidians are
enveloped in a peritoneum^, and the heart has,
besides, its own membranous sac or pericar-
dium. Thus the body, properly so called,
appears as if divided into three cavities ; that
of the branchiae, communicating with the
exterior by the superior opening of the sac,

* Hist. Brit. Molluscs, vol. i. p. 6.

f According to Yan Beneden, the longitudinal
vessels of the branchiae of the Ascidice are more par-
ticularly the analogues of the ciliated tentacles of
the Bryozoa.

I The peritoneum of Ascidia intestinalis offers a
good example, being of firm consistence, circum-
scribing and protecting the abdomen.

TUNICATA.

1201

and in the base of which opens the mouth;
that of the peritoneum, which does not com-
municate with the exterior by itself, but is
traversed by the intestinal tube, which, arising
in the branchial cavity, communicates with
the exterior by the rectum and the anal aper-
ture of the test ; and, lastly, that of the peri-
cardium, which has no direct communication
with the exterior.

The position of the animal is always such,
that of the two orifices the branchial is always
the highest ; the entrance into the branchial
sac being generally placed at or near the
superior extremity of the body, and the oeso-
phageal opening, at the base of the branchial
sac, having an upward direction. In Boltenia
and Cystingia the flexible peduncle, which is
attached at the summit of the body, above the
branchial orifice, allows the body to droop,
thus giving the animal its normal position. In
the Clavellinidce, which have rigid peduncles
continuous with the base of the test, the same
normal relation of the internal parts is pre-
served ; and although the intestinal loop in
Boltenia and Clavellina is always directed to-
wards the pedicle, yet this arises from the loop
having, in the former an ascending, and in the
latter a descending, direction.

The muscular sac or mantle , enclosed in
the external envelope, is attached to the in*
ternal surface of the latter by an adhesion
of the external surface of the extremities of
its two tubular processes, which correspond
to the two external orifices of the test, to
the inner borders of these outer orifices
{fig. 780.). In Ascidia there is often no in-
timate cohesion at these points, merely an
adaptation easily disturbed after death. In
Cynthia, Boltenia, & c., on the contrary, the
test and the tubular prolongations are strongly
adherent. Beside this mode of attachment,
there is sometimes a general loose adhesion
formed by the epithelial tissue between the
surfaces of the test and mantle ; and in Cynthia
papillata there is a partial transmission of mus-
cular fibres from the latter to the former ;
and, lastly, there is the very slight attachment
arising from the passage of bloodvessels from
the body to the test.

This free condition of the mantle within
the external sac occurs throughout the Asci-
diadce, Clavellinidcc, Botryllidce, and Pyroso-
midce. In the Salpidce and the Pelonaiadce,
on the other hand, the mantle and the test
are connected at very many points, or even
throughout the extent of their contiguous
surfaces.

The mantle in Chelyosoma is more closely
attached to the internal surface of the test
than in other Ascidians ; its muscular tissue
forming intimate connections between the
various plates of the external envelope, and
not only supplying the valvular pieces of the
apertures, but also edging each of the larger
plates with interlacing connecting fibres. Ex-
cept at these muscular spaces the mantle ap-
pears as a thin serous membrane.

The interval between these two sacs is,
during life, filled with some fluid; possibly a

VOL. IV.

secretion, or transudation through the one
or the other of these envelopes ; for, except
in the case of those Ascidians whose mantle-
tubes are not intimately connected with the
test, the sea-water cannot be directly admitted
into this cavity.

The mantle is reflected upon the body,
properly so called, and covers it externally,
just as the peritoneum, after having coated
the walls of the abdomen, is reflected upon
the intestines ; with this difference, however,
that it has no mesentery, and that the con-
nection is only at the two orifices. It has
an external serous layer, continuous with the
internal membrane of the test, a muscular
tissue more or less extensive, and an internal
serous layer. It has also numerous ramifica-
tions of nerves and bloodvessels. In Boltenia,
Cystingia, and probably Bipapillaria, a tubu-
lar prolongation of the mantle traverses the
peduncle.

The two tubes on the superior aspect of
the mantle, which are directed towards, and
protruding into, the two somewhat tubular
orifices of the test, are more muscular than
the rest of the sac, being surrounded with,
generally very distinct, sphincters in addition
to the fascicles of muscles that traverse them
longitudinally, and are continued diagonally
across the sac (fig. 780.). When open, the
margins of these tubes are crenulate. The
free extremity of the branchial orifice is some-
times quite entire, but occasionally terminates
in a circle of regular tooth-like processes,
which are regarded bv Dr. A. Farre as the ana-
logues of the tentacles of the Bryozoa. By con-
traction, the tubes are thrown into 5 or 6 folds.
At the exterior angles of these folds in some
Ascidians (A. intestinalis, Cynthia ampulla, &c.)
there is a minute red spot ; in A. mammillata,
the edges of the folds are more or less red-
dened by an increase and diffusion, as it were,
of these little red granules. Internally each
tube has frequently at its base some slight
valve-like prominences or folds ; and the in-
ner extremity of the branchial tube is always
fringed with a circlet of simple or compound
tentacular filaments. These, however, may
more properly be said to belong to the bran-
chial sac.

The mantle becomes dusky and opaque,
and its muscular tissue more distinctly
seen, in preserved specimens. In its recent
state it is more or less diaphanous, and
usually of a sober tint ; but occasionally, in
Ascidicc, it is of a fine crimson (A. venosa), or
variegated with crimson and white (A. virgi -
nea), or spotted with red (A. aspersa ) ; and
in A. parallelogramma it is ornamented with
rectangular reticulating white lines and occa-
sional bright yellow or crimson spots. In A.
conchilega it is white, passing to blue ; and in
A. arachnoidca it is dark blue.

The branchiae of the Ascidiadce is a large
bag of fine vascular network furnished with
vibratile cilia, contained within the mantle of
the animal, and lining the walls of that
cavity {fig. 778.). Sometimes the branchial
sac is oblong, oval, or rectangular ; and then

4 h

TUNICATA.

1202

it occupies all the length and one of the
sides of the cavity of the mantle {Cynthia).
In Asciclia mammillata and A. monacha it is
very long; and, after having descended to the
bottom of the mantle, it is bent upwards upon
itself, extending half way up the cavity again.

A tube, differing in size in various species,
which has its analogue, perhaps, in the retrac-
tile operculum of the Bryozoa, conducts the
water from the buccal aperture to the respira-
tory sac. This tube or process of the mantle
encloses the neck of the branchial sac. At
the inner extremity of the tube, where it
widens into, and is continuous with, the bran-
chial sac, are frequently observed about five
small valvular folds ; and below these there
is always a circle of fleshy filaments or
tentacular appendages {fig. 778. and fig.
39 d. Yol. I. page 112. Animal Kingdom*).
These are present also in the Clavellinidce
and the Botryllidce. They vary from 6 to
26 in number, and are either simple, as
in Phallusia, or branched, as in Cynthia , BoL-
tenia, &c. By detaching the anterior part
of the respiratory sac of Cynthia, or others,
and examining it from its inner and inferior
aspect, one may perceive, at the inner mar-
gin of the tube, several arboriform append-
ages, somewhat large at the base, and having
the branches either swollen at their extremi-
ties, or finely laciniate and almost plumiform :
in Cynthia Dione they are somewhat bipinnate.
The number of the tentacles is difficult to be
arrived at, as smaller filaments appear amongst
the six or seven larger ones. The branches
are generally directed downwards, towards
the bottom of the sac, but sometimes are
slightly curled upwards. Seen under the mi-
croscope, these filaments are hollow; and the
extremities and swellings of the branches are
cul-de-sacs. The several tentacles intercom-
municate with each other by their hollow
bases, and with the vascular network of the
respiratory sac.

The walls of these tubular organs are very
thin and transparent ; traces of muscular
fibre have been detected in their substance,
and a circulation ; but no trace of vibratile
cilia, either on their outside or within their
cavity. Van Beneden observes that a fluid
traverses their cavity in a similar manner to
the blood in the branchiae of the Doris. In
Actinia and Holothuria simple and ramified
filaments occur, that offer considerable analo-
gies to the arborescent tentacles of Ascidia;.
They are all hollow; and the fluid moving in
their interior comes directly from the peri-
intestinal cavity ; this great cavity, commu-
nicating as in Biyozoa, with the tentacular
appendages.

The internal surface of the respiratory sac
is sometimes uniform (in Ascidia, Phallusia,
&c.), and frequently longitudinally plicated
and disposed in deep and regular folds, all
following the curve of the cavity, and termi-

* This figure represents a Cyntlda canopus cut open ;
a, oesophagus ; b, stomach ; c, anus ; d, external
anal orifice, closed ; e , branchial orifice, laid open ;
f, branchial tentacles ; g, nerve-ganglion ; h, dorsal
sinus; It, ovary ( ? ) ; i,l, indeterminate bodies.

nating at a little smooth area above the pha-
rynx {Cynthia, Boltenia, &c.). The folds
are from 8 to 18 in number, and form the
first indication of the four branchial laminae
of the bivalve Acephalans. The structure
of the membrane consists of an infinity of
small, anastomosing vessels, generally cross-
ing each other at right angles, and forming
quadrangular interspaces, which, under the
microscope, are seen to be still more mi-
nutely subdivided in the same manner. Milne-
Ed wards observes that in Phallusia each of the
meshes of the respiratory membrane is occu-
pied by a minute spiracle, that allows of a
communication between the interior of the
branchial sac and the cavity of the mantle
(the “thoracic chamber” of Milne-Edwards),
the dorsal portion of this chamber being the
cloaca, the base of which is occupied by the
orifices of the digestive and generative tubes,
and the summit of which opens externally by
the anal aperture. In Cynthia ampulla the
meshes are very irregular and almost inextri-
cable, some of the minute vessels having
apparently a spiral arrangement ; and the
vessels are rather more numerously disposed
around the oesophageal orifice. A somewhat
spiral or vermicular arrangement of the ex-
tremities of the branchial vessels exists also
in Ckelyosoma, as figured by Eschricht ; * and
as seen in a very minute sessile Ascidia, from
South America, in the collection of Mr. Bower-
bank. In the respiratory network of Cynthia
the large longitudinal vessels are seen to be the
most prominent of all. They form, with the
large transverse vessels, square meshes, which
three other shorter vessels subdivide into four
transverse meshes; and these are further
intercepted by extremely fine longitudinal
vessels. The vertical vessels of this quadran-
gular network may be said to arise from the
transverse vessels, which communicate by
each extremity with two vertical trunks, placed
at opposite sides of the sac, and representing
respectively the branchial artery and vein.
The latter, in C. microcosmus and other As-
cidians, bears a longitudinal series of small
transverse tentacular filaments. Similar ten-
tacles we shall have to describe as belonging
to Chelyosoma {fig. 777. i).

The angles of the meshes of the branchial
tissue bear papillae, more or less prominent,
in some genera {Ascidia, Chelyosoma, Sic.) ; but
in others they are not papillated {Cynthia,
&c.). These papillae, or minute pouches, are,
according to Savigny, analogous to the fila-
ments that border the branchial vein, in most
of the simple and compound Ascidians, indi-
cating the junction of the transverse vessels
with that vein. The appearance of the reticu-
lation is large and coarse in Cynthia, minute in
Ascidia, and indistinct in Cystingia.

Each mesh of this respiratory network is
thickly fringed with vibratile cilia, as in the
rest of the Tunicates and Acephalans; and
Van Beneden points out that this ciliated ex-
terior of the branchial vessels is analogous
to the ciliated tentacles of the Biyozoa. By the

* Boy. Danish Transact, vol. ix. pi. 1. fig. G & 7.

TUNICATA.

1203

action of the cilia the currents are sent in the
direction of the oesophageal aperture.

In Ascidia papillosa and Cynthia microcosmus,
a little soft tubercle is situated on the interior
ot the branchial sac, not far from the orifice,
between the two branchial veins, not observed
in other Ascidians, but seen in all the Botryl-
Iians. On the internal surface of the sac are
also seen several prominent lines, 12-15 in A.
mamviillaris and A. papillaris , 5-6 in C. am-
pulla, more or less distant from one another
according to their length. These are folds
forming gutters converging towards the mouth,
and having also transverse channels leading
from one to another. Above they appear to
terminate in culs-de-sac. The vibratile cilia
covering them are very long and numerous.

Van Beneden found that, on placing for a
short time a living Ascidian in water coloured
with carmine, the particles of the colouring
matter quickly filled these little ducts, making
them appear like injected vessels. This dis-
tinguished naturalist considered them to be
somehow connected with the digestive appa-
ratus, moulding, perhaps, the particles of food
into cord-like masses before entering the
stomach.

In Chelyosoma ( f g . 777. i ) there is a remark-

Fig. 777.

Anatomy of Chelyosoma 3Tacleayanum. ( After
Eschricht.')

The inner or under side of the superior plated
surface of the animal is shown, the branchial cavity
being split open, and the abdominal viscera re-
moved. a, branchial orifice, partly closed by a
membrane, and surrounded by its hexagonal
sphincter muscle and the accompanying six fan-
shaped muscles ; b, anal orifice, similarly provided
with muscles; c, c, muscles bordering the carapace-
plates; el, the central hexagonal plate; e, e, e, e, the
surrounding plates ; f the nerve-ganglion and
nerve-fibres ; y, h, the auditory apparatus ( ?) ; i, the
row of tentacles anterior to the oesophagus ; j,
stomach ; k, part of the intestine.

ably large row of simple tentacles running
from the interior of the branchial orifice to
the entrance of the oesophagus, and closely
connected with the branchial tissue, as in
Cynthia microcosmus , &c. They appear to
surmount a longitudinal vessel or duct, pos-
sibly the branchial vein ; they are about 23
in number, and have a transverse direction
towards the left side. The posterior tenta-
cles are the largest, of about a similar size to
the tentacles of the branchial orifice ; the
others, towards the anterior extremity of the
row, become gradually smaller. Their use is
not very evident ; possibly they are connected
with the organs of digestion ; but, more pro-
bably, they are auxiliary respiratory organs,
like the circlet of tentacles within the branchial
tube.

The respiratory cavity, in addition to
its external or oral orifice and its oesopha-
geal aperture, presents also, in some cases at
least, a lateral opening, first noticed by
Cams*, and since by Van Beneden. The
presence of this communication allows the
water, received into the branchial sac for
respiration and the conveyance of food, to
pass directly out by the anal aperture. Other-
wise, when no such communication exists,
the water must be ejected through the oral
aperture by muscular contraction, as in the
Acephala.

In ClaveUinidce and Botryllidae the open
meshes of the respiratory network j-, or bran-
chial stigmata, also allow of the free passage
of water from the respiratory cavity to the
cloaca. In Pyrosoma, Pelonaia, and Salpa,
the disposition of parts admits of the free pas-
sage for the water from the one external
orifice to the other.

Externally the branchial membrane presents
very similar appearances to its net-like interior
surface : where folded, however, of course the
folds and sulci are reversed. It is attached
more or less firmly to the inner surface of the
mantle on the one side, and on the other to the
intestines, stomach, and ovaries, by transverse,
short, delicate, perhaps vascular, threads, one
of which proceeds from each angle of the
meshes.

“ In the young Ascidian,” says Cams, “ the
respiratory sac can be distinctly recognised as
an integral part of the intestinal canal. As
the body increases, this originally crop-like
dilatation gradually attains a more consider-
able extent, and differs in structure from the
intestinal canal in having exceedingly delicate
and transparent parietes ; in a word, diverg-
ing more and more from the intestine.”

We may further observe, that the vertical
vessels entering into the composition of the
framework of this branchiferous pharyngeal
sac, and representing, according to Van Bene-
den, the tentacula of the Bryozoa, are not
only analogous to the latter in their respira-
tory function, but are subservient also to the
purposes of alimentation, like the tentacles

* Meckel’s Archiv f. Plivsiologie, B. ii. 1. 4.

f M. Coste (Comptes itendus, vol. xiv. p. 182.
1844) denies the existence of open stigmata.

4 u 2

1204. TUNICATA.

referred to, by producing, and being traversed
by, the ciliary currents that bring the food to
the cesophageal aperture ; and that the ten-
tacula of Bryozoa are essentially members of
the alimentary apparatus is shown by the fact,
that animalcules, &c. are frequently caught
and detained by the action of the tentacles,
one or more of which, and sometimes even
the whole, bend suddenly inwards, and secure
such particles as come within their reach,
thus taking the character of prehensile labial
or oral appendages.*

The cavity of the branchial sac is often the
habitation of parasitical Entomostraea.

The buccal or branchial orifice of the Asci-
dians terminates, as we have already noticed,
by a valvular opening in the large delicate
membranous sac, which in some respects ap-
pears to be a kind of crop, and in others a
respiratory cavity. Opposite to it, and in the
lower part of this cavity, is the commence-
ment of the oesophagus (Jig. 778. d), which
leads to the stomach and thence to the in-
testine. The viscera are always more or less

Anatomy of Dendrodoa glandaria, magnified about 3 times. ( After MacLeay .)

a, summit of the test open and thrown hack ; b, upper part of the branchial sac opened and thrown
back with the test, so as to expose its inner surface and the circlet of tentacles surrounding the
inside of the branchial orifice ; c, the ventral sinus ; d, cesophageal aperture ; e, stomach ; f intestine ;
g. anus ; h, inner aspect of the external anal orifice ; i, nerve-ganglion, situate between the two external
orifices, and cut through in opening the animal ; j, part of the test or external envelope ; k, h, branched
ovary, single, and on the left side.

lateral, except in Chelyosoma, where they are
disposed flatwise, below the branchial sac.
The convolutions of the intestine are placed
between the respiratory sac and the muscular
envelope or mantle, and are either unattached,
except by slight filamentous processes arising
from the external surface of the branchial sac,
or buried in the substance of the liver and
ovaries.

* Mr. A. Hancock, on the Anatomy of the Fresh-
water Bryozoa, Annals and Mag. Nat. History,
2d series, vol. v. p. 176. See also Lister and Farre,
loc. cit.

The mouth, or cesophageal orifice, is at the
base of the branchial sac ; so that when the
latter extends to the bottom of the cavity of
the mantle, the mouth is also at the base of
the mantle. When the branchial sac stops
short at the middle of the muscular sac, or
when it is bent upon itself, the mouth also is
near the middle. In the species that have an
oblong, transverse cavity, the mouth is at the
postero-inferior angle of the branchial sac.
The mouth is either a simple round hole or a
slit, or it is an aperture divided up by slight
folds or ridges. It is always destitute of lips

TUNICATA.

1205

or tentacles, unless we except the peculiar
longitudinal row of tentacles passing forward
from the oesophageal aperture along the wall
of the branchial sac in Chelyosoma and other
genera. The oesophagus, sometimes obsolete,
is always very short, and is more or less pli-
cated longitudinally.

The stomach is simple, generally merely a
slight dilatation of the alimentary tube (jigs.
777. j, and 778. e). In A. mammillata it is
strongly plicated, and the pyloric extremity
narrowed by little fleshy papillae. It is some-
times bent upon the intestine and adherent to
it, and is often enveloped in the liver, with
which it is intimately adherent. Its walls are
very unequal, internally forming various la-
cunae, through which the bile penetrates, as in
the Bivalves ; the little bile-ducts are guarded
with valvules. In Boltenia reniformis the sto-
mach is destitute of any internal folioles or
lacunae ; but in Ascidia intestinalis, Cynthia
papil/ata, C. canopus , and others, internal
plicae are present ; and in C. ampulla the sto-
mach is almost filled up with longish folioles,
and is of a light yellow colour from numerous
yellowish granules contained in its tissue.

In Dendrodoa the stomach is striated ex-
ternally (fig. 778. e ). In Cystingia it is very-
large, extending almost the whole length of
the body, and bears externally a deep longi-
tudinal depression, and is marked internally'
with faint transverse striae. In Cynthia poly-
carpa and C. pomaria, a little ccecum occurs
just anterior to the pylorus.

The intestine is usually short, simple, and
without cceca. In several species of Ascidia
its internal surface is traversed throughout
nearly its whole length by a semicylindrical,
hollow, ridgelike plication, the “ intestinal rib”
of Savigny, having the appearance of an inva-
ginated intestine. In its course, the intestine
generally makes one or two folds. Its walls
are thickened frequently by a glandular tissue,
probably supplying some fluid necessary to
digestion ; and its internal surface sometimes
bears biliary lacunae. The rectum leaving the
peritoneum floats unattached, and opens oppo-
site to the second or anal orifice of the mantle,
so that the excrements falling into the cloacal
cavity are carried away by the current of
water leaving the body. In the stomach and
intestines is usually found a mass of finely
divided matter, chiefly, if not wholly, derived
from diatomaceous plants. Towards the
posterior extremity of the intestines the ex-
crements are usually moulded into little
earthy-looking filaments, as in most of the
Molluscs. The faeces appear to be formed
into these vermiform cords in the sulcus along
the side of the longitudinal intestinal fold.

In A. mammillata the duodenum has several
slight transverse striae. In Cynthia ampulla the
intestinal walls are internally hollowed into
lacunae and little folds, which, like the coats
of the stomach, pour out a yellowish fluid like
bile. In Dendrodoa the intestine is of con-
siderable length. In Boltenia reniformis also
the intestine is long, mounting up as high as
the base of the pedicle, then descending nearly

parallel with itself and terminating in an as-
cending conical rectum, the anus having a
scalloped margin. In this species there are
twelve subcubical bodies, separate from each
other, adherent to the upper and inner surface
of the rectum, having the free edge of a part
of the ovary between them and the liver. In
size they differ among themselves, the largest
lying towards the anus, and the smallest in
the opposite direction ; they have no apparent
communication either with the intestines, with
each other, or externally. Under the micro-
scope their structure appears to consist of a
very fine homogeneous colourless membrane,
enclosing an infinite number of excessively
minute nucleated cells, readily separable from
the tissue, which have much the appearance
of blood globules. In Chelyosoma the digestive
apparatus is large, and, from the shape of the
animal, is arranged flatwise. The oesophagus
commences at the posterior left corner of the
branchial sac, between the two chambers of
the heart. Advancing obliquely forwards, it
enters the stomach, around which are clus-
tered the biliary cceca. The intestine goes on
to make a single bend, and, coming back to
the left posterior corner, proceeds towards,
and terminates abruptly at a very short dis-
tance from, the anal orifice.

The liver of the Ascidiadce generally occurs
in a very degraded form ; it is either absent,
as in Ascidia, Dendrodoa, and some Cynthice,
or its place is supplied by lacunae and folioles
on the inner coats of the intestinal canal, oc-
curring, in Cynthia ampulla, both in the sto-
mach and duodenum ; or, on the other hand,
it is more or less amply developed, as in Bol-
tenia, where it appears as an irregularly lobu-
lated body, coating the stomach externally
behind the right ovary, and passing from the
lower extremity of the body, half-way up, in
the cavity of the mantle. The lobes differ in
size: the largest are placed towards the pyloric
or highest end of the stomach, and are more
distinctly separated from each other than the
smaller ones ; they are more or less rounded
and granulated, their surface being minutelj
papillated and composed of minute round
bodies, at first sight resembling ova. In Cyn-
thia the liver is greenish, granulated, foliated,
or, as in C. Dione, caniculate. It is sometimes
formed of clustered groups of flask-shaped
cellular bodies, the individual cells being fixed
by their larger ends, and having a radiate ar-
rangement. It is intimately adherent to the
external surface of the stomach, which fre-
quently is totally enveloped by it. The bile
enters the stomach by distinct holes at the
bottom of the cavities of the little lacunae
before-mentioned. In C. microcosmus, and
others, the liver is divided into masses, one of
which is situated on the left of the bran-
chial sac and quite free of the abdomen. The
liver in Ascidia intestinalis has the appearance
of somewhat salient glandular bodies, situated
as well on part of the intestine as on the sto-
mach. In Chelyosoma this organ is represented
by a cluster of short ccecal tubes lying all over
the external surface of the stomach. The
1h 3

1206

TUNICATA.

liver cells in Bo/tenia are elongated cceca, thick,
and sometimes deeply divided at the outer
extremity, attached by their thin ends, and
arranged in eccentrically radiated groups, en-
closed in an epithelial membrane, the whole
having externally a racemiform appearance.

The digestive organs of the Tunicata are
subject to congenital malposition ; of which M.
Savigny has described two remarkable exam-
ples, in Cynthia Momns and Phallusia Turcica;
and Mr. MacLeay was inclined to regard as a
malformation a peculiar arrangement of the
intestinal canal that was presented by the
unique specimen of Cystmg’a Griffithsii de-
scribed by him. In a unique specimen of P.
Turcica, examined by M. Savigny, the intestine
lay to the left instead of the right of the bran-
chial sac, and was found bending backwards
and embracing the stomach from below, in-
stead of bending forwards at some distance
from the pylorus, approaching the superior
border of the stomach, and then terminating
in the rectum. In a specimen of C, Momus,
the alimentary canal was also found on the
left-hand side ; but, by a very peculiar intro-
version, the pharynx was placed at the pos-
terior instead of the anterior extremity of the
branchial sac. The intestine descended as
far as the bottom of the mantle, folded it-
self forward, and ascending parallel to itself,
terminated opposite to the pharynx ; so that
the anus and the oesophageal aperture both
opened into the branchial orifice. The ex-
ternal communication through the anal orifice
existed as usual. Both of these malformed
individuals had their ovaries full of eggs, but
were not, apparently, in strong health, and
were more than usually infested with ento-
mostraca. In the catalogue of the Hunterian
Museum (vol.i. pl.5.y?g. 2.), a dissection of an
Ascidian is figured after a drawing by John
Hunter (the original specimen, however, has
not been found), in which there is, apparently,
an abnormal elongation of the oviduct, which
is accompanied by a slight granular line, both
lying on a large tapering tube having much
the appearance of intestine; the anus, how-
ever, shows itself projecting from the side of
this tubular body some way lower down, in
its usual place. The oviduct, and, apparently,
the accompanying elongated tube, terminate
externally at a minute aperture placed in the
sulcus between the two projecting terminal
orifices of the test. The oviduct, however,
barely reaches this aperture ; and its accom-
panying granular line terminates still lower
down.

Organs of circulation. — In the Ascidiadce
there are two large vessels or sinuses, the
dorsal and ventral, to which the branchial
capillaries, on the one hand, and the heart
and peri-intestinal cavity, on the other, are
intermediate. The circulation is of the mixed
or reptilian type ; both sinuses being in con-
nection with systemic and respiratory capil-
laries, and the blood, consequently, being sent
by one impulse both to the system and to the
branchiae, and ultimately returning from both
by the same channel. We are prevented

from calling either of these sinuses arterial or
venous, on account of the periodic reversal of
the circulation, mentioned incidentally above,
and more fully detailed hereafter, whereby
they are alternately changed from vein to artery
and from artery to vein. One of the branchial
trunks, terminating at the heart, however,
answers to the branchial veins of the Gastero-
pods and Bivalves ; the opposite, and often
double, trunk may therefore be looked upon
as the branchial artery, and is connected with
the veins of the body. The Ascidia, like
the rest of the Acephala, has but a left or
aortic ventricle, and no ventricle at the union
of the vena cava and the pulmonary artery.
This aortic heart or ventricle is not always
easy to be seen. When the branchial sac is
simply oblong, it is situated towards its base ;
and consequently, when the branchial sac is
as long as the body, it is situated towards the
base of the mantle ; and when the sac is
shorter than the body, it is placed near the
centre of the mantle. When the branchial
sac is bent upon itself, the heart is situated at
the curve, and then it is always near the
middle of the body. In general its position,
according to Cuvier, appears to be deter-
mined rather by that of the mouth, than that
of the rectum ; but M. Milne-Edwards and
Van Beneden consider that it follows in its
displacement the organs of generation rather
than the mouth. The heart in the Tunicata
is never traversed by the rectum, as in other
Acephala.

In the Ascidians the form of the heart is
oblong, and thin at the two ends, or more
or less tubular. Its substance is contractile,
but extremely thin and transparent, so that
it is scarcely distinguishable in the cavity of
its highly pellucid pericardium. Cuvier ob-
served that, in the species in which the
branchial sac is bent upwards, he was not
able clearly to discern a dilatation sufficiently
marked to deserve the name of a heart, and
was inclined to think that possibly in this
case the heart’s function was performed by
the artery. Here, however, we may notice
that specimens preserved in spirit generally
afford but very indistinct traces of this organ ;
and Cuvier does not appear to have had the
opportunity of studying transparent specimens
of the living animal, in which the heart can
be detected by its pulsating movements.

In Ascidia intestinalis the heart, which is
very long, and extended under the ventral
border of the respiratory sac, communicates
with the great thoracic sinus by a longitudinal
slit situated at a little distance from its an-
terior extremity ; and when the peristaltic
movements of the heart advance from behind
forwards nearly all the blood contained in its
cavity passes into this sinus, penetrating the
vascular network of the branchial sac, and
passing into the dorsal sinus, whence it is
spread amongst the viscera, and returns to
the posterior extremity of the heart not far
from the anus. During this time the heart
consequently performs the functions of a
branchial ventricle, and the great thoracic

TUNICATA.

sinus is a kind of pulmonary artery. But
when this state of things has lasted some
minutes, the direction of the peristaltic move-
ment of the heart is inverted, and the blood,
instead of traversing the branchial network
from below upwards as previously, moves
from above downwards, and passes from the
great thoracic sinus into the heart. The
latter is then an aortic ventricle, and the sinus
a branchial vein or aortic auricle. In a very
fresh and uninjured individual, of Cynthia am-
pulla, Van Beneden counted 45 contractions
in one direction ; and then, after a rest during
the space of two pulsations, he counted ICO to
170 in the other, the pulsations being about
70 per minute.

In injecting the vascular system of the
simple Ascidians, M. Delle Chiaje thought he
found certain valvules so disposed as to hinder
the return of the blood from the aorta into
the cavity of the heart, or from passing again
from the heart into the vessels through which
it had arrived there. But by careful observa-
tions on living specimens, both Milne Edwards
and Van Beneden have established the fact,
that, as in the Botryllidce, the Salpidce, and
the other Ascidian families, the blood of the
Ascidiadce, after having flowed for some time
in one direction, traverses the same circle in
an opposite direction; a condition that would
be impossible were an)' valvular hindrances to
return currents of the blood present.

In Che/yosoma*, the heart is very distinctly
seen in the animal when dissected ; it lies near
the oesophagus, and has two distinct chambers.
The aorta rising from its anterior part is a
stoutish vessel, and at first lies close to the in-
testine : it afterwards runs in the space within
the intestinal loop, ultimately breaking up into
largish branches, distributed on every side.
The ramifications divide some 4 or 5 times,
and terminate somewhat abruptly, the extre-
mities appearing as if closed. Throughout
the surrounding generative organs there is a
very fine network of vessels, but whether
they are arteries, veins, or gland-ducts is un-
decided. A largish vessel running along the
left side of the stomach and duodenum ap-
pears to return the blood to the branchial sac.

Mr. MacLeay describes the heart of Cys-
tingia as being large, ovoidal, and of a lobular
appearance ; and having four vertical, lateral
openings, capable of considerable dilatation.

In Cynthia ampulla the heart is placed a
little within the great intestinal loop, and
near the middle of the body : it is fixed on an
oblong vesicle, enclosing calcareous concre-
tions. This vesicle is situated exterior to
and above the first or principal bend of the
intestine. Its colour is a greenish yellow,
and it has apparently no aperture, or commu-
nication with other organs. The heart itself
is a slightly bent tube, with very elastic walls :
it has two openings ; a single large aperture
on one part, and opposite to it three ves-

* Described by Eschricht (Royal Danish Trans,
vol. ix. p. 12.), to whom we are indebted for much
valuable information, both with respect to this
genus and the Salpians.

1207

sels that carry off the blood in different di-
rections.*

“ The circulation of the Ascidians,” says
Van Beneden, “ differs but little from that of
the Bryozoa; and is transitional between that of
the Polypes and of the Molluscs. If we re-
move the heart of the Ascidian, the disposi-
tion of parts is very similar, and the simpli-
fication of an apparatus cannot more visibly
take place. The Ascidia is but a digestive
canal suspended in the midst of external mem-
branes, with a liquid moving in the peri-
intestinal space. A colourless liquid (blood)
occupies this cavity ; but it is only in the
branchial network and tentacles that it can
be said to be contained in vessels. All
around the intestinal tube this fluid is alter-
nately moved from right to left, and vice versa.
In the vessels composing the vascular net-
work, and in the respiratory tentacles, the
same movement of the nutrient fluid takes
place. This blood contains somewhat regular
globules, white as the containing liquid, that
indicate the course of the fluid. In some in-
dividuals the blood is yellowish. M. Milne-
Edwards has observed an Ascidia with red
blood.”)- Mr. Lister observed that in a sessile
Ascidian half an inch long, the blood-globules
were about the same size as those of the
minute Perophora, viz. from '00025 to '0002
inch in diameter.

Van Beneden, to whom we are indebted for
so much information with regard to simple
Ascidians in general and Cynthia ampulla in
particular, has observed in living specimens of
this species, that the blood is distributed to
each branchial trunk at the same time, and
with the same direction, ascending and de-
scending alternately. According to this, the
heart, contracting in one direction, sends
blood towards the branchiae, filling all the
vessels at one time, and recalls it by contract-
ing in an opposite direction. That a series of
contractions in one direction, during a certain
time, may take place without engorgement,
there must be a direct communication between
thebranchiee and the peri-intestinal cavity; and
this is afforded, according to Van Beneden,
by the respiratory tentacles, see p. 1202.

Seen under the microscope, the contractile
tissue of the heart affords no trace of mus-
cular fibre. The contractility remains some
time after the removal of this organ from the
body ; and that without being irritated.

Nervous system. — A single ganglion, oval,
soft, consisting of a saclike neurilemma, enclos-
ing nerve-cells or neurine, placed in the sub-
stance of the mantle, and between its two tabu-
lar orifices, gives off' four branches, two of the
branches forming a loop around either tube,
and other lesser filaments distributed about

* In the Physiological Series of the Hunterian
Museum there is a highly illustrative dissection
of ,C. tuberculata (No. 898. B.), prepared by Prof.
Owen, that beautifully exhibits the heart and its
pericardium, the branchial vessels, partially in •
jected, and other organs.

j- Recherches Zoologiques faites pendant un
Voyage en Sicile. Comptes Rendus, 23 Nov. 1844.

4 h 4

1208

TUNICATA.

the mantle. Besides these, Meckel* found
in the Ascidia gelatinosa one larger and two
smaller ganglia between the stomach and the
branchial sac. Cuvier considered the large
ganglion to be the analogue of the “ inferior ”
ganglion of Molluscs, found in the Bivalves
between the branchiae and towards the origin
of the tube that admits the water ; and ob-
served that he had not seen any nerves ter-
minating at a brain, nor the brain itself, which
must be situated by the mouth at the base of
the branchiae.

The great nerve-ganglion in Chelyosoma,
long and broad, cylindrical, and yellow-
coloured, lies near the middle of the inferior
surface of the plated test, and a little to the
left (fig. 777. f). From its anterior angle it
sends four branches, two of which form a half-
circle around the star-shaped muscular ap-
paratus of the branchial orifice, the other two
losing themselves in the muscles bordering the
nearest plates. From the posterior angle arise
eight nerves, four going to the anal orifice,
and four to the lateral muscles of the plates
( fig. 777. d, g).

Special senses. — In the last-named genus
there are two remarkable bodies found in
connection with the nerve-ganglion, which
Professor Eschricht, to whom we are indebted
for a careful anatomical description of Che-
lyosoma, considers probably to appertain to the
function of hearing (fig. 777. g, h). One of
these bodies has the appearance of a minute
bladder, filled with a whitish substance. It
measures V" long, and broad, and lies to
the left of, and quite close to, the ganglion,
being at its posterior extremity strongly ad-
herent to it, or to the base of one of the nerves
proceeding from it, by means of a stalk-like
attachment. Through its diaphanous walls a
row of arched transverse striae arc discernible,
which are either folds of the parietes, or a par-
tition. The other body is pear-shaped, about
long, lying anterior to the ganglion and the
little bladder-like body, and, like them, be-
tween the serous membrane and the respira-
tory sac ; its stem is placed between these
two bodies, and its head advances up to the
hindmost muscle of the branchial orifice. It
seems to be of tolerably firm consistence, but
it is not at all bony or horny. Its thick, an-
terior portion is barely broad, and has
anteriorly a deep hole, which seems to lead
into a large cavity ; the border on all sides of
this pit is prominent, gently declining to a
blackish little body within.

The Ascidiee have frequently around the ex-
tremity of each process of the mantle, i.e. the
branchial and anal tubes, a row of coloured
points or ocelli, similar to the imperfect organs
of sight present in the majority of the bivalve
Acephalans, where they are arranged along
the margin of the mantle, or dotting the edges
of the siphonal orifices. The number of these
oculiform points correspond with the number
of processes or folds that the margins of the
tubes respectively bear ; about eight in the

branchial, and six in the anal tube. They are
usually red, as in A.vilrea, A. virginea, A. pru~
num, and others; in A. vientula they are yellow,
with a central red spot.

M. Milne-Edwards has observed similar eye-
like points around the oral tubes of Amaurou -
cium and Parascidia, belonging to the botryl-
lian group of Tunicates.

Some of the Salpa also have ocular spots.

Besides these oculiform points in the adult
animals, Van Beneden has observed in the
larvae of Cynthia amjmlla, on the side of the
gibbous or anterior portion representing the
head, some black points that he regards as
true eyes. Speaking of the development of
the young Ascidian in the egg, Van Beneden
describes the separation of the contents of
the incubated ovum into an external layer, to
form the skin and the tail of the young animal,
and a second layer, of which subsequently the
walls of the alimentary canal are formed ; and,
thirdly, an internal vitelline mass. “ In the
thickness of the external layer,” says Van
Beneden, “ there appears towards the middle
of the body, and rather inferiorly, a cell filled
with black pigment, which must be regarded
as the organ of vision. It persists during the
whole term of the animal’s locomotive exist-
ence, and disappears after it becomes fixed.
These organs,” he adds, “ which we may well
call eyes, although so simple, are constant ;
sometimes two are discernible on one side.”

M. Milne-Edwards has also seen in the
larvae of the compound Ascidians one or two
blackish points, but towards the posterior
extremity of the body ; he merely notices
them, without assigning for them any function.
“ We consider ourselves,” says Van Beneden,
“ sufficiently authorised, by all that we have
seen in the embryos of the free inferior ani-
mals, to elevate these pigment-cells to the
dignity of an organ of special sense. To say
that the presence of an eye implies that of an
optic nerve and of a brain does not appear to
us to be more just than to say that there are
muscles when there is movement. We have
the example of the Hydra;, that, without mus-
cles, without nerves, without brain, and with-
out a special organ of feeling, are sensible to
light, anil avoid or approach at will bodies
whereby they are affected. And if the Hydra,
without special apparatus, is sensible to light,
we do not see why a cell of pigment may not
be the first rudiment of the organ of sight.
The appearance of the eye and the ear, in the
animal series, takes place in similarly simple
rudimentary forms.”*

Generation. — The Ascidiadae are all herma-
phrodites. Between the fold of the intestine,
and close to the liver, when the latter exists,
there is observed a whitish glandular organ;
this is the ovary. An undulatory duct passes
from it, which, following the rectum, opens
near its extremity into the cloaca. Opposite to
the opening of the oviduct, Carus noticed the
orifice of another glandular organ, which he
thought to be either a male organ, or serving

Schalk, De Ascidiarum Structure, Halle, 1814.

* Van Beneden, Mem. Brux. Acad. vol. xx. p. 40.

1209

TUNICATA.

to furnish the gelatinous covering of the
ova.

The ova of Ascidice, instead of passing from
the ovary to the branchiae, there to be deve-
loped as in a uterus, are emitted externally, by
the oviduct conveying them into the cloacal
cavity, whence they are carried outwardly by
the current of water through the external
anal aperture, or through the communicating
lateral opening into the branchial sac, and
thence through the branchial aperture. Cuvier
says that he found some minute egg-like
bodies between the branchial sac and the
mantle ; a position very analogous to that
held by the ova of the bivalve Molluscs ; and
he thought it probable that ova so placed
were fecundated by seminal fluid emitted by
the same duct that leads from the ovary.
These granules, however, M. Savigny appa-
rently regards as little glands.

The generative organs are sometimes single
and sometimes double ; in the latter case, the
two halves, right and left, are completely se-
parate, as in other Acephalans, and emit their
products separately into the cloaca, which
serves as a kind of incubational or marsupial
pouch.

The ovary is single in Phallusia, Pandocia,
and Dendrodoa ; it is usually double in Bol-
tenin, &c. In Cynthia the ovary is either
single or multiple, sometimes very large, form-
ing long groups of clustered globules, each
globule being crowded with ova.

The single ovary is sometimes enclosed
within the intestinal loop, without adhering
to it, and sometimes, as in C. papil/ata, &c., it
lies against, and is adherent to, the rectum.
In C. papil/ata the ovary is bent on itself and
terminates by an oviduct at each end. In C.
canopus there are 2 — 4 or more ovaries ; those
on the right side are placed against the rectum,
and all terminate, as usual, by oviducts. In
C. microcosmus there are two ovaries on the
left side. They are composed of separate
gelatinous lobes, having the appearance of a
bunch of grapes. In C. mytiligera the ovary
has the form of a membranous pouch, which
furnishes points of attachment to the exterior
of the branchial sac, and is fixed to the mantle
and to the inner part of the intestinal loop.
Its duct is very thin, and follows the usual
course by the side of the rectum. In C.
polycarpa and C. pomaria, Savigny describes
certain numerous hemispherical or conical
bodies adhering to the mantle, almost fifty in
number, and disposed in rows, somewhat cor-
responding to the six branchial folds, as being
possibly the ovaries of these species. These
bodies are without ducts ; they are formed of
a mass of granules resembling the eggs of
some other Ascidians ; they are much com-
pressed, and resemble a compound berry held
in a 5-fid cup ; they have apparently no com-
munication with each other or externally, and
are accompanied at their base with gelatinous,
transparent, subpedunculated vesicles, appa-
rently empty. In C.papUlata, which has other
generative organs, there are many rows of
isolated, gelatinous, semitransparent, wrinkled

vesicles, corresponding to the arrangement of
the branchial folds, attached to the mantle, and
receiving bloodvessels from it. The lobes
of the ovary in C. microcosmus, after the emis-
sion of the eggs, wither into wrinkled vesicles
closely resembling these sessile vesicles in C.
papil/ata. Certain soft bodies observed in
C. microcosmus, and somewhat similar to the
above, Cuvier regarded as fat, serving as stores
of nutritive matter ; but with this Savigny
cannot agree. Savigny also points out the
occurrence of various irregular, but somewhat
similar fungous or fleshy excrescences on the
mantle (Jig. 39. i,l, Vol. I. p. 112.), ovaries,
and intestines, sometimes even quite investing
the latter ; but these are quite distinct from
the ovary-like bodies above described.

In Boltenia reniformis the ovaries are double,
unequal in size, elongate, formed of coarse
subcubical lobes, situated one on each side of
the body, and directed towards the anal
orifice; the right or smaller ovary, straight,
claviform, fitting closely into the ascending
loop formed by the stomach and intestine.
The left ovary, larger and less lobulated, is
on the opposite side, between the mantle
and the branchial sac ; it is undulating, and
extends downwards behind the branchial vein.
The tissue of these ovaries is a yellowish
membrane of distinctly cellular structure,
containing groups of large opaque ova and
smaller clusters of exceedingly minute diapha-
nous granules. The ovaries of Cystingia are
two free racemes composed of globular bodies,
as in CynthicE, arranged on the two sides of
the body with the branchial sac and stomach
between them. In Dendrodoa (Jig. 778. k)
the ovary is single and branched, consisting
of a trifurcate, cylindrical stem, bearing at
its base on one side a forked branch, and
on the other a simple one, all of the same
thickness ; it is situated on the left side of
the body between the mantle and the branchial
sac. In Chelyosoma, Professor Eschricht de-
scribes as an ovary two darkish bodies, filled
with vascular ramifications ; placed, one be-
tween the liver and the rectum, and the other
around the fold of the intestine. Another
somewhat similar organ, traversed by rami-
fying vessels, and placed at the anterior ex-
tremity of the body, is apparently the testicle.
Connected with this organ, a distinct sigmoid
duct runs to the right posterior angle of the
body, from whence a filamentous tube passes
along to the left posterior corner.* In Cynthia
ampulla the generative organs are situated in
the intestinal fold, and appear at first sight to
form a single organ ; but by the aid of the mi-
croscope two distinct organs, male and female,
are easily recognised (Jig. 779. a). The testicle
forms a sort of framework around the ovary ;
it is of a milky white colour, and is composed
of an infinite number of short, twisted cceca,
visible to the naked eye, and somewhat ana-
logous to the seminiferous canals composing
the testicles of higher animals. Three or four
mammillary processes rise from the anterior

* Royal Danish Transact, vol. ix. p. 13.

1210

TUNICATA.

surface of this organ : they are hollow in the
centre, and emit a milky fluid, which is shed

Fig. 779.

A, generative organs of Cynthia ampulla, situated

in the fold of the intestine. ( After Van Beneden.')

a, stomach and its aperture (destitute of oeso-
phagus) ; h, rectum and anus ; c, ovary, with its
outlet into the cloaca; d, testicle, enveloping the
edges of the ovary.

B, magnified portion of the reproductive organs of
Ascidia grossularia. ( After Van Beneden. )

a, testicle ; b, ovary and ova.

into the cloaca, and contains, or rather is
almost composed of, spermatozoa, with dis-
ciform heads and filamentous tails. The ovary
is blackish, and is situated in the midst of the
testicle. Its situation corresponds to that of the
ovary of the Limaces among the Gasteropods,
which is surrounded by the liver. It is easily-
distinguished from the testicle by its colour
and by the appearance of its contained eggs.
The oviduct opens into the cloaca by the side
of the anus. In Ascidia grossularia the eggs,
seen through the walls of the ovary, are of a
fine red colour, and are contained in separate
sacs, the ovary appearing like a bunch of grapes
( fig. 779. b). Van Beneden has distinctly
seen in all of these ova the two germinal vesi-
cles. The vitellus is at first white, but during
development it becomes of a deep red. By the
side of the ovary is another series of sacs
without ova, and some free cells containing a
great number of other more minute cells
moving about in their interior, and which
when shed swarm about like spermatozoa.
These appear to constitute the male organ,
and its disposition accords with that of the
Amaroucium argus, and with that of the
Bryozoa (Van Beneden).

There remains much to be elucidated with
regard to the generative functions of the Asci-
dians. The male and female organs are always
associated together, and are apparently each
provided with efferent ducts. It appears,
however, doubtful whether or not occasion-
ally the ova and the spermatozoa may not be
brought into contact either in the organs them-
selves or in the ducts, as well as in the cloaca.
We may notice that the disposition of the
sexual organs in the Bryozoa, to which in
so many respects the Tunicata bear reference,
appears to be, from Van Beneden’s observa-
tions, as follows. A male and a female organ
are separately developed in the peri-intestinal
cavity'. Each is formed of cells, and in

these cells are formed others, which become
either vitellus or spermatozoa. When the
latter cells are matured, the walls of the ex-
terior or mother-cells are burst, and their con-
tents are shed into the fluid filling the cavity
around the intestine. It is here the male and
female elements come into contact, and the
ova are subsequently discharged by an orifice
at the side of the anus.

In some compound Ascidians the peduncle-
like post-abdomen forms a receptacle for
the ova ; and so does the pedicle of Clavel-
lina, as in Cirrhipeds ; but the pedicle of
Bo/tenia and similar forms does not appear to
be used for that purpose.

Muscular system. — The Ascidiadee being
fixed in their adult state, have no muscles of
general locomotion ; but they have numerous
muscular bands by which they can effect cer-
tain movements of contraction and extension.
The muscles do not consist, as in Bryozoa, of
isolated fibres folding themselves irregularly
during contraction ; but each muscle is com-
posed of many fibres united. They make their
appearance in the young individuals contem-
poraneously with the appearance of the respi-
ratory sac. The muscular fibre of Tunicata,
like that of the whole of the Acephala, is of
the organic or unstriped type.

In the Ascidiadee, as in other Tunicates, the
muscular tissue is chiefly developed in the
mantle ; the muscles of the heart and in-
tesinal canal (if present) have not been
observed. The muscles of the mantle are
very thin and narrow bands, generally at
considerable distances from one another, sur-
rounding all the body of the animal from
the anterior to the posterior extremity, and
uniting in part with one another on the
median line of the dorsal walls (fig. 780.).

Fig. 780.

Muscular sac or mantle of Boltenia reniformis.

( Original .)

In Ascidiee the mantle is more muscular on
the anterior and largest part, and more
membranous posteriorly. Externally there
is a layer of longitudinal muscular bands,
and internally of transverse bands. In some

TUNICATA.

1211

(A. intestinalis , &c.) the exterior layer is much
the thickest, and is composed of about twelve
distinct fascicles, the fibres ot which are
somewhat separated from one another, insensi-
bly disappearing on the anterior and superior
borders. In others ( Cynthia microcosmus, Szc.),
this external layer is very slight, and formed
of distinct fibres, whilst the internal fibres are
stronger, transversely oblique, and interlacing.
Circular bands of muscles generally surround
the tube of each orifice, and are rather
stronger towards its base. The fibres forming
these collars of the two tubes occasionally in-
terlace with each other at the interval between
the tubes, in a figure-of-eight pattern. Some-
times these muscular collars or sphincters are
very indistinct, and not so apparent as another
set of fascicles, which run in a diagonally
transverse direction across the sac, and pass
up the sides of the tubes, converging at the
orifices. The latter bands diverge from the
two orifices in two sets, which in part cross
each other obliquely, and form an open net-
work.

In Chelyosoma (fg.177.a,b') each of the six
triangular valvules that surround either orifice
is furnished with a fan-shaped set oi muscular
fibres, adhering at one end to the inner sur-
face of the test, and at the other extremity to
a small papillary process on the valvule. Be-
sides this set of muscles, and within them, is
another set which passes laterally from one
papilla to another, forming a sphincter, the
base of which is hexagonal. There are other
strong subcutaneous muscular fibres passing
from the edge of the upper part of the tunic
to that of the lower, and also from the edge of
each of the coriaceous plates forming the
upper surface (c, c).

By the action of these muscles, the body or
inner sac of the animal is transversely con-
tracted and somewhat lengthened; the tubular
processes also of the mantle are closed, and
more or less retracted. When the animal is
alarmed, the contraction takes place rapidly,
causing the water contained in the respiratory
and cloacal cavities to be ejected by one or
other of the orifices to the height of even
three feet.

There is considerable analogy between the
muscular system of the Ascidice and that of
the Bryozoa. In the latter there are retractor
muscles of the sheath and the intestinal tube;
and in the interior of the cells there exist also
transverse oblique cords, traversing the peri-
intestinal cavity, and attached to one or the
other surface of the skin. These transverse
muscles contribute to open the tentacular
circlet; and in the Ascidice, by their contraction,
produce the jet that escapes from each of the
two apertures.

Embryo-genesis of the Simple As cidians. — In
examining under the microscope a portion of
the ovary of a recent Ascidia, eggs in all stages
of development may often be observed. In
describing the various conditions and^ modifi-
cations of the ova of this family in course of
development, we shall borrow largely from the
careful and extensive researches given to the

world by Professor Van Beneden, to whom
naturalists are so deeply indebted for much
valuable information on the subject of the em-
bryo-genesis of many of the Polypif era* and
other groups of animals. The earliest form of
the ovum is a simple vesicle; it next appears
as a vesicle with an inner vesicle, which is
evidently “the vesicle of Purkinje;” and,
thirdly, with a second, still smaller vesicle,
“ the vesicle of Wagner ;” these latter vesicles,
one within the other, being enveloped in the
outer or vitelline membrane (Jig- 781. a).

The space between the external membrane
and Purkinje’s vesicle is occupied by a sub-
stance, at first clear and probably fluid, but
soon appearing granulated, constituting the
vitellus. This yolk increases rapidly, soon oc-
cupying the whole ovum : at the periphery its
granules or cells become organised (Jig. 781.
b), uniting among themselves, and forming a
continuous sacciform membrane. The mode of
growth of the vitellus is by new cells being
formed in the interior of the large older cells,
and subsequently producing others in their
own interior. The growth of the whole ovum
is evidently carried on by this process.

The whole surface of the vitellus soon after-
wards becomes embossed, presenting a mul-
berry-like appearance ( Jig. 781. c). The ger-
minal vesicles disappear. At the centre of
each little mammilla of the surface a trans-
parent vesicle becomes distinctly visible, and
the whole appear like so many ova each with
the vesicle of Purkinje. These mammill® in-
crease, and their peripheral substance rapidly
becomes granulated, in a similar manner to
the change that took place in the w'hole vi-
tellus. The mammillated appearance is now
soon lost from the growth of the granules,
and the surface becomes uniform, the mam-
mills of the periphery uniting into a mem-
brane, which constitutes the blastoderm. Ac-
cording to Milne-Edwards, the blastoderm in
the Botryllidee is formed at a determinate point
only; but in Cynthia ampulla (the species in
which Van Beneden watched the modifica-
tions of the ovum) the latter observer feels
assured that it is formed simultaneously all
over the yolk, as in all the inferior animals.
At this period a number of vesicles become
somewhat regularly arranged over the exterior
of the ovum, which by their union with one
another form a new enveloping membrane.
Beneath this membrane a space, occupied by
fluid, soon becomes apparent. All over the
exterior of this new membrane are distributed
white, transparent vesicles, having much the
appearance of oil globules. This envelope
soon becomes more and more extended by
the increase of the contained albuminous fluid,
and a second membrane appears beneath it,
on the surface of which also oil- like globules
become apparent, as on the external mem-
brane (Jig. 781. d). The ovum is now com-
posed of an external membrane, of a white

* See Poltpifera ; also Papers by Prof. Van
Beneden on Campanularia, Tubularia, and Bryozoa,
Mem. Brux. Acad. tom. xvii. xviii. and six.

1212

TUNICATA.

fluid layer, anotherthin transparent membrane,
an organised layer forming the periphery of
the vitellus, and lastly of the soft yolk in the
centre, the vitelline membrane and the blas-
toderm forming one with the vitelline mass.

The external membrane and the albuminous
layer beneath it appear to be formed exter-
nally to the ovum by the oviduct or the ovary;
and as they envelop the ovum after its com-
plete development, they may be considered
only as accessory parts.

It being uncertain whether the ova in which
these changes take place, have been subjected
to fecundation whilst still in the ovary or ovi-
duct, there arises the interesting question as
to what extent of modification, even to the
disappearance of Purkinje’s vesicle, and the
mulberry-like condition of the vitellus, can
take place before the ovum has received the
stimulus of the seminal element.

Fig.

During the changes of the ovum in this first
period of its development, the colour of the
egg is occasionally subject to certain modifica-
tions. In Ascidia grossularia, the ova become
of a bright red colour, and in some species no
change of colour takes place. In Amaroucium ,
a compound Ascidian, the ova change from a
pale to a deep yellow.

The second period of development is
marked by the prolongation of one side of the
yolk to form the caudal appendage. The ovum
lias now a chorion, albumen, and yolk, the two
latter being separated by a fine membrane.
The vitelline or embryonic mass becomes con-
tracted about its middle, and is somewhat
bean-shaped. From this time there are ob-
servable two extremities, one lengthening it-
self, as the other becomes more and more
globular; and respectively representing the
caudal appendage and the body (Jig . 781. e).

781.

Development of Cynthia ampulla. ( After Van Benedeni)

A, ovum, with the vesicles of Purkinje and Wagner, b, the same further advanced, with surrounding
vitelline globules, c, the central vesicles have disappeared, owing to the development of the vitellus ; the
ovum presents the appearance of an agglomeration of ova, or the mulberry-like aspect, d, further
developed ovum, with double external membrane and intervening transparent liquid, e, the yolk
elongated, partially divided in the middle ; the larger portion becoming the trunk, and the narrow portion
the tail, of the larva, r, the embryo at the full term of incubation : a, anterior process ; b, eye ; c, integu-
ment. g, the same, further advanced ; the caudal portion entirely absorbed, leaving the teguiuentary

elongation empty; a, anterior process, h, the s;
present; internal organs more distinct, i, embryc
b, anal orifice ; c, eye ; d, oesophageal collar ; e, ( ?) ;
g, g, g, muscular bands.

The former of these becomes more arid more
elongated, following the outline of, and fold-
ing itself around, the body, which is included
in the ovum, as in many reptiles.

In Amaroucium, according to Milne-Ed-
wards’ observations, the tail is formed by the
marginal portion of the yolk being condensed,
at the same time that the body is flattened, and
then separated from it throughout its length.
Van Beneden, however, remarks, that in the
simple Ascidians, as we have stated above, the
tail is rather an elongation of one part of the
yolk, and that, like the exterior organs of all
other animals, it is formed by extension and
not by division or separation.

The body part of the embryo has an in-
ternal cavity, and is formed of the yolk; it is
surrounded by the membrane, which becomes
the skin of the body and tail. The caudal
appendage is hollow, and communicates with
the central cavity ; it does not in Ascidicc pre-

mie, further advanced ; superficial appendages still
nearly perfect; a, branchial orifice with tentacles;
f f ciliated circles, rudiments of respiratory organs ;

sent the spiral or zigzag cavity observed in the

Botrr/llidce.

There is soon formed within the embryo
another layer distinct from the exterior, and
which is destined to become the parietes of
the intestinal tube. There exist then two
layers, internal and external, from which all
the organs are derived. In the thickness of
the external layer, near the middle of the body,
and rather superiorly, occurs a black pigment-
cell, which Van Beneden regards as a rudi-
mentary eye. In Amaroucium, Milne-Edwards
has observed one or two blackish oculiform
points towards the posterior extremity of
the bod}'.

The chorion is now ruptured, and the larval
embryo appears with a pellucid membrane
covering its body and tail (fig. 781. f). This
membrane has been already mentioned as in-
vesting the ovum at a late stage of the first
period of its development, immediately after

TUNICATA.

1213

the vitellus lost its mulberry aspect, and
when the albumen was formed. It closely
envelopes the caudal appendage, and termi-
nates beyond it by a tapering prolongation :
subsequently it becomes the test of the ani-
mal. The larva, resembling in appearance
a frog-tadpoie, still remains a while in the
cloacal pouch, but is soon carried out by
the current leaving the animal : it is very
active, wriggling about for hours. After a
brisk locomotive existence for about twelve
hours, the embryo fixes itself to a foreign
body. The tail then begins to disappear,
being slowly absorbed; its pellucid membrane
remains entire fora little time, but is ultimately
detached from the body. At the same time
other appendages spring from the body, the
principal one of which arises from the an-
terior extremity, elongates itself more and
more, attains a trumpet-like shape, and may
be considered as the future mouth (Jig.
781. g). In Amaroucium, Milne-Edwards ob-
served generally five appendages arising from
the anterior extremity of the body, two of
which soon disappear, and the three others,
which are persistent for a while, terminate
in button-shaped, dilated suckers, touching
the parietes of the external integument. In
Cynthia ampulla other processes or appendages
occur all over the body ; these are somewhat
similar to the anterior appendage, but are
never constant, either in direction or number;
one specimen had seven appendages on one
side. Sometimes the numerous appendages
resemble tentacles, giving the embryos the
appearance of young Tubularice.

These processes are hollow, communicating
with the central cavity. None of them appear
to open externally, or to be at all like suckers;
and a considerable space frequently exists
between them and the enveloping membrane.

The young animals are attached to solid
bodies by this external tunic, on a different
side to that at which the orifices make their
appearance. “ If,” says Van Beneden, “ the
appendages served as suckers for attachment,
the animals would have the mouth on the side
by which they are attached.”

It is at this stage of growth that the walls of
the internal cavity are distinctly seen through
the external membranes. The contents of the
digestive tube are seen to consist of a rather
opaque mass, distinct from the surrounding
clear space.

As soon as the animal is fixed, the trans-
parent membrane that has remained floating
since the absorption of the caudal appendage,
is completely detached, and the integument
and the test begin to be formed.

In the third period of development the
embryo takes on the ascidian character. The
development of the internal organs progresses,
and the external orifices become apparent
(Jig. 781. h). At the commencement of this
period, the form of the young Ascidian varies
considerably. The numerous appendages dis-
appear, just as the caudal appendage was lost.
The embryo becomes rounded anil larger, and
its substance is distinctly seen to be disposed

in three layers. Up to the present time the
vitelline cavity has had no external communi-
cation, but the mucous cavity is now extended
on one side, to form the mouth. The mucous
layer is elongated also on the opposite side,
but instead of reaching the exterior, it is folded
back on itself, forming the intestinal loop.
The yolk soon opens a passage on each side,
constituting the oral or branchial, and the
ventral or anal, orifices. The intestinal tube
becomes completed by its ^separation into
the respiratory, the digestive, and the cloacal
cavities. Around each external orifice certain
nipple-like, palpiform bodies appear, which
soon lengthen, but before long they are
hidden by the integument (Jig. 781. i). The
eye-like pigmentary spot still continues for
some little time, and is situated in the middle
of a band (the oesophageal collar) that seems
to embrace the respiratory cavity. At the
base of the intestinal cavity, the opaque
concretionary body appears, to which the
heart is subsequently attached, and which Van
Beneden considers to be analogous to the
internal shell of the Limaces. This is furnished
with vibratile cilia, which occasion circulatory
currents, until the heart makes its appearance
in the form of a thin, gently pulsating, mem-
branous body. Contemporaneously with these
cilia, others appear in the interior of the bran-
chial sac, in the form of a ciliatedjjcirclet, to
which a second and afterwards others are
added, forming altogether the peculiar bran-
chial tissue. These cilia give rise to currents
in the digestive and subcutaneous cavities.
The young Ascidian can now carry on the
functions of respiration and digestion.

At the surface of the skin, and around the
anal and branchial cavities there are apparent
longitudinal striae, which are evidently the rudi-
mentary muscular bands. The sphincters, also,
at the two extremities of the intestinal tube,
are brought into action. Some slight further
modifications only are now required to perfect
the development of the little Ascidia.

Anatomy of Clavellinidje. — Clave/lina.
— At the superior extremity is the buccal
orifice, which is circular, looking directly
upwards (Jig. 768. c ), and furnished with a
very thin, prominent, cylindrical margin ; to
the interior of which is attached a ring or
circlet of simple tentacular filaments, about
thirty in number, of which about ten are
long enough to reach to the centre of the
cavity of the tube, whilst the others are
very short, and situated between the first.
Near this first orifice, and toward the supe-
rior part of the dorsal aspect of the thorax, is
the second or anal orifice, which is also cir-
cular, with an entire rim. The external
tunic or tegumentary membrane (test) of the
body is thin, but subcartilaginous. It adheres
feebly to the other parts, except around the
two orifices. At its base, or inferior extre-
mity, there are a variable number of radici-
form prolongations, which serve to fix the
animal, and some of which often bear at in-
tervals little pyriform tubercles, which be-
come developed into new individuals.

12]

TUNICATA.

The test is so transparent and colourless,
that the interior structure of the animal may
be easily studied without having recourse
to dissection. There is observable, however,
certain yellowish lines traversing the transpa-
rent test, which have a granular appearance,
and correspond, according to M. Milne-Ed-
wards, to the lines of junction of certain parts
of the interior. Two of these bands descend
vertically, very near one another, throughout
the medial line of the ventral surface of the
thorax, and are separated by a linear, colour-
less, semi-opaque space. A third line rises on
the right and left of the test, at the superior
part of the thorax, and is directed horizon-
tally backwards, describing a circle around
the base of the oral orifice. A fourth line,
also annular, encircles the inferior extremity
of the thorax. A fifth surrounds the anal ori-
fice, and is prolonged upwards and forwards,
almost to the posterior margin of the oral
orifice. There is generally a sixth line, much
paler than the others, and more deeply situ-
ated, at some distance from the dorsal surface
of the thorax, descending vertically from the
superior to the inferior ring.

Towards the middle of the abdominal por-
tion of the body the stomach appears, as a
small, orange-yellow, oval mass, bearing four
yellow vertical lines, like those of the tho-
rax. Lastly, close to the stomach, is another
orange-coloured spot, formed by a coloured
portion of the intestine, and, still lower, the
whitish gland-like mass, comprising the gene-
rative organs (fig. 768. p).

The mantle is suspended within the first
tunic ; it is membranous and extremely deli-
cate. Superiorly it is attached around the
two orifices, and inferiorly it terminates in a
cul-cle-sac. It often presents inferiorly some tu-
bular prolongations, sometimes simple, some-
times ramified ; which descend towards the
base of the animal, and sometimes project
into the interior of the root-like processes of
the external tunic. Its surface is traversed
with divers muscular .fibres, some of which
are 1 circular, and constitute the sphincters
around the mouth and anus ; whilst others, to
the number of nine or ten pairs, arise from a
kind of tendinous collar surrounding the
mouth, and descend vertically to the inferior
extremity of the abdomen. These last muscles
serve to shorten or bend the body, and it
would appear that it is by the elasticity of the
external tunic that they are lengthened again,
after having been so contracted, for there do
not appear to be any traces of transverse
muscular fibres proper to act as antagonists
to the vertical fibres.

In all the thoracic portion of the body a
third tunic is present. This, like the pre-
ceding, is membranous, and is suspended in
a kind of sac formed by the latter ; it adheres
to it by the rim of the anal orifice and along
the collar around the base of the mouth.
Inferiorly this membranous pouch is united
in its extent to the two orifices of the diges-
tive canal, where for the most part it is con-
tinuous with the wall of that tube. Its cavity

constitutes the thoracic chamber. It encloses
the branchial organs, and presents on the
dorsal side a free space, which forms a kind
of cloaca, ending at the anal orifice of the ex-
ternal tunic. Along the medio-ventral line
a vertical groove is observable, and at the point
where it adheres to the second tunic, between
the mouth and the anus, we can perceive a
minute tubercle, which is the nervous gan-
glion, This thoracic chamber exactly re-
sembles the great cavity of the Salpians, and
would scarcely differ at all, if the cloaca were
shorter, and the anal orifice more distant from
the mouth, and directed backwards.

The branchiae (fig. 768. e) exist as a large
membranous band, arising from the dorsal sur-
face of the thoracic cavity, below the gangliform
tubercle, and by its opposite extremity fixed to
the space situated between the oesophageal ori-
fice and the termination of the intestine, thus
separating the cloacal from the great pharyn-
geal or respiratory cavity ; only, in place of
presenting on each side simple striae furnished
with vibratile cilia, as in the Salpians, this
kind of vertical body bears right and left a
series of filiform appendages, directed hori-
zontally towards the ventral side of the respi-
ratory cavity, where they are fixed on each side
of the middle sulcus, and, during their passage
across, are united together by a number of
other slender vertical filaments. From this
disposition of the parts there results a kind of
trellis-work, which fills up all the pharyngeal
portion of the branchial chamber, permitting
no communication between the latter and the
cloaca, except through the meshes of its net-
work, which are bordered all around with
vibratile cilia. This complicated branchial
apparatus adheres also to the thoracic tunic
by its two extremities. The dorsal column,
which thus forms the base of the branchial
organ, and which represents the simple bran-
cilia of the Salpians, is considerably prominent
in the interior of the respiratory cavity, and
exhibits along its ventral margin a series of
ten membranous languets, which are usually
straight, and are apparently susceptible of a
kind of erection. The interior of this mem-
branous band is occupied by a large vascular
cavity, which M. Milne Edwards terms the
branchial ox dorsal sinus. The transverse little
fillets which spring therefrom are in number
about twelve pairs, and the vertical filaments
that unite the latter are nearly of the same
size : these are about thirty in a rank, and
there are thirteen ranks, viz. eleven situated
between the two transverse fillets, and two
which stretch from the first and second fillets
to the wall of the thoracic chamber, and are
fixed along the two yellow lines, placed as
rings at the two extremities of that chamber.
Some membranous processes appear also to
stretch from different points of the surface of
the branchial net-work to the walls of the
cavi'y in which the latter is suspended ; hut
these are few, and do not hinder the eggs,
deposited in the cloaca, from insinuating
themselves frequently into that portion of the
cavity situated on each side of the respiratory

TUNICATA.

1215

sac. The spaces circumscribed by the narrow
elongated meshes, supported by the vertical
filaments, and bordered with vibratile cilia,
are not occupied by a membrane, but form
openings, somewhat like a button-hole, called
branchial stigmata. These chinks or spiracles,
through which the water passes from the
branchial sac in the thoracic chamber to es-
cape outwards by the anal orifice, are conse-
quently disposed in the same manner as the
vertical filaments that circumscribe them, that
is, parallel to each other and in transverse
ranks, thirteen in number. Lastly, each of
these vertical filaments is perforated by a
canal, opening by its two extremities in other
similar but larger canals, that occupy the in-
terior of the transverse fillets. The latter
vessels in their turn empty themselves by one
of their extremities into the great dorsal or
branchial sinus, and by the opposite extremity
into the vertical fold of the ventral wall of
the thoracic chambers, which is circumscribed
by two parallel, vertical, yellow lines, and
which places the respiratory organs in relation
with the great thoracic sinus, lying between
this chamber and the ventral portion of the
internal tunic of the body. These two sinuses
communicate also one with another by the
vessels that surround the branchial orifice,
and from which spring other vessels’that de-
scend towards the abdomen.

The pharyngeal portion of the thoracic
chamber, tapestried with the branchial net-
work, opens externally at its upper extremity,
by the branchial aperture, which occupies
nearly the whole of its diameter, and is
furnished with a kind of radiating net-work of
tentacular filaments. This cavity is cylindrical,
and at its inferior extremity has a large trans-
verse slit, the opening of the (Esophagus, oppo-
site to the external oral aperture. The oeso-
phagus is large, and descends vertically into the
abdomen terminating in the stomach (Jig. 768.1),
which is ovoid and swollen. The intestine (m)
springs from the inferior extremity' of the
stomach, and at first running vertically down-
wards, and then bending forwards and upwards,
so as to form a loop, it ascends towards the
thorax by the side of the stomach and
oesophagus, slightly covering them on the right
side. Arrived at the superior part of the
abdomen, it is again bent, passes by the side
of the oesophagus, ascends rather behind the
branchial sac, and terminates at the inferior
part of the cloaca (n), at about the level of the
antepenultimate row of the branchial stigmata.
Throughout its length the intestine preserves
nearly an equal calibre, but varies in its ap-
pearance, and is divisible into three portions.

The first part, the duodenum, succeeding to
the stomach and forming the intestinal loop,
is colourless and transparent. The next por-
tion, placed on a level with the stomach, but
on the ventral side of the body, is on the
contrary of a dull-yellow colour, and the
tissue of its walls has a glandular appearance.
This M. Milne-Edwards considers to be the
hepatic portion of the alimentary canal, and
comparable to the organ known in insects as

the chylific ventricle. Lastly, in its third
portion, the intestine again becomes mem-
branous and colourless : here the fecal matter
is collected into brownish pellets, and from its
functions and position this portion of the tube
is termed the great intestine, or rectum.

To the right of the intestinal loop is placed a
glandular mass, the chief part of which is formed
by the ovary, recognised by its vesicles, and by
the eggs oi different degrees of development
contained in it. Below the ovary is the
testicle, a mass of whitish and ramifying fila-
ments, spread out in some degree on the
intestine. From this glandular mass arises a
milk-white filiform canal, which ascends be-
tween the stomach and the intestine, passes
on the left side of the cesophagus, and opens
into the cloaca, near the orifice of the rectum.
This canal contains a silvery white fluid,
crowded with spermatozoa, and must be con-
sidered as a vas deferens. There being no other
visible duct leading from the ovary, this canal
perhaps serves also as an oviduct. The eggs are
minute, circular, and of a greenish yellow colour.

The heart is situated at the inferior part of
the abdomen, lying against the intestine and
the ovary, to the right and in front of the
former, at the posterior part of the cavity
of the mantle, between the tunic and the
intestine, and much resembles that of Ascidia
intestinalis. It is enclosed in a membranous
sac or pericardium, and is cylindrical in form ;
its superior extremity is on a level with the
centre of the stomach, and its lower ex-
tremity, turned up a little behind, passes some-
times a little beyond the intestinal loop.

The Perophora, first described by M.
Lister in Phil. Transact. 1834, p. 378., as a
“ small Ascidia,” is parasitic on Confervas, &c.,
and appears to the eye like minute lumps of
pellucid jelly, with a spot of orange and grey.
The group consists of several individuals,
each having its own circulatory', respiratory,
and digestive systems, but fixed on a pedicle
that branches from a common creeping stem,
and all are connected by a circulation that
extends throughout. They are very trans-
parent, and their interior is easily seen. The
two orifices are very short tubes ; the bran-
chial is at the summit, and the anal is a little
lower down. The longest diameter from the
peduncle to the space between the openings is
about *085 inch (see fig. 306. a and b, p. 623.
Vol. I. Cilici). The test is subcartilaginous
and tough, more pliable near the orifices. It is
lined internally with the soft mantle, in which
a ramifying circulation is very distinct. A
great part of the interior is occupied by the
branchial sac, which is subcylindrical, flattened
at the sides, and has its axis vertical. It is
united to the mantle above and behind ; the
juncture, beginning in front of the oral open-
ing, extends backwards on each side of it,
and then downwards in two lines ; between
these, along the middle of the back, is a
vertical compound stripe. At the bottom, the
branchial sac appears to be in contact with
the mantle, but at its sides and front a vacant
space is left between them, communicating

1210

TUNICATA.

with the anal orifice (see Jig. 306. is,/ loc. cit.).
The sac is more compressed towards its lower
part ; and here are placed, externally to it,
the heart on the left, and the stomach and
the other viscera on the right side, the anus
opening upwards into the cloaca. On its sides
and front the sac is perforated by four rows
of narrow, vertical, irregularly oval holes or
spiracles, about sixteen in each row, placed at
less than the diameter of one of them apart
from each other. Through these the water,
which flows constantly in at the mouth when
its orifice is open, is apparently conveyed to the
vacant space between the sac and the mantle,
and it then escapes by the anal orifice. The
branchial tissue is extremely thin between the
stigmata, but their edges are thickened, and are
lined with closely set cilia, which by their
motion cause the current of water. When
these are in full activity, the effect upon the
eye is that of delicately toothed, oval wheels,
revolving continually in a direction ascending
on the right and descending on the left of
each oval, as viewed from without ; but the
cilia themselves are very much closer than
the apparent teeth, and the illusion seems to
be caused by a fanning motion made by them
in regular and quick succession, producing
the appearance of waves, and each wave an-
swering to the apparent tooth. The spaces
between the rows of spiracles are of much
more substance than the intervals between
the spiracles in a row ; filamentous processes
are stretched from them across the side cavi-
ties, attaching the branchial sac to the mantle :
these spaces also support finger-like processes,
about eight in a row, that project nearly at
right angles into the central cavity.

The large short tubes of the branchial and
anal orifices have each five or six obscure
marginal indentations, and can be drawn in and
closed at the will of the animal. Within and
at the bottom of the branchial tube are nu-
merous, simple, tentacularfilaments of different
lengths. The particles drawn into the bran-
chial sac by the current of water are seldom
stopped by these tentacles, but lodge some-
where on the branchial net-work. A lively
animalcule will sometimes disengage himself
by struggling, and dart about in the cavity
until he lodges on some other part ; or if a
morsel is found unsuitable, it is ejected by
the funnel’s being closed, and the branchial
sac suddenly contracted vertically. Mostly,
however, whatever part the food lodges on,
it travels from thence horizontally with a
steady slow course towards the front of the
cavity, where it reaches a downward stream
of similar materials ; and they proceed to-
gether, receiving accessions from both sides,
and enter at last, at the bottom, the oesopha-
gus; which is a small flattened tube, carrying
them, without any effort of swallowing, towards
the stomach : the oesophagus takes a sharp
curve upwards and backwards before arriving
there. “ It is extraordinary,” observes Mr. Lis-
ter, “ that the particles pass along so near to the
spiracles, with their cilia in full activity, with-
out being at all affected by them.” “ I have,

says he, “ in some positions, seemed to catch
a glimpse of a membrane suspended within,
too transparent to be commonly seen. One
may imagine the water to pass to the spiracles
strained through the meshes of such a mem-
brane, and the food to be carried along it by
invisible villi ; but this is mere conjecture.”

The stomach runs backward horizontally.
When seen from the side, its anterior portion
has an inflated appearance, and, when from
below, it seems to possess two lateral lobes.
The liver has an ochreous tint, and envelopes
the anterior portion of the stomach. The in-
testine on leaving the stomach rises, and then
bends forward with a sigmoid flexure, and ter-
minates in an ascending rectum and sphincter.

Transparent vessels ramify along a part of
the intestine, and meet at a collection of
globular bodies, from whence, in one indivi-
dual, two flattish lobes were observed to
extend backwards. These globular and lobate
bodies probably constitute the generative organs.
From the meeting of the above-mentioned
vessels two branches run ; one downwards
and backwards, but under the stomach, the
other forwards. From their direction Mr. Lis-
ter supposed them to communicate with a main
stream of blood near the heart.

The circulation in these animals is very
interesting, and easily discerned through their
transparent tissues. The blood circulating in
one individual of the group descends by the
peduncle into the common root-like stem, and
penetrates into the next member of the group,
so that there exists in these Ascidians a com-
mon circulation, having as many centres and
motive organs as there are animals growing
on the same stem. The blood-globules are
very numerous, and though not uniform in
size or shape, are mostly between -00025 and
'0002 inch in diameter, and approaching to
globular. They are easily measured, as in the
intervals between the stigmata they pass mostly
but one at a time. The creeping tube, which
unites the individuals of a group, contains two
channels for two separate currents of blood, an
upward and a downward one, that are flowing
at the same time, and that send off each a
branch to every peduncle. The blood then
passes into the animal by one current, while
another carries it back. One of these canals
communicates, at the termination of the
peduncle, with the heart, which is placed, as
before mentioned, near the bottom of the
branchial sac on the left side, and consists of
a transparent ventricle or tube, running for-
ward and a little downward, in a channel |
hollowed to contain it. Along the whole
length of this tube, a part on one side of its
axis seems fixed to the channel, the rest is
free and contractile. Mr. Lister observed that
when the blood entered the heart from the
peduncle, contraction began at the middle of
the ventricle, impelling onward the contents ;
of the forepart ; and the contraction of the
back part followed in the same direction, so
as for the whole to have the effect of one
pulsation. The heart was then filled again
by a flow from the peduncle. The intervals

TUNICATA. 12] 7

of the pulse were pretty regular in the same
individual ; but in different ones they varied
from two seconds to one and a half second.
Part of the blood thus impelled formed a main
upward stream along the front of the branchial
organ, branching off’ at each of the horizontal
passages between the rows of spiracles, and
traversing the space above them on a line with
the junction of the branchial sac and the mantle
on each side. All these streams again united,
and formed a downward current behind. The
horizontal vessels were connected also by the
smaller vertical channels between the spiracles ;
the set of the current in the latter being up-
wards for the two lower rows, and downwards
for the two upper rows.

Another large portion of the blood, on
leaving the heart, immediately divided into
many ramifications, that spread like a net-work
over the stomach and intestines, and over the
mantle. Of these, a part ran into the hori-
zontal passages above the branchial sac, a part
into the descending dorsal vessel. A large
proportion, after leaving the intestines, took a
short course, and collecting into one channel,
flowed into the dorsal vessel near the bottom,
and all, united, then entered the peduncle,
and constituted the returning current that
went to circulate in other animals of the group.
After this circulation had gone on for a while,
the pulsations became fainter for a few beats,
and the flow slower, and suddenly, with but
slight pause, the whole current was reversed,
the heart gave the opposite impulse. The
vessel in the peduncle that before poured in
the blood, now carried it back, and the other
channel the contrai’y, and every artery became
a vein. These changes continued to succeed
each other alternately'. The average time of
the currents being the same in both directions,
but the period of each varying within a single
observation as much as from thirty seconds to
two minutes. Mr. Lister points out the ana-
logy between this phenomenon and the very
similar circulation that obtains in the stem of
the Sertularia, described by him in the same
volume of the Philosophical Transactions.
This acute observer goes on to say', that some-
times, when the creeping tube, or the peduncle,
has been injured, the circulation of an indi-
vidual is in consequence insulated, but without
appearing to impair any of its functions. In
one animal which was severed from the pe-
duncle, the pulsation ceased for a few seconds.
It then began irregularly, and with consider-
able pauses, inci'easing in steadiness as it went
on. At first the impulse given by the heai't
was towards the front ; and the downward
back stream, instead of flowing out at the
wound, was poured into the hinder end of the
venti’icle ; the cut end of the vessel leading
from the heart being neai’ly opposed to the
bleeding dorsal vessel cut through at the same
place, and the two vessels, in their undisturbed
state, lying aci'oss each other at this point.
But when the current was reversed, part of
the blood was driven for a time through the
stump of the peduncle into the water; how-
ever, it soon staunched, and all the vital

VOL. IV,

actions went on as befoi'e the separation, ex-
cept that at the beginning of every pulsation
there was a slight recoil.

In one case, wrhere the circulation did not
extend to another animal, one channel only
was observed to be open in the peduncle, and
in this a small curi'ent ran to and fro accord-
ing to the direction of the impulse given by the
heart. Some animals, which had probably
been injui'ed, but were still connected with
other vigorous ones, seemed to be in course
of absorption. One wras observed in which
the soft parts were so shrunk as to occupy a
small part only of the tunic. The cui'rents of
its peduncle extended into this mass, but no
heart or motion of branchiae was visible.
Upon looking at the same the next day, the
tunic was empty, the soft matter and the cir-
culation reaching only to the end of the pe-
duncle. Mr. Lister also once noticed a flux
and reflux of the blood in a creeping stem,
whei'e the current did not communicate with
any animal. In the buds sprouting from the
stem, and destined to become new animals,
the two streams of the stem run through the
germ before its organs are developed.

The generation of the Clavellinidce takes
place in two ways — by ova and by buds. The
genesis of the larvae of Clavellina from the ova
is vei'y similar to that of the larval Ascidice.
The young of Perophora have not yet been
observed. The method of the gemmipai'ous
repi’oduction, accoi’ding to the observations
of Milne-Edwards, is as follows : Amongst
the radiciform processes springing from the
base of the test of Clavellina, and tending to
preserve the animal in its position, are other
filamentous pi’olongations which are hollow,
and enclose a membranous tube, continuous
with the internal tunic of the animal, and
through which the circulation seen in the in-
terior of the abdomen is also continued. This
stolon-like body is closed at the fi'ee extrem-
ity ; it is at first simple, but as it lengthens,
it becomes ramified ; and when its growth is
further advanced, there ai-e developed on the
extremities of its branches, and even at dif-
ferent points along its length, tubercles, en-
closing in their interior a minute oi'ganic
mass connected with the interior tube. These
tubercles l’ise vertically, and become elongate
and claviform. The blood that circulates in
the stem at first penetrates into the soft, pear-
shaped, pedunculated mass occupying each of
the tubercles ; but after a while these little
germ-masses lose their peduncle and their at-
tachment to the internal tunic of the principal
canal, and participate no more in the circula-
tion of the mother-animal. By further de-
velopment they soon put on the ascidian
character. The branchial sac is perfectly' dis-
tinct, although not yet communicating with
the extei'ior ; and the digestive tube bent
loop-wise, below the thoi-ax, is plainly discern-
ible. Lastly, the oral orifice appeal's, and the
general form of the young animal approaches
more and more that of the adult. From this
a new individual is then in like manner pro-
duced by stolon and bud, remaining attached

4 i

1218 TUNICATA.

to the mother by the former, and which at
first has a circulation in common with the
older animal, but soon enjoys an independent
existence. The individuals either remain at-
tached by the intermediate root-like prolonga-
tions, or become separate by the disunion of
these slender filaments.

In one species of Clavellina, the bud-like
bodies and young animals are produced not
only on the root-like stolons, but also on the
walls of the test itself {fig- 768. u, ur).

In Perophora the growth of the buds is con-
fined to the extremity of the creeping, root-
like tube, and the attachment of the indi-
viduals by the common root-stem is perma-
nent through life, and not merely existent
during the young state.

Anatomy of the BoTRYLLiDiE. — A de-
scription of the form and structure of the test
of these compound Ascidians has been already
given. The in- and out-lets of the aggregated
individuals, as we have already seen, have
either separate external openings, or the several
vents of a “ system ” of animals unite to form
one large common cloaca and external anal
orifice.

All these external orifices are more or less
irritable and contractile. When the little
animals dilate their branchial orifice, a part of
their body is raised so as to slightly emboss
the general surface of the mass, and they pro-
trude a membranous circlet or ring, the free
border of which is cut into, generally six, regu-
lar lobes, but sometimes into eight. In Poly-
clinum, the mouth is very contractile, and is
surrounded by six little digitiform processes.
Parascidia has eight of these tentaculiform
bodies. Frequently, after death, as in Lepto-
clinum, these orifices contract, and their bor-
ders sink in so as to be discerned with diffi-
culty. In the interior of this orifice, and
towards the base of the collar, a series of
minute tentacular filaments can be perceived
by the aid of a lens, which are directed, like the
spokes of a wheel, towards the centre of the
opening, or have a more or less curled ap-
pearance, in a similar manner to the tentacles
occupying the same position in the simple
Ascidians and in the Clavellinidcs. The ten-
tacles vary from four to twelve or more, but
nine or ten is their usual number ; they differ
materially in length, some being nearly ru-
dimentary, whilst others, alternating with the
first, are long enough to meet across the open-
ing. In Amaroucium Nordmanni there are six
long and six short tentacles within the bran-
chial tube. In Botryllus smaragdus, in which
the buccal orifice admits of considerable dila-
tation, a circlet of four longish filiform ten-
tacles may be seen. The tentacles in B.
aureus are more numerous than usual, but
both in this species and in B. violaceus they
are almost rudimentary. Diazona has fifteen
or sixteen simple tentacles, and in Sigillina
there are twelve.

Around the base of the denticulated rim of
the branchial orifice in Amaroucium argus
{fig. 782.) there are seen four minute pinkish
spots, which are probably rudimentary organs of

sight. Similar, but more numerous, pigment-
spots are observed in Leptoclinum Listen, Pa-
rascidia, and other genera.

Fig. 782.

Anatomy of Amaroucium argus. {After Milne-

Edwards.) An isolated individual considerably

magnified.

a, thorax ; b, superior abdomen ; c, post-abdomen ;
a, proper tunic of the individual ; b, thoracic tunic ;
V, longitudinal muscular fibres of the inner tunic;
c, branchial orifice ; d, branchial collar, below which
are seen the oculiform points ; e, branchial sac ;
f thoracic sinus ; f, transverse vessels of the bran-
chial sac ; h, cloaca ; i, anal orifice ; i', and appendage
or languet ; j, nerve-ganglion ; h, oesophagus ; l,
stomach ; m, intestine ; n, anus, opening into the
cloaca ; o, heart ; o', pericardium ; p, ovary ; p', p",
ova, passing towards the cloaca ; q, testicle ; r, r>,
vas deferens, and its opening in the cloaca.

The separate anal orifices are frequently
destitute of the crenulated or denticulated
margin that surrounds the branchial tube.
This condition has afforded a distinguishing
character for some of the minor groups in
Milne Edwards’ classification of the Bo-
iryllidce. In Polyclinum, Amaroucium, Bo-
tryllus, and other genera, the anus, instead of
opening directly outwards, empties itself into
a common cloacal cavity, that belongs to a
number of individuals, and is in the form of
a large canal hollowed out of the common
tegumentary mass. This is frequently rami-
fied interiorly, as in Botrylloides, and termi-
nates at the opposite extremity by a simple

TUNICATA.

1219

excretory orifice, not occupying the centre of
the “ system,” hut placed nearly at one of the
extremities, and communicating with the in-
dividuals situated at the other end of the
group by means of the interior canal.

In Amaroucium the fecal or anal orifices,
by which the common cloacae open externally,
are wide open during life, and easily per-
ceived ; their form is round and their border
thick ; but after death they contract, and are
so much sunk in that they are demonstrated
with difficulty.

The anal orifice in some genera is sur-
mounted by a membranous languet, either
simple or trifid (Jig. 783. i').

Fig. 783.

Anatomy of Botrylloides rotifera. ( After Jtlilne-

Edwards .) Lateral view of an isolated individual

magnified.

c, branchial orifice; e, branchial stigmata; f
thoracic sinus ; A, cloaca ; i, anal orifice ; i’, supra-
anal languet; j, nerve-ganglion; A, oesophagus,
1, stomach; m, first portion of intestine, or duo-
denum ; m>, second portion, or chylific ventricle ;
r/t", third portion, or rectum ; n, anus, opening into
the cloaca ; q, testicle ; r, vas deferens ; t, radiciform
appendage, or proliferous stolon; t’, reproductive
germs; x, liver (?) ; x', its excretory duct.

In pointing out the natural groups of the
associated Ascidians we have spoken of the
division of the body into distinct portions,
as the thorax, and super- and post-abdomen
in Amaroucium (Jig. 782.), and in Polyclinum ,
where they correspond to the three vertical
chambers of the animal's cell ; and into the
thorax and abdomen in Didemnum. The
latter arrangement resembles that of the Cla-
vellince ; but in the Botryllians, on the other
hand, no distinct separation is observable, the
viscera being pushed up by the side of the
branchial sac, as in the Perophorce and the
simple Ascidians (Jig. 783.). The thorax is
generally more or less cylindrical, sometimes
hemispherical (Jig. 769.) or subglobose, and
■contains the branchial organs. In Botryllus

violaceus there are two little glandular tuber-
cles, one on the right and one on the left of
the buccal orifice, and situated at a nearly
equal distance from the superior extremity of
the ventral sinus and the dorsal nucleus or
nerve-ganglion.

The branchial sac of the Botryllidce is very
similar to that of the Claveltinidce. The bran-
chial spiracles, or intervascular spaces, are
variable in number, and the crest or fold cor-
responding to the anterior border of the
branchial sinus has no membranous languet ;
but in Diazona, Synoicum, and Polyclinum it
bears a row of minute tentacular filaments.
The branchial sac of Sigi/lina has 4 large,
salient, transverse vessels on each side, united
by 15 or 16 smaller longitudinal vessels ;
and in Aplidium there are 10 to 12 trans-
verse branchial vessels. Polyclinum has 14
transverse branchial vessels anastomosing with
15 to 18 finer longitudinal vessels. In Ama-
roucium there are 10 to 12 rows of stigmata,
and in Polyclinum 13 rows. Didemnum and
Leptoclinum have 5 rows. In Botrylloides
the respiratory sac presents 10 vertical rows
of spiracles, parcelled into threes by vertical
folds. There are 9 of these chink-like open-
ings on each lateral rank, and at each of their
four angles is a little tubercle. In Botryllus
the respiratory sac lies almost horizontally,
and has on each side 9 transverse rows of
stigmata, grouped into threes by the longi-
tudinal folds. The angles of the branchial
net-work are marked with papillae in Distoma
and Diazona.

Instead of papillae on the spaces between
the branchial meshes, Leptoclinum Listen has
a thin ledge between each row of spiracles ;
and in front there are three tapering moveable
prominences, one connected with each ledge,
either stretched forward horizontally into the
cavity, or bent downwards with a spiral curve.
These laminae, observes Mr. Lister, seemed to
suspend a generally invisible vertical mem-
brane, and to assist in giving the food its
direction towards the stomach ; for it moved
horizontally along the sides of the cavity, as
in Perophora, and when it reached the front,
took a spiral motion downwards. When the
branchial sac of the Leptoclinum contracted
forcibly to reject what had been stopped by
the tentacles, or found unfit for food, the oral
orifice, instead of projecting, was then drawn
down below the level of the external test,
and depressed it, the cilia being also closely
stretched across the openings of the spiracles.
When the cilia were thus stopped in their
action, they were seen to be very numerous,
and being in close contiguity one with another,
the neighbours by their sides, and the oppo-
sites by their ends, appeared almost as a con-
tinuous membrane.

The superior abdomen of the Polyclina
contains the digestive apparatus, and the post-
abdomen the organs of generation and the
heart. The intestines of the Botryllidce are
always subject to one or more foldings, and
their several portions are frequently distin-
guished by different tints of colour.

4 i 2

1220

TUNICATA.

The superior abdomen in Amaroucium is
short and rounded, and slightly separated from
the thorax. The oesophagus is very short ;
the stomach in A. proVfcrum is marked ex-
ternally with a series of vertical folds, the
edges of which, seen under the microscope,
are furnished with secretory follicles. In A.
argns, the exterior of the stomach is coated
with a tessellated series of irregularly hexa-
gonal, gland-like, bodies, having the appear-
ance of a number of minute honeycomb com-
partments, around each of which are radiating
lamellae or folds. In Sidnyum the stomach
is also surrounded with glands ; and in this
genus the intestine is spirally folded. In
JJiazona the stomach is striated externally;
its inner surface is provided with numerous
salient folioles ; and the pyloric entrance is
guarded with an annular fold or valvule. The
intestine in its first part is simply membran-
ous, but afterwards it is furnished with irre-
gularly disposed glands, which have the form
of caeca! tubes. The stomach of Sigillina
bears some slight ridges on its inner surface,
the strongest of which correspond to external
furrows. In Aplidium the stomach is some-
what oblong and truncate, and is divided by
deep plications into three longitudinal cavities,
or rather into five, the lateral ones being sub-
divided. The intestine is bent sometimes
forward and sometimes backward ; in the
latter case it passes upward obliquely on the
right side of the stomach ; the rectum is
sometimes spirally arranged, and sometimes
straight. In Polyclinum also the intestine is
spirally folded, obliquely traversing the left
side towards the anal orifice. In A. proli-
ferum and A. argus the rectum ascends to
the middle of the cloaca. The post-abdo-
men is elongated, narrow, and tapering,
divided from the digestive cavity by a marked
constriction. The ovary occupies nearly the
whole length of this cavity (fig. 782. p),
and is partially surrounded by the glandular
mass of the testicle, from which latter an
undulatory vas deferens runs upwards to
end in the cloaca near the termination of
the rectum. The ova are whitish, yellow,
or brown, and on escaping from the ovary
appear to pass to the cloaca by the vacant
space between the intestines and the interior
of the mantle. The heart is a tubular vesicle,
bent on itself, and situated at the inferior
apex of the ovary.

In the Didemnians the digestive, generative,
and circulatory organs are grouped together
in the pedunculated abdomen, and offer no-
thing remarkable. The ovary is situated by
the side of the intestine, and protrudes down-
wards only when full of eggs, which in this
case have, when fully developed, a large size,
compared with that of the animals. The
mantle of the Didemnum, as in many other
Botryllidce, is frequently produced in the ab-
dominal region into stolon-like processes,
which traverse the common test. These swell
at their extremities into reproductive buds,
from whence arise new animals. Of these proli-
ferous tubes we shall have to speak hereafter.

The stomach of Botrylloides rotifcra(fg. 78.3.)
is pyriform and divided into seven or eight lobes
by furrows that pass horizontally from the car-
diac to the pyloric extremity. The intestine
is sigmoid, and is divisible into three portions;
the first part is smooth and transparent, the
second is surrounded with a granular tissue,
and the third is membranous like the first.
A glandular mass, apparently the hepatic
organ, is situated at the commencement of the
third portion of the intestine, and gives rise to
many minute excretory ducts that soon unite
into a single trunk, which appears to empty
itself into the intestine near the pylorus. Be-
low this organ and more behind, is another
glandular mass, which apparently belongs to the
generative organs, and gives origin to a little
duct passing upwards to the cloaca. The
heart is situated laterally, reposing on the
cardiac side of the stomach. In B. rubrum
the ovary is double, one part being situated
on either side of the thoracic chamber. The
testicle is seldom very distinct in the Didem-
nina and Botryllina, but has been occasionally
observed.

The nerve-ganglion between the two orifices,
or rather on the dorsal side of the buccal
orifice, is generally more or less distinct in

the Botryllidce.

The circulation of the Botryllida; does not
materially differ from that of the other Asci-
dians, and has the same peculiar periodical
change in the direction of the blood-currents.
In the Polyclinina the heart is placed quite at
the inferior extremity of the post-abdomen.
It is invested with a thin, transparent pericar-
dium, and has the form of a large contractile
tube, bent on itself, and tapering at the ex-
tremities. In the Didemnina the heart is
shorter, and instead of being situated beneath
the ovary, it is lodged with that organ, by the
side of the intestinal loop, this condition
approaching that existing in the Clavellinidce .
Lastly, in the Botryllina, it ascends still higher,
being seated near the stomach, nearly at the
base of the branchial sac. Milne-Edwards,
to whom we are indebted for the preceding
facts, remarks that these different positions of
the heart always coincide with analogous
changes in the position of the ovarium. It is
also the same, says he, in the simple Asci-
dians ; and Cuvier was, without sufficient
reasons, led to consider that the heart fol-
lowed in its position that of the mouth.

If, says M. Edwards, we separate from the
common test of any of the Polyclinian species
a lively individual, and place it under the mi-
croscope with a little sea-water, the move-
ments of the heart may be easily studied.
The heart’s contractions succeed each other
somewhat regularly, but they are not brisk
and extending at once through the organ, as
in the generality of animals. The contraction
commences at one of its extremities, and the
narrowing of the tube is propagated in an
undulatory manner towards the opposite ex-
tremity, in a manner somewhat similar to the
peristaltic movements of the intestines in the
higher animals. For some time the contrac-

TUNICATA.

1221

tions follow each other somewhat rapidly, and
have all the same direction ; but suddenly they
are arrested, and then recommence in a con-
trary direction. The blood thus sent sometimes
from behind forwards, and sometimes vice
versa, ascends towards the thorax ; but does
not appear to be conducted thither by vessels.
It is poured out between the inner tunic of the
abdomen and the viscera lodged in that cavity ;
and here it forms currents, which vary in their
position according as the movements of the
animal, or any other mechanical causes, op-
pose their passage. In general, however, the
chief portion of the blood ascends by the
dorsal or the ventral surface of the abdomen ;
and after having bathed the surface of the
viscera, it gains the base of the branchial sac.
When the heart’s contraction is from behind
forward, the ascending current passes along
the anterior side of the abdomen, and the
blood enters a large vertical canal, on the
front of the respiratory cavity, termed by
Milne-Ed wards the great thoracic or ventral
sinus. This median sinus gives rise on each
side to a series of large transverse vessels,
which intercommunicate by means of a num-
ber of minute vertical vessels, and which,
after having formed a kind of vascular net-
work, spread over the walls of the branchial
cavity, and terminate in another vertical canal
parallel to the ventral sinus, but situated on
the opposite side of the thorax. A portion
of the blood arrives at the same time in this
dorsal sinus without having traversed the
branchial net-work, by means of a vessel that
arises from the superior extremity of the great
ventral sinus and surrounds the base of the
branchial orifice. Lastly the blood spreads
out between the viscera and the internal tunic
of the body, descends along the dorsal side of
the abdomen, and again reaches the heart.
If the circulation were constant in the above
direction, it would somewhat resemble that of
the other Acephalans. The heart might then
be compared to an aortic ventricle, the tho-
racic sinus to a great branchial artery, and the
dorsal sinus to a branchial vein. But owing
to the contrary directions of the blood-cur-
rents, from the periodically varying impulses
of the heart, the vessels that fulfil at one
time the functions of veins, at another become
arteries, and vice versa.

This peculiar extra-vascular circulation, so
well described by Milne-Edwards, is also very
distinctly seen in the Clavellince. The learned
professor especially notices C. nana as highly
illustrative of this phenomenon, the inter-
abdominal space being in this case very large,
and the currents of the nutritive fluid, with
its suspended spherical globules, being easily
discernible through the transparent integu-
ments.

Mr. Bowerbank has favoured me with an
account of some observations made by him on
the circulation in the common tegumentary
mass of Botry/lus. Under the microscope,
the more transparent portion of the test ex-
hibited a reticulated arrangement of sangui-
ferous channels or vessels ; perhaps the true

“ marginal vessels ” of Savigny ; each mesh,
formed by the anastomosing currents, being
occupied by one of the star-like “ systems ” of
animals. No communication could be traced
between the circulation and that of the ani-
mals themselves ; the former appearing to be
analogous to the peculiar stem-circulation of
the polypifera, to which also the circulation of
the nutrient fluid in the budless stems of
Perophora, noticed by Mr. Lister, vide supra ,
has reference.

Embryogenesis of the Botryllidce. — Tn the de-
velopment of the ova of the compound Asci-
dians, there are certain striking differences from
the conditions that take place during the em-
bryo-genesis of the Ascidiadee. These, however,
are chiefly confined to the composition of the
egg, the formation of the Blastoderm, the mode
of growth of the caudal appendage, the organs
of vision, and the anterior appendages. From
the elaborate observations of this family,
given by Professor Milne-Edwards in his
Paper before referred to *, it appears that
the ova of several species of the Polyclinina
are, whilst still enclosed in the ovary, and
before that their development is much ad-
vanced, of an ellipsoid form, and are com-
posed of a very thin external membrane, a
subgelatinous whitish and granular inner mass,
and a minute central vesicle filled with a
watery fluid. The internal vesicle is the
vesicle of Purkinje, or the proligerous vesicle ;
the granular substance surrounding the ve-
sicle is the imperfect vitellus, the vitelline
membrane being the external envelope.

Whilst these ova are still enclosed in the
upper part of the post-abdomen, they grow
rapidly and become spherical. But the most
remarkable change that takes place consists
in the colour of the vitellus, which is at first
a pale, and afterwards a deep yellow. The
vesicle of Purkinje is still visible at the com-
mencement of this period of the development,
but it soon disappears, and there then appears
on the surface of the vitellus a nebulose spot
of pale yellow, which appears to be the blasto-
derm or proligerous layer destined to become
the embryo of the young Ascidian.

The ova arrive in the cloaca, and sometimes
are even lodged in the lateral portions of the
thoracic chamber, without having undergone
any other appreciable modification. M. Milne-
Edwards considers it probable that the fecun-
dation of the ova takes place in the interior
of this cavity. They are here brought into
contact with the spermatozoa, and very shortly
after having arrived here, they exhibit evi-
dences of active internal changes.

The granules composing the vitelline mass
become grouped into clusters, forming them-
selves, as it were, into balls, and giving the
surface an embossed or mulberry- like aspect.
At the same time there is formed between the
yolk and the external membrane of the ovum,
a gelatinous, transparent, and nearly colourless
layer, which apparently becomes the external
tunic or test of the young animal.

* Observations sur les Ascidies compose'es.

4 i 3

1222

TUNICATA.

When the ova, lodged in the marsupial
pouch or cloaca, have arrived at a rather more
advanced period of their development, the vi-
tellus loses the mulberry appearance it had
but lately put on, and, if compressed between
two slips of glass, it is seen to be wholly com-
posed of minute globules or granules of dif-
ferent sizes. The ovum is soon a little flat-
tened, and the yolk appears to be concentrated

Fig.

towards the middle, forming an ovoid mass of
a deep yellow colour, surrounded by a some-
what large border of a clearer tint. This mar-
ginal portion of the yolk is condensed in its
turn, and although at first sight appearing to
constitute a sort of ring, becomes along taper-
ing prolongation, which encircles the central
part of the yolk, adhering by its base, and
having its pointed extremity free (Jig. 784. a).
784.

Tiie Development of the Larva of Amaroucium proliferum. ( After Milne- Edwards.')

A. An ovum the incubation of winch is far advanced, magnified about 30 times. The tail, (fit) is becoming
distinct from the trunk (b) ; and two lobules begin to appear on the anterior extremity of the iatter ( b" ).

B. An ovum arrived at the full term of incubation, magnified about 30 times, a, the tegumentary portion ;
V, caudal portion ; b", b anterior appendages.

c. Larval ascidia lately born, magnified about 25 times, a, tegumentary portion ; b, sac enclosing the yolk
and forming the proper tunic of the body of the larva ; b", processes terminating in suckers, and serving
to fix the animal ; a, tail formed by a prolongation of the integuments, and enclosing a tubular ap-
pendage of the vitelline sac.

i>. The same larva, observed some hours after having fixed itself, magnified about 20 times, b", traces of the
anterior processes ; b1, vitelline prolongation of tail nearly absorbed, and the central sac, enclosing vi-
tellus, is spherically contracted.

E. The same larva about 20 hours after fixing, magnified about 25 times. The caudal elongation of the
internal tunic (containing the vitelline matter) has entirely disappeared, and this tunic ( b ) has taken
the form of an ovoid sac, slightly contracted in the middle ; a pale yellow circle ( d ) at the anterior ex-
tremity surrounds a spot that will become the mouth, and posteriorly another, clear, spot (c) appears,
in which the heart will be developed.

F. The same larva seen at the end of the second day of its sedentary state, magnified about 25 times, b, tunic
proper; c, pericardium spot ; e, branchial sac, beginning to be developed;^ thoracic sinus; g, cloaca;
l, stomach ; m, intestine, full of fecal matter ; a, vestige of tail, of which a part only is figured. The
external orifices are not yet formed. The development of this individual was much more rapid than
usually is the case.

G. Another individual, about 8 days old, magnified. Animal completely reversed in the interior of the
tegumentary envelope ; d, oral orifice ; i, anal orifice ; I, stomach ; m, intestine ; o, heart.

h. Individual about 20 days old, magnified (lying with its anterior extremity to the right), a, tegu-
mentary envelope ; m, fecal matter in the intestine.

In the course of incubation, the ovum in-
creases in size, becoming flatter and more
oval. The vitelline mass becomes more com-
pact, and its surface denser; and the latter
seems to be organised into a membrane, dis-
tinct from the yolk beneath. The two por-
tions of the ovum, before described, become
more and more separate; that which occupies
the centre of the ovum becomes ovoid, and
knotty at one of its extremities; near the other
extremity, which is continuous with the mar-
ginal portion, are seen one or two blackish
minute points. This ring-like portion is now
seen to be a caudal prolongation, too short
completely to encircle the central part, from

which also it is distinctly divided a little in
front. Lastly, the whitish substance sur-
rounding the vitellus, and constituting the
tegumentary mass, increases considerably in
thickness.

When the ova more nearly approach ma-
turity, the tail-part of the vitellus is shortened,
and its central part, or body of the embryo, is
more and more condensed. Its anterior ex-
tremity becomes lobulated and encircled with
a series of five cylindrical processes, which have
a divergent arrangement, and advance towards
the border of the egg. Three of these ap-
pendages terminate in a kind of button, and
the intervening two are tapering anteriorly.

TUNICATA.

1223

At each side of the base of the group of ten-
tacles, a little prominent lobular process is
present. Lastly, the side of the body, opposite
to that on which the tail is placed, becomes
somewhat strongly embossed near its pos-
terior extremity, and towards the space where
the above-mentioned black points occur {Jig.
784. b).

The ovum ready for exclusion differs ap-
parently little from the foregoing state. The
two anterior styliform appendages have almost
entirely disappeared, and the three obtuse
processes are further developed. The trunk
is contracted towards its anterior extremity,
and the yolk-mass still further condensed at
the centre of the ovum.

The external membrane of the ovum becomes
excessively thin, and then breaks and allows
the embryo to escape. Generally this ex-
clusion takes place in the interior of the cloaca,
but sometimes not until the ova have passed
out by the anal orifice. However that may
be, the young animal, free from its envelopes,
soon extends its tail, and swims in the ambient
fluid by the aid of its undulatory movements.
In its general form the young Ascidian re-
sembles somewhat that of a newl}7 born tad-
pole {Jig. 784. c) ; but it still more resembles a
Cercaria. The trunk or body of the larval Poly-
clinuvi is oval and rather depressed. The
whitish tissue of the future integument occupies
all the surface, and is considerably developed
at the margins ; its substance is granular and
apparently subgelatinous ; its consistence is
greatest at the surface; and it does not appear
to possess a membranous investment. To-
wards the centre of the trunk is a large ellip-
tical membranous sac, the internal tunic of
Milne-Edwards ; this is filled with the yellow
substance of the vitellus, and is continuous
anteriorly with the three tubes dilated at the
end, and terminating at the anterior wall of
the egg in a sort of sucker. By means of
gentle graduated pressure, some of the yolk
may be easily made to pass from the principal
sac into these appendages, and vice versa ; the
little capsule, also, terminating each of these
appendages can be made to protrude exter-
nally by the same means. At the base of these
three processes the vestiges of the others
formerly occupying the intervening spaces may
be observed. The yellow substance contained
in the internal tunic appears to be separated
into two portions ; the one is clear, and situated
near the wall of this sac, and the other, denser
and of a deeper tint, occupies the centre. Pos-
teriorly a little marginal space, clearer than the
neighbouring parts, is also visible, and on one
of the sides the above-mentioned minute black
spots are visible. The tail is very large, and,
like the trunk, is composed of two distinct
parts ; the one superficial, colourless, diapha-
nous, gelatinous, and much resembling the al-
bumen of the eggs of frogs ; the other, central
and yellow. This latter part is continuous
anteriorly with the central sac of the trunk,
and is also composed of a membranous tunic,
enclosing a yellow granular and semi-fluid
substance. It sometimes appeared to have a

central canal. The larvae, after swimrningabout
with an active wriggling motion for a few hours,
attach themselves to the surface of a solid
body, and, if disturbed from their position,
swim about as before until they meet with a
similar situation. Their activity having ceased,
they become permanently fixed, and are then
about the size of the head of a very small pin.
They appear to affix themselves to their rest-
ing place by means of one of the little suckers
with which their anterior extremity is fur-
nished.

The larva has now lost all power of loco-
motion, and quickly undergoes further changes
of form. The anterior extremity of the trunk
is widened, and the prolongations of the in-
ternal tunic quickly disappear. The central
portion of the tail becomes at the same time
empty, its contents being returned to the cen-
tral yolk-mass of the body. The sac or internal
tunic enclosing the yolk becomes much con-
tracted andspherical ; lastly, the yellow matter,
which was unequally divided, seems again to
be rearranged. The tail, which during the
early period of the existence of the larva per-
formed so important a part, being the only
instrument of locomotion, is now reduced to
its gelatinous or tegumentary portion ; and
this, after becoming more and more trans-
parent, withers, and finally is detached, or falls
away in shreds at a more advanced period of
the growth of the animal. The trunk, on the
other hand, is the seat of important and active
changes. The tegumentary portion of the
body is much widened, taking an oval out-
line, and is visibly augmented in bulk. The
interior tunic continues at first to lessen, and
becomes quite spherical, and many large
patches of a lighter yellow than the rest are
apparent, one of which occupies the anterior,
and two others the posterior portions of the
tunic (Jig. 784. d).

M. Milne-Edwards further remarks, that
the modifications already noticed ordinarily
occupy the space of from ten to twelve
hours ; and if the larvae are again examined
towards the end of the first day of their
sedentary existence, further changes in the
interior tunic may be observed. In a speci-
men carefully watched by him, the follow-
ing changes were noted. Instead of being
spherical, the large yellow sac became oval,
and its anterior part much thinned. It soon
afterwards again became elongated, and a
circular contraction divided it into two por-
tions (Jig. 784. e). The anterior portion,
smaller and lighter coloured than the pos-
terior, was rounded in front, and presented at
that part a large annular patch of a deep yel-
low, vaguely circumscribing a central paler
portion. The posterior part was swollen and
of a deeper yellow than the anterior, and quite
behind there was observable a minute patch
of a very clear yellow. This latter spot sub-
sequently became the heart, and the annular
spot on the other extremity of the body was
developed into the thorax of the animal. The
following day all these parts grew still more
distinct. The anterior portion of the inter-

4 i 4

1224

TUNICATA.

nal tunic or the thorax, which had been
smaller than the abdominal or posterior por-
tion, was much increased, and far more dia-
phanous, and the part, occupied by the whitish
anterior spot was somewhat elevated in the
form of a nipple, marking the future position
of the mouth. The obscure circle that sur-
rounded the base of the buccal region was now
replaced by a very narrow yellow band ; and
on the inferior part of this thoracic portion
of the body there were observed two yellow
lines, vertically dividing it into three nearly
equal lobes. The abdominal portion of the
internal tunic was, on the contrary, much
straitened ; the pericardial spot was more dis-
tinct; and another less distinctly limited spot,
situated more in front, presented apparently
the first indication of the stomach. Towards
the middle of the second day, the middle
lobe of the thorax was much enlarged, and in
certain positions of the animal appeared to be
formed by a new interior cylindrical sac, which
in front united with the anterior wall of the
thorax at the point occupied by the yellow
ring before described, whilst laterally it was
separated from the internal tunic by the spaces
corresponding to the lateral lobes already men-
tioned. One of these lobes became very much
narrowed, and seemed destined to form the
great vascular sinus: subsequently, traversing
the anterior surface of the thorax, the other
lateral lobe appeared to correspond to the
future cloaca ; and the middle lobe was evi-
dently the branchial sac, from the base of
which arises the digestive tube.

A few hours after, the anterior nipple-like
prominence was more salient, and seemed to
be contractile. The situation of the stomach
and the course of intestine were also distin-
guishable in the abdomen {fig. 784. f). The
yellow substance had now in a great degree
disappeared, but it was still present in a pretty
considerable quantity in the alimentary tube,
and appeared to pervade all the interior parts
of the young animal.

Towards the end of the second day, the bran-
chial orifice was easily distinguished at the
summit of the thorax, and its margin began to
be somewhat crenulated. This orifice, how-
ever, was present only in the internal tunic, the
tegumentary substance being continued over
it without interruption. The nerve-ganglion
appeared in the form of a minute tubercle.
The yellow line encircling the summit of the
thorax appeared as the superior margin of the
branchial sac. All the thoracic portion of the
body contracted itself from time to time.
Lastly, the anal orifice began to be visible.

On the third day, the heart was seen to
pulsate, and pellets of faecal matter were visi-
ble in the intestine. The following day, the
mouth opened externally, and the water passed
through it to the branchial cavity. About the
same time, the integument was perforated also
by the anal orifice, from which faecal matter
was discharged, provided without doubt by
the digestion of nutritive matter furnished by
the vitelline mass {fig. 784. g).

On the following days, the growth of the

young animal was more rapid, its organs
became more distinct, and soon afterwards
the spiracles of the branchial sac, disposed in
transverse rows, were visible, as well as the
vibratile movements of the cilia, with which
the stigmata are fringed. The number of these
rows, however, was but four, the adult animal
having ten.

The young Amaroucium was now provided
with all its necessary organs except those of
generation, of which no trace was yet visible,
and the future situation of which was occupied
by other organs, the heart being close up to
the intestinal tube. The general form of the
body resembled more that of a Didemnian than
of a Polyclinian, for it had as yet no post-
abdomen, and the loop of the intestine was
folded up against the inferior extremity of the
thorax. Lastly, during the succeeding days,
the abdomen very much lengthened itself {fig.
784. h), and at the end of the second week
there was present, between the heart and the
intestine, a granular mass, which by its ap-
pearance and position could readily be re-
cognised as the generative organs.

With regard to the development of the
integument of this, at first solitary, but sub-
sequently compound, Ascidian, and which is
evidently the analogue of the polypary of
the Polypifera, we have mentioned that at
first it is a gelatinous layer, surrounding the
yolk. An inner membrane, immediately in-
vesting the yolk, and regarded as the blasto-
derm, becomes the internal tunic of the
animal. Whilst the larva goes through its
early changes, there appears no connection at
all between the inner tunic and the integu-
ment. Indeed, says M. Milne-Edwards, the
larva may be seen sometimes to be entirely
turned round in the cavity of the tegumentary
envelope; and sometimes, when it abandons
its original position, it forms a kind of hernia
on the exterior of this envelope, by distending
it at a weak spot {fig. 784. g). The learned
professor does not, however, regard this en-
velope as being either a deposit produced by
secretion, or as an organised body that had
ceased to live since it had ceased to be attached
to the interior parts of the animal ; because, as
he observes, it continues to grow and gives un-
mistakable signs of vitality. Thus, not only
does its bulk rapidly increase, but it frequently
gives rise, as in Amaroucium Nordmanni , to
lobe-like expansions, frequently changing their
form, contracting and dilating very gently,
and appearing to have some analogy to the
proteiform expansions of the Amcebce and
other inferior animals. Of these changes
Professor Milne-Edwards has given an inte-
resting series of figures.

It is only when the mouth and the anus
open externally, that an attachment is estab-
lished between the integument and the inter-
nal tunic of the animal ; and then, as through-
out its future existence, it is around the two
orifices only that organic continuity exists be-
tween the two parts, one only of which is in
direct relation with the organs of animal life.
It is consequently probable that the nutrition

TUNICATA

1225

of the test is carried on by imbibition only ;
and M. Milne-Edwards points out the fact of
the independence of these two portions of the
body of these Ascidians during the early
periods of their life, as worthy the considera-
tion of physiologists ; and he adds, that proba-
bly this kind of vitality of the integument of
the larval Ascidians has some analogy with
what obtains in Sponges, and may, perhaps,
throw some light on the peculiar existence of
the basilar portion of the Sertularice and
other Polyps, that continue to live for some
time after the loss of the soft parts that are
generally, but wrongly, regarded as constitut-
ing the entire animat.

From observations made by the same natu-
ralist on the development of the ova and
larvae of other species of the Polyclinina, and
of the Didemnina and Clavellince , it appears
that very similar modifications take place ;
the time occupied in the development being
of course variable according to specific and
external conditions. The larvae of Clavellina
have the internal tunic strongly lobed in front,
very tumid behind, and destitute of the pecu-
liar appendages observed in the Polyclinina.
These appendages exist in the Didemnina , but
are very short ; and at their base are seen a
row of pyriform lobules, which might easily be
taken for the germs of young individuals, but
all of which really belong to one individual.

The observations made by MM. Lowig and
Kolliker on the embryogeny of some of these
animals are generally in accordance with those
of M. Milne-Edwards, but on some points,
and especially with regard to the develop-
ment of the Botrylli, there exists considerable
discordance of opinion. The points involved
being not only of interest, but of no slight im-
portance, it is necessary to give in detail some
of the most important observations recorded by
the above-named naturalists.

In Botryllus violaceus, B. aureus, Apli-
dium gibbulosum, and Amaroucium Nordmanni,
MM. Lowig and Kolliker observed, in the
first stages of development, a division of the
yolk similar to that taking place in the eggs
of frogs, and described also by M. Milne-Ed-
wards, and established also in the case of the
simple Ascidians by Van Beneden. This divi-
sion takes place as in the intestinal worms ;
that is to say, the simple nuclei, contained in
the globules, which, as everywhere, are only
aggregations of granules, always become double
before the globules are divided in two. As
soon as the division has arrived at a certain
degree, the spherical form of the mass of glo-
bules becomes elongated, and takes more and
more the form of an embryo, its tail making a
semicircle about its body. The tail is distinct
before any other part, and this, according to
these observers, is evidently formed, not by an
elongation of the embryo, but by the separa-
tion of a portion of the globules from the sur-
face. In Amaroucium and Aplidium, at the same
time as the exterior form of the embryo, and
at a very early period, the two ocular points,
remarked by Milne-Edwards, make their ap-
pearance; presenting as yet no trace of an

envelope or of anterior processes. At a later
period only is there formed around the em-
bryo a transparent, colourless border, which,
in Amaroucium and Aplidium, increasing more
and more, especially at the thick end of the
body, appears as a very strong lamina, but
remains without structure all the time the
embryos are contained in the membranes of
the egg. Cotemporaneously with the forma-
tion of the envelopes, the embryos themselves
commence also to undergo a series of changes.
Firstly, towards the anterior extremity, there
appear the three appendages of peculiar form ;
secondly, the yellowish substance in the in-
terior of the body separates into two laminae ;
the one, external, remains diaphanous ; the
other, internal, becomes opaque, and divides,
in the Botrylli, into eight conical corpuscles,
which surround a somewhat large, round,
perforated nipple ; lastly, a great number of
structural modifications take place. The
mature embryos of B. aureus are formed of a
spherical body, 0'28"' broad and 0'38"' long,
possessing an orifice surrounded anteriorly
with three lobules, and posteriorly bearing a
thin, tapering tail, 0‘72w long. These em-
bryos present exteriorly the thin, transparent,
structureless layer (tegumentary layer) before
referred to, from which almost solely the lobes,
or lanceolate appendages of the head, are
formed, and which terminate at the opposite
extremity in a prolongation exceeding in length
those parts of the tail enclosed within it. In-
terior to this, in the anterior part of the body,
is a second delicate envelope, formed of cells
either round or changed into fibres, which
does not enter into the composition of the
lobes of the head, but encases the mammil-
lated prominence before described, and also
the eight spherical bodies surrounding it, and is
attached at one end to the edge of the nipple,
and at the other to the interior part of the
tail.

The internal substance, constituting the
chief mass of the embryos, is, according to
MM. Lowig and Kolliker, evidently a group
of individuals, as M. Sars, who discovered
those curious embryos of the Botrylli, has
already shown. The eight spherical corpuscles,
united at their bases, and provided with a
kind of common stem, are so many individuals,
and the prominent nipple situated in their
centre represents the common excretory tube.
This salient tube at its extremity has three
lobules, which project into the base of the
lobes of the exterior envelope : from its base
three filaments (nerves?) arise, which passing
upwards bifurcate each into two, one of
which terminates at the orifice of the tube ;
the second reaches the summits of the lo-
bules, and, passing beyond them, spread into
five or six branches, extending almost to the
edge of the lobes of the exterior envelope.
In the eight embryos no orifice is perceptible,
nor any other organs, except some canals
(intestine) indistinctly rolled up. Their mi-
croscopic elements, however, are very dis-
tinct ; namely, various-sized nucleated cells,
filled with pale red granules and fibres in

1226 TUNICATA.

process of formation ; the former constitutes
the principal mass of the excretory tube. The
internal part of the tail, which is apparently
a direct continuation of the substance of
the embryo, possesses an interior cavity,
and its walls are composed of two layers
of cells. The internal layer is formed of cells
of 0'012/// diameter, rectangular, with the
angles slightly rounded, distinctly nucleated,
and containing fine yellowish granules. They
are very regularly arranged side by side in
transverse series, so that the cavity of the tail
is always surrounded by 10 — 12 cells. The
external layer is composed of a continuous,
simple layer, formed of minute cells, measur-
ing 0'003'" — O'OOV", without any distinct ar-
rangement. It is to be observed that this tail,
formed simply of cells and a homogeneous
envelope, exhibits very active movements,
affording a new proof of the contractility of
parts composed merely of simple cells.

The body of the embryos of Aplidium and
Amaroucium is formed (at an early stage) of
a thick, homogeneous, external layer, and a
yellowish mass enclosed within it. In the
spherical portion of the body, this mass is ap-
parently wholly composed of round cells, of
different sizes, and containing nuclei, and,
towards the interior, probably unaltered glo-
bules produced by the division of the vitellus.
These two elements do not compose any dis-
tinct organ ; but only form two layers, one
internal and opaque, and the other external
and diaphanous. In Amaroucium Nordmanni
there is no canal within the tail, but its centre
is occupied by a simple series of large rectan-
gular nucleated cells, producing a transversely
radiated appearance, visible even when mode-
rately magnified ; the tail has also an external
simple layer of minute celis, as in Botryllus.

Savigny, also, was led by his researches to
regard both the ovum of Botryllus and that of
Pyrosoma as giving birth to several individuals
having already a certain order of arrangement.
This view, in the case of the Botryllus, is, as
we have seen, supported by Lowig, Kolliker,
and Sars, and is considered by Van Beneden
as founded on fact and supported by analogy.
Milne-Edwards, however, is not disposed to
admit this conclusion ; for, in his opinion, the
existence of the four embryos united in a
circle in the Pyrosoma, and the development
of a single star of germs in the larval Botryl-
lus, do not sufficiently account for the associa-
tion of many such groups in the adult age;
there being, for instance, in the adult Pyrosoma,
many hundred individuals of different de-
grees of development. Van Beneden thinks it
probable that the presumed aggregate larvae
produce colonies similar to themselves by fis-
siparous reproduction ; but Milne-Edwards
gives it as his confirmed opinion that, from the
single product of the ovum, the other asso-
ciated individuals arise by gemmiparous repro-
duction only. Of this mode of generation in
the Botryllidcc we will now proceed to give a
slight sketch, again acknowledging the labours
of the learned Professor of the Garden of
Plants as the chief source of our information.

In Diazona, Didemnum, Botryllus, and Bo-
trylloides, the common test is traversed by
numerous ramifying prolongations of the inner
tunic of the individual animals, terminating
either simply in culs-de-sac, or swelling out
into germs (Jig. 785.). Savigny figured these

Fig. 785.

Vertical Section halfway through a Mass of Botryllus,
magnified about 6 diameters. ( Original).

a, animals on one of the exterior surfaces of the
mass ; b, proliferous stolons, traversing the mass, and
bearing reproductive germs.

tubular bodies, and vaguely described them
under the name of “marginal tubes” and
“ vascular branches.” And Belle G'hiaje*, in
treating of Polyclinium, figures and describes
“ vessels ” which are probably these ramifying
canals. These membranous tubes, with their
terminal vesicular enlargements, are readily
seen during life in those species that possess
a semitransparent test. Milne-Edwards ob-
serves that in Botryllus and Botrylluides, (Jigs.
785 and 783, t, t'), each of these interior ap-
pendages appears at first as a little tubercle
on the surface of the abdominal portion of the
inner tunic of the adult animal. The tubercle
then becomes elongated, forming a tube, the
free extremity of which is closed, its cavity
communicating with the abdominal cavity of
the animal from which it springs. The blood
from the abdominal cavity circulates through-
out this csecal tube, with a very active double
current. As the tubes lengthen, they generally
become ramified, and soon present swollen
or claviform extremities. The circulation con-
tinues active, and before long there is visible
towards the summit of each terminal swelling
a minute granular mass, the colour of which
approaches that of the thorax of the adult
animals situated close by. A little later this
organised mass begins to present the form of
a little Ascidian, and soon afterwards becomes
a young animal, similar to those already occu-

* Memoirs, second edition, tom. i. p. 34. tabl. 83.
figs. 13. and 15.

TUNICATA. 1227

pying the common mass, of which it becomes
a new inhabitant. The communication be-
tween the mother and the young animal be-
comes obliterated ; but for some time yet, all
the young individuals growing from the same
branch remain united by their pedicle, and it
is this union, apparently, that determines their
mode of grouping into “systems.”* In Di-
demnum gelatinosum, the buds growing on
these proliferous stolons are very different
in appearance from the ova expelled by
the animals ; for not only did they differ in
aspect and form, but their bulk is at first
twenty or thirty times less than that of the
vitelline mass of the ova. In the Amaroucium
proliferum, Milne-Edwards has frequently
found on the surface of a rounded mass, formed
by a colony of these animals, many little
filiform twigs, simple or branched, formed by
a prolongation of the common tegumentary
substance, and consisting of a tube closed at
the end, and enclosing, in its interior, one or
more embryos in different states of develop-
ment. These young individuals terminated
inferiorly by a peduncle, prolonged in form of
a slender tube into the common mass, and
springing apparently from the abdominal tunic
of an adult individual. This mode of propa-
gation by buds, which the compound Ascidians
possess in common with the Polypifera, is, as
we have above described, found in the Clavel-
linidce ; the only important difference being,
that in the latter the tegumentary envelope of
the young is not so largely developed as in
the BotryllidcE, and does not become fused
with that of the adults; whence it results that
the individuals springing from the same stem
remain isolated, instead of being united into
a common mass.

Anatomy of Pyrosoma. — The common
tegumentary mass of Pyrosoma is semitrans-
parent, subcartilaginous, toughish, and some-
what extensile. The exterior of the hollow,
conical, or cylindrical body, formed by the ag-
gregation of the individual Pyrosomata, is co-
vered with numerous elongated tubercles, of a
rather firmer consistence than the rest of the
mass. Each of these constitutes one extremity
of an individual member of the living group.
The opposite extremity opens into the cavity of
the cylinder, and is not free, but, like the trunk
of the individual’s body, is closely connected
by the common mass with the similar parts of
other individuals lying above, below, and on

* M. Savigny figures a nascent system, originated
apparently by this grouping of the buds; and
Professor Yan Beneden coincides with M. Milne-
Edwards in the above view of the subject, but M.
Steenstrup expresses his opinion that the mode in
which the colonies and systems of the Botryllidaz are
formed, is not sufficiently explained by this hypo-
thesis ; and, although (following Milne-Edwards)
he considers M. Sars to have been misled in re-
garding the ova of the Botrylli as producing
groups of animals, yet he is inclined to consider this
grouping to be really a foetal condition, but occur-
ring in some hitherto unnoticed “ aggregate ” form
of animal, produced from the “solitary” larvse de-
scribed by Milne-Edwards, just as the solitary Salpce
bring forth Salpa-chains.

either side of it. In some species the animals
are arranged much more regularly than in
others, and appear to form piled-up rings or
circles of individuals, more or less analogous
to the otherwise disposed circular systems of
some of the Botryllidce. In Pyrosoma atlan-
ticuvi the tubercles are simply conical, and
are perforated terminally. In P. elegans , also,
the external orifice of the individual opens at
the extremity of the tubercle, and through it
the water contained in the great cylinder has
been seen to escape freely in little jets, when
the Pyrosome has been taken out of the sea.
In P. giganteum the tubercles are of various
sizes, some being short and indistinct, and
others, on the contrary, very much deve-
loped. The largest are conico-cylindrical flat,
and lanceolate at the extremity, with the
minute branchial orifice on the inferior aspect.
This lanceolate extremity is crenulated on its
sharp edges, and presents on its inferior aspect,
between its point and the aperture, a slightly
prominent keel. The branchial orifice is
sometimes surrounded by a slight, free, crenu-
lated membrane.

The interior of the great cavity is generally
smooth. Its walls are perforated by the
numerous minute anal orifices of the com-
ponent individuals ; and, at a slight depth, its
surface is studded with a great number of
yellowish, rose-coloured, or carmine spots,
which are the hepatic and other visceral
organs of the numerous animals. The ter-
minal aperture of the large, conical, compound
body of the Pyrosoma has, according to Le-
sueur and Savigny, a membranous border,
which can be sometimes drawn together so as
to close the cavity ; and Mr. F. D. Bennett
observed that, when first removed from the
sea, the broader extremity of the cylinder pre-
sented a wide and circular orifice, forming
nearly a continuous surface with the central
tube ; but when the animal was kept in a
vessel of sea-water, or much handled, this
orifice was closed by the contraction of a
smooth, dense membrane at its margin, and
which either obliterated the aperture, or left
but a minute central orifice; water at the
same time being contained in the barrel or
tube of the body.

Besides the common envelope or test, each
individual animal has an inner tunic or man-
tle. This is a very thin, delicate membrane,
attached apparently at four points only, two
of which are at the extremities; that is, at the
branchial and anal orifices ; and the other two
are at two rounded, compressed bodies, one
on either side, just beyond the anterior mar-
gin of the branchiae, and regarded by Savigny
as ovaries.

The branchice line the inner surface of this
inner tunic. They are oval in form, and then-
dorsal borders meet each other, and are at-
tached along the dorsal aspect of the mantle ;
but they are separated, at their anterior and
ventral borders, by a considerable space, which
is partly occupied by the ventral sinus {Jig.
786. i, t). The branchial tissue is traversed
by numerous vessels anastomosing with each

1228

TUNICATA.

other at right angles. The transverse vessels,
varying from 18 to 25 in number, are the

Fig. 786.

Anatomy of Pyrosoma yiganteum, magnified.

A. A portion of the common mass with animals im-
bedded in its substance. ( After Savigny.) a , a, a, a,
the liver ; b, b, b, ova in the posterior cavity ; c, ovum
in the substance of the common test ; d, d, d, full-
grown individuals ; e, e, e, undeveloped individuals.

B. A single individual cut out of the common test,
with a portion of the latter surrounding it, seen from
below. ( After Lesueur.') a, branchial or external ori-
fice ; b, anal or internal orifice ; c, c, delicate fibres
traversing the test ; cl, stomach ; e, liver ; /,/, bran-
chiae ; g, oviduct ( ?) ; h, ovary ; i, ventral sinus ; j,
nerve-ganglion.

c. The viscera of an individual Pyrosome. ( After
Lesueur .) d, e, g, h, i, j, as in Jig. b ; h, ovum.

largest and most distinct, and are folded back
on themselves at the free edges of the tissue.
The longitudinal vessels are from 11 to 17 in
number. “ Nothing is more curious,” says
Milne-Ed wards*, “than the respiratory ap-
paratus of these little animals, when the vi-
bratile cilia, with which each of the branchial
stigmata is furnished, are simultaneously ef-
fecting their vorticiform movements with ra-
pidity and perfect harmony.”

The oesophagus is curved, and is of a
bright red colour. The stomach is subglo-
bular, yellowish, and opaque. The intestine
is short, and strongly bent on itself ; the anus
is directed backwards towards the posterior

* Annales des Sciences Naturelles, sec. ser. tom.
xii. p. 375. 1835.

orifice. The liver is a globular body, which
is but slightly^ developed in young individuals ;
its postero-inferior portion is formed of several
sections united by a centre, around which
they converge, presenting the appearance of
a flower with many petals, or a calyx with,
most usually, 7, 8, or 10 divisions. The sec-
tions are not always equal. Their centre is
occupied by a somewhat solid, granular sub-
stance, which they more or less perfectly
enclose. Its colour is generally whitish, or
of a light pink. It lies free in a cavity hol-
lowed out of the test, and is attached by
a membranous peduncle to the stomach,
or rather to the intestinal loop ( fig. 786.
a, a, a, b and c e, e). These viscera are si-
tuated posteriorly to the branchial sac. By
their disposition they leave a free passage to
the water which traverses the branchial ca-
vity. The nerve-ganglion is present at the
anterior extremity of the dorsal border of the
branchial sac. From it there proceed filiform
branches towards the neck of the external
tubercle and in other directions. The vessel
or sinus that runs between the two free edges
of the branchiae is of considerable length, and
lias a slight general curve. It is divided, as it
were, into four, towards its largest and an-
terior portion, or rather seems to be com-
posed of two contiguous vessels bent upon
themselves. These diminish in calibre as they
run backwards, and, passing into a delicate
filiform vessel, are lost near the stomach.

Two arching vessels, one on either side, pass
from near the nerve-ganglion to the com-
pressed oval bodies on the anterior lateral
points of the branchim, and a similar pair of
vessels unite these latter bodies with the
extremity of the loop formed by the vessel
that lies between the free ventral margins of
the branchiaa. These four arched vessels form
therefore a circlet around the anterior ex-
tremity of the branchial sac (fig. 786. b, h).

The heart is placed at the posterior part of
the body, at the side of, and below, the visceral
mass. Its character is perfectly analogous to
that of the heart of other Ascidians. It con-
tracts with the usual peristaltic movement,
and changes periodically the direction of this
vermicular movement, the vessels alternately
playing the part of artery and vein.

With regard to the generation of the Pyroso-
midee, very Jittle has yet been observed. Sa-
vigny describes as “oviduct” and “siphon-
canal” the vessels that occupy the usual
position of the dorsal sinus, running along the
dorsal or superior surface of the branchial
sac (fig- 786. g, g). They have, however, no
apparent connection either with the pre-
sumed oviferous bodies situated at the an-
terior points of the branchiae, or with the cavity
posterior to the abdominal viscera occupied
by the ova in Savigny’s specimens (fig. 786.
a, b). Lesueur discovered and described cer-
tain globular, transparent bodies in Pyrosoma,
situated near the liver ( fig. 786. c, lc), which
he regarded as ova ; these were noticed also
by Savigny. Each enclosed four minute Py-
rosomes, symmetrically disposed, and readily

TUNIC AT A. 1229

recognised by the form and arrangement of
their double branchiae.

Whether the ova of Pyrosoma be always
composed of four, or a greater or less number
of young individuals, or whether they ge-
nerally contain but a single one, it is still
highly probable that gemmiparous reproduc-
tion obtains with these animals ; the fssi-
parous mode, however, imagined by Peron as
possibly occurring in the adult Pyrosome, is
totally unsupported by evidence. The several
stages of development in which the individual
animals are found to exist in the common
mass of the test, as noticed by Savigny, point
to this conclusion ; and possibly the delicate
filaments regarded as muscular fibres by Sa-
vigny, first pointed out by the acute observer
of these creatures, Lesueur, as traversing the
test in a line with the abdominal cavities of
the adult animals (Jig. 786. n, c ), may be the
proliferous stolons as yet untraced throughout
their course.

Phosphorescence of Pyrosoma. — M. Peron,
who first discovered and established the genus,
has given a lively description of the circum-
stances under which the P. atlant.icum were
first met with by him, in his Memoire sur le
Pyrosome. * “ We had,” says he, “ for a long
time been detained by calms in the equatorial
regions, between 19° and 20° long, west of
Paris, and 3° and 4° north lat., the temperature
of the sea being at the surface 22° Reaumur ;
and we could make no progress except by the
aid of the short-lived storms peculiar to these
climates. In the evening of the 13th Frimaire
we experienced one of the strongest of these
squalls ; the sky was on all sides loaded with
heavy clouds ; all around the obscurity was
profound ; the wind blew violently; and the
ship cut her way with rapidity. Suddenly
we discovered, at some distance, a great phos-
phorescent band stretched across the waves,
and occupying an immense tract in advance
of the ship. Heightened by the surrounding
circumstances, the effect of this spectacle was
romantic, imposing, sublime, rivetting the at-
tention of all on board. Soon we reached
the illuminated tract, and perceived that the
prodigious brightness was certainly and only
attributable to the presence of an innumerable
multitude of largish animals floating with the
waves. From their swimming at different
depths they took apparently different forms ;
those at the greatest depth were very inde-
finite, presenting much the appearance of
great masses of fire, or rather of enormous red-
hot cannon-balls ; whilst those more distinctly
seen near the surface perfectly resembled in-
candescent cylinders of iron.

“ Taken from the water, these animals per-
fectly resembled each other in form, colour,
substance, and the property of phosphores-
cence, differing only in their sizes, which
varied from 3 to 7 inches. The large, longish
tubercles with which the exterior of the Pyro-
somes was bristled were of a firmer substance
and more transparent than the rest of the

* Annales du Museum d’Hist. Nat. tome iv. 1804.

bod)', and were brilliant and polished like
diamonds. These were the principal seat of
phosphorescence. Between these large tu-
bercles, smaller ones, shorter and more ob-
tuse, could be distinguished ; these also were
phosphorescent. Lastly, in the interior of
the substance of the animal, could be seen,
by the aid of the transparency, a number
of little, elongated, narrow bodies (viscera),
about a millimetre in length, which also
participated in a high degree in the possession
of the phosphoric light.

“ The colour of the animals, when at rest
or when moribund, was observed to be of an
opaline yellow, mingled with a disagreeable
green ; but during the spontaneous contrac-
tions of the animals, and which were also
easily excited at the pleasure of the observer,
the body seemed to burn, becoming instantly
like molten iron, with an extremely bright
light ; but, as the phosphorescence again
ceased, the colour of the animal passed suc-
cessively through a number of extremely
agreeable, light, and varied tints, such as
red, yellow, orange, green, and azure blue,
the last shade being extremely lively and pure.

“Left to itself in a glass of sea-water, the
Pyrosome exhibited at regular intervals of
time a slight alternating movement of con-
traction and dilatation. In these movements,
the phosphorescence was seen to be deve-
loped during the contraction, then to grow
insensibly feebler, and entirely disappear,
until in the next contractile movement it was
quickly re-established.

“ By often irritating the animal, either by
touching it or by shaking the water in which
it floated, the phosphorescence could be ex-
cited and maintained fora much longer time.
Evidently dependent on the organisation and
the life of the individual, after death, as is
the case with all other phosphorescent marine
animals, it could not be reproduced.”

We may remark that the observations
made by Mr. F. D. Bennett *, who more than
once met with shoals of P. atlanticum in lat.
1° 4F N., long. U°56'W., and lat. 4° S.,
long. 18° W., differ but slightly from M.
Peron’s notices of the same animal. The
former observed, that when the specimens
were taken in the hand from a vessel of sea-
water, the whole mass of the animal became
instantly illuminated by myriads of bright
dots, much resembling in hue the points on the
wing-cases of the diamond-beetle ; and that the
small specks of a brown or red colour, that
were imbedded in the general tissue, and in-
termingled with the prominent, rigid, pearly
tubercles, appeared to him to be the chief
seat of the phosphoric light, frequently re-
maining bright, whilst the remainder of the
body exhibited only its naturally white or
yellowish hue — a hue which changed after
death into a red tinge. In making a close
examination of the animal, Mr. Bennett re-
marked that no luminous matter was com-
municated from the surface of the animal to

* Proceedings of the Zoological Society, 1833
and 1837.

1230

TUNICATA.

any fluid or solid in contact with it. But if
the Pyrosoma were cut open and immersed
in water, the brown particles that escaped
diffused themselves through the fluid, and
shone as numerous scintillations, independent
of the perfect structure. General friction or
contact was not essential to elicit the perfect
light of the Pyrosome, since touching one
small portion of the body was sufficient to
produce a brilliant glow throughout the
whole.

Mr. Bennett at the same time made the
following observations on the effect of fresh
water on phosphorescent marine animals.
“ Fresh water appears to act as a powerful
and permanent stimulus on marine Noctilncce.
Those that have intervals of repose from
their phosphorescence immediately emit light
when brought into contact with fresh water ;
and this fact was strikingly exhibited in the
Pyrosomata „ When placed in a vessel of sea-
water and permitted to remain quiet, these
Molluscs afforded no light, and, when touched,
gleamed forth only as long as the irritating
cause remained, and then gradually returned
to their original state. When, however, the
same creatures were placed in a vessel of fresh
water, they never ceased glowing with their
brightest refulgence until life was extinct,
which was not until the lapse of several hours.
When also the same Molluscs were mutilated,
or so near death as to refuse to emit light
upon irritation in sea-water, immersing them
in fresh water produced at least a temporary
revival of their brightest gleam.”

Anatomy of Salpte. — The subcartilagi-
nous test of Salpce is more or less cylindrical
and flexible, and when taken out of the sea,
often collapses into an amorphous mass. Float-
ing in the water, it is iridescent or opaline,
reflecting the sun’s rays in beautiful rainbow
tints, and hence has been derived its name of
“ sun-fish.” The test and its lining membrane
are so diaphanous, that the whole structure of
the animal can be seen through them. The
exterior of the test is generally smooth, but
sometimes bears minute shiny protuberances of
a tissue similar to its own, as in S. Tilesii. The
integument over the viscera is thicker and
often of a firmer consistence than the rest of
the test. Its form varies considerably, not only
in different species, but in the conditions of
isolation and aggregation, in which each species
alternately exists, and also in the different
stages of growth of the individual, especially
in an associated state.

The test is usually either oval or oblong,
but various terminal and lateral processes
considerably affect its general contour. Each
of its extremities is open by an orifice ; and,
in the aggregated individuals, it is perfo-
rated by other much smaller apertures at
the points of contact between the neighbour-
ing individuals of a group.

The internal surface of the test is lined by
the mantle, a thin, toughish membrane, which
is often more conspicuous than the highly
transparent external envelope. The mantle
is furnished with large, generally transverse,

muscular bands, the arrangement of which
differs according to the species and according
to the separate or associated state of existence.
Its inner surface is lined with a soft mucous
coat of fine epithelial tissue. The mantle is
more or less closely attached to the inner sur-
face of the test, especially at the two orifices
(being, indeed, continuous with the test at
these points), at the protuberances that arise
from the test, and along the inner surfaces of
the longitudinal furrows that sometimes tra-
verse its external surface, as in S. cordiformis,
where, on the superior and inferior surfaces,
the test is depressed into broad, deep sulci.
In specimens preserved in spirit, and even in
some recent specimens, this membrane will
sometimes separate itself, together with the
viscera and vessels, from the outer tunic, and
fall through one of the external orifices.
Salpce have been met with floating in the sea,
and executing, in some degree, their usual
movements of contraction and dilatation; in
which, from mutilations caused by parasites
or other accidents, little remained except a
few muscular bands of the mantle.

Considerable confusion has existed among
naturalists as to which is the anterior extre-
mity, and which the superior surface of the
Salpa. We shall regard, as the anterior or
branchial orifice, that in the neighbourhood of
which the stomach and heart are usually found
(Jig. 787.); and as the posterior or anal orifice,
that which points in the direction of the ani-
mal’s retrograde motion ; and as the superior
or dorsal surface, that on which the nerve-
ganglion is present; and as the inferior or
ventral, that in close contact with which the
viscera and heart, forming the “ nucleus ” or
“ paquet ” of authors, are placed.

The orifices are either terminal, or are situ-
ated at the base of the terminal prolongations
of the test. The anterior orifice is destitute
of tentacular appendages ; it is furnished with
sphincter muscles ; it is simple and tubular
in S. cristata, S. Tilesii, and S. scutigera, &c.,
and transverse in S. cordiformis, S. zonaria,
&c. When the dilatation of the animal is
drawing water into the cavity of the body, the
sphincters of this orifice are brought into action
and close it, so that the water enters by the
opposite extremity.

The posterior orifice is a transverse slit,
furnished with a few muscular fascicles, and
is larger than the opposite orifice. In S. cris-
tata its superior lip is simple and thin; its
inferior lip is externally a rounded ridge,
formed by a fold of the test, which, within its
inner border, constitutes a semilunar valve.
This allows the water to enter easily, but pre-
vents its escape when the animal contracts
itself.

The constrictor muscles of the mantle are
often subannular, interrupted on one or the
other surface, decussating in some, connected
in others. The following are a few examples
of the disposition of these muscular bands.
In S. cristata, around the tubular anterior ori-
fice, are 4 — 5 sphincter muscles ; the first of
which, as well as the last two, are continuous

TUNICATA.

1231

around the tube. The last two send lateral
processes backwards, forming, with the suc-
ceeding band, the first on the trunk, and also
annular, large rhomboidal meshes ; two other
annular bands succeed and form large meshes
by intercommunications on the upper and
lower surfaces. From these last muscles two
intercommunicating processes are sent off on
each side to the crestlike prominence of the
test. From the last band several branches
run backwards to be distributed to the upper
and lower lips of the posterior orifices.

In S. Tilesii the anterior orifice is provided
with two lateral penniform muscles. The
other muscles form six bands nearly parallel
with each other, interrupted along the me-
dian line of the superior surface, and not
reaching further than halfway down the sides
of the body. The most anterior band is
somewhat forked, and the most posterior
gives some branches to the superior lip of the
posterior orifice, and joins, at the angle of the
lips, a radiating group of other fascicles, that
are distributed to the inferior lip.

In S. scutigera the muscular bands are few.
On the superior surface, two pairs of decus-
sating muscles are seen, and other smaller
bands occur near the extremities. In S. cy-
lindrica there are eleven transverse bands,
interrupted and separated by a considerable
space on the inferior surface of the body ; the
first six of which are parallel one to another,
whilst the four following are bent towards
each other on the median line of the body ;
the last band, and some short lateral fascicles,
are arranged close by the posterior ex-
tremity. In S. fusifonnis there are seven
transverse bands ; some of which are parallel
with, and approaching others on the sides of
the animal, and others are more or less
obliquely arranged. In S. cordiformis there are
six broad transverse muscles on each side of
the animal, not meeting on either surface.
Two narrow, looplike fascicles, one above and
one below, arising from the last branchial
bands, and two short, transverse, lateral slips,
act as sphincters to the posterior orifice.
A pair of narrow muscular fascicles are
sent off from the first of the branchial muscles
to the anterior orifice. In S. zonaria (the
aggregate form or “ proles ” of S. cordiformis)
there are also six transverse bands interrupted
only on one surface, and differing consider-
ably from those of S. cordiformis, as do the
distinct sets of muscles distributed to the two
orifices. In S.runcinata (solitary) (/z'g.77'2. a)
the muscular bands are nine in number, placed
on the dorsal surface ; three anterior and
three posterior, approximated at their centres,
and three parallel bands in the middle. In
S. runcinata (aggregate) (fig. 772. b) there are
six muscles, besides those of the orifices; four
anterior and two posterior, approximating on
the median lines.

The branchia is single, in the form of a
riband-like tube, stretched, on a vertical plane,
obliquely across the central or branchial cavity
of the body, so that it is constantly bathed by
the water traversing this cavity. It consists

of a double membrane formed by a fold of the
internal tunic or mantle, and springs anteriorly
from the visceral nucleus between the oeso-
phageal opening and the orifice of the rectum ;
it then becomes free, and ultimately terminates
on the superior part of the thoracic cavity,
below the point where the nerve-ganglion and
the oculiform organ are found. It thus di-
vides the branchial cavity into two portions
— the antero-dorsal or pharyngeal, and the
postero-ventral or cloacal

The inferior border of the branchia exhibits
an infinite number of minute transverse ves-
sels, all parallel to each other. There is
usually only a single row of these transverse
vessels on each side of the foliole of the bran-
chia ; but sometimes there are many rows,
which indicate the presence of many longi-
tudinal vessels, and thereby approach the
character of the branchial tissue of the As-
cidians.

Savigny observed in .S', octofora another
small branchia near the anterior insertion of
the large branchia.

The whole inner surface of the branchial sac
of the Salpse seems, from its high degree of
vascularity, to be subservient to the purposes
of respiration. The vascular tissue of the bran-
chia, consisting of longitudinal and transverse
vessels, is equivalent to the vertical bran-
chial network dividing transversely the respi-
ratory cavity of the ClaveUinac.

The single branchial lamina of Salpce ap-
pears to constitute the transition from the
Ascidice to the Teredines; in the latter there
are two elongated branchial laminae above the
intestine, and within the tubular mantle, to
which the water has access and egress by
means of two tubes placed at the posterioi
extremity of the body.

The intestinal canal is opaque, fuscous,
or variously tinted, generally closely folded
or convolute, and sometimes enveloped in
the liver, forming altogether the “ visceral
nucleus.” This, together with the heart, lies
external to the mantle, between it and the
test. The oesophageal aperture is in the
antero-inferior part of the body, behind the
heart, more or less conspicuous and variously
modified; dissimilar in the alternate “ proles”
of the same species. In the solitary “ proles”
of S. pinnata and S. affinis it is stretched
above the branchia. In the aggregate “ pro-
les ” of S. pinnata it is opened out longwise,
and of a violet colour in the living specimen.

In S. cristata the intestinal canal has the
following characters. The oesophagus is
round, with a loosely plicated margin ; the sto-
mach has a contrary direction to the rest of
the canal, being a cul-de-sac pointing ante-
riorly, and situated in the thickness of the
antero-inferior protuberance of the test. It
is membranous and transparent, and is de-
scribed by Cuvier as ordinarily containing a
little greyish fluid. The intestine is a simple
tube having a direction unusual among the
Salpians ; it runs from the stomach towards
the posterior extremity of the body, where it
opens into the branchial cavity by a rather

1232

TUNICATA.

large anus. The faecal matter contained in
it is greenish and vermiform. The liver (testicle,
Krohn) in this species appears to be composed
of large, parallel, longitudinal filaments, and
terminates posteriorly in a delicate, tapering
point. It differs also from the liver of other
species in being of a whitish colour.

The intestine of the Salpians is usually
twisted once or twice either around or within
the liver, with the anus terminating nearly free
of the latter, near the anterior attachment of
the branchia. The anus is generally on the
left side, opening posteriorly. The rectum
never traverses the heart. In S. gibbosa and
S. infundibuliformis the intestine makes a little
more than one turn, the two ends crossing
one another a little. It has two coeca, one on
each side, which are turned into the centre of
the loop of the intestine. Eschricht describes
the liver of S. zonaria as conspicuous, enve-
loping nearly all the alimentary canal, and
consisting of a mass of coecal tubes, each of
which bear, near their free extremities and on
one side only, a group of 2 — 6 minute, short
coecal appendages.

The heart is with difficulty observed in
dead specimens, but, from its pulsating move-
ments, is generally conspicuous in the living
animals; and in these only can the circulatory
apparatus be traced out. It is situated in the
antero-inferior region of the body, near the
visceral nucleus, the anterior attachment of
the branchia, and the generative organs. It
is a somewhat long, pellucid, tubuliform ve-
sicle, enclosed in an immoveable pericardium.
A longitudinal vessel or sinus (aorta, of Van
Hasselt) traverses the inferior surface of the
branchial cavity, and is continued into the in-
ferior lip of the posterior orifice, and into the
base of the posterior prolongation (if present)
of the test. Hence it is retroflexed and recur-
rent. It gives off numerous branches at right
angles on either side (Jig. 787.) from which arise

Fig. 787.

Salpa maxima; showing the viscera and large vessels.
The fine vascular net-work of the branchial sac is
not introduced. ( After Milne- Edwards.)

a, upper lip of posterior orifice ; b, anterior orifice ;
c, abdomen, containing the visceral nucleus ; d, bran-
chial lamina ; e, heart;/, oculiform point; g, g, pro-
longations of the test, by which the animal' is ad-
herent to its neighbours.

a great number of smaller branches, that sub-
divide, anastomose, and spread out in different
parts of the body, forming a fine vascular net-
work. All the transverse canals open into a
large dorsal vessel, which thus receives all
the blood which has passed through the

vessels of the branchial sac ; but, besides this,
some blood is also received by it, which has
not passed through this tissue, in consequence
of the great dorsal vessel being connected at
each extremity with the great thoracic or
abdominal vessel by two considerable annular
vessels. The blood returns downwards from
the dorsal vessel through a canal lying on
the dorsal surface of the abdomen (dorsal
canal) to the opposite end of the heart. The
vascular net-work is very conspicuous in S.
aspcra, anil is sometimes particularly distinct
in the appendages. These ramifications go
off from one another at right angles, and
afterwards are, for the most part, bent back
archwise, as Chamisso and Van Hasselt have
observed ; so that, with the exception of
those running transversely, all these little
vessels have a direction contrary to that of
the principal vessels ; that is to say, they
are directed from behind forwards, whilst the
aorta runs, from before backwards. At the
anterior extremity of the heart are two ves-
sels, that answer to the pulmonary veins
(dorsal sinus). They are equally distributed
in the body of the animal, anastomosing with
the branches of the principal sinus (aorta).
The circulation of the blood among the vis-
cera is carried on by means of variable in-
terspaces occurring between these organs.
The motions of the heart are made spirally, by
a twisting of its parietes, and always begin from
one or other of its extremities. As in other
Tunicata, this action is oscillatory, having an
alternately contrary direction, first impelling
the blood in one direction, then stopping,
contracting again, and soon impelling it in
an opposite direction ; so that, after the blood
has been flowing for some time from the heart
to the aorta, to be distributed to the body,
it stops, and then begins to run by the ar-
teries and the aorta to the heart, and from
thence, by the pulmonary veins and their anas-
tomoses, it returns into the arteries and aorta.
The contractions of the heart, in general
very regular, diminish in rapidity at the ap-
proach of the periodic change in the circu-
lation, the blood stopping, and even retreat-
ing a little until a general contraction of the
body determines it to take an opposite
direction. The duration of the opposite cir-
culation is not always the same. Van Has-
selt saw the blood flow for three-fourths of a
minute from the heart to the aorta; and, dur-
ing this time he observed forty-two contrac-
tions of the heart ; and he saw it reflow from
the arteries to the heart and the pulmonary
veins for a third of a minute, and in this inter-
val he counted sixty-two pulsations.

The motion of the blood is the more per-
ceptible as it is full of minute white globules,
which pass through the minute vessels in a sin-
gle row, and are easily seen through the trans-
parent parietes. These observations may be still
more assisted by holding the animal vertically,
with the nucleus downwards ; when, as the
blood, driven into the ventral sinus, is forced to
ascend against its own weight, its current is less

TUNICATA. 1233

rapid, and the movements of the blood-discs
can be more easily followed. “As these blood-
globules are of a certain consistence, a resist-
ance,” says Van Hasselt, “ is necessarily cre-
ated in the whole mass of the blood, which
ultimately overcomes the projectile power of
the heart. After a short interval, during which
the opposite forces are balanced, the heart
assumes a spiral movement, contrary to
the preceding. Hence it follows,” he ob-
serves, “ that, since the blood is driven as
much backward as forward in the vessels of
the body, and since it is only by their anas-
tomoses that the circulation can be said to be
carried on, all the system of the pulmonary
vessels can consist only in accessory ramifica-
tions, which have no direct influence on the
principal circulation ; and that two separate
systems, arterial and venous, do not exist,
the two being united, or rather never having
been separate.”*

The nerve-ganglion is more or less de-
veloped in all the Salpians. It is situated on
the superior surface of the thoracic chamber,
near the posterior extremity, and just above
the insertion of the branchia. In its neigh-
bourhood is often observed a pigmentary spot,
or rudimentary organ of vision.

In S. cordiformis the ganglion appears as a
compound body, formed of two central glo-
bular portions and four irregular lateral ap-
pendages, two on a side. Numerous filaments
radiate off in every direction. Four of these
filaments are sent towards the posterior ori-
fice, two of them passing on either side of the
space described by Prof. Eschricht as the
“ oval organ.” This latter is a long slit with
an inner smooth rim, and an outer oval, trans-
versely striated border. In S. zonaria the gan-
glion is a somewhat triangular, globose body,
with a single appendix on each side, sending
off’ four anterior filaments, two lateral pairs
and a posterior pair. The “ oval organ,” situ-
ated between the last pair, is close up to the
ganglion, and less distinct than in S. cordiformis.

Many of the Snipes are highly phosphores-
cent f ; but sometimes this condition is due
to the presence of phosphorescent Crusta-
ceans inhabiting their internal cavity. The
long chains of phosphorescent Salpce swim-
ming near the surface, have been described
as occasionally producing the effect of long
ribands of fire drawn along by the currents.

Generation of Snlpce. — “ One of the most
important discoveries,” says M. Krohn J , “ with
which physiology has been enriched in our
days, is without contradiction that of the

* Extrait d’un Lettre de Van Hasselt, snr les
Biphores, le 12 Aout, 1821 (Algem. Ivonst-en Let-
terbode, 1822). Annales des Sciences Naturelles,
tom. iii. 1824, p. 78. Bull, des Sciences, tom. ii. p. 212.

t See Mr. G. Bennett’s Observations on the
Phosphorescence of the Ocean, “ Proceedings of the
Zoological Society, 1837 ; ” and his “ Wanderings
in New South Wales.” See also the Article, Lumi-
nousness, Animal.

+ Observations surle Generation et la Developpe-
ment des Biphores. Annales des Sciences Natu-
relles, 3e series, tom. vi. 1846.

VOL. IV.

remarkable phenomena observed in many
inferior animals, and termed, ‘propagation by
alternate generations.’” To M. Steenstrup*
the merit is incontestably due, of having been
the first to bring together, in an ingenious man-
ner, all the facts belonging to the subject. In
treating of the phenomena observed by Cha-
misso in one species of Salpa, and analogous
phenomena studied in other groups of animals,
and in his generalisations of the facts, M. Steen-
strup has placed them in a strong light, and
given them their full value. M. Steenstrup's
observations have also tended to strengthen the
views of Chamisso j- so often contested; and
the researches of M. Krohn, on the natural
history and zootomy of eight species of
Snlpce, fully confirm them. J Every Salpian
is viviparous ; and each species, as show n by
Chamisso, is propagated by an alternate suc-
cession of dissimilar generations. One of
these generations is represented by solitary or
isolated individuals ; the other by aggregated
or associated individuals, united into groups
known as “ chains.” Each isolated individual
engenders a group of aggregated individuals,
and each of these produces in its turn a
solitary individual. The isolated individuals
are therefore multiparous, and the associated
individuals uniparous. This is not the only
difference existing between the two alternating
generations ; for, if we compare the associated
individuals representing the aggregate gener-
ation, with the solitary individual forming the
isolated generation, we shall find that they
differ amongst themselves not only with
respect to external conformation, but also in
many particulars of organisation.

The definition, then, of species should in
this case include the characteristics of the two
dissimilar generations, isolated and aggregate,
which alternately succeed each other. It is
desirable therefore, for the determination of
each species, to preserve but one name. This

* Ueber den Generationswechsels in den Niedern
Thierldassen, 1842.

f De Animalibus quibusdam a Classe Vermium
Linneana. Fasc. 1. “De Salpa.” Berolini, 1849, 4to.

X M. Steenstrup, in his memoir on the Alternation
of Generation (edit. Roy. Soc. pp. 39 and following),
gives a full account of the different views of Chamisso,
Meyer, and Eschricht, with regard to the develop-
ment of the Salpce. He allots considerable space to
the consideration of the arguments of the learned
Danish professor, with -whose opinions, however, he
does not coincide, acknowledging that all his own re-
searches tend to support the observations of Chamisso.

M. Steenstrup notices that the alternate genera-
tions of Salpce are precisely analogous to the phe-
nomena observed in the propagation of Medusa
aurita. This free-swimming Medusa always pro-
duces a progeny which is polypiform and destitute
of the power of locomotion, but which ultimately
brings forth, by tissiparous generation, a progeny
consisting of free-swimming Medusae, which never
assume the polypoid form ; and this alternation is
constant. M. Sars observes, on the generation of
Salpce (Erichson’s Archiv. 1841, t. i. p. 29.), that
“ the Salpa; correspond in this with the Medusa;,
that it is not their larvae which are developed into
the pei'fect animal, but the progeny of the larvce ; it
is not the individual, but the generation, which is
metamorphosed.”

4 K

TUNICATA.

1234

must comprehend the two dissimilar states
which have hitherto been falsely considered as
two distinct species, and to which have been
given specific names, that can now serve only
to designate one or the other of the hetero-
morphous conditions.*

Amongst the characters that distinguish
the different generations of each species of
Salpa, one of the most remarkable is offered
by the disposition of the muscular bands.
These are variable in the two generations,
but constant for each of them. There is,
however, a still more essential difference, and
that is, the mode of propagation peculiar to
each generation. The aggregate individuals
proceeding from the isolated individuals grow
by gemmation within the mother animals, on a
cylindrical prolongation, which may justly be
termed a proliferous f stolon, but which
differs from stolons observed in many other
animals, in not ever appearing externally. —
The stolons of the “ social ” Ascidians spring
up bare, the animal not being connected by a
common gelatinous envelope, as is the case
with the “compound” Ascidians; in which
latter group the stolons necessarily remain
hidden in the common envelope, somewhat
approaching in this respect the stolons of the
Salpians.

The solitary Salpians derived from the
aggregate generation are, on the contrary,
produced by a process more complicated
namely, by means of the sexual functions, — the
concurrence of the eggs and the sperm.

Generation in the “ aggregate ” Salpians.
— With very few exceptions, the individual
aggregate Salpians produce only one offspring
throughout their lifej, so that, if we examine
them at one period, anterior to fecundation,
we find a single egg, and, at a later period, a
foetus. The egg is distinctly visible within
the young aggregate individual before it
has left its parent (isolated) Salpian ; and

as the fecundation of this egg takes place
immediately, or at least a very short time
after, the birth of the young aggregate Salpa,
it can be examined before fecundation, that
is, during the development of the aggregate
within the isolated individual, or shortly after
its birth. The egg is lodged in the thickness of
the internal tunic of the mother, at a little dis-
tance from the inner wall of the respiratory
cavity. It is very clearly distinguishable in the
aggregate embryo at a period intermediate be-
tween the appearance of the solitary embryo
as a bud and its full development. It is then
situated above the visceral mass, at the an-
terior extremity of the body, and nearly in the
middle line, raising the external tunic into a
slight prominence. It is spherical, and consists
of a vitellus, containing the germinal vesicle
and spot, and invested with a membrane so
thick, that M. Krohn is led to regard it as
comparable with the “ calyx” in birds. During
the progress of the development of the ani-
mal, the position of the egg is altered, and it
becomes situated on the side of the body,
somewhat approaching towards its superior
surface, and behind the second muscular band.
This position is retained by the egg, and sub-
sequently by the foetus.

To the posterior extremity of the egg a cord
is attached, which serves as a sort of peduncle,
in general directed nearly horizontally back-
wards, and consisting apparently of a pro-
longation of the membrane that covers the
vitellus. At the period when the egg oc-
cupies the anterior extremity of the embryo,
this cord is proportionally thicker and shorter
than at the subsequent periods of the em-
bryo’s development. M. Krohn considered
it as being the nutritive peduncle of the
ovarian capsule, or membrane, enveloping the
egg. This cord exists, as above described, up
to the time of fecundation, but it soon after-
wards disappears. The ovary, we see, is

* To the above observations, M. Krohn has added the following list of such species of Salpa as he had
been enabled to recognise in the two states : —

In the Solitary State ( Proles solitaria,

Chamisso).

Species.

1.

{Salpa democratica, Forskahll
S. spinosa, Otto j

Salpa africana, Forskahl

{

Salpa runcinata, Chamisso -

Salpa, observed by Krohn -
Salpa scutigera, Cuvier
S. vivipara, Peron and Lesueur
S. gibba, Bose

S. dolium, Quoy and Gaimard
Salpa, observed by Krohn

Salpa cordiformis, Quoy and Gaimard

In the Aggregated State ( Proles gregata,
Chamisso).

f Salpa mucronata, Forskahl.

\ S. pyramidalis, Quoy and Gaimard.
f Salpa maxima, Forskahl.

\ S. Forskahlii, Lesson.

C Salpa fusiformis, Cuvier.

4 S. maxima, var. prima, Forskahl.

(_S. runcinata, gregata, Chamisso.

Salpa punctata, Forskahl.

j" Salpa bicaudata, Quoy and Gaimard.

( S. nephodea, Lesson.

Salpa proboscidalis, Lesson,
f Salpa zonaria, Chamisso.

^ S. polycratica, Forskahl.

The recognition of the two forms of this species was made by Prof. Eschricht, and con-
firmed by M. Krohn.

{Salpa costata, Quoy and Gaimard \ f Salpa Tilesii, Cuvier.

Dagysa strumosa, Banks } ( S. infunclibuliformis, Quoy and Gaimard.

M. Krohn observes also, that Salpa ferruginea, Chamisso; S. confoederata, Forskahl; S. socia, Bose;
S. octofora, Cuvier (?) ; S. lajvis, Lesson, and S. femoralis, Quoy and Gaimard, do not materially differ
from S. bicaudata.

j- Professor Eschricht was the first to recognise J S. zonaria is the only example of an aggregate
the true signification of this part. Salpa producing several (four) foetuses.

8.

TUNICATA.

1235

represented merely by the membrane that
surrounds the egg, and which, as before re-
marked, may be compared to the calyx of
birds. Tlie testicle, on the contrary, is well
developed, but, not increasing in bulk in
proportion to the growth of the young Salpa,
it only acquires its greatest development in
nearly adult animals. It is always found in
the neighbourhood of the intestine, but its
position varies in different species. Some-
times occupying the centre of the visceral
mass or nucleus, formed by the intestinal loop
and its appendages, its presence is evident
only in proportion as it raises those parts ;
sometimes showing itself quite exposed,
it more or less covers a large portion
of the digestive apparatus. This organ in
the aggregate form of Salpa pinnata, S. pro-
boscida/is, &c. is spindle-shaped, and rests
against the intestine, and has been taken for
the liver bv Cuvier, Chamisso, and Meyen.
The testicle is composed of a greater or less
number of ramified canals, the last ramifica-
tions of which end in culs-de-sac. All these
canals end in a principal duct, which, passing
along the terminal portion of the intestine,
opens at the side of the anus in the great
natatory or respiratory' cavity traversing the
body of the Salpa.

The testicle is very much slower in its de-
velopment than the egg organ in these ani-
mals ; and, as young aggregate Salpians are
met with in which a fecundated egg and
undeveloped testicle are co-existent, these
individuals must have had connection with
others in which the development of the
latter organ was further advanced ; the sperm
that fecundated the eggs being supplied by
another group of animals. The maturity of
the sperm does not coincide with that of the
egg, yet, as the two sexual organs are present
in the same body', these animals are herma-
phrodite, although probably not self-impreg-
nating. They have two generative functions
to perform : the one to produce a new being,
the other to fecundate an ulterior genera-
tion of animals similar in all respects to
themselves. The “ aggregate” Salpians pro-
bably perish soon after they have given birth
to their “isolate” offspring.

The placenta, or attachment of the fcetal “iso-
late” in the “ aggregate ” Salpce. — The embryos
of the Salpce , undergoing all the phases of de-
velopment within their mother, adhere to her by
the aid of an organ, the use of which is to
furnish them with the necessary nutritive ele-
ments. These elements being derived from the
blood of the mother, the vessels of the latter
enter largely into the composition of this organ.
Its structure and form vary much according
to the mode of propagation peculiar to each
generation. The propagation in the “iso-
lated ” Salpians is by gemmation, and here
the organ in question is the proliferous stolon.
In the “aggregate” Salpian, on the other
hand, this organ is represented by a body
generally round, situated on the inferior
surface of their single fcetus, and fixed to the

internal wall of the maternal cavity, precisely
in the position occupied by the egg, and to
this organ many naturalists have with reason
attributed the functions of a placenta. This
Dlacenta is ordinarily situated in the external
tunic of the fetus ; its structure is far from
being well known. In appearance it is a soft,
whitish, or brownish pulp, traversed by nu-
merous vessels ; it is attached by a very short
pedicle, which is formed by a prolongation
proceeding from the inner tunic, and envelop-
ing this organ. The vessels distributed in the
interior of the placenta communicate with
four trunks, two of which communicate with
the vascular system of the fetus, and the
other two with that of the mother. Those of
the fetus, in descending towards the placenta,
traverse the peduncle ; the one conducting
the blood to this organ, and the other re-
turning it to the foetus. The two maternal
trunks have analogous functions ; they ter-
minate at the point where the placenta is
attached to the mother. Each of these fetal
and maternal trunks alternately act as arteries
and veins. This alternation is due to the
periodic changes that determine the contrac-
tions of the heart in Tunicates generally. The
vessels of the foetus and of the mother are
not in direct communication ; but, as in
Mammalia , they are merely contiguous. M.
Krohn’s microscopical observations also tend
to prove that the maternal blood never com-
mingles with the fetal blood. The blood-cor-
puscles of the fetus are distinguishable from
those of the mother by their less size and
by the more constant regularity of their forms.

The development of the placenta com-
mences at any early stage of enbryonic life,
and in its progress corresponds to that of
the fetus. Ultimately the placenta becomes
detached from the maternal tissues, and is
carried away by the young born animal. It
remains for a long time in connection with the
young animal, but decreases rapidly in size, and
ultimately disappears before the full growth
of the animal is perfected.

Eleoblast of the fcetal Salpce. — There is
another organ belonging to the fetus, men-
tioned by authors, especially Chamisso, Me} en,
and Krohn, which is a round whitish body,
lodged, like the placenta, in the external
tunic of the fcetus. Its use is entirely un-
known. It appears to be composed of a
multitude of fascicles or lamellae, that, by
their intercrossing with one another, cir-
cumscribe cellular cavities, filled with a per-
fectly clear oily liquid, composed chiefly of
globules. The fascicles or lamellae are tra-
versed by numerous vessels opening into
two trunks, which apparently form the at-
tachment between this organ and the visceral
nucleus. Meyen thought it to be the vitelline
sac of the fetus ; but, according to M. Krohn,
this opinion is inadmissible, because the
“ aggregate ” embryos, which we know are
not produced from eggs, are provided with it.
This body, M. Krohn terms the “eleoblast.”
During the incubation of the fetus, and after
4 k 2

1236 TUNICATA.

the birth of the individual, the changes of
volume undergone by this organ correspond
in general to those of the placenta ; but its
decrease proceeds more slowly, and its re-
mains are observable long after the placenta
has disappeared.

Development of the foetal “ isolate ” Salpce.
— The development of the foetal “ isolate ”
Salpa occupies a considerable time, not being
accomplished until the mother has almost
attained her full growth. Of the progress of
the genesic phenomena, there is as yet but
little clearly known. The first changes mani-
fest in the egg after fecundation, are the early
disappearance of the germinal vesicle and spot,
the increase of the egg in size, and the loss
of its ovular, and assumption of a spherical,
form. Soon afterwards the egg, so transformed,
is replaced by a round body, which raises
the internal tunic of the mother into a slight
nipple-like prominence, projecting into the
internal cavity of the latter. This is the rudi-
mentary placenta, and is channelled by a
cavity which is in direct communication with
the two maternal vessels previously spoken
of. These vessels are at this period very mi-
nute, but they quickly increase in size. By
their means a current of blood is already es-
tablished in the interior of the rudimentary
placenta. The maternal blood carried by one
of the vessels of the cavity rises on one side
towards its base, and then, describing an
arch, descends on the other side, to return to
the mother by the opposite vessel The first
rudiment of the foetus is, it seems, developed
after the appearance of the placenta. It is at
first a very minute body, formed on the sum-
mit of the placenta and under its envelope :
this covering is a continuation of the internal
tunic of the mother, and becomes, at a later
period, the external tunic of the foetus. The
organs soon appear in the rudimentary embry-
onic mass. The respiratory cavity, M.
Krohn observes, is, probably, one of the first
parts formed, the foetus, previously solid, be-
coming evidently hollow ; immediately after-
wards the rudiments of the hranchia and the
nervous ganglion are perceptible ; the visceral
nucleus, the eleoblast, and the heart become
distinct only at a late period. When the
eleoblast is developed, it is placed anterior to
the visceral nucleus, and the heart then begins
to contract, although feebly. It is only when
the foetus acquires a better determined form,
that the two orifices of the body become
visible, the posterior at an earlier period than
the anterior. The foetus now' surpasses the
placenta in volume, although the latter has
not, since its appearance, ceased to grow ;
and the nervous ganglion, distinguishable
from all other parts by its rapid growth, is
conspicuous from its volume, compared to
that of the other organs, and gives origin
to numerous nerve-filaments. The eleoblast,
the volume of which is considerably increased,
tends to place itself below the nucleus. It is
at this period also that we can clearly dis-
tinguish the muscular bands, although in a
yet imperfect state. Each band is represented

by two lateral symmetrical portions, separated
one from another by a large interval along the
superior surface of the body ; it is not until
a later period that the two portions are united
into a single band. The placenta also exhibits
a marked change. The cavity that it con-
tained disappears, anti its place is occupied
by the pulpy w hitish substance before spoken
of. At a more advanced stage, but still far
from the full term of development, the foetus
presents a form that subsequently is but little
altered. Its volume, compared with that of
the placenta, is greater than before. The
eleoblast, as yet less than the placenta, is now
placed behind it, and soon equals it in size.
The distribution of the vessels on the different
parts of the foetus is become more apparent ;
and the two trunks enclosed in the peduncle
of the placenta are distinguishable. Now also
the contractions of the heart may be seen to
change their direction periodically, the blood
consequently circulating in the same singular
manner as in the adult Salpians. But another
still more remarkable phenomenon manifests
itself at this period, viz. the precocious form-
ation of the stolon proliferum, which springs
from near the heart, in the form of a little
button.

During the later periods of development,
the resemblance of the foetus to the adult be-
comes more marked daily, as well as its
increase of volume compared with the pla-
centa. The foetus, which in the last period
referred to already showed some indication of
spontaneous movement, commences to alter-
nately contract and dilate its body, like the
adult animal. These movements, feeble at
first, are before long, as the animal approaches
its full term, executed with considerable
vigour. The foetus being attached to its mo-
ther, these movements cannot displace it;
and their only end, without doubt, is to draw
towards it the supply of water necessary for
its respiration. As regards the stolon proli-
ferum, its growth during all this time is so
slow, that, even at the time of the birth of the
animal, it is but a short, delicate filament.
Nevertheless, on a close examination, there
may be perceived on its surface a serrated
edge of minute elevations, indicating the first
vestiges of the buds that will subsequently be
developed into embryos.

Generation in the “ isolate'’’ Salpians. — The
“ isolate ” Salpians are, as we before mentioned,
gemmiparous, and have their young produced
on a small pedunculated organ, the stolon
proliferum, which is visible within the single
foetus whilst still contained within its “aggre-
gate ” mother. It then exists as a very slen-
der short filament, but already gives indica-
tions of buds upon its surface. After the
birth of the animal, it increases in size in pro-
portion to the continually increasing number
of buds that spring from it. It is fixed by one
of its extremities to the heart of the mother :
and it is always at this extremity that the
stolon produces new germs. The grow th of
the buds, just as the nutrition of the embryos,
being entirely dependent on the blood of the

TUNICATA.

1237

mother, the stolon is constructed to admit a
proportional quantity of the vital fluid. Two
vessels traverse it throughout its length, one
proceeding from the anterior extremity of the
maternal heart, and the other from the oppo-
site end. Hence the blood, forced into one of
these vessels by the contraction of the heart,
returns by the other ; and at each time the
heart commences to contract in an opposite
direction, the two vessels quickly coincide in
the change. M. Milne Edwards has demon-
strated that the proliferous stolons of the so-
cial and compound Ascidians are likewise
traversed by two similar vessels, one of which
has an ascending current of blood, and the
other a descending current. In examining the
stolon at a more advanced period of its
growth, one may embrace at a view, owing
to the successive germination of buds, the
complete series of the phases passed through
by each embryo, from the time of its first ap-
pearance in the form of a little button, to the
full term of its development (Jig. 788.). The

Fig. 788.

Salpa zonaria ( aggregate ) in its foetal state. Magni-
fied about 4 times. ( After Eschrkht.)

a, b, part of the first set of the young Salpas ; e,
d, the second set ; e, f, the third set ; g, the stem
with its germs ; h, h, the anterior orifices ; i, i, vis-
cera ; j, j, ganglia ; h, k, posterior orifices ; l, ves-
sels ; m, muscular hands of the branchial sacs.

phases passed through by the different organs
correspond to those that the same organs
present during the development of the “ iso-
lated” foetus.*

Development of the festal “ aggregate ” Salpce
within the “ solitary fi — Whatever may be the
mode of aggregation of the associated Salpae
at the adult age, their germs are always dis-
posed in the same pattern along the stolon
in two parallel rows, so that the germs
alternate one with another. It necessarily
follows that the embryos during growth must
be arranged in the same manner. The em-
bryos are always placed in such a manner that
the axes of their bodies cross the axis of the

* The development of the foetal “aggregate”
Salpians is beautifully illustrated in the fourth and
fifth plates of Prof. Eschricht’s Paper on the Salpas,
in the Royal Trans. Copenhag. vol. viii. 1841.

stolon at a right angle : they adhere among
themselves by means of their organs of attach-
ment. The development of the “ isolate,”
like that of the “ aggregate,” foetus proceeds
but slowly: the growth of those foetuses that
spring from the first-formed germs is not ter-
minated until after the mother has almost at-
tained her full age. It is easily conceived that,
as the number of buds continues to augment
during all the time the mother grows, the
form of the germs and the embryos, or the
embryonic chain, acquires lastly a consider-
able length. Lodged in the external tunic of
the mother, and adhering to the heart of the
latter by the aid of the vessels of the stolon,
this embryonic chain sometimes passes directly
backward, and terminates before reaching the
posterior extremity of the body, as in the iso-
lated generation of Salpa pinnata and some
allied species : sometimes, as in most other
species, it curls itself around the visceral
nucleus, describing several spiral turns, and
terminates at the anterior extremity of the
body. If we examine the embryonic chain
at this period, we may observe three very
distinct groups of embryos (fg. 788.). The
proximal group (f, e) is made up of the germs
and of the embryos, as yet but little deve-
loped, that succeed them. These present a
progressive series of the early phases of em-
bryonic development ; but the next group
(el, e) is composed of embryos much further
developed, and these being nearly all of the
same size, offer but a slight trace of gradation.
The distal group of embryos (b, a) having
arrived almost at their full growth, present no
great difference among themselves. The em-
bryos, products of the same stolons, leave the
mother in groups, and the group most deve-
loped is necessarily the first to be born. The
perfect uniformity in the size of the newly
born individuals explains also why the ani-
mals of Salpa-chains are all of the same
size and form. The embryonic chain of
S. pinnata, however, and allied species, never
presents these distinct groupings. Here,
on the contrary, the phases of development
proceed regularly, following the order of pro-
gression throughout the chain. Hence the
newly born animals, grouped in a circle, are
often somewhat unequal in size ; but this irre-
gularity soon disappears.

The embryonic chain, as we have seen, is
lodged in the external tunic of the mother.
During the earlier periods of its growth, the
substance of the tunic envelops it so closely,
that no interval is apparent between them ;
but, as the mass of embryos increases in size,
there is formed around it, and chiefly around
the most fully developed group of embryos, a
cavity which is prolonged towards the surface
of the mother’s body, and opens externally by
a large orifice. By this orifice the embryos,
when mature, make their exit. The posi-
tion of this opening always corresponds with
the point where the embryonic chain happens
to terminate, which is sometimes near the
anterior extremity, but sometimes even at
the posterior extremity of the body of the
4 k 3

1238

TUNICATA.

mother. At the moment of the birth of a
set of embryos, they detach themselves from
that part of the stolon which supported them,
and it then withers and disappears.

The embryos, as we have seen, are placed
along the stolon in such a manner, that the
axes of their bodies cross the axis of the
stolon at right angles. This original position
of the individual either persists from birth
throughout life, or is changed, accordingly as
the new-born animals belong to one or other
of the three types of aggregate form to which
the associated Salpes are hereafter referred.
In the associated Salpce of the first type, the
relative position of the individuals remains
such as it was at birth. In the Salpians of
the third type, however, a change of posi-
tion of the young individuals is very mani-
fest, fur the form of the generality of these
Salpians is not quite perfected at birth. The
two pyramidal processes with which the bodies
of S. maxima and S. fusiformis are furnished,
are but slightly developed in the newly born
animals. The growth of these prolongations
during youth is accompanied with marked
changes in the position of the respective in-
dividuals of the group. When these processes
are but small, the body of the animal is slightly
inclined to the axis of the chain. This direc-
tion becomes the more oblique as the two
prolongations increase ; anil lastly, when they
have attained their full growth, the animal is
perfectly parallel to the axis of the chain ; and
now the development of the “ aggregate ”
Salpian is accomplished.

Mode of arrangement and attachment of adult
“ aggregate ” Salpce. — Each group of aggregate
Salpce is composed of a greater or less number
of individuals of the same size. Sometimes
the individuals are grouped in a simple cir-
cular series around a common axis, as in S.
pinnata, and some allied species. Sometimes
the individuals are arranged one after another
in two longitudinal, parallel series, and so dis-
posed that the individuals of one series alter-
nate with those of the opposite series (fig.
772. c). The biserial aggregation presents
numerous variations, according to the diver-
sities and forms peculiar to the associated
individuals of different species. In these
diversified modes of assemblage, M. Krohn
points out three types, to which all the va-
riations are reducible. The first is charac-
terised by the vertical position of the animals
forming the chain, so that the axes of their
bodies cross the axis of the chain at a right
angle ( Sa/pa bicaudata^S. ferruginea) . In the
second type the bodies of the individuals are
more or less inclined to the axis of the chain
{S. mucronata, S. Tilesii). The third group is
distinguished by the horizontal position of
the component animals, the axis of their
bodies being more or less parallel to the
axis of the chain ( S . maxima, S. fusiformis,
S. punctata, S. zonaria).*

* Meyen also made an analogous distribution of
the aggregate Salpians. Vide Nova Acta Nat. Cur.
tom. xvi. “ Supplementum.”

In each group the individuals are in such
close approximation, that there exists no in-
terval between them, and the entire group
appears as one mass. The individuals touch
one another by the inferior surface, and more
or less also by the lateral surfaces of their
bodies. The superior surface, that where the
nervous ganglion is situated, and the two
orifices, remain perfectly free. Thus, for ex-
ample, in a chain in which the individuals are
disposed vertically or obliquely to its axis, the
members of each rank are united to those of
the opposite rank by their inferior surfaces,
and to their collateral neighbours by their
lateral surfaces. But, however closely the
individuals may adhere one to another, mutual
contact of the surfaces would not have been
sufficient to maintain their juxtaposition, had
not other appliances been furnished. There
are sometimes appendages of considerable
size, sometimes small protuberances, or only
circumscribed points of the surface of the
body, by the aid of which the animals adhere
among themselves so strongly, that they can
rarely be separated without some effort. These
special organs and facets of attachment have
been very incorrectly regarded by some authors
as suckers. Their number varies according
to the mode of aggregation. The associated
individuals of Sa/pa pinnata and allied species,
grouped in a circle, are provided with only a
single large appendage, springing from the in-
ferior surface of the body, and resembling
sometimes a crest (S. pinnata), sometimes a
horn (S', prohoscidalis) . The individuals, few
in number, are united by the extremities of
these appendages, which meet one another
in the centre of the group. The organs
of attachment of Salpce aggregated in chains
are protuberances and facets, generally about
eight in number. Four are placed in pairs
on the inferior aspect of each animal, and
serve to unite it to its two neighbours in
the opposite series ; of the two other pairs,
one pair occupies one of the lateral faces,
the other the opposite lateral surface, uniting
the individual to its two collateral neighbours.
The position of these organs varies accord-
ing to the form of the associated individuals,
and accordingly as they belong to one or the
other of the above mentioned types. Of these
appendages we may notice the two prolonga-
tions of the body common in most of the
aggregate forms of the third type, as in S.
maxima, S. fusiformis, and chiefly by means of
which the contact of the individuals is pre-
served. Both are pyramidal in form, and arise
one from the anterior and the other from the
posterior extremity of the body.

We will here remark that an individual
cannot spontaneously separate itself from the
group of which it forms a part. It is true
that free individuals are often met with, but
their separation is always due to some acci-
dent. M. Krohn thinks even that the union
in groups is so necessary to the maintenance
of the life of each animal, that it soon perishes
if by chance it becomes detached.

1239

TUNICATA.

Anatomy of Pelonaia.* — Muscular sys-
tem.— The mantle is similar to that of other
Tunicates, possessing longitudinal and circular
fibres ; the former in P. eorrucala forming a
thick bundle at their origin round the respira-
tory opening. A strong band of transverse
fibres passes round it, in one species, imme-
diately below the anal orifice, encroaching on
the cavity principally on that side. The chief
peculiarity of the mantle is its firm adhesion
to the test.

Fig. 789.

Anatomy of Pelonaia glabra. ( After Forbes and
Goodsir .)

a, a bristle inserted into the respiratory sac
through the oral orifice ; b, a bristle inserted into
the mantle cavity through the anal orifice of the
test ; e, ganglion, with the nerves proceeding from
it ; d, the shelf, or transverse ridge, in the interior
of the test and mantle ; e, branchial vein, enclosed
ill a serpentine band, as in some of the other Asci-
dians ; f branchial artery ; g, generative organ on
the left side, with a bristle inserted into its duct ;
h, the stomach ; i, anus ; k, k, cut edge of the test.

Digestive and respiratory systems. — The
respiratory opening is of small size, and ex-
hibits no folds or tentacular fringes. The
respiratory sac is elongated, cylindrical, con-
tracting rather suddenly towards one side to
become continuous with the oesophagus. On
the external surface of the sac there are about
thirty parallel transverse ridges, which give it
the appearance of a plaited frill. These plaits
are less apparent along the course of the

branchial artery and vein, but midway between
them on each side they are very prominent,
and are tied, each by a minute cord, to the
inner surface of the test. The internal sur-
face of the sac exhibits along one side the ser-
pentine double cord which contains the bran-
chial vein ; along the other side the branchial
artery; and from these primary and secondary
perpendicular branches proceed, as in other
Tunicata. The transverse plaits on the ex-
ternal surface of the sac correspond to the
primary or transverse branches of the vessels
on the internal surface. During the life of
the animal, without doubt, cilia exist in great
abundance on the edges of the lozenge-shaped
spaces of the sac.

The oesophagus commences by a white
plicated opening at the lower end, and on one
side of the sac (fig. 789.). It is curved in a
sigmoid form, and exhibits longitudinal rugae
through its coats. Near the lower end of the
mantle-cavity it terminates by suddenly dilating
into the stomach (4), which is pear-shaped, and
directed obliquely upwards towards the side
opposite to the oesophagus. The internal
surface of the stomach presents longitudinal
plicte. It is succeeded by the intestine, which
at first curves upward, and then down to the
bottom of the branchial cavity7, up along the
oesophageal side of that cavity and between its
walls and the branchial artery, terminating
about the anterior third of the animal in a
funnel-shaped anus (i), which is cut into ten
or eleven processes, like the petals of a flower.
The first part of the intestine is white, and
longitudinally plicated ; the rectum is dilated,
and its coats are attenuated.

Vascular system. — The vascular system re-
sembles that of the Ascidiadee, except that
there is no heart. It consists of two sets of
vessels, w’ith four sets of capillaries ; a circle
in fact twice interrupted, once in the respira-
tory sac, and again throughout the body. The
branchial veins run along the transverse plaits
of the sac, receiving secondary and ternary
twigs at right angles. The primary branchial
venous branches empty themselves on each
side into the branchial trunk, which runs in
the substance of the double cord which coasts
the superior aspect of the sac. This double
cord terminates in an abrupt manner anteri-
orly near the oral orifice, and in a similar
manner, but often becoming smaller near the
orifice leading to the oesophagus. At this
point the vein becomes an artery, and pro-
bably sends back vessels to nourish the sac.
It now runs along the oesophagus, supplying
the stomach and intestine, and giving off in
its course branches to the mantle. The veins
arising from the arterial capillaries of the
body meet near the commencement of the
oesophagus in one trunk, which, passing along
the inferior wall of the respiratory sac, oppo-
site to the branchial vein, performs the (unc-
tions of a branchial artery. It is interesting
to observe here the differences between the
modes in which the branches enter the
branchial vein, and strike off from the bran-
chial artery. In the former, just before the
4 k 4

From Forbes and Goodsir, he. cit.

1240

TUNICATA.

branches enter the trunk, they give off a
number of vessels, which enter a trunk along-
side of the parent trunk, the combination
forming a sort of delta ; in the latter, they
leave the trunk singly, and send off their
branches in a radiating direction. At a little
distance from the trunks of both artery and
vein, the secondary branches become parallel
to one another and perpendicular to their
primary branches, the more minute divisions
following the same mode of ramification.

Nervous system. — This system consists, as
in other Tunicates, of a ganglion situated in
the substance of the mantle, between the oral
and anal orifices. It is globular, and sends
off nervous twigs, firstly, to the respiratory
orifice of the mantle ; secondly, to the respira-
tory sac, where it begins to exhibit the trans-
verse plates ; and thirdly, to the anal orifice
of the mantle.

Generative system. — The generative organs
consist of two elongated tubes, closed at one
end, open at the other, and having a great
number of close-set parallel cceca arranged at
right angles, and opening into them along each
side. These tubes are attached to the internal
surface of the mantle ; their mouths are free
for a short distance, and prominent the rest
of their extent, and the attached coeca
adherent. The orifices of these organs are
situate at the junction of the first with the
second quarter of the animal, and one third
of the other end of each turns in towards its
neighbour, and then proceeds forward parallel
to itself. The branchial vein runs midway
between the generative tubes above, anil the
branchial artery in a corresponding course
below, so that the threads of the attachment
of the plaits on the external surface of the
sac are fixed into the tubes in a series on
each side.

From the details of the structure above
given, it is evident that the Pelvnaia is a
true Tunicate. Its anatomy is important, and
assists in the elucidation of the nature of the
parts and organs in other members of the
group. They present the positive anatomical
character of a union of the mantle with the
test ; so that there can be little question of their
right to be regarded as members of a distinct
family of Tunicata ; and it is worthy of
notice, says Prof. Forbes, that Mr. Mac Lea}',
in his valuable remarks on the arrangement
of the Tunicates (Linnaean Transact, vol.xiv.)
had hypothetically indicated such a group as
this now constituted. Whilst in many of
their characters they approach the true As-
cidians, especially the unattached species of
the genus Cynthia, in others they indicate a
relationship with the cirrhograde Echinoder-
mata. They differ from their Tunicate allies
chiefly by their not being fixed, and by their
form, which reminds one more of that of a
Siphunculus than of an Ascidia ; indeed, they
may be regarded as analogous to certain
Siphunculidce ; and in that point of view the
details of their form and structure are of
much interest to the naturalist. They differ
also, add Messrs. Forbes and Goodsir, from

the Ascidians, more particularly in being bila-
teral. The generative organs are symmetrical,
and open one on each side of the anus,
which is directed towards the ventral surface
of the animal, in a line with the mouth and
the nervous ganglion. The latter is thus
proved to be an abdominal or suboesophageal
ganglion, corresponding to or forming one of
the chains of ganglia on the abdominal surface
of the Articulata. In the same manner, the
branchial artery or heart is proved to be the
pulsating dorsal vessel, and the branchial vein
the abdominal vessel (when that vessel exists)
in the Annulosa. It is interesting also to
perceive, that, co-existing with this decided
approach to the annular type of form, we
have the transverse plaits of the respiratory
sac corresponding to the rings of an articu-
lated animal. The disappearance of a separate
test is also a departure from the plan of
formation in the Ascidiadce and their allied
groups, and an approach to other types of
form, and more particularly to the cirrhograde
Echinoderms, with certain of which Pelonaia
has at least an analogical relation, in the
water-filled body, and in the external form.

Pelonaia, in fine, is one of those connecting
genera so valuable as filling up gaps in the
system, and supplying links in the chain of
structures which runs through the series of
organised bodies.

Locomotion of Tunicata. — Generally
speaking, the muscular tissue of the Ascidiadce,
BotrylUdce, and Pelonaiadce is not subservient
to the purposes of locomotion, and merely
effects the sudden removal of water and
noxious objects from the branchial sac. The
entrance and exit of water through the ex-
ternal orifices, constituting the chief sign of
vitality in these apathetic creatures, are ge-
nerally caused by the ciliary currents.

But the water may be driven out by an
ejaculatory effort of the constrictor muscles
of the mantle ; which action would be followed
by a more or less rapid expansion or dilata-
tion of the mantle and test, effected by the
elasticity of the latter. In such species as
occasionally occur unattached, or even float-
ing about freely, such an ejaculatory action
would effect a transitory retrograde move-
ment ; but we have no evidence that any of
the Ascidiadce or Pelonaiadce make use of this
propulsive agent in the manner of the Pyro-
somata and the Salpee. Nearly all the Asci-
diadce and Potryllidce are sessile, but some
few, mounted on flexible pedicles as Boltenia
and Sigillina, may be said to enjoy a limited
freedom of movement, necessary perhaps to
their well being ; and the same may be said
of such species as are attached to the floating
branches of flexible algae and corallines.

According to Mr. F. D. Bennett, except in
the action of the sphincter-like membrane,
surrounding the open extremity of the com-
pound cylinder, there was but very slight
evidence of motive power in the specimens of
Pyrosoma examined by him. MM. Peron and
Lesneur, however, describe a slight retrograde
motion observable in this animal. The

TUNICATA.

1241

method in which this is brought about is not
very clear ; it appears to be caused either by
the synchronous contraction of the individual
animals, causing a diminution in the general
calibre of the cylinder, and thus effecting a
faint ejaculation of water from the cavity ot the
latter ; or by the posterior current of water from
the anal orifice of each animal being synchron-
ously ejected into the cavity of the cylinder,
and thus giving a motive power to the whole.

We have a more decided locomotion ex-
hibited in the Sa/pa, which is treated of by Mr.
Bishop* as a “ syringograde” animal, in the
same category as “ the Holothuria, and the
larvae of those insects whose progression is
effected by the alternate reception and expul-
sion of water to and from their respiratory
organs by an action similar to that of the
syringe.” In Sa/pa the dilatation of the test
and its membranous lining causes the water
necessary for respiration and nutrition to
enter through the b. labiate posterior orifice,
which has a valve preventing the return of
the water by the same aperture f; a trans-
verse contraction of the body then expels the
water through the anterior orifice, and the
result is, that the animal is forced backwards,
being carried in an inverse direction to that of
the ejected water, j: This retrograde motion

* See art. Motion, Yol. III. p. 433.

f See figure of Salpa cristata, showing most of
the branchial muscles and the position of the valve
(the latter is ideal, not being visible externally
in the animal), fig. 228. p. 434. Vol. HI.

J In a communication from my friend Mr. Pittard
on the subject of Syringograde movement, he re-
marks as follows : “ I am not aware that a true and
satisfactory explanation has ever been given of the
backward motion of bodies resulting from the ejec-
tion out of them of jets or currents of fluid. That
the action of such jets is at all comparable to the
thrusting out of a solid body, or pole, against some
resisting object, is by no means maintainable; for
the property of rigidity, which is totally and in all
circumstancss absent in fluids, is an indispensable
condition for the production of such a result. Nor
is the action due to the resistance of the external
medium in any other way, but solely to the hy-
draulic pressure of the contained fluid on the in-
ternal surface of the walls of the hollow body. It
has been supposed that the resistance of the sur-
rounding medium acts in some degree like the walls
of a cannon would in the following case : — If a
bomb-shell, containing gunpowder, in the act of
exploding, were placed in a cannon with the match-
hole of the shell open and turned towards the
breech, so that an explosive jet should be projected
into the cavity of the cannon, the shell would be
forced out with a much greater impetus than it
would have if, cceteris paribus, it were in the open
air. But this is not a parallel case, for here you
have the resistance of the closed end of the cannon
in one direction, and an open end, or no resistance,
in the opposite direction ; whereas, in the case
under consideration, you have just the same re-
sistance from the external medium in front of the
body moved, as you have behind it ; and whatever
tendency to motion might result from such a re-
sistance of the medium to the jet behind, just so
much would there be resisting motion in front ; so
that the effect would be neutralised, and no motion
would result. The truth is, that from the two
absolute laws of hydraulics, — that a fluid presses
equally on all portions of the surface on which it
acts, and that the direction of this pressure or

has caused the posterior orifice to be regarded
by some naturalists as the true oral orifice. The
alternate action, of dilatation and contraction,
have been observed to take place about fifteen
times in a minute ; and have sometimes been
termed the systole and the diastole. The
contraction is effected rapidly, but the relax-
ation, or rather the dilatation of the sub-
elastic test, takes place but slowly. These
movements are synchronous throughout a
chain or group of Salpce.

After all, this is but an imperfect amount of
locomotion, and it is extremely probable
that both the single Salpce and the Salpian
wreaths and chains, the latter often several ) ards
in length, are, like the feebly moving Pyrosoma,
the sport of wind and wave, wafting them
hither and thither, either to bask calmly in the
sunshine, or to be broken on the rocky shore.

Affinities of the Tunicata. — Many
of the early naturalists (as we have noticed
in the first part of the article) noticed the
analogies existing between the Ascidia and
the Ostrea, Mytilus, and other Mollusca.
The compound Ascidians, however, long
remained grouped with Alcyoniuvi, until Sa-
vigny, Lesueur, and Desmarest pointed out
their alliances with the simple Ascidians and
with Molluscs. Lesueur also demonstrated
the ascidian character of Pyrosoma, and re-
moved it from the Radiata, amongst which it
had been grouped ; and Cuvier pointed out
the alliance of Salpa with Ascidia and Mollusca.
Soon after the publication of the important
zoological conclusions thus arrived at by his
distinguished countrymen, Lamarck formed
these animals into a new group, under the ap-
pellation o f Tuniciers* (I'linicata) , provision-
ally placing them between the Radiata and
Venues, and expressed strong doubt of their
general alliance with the Mollusca.

John Hunter, who perceived the relations

force is at right angles to such surface, — it results
that the force exerted by or through a fluid con-
tained in a closed hollow body is exactly equal in
opposite directions ; that is to say, whatever may
be its force impelling towards the right, by just so
much does it impel towards the left ; however
much it impels forwards, by just so much does it
impel backwards ; and so on for up and down, and
all other opposite directions : so that the one exactly
antagonises the other, and an equilibrium results.
But remove a portion of the wall ; in other words,
make a hole through which the fluid may escape,
and then the pressure, in the direction of the side
in which the hole is made, is minus, or less than
the force in the opposite direction, by the size of the
hole. The body, therefore, moves in the direction
opposite to the hole, in obedience to the plus, or
excess of hydraulic pressure in that direction.” The
Salpa, compressing the water in its interior, pro-
duces a large amount of hydraulic force. Its pos-
terior orifice being closed, it presents a hole or
deficiency in the front only, and is impelled in the
opposite direction. Also, during the act of taking
in water behind, the animal moves likewise back-
wards, for then there is, so to speak, an inversion of
the process described above. The pressure of the
external water, otherwise equal on all parts of its
surface, is minus behind by the size of the posterior
orifice, and therefore plus in front, again impelling it
backwards.

* Applied at first to the Botryllidce only.

1212

TUNICATA.

subsisting between Ascidia and Salpa, and
knew the true analogy of their exterior co-
vering, proposed to distinguish them as a dis-
tinct group of Molluscs, under the term “ soft-
shells,” which more truly accords with their
real nature than “shell-less” ( Acephales sans
coquil/es ), as they have been subsequently de-
signated by Cuvier*, who also, together with
Blainville, regarded them as acephalous Mol-
luscs, and sufficiently distinct to form a sepa-
rate class.

In many of the Acephala we find two tubes
for the ingress and egress water, like those of
the Ascid'uB, and the mantle closed throughout
its length, the walls of its cavity lined with
the branchiae, and the mouth at the base of
this cavity. The Ascidia being immovable,
has neither adductor nor foot-muscles; for,
being destitute of a locomotive organ and of
valves, the muscles disappear, with the excep-
tion of some sphincter-like bands. Together
with the muscles, the pedal nerve-ganglions,
or rather suboesophageal or posterior ganglions
are lost, and there remain only the buccal or
supra-oesophageal ganglions. The differences
between the heart and auricles of the Asci-
dians and the other Molluscs are dependent
on the modification of the branchiae ; the
latter, in Ascidians, never being arranged in
the four lamellae usually found in Molluscs.
The digestive tube and the generative organs
are essentially the same in Tunicata and Ace-
johala, and in the latter, as in the former, the
ovary and testicle are enclosed in the intes-
tinal loops.

Yet however much resemblance we may
find between the Acephala and the Tunicata ,
there is still more between the latter and
the Bryozoa. Van Beneden observes, that if
a Bryozoon was confined to its cell, and still to
carry on its respiratory function by its un-
protruded tentacles, and if anastomosing com-
munications were established between the
tentacles and a heart at their base, we should
have the complete idea of an Ascidian. There
would be two external orifices, a single
mouth situated at the base of the branchial
sac, vibratile cilia throughout the extent of
the anastomosing tentacles, a folded intestinal
canal, a supra-cesophageal ganglion, some
muscular bands, and organs of generation
developed around the digestive tube. There
would be only wanting to complete the animal,
a cloaca to receive the excrements, the sperm,
and the ova, and a direct passage of commu-
nication between the respiratory and the

cloacal cavities. The gemmiparous mode of
reproduction observed in the Clavellinas, and
Botryllidce closely resembles that which ob-
tains in the Bryozoa. With regard to the de-
velopment of the Acephala, compared with

Fig. 790.

A, Ideal figure of an

Ascidia. ( After Van

Beneden).

a, a, the external ori-
fices, branchial and anal ;
b, straight branchial ves-
sels ; c, transverse and
anastomosing branchial
vessels ; d, respiratory
cavity ; e, oesophagus ; f,
digestive cavity ; g, rec-
tum ; h, cloaca, commu-
nicating with branchial
cavity, rectum, and ge-
nerative organs ; i, inte-
gument ; k, peri-intesti-
nal cavity.

B, Ideal figure of a
Bryozoon.

a, entrance of the
sheath ; b, tentacles, hol-
low throughout their
length, equivalent to the
straight branchial ves-
sels ; d, the sheath ; c,
mouth, leading to the di-
gestive cavity ; g, anus ;
i, integuments; h, peri-
intestinal cavity.

that of the Tunicata and Bryozoa, Van
Beneden points out the following analogies ;
— “ There exist common characters between
the Bryozoa and the Anodonta in this re-
spect ; their larvae respectively swim about
by means of vibratile cilia. They have a dif-
ferent form in the young and the adult states,
and they undergo true metamorphoses. The
same phenomena are seen in the Ascidians.
These also have metamorphoses, perhaps,
even more complete, but instead of vibratile
cilia, the embryo is provided with a caudal
appendage sufficiently long to serve for the
purposes of locomotion ; which tail disappears,
just as the vibratile cilia of the former, as soon
as the animal becomes definitely fixed.”

The embryogenic characters appear to en-
tirely accord with the anatomical dispositions
of these groups ; and altogether we are, per-
haps, justified in considering, that they ap-
proach on one side to the Acephala, and,
through the Pedicel/inaf, they are, on the
other hand, allied to the Bryozoa, forming a
closely uniting link between these two impor-
tant groups. J

* Catal. Hunterian Museum, vol. i. p. 260. note.

f For Van Beneden’s researches on the development of the Pedicellina, &c. see art. Polyfifera.
j The following tabular arrangement, given by Prof. Van Beneden in his clever exposition of the
alliances of the simple Ascidians {loc. cit. p. 58.) is a valuable illustration of the subject.

f IPypocotyledones.
Epicotyledones.

Ax DIALS

-- Allocotylddonfis

|"Mollusques
(^Polypes -

{C^phalopodes.
Gasteropodes.
Acephales.
Tuniciers

{Bryozoaires.
Medusaires.
Anthozoaires.
Alyconaires.

(Salpiens.
Pyrosomiens.
Ascidiens.
Polyascidiens.
Pe'rophoriens.

Echinodermes.

TUNIC AT A.

There have been certain organic remains*
figured and described as belonging to the
Tunicate family, but which (with the exception
of the obscure and indeterminate Ischadites
Kcenigii ) have been found to belong to the
family of the Cystidea of Von Buch, closely
allied to the crinoidean family of the Radiata.

At first sight there is considerable resem-
blance between many of these cystidean forms
and the ascidian genus Boltenia, the body
being globose or subcylindrical and pedun-
culated. In the Cystidea there are two more
or less terminal orifices, and a third lateral
aperture. The whole animal is coated with hex-
agonal plates variously ornamented ; the stem,
perforated throughout and giving evidence
of quinary arrangement. “ The mouth,” says
Von Buch, “is planted in the central part of
the upper surface, generally in a moveable
proboscis, covered with minute plates ; the
anal orifice is small, close to the mouth, per-
forating a plate, not surrounded by separate
valvules ; and the third aperture, probably
the ovarial orifice of the animal, is placed
further towards the middle, but almost inva-
riably on the upper half of the body on which
the mouth is placed. It is round or oval in
form, not connected with the mouth, and often
covered by a five or six-sided pyramid, which
seems to be composed of as many little valves.”

We have introduced this description that
we may here point out the general similarity
of the external form of these obsolete radiate
animals to some of the ascidian group, and
that we may in particular point out the very
similar armature of ornamented hexagonal
plates present in Chelyosoma, with its valve-
surrounded orifices. With regard to the ad-
ditional orifices, we have but to lengthen out
the oviduct or efferent vessel of the Ascidia,
and continue it to the surface, as in the mal-
formation noticed and drawn by John Hunter,
and a very similar arrangement of parts will
apparently exist.

There are several points of analogy between
some forms of Ascidice and of Zoophyta asci-
doida ( Bowerbankia , &c.) and the Radiata:
into this subject we must not now enter ; we
can only allude to the observations of Messrs.
Forbes and Goodsir on the Pe/onaia (see
p. 1239.), and leave the subject open to further
investigation.

Bibliography. — Besides the works, connected
with the subject, that are referred to in the text,
the following are some of the most important : —
Peron, Memoire sur le Noveau Genre Pyrosoma.
Annales du Museum d’Histoire Naturelle, t. iv. 1804.
Lesueur, Memoire sur l’Organisation des Pyrosomes,
et sur la Place qu’ils doivent occuper dans une
Classification Naturelle. Lu a la Societd Philo-
matique de Paris, le 4. Mars, 1815. Journal de
Physique, Juin, 1815, t. lxxx. Desniarest et
Lesueur, Memoire sur le Botrylle etoile ( Botrylhis
stellatus ). Lu a la Societe Philomatique de Paris,
le 22. Avril, 1815. Journal de Physique, Juin, 1815,
t. lxxx. Desmarest et Lesueur, Extraits de deux
Mdmoires lus it la Societe Philomatique de Paris,
en Mars et Avril, 1815, sur 1’ Organization de deux

* Leucophthalmus, Koenig ( Sphaironites ), Sa-
eonites, Raftnesque, &c.

1243

Animaux Marins places jusqu’ici dans la Classe des
Radiaires, et qui doivent etre rapportes h celles des
Mollusques, &c. Bulletin de la Societe Philoma-
tique de Paris, livraison de Mai, 1815. Cuvier,
Memoire sur les Tkalides ( Thalia, Brown), et
sur les Biphores ( Salpa , Forskaohl). Annales du
Museum d’Histoire Naturelle, t. iv. 1804. Cuvier,
Me'moire sur les Ascidies et sur leur Anatomie.
Memoires du Museum d’Histoire Naturelle, t. ii.
1815. Cliiaje, S. delle, Memoria sulla Storia e
Notomia degli Animali senza Vertebre del Regno
di Napoli, 4 vols. 4to. Napoli, 1823 — 1829. Ibid.

Figure, 4to. 1822 — 1828. Savigny, J. C., Me-

moires sur les Animaux sans Vertdbres, pt. i. and
fasc. 1. de pt. ii. Recherches Anatomiques sur les
Ascidies Composees, et sur les Ascidies Simples,
8vo. Paris, 1816. Fleming (Dr.), British Animals,
8vo. Edinburgh. Supplem. Encyclop. Brit. art.
Molluscs. Quoy et Gaimard, V oyage de 1’ Astro-
labe, Zoologie, t. iii. Quoy et Gaimard, Voyage
de l’Oranie, t. ii Blainville, Dictionnaire des Sciences
Naturelles, art. Mollusques. Chamis'O, Dissertatio
de quibusdam Animalibus e Vermium Classe Lin-
nteana. Fasc. 1. De Salpa. Berolini, 1819, 4to.
MacLeay, Anatomical Observations on the Natural
Group of Tunieata, with the Description of three
Species collected in Fox Channel during the late
Northern Expedition. Read June 15. 1824. Trans.
Linn. Soc. vol. xiv. 1825. Meyen, Beitrage zur
Zoologie, gesammelt auf einer Reise um die Erde.
Erste Abtheilung, fiber die Salpen. Nova Acta
Acad. Cies. Leop. Car. Natur. Curios, t. xvi. pars
prior, 1832. Eschricht, Anatomisk-physiologiske
Undersogelser over Salperne. Royal Danish Trans-
actions, vol. viii. 1841. Eschricht, Anatomisk
Beskrivelse af Chelyosoma Mac-Leayanum. Royal
Danish Transactions, vol. ix. 1842. Sars, Beskri-
velser og Iagttagelser oder Nogle Mserkelige eller
nye i habet bed den Bergenske Kyst lebende dyr
af Polypernes, Aealepliemes, Radiathemes, An-
nelidernes og Molluskernes Classer, 4to. Bergen,
1835. Sars, Fauna littoralis Norwegiaa, 1st part
( Salpa ). Dalzell, A singular Mode of Propagation
among the lower Animals ( Ascidia and Aplidium).
Edinb. New Philos. Journ. vol. xxvi. 1839; and
Isis, viii. 1839. Dalzell, On some of the rarer
Animals on the Coast of Scotland, &c. Home ( Sir
E.), Lectures on Comparative Anatomy, vol. ii.
(Salpa). 4to. London, 1814. Carus, Beitrage zur
Kenntniss des inneren Baues imd der Entwicke-
lungs Geschichte der Ascidien. Nov. Act. Nat.
Cur. vol. x. Carus, Beitrage zur Anatomie und
Physiologie der Seescheiden. Meckel’s Archiv. f.
Physiol. B. ii. H. iv. Cams, Anatomie Compar. vol.
ii. Eysenhardt, Ueber einige merkwurdige Lebens-
erscheinungen an Ascidien. Nov. Act. Nat. Cur.
t. xi. Lister, Phil. Trans. 1834, part ii. Milne Ed-
wards, Observations sur les Ascidies Composees, qui
se trouvent aux Cotes de la Manche. Mdm. Acad, des
Sciences, t. xviii. Milne Edwards, Sur la Circula-
tion du Sang chez les Pyrosomes. Comptes Rendus
de l’Acad. des Sciences, t. x. 1840, p. 284. ; Sur la
Circulation et sur i’Existence d’un Systemes Ner •
veux chez les Salpes. Ibid. p. 408. Annales
des Sc. Nat. 2de sdries, t. xiii. Milne Edwards,
Recherches Zoolog. faites pendant un Voyage en
Sicile. Comptes Rendus, 1844, t. xix. p. 1137. Milne
Edwards et Audouin, Rdsume des Recherches
faites aux lies Chaussey. Ann. Sc. Nat. t. xv.
Gervais, Suppl. Diet. Sc. Nat. lme vol. art. Asci-
dies. Coste, Recherches sur l’Appareil respira-
toire des Ascidiens. Comptes Rendus, 1842, t. xiv.
Broderip and Sowerhy, Observations on New Mol-
lusca, &c. ( Chelyosoma ) Zoolog. Journal, vol. v.
Johnson, Mag. Nat, Hist. 1834 (Aplidium). Penny
Cyclopedia, articles S alp ace A and Tunicata. Van
Beneden, Recherches sur 1’ Embryogenie, 1’Ana-
tomie, et la Physiologie des Ascidies Simples.
Mdmoires de l’Academie Royal de Belgique, t. xx.
1847. Forbes (E ), Forbes and Hanley’s History of
British Mollusca, 8vo. London, parts i. and ii. 1848.

(T. Rupert Jones.')

1241

URETHRA.

URETHRA. — (Lat. Urethra ; Gr. ovpijdpa;
Fr. Urethre .)

In the Male. — The urethra, or uro-sexual
canal, is the canal by which the urine, the secre-
tion of the testes, of the prostate and Cowper’s
glands, with that of the vesiculae seminales,are
discharged. It commences at the opening in
the anterior part of the neck of the bladder,
and terminates at the extremity of the glans
penis. In the beginning of its course it tra-
verses the prostate gland ; it then perforates
the triangular ligament, which is stretched
across beneath the arch of the pubis ; and
after passing through this it enters the groove
between and beneath the corpora cavernosa
penis, and is now surrounded by the corpus
spongiosum urethrae; and passing through the
glands, an expansion of the latter body, it ends
in a slit-like orifice, the meatus urinarius.

Direction. — The direction of the canal
varies according to the state of the penis :
thus in the relaxed condition of this organ
it presents curves like the italic Co procum-
bent ; if we trace it backwards from the
meatus, it will be seen to rise towards the
pubis ; thence it descends slightly, and passes
beneath the arch of that bone, after which
it makes a gentle curve upwards to the neck
of the bladder.

When the penis is erect, the urethra is
straight for at least three-fourths of its course,
that is, whilst it traverses the spongy body ;
after which it makes a rather abrupt curve
towards the opening into the bladder. In the
introduction of the catheter, the surgeon, by
drawing the penis forwards and upwards,
straightens the anterior three-fourths of the
canal, thus approximating its direction to that
which it assumes in the erect state of the
penis ; and now, by careful manipulation, in
depressing the handle of the instrument be-
tween the thighs, to a level with the urethral
opening in the triangular ligament, he can,
without any difficulty, succeed in passing even
a straight catheter into the bladder.

It is important to remark that the anterior
three-fourths of the urethra are loose and
pendulous, whilst the remainder is fixed to
the pubis in a manner presently to be de-
scribed; a circumstance to be borne in mind
in catheterisation.

The urethra is divided by anatomists into
th.ee parts, each presenting characteristic
peculiarities. Thus the first part is termed
the prostatic portion, because it is surrounded
by the prostate gland ; the second is de-
nominated the membranous portion, because,
when deprived of its surrounding structures,
it is little more than a simple membrane ; it is
also called the muscular part, because it is
encircled by muscular fibres ; and the last,
being entirely invested by the corpus spon-
giosum, is designated the spongy portion.

According to a rough measurement, it may
be stated that the spongy portion occupies
about seven parts, the membranous rather
less than one part, and the prostatic rather
more than one part of the entire length of the
tube.

Length. — The urethra has been frequently
measured to ascertain its length and diameter ;
and much attention has been devoted to
this subject by various observers, with the
view to the treatment of strictures and
other diseases incidental to this canal. It
need scarcely be remarked that the urethra
varies at different periods of life, according to
the evolution of the generative organs ; and
hence it is much shorter in the child than in
the adult, and it is well known frequently to
undergo a marked elongation in old persons,
in consequence of hypertrophy of the pro-
state gland.

I shall here introduce the measurements in
length, as given us by some practical surgeons,
whose attention has been especially directed
to this subject, observing that the length of
the urethra is expressed by the extent to
which it can be stretched, by drawing the
penis somewhat forcibly forward.

According to Ducarp, it rarely exceeds nine
inches in length. Whately examined the
urethra in forty-eight subjects of different
heights : these he arranged under three heads,
viz. tall, middling, and short.

In 16 subjects of tall stature, the urethra
measured

In 1 subject, 9 inches 6 lines.

8 „ 9 inches.

2 „ 8 inches.

5 „ 8 inches 6 lines.

In 23 of medium stature, it measured

In 3 subjects, 9 inches.

1 „ 8 inches 9 lines.

7 „ 8 inches 6 lines.

2 „ 8 inches 3 lines.

1 „ 7 inches 6 lines.

Whilst in 9 of short stature, it measured

In 1 subject, 8 inches 9 lines.

2 „ 8 inches 6 lines.

4 „ 8 inches.

2 „ 7 inches 9 lines.

The collective average is therefore nearly
8J inches, and the respective averages would
stand thus: —

For those of tall stature, it would be 8in. 91.
For those of middling stature - 8in. 21.

For those of short stature - - 8in. 31.

Lisfranc examined the urethra in twelve
adults, and he found its length to vary from
9 to 10 inches. In a negro it measured 12
inches.

M. Petrequin has collected the various
measurements of the canal, as given by the
French writers on this subject, by which
it appears that the estimated length varies
front inches to 12 inches. Petrequin con-
ducted his own examinations with both
straight and curved instruments. With the
straight instrument he found the length of the
urethra between 5f and 64 inches, whilst with
a curved instrument it measured from 64 to 7
inches. The difference he explains by the fact,
that, inasmuch as the urethra is not recti-
linear, a straight instrument cannot be passed
through it without effacing the angle between

URETHRA.

1245

the bulbous and membranous portions of the
canal.*

Mr. Briggs observing that most of his pre-
decessors had examined the length of the
urethra after death, made a series of examina-
tions of the canal in the living subject; and
he adopted the following mode of examina-
tion : — He introduced into the bladder a ca-
theter without a stilet, on the stem of which
was marked a graduated scale of inches and
fractional parts, measured from the eye of the
instrument. He observes, “ as soon as the
urine begins to flow from the catheter, which
has only one eye, the line marked on the stem
corresponding with the external meatus will
necessarily indicate the exact length of the
canal, or the distance from the meatus to its
termination in the bladder. Of sixty persons
in whom the urethra was measured thus, the
length was found to vary from 6f to 8^ inches.
In eight instances, or rather less than one-
seventh of the whole (twenty of them being
persons of short stature, or not exceeding
5 feet 4 inches in height), the length of the
urethra was found to be under 7 inches. In
forty-five instances, or three-fourths of the
number, i. e. in persons of middle stature, the
measurement was found to be between 7 and

8 inches, and in a few it exceeded 8. In some
instances of very corpulent subjects, at an
advanced age, the urethra was found to be 10
inches in length.” He considers the average
length of the passage to be 7i or 7f inches,
the external parts being in a natural condition,
neither hanging in a loose, flabby state, nor
unusually retracted. Briggs found the pro-
portions of the various parts of the canal to
stand relatively thus : — from the orifice to
the membranous part, inches ; from thence
to the bladder, If inch inches. As there
was no stretching of the penis in the examina-
tions thus made, it is easy to reconcile the
discrepancies between Briggs’s and Whately’s
measurements.

Of the relative length of the different por-
tions of the canal, M. Petrequin cites the fol-
lowing authorities : — The prostatic portion
measures, according to Boyer, 15 or 16 lines ;
Littre, 15 lines; Du camp and Blandin, from
12 to 15; Senn, 13; J. Cloquet, 15. M.
Petrequin agrees with Lisfranc, that the most
exact measurement is from 8 to 1 1 lines.

Boyer estimates the length of the mem-
branous portion at 12 lines ; Ducamp, from

9 to 12 ; Blandin, at 10 ; Lisfranc, from 7 to 1 1.
M. Petrequin has found it to vary from 6 to
9 lines, when measured by its central axis ;
its upper surface measuring from 8 to 10 lines,
its under surface from 4 to 5 and sometimes 6,
the difference arising from the projection of
the bulb beneath. The mean length of the
prostatic and membranous portions taken to-
gether is, according to Malgaigne, 13 lines,
but it varies from 11 to 15 lines. Petrequin

has found it to vary from 14 to 18 and some-
times 20. As to the bulbous and pendulous
portions of the urethra, their rectilinear mea-
surement is 6 inches or 6 inches and 10 lines,
and the curvilinear 5 inches or 5 inches and
4 lines.*

Diameter. — In diameter, also, the urethra
varies according to age: thus in the young sub-
ject it is small ; indeed its diameter increases in
proportion to the age of the individual; and
in the aged, partly in consequence of the flac-
cidity of the parts surrounding it, partly from
the loss of contractility in its own tissue, its
capacity becomes immensely increased, so
that it will readily admit a catheter of half-
an-inch bore, and the escape of fragments of
stone of equal size.

Even in the infant, however, the urethra is
more capacious than is generally imagined,
and will admit a much larger sound than we
should a priori suppose ; a fact of no small im-
portance in sounding at this early period of
life. When the penis is erect, the urethra is
diminished in diameter, from the pressure of
the turgid veins of the spongy body, and from
the increased distension of its own blood-
vessels.

To ascertain the diameter of the urethra,
and to compare it in persons of different
ages, Sir E. Home examined the canal in
two persons — one of the age of 80, and the
other 30.

At 80.

At 9 lines from the meatus

it measured - - - 5 lines

At 4 inches 3 lines from ditto 4
At 6 inches from the meatus
(at the bulb) - - - 7

At 7 inches (beginning of
membranous part) - - 4

At 7 inches 9 lines (near the
prostate) - - - 5

At 8 inches (beginning of
the prostatic part) - 4
At 8 inches 3 lines (the
middle of ditto) - - 6

At 8i- inches (near the neck
of the bladder) - - 5

At 30.

4? lines.
4'

2i

4

Si

Briggs directed his attention to the dia-
meter of the urethra in the various parts of
its course, and he found the dimensions ma-
terially altered if the urethra be injected with
wax or any other substance ; and the result
of his examination throws considerable doubt
on the conclusions of Sir Everard Home.
From the casts which he made he failed to
discover any sudden narrowing or constric-
tion at the termination of the membranous
part of the urethra, or any resemblance in
the shape of the curve as represented in
Home’s plates. f

Briggs remarks, “ The portion of the urethra
which extends from the apex of the prostate

* See the revie-w of M. Petrequin’s work ( Traite
cF Anatomie Medico-cliirurgique, &'e.), in the British
and Foreign Medical Review, vol. xx. p. 136.

* Ibid.

t From examinations I have made myself of wax
casts of the urethra, I believe the representations of
Home not to be exaggerated.

1246

URETHRA.

forwards to a short distance beyond the arch
of the pubis, and in the natural state is the
narrowest part of it, when distended, greatly
exceeds the rest of the canal in its dimensions,
and forms a large oblong sinus from 1 J to la of
an inch in length ; and in its transverse dia-
meter at its broadest part, from igths to ^-g-ths
of an inch, the part of the urethra anterior
to it not exceeding ^V-hs of an inch. The
broadest part of this sinus lies directly under
the arch of the symphysis pubis. The narrow
part of the canal, as seen in these injections, is
at the point of union between the prostatic
and membranous portions.”

The irregularities in the form of the urethra
here noticed do not appear to exist at the
earlier periods of life. In a cast of the urethra
of a boy 1 1 years old, made by injecting wax,
no inequalities such as those mentioned above
in the adult were observable throughout its
course, the diameter of the cast, which is
nearly cylindrical, measuring pretty uniformly
ith of an inch.

Briggs found the curve of the urethra to
commence 14 inch anterior to the bulb ; and
from this point to its termination in the
bladder, to form an arc of a circle of 3J; inches
in diameter, the chord of the arc being 2f
inches, or rather less than one third of the
circumference. In another cast the chord
of the segment was found to measure 2T8^
inches of a circle of 3^ inches in diameter,
the inclination of the internal orifice, or en-
trance into the bladder, forming an obtuse
angle with the general course of the urethra.

The same surgeon remarks, that in young
subjects the posterior portion rises nearly
at right angles from the rest of the canal,
and consequently makes a much sharper bend ;
and that this ascending portion is com-
paratively longer than in the adult, as was
observed by Camper, who justly attributes
the circumstances to the higher position of
the bladder in early age. A similar remark
was made by Bichat ; and the fact is well
known to the lithotomist, who, in directing
the cutting instrument into the bladder of the
child, raises the point by depressing the handle
at this important stage of the operation.

According to Briggs, the most depending
part of the curve is at the point where the
membranous portion would be intersected by
a line drawn through the longitudinal axis of
the symphysis pubis to the anus : this would
divide the membranous part into two equal
parts, and pass through the most dilated part
of this portion of the canal *

I shall now pursue the description of the
canal, commencing at that part which leads
immediately from the bladder, namely the pro-
static portion, observing that this, together
with the membranous part, is contained almost
wholly within the pelvis, and the two con-
stitute therefore the pelvic portion of the
urethra, and form the true representative of
the female urethra.

* Briggs, on the Treatment of Strictures of the
Urethra by Mechanical Dilatation.

The prostatic portion traverses the prostate
gland at the distance of about two lines from
the anterior, four from the posterior, and
seven from the lateral surface of the gland.
In this respect, however, it varies considerably:
thus, in some cases, it is very close to the
posterior surface, especially where the isthmus
of the prostate is imperfectly developed.*
The prostatic portion is from 12 to 15 lines
in length, and it commences at the neck
of the bladder by a round opening, which is
slightly raised ; it then expands to the width
of 4 or 5 lines, and gradually contracts
itself into the membranous portion. It varies
in length and direction in different subjects,
and differs materially in these respects ac-
cording to age. Lisfranc examined it in eight
healthy subjects, and found the diameter of
the anterior and posterior portions to vary
from 3 to 4 lines, whilst the middle portion
measured from 4 to 5-t- lines.

Although closely invested by the dense
tissue of the prostate and its capsule, this is
nevertheless the most dilatable part of the
whole urethra, and will readily admit the
introduction of the fore-finger. The levatores
prostata muscles, together with the pubo-
prostatic ligaments, support it, and attach it to
the pubis, and it is compressed by the /evatores
ani. The general direction of this division
of the canal is obliquely downwards ; it pre-
sents a slight concavity ( the prostatic sinus)
at its floor, where it is traversed hy the caput
gallinaginis, which, running from behind for-
wards, divides the sinus into two equal parts.
In the prostatic sinus the ducts of the prostate
open, assuming a crescentic arrangement
around the base of the caput gallinaginis,
whilst the vasa ejaculatoria terminate usually
on the side of the latter body.

The description of the urethral orifice of
the bladder belongs to the anatomy of this
viscus, and to the article Bladder the reader
is referred ; but it is requisite here slightly to
allude to it, as it bears materially upon the
general direction of this part of the urethra.
When viewed from before backwards, the
opening will be generally found somewhat
raised, so that the floor of the urethra forms
a slight depression ; and this depression is
materially increased in hypertrophy of the
prostate, a circumstance always to be remem-
bered in the introduction of the catheter in
such cases.

In infancy the direction of the prostatic part
is very different from what it is in after life.
In consequence of the bladder at this early
period being situated higher up, that is, more
in the abdomen, the urethra at this part rises
more vertically, and thus forms an angle with
the membranous portion ; hence, as in the
aged, the necessity, in passing a sound or ca-
theter, to depress the handle to a considerable
extent, and thus to raise the point of the in-
strument. As the prostate becomes evolved,

* Lisfranc mentions an instance wrhere tlie isth-
mus was wholly wanting, and the urethra formed a
remarkable pouch at this part.

URETHRA,

1247

the prostatic part of the urethra gradually de-
scends, until its general direction is more con-
tinuous with that of the membranous part. 1
shall defer the description of the caput gal-
linaginis until I come to that of the general
surface of the urethra.

The connection of the urethra to the pro-
state is very close, the ducts of the gland
passing directly into it ; it is therefore im-
possible to raise it from its attachment without
division of the prostatic ducts. When a ca-
theter is introduced, the course of the canal
invested by the prostate can be indistinctly
traced by the finger introduced into the
rectum.

The membranous portion ( pars muscularis,
isthmus urethra: ) commences from the anterior
part of the prostate, and extends beneath
the arch of the pubis as far as the bulb : it is
included between the prostatic and spongy
portions, and is covered slightly at its anterior
and under part by the bulb, so that it is
really shorter below than above. It makes a
slight curve, the concavity facing upwards.
The concavity is at the distance of nearly an
inch from the interpubic substance ; the con-
vexity looks towards the perinaeum. Be-
tween it and the pubis, and just beneath the
pubic arch, the dorsal veins of the penis run.

Proceeding from the anterior extremity of
the prostate, the membranous portion of the
urethra traverses the triangular ligament,
which splits into two lamellae : one passing
backwards over the prostate, is continuous
with the capsule of the gland, the other ad-
vances forwards over the bulb, and blends
with the tendinous investment of the spongy
body. The opening through which the ure-
thra passes is round. The membranous por-
tion forms the segment of a circle, whose
radius is, according to Krause, 2^ lines. This
part of the canal has been termed membran-
ous, from the idea that it represented a simple
membrane when deprived of its surrounding
muscular structure, and that it was wholly
destitute of any investment of the spongy
body. This, however, is not correct ; there is
a thin layer of vascular tissue, continuous in
front with the spongy body, and closely sur-
rounding the mucous membrane of this part
of the urethra, between it and its muscular
layers. The vessels of this extension of the
spongy body pass backwards, to terminate in
the plexus surrounding the neck of the blad-
der : this is mixed up with elastic tissue, and
constitutes a truly erectile tissue. An exten-
sion of the same structure enters into the for-
mation of the caput gallinaginis.

Between the layers of the triangular liga-
ment, and in close connection with the mem-
branous part of the urethra, are found three
sets of muscular fibres ( nucsculus urethralis ) :
they consist of the two pairs of muscles de-
scribed, one by Wilson and the other by
Guthrie ; and the circular fibres of Santorini,
which closely surround the urethra. The
anteprostate, or Cowper’s glands, covered by
the inferior stratum of the compressor urethrae,
are placed beneath this part, and the arteries

of the bulb are in close approximation to it,
running beneath and on either side of it. The
floor of the membranous portion is traversed
longitudinally in the median line by the pointed
end of the caput gallinaginis.

If a catheter be passed into the bladder,
the membranous portion can be distinguished
by the finger introduced into the rectum and
drawn forwards, there being only a small quan-
tity of cellular membrane interposed between
the under part of its muscular investment and
the intestine.

Boyer estimated the length of the mem-
branous portion at about 1 inch ; Ducamp
from 9 to 10 lines ; Lisfranc found it in twelve
subjects to vary from 7 to 1 1 lines. In these
its anterior diameter varied from 3£ to 41-
lines, its posterior from 4i to 5 lines, and just
behind the bulb it measured at least 14 line
less than in any other part. It is universally
admitted that the point of junction between
the membranous and spongy portions is the
narrowest part of the urethra, with the excep-
tion of the meatus.

The membranous part of the urethra is sur-
rounded by muscular fibres, which have been
variously described by different anatomical
writers. Thus Santorini, as early as 1724, in
his Observationes Anatomica, pointed out some
transverse fibres as encircling the urethra at
this part: he terms them “the elevator or eja-
culator urethrae,” and describes them as being
inserted into the lower part of the urethra.
Mr. Wilson, in the year 1808, gave a descrip-
tion of two muscles surrounding the mem-
branous part of the urethra, the origin of
which is from a tendon attached to the pos-
terior part of the symphysis pubis, a little
above its lower border: the muscle thus arising
from a single origin then descends, and divides
into two portions, which, reaching the mem-
branous portion of the urethra, spread them-
selves out by its side, and are implanted into
a common tendon below it. The muscle is
termed by Wilson the compressor urethrae.
In 1834, Mr. Guthrie, in his lectures at the
Royal College of Surgeons, demonstrated
another series of muscular fibres, as sur-
rounding the membranous portion of the
urethra, and of which he considers Wilson’s
muscle as a part. That portion described by
Guthrie, and now known by his name, arises
by a thin tendon on either side, from the ra-
mus of the ischium, and, passing transversely,
splits into two portions, one above and the
other below the urethra ; the two muscles
are connected together above by a mesial
tendon, which, passing forwards, is inserted in
part into the upper part of the urethra, whilst
another portion, passing backwards, is im-
planted into the upper surface of the front of
the prostate. The under portion of the muscle
is also connected with its fellow by a similar
mesian tendon, which, advancing forwards,
goes to the central tendon of the perinaeum,
and, sending a slip backwards, is inserted into
the under part of the prostate.

The muscles are included between the two
layers of the triangular ligament ; and the

1248

URETHRA.

effect of this muscular apparatus must be to
support and compress this part of the urethra,
and to prevent any retrogression of the
seminal fluid in the venereal act.

The urethra now enters the corpus spongi-
osum, by which it is surrounded, until its ter-
mination at the extremity of the glans penis.
The spongy body surrounds the urethra
equally, except at the bulb and at the glands :
in the former situation there is a much thicker
layer below than above, which gives to the
bulb an appearance of great dilatation, whilst
at the glans there is but very little of this
structure at the under part. The bulb and
the glans, both dilatations of the spongy body,
bear a tolerably constant relation to each
other.

This part of the canal is called the spongy
portion: it has already been stated that its
length varies in different subjects, and accord-
ing to the condition of the penis, being 4 or 5
inches in the flaccid state, and 6 or 8 inches in
the erect condition of the organ. It com-
mences at the termination of the membranous
portion, and is lodged in a groove between
and beneath the corpora cavernosa penis,
forming, with its investing corpus spongiosum,
a convexity, projecting beyond the general
circumference of the penis.

The direction of the spongy portion is
curved ; it passes upwards in front of the
lower part of the symphysis pubis as high as
the suspended part of the penis ; and then
taking the direction of this organ, it bends
downwards, thus forming an abrupt curve :
by simple traction of the penis forwards and
upwards, it can be rendered perfectly straight.

If the spongy part of the canal be laid
open longitudinally, it is found to be plicated,
the folds running from behind forwards, and
dovetailing with one another when the urethra
is closed. This plicated arrangement of the
mucous membrane of the spongy portion
was observed by Bichat and others, and is
due to the contraction of the submucous tis-
sue : if the urethra be immersed in alcohol
and examined with the aid of a simple lens,
an arborescent arrangement of the folds is
visible at the anterior part of the canal, in
appearance not unlike the plicas in the mu-
cous membrane of the cervix uteri.

The spongy portion varies in diameter in
different parts ; thus, dilated at its commence-
ment in the bulb, it gradually tapers until it
reaches the glans, when it suddenly expands
into the fossa navicularis, to be again con-
tracted at the meatus.

The bulb (pars bulbosa urethrae et pars sub-
pubica') is the widest part of the spongy por-
tion. Lisfranc found in twelve subjects it
varied in diameter from 5 to 7 lines. Home
and most anatomists who have examined the
urethra, have come to the general conclu-
sion that the bulbous portion presents a de-
cided dilatation, and a simple examination of
the part would lead to a similar conclusion.

I cannot, therefore, conceive why there should
be any doubt on the subject. Injections of
wax prove to my mind an undoubted dilata-

tion of the bulbous part ; Krause and Guthrie,
how ever, deny that any such exists.

Kobelt has shown, that if the bulb be in-
jected, the corpus spongiosum at this part
presents tw'o lateral hemispherical swellings,
separated from each other in the middle line
by a longitudinal depression. “ This is caused
by a septum which divides the posterior part
of the bulb into two lateral symmetrical halves;
but anteriorly it is gradually lost. The tw'o
portions of which it indicates that the bnlb
is composed, are the analogues of the com-
pletely divided portions of the bulb and corpus
spongiosum in the whole of the marsupial
tribe.”* “ In the middle of the bulb there is
a slight superficial elevation (colliculus bulbi
medius), which is situated above and between
them, but does not extend so far backwards
as they do, and gives passage to the mem-
branous part of the urethra, the vessels and
nerves of the bulb, and the ducts of Cowper’s
glands.” -J-

The extremity of the caput gallinaginis
sometimes reaches the bulbous portion, and
the ducts of Cowper's glands terminate in its
floor by two minute orifices, extremely dif-
ficult to find. This part of the canal extends
for about the fourth part of an inch or less,
the anterior layer of the deep perinseal fascia
covers it underneath, and it is completely in-
vested by the acceleratores urinas.

The remainder of the spongy portion is
united to the bulbous at an angle of 45 in the
flaccid state of the penis ; but when this organ
is erect, this part of the canal is rendered
perfectly straight : it terminates at the meatus
urinarius.

The extremity of the spongy portion is called
the glandular part (pars glandularis), being
surrounded by the glans penis. When the
urethra has entered the glands, it dilates into
a fossa from 4 to 6 lines in length, this is
termed the fossa navicularis Morgagrdi. When
cut transversely, it has the appearance of a
longitudinal fissure. The urethra is sur-
rounded unequally by the glans penis ; the
floor of the navicular fossa is covered by a
very thin layer of this extension of the spongy
body, whilst its sides and upper surface have
a considerable investment from the glans.

The urethra having traversed the corpus
spongiosum and the glands, terminates at the
anterior and inferior part of this body, by a
small slit-like orifice of two or three lines, the
long axis of which is vertical : from this a
small fold of membrane passes down to join
the prepuce, and is termed the freenum pree-
putii. The effect of this latter is, when the
penis is erect, to draw down the opening of
the urethra, and thus to narrow the orifice,
and direct the contents of the urethra down-
wards and forwards. The two sides of the
meatus urinarius are kept in apposition by
the projection of the glans, and they are
joined below by a delicate fold of mucous

* British and Foreign Quarterly Review, vol. xix.
p. 508.

t Ibid.

URETHRA.

1249

membrane, not unlike the fourchette of the
female labia.

The urethral orifice is surrounded, accord-
ing to Guthrie*, by a peculiar dense struc-
ture, which he considers analogous to that
which forms the edge of the eyelid, and which
he believes to be requisite to maintain the
patency of the opening ; for if this be de-
stroyed by ulceration, the part from which it
has been removed contracts, and the opening
becomes so small, as to give rise to a most
troublesome form of stricture. The opening
of the urethra is almost invariably the nar-
rowest part of the canal ; and hence, if an
instrument has been introduced through this,
it will with facility traverse the remainder of
the passage, unless there be some mechanical
impediment from spasm or disease ; and hence
a trifling division of this part will permit the
passage of a large instrument, and the escape
of fragments of stone, which are frequently
arrested here after the operation of lithotrity.
It is but sparingly elastic. After immersion
in alcohol, the mucous membrane at the meatus
urinarius will be found arranged in circular
folds.

In briefly reviewing the condition of the
urethra as connected with the structures in-
vesting it, we observe that the prostatic por-
tion, being surrounded by a body possessing
considerably dilatability, remains under almost
every condition passive and yielding; and hence
it happens that a catheter, having reached this
part of the canal, must, if its point be properly
directed, enter the bladder, unless there be
some enlargement of the prostate itself; and
hence the inference that no force is to be
employed in passing the catheter under these
circumstances.

On the contrary, the membranous portion
of the urethra is a part of high irritability.
This depends partly on the nature of the tissue
itself, but mainly on the muscular apparatus
connected with it. This part of the canal is
most liable to irritation ami spasm from general
and local causes ; and is well known to be
the most frequent seat of stricture. The
remainder of the urethra is entirely sur-
rounded by the corpus spongiosum, and must
necessarily be influenced by the condition of
that body. When the latter is distended, as in
erection, the diameter of the urethra must be
proportionally diminished ; and, in the undis-
tended state of the former, it assumes its
greatest degree of dilatability. Consequently',
in the introduction of the catheter, the chief
difficulty, even independent of organic disease,
is experienced at the meatus, or at the angle
formed at the junction of the bulb and anterior
part of the spongy portion, or at the mem-
branous part, the remainder of the spongy por-
tion in the healthy state seldom offering any
resistance to the progress of the instrument.

It will also be further remarked, that the
dorsal surface of the urethra is smooth and
even throughout, except in the situation of the
lacuna magna, whilst its depressions and eleva-

* Lectures on Diseases of the Bladder and
Urethra.

VOL. IV.

tions are found upon the floor of the canal,
and hence the importance in catheterisation of
keeping the beak of the instrument against the
superior part of the urethra.

Mucous Membrane. — The urethra is es-
sentially a mucous canal, forming an important
part of the genito-urinary mucous system.
It is continuous with the mucous mem-
brane of the bladder, and blends at the meatus
with the cutaneous covering of the glans
penis. There is alway s a distinct line of de-
marcation at this part, the urethral surface
being moistened by a mucous secretion. When
laid open, it can be frequently seen to present
two distinct white lines, one at the upper, and
the other at the under surface, running longi-
tudinally ; these are supposed to indicate the
original lateral division of the canal. Inde-
pendent of this, the mucous membrane will
be generally found arranged in longitudinal
folds, with furrows between them. The folds
vary in depth and breadth, the larger are
found on the under surface, and they are
more numerous in this situation than above.
They commence at the bulb and run forwards,
sometimes continuing of the same size through-
out, frequently tapering and sending off, as
they approach the extremity of the penis,
delicate processes, which present a somewhat
arborescent arrangement, not unlike that pre-
sented by the lining membrane of the uterus ;
many on the dorsal aspect will be seen to
terminate on either side of the lacuna magna.
The folds of the urethra, which are not al-
ways visible after death, result from the con-
traction of the submucous layer, and are so
arranged, that, when the two surfaces are in ap-
position, especially if the vessels of the urethra
be injected, a sort of dovetailing of the mucous
membrane occurs, bearing a slight resemblance
to the plicated arrangement of the oesophagus
of the whale.

The urethra after death is whitish in colour,
and in some parts so transparent as to permit
the veins of the corpus spongiosum to be
seen through it. Its bloodvessels are readily
injected, when the whole canal presents a beau-
tiful vermilion tint. At the membranous por-
tion, Shaw has described a considerable plexus
of veins beneath the mucous membrane of the
urethra: these veins are spread all over the
canal, but are accumulated at the membranous
part, lying one over the other in its long axis,
so as to form two distinct columns with a
groove between them : they unite and sur-
round the sinus pocularis. Wilson had ob-
served this arrangement of vessels, before
Shaw published his description of them.
These veins communicate with the plexus
surrounding the prostate and neck of the
bladder. They are best seen by inserting a
tube beneath the mucous membrane, and in-
jecting them with mercury. Shaw supposes
them capable of considerable distension, and
thus of producing a species of erection of this
part of the tube.* In rude attempts to pass
a catheter, the vessels of this part are often

* Medico-chjrurg. Trans, vol. x.

4 L

URETHRA.

1250

lacerated, and pour out a large quantity of
blood. They have no communication with the
veins of the corpus spongiosum itself, properly
so called.

The colour of the mucous membrane de-
pends on the degreee of vascularity in dif-
ferent parts. Thus, at the meatus, it is of a
pink aspect, becoming gradually pale towards
the bladder. But in the membranous por-
tion, owing to congestion in the veins, it is
very frequently much darker, as these vessels
are readily distinguishable through the mem-
brane, whilst in the prostatic part it is white.
The colour of the mucous membrane is much
heightened under inflammation : this is espe-
cially visible in the fossa navicularis, and at
the orifice in severe attacks of gonorrhoea;
and the same has been witnessed in other
parts of the canal after division of the urethra,
during an attack of gonorrhoea. Under in-
flammation it loses its smooth, polished aspect,
and presents a velvety appearance.

Mr. Quekett has lately made some beautiful
injections of the vessels of the mucous mem-
brane of the urethra, in which it is seen that,
in the bulbous portion, the bloodvessels run-
ning in the valleculas between the columns are
larger and more numerous than those of the
columns themselves ; whilst nearer the meatus,
where the columns are either small or alto-
gether absent, the membrane is not unfre-
quently provided with villi, which resemble
those of the lips and extremities of the fingers
and toes in having each a single looped capil-
lary.

Lacuna. — The whole of the urethra, ex-
cept the prostatic portion, is marked by minute
openings, distinctly perceptible at the upper
and under surface, but they are certainly larger
and more numerous on the upper. They are
the openings of the lacuna or mucous glands,
whose office it is to secrete a bland fluid for
the lubrication of the canal, and thus to facili-
tate the onward progress of the contents of
the urethra. The lacunas vary in different
individuals in size and number : some anato-
mists believe them to be more numerous in
the membranous portion : my own observa-
tions would lead me to the conclusion, that
the greater number are to be found in the
spongy portion. They are termed indiscrimi-
nately the glands of Littre and Morgagni, or
the orifices are called the lacunas of Morgagni,
whilst the crypts opening into them are termed
glands of Littre. The lacunae vary in depth :
in some situations they admit the passage of
bristles, to the depth of two or three lines; in
others they are by no means so deep, whilst
in other cases they are scarcely perceptible.
Their orifices face for the most part obliquely
forwards towards the meatus, but now and
then they pass vertically to the surface; they
are found between and upon the columns of
the urethra. A simple examination of the
lacunae would represent them as mere in-
flexions of the mucous membrane of the
urethra, and many of the smaller ones are of
this nature: some, however, present a cellular
appearance, but this seems to arise from the
anastomosis of vessels distributed on them ;

they are lined with epithelium of a character
similar to that lining the urethral membrane
generally, and a considerable plexus of vessels
is distributed around them. Under inflamma-
tion they pour out a copious secretion, and
are not unfrequently the seat of special disease.
The use of the lacunae is to extend the secret-
ing surface of the mucous membrane of the
urethra, in situations where any glandular ap-
paratus would have been obviously incon-
venient.

In old cases of stricture, and other diseases
of the canal, they become exceedingly enlarged.

The lacuna magna. — Near the termina-
tion of the urethra, and within a few lines of
the meatus urinarius, will be seen an inflexion
of the urethral membrane, forming a cul-de-sac,
into which the b unt end of a probe can be
passed : this is denominated the lacuna magna,
being in structure and function analogous to
the other lacunae of the urethra. The lacuna
magna is a point in the anatomy of the urethra
of some practical import, inasmuch as it is
likely to arrest the entrance of a catheter,
and to convey to the ignorant an erroneous
idea of stricture. It varies in situation in
different individuals. It is usually placed at
about one-third of an inch from the meatus
on the dorsal aspect of the fossa navicularis,
so that, on separating the lips of the meatus,
it can be brought into view; but it is occa-
sionally further back, and now and then is
placed on the under surface, and in many
cases I have in vain tried to find it. I believe
it is occasionally altogether absent. It will
be found, where the columns of the urethra
are developed, that they take their course
towards the lacuna, and, on reaching it, pass
off in slender processes to the meatus. In
an urethra which I recently examined, I
found a lacuna magna of considerable size
in the under surface of the urethra, behind
the middle of the spongy body. Into this the
point of a catheter could be readily passed,
and it might have been easily mistaken for
stricture.

Hunter, and most of his successors, believe
the matter of gonorrhoea to be incubated in
the lacuna magna.

Structure. — The urethral membrane is divi-
sible into two distinct layers. The inner,
which is analogous to other mucous surfaces,
consists of a basement membrane covered
throughout by epithelium. This, according to
Quain and Sharpey, for the most part, is of
the scaly character, but in the vicinity of the
bladder it is spheroidal. Henle describes
the fossa navicularis as covered with small
flat and roundish scales, whilst the remaining
part of the urethra is covered with a single
series of prismatic particles.*

Beneath the mucous membrane there is a
layer composed of a tissue or structure of a
mixed character, containing some contractile
fibres, supposed to be muscular, blended with
elastic tissue. It is connected to the delicate
tendinous covering of the corpus spongiosum,
and is supported by transverse tendinous
bands distinctly visible beneath it. This layer

* See article Mucous Membrane.

URETHRA.

1251

varies in depth in different parts, and is thicker
in the membranous than in other parts of the
urethra. When examined with the micro-
scope, it presents abundant evidence of the
existence of contractile fibre mixed with com-
mon elastic tissue. The relative quantity of
these elements varies according to situation :
thus, in the membranous portion, there is less
of the contractile tissue than in the spongy
portion ; a circumstance of some interest, as,
this part being surrounded by a distinct mus-
cular covering, there would be less necessity
for it than in other situations where muscle
is absent. The bloodvessels from the spongy
body shoot through it. This contractile tissue
is identical with that recently described by
Kolliker as entering into the structure of the
spleen and mucous canals, which have an
evidently contractile power.

The existence of this layer has been long
recognised, and the attention of anatomists
was directed specially to it by Sir E. Home,
who believed it to be muscular ; and his
opinion was supported by the observations
of Mr. Wilson, who attributes the resist-
ance occasionally, in irritable states of the
urethra, offered to the introduction of the
catheter, and the expulsion of bougies in like
conditions, to spasm of these supposed mus-
cular fibres. This idea, however, was opposed
by Sir Charles Bell ; but the dispute is de-
prived of its interest since the discovery by
Kolliker of the true nature of this peculiar
tissue, which combines to a certain extent the
attributes of organic muscular fibre and elastic
tissue. This layer varies in depth in different
subjects, and is generally highly developed in
the robust and muscular, so as in some in-
dividuals to grasp with considerable firmness
a bougie when introduced into the canal.
Wilson mentions an instance of a gentleman
who could “ as distinctly feel a contraction
of the passage coming on, and taking place at
one part, as he could feel any muscle act.”
The use of this layer must necessarily be to
regulate the force of the current of fluids
through the urethra.

According to Kolliker the following is the
arrangement of the submucous layer in various
parts of the urethra. It is termed by him
the simple muscular tissue. “ Its relations
are most complicated in the prostate gland,
and the prostatic portion of the urethra,
which is rich in muscular fibres. So large is
the quantity of this tissue in the gland itself,
that the true glandular structure constitutes
scarcely one third or one fourth of the whole.
On removing the mucous membrane from the
prostatic portion of the urethra, the yellow
longitudinal fibres of the caput gallinaginis
come first into view', which form the lower
end of the trigone, and contain very few mus-
cular fibres. On both sides of the caput gal-
linaginis, and extending to the anterior wall
of the urethra, similar yellowish longitudinal
fibres present themselves, and form a strong
layer towards the neck of the bladder ; but
towards the membranous part of the urethra
they gradually decrease to a very delicate

layer. This longitudinal fibrous layer of the
prostatic part is connected, internally to the
sphincter vesicas, by a thin and indistinct layer
of fibres with some of the longitudinal mus-
cular fibres of the bladder ; but by far the
greater part of it is unconnected with this
latter : it consists of half fibro-cellular tissue
with many nucleus-fibres, and half of evident,
smooth, muscular fibres with characteristic
nuclei. After this, and external to it, follows,
secondly a strong layer of yellowish circular,
fibres of muscular and elastic tissue. This
layer is connected above with the sphincter
vesicae, where also it is most developed ; whilst
below it becomes gradually thinner, and below
the caput gallinaginis is either lost, or appears
only in very small quantities. On removing
the several muscular layers, we come at last
to the proper glandular tissue of the prostate,
of which individual lobes penetrate among
the circular fibres just mentioned, their ex-
cretory ducts passing through the longitudinal
fibres.

In the membranous part of the urethra the
smooth muscular tissue is less developed.
Under the mucous membrane, whose cellular
tissue is remarkable for abundance of elastic
fibres, there is a layer of longitudinal fibres,
which are connected with those of the pro-
static portion. These fibres consist for the
most part of fibro-cellular tissue with nucleus-
fibres, and include, in smallnumbers, undulating,
delicate, and curved contracting fibre-cells (of
the nature of smooth muscular fibres), which
may be, in part, isolated ; and are from 0'07 to
OT of a line long, from T002 to 0’003 wide.
They contain small nuclei from 0‘012 to O'Ol-f
long, and are more easily found in recent
specimens than in those treated with acetic
acid. External to these longitudinal fibres
there is a strong layer of transverse fibres,
which belong for the most part to the vms -
cuius uretliralis. Some of these, however,
especially those belonging to the inner layer,
display some strong bundles of smooth mus-
cular fibres, together with fibro-cellular tissue
and nucleus-fibres, and a partial mixture of
fasciculi of the transversely striated fibres of
the muscu/us uretliralis.

The smooth muscular fibres are generally
still less developed in the spongy portion of
the urethra. In some cases they appear in
exactly the same manner as the longitudinal
fibres in the membranous portion ; in other
cases, longitudinal fibres may be seen, but no
muscular tissue can be found mingled with
the cellular tissue and nucleus-fibres of which
they consist. At a certain depth, however
some longitudinal fibres are distinguishable,
with a more or less considerable admixture
of smooth muscle, which fibres cannot be re-
garded as beams of the corpus cavernosum
urethrae ( corpus spongiosum ), since they have
no venous spaces between them, but rather
form a continuous membrane, which limits
the corpus cavernosum urethrae towards
the mucous membrane. One might con-
sider this part as belonging to the corpus
cavernosum urethrae ; in which point of view

4 L 2

1252

URETHRA.

we shall deny any muscular membrane to this
region of the urethra: but it seems more na-
tural to regard the whole corpus cavernosum
as a highly developed muscular layer provided
witli peculiar bloodvessels ; for a large quan-
tity of smooth muscular fibres, together with
the cellular tissue, vessels, and nerves, en-
tering into the structure of its beams and
cords as far as the glans, render this body an
eminently contractile structure.”*

On laying open the urethra from its origin
at the neck of the badder, the first structure
we meet with is the caput gallinaginis ( colli-
culus scminalis, caruncula seminalis, veru mon-
tanum, crista urethra ?). This is an elongated
body situated on the floor of the prostatic
part of the urethra : it varies in length from
three quarters of an inch to an inch. Com-
mencing by a gentle elevation of the urethra,
towards which, on either side, are seen some
delicate folds of membrane passing, it expands
into a small oblong rounded eminence, com-
pared to the head of a woodcock, and hence
its name : it then advances gradually, tapering
to a slender point, which, being continued
onwards for some distance, is lost at the
beginning of the membranous portion in one
or two delicate longitudinal folds, and is con-
founded with the general surface of the
urethra : the latter part is compared to the
beak of the bird. The caput gallinaginis di-
vides the prostatic sinus into two lateral de-
pressions, into which the secretion of the
prostate gland is poured.

At the most elevated portion of the caput
gallinaginis there is a depression formed by an
inflexion of mucous membrane, facing for-
wards, variable in size and depth, and gene-
rally capable of admitting the blunt end of
an ordinary probe : in some cases it can be
traced down beneath the third lobe of the
prostate, to the extent of the third, or even
the half, of an inch. It is called the sinus pocu-
laris, utriculus prostaticus, or vesica prostatica ,
and is the homologue of the protometra, from
which the female uterus is evolved. f On
either side of this, between its lamina, or
beneath it, are the terminations of the ejacu-
latory ducts. A general description of this
small cavity has been given under the head of
Prostate Gland.

The structure of the caput gallinaginis is
this : it is for the most part formed of a
raised fold of the ordinary mucous membrane
of the urethra, beneath which is a longitudinal
layer of elastic tissue continuous with the
trigone. Some anatomists also affirm that
there is mixed up in the tissue of the body
a plexus of vessels, constituting a distinct
erectile tissue ; and hence it has been ima-
gined, that when its vessels are distended with
blood, as during erection of the penis, it shuts
up the prostatic portion of the urethra, and
thus prevents the passage of the semen in a
retrograde direction into the bladder. My

* Kolliker, Beitrage zur Kenntniss der glatten
Muskeln, in the Zeitschrift fur Wissen.

t See article Prostate.

own opinion as to its use is, that, independent
of this office, it is endowed with special sensi-
bility, like the papillary orifices of the ducts
of Steno and Wharton ; and that it is capable,
under the influence of a stimulus, of becom-
ing erect, and thus straightening the termina-
tion of the canals connected with it, by which
the exit of the secretion of the testes and
vesiculae seminales is favoured. I believe,
further, that something more is due to these
papillary orifices of the ducts of glands, and
that, in consequence of their exquisite sensi-
bility and sympathy with the glands, they
possess a power, under stimulation, of elicit-
ing the secretion and expulsion of the fluid of
the bodies with which they are connected. A
proof of its sensibility may be deduced from
the fact, that when a bougie, introduced for
the first tim e per urethram, reaches this point
of the canal, it frequently gives rise to faint-
ness and sickness ; and this is usually attended
with an almost irresistible desire to micturate ;
and further, that if this be frequently re-
peated, and the caput gallinaginis be irritated,
a flow of semen and vesicular secretion can
be excited.

The pathology of this portion of the canal
leads to the same conclusion. For the relief
of nocturnal emissions, so frequently the result
of repeated self-pollution, the preternatural
irritability of this part may be successfully
destroyed by the application of the nitrate of
silver.

If the caput gallinaginis be gently raised by
dissection from the subjacent tissue, it will be
found lying on a delicate tendinous layer, with
which it is intimately connected. This layer in
shape resembles the body itself, being broader
behind and tapering in front, and is gradually
confounded with the tendinous covering of
the spongy body: it is also continuous with
the fascial layer of the utriculus prostaticus.

The caput gallinaginis results in a great
measure from the coalition of the two lateral
portions of the urethra, during the develop-
ment of the back part of the canal, from that
portion of the uro-genital sinus which gives
origin to the prostate and vesiculae semi-
nales, &c.

In the membranous portion there is nothing
specially remarkable, except that delicate
venous plexus, to which allusion has been
already made. In the bulbous part are the
terminations of the ducts of Cowper’s glands ;
and to these bodies I shall now direct attention.

Cowper’s glands — ( glanclu/ce Cowperi,
gladnulce antiprostaticce vel prostaticce inferiores )
are two glands situated beneath the anterior
portion of the membranous part of the urethra,
just behind the bulb, between the layers of
the triangular ligament. A few fibres of the
compressor urethrae pass beneath them. Some-
times a single gland only is found, and occa-
sionally there are three ; in which case, ac-
cording to Cowper, the additional gland is
placed just beneath the pubis. These bodies
are frequently difficult to find, and in old
persons they either disappear altogether, or
become so soft that it is impossible to recog-

URETHRA.

nise them. In their natural condition they
are rounded, or nearly so, and equal in size
to an ordinary pea. Solid and resisting to the
feel, they are of a palish red colour, and dis-
tinctly conglomerated, or composed of small
lobules. The lobules of the glands are con-
nected together by cellular membrane, and by
their efferent ducts. The glands are sur-
rounded by a strong capsule of fibrous mem-
brane. On section they present an appear-
ance like the pancreas, and are composed in-
ternally of elongated cellular follicles, which,
according to Krause, vary from the 50th to
the 25th of a line in length, and are about the
36th of a line in breadth. Some of these
follicles equal in size a 16th or 25th of a line.
They unite into slender ducts of about the
18th or 16th of a line in diameter; these
usually coalesce into a single excretory duct.
The excretory duct of each gland is occa-
sionally double : the ducts run parallel for the
distance of half an inch beneath the mucous
membrane of the bulb, and approaching each
other, they pierce the urethra by two exceed-
ingly minute orifices, which are scarcely distin-
guishable : the best mode of demonstrating
the openings of the ducts is gently to press
the mucous membrane forwards with the
handle of a scalpel, when a small quantity of
secretion contained in them will escape, and
indicate their termination on the mucous
membrane.

Each gland receives a branch from the
artery of the bulb, and its veins terminate in
the pudie vein.

It is impossible to collect any quantity of
the secretion of (Jowper’s glands sufficient
for chemical analysis. According to Krause;
the fluid is somewhat similar to that secreted
by the prostate ; it is of a viscid character,
transparent, containing floeculi and small
granulations, probably the detritus of epithe-
lial cells, varying in size from the 900th to
the 370th of a line, the greater number being
about the 455th of a line.

Comparative anatomy. — As there is so little
of a satisfactory nature known about the use
of Cowper’s glands in man, it may not be un-
interesting to examine their condition in the
animal kingdom generally. To elucidate this
part of the subject, I select the following
observations from the Lecons d’Anatomie
Comparee of Cuvier.

According to Cuvier, Cowper’s glands exist
in all the Quadrumana and Cheiroptera, and
amongst the Feres the}’ are found in th e ichneu-
mon, in the civet, hyena, cats ; in the Rodentia,
except the hare ; also in the Pachydermata,
most of the Ruminants, and all the Marsupiata ,
They are absent in the Insectivora, the bears,
the racoon, otter, and marten, and in the dog.
Amongst the Ruminants, they are wanting in
the deer; they are absent in the Solipeds,
Phoci, the amphibious Quadriremes, and the
Cetacea. It will be found that they often co-
exist with the prostate and vesicul® semi-
nales, or with these and the vesiculae acces-
sorise, or with the prostate alone.

1253

In the flesh-eating opossum, they are the
only accessory glands, and they appear essen-
tial to this division of the Marsupiata.

In structure they vary considerably, but
may all be arranged under one or two heads.
Thus like the prostate, in some animals,
there is a large reservoir in the centre of each
gland, from which the excretory duct arises ;
whilst in others the gland is composed of a
number of minute follicles, all terminating in
one common excretory duct.

In the squirrels and marmots they are large
and vesicular, and were mistaken for vesiculae
seminales. The fluid which they contain is
semi-transparent, or of a bluish, opaline ap-
pearance, of the consistence of starch, and it
is poured into the bulbous portion of the
urethra by a single orifice. They are com-
pletely surrounded by a muscular or musculo-
membranous envelope.

In the ape tribe they are proportionally
much larger than in man. In the mantis they
are remarkable in size. Them excretory ducts
run close together prior to their termination.

In the bat, amongst the Cheiroptera, they
are very large.

In the dismar of Russia they are elongated,
and bent in the form of the knee,

In the hedgehog they are broad and round
composed of a number of straight, short
tubes, lying parallel, and dividing into- a num-
ber of exceedingly small ramuseules. The tubes
unite into a single canal, which opens into
the pelvic portion of the urethra.

In the civet and cat they are large, and.
enveloped in a thick muscular layer ; but,
amongst the Carnivora, they are largest in the
hyesna ; the lobes and branches of their
secreting tubes are exceedingly distinct and
large.

The anti-prostate glands of the ichneu-
mon form a remarkable swelling at the com-
mencement of the bulb; they are rounded,
and composed of vesicules communicating
together ; these unite into a single canal in
each gland, which passes beneath the penis,
and opens separately into a cul-de-sac, into
which the urethra opens. They are sur-
rounded by an aponeurotic and muscular
layer.

There is a similar structure in the marmot;
they are shaped like a club, the broad end folded
upwards against the handle, which contains the
duct ; the mass is divided into a number of
glandular cells. The excretory duct opens into
a cul-de-sac, hollo wed out in the bulb: this con-
tracts into a narrow canal, which opens into
the urethra, near the middle of the penis.

In the rat they are of large size, whitish
externally, and pyriform in shape. In the
agouti they are broad, rounded, and very
vascular.

In the guinea-pig they are more rounded,
but of the same structure.

They are spherical, and situated behind
the accelerators arising in the gerboa de
Mauritanie , and pyramidal in the gerboa de
Schaw. They are broad and rounded in the

4 l 3

1254

URETHRA.

elephant ; they have a similar structure as the
prostate, but are comparatively larger ; they
are reddish in colour, vei'3' irregular exter-
nally, and present a lobular appearance. They
are divided into two portions ; a smaller, near
the bulb, and another large portion. In the
centre of the first there is a considerable
cavity, which receives the fluid poured into it
by smaller cavities, and these communicate
with still smaller cellules. From the prin-
cipal cavity a canal arises, which, communicat-
ing with that of the other portion of the
gland, forms a single common canal. The ex-
cretory duct is formed of two branches ; it
passes a short distance in the walls of the
urethra, before it opens into the bulb. The
glands are covered by a thick muscular layer,
the fibres of which converge to a tendon,
which is fixed to each corpus cavernosum.

In the wild boar the gland is elongated and
cylindrical, formed of a firm substance com-
posed of minute cells, which uniting form
larger cells, and these communicate with a
common central cavity, from which an excre-
tory duct arises ; this opens on the side of a
cul-de-sac in the commencement of the bulb
of the urethra. They are each completely
surrounded bv a muscle. In Solipeds they
form an oval swelling on each side of the
pelvic portion of the urethra. They are sur-
rounded by muscular and tendinous fibres :
each opens by a dozen orifices, ranged in
rows, into the adjacent part of the urethra.

Amongst the Ruminants, in the chamois, they
are of the shape and size of a pigeon’s egg;
its canal terminates in the usual situation. They
are similar in all ruminants where they exist.

Amongst the Marsupialia they are remark-
able for their number : thus, there are as many
as six in the Mexican opossum, phalangers,
phascolymus, and giant kangaroo; four in the
sarigue and kangaroo-rat. In the giant kan-
garoo two are placed, one by the side of the
other, over the urethra, just behind the crura
penis; two others are situated on each side
behind the crura, and are larger than the
others. They are all invested by a muscular
and aponeurotic envelope, and are composed
of canals passing lengthways : they resemble
in structure the prostate.

In the echidna and ornithorynchus, amongst
the Monotremata, there is a gland on each
side of the cloaca, small, and of an oval
shape, containing within it a central canal
opening into an excretory duct: this pene-
trates the constrictor cloacae, and joins a small
seminal canal detached from the urethra, near
its termination in the cloaca. The gland is
surrounded by a thick muscle, the action of
which is forcibly to throw forwards the fluid
along the long excretory canal with which it
is provided.

Cowper’s glands are altogether wanting in
birds. They are not found in reptiles gene-
rally ; but in the amphibious Urodeles the
genito-urinary opening is surrounded by a
glandular apparatus in some respects ana-
logous. In fishes they are wanting.

They belong to the class of glands desig-
nated by Cuvier as supplementary to the
male organs of generation, and their use is
to pour out a fluid to lubricate the spongy
portion of the urethra, and by blending with
the seminal and other fluids, to assist in the
general distension of the canal.

Bloodvessels of the Urethra. — The urethra
is a highly vascular membrane, and its
arteries are derived on either side from
that branch of the pudic which enters
the corpus spongiosum at the bulb, and is
known by the name of the arteria corporis
spongiosi urethrae vel arteria bulbi. This artery
divides into small branches, many of which
are distributed on the cells of the corpus
spongiosum, whilst others pass through this
body, and penetrating the elastic tunic of the
urethra are distributed upon its mucous sur-
face, forming intricate plexuses between and
at the basis of its columns : others are des-
tined to the lacunae over which they form a
delicate network, which conveys to these
crypts a cellular appearance. They all freely
anastomose on the general surface of the
urethra, and at the meatus communicate with
those minute branches of the arteria dorsalis
penis, which, having reached the prepuce, are
reflected over the cutaneous surface of the
glans penis.

The veins either communicate with those
of the spongy body, and empty themselves
into the dorsal vein of the penis, or terminate
at once in the prostatic plexus by means of
those already described in the membranous
portion.

Nerves. — The nerves are exceedingly
small ; they accompany the arteries of the
bulb, but cannot be traced into the urethral
membrane, although the high sensibility of
this structure even in health, and especially
under disease, indicates at once a considerable
nervous supply. The nerves are derived
partly from the pudic nerves, which give
minute branches, taking the course of the
arteries of the bulb, and partly from the
plexus situated beneath the neck of the blad-
der formed by some small branches of the
sacral nerves and sacral ganglion of the sym-
pathetic.

The lymphatics — join the superficial and
deep lymphatics of the penis, and either ter-
minate in the inguinal glands, or, passing into
the pelvis with the pudic vessels, join the
ganglion situated around the internal iliac
artery.

Function. — The office of the urethra is
to give exit to the urine from the bladder, and
the secretions of the testes and their ap-
pendages the vesiculae seminales, the prostate
and Cowper’s glands. For the free discharge
of the urine, the urethra is in a passive con-
dition, and the penis relaxed, and as free as
possible of blood ; the muscles surrounding
the membranous portion together with the
slightly resisting urethra yield to the efforts
of the detrusor urinae, and the urine passes
in a stream varying in size and force ac-

URETHRA.

cording to the condition of the canal. If
any obstruction exists either at the prostatic
part, or in any other situation, the force, size,
shape, or direction, of the urinary stream is
altered accordingto circumstances; and hence,
by inspection during the passage of the urine,
we can often arrive at a satisfactory conclu-
sion of the nature of the obstruction without
the introduction of instruments.

When, however, the seminal secretion is to
be expelled, the condition of the urethra is
totally altered, and the canal is diminished in
diameter but increased in length from the
general distension of the penis with blood,
and the consequent erection of the organ.
The direction of the anterior part of the
urethra is altered and straightened to the
utmost ; the prostatic part is raised by the
action of the levator prostates, and thus forms
a gentle inclination with the membranous
part'; and the fluid oozing through the vasa
ejaculatoria is collected in the bulb, which
thus becomes distended. Although it is not
possible to see what is going on, yet we may
imagine that at this period of the orgasm a
sort of vermicular movement takes place, and
that successive contractions and relaxations
of the muscular apparatus of this part of the
genito-urinary system occur. Thus I appre-
hend that the sphincter vesicas effectually
closes up the orifice of the bladder, whilst
the levator ani and compressor prostatas ex-
pel the contents of the vesiculas and the pro-
state ; and further, that after the bulb is dis-
tended with fluid, the acceleratores urinae con-
tract wifh considerable and successive effort,
and at this moment the muscles surrounding
the membranous part contracting prevent any
retrogression of the seminal and vesicular se-
cretions, and thus the contents of the urethra
are forcibly expelled through the anterior part
of the canal, now made rigid by the distension
of the penis, and by the contraction of its
own peculiar tissue, a forcible muscular
effort being required to expel the somewhat
inspissated fluids. The erection of the caput
gallinaginis, by the distension of its erectile
tissue, has considerable influence in closing
up the prostatic part of the urethra, and thus
assists in preventing its retrogression into the
bladder.

The action of the accelerators, ? urines in
expelling the contents of the urethra in the
venereal orgasm, has been denied on the high
authority of Cuvier. Kobelt believes that
their sole action is to compress the bulb,
and thus to force the blood onwards into the
glans penis, and to increase the turgescence
ol this body ; but that they have no direct
influence either in accelerating the flow of
urine as their name implies, or in the evacua-
tion of the urethra during the act of copu-
lation.*

There are few parts with which the consti-
tution has a more close sympathy than the

* Die Mannlichen und Weiblichen Wollust-
organe des Menscken, &c. Yon Kobelt. Frei-
burg, 1844.

1255

urethra : this is evinced by the general disturb-
ance of health under the influence of diseases
of this canal : thus, in inflammation from
gonorrhoea, or even common causes, irritative
fever is set up, persisting frequently as long as
the disease lasts. So also, when in suspected
or actual stricture, a bougie is passed along
the canal, faintness occurs, followed by a class
of symptoms resembling those of the suc-
cessive stages of an ordinary intermittent.
When ulceration takes place, a similar train
of symptoms sets in. The same is also fre-
quently remarked during the passage of stones,
or fragments of stone, along the canal. This
sympathy must be referred to the general
nervous supply derived from the filaments of
the sympathetic and cerebro-spinal axis. The
sensibility of the urethra is not the same
throughout ; it is evidently more intense at
the commencement, in the prostatic and mem-
branous portions, and near the meatus, than
in the spongy part generally. The pain, how-
ever, accompanying diseases of the urethra is
commonly referred to the meatus, in obedi-
ence to the well-known law, that when irrita-
tion of any of the mucous surfaces produces
pain, this is principally felt at the point where
the mucous and cutaneous systems blend into
one another, namely at the outlet of the
mucous canal.

Development. — The development of the
male urethra is a subject of considerable
interest both in a physiological and patho-
logical point of view, as a comprehension of
the phenomena attending it enables us to offer
a ready explanation of those curious mal-
formations to which this canal is not un-
frequently liable.

For the description of the development of
the intra-pelvic portion of the urethra from
the uro-genital sinus, the reader is referred
to the article Prostate, in which the separa-
tion between the bladder and rectum in the
male, and the bladder, rectum, and vagina of
the female, is considered ; and we have, there-
fore, now only to trace the growth and exten-
sion of that portion of the urethra which
traverses the body of the penis.

Up to the end of the fifth or beginning of
the sixth week, the external organs of ge-
neration in the male resemble those of the
female, and a common opening or cloaca exists,
into which the rectum, bladder, and genital
organs terminate. At the anterior part of
this common outlet a small projection is
formed, presenting a concavity below, along
which there runs a superficial groove towards
the anus. This corresponds to the clitoris in
the female, and the penis in the male. A
slight enlargement now takes place at the
extremity, which becomes the glans. In the
female the two sides of the groove begin to
swell out, and become the labia majora. A
separation now takes place between the open-
ings of the anus and vagina, and the perinacum
begins to be formed. The opening of the
uro-genital canal is a small aperture in front
of the anus, at the extremity of a slit, which
proceeds as far as the root of the penis or

n i

1256 URETHRA.

clitoris, and becomes surrounded by two folds
of skin which form its sides.

In the male, the two folds of skin which
correspond to the labia majora become blended
together, and form a projecting ridge, called
the raphe; they also form the scrotum. The
penis continues to increase in size, but the
groove which runs along its under-surface as
far as the glans, remains patent until the four-
teenth or fifteenth week, when its sides swell,
out and adhere together, and hence the
urethral canal, which is completed about the
fifteenth week. The prepuce is formed at the
fourth month, and at this period the orifice of
the urethra appears in the form of a small slit
at the extremity of the glans, but it is com-
pletely closed at first.

At the period of birth the pelvic portion of
the urethra is more vertical than in the adult,
in consequence of the position of the bladder,
a great part of which is now situated in the
abdomen ; the bulbous portion is situated at
a greater distance from the anus than after-
wards.

The rudiments of Cowper’s glands are
formed at a very early period, on each side of
the genito-urinary passage.

Pathology. — Under this head are in-
cluded, first, all deviations from the normal
condition arising from arrest of development ;
secondly, all changes in the direction and con-
dition of the urethra depending on disease.
The first are necessarily congenital, the second
acquired.

Congenital malformations. — The urethra is
seldom altogether absent: it is, however,
wanting in cases of decided cloacal formation,
and in the female, where there is partial
deficiency of the bladder (ectrophy) ; but in
those cases in which the urachus remains
patent, and where the urine is discharged by
this canal, the urethra is always met with.

The urethra sometimes runs along the
dorsum of the penis in the form of a broad
groove. This malformation is termed epispadias,
from the Greek word i7nmrd.11>, in contradis-
tinction to hypospadias, from wwomrdio, sub-
traho, as in the latter malformation the penis
is drawn down.

Epispadias is frequently complicated with
ectrophy of the bladder, but often exists in-
dependent of this congenital malformation.

In either case there is generally consider-
able diastasis of the symphyses pubis, the
bones being united together by a long inter-
vening ligamentous structure. In epispadias
there is also a deficiency in the superior part
of the prostate gland, the lobes of which are
seen only below, and the veru montanum is
found in its usual situation; the prostate is
generally smaller than common; the penis
also is but imperfectly developed. The urethra
itself forms a mere superficial channel along
the dorsum penis; it is copiously supplied with
large lacunae, the corpus spongiosum is want-
ing above, and the glans is cleft; the prepuce
ceases at the corona glandis.

In a case which I recently examined, thb
bladder was small, and, as if to supply the

deficiency in the muscular apparatus of the
membranous part of the urethra, which was
necessarily wanting, the acceleratores urinas
were immensely developed ; their superior
attachment was of course deficient.

Hypospadias implies that form of malforma-
tion in which the urethra runs in a groove
beneath the penis ; it is subject to considerable
variation. The most common variety is that
where the urethra forms a simple groove, and
the penis is bent downwards, the prepuce being
wanting. If this groove be continued down
deeply to the perinaeum, between the two sides
of a fissured scrotum, the whole genital system
takes on more or less of the female character,
and hence has arisen the false notion of the
subject of hermaphroditism.

There are many modifications of this mal-
formation. Otto* mentions one case where
the penis was cleft, and the vestige of the
divided urethra was easily recognised, a fossa
navicularis being distinguishable on either side,
as well as the termination of an ejaculatory
duct. The prostate was wanting. Some-
times the urethra is perfect in the glans, and
throughout the remainder of its course it is
open beneath the penis.

The urethra sometimes terminates before it
reaches its usual destination. Thus it opens
into the rectum, or into the perinaeum; in
other cases it goes no further than the root
of the scrotum ; sometimes it ends at the
corona glandis, or it may end at any distance
between this body and the bulb. Occasion-
ally the opening is altogether wanting {atresia,
urethra), or it is covered by a delicate fold
of skin. When it terminates in any of these
unusual situations, the opening is very small,
sometimes so small as not to admit the in-
troduction of a bristle. Now and then we
meet with a rudimentary meatus in the usual
situation, terminating in a cul-de-sac , and
beneath this a small urethral orifice. When
the urethra ends at the corona glandis, the
prepuce is imperfect ; it is thrown into a fold
resembling the hood of a monk, and is
hence denominated the monk's hood prepuce,
and the glans is uncovered.

Deviations in diamater, although occasion-
ally congenital, are generally the result of
disease. A preternaturally contracted state
of the urethra is sometimes found at birth.
This may happen at the orifice as before men-
tioned, or in other parts of the canal. Under
this condition, the bladder, ureters, and pelves
of the kidneys are sometimes dilated, as in
ordinary cases of stricture. -j- Congenital stric-
ture of the urethra is nevertheless exceedingly
rare.

Diseases and accidents. — Dilated urethra is
not uncommon as the consequence of stric-
ture. When the bladder is unable to get rid
of its contents, the inordinate efforts to
overcome the resistance occasion sometimes
a gradual dilatation of the urethra behind
the seat of stricture. This condition is at-

* Monstrorum Sexcentorum Descriptio Ana-
tomica.

f See article Tekatology.

URETHRA.

1257

tended with excessive irritation along the
whole coarse of the canal, and the prostate
gland becomes hypertrophied in consequence.
Sir Benjamin Brodie mentions a remarkable
case of this description. In this case the
urethra, behind the obstruction, was so di-
lated, that, whenever the patient attempted to
pass his urine, a fluctuating tumour, as large
as a small orange, was felt in the perineum.
It was punctured, and immediately the urine
gushed out in a full stream.

The escape of calculi from the bladder
often occasions dilatation of the urethra into
pouches ; and such dilatations occur inde-
pendent of ulceration.

On dissection of these pouches, the mucous
membrane is usually found injected and
thickened, presenting fungous vegetations,
and occasionally coated with lymph.

The urethra deviates frequently from its
norma! direction : thus, in large scrotal hernias,
and hydroceles of large size, it takes a ser-
pentine course: so also, when tumours press
on the canal, its course is altered. The same
happens in enlargement of the prostate gland,
and from the projection of its middle lobe,
the urethra divides itself into two streams.
Abscesses also distort the canal from its na-
tural direction. Tumours in the pelvis, as a
collection of hydatids between the bladder and
rectum, in consequence of the influence they
exert on the bladder, frequently distort the
urethra from its normal direction. This dis-
tortion occurs more especially to the pelvic
part of the canal. Under these circumstances
the urethra is generally lengthened to a greater
or less extent.

Solutions of continuity result either from
mechanical injury, or from disease. The urethra
may be wholly or in part divided. Most
commonly, if the division be incomplete, a
small fistulous opening remains for a short
time, which subsequently, if let alone, com-
pletely closes. Incisions through the mem-
branous part of the urethra, as in the opera-
tion of lithotomy, speedily cicatrise.

The most serious injuries to the urethra
are those resulting from blows or falls on the
perinseum, especially when they are accom-
panied by fracture of the ossa pubis. In these
cases there is either partial or complete solu-
tion of continuity. The membranous part of
the urethra, from its position beneath the
pubic arch, most frequently suffers. The na-
ture of the injury may be generally recognised
by the escape of blood with the urine, or by
complete retention of urine. An elastic ca-
theter, carefully introduced, will in the former
case generally grate against the torn part In
complete division of the urethra, if the patient
survive the injury, the torn ends are, in
the progress of the cicatrisation and con-
traction, brought into apposition, and the con-
tinuity of the tube is restored : stricture is
the almost necessary consequence. If, how-
ever, the cure is not accomplished, urinary
fistula is the unfortunate result. When the
complete division of the urethra is accom-
panied with fracture of the pubis, the two

ends of the canal are frequently so completely-
separated, that extensive extravasation of urine
ensues, and the case is generally fatal.

Severe contusion of the urethra, inde-
pendent of rupture, sometimes leads to ul-
ceration or sloughing, and occasionally gives
rise to stricture by inducing chronic inflam-
mation of the injured part.

Laceration of the urethra occasionally hap-
pens from the introduction of foreign bodies,
or from the escape of fragments of calculi,
especially after the operation of lithotrity.
Tlie torn part generally heals under simple
treatment, or the urine is infiltrated into the
spongy body, and abscess is the consequence.
Laceration often attends violent efforts to
force a stricture with the sound or catheter :
these injuries usually happen at the under
part of the canal, and frequently heal if all
violence be desisted from. In a case of la-
cerated urethra brought into the London
Hospital, a large pouch as big as a small
orange was formed in the scrotum, into which,
when the man attempted to micturate, the
urine was forced ; he then squeezed it through
the natural passage. By degrees this pouch
gradually contracted, and no vestige of it
remained.

Inflammation of the urethra, whether com-
mon or specific, is usually of the catarrhal
form : common inflammation is comparatively
rare ; but it may be excited by chemical and
mechanical stimuli, or it may depend entirely
on constitutional indisposition : thus strong
injections have been known to induce every
symptom of severe urethritis simulating an
attack of gonorrhoea; but the disease is speedily
arrested by ordinary antiphlogistic treatment.
Under the head of mechanical causes may be
enumerated the introduction of the catheter
or bougie, and other foreign bodies, and the
passage of calculi entire or in fragments, and
blows on the perinseum.

The urethra is sometimes inflamed from
constitutional causes, or sympathetically : thus
stone or calculus in the bladder and kidneys
frequently leads to urethritis ; some substances
taken into the stomach produce the disease,
as asparagus, cantharides, and turpentine, and
arsenic if administered in large doses, espe-
cially if the poison be allowed to accumulate
in the system.

In persons of a gouty diathesis, urethritis
occasionally occurs, followed by a discharge
of muco-pus. According to Prout, “gouty
irritation of the urethra often assumes all the
characters of gonorrhoea, and is not only
attended by a profuse discharge, but with
great irritation and scalding in passing water.”
During the prevalence of influenza, I have
witnessed a severe attack of urethral inflam-
mation accompanied with copious puriform
secretion, and attended with the ordinary
symptoms of clap ; under the influence of a
purge it passed off entirely in a few days.
Suppression of cutaneous eruptions, according
to the German pathologists, not unfrequently
causes urethritis. Inordinate indulgence in
venery, and masturbation, produce inflamma-

1258

URETHRA.

tion of the urethra by the constant irritation
of the part. So also the irritation of the
menstrual and leucorrhceal discharges, when
applied to the male urethra under states of
high excitation, induces a similar pathological
condition.

Croupal exudations are sometimes found in
the urethra. These assume either a tubular
form, or the lymph is effused in the form
of long shreds.* The mucous follicles situ-
ated in the vicinity of the meatus are, ac-
cording to Kleeberg, of Konigsberg, liable
to a form of inflammation similar to that
which attacks the follicles of the genital
organs of the female. He thinks that it is
sometimes connected with clap, or gleet, and
often independent of either. It is indicated
by a swollen state of the circumference of the
mouth of the urethra, which is of a brownish
red colour. There is slight pain in making
water. The orifices of the lacunae become
closed by inflammation, and, in the course of
two or three days, pustules are formed in their
places, which break and discharge a yellow
pus. “ The orifices of the large mucous fol-
licles are now seen dilated and surrounded by
a swollen dark-red border, and they discharge
a muco-purulent fluid into the urethra : if this
be washed off, and the glands compressed, the
fluid is distinctly seen issuing from these
openings.” f The disease sometimes assumes
a chronic form. J

The specific causes of inflammation of the
urethra are syphilis, gonorrhoea, and small
pox. Of these, gonorrhoea is the most fre-
quent. Syphilitic inflammation, producing
chancre, is by no means unfrequent, as
Ricord has proved. The disease makes its
appearance on the 6th, 8th, and 12th days
after connection. Inoculation from the dis-
charge produces the true syphilitic pustule.
It often attacks the meatus urinarius.

Inflammation from gonorrhoea may be either
acute or subacute, or the disease may be viru-
lent or simple, the difference being in degree
rather than in kind. The disease begins in
the anterior part of the canal, and is supposed
to attack first the lacuna magna. Hunter
limited its specific extent to an inch and a
half from the meatus. The period of incuba-
tion of the poison varies from one to ten days,
and is sometimes prolonged even beyond this,
if we can believe the accounts of patients.
Hunter has known it to appear a few hours
after connection, and Sir Astley Cooper met
with a case in which it did not make its ap-
pearance until after fourteen weeks from the
time of inoculation.

The pathological changes in the urethra from
this disease may be briefly described. The dis-
ease, commencing at the part indicated, if left
to take its own course, gradually extends itself
in a retrograde direction as far as the neck of
the bladder, and, in very severe cases, the

* See Pathological Museum of the College of
Surgeons, Preparation No. 2576.

t Zeitschrift fur die gesammte Mediein, Band ii.
Heft 2.

t British and Foreign Med. Review, vol. iii.

mucous membrane of this viscus becomes
involved. The urethral membrane is swollen,
red, anil exceedingly vascular : this can only be
generally observed at the orifice, but it has
also been seen in the middle of the canal in
cases where, during an attack of gonorrhoea,
the urethra has been divided. The intensity
of the inflammation is not uniform. Thus,
the lacuna magna, and the beginning of the
spongy portion, are most Severely attacked.
The inflammation attacks the lacunas, giving
rise to pain and swelling in various parts of
the canal ; even the spongy body itself be-
comes, by contiguity, implicated in the dis-
ease, and interstitial deposition of fibrin
takes place in its cells, causing unequal dis-
tension of this body during erection, and
hence painful chordee. Abscess in this body
is not very unfrequent. By continuity of
surface, the disease attacks the mucous lining
of Cowper’s glands and the ducts of the
prostate, whilst through the ejaculatory ves-
sels it passes to the vesiculae seminales, and
by the vasa deferentia to the epididymis,
causing hernia humoralis. When the latter
structures become affected, the inflammation
of the urethra itself in a great measure sub-
sides, and the discharge ceases, usually to
reappear in a mitigated form.

The inflammation of gonorrhoea is neces-
sarily of the catarrhal character. At the first
onset of the affection there is a slight weeping
from the meatus of a transparent fluid, in
which mucus particles are floating, probably
only the natural secretion of the urethra in
excess. This soon gives place to a semi-
puriform secretion, which glues the edges of
the orifice together. It afterwards becomes
more distinctly puriform, and at the height of
the inflammation, the discharge, which has
increased in quantity, puts on a greenish hue,
and is of a faint, sickly odour, as the disease
subsides. It changes again as to its character
in exactly the inverse order of its appearance.
It frequently leaves behind it a gleety dis-
charge. The seat of this discharge in gleet
is either the general mucous surface of the
urethra, the lacunae, or the anti-prostatic
ducts, and in many instances the ducts of the
prostate gland are alone affected in long per-
sistent gleets.

When gonorrhoea coexists with chancre,
the discharge has usually a greyish or reddish
tint, or sanious aspect.

Among the most important consequences
of this affection, we may mention simple
erosion and cicatrices from ulceration produc-
ing stricture, and, which is much more com-
mon, chronic thickening of the urethra giving
rise to stricture. If the diseased urethra be
examined after death, according to Hunter,
the fossa navicularis and its lacunae are found
more vascular than usual, and the lacunas
filled with matter. In more severe cases the
membranous part, Cowper’s glands, and their
ducts, are involved in the disease. Littre
found, after examining forty cases, Cowper’s
glands morbid in one only ; and Morgagni
met with only one or two instances of a

URETHRA.

1259

similar kind. The prostatic part of the ure-
thra evinces signs of disease in severe attacks
of clap.

The glands of Cowper are sometimes in-
flamed, independent of gonorrhoea, and be-
come indurated ; or they occasionally suppu-
rate.

Ulceration of the urethra may arise from
common and specific causes. In the latter
category, chancres take the first rank ; these
can only occur in the anterior part of the
canal, and are generally found at the urethral
orifice.

Ulceration, independent of specific cause,
is sufficiently common : thus, it may arise
spontaneously, or as the consequence of stric-
ture, or foreign bodies in the canal, as calculi,
pieces of bone, bougies, &c. Spontaneous
ulceration of the urethra is exceedingly rare ;
it is not mentioned, usually, by writers on the
diseases of the urethra. 1 have met with one
instance of it myself : in this case three suc-
cessive attacks of ulceration had occurred,
which terminated in urinary fistulas, one an-
terior to the scrotum, one in the perinaeum,
and one in the vicinity of the tuber ischii.
They were each preceded by rigors, and other
signs of fever, and were accompanied by much
constitutional disturbance ; no stricture, or
other appreciable disease of the urethra what-
ever, had preceded the ulcerative process.

Ulceration behind a stricture is very com-
mon ; it depends on inflammation attacking the
part as the result of long continued irritation.

A stricture itself sometimes becomes the
seat of ulceration, when bougies and catheters
are used with violence for its cure. It also
happens, though rarely, that spontaneous ulcer-
ation of the stricture occurs, by which the
stricture is cured. Sir Benjamin Brodie re-
lates an instance of this.

Ulceration consequent on tubercular deposit
now and then occurs in the urethra, but only
in cases where tuberculosis prevails over the
entire urinary apparatus.*' An instance of
this description occurred to Mr. Robinson of
Peckham, in a man who had been the subject
of extensive tuberculosis in the urinary and
genital organs. The disease appears to attack
the follicles.

Cancerous ulceration attacks the male
urethra in carcinoma of the glans penis and
other parts of the organ.

Sloughing of the urethra, as a consequence
of stricture and violent catheterisation, often
leads to the destruction of a considerable por-
tion of the. canal.

In severe cases of small pox, pustules are
not unfrequently found in the urethral mem-
brane.

Abscesses. — As a consequence of inflam-
mation, abscesses form in connection with
the urethra : they may be acute or chronic :
sometimes they communicate with the urethra,
but frequently they have no such commu-
nication. Abscesses may take place in any
part adjacent to the canal: thus, in severe

* See Rokitansky.

gonorrhoeas, suppuration in the spongy body
from inflammation of contiguous parts is not
very uncommon ; the same also is occasion-
ally met with in the perinaeum, in Cowper’s
glands, and even in the prostate. Abscesses
are not unfrequently met with as the conse-
quence of injury to the urethra from blows or
falls upon the part. In all such cases the
abscess communicates with the canal, and
frequently, if not generally, is attended with
extravasation of urine.

The most common forms are those depend-
ing on stricture ; they are preceded by ulcer-
ation or sloughing, which generally takes
place behind the seat of stricture. Syme
thinks that ulceration of the urethra is se-
condary to the formation of matter, which is
external to the urethra, and precedes the ul-
ceration. Abscesses now and then form in
the vicinity of the urethra without any direct,
or indirect communication with the canal ;
this happens occasionally in cachectic states of
the constitution, in which abscesses are not
unfrequent in the vicinity of other mucous out-
lets, as the rectum. When these are opened,
the matter is disgustingly foetid, and is strongly
impregnated with an urinary odour, although
no urine has become mixed with it, no breach
having occurred in the urethral membrane.

One of the most common forms of abscesses
connected with the urethra arises from in-
flammation of the lacunae during a severe
attack of gonorrhoea. Under these circum-
stances the orifice of the lacuna, the subject
of the disease, probably becomes closed by
adhesive inflammation, a small, round, indo-
lent tumour is formed in the direction of the
spongy body, or in the perinaeum. Ulcera-
tion or bursting into the urethral canal often
occurs, and the urine escapes into the sac,
causing increase of inflammation ; and now
distinct suppuration having taken place,
fluctuation becomes evident, and either the
matter escapes externally by ulceration, or
the surgeon is induced to puncture it with a
lancet.

Tubercles. — Louis states that he has rarely
examined the urethra of tuberculous subjects.
Rayer, however, quotes two cases, one of
which he witnessed himself, and the other
was communicated to him by Vernois. The
former occurred in a man thirty-six years of
age, who had tubercles in his kidneys, testicles,
and prostate ; the latter in a boy, aged twelve,
with tubercles in the kidneys and on the sur-
face of the peritoneum ; in this case the
whole urethra was apparently affected ; in the
other, only two inches and four lines of the
vesical end were diseased.

Ricord presented to the Academy of Me-
dicine* a curious specimen of an urethra
completely studded with miliary tubercles. It
was removed from a man who had undergone
the operation of castration for tubercular
deposit in the testicle some years previously.
The prostate contained a tubercular excava-
tion.

* Seance du 2 Avril.

12C0

URETHRA.

The urethra is sometimes traversed by
cords, in some respects resembling at first
sight the cordcB ViUisii of the longitudinal
sinus. I presume they are formed by organi-
sation of effused lymph. There is a curious
specimen of this disease in the Museum of St.
Bartholomew’s Hospital, marked in the Cata-
logue 30. 37. The patient from whom the
preparation was taken had been frequently
the subject of catheterization. The disease is
exceedingly rare.

Stricture. — Under this head are enumerated
all contractions of the urethra depending on
alteration of the tissue of the canal itself, or
the parts immediately surrounding it. Stric-
tures are commonly arranged under three
heads — spasmodic, permanent or organic, and
inflammatory or irritable stricture.

A spasmodic stricture may be defined to be
a temporary diminution in the diameter of the
urethra, sometimes to such an extent as to
effect its complete closure, from spasm of the
muscles surrounding it. The term can only,
with strict propriety, be applied to a tem-
porary contraction of the muscles investing
the membranous portion, as no action of the
acceleratores urinae is equal to the complete
closure of the spongy part. The common
seat of spasmodic stricture is therefore the
membranous part.

Spasm of the urethra arises from various
causes, as exposure to cold, indulgence in
wine and venery, and gonorrhoeal inflamma-
tion. So also, certain medicines, as cantha-
rides, when taken into the stomach, or ap-
plied endermically, may induce a similar con-
dition.

Although genuine spasm is confined to the
membranous part, yet the remainder of the
urethra is liable to temporary contraction
from general irritation of the mucous surface,
as where the urine is loaded with lithates,
and hence becomes exceedingly irritating.
Under these circumstances the stream of
urine is diminished, and the urethra resists
the introduction of the catheter. This con-
dition probably depends on irritability of
those fibres, be they muscular or not, which
enter so largely into the structure of the
outer layer of the urethra.

Spasmodic stricture may be recognised in
the following manner : a patient observes a
sensible diminution in the stream of water,
aggravated by drinking and free living. After
unusual indulgence in wine or venery, he
finds suddenly that he is unable to pass a
drop of water ; the surgeon, on attempting
to introduce an elastic catheter, which is the
best adapted for the case, finds the progress
of the instrument impeded at the membranous
part of the urethra ; by gentle pressure, how-
ever, the spasm yields, and the instrument
enters the bladder suddenly, and all sense of
contraction disappears. On using the instru-
ment on the following day, he finds that it
passes with perfect freedom.

By permanent stricture is understood a
narrowing of the canal from organic change
in the tissue of the urethra itself, or the corpus

examination, and he found that

In 9

cases the stricture was

distant fr

meatus -

-

1

inch.

8

yy

„ from

1

to 2

13

37

yy

2

to 3

11

yy

3

to 4

98

yy

yy

4

to 5i

40

yy

yy

5*

to 6i

10

„

yy

6-i

to 7i

spongiosum. Permanent stricture may at-
tack any portion of the urethra ; even the
prostatic part, the fossa navicularis, and the
bulb have been the seat of stricture : thus,
Ricord and Cross have met with stricture in
the prostatic portions, and the fossa navicu-
laris has been found to be the seat of the dis-
ease (after ulceration) ; but, although it is by
no means unfrequent in the spongy portion,
it is most common in the anterior part of the
membranous part of the canal. This subject
has been examined by various writers on
urethral diseases, but the most extended re-
searches are those of Mr. Phillips, and I
therefore append the result of his observa-
tions. He selected a number of cases for

inches.

This corresponds with the observations of
Ducamp, who found that, in five cases out of
six, strictures are found at the distance of
about 5 inches from the meatus, or from 4
inches 9 lines to 5 inches 3 lines. Amussat
states that the most common seat of the dis-
ease is the point of junction between the bulb
and membranous portions.

Varieties of permanent stricture. — Stricture's
may be spontaneous or traumatic. Traumatic
strictures generally occur at the membranous
portion, but they are occasionally found in
the spongy part. The former result from
contusions or lacerations, the latter from di-
vision of the canal by cutting instruments, as
after the extraction of impacted calculi, or
after complete division. Whatever be the
cause of traumatic stricture, if stricture en-
sues after a wound of the urethra, a cicatrix
occurs, as in other situations, and a tendinous
puckering of the membrane takes place, giving
rise to the most intractable form of the dis-
ease. If, however, the stricture results from
simple contusion inflammation attacks the
part and the stricture is produced as in the
common class. After ulceration of the ure-
thra from chancre a puckering of the mem-
brane gives rise to stricture in its character
resembling the ordinary traumatic variety.

The most simple form of permanent stric-
ture is where the urethra is traversed by a
fold of membrane thrown across in the form
of a bridle. In this case the stricture is
usually in the floor of the canal. It may
occur in any part, except the prostatic, but its
usual seat is the commencement of the spongy
portion. The diameter of the urethra is thus
only partially occluded, the shape of the
stricture being somewhat crescentic. When
the urethra is completely encircled, it appears
as if a slender thread were tied around it, and
thus an annular stricture, or bridle, is formed,
the opening being usually in the middle. The
efforts to micturate often push forward the

URETHRA. 12G1

strictured part, thus inducing a valvular ap-
pearance. Authorities vary as to the forma-
tion of this stricture. Some, as Ducamp and
Laennec, believe it to depend on the organ-
isation of false membrane thrown out on the
mucous surface. Amussat attributes it to the
healing of an ulcer, but there can be little
doubt that both causes may give rise to a
similar condition. Arutzenius considers it
due to a swelling of the mucous membrane,
and consequent loosening from the subjacent
tissue : thus the membrane becomes wrinkled,
and a fold is formed on its surface.

Hunter attributes the origin of these stric-
tures to spasm of the circular muscular fibres
of the urethra. Sir C. Bell describes them
as occasionally splitting into branches, and
running in a longitudinal rather than a circular
direction. He considers them as the result of
inflammation of the mucous surface : to this
opinion most modern surgeons subscribe.
Sometimes two or more annular or bridle
strictures coexist at short intervals in the same
urethra. Hunter met with six, Lallemand
seven, and Calot as many as eight.

The next variety of permanent or organic
stricture is that in which the urethra is nar-
rowed to a much greater extent of its course
than in the former case. In these cases half
an inch or an inch, or even the 'whole extent
of the spongy part of the urethra, is more or
less contracted. The stricture occupies one
or other side, or it completely encircles the
tube. It varies in consistence, from a soft,
yielding thickening of the membrane, to a
complete cartilaginous hardening. The dis-
ease in its most simple form occupies either
the mucous layer alone, or the submucous
elastic layer ; but it is not limited to this, for
in many cases the tissue intervening between
the submucous layer and the spongy body is
the seat of disease, whilst in others even the
spongy body itself, whose cells are obliterated
by the deposition of lymph, becomes thick-
ened and indurated, and thus encroaches on
the urethral tube. I regard genuine simple
stricture as dependent on hypertrophy of the
mucous or epithelial layer and the submucous
elastic lamina of the urethra.

Stricture in its progress passes through
various stages, from simple thickening to
complete cartilaginous induration. The com-
plete cartilaginous conversion of stricture is
more frequently found where the stricture is
situated in the spongy portion.

The most intractable stricture is that which
results from ulceration of the meatus ; it is
frequently associated with adhesion of the
prepuce to the glands ; sometimes the stric -
tured part will not permit the passage of a
bristle. For the cure of this disease incision
is necessary.

Among the most common attendants on
stricture of the urethra are hernial protrusions
of the mucous membrane of the bladder, be-
tween the columns of the detrusor urince, in
the form of sacculi. As a consequence of
stricture of the urethra, may be mentioned
rupture of the canal and of the bladder itself.

It is probable that these are preceded by
interstitial absorption, and not unlikely by
sloughing or ulceration. And the straining to
overcome the impediment to the exit of the
urine leads frequently to the formation of
hernia at the groin, and has been attended
with rupture of the rectus abdominis muscle.*

In old strictures the membrane of the
urethra is usually hypertrophied, the orifices
of the lacunae are enlarged, and the prostatic
ducts considerably dilated. The prostate
gland itself is frequently hypertrophied in
consequence of the general irritation of the
urethra.

False passages. — A false passage may be
formed in any part of the canal, according to
the seat of stricture ; there may be one only,
or several may co-exist. The under part of
the urethra usually gives way, owing to the
direction given to the point of the catheter.
Sometimes the catheter, passing beneath the
stricture, re-enters the urethra, and is then
directed into the bladder, or it may be forced
onwards through the prostate gland ; occa-
sionally the catheter penetrates but a short
distance, and on withdrawal enters the na-
tural passage. False passages through the
third lobe of the prostate gland not unfre-
quently result from unskilful attempts to re-
lieve retention of urine from enlarged pro-
state ; in this way the gland may be perforated
in three or four places.

When false passages are maintained by the
frequent attempts to pass the catheter, they
become lined by a mucous membrane, and the
urine is in some ever afterwards discharged
through the newly formed canals.

Fistu/ee in perinceo (urinary fistulas) — are
a common consequence of ulceration behind
a stricture ; they are generally preceded by
abscess, and sometimes by gangrene. Not
unfrequently they arise independently of any
obstruction, as after abscess from acute go-
norrhoeal inflammation. Urinary fistulas result
also from w'ounds of the canal, as after the
operation of lithotomy, or the extraction of
calculi from the urethra. Suppuration of the
lacunae sometimes leads to urinary fistula :
this happens occasionally to the lacuna magna.

In urinary fistula there is sometimes a
single opening into the urethra, with many
external openings. These are found in various
situations : thus they occasionally exist anterior
to the scrotum, sometimes in the perinaeum,
and now and then they open into the rectum,
or even as low down as the tuberosities of
the ischia : the external and internal openings
do not always correspond, the intervening
tract taking a tortuous course. The walls of
the fistula are much thickened and indurated,
and this induration extends for some distance
to the parts around, and involves a large extent
of the cellular tissue and skin, so that the
perinaeum feels as hard as cartilage : the canal
of the fistula is lined by a mucous membrane.

Sometimes the fistula passes upwards to-

* See Dublin Journal of Medical Science, May
1842, p. 308.

1262 URETHRA.

wards the pubis, and gives rise to inflamma-
tion and caries of the bone ; nay, it may take
its course even to the groin and lower part
of the abdomen.

For obvious reasons, stricture seldom
happens prior to puberty; nevertheless some
rare instances are recorded of the disease
in young children. I do not here allude to
such as result from mechanical injury, for
these may happen at any age. Hunter
mentions a case of stricture accompanied
with fistula in perineeo in a boy four years
old, but he does not speak of the cause.*
Fie also mentions one in a boy eleven years
old. In the Museum of the College of Sur-
geons there is a preparation (No. 2535.) of
the bladder and penis of a boy seven years of
age, laid open to show a stricture at the mem-
branous part of the urethra, and behind the
stricture a small stone is lodged. The case
occurred to Sir E. Home, who also mentions a
case of stricture occurring at ten years of age.

What is the true nature of a stricture ? I
believe that a stricture (l speak of the per-
manent class) may result from the organisa-
tion of lymph effused upon the surface of the
mucous membrane, as in the formation of
bridle strictures. Secondly, that it may arise
from the healing or cicatrisation of an ulcer,
in which case a fibrous puckering is produced.
Thirdly, that it may arise from hypertrophy
of the elastic layer beneath the mucous mem-
brane. Fourthly, from deposition of lymph
between the urethra and spongy body; and,
lastly, from deposit and organisation of lymph
in the cells of the spongy body ; and that these
conditions may all co-exist.

When the strictured part is laid open, it
will be found that at the exact seat of stricture
the mucous surface is raised; and beneath this
the submucous elastic lamina is observed dis-
tinctly thickened, of a firm texture, and de-
prived more or less of its natural elasticity,
this thickening passing off gradually and in-
sensibly in a longitudinal direction until it
altogether disappears and the canal resumes
its natural diameter, or is dilated or contracted
according to circumstances. The thickening
usually extends equally around the urethra,
so that the opening of the canal is in the
middle of the stricture, but in some instances
it is confined to one side. On attempting to
dissect the urethra from the subjacent spongy
body, it will be found that its adhesion at the
seat of stricture is so complete, that it cannot
be raised without much difficulty, and in
many cases the separation of the two struc-
tures cannot be accomplished at all. The
spongy body itself is frequently thickened, and
the delicate tissue forming the septa of its
cells is much hypertrophied.

Causes of stricture. — Most strictures are the
result of inflammation of the urethra. Long
persistent and neglected claps constitute by far
the most common of the causes of the disease.

I have no hesitation in admitting that the
indiscriminate use of stimulating injections

* Hunter, On the Venereal Disease, p. 115.

may be fairly set down as the occasional cause
of stricture. Masturbation, and the too frequent
indulgence in the venereal act, may be enu-
merated amongst the occasional causes of the
disease.

Co-existence of stone ivith stricture. — It often
happens that calculus in the bladder co-exists
with stricture in the urethra, and the con-
nection between the two diseases appears
easily accounted for. But some curious cir-
cumstances occasionally occurring in these
cases, render it very doubtful whether we are
justified in indiscriminately attributing the
formation of stone to the impediment to the
discharge of water from the stricture ; nay,
the circumstances to which I allude rather
tend to prove the converse of the proposition,
namely, that the stricture depends on the ir-
ritation in the urethra, maintained by the pre-
sence of stone in the bladder. The inference
appears legitimately deducible from the fact,
that cases of severe stricture have been entirely
cured by tbe removal of the stone from the
bladder by lithotomy.*

Diseased lacuna:. — Sometimes one of the
lacunae becomes the seat of chronic inflamma-
tion, and is converted into a small indurated
tumour, varying from the size of a hemp-seed
to a horse-bean. It becomes imbedded in the
spongy body, j- According to Sir B. Brodie,
the usual situation is about two or three
inches from the orifice, but it is sometimes
perceptible close to the frtenum, at others
within the scrotum.

Rokitansky mentions a curious form of
disease occurring after repeated attacks of go-
norrhoea. “ The urethra presented numerous
cartilaginous protuberances, from the size of a
millet-seed to that of a pea, in part coalescing,
and scattered over the inner surface as far
back as the bulb, leaving the passage, however,
of adequate dimensions.” J

Obstruction from other causes. — The urethra
is sometimes occupied by verrucous vegeta-
tions, the result of gonorrhoea. Numerous
instances of this are given by Ricord ; they
are usually found near the meatus, and are
remarkably vascular; but sometimes they
exist in tbe membranous, or even the pro-
static, portion. They are distinguishable by
their greater vascularity from another form
of excrescence or caruncle, which co-exists
occasionally with stricture. Both, however,
are formed in consequence of irritation of the
urethral membrane, and represent simple or-
ganised structures connected with the urethra
by a base or stem.

Hunter met with two, and these were in
cases of very old stricture, where the urethra
had suffered considerably. Home says, that
with all his opportunity in inspecting these
diseases in the dead body, he never met with
them. Rokitansky) also affirms their extreme

* See Edinburgh Monthly Journal for April,
1850, p. 367.

f Home, On Strictures.

) Eold tan sky’s Pathology; Sydenham Society’s
edition, vol. ii.

§ Loc. cit.

URETHRA.

1263

rarity. Chelius * says, “ they are found as
little masses of soft warts behind the stric-
ture ; at other times they are found before the
stricture ; they are similar to those growths
observed on the prepuce and glans. I have
seen in one person, who had frequent claps,
the urethra filled with round excrescences
from an inch behind the fossa navicu/aris.”
Morgagni found one in a case of stricture. -j-

These excrescences are developed from the
mucous membrane as the result of simple as
well as specific irritation, and are limited in
the extent of their growth by the walls of the
canal.

We sometimes meet with a more perfectly
organised structure in the urethra in the form
of polypi. They, however, are by no means
common. Rokitansky met with one in the
prostatic part of the urethra, in which situa-
tion they are usually found.

In the Museum of the Royal College of
Surgeons there is a preparation (2578 ) of the
urethra of an ox, with a large polypus hanging
from the verumontanum.

Irritable Urethra. — This condition maybe
recognised by the following symptoms : there
is slight increased vascularity of the canal as
indicated by the redness of the meatus : the
lips of the meatus are glued together in the
morning by mucus, slightly tinged : there is a
very trilling discharge, scarcely sufficient to
discolour the linen ; this is increased by indul-
gence in wine ; a sense of uneasiness is per-
ceived along the canal, and this extends to
the testicles and the rectum. The patient
has a more frequent desire than natural to
pass his water, the stream is diminished, and
a scalding sensation is experienced at the
extremity of the glans whilst the urine is
passing. These symptoms are exacerbated
by indulgence in venereal pleasures, and are
often associated with increased acidity of the
urine ; not unfrequently pain is experienced
down the thighs in the course of the nerves,
and the patient suffers a slight febrile attack.
This state exists, very frequently, altogether
independently of gonorrhoea, and appears really
to result from a mental cause, the patient being
strongly impressed, after a suspicious con-
nection, with the idea of impending gonorrhoea.
Under the use of diluents and the warm
bath this disease very generally passes off. The
true pathology of this state I believe to con-
sist in an increased vascularity of the urethra
and its follicles, with a similar condition of
the glands of Cowper and the prostate, under
the influence of nervous irritability.

The prostatic part of the urethra is liable
to irritation from long continued masturba-
tion. The orifices of the ejaculatory ducts
are the special sources of this irritation, but
the general mucous surface around partakes
of the disease.

Neuralgia of the Urethra. — The urethra
and neck of the bladder are consentaneously
affected in this disease. The periodic and

* Chelius’ Surgery, translated by South, vol. li.
p. 356.

t Liv. xix. ch. 23.

remittent forms of neuralgia attack the
urethra : the periodic disease is characterised
by deep shooting pains in the canal extending
over the loins and sacrum, and down the
thighs, occurring in paroxysms, and generally
accompanied by sudden and urgent desire to
micturate. The attacks recur at a certain
hour, generally night and morning, or every
second or third day, and during the intermis-
sions the patient is altogether free from pain.

The urine is thrown out in jets, and some-
times stops suddenly, and many of the ordi-
nary symptoms of stone in the bladder are
present, and hence the great importance of
the diagnosis, for there is no doubt that, under
this condition, many patients have been sub-
jected needlessly to the operation of litho-
tomy. The sound alone can decide the
question. This disease may originate en-
tirely from the ordinary causes of neuralgic
affections, or it may depend on local causes,
as the use of stimulating injections, the fre-
quent use of the catheter, constipated bowels,
worms in the rectum : it is often associated
with acrid urine, and either leads to, or is ac-
companied with, hypertrophy of the detrusor
urines.*

In the female. — The female urethra
is a short tube by which the urine alone is ex-
creted. It commences at the neck of the
bladder, and terminates at the meatus urin-
arius. The direction of the urethra in the
female is similar to the first or pelvic division
of that of the male ; thus it descends slightly,
and, passing forwards, in nearly a straight
direction, beneath the pubis, it makes a
gentle ascent just at its termination : it there-
fore forms a curve, the concavity of which
faces upwards, the convexity downwards, to-
wards the anterior wall of the vagina, in which
it appears imbedded, and to which it is so
closely connected, that it is almost impossible
to separate one from the other. In its course
it perforates the triangular ligament, which is
stretched across beneath the arch of the pubis,
and is but an imperfect representative of the
corresponding part in the male. The urethra
thus forms the first and smallest of the three
outlets beneath the pubis.

The commencement of the urethra is situ-
ated within the pelvis, behind the symphysis
pubis, to which it is suspended by the appa-
ratus which supports the neck of the blad-
der : its next division is directly beneath the
inferior pubic ligament, and is connected to
it by condensed cellular membrane : the last
portion of the urethra passes between the
origins of the crura clitoridis, and terminates
by a rounded aperture at the anterior part of
the vagina, and a little in front of the pubic
arch : this aperture is called the meatus
urinarius.

The female urethra is invested by a muscu-
lar apparatus, analogous to that surrounding
the membranous portion of the male canal :
thus Santorius described some tranverse and
circular fibres connected with this part, the
latter being situated deepest, and the former

* Rowland, On Neuralgia.

1-264

UllETIIRA.

passing over the canal, and termed by him
“ the depressor urethra;.” So also often ver-
tical fibres can be distinguished arising from
the back of the symphysis pubis, and analo-
gous to Wilson’s Muscles, in the male.
Guthrie* also has given a representation of a
muscle arising from the rami of the pubis, and
splitting into an upper and under part, and
thus completely surrounding the tube, as the
muscle known by the name of “ Guthrie’s
muscle” does in the male: this apparatus in
the female can only have the effect of effect-
ually closing the canal. The length of the fe-
male urethra varies from an inch and a half to
two inches ; but its diameter is considerably
greater than that of the male urethra : thus
at its commencement, at the neck of the
bladder, it is nearly half an inch in diameter,
but it is nearly cylindrical in the remainder.of
its course, and does not exceed three or four
lines in diameter. It is contracted at the
meatus urinarius. There are few points of
higher practical importance in reference to the
surgery of the urinary organs of the female
than the extreme dilatability of the urethra.
It is well understood that, by the introduction
of sponged tents or other mechanical contriv-
ances, gradually increased in diameter, this
canal may be so far dilated as readily to per-
mit the extraction of urinary calculi of at least
an inch and a half in diameter; and hence the
operation of lithotomy is almost superseded
by the more simple procedure of extracting
the stone by dilatation.

The orifice of the urethra or meatus urin-
arius is situated above and in front of the
entrance of the vagina, at the further end of
the vestibulum, between the nymph®, and
anterior to the hymen in the virgin : it is
placed at the distance of an inch from the
clitoris. To the eye it presents the appear-
ance of a closed circular aperture, slightly
raised and thickened at its under edge, with a
depression in its centre. Without ocular in-
spection, it may be found by carrying the fore
finger below the clitoris, down along the sym-
physis pubis for a short distance, when it can
be distinguished by its forming a soft semi-
circular projection, and its corresponding de-
pression can be readily felt. Under examina-
tion with the finger the projection of the mea-
tus increases as if by erection, and thus at
once becomes more perceptible to the touch :
the inferior lip of the meatus is continuous
with the anterior mesian column of the va-
gina, and contains within it some large mucous
crypts ; this was formerly termed the corpus
glandulosum. In order to avoid touching the
clitoris, which, as a matter of delicacy, is of
no slight importance, the meatus may be easily
found without exposure, by carrying the finger
into the vagina, along the anterior wall of
which an elongated spongy swelling will be
perceived ; by advancing the finger along this
swelling the meatus may be readily reached.

If the urethra be laid open, its mucous

* Gutlirie on Diseases of the Bladder, &c.,
pp. 47, 48.

membrane is seen thrown into longitudinal
plicae, with valleculas or depressions between
them. Some of the plicae are larger than the
rest : there is usually one large fold along the
posterior wall ot the canal, and one on either
side ; the fold at the back part, after passing
for a short distance, generally divides into
two branches : it has been compared to the
caput gallinaginis in the male. Besides these
there are other folds, which, when the urethra
is closed, dove-tail into corresponding depres-
sions. The mucous membrane is of a rosy tint
at the meatus, but becomes paler towards the
bladder : it is copiously supplied with mucous
follicles. These open generally in the depres-
sions between the rugae ; but there are some
large depressions or crypts, into which nu-
merous smaller follicles open, situated just
within the meatus : these equal in size the
blunt end of and ordinary probe ; they are
imbedded in the under labium of the meatus,
and, forming a considerable projection, consti-
tute the corpus glandulosum of some authors.
So also, in the vicinity of the commencement
ot the urethra, there is a collection of large
lacunae visible : indeed the under part of the
mucous membrane is at this part studded with
small orifices of mucous crypts. These are
evidently different from the ordinary lacunae
of the urethra : the latter are analogous to
those of the male canal, and, being situated
between the longitudinal plicae, open obliquely
forwards. They are the seat of a copious
mucous secretion.

The mucous membrane within the meatus
is slightly depressed at its floor, which gives
the urine a direction forwards and upwards.
The whole canal is surrounded with a plexus
of numerous small veins, mixed with a consi-
derable quantity of elastic or contractile tis-
sue (the corpus spongiosum) ; hence the female
urethra possesses the undoubted attributes of
an erectile structure.

Organization. — The organization of the fe-
male urethra is analogous to that of the male:
it is essentially a mucous canal, belonging to
the genito-urinary division of mucous mem-
branes, and is composed of a mucous layer,
covered externally by a layer of contractile
tissue. The mucous layer is formed of the
ordinary basement membrane, covered with a
dense pavement epithelium, formed of broad,
oval, and conical, compressed cells. External
to this is a layer of that remarkable tissue de-
scribed by Kblliker as entering so extensively
into the structure of the male urethra, as well
as all the other mucous outlets of the body ;
this is necessarily much more simple in its
arrangement than the corresponding layer of
the male urethra, and is continuous with some
of the longitudinal muscular fibres of the
bladder.

The arteries supplying the urethra are de-
rived from the inferior vesicle, the uterine, and
vaginal.

The veins terminate in the pudic or branches
of the internal iliac.

The lymphatics terminate in the hypogas-
tric ganglia.

12G5

URETHRA.

Its nerves arise from the pudic and the hy-
pogastric plexus of the sympathetic.

Prostate gland of the female. — — Has the fe-
male a prostate ? Guthrie, in his work on
“ Diseases of the Bladder and Urethra, ’ as-
signs a prostate to the female, which, accord-
ing to him, has a form like that ot the male
prostate, and nearly a similar structure. He
says it surrounds the commencement of the
urethra. He further states it to be the size
of the prostate of a boy before the age of pu-
berty ; and rather regards it as existing in a
rudimentary form than as an organ possessing
any follicular or glandular structure. He con-
siders it as of use in giving the urethra support,
and as affording a fixed point for the action of
some of the muscular fibres of the bladder.

Guthrie quotes the authority of De Graaf,
“ De Mulierum Organis,” in support ot his
opinion. “ Sed ulterius, inquiret aliquis, unde
illi ductus sive lacunce humorem ilium hauriant?
priores ilia scilicet, quocirca colli orijicium et
meatus urinarii exilum conspiciuntur ex parasta-
tis mulierum seu potius crasso et membranoso
corpore circumcirca meatum urinarium existente
humorem mum accipiunt ; postenores vero ex
nervoso-membranosd colli uterini substantia liqito-
rem suum col/igunt.”

De Graaf, however, refers to that mass of
follicles surrounding the meatus and com-
mencement of the urethra, rather than to any
special organ worthy of the designation of
prostate. Cowper also denominates the mass
of follicles surrounding the meatus as the
“ corpus glandulosum.”

I confess that I have not been able to trace a
prostate in connection with the female urethra:
there is, however, generally found a firm mass
around the canal, which is much thicker at the
under part than at the upper, and to which I
believe Mr. Guthrie refers. It is certainly not
muscular; but it does not present evidences of
glandular structure ; containing merely a large
quantity of areolar and elastic fibre. Accord-
ing to the notions of the homologies of the
male and female now prevalent, the prostate
should be represented in the female by a rudi-
mentary structure in connection with the
uterus rather than the urethra, inasmuch as it
is essentially a sexual organ, and developed in
the embryo from the prolometra.

Pathology. — The female urethra is
wanting where the entire uropoietic system
is absent, as also when the bladder is defi-
cient : it is also wanting in cases of ecrophy of
the female bladder, and in cloaca! formation.

In consequence of arrest of development,
it may terminate in the vagina, or may receive
the vagina or rectum at the posterior part.

Sometimes the urethra is abnormally di-
lated, as a congenital malformation.* This is
rare : it is more frequently dilated after the
removal of calculi, &c., from the bladder.
Rare instances have been known in which the
act of copulation has been performed through
the urethra instead of the vagina.

* Rokitansky’s Pathological Anatomy, vol. ii.,
Sydenham Society’s edition.

VOL. IV.

Preternatural contractions of the urethra
sometimes occur from pressure of the displaced
uterus or the prolapsed vagina : they some-
times arise, as in the male, from inflammation,
and constitute true stricture of the canal : this
is exceedingly rare.

The urethra deviates from its normal direc-
tion in prolapsus of the bladder and uterus ; —
it takes on more or less of a serpentine direc-
tion ; — this distortion of the canal not unfre-
quently gives rise to retention of urine. As
the uterus enlarges during pregnancy the blad-
der is carried upwards, and, with it, the urethra
is slightly raised.

The urethra may, however, be excessively
dilated without incontinence of urine, of
which an instance has come to my own know-
ledge. A woman of the town w'as admitted
into the London Hospital, in consequence of
retention of the menses : she had imperforate
hymen ; the urethra was enormously dilated,
and no doubt she had admitted sexual inter-
course through. She had no incontinence of
urine.

Dr. Chamberlain also met with a case of
imperforate hymen, where the uret'nia ad-
mitted the forefinger.* Dr. Oldham has ob-
served the same in atresia vaginas, unattended
with incontinence of urine.

The urethra suffers a partial or total in-
version, forming a tumour at the vulva,
attended with difficulty and pain in voiding
urine.

M. Sernin mentions the case of a girl eleven
years of age, who experienced difficulty in
making water. He examined her after a vio-
lent attack, and found a cylindrical body', four
inches long, hanging from the vulva ; and
whenever she attempted to make w'ater this
projection swelled up. It was removed with
success. It was presumed to be an inverted
urethra.-}-

The female urethra is liable to injuries of
various characters : the most common are
simple contusions and lacerations, or it may
be divided partially or completely by cutting
instruments. The urethra frequently suffers
contusion with the neck of the bladder in
cases of protracted labour, from pressure of
the child’s head against the pubis. Under these
circumstances sloughing often succeeds, and a
fistulous communication between the urethral
orifice of the bladder and vagina results, lead-
ing to incontinence of urine.

Lacerations of the female urethra are very
uncommon, and require no particular observa-
tions ; a simple retention of the parts by suture
would be advisable to secure their re-union.

Simple incisions of the urethra, as in the
operation of lithotomy, generally reunite suc-
cessfully : this, however, is not invariably the
result, and hence the occasional occurrence of
incontinence of urine. The urethra, although
extremely dilatable, is occasionally stretched
beyond its natural capacity, in the removal of

* See also Portal, Ccurs d’Anat. Me'd. vol. iii.
p. 476.

f Rectd. Period, tom, xvii. p. 304.

4 M

126G

URETHRA.

calculi or foreign bodies from the bladder,
and thus becomes paralysed, and never after-
wards recovers its normal tone. This is an
unfortunate condition, as it admits of no
remedy.

The female urethra is occasionally the seat
of inflammation : this is almost invariably of
the catarrhal form, and may arise spontane-
ously or as the consequence of gonorrhoea.
The follicles at the meatus are especially liable
to inflammation, in conjunction with the fol-
licles of the vulva and margins of thenymphae.
The disease is described by Dr. Oldham under
the head of the “ Follicular Inflammation of
the V ulva." It consists of a number of slightly
raised vascular points, clustering around the
elevated border of the orifice of the urethra,
and skirting the margins of the nymphae. The
points are isolated and small ; but, as the
disease progresses, several of them coalesce,
and here and there a minute speck of ulcera-
tion may be seen in their centre ; but little or
no swelling accompanies it.

Dr. Ashwell has recognised the same dis-
ease, and concludes that the same is alluded
to by Dr. Churchill, where he speaks of “ a
more circumscribed inflammation which may
attack any portion of the vulva, and is often
seen merely surrounding the orifice of the
urethra, and occasionally confined to the
clitoris.” *

Specific inflammation of the urethra is
usually the consequence of gonorrhoea. The
disease seldom attacks the female urethra until
after the vagina has been some time affected.
It is easily recognised by a swelling or pouting
of the meatus ; and on pressing upwards
against the pubis the true gonorrhoeal dis-
charge appears. It is accompanied with a
sense of scalding on micturition and pain ; but
the symptoms, for obvious reasons, are much
milder than in gonorrhoea of the male. It is
amenable to the same treatment.

Tumours of various kinds are occasionally
found connected with the meatus and the
urethra itself ; the former have their seat
especially in the inferior labium of the ure-
thral orifice. The most common is the simple
vascular tumour, first described by Morgagni
as “ a red fungous excrescence, the size of a
bean, sometimes to be observed [attached to
the orifice of the urethra.” It has since been
recognised by others ; and lias been well de-
scribed by Sir Charles M. Clarke. Sir C.
Clarke describes it as a vascular tumour, arising
from the meatus urinarius. “ Its texture is
seldom firm ; it is of a florid scarlet colour,
resembling arterial blood, and if violence is
offered to it, blood of the same colour is ef-
fused. It is exquisitely tender to the touch,
and if an accurate examination of it be made,
it appears to shoot from the inside of the
urethra. Its attachment is so slight that it
appears like a detached body lying upon the
parts.” It is sometimes connected higher
up with the urethra, and can then only be
brought into view by introducing a catheter or

* Ashwell, on the Diseases of Women.

probe, and separating forcibly the walls of the
urethra, when it will be found attached to the
mucous membrane.

Mr. Hughes, of Stroudwater, described a
tumour “ of a red colour, and of a soft, spongy
texture, with an irregular, jagged surface,
connected with the meatus.” He removed
the meatus, which completely included the
disease.

Carcinomatous tumours are also met with
in connection with this part. They have been
described by Boivin and Duges. They are
frequently associated with similar diseases of
the uterus. They are generally of the ence-
phaloid character, present a lobulated ap-
pearance, and are exceedingly painful. If un-
accompanied by disease of other organs, they
can be successfully removed.

Fungoid tumours of the malignant class
spring occasionally from the mucous membrane
of the urethra. After excision they have a
great tendency to recur. They are occasion-
ally associated with a similar disease of the
bladder.

The urethra sometimes becomes thickened
along its whole extent. According to Clarke,
this thickening exists principally in the cellu-
lar membrane surrounding the urethra, and is
accompanied by a varicose state of the cir-
cumjacent veins. On examination, a bulbous
tumour will be found behind the pubis, and if
much pressure is made upon it, pain will be
produced, but not of a severe kind.”* It is
accompanied with a mucous discharge from
the urethra and vagina. The vessels on the
surface of the tumour become so large as to
admit of being opened with a lancet. When
the patient is erect the size of the vessels
increases, and they diminish in the recumbent
position. Sometimes a pouch forms in the
urethra, in which a few drops of urine are
lodged : this can be emptied by pressure with
the finger. The mucous membrane covering
the tumour is sometimes thick, occasionally
thin and shining. The disease occurs princi-
pally in married women who have had child-
ren ; and, according to Clarke, in those with
red or auburn hair and fair complexions. The
disease seems to consist of an enlargement
of the veins of the part, with hypertrophy of
the cellular membrane.

The female urethra is rarely the seat of
stricture. I have made inquiries of some of
the most experienced accoucheurs in London,
and they agree that stricture of the female
urethra is very rare. The circumstance clearly
depends on two causes ; the first is the ex-
treme natural dilatability of the urethra in
women ; and the second is, that, although it
is liable to gonorrhceal inflammation, the dis-
ease does not persist long in the canal, and
consequently its tissues are not involved in
protracted chronic inflammation, as is so com-
mon in the male.

Sir Benjamin Brodie, however, met with a
case of stricture in the female urethra: it
commenced at the extremity of the canal,

* C. M. Clarke, on some of the Diseases of Fe-
males.

URETHRA.

and extended half an inch back, and was so
tight that it scarcely admitted the finest probe.
My friend Curling also met with a- case of
stricture, attended with retention of urine.
Being foiled in the introduction of the ca-
theter, he was compelled to puncture the
bladder in the direction of the canal beneath
the pubis. The disease had arisen from the
contusion to which the urethra had been sub-
jected in a protracted labour, which had taken
place twenty-eight years before. Since that
time the woman had always experienced dif-
ficulty in making water, and had twice suffered
retention, but no catheter could ever be
passed. The aperture of the meatus was large,
and there was great induration around : a
small catheter was passed about an inch and
a half, but could not be made to enter the
bladder. The bladder was punctured, and be-
tween thirty and forty ounces of urine drawn
off. The stricture was afterwards dilated with
bougies.

COMPARATIVE ANATOMY.

The comparative anatomy of the urethra
has been most carefully examined by Cuvier ;
and I have borrowed largely from his cele-
brated Lecons d’Anatomie Comparee, in my
description.

Cuvier divides the 'urethra into two por-
tions ; the first extends from the orifice of
the bladder to a short distance anterior to the
prostate, whilst the second is continued thence
to the orifice at the glans.

In the first portion of the canal in mam-
miferous animals generally, — that is, in what is
termed in man the prostatic portion, — we find
the verumontanum surrounded by prostatic
ducts and terminations of vasa ejaculatoria ;
whilst in many the sinus prostatieus is of an
enormous size : this is especially the case in
the elephant.

In many animals we find temporary lon-
gitudinal folds of membrane : these are,

however, permanent in some, as in the mar-
mot : in this animal as many as twelve pass
off on each side, and, enclosing small spaces,
render the canal exceedingly irregular, and
thus retard the flow of urine and semen.

With respect to the comparative length of
this part of the canal there is great variety.
Thus in man and the apes it is short, and
surrounded by the prostate. In the makis
it is long and slender; it is long in the
Cheiropiea ; and of medium length in the
bears. In the hedgehog it is about one third
the entire length ; it is more than half in
the civet , cat, sarigue, kangaroo, and phasco-
lonie ; it scarcely reaches this length in the
giant kangaroo ; and is of less extent in the
dog. It is actually longer, and its diameter is
larger, in the marmot ; scarcely half the length
in the rat and guinea-pig; somewhat less
than half in the hare ; short, and not a quar-
ter of the entire length in the squirrel; it
is not more than a third or fourth in the ele-
phant, Pacliydermata, Solidungula, Ruminants,
the dolphin, and porpoise. It is usually re-
latively shorter in man and th e'apes than in all

1267

other mammiferous animals ; and it is amongst
the Carnivora, in whom the penis is com-
paratively short, as the cat and civet, that it
appears to bear the largest proportion to the
other part of the canal. Cuvier denominates
this pelvic part of the canal the muscular por-
tion, because it is usually surrounded by a
muscular layer. Thus in man and the apes
this is especially remarkable on the sides of
the prostate, where the levator ani and leva-
tor prostate are situated.

In the rest of the mammifera the muscular
layer is circular. In the Cheiroptera, mole,
hedgehog, and cat, it is remarkably thick ; in
the dog, civet, and sarigue it is thin ; it is
scarcely perceptible in the marmot, where there
is scarcely any tiling more than a tendinous
covering. In the Rodents it is generally of
moderate thickness ; but in the Pacliydermata
and Ruminants it is of great thickness.

Cuvier suggests that the object of this mus-
cular layer is to expel the urine and seminal
secretion, by forcibly contracting the first por-
tion of the urethra; and hence it is found so
fully developed in those animals whose penis
is long, as in the Ruminants, and in those in
whom that organ is short, as in the cat ; for in
the first it is requisite to force the fluid along
the lengthened penis, in the latter it becomes
necessary to expel it beyond the limits of the
penis. He says that this species of ejacula-
tion is requisite, when any obstacle exists in
the urethra, to the free discharge of semen,
as is the case in the porpoise and the dolphin,
where the membranous part of the urethra,
being wholly surrounded by the prostate,
forms an acute angle with the remainder
of the canal, and becomes considerably con-
tracted at that part. In these animals there
is a thick muscle, attached behind to the front
of the corpora cavernosa ; the fibres of which,
directed backwards, cover the prostate gland,
and pass as far as the under part of the neck
of the bladder. The office of this is neces-
sarily to overcome the difficulty in the expul-
sion of the contents of the urethra, arising
from the peculiarity just mentioned.

In many animals, as in the Ruminants and
Pacliydermata, the communication between
the former part of the urethra and the second
or spongy portion is by no means direct ; but
it takes place at the superior part of the
latter by a sort of opening at a short distance
from its commencement : this is the case also in
the wild boar. The spongy portion begins under
this condition in the form of a cul-de-sac of
varied diameter, — a sort of bulb, — into which
the semen is received after it has traversed
the muscular portion of the urethra, whilst
the secretion of Cowper’s glands escapes into
its sides. In other cases, as in the squirrels
and marmots, this cul-de-sac receives only the
orifices of these glands, and continues in the
form of a short canal, which opens into the
urethra either at the middle of the penis, or
at a short distance beyond. The urethra in
this instance passes over it, and they are both
surrounded by the vascular tissue investing
the bulb.

4 m 2

1268

URINE.

According to Owen, in the kangaroo the
combined prostatic and membranous or mus-
cular part of the urethra is proportionally
longer and wider in the marsupial than in
any other mammiferous quadrupeds. It swells
out immediately beyond the neck of the
bladder, and then gradually tapers to its
junction with the spongy part of the urethra;
it is not, however, divided like the vagina.
Its walls are thick, formed of an external
thin stratum of nearly transverse muscular
fibres, and a thick glandular layer, the secre-
tion of which exudes by innumerable pores
upon the lining membrane of this part of the
urethra.*

The urethra in the Monotremata approx-
imates in many of its characters to that of
the bird. “ It begins by a small orifice at
the root of the penis, near the termination of
the pro-genital passage, and, by the action of
certain muscles, it can be brought into closer
approximation with the tiro-genital passage.”
Owen supposes that this temporary continua-
tion of the urethra and uro-genital passages
takes place during the vigorous muscular and
vascular actions of the parts in coitu, and
that the semen is then propelled from one
along the other without escaping into the com-
mon ventricular compartment of the cloaca ”f
According to Cuvier, in the Gerboise de Mau-
ritania the spongy portion of the urethra does
not join the corpora cavernosa until it reaches
the glans.

For the comparative anatomy of the urinary
apparatus in birds, reptiles, and fish, see the
separate articles on these subjects.

fhe urethra in the females of the lower
animals offers no peculiarity worthy of notice.

Bibliography. — Male. — On the anatomy of the
urethra, see various anatomical works ; and on the
muscles surrounding the membranous portion, see
Wilson , on the Structure and Diseases of the Urinary
Organs ; and Guthrie, on Diseases of the Bladder
and Urethra. Damn, Observations Chirurgicales
sur les Maladies de 1’Uretre, traitdes suivant lanou-
velle Methode. Paris, 1748. Guerin, Dissert, sur
les Maladies de 1’ Urot.ro, avec des Inflexions sur la
mdtliode qu’ont employee jusqu’5 present les Pra-
ticiens. Paris, 1780. Hunter, on the Venereal
Disease. 2nd Edition. 1788. Whately ( Thomas),
An Improved Method of treating Strictures of the
Urethra. London, 1801. Labraud, Sur le Retre-
cissement Chronique de l’Urfetre. Paris, 1805.
Home, Practical Observations on the Treatment of
Strictures of the Urethra. 1805. Kleeman, Dis-
sertatio de curandis Urethrae Chronicis. Erlangen,
1811. Howship ( John), Practical Observations on
the Diseases of the Urinary Organs, &c. London,
1816. Desault, Maladies des Voies Urinaires
(CEuvres Chirurgicales, vol. iii.). Paris, 1813.
Arnott (James), M. D., A Treatise on Strictures of
the Urethra, containing an Account of an improved
Method of Treatment. London, 1819. Bell (Charles),
A Treatise on Diseases of the Urethra, &c. &c.
3rd Edition, by Shaw. London, 1822. Ducamp,
Traite des Retentions d’Urine causdes par le Re'tre-
cissement de l’Urfetre, & c. Paris, 1822. Lisfranc,
Des Retre'cissements de l’Uretre. Paris, 1824.
Lallemand, Observations sur les Maladies des Or-
ganes Genito-Urinaires. Paris, 1825-27. Winz-
lieimer, Ueber die Organische Harnrohrenverenge-
rung und tdie verschiedenen Untersuchungs- und

* See article Marsupialia. j

f See article Monotremata.

ITeilungs-Methoden derselben. Erlangen, 1832.
Amussat, Lemons sur les Retentions d’Urine causees
par le Ketrdcissement du Canal de l’Uretre, &c.
1832. Tanchon, Traite des Re'trecissements du
Canal de l’Uretre. 1835. D. J. Arntzenius, De
Organische Gebrechen der Urethra. Utrecht, 1840.
Brodie (Sir Benj.), Lectures on the Diseases of the
Urinary Organs. 3rd Edition. 1842. Kugler,
Praktische Abhandlung liber die Verengerung der
Harnrohre, und ihre Heilung ohne Aetzmittel.
Wien, 1843. Guthrie, On the Anatomy and Dis-
eases of the Neck of the Bladder and of the Urethra.
London, 1834. Civiale, Sur les Maladies des Or-
ganes Gdnito-Urinaires, 1850.

Female. — For the anatomy of the female
urethra, see the various works on Descriptive
Anatomy. — For the morbid anatomy, the following
works may be referred to : Morgagni, De Sedibus et
Causis Morborum ; Churchill, On the principal Dis-
eases of Females, 1844, in which reference is made
to the writings of Warner, Jenner, Sir C. M. Clarke,
W ardrop, V elpeau, Hosack, Rosenm tiller, Vogel, Kal-
debrand, and Drokaska: also to Hughes, in Medi-
cal Facts and Observations, vol. ii. p. 26. ; to the
Lancet, vol. xiii. p. 784. ; to the Jo urn. Hebdom.,
July, 1836 ; to the New York Journal of Medicine
and Surgery, No. 1. p. 29. ; to Dughs, on Diseases
of the Uterus (Ileming’s Trans.), p. 546. ; and the
fourth volume of the Transactions of the Provincial
Medical and Surgical Association. The Principles
of Midwifery, &e,, by John Burns, Glasgow, 1820.
Dr. Bamsbotham’s Lectures on Midwifery, Med. Ga-
zette for June 6th, 1835. The British and Foreign
Medical Review, vol. viii. 1839. Grosse’s Patho-
logical Anatomy, vol. ii. 1839. Dr. Ashwell, On
Diseases of Women, 1846.

•John Adams.

URINE. — Lat. Urina ; Gr. to ovpov ;
French, V Urine; Ital. V Urina; Germ, das
Harm.

The urine may be defined as that fluid
which is eliminated by the kidneys in the dis-
charge of their excretory function.

The human urine being that of an omnivo-
rous feeder, differs materially from that which
is excreted by animals purely carnivorous or
herbivorous. In cases occasionally met with,
however, where, either from congenital taste,
want, or the indulgence of eccentricity or
curiosity, vegetable food alone has been taken
by human beings, the urine has been observed
to undergo certain modifications as a conse-
quence.

The urine, it is obvious, must vary much
in constitution, according to the conditions
under which the organism is placed, both in
respect to external and internal circumstances.
Thus the state of the atmosphere, as respects
heat and cold, dryness and moisture, will
affect the quantity of water excreted, as a
constituent of the urine, while the quality and
quantity of the ingesta, the state of the chylo-
poietic organs, and the amount of exertion
to which the body has been subjected, are all
causes tending to modify the amount, and
perhaps also the nature and quality, of the
solid matters excreted by the kidneys.

When treating, therefore, of the chemistry
of normal urine, it must be borne in mind
that, in fixing a standard, we are but giving a
result more or less approaching to the truth,
and that the real method of obtaining a philo-
sophical view of its chemical constitution is,
to regard the urine in its variations, in the

r URINE.

1269

liope of obtaining some fixed law whereon to
base a knowledge of the peculiar influence of
the several circumstances on which the varia-
tions depend.

The chemical analysis of this complex fluid
was undertaken by Berzelius, who, with his
accustomed accuracy, produced a result in
which the various improvements and advances
in chemistry have rendered it necessary to
make but little change.

The number of constituents of healthy
urine has been but little increased b}' discovery
since Berzelius wrote, one or two only having
to be added to his list.

It will be our object to enumerate these
constituents, and describe such as may require
especial notice, before proceeding to consider
the quantitative analysis of the urine.

The following, then, may be regarded as a
list of the constituents of healthy urine : —
Water.

Urea.

Extractive matters.

Colouring matter.

Mucus.

Uric acid.
Ilippuric acid.
Carbonic acid.
Lactic acid.
Sulphuric acid.
Hydrochloric acid.
Phosphoric acid.
Silicic acid.
Hydrofluoric acid.
Soda.

Potash.

Lime.

Magnesia.

Ammonia.

Oxide of iron.

(Of four kinds, dif-
fering in their reactions
and solubility in men-
strua.

f Of two kinds, brown,
-! (or hoemaphcein), and
(red (or uroerythrin').

Other acids, peculiar to urine, have been
described by authors, but their qualities are
not sufficiently determined to admit of their
being yet classified as constituents.

Urea. — This constituent of the urine has
been supposed by some to form during the
evaporations necessary for its extraction.
This, however, is not the case, as I have been
able to obtain it by agitating the officinal
rectified ether with urine in the natural
state, and then allowing the ethereal solution,
which separates above the urine, to evaporate
spontaneously. The urea so obtained is free
from lactic acid, showing that the view of
MM. Cass and Henry, who consider urea to
exist in urine in the form of lactate, is in all
probability erroneous.

Urea possesses the following ultimate con-
stitution: —

C2, N 2, H4, 0 2.

Its chemical properties are as follows: —
When heated on platinum foil it fuses, and
on the heat being urged, it yields fumes of

carbonate of ammonia. It is very soluble in
both cold and warm water.

A concentrated solution of urea will bear a
heat of 212° Fahr. without decomposition,
but it quickly decomposes at that temperature
when in dilute solution.

Alcohol of specific gravity 0816 dissolves
one-fifth of its weight of urea at 60° Fahr. ;
boiling alcohol dissolves nearly its own
weight.

Urea is slightly soluble in ether.

The caustic alkalies boiled with urea de-
compose it into carbonate of ammonia.

The nitric and oxalic acids combine with
urea, forming more or less insoluble salts, and
on this fact the processes for the extraction
of urea, from its combinations, chiefly de-
pend.

Urea possesses neither an acid nor alkaline
reaction. Its crystalline form is that of a
four-sided prism.

Extractive matters of Urine. — There are
four of these extractives ; one soluble in
alcohol as well as in water, and three soluble
in water, and not in alcohol.

That which is soluble in alcohol may be ob-
tained from the urine by digesting alcohol of
specific gravity 0'833 on an extract of urine,
and after crystallising the urea by means of
nitric acid from the products of the alcoholic
solution dissolved in water, separating the un-
crystallisable matter, and neutralising it with
carbonate of baryta : the mass must then be
dried, and alcohol must be used to separate
the extractive from the barytic salt.

Its chemical properties are as follow : —

When heated, it swells much, and leaves a
copious alkaline carbonaceous mass.* It red-
dens litmus paper.

Neither bi-chloride of mercury, nor the
acetate of lead, is capable of precipitating its
watery solution.^

Both acid and alkaline solutions are inca-
pable of effecting any precipitation of this ex-
tract from its solution in water.

Protochloride of tin, nitrate of silver, and
di-acetate of lead, produce precipitates.

It may be well to mention, that if anhy-
drous alcohol be digested on this extractive,
which has been called osmazome, it is capable
of being divided into two portions; the one
soluble and the other insoluble in that fluid.

The property of being precipitated by the
di-acetate of lead, nitrate of silver, and pro-
tochloride of tin, belongs peculiarly to that
part of the extractive matter which is soluble
in anhydrous alcohol.

Animal extractive soluble in water only. —
This may be procured by dissolving in water
an extract of urine, which has been digested
with alcohol of specific gravity 0‘833. By
the re-solution we separate any vesical mucus,
lithic acid, earthy phosphate, or silica, which
may be contained in the mass. The solution

* It contains an alkaline lactate.

f If these salts produce a precipitate, it is because
alcohol has been used of higher specific gravity
than U 833.

4 m 3

] 270

URINE

is now precipitated with acetate of baryta, in
order to rid it of sulphuric acid. The sulphate
of baryta is collected on a filter, and the
filtered liquor neutralised with ammonia, and
then again thrown down with the acetate,
which now causes a precipitate of phosphate
of baryta.* This is to be collected, and the
filtered liquor evaporated in order to drive
off the ammonia ; or, what is better, it may be
neutralised by acetic acid. Neutral acetate of
lead is now added to the solution, which
causes a copious precipitate. This must
be collected and washed, and then decom-
posed by sulphuretted hydrogen, which pre-
cipitates sulphuret of lead, and leaves the
animal extractive in solution. This may be
obtained by evaporation. This extractive is,
however, but part of that meant to be under-
stood as the “ animal extractive soluble in
water only,” so often mentioned in analyses.
The remainder of it may be procured by pre-
cipitating the liquor (in which the precipitate
by neutral acetate oflead subsides), by means
of the di-acetate of lead ; then collecting the
precipitate, decomposing it as before by sul-
phuretted hydrogen, and procuring the ex-
tractive from the clear liquor. It must be re-
membered that each of these extractives has
peculiar properties, perhaps dependent on the
processes used to obtain them. There is
also a portion of animal extractive left unpre-
cipitated by the di-acetate of lead. It is
easily obtained from the liquor by ridding the
solution of any lead which may exist in it by
means of sulphuretted hydrogen, filtering, and
then evaporating to dryness.

It is a mixture of these three peculiar ex-
tractives which constitutes the “animal ex-
tractive soluble in water only” of Berzelius.

The properties of the extractive matter pre-
cipitated by the neutral acetate of lead are
as follows : —

It is of a brownish colour, translucid, and
does not deliquesce ; has no taste, and scarcely
affects litmus paper.

Its solution is rendered cloudy by corrosive
sublimate, and more so by the protochloride
of tin.

The extractive precipitable by the di-ace-
tate oflead has the following properties: — -

It is of a yellowish brown colour ; it has a
slightly bitter taste, and does not deliquesce.

The watery solution of this extract is of a
deep yellow colour.

It is not precipitable by the solution of bi-
chloride of mercury ; but the protochloride of
tin, the di-acetate of lead, and nitrate of silver
precipitate it of a dark brown colour.

The third extractive, which was precipitated
neither by the acetate nor di-acetate of lead,
possesses tiie following characters : —

It is of a yellow colour. Solutions of bi-
chloride of mercury, protochloride of tin, and
nitrate of silver precipitate its aqueous solu-
tion. The precipitate produced by the last of

* Both these precipitates produced by acetate of
baryta contain animal matter, which, in the latter
case, is in very considerable proportion.

these re-agents is of a dirty yellowish red
colour.*

Colouring matters. — These are two in num-
ber, Haemaphaein or the brown; and Uroery-
thrin, or the red.

a. Haemaphaein. — This is the substance which
gives the yellow or brownish yellow tint to
urine, and according to its proportion the
urine assumes a lighter or deeper colour. Ac-
cording to Scharling, the odour also of the
urine depends on this principle. It is soluble
in alcohol, and the alcoholic solution reddens
litmus. The odour, when concentrated, is
said to resemble that of castor. Scharling be-
lieves this colouring matter to be an oxide
of a radical, to which he has given the name
of omichmyle.

(8. Uroerytlirvn. — This exists but in very
minute quantity in healthy urine; it attaches
itself especially to the lithic acid, being pre-
cipitated with that principle on all occasions.
It becomes abundant in some forms of disease.

Mucus. — For the history of this substance
see article Mucus.

Uric or lithic acid. — This acid may be pro-
cured from the urine by the addition of a few
drops of strong hydrochloric acid, which, after
the lapse of some hours, produces a reddish
crystalline precipitate of lithic acid. This red
colour is caused by an admixture of colouring
matter of urine, for pure lithic acid is per-
fectly white. It may be obtained in a pure
state from the red crystals by being dissolved
in caustic potash, and then precipitated from
its solution by the addition of hydrochloric
acid. The precipitate may now be collected,
and washed on a filter.

Lithic acid possesses the following chemical
properties : —

It is insoluble in water.

It is easily soluble in a solution of caustic
alkali, and precipitated from such solution by
the addition of an acid.

It is dissolved by nitric acid with efferves-
cence; and, by careful evaporation to dry-
ness, yields a red or rather pink colour, which
becomes of a fine violet tint when ammonia
is dropped on it, or even when it is subjected
to the action of strong ammoniacal fumes.
This reaction of ammonia is very useful, in-
asmuch as it prevents the yellow stain which
many animal matters produce with nitric acid
from being mistaken for this reaction of lithic
acid. In the former case, the ammonia in-
creases the yellow tinge to an orange colour,
which is very distinct from the beautiful violet
tint of what is now known as murexid.

Before the blowpipe, this substance emits a
fetid smell of burnt horn, mixed with an odour
approaching to that of hydrocyanic acid.

The ultimate analysis of lithic acid shows
its composition to be C 5, N 2, FI 2, 0 3.

Hippuric acid. — This acid is considered by
Liebig to be constantly present in human
urine.

* For further examination of these extractive
matters, see the article by Berzelius, in his Traits
de Chimie, vol. vii. p. 380. ; Sur les Matieres inde-
terminees dans F Urine.

URINE.

1271

He states its quantity as equal to that of
the lithic acid, in all persons feeding on a
mixed diet. This, however, is certainly an
over statement. It is present, but in small
proportion, in healthy urine.

The ultimate composition of hippuric acid
is as follows: —

C 18, H9, N 1, 0 6.

It crystallises in four-sided prisms, obliquely
truncated.

When heated it gives out an odour resem-
bling that of the tonquin bean.

Lactic acid. — The lactic acid was first dis-
covered in the urine by Berzelius, who ex-
tracted it by the following process : —

A portion of urine was evaporated to dry-
ness, and alcohol of specific gravity 0'833
boiled on the solid residuum.

The alcoholic solution was next evaporated,
and the mass dissolved in water.

The watery solution was then boiled with
a considerable quantity of hydrate of lime,
till all ammoniacal fumes (from decomposing
urea) were dissipated ; the hydrate of lime
now became coloured yellow, owing to the
decomposition of animal matter.

The colourless solution was filtered, dried,
and then treated with alcohol of specific
gravity -843. Equal parts of strong sulphuric
acid and water were now added, guttatim, to
the alcoholic solution, until sulphate of lime
no longer precipitated ; the clear liquor being
decanted was next treated with carbonate of
lead (recently precipitated), and was then
filtered and evaporated to dryness.

The residue was treated with oxide of lead
and a little water, by which means the lactic
acid was converted into a sub-salt of consider-
able insolubility. This was collected, washed
with water, and then decomposed by sul-
phuretted hydrogen. Thus, sulphuret of lead
subsided, leaving the lactic acid free in the
supernatant liquor, w'hich, by evaporation,
yielded it in the form of an acid yellow syrup,
exceedingly deliquescent, and incapable of
being thoroughly dried by heat.

Its chemical properties are the following: —

It gives out an acrid odour * when heated,
and leaves a porous charcoal if the heat be
continued. Alcohol dissolves it in all propor-
tions. It is nearly insoluble in ether.

Its salts are all of a gummy and uncrystal-
lisable nature, excepting the lactates of zinc
and magnesia, which have been obtained in a
crystalline form.

When lactic acid is added to a strong solu-
tion of the acetates of magnesia or oxide of
zinc, the lactates of those bases are pre-
cipitated.

The existence of lactic acid, as a consti-
tuent of urine, has been denied by Liebig, and
the question is as yet far from being satisfac-
torily settled.

The admission made of late by Liebig, how-
ever(asthe result of his researches on muscle),
that lactic acid exists in the juice of flesh,
gives great probability to the correctness of
Berzelius’s statement.

* Not unlike that of the tartrates.

The other constituents of the urine which
1 have enumerated, require no particular
notice in this place ; and for the methods of
quantitatively examining the fluid, I must
refer to the article Organic Analysis,
contained in this work.

Healthy urine possesses the following phy-
sical characters : — It is of a pale straw colour,
limpid and acid ; after standing some hours,
it deposits a light, floeculent sediment, com-
posed of mucus. This mucus, as it exists
in health, suspended in the urine, does not
materially interfere with the transparency of
the fluid. The odour of urine is peculiar, and
subject to modification from the use of various
articles of diet, and remedies. Its specific
gravity varies, owing principally to two causes
— the condition of the atmosphere, as affect-
ing the proportion of water exhaled by the
skin, and the quantity and quality of the in-
gesta taken.

Healthy urine may, under these considera-
tions, be said to vary in specific gravity from
1004 to 1032 ; while perhaps, under ordinary
or average conditions of diet, temperature, &c.,
we may place its specific gravity at 1015 to
1022.

Quantitative composition of healthy Urine. —
The quantitative composition of urine must of
course vary considerabl}-, owing to the condi-
tions noticed above, as affecting its specific
gravity. The following is the result of an
analysis made on 1000 parts by Berzelius, on
a specimen considered as healthy: —

Water - - -

-

-

-

933-0

Urea ...

-

-

-

30-10

Free lactic acid

.

-

-l

Lactate of ammonia

_

_

-1

l 17-14

Extractive matters (alcoholic

and 1

watery)

-

-

-J

1

Lithic acid -

-

-

1-00

Vesical mueus

-

-

-

0-32

Sulphate of potassa

-

-

-

3-71

Sulphate of soda -

-

-

-

316

Phosphate of soda

-

-

-

2-94

Superphosphate of ammonia

-

-

P65

Chloride of sodium

-

-

-

4-45

Chloride of ammonium

-

-

.

1-50

Phosphate of lime and

magnesia

-

l-(>0

Silicic acid -

-

-

-

0-03

Dr. Bence Jones has experimented very
carefully on the acidity of urine in health. His
results show that the amount of acidity is
always varying. Thus the urine passed longest
after food was generally the most acid, and
that voided while digestion was going on,
much less so, and in some cases even alkaline,
though the patient was in perfect health.
These conditions pertained, whether a pure
vegetable or animal diet was taken. In the
case of a pure vegetable diet, however, the
decrease in acidity, after taking food, was not
so marked as when a pure animal diet was
observed ; the urine in the latter case some-
times becoming highly alkaline, but in the
former never exceeding neutrality.

Other analyses of more recent date have
4 m 4

1272

URINE.

been published by the following observers,
viz. March and, Simon, Becquerel, Leh-
mann, &c. I shall quote several of these
from the work of Franz Simon, which has
been excellently translated into English by
Dr. Day, for the Sydenham Society.

Simon analysed two specimens of the urine
of a healthy man, 33 years of age. He was
of sanguineous temperament. The specific
gravity was in the first case 1011, and in the
second 1012.

1000 parts yielded —

Water -
Urea -
Uric acid

Alcoholic extractive,!

free lactic acid - J
Spirituous extractive
Extractive, soluble in
water only, and ves-
ical mucus

Lactate of ammonia
Chloride of ammo- 1
nium - - -J

Chloride of sodium -
Sulphate of potassa -
Phosphate of soda -
Phosphates of lime!

and magnesia - J
Silicic acid

1st.

963-20

12-46

0-52

5-10
2- GO

1-00 !>•

1- 03

0-41 !

5 20
3-00

2- 41

0-58
a trace

2nd.

956-00

14-578

0-710

4-800
- 5-590

2-550

7-280

3-508

2-330

0-654
a trace.

The urine of the same individual was also
examined under three varying conditions, as
follow: — A, on rising in the morning, several
glasses of water having been drunk the pre-
vious evening ; B, water and some coffee
taken, and violent exercise had recourse to
during two hours, pulse 100, with occasional
intermissions ; C, urine voided half an hour
after urine B. These urines were all acid;
C most so, and B the least. All three speci-
mens were clear, and B the least coloured.

The following is the result of the analyses :

A.

B.

c.

Water

972-600

98P000

957-600

Urea

Uric acid, ex-’’
tractives, and

8-402

7-568

15-257

ammoniacal
salts and chlo-
rides

>-

13-960

8-618

19-140

Phosphate of soda

1-850

1-250

2-750

Sulphate of po- "
tassa

Phosphates of'

2-790

2-200

5-000

lime and mag-
nesia - -!

0-479

0-264

0-656

The specific gravities of the above speci-
mens were respectively 1010, 1008, and 1014.

Lehmann has analysed the urine collected
during 24 hours, from a well-fed and healthy
young man. The following three results were
thus obtained by him : —

i.

2.

3.

Water -

937-682

934-002

932-019

Urea

31-450

32-914

32-909

Lithic acid

1-021

1-073

1-098

Lactic acid

1-496

1-551

1-513

Aqueous ex- "
tractive

Spirituous and

0-621

0-591

0-632

alcoholic ex-

r

10-059

9-871

10-872

tractives
Lactates
Chlorides of so- '

1-897

1-066

1-732

diuni and am-

-

3-646

3-602

3-712

mo nium

Alkaline sul-
phates

7-314

7-289

7-321

Phosphate of
soda - - J

3-765

3-666

3-989

Phosphates of

lime and mag-

1-132

1-187

1-108

nesia

| Mucus -

0-112

0-101

0-110

The specific gravities of the urines which
yielded these above analyses, judging from the
amount of solid content, must have been as
high as from 1022 to 1029. This is very
high, indeed, as an average of 24 hours.

The mean composition of urine is stated
by Becquerel as follows: —

Mean from
four healthy
Men.

Mean from
four healthy
Women.

Specific gravity

1018-9

1015-12

Water - - -

968-815

975-052

Solid matters -

31-185

24-948

Urea ...

13-838

IQ-366

LTric acid

0-391

0.406

Fixed salts

7-695

6-143

Organic matters

9-261

8-033

Simon very properly remarks on the above
analyses, that the discrepancies to be ob-
served in the composition of the urine, princi-
pally depend on the variation in (he propor-
tion of water ; and that if we consider the pro-
portion of each sn/id constituent to the whole
amount of solid matters, the differences will
not appear nearly so great.

The variations caused in the urine by the
ingestion of various mineral substances, and
of organic compounds taken either as food or
medicine, have attracted the attention of
several chemists of eminence. Liebig has
theorised freely on this subject, and it is but
right that what he has published should he
copied into this article, if only as part of the
history of the urine, while I would warn the
reader carefully to separate in his mind the
matters of fact from the theoretical part of the
subject, inasmuch as a great deal yet remains
to be done. The position of the inquiry is
indeed at present such, that further advances
may very probably lead us to detect the fallacy
of theories which, it is to be feared, the pre-

URINE.

sent state of our knowledge may permit us to
see in too attractive a form.

Liebig remarks, “ When the hydrochloric
acid (in the stomach) has exercised its solvent
action upon the aliments, and the latter have
passed into a state of solution, the soda
which originally entered the organism in com-
bination with the hydrochloric acid, that is, as
common salt, rejoins the hydrochloric acid
during the preparation of the chyme, and pre-
vious to its transformation into chyle, the
soda and the hydrochloric acid thus reunited
combine again and form common salt : chyle
and lymph have no longer any acid reaction,
but, on the contrary, they manifest alkaline
properties.”* The alkaline reaction of the
lymph, chyle, and blood of man and of the car-
nivorous animals cannot be owing to the pre-
sence of a free alkali, as is evident from the
preceding observations ; for the nutriments
of man and of the carnivorous, as well as the
graminivorous, animals, contain no free alkali,
nor any salt formed of an alkaline base and
an acid which might be destroyed in the
organism by the vital process, and thus cause
the alkaline base to be liberated. The blood
must contain the same salts as exist in the
aliments. With the exception of common
salt, nothing is added during the digestion of
the aliments. We have seen that this substance
undergoes decomposition in the upper part
of the digestive apparatus, being resolved
into free soda and free hydrochloric acid ; but
we have also seen that the liberated soda
rejoins the hydrochloric acid during the pre-
paration of the chyme, and previous to the
transformation of the latter into chyle ; that
is, when the acid has performed its function,
viz. the solution of the aliments, — the salt
formed by this combination, that is, common
salt, has neither an acid nor an alkaline re-
action. The salts with alkaline reaction con-
tained in meat, flour, or grain, are alkaline
phosphates. It is obvious that the alkaline
reaction of the chyle, lymph, and blood of
animals feeding upon animal and vegetable
substances can only be derived from their
alkaline phosphates. The serum of the blood
can only be considered as a combination of
albumen with an alkaline phosphate ; the fibrin
of the blood, or the fibrin of the muscular
fibre, is a combination of albumen with phos-
phate of lime.

“ The bibasic phosphates of soda and of
potash are in many respects highly remarkable
salts. Although of a tolerably strong alkaline
reaction, yet they exercise no destructive
action upon the skin, nor upon organic forma-
tions. They possess all the properties of the
free alkalies, without being such : thus, for
instance, they absorb a large amount of car-
bonic acid, and this in such a manner that
acids produce effervescence in a saturated so-
lution of this kind, just as they would in
alkaline carbonates. They dissolve coagulated
curd of milk or cheese, as well as coagulated
albumen, into clear fluids with the greatest

* Lancet, 1844.

1273

facility, just as caustic or carbonated alkalies
do. But of still greater importance in relation
to the secretion of urine is their deportment
towards hippuric acid and uric acid. Hippuric
acid dissolves with the greatest facility in
water to which common phosphate of soda
has been added. Uric acid possesses the same
property at a high temperature; the phosphate
of soda, in this process, loses its alkaline re-
action completely upon the addition of uric
acid and hippuric acid, and assumes an acid
reaction. The acid nature of the urine of
man, and of the carnivorous and graminivorous
animals, is thus explained in a very simple
manner.

“ There are but two principal channels
through which the salts entering the organism
with the aliments can effect their exit from
the body, viz. they must either be carried off
in the fasces, or in the urine. The most simple
experiments show that soluble salts are car-
ried off' by the feces only when the amount
of salt contained in the fluids in the intestines
is larger than that contained in the blood.
If the amount of salt in these fluids is equal
or inferior to that of the blood, the soluble
salts are re-absorbed by the absorbing vessels
of the intestinal tube, and enter the circula-
tion, and are then removed from the body
by the urinary organs and channels. If the
amount of salt contained in the intestinal
tube is larger than that contained in the
blood, the salts exercise a purgative action.

“ If, after previous evacuation of the rec-
tum, a weak solution of common salt (one
part of salt to sixty parts of water) be taken
by means of a clyster, no second evacuation
will take place : the fluid is absorbed, and all
the salt is found in the urine. This experiment
yields the most convincing results if ferro-
cyanide of potassium is substituted for com-
mon salt. In this case the first urine excreted
after the injection of the saline solution, and
frequently even after so short a time as fifteen
minutes, contains so copious an amount of
ferrocyanide of potassium as to yield, upon
the addition of persalts of iron, a copious pre-
cipitate of Prussian blue.

“ The influence which salts in general ex-
ercise upon the secretion of urine is in the
highest degree worthy of attention. It is a
well known fact, that a very speedy emission
of urine takes place in healthy individuals
after drinking fresh pump-water. If ten
glasses of water of from six to eight ounces
each, containing no more than 7-i„th of its
amount in salts, be drunk at short intervals,
an emission of urine of the usual colour will,
after the lapse of about ten minutes, follow
the second glass, and from eight to nine eva-
cuations of urine will generally occur in the
course of an hour and a half. The urine in
this experiment emitted in the last evacuation
will be clear and colourless like pump-water,
and the amount of salts it contains is little
more than is contained in pump-water. There
are individuals who are capable of thus im-
bibing from six to eight quarts of water con-
secutively without any inconvenience ! 1

1274

URINE.

“ But the case is quite different with water
possessing an amount of salts equal to that of
the blood; if even as little as 1 - 1 00th part of
common salt be added to pump-water, and
from three to four glasses drank, no evacua-
tion of urine will take place, even two hours
after drinking. It is almost impossible to drink
more than three glasses of this saline water,
for it weighs heavily on the stomach, as if the
absorbent vessels had no power of taking it
up. This obviously arises from the fluid with-
in the channels of circulation, i. e. the blood,
and the fluid without these vessels, he. the sa-
line water, not exercising any physical action
upon one another, i. e. not intermixing by
endosmose or exosmose.

“ Water containing a larger amount o.
salts than the blood, such as common sea-
water, for instance, and even the weaker kinds
of saline mineral waters, exercise again a dif-
ferent action from that of pump-water mixed
with l-100th of common salt ; not only no
emission of urine takes place after the imbibi-
tion of such saline water, but water exudes
from the circulating vessels into the intestinal
tube, and, together with the saline solution, is
carried off through the rectum ; purgation
takes place, attended with much thirst, if the
saline solution be in some measure concen-
trated.

“ Considering that a certain amount of salts
is absolutely necessary to constitute normal
blood, vve may deduce from these observations
and experiments (which any one may easily
imitate anti verify upon his own person) that
the physical condition of the tissues or of the
bloodvessels opposes an obstacle to any in-
crease or decrease of the amount of salts in
the blood ; and thus that the blood cannot
become richer or poorer in salts beyond a cer-
tain limit.

“ Fluids containing a larger amount of salts
than the blood remain unabsorbed, and leave
the organism through the rectum ; fluids con-
taining a smaller amount of salts than the
blood enter into the circulation, absorb, and
remove from the organism, through the uri-
nary channels, all the soluble salts and other
substances which do not belong to the con-
stitution of the blood ; so that, finally, only
those substances remain in the organism which
exist in chemical combination with the con-
stituents of the blood, and which, therefore,
are incapable of being excreted by the healthy
kidneys.

“ I have convinced myself, by careful and
minute examinations, that urine emitted after
drinking a copious amount of water invariably
contains a somewhat larger amount of salts
than the water which has been drank ; whilst
the amount of phosphates contained in the
last emitted portions of the urine is extremely
minute, and no longer detectable by the ordi-
nary tests. It is, therefore, obvious that all
the salts, without exception, contained in the
urine, are to be considered as accidental con-
stituents of the blood, which are excreted and
removed from the organism precisely because
they no longer form part of the normal consti-

tution of the hlood. The phosphates emitted
with the urine were, previously, constituent
substances which have been decomposed in
the vital processes, or they existed as consti-
tuents of the blood, but upon its transforma-
tion into living tissues they were not admitted
into their composition, they were not required
in the constitution of the latter.

“ Now, among the products of the vital
processes, which, together with the soluble
phosphates, are removed from the organism
through the urinary organs and channels, there
are two organic acids, namely, uric acid and
hippuric acid, both possessing the property of
combining with the soda or potass of the
alkaline phosphates, and acquiring in the com-
bination a higher degree of solubility than they
possess, per se, at the common temperature of
the body. It is obvious that, by the accession of
these two acids, and by their action upon the
phosphates of soda, an urate and hippurate of
soda must be formed on the one hand, and
an acid phosphate of soda on the other ; and
that, consequently, the urine must acquire an
acid reaction.

“ But the presence of these two acids in the
urine is not the only cause of its acid nature ,
there exists another cause, which tends pow-
erfully to maintain and increase it.

“ According to the preceding remarks we
ought to find in the urine all the soluble sabs
of the food, as well as a small amount of the
phosphate of lime, which is soluble to a cer-
tain extent in acid fluids, together with mag-
nesia. The amount of these latter substances
will be in proportion to their solubility in acid
phosphate of soda. The other insoluble salts
of the aliments we ought to find in the feces.
In other words, assuming that the materials
composing the aliments become converted into
oxygen compounds, that is, are burnt in the
organism, we ought to find in the urine all the
soluble salts of their ashes, and in the feces
all the insoluble salts. Now, upon comparing
the constitution of the ashes of the blood or
of the aliments, or, rather, the salts contained
therein, with those contained in the urine, we
find that there exists a striking difference be-
tween their respective amounts of sulphates.

“ According to the analyses of the ashes of
the grains of wheat and rye*, the urine of an
individual feeding exclusively upon bread
ought not to contain a single trace of a sul-
phate, whilst the urine of an animal fed upon
peas or beans ought to contain sulphates toge-
ther with phosphates, in the proportion of nine
of the former to sixty of the latter. Finally,
as flesh contains no soluble alkaline sulphate
(broth does not yield any precipitate of
sulphate of barytes when tested with salts of
barytes), the urine of carnivorous animals
ought to be equally free from soluble sul-
phates. We find, on the contrary, that the
urine of man, according to the most correct
analyses, contains a far larger proportion of
sulphates than the aliments partaken of ; nay,
even that the amount of the sulphuric acid

* Ann. der Chemie, Bd. xlvi. S. 79.

URINE. 1275

received into the system must, in many cases,
be equal or superior to that of the phosphoric
acid contained in the aliments. According to
the analysis of human urine made by Berze-
lius and Lehmann, the amount of the sul-
phates present in urine is nearly double that
of all the soluble phosphates together. Hie-
ronymi found the amount of sulphate of
potass contained in the urine of the tiger, the
lion, and the leopard, compared with that of
the phosphates, to be as 1 to 7). It can be
distinctly and positively proved that these
salts have not been partaken of in such pro-
portions. But we now know the origin of the
greatest portion of the sulphuric acid con-
tained in the urine; this acid has entered the
organism with the food, not in the form of a
sulphate, but as sulji/nir.

“ Gluten*, vegetable casein, flesh, albumen,
fibrin, and the cartilages and bones, contain
sulphur in a form quite different from the
oxygen compounds of this substance. This
sulphur is separated as sulphuretted hydrogen
during the putrefaction of these substances ;
it combines with the alkalies, operating upon
these animal substances, and may be ob-
tained from such combinations in the form
of sulphuretted hydrogen by means of stronger
acids.

“ Now, we know from the experiments of
Wohler, that the soluble sulphurets become
oxidised in the organism; and that thus, for
instance, sulphuret of potassium becomes con-
verted into sulphate of potass ; and it is there-
fore unquestionable that the sulphur of the
constituents of the blood, derived from the
aliments, or, what comes to the same point,
the sulphur of the transformed tissues be-
comes finally converted into sulphuric acid
by the oxygen absorbed in the process of
respiration, and thus that in the urine it must
appear in the form of sulphates ; and from
this cause the original amount of these salts
contained in the aliments becomes increased.
The alkaline base which we find in the urine,
in combination with this sulphuric acid, is
supplied by the soluble alkaline phosphates ;
and the latter, in consequence of the loss of
part of this base, are converted into acid salts.

“ By these considerations and views re-
specting the cause of the acid reaction of
urine, 1 have been induced to prepare an arti-
ficial urine, which possesses the properties of
natural urine, even although sulphuric acid
be altogether excluded.

“ If 40 grains of dry phosphate of soda
(or 90 grains of the crystallised salt, POs 2

{? O + 24 Aq.) be dissolved in one pound

of water, a fluid will be obtained having an
alkaline reaction ; if to this fluid we add 15
grains of uric acid and 15 grains of hippuric
acid, and the mixture is heated, both acids

* Dietrich (in the laboratory of Giessen) has
examined gluten with regard to its amount of sul-
phur; he found wheat-gluten to contain from 0'033
per cent, to 0-035 per cent, of sulphur, exactly the
same proportion as is contained in albumen or
fibrin.

will completely dissolve, imparting a strong
acid reaction to the fluid. The solution thus
prepared does not deposit a trace of uric acid
at a temperature from 37° to 38° (— 98°, 100°
Fahrenheit = the heat of the blood); nay, it
is even only several hours after complete re-
frigeration that a sediment is formed, consist-
ing of uric acid containing soda : this sediment
is of an analogous form to that deposited by
natural urine after standing at rest for a long
time. Upon collecting this sediment, in one
of my experiments, after the lapse of twenty-
four hours, I found that it weighed 7) grains,
so that there remained still in solution 22)
grains of the organic acids. Dilute mineral
acids produce immediately, in the fluids fil-
tered off from the sediment, a precipitate of
uric acid.

“ Proust, Prout, and all the other chemists
who examined the urine previous to, or about
the same period as, Berzelius, ascribed its
acid reaction to the uric acid or phosphoric
acid; hippuric acid was not known as a con-
stant attendant upon uric acid.

“ It follows, from all, we have hitherto
stated, that the acid nature of the urine of
carnivorous animals, as well as that of man,
depends upon the nature of the bases par-
taken of in the aliments, and upon the parti-
cular form of their combinations. In the
flesh, blood, and other parts of animals, as
well as in the grains of the cereal and legu-
minous plants, there exists no free alkali. The
alkali which these substances contain is in-
variably combined with phosphoric acid ; the
acids formed in the organism by the vital
process, namely, sulphuric acid, hippuric acid,
and uric acid, share the alkali amongst them ;
and this, of course, must give rise to the
liberation of a certain amount of phosphoric
acid, or, what comes to the same point, to the
formation of a certain amount of acid phos-
phates of soda, lime, and magnesia. The
proportional amount of the liberated phos-
phoric acid varies with the temperature ; at a
higher temperature the phosphate of soda
dissolves a larger amount of uric acid anti
hippuric acid than at a lower temperature — -
at from 37° to 38° more than at 15°. It is
owing to this that urine, upon refrigeration,
sometimes deposits uric acid, or urate of soda
in a crystalline state, which, of course, can
only take place by the uric acid, at a lower
temperature, restoring to the phosphoric acid
the soda or potass which, at a higher temper-
ature, it had withdrawn from it. At the
common temperature phosphoric acid decom-
poses urate of soda, whilst, at a higher tem-
perature, uric acid decomposes phosphate of
soda. When urine, containing uric acid, and
manifesting an acid reaction, forms no sedi-
ment upon cooling, it shows that the amount
of the phosphoric acid and that of the uric
acid exactly balance each other with regard to
their affinity for soda. Had there been pre-
sent a larger proportion of uric acid, this
would have separated upon cooling ; whilst,
on the other hand, the presence of a prepon-
derating proportion of phosphoric acid would

1276

URINE.

likewise have caused the precipitation of uric
acid, because the affinity of the former for
soda would then exceed that of the latter.
This explains the circumstance that urine, in
certain states, when from some cause or other
its amount of sulphuric, hippuric, or other
acid, becomes increased, precipitates a larger
proportion of uric acid than urine in its
normal state. The solubility of uric acid in
urine must decrease in proportion as the
amount of the other acids present in the
urine increases, because those acids share the
soda with the uric acid ; and, of course, the
larger the amount of soda which combines
with these other acids, the less comes to the
share of the uric acid. It is likewise owing
to this, that uric acid very frequently preci-
pitates from urine upon the addition of mineral
or other acids, and that urine of a turbid,
whey-like appearance, from the presence of
uric acid, frequently manifests a far more
strongly acid reaction than normal urine.

“Now, bearing in mind that the use of
alkaline citrate (Gilbert Blane), of neutral
paratartrate of potass, bi-tartrate of potass,
tartarised soda, acetates of potass and soda,
and tartarised borax, renders the urine alkaline
by creating in it an amount of carbonated
alkali ; and that, likewise, after the eating of
fruit, such as cherries, strawberries, '&c., the
urine is of an alkaline nature, inasmuch as
these fruits contain alkalies combined with
vegetable acids, it is obvious that the acid re-
action of healthy urine is purely accidental,
and that urine of an alkaline or neutral re-
action cannot be considered as a symptom of
a diseased condition of the body. All vege-
table aliments, without exception, — tubers,
roots and leaves, potatoes, turnips, greens,
&c., — contain alkalies in combination with ve-
getable acids ; potatoes, for instance, contain
alkaline citrates ; turnips, alkaline racemates
and oxalates, &c. All these plants yield,
upon incineration, more or less strongly alka-
line ashes, the bases of which were contained
in the living plants, as salts of vegetable acids.

“ It is obvious that by adding these vege-
tables to a meat diet, to bread and to other
aliments prepared from flour, the nature of
the urine must become thoroughly altered ;
for the alkalies which these vegetables con-
tain in combination with vegetable acids, enter
the urine in the form of carbonated alkalies,
and neutralise the acids, of whatever kind,
which may be present. When partaken of in
a certain proportion, they render the urine
neutral ; when partaken of in a larger pro-
portion, they impart to it an alkaline reaction.

“ The urine of all animals feeding upon
vegetables, such as grass, herbs, roots, &c.,
has an alkaline reaction. The urine of the
horse, of the cow, of the sheep, of the camel,
of the rabbit, of the guinea-pig, of the ass, &c.
is alkaline ; it contains alkaline carbonates,
and acids produce in it a lively effervescence.

“ The acid, neutral, or alkaline reaction of the
urine of healthy individuals does not depend
upon any difference in the processes of di-
gestion, respiration, or secretion, in the various

classes of animals, but upon the constitution
of the aliments, and upon the alkaline bases
which enter the organism through the medium
of these aliments. If the amount of these
bases is sufficiently large to neutralise the
acids formed in the organism, or supplied by
the aliments, the urine is neutral , whilst it
manifests an alkaline reaction when the
amount of alkaline bases thus supplied to the
organism is more than sufficient to neutralise
the acids ; but in all these cases the urine
accords with the nature of the aliments taken.

“ The inorganic bases and acids contained
in the urine were, with the exception of sul-
phuric acid, which joins them in the organism,
constituents of the aliments. The amount
of inorganic bases and acids emitted through
the urine in twenty-four hours must, in adult
individuals, be equal to that of these bases
and acids supplied to the organism, during
the same period, through the medium of the
aliments.

“From these data it follows necessarily,
first, that the analysis of urine when made
without respect to the inorganic salts, acids,
and bases, supplied by the aliments, teaches
nothing whatever, and by no means justifies
us in drawing therefrom any physiological or
pathological inference; secondly, that from
the nature of the ashes of the aliments we
are able to determine, positively, the con-
stituents of the urine emitted ; and thirdly,
that only when these latter have been dis-
tinctly ascertained, can we expect to derive,
from the analysis of the urine, any correct
information with respect to the inorganic
matters which have come to be present in it
through processes of disease ; this, at least, is
the chemical method of quantitative investiga-
tion.

“Bearing in mind that the urine contains
the soluble constituents of the ashes of the
aliments, whilst the faeces contain the insolu-
ble part of these constituents, we may form
an accurate knowledge of both, at once de-
termine in which urine soluble alkaline phos-
phates must be present, and in which they
cannot exist. The ashes of all seeds, and of
flesh and blood, contain a certain amount of
soluble and insoluble phosphates, whilst the
ashes of vegetables contain no free alkaline
phosphate, but only insoluble phosphates.
These vegetable ashes contain far more lime
and magnesia than is required for the neutral-
isation of the phosphoric acid present.
Hence, upon incinerating a plant, together
with its seed, and lixiviating the ashes, we find
no alkaline phosphate in the fluid obtained,
although the lixivium of the ashes of the
seeds, when incinerated and lixiviated by
themselves, yields a considerable amount of
these phosphates : the excess of lime and
magnesia contained in the leaves and the
straw enter here into combination with the
phosphoric acid of the soluble alkaline phos-
phates, forming an insoluble compound.

“ It will now be understood why the alka-
line phosphates are generally absent from the
urine of herbivorous animals, and also why,

URINE.

1277

in certain cases, they may be found in the
urine of these animals. If the nutriment of
these animals contains no soluble phosphates,
their urine cannot contain any ; whilst, if we
add a certain proportion of grain to their
food, the alkaline phosphates may be detected
in their urine. Thus it is obvious, likewise,
that the soluble phosphates in the urine of
man are merely accidental constituents, and
that by simply adding lime or magnesia to the
aliments, and thus assimilating the constitution
of these aliments to that of the food of herbi-
vorous animals, the urine must become altered
in its nature and properties. The knowledge
of the influence which alkalies, magnesia, and
lime, or acids, exercise upon the properties of
the urine, or, in other words, upon the secre-
tory process of the kidneys, in the healthy
organism, is of the highest importance for the
curing of diseases.

“ I believe that there is now required only
a small number of good and correct observa-
tions to establish a fixed rule for the remedies
necessary in various cases. Future properly-
directed experiments will prove whether san-
guification is absolutely dependent upon the
presence of alkaline phosphates or not ; we
shall be able to determine whether weak so-
lutions of alkaline phosphates are not the
best solvents for uric acid deposited in the
bladder ; and likewise what is the influence
which aliments rich in sulphur, such as mus-
tard, for instance, exercise upon the se-
paration of uric acid in the bladder, in con-
sequence of the formation of sulphuric
acid. At any rate, we may, by a judi-
ciously-selected diet, alter with positive cer-
tainty, and at pleasure, the nature of the
urine ; we may, without causing any injury to
health, keep it alkaline for a long time, by
adopting a vegetable diet ; and this is cer-
tainly the first condition necessary to insure
the entire prevention of the formation of uric
acid, as is the case with the herbivorous
animals. By its combination with an alkaline
base, uric acid must in the organism resolve
itself into its ultimate oxj'gen compounds
with the same facility as other organic acids,
if the physician prohibits all substances to be
taken as food which, like wine or fat, take
possession of the oxygen necessary for the
transformation of uric acid into carbonic acid
and urea.

“ The carbonated alkali in the urine of
herbivorous animals is separated from the
blood by the kidneys ; the urine derives it
from the blood ; it is certain, therefore, if we
examine the blood one hour or a few hours
after the animal has partaken of food, we
must find in it this alkali in the same state as
it is found in the urine, and that at other
periods of the day the ashes of the blood may
not contain the least trace of free alkali. But
the free alkali does not co-operate in the vital
process in the animal organism ; or, if it is
necessary in this process, the part which it
has to perform may be undertaken with the
very same effect by the bibasic and tribasic
alkaline phosphates.

“ In like manner, when we are contemplat-
ing the presence of hydrochloric acid in the
gastric juice, we must remember that the alka-
line bases, soda, potass, lime, magnesia, are
present in the aliments whilst in their natural
state, invariably in the form of salts ; that is,
in combination with phosphoric acid, or with
organic acids. When, therefore, in the diges-
tive process, hydrochloric acid is supplied by
the gastric juice, the first action of this acid
is confined to the decomposition of these
salts ; the hydrochloric acid withdraws lime
from the phosphate of lime ; potass, or soda,
chloride of calcium, or chloride of sodium or
potassium, is formed on the one hand, and
acid phosphate of soda or potass, or acid
phosphate of lime, on the other ; or acetic
acid, paratartaric acid, or citric acid, are liber-
ated by the decomposition of the salts of
these vegetable acids contained in the ali-
ments. At a certain stage of digestion the
chyme will, according to the nature of the
food partaken of, contain acid phosphates
or free vegetable acids ; and it is only upon
the supply of gastric juice continuing, that
thus, upon the amount of the hydrochloric
acid increasing, we may detect, by analysis,
free hydrochloric acid in the chyme : the gas-
tric juice taken from an empty stomach con-
tains invariably free hydrochloric acid, or acid
phosphates.”

Lehmann has made some very interesting
observations, published in the “ Journal fiir
Praktische Chemie,” by which he has shown
the effects of diet on his own urine. He first
observed the results produced by his ordinary
diet during thirteen days, and found that the
urea amounted on an average to about 46 per-
cent. of the whole of the solid matter excreted.
The average quantity of urea excreted during
the 24 hours amounted to about 500 grains.

During six days, on an ordinary diet, the
uric acid excreted averaged about 1 089 parts
per 1000, and the amount excreted during the
24 hours was about 18 grains.

On a purely animal diet, Lehmann found
the amount of solid matters discharged in the
urine during the 24 hours was much increased.
The urine became pale in colour and strongly
acid. On the addition of nitric acid, crystals
of nitrate of urea were immediately formed,
and uric acid was deposited in large crystals.

By careful analysis, however, Lehmann de-
termined, that though a purely animal diet
increases the proportion of urea excreted
during the 24 hours, the amount of uric acid
is not by any means materially influenced.

The earthy phosphates were discharged in
large quantities under a purely animal diet,
rising to about three and a quarter times as
much as when ordinary mixed diet was taken.

With respect to the effects of a vegetable
diet, Lehmann observed the urine to become
of a darker colour than natural, and to remain
of an acid reaction much longer than ordinary
human urine. The following tables of com-
parison have been constructed by Franz Si-
mon from the results of Lehmann : they
possess a high physiological value.

1278

URINE.

Oil

On

On

mixed

animal

v -getable

Diet.

Food .

Food.

grammes.*

grammes.

grammes.

Amount of

urine in 24
hours -

1057-8

1202-5

909-

Specific gravity
Solid residue’

1022-

1027-1

1027-5

from 1000

parts of urine

05-82

75-48

06-41

Solid matter

passed in 24
hours -

07-82

87-44

59*23

In 100 Parts
of solid
Residue.

Daily
Amount in
Grammes.

Urea during a mixed diet

46-230

32-498

Urea during an ani- j
mal diet - - J

61-297

53-198

Urea during a vege- j
table diet - - J

39-086

22-481

In 100 Parts
of solid
Residue.

Daily
Amount in
Grammes.

Uric acid during a"
mixed diet -

1-710

1-183

Uric acid during an
animal diet -

1-674

1-478

Uric acid during a
vegetable diet

1-737

1-021

From the above it would appear, that the
amount of urea is always diminished by a
vegetable diet, while the proportion of uric
acid excreted is not materially affected. Leh-
mann ascertained also, by other experiments,
that the amount of lactic acid, phosphates,
and lactates was scarcely changed, whether
the subject of experiment lived on an animal,
or vegetable, or a mixed diet. A vegetable
diet was found to increase considerably the
daily discharge of extractive matters; while
far less was passed under an animal diet than
when either a mixed or vegetable dietVas used.

The following table, containing the results of
Lehmann on different forms of diet, as affecting
the daily amount of the various solid matters
discharged by the urine, is a very important ad-
dition to our knowledge of this subject : —

o*

O

o.2

5

5

3 •

ta

T3

O

X

'cS

£

O; IT
o>

c </>

» 3
C O
O G

S

<

>

'Z

^ Ui

gramm

gramm .

gramm.

gramm.

Solid constituents

67-82

87-44

59-24

41-68

Urea

32-50

53-20

22-48

15-41

Uric acid

1-18

1-48

1-02

0 73

Lactic acid and j
lactates - J

2-72

2-17

2-68

5-82

Extractive mat- 1

10-49

5-20

16-50

11-85

ters - - j

* The gramme is equal to 15"4 grains troy.

Severe and continued bodily exercise was
found by Lehmann to increase the discharge
of urea, lactic acid, phosphates, and sulphates.
He observed a diminution, however, in the
proportion of uric acid and extractives dis-
charged under the same conditions.

Simon, simultaneously with Lehmann, as-
certained that the amount of urea, sulphates,
and phosphates excreted, is increased by
strong bodily exercise. Simon remarks upon
this result: — “ Further confirmation of the
above observation is certainly desirable. If,
however, we might assume it as a general
fact, it would be an additional argument in
favour of my view regarding the formation of
urea ; for it would then become still clearer
that the urea is not formed during the change
which occurs in the blood as a consequence
of peripheral nutrition, but that it is formed
during those processes which are dependent
on the respiratory and circulatory functions,
in which we must seek for the greater part
of the carbonic acid which is exhaled, and for
the principal source of animal heat. I refer
to the active metamorphosis of the blood, or
to the mutual action excited by the blood
corpuscles, the plasma, and the oxygen held
in solution in the blood, on each other.”

Dr. Percy has made experiments corro-
borative of the views of Simon. He did not,
however, observe any augmentation of the
soluble salts, viz. phosphates, sulphates, and
chlorides.

In relation to this subject, Simon alludes to
the opinion expressed by Berzelius, that at
least a portion of the sulphates and phosphates
occurring in the urine, are derived from the
oxidation of phosphorus and sulphur which
previously existed as components of protein
compounds, which become changed during the
metamorphosis of the blood. This view I
hold to be especially true as respects the
phosphates, and would here refer the reader
to a paper of mine printed in the Philoso-
phical Magazine *, in which I showed that the
amount of alkaline phosphate contained in the
serum of arterial blood is much greater than
in that of venous, and that the amount of such
salt in venous serum can be at once increased
by exposing the blood corpuscles to air, and
consequently to the action of oxygen during
the coagulation of the fluid.

I feel satisfied, indeed, from my results, that
one great and essential difference between
arterial and venous blood consists in the great
excess of alkaline phosphate contained in the
scrum of the blood of the arteries as compared
with that of the veins.

With respect to the quantity of chloride of
sodium excreted by the urine, it is subject
to great variation. Simon remarks, that the
urine in disease is sometimes deficient in salts,
and that this deficiency takes place at the
expense of the chloride of sodium. He found
but a trace of chloride of sodium in the urine
of a patient suffering from typhus.

Dr. Bence Jones has made experiments on

* On a Function of the Eed Corpuscles of the
Blood, by G. Owen Kees.

URINE.

1279

the variation of the sulphates in urine, and has
arrived at the following conclusions : —

1. The sulphates are increased by food, both
animal and vegetable.

2. Exercise does not produce so marked an
increase in the sulphates.

3. Sulphuric acid in large doses increases
the proportion of sulphates ; in small doses
it produces little or no effect.

4. Sulphur, when taken, increases the sul-
phates in the urine, and sulphate of soda or
magnesia produces the greatest effect on the
quantity of sulphates in the urine.

With respect to the phosphates contained
in the urine. Dr. Jones has arrived at the
conclusion, that the quantity of earthy phos-
phates depends on the quantity contained in
the ingesta, and that this is also the case with
the alkaline phosphates. These latter, how-
ever, are to a certain extent increased by
exercise.

URINE OF ANIMALS.

The urine of animals varies much in cha-
racter, according to the kind of food taken.
Thus, there are striking differences between
the urine of the carnivora and the herbivora.
The urine of carnivorous animals is ge-
nerally acid when discharged, but becomes
alkaline and ammoniacal very rapidly. The
urine of herbivorous animals, on the con-
trary, is alkaline when passed, and contains a
large proportion of alkaline and earthy car-
bonates. Simon, however, states the urine of
horses immediately after it is passed, to be
occasionally acid. The urine of the carnivora,
according to the observations of Vanquelin
and Hunefeld, contains neither the uric nor
hippuric acids. Hieronymi, however, who
examined the urine of the lion, the tiger, and
the leopard, detected uric acid in small pro-
portions. The urine of the herbivora con-
tains hippuric acid in large quantities, in the
form of hippurate of soda. No uric acid is
present according to the analyses of most
chemists, but traces of it have occasionally
been found in the urine of the graminivora.

Hieronymi obtained the following result
by the analysis of the mixed urines of the lion,
tiger, and leopard. This may, therefore, be
regarded as the type of the urine of the car-
nivora : —

Water ----- 846-00
Urea, alcoholic extractive and free

lactic acid -

132-20

Uric acid -

0-22

Vesical mucus - - - -

5-10

Sulphate of potassa - - -

Chloride of ammonium, and traces

P22

of chloride of sodium -

P16

Earthy phosphates -

1-76

Phosphates of soda and potassa

8-02

Phosphate of ammonia

1-02

Lactate of potassa -

3-30

The specific gravity of the urine

of these

large carnivorous animals varies, according to

Hieronymi, from 1059 to 1076. It is clear
when passed, and of a bright yellow colour.

The urine of the herbivora is turbid when
passed, and generally possesses a lower spe-
cific gravity than that of carnivorous animals.
Thus, the urine of horses, according to Simon,
is about 1045. That of oxen, according to
Von Bibra, varies from 1040 to 1032.

The following are two analyses of the urine
of horses by Von Bibra : —

Water -

885-09

912-84

Urea - - - -

12-44

8-36

Hippuric acid

12-60

1 23

Watery extractive

21-32

19-25

Alcoholic extractive

25-50

18-26

Mucus

0-05

0-06

Salts soluble in water -

23-40 ~\

j- 40-00

Salts insoluble in water

18-80 J

With respect to the hippuric acid present,
Von Bibra found that it varied extremely in
proportion in different specimens of urine.
He never found that it became replaced by
the benzoic acid when horses were exposed to
excessive labour, an opinion which has been
very generally received by chemists. He never,
indeed, could detect benzoic acid under any
circumstances, except in such small quantities
as to require the assistance of the microscope
to show its presence.

The deposit which causes the turbidity
observed in the urine of the horse, is com-
posed as follows, according to Von Bibra : —
Carbonate of lime ... 809
Carbonate of magnesia - - 12T

Organic matter - - - .70

The horses that supplied the above de-
scribed specimens of urine, were fed on hay
and oats, and used in agriculture.

Boussingault examined the urine of a horse
fed on trefoil and vetches, and states its
composition as follows : —

Water - - - - -

910-76

Urea -

3100

Hippurate of potassa

4-74

Lactate of potassa - - -

11-28

Lactate of soda ...

8-81

Bicarbonate of potassa

15-50

Carbonate of lime - - -

10-82

Carbonate of magnesia

4-16

Sulphate of potassa - - -

1-18

Chloride of sodium - - -

0-74

Silica -

1-01

Phosphates, — none present.

Chemists have described a red

oil as ex'

isting in the urine of herbivorous animals, and
have attributed the peculiar odour of the
secretion to the presence of that substance.

Boussingault carefully examined the urine
of horses with a view to obtain this oil for
examination, but failed to extract it, though
he operated on twenty-six gallons. He dis-
tilled the whole quantity, but no trace of oil
came over into the receiver. All that he ob-
tained was a colourless fluid, strongly im-
pregnated with the odour of horse’s urine.

He considers this odour dependent upon
the presence of a volatile acid, and believes
that the volatile red oil obtained by chemists
results from the decomposition of the alkaline

1280

URINE.

hippurates, and that it is not produced until
the urine is evaporated to dryness.

The following are two analyses, by Von
Bibra, of the urine of oxen obtained at different
times. The animals had been fed on clover and
hay : —

Water

- 912-01

923-1 1

Urea

1976

10-21

Hippuric acid

- 5"55

12-00

Mucus

0-07

0-06

Alcoholic extract

14-21

1020

Watery extract -

- 22-48

16-43

Soluble salts

- 24-42

25 77

Insoluble salts -

1-50

2-22

It will be perceived

that the insoluble salts

or earthy carbonates are in small proportion
in the urine of oxen, while in the urine of

horses they are present in about equal pro-
portion to the alkaline carbonates. The urine
of a cow, which was submitted to analysis by
Boussingault, gave a result varying consider-
ably from that obtained by Von Bibra from
the" urine of oxen, as above quoted. It

yielded in 1000 parts: —

Water ----- 921 '32

Urea ----- 18-48

Hippurate of potassa - - 10-5l

Lactate of potassa - - - 1 7 • 1 6

Bicarbonate of potassa - - 16-12

Carbonate of magnesia - - 4-74

Carbonate of lime - - - 0-55

Sulphate of potassa - - 3 60

Chloride of sodium - - 1"52

Silica, a trace.

Phosphoric acid, none.

The great excess of the earthy salts ob-
served in the urine of horses, as compared
with that of oxen, is a remarkable circum-
stance, and would appear to be in some way
connected with the difference in conformation
of the two animals rather than on differences
in diet. Thus the conditions alluded to per-
tained whether the horses were fed on hay
and oats, or on trefoil and vetches. The oxen
too, the urine of which was examined by Von
Bibra, were fed on hay and clover, a diet
closely resembling that of the horses ; but the
earthy salts were, notwithstanding, found in
the urine in very small proportion.

Voo-el has examined the urine of the ele-
phant and the rhinoceros. That of the elephant
possessed the following characters :

1. It was turbid, owing to carbonates of
lime and magnesia.

2. It contained more urea than the urine
of the rhinoceros.

3. No hippuric acid was present.*

The urine of the rhinoceros is described
as follows: —

1. It was turbid, owing to the presence of
carbonate of lime, earthy phosphates, silica
and peroxide of iron.

2. It gave out the odour of formic acid.

3. It yielded hippuric acid in considerable
quantity.

* Brandes believed lie detected the hippuric acid
in this urine in combination with urea and an
alkali.

Chevreul examined the urine of the camel.

1. It contained no uric acid.

2. Urea was present in abundance.

3. No phosphates could be detected.

4. The chief constituents, in addition to
urea, were chloride of sodium, hippurate of
soda, carbonate of soda, sulphate of potassa,
carbonate of ammonia, and traces of sulphate
of soda and oxide of iron.

Chevreul considers this urine to contain
a volatile oil to which it owes its colour, and
to which he ascribes the property it possesses
of becoming red on the addition of the mi-
neral acids.

The urine of pigs has been examined by
Lassaigne, Van Setten, and Boussingault.
Its specific gravity appears to vary between
1003 and 1013.

Van Setten’s analysis is as follows : —

Water - - - -

-

990-028

Urea - - - -

_

0-750

Uric acid -

-

0-195

Watery extractive

-

1-708

Alcoholic extractive

-

1-105

Resinous matter -

_

0425

Albumen and mucus

-

0-72 1

Lactic acid -

_

0-490

Stearin -

-

0-092

Sugar -

-

0375

Phosphate of soda

-

1-37G

Sulphate of potassa, chlorides
of potassium and sodium

2-075

Sulphates of lime and magnesia

0-425

Sulphate of ammonia

-

0-196

Chloride of ammonium -

-

o-oio

Von Bibra describes the urine of the pig
as clear, odourless, and of alkaline re-action.
He could not detect uric, hippuric, or benzoic
acid in it when operating on three ounces of
the fluid; but he subsequently obtained mi-
croscopic crystals of hippuric acid. No trace
of uric acid could be discovered.

Boussingault could not detect hippuric acid
in the urine of a pig fed on potatoes and salt.
He varied the diet by the addition of green
trefoil, but still he could not discover the
acid.

Von Bibra analysed the urine of the goat.
He found it alkaline and of pungent odour,
of specific gravity 1008 or 1009. The animals
had been kept in a stable and fed on bad
hay. From two analyses made on 1000 parts,
the following results were obtained: —

Water ...

980-07

983-99

Urea - - -

3-78

0-76

Hippuric acid -

1-25

0-88

Alcoholic extractive -

4-54

4-66

Watery extractive

1-00

0-56

Mucus -

0-06

0-05

Soluble salts

8-50

8-70

Insoluble salts -

080

0-40

In this urine, as in

that of

oxen, the

alkaline carbonates greatly predominate over
the earthy salts.

According to Vnnquelin, the urine of the
beaver contains the colouring matter of the
bark of the willow, which is the food of the

URINE. 1§81

animal. He detected it by using alum as a
mordant for pieces of cloth soaked in the
urine. He detected the presence of bicar-
bonates of lime and magnesia, and hippurate of
soda. He could not find any phosphates, nor
uric acid.

The urine of rabbits and guinea-pigs has an
alkaline reaction, and contains alkaline and
earthy carbonates. It presents no peculiar
qualities.

Von Bibra analysed the urine of the Imre,
both in summer and in winter. In December
he found the urine turbid and alkaline, de-
positing phosphate of magnesia. In June it
was only faintly alkaline. The proportion of
earthy phosphates present was more than
twice as great in summer as in winter, which
Simon remarks upon as probably caused by
the great difference in the food of the hare
during the two seasons. With respect to his
examination of the urines of herbivora, Von
Bibra states he obtained in most of them
indications of the presence of humic acid, or
a substance closely allied to it.

As regards these analyses, which are
quoted from Simon’s work on animal che-
mistry, it would appear a matter of regret
that experiments have not been made on an
extended scale on the same animal, under
different conditions ; more especially under
variations in food, temperature, and moisture.
Such form of inquiry could not fail to be of
eminent service to physiology, and much light
might thus be thrown on the question of
diet, in respect to constitution and predis-
position to disease, a subject greatly needing
elucidation, notwithstanding the labour and
ingenious activity which has been devoted to
it during the last few years.

Urine of Birds, &c. — The urine of birds is
excreted from the cloaca in the form of a thin
paste, which hardens by exposure. Urate of
ammonia is the principal constituent. The
urine of carnivorous birds, however, contains
urea in considerable quail tit}', which distin-
guishes it from that of birds feeding on vege-
table substances. Chemists have also described
a green colouring matter, as peculiar to the
urine of carnivorous birds.

The constituents of the urine of the ostrich,
according to Vanquelin and Fourcroy, are —

Uric acid.

Sulphate of potassa.

Sulphate of lime.

Chloride of ammonia.

Oily matter. ,

A peculiar animal matter.

Acetic acid (?)

The urine of serpents is excreted in the
form of a white, earthy mass. It is made up
of uric acid, combined with potassa, soda, and
ammonia. Phosphate of lime is also present.

Cass and Henry state that they obtained
urea from the urine of serpents. That prin-
ciple was sought for in vain, however, by
Vanquelin and Fourcroy.

Simon gives the following as the result of
an analysis of the urine of a rattle-snake. He

VOL. iv.

operated on 100 parts, weighed, when quite
dry.

Free uric acid, some fat, and ex- ) ,

i oG'-i

tractive matters J

Urate of ammonia - 31T

Urate of soda, with some chloride "1 c,.„

of sodium J

Urate of lime - - - I'd

Phosphate of lime - - - 1'3

Dr. J. Davey examined the urine of the
bull-frog ( rana taurina ). He found it of spe-

cific gravity 1003. Urea, chloride of sodium,
and a little phosphate of lime were also pre-
sent.

Marchand’s analysis of the urine of the
land-tortoise ( testudo tuhulata ) yielded the
following result, —

Water ----- 950-64

Urea ----- 6'40

Uric acid - 17‘25

Salts and indeterminate organic ~| „ -

e > 2o-70

matter j

There was no hippuric acid in this urine. It
possessed a faintly' acid reaction, and is stated
to have presented the appearance of pus.
Ether extracted a brownish-coloured fat,
having an urinous odour.*

URINE IN DISEASE.

With respect to the urine of the human
subject, it has been shown that considerable
variation occurs in health according to the
modifications which may have been made in
diet. The urine of the lower animals is doubt-
less, to a certain extent, amenable to the same
rule. We observe also striking differences
in the urine of herbivora fed on similar diets,
as has been noticed above in the case of the
horse and the ox, both graminivorous animals
and fed nearly alike for experiment, but whose
urine showed, on analysis, very marked and
important differences. This variation in the
result of the digestive process would appear,
in such case, to depend upon the internal
arrangement of the chylopoietic organs, and
should perhaps more especially be attributed
to differences in the minute anatomy of the
mucous secreting surfaces. Certain fixed
variations, then, are to be observed in the
constitution of the urine as results of differ-
ence in healthy anatomy ; and so in the same
way, when certain organs are affected by dis-
ease, we find a set of changes occurring in
the urine quite as marked in character ; and
it is of especial moment to the physician
that he should be able easily and accurately
to appreciate them. While studying those
conditions, it is however of the highest im-
portance that the changes which diet, the
temperature to which the body may have
been exposed, the amount of moisture in the
air, &c., should be considered, and that the
physician should be able to separate in his
mind those phenomena which are indicative

* Quoted by Simon from Erdmann and Mar-
chand’s Journal, 1845. iv. 4.

4 N

J 282 URINE.

of morbid change in important organs, from
such as may merely be the results of actions
occurring in perfect health, and consistent
with its preservation.

Many pathological conditions of the urine
are indeed closely simulated by the unim-
portant changes to which I have alluded.
Thus the urine of diabetes insipidus, often a
most severe and unmanageable disease, can
scarcely be distinguished from that occasionally
secreted by healthy persons exposed to cold
or moisture, or both, without sufficient exer-
cise to maintain the full amount of cutaneous
exhalation. Such a specimen, were it ex-
amined carelessly, or allowed to guide the
judgment without due attention to con-
comitant circumstances and previous history,
might lead (and I may say has led) to mis-
takes both injurious to the patient and vexa-
tious to the practitioner.

In studying the pathology of the urine, it
is also especially important that we should
not give undue regard to chemistry, nor be
led astray by theories and generalisations such
as that fascinating science so constantly
would tempt us to enter upon. It must be
remembered that in most cases chemistry as
yet only assists us in the detection of symp-
toms, and in the present state of our know-
ledge can only thus far serve us, but must
fail as a guide to a true knowledge of diseased
action or appropriate methods of treatment.
This consideration, however, is far from de-
pressing to those who regard the subject in
a truly philosophical spirit; for be it remem-
bered that when we have detected sugar or
albumen in the urine, and when the modes of
examination are rendered both easy and exact
by chemical labour, we have reaped a most va-
luable advantage by becoming acquainted with
a symptom, without which, we should have
been left in such a position that we might have
despaired of ever obtaining an insight into
the pathology of two most important diseases.
A knowledge of symptoms thus acquired by
chemistry at once enables us to make use
of a large amount of valuable information
derived from experience, and to bring to our
assistance remedies which would not other-
wise have suggested themselves, or perhaps
have been considered inapplicable. It has
unfortunately too often been attempted to
push chemical reasoning to the uttermost in
considering urinary diseases ; and there is a
class of persons, greatly increasing in the
present day, who have thus inflicted much
mischief on a science which requires great
labour in its prosecution, and consequently
is the more eagerly condemned as useless by
the idle or ungifted practitioner. If we con-
fine the application of chemistry, in urinary
disease, merely to symptomatology, it is easy
to show that we are deeply indebted to the
science, and it is the especial duty of those
who are most conversant with it to regard
its further application with great jealousy.

I shall now proceed to describe the urine
as it appears in various diseased conditions of
the bod}', beginning with those variations

from healthy constitution characterised by
the existence of deposits of various kinds
known as urinary deposits. It is not, how-
ever, within the province of this article to
enter upon any pathological considerations
relating to these abnormal conditions.

Lithic acid Deposit.

This deposit (commonly known as “red
sand” or gravel) occurs in urine in many
forms, the crystals as seen under the micros-
cope presenting the appearances figured below
{jig. 191).

Fig. 791.

Urine depositing lithic acid is generally of
a deep yellow colour, and acid beyond the
normal degree. Its specific gravity is mostly
somewhat above that of health. Lithic acid
occasionally deposits from urine in an amor-
phous concrete form, and is seen in rounded
or flattened masses adhering to the bottom
of the chamber vessel. This latter kind of
deposit is the most dangerous as respects the
formation of calculi.

Deposit of Litiiates.

This form of deposit, known as the lateri-
tious deposit, from ts resemblance to brick
dust, consists of lithic acid combined with
ammonia, and in some few cases with lime,
magnesia, or soda. The microscopic appear-
ances shown by the lithates are as under
{fig. 792).

Fig. 792.

The spheroidal masses with projecting needle
points (b), I believe to indicate lithate of lime,
while the masses having projecting crystals
with truncated ends (c), 1 believe consist
chiefly of lithate of magnesia. The lithate of
ammonia is amorphous, sometimes spheroidal
with adhering spicula, or is seen making up
a dotted background (a). Urine depositing
the lithates is generally of a higher specific
gravity than natural, and is passed clear.
After the deposit has occurred, the applica-
tion of a gentle heat is always sufficient to
rc-dissolve it.

URINE.

1283

Deposit of Earthy Phosphates.

The earthy phosphates, consisting of mag-
nesia in combination with ammonia and phos-
phoric acid, are seen as deposits in the urine
in two forms, viz. as a monobasic and a bi-
basic salt. The monobasic phosphate, which
is seen in neutral or only slightly alkaline
urine, presents the microscopic appearances
as under (fig . 793).

Fig. 793.

The bibasic salt, which is observed in highly
ammoniacal urine, gives the following figures

(fig- 7W).

Fig. 794.

Urine depositing the first of these two
varieties of sediment is generally of lighter
colour than natural, and of moderately high
specific gravity.

The second variety, if not occasioned by
the use of alkaline remedies, generally indi-
cates important mischief in some part of the
urinary apparatus, and is often combined with
large quantities of epithelium, mucus, pus, and
blood corpuscles.

Deposit of Oxalate of Lime.

This deposit, which is composed of lime in
combination with an acid foreign to the con-
stitution of healthy urine, presents itself under
the microscope in the following forms, first
described by Dr. Golding Bird (fig. 795).

Fig. 795.

The appearance of dark crystals, looking
like cubes, is observed when this deposit is
allowed to dry. The transparent spot in the
centre is caused by reflection from the sides
of the octohedron.

Urine depositing oxalate of lime is generally
of about the normal specific gravity. It oc-

casionally has a light greenish hue. The de-
posit when allowed to collect in a glass vessel
is rarely seen otherwise than as a floating
cloud collecting at bottom, and closely re-
sembling the appearance which would be put
on by the presence of an excess of the mucus
of the bladder natural to the urine.

It has recently been stated, by Dr. Frick, of
Baltimore, that the crystalline masses, in the
form of dumb-bells, described by Dr. Bird as
consisting of oxalate of lime, are really com-
posed of lithic acid. It is true that lithic acid
occasionally assumes a form more or less re-
sembling the dumb-bells figured by Dr. Bird,
but scarcely so nearly as to be easily mis-
taken for them. Dr. Marris Wilson has also
recently shown that lithic acid may be made
to assume a form nearly approaching in
character to the dumb-bells. I have ex-
amined, with Dr. Bird, some specimens of the
dumb-bells, and am satisfied that those we
operated upon were composed of lime in com-
bination with an organic acid. In a paper
recently published by Dr. Bird in the Medical
Gazette, some reasons are given by him for
believing that acid to be the oxaluric, and not
the oxalic, and there would appear good
grounds for the adoption of that opinion.

Deposit of Cystine.

This substance, which is not one of the
ingredients of normal urine, is an organic
bodj', occasionally existing as a deposit in the
form of flattened hexagonal plates. Under
the microscope it presents the following ap-
pearances (fig. 796).

Fig. 796.

Carbonate of Lime Deposit.

This rare deposit exists in the form of
spherical masses, more or less crystalline, and
apparently made up of slender rhomboidal
prisms, diverging from a centre. It presents
the following appearance under the micro-
scope (fig. 797).

Fig. 797.

Hippuric Acid.

This exists occasionally in excessive quantity
in human urine in disease. Under the micro-
scope it shows the following appearance (fig.
798).

4 n 2

1284

URINE.

Besides these more or less crystalline de-
posits, the urine in disease frequently contains
blood, mucus and pus corpuscles, and also
epithelial scales, and other bodies of various
kinds ; with all of which it is necessary the
physician should be familiar, as symptomatic of
different diseases.

In order satisfactorily to detect these, the
microscope is of course indispensable.

The following are the appearances shown
by these more or less organised bodies, when
existing in the urineg (fig. 799).

Fig. 799.

a, Blood corpuscles endosmosed or distended,
owing to the entrance of the urine through their
membrane. This effect is the consequence of the
contained fluid of the corpuscles having been heavier
than the urine in which they float, in virtue of which
condition more fluid passed into the corpuscle than
could escape out. b, Mucous corpuscles, c, Pus cor-
puscles. d, Scales of epithelium, e, Fibrinous casts of
the urinary tubules of the kidney, seen in the morbus
Brightii, deposited from albuminous urine — sphe-
roidal epithelium from the tubules is seen embedded
in these fibrinous casts. /, Spermatozoa, g, Torula
diabetica, seen in diabetic urine during its fermenta-
tion.

A tendency to the secretion in excessive
quantity of the unorganised deposits, such as
lithic acid and the lithates, oxalate of lime,
&c , leads not unfrequently to the formation
of urinary calculi. These are either made up,
as is most frequently the case, of several of
the constituents of the urine, or may be en-
tirely constituted of one of them.

The following table, constructed by the late
Dr. Prout, exhibits a general view of the
relative frequency of the different kinds of
urinary calculi in England, Swabia, Germany,
and Denmark. The hospitals of St. Bartho-
lomew and of Guy in London, and those of
Norwich, Manchester, and Bristol, principally
supplied the specimens quoted in this table.

The ingredients of particular species of cal-
culi included between parentheses, are to be
considered as existing in a mixed state.

* For further information respecting urinary
deposits, I must refer to Dr. Golding Bird’s work on
the subject, and my Treatise “ on Analysis, and the
Treatment of Urinary Diseases.”

General Character
of Calculi.

Particular Species of Calculi.

England.

Conti-

nent.

Particular Totals.

General Totals.

Bartholomew’s
Hospital, Lon-
| don.

1 Guy’s Hospital,
1 London.

I Norwich Hos-
pital.

Manchester

Hospital.

| Bristol Hospital.

Swabia, Ger-
many.

Copenhagen,

Denmark.

1. Lithic acid.

Lithic acid, nearly pure

li

16

164

1

7

32

230

Liihate of

Litbate of ammonia, nearly pure

55

1

3

59

ammonia.

Lithate of ammonia, mixed with]vari-

r 71

74

145

>448

able proportions of the litbate and

oxalates of lime and phosphates

8

6

14

2. Oxalate of lime.

Oxalate of lime, nearly pure -

8

22

21

ii

33

3

98

98

3. Cystic oxide .

Cystic oxide, nearly pure

2

i

2

5

5

4. Phosphates .

Phosphate of lime, nearly pure

4

3

5

1

...

13

13

Triple phosphate, nearly pure

1

2

1

8

12

12

Mixed phosphates - - -

10

24

35

4

18

7

8

106

106

(Phosphate of lime, with carbonate of

lime) ....

1

1

2

2

mixed with a little lithic acid

18

...

18

18

deposited on foreign bodies

3

2

5

5

Carbonate of lime.

(Carbonate of lime and silex)

1

1

1

Silex.

Siliceous - -

1

1

1

5. a. Alternating

Lithic acid, and lithate of ammonia

4

49

1

54

1

calculi com-

and oxalate of lime

3

10

53

66

posed of two

and phosphate of lime

8

8

layers,

and mixed phosphates

6

15

39

12

9

13

94

General Character
of Calculi.

5. a. Alternating
calculi com-
posed of two
layers.

b. Alternating
calculi com-
posed of three
layers.

i

URINE. 1285

England.

Conti-

nent.

Particular Species of Calculi.

> c

y’s Hospital,
London.

x .

E a

anchester

Hospital.

•5.

X

"T 5
1 £

ti.

11

h

a

h

‘PS'S

3

o

55

2

do

S°

a.

O

(Lithic acid, lithate of ammonia,) and

(lithate of magnesia and mixed phos-
phates) -

...

2

2

(Lithic acid and lithate of lime) and
mixed phosphates) -
(Lithic acid, lithate and oxalate of

...

2

2

lime,) and lithic acid
( Lithic acid, lithate of ammonia and ox-

...

...

27

27

alate of lime,) and mixed phosphates

...

2

2

Lithate of ammonia and lithic acid

2

21

23

and oxalate of lime

7

63

70

and phosphate of lime -

IS

9

9

and mixed phosphates -

22

35

Lithate of soda and lithic acid
Lithate of lime, and (lithate and oxa-
late of lime and lithate of ammonia)
(Lithate and oxalate of lime,) and oxa-
late of lime -

(Lithate of ammonia and of lime,) and

...

i

i

8

1

1

8

>566

lithate of ammonia and lime, alter-
nately -

2

2

Oxalate of lime and lithic aeid

3

15

n

29

3

61

and lithate of ammonia

1

3

4

and phosphate of lime

7

7

and mixed phosphates

and (lithic acid and mixed

13

...

20

16

32

81

phosphates)

...

1

1

and silex ...

...

1

...

1

Mixed phosphates and oxalate of lime

1

1

and phosphate of lime

Phosphate of lime and mixed phos-

2

2

phates -

3

...

3

and oxalate of lime

Lithic acid, oxalate of lime, and phos-

1

1

phate of lime - - -

...

2

2

, oxalate of lime, and lithate of

ammonia -

4

4

, oxalate of lime, and lithic acid

5

5

, lithate of ammonia, and oxa-

late of lime - - - -

2

2

, lithate of ammonia, and lithic

acid -

2

...

...

2

, lithate of ammonia and phos-

phates -

3

2

5

oxalate of lime and phos-

phates -

1

3

4

(Lithic acid and lithate of lime,) oxa-
late of lime and mixed phosphates -
(Lithic acid, lithate and oxalate of linte)

...

...

2

2

lithic acid and mixed phosphates

...

...

17

17

Lithate of ammonia, oxalate of lime,

and mixed phosphates

13

13

26

, oxalate of lime, and phosphate

of lime -

13

13

, oxalate of lime and lithic acid

1

16

17

, oxalate of lime, and lithate of

ammonia -

1

7

...

8

, phosphate of lime, and lithate

1

1

of ammonia ...

...

, phosphate of lime and lithic

acid -

1

1

[> 172

, phosphate of lime and oxalate

of lime -

1

...

1

, phosphate of lime, and mixed

phosphates -

...

4

4

4 n 3

1286

URINE.

General Character
of Calculi.

England.

Conti-

nent.

Particular Species of Calculi.

Bartholomew's
Hospital, Lon-
don.

Guy’s Hospital,
London.

Norwich Hos-
pital.

Manchester

Hospital.

Bristol Hospital.

5

| i

o n

Copenhagen,

Denmark.

Lithate of ammonia, lithic acid, and

phosphates -

, lithic acid, and lithate of am-

l

6

monia -

, lithic acid, and phosphate of lime

, lithic acid, and oxalate of lime

(Lithate and oxalate of lime,) oxalate

1

4

3

of lime, and mixed phosphates
(Lithate and oxalate of lime,) (ditto al-

13

ternately,) and phosphates -
Oxalate of lime, lithic acid and lithate

3

of ammonia ...

, lithic acid and oxalate of lime

, lithic acid, and phosphate of

i

i

3

3

lime -

, lithic acid, and mixed phos-

1

phates - - -

, lithate of ammonia, and phos-

5

7

phate of lime ...

, lithate of ammonia, and oxalate

3

of lime - - - -

Mixed phosphates, phosphate of lime,

2

and mixed phosphates
Lithic acid, lithate of ammonia, lithic

i

acid, and lithate of ammonia
, oxalate of lime, lithate of am-

i

...

monia, and phosphate of lime
, oxalate of lime, lithic acid and

i

oxalate of lime - - -

, oxalate of lime, lithic acid, and

i

lithate of ammonia - - -

Lithate of ammonia, oxalate of lime,

2

lithate of ammonia, and phosphates
. oxalate of lime, lithate of am-

5

monia, and oxalate of lime -
— — , oxalate of lime, phosphates

3

and oxalate of lime - - -

, oxalate of lime, lithic acid,

2

and lithate of ammonia
— oxalate of lime, phosphate of

...

1

...

lime, and phosphates
■ — -, oxalate of lime, lithic acid,

1

...

and phosphates ...

, oxalate of lime, lithic acid,

1

and oxalate of lime

, oxalate of lime, lithate of am-

1

monia, and lithic acid
, phosphate of lime oxalate of

...

1

lime, and lithate of ammonia
Oxalate of lime, lithic acid, lithate of

1

ammonia, and lithic acid
, lithic acid, oxalate of lime, and

1

phosphate of lime ...
, lithic acid, oxalate of lime, and

]

phosphates -

, lithic acid, lithate of ammonia,

1

...

and phosphates -

1

Composition not mentioned

8

6

10

Mixture not mentioned

7

8

8

Fibrous matter and phosphates

...

1

129|

87j

663

1 87|

218

81

155

b. Alternating
calculi com-
posed of three
layers.

Alternating
calculi com-
posed of four
layers.

d. Alternating
calculi com-
posed of seve-
ral layers.

6. Mixed or com-
pound calculi.

1

4

3

13

3

4

4

1

12

3

2

1

1

1

1

2

5

25

24

23

1

1520

URINE.

1287

To this table Dr. Prout appends the fol-
lowing valuable remarks in his work “ On
Stomach and Urinary Diseases” : —

“ In this table the urinary calculi contained
in the museums of Bartholomew’s and Guy’s
Hospitals in London, and of the provincial
hospitals of Norwich, Manchester, and Bris-
tol, are contrasted with the calculi existing in
Swabia in Germany, and in Copenhagen in
Denmark. The data here collected are too
limited to throw much light on the relative
prevalence of calculous affections in different
parts of England, much less in England as
compared with the different countries of Eu-
rope ; yet in other .points of view, and par-
ticularly in demonstrating the relative pre-
valence of the different species of calculi, and
the order of the succession of the different
layers of which calculi are composed, &c.,
they are highly interesting and important.

“ In this table, the whole of the data com-
prising the analysis of 1520 calculi, are col-
lected into one point of view, under the
general heads of 1 . Lit/iic acid, 2. Mulberry,
2. Cystic oxide , 4. Phosphatic, 5, Alternating ,
and 6. Compound Calculi.

“ On each of these heads we shall make a
few remarks.

“ 1 .Of litJiic acid calculi. — The proportions
of pure lithic acid calculi to the whole num-
bers contained in the different museums, are
as follow: — In Bartholomew’s Hospital, as
1 : 11+, ; in Guy’s Hospital, as 1 : 5+ ; in
the Norwich Hospital, as 1 : 4+ ; in Swabia,
as 1 : 11A ; in Copenhagen, as 1 1 5 — . The
relative proportions of pure lithic acid calculi
in the Manchester and Bristol Museums are
not mentioned ; hence, abstracting the Man-
chester and Bristol, the general proportion of
pure lithic acid calculi is as 1 ; 64, nearly.

“ The relative proportions of calculi in the
different museums, composed essentially of
lithic acid, (i, e. consisting of pure lithic acid,
lithate of ammonia, and the latter ingredient
mixed with minute quantities of the lithate
and oxalate of lime, and the phosphates,) are,
in Bartholomew’s Hospital, as 1:7 — ; in
Guy’s Hospital, as 1 : 4 — ; in the Norwich
Hospital, as 1 : 3+ ; in the Manchester
Hospital, as l : 24+ ; in the Bristol Hos-
pital, as 1 : 3 — ; in Swabia, as 1 : 10+ ; and
in Copenhagen, as 1 : 44 — . The general
proportion in all the collections is as 1 : 34 — .

“If we take into account all the calculi of
which the lithic acid or its compounds form
the nucleus, the proportions of calculi originat-
ing with this principle (and which probably
would otherwise have not been formed) is
very much greater. Thus in Bartholomew’s
Hospital the proportion of calculi containing
the lithic acid or some of its compounds as a
nucleus, is to the whole number of calculi as
1 : If — ; in Guy’s Hospital, as 1 : 4 — , (not
fairly comparable, as the calculi do not appear
to be divided ;) in the Norwich Hospital, as
1 : I4+ ; in the Manchester Hospital, as
1 : If — ; in the Bristol, as 1 : 24+ ; in
Swabia, 1 ; 14 + ; and in Copenhagen, as

1 : 14. The relative proportions of all the
calculi originating in some form or combina-
tion of lithic acid, in all the different collec-
tions, is nearly as 1 : If, which is equal to
saying, that if a lithic acid nucleus had not
been formed and detained in the bladder, two
persons at least out of three who suffer from
calculus would have never been troubled with
that affection.

“ Of mulberry or oxalate of lime calculi. —
The proportions of mulberry calculi in the
different hospitals are nearly as follow : in
Bartholomew’s Hospital, as 1 : 16+ ; in
Guy’s Hospital, as 1 : 4 — ; in the Norwich
Hospital, as 1 : 31+ — ; in the Manchester
Hospital, as 1 : 17; in the Bristol Hospital,
as 1 : 6f — ; in Swabia, as 1 : 27 ; in Copen-
hagen there does not appear to be any cal-
culus composed throughout of oxalate of
lime ; but if we take the nearest approach to
such composition, in which calculi are com-
posed principally of this salt with a mixed
nucleus, likewise containing oxalate of lime,
the proportions will be as 1 ' 1 9+ — ; the
general proportions in all the museums are as
1 : 14+

“ If we take into account all the calculi of
which the oxalate of lime constitutes more or
less of the nucleus, the proportions in the
different museums will be, — in Bartholo-
mew’s, 1 : 4f + ; in Guy’s, 1 : 4 — ; in Nor-
wich, 1 : 74+ ; in Manchester, 1 44 + ; in

Bristol, 1 : 34 — ; in Swabia, 1 : 27 ; and in
Copenhagen, 1 : 2J„+. The general pro-
portion of calculi, into the nucleus of which
oxalate of lime largely enters, in all the
museums, is as 1 : 44+ ; which is equivalent
to saying, that if a mulberry stone had not
been formed and detained in the bladder, two
persons out of about nine who suffer from
calculus would not have been troubled with
that affection.

“ 3. Of cystic oxide calculi. — Of this rare
form of urinary calculus, four out of the seven
museums contain no specimen. Calculi of
this substance exist in the museums of Bar-
tholomew’s, Guy’s, and the Manchester Hos-
pitals, amounting altogether to five only.
Hence the general proportion to the whole
number of cystic oxide calculi examined, is
only as 1 t 304.

“ 4. Of phosphatic calculi. — Calculi com-
posed throughout of the phosphates are com-
paratively of uncommon occurrence ; while
calculi consisting externally of the phosphates,
as will be presently shown, are the most fre-
quent of all others. At present we have to
do with calculi composed essentially of the
phosphates.

“ The proportion of calculi composed of the
phosphate of lime, in Bartholomew’s Hospital,
is as 1 : 324 ; in Guy’s Hospital, as 1 : 29 ;
in the Norwich Hospital, as 1 : 132|. ; in the
Bristol, as 1 : 155. The other museums
contain no specimen. The general proportion
of phosphate of lime calculi, to the whole
number, is as 1 : 117 — .

“ The proportion of calculi composed of the
4 n 4

1288

URINE.

pure triple phosphate is still less ; thus in
Bartholomew’s Hospital the proportion is as
1 : 129 ; in Guy’s, as 1 : 43£ ; in the Bristol,
as 1 : 218 ; in Copenhagen, as 1 : 19i — .
The other museums contain no specimen.
The general relation of the triple phosphate
in all the collections, is as 1 : 126f.

“ On the other hand, the proportion of cal-
culi composed of the mixed phosphates is
very considerable ; thus, in Bartholomew’s
Hospital, the proportion is as 1 : 12-ftj ; in
Guy’s, as 1 : 3)-+ ; in the Norwich, as
1 : 19 — ; in the Manchester, (including those
containing a little lithic acid,) as 1 : 8} ; in
the Bristol, as 1 : 12 + ; in Swabia, as
1 : IT)-)-; in Copenhagen, as 1 : 19-|. The
relative proportion of the mixed phosphates
in all the collections is as 1 : 1 2^ -j- .

“ Under the head of the phosphates are
included a few rare specimens of other cal-
culi, e. g. carbonate of lime and siliceous cal-
culi. Of these two varieties, there is only
one of each reported to exist in the Copen-
hagen collection ; and one containing silex in
the Norwich collection.

“ The general proportion of all the calculi
arranged under the heads of the phosphates,
in the different museums, is as 1 : 10 — .

“ 5. Of alternating calculi. — Calculi com-
posed of different layers constitute by far the
most frequent results of urinary diseases ; of
the successive forms assumed by which, they
may be said to constitute the index. We
shall first consider the relative proportions of
the calculi composed of two, three, and four
deposits ; and afterwards of the whole con-
jointly.

“ The proportion of alternating calculi com-
posed of two deposits is, in Bartholomew’s
Hospital, as 1 : 2(- — ; in Guy’s, none are
reported, probably on account of the calculi
not having been divided ; in Norwich, the
proportion of alternating calculi composed of
two layers is stated to be as 1 : 2§ — ; in
Manchester, as 1 : 2f ; in the Bristol, as
1 : 3 — ; in Swabia, as 1 : 1-J-+ ; and in Co-
penhagen, as 1 : 2\ — . The proportion of
alternating calculi composed of two layers, in
the conjoint collections, is as 1 : 2f+.

“ The proportion of alternating calculi com-
posed of three deposits, is, in Bartholomew’s
Hospital, as 1 : 6 — ; in Guy’s Hospital, none
is reported; in the Norwich Hospital, the
proportion is as 1 : 0+ ; in the Manchester,
as 1 : 26f ; in the Bristol and Swabia collec-
tions, none is reported ; in Copenhagen, the
proportion is stated to be as 1 : 41 — . The
proportion in all the collections, is as 1 ; Sf- — .

“ Alternating calculi composed of four de-
posits are only reported to exist in the Nor-
wich Hospital, and the proportion stated is as
1 : 2 6i+. In the different collections there
are twenty-four alternating calculi, the com-
position of which is not stated. The propor-
tion of all the varieties of alternating calculi
in the different collections, is somewhat more
than one-half ; that is, as 1 : 2 — .

“ 6. Of mixed or compound calculi. — In one
sense of the term, all calculi may be said to be
mixed or compound, as there are perhaps none
absolutely pure, i. e., formed of a single in-
gredient. But in the sense in which the term
is here applied, namely, as expressive of cal-
culi composed of different ingredients mixed
together in large or nearly equal proportions,
compound calculi may be said to be rare. The
most usual mixtures consist of the lithate of
ammonia and of lime; of the oxalate, car-
bonate, and phosphate of lime ; of the lithate
of ammonia, and the mixed phosphates, &c. ;
and such mixtures are usually confined to
small calculi or calculous nuclei. Calculi
composed of pure lithic acid, or of any other
pure ingredient, with the phosphates or other
compounds, do not appear to exist ; at least
I have met with no such mixtures.

“ Lastly, it remains to make a few remarks
on the order of calculous deposits ; an inquiry
that throws considerable light on the laws of
their formation and general pathology.

“ On reference to the table it will be found,
that in the different alternating calculi, the
ratio in which the oxalate of lime succeeds to
lithic acid, is as 1 : 15£+ ; on the contrary,
that the ratio in which lithic acid succeeds to
oxalic acid, is as 1 .' 13^-. Hence the alter-
nation of the two ingredients may be con-
sidered as nearly equal. It will be found,
however, that the oxalate of lime succeeds to
the lithate of ammonia, &c., more frequently
than to lithic acid; thus the ratio in which
the oxalate of lime succeeds to the lithate of
ammonia was 1 ; 9-f — . On the contrary, the
ratio in which the lithate of ammonia succeeds
to the oxalate of lime, is only as 1 : 38 ; a
very striking distinction. The ratio in which
the phosphates succeed to lithic acid, is as
1 : 9i — ; in which the phosphates succeed to
the lithate of ammonia, is as 1 : 12} — ; and
in which the phosphates succeed to the oxa-
late of lime, is as 1 : 7 On the contrary,
three instances only occur in which the lithic
acid or lithate of ammonia succeeds to a
phosphate ; and the proportion in which the
oxalate of lime succeeds to the phosphates is
as 1 ; 253} only. The general proportion in
which the phosphates succeed to the other
ingredients in all the collections, is as
I : 4t*5 + . Hence the generality of the im-
portant law alluded to in various parts of this
volume, that in urinary calculi a decided depo-
sition of the mixed phosphates is not followed by
other depositions.”

The following table, constructed by Dr.
Prout, illustrating the frequency of calculous
affections at different ages, and in the different
sexes, is from a paper published by Mr. Smith-
in the eleventh volume of the Med. Chirurg.
Transactions, and from “ A Treatise on the
Formation, Constituents, and Extraction of
Urinary Calculi. By John Green Crosse,
Esq., Surgeon to the Norfolk and Norwich
Hospital. London. 1835.”

URINE.

1289

0> .

—

- ‘2,

rs

<v

O

3 ®

o K

«

h-I

'A

r* co

Under 10 years

of age

136

83

281

500

Between 10 and

20

65

21

106

192

20 and 30 -

35

21

48

104

30 and 40 -

34

12

48

94

40 and 50 -

37

28

47

112

50 and 60 -

28

21

96

145

60 and 70 -

18

9

70

97

70 and 80 -

2

2

8

12

355 197

704

1256

r~

Urine in disease may not only show a
tendency to deposit matters of an insoluble
character in the form of urinary deposits or
calculi, but it may also contain in solution an
excess or deficiency of any one or more of its
normal constituents. There may likewise be
present in solution matters altogether foreign
to the healthy constitution of the fluid. The
urine in disease may then, so far as its dis-
solved matters are concerned, be considered
in two points of view, viz. 1. Excess or defi-
ciency of normal constituents ; 2. Presence
of matters not existing in healthy urine.

I shall proceed to notice the state of the
urine in those forms of disease in which it
has received attention, and shall quote from
the work of Franz Simon, who not only
laboured long and well on the subject, but
collected much valuable information relating
to it. Before doing this, however, I must
notice the ingenious attempt made by Bee-
querel to classify all diseased conditions of
urine under four heads, viz. 1. Febrile urine ;

2. Anaemic urine ; 3. Alkaline urine ; 4. Urine
but slightly varying from the conditions of
health.

I will shortly notice the principal cha-
racters of these four varieties.

1. Febrile urine. — a. Febiile urine, strictly
speaking. — The proportion of water passed
in the twenty-four hours less than in health.
Solid matters slightly diminished in propor-
tion. Urea and inorganic salts deficient.
Uric acid increased in proportion. Colour
high. Specific gravity above the normal
standard. Often turbid from lithates. Some-
times contain albumen.

This latter statement of Becquerel’s must
be received with some reservation. Thus I
have several times known a deposit produced
in urine in adynamic forms of fever on the
addition of nitric acid, which proved, on ex-
amination, to be lithic acid and not albumen.

The following are the conditions in which,
according to Becquerel, the urine assumes
the febrile character ; viz., in chronic and acute
inflammations ; in diseases of the liver, heart,
and lungs ; in haemorrhages, and in organic
degenerations of organs resulting from fever
or long functional derangement.

Febrile urine, with debility. — The pro-

portion of water diminished. Specific gravity
less than in a. Solid matters also less in the
twenty-four hours. Uric acid in normal
proportion. All other constituents absolutely
but not relatively diminished. This urine is
then less concentrated than that of health. It
is deeply coloured, often turbid from deposit
of uric acid. It occurs in adynamic fevers.

y. Febrile urine containing the natural pro-
portion of water. — Urea and fixed salts dimi-
nished in proportion. Uric acid and other
organic matters normal. Specific gravity low.
Colour deep. No sediment.

2. Ancemic urine. — a. True anaemic urine. —
Water in the twenty-four hours nearly normal.
Solids discharged much less than in health.
Urea, uric acid, and fixed salts diminished.
Other organic matters decreased in slighter
degree than the above. Specific gravity low.
Colour light. No sediment.

/3. — Concentrated ancemic urine. — Water in
twenty-four hours diminished, although the
solids are then relatively increased, still they
are absolutely diminished. Urea, uric acid,
and fixed salts especially diminished. Other
organic matters less so. Urine of livid or
greenish tint.

3. Alkaline urine. — Distinguished by alkaline
reaction on test paper. Odour ammoniacal :
occurs in acute and chronic nephritis, diseases
of the bladder with secretion of pus, and in
certain cerebral diseases; occasionally in the
“ morbus Brightii.”

4. Urine nearly normal. — Nearly that of
health. Occurs in mild disorders unaccom-
panied by fever.

With respect to this classification of Bec-
querel, it may be observed that the heads of
arrangement by no means embrace all the
forms of diseased urine met with in practice,
— an end, indeed, which will scarcely be com-
passed by any attempts of the kind. There
appears no advantage in making such clas-
sifications; and indeed much evil must result
from the necessary endeavour which will be
made in such a table to place diseases under
headings which either imperfectly or incor-
rectly express their real character. The table,
however, is of some value, as showing the
genei'al results obtained in fevers and in
ansemia ; but further than this the student
need not regard it.

The following introductory remarks by Franz
Simon are extremely valuable, and wdl well
repay the reader for the trouble taken in their
careful perusal. I transcribe them from Dr.
Day’s translation for the Sydenham Society: —

“ In inflammatory affections, and in those
diseases which are accompanied by that form
of fever which is termed sthenic or synochal,
the urine differs greatly in its properties from
normal urine. In speaking of the probable
cause of the changed constitution of the blood
in the phlogoses, I showed that it is not to be
referred to the diseased organ, but to the re-
action which manifests itself throughout the
vascular system. If the change in the con-
stitution of the blood bears an accurate and
inseparable relation to the fever, there can be

1290

URINE.

no doubt that the change in the constitution
of' the urine must be in relation to the same
cause; for the urine is separated from the blood,
and was previously an integral constituent of
it : and because, further, every alteration in
the constitution of the blood must involve
corresponding changes in the secretions and
excretions, and more especially in the urine.
Since like effects follow like causes, and since
in inflammatory affections the vascular system
similarly participates in the disturbance, we
may assume a priori that similar changes will
occur in the urine, — a point confirmed by ex-
perience.

“ The urine discharged during inflammations
is usually termed febrile urine. There is no
objection to this term, since the cause of the
change in the urine must be sought for in the
fever. I shall not, however, introduce the
term ‘ febrile urine ’ here, since it is more
than probable that the changes in the compo-
sition of the urine vary according as the cha-
racter of the fever is synochal or torpid.

“ My analyses show, in fact, that the relative
proportions of urea in fevers of a torpid and
of a synochal character are different ; and al-
though the analyses are not yet sufficiently
numerous to establish the difference with cer-
tainty, it still appears to me to be a point of
sufficient importance to demand attention, and
one that should be carefully worked out. In
order to take a correct view of the compo-
sition of the urine, we must bear in mind the
composition of the blood, the reaction of the
vascular system, and the diet, since the mix-
ture of the proximate constituents is de-
pendent upon these circumstances.

“ The following are the general characteris-
tics of the urine in inflammatory affections. It
is darker than usual, and of a yellow, brown,
or reddish-brown tint; it has an acid reaction,
and is generally of a high specific gravity.
With respect to its most important consti-
tuents, the urea is either absolutely increased,
or is at the ordinary physiological average, or
may be a little below it ; the uric acid is
always absolutely increased, and so are the
extractive matters, especially the alcoholic
extract. The salts are always absolutely di-
minished, especially the chloride of sodium.
The sulphates, on the other hand, either ap-
proximate to the physiological average, or are
not far below it.

“ Assuming as the mean of numerous ana-
lyses, that the urea constitutes 39 per cent,
of the solid residue of normal urine, 1 have
found it as high as 46’ 8 in inflammatory af-
fections. (In abdominal typhus, with a quick
small pulse, I have seen it as low as 22.)

“ The physiological average of uric acid may
be placed at; I -5 per cent, of the solid residue ;
in the phlogoses I have observed it amount to
nearly 3 per cent., and Becquerel even found
it rise as high as 5'9 per cent. The quan-
tity of extractive matter, &c., which in normal
urine amounts to 23’5 per cent, of the solid
residue, rises in inflammations to 43 per cent.
The fixed salts, which in healthy urine con-

stitute about 25 per cent, of the solid residue,
diminish here to 12 per cent. The sulphate
of potash, which in healthy urine forms about
10 per cent, of the solid residue, I found to
vary in inflammation between 7 and 9 per
cent.

“ The composition of the urine becomes
changed if much blood is abstracted during
the inflammation. It becomes clearer, speci-
fically lighter, and the amount of urea de-
creases absolutely and relatively.

“ At the height of the inflammation, or (per-
haps it would be better to say) at the time
when the fever puts on the synochal type
most strongly, the urine is usually clear and
deeply coloured ; it subsequently forms a
sediment of a yellow or red colour, composed
of uric acid and urates.”

I shall now proceed to describe the state of
the urine as it is observed in different diseases.

Pericarditis. — A managed 36. Acute pe-
ricarditis ; pulse 108, full, and hard; urine
clear, deep red colour; specific gravity 1023’5;
indications of albumen by heat. Analysis
showed : —

Water -

_

-

937-50

Solid residue -

-

-

62-50

Urea - - -

-

-

29-30

Uric acid

-

-

1-50

Extractive matters -

-

-

22-70

Earthy phosphates -

-

-

0-55

Sulphate of potash -

-

-

4-89

Phosphate of soda -
Chloride of sodium, and

carbonate

056

of soda

-

-

1-40

In the above case, after a large quantity of
blood had been drawn, the urine changed as
follows. Colour, that of health; acid re-
action ; devoid of albumen ; specific gravity
1018. Its composition was now, —

Water -

-

- 960-10

Solid residue

-

- 39 90

Urea

-

17-50

Uric acid

-

0-99

Extractive matters

-

15-10

Fixed salts

*

3-65

The first of these

analyses

is that of in-

flammatory urine. The second shows the
effects of the copious bleedings in reducing
the excretion nearer to the normal standard.

With respect to the presence of albumen
in the urine in this and other inflammatory
affections unconnected with disease of the
kidneys, there is in my mind no doubt what-
ever that the opinion is founded in error.
There is no institution in the world at which
the question has been so thoroughly investi-
gated as at Guy’s Hospital; and our daily ex-
perience still confirms the opinions arrived at
by Hr. Bright in his first experiments. It
will be observed that the test of heat (a most
inefficient one in itself) is alone referred to
in the above-described case; and I have little
doubt the precipitate produced was composed
of phosphate of lime, a common source of

URINE.

1291

fallacy which I pointed out some years ago in
connection with this subject.*

Phlebitis Uterina.

The following is a description, by F. Simon’
of specimens of urine in this disease. 1. Co-
lour dark ; reaction acid ; deposit of uric acid
and urate of ammonia. 2. Colour dark ; al-
kaline reaction ; ammoniacal odour ; deposit
dirty yellow in colour, composed of mucus,
ammoniaco-magnesian phosphate, amorphous
precipitate of phosphate of lime, and urate of
ammonia.

Meningitis.

The urine in this disease assumes the or-
dinary inflammatory type. It is described as
dark red, scanty (8 to 9 fluid ounces in the
twenty-four hours), strongly acid ; specific
gravity high. According to Becquerel, the
mean of four cases was 1025'2. Deposit of
uric acid, which, if not present spontaneously,
is immediately produced by the addition of
nitric acid.

Encephalitis.

Urine much the same as in meningitis ;
sometimes a sediment. Spec, gravity, 1020'2.

Observations have been made by several
foreign writers on the state of the urine in
insanity. Drs. Sutherland and Rigby have
also paid some attention to the subject. It
appears to be generally alkaline, and to con-
tain much ammonia in these cases ; the whole
subject, however, needs further and careful
investigation. Dr. Bence Jones states, that in
acute inflammation of the brain there is an
increase in the total amount of phosphates
excreted in the urine.

Delirium Tremens.

In this disease the urine is said to present
the general features of the inflammatory type.

Dr. Bence Jones states, that in delirium
tremens the phosphates are decreased in quan-
tity in the urine, provided no food is taken.
If food be taken, this diminution is not ob-
served.

Myelitis.

In this disease the urine is of much the
same character as in inflammation of the brain,
viz. red, acid, thick, and containing a sediment.
Cases are, however, recorded by Becquerel,
in which the urine did not greatly vary from
the natural standard. There appears no ex-
cessive excretion of the phosphates in this
disease, according to Dr. Jones’s experiments.

Bronchitis.

All that we gather worthy of notice from
the detailed examinations of Becquerel in
respect to the state of the urine in this dis-
ease is, that it occasionally contains albumen.
This may perhaps sometimes happen when
great obstruction to the circulation of blood
through the lungs has existed for any length

* For the proper method of examining the urine
in order to determine the presence or absence of
albumen, I beg to refer to my work on Diseases of
the Kidney connected with albuminous urine.

of time. In by far the greater number of
cases, however, no indication of this kind is
found, unless the kidneys be predisposed to
such form of disease as favours the effusion
of serum.

Pneumonia.

In pneumonia the urea excreted is less
than in health ; the uric acid is increased, the
salts diminished, and the extractive matters
increased, and more especially the alcoholic
extract.

The following are comparative analyses of
the solid matters in 100 parts : —

Becquerel.

Simon.

Urine of
health.

Urea - - - 37’6

39-0

37-2

39-0

Uric acid - - 2‘0

1-7

2-8

1-5

Fixed salts - 14'0

18-3

14-0

25-8

Extractives - 45'4

400

370

23-6

Sulphate of potassa

9

10-3

During the resolution of pneumonia, Simon
and Schonlein have observed that a deposit
occurs in the urine composed of the mono-
basic ammoniaco-magnesian phosphate. Uric
acid was also thrown down on the addition
of acids. This latter reaction, however, is
not peculiar to this disease, I having myself
often observed it in low forms of fever and
also in small-pox. Heller relates the case of
a boy in which the urine had the odour of
hydrosulphate of ammonia, and deposited urate
of soda.

Pi.euritis.

In this disease the urine in general exhibits
much the same characters as in pneumonia.

Empyema.

In cases of empyema the urine has been
observed to contain pus by Schonlein and
Simon. The empyema gradually disappeared,
the urine containing albumen, and the deposit,
when examined, showing the ordinary pus
corpuscles.

Hepatitis.

In hepatitis the urine is extremely deficient
in urea, according to Rose, who in one case
believed it absent. Henry agrees in this
opinion ; and Coindet states that, instead of
urea, the urine contains a substance resembling
bilin. Simon and Becquerel, however, differ
from Rose and Henry, and mention a case of
hepatitis in which urea was excreted in excess.

Nephritis.

fn this disease, when it assumes the acute
character, the urine is often bloody and very
acid, and deposits the uric acid crystalline
deposit. In arthritic nephritis the quantity
of the uric acid crystals is sometimes ex-
tremely great. In a case mentioned by Schon-
lein the sediment occupied half the volume
of the urine.

Chronic Nephritis, Albuminous Nephri-
tis, Morbus Brightii.

In the morbus Brightii the urine contains
abundance of albumen. Blood is occasionally
observed in the early stages. It is generally
acid, far less frequently alkaline, and occasion-

1292

URINE.

ally neutral. Its specific gravity is nearly
always lower than that of health. The uric
acid is usually in very small proportion, and
sometimes altogether absent. This is not,
however, always the case ; and I have some-
times seen the lithic acid in excess existing
as a deposit. Simon believes albumen not
unfrequently present in diseases quite uncon-
nected with affections of the kidneys. His
facts, however, are not satisfactorily stated,
and I believe him to have been greatly mis-
taken in this opinion. In connection with
the morbus Brightii, we have to notice two
substances which, according to Heller, are
often present as deposits in that disease, viz.
uroglaucin and urrhodin. These are colour-
ing matters, derived by oxidation from uro-
xanthin, or a yellow colouring matter of urine,
which exists only in small proportion in
healthy urine, but which is greatly increased
in Bright’s disease. The deposits observed
in the morbus Brightii consist of the casts
of the urinary tubules of the kidney — epi-
thelium of two kinds, viz. spheroidal and
pavement epithelium. ( Vide woodcut of urin-
ary deposits, jig. 799.)

Cystitis.

The urine in this disease is alkaline, the
alkalinity increasing rapidly after the urine is
voided, owing to the formation of carbonate
of ammonia. Mucus and pus are present in
quantity. Albumen can always be detected
in solution when the pus corpuscles are pre-
sent in the deposit. As cure is effecting,
this albumen is found to decrease in propor-
tion as the pus corpucles disappear.

Typhus.

In typhus the urine shows no great va-
riation from the normal standard, so far as
specific gravity and amount of solid consti-
tuents is concerned. The urea is generally
in deficient proportion, the uric acid in-
creased. The salts are much diminished.
During the progress of typhus, the urine very
generally becomes alkaline. Becquerel and
Andral have made many experiments on the
state of the urine both in typhus and typhoid
fevers. They both have met with a large
number of cases in which it was precipitabie
by nitric acid ; this is quite in accordance with
my own observations ; the precipitate, how-
ever, is lithic acid, and not albumen.

Scherer found, like former observers, that
the salts were much decreased in the urine
of typhus, and that there was always an excess
of uric acid.

The following analyses are worthy of note.
They were made by Scherer at the 9th, 12th,
and 15th day of a slow nervous fever, which
occurred in the person of a woman aged thirty-

eight years.

9th Day.

Water -

- 945-48

Urea -

8-60

Uric acid - - -

0-60

Alcoholic extractive

- 2750

Watery ditto - - -

7-40

Albumen ...

1-80

Fixed salts soluble in water

6-20

Earthy phosphates -

2-30

12th Day.

Water -

- 95T26

Urea ....

10-40

Uric acid - - -

0-70

Alcoholic extractive

- 21-80

Watery ditto

7'90

Albumen -

TOO

Fixed salts soluble in water

5-30

Earthy phosphates -

T20

15th Day.

Water - - - -

- 959-29

Urea ....

- 1T40

Uric acid

0-80

Alcoholic extract

15-70

Watery ditto -

6-20

Albumen and mucus

0 90

Fixed salts soluble in water

4-50

Earthy phosphates

0G0

It will be observed that, as

the disease pro-

gressed, the urea increased, while the ex-
tractive matters diminished. The “ salts so-
luble in water” also diminished in quantity.

Intermittent Fever.

L’Heritier has made analyses of the urine
in this disease, and has drawn up the follow-
ing table, which represents its composition in
the different stages, as deduced from a mean
obtained from twelve cases.

Cold Stage.

Hot Stage.

Sweating

Stage.

Specific gra-

1017-330

1020-304

1022-820

vity - J

Water

967-520

964-680

961 -845

Urea

9-845

9-015

- 7-624

Uric acid

0-660

0-980

1-029

Salts and '

organic

2T975

25-325

29-502

matter -

I

Notwithstanding the variations from the
natural standard shown by the above table,
it often happens that the urine in agues differs
but little from that of health in every stage of
the disease.

Cholera.

In this disease the urine is often altogether
suppressed. When it can be collected in any
quantity, its specific gravity is generally below
the natural standard, and it has only a feeble
acid reaction. Albumen is very often to be
found it it. The urea is below the standard
of health. Vogel states that the urine, in a
case of this disease which he examined, was
entirely wanting in the salts of lime and mag-
nesia, and that the chloride of sodium was
deficient. The sulphates, however, were in
larger proportion than in health. Albumen
and biliary colouring matter could be detected
by the appropriate tests.

URINE.

1293

Rheumatism.

In this disease the urine shows the usual
appearances of the inflammatory type, accord-
ing to Becquerel. Oxalate of lime not un-
frequently exists as a deposit.

Phthisis.

In this disease the principal feature ob-
served in the urine is the increase in the
quantity of uric acid. One analysis gave as
much as 2'40 of this acid in 1000 parts of
urine.

Struma.

In struma, generally speaking, the urine is
deficient in urea and uric acid. The phos-
phates are often excreted in excess, and there
is a tendency to the deposit of oxalate of lime.
In mollities ossium and rachitis the earthy
phosphates are excreted in very large quantity,
the alkaline salts are increased, and the urea
and uric acid diminished in proportion. The
analyses which showed the above results
were made on the urine of children, which
always contains less urea and salts than that
of adults.

The following is an analysis, by Marchand,
of the urine of a child suffering from mollities

ossium. It was acid.

Water 938-2

Urea 27 -3

Uric acid - - - 0"9

Lactic acid and lactates - - 14-2

Phosphates of lime and magnesia 5-7
Other constituents (loss) - - 13"7

Diabetes Mellitus.

The urine in this disease contains a sugar
which may be regarded as identical with sugar
of grapes. It is generally of very high specific
gravity, varying from the highest specific gravity
observed in health to 1055 or even 1060.

Schonlein has an opinion that in the first
stages of diabetes there is albumen in the
urine, and that this becomes replaced by sugar.
This opinion I scarcely can believe correct.
The fact, indeed, could not well have escaped
my notice, my attention having been parti-
cularly directed to the study of albuminaria
for some years past. The experiments of
Kant have shown that urea is generally ex-
creted in diabetes mellitus to the same amount
as in health in the twenty-four hours. During
the progress of the disease I have several
times observed the whole of the sugar sud-
denly disappear from the urine, and its place
supplied by an enormous excretion of urea.
I at first was inclined to regard this as a
favourable indication, but experience has not
confirmed that belief. Uric acid is jnot un-
commonly present in considerable quantity,
and this I believe to be a favourable indication
in diabetes. Simon has shown that the ab-
solute quantity of urea excreted in twenty-
four hours is occasionally diminished; but the
general rule is that the quantity approaches
that of health. Caseous matter is sometimes
found in diabetic urine, and, when present, it
excites rapid fermentation immediately after
the urine is voided.

Bouchardat has described a form of sugar
which occasionally exists in diabetes, which is
insipid, but which corresponds in every other
respect with the sweet sugar. Simon says he
once met with it.

Lehmann, Ambrosiani, Muller, and Simon
have observed the presence of hippuric acid
in diabetic urine.

Diabetes Insipidus.

In this disease the urine contains an excess
of water, and varies in specific gravity from
1001 to 1006. The urea, if regarded in pro-
portion to the other solid matters excreted,
is excessive in quantity, but the proportion
discharged during the twenty-four hours is
generally far below that of health.

This excessive discharge of urea, as com-
pared with the other solids, may be accom-
panied by a less discharge of water than that
which is generally found to accompany it.
Then the urine attains a specific gravity ap-
proaching that of health, and sometimes even
exceeding it. Chemically, these two con-
ditions so nearly approach, as scarcely to need
division. Pathologically considered, however,
the latter is the more serious form of disease,
and is believed by some to be not an unfre-
quent forerunner of diabetes mellitus.

Diabetes Chylosus.

This disease is characterised by the dis-
charge of chyle in the urine. It is quite milky
in appearance. A specimen I examined some
few years ago yielded the following results ;

Specific gravity 1021.

Acid in slight degree only.

Milkiness, not changed from subsidence by
standing.

Agitated with ether the urine was cleared,
and the ethereal solution, which then floated
above, contained a fat, yielding an alkaline ash
on incineration. This fat was not saponifiable
by boiling with a solution of potassa. The
urine cleared from the fat coagulated by boil-
ing, and also on the addition of nitric acid.

Jaundice.

The elements of bile exist in the urine in
cases of jaundice. Simon has published the
following result, obtained from the urine of a
female, aged twenty, suffering from inflamma-
tory icterus.

The urine was brownish red, and of specific
gravity 1020, and very acid.

Water - - - -

- 951-50

Urea -

12-34

Uric acid, with biliphaein

2-90

Alcoholic extractive

4-35

Spirituous ditto

529

Aqueous ditto, with mucus

| 5' 14

and bile pigment -

Biliary resin - - -

1-45

Biliverdin -

1-08

Earthy phosphates -
Chloride of sodium and lactate

3-14

of soda ...

Alkaline phosphates and sul-

j- 2‘61
1

phates, with traces of chlo-
ride of sodium

I 3-90

1294

VARIETIES OF MANKIND.

The urea is here below the normal standard ;
the uric acid increased.

Scherer examined urine obtained from a
person labouring under long-continued icterus,
dependent on chronic inflammation of the
hepatic structure. On emission this urine
was clear, yellow, and perfectly neutral : it
subsequently became acid, and deposited uric
acid and bile pigment. This acidity Scherer
believes was owing to the development of
lactic acid.

The specific gravity of the specimen was
1018 ; 1000 parts yielded 4 3 of urea only,
and as much as 1*8 of uric acid. Silica was
also found in this urine.

Urine of Pregnancy.

The urine of pregnant women often con-
tains a peculiar substance, to which the name
of kystein has been given. It appears as a
white scum when the urine has stood some
hours. I have frequently found this substance
in urine at the third and fourth months ofgesta-
tion, and have no doubt that its appearance is
closely connected with the phenomenon of the
secretion of milk. In several instances I
succeeded in detecting distinct milk globules
in such urine.

Foreign Substances in the Urine.

Medicines, and substances taken for food,
are occasionally found in the urine. Some of
these, however, undergo changes in the organ-
ism before they are excreted by the kidneys.

Simon has classified these bodies ; and I
shall here enumerate them according to his
arrangement.

Inorganic non-metallic bodies. — Iodine,
bromine, chlorine, sulphur*, iodide of potas-
sium, alkaline borates, silicates, chlorates, and
carbonates, chloride of barium, ferridcyanide
of potassium, sulphocyanide of potassium.
The ferridcyanide was converted, however,
into the ferrocyanide in the system.

Metallic substances. — Arsenic, antimony,
iron, nickel, gold, silver, tin, lead, bismuth,
copper, and manganese. I have sought in
vain for mercury in the urine. Lehmann and
L’Heritier have also failed to find it where it
has been largely exhibited. Several chemists,
however, declare they have detected it.

Inorganic acids. — Nitricf, hydrochloric,
and sulphuric.

Organic acids. — Oxalic, citric, malic, tar-
taric, succinic, gallic, and acetic.

Pereira has succeeded in detecting meconic
acid in the urine of animals poisoned by opium.

Vegetable bases. — Quina, morphia.

Indifferent organic substances. — Colouring
matters of indigo, gamboge, rhubarb, red beet-
root, madder, logwood, mulberries, black
cherries ; odorous principles of valerian,

* This, if exhibited in combination in sulphurets,
is excreted as sulphate of the base.

t Dr. Bence Jones believes that nitric acid is com-
monly present in healthy urine, and appears as the
result of the oxidation of nitrogenised food.

assafoetida, garlic, castoreum, saffron, turpen-
tine.

Liebig and Wohler both state that alcohol
cannot be detected in the urine. Percy, how-
ever, has proved that it can. Dr. Wright has
corroborated Percy’s experiments, and ob-
tained alcohol by the same plan of analysis.

Lehmann anti others sought unsuccessfully
for the following substances in the urine :
viz., salicin, phloridzin, caffein, theobromin, as-
paragin, and amygdalin. These substances
probably undergo changes in the organism.

Lehmann has shown that salicin becomes
converted into salicylous acid ; this was taken
up by ether with the oxide of omichmyle.
The addition of nitrate of iron produced the
fine violet colour characteristic of salicylous
acid. Hippuric acid and oxalate of lime were
also produced.

Phloridzin is converted into oxalic and
hippuric acids during its passage through the
organism, according to Lehmann.

For the Bibliography reference is made to the
works of Berzelius, Prout, Simon, Liebig, Dumas,
Lehmann, on Animal Chemistry, and to those
quoted in the foot notes.

( G . Owen Sees.)

VARIETIES OF MANKIND.— Under
this head it is intended to give a general ac-
count of the distinctive characters, — struc-
tural, physiological, and psychological — of
the principal Races of Men ; and to inquire
into the nature and degree of their mutual
affinity. Before entering upon these subjects,
however, it will be desirable, in the first place,
to set forth the most important characters by
which Man, under whatever form, is distin-
guished from the Mammalia which approach
most nearly to him ; and, secondly, to lay a
foundation in the recognised principles of
natural history and physiology, for a true ap-
preciation of the characters which serve to
distinguish species from each other, as con-
trasted with those which may be presented
by varieties , whose original stock is known, or
believed, to have been identical.

I. Distinctive Characteristics of Man.

By Cuvier and nearly all modern zoologists,
the various races of mankind are included
under one genus, Homo ; and this genus
takes rank, in the classification of Mam-
malia, as a distinct order, Bimana, of which
it is the sole representative. Of all the cha-
racters which distinguish Man from the in-
ferior Mammalia, the possession of two hands
is doubtless the most easily recognised, and at
the same time the most intimately related to
the general organisation of the body ; and
there is none, therefore, which could be more
appropriately selected as the basis of a dis-
tinctive designation for this order. At first
sight it might be considered that the pos-
session of only two hands, whilst Apes and
Monkeys and their allies are designated as
possessing four, is a character of inferiority ;
but such is not really the case ; for none

VARIETIES OF MANKIND. 1295

of these four hands are adapted to the va-
riety of actions of which those ot man are
capable, and they are all in some degree re-
quired for support ; so that whilst in the
higher forms of the Quadrumanous order, the
extremities present a certain approximation
in structure to those of man, in the lower
they gradually assimilate to the ordinary
quadrupedal type. “ That,” says Cuvier,

“ which constitutes the hand, properly so
called, is the faculty of opposing the thumb
to the other fingers, so as to seize upon the
most minute objects ; a faculty which is car-
ried to its highest degree of perfection in Man,
in whom the whole anterior extremity is free,
and can be employed in prehension.” The
peculiar prehensile power possessed by man is
chiefly dependent upon the size and power of
the thumb ; which is more developed in Man
than it is in the highest apes. The thumb of
the human hand can be brought into exact
opposition to the extremities of all the fingers,
whether singly or in combination ; whilst in
those Quadrumana which most nearly ap-
proach man, the thumb is so short, and the
fingers so much elongated, that their tips can
scarcely be brought into opposition ; and the
thumb and fingers are so weak, that they can
never be opposed to each other with any de-
gree of force. Hence, although admirably
adapted for clinging round bodies of a certain
size, such as the small branches of trees, &c.,
the extremities of the Quadrumana can nei-
ther seize very minute objects with such pre-
cision, nor support large ones with such
firmness, as are essential to the dexterous per-
formance of a variety of operations, for which
the hand of Man is admirably adapted. There
is much truth, then, in Sir C. Bell's remark,
that “ we ought to define the hand as belong-
ing exclusive!}' to man.” There is in him,
what we observe in none of the Mammalia
which approach him in other respects, a com-
plete distinction in the functional character
of the anterior and posterior extremities ; the
former being adapted for prehension alone,
and the latter for support and progression
alone; and thus each function is performed
in a much higher degree of perfection, than it
can be when two such opposite purposes
have to be united. For not only is the hand
of man a much more perfect prehensile in-
strument than that of the orang or chim-
panzee, but his foot is a much more perfect
organ of support and progression than theirs,
being adapted to maintain his body in an
erect position, alike during rest and whilst in
motion, — an attitude which even the most
anthropoid apes can only sustain for a short
time, and with an obvious effort. The arm
of the higher apes has as wide a range of
motion as that of man, so far as its articu-
lation is concerned ; but it is only when the
animal is in the erect attitude, that the limb
can have free play. Thus the structure of the
whole frame must be conformable to that of
the hand, in the way that we find it to be in
man, in order that this organ may be advan-
tageously applied to the purposes which it is

adapted to perform. But it cannot be said
with truth (as some have maintained) that Man
owes his superiority to his hand alone ; for
without the mind by which it is directed, and
the senses by which its operations are guided,
it would be a comparatively valueless in-
strument. Man’s elevated position is due to
the superiority of his mind and of its ma-
terial instruments conjointly ; for if destitute
of either, the human race must be speedily ex-
tinguished altogether, or reduced to a very
subordinate grade of existence.

The next series of characters to be con-
sidered, are those by which man is adapted to
the erect attitude. On examining his cra-
nium, we remark that the occipital condyles
are so placed, that a perpendicular dropped
from the centre of gravity of the head would
nearly fall between them, so as to be within
the base on which it rests upon the spinal
column. The foramen magnum is not placed
in the centre of the skull, but just behind it ;
so that the greater specific gravity of the pos-
terior part of the head, which is entirely filled
with solid matter, is compensated by the greater
length of the anterior part, which contains
many cavities. There is, indeed, a little over-
compensation, which gives a slight prepon-
derance to the front of the head, so that it
drops forwards and downwards, when all the
muscles are relaxed ; but the muscles which
are attached to the occiput are larger and far
more numerous than those in front of the
condyles, so that they are evidently intended
to counteract this disposition ; and we find,
accordingly, that we can keep up the head for
a whole day, with so slight and involuntary
effort, that no fatigue is produced by it. More-
over, the plane of the foramen magnum, and
the surfaces of the condyles, have a nearly
horizontal direction when the head is upright ;
and thus the weight of the skull is laid verti-
cally upon the top of the vertebral column.
If these arrangements be compared with those
which prevail in other Mammalia, it will be
found that the foramen and condyles are placed
in the latter much nearer the back of the
head, and that their plane is more oblique.
Thus, whilst the foramen magnum is situated,
in Man, just behind the centre of the base of
the skull, it is found in the Chimpanzee and
Orang to occupy the middle of the poste-
rior third ; and as we descend through the
scale of Mammalia, we observe that it gra-
dually approaches the back of the skull, and
at last comes nearly into the line of its longest
diameter, as we see in the Horse. So the
angle of inclination which the condyles make
with the horizontal is very small in Man, but
rises in the Orang to 37° ; whilst in the Horse
their plane is vertical, making the angle 90°.
If, therefore, the natural posture of man had
been horizontal, the plane of his condyles
would be brought, like that of the horse,
into the vertical position ; and the head,
instead of being nearly balanced upon the
summit of the vertebral column, would hang
at the end of the neck, so that its whole
weight would have to be supported by some

129G

VARIETIES OF MANKIND.

external anti constantly-acting power. But
for this there is neither in the skeleton, the
ligamentous apparatus, nor the muscular sys-
tem of Man, any adequate provision ; so that
in any other than the vertical position, his
head, which is relatively heavier than that of
most Mammalia, would be supported with
more difficulty and effort than it is in any
other animal.

The position of the face immediately be-
neath the anterior portion of the cranial
cavity, so that its front is nearly in the same
plane as the forehead, is peculiarly character-
istic of Man ; for the crania of the Chimpanzee
and Orang, which approach most nearly to that
of man, are entirely posterior to, not above,
the face (see Jigs. 800 — 802.). It should

be remarked that in the young ape, there is a
much greater resemblance to man in this re-
spect, than there is in the adult ; for it is at
the time of the second dentition, that the
muzzle of the ape acquires its peculiar elonga-
tion and consequent projection in front of the
forehead ; and the whole cast of the features
is altered at the same time, so as to approxi-
mate much more closely to that of the lower
Quadrumana than would have been thought
likely from the inspection of the young ani-
mal only. This projection of the muzzle,
taken in connection with the obliquity of
the condyles, is another evidence of want of
adaptation to the erect posture ; whilst
the want of prominence in the face of Man
shows that none but the erect position
can be natural to him. For supposing that
with a head formed and situated as at pre-
sent, he were to move upon all fours, his
face would be brought into a plane parallel
with the ground ; so that as painful an effort
would be required to examine with the eyes
an object placed in front of the body, as is
now necessary to keep the eyes fixed on the
zenith ; the nose would then be almost inca-
pacitated for receiving any other odorous
emanations, than those proceeding from the
earth or from the body itself; and the mouth
could not touch the ground, without bringing
the forehead and chin also in contact with it.
The obliquity of the condyles in the Qua-
drumana enables them without much difficulty
to adapt the inclination of their heads either
to the horizontal or to the erect posture ; but
the natural position, in the highest among
them, is unquestionably one in which the
spinal column is inclined, the body being par-
tially thrown forwards, so as to rest upon the
anterior extremities ; and in this position, the
face is directed forwards without any effort.

Th e vertebral column in Man, although not
absolutely straight, has its curves so arranged,
that when the body is in the erect posture, a
vertical line from its summit would fall exactly
on the centre of its base. It increases con-
siderably in size in the lumbar region, so as
to be altogether somewhat pyramidal in its
form. The lumbar portion, in the chim-
panzee and orang, is by no means of the same
proportional strength, and contains but four
vertebras instead of five. The processes for

the attachment of the dorso-spinal muscles to
this part, are peculiarly large and strong in
man ; and this arrangement is obviously
adapted to overcome the tendency, which the
weight of the trunk in front of' the column
would have to draw it forwards and down-
wards. On the other hand, the spinous pro-
cesses of the cervical and dorsal vertebrae,
which in other Mammalia are large and strong,
for the attachment of the ligaments and
muscles that support the head, have compara-
tively little prominence in man, whose head is
balanced upon the summit of the column.

The base of the human vertebral column
is placed on a sacrum of greater proportional
breadth than that of any other animal ;
this sacrum is fixed between two widely
expanded ilia ; and the whole pelvis is thus
peculiarly broad. In this manner the fe-
moral articulations are thrown very far apart,
so as to give a wide basis of support ;
and by the oblique direction of the axis of
the pelvis, the weight of the body is trans-
mitted almost vertically from the top of the
sacrum to the upper part of the thigh bones.
The pelvis of the anthropoid apes is very
differently constructed. That of the orang,
for example, is much longer and narrower ;
its alas extend upwards rather than outwards,
so that the space between the lowest ribs and
the crest of the iliac bones is much less than
in man ; their surfaces are nearly parallel
to that of the sacrum, which is itself longer
and narrower ; and the axis of the pelvis
is nearly parallel with that of the verte-
bral column. The position of the human
femur, in which its head is most securely1
retained in its deep acetabulum, is that
which it has when supporting the body in
the erect attitude ; in the chimpanzee and
orang, its analogous position is at an oblique
angle to the long axis of the pelvis, so that the
body leans forwards in front of it ; in many of
the four-footed Mammalia, as the elephant,
it makes a right angle with the vertebral
column ; and in several others, as the horse,
ox, &c., the angle which it makes with the
axis of the pelvis and vertebral column is
acute. In this respect, then, the skeleton of
man presents an adaptation to the erect pos-
ture, which is exhibited by that of ho other
mammal.

The lower extremities of Man are remark-
able for their length, which is proportionally
greater than that which we find in any other
mammalia, excepting the kangaroo and a few
other leaping animals. The chief difference
in their proportional length, between man and
the semi-erect apes, is seen in the thigh ; and
from the relative length of this part in him,
and the comparative shortness of his anterior
extremities, it happens that the hands of Man,
when he is standing erect, only reach to the
middle of his thighs, whilst in the Chimpanzee
they hang on a level with the knees, and in
the Orang they descend to the ancles. The
human femur is distinguished by its form and
position, as well as by its length. The obli-
quity of its neck still further increases the

1297

VARIETIES OF MANKIND.

breadth of the hips ; whilst it causes the
lower extremities of the femora to he some-
what obliquely directed towards each other,
so that the knees are brought more nearly
into the line of the axis of the body. This
arrangement is of the greatest importance in
facilitating the purely biped progression of
Man, in which the entire weight of the body
must be alternately supported upon each
limb ; for if the knees had been kept further
apart, the whole body must have been swung
from side to side at each step, so as to bring
the centre of gravity over each tibia, — as is
seen, to a certain extent, in the female sex,
whose walk, owing to the greater breadth of
the pelvis, and the separation between the
knees, is less steady than that of the male.
There is a very marked contrast between the
knee-joint of Man, and that of even the high-
est Apes. In the former the opposed extre-
mities of the femur and tibia are so expanded
as to present a very broad articulating sur-
face ; and the internal condyle of the femur
being the longer of the two, they are in the same
horizontal plane in the usual oblique position
of that bone; so that by this arrangement
the whole weight of the body, in its erect
posture, falls vertically on the head of the
tibia, when the joint is in the firmest posi-
tion in which it can be placed. The knee-
joint of the Orang, on the other hand, is
comparatively deficient in extent of articu-
lating surface ; and its whole conformation
indicates that it is not intended to serve as
more than a partial support. The human
foot is, in proportion to the size of the whole
body, larger, broader, and stronger than that
of any other existing mammal, save the kan-
garoo. Its plane is directed at right angles
to that of the leg ; and its sole is concave,
so that the whole weight of the body falls on
the summit of an arch, of which the os calcis
and the metatarsal bones form the two points
of support. This arched form of the foot, and
the habitual contact of the os calcis with the
ground, are peculiar to Man alone. All the
apes have the os calcis small, straight, and
more or less raised from the ground, which
they touch, when standing erect, with the
outer side of the foot only ; whilst in animals
more remote from man, the os calcis is
brought still more into the line of the tibia ;
and the foot being more elongated and nar-
rowed, only the extremities of the toes come
in contact with the ground. Hence Man is
the only species of mammal which can stand
on one leg. The points in which the feet of
the anthropoid apes differ from his, all assi-
milate them to the manual type of conforma-
tion, and enable them to serve as more efficient
prehensile organs, whilst they diminish their
capacity to sustain the weight of the body
when it simply rests upon them.

There is a considerable difference in the
form of the trunk, between Man and most
other mammalia ; for his thorax is expanded
laterally, and flattened in front, so as to pre-
vent the centre of gravity from being carried
too far forwards. His sternum is short and

VOL. IV.

broad compared with that of quadrupeds
generally; and there is consequently a con-
siderable space between its lower extremity
and the symphysis pubis, occupied solely by
muscular parts, which would be quite inade-
quate to sustain the weight of the viscera, if
the habitual position of the trunk had been
horizontal. In these particulars, however,
the most anthropoid Apes agree with Man.

Returning now to the skull for a more
minute examination, and referring to the ar-
ticle Quadrumana for an account of the
principal differences presented between the
skulls of the ordinary Chimpanzee and Orang,
and that of Man, we shall take as our standard
of comparison the recently-discovered species
of Chimpanzee, designated as the Troglodytes
gorilla, whose cranium is considered by Prof.
Owen to approach in some respects more
nearly to that of man, than do either of the
preceding. This species differs from the T.
rtiger ( Simia troglodytes, Vrolik) by its con-
siderably greater dimensions, by the greater
prominence of the supra-orbital ridges, the
enormous development of the crest, which oc-
cupies the place of the sagittal suture, the
greater strength of the zygomatic arches,
and the greater size of the temporal fossa.
For the more minute, but definite cha-
racters, on which the specific distinction is
grounded, the description by Prof. Owen
must be consulted.* The slightest glance at
Jigs. 8G0, 801, 802. is sufficient to show
how strongly marked are the features by which
the skull of this Chimpanzee differs from that
of even the most degraded of the Human
family but it will be advantageous to sub-
join Prof. Owen’s enumeration of the chief
differences which are revealed by a careful
anatomical survev. These are : —

“ 1. The smaller proportional size of the
cranium.

“ 2. The more backward position of the
foramen magnum, and its more oblique plane
in relation to that of the base of the skull.

“ 3. The smaller relative size, and more
backward position, of the occipital condyles.

“ 4. The longer basi-occipital, and broader,
flatter, and lower supra-occipital.

“ 5. The longer basisphenoid, and shorter
alisphenoids.

“ 6. The smaller size of the coalesced pa-
rietals, and their separation from the alisphe-
noids.

“ 7. The conversion of a greater part of
the outer surface of the parietals into con-
cavities or depressions for the lodgment ot
the temporal muscles, by reason of the bony
crest developed from the line of the obliterated
sagittal suture, and of the lambdoidal crest.

“ 8. The larger proportion of this crest
and of the squamosal plate developed from
the mastoid, and the smaller size of the proper
mastoid processes.

“ 9. The smaller size of the vaginal and
styliform processes, and the absence of the

* Transactions of the Zoological Society, vol. iii.
p. 392. et seq.

4 o

1298

VARIETIES OF MANKIND.

styloid process, arising from the non-anchy-
losis of the stylo-hyal bone.

Fig. 800.

Front, side, and basal views of the skull o f the Trog-
lodytes gorilla. ( After Owen.)

“ 10. The larger post-glenoid process, and
the longer auditory process (tympanic bone),
with their relative position, one behind, but
not below, the other.

“ 11. The position of the stronger zygo-
mata opposite the middle third of the basis
cranii.

“ 12. The prominent supra-orbital ridge.

“ 13. The longer nasal bones, anchylosed
together, and flattened at their lower half.

“ 14'. The greater proportional size, and
greater prominence of the upper and lower
jaws.

“ 15. The longer osseous palate, and the
median emargination of its posterior border.

“ 1G. The parallelism of the alveoli of the
molars and canine of one side, with those of
the other.

“ 17. The diastema, or vacant place, in
front of the socket of the canine in the upper
jaw, and behind that socket in the lower
jaw.

“ 18. The larger and more produced pre-
maxillaries, the persistence of more or less
of their sutures, showing the intervention of
their upper extremities between the nasal and
maxillary bones.

“ 19. The minor extent of connection of
the lachrymal with the ‘ pars plana ’ of the
aethmoid, or their separation by the junction
of the orbital plate of the maxillary with that
of the frontal behind the lachrymal.

“ 20. The depth of the olfactory fossa, and
the absence or rudimental state of the crista
galli.

“21. The squamosal, lambdoidal, alisphe-
noidal and pterygoid air-cells.

“ 22. The more prominent cusps of the
molar teeth.

“ 23. The larger relative size, and more
complex grinding surface of the last molar
tooth in both jaws.

“ 24. The larger relative size of the pre-
molars, especially of the first.

“ 25. The more complex implantation of
the premolars by three roots, two external
and one internal.

“ 2G. The much larger and longer canines.

“ 27. The sexual distinction in the develop-
ment of these teeth.

“ 28. The more sloping position of the
crowns of the incisors.

“ 29. The broader and higher ascending
ramus of the lower jaw.

“ 30. The total absence of the prominence
of the symphysis forming the chin.

“ In the form of the premaxillaries, and the
earlier obliteration of their sutures,” Prof.
Owen continues, “ the smaller chimpanzee
more nearly resembles man than the great
gorilla does ; it seems also to deviate less
through the minor development of the canine
teeth, and of the parietal and sagittal crests ;
but it has been shown, in the comparison of
the skulls of Troglodytes gorilla and T. n’ger,
that the latter departs in more numerous and
important particulars further from the human

type-” . ,

Now, of the foregoing characters, some ot
those which constitute the most striking fea-
tures in the cranium of the Chimpanzee, are
those which must be admitted from analogy
to be liable to variation under the influence

VARIETIES OF MANKIND.

1299

of a change of habits, provided such change
could be induced. Thus we find that in dogs,
the general form of the cranium, and the
sagittal crest, undergo considerable modifica-
tion ; the brain acquiring a very large size, in
several of the domesticated races, at an early
period of life ; and the parietal bones being
expanded over it so as to form a smooth
dome, instead of rising up to meet in a ver-
tical ridge. But the prominence of the supra-
orbital ridge does not seem to be in any way
connected with the relative development of
the cerebrum and of the muscular system ;
and as Prof. Owen remarks, “ We have no
grounds from observation or experiment to
believe the absence or the presence of a pro-
minent supra-orbital ridge to be a modifiable
character, or one to be gained or lost through
the operation of external causes, inducing
particular habits through successive genera-
tions of a species. It may be concluded,
therefore, that such feeble indication of the
supra-orbital ridge, aided by the expansion of
the frontal sinuses, as exists in man, is as
much a specific peculiarity of the human
skull, in the present comparison, as the ex-
aggeration or suppression of this ridge is
respectively characteristic of the chimpanzees
and orangs.” The same may be said of nearly
all the other distinctive characters which
have been so minutely enumerated ; for they
serve to distinguish the great chimpanzee
from all the varieties of the human race, —
from the most degraded African, as well as
from the most elevated European. The
shape, size, and construction of the “ pre-
maxillary ” bones (“ inter-maxillaries ” of the
ordinary nomenclature) are peculiarly distinc-
tive ; for they not only differ from those of
Man in their vastly greater proportional size,
their greater prominence, and the longer per-
sistence of their sutures, but also in their
upward extension around the nostrils, so that
they completely exclude the maxillary bones
from their borders, and form the bases of
support for the nasal bones (Jig. 800.) It
is to be remembered that the apparent defi-
ciency of the inter-maxillary bone in the human
subject is the result of its early coalescence
with the maxillary; and that this coalescence
may be prevented by an arrest of development,
so that the two bones remain permanently
distinct.*

Having dwelt thus fully on the distinctive
features of the Osteology of Man, it will be
sufficient to pass over his other peculiarities
of conformation more cursorily, referring to
the article Quadrumana for more minute
details. In his Myology, the most charac-
teristic difference is the much greater de-
velopment of those muscles of the trunk and
limbs, which contribute to the maintenance of
the erect posture. Thus the gastrocnemii
and the other muscles which tend to keep
the leg erect upon the foot, form a much

* A very definite account of the early embryonic
state of the intermaxillary bone, is given by Dr.
Leidy in the Proceedings of the Academy of the
Natural Sciences of Philadelphia for 1848.

more prominent “ calf” than is seen in any
other animal. So, again, the extensors of the
leg upon the thigh are much more powerful
than the flexors ; a character which is pecu-
liar to man. The glutaei, by which the pelvis
is kept erect upon the thigh, are of far greater
size than is elsewhere seen. The superior
power of the muscles tending to draw the
head and spine backwards, has been already
referred to. Among the differences in the
attachment of individual muscles, we may no-
tice that the flexor longus pollicis pedis pro-
ceeds in man to the great toe alone, on which
the weight of the body is often supported ;
whilst it is attached in the chimpanzee and
orang to the three middle toes. The latissi-
mus dorsi of man is destitute of that pro-
longation attached to the olecranon, which is
found in most of the lower Mammalia, and
which exists even in the chimpanzee, pro-
bably giving assistance in its climbing
movements. The larger size of the muscles
of the thumb is, as might be expected, a
characteristic of the hand of man, though the
number of muscles by which that digit is
moved is the same in the chimpanzee as in
the human subject. The existence of the
extensor digiti indicis, as a distinct muscle,
however, is peculiar to man.

The visceral apparatus of Man presents
very few characteristic peculiarities, by which
it can be distinguished from that of the
higher Quadrumana ; among the most re-
markable is the absence of the laryngeal
pouches, which exist even in the chimpanzee
and orang-outan, as dilatations of the laryngeal
ventricles. Of the anatomy of the last-named
animals in their adult condition, however, we
know as yet too little, to enable its resem-
blance to that of man to be confidently pro-
nounced upon.

The conformation of the brain of Man
does not differ so much from that of the
chimpanzee and orang, as the superiority of
his mental endowments might have led us to
anticipate. The following are the principal
differences which it seems to present: — 1.
The mass of the entire brain is considerably
larger in proportion to that of the body, and
in proportion also to the diameter of the
nerves which are connected with it. 2. In
the external configuration of the cerebrum,
we notice that the posterior lobes are more
developed, so as to project further beyond
the cerebellum than they do in any of the
quadrumana ; the convolutions are more nu-
merous, and the sulci are deeper. 3. On ex-
amining the internal structure, it is found
that the peripheral layer of grey matter is
thicker, the corpus callosum extends further
backwards, and the posterior cornua of the
lateral ventricles are relatively longer and
larger than they are in any Quadrumana. 4.
The cerebellum, also, is proportionally larger.
— The great size of the cranial portion of the
skull in Man, as compared with the facial,
produces a marked difference between his
facial angle, and that of even the highest
Quadrumana. According to Camper, who first
4 o 2

1300

VARIETIES OF MANKIND.

applied this method of measurement, the facial
angle of the average of European skulls is
80°, whilst in the ideal heads of the Grecian
gods it is increased to 90° ; on the other hand,
in the skull of a Kalmuck he found it to
be 75°, and in that of a Negro only 70° ;
and applying the same system of measure-
ment to the skulls of Apes, he found them to
range from 64° to 60°. But these last mea-
surements were all taken from young skulls,
in which the forward extension of the jaws,
which takes place on the second dentition,
had not yet occurred. In the adult Chim-
panzee, as we learn from the measurements
of Prof. Owen, the facial angle is no more
than 33°, and in the adult Orang only309;
so that instead of the Negro being nearer to
the Ape than to the European, as Camper’s
estimate would make him, the interval be-
tween the most degraded human races and
the most elevated Quadrumana is vastly
greater than between the highest and lowest
forms of humanity. It must be borne in mind
that the facial angle is so much affected by
the degree of prominence of the jaws, that it
can never afford any certain information con-
cerning the elevation of the forehead and the
capacity of the cranium ; all that it can in
any degree serve to indicate, is the relative
proportion between the facial and cranial
parts of the skull. The small size of the face
of Man, compared with that of the cranium,
is an indication that in him the senses are sub-
ordinated to the intelligence. Accordingly we
find that he is surpassed by many of the
lower animals in acuteness of sensibility to
light, sound, &c. ; but he stands preeminent
in the power of comparing and judging of
his sensations, and of drawing conclusions
from them as to their objective sources.
Moreover, although none of his senses are
very acute in his natural state, they are all
moderately so ; and they are capable of being
wonderfully improved by practice, when cir-
cumstances strongly call for their exercise.
This seems especially the case with the tactile
sense (see article Touch, p. 1177), of which
man can make greater use than any other
animal, in consequence of the entire freedom
of his anterior extremities, although there are
many which surpass him in their power of
appreciating certain classes of tactile impres-
sions. So, again, Man’s nervo-muscular power
is inferior to that of most other animals of
his size; the full grown Orang, for example,
surpasses him both in strength and agility ;
and the larger Chimpanzee, according to the
statements of the negroes who have en-
countered it, is far more than a match for any
single man, and is almost certain to destroy
any human opponent when once within his
grasp. The absence of any natural weapons of
offence, and of direct means of defence, are
remarkable characteristics of Man, and dis-
tinguish him not only from the lower Mam-
malia, but also from the most anthropoid
Apes ; in which it is obvious (both from their
habits and general organisation) that the
enormous canines have no relation to a car-

nivorous regimen, but are instruments of war-
fare. On those animals to which nature has
denied weapons of attack, she has bestowed
the means either of passive defence, of con-
cealment, or of flight ; in each of which Man
is deficient. Yet, by his superior reason, he
has not only been enabled to resist the at-
tacks of other animals, but even to bring them
into subjection to himself. His intellect can
scarcely suggest the mechanism which his
hands cannot frame ; and he has devised and
constructed arms more powerful than those
which any other creature wields, and defences
so secure as to defy the assaults of all but
his fellow men.

The power of adaptation to varieties in
external condition, which renders Man to a
great extent independent of them, is one of
the most remarkable peculiarities of his
economy. He is capable of sustaining the
lowest as well as the highest extremes of
temperature and of atmospheric pressure. In
the former of these particulars he is strikingly
contrasted with the anthropoid apes ; the
Chimpanzee being restricted to the hottest
parts of Africa, and the Orang outan to the
tropical portions of the Indian Archipelago';
and neither of these animals being capable
of living in temperate climates without the
assistance of artificial heat, even with the aid
of which they have not hitherto survived their
second dentition. So, again, although Man’s
diet seems naturally of a mixed character, he
can support himself in health and strength
either on an exclusively vegetable diet, or,
under particular circumstances, on an almost
exclusively animal diet. It is in thus adapt-
ing himself to the conditions of his existence,
in providing himself with food, shelter, wea-
pons of attack and defence, &c., that man’s
intellectual powers are first called into active
operation ; and when thus aroused, their
development has no assignable limit. The
will, guided by the intelligence, and acted on
by the desires and emotions, takes the place
in man of the instinctive propensities which
are the usual springs of action in the lower
animals ; anti although, among the most ele-
vated of these, the intelligent will is called
into exercise to a certain extent, yet it never
acquires among them, the dominance which
it possesses in man. The capacity for intel-
lectual progress is a remarkable peculiarity of
man’s psychical nature. The instinctive
habits of the lower animals are limited, and
peculiar to each species, and have immediate
reference to their bodily wants. Where a
particular adaptation of means to ends, of
actions to circumstances, is made by an indi-
vidual (as is frequently the case, when some
amount of intelligence or rationality exists),
the rest do not seem to profit by it ; so that,
although (as will be shown hereafter) the in-
stincts of particular animals may be modified
by the training of man, or by the education
of circumstances, so as to show themselves
after a few generations under new forms,
no elevation in intelligence appears ever to
take place spontaneously, no psychical im-

VARIETIES OF MANKIND.

1301

provement is manifested in the species at
large. One of the most important aids in the
use and development of the human mind, is
the capacity for articulate speech; of which,
so far as we know, man is the only animal in
possession. There is no doubt that many
other species have certain powers of com-
munication between individuals; but these
are probably very limited, and of a kind more
allied to the “ language of signs,” than to a
proper verbal language. In fact it is obvious
that the use of a language composed of a cer-
certain number of distinct sounds, combined
into words in a multitude of different modes,
requires a certain degree of that power of
abstraction and generalisation, in which (as
elsewhere remarked*) it appears that the
lower animals are altogether deficient. The
correspondence between the psychical endow-
ments of the Chimpanzee and those of the
Human infant before it begins to speak, is
extremely close ; and those who have perused
the interesting narrative given by Dr. Howe,
of his successful training of Laura Bridgeman,
will remember how marked was the improve-
ment in her mental condition, from the time
when she first apprehended the idea that she
could give such expression to her thoughts,
feelings and desires, as should secure their
being comprehended by others.

Now, this capacity for progress is con-
nected with another element in Man’s nature,
which it is difficult to isolate and define, but
which interpenetrates and blends with his
whole psychical character. “ The soul,” it
has been remarked, “ is that side of our nature
which is in relation with the infinite and it
is the existence of this relation, in whatever
way we may describe it, which seems to con-
stitute the most distinctive peculiarity of man.
It is in the desire for an improvement in his
condition, occasioned by an aspiration after
something nobler and purer, that the main-
spring of human progress may be said to lie;
among the lowest races of mankind, the capa-
city exists, but the desire seems dormant.
When once thoroughly awakened, however,
it seems to “ grow by what it feeds on ; ” and
the advance once commenced, little external
stimulus is needed; for the desire increases
at least as fast as the capacity. In the higher
grades of mental development, there is a con-
tinual looking upwards, not (as in the lower)
towards a more elevated human standard, but
at once to something beyond and above man
and material nature. This seems the chief
source of the tendency to believe in some
unseen existence ; which may take various
forms, but seems never entirely absent from
any race or nation, although, like other innate
tendencies, it may be deficient in individuals.
Attempts have been made by some travellers
to prove that particular nations are destitute
of it ; but such assertions have been based
only upon a limited acquaintance with their
habits of thought, and with their outward
observances ; for there are probably none

who do not possess the idea of some invisible
power, external to themselves, whose favour
they seek, and whose anger they deprecate,
by sacrifice and other ceremonials. It re-
quires a higher mental cultivation than is
commonly met with, to conceive of this
power as having a spiritual existence ; but
wherever the idea of spirituality can be de-
fined, it seems connected with it. The vulgar
readiness to believe in demons, ghosts, &c. is
only an irregular or depraved manifestation
of the same tendency. Closely connected
with it, is the desire to participate in this
spiritual existence, which has been implanted
in the mind of man, and which, developed as
it is by the mental cultivation that is almost
necessary for the formation of the idea, has
been regarded by philosophers in all ages as
one of the chief natural arguments for the
immortality of the soul. By this immortal
soul, Man is connected with that higher order
of being, in which Intelligence exists, un-
restrained in its exercise by the imperfections
of that corporeal mechanism through which it
here operates; and to this state, — a state of
more intimate communion of mind with mind,
and of creatures with their Creator, — he is
encouraged to aspire, as the reward of his
improvement of the talents here committed to
his charge.

II. Of Species and Varieties, zoologi-
cally CONSIDERED.

The meaning which the scientific Na-
turalist attaches to the term Species, is not
always defined in the same manner, although
the notions which the various definitions are
intended to convey, are for the most part
essentially similar. Thus a species has been
described as “ a race of animals or of plants,
marked by any peculiar character which has
always been constant and undeviating;” it
being obvious, from this definition, which
carries us backwards from the present to the
past, that the first parents or “ protoplasts ” of
such a race must have been distinguished by
the same characters as those by which their
descendants are now recognised. But, again,
this community of parentage is made by
Cuvier to constitute the leading idea con-
veyed by the term ; for he defines a species
to be “ the collection of all the beings de-
scended the one from the other, or from com-
mon parents ; and of those which bear as close
a resemblance to these, as they bear to each
other.” “We are under the necessity,” he
elsewhere remarks, “ of admitting the exist-
ence of certain forms, which have perpetuated
themselves from the beginning of the world,
without exceeding the limits first prescribed ;
all the individuals belonging to one of these
forms, constitute what is termed a species.”
And M. De Candolle, in like manner, ob-
serves that “ we unite, under the designation
of a species, all those individuals which mu-
tually bear to each other so close a resem-
blance, as to allow of our supposing that they
may have proceeded originally from a single
4 o 3

See Art. Instinct, vol. iii. p. 2.

1302

VARIETIES OF MANKIND.

being or a single pair.” Thus it appears
that, in one mode or another, the fundamental
idea of the term, among all those naturalists
who admit the “ permanence of species,” con-
nects itself with the notion of community of
descent. This notion, as M. De Candolle
admits, is hypothetical, so far at least as its
particular applications are concerned ; since
in no one case have we the power either of
looking back to the epoch of the first pro-
duction of a species, or of tracing downwards
the whole line of descent from any original
pair. Still, as it is the only definition which
conveys the essence of what naturalists or-
dinarily mean by specks, we shall accept it as
the basis of our further inquiries ; and shall
now point out the mode, in which it is brought
into application in the actual study of natural
history.

We will suppose the Zoologist to have two
new specimens of shells or insects placed
before him, or the Botanist to be examining
two new specimens of plants. If the con-
formity between the two is so extremely close,
that the differences do not exceed the limits
of variation which are commonly seen to
prevail in the offspring of a common parentage,
lie places them in the same species ; because
he considers that each may produce a form
resembling the other, or may have been pro-
duced by it, so that there is no sufficient
ground for assigning to the two a distinct
ancestry. But supposing that the differences
should be more strongly marked, and the
naturalist should be tempted to assign dif-
ferent specific names to his two shells, or
insects, or plants : in what way is he to diag-
nose their similarity or diversity of origin ?
He forms his judgment, in the first place, by
the nature of the characteristic difference ; for
this may be of such a kind, that its variability
could not be reasonably suspected. Yet this
is not a point on which much stress can be
laid, when it stands alone ; for although in
many groups there are certain characters
which present such constancy, that a pre-
sumption of specific diversity may be fairly
entertained if these should exhibit well-marked
differences, yet there are too many exceptions
to allow such differences to be unhesitatingly
admitted as valid specific characters. They
may arise, in fact, from three sets of causes ;
namely, differences in age and degree of de-
velopment, differences in the conditions under
which the individuals have existed, and tend-
ency to spontaneous variation inherent in
the race. It is necessary, therefore, to ex-
clude each of these possible sources of error,
before the specific diversity of our two objects
can be established.

1. It is now universally admitted that the
cases are extremely numerous, in which diver-
sities of age have led to the establishment of
species which have no existence in nature ;
the forms thus distinguished being those of
the same species in different grades of de-
velopment. The more our knowledge of the
history of the lower tribes of animals in-
creases, the more is it found that metamor-

phosis is with them the rule, and not the ex-
ception ; so that the cases seem comparatively
rare, in which an invertebrated animal at its
emersion from the egg possesses the cha-
racters that serve to distinguish it in its adult
condition. And just as the larva, pupa, and
imago states of any insect, are all compre-
hended in a complete account of the species, so
must we rank the extraordinary diversities of
form presented by the Medusa; or the Balani,
in the early period of their lives, as coming
within the limits of their specific definitions.
It is obvious that this source of fallacy can
only be completely avoided, when we have
obtained an acquaintance with the whole his-
tory of the life of any individual, from its com-
mencement to its dissolution, and are thus
enabled to say positively what are, and what
are not, alterations producible by age. Where
this knowledge cannot be acquired, the only
safe basis on which the naturalist can pro-
ceed, is that which is derived from a know-
ledge of these phenomena as presented in
the most nearly allied forms ; and yet this
often fails, as in the case of the Astacus fiuvia-
tilis (river cray-fish), and Gccarcinus (land
crab), which undergo no change that can be
called a metamorphosis, notwithstanding that
in all other Macrourous and Brachyourous
Decapods yet observed, a real metamorphosis
takes place. Even in the case of extinct
species, the history of whose life can never
become known to us by any other means
than by the preservation of their remains in
different stages of growth, the careful com-
parison of a sufficient series of these remains
will sometimes establish a strong probability,
if not a positive certainty, as to their mutual
relationship : thus, M. Barrande, of Prague,
has succeeded in showing that it is next to
certain that no fewer than eighteen forms of
Trilobites, which have been described as dis-
tinct species and ranked under ten different
genera, are really the successive forms of one
and the same species ; the differences which
they present both in size and conformation
being analogous to those that we see in the
existing tribes most nearly allied to them,
and the whole series constituting one con-
tinuous succession. Instances in which new
species have been erected among the higher
classes of animals, especially among Birds, for
the reception of individuals whose differences
were only seasonal, have been so frequently
recorded, that it is sufficient here to mention
them. It is obvious that such errors can
only be corrected by a knowledge of the
seasonal changes which the species is liable
to undergo. Of this source of difficulty in
the discrimination of species, we need take no
account in our future inquiries; for although,
in the Orang and Chimpanzee, the alteration
in the conformation of the cranium which
takes place at the period of second dentition,
is so very decided, that it formerly gave rise
to much confusion, which has only disap-
peared before a fuller knowledge of the
history of these animals, yet no change of
such magnitude occurs in Man ; and of the

VARIETIES OF MANKIND.

1303

degree of change which does take place in
the several races of mankind, between infancy
and old age, there is seldom much difficulty
in collecting information.

2. The influence of external conditions in
modifying the conformation both of Plants
and Animals, is a question of fundamental
importance in the determination of the value
of specific characters. In this respect there
is a very extraordinary diversity among the
several races of living beings, even among
those which are most nearly allied to each
other ; for whilst some possess such a capacity
for variation, that they are easily influenced
by changes in external conditions, and can, in
consequence, readily adapt themselves to
these, to others this capacity seems altogether
denied. It is from this circumstance that we
find particular species, of plants, as well as of
animals, restricted to particular conditions in
regard to climate, food, &c., their constitu-
tions not being able to adapt themselves to
any considerable change ; whilst others are
more widely dispersed, simply because their
constitutions can accommodate themselves to
alterations in these conditions. Hence a
change of food or climate, to which the latter
soon become habituated, is fatal to the former.
We see this difference well marked in the
Feline tribe ; for whilst the greater part of the
larger species, such as the lion and tiger, are
inhabitants of tropical regions, and cannot
endure the winter’s cold, even in the temperate
zone, the domestic cat follows man in almost
all his wanderings, and can sustain extremes
of heat and cold as well as he can himself.
This accommodation is effected by a change
in the organism itself, of which evident
indications are frequently presented, even
within the course of a short time : thus, sheep
transported from this country to the West
Indies soon loose their covering of thick
wool, and acquire in the place of it a short,
fine hah-, shining and smooth, like that of the
goat in his best state, so that after a few
years the sheep can scarcely be distinguished
from the goats, save by their general con-
formation ; and in this, too, from the usual
absence of any considerable accumulation of
fat in the bodies of the sheep, there is not
nearly so much difference between the two
races, as there is in temperate climates.

The continued action of the same cir-
cumstances for a few generations, gives in-
creased permanence to the new characters of
the breed, so that acquired peculiarities of
conformation become congenital. Thus, Sir
C. Lyell mentions* that some Englishmen
engaged in conducting the mining operations
of the Real del Monte Company in Mexico,
carried out with them some greyhounds of the
best, breed, to hunt the hares which abound
in that country. The great platform, which
is the scene of sport, is at an elevation of
about 9000 feet above the level of the sea,
and the mercury in the barometer stands
habitually at the height of about 19 inches.

* Principles of Geology, seventh edit. p. 568.

It was found that the greyhounds could not
support the fatigues of a long chase in this
attenuated atmosphere, and before they could
come up with their prey, they lay down
gasping for breath ; but these same animals
have produced whelps, which have grown up,
and are not in the least degree incommoded by
the want of density in the air, but run down
the hares with as much ease as the fleetest
of their race in this countrj'. In fact, it can-
not be reasonably questioned, if the history of
the domesticated races of animals be fairly
considered, that changes in external condi-
tions are capable of exerting a very decided
influence upon the physical form, the habits
and instincts, and the various functions of
life, in species possessing this adaptiveness.
The variations thus induced extend to con-
siderable modifications in the external aspect,
such as the colour, the texture, and the
thickness of the external covering; to the
structure of limbs and proportional size of
parts ; to the relative development of the
organs of the senses and of the psychical
powers, involving changes in the form of the
cranium, and to acquired propensities, which,
within certain limits (depending, it would
appear, on their connexion with the natural
habits of the species) may become hereditary.
Of the changes in psychical characters thus
induced by external circumstances, the fol-
lowing are trustworthy examples. We are
informed by M. Roulin (to whose researches
on the changes which the domesticated races,
introduced by the Spaniards into South Ame-
rica, have subsequently undergone, we shall
frequently have occasion to refer), that a race
of dogs employed for hunting deer in the
platform of Santa Fe, in Mexico, is distin-
guished by the peculiar mode in which they
attack their game. This consists in seizing
the animal by the belly, and overturning it by
a sudden effort, taking advantage of the
moment when the body of the deer rests only
upon the fore-legs; the weight of the animal
thus thrown over, being often six times that
of its antagonist. Now, the dog of pure
breed inherits a disposition to this kind of
chase, and never attacks a deer from before
while running ; and even should the deer, not
perceiving him, come directly upon him, the
dog steps aside, and makes his assault upon
the flank. On the other hand, European
dogs, though of superior strength and general
sagacity, are destitute of this instinct; and for
want of similar precautions, they are often
killed by the deer on the spot, the cervical
vertebrae being dislocated by the violence of
the shock.* A new instinct has also become
hereditary in a mongrel race of dogs, employed
by the inhabitants of the banks of the Magda-
lena almost exclusively in hunting the white-
lipped peccari. The address of these dogs
consists in restraining then- ardour and attach-
ing themselves to no individual in particular,
but keeping the whole in check. Now, among
these dogs, some are found, which, the very

* Annales des Sciences Naturelles, 1829, tom,
xvi. p. 16.

4 0 4

1304.

VARIETIES OF MANKIND.

first time they are taken to the woods, are
acquainted with this mode of attack ; whereas
a dog of another breed starts forward at once,
is surrounded by the peccari, and, whatever
may be his strength, is destroyed in a moment.
The fixed and deliberate stand of the pointer,
again, whether taught by the agency of man,
or a habit engendered, like the preceding, by
the force of circumstances, is so intimately con-
nected with the constitution of the race, that
occasionally it becomes hereditary ; a young
pointer, taken into the field for the first time,
being often observed to perform its duty
as well as its long-trained seniors. A still
more remarkable example of the transmission
of acquired psychical peculiarities, is afforded
by the case of the retriever, a breed of dogs
which has been trained to keep close to the
sportsman until he has fired, and then to go
in search of the game which he has wounded
or brought down. It is obvious that this
habit could only have been taught by the
agency of man ; and yet it has been frequently
observed that a young retriever, on the very
first occasion of being taken into the field,
has conducted itself as well, and brought back
game with as much steadiness, as older dogs
which had been schooled into the same ma-
noeuvre by means of the whip and collar.*

No really philosophical botanist or zoolo-
gist, then, should venture to establish specific
distinctions between two races, otherwise
than provisionally , until he has been able to
assure himself that the one may not be con-
verted into the other by a change in external
conditions. Characters which are of the
most trivial kind in themselves, may be valid
grounds of specific distinction, if they are not
liable to be thus affected ; on the other hand,
characters which would be accepted in one
group as sufficient for the separation of ge-
nera, may be found totally inadequate in an-
other for the discrimination of species, being
liable to modification under a very slight
change of external conditions. Every one is
familiar with the changes which have been in-
duced in plants by cultivation, — how a “ sin-
gle ” flower is converted into a “ double ”
one ; how the spines, prickles, and thorns
covering the surface may be obliterated (a
change which was fancifully, but not impro-
perly, termed by Linnaeus “ the taming of wild
fruits ”) ; and how the wavy leaves may be-
come thick and fleshy (as in the change of the
Brassica o/eracea into the cabbage), or the
slender flower-stalks may be converted into a
substantial mass (as in the conversion of the
same plant into the cauliflower). These
changes do not, as some have alleged, throw
the least doubt on the “ permanence of spe-
cies,” or favour the doctrine of “ transmuta-
tion ” in the slightest degree ; for however
wide may be limits of variation, each species
has its limits ; and so far from having per-
manently advanced, under the influence of

* See Mr. P. A. Knight’s Paper on the Heredi-
tary and Acquired Instincts of Animals, in the Phi-
losophical Transactions for 1837.

cultivation, to a superior type of structure, the
plants thus modified will all return to their
original form, when subjected to their original
conditions. Numerous instances might be
cited from the British Flora alone, in which
the most experienced botanists are in dis-
agreement upon the question of specific unity
or diversity, simply because they have not yet
ascertained the limits to the variations which
the same plant may present, when growing
under a variety of external conditions ; and
the difficulty is yet greater when British and
Continental species are compared, the variety
of external conditions being greater, and the
amount of allowance which should be made
for their influence being known in but a few
cases. The same may be said of Animals ;
particularly of those on which the influence
of domestication has been brought to bear.
Upon this point, however, we shall defer en-
larging, until the next head of the inquiry has
been considered.

3. A tendency to variation exists in many
races, which manifests itself rather in modi-
fications of the specific type presented in the
course of successive generations, than in the
alterations induced by external agencies in
the individuals of one generation. Thus we
find that the offspring of any one pair do not
all precisely agree among themselves, or with
their parents, in bodily conformation or in
psychical character ; but that individual differ-
ences (as they are termed) exist among them.
Now, as this tendency to variation cannot be
clearly traced to any influence of external cir-
cumstances, it is commonly distinguished by
the term ‘ spontaneous ; ’ but there is much
to favour the belief, that such variations are
attributable to agencies operating either on
both parents, previous to their intercourse,
or at the time of coition, or to influences
acting on the female during the period of
utero-gestation.* For it may be uniformly
observed, that those animals exhibit the
greatest tendency to this ‘ spontaneous ’ va-
riation, which present the greatest constitu-
tional adaptiveness to a variety of external
conditions. And there are many cases in
which it seems pretty clear, that the cause of
this variation must be looked for in that com-
bination of influences, which is known under
the general term domestication. Thus it may
be stated as a general fact, that the varieties
of colour so remarkable in domesticated races,
tend to disappear when these races return in
any considerable degree towards their primi-
tive wild state. This has been especially
noticed in the horses, cattle, sheep, hogs, and
dogs, introduced by the Spaniards into South
America ; and the observation has been con-
firmed in other parts of the globe, showing
that there is nothing peculiar to the climate
of that country, which brings about the altera-

* As these modifications are witnessed in domes-
ticated birds no less than in mammals, it is obvious
that the latter source of influence is excluded in
their case ; and we must fall back upon the pro-
bability of a change in the constitution of the pa-
rents, previously to the generative act.

VARIETIES OF MANKIND.

1305

tion. Now this has been attributed to the
free intermixture of differently-coloured pa-
rents, which tends to confuse the breeds, and
to merge those varieties which are artificially
kept up among domesticated races by the
matching of similar parents. But although
this cause doubtless operates, yet it is far
from being the whole truth ; for the converse
occurrence may take place in animals which
are in process of being reclaimed from their
wild state, under circumstances that forbid
the idea of any such intermixture. Thus,
Mr. Bell informs 11s that an Australian bitch,
or dingo, had a litter of puppies, the father of
which was also of that breed ; both parents
had been taken in the wild state ; both were
of the uniform reddish-brown colour which
belongs to the race ; and the mother had never
bred before ; but the young, bred in confine-
ment, and in a half-domesticated state, were
all more or less spotted.* Now, considering
the strong evidence which exists, that the
colour of the offspring, in animals in which
the hue is disposed to vary, may be affected
by a mental impression at the time of im-
pregnation jq it does not seem improbable that
various differences in the general condition of
a wild and of a domesticated animal, should
so affect the constitution of the latter, as to
occasion an amount of variation in its off-
spring which does not exist in the former. —
The same general rule holds good in Plants.
The tendency to the (so called) spontaneous
production of varieties, is the greatest in those
species which are most susceptible of influence
by cultivation; and those which are themselves
least changed by external conditions, are those
which are observed to transmit their distinc-
tive characters most constantly and uninter-
ruptedly from one generation to another. Fur-
ther, the influence of cultivation will sometimes
develop in the individual the very same de-
partures from the usual specific type, which
are, in other cases, ‘spontaneously ’ manifested
in the offspring of a common parent. Thus,
it is well known that, by cultivation, the prim-
rose may be converted into the polyanthus,
and the cowslip into the oxslip; but the late
Dean of Manchester raised all these four
forms from the seeds of the same plant ; and
Professor Henslow has been equally suc-
cessful.

Until the limits of this tendency to spon-
taneous variation have been determined, there-
fore, in each particular instance, no valid
specific distinctions can be erected. It hap-
pens, in certain groups, that a peculiarity, in
itself very trivial, is transmitted uninterrupt-
edly from one generation to another, with
such constancy and regularity as to justify us
in believing that it has been always manifested.
Thus many of the reputed specific differences
of Moths and Butterflies- rest on no other
foundation, than the constant presence of a
certain spot on some part of their wings ; and

* British Quadrupeds, 2d edit. p. 203.

f See a valuable collection of such cases by Dr.
Harvey, in the Edinburgh Monthly Journal for
November, 1850.

there are Felines, which agree so closely in the
structure of their skeletons as not to be dis-
tinguishable osteologically, and which are only
regarded as belonging to distinct species, be-
cause a certain stripe or spot, which uniformly
shows itself on the skin of one, is as uniformly
absent from that of the other. On the other
hand, we see, in all our domesticated races,
great diversities among the offspring of a
common parentage ; and these differences are
sometimes so marked, that if he had not
positive evidence of this common parentage,
the naturalist would undoubtedly be justified,
by the importance of the diversity, in the es-
tablishment of numerous specific types, when
he has really seen but a few of the varieties
into which one and the same may pass.

Of this tendency to “ spontaneous ” varia-
tion, it may be remarked, further, that like the
variation which may be traced to external
conditions, it has its limits, and does not
really tend to confuse the boundaries of
species, although it may frequently show the
necessity for their extension. Thus, notwith-
standing the multitude of varieties of the
Apple and the Pear which we possess, and
notwithstanding the apparent triviality of the
specific distinction between them (this being
little else than the existence of a gritty centre
in the pear, which is absent in the apple), yet
we never find this distinction confounded by
the presence of the distinctive characters of
the pear in the descendant of an apple, or by
the absence of it in the descendant of a pear.
So we find that, notwithstanding the multi-
plication of breeds of dogs and horses, sheep
and oxen, pigs and poultry, they all retain the
characters by which their respective kinds are
distinguished from their congeners. There
is no tendency to an obliteration of the dis-
tinctions between a dog and a fox, or between
a horse and an ass ; but these distinctions are
perpetuated with the same regularity, that
marks the stripes of the leopard or the spots
on the wing of a moth. But, on the other
hand, by observation of the spontaneous
changes which particular tribes of plants or
animals are liable to exhibit, we are some-
times led to extend our ideas of the compre-
hensiveness of species, and to bring into the
same category forms which were previously
supposed to be distinct types. Thus, for
example, it is the opinion of many distin-
guished naturalists, that not only are all the
breeds of Dogs to be considered as consti-
tuting one species, but that this species must
also include the Wolf ; or, in other words,
that the wolf and the dog are to be con-
sidered as collateral descendants from the
same original parents. We shall presently
examine more in detail the evidence on which
this belief is founded ; supposing it to be
correct, we are only required to enlarge our
idea of the comprehensiveness of the species
Cants lupus, which must then include all the
breeds of C. familiaris as its varieties : and
none of them are in any more danger than
before, of being confounded with the fox or
the jackal. Until, however, the limits of

1306

VARIETIES OF MANKIND.

variation have been clearly determined in the
case of any species which is known to exhibit
the tendency, it is obviously impossible to
erect specific distinctions that shall possess
anything but a provisional value ; and thus
the naturalist may feel a confident assurance
of the genuineness of one set of species in a
natural group, whilst he is utterly at a loss
respecting another.

Reverting, then, to the “ idea” of a species,
as involving descent from a common, or at any
rate from a similar parentage, in all the in-
dividuals composing it, we have to aim at
ascertaining, in the case of two or more beings
whose specific identity or distinctness is a
question for our determination, whether their
characters are presented so fixedly and deter-
minately in all the individuals of the sameand
of successive generations, as to justify us in
believing that they have been thus preserved
through all time, and under all changes of
external conditions. According to the amount
and correctness of our information upon this
question, will be the validity of our specific
distinctions ; on the other hand, according to
the hastiness and crudity of our decision, will
be its liability to be overthrown by subsequent
researches. Of course, where the progeny of
any known stock can be traced through a
long period of time, and under great varieties
of external conditions, and their successive
variations have been noted, this evidence must
outweigh every argument founded upon the
supposed importance of the characters which
are found to undergo modification. But such
opportunities are too frequently wanting ; and
the naturalist is obliged to have recourse to
means of discrimination which are less certain,
but which will frequently conduct him, pro-
vided that his researches have been sufficiently
extensive, to a satisfactory conclusion. The
great point at which he should aim, is the
assemblage of as many forms as possible of
each type ; and having done so, he will care-
fully compare them with each other, for the
sake of determining whether the supposed
specific characters are constant and well-
marked throughout, or whether they tend to
run together by intermediate gradations. If
the first of these should prove to be the case,
great confidence may be entertained of their
genuineness; but if the second, we may feel
an almost certain assurance of their invalidity.
Thus, to revert to the case of the apple and
the pear, the persistence of their distinctive
characters through all the numerous varieties
of each, renders it almost certain, that in all
other varieties which may hereafter present
themselves, the same constancy will obtain;
and that it has obtained during the entire suc-
cession of generations of pears and apples,
from the time of their first propagation. But
let us take an opposite case. Two Terebratulce
are brought together from different parts of
the great Southern Ocean, the one of which
has the edges of the valves of the shell thrown
into deep plications, whilst in the other they
are quite smooth. Now in most other Bivalve

Mollusca, such a difference would be justly
admitted to afford a valid specific character ,
and the conchologist who had only these
two shells before him, would be justified,
by the usual rules of the science, in ranking
each as a distinct specific type. But as his col-
lection extends, intermediate forms come into
his possession ; and at last he finds that he
can make a continuous series, passing, by the
most gradual transition, from the smoothest to
the most deeply plicated form. Thus, then,
the supposed validity of this distinction is
altogether destroyed ; and it becomes evident
that the most plicated and the smoothest of
these Terebratulce must be regarded as be-
longing to one and the same species, notwith-
standing the marked diversity of their extreme
forms.

Hence, whilst new types are continually
being discovered, the progress of research
is tending to diminish the number of species
previously enumerated ; for there are many
groups in which an immense reduction has
been effected, by bringing together all those
which are found to be nothing else than suc-
cessive stages of the same individual, and by
ranking under one designation all those which
are either known or strongly suspected to be
mere varieties, resulting from the direct influ-
ence of external conditions upon themselves
or upon their ancestors, or produced through
the obscurer operation of these influences on
the act of generation. Frequently it is found
that forms which have even been accounted
genericalty distinct, are in reality specifically
identical. Thus it has been shown by Pro-
fessor Henslow, that the “rust of corn”
(Uredo rubigo ) is but an earlier form of the
“ mildew ” ( Puccinia graminis ) ; the one form
being capable of development into the other ;
and the fructification characteristic of the two
supposed genera having been produced from
the same individual. And it is asserted by
Fries, that out of a single species otTke/ephora,
more than eight genera of Fungi have been con-
structed by various authors. So among higher
plants, the invalidity of the generic distinctions
on which reliance is usually placed, has been
shown, so far as the Urchideous tribe is con-
cerned, by the fact that the same individual
has borne the flowers and pseudo-bulbs usually
accounted characteristic of three distinct
genera, and that another individual has pre-
sented the character of a fourth.* So in the
animal kingdom, it has been shown by Pro-
fessor Milne Edwards, that the polypidom of
Tubidipora verrucosa, according to the circum-
stances under which it grows, may present the
characters of three other reputed genera. If it
be attached to a plane surface, as the expanded
lamina of a sea-weed, it remains circular, and

* For the first of these cases, see the Linnsean
Transactions, vol. xvii. The second fell under the
writer’s own observation in the Durham Down
Nursery, near Bristol; here, also, three different
forms, generally considered as generically distinct
were presented ; and two of them were the same as
in the preceding case : but the third was one not
exhibited by that plant.

VARIETIES OF MANKIND.

1307

increases with great regularity, constituting
the Madrepora verrucosa of Fabricius. If it
cluster round the cylindrical and branching
stem of a Fucus, it increases irregularly, and
assumes the form of the Millepora tubulosa of
Ellis. If its development in any direction be
checked by a mechanical obstacle, the form of
the mass will again be changed, and its tubes
will he recurved backwards; a character on
which Lamouroux founded his genus Obella.
Sometimes on the very same polypidom, we
find one portion whose disposition corre-
sponds with that of Millepora tubulosa, and
another which, if detached, would be con-
sidered a specimen of Obelia tubulifera .*
Many similar cases might be quoted ; all of
them showing, not that there is any real con-
fusion amongst species and genera, but that
naturalists have too often assumed variable
and non-essential characters as the basis of
their systematic distinctions, in ignorance of
those which are fixed and determinate. Thus,
in the case in question, it is on the structure
of the animal, not on the form of the poly-
pidom, that the modern Zoophytologist places
his chief reliance ; and a knowledge of this
would have prevented the assignment of the
varieties of coral, formed by one and the same
kind of animal, to three different genera. So
among Mollusca, it has been shown by Mr.
Gray f that a large number of species have been
formed, in consequence of the variations pre-
sented by the shells of the same species at
different periods of life, or developed under
different circumstances. The change from
salt or fresh water to brackish, or from
brackish to salt or fresh, which many species
are able to sustain, appears to have a con-
siderable influence on the form of their shells ;
thus Professor E. Forbes has shown that
certain Paludines and Naticce, which are found
in successive tertiary strata in the island of
Cos, associated in some cases with decidedly
fresh-water, and in others with decidedly
marine, testacea, are probably to be regarded
as varieties of the same species, notwith-
standing that they would be regarded by
conchologists as distinct ; gradations being
traceable between one form and another,
and the changes being of a kind which are
known to take place among fresh-water mol-
lusca. t

As an example of the mode in which the
philosophic zoologist proceeds in his exami-
nation of a doubtful case of unity or diversity
of species, in a group more closely related to
man, we shall consider the question of the
relations of the several races of Dogs to each
other. Every one is familiar with the fact
that numerous breeds of dogs exist in
almost every part of the world inhabited by
civilised man, distinguished from each other
by well-marked peculiarities, which appear
to be transmitted continuously from parent

* Memoire sur les Tubulipores, in Ann. ties Sci.
Nat., 2eme serie, Zool. tom. viii.

t On the Structure of the Shells of Mollusca,
Philosophical Transactions, 1833.

t Travels in Lycia, vol. ii. p. 199.

to offspring, and thus to possess a claim
to rank as specific distinctions. These dif-
ferences extend to stature, form, proportions,
swiftness of foot, colour and texture of hair,
acuteness of sensations, intelligence, and at-
tachment to man ; and they are particularly
well marked in the conformation of the cra-
nium, the part to which the anatomist first
looks for his distinctive characters.

. The changes in the conformation of the
cranial portion of the skull, which distinguish
the domesticated races of the dog from those
which have been less modified by the , in-
fluence of man, partly consist in the obli-
teration of the sagittal crest, which rises
up on the line of junction of the parietal
bones, and of its continuation on the occipital
bone. In the large deer-hound, we are
assured by Prof. Owen, these cristae are as
strongly developed as in the wolf ; whilst in
the smaller spaniel or pug, they are entirely
wanting, the cranial dome being smooth and
round. But “ such modifications,” as Prof.
Owen remarks, “ are unaccompanied by any
change in the connections, that is in the dis-
position of the sutures, of the cranial bones ;
they are chiefly due to arrests of develop-
ment, — to retention of more or less of the
character of immaturity ; even the large pro-
portional size of the brain in the smaller va-
rieties of house-dog, is in a great degree due
to the rapid acquisition by the cerebral organ
of its specific size, agreeably with the general
law of its development, but which is attended
in the varieties cited by an arrest of the gene-
ral growth of its body, as well as of the par-
ticular developments of the skull in relation
to the muscles of the jaws.” Such an altera-
tion is considered by this eminent anatomist
as fairly referable to the influence of domes-
tication ; since, as he remarks, “ no other
domestic animal manifests so great a range of
variety in regard to general size, to the colour
and character of the hair, and to the form of
the head, as it is affected by different propor-
tions of cranium and face, and by the inter-
muscular crests superadded to the cranial
parietes.” “ Yet under the extremest mask of
variety so superinduced,” he continues, “ the
naturalist detects in the dental formula, and
in the construction of the cranium, the un-
mistakable generic and specific characters of
the Cams familiaris.” * Generally speaking,
the cranial cavitjf of the domesticated dogs is
relatively increased in capacity ; the facial por-
tion, on the other hand, is oftener shortened.
The skull of the Australian dingo differs but
little from that of a wolf. In both, the arch
formed by the temporal and parietal bones is
much depressed, so that the cranial cavity is
small, and the head flat. The Danish dog
and the mastiff resemble the dingo in the
shape of their heads, and display as little of
intellect or sagacity. The terrier and the
hound have the parietal bones more arched,
and, consequently, possess a larger cranial
cavity. The greyhound has a longer muzzle,
and smaller frontal sinuses than the hound ;

* Zoological Transactions, voL ill. p. 415.

1308

VARIETIES OF MANKIND.

and the nasal cavity, though elongated, is
much contracted, especially at its upper part,
so that the sense of smell is less acute in
this breed than in most others. The shep-
herd’s dog, which Buffon very erroneously
considered as the breed least modified by
domestication, is distinguished by its remark-
ably capacious cranium ; the temporal bones
not beginning to arch over the cavity, until
they have risen perpendicularly to half their
height. In the spaniel and Newfoundland
dog, the capacity of the cranium is yet greater
than in the preceding ; and they are also dis-
tinguished by the remarkable size of their
frontal sinuses, which causes the forehead to
rise almost perpendicularly from the nasal
bones. The bull-dog, on the other hand, is
distinguished by the shortness and extraordi-
nary breadth of its muzzle ; while its cranium
is less capacious than that of the shepherd’s
dog. The varieties in general conformation
are not less remarkable than those in cranial
configuration. Thus, the relative length of
the tail is subject to great variation, even the
number of its vertebrae differing so widely as
from 16 to 21. Some races have an addi-
tional claw on the hind foot; and many have
an additional false molar on one or both sides.
The nature of the hairy covering, too, varies
in regard to its closeness or scantiness, its
length, its colour, the fineness or coarseness
of its texture, &e. &c. ; so that, as M. Fred.
Cuvier remarks, the dog-kind presents all the
varieties, in respect to the nature of the hairy
covering of the body, that are to be found in
the entire class of Mammalia. The form of
the ears, too, is another marked feature of
distinction ; these organs being short and
erect in some, long and pendulous in others.
The differences in habit and psychical cha-
racter, also, are almost as characteristic as
those of form. The greater number of dogs
track their prey by scent ; and this quality
may be developed by care in breeding*, so
that it attains its greatest excellence in the
highest-bred fox-hounds, blood-hounds, and
pointers. But the greyhound hunts almost
solely by sight ; and, in breeding it, every
care is taken to obtain swiftness and “ wind,”
and power of enduring sudden and violent
bursts of exertion. In the degree and nature
of their attachment to man, again, which is
the most marked psychical feature common to
them all, we observe a very striking diversity.
Perhaps the bull-dog is, of all the domestic-
ated races, that which is least prone to seek the
society of man ; yet, notwithstanding its obsti-
nacy and ferocity, it does form attachments to
human beings, and especially to those 'whose
savage nature is most akin to its own. On. the
other hand, the pug, which seems like a dwarf-
variety of the bull-dog, is remarkably timid ;
and, though possessing but little sagacity, is
tolerably good tempered. The mastiff, again,

* The principal mode in which the influence of man
is exerted in modifying the characters of the races
under his control, consists in the selection of those
individuals only for propagation, which display the
desired attributes in the greatest perfection.

possesses the determined courage of the bull-
dog, but is greatly influenced by kindness,
and shows a generous and intelligent nature.
The setter, with a considerable degree of
sagacity and intelligence, is remarkable for its
affectionate and grateful nature, for its docility,
and for its humble and anxious solicitude to
please. Of all the races of dogs, the spaniel
is the one most distinguished for attachment
to man ; the most timid, fond, and affec-
tionate; the most patient under ill treatment:
it is, however, by' no means distinguished for
courage ; and though very docile, is not re-
markable for native sagacity. It is perhaps
in the shepherd’s dog that the attribute of
intelligence is most strikingly displayed, in
combination with courage, fidelity, and per-
severance : he lives in habits of constant
familiarity with his master, learns to interpret
his looks and words with an intuitive com-
prehension, and allows no difficulty or danger
to prevent him from carrying his directions
into effect. The Newfoundland dog, perhaps,
combines more than any other breed the
qualities which render the race most generally
serviceable to man ; although this combination
is not such as fits him for any of those special
uses, to which other breeds are particularly
adapted.

Now these differences are far greater than
those which exist among the acknowledged
species of the feline race * ; and therefore, at
first sight, might be considered as amply jus-
tifying the erection of specific distinctions
among the several breeds of the canine. But
the endeavour to do so would be attended
with insuperable difficulties ; for, in the first
place, it has been shown by M. Fred. Cuvierf,
who has paid particular attention to this
question, that if we assume the varieties to
be permanent races, or originally distinct
species, and predetermine that these races are
susceptible of few or no modifications, it will
be requisite to institute at least fifty different
species of dogs, all distinguished from each
other by recognisable characters, — a hypo-
thesis which cannot for a moment be enter-
tained. Moreover, every one who has much
intercourse with the canine races becomes im-
pressed with the feeling, that, notwithstanding
the diversities of the greyhound and the bull-
dog, the blood-hound and the spaniel, the
Newfoundland and the terrier, they are all
dogs; and there is obviously an instinctive
recognition of this fact among the animals
themselves, as is seen by the readiness in
which the individuals of the most dissimilar
breeds will fraternise together. Further, as
already remarked, there is a marked ab-
sence of tendency to variation in the cha-
racters of the feline races, the limits of each

8 The writer has been assured by Mr. S. Stutch-
bury, who was formerly sub-curator of the museum
of the Royal College of Surgeons, that eveu Cuvier
proved himself unable to distinguish the cranium of
a lion from that of a tiger.

f Becherehes sur les Caracteres Ostdologiques,
qui distinguent les principales Races du Cliien do-
mestique. Annales du Museum, tom. xviii.

VARIETIES OF MANKIND.

1309

species being defined by the preservation of
its characters through successive genera-
tions and under all circumstances ; the only
exception to this general statement, being in
the case of the domestic cat, which, like the
dog, passes into numerous varieties, none of
which, however, show an approximation to
the characters of any other species. Hence,
notwithstanding the extent of variation pre-
sented among dogs, the characters of the
breeds do not bear a specific value ; for an
amount of variation may be seen among the
successive generations of the same breed, how-
ever pure it may be kept, or even among the
offspring of the same litter, quite sufficient to
show that a strong capacity for modification
exists in this species. It would not be diffi-
cult, moreover, to bring together a series of
individuals, that should connect the most ex-
treme forms by imperceptible gradations ; all
the different races breed together with the
most complete freedom ; and, as already re-
marked, there is a continual tendency amongst
them, if they escape from the influence of
man, and intermingle unrestrainedly in a state
approaching to then- original wildness, to a
return to one uniform type of configuration
and of hue. Further, whatever their other
differences in psychical character, we find that
they all agree in that tendency to association
with man, which is pretty obviously the chief
source of those diversities ; the most impor-
tant departures from the natural habits of a
wild race, being those which have been im-
pressed upon the several breeds by a long
course of training, whose influence has been
transmitted, to a certain extent, from one
generation to another. We have seen that,
in particular races of dogs existing in a half
wild state, the force of circumstances, without
any human intervention, has developed a new
instinct, which has become hereditary within
a few generations ; and there can be no diffi-
culty in understanding, therefore, that the
psychical as well as the physical characters
of the dog may have undergone a far more
marked alteration, in the prolonged period
during which he has been under the influence
of man. However considerable, then, are the
anatomical and psychological differences of the
most diverse breeds, these are perpetuated
only by the agency of man, and tend to
merge themselves in a common type as soon
as this is withdrawn ; and through all these
changes, the physiological conformity, as
marked especially by the generative function,
is constantly preserved. And thus it may be
unhesitatingly asserted, that there is no such
clear and well-marked natural distinction be-
tween the several breeds of dogs, as can serve
to justify the assignment of a separate parent-
age to any of them.

The question next arises, whether the dog
is a domesticated form of any other species
of the genus Canis, e. g. the wolf, the fox,
or the jackal ; or whether it is descended
from an original wild stock, which has sub-
sequently become extinct. Now the fox
may be at once excluded, as differing in the

vertical elongation of the pupil, the peculiar
bushiness of the tail, and in other charac-
ters. The affinity of the dog to the jackal
is certainly not so close as that which it
bears to the wolf ; and there are many dis-
tinguished naturalists who regard the latter
as its original. In support of this view, the
following considerations may be urged. No
specific character has yet been framed so as to
be equally applicable to all the breeds of dogs,
which does not include the wolf also ; and it
does not seem likely that any valid specific
distinction can be established upon anatomical
grounds only. The various races of wild
dogs, in proportion to their entire emancipa-
tion from the influence of man, exhibit more
and more of the lank and gaunt form, the
lengthened limbs, the long and slender muzzle,
and the great comparative strength, which cha-
racterise the wolf; and in the dingo of Aus-
tralia, which presents these peculiarities in the
most marked degree, and which may be con-
sidered as the most remote from a state of do-
mestication, the tail assumes the slightly bushy
form of that of the wolf. In no point of its
osteology does the wolf differ more from
dogs in general, than they differ from each
other; and the interval, in fact, is much less
between the wolf and the races of dogs just
alluded to, than it is between these and the
races which most strongly exhibit the influ-
ence of domestication. Further, the wolf
and the dog readily breed together, and their
progeny is fertile with either of the parent
races ; but whether the hybrids thus produced
are fertile with each other, and a new race
can be thus established, has not yet been
ascertained. The term of utero-gestation is
the same for the wolf as for the dog, viz,
sixty-three days ; that of the jackal, on the
other hand, is but fifty-nine. It is a remark-
able fact, that the habit of barking is pe-
culiar to dogs which have been accustomed
to intimate association with Man ; and, like
variety of colour, it is soon induced in the
progeny of those to whom it is not natural,
when these are reared in a state of domes-
tication. Thus, the puppies of the Esqui-
maux dogs brought home by our Arctic ex-
plorers, being accustomed to the sound of the
human voice from the earliest period, learn
to bark, whilst their parents remain confined
to their original sounds.

The principal objection to the idea of the
specific identity of the two races, lies in
their difference of psychical character; the
wolf being apparently altogether destitute of
that disposition to attach itself to man, and
of that capacity of modification under his in-
fluence, which is so marked a feature in the
nature of the dog. It has been asserted that
the wolf is so untameably savage, that it
would require ages of domestication to render
it even moderately tractable, if, indeed it
could ever be brought under subjection.
Such an assertion, however, does not seem
borne out by facts. Mr. T. Bell* relates an

* British Quadrupeds, p. 199.

1310

VARIETIES OF MANKIND.

instance of friendly recognition towards him-
self and other persons, shown by a bitch wolf
at the Zoological Gardens ; and cites from
Mr. Fred. Cuvier a very remarkable instance
of affectionate and submissive attachment
shown by a young wolf towards the individual
by whom he had been brought up, in a degree
that scarcely seems inferior to that manifested
b}^ the dog. “ Now, if we find,” he remarks,
“ that the mere education of a young wolf,
taken from its parents in a wild state, could
so far change its natural disposition, and
render it so fond, so intelligent, and so grate-
ful as this, what may we not expect from the
successive transmission of improvement by
the culture and training of a whole race for
ages?” On the other hand, in those races
of dogs which have become emancipated from
human control, the psychical nature of the
wolf developes itself, in precise proportion to
the approach presented to its physical charac-
ters. And even in the most domesticated
breeds, instances of spontaneous reversion to
wild habits are occasionally to be met with.
“ Thus,” says Mr. Blyth, “ I have known this
to occur in a male pointer and a female grey-
hound ; the latter was so fine a specimen of
the breed, that on being entrapped, it was
thought desirable to obtain a litter from her,
which was accordingly effected ; but while
her puppies were very young, she managed to
escape to the woods, and never returned ;
three of her progeny grew to be excellent
hounds, but two others proved quite irreclaim-
able, and escaping from servitude, like their
dam, were finally shot, for their destructive
poaching propensities.”*

Thus it appears that, even if we hesitate in
pronouncing in favour of the specific identity
of the dog and the wolf, there is, at any rate,
no valid ground for the establishment of a
specific distinction between them ; and if it
should prove that the hybrid offspring are fer-
tile amongst themselves, and that a vigorous
mixed race is the result, the probability of
their specific identity would be greatly in-
creased. The required proof, however, could
only be afforded by the actual production from
the wolf stock, of a race having the aptitude
for domestication, and capacity for variation,
exhibited by the dog.

There is another mode of looking at the
question, however, which has been recently
suggested by Professor Agassiz, j This distin-
guished naturalist thinks it impossible to ac-
count for the geographical distribution and va-
rieties of conformation of many existing species
of animals, without having recourse to the idea
that, instead of all the individuals of that spe-
cies having descended from a single parentage,
or pair of ‘ protoplasts,’ they are the offspring
of several distinct pairs of ‘ protoplasts,’ first
introduced in different localities, all possessing
the same essential nature, but having that
nature modified in accordance with the spe-

* Translation of Cuvier’s Regne Animal, p. 90.

t See liis recent work on the Fishes of Lake Su-
perior ; also the Edinb. New Philos. Journ., April,
1850.

cial conditions in which each was destined to
exist. From the definition of species, there-
fore, he would exclude the idea of identity of
descent, and would substitute that of similarity ;
but would still base his distinction of species,
as do other naturalists, on the constant trans-
mission of some well-marked peculiarity com-
mon to all the races, and would thus as-
sociate all those which obviously partake of
a common nature, and are disposed to free
intermixture, notwithstanding the non-iden-
tity of their parentage.* He would probably
accord with other naturalists, therefore, in
regarding the different breeds of dogs as va-
rieties of one species ; but would attribute the
origin of their several peculiarities in part to
the differences in their first parents, which
were not, however, sufficient to constitute
specific distinctions. Although there may be
cases in which such an hypothesis presents
the readiest solution of the difficulty, yet it
can scarcely be accepted as applicable to that
of the dog ; for we do not here find that the
races which most nearly approximate to the
wild state in different parts of the world, do
present any differences that enable us to re-
gard them as the respective ancestors of our
most diverse domesticated breeds. If, for
example, it could be shown that the Esqui-
maux dog peculiarly resembled the mastiff,
that the Indian dhole might be regarded as
the progenitor of the greyhound, that the

* Of the hypothesis of the radiation of species
from several distinct centres, Prof. E. Forbes may
be regarded as the most conspicuous opponent. He
has laboured to show that the peculiarities in the
geographical distribution of existing species are
quite reconcilable with the idea of migration from
single centres, and that, generally speaking, they
necessarily lead to that idea ; whilst, on the other
hand, in those instances in which detached or out-
lying spots occur, remote from the principal area of
distribution, and from each other, he considers that
these represent the original extent of range, which
has been subsequently interrupted by geological
changes that have been fatal to the existence of the
species over the intermediate connecting areas, —
as, by the substitution of water for land, or of land
for water ; by the elevation or depression of the sea-
bottom, in a degree incompatible with the continued
existence of the species if it be marine ; by similar
changes in the land, exerting a like influence on ter-
restrial species ; by alterations thus induced in the
course and connection of rivers and watercourses,
which have broken up the areas of fluviatile and la-
custrine species ; by changes of temperature conse-
quent upon remoter causes ; and many other in-
fluences too numerous here to recount. He affirms
that, in so many cases, these peculiarities may be
thus explained by known geological changes, which
have occurred since the introduction of the species
in question (this being the case peculiarly with
those that existed in the glacial epoch, and then had
an extensive southern range, which is now only in-
dicated by their occurrence in outlying spots, the
principal area of the species being now restricted to
the circum-polar regions, in consequence of the more
elevated temperature of the parts be37ond), that we
have fair ground for extending this view to all, and
for inferring the occurrence of geological changes,
subsequently to the first diffusion of particular
species, from the peculiarities of its existing distri-
bution. As yet, however, his views on this subject
have not been given to the world in any complete
form, save by oral discourses.

VARIETIES OF MANKIND.

1311

Australian dingo was the probable ancestor of
the spaniel, and that the American wild-dog
gives us the type of the pug, the hypothesis
of Professor Agassiz might be admitted to
possess a considerable claim to our reception.
But so far is this from being the case, that, as
already pointed out, the several races of wild
dogs present a remarkable conformity to a
common type ; and neither of them can be
looked to, in preference to the others, as the
probable source of those domesticated breeds
which are most diverse from each other, and
from the supposed common type. Moreover,
there is a strong probability, considering the
very remarkable character of the zoology of
New Holland, that the dingo was not indige-
nous to that country, but that it was intro-
duced there by its human colonizers ; thus,
being a descendant of the Indian dhole , or of
the same stock with it. Hence, even if we
admit the multiplication of ‘ protoplasts’ in the
case of the dog, we are still driven back upon
the influences of domestication as the direct
or indirect source of those variations from the
fundamental type, by which the existing races
are severally characterised.

The historical evidence of modification in
successive generations, which is inadequate
to prove the specific identity of the several
races of Dogs, is much more fully supplied in
the case of some other domesticated animals ;
and suffices to show that although the
tendency to spontaneous variation may seem
to have nearly exhausted itself heretofore in
the production of the most divergent forms,
still there remains enough to originate new
races, distinguished by well-marked pecu-
liarities of conformation, even under our own
eyes. Some of our most valuable information
on this subject, is derived from the changes
which have taken place in the races of do-
mesticated animals introduced into the West
Indies and South America, by the Spaniards,
three centuries and a half since. Many of
these races have multiplied extremely in a
soil and in a climate congenial to their na-
ture; and several of them have run wild in
the vast forests of America, and have lost all
the most obvious appearances of domestica-
tion, whilst they have acquired various pecu-
liarities which distinguish them from their
domesticated progenitors, some of these, per-
haps, being indications of a partial restoration
to the primitive characteristics of their re-
spective races. The greatest part of our
knowledge on this subject is derived from the
researches of M. Roulin (already referred to)
which relate to New Grenada and Venezuela,
and from the well-known and justly esteemed
work of D’Azara on the natural history of
Paraguay.

No zoologist has any doubt whatever, that
the ivild boar is the original of our domesti-
cated sivine ; the change from the one form
and condition to the other being capable of
accomplishment in the course of a few gene-
rations. Yet, as Blumenbach has remarked,
the difference between the two forms of crania
is as great as that between the Negro and the

European skulls. And the same eminent
physiologist has pointed out, that the varie-
ties of swine in various countries, all clearly
referable to one stock, exceed in their extent
of divergence from it, the very widest de-
partures of the human conformation from any
one type. Thus, swine with solid hoofs were
known to the ancients ; and large breeds of
them are found in Hungary and Sweden, as
also in some parts of England. In some
other breeds there are five distinct toes, each
having its own hoof. The European swine,
first carried by the Spaniards to the island of
Cubagua, in 1509, have been the progenitors
of a race now found there, possessing toes of
half a span in length. The hogs which were
first introduced into South America by the
Spaniards at about the same period, rapidly
extended themselves over the northern and
central parts of that continent ; and whilst
wandering at large in the vast forests of the
New World, and feeding on their original diet
of fruits and seeds, they have reverted very
nearly to the type of the European boar.
Their colour, too, has lost the variety ob-
servable in the domestic breeds, the wild
hogs of the American forests being for the
most part uniformly black. The hogs which
cover the mountains of the Paramos, where
they are subject to severe cold and deficient
nourishment, are small and of a stunted figure ;
but their skins are covered with thick fur,
often somewhat crisp, beneath which is found
in some individuals a species of wool. In
some of the warmest regions, the swine are
not uniformly black, but red like the young
peccari ; and elsewhere there are some, whose
blackness gives place under the belly to a
white band, which reaches up to the back.

The question of the original source of the
various breeds of ox, will not be now dis-
cussed ; it is sufficient for our present pur-
pose to notice some of the most remarkable
departures from the European type, which
have shown themselves in the South Ameri-
can descendants of the individuals first intro-
duced there by the Spaniards. In the year
1770, as we learn from D’Azara, a hornless
bull was produced in Paraguay, which has
been the progenitor of a race of hornless
cattle that has since multiplied extensively in
that country. So, again, as we are informed
by M. Roulin, in some of the hot provinces
of South America, a variety of ox has been
produced, which is noted for its extremely
rare and fine fur. This variety tends to per-
petuate itself ; but it is not encouraged, be-
cause the “ pelones” (as they are termed) are
too delicate in constitution to bear the cold
of the Cordilleras, to which the cattle are
driven for the provision of the towns situated
upon them. These pelones obviously con-
stitute a variety adapted for a particular
climate ; oxen of other breeds frequently
perishing when driven into the provinces in-
habited by them, or being with difficulty
acclimatised.* But the same hot provinces

* Hence we see that so much of Prof. Agassiz’
argument for the multiplicity of specific centres, as

1312

VARIETIES OF MANKIND.

occasionally produce another curious variety,
characterised by the entire absence of hair;
these naked-skinned oxen, which are called
“ calongos,” are, like the pelones, unable to
bear a cold climate, and are very delicate and
weak. Another remarkable fact, relative to
the oxen of South America, is recorded by
M. Roulin. In Columbia, the practice of
milking cows was laid aside, owing to the
great extent of the farms and other circum-
stances. In a few generations, the natural
structure of the parts and the natural state
of the function have been restored ; the se-
cretion of milk taking place only so long
as the calf remains with the mother, and
ceasing if it dies or is removed. Hence we
have a valuable confirmation of the belief
previously entertained, that the continued
production of milk by the European breeds
of cows is a modified function in the animal
economy, originating in an artificial habit
kept up through many generations, and depend-
ent upon a modification of structure which
that habit has been the means of inducing.

That the various breeds of sheep at present
domesticated in Europe, have had a common
origin, is not doubted by any zoologist, not-
withstanding the differences in their stature
and proportions, the texture and colour of
their wool, the presence or absence of horns,
&c. The most marked deviation from the
usual type is presented by a breed of Spanish
sheep, distinguished by the length and
straightness of the hair, and by the length and
spiral twist of the horns. Various breeds
are found in Asia and Africa, as to whose
specific unity with each other, and with Eu-
ropean sheep, zoologists are not agreed. We
have a remarkable example of climatic varia-
tion, however, in the fact, that in the races
spread through Persia, Tartary, and China,
the tail seems replaced by a double spherical
mass of fat, which forms a most awkward
excrescence on the rump, and is nearly desti-
tute of hair; whilst these sheep, transferred to
the cold, dry pastures of Siberia, are affirmed
by Ermann to lose this peculiar conformation
in the course of a few generations. The
sheep of Syria and Barbary, on the other
hand, have an accumulation of fat in the tail
itself, which is long, and sometimes attains a
weight of from seventy to one hundred pounds.
It is a curious and very significant fact, that
the sheep of the Cape of Good Hope, which
are descended from the European stocks,
should exhibit the same tendency to the
accumulation of fat about the rump, as is
seen in the human races indigenous to that
region. The sheep which were transported
into South America by the Spaniards, have
not multiplied so extensively as the oxen and
swine ; and from their more limited diffusion,
we find, as might be expected, that they ex-
hibit but a comparatively slight amount of
variation. The remarkable change in the

depends upon the adaptation between the constitu-
tion of the several races and the climates in which
we find them, is deficient in solidity of foundation.

character of the hair, presented by the sheep
in the West Indies has been already referred
to. — Among sheep, as among other do-
mesticated animals, new races are continually
being produced by breeders, not merely by
crossing or intermixing races already con-
stituted and well known, but also by taking
advantage of peculiarities which occasion-
ally present themselves spontaneously, and
using means to perpetuate these. The fol-
lowing is one of the most curious examples
of this kind upon record. In the year 1791,
a ewe on the farm of Seth Wright, in the
state of Massachusetts, gave birth to a male
lamb, which, without any known cause, had a
longer body and shorter legs than the rest of
the breed ; the joints also were peculiarly
formed, and the fore-legs crooked. The con-
formation of this animal rendering it unable
to leap over fences, it was thought desirable to
endeavour to propagate its peculiarities ; and
accordingly when it was fit for procreation,
several ewes were impregnated by it. Out of
the lambs first produced, only two presented
the same peculiarities ; more were obtained
in subsequent years ; and when they became
capable of breeding with each other, the new
race was completely established ; its distinc-
tive characters being uniformly presented when
both parents possessed them, but tending to
disappear when the sheep of the “ ancon” or
“otter” breed (as it is called) were allowed
to breed with those of the ordinary type.*
This fact, as we shall hereafter see, has an
important bearing on the question of the
spontaneous origination of permanent varieties,
in the human or any other species that is
disposed to undergo occasional modifications ;
which modifications, under ordinary circum-
stances, disappear as often as they recur.
Thus it is not uncommon to meet with fami-
lies distinguished by the possession of some
peculiarity of feature, or by some well marked
departure from the ordinary conformation,
such as the possession of six fingers on each
hand and six toes on each foot. If such were
to intermarry exclusively with one another,
there can be no reasonable doubt that the
children would invariably exhibit the same
peculiarity ; and that the six-fingered race,
which now tends, whenever it is originated,
to merge in the prevailing five-fingered type,
would then become permanent. When it is
considered that the influence of a scanty
population, in the early ages of the world,
by isolating different families from each other,
and causing inter-marriages amongst even
very near relatives, would have been precisely
the same with that which is now exercised by
the breeders of animals, we see one reason
why the varieties which then arose should
have had a much greater tendency to per-
petuation, than those which now occasionally
present themselves.

In regard to the horse, it will be sufficient
to observe that no zoologist has ever ex-

* See Col. Hutchinson’s Memoir in the Philo-
sophical Transactions for 1813.

1313

VARIETIES OF MANKIND.

pressed any doubt of the specific unity of all
the domesticated breeds, or of their identity
of origin with the so called “ wild horses ” of
Northern Asia : which are probably descended
from domesticated progenitors. Yet their
diversities in stature, conformation, &c. are
very considerable. Thus the ordinary height
of the Shetland pony is from eight to ten
hands ; and individuals have been occasionally
seen which were no more than seven. On
the other hand, the draught horse commonly
stands from sixteen to seventeen hands ; and
not unfrequently surpasses this height. In
regard to the conformation of the skull, again,
it has been remarked by Blumenbach, that
there is more difference between the elon-
gated head of the Neapolitan horse and the
skull of the Hungarian breed, which last is re-
markable for its shortness and the breadth of
the lower jaw, than there is between the most
dissimilar human crania. The differences in
general constitution, also, as regards the power
of sustained effort on the one hand, or of
intense exertion for a short period on the
other, are no less remarkable. But the
breeds which are furthest removed from each
other in these particulars are connected by
such a gradual series of transitional forms,
that there is no possibility of drawing a
line between them ; and, like the various
races of dogs, sheep, &c., they freely inter-
mingle with each other, and produce offspring
which are as fertile with their own kind, as
with either of the parent stocks. It has
been, in fact, by such intermixture of the
large and powerful races of Northern Asia
with the lighter and more agile horses of
Arabia and Barbary, that many of the Euro-
pean breeds have been obtained. The wild
horses which at present range over the plains
of Tartary differ from the domesticated races
in several particulars ; thus, as we are in-
formed by Pallas, the cranium is relatively
larger and more vaulted, the limbs are
stronger, the back is less arched ; their
hoofs are smaller and more pointed ; their
ears are longer and bent more forward. Tbeir
habits, moreover, are peculiar; for they asso-
ciate together in herds or troops to the
number ot several thousands, spreading abroad
to feed, but congregating together on the
appearance of danger, and seemingly putting
themselves under the direction of a leader ;
on the approach of an enemy they close into
a dense crowd, and, attacking the intruder,
trample him to death ; or, like many other
gregarious animals, the females, the young,
and the weak being placed in the rear, the
stronger individuals array themselves in front,
and fight most vigorously with their heels.
Now these peculiarities of structure and habit
are not only seen in the wild horses of
Northern Asia, but also in those which have
spread themselves over the extensive plains
of South America, since their introduction
into that continent by the Spaniards ; and it
is nearly certain that the former, like the
latter, are the descendants of a domesticated
stock, whose return to something like the

VOL. IV.

original condition of the species, has repro-
duced (at least in some degree) the original
instincts, which had been entirely subdued
for a time by the influence of domestication.
In the horse, as in the dog, we have evidence
that the habits which are developed by human
training may become, to a certain extent,
hereditary'. Thus, it is observed that the
wild horse has no pace but the walk and the
gallop; the trot, to which European horses
are usually trained, is an acquired habit, yet
it obviously “ comes naturally” to the colt of
a domesticated breed ; and, in like manner,
the peculiar pace to which the South Ame-
rican horses are trained (which is a kind of
running amble, the two legs of the same side
being moved forwards together) is used with-
out any instruction by the offspring of those
by whom it has been acquired. Another ex-
ample of the transmission of acquired pro-
pensities in horses is mentioned by Mr. Knight:
the Norwegian ponies have been taught to
obey the voice of their riders rather than the
bridle ; and the English horse-breakers com-
plain that it is impossible to produce the
latter habit in the offspring of this race placed
under their tuition, notwithstanding that they
are exceedingly docile and obedient when
they understand the commands of their master,
as imparted by word of mouth. It is equally
difficult, he adds, to keep them within hedges,
owing, perhaps, to the unrestrained liberty to
which the race may have been accustomed in
Norway.

From the present condition and past his-
tory of the domesticated races of Mammalia,
of which a general survey has thus been taken,
some important inferences may' be drawn,
which it may be advisable to put in the shape
of formal propositions ; since in this manner
we shall be able to define our terms more
strictly, and to use these definitions as the
foundation for our future investigations into
the relationship of the several branches of the
Human family.

1. Races of living beings are, properly',
successions of individuals propagated from
any' given stock ; and the term implies no more
than the fact of the transmission of a distinctive
character by descent.

2. Two races, distinguished by well-marked
peculiarities, may rank either as distinct spe-
cies, or as varieties of the same species ; being
supposed, in the first case, to be descended
from parents which themselves originally ex-
hibited the same peculiarities ; and being
considered, in the second, as the descendants
of an identical, or, at any rate, of a similar,
parentage.

3. The question of unity or diversity of
species, between two races, cannot be decided
by the degree of difference which exists be-
tween them ; for the answer to it entirely
depends upon the constancy with which the
peculiarity (of whatever nature it may be) is
transmitted from parent to offspring, and upon
the amount of variation which is exhibited
even within the acknowledged limits of the

4 p

1314

VARIETIES OF MANKIND.

respective races. And thus a character which
is perfectly valid in one group, may be en-
tirely inapplicable in another.

4. Two races can only be regarded ' as
specifically distinct, when the characters which
separate them are transmitted with complete
uniformity from parent to offspring ; when
there are no intermediate gradations tending
to connect them ; and when no such tendency
to variation has manifested itself in either
race, as shall make it probable, or, at any
rate, possible, that their differences may be
the direct result of external influences, or
may be attributed to an unusual divergence
in the characters of the offspring from those
of the parents.

5. On the other hand, two races may un-
doubtedly be regarded as specifically identical,
when, however great the differences in stature,
conformation, psychical character, &c., pre-
sented by their respective types, these types
are connected with each other by inter-
mediate gradations, so close as to render it
impossible to establish a definite boundary-
line between the collections of individuals
which are assembled around them.

6. Again, two races may be undoubtedly
regarded as specifically identical, when in either
race varieties present themselves, which ex-
hibit the distinctive characters of the other
race ; since we then have evidence, that, al-
though these peculiarities are so generally
transmitted from parent to offspring that each
race possesses a certain degree of permanence,
yet they are not thus uniformly inherited ;
and, consequently, there is nothing to pre-
vent the transformation of the one race into
the other, if the circumstances which have
originated the variation, even in a single case,
should act with sufficient potency on the
whole mass.

7. No character can be safely adopted as
justifying the assumption of the specific di-
versity of two races, which has been found by
experience to undergo considerable modifica-
tion in either race, even though such mo-
dification should not proceed to the extent of
conversion into the character of the other ;
for if a limited amount of change in external
conditions be found capable of effecting a
certain degree of alteration, the probability is
strong that the higher difference may have
had its origin in the more potent operation of
the same class of causes.

8. The very fact of the extensive dispersion
of a race, and of its existence under a great
variety of external conditions, implies a
marked capacity for variation ; since without
such capacity', the race could not continue to
flourish.

9. Among the conditions which most tend
thus to produce varieties, within the limits of
species, are those that are included under the
general term domestication ; and the widest
divergence among these varieties is to be
found in those species, which are brought into
the closest relation to Man.

10. Among the domesticated races of quad-
rupeds, the characters most susceptible of

variation are, — 1. Stature ; — 2. General con-
formation of the body, as dependent upon the
proportionate development of the limbs and
trunk, the proportion of the breadth and
thickness of bones to their length, the relative
development of the soft tissues in different
parts, &c. &c. ; — 3. Conformation of the skull, as
shown especially in the relative development
of the cranial and facial portions, the capacity
of the cranial cavity, and the elongation of the
muzzle ; — 4. Quantity, texture, and colour of
the hairy covering ; — 5. Psychical character,
as shown in the increase of intelligence, in
the acquirement of new methods of action,
and in the disappearance of some of the na-
tural instinctive propensities.

11. In every race of domesticated animals,
new varieties, departing more or less from the
parent stock, in one or more of these charac-
ters, are occasionally produced ; some of
these being directly traceable to the influence
of external conditions, whose action upon a
long succession of generations gradually mo-
difies the character of that part of the race
which is exposed to it; whilst others originate
in the production of offspring, which, from
some cause not understood, present a marked
departure from the parental type. In the
first case, the variety is permanent, that is, it
tends to hereditary transmission so long as
the same conditions exist ; anil thus arise the
peculiar adaptations between the characters
and constitutions of races, which have been
dispersed through regions very dissimilar in
their physical conditions, and the climate,
food, &c., to which they have been respec-
tively habituated. In the second case, the
variety is transitory, the individual peculiarity
tending to disappear in the course of two or
three generations, by becoming merged in the
more general type ; but if it should happen
that the individuals thus distinguished should
breed together, the peculiarity shows a ten-
dency to perpetuation by hereditary trans-
mission ; and thus an entirely new race may
originate, which remains distinct so long as
it is not allowed to breed with others.

12. The several races of any kind of do-
mesticated animals, which, according to the
foregoing criteria, are accounted as belonging
to the same species, breed freely and sponta-
neously with each other, when allowed to do
so ; and the offspring are fertile, not only with
either of the parent races, but with each
other. The mixed races thus originating, it
may be added, frequently surpass either of
their parent stocks, not only in the advanta-
geous combination of different attributes, but
also in general vigour, and in procreative
capacity ; so that the mixture of races which
are specifically identical, tends to the multi-
plication of the species as a whole.

13. On the other hand, although propaga-
tion may take place between individuals of
undoubtedly distinct species, yet there is
little spontaneous tendency to such admix-
ture ; for each animal will select one of its own
species for sexual intercourse, in preference
to one of another species ; and it is, con-

VARIETIES OF MANKIND.

1315

sequently, only when restricted by artificial
interference, that a male and a female of
different species are disposed to copulation
with each other. The hybrid offspring of
this act partake of the characters of both
the parent stocks, but are deficient in genera-
tive power ; so that, although a mule may be
fertile when paired with an individual of either
of the parent races, it is seldom or never
fertile with one of its own kind. Thus the
peculiarities introduced by hybridity are
speedily merged into those of the parent
stocks ; and no new race has ever been known
to originate from this kind of union.*

14. Among all those races which are en-
titled to rank as varieties only, the physiological
conformity is often closer than the structural ;
thus, as Dr. Prichard has pointed out “ the
great laws of the animal economy, all the
principal facts which relate to the natural
and vital functions, the periods and duration
of life, the economy of the sexes, the pheno-
mena of parturition and reproduction, are,
with slight deviations resulting from external
agencies, constant and uniform in each par-
ticular species.”

15. So, again, among the varieties of the

same species, there is, with subordinate dif-
ferences, such as can be traced to external
agencies, and particularly to human influence,
a very close psychical conformity ; the capa-
cities of the several races being fundamentally
the same, although varying in their degree of
relative development.

III. General Survey of the Diversities,

in Physical and Psychical Charac-
ters, PRESENTED BY THE DIFFERENT

Races of Mankind.

If it were possible to bring together under
one view, characteristic examples of every
type of Human conformation which the pro-
gress of Ethnological research has hitherto
made known, it would be found that they
all accord in the peculiarities by which
Man has been shown (Sect. 1.) to be dis-
tinguished from even the highest of the
Quadrumanous order ; and that, notwith-
standing a certain amount of approximation
which is presented to that order in the aspect
of certain human countenances {Jigs. 803, 804,
80.5.), and even in the habits of life of cer-
tain tribes, yet the essential and fundamental

Fig. 803.

Negro of Bournou. ( From a portrait taken

points of difference are never obliterated.
But among these types we should find so
wide a diversity, that we should naturally be
led to question their relationship to each
other and to ourselves ; and should seek to
determine whether these differences are in-
herent and unalterable in each race, so as to

* It is not quite certain whether mule or hybrid
Animals have ever produced fertile offspring when
matched with each other ; but it is quite certain
that if a second generation of hybrids has thus been
engendered, a third has never been, the race having
no capacity for perpetuation. Among Plants, the
limits are wider, a third and even a fourth genera-
tion having been thus sometimes produced ; but
there is obviously a want of fei'tility, and a conse-
quent tendency to extinction, in all hybrid races
whose parents are specifically different.

Fig. 804.

under the direction of Prof. Milne-Edwards.')

forbid the idea of any essential modification,
either in the past or the future, from the in-
fluence of external circumstances ; or whe-
ther there is any probable evidence that they
may have been produced by those external
agencies, which we have seen to possess such
a remarkable power of altering the conforma-
tion, and even the instinctive propensities, of
domesticated animals. Such is the first ques-
tion which we should have to answer ; and
in a practical point of view, as influencing our
conduct towards the races which differ more
or less widely from our own, it is undoubtedly
the most important. But the physiologist
and the zoologist seek to attain a more
positive scientific determination of this rela-
tionship ; and since, if such a determination

4 p 2

1316

VARIETIES OF MANKIND.

can he attained, the practical question is at
once and completely settled, we shall apply

Fig. 805.

j Tasmanian female. ( From the “ Atlas du Voyage
de V Astrolabe.'")

What, then, is the true zoological relation-
ship between these different races, so dissi-
milar in colour, features, bodily conformation,
stature, habits of life, and moral and intel-
lectual cultivation ? Have we any ground to
consider them as distinct species ? or are we
to regard them as varieties of one and the same
species? Are the fair Circassian and the jet-
black African, the olive Malay and the red
American, the dusky New Zealander and the
florid Saxon, all of one original stock ? Did
the Patagonians, whose average height is
nearly six feet, spring from the same parents
with the pigmy Bosjesmans, whose usual
height is under five, that of the females rarely
much exceeding four ? Are the fat, blubber-
fed, flat-visaged Esquimaux even most distantly
related to the lean, date-eating, hatchet-faced
Arab ? “ Does the Bosjesman, who lives in

holes and caves, and devours ants’ eggs,
locusts, and snakes, belong to the same species
as the men who luxuriated in the hanging
gardens of Babylon, or walked the olive-grove
of Academe, or sat enthroned in the imperial
homes of the Caesars, or reposed in the mar-
ble palaces of the Adriatic, or held sumptuous
festivals in the gay salons of Versailles ? Can
the grovelling Wawa, prostrate before his
fetish, claim a community of origin with those
whose religious sentiments inspired them to
pile the prodigious temples of Thebes and
Memphis, to carve the friezes of the Parthe-
non, or to raise the heaven-pointing arches
of Cologne ? That ignorant Ibo, muttering
his all-but inarticulate prayer, is he of the
same ultimate ancestry as those who sang
deathless strains in honour of Olympian Jove,
or of Pallas Athene ; or of those wrho, in a
purer worship, are chanting their glorious
hymns or solemn litanies in the churches of
Christendom ? That Alfouro woman, with

ourselves to the search for it, as fully as our
present limits permit.

Fig. 806.

Aramanga youth. ( From a portrait in Dr. Picker-
ing's “ Natural History of Man." )

her flattened face, transverse nostrils, thick
lips, wide mouth, projecting teeth, eyes half
closed by the loose swollen upper eyelids,
ears circular, pendulous, and flapping ; the
hue of her skin of a smoky black, and, by
way of ornament, the septum of her nose
pierced with a round stick some inches long,
— is she of the same original parentage as
those whose transcendent and perilous beauty
brought unnumbered woes on the people of
ancient story, convulsed kingdoms, entranced
poets, and made scholars and sages forget
their wisdom ? Did they all spring from one
common mother ? Were Helen of Greece, and
Cleopatra of Egypt, and Joanna of Arragon,
and Rosamond of England, and Mary of
Scotland, and the Eloisas, and Lauras, and
Ianthes, — were all these, and our poor
Alfouro, daughters of her who was ‘ fairest of
all her daughters, Eve ? ’ The Quaiqua or
Saboo, whose language is described as con-
sisting of certain snapping, hissing, grunting
sounds, all more or less nasal, — is he, too, of
the same descent as those whose eloquent
voices ‘ fulmined over Greece,’ or shook the
forum of Rome, or as that saint and father of
the church surnamed the ‘golden-mouthed,’
or as those whose accents have thrilled all
hearts with indignation, or melted them with
pity and ruth, in the time-honoured halls of
Westminster ?”*

This question is capable of being considered
under a great variety of aspects. There are
many very excellent persons, who think it
quite sufficiently answered by the authority of
the Scriptural narrative, and who maintain that
to this authority all opposing considerations

* From an Introductory Lecture, entitled “Our
Institution and its Studies ; ” by Dr. J. A. Symonds.
Bristol, 1850.

1317

VARIETIES OF MANKIND.

must give way. But, on the other hand, the
conviction is now fast spreading among en-
lightened thinkers, that the Scriptures are no
more intended to teach men Ethnology than
to instructthem in Geology or Astronomy; and
that the former, like the latter, is a legitimate
object of scientific investigation, and should
be pursued without fear as to the results.
Any attempt, in fact, to fetter the scientific
inquirer by the supposed authority of inspira-
tion, is certain to damage the latter in the
estimation of the most intelligent part of man-
kind ; for, as has been well remarked by a
very orthodox theologian, Dr. Henry More,
“ the unskilful insisting of our divines upon
the literal sense of Moses has bred many
hundred thousands of atheists.” But even
those who profess to place the most implicit
confidence in the declarations of the Scriptures,
as to the common origin of all the races of
mankind, do, in effect, get rid of all the force
of these declarations, when it suits their pur-
pose to do so, by the mode of interpreting
them which they adopt. They assert that the
Adamic race does not include the barbarous
inhabitants of remote regions ; and that Ne-
groes, Hottentots, Esquimaux, and Austra-
lians are not, in fact, men in the full sense of
the term, or beings endowed with mental
faculties similar to our own. They contend
that these and other uncivilised tribes are
inferior in their original endowments to the
proper hnman family, which supplied Europe
and Asia with inhabitants ; and that, being
organically different, they are separated by an
“ impassable barrier” from the race which dis-
plays in the highest degree all the attributes
of humanity, and can never be raised to an
equality with it. They maintain that the
ultimate lot of the ruder tribes is a state of
perpetual servitude ; and that if, in some in-
stances, they should continue to repel the
attempts of the civilised nations to subdue
them, they will at length be rooted out and
exterminated from every country on whose
shores Europeans shall have set their feet.

Now if the distinct origin of these tribes be
admitted, — if we are to regard the Negro and
Australian, not as our fellow-men, brethren
of the same great family as ourselves, but as
beings of an inferior order, — and if duties
towards them were not contemplated, as we
may in that case presume them not to have
been, in any of the positive commands on
which the morality of the Christian world is
founded, our relations to those tribes will ap-
pear not to be very different from those which
we might consider ourselves to hold towards
the higher races of brutes. If such races be
not men, then the golden rule, “ Whatsoever
ye would that men should do unto you, do
ye even so unto them,” is not applicable to
our intercourse with them. We can scarcely
imagine a Grotius or a Puffendorf, or any
other great jurist, attempting to determine the
jus belli or pads between ourselves and a tribe
of orangs, who had just sense enough to pass
for men, and began to be suspected of the
cheat, — which is nearly the true character

of the Negroes, if those are right who maintain
the doctrines just alluded to. And we may
go a step further, and assert that there is, in
such a case, no moral principle winch should
prevent a hungry wanderer in Negroland or
Australia from satisfying his appetite, by killing
and eating the first native he might happen
to meet.

Thus, then, the widest extremes of opinion,
and the greatest diversity in those rules of
conduct which are founded upon such opi-
nions, may exist among those who profess the
most implicit reverence for the scriptural dic-
tum, that “ God hath made of one blood all
nations of men, for to dwell on all the face of
the earth.” For, whilst some include under
the term “men,” all the individuals grouped
together by the naturalist under the genus
homo, and regard this genus as consisting of
but a single species, of which the several races
are only to be ranked as varieties, others assert
that this genus includes several species, which
form a gradual transition from the highest and
most cultivated races of mankind, to those
degraded races, which (as they affirm) have
more in common with the brutes ; the former
alone being really entitled to the appellation
men, whilst the latter should be called by some
other name indicating their close affinity to
chimpanzees and orangs. Thus we are
thrown back upon scientific inquiry, as the
only legitimate means of bringing this ques-
tion to an issue ; and such an inquiry can
only be rightly pursued, when it is prosecuted
upon the broadest possible basis, and is made
to comprehend every kind of information which
can be brought to bear upon it. Nothing
can be easier than to bring together an ex
parte collection of facts, which shall give
to either doctrine, — that of the specific unity,
or that of the sjiecific diversity, of the human
races, — an apparently fair claim to recep-
tion. But since both cannot be true, and
since the question can only be decided by
the balance of probabilities, no evidentiary fact
having any relation to the subject ought to
be left out of view ; and thus the science of
Ethnology must be built upon the foundation
afforded by numerous other departments of
scientific inquiry. The anatomist examines
the configuration of the body, and compares
the peculiarities of the various tribes, with the
view of determining how far structural dif-
ferences prevail over resemblances, and of
ascertaining whether these differences possess
that constant and untransitive character, which
the naturalist requires as a justification of
specific distinction. Th e physiologist searches
into the history of the vital functions in the
several types of humanity, and seeks for in-
formation with regard to the permanence of
anatomical differences, the effects of external
agencies in modifying the configuration or
constitution of the body, and the tendenev to
spontaneous variation in the forms presented
by individuals, families, or tribes, known to be
of the same stock. The psychologist has a
most interesting subject of investigation, in
the study of the psychical constitution of the
4 p 3

1318

VARIETIES OF MANKIND.

several races, and in the extraction (so to
speak) of their respective mental and moral
characters, from their habits of life, their
languages, and their religious observances.
It is his business to inquire how far one com-
mon psychical character can be inferred from
such diverse manifestations ; that is, how far
the differences which he cannot but observe
in intellectual capacity, and in moral and even
instinctive tendencies, are fixed and per-
manent, or are liable to spontaneous variation,
or to alteration from the modifying influence
of education and other external conditions.
The ‘physical geographer lends his aid, by
bringing to bear upon the inquiry his know-
ledge of the outward circumstances under
which these variations in bodily and mental
constitution are most constantly found. And
it is from the materials which he contributes,
that the physiologist and the anatomist have
to determine the degree in which these cir-
cumstances can be justly considered as the
causes of variation ; and, more especially,
whether the coincidences between particular
bodily configurations or mental constitutions,
and certain combinations of climatic and geo-
logical conditions, are the result of induced
differences among the human races which are
respectively subject to the latter, or are to be
attributed to the implantation of originally
dissimilar stocks in the respective localities in
which their descendants are now found. But
in order to carry on these researches, the
information of the historian is continually
needed, on the actual descent, migrations,
conquests, &c. of the nations whose physical
and mental characters we are comparing. The
question of the fixity of all or any of the
characters by which the races of mankind are
at present distinguished from each other,
requires for its solution a comparison of the
present with the past. No valid proof of
their permanence can be drawn from the
limited experience of a few generations; and
no evidence of change can be reasonably
looked for, except under the long-continued
agency of modifying causes. The required
information is sometimes supplied by direct
historical testimony ; but this is frequently
insufficient, and recourse must be then had to
the philologist, who derives from the compara-
tive study of the languages of different tribes,
most important evidence as to their degree of
filiation, and thus extends, combines, and con-
firms the indications, which the historian had
drawn from other sources. Independent of
the aid which philological research affords to
other departments of ethnology, it directly
bears upon the great problem of the unity or
identity of mankind ; for it not only answers
a common purpose with historical testimony,
in establishing the genealogical relations of
tribes long since dispersed from their original
centres, and separated at present by strongly-
marked physical and psychical differences ;
but it also affords important evidence as to
the fundamental similarity, if not identity, of
the primitive stocks.

It is obviously impossible to enter at any

length into any one of these topics of inquiry,
within the limits of the present article ; and
all that will be here attempted, will be to place
before the reader a general resume of the whole
subject, carrying out those portions into some-
what more of detail, in which the anatomist
and physiologist are most concerned.

The question at issue has usually been con-
sidered under the simple aspect of specific
unity or diversity ; — that is, in the first place,
whether all the existing races may be sup-
posed to be the descendants of one pair of
“protoplasts;” all their diversities in physical
conformation, in language, in mental character,
and in social condition, having since arisen ;

— or whether, secondly, the existing races must
be regarded as having sprung from several
distinct pairs of protoplasts ; which originally
presented differences amongst themselves,
nearly the same with those which now exist
amongst the races that seem most remote
from each other. Now the first of these
suppositions requires that evidence should be
given of a very considerable amount of vari-
ability from the original type (whatever that
may have been) amongst the descendants from
the common ancestry : whilst the second is
based on the idea, that the leading characters
which now separate the different races are per-
manent, and must have been presented by their
original progenitors. A third supposition,
which has been put forward within the last
few years, regards the existing races as not all
proceeding from one pair of “ protoplasts,”
but from several; but considers that these,
though scattered over the globe, were funda-
mentally similar in corporeal and mental con-
stitution, and differed only in the adaptation
of certain of their physical characters to the
different circumstances of their several abodes,

— thus being all comprehensible within the
limits of one species, — and all possessing,
too, a certain capacity for variation, which has
been manifested in the production of subor-
dinate diversities, and has even proceeded, in
some instances, under the prolonged influence
of change of climate, civilization, &c., to soften
down, if not entirely to obliterate, the original
differences. On the general bearing of the
last of these hypotheses, a few remarks seem
called for.

Although the same affinity or blood-rela-
tionship would not exist between the de-
scendants of several distinct pairs of “ proto-
plasts,” as between those of a common
ancestry, yet the moral relations between
them would be as close as on the supposition
of their consanguinity. For, as has been
justly observed, “ the moral rights of men
depend on their moral nature ; and while
Africans have the hearts and consciences of
human beings, it could never be right to treat
them as domestic cattle or as wild fowl, if it
were ever so abundantly demonstrated that
their race was but an improved species of
ape, and ours a degenerate kind of god.”*
This view has recently been very forcibly

* New Quarterly Review, No. XV. p. 131.

VARIETIES OF MANKIND.

urged by Professor Agassiz, who has adopted
in regard to the human races the same views
as he has put forth with respect to many other
species (p. 1310.) ; and who thus upholds the
“ unity of mankind,” whilst contending for the
diversity of “ protoplasts.”

“ We recognise,” he says, “ the fact of the
unity of mankind. It excites afeeling that raises
men to the most elevated sense of their connec-
tion with each other. It is but the reflection of
that Divine nature which pervades their whole
being. It is because men feel thus related to
each other that they acknowledge those ob-
ligations of kindness and moral responsibility
which rest upon them in their mutual relations.
And it is because they have this innate feeling,
that they are capable of joining in regular
societies, with all their social and domestic
affinities. This feeling unites men from the
most diversified regions. Do we cease to
recognise this unity of mankind, because we
are not of the same family, because we ori-
ginate in various countries, and are born in
America, England, Germany, France, Switzer-
land ? Where the relationship of blood has
ceased, do we cease to acknowledge that ge-
neral bond which unites all men of every na-
tion? By no means. This is a bond which
every man feels more and more, the farther he
advances in his intellectual and moral culture,
and which in this development is continually
placed upon higher and higher ground ; so
much so, that the physical relation arising
from a common descent is finally entirely lost
sight of, in the consciousness of the higher
moral obligations. It is this consciousness
which constitutes the true unity of mankind.”
This unity, he continues, may become a yet
stronger bond of moral affinity, than that
afforded by community of descent. “ Where
men of the same nation, individuals whose
studies, whose calling in life have developed
in them the same faculties, the same feelings,
are brought closely together, relations spring
up between them so intimate as by far to
outweigh the natural bonds which a com-
mon parentage may establish between men.
Such individuals do not feel themselves to be
near each other, do not sympathise in their
aspirations, do not join in the same purposes,
because they are brothers, because they belong
to the same family, because they are of the
same nation; but because they feel that they
are men, and that the natural dispositions
wherewith they are endowed as men are de-
veloped in them in a similar manner, and with
reference to the same great human interests.
Is there any one who would consider the ties
between two such individuals on that intel-
lectual and moral ground, as lessened because
they may not be physically related at all ? or
who would consider the differences in their
physical features as an objection to their being
more intimately connected than other men
who in features resembled them more, or are
related to them more closely, perhaps by the
nearest ties of blood ? We can therefore take
it as a matter of fact, that, as we find men
actually living together in the world, it is not

1319

the physical relation which establishes the
closest connection between them, but that
higher relation arising from the intellectual
constitution of man.” Professor Agassiz then
refers to various departments of Natural His-
tory, as affording proof “ that the closest and
most intimate unity may exist without a com-
mon origin, without a common descent, with-
out that relationship which is often denoted
by the expression ‘ ties of blood.’ On the
other hand, that these ties of blood may exist,
without necessarily calling forth the higher
connections which may be found between in-
dividuals of the same type, is, alas ! too plainly
shown by the history of mankind. The im-
mediate conclusion from these facts, however,
is the distinction we have made above, that
to acknowledge a unity in mankind, to show
that such a unity exists, is not to admit that
men have a common origin, nor to grant that
such a conclusion may be justly deri ved from
such premises. We maintain, therefore, that
the unity of mankind does not imply a com-
munity of origin for men ; we believe, on the
contrary, that a higher view of this unity of
mankind can be taken, than that which is de-
rived from a mere sensual connection; that
we need not search for the highest bond of
humanity in a mere animal function, whereby
wre are most closely related to the brutes.”*

The Anatomical differences by which the
several races of Mankind are distinguished
from each other, may be referred to the fol-
lowing heads : —

1. Conformation of the cranium.

2. Conformation of the pelvis.

3. Conformation of other parts of the
skeleton.

4. Colour of the skin.

5. Colour, texture, and mode of growth of
the hair.

By most writers on the diversities of
mankind, the varieties which are observable
in the conformation of the bony skeleton,
and particularly in that of the cranium and
pelvis, have been thought to furnish distinc-
tive characters of more importance than those
derived from the colour of the skin, or the
texture of the hair; since, while a certain
capability of alteration in the latter, under
climatic influences, can scarcely be gainsayed,
it might be supposed, a priori , that strongly
marked peculiarities in the configuration of
the skull, in the proportion of the parts of the
body, and in the development of the brain,
would be less likely to undergo alteration.
Special attention will be here bestowed, there-
fore, upon the first three of this series of
characters.

1. Conformation of the Cranium. — In esti-
mating the degrees of diversity presented by
the skulls of various races, it is absolutely
necessary that some definite method of com-
parison should be fixed upon. The first
attempt of this kind of which we have any
account, was made by Camper ; who main-

* Christian Examiner, Boston, N.E. Jan. 1850.

4 P 4

1320

VARIETIES OF MANKIND.

tained that the profile view is the most cha-
racteristic, and that the “ facial angles ” of
the different races vary so greatly and so con-
stantly, that upon this character alone a valid
distinction might be founded. By Blumen-
bach, on the other hand, it was considered
that the comparison of the breadth of the
head, particularly as seen in the vertical
aspect, is the method by which the most
strongly-marked differences are brought into
view. By Professor Owen the importance of
th e basal aspect has been especially dwelt upon,
in his comparison of the skulls of the higher
Quadrumana with that of Man, as more fully
indicating the relative proportions and extent,
and the peculiarities of formation, of different
parts of the cranium, than any other method.
By Dr. Pritchard, again, the importance of
the front or facial view has been clearly
shown, in regard, at least, to one variety of
cranial conformation. Lastly, by Prof. Ret-
zius, the length of the cranial cavity in pro-
portion to its breadth is considered as the
character of greatest importance; this being
regarded by him as indicative of the relative
development of the posterior lobes of the
cerebral hemispheres, and of the degree in
which they cover-in, or extend beyond, the
cerebellum. As we have already seen, the
superior development of these posterior lobes
constitutes a marked difference between the
cerebrum of Man and that of the higher
Quadrumana ; and in this respect it would
appear from the evidence afforded by cranial
conformation *, that there is a marked differ-
ence among the several races of mankind.

The only method of comparison which can
be fairly relied on, is that in which all the
points of difference are taken into account;
and as this has been done more fully by Dr.
Prichard than by any other ethnologist, his
arrangement will be taken as the chief guide
in the present instance. — If we were to select
from a large collection of human crania,
brought together from all quarters of the
globe, those which differed most widely from
each other, and which might, therefore, be
considered as types of certain peculiarities of
conformation, and if we were then to com-
pare these more closely, so as to eliminate
those which might be regarded as presenting
mixtures or combinations of the most di-
vergent types (just as in studying the solar
spectrum, the optical investigator eliminates
all the colours which can be generated by ad-
mixture, and leaves only the three primaries,
red, blue, and yellow), we should find our-
selves reduced at last to three forms, which
would probably be the crania — (1) of a
Negro of the Guinea coast, or of a Negrito
of Australia, (2) of a Mongolian or Tun-
gusian of Central Asia, or of an Esquimaux
or Greenlander, — and (3) of a native of
Western or Southern Europe. The most
marked feature of the first of these would
be the projection of the jaws ; hence this
type is called by Dr. Prichard the jrrog-
nathous. That of the second would be the
breadth and flatness of the face, which, with
the narrowness of the forehead, gives to
the facial aspect somewhat of a pyramidal
form, which is the designation applied to this

Prognathous Cranium of a native Australian of the W astern Port tribe. ( From a specimen in the Museum

of the Royal College of Surgeons.')

type by Dr. Prichard. The third form would
not be distinguished by any particular fea-

* The author would remark, however, that this
evidence cannot by any means be implicitly relied
on ; since the relative positions of the different parts
of the encephalon may vary, without a corresponding
alteration in their development, as is seen when the
form of the cranium has been altered by compres-
sion. Of the fallacy of inferences drawn from an
inspection of the cranium, as to the development of
the different parts of the encephalon, we have an
example in the assertion of Gall, that castration oc-
casions atrophy of the cerebellum ; a statement
which has been completely negatived by the ob-
servations of Leuret.

tures so much as by an absence of the longi-
tudinal projection of the first, or the lateral
projection of the second, and by a general
symmetry of the whole configuration, which
maybe characterised as oval or elliptical-, such
being the form presented when the cranium is
viewed either facially, basally, or vertically.
The distinctive characters of these three types
will now be more particularly considered ;
and the European type may be conveniently
taken as the standard of comparison, since it
is in many respects intermediate between the
two others; one of these departing from it in
one direction, and the other in the opposite.

VARIETIES OF MANKIND.

1321

Of the Prognathous type. — The most
marked feature of the typical prognathous
skull, as already remarked, is the prominence
of the jaws, as seen in profile (Jig. 807). It
is this which gives to the features of the Ne-
gro and Australian their peculiar ugliness ;
and it is on this that the difference of the
facial angle between the Negro and the Eu-
ropean chiefly depends. In both jaws we
observe that the alveolar ridges project in
such a manner, that the front teeth implanted
in them meet at an angle, instead of being in
the same, or in parallel planes, as in those
skulls which are termed for the sake of dis-
tinction, orthognathic. Independently of the
projection of the muzzle, however, there is
an appearance of general elongation of the
cranium from back to front, so that the antero-
posterior diameter of the cranial cavity is
greater in proportion to the lateral, than it is
in the oval cranium. Thus the average
length of ten Negro skulls measured by Pro-
fessor Van der Hoeven*, was 6’96 inches, while
their average breadth was 5’ 11 inches; so
that the relation of their length to their
breadth was as l-36 to l'OO. On the other
hand, the average length of twenty European
skulls was 7-04 inches, and their breadth 5'47
inches ; so that the relation of their length to
their breadth was P30 to POO. But this
difference (which is by no means great) seems
to depend rather upon the relative narrow-
ness, than upon the elongation, of the Negro
cranium ; for it will be observed that its ab-
solute length is less than that of the European,
and that the difference in the dimensions of
the two consists chiefly in the inferior breadth.
The form of the whole cranium suggests
the idea of lateral compression. The tem-
poral muscles cover a large surface, and rise
high upon the. parietal bones; and the zygo-
matic arch has a large opening, but this is
given by a forward rather than a lateral pro-
jection of the cheek bones. Although the
forehead very commonly recedes in the prog-
nathous skull, this is by no means a constant
character (fig. 810) ; even where it is high,
however, it is seldom or never broad or full.
The position of the foramen magnum has
been affirmed to be, in the Negro, so far be-
hind the nearly central place which it holds
at the base of the European skull, as to
constitute a marked character of approxi-
mation to the quadrumanous type ; but it
has been shown by Dr. Prichard, that, when
due allowance is made for the projection
of the alveolar processes, the position of
the foramen magnum in the Negro is as
central as in the other races f, its anterior
border being immediately behind the trans-
verse line bisecting the antero-posterior dia-
meter of the base of the cranium. The
height of the Negro skull seems to be rather
less than that of the European ; but there
is a more marked inferiority in the capacity

* Bijdragen tot de Natuurlijke Gesckiedeniss van
den Negerstam ; Leiden, 1842.

t See Physical History of Mankind, vol. i. p. 290.

of the Negro cranium, as shown by the
length of the vault over the vertex, and in

Fig. 810.

Young Negro of Benguela. ( After Jtugendas.')

the circumference; for the former averaged,
in the measurements of Professor Van der
Hoeven, 13‘8 1 inches in the Negro, and 14-67
inches in the European ; whilst the average
of the latter was 19-75 inches in the Negro,
and 20’51 in the European. Although Pro-
fessor Tiedemann attempted to prove *, by
filling the cranial cavity with millet-seed, and
then weighing the quantity which it was
found to contain, that the capacity of the
Negro’s cranium is equal to that of the Eu-
ropean’s, yet, as Professor Van der Hoeven
has pointed out, the average capacity of the
Negro skulls thus examined by Tiedemann
was about one-twentieth less than the average
capacity of European skulls. On the other
hand, the facial portion of the prognathous
skull is relatively, and even absolutely larger.
It has been usually described as being cha-
racterised by the large relative size of the
parts subservient to the organs of the senses ;
but although it certainly appears that both
the anterior and posterior nares are wider
than in the European, that the nasal cavity
is altogether more capacious (so as to allow
a more extended surface for the distribution
of the olfactive nerve), and that the external
auditory meatus is remarkably large, it does
not appear that the same holds good of the
orbits, which, though sometimes larger, are
sometimes smaller than in the average of
Europeans, f

This prognathous type, although most re-
markably developed among the Negroes of
the Delta of the Niger, is by no means
confined to them, nor to the African race3
in general, of which it is usually regarded

* Das Him des Negers, mit dem des Europaers
und Orang Outangs verglichen. Heidelberg ; 1837.

j- See Prichard, dp. cit. p. 292.

1322

VARIETIES OF MANKIND.

as characteristic. It is met with among in-
habitants of various quarters of the globe ;
but is nearly always associated with squalor
and destitution, ignorance and brutality. In-
stead of following an agricultural or pas-
toral life, the people among whom it pre-
vails are, for the most part, hunters, or
inhabitants of low marshy forests, dependent
for their supplies of food upon the chase, or
upon the accidental produce of the soil, and
but little advanced in any of the arts which
are characteristic of civilisation. Such is the
character of those aborigines of Australia,
and of certain islands of the Polynesian Ar-
chipelago, amongst whom the prognathous
type is presented almost, if not quite, as
characteristically as among the Negroes of the
Guinea coast.

The skulls of some of these inferior races
have been asserted by Dr. John Neill * to pre-
sent a division of the articulating surface of
each occipital condyle into two facets, by a
groove or ridge ; which appears to be the
persistent indication of the fissure that
originally separates the basi-occipital bone
from the ex-occipitals. This character, how-
ever, is far from being constant in any one
family. Thus it was only found in 30 out of
81 African crania; whilst it presented itself
in only 4 pure Egyptian heads in Dr. Mor-
ton’s collection, in 3 out of 105 skulls of

Fig. SI 1. Fig. 8

aboriginal Americans, and in none of the
other 129 skulls of different nations whose
history was well known. Thus, although
more common among the African races than
in the others, and marking in them (like the
occasional persistence of the separate inter-
maxillary bone to a later period than usual)
a less complete development, yet its presence
in but little more than one-third even of the
Negro-crania, and its occasional existence
elsewhere, altogether destroy its title to be
considered a mark of separation between dif-
ferent branches of the human family. The
writer has looked for this character in at least
twenty African crania, without once meeting
with it ; the only skull which unequivocally
presented it being that of a Tasmanian female,
act. 14. — Dr. Neill points out, also, that the
lower boundary of the anterior nares in the
Negro skull wants the sharp edge which is
found in the higher races ; and that this,
also, may be regarded as a retention of the
foetal type. This character, however, is at
least as strongly marked in Australians as in
Negroes ; and an approximation to it is
shown wherever there is a tendency to the
prognathous conformation.

Of the pyramidal type. — The most striking
feature in this type of cranial conformation,
which is best seen in the front and basal
views {figs. 811. 813.), is the lateral or out-

2. Fig. 813.

Pyramidal Cranium of Mongolian race. ( From a specimen in the Museum of the Royal College of

Surgeons.)

ward projection of the zygomatic arches ; this
is principally due to the peculiar form of the
malar bones, whose facial surface is very
broad and flat ; but partly, also, to that of
the zygomatic process of the temporal bone,
which forms a large rounded sweep. From
this peculiarity, in conjunction with the nar-
rowness of the forehead, it results that lines
drawn from the zygomatic arches, touching
the temples on either side, instead of being
parallel, or nearly so, as amongst Europeans,
meet at no great distance over the forehead,
so as to form, with the line joining their bases,
a triangular figure. The upper part of the
face being remarkably flat, the nose also being
flat, and the nasal bones, as well as the space

* American Journal of the Medical Sciences,
Jan. 1850.

between the eyebrows, being nearly in the
same plane with the cheek-bones, the trian-
gular space bounded by these lines may be
compared to one of the faces of a pyramid.
This, however, is by no means the most im-
portant peculiarity of this type ; for the
shortness of the antero-posterior diameter of
the cranium, in relation to the lateral, is, as
pointed out by Professor Retzius, at least
equally characteristic. Thus the average length
of sixteen Laplander’s skulls measured by him
was about 6’90 inches, while the average
breadth was as much as 5'78 inches ; making
the proportion of the former to the latter
no more than P20 to LOU. The greatest
longitudinal dimension among all these skulls
was only 7'08 inches, while the greatest late-
ral extension was as much as 6‘16 inches ;
thus reducing the proDortion to P15 to POO.

1323

VARIETIES OF MANKIND.

The orbits in these skulls are large and deep ;
ami the peculiar conformation of the bones
which surround them give to the aperture of
the lids an appearance of obliquity, the inner
angle being directed downwards (Jig. 814).

Fig. 814.

Portrait of one of the “Siamese Twins.” (Talien in
Paris in 1830.)

The whole face, instead of approaching the oval,
as in Europeans, is of a lozenge-shape; and the
greater relative development of the zygomatic
bones, and of the bones of the face altogether,
when compared with the capacity of the
cranium, indicate in the pyramidal skull, as
in the prognathous, a more ample develop-
ment of the organs immediately subservient
to sensation ; the lateral expansion being
attended with a similar result in this respect,
to that which is consequent upon the forward
prolongation of the prognathous skulls. In
the breadth of the lower jaw (.fig. 813) a
remarkable contrast will be noticed with that

of the prognathous type (Jig. 809). The
greater part of the races representing the
pyramidal type in a well marked degree, may
be designated as pastoral nomades ; some of
them wandering with their Hocks and herds
over the vast plains of high Asia, whilst
others creep along the shores of the Icy sea,
supporting themselves partly by fishing, but
living in part upon the flesh of their rein-deer.
As in the preceding case, however, the same
type is encountered in a remote quarter of
the globe, among tribes whose descent would
seem to be altogether different, yet which
closely corresponds with the nomadic races
of high Asia as to the physical conditions
under which they live ; namely, the Hottentots
of South Africa, whose resemblance to Mon-
golians in cranial conformation, as well as in
complexion, hair, and several other charac-
ters, is so striking as to have been noticed by
all travellers familiar with both, and to have
given rise to many speculations as to their
possible blood-relationship. It will be here-
after shown, however, that there is no valid
reason for separating the Hottentots from
the general mass of the African nations ; and
just as the Australians repeat the progna-
thous type at a distance from its chief centre,
with a slight admixture of the pyramidal, so
do the Hottentots in some degree repeat the
pyramidal, with an admixture of the prog-
nathous.

Of the Oval or Elliptical type. — This form
of cranial configuration at once approves
itself to the educated eye, as distinguished
by its symmetrical contour; neither the muzzle
nor the zygomatic arches having an undue
prominence, whilst, on the other hand, there
is no appearance of flattening or compression.
The cranium, in its fullest development, may
be said to have the length of that of the Negro
with the breadth of that of the Mongolian ;
and it is particularly distinguished by the
lateral fulness, as well as by the elevation, of
the forehead. This will be especially appa-
rent on the comparison of Jig. 815 with

Fig. 815.

Elliptical Cranium of European.

Fig. 816.

Fig. 817.

( From a specimen in the Museum of the Royal College of Surgeons .)

the corresponding view in Jigs. 807. and 811.;
for in the former it will be seen that the
breadth continues to increase above the
orbits, and that the cranial vault is rounded
and capacious ; whilst in the other two, the
breadth diminishes rapidly, especially in the

frontal region, from the floor of the orbits
upwards. The form of the zygomatic arches
is such, that in the facial view they do not
project laterally beyond the general boundary
line, as they do in the Mongolian ; whilst the
conformation of the jaws is such, that they

1324-

VARIETIES OF MANKIND.

do not form nearly as great a projection be-
yond the ellipse which would include the
whole cranium and the greater part of the
face, when seen in profile, as they do in the
Negro. Owing to the more perpendicular
direction of the alveolar processes, the front
teeth of the two jaws are fixed in planes
which are nearly or quite parallel to each other.
The chief positive distinction of this form of
cranium, is the large development of the cranial
cavity, and especially the fullness and eleva-
tion of the forehead, in proportion to the size
of the face ; indicating the predominance of
the intellectual powers over those merely
instinctive propensities which are more di-
rectly connected with sensations. Among
European nations, the Greeks have probably
displayed the greatest symmetry in the form
of the head, in the largest proportion of in-
dividuals ; but examples of equal symmetry
might be found amongst any of the great
group of nations now termed Indo-Atlantidac,
and even, as will hereafter appear, in na-
tions of entirely different descent. Nearly
all of these have acquired a certain amount
of civilisation, living by agriculture, and
possessing settled habitations ; and among
them, or among the offsets which have pro-
ceeded from them (as the people of the
United States), we find all the nations which
have been most distinguished for intellectual
advancement, for the successful cultivation of
the fine arts, and for the various improve-
ments which distinguish the state of civilisa-
tion from that of barbarism.

To the foregoing general account of the
three principal types of cranial conformation,
may be added the results of the observations
recently made public by Dr. Morton *, as to
the capacity of the cranium of different races,
measured after the manner adopted by Tiede-
mann (p. 1321.). The number of crania ex-
amined was 623 ; and they were derived from
various races and families, as shown in the
following table, which is here given without
modification, although the writer (as will
hereafter appear) is far from agreeing with
Dr. Morton in the classification of these
varieties which he has adopted.

It appears from this comparison, that the
Teutonic race, and the nations chiefly de-
rived from it, take the highest rank among
those examined in regard to cranial capacity ;
whilst the lowest is occupied, not by the
Negroes, but by the Hottentots, the Austra-
lians, and the ancient Peruvians and Mexi-
cans. The Negro race seems to be scarcely or
not at all inferior in this particular to the Per-
sians, the Bengalees, the Fellahs, the ancient
Egyptians, the modern Fellahs, the Chinese,
the Polynesians, and the North American In-
dians. It must be remarked, however, that
the number of crania examined is too small, in
some of the families, to admit of a fair aver-
age. This, however, it is most important to

* Transactions of the American Medical Associ-
ation, vol. iii. p. 57.

TABLE

Showing the Size of the Cranial Cavity in
Cubic Inches.

*

Races and Families.

o> — :

€1

C

c3

i

A V)

n

h-JCG

£ <z>
c n

S

s

MODERN CAUCASIAN

GROUP.

Teutonic Family.

Germans -

18

114

70

90

)

English -

5

105

91

96

>92

Anglo-Americans
Pelasgic Family.

7

97

82

90

Persians )
Armenians > -
Circassians J

10

94

75

84

Celtic Family.

Native Irish
Indostanic Family.

6

97

78

87

Bengalees, &e. -
Semitic Family.

32

91

67

80

Arabs -
Nilotic Family.

3

98

84

89

Fellahs -

17

96

66

80

ANCIENT CAUCASIAN

GROUP.

Pelasgic Family.

Graeco-Egyptians
Nilotic Family.

18

97

74

88

Egyptians

55

96

68

80

MONGOLIAN GROUP.
Chinese Family

6

91

70

82

V

MALAY GROUP.

Malayan Family

20

97

08

86

| 85

Polynesian Family -

3

84

82

83

AMERICAN GROUP.

Toltecan Family.

Peruvians

155

101

58

75

| 79

Mexicans

Barbarous Tribes.

22

92

67

79

Iroquois h

Lenape (

Cherokee L

161

104

70

84

l79

Shoshond, &c.J

)

NEGRO GROUP.

Native African Family
American-born Ne-

62

99

65

83

j-83

GROES -

12

89

73

82

Hottentot Family -
Alforian Family.

3

83

68

75

Australians

8

83 1

63 ■

75

observe, that in the skull of largest capacity
amongst the races whose average is the lowest,
the cubical content is greater than that of
the smallest skull among the highest. Thus
we see that the largest native African skull
contained 99 cubic inches ; the largest Ame-
rican-born Negro, 89 cubic inches ; and the
largest Hottentot and Alforian skulls, 83
cubic inches ; whilst, on the other hand, the
smallest German skull contained but 70 cubic
inches ; the smallest English, 91 inches; and
the smallest Anglo-American, 82 cubic inches.
It is worthy of note, too, that the largest
Negro skull possesses two inches more capa-

VARIETIES OF MANKIND.

1325

city than the largest Anglo-American. It is
obvious, then, that no constant and impass-
able line of distinction can be drawn on this
basis, between any of the varieties of the
human race.

We have now to inquire if the foregoing
types of cranial conformation are sufficiently
fixed and definite to furnish specific characters ;
that is (1.), whether they are always clearly
distinguishable from each other, or are con-
nected together by a succession of gradations
that renders it impossible to draw a distinct
line of demarcation between them : and (2.)
whether they are so invariably transmitted
from one generation to another, where the
purity of the race has been preserved, as to
entitle them to be regarded as permanent and
unalterable ; or are occasionally seen to vary
in a succession of generations, so that a race
loses more or less completely its original
type, and assumes some other.

When the cranial conformation of the
whole Indo- Atlantic group of nations is care-
fully examined, it is perceived that although
the elliptical type prevails among them, it is
comparatively seldom seen in its perfection,
and that a decided tendency is frequently
seen towards one or other of the other types,
or towards a mixture of the characters of all.
Considerable variation is thus presented, not
merely by the different races, but by different
individuals of the same race. Thus in every
large collection of English skulls, for example,
crania would probably be found differing
nearly as widely from each other in the
proportion of length to breadth, as do the
average of Negro and Mongolian crania ;
whilst, again, some would exhibit more or
less of approximation to the prognathous
type, and others to the pyramidal. Of the
former we have an example in fig. 818., and

Fig. 818.

Dolichocephalic Cranium of European. ( From a
specimen in the Museum of the Royal College of
Surgeons.')

of the latter in /zg. 819.*; the first of these
skulls would certainly be placed, if the dimen-

* Of these and most of the other figures of crania
illustrating this article, the author would remark
that, although every pains has been taken by the
artist, it has been found impossible to express
adequately on a small scale some of those nicer
features of distinction, which are obvious enough in
the skulls themselves.

Fig. 819.

Brachycephalic Cranium of an Englishman. ( From
a specimen in the Museum of the Royal College of
Surgeons.)

sions of its cranial portion were alone re-
garded, in the “ dolichocephalic ” division of
Professor Retzius, and only wants a little
more elongation of the muzzle to be almost
as prognathous as many African skulls ; whilst
in the second, the breadth and front-flattening
of the malar bones, with the inferior breadth
of the forehead, show that it is obviously in-
termediate in character between the typical
oval (fig. 815) and the typical pyramidal
(fig. 81 1). So, again, if the so-called Mon-
golian group be surveyed, it will be found
that the peculiarities of the pyramidal skull
are often softened down, so as to present an
approach to the elliptical form, sometimes
through the whole of certain races, occasion-
ally only in individuals. Here, too, there is
a tendency to an admixture of types ; for we
find among the American nations a very
gradual transition from the truly pyramidal,
such as is seen in the Esquimaux (fig. 820),

Fig. 820.

Cranium of Esquimaux. ( From a specimen in the
Museum of the Royal College of Surgeons.)

to a form in which there is at least as great
an admixture of the prognathous (fig. 822) ;
whilst among the Chinese and other civilised
nations of South-eastern Asia, we find so
close an approximation to the oval type, that
individuals are not unfrequently met with
amongst them, whose skulls might be taken
for those of Europeans.* So, again, if we

* Such was the case, for example, with the
Chinese skull, whose measurements are given by
Professor Van der Hoeven (op. cit.) ; for in every
one of its dimensions it varied less from the aver-

132G

VARIETIES OF MANKIND.

{From, a specimen in the Museum of the Royal College of Surgeons.')

Cranium of Masacusi Indian.

take a survey of the African nations, we find
the prognathous type gradually softened down
(so to speak) among them, until in some of
the races of undoubted African descent, in-
habiting the Nile valley, it merges into the
oval. We have already noticed the curious
admixture of the pyramidal and prognathous
types which is seen in the Hottentot races ; and
among the widely spread and isolated tribes
by which Oceania is peopled, the same com-
bination is exhibited in various degrees. For

Fig. 823.

whilst the skulls of the Malayan portion of
the population are referable to the pyramidal
type rather than to any other, those of many
native Australians, and of various islanders
designated as “ Pelagian Negroes,” are almost
purely prognathous, presenting but a very
slight indication of a pyramidal tendency
about the upper part of the face ; and between
these there is every degree of gradation. Thus,
in the Australian skull, delineated in figs.
823, 824, there is decidedly less prognathism

Fig. 824.

Cranium of Aboriginal Australian. ( From a specimen in the Museum of the Royal College of Surgeons.)

than in that already described (fig. 808.) ; and
in the skull of the Tahitian (fig. 825), with
about the same amount of prognathism, there

Fig. 825.

Cranium of a Tahitian. ( From a specimen in the
Museum of the Royal College of Surgeons.)

is a considerably less degree of antero-
posterior elongation ; in both these skulls,

age of European skulls, than the latter varied from
each other.

moreover, the upper part of the face, when
seen in front, shows a decidedly pyramidal
tendency. So, again, the Greenlanders are
ranked by Professor Retzius among his Doli-
chocephalic prognathcc, along with the Negroes
and Australians, although the upper part of
the face is often most characteristically pyra-
midal ; and even the Br achy cephalic Tartars
and Kalmuks are reckoned by him suffi-
ciently prognathous to be separated from the
Finns, Lapps, Turks, &c.

These facts, to which many more might be
added, should be sufficient to convince every
philosophic naturalist, who duly estimates
what is required for the establishment of spe-
cific distinctions, that none such can be laid
down among the different races of mankind,
upon the foundation of cranial conformation
alone. Those ethnologists who hold the
doctrine of originally distinct stocks, which
(they maintain) have continued to preserve
their characteristic features through succes-
sive generations, have been obliged to admit,
not three or five varieties of cranial conform-

1327

VARIETIES OF MANKIND.

ation, but twenty or thirty ; and as we in-
crease our acquaintance with the physical
characters of tribes at present little known,
the number requires continual enlargement.
And whether the types selected be few or
many, they are always found to be con-
nected by such a gradation of intermediate
or transitional forms, that the well-marked
boundary-lines which are necessary for the
limitation of species, cannot be drawn with
the slightest show of justification. It is not
meant to be here asserted, that the absence of
any such definite peculiarities of cranial con-
formation is of itself a sufficient reason for
regarding the several races of mankind as
specifically identical. On the contrary, as we
have already seen, the genus Felis contains
species as unmistakeably distinct as the lion
and the tiger, between which there is no
appreciable difference in cranial conformation
All that we have a right to affirm is (1.), that
the most extreme differences in (he configura-
tion of the skull, existing among the several
races of men, are not greater than those which
present themselves among races of domesti-
cated mammals known to have had a common
origin (e.g. those of the hog), and are not
nearly so great as those existing among other
races of mammals (as the various breeds of
dog,) which are generally believed to have had
a common origin ; and (2.) that, as in the
case of the domesticated races, the distinctive
characters are by no means clearly marked
out, but that those of the typical forms are
softened down in intermediate gradations, so
as to present a continuous series from one
type to another, in which no such hiatus is
left, as would justify the assumption of the
specific distinctness of those types. This
last fact of itself invalidates that supposition
of the uniform transmission of physical cha-
racters from parent to offspring, on which the
presumption of original distinctness mainly
rests. For, on the theory of specific distinct-
ness, all the descendants of the same parentage
should repeat the characters of their ances-
tors without essential modification ; whereas
we find, as a matter of fact, that the distinc-
tive characters are perpetuated in their full
intensity in only a small proportion of each
race, and that in the great masses they are so
shaded off as gradually to disappear. And
this must be admitted, whatever types we
may select as those representing the original
species ; unless we go to the extreme length
of selecting a distinct type for every distin-
guishable modification in the conformation of
the skull, which would be a sort of reductio
ad absurdum of the hypothesis.

We are thus led to the second branch of
the inquiry, namely, whether there is ade-
quate evidence that the cranial characters of
the several races are really thus transmitted,
with little or no modification, from generation
to generation, or whether an actual passage
may be effected in time from one type to
another. Now, every one who has been
accustomed to discriminate the varieties of
cranial conformation which present them-

selves within his own range of observation,
must have noticed that not only between the
parents and their offspring, but also among
the different children of the same parentage,
a considerable diversity not unfrequently
exists. Further, on looking at the various
individuals composing the ramifications of a
particular family, it is frequently observable
that they agree among themselves in some
peculiarity of cranial configuration, which
seems (from the evidence of portraits, busts,
&c.) to have been transmitted downwards
for centuries; and by this very character it
may be separated from other families, which
are in like manner distinguished for their re-
spective peculiarities. Now, there can be no
reasonable doubt that many such families had
originally a common ancestry, so that there
must have been a time when each of these
peculiarities first manifested itself in its own
branch of the common stock ; for, if this be
not admitted, we must suppose each of them
to have descended from a distinct pair of
“ protoplasts.” It is obvious, then, that the
question of possible modification is only one
of degree ; and judging by the analogy of the
domesticated races, by the amount of varia-
tion exhibited under circumstances not very
dissimilar, and by the considerations already
advanced (p. 1303. et seq .) respecting the pro-
bable sources of such variations, we should be
prepared to expect that even the widest diver-
sities which have been described, might have
been occasioned by the sufficiently-prolonged
influence of external causes acting upon a
succession of generations. That such has
been the case to a considerable extent, would
appear in some instances from the direct evi-
dence of history; in other instances it would
seem a necessary inference from the facts of
philology ; whilst in others, again, the two
classes of evidentiary facts, neither of them
sufficient in themselves, tend to confirm each
other.

One of the most striking examples of
this kind is afforded by the change in cranial
conformation from the pyramidal to the ellip-
tical, as well as in other characters, especially
the length and abundance of the beard, —
which has taken place among the Turks of
Europe and Western Asia. These so closely
accord in physical characters with the great
bulk of European nations, and depart so
widely from the Turks of Central Asia, that
many writers have referred the former to the
(so-called) Caucasian, rather than to the
Mongolian stock. Yet historical and philo-
logical evidence sufficiently proves, that the
Western Turks originally belonged to the
Central Asiatic group of nations; with which
the eastern portion of their nation still re-
mains associated, not only in its geographical
position, but in its language, physical charac-
ters, and habits of life ; and that it is in the
western branch, not in the eastern, that the
change has taken place. Some writers have
supposed that this change might be explained
as the result of an intermixture of the Turkish
race with the inhabitants of the countries they

1328

VARIETIES OF MANKIND.

have conquered, or by the introduction of
Georgian or Circassian slaves into their
harems. But the cause suggested is plainly
inadequate to the effect. For we know that
in the Christian countries subjugated by the
Turks, the conquering and the conquered
races have been kept from properly domestic
intermixture by mutual hatred, fostered by
their difference in religion and manners ; and
although Greek, Georgian, and Circassian
females have been introduced into the harems
of those who could afford to purchase them,
yet any other modification which has been
effected by their means must have had but
an insignificant effect upon the mass of the
population, since the pure Turkish descent of
the poorer classes must have been but little
interrupted, and universal experience shows
that if the “ cross-breeding” be not kept up,
any new element introduced into a race
speedily disappears. Even admitting that
some modification may have been thus engen-
dered, we cannot fairly attribute to it more
than a very trifling share in the result ; since
the effect of intermixture would simply have
been to produce a hybrid or intermediate
race, instead of the entire substitution of the
elliptical type, which now manifests itself
among the comparatively civilised Western
Turks, whilst those which inhabit Central
Asia, and retain the nomadic habits of their
ancestors, have retained also their cranial
conformation.

Another instance of the same modification
is to be found in the Magyar race, which
forms a large part of the population of Hun-
gary, including the entire nobility of that
country. This race, which is not inferior in
physical or mental characters to any in
Europe, is proved by historical and philolo-
gical evidence to have been a branch of the
great Northern Asiatic stock, which was ex-
pelled about ten centuries since from the
country it then inhabited (which bordered on
the Uralian mountains), and, in its turn, ex-
pelled the Slavonian nations from the fertile
parts of Hungary, which it has occupied ever
since. Having thus exchanged their abode,
from the most rigorous climate of the old
Continent, — a wilderness in which Ostiaks
and Samoiedes pursue the chase during only
the mildest season, — for one in the South of
Europe, amid fertile plains abounding in rich
harvests, the Magyars gradually laid aside the
rude and savage habits which they arc recorded
to have brought with them, and adopted a more
settled mode of life. In the course of a thou-
sand years, their type of cranial conformation
has been changed from the pyramidal to the
elliptical ; and they have become a handsome
people, with fine stature and regular Euro-
pean features, with just enough of the Tartar
cast of countenance, in some instances, to
recal their origin to mind. Here, again, it
may be said that the intermixture of the con-
quering with the conquered race has had a
great share in bringing about this change ;
but a similar reply must be returned ; for the

existing Magyars pride themselves greatly on
the purity of their descent ; and the small
infusion of Slavonic blood, which may have
taken place from time to time, is by no means
sufficient to account for the complete change
of type which now manifests itself. The
women of pure Magyar race are said by good
judges to be singularly beautiful, far surpass-
ing either German or Slavonian females.

A similar modification, but less in degree, ap-
pears to have taken place among the Finnish
tribes of Scandinavia. These may be almost
certainly affirmed to have had the same origin
with the Lapps* ; but whilst the latter re-
tain (although inhabiting Europe) the no-
madic habits of their Mongolian ancestors,
the former have adopted a much more settled
mode of life, and have made considerable ad-
vances in civilisation, especially in Esthonia,
where they assimilate with their Russian neigh-
bours. And thus we have in the Lapps,
Finns, and Magyars, three nations or tribes,
of whose descent from a common stock no
reasonable doubt can be entertained, and
which yet exhibit the most marked differences
in cranial characters, and also in general con-
formation, the Magyars being as tall and well-
made, as the Lapps are short and uncouth.

Another instance of the same kind, which
is still more remarkable if it can be entirely
substantiated, is the conversion of the Geor-
gian and Caucasian nations from the pyra-
midal or Mongolian to the elliptical or Indo-
European type. The designation Caucasian
seems to have been given to the latter on the
following most unsatisfactory ground. “ Blu-
menbach had a solitary Georgian skull ; and
that solitary skull was the finest in his collec-
tion, that ol a Greek being next. Hence it
was taken as the type of the skull of the more
organised divisions of the species. More
than this, it gave its name to the type, and
introduced the term Caucasian.” f Now the
fact is, that the Georgian and Circassian

* This proposition, which is supported by the
almost unanimous voice of the learned historians of
Germany, was assailed a few years since by Profs.
Nilson, Retzius, and other Scandinavian savans,
who endeavoured to prove by archaiological and
anatomical evidence, that the origin of the Finnish
race was not the same with that of the Lapps, but
that it was more nearly connected with the Swedish
nation, which is a northern branch of the great
Indo-European family. Much of the archeological
evidence adduced, however, is capable of receiving
a directly opposite interpretation ; and the philo-
logical evidence, derived from the comparative study
of the Finnish and Swedish languages, shows that
the basis of the former was essentially peculiar to it,
and that the nature of the modification which it has
undergone from Swedish influence, indicates a con-
siderable advance in civilisation previously to the
subjugation of the race by foreign invaders. Dr.
Latham, the latest authority on this subject, ex-
presses himself very decidedly as to the affinity of
the Finns, Lapps, and Hungarians, whom he ranks
with the Yoguls, Ostiaks, and Permians, as off-sets
of the Ugrian branch of the Turanian (Mongolian)
stock. — See his Natural History of the Varieties of
Man, p. 100.

f Latham, op. cit. p. 108.

VARIETIES OF MANKIND. 1329

nations are composed of an assemblage of country in which they located themselves,
tribes inhabiting a mountainous country, speak- whilst these same characters tended to modify
ing languages almost unintelligible to each their physical conformation. For the area
other, and remarkably isolated from the na- which they occupy is at once temperate,
tions which inhabit the countries border- mountainous, and wooded : “ in other words.”

ing on theirs. The beauty of form and feature,
and the delicacy of complexion, which charac-
terise individuals and families among these

Fig. 826.

Portrait of a young Circassian, belonging to the suite
of the Persian Ambassador. ( From a portrait

taken in Paris by M. A. Colin.')

tribes, are well known (Jig. 826.) and have
led to a regular consignment of the youth of
both sexes to the Turkish market, the females
to be introduced into the harems, whilst the
youths are valued for their superior energy
and intelligence, and are frequently adopted
as sons. But these attributes are for the
most part confined to the families of the chiefs;
and they are carefully cherished by exemp-
tion from labour, and by seclusion from undue
exposure. The common people, who are en-
gaged in the cultivation of the soil, are de-
scribed by travellers as being for the most
part coarse and unshapely. — Now from a
careful comparison and analysis of the lan-
guages of these races, Dr. Latham and Mr.
Norris have independently arrived, on different
grounds (the one from the words and the
other from the grammar ), at the same result ;
namely, that they are aptotic, or destitute
of inflexions, like the Chinese ; and that the
people must have been of Mongolian origin,
but separated from the common stock at a
very early period ; the perpetuation of the
low development of their language being fa-
voured by the peculiar characters of the

VOL. IV.

as Dr. Latham remarks, “ the reverse of the
true Mongol areas.” And thus, if this view
should be confirmed, we must regard the
very people which has been selected as fur-
nishing the type of the most perfect con-
formation, as an improved race of a decidedly
inferior stock.

The Negro type is one which is not unfre-
quently cited as an example of the perma-
nence of the physical characters of races, and
especially of types of cranial conformation.
The existing Ethiopian physiognomy is said
to agree with the representations transmitted
to us from the remotest times in Egyptian
pictures ; and this physiognomy, it is further
maintained, continues to be transmitted un-
changed from parent to child, even where the
transportation of a Negro population to tem-
perate climates and civilised associates (as in
the United States of America) has entirely
changed the external conditions, of their ex-
istence. Now it is perfectly true that the
Negro races which continue to inhabit their
original localities, and maintain their barba-
rous habits of life, retain the prognathous
type ; and this is precisely what we should
expect. But it is not true that no modifica-
tion has taken place in them, either under
the influence of civilisation, or from a change
in the physical conditions of their existence.
For the most elevated forms of sktdl occurring
among the African nations, are found in those
which have emerged in a greater or less degree
from their original barbarism ; their civilis-
ation having been due to external influences
brought to bear upon them. We shall here-
after see that there is strong evidence that
even the Syro- Arabian or Semitic nations
may be referred to the African stock; at
any rate, there are numerous tribes in the
interior of Africa, whose affinity with the true
Negroes cannot be disputed, and which yet
present a far superior cranial organisation ;
so that we must either regard the one form to
be the result of improvement, or the other to
have preceded from degeneration. In regard
to the transplanted Negroes, it is obvious that
the time which has elapsed since their re-
moval, is as yet too short to justify us in ex-
pecting any considerable alteration in cranial
configuration. Many of the Negroes now
living in the West Indian islands are natives
of Africa ; and a large proportion of the Negro
population, both there and in the United
States, are removed by no more than one or
two descents from their African progenitors.
The climate, too, of the southern states of
the North American Union, as of the West
Indies, is not very different from that of the
Guinea Coast, in regard to temperature ; and
the low undrained character of much of the
soil which they are employed in cultivating,
still further tends to keep up the correspond-
ence. Still, according to the concurrent

Uq

1330

VARIETIES OF MANKIND.

testimony of disinterested observers, both in
the West Indies and in the United States, an
approximation in the Negro physiognomy to
the European model is progressively taking
place, in instances in which, although there
lias been no intermixture of European blood,
the influence of a higher civilisation has been
powerfully exercised for a lengthened period.
This is particularly the case with Negroes
employed as domestic servants. Dr. Han-
cock, a most intelligent physician of Guiana,
even asserts that it is frequently not at all
difficult to distinguish a Negro of pure blood,
belonging to the Dutch portion of the colony,
from another belonging to the English settle-
ments, by the correspondence between the
features and expression of each, and those
which are characteristic of their respective
masters. This alteration, too, is not confined
to a change of form in the skull, or to a di-
minution in the projection of the jaw ; but it
is also seen in the general figure, and in the
form of the soft parts, as the lips and nose.
And the writer has been informed by Sir
Charles Lyell, that during his recent tour in
America, he was assured by numerous me-
dical men residing in the slave states of the
North American Union, that a gradual ap-
proximation is taking place in the configura-
tion of the head and body of the Negroes to
the European model, each successive gene-
ration exhibiting an improvement in these
respects. The change is most apparent in
such as are brought into closest and most
habitual relation with the whites (as by do-
mestic servitude), without any actual inter-
mixture of races, which would be at once be-
trayed by the change of complexion, and by
the more strongly marked indications of
hybridism.

It is more easy to imagine that a pyramidal
or a prognathous cranium can be metamor-
phosed into an elliptical one, than that either
of the two first-named forms can be converted
into the other. Yet very strong evidence is
furnished by philological considerations, that
the Hottentot races constitute a branch of
the common African stock ; and the approx-
imation which their skulls present to the
pyramidal type cannot be for a moment attri-
buted to intermixture with any Mongolian
race. On the other hand, among the in-
habitants of Oceania, there are many races
which present, more or less decidedly, the
prognathous type ; and this sometimes asso-
ciated with woolly or “ frizzled,” sometimes
with long and straight hair. Yet there is
strong philological evidence for regarding
these as descendants of colonists who spread
themselves (probably by various lines, of
migration) from south-eastern Asia, and who
carried to the various islands of the vast
Malayo-Polynesian Archipelago, the pyra-
midal type more or less softened down. On
no other hypothesis can the extraordinary
community in the fundamental elements of
their languages be accounted for, the tribes
which use them being in a state of complete
isolation from each other. Where, as is

frequently the case, the same island or group
is peopled by two or more races, having
different physical characters, it is always found
that the greatest tendency to the prognathous
type shows itself among those which appear
to have longest dwelt there in a state of
barbarism ; and that it is most strongly
marked, when, to other degrading agencies,
that of a low and marshy soil has been
added.

Even the elliptical type, as already re-
marked, may occasionally present indications
of degradation towards one of the others.
Want, squalor, and ignorance, have a special
tendency to induce that diminution of the
cranial portion of the skull, and that increase
of the facial, which characterise the prog-
nathous type; as cannot but be observed by
any one w'ho takes an accurate and candid
survey of the condition of the most degraded
part of the population of the great towns of
this country, but as is seen to be pre-
eminently the case with regard to the lowest
classes of Irish immigrants. A certain degree
of regression to the pyramidal type is also to
be noticed among the “nomadic” tribes
which are to be found in every civilised
community. Among these, as has been re-
marked by a very acute observer, “ accord-
ing as they partake more or less of the purely
vagabond nature, doing nothing whatsoever
for their living, but moving from place to
place, preying on the earnings of the more
industrious portion of the community, so will
the attributes of the nomade races be found
more or less marked in them ; and they
are all more or less distinguished for their
high cheek bones and protruding ja ws * thus
showing that kind of mixture of the pyra-
midal with the prognathous type, which is to
be seen among the most degraded of the
Malayo-Polynesian races.

It has not been pointed out, so far as the
writer is aware, by any ethnologist, that the
conformation of the cranium seems to have
undergone a certain amount of alteration even
in the Anglo- Saxon race of the United States,
which assimilates it in some degree to that of
the aboriginal inhabitants. Certain it is, that,
among New Englanders more particularly, a
cast of countenance prevails, which usually
renders it easy for any one familiar with it to
point out an individual of that country in the
midst of an assemblage of Englishmen ; and
although this may chiefly depend upon the
conformation of the soft parts, yet there is a
certain sharpness, and an angularity of feature
about a genuine “ Yankee,” which would
probably display itself in the contour of the
bones. So far as the writer’s observation
has extended, there is especially to be noticed
an excess of breadth between the rami of the
lower jaw, giving to the lower part of the face
a peculiar squareness (something like that
which is shown in Jig. 821), that is in strik-
ing contrast with the tendency to an oval

* London Labour and tko London Poor; by
Henry Mayhew, p. 2.

VARIETIES

narrowing which is roost common among the
inhabitants of the “ old country.” And it is
not a little significant, that the well-marked
change which has thus shown itself in the
course of a very few generations, should tend
to assimilate the Anglo-American race to the
aborigines of the country ; the peculiar phy-
siognomy here adverted to, most assuredly
presenting a transition, however slight, to-
wards that of the North- American Indian.

2. Conformation of the Pelvis. — - Certain
differences in the pelvis have been thought
to be characteristic of particular nations or
groups of nations. According to Professor
Vrolik *, wdto was the first to take up the
enquiry systematically, the difference between
the male and the female pelvis is much more
strongly marked in the Negro than in the Eu-
ropean. The pelvis of the male Negro, in the
strength and density of its substance, and in
the form of its component bones, resembles the
pelvis of a wild beast ; while, on the contrary,
the pelvis of the female of the same race com-
bines lightness of substance and delicacy of
form and structure. Notwithstanding this
delicacy of conformation, it is considered by
Professor Vrolik to present characters which
indicate an approximation to that of the
Quadrumana ; for the ossa ilii are unusually
vertical in their direction, and the highest part
of their crest is situated immediately above
the posterior and upper tuberosity, instead of
being midway between the anterior spine and
posterior tuberosity ; the length of the an-
tero-posterior diameter at the brim is very
great in proportion to the transverse diameter;
the sacrum is narrower, and the angle beneath
the pubic articulation more acute ; the whole
pelvis is longer ; but the diameters at the
outlet are not sensibly different from those of
the European pelvis. The conformation of
the pelvis in the female Hottentot, who died
in Paris in 1815, is considered by Professor
Vrolik to present a still wider departure from
the European form, and a correspondingly
nearer approximation to the quadrumanous ;
the ilia are so vertical in their direction, and
are so much lengthened upwards, as to rise
above the level of the middle of the fourth
lumbar vertebra. In the Javanese (Malay),
the pelvis is distinguished by its smallness, its
peculiar lightness of substance, and the cir-
cular form of its upper aperture ; the pro-
montory of the sacrum projects very little ;
and the ischiadic spines are remarkably turned
inwards.

A more extended comparison of the pelvis
of different races, however, has been made by
Professor M. I. Weber ; who classifies all the
varieties he has met with under the four fol-
lowing heads, which are named according to
the form of the aperture of the brim : —

1. The oval, in which the aperture has
somewhat the form of an egg, the narrowest
end of the ellipse being at the symphysis

* Platen behooi'ende tot de Besckowing van het
Verschel der Bekkens in onderscheidene Volkstam-
men. Amsterdam : 1826.

OF MANKIND. ' 1331

pubis : but the antero-posterior diameter is
shorter than the transverse.

2. The round , in which the antero-pos-
terior and transverse diameters are nearly
equal.

3. The square , or four-sided ; in which the
sides, especially that formed by the os pubis,
are flat and broad, so that the aperture forms
nearly a perfect square ; the transverse di-
ameter is greater than the antero-posterior.

4. The oblong ; in which the sides are com-
pressed, and the transverse diameter is con-
sequently the least ; the sacrum is narrow ;
and the angle at which the ossa pubis unite is
very acute ; the ossa ilii are high, and nearer
to each other than in the previous forms.

Now, if any attempt be made to assign any
one of these forms of pelvis to a particular
nation or group of nations, it fails in toto ;
because, although particular types are more
common than others in each principal variety,
yet each kind may present itself in other
individuals of the same race. Thus, the oval
type is most common in the European, where
it is in accordance with the oval form of the
skull ; but round, square, and wedge-shaped
pelves also present themselves occasionally ;
and the oval form is met with again in the
pelvis of a Botacudo, a people reputed to be
the most savage of all the American nations.
The round type seems most frequent among
the American and Malayan nations ; but it
has been observed by Weber not merely in
the European, but in a Negress, andin a female
Hottentot. The square form seems most
common among the nations with decidedly
pyramidal skulls, especially the Northern
Asiatics ; but it occurs also in Europeans,
and in the mixed race of Mestizos. Finally,
the oblong pelvis is most common among the
African races, and is conformable to the
elongated shape usually possessed by their
crania ; but it has been observed also among
Europeans and Botocudos,*- — The writer’s
own observations, so far as they extend, con-
firm this view, as to the conformity between
the shape of the pelvis and that of the skull;
which renders it probable that the influences
which affect the latter will modify the former
also.

3. Conformation of other parts of the ske-
leton. — Other characters have been at dif-
ferent times adduced, as showing that the
Negro and other degraded races are really to
be considered as forming a distinct group, in-
termediate between the higher specimens of
humanity and the superior apes. Of these,
the most important will be now inquired into.
It was maintained by Soemmering, and since
his time very generally believed, that the
position of the foramen magnum in the Negro
skull is intermediate between that which it
holds in man, and that which it presents in
the anthropoid Simiae ; but this, as already
shown, is a mistaken view of the case ; for,

* Die Lehre von den Ur- und Raeenformen der
Sehaedel und Beckon des Menschen, von Dr. M. I.
Weber. Diisseldorf: 1830.

4 ci 2

1332

VARIETIES OF MANKIND.

if we make allowance for the projection of the
jaws, and consider only its relation to the
cranial portion of the skull, the position of
the foramen magnum is found to be the same
in the Negro as in the European ; whilst in
the adult forms of the highest apes, as shown
by Professor Owen, it is removed very much
further back, although in the young it is nearer
the centre of the base. Again, it was stated
by White, and has been generally believed,
that the length of the fore arm in the Negro
is so much greater than in the European, as
to constitute a real approximation to the
quadrumanous type. But an extended com-
parison proves, that only a very slight differ-
ence exists between the average length of this
part in the two races ; and that this difference
is by no means greater than that which may
be observed on comparing the individuals of
which any single race or nation is composed.
On the other hand, a constant and decided
difference exists, as already pointed out, be-
tween all races of mankind and the highest
Quadrumana. Again, it has been supposed
that the Negro races are characterised by that
peculiar curved form of the bones of the leg,
which gives rise to what is popularly desig-
nated as the “cucumber-shin;” also by the
great elongation of the heel; and by the

breadth and flatness of the foot. Such pecu-
liarities are doubtless to be observed among
individuals, and may be said to be general
among the inferior Negro tribes ; but they are
scarcely discoverable in the higher, among
which a remarkable degree of symmetry in
the conformation of these parts is often dis-
cernible. And it should not be forgotten that
the increased development of the heel, and
the flattening of the foot, are characters which
remove the Negro from the anthropoid apes,
still more widely than the European, instead
of being a character of approximation. It
has been further asserted, that the inferior
races generally are characterised by slender,
elongated, and mis-shapen limbs, and by a great
deficiency of physical power, as compared with
Europeans. This is undoubtedly true of
such as are habitually ill-fed, and live in a
condition of squalid ignorance. But it is
scarcely less true of those individuals among
any of the higher races, who are subjected
to the same conditions. Thus, although the
extreme of this condition is witnessed among
the Bosjesmans and Alfourous, yet approaches
to it may be seen among the lowest grades of
the population in the most civilised nations.
The accompanying figure {Jig. 827), which
represents a group of Australians looking at a

Fig. 827.

mirror that had been presented to one of their
tribe, who had been clothed by the sailors of
the Astrolabe, might almost be supposed to be
intended for a set of half-starved Irish. More-
over, among the races which are considered
to exhibit this character in its most decided
form, individuals are often found, who, having
grown up under more favourable conditions,

exhibit the most complete symmetry, and the
greatest vigour. Such, for example, are not
wanting among the Australian races, which
present a remarkable variety in this particular.
Among most savage races, the families of the
chiefs exhibit a higher grade of physical de-
velopment than the ordinary popidation ; and
this is quite sufficiently accounted for by the

VARIETIES OF MANKIND.

1333

difference of the conditions under which they
live, especially in regard to food.

It may be safely asserted, then, that on
none of the foregoing characters can specific
distinctions be justly based, since none of
them possess the constancy which is required
to give them such a rank; and those which
are most strongly marked in particular cases,
are such as can be proved to be most liable
to modification from external conditions.

4. We next have to inquire into the dis-
tinctions founded upon the Colour of the Skin;
which, at first sight, appear to present a
degree of constancy that gives them a strong
claim to be regarded as permanent, and there-
fore as valid distinctive characters between
the several races of mankind. The hue of
the Skin, it is now well known, exists in the
epidermis only, and depends upon the pre-
sence of pigmentary matter in the ordinary
cells of that part. What was formerly known
as the “rete mucosum,” or “ rete Malpighii,”
and described as a distinct colouring layer
between the epidermis and cutis vera, is now
known to be nothing else than the newest
and softest layer of epidermis. There is no
structure (as has been affirmed by some ana-
tomists) in the skin of the dark races, that is
at all peculiar to it ; the very same dark
matter being found in particular spots of the
fairest skins, as in that of the areola sur-
rounding the nipple during pregnancy. The
following is the description of the structure
given by Messrs. Todd and Bowman, the
accuracy of which the author can fully confirm
from his own observation : — “ However vari-
ous in colour and hue, the colouring matter
always consists of oblong or oval grains of
extreme minuteness (1-20, 000th of an inch
in their long diameter), and occupying the
interior of some of the epidermic particles.
In the Negro it is accumulated in enormous
quantity, and completely envelopes the nu-
clei immediately resting on the cutis. On
examining a vertical section of the whole
cuticle, we find the colouring matter gradually
diminishing as we approach the surface ; and
it is most clear that there is no true line of
demarcation between the two portions. We
may observe the colour of the rete muco-
sum deeper at points; and a greater propor-
tionate depth of colour is traceable over such
points, through all the layers, as far as the sur-
face ; we may even discern a sort of stream of
coloured grains advancing towards the surface.
Hence there can be little doubt that the de-
crease of colour in the superficial laminae is
due to that chemical change which has been
described as gradually taking place in the
interior of the epidermic particles.”*

Still it might be affirmed that the presence
of a large amount of pigmentary matter, of a

* Physiological Anatomy, vol. i. p. 415. — The
Eete Malpighii is represented by Prof. Kolliker as
more distinct from the superjacent layers; but the
writer has not been able to satisfy himself of the
accuracy of the descriptions and figures of Prof.
Kolliker on this point. See his Microskopische Ana-
tomie ; Zweiter Band, §§ 14 — 22.

peculiar tint, in the substance of the epider-
mis, constitutes a typical character of par-
ticular races, even though there be no distinct
pigmentary layer : since spots and patches of
colour are often admitted as specific distinc-
tions among the lower animals. Thus, for
example, it has been maintained that the fair
and ruddy Saxon, the jet-black Negro, the
olive Mongolian, and the copper-coloured
North-American, have as good a claim to be
ranked as distinct species, on the score of
the uniform transmission of their respective
hues from generation to generation, as have
many races of Lepidoptera (for example)
which are regarded by naturalists as specifi-
cally diverse on account of the distribution of
colour in the scales of their wings. But as
the validity of the specific distinction among
these last entirely rests upon the intransitive
nature of the character, the several individuals
that constitute either race exhibiting no ap-
proximation towards those of the other, and
the successive generations repeating the re-
spective peculiarities of each race with great
exactness, we must apply the same test to
the Human races.

Now, if we take anyone of those groups of
nations which are usually regarded as alto-
gether constituting a race, such as the (so-
called) Caucasian, the Mongolian, the African
the American, or the Polynesian, it will be
found that the greatest diversity of com-
plexion exists within its limits. Thus, among
the “ Japetic ” races, — which are cha-
racterised by the possession of the oval type
of cranial conformation, and whose languages
are so clearly traceable to a common stock,
that no philologist now questions the identity
of their origin, — we find every range of colour,
from the fair Saxon and Celtic nations, to the
deep brown of the Indian Brahmin.* Among
the Syro- Arabian, or “ Semitic” races, again,
which are spread over South-western Asia
and Northern Africa, and which are connected
by close affinity of language, there is an equal
variety of complexion. All travellers who
have visited the high lands of Arabia, repre-
sent the inhabitants as having light com-
plexions, their eyes being often blue, and
their hair red. The Arabs near Muscat are
of a sickly yellow hue ; those of the neigh-
bourhood of Mecca are of a yellowish brown,
while those of the low countries bordering on
the Nile are almost jet-black. So, again,
among the various tribes referable to the same
stock, which inhabit the Atlantic region of the
north of Africa, similar differences of com-
plexion prevail; for whilst those which inhabit
the higher lands and mountain passes, such as
the tribe of Mozabi among the Kabyles, are
remarkably fair, those which dwell in the
more level parts of the country are swarthy,

* The hue of many of the races of Lower India is
as black as that of any Negroes ; but there is a doubt
(as will hereafter appear) as to their origin. If not
Indo- Atlantic, however, they are Mongolian ; and
the peculiarity is at least as striking, when they are
viewed as off-sets from the latter stock, as when they
are considered as appertaining to the former.

4 o 3

1334-

VARIETIES OF MANKIND.

and some of the Tuaryks which inhabit the
borders of the Great Desert, are as black as
the darkest Negro.

Among the proper African nations, it may
be supposed that no such variety would
embarrass us ; blackness, with a reddish or
yellowish tinge, being accounted the uni-
versal hue of the Ethiopian race. But this
notion is chiefly founded upon the com-
plexion which prevails in a very small part
of the great African continent ; and no
fact is really better established, than that of
the great diversity of complexion which pre-
vails among its different inhabitants. Thus,
among some of the Kaffir tribes, — which often
possess high foreheads and prominent noses, —
light brown complexions, and reddish hair are
often met with ; yet there is every reason for
the belief that they are of the same stock
with the Negroes of the Guinea coast, and
intermediate gradations in complexion are
presented by the nations which occupy an
intermediate geographical position. There
are tribes even upon the gold and slave
coasts, which are considerably lighter than
ordinary Negroes. Moreover, the Hottentot
has a large admixture of yellow in his com-
plexion, whilst the Fulahs of Central Africa
are of a dark copper colour. The African
tribes which border on the Red Sea, arid which
seem to constitute the link of transition be-
tween the Ethiopian and the Semitic races,
present every grade of colour, from the deep
black of the Negro to the swarthiness of the
lighter Arabs, notwithstanding that there is
no reason to believe these characters to have
been acquired by the intermixture either of
an Ethiopian stock with Arabs, or of an Arab
stock with Ethiopians. There is strong
ground for the opinion, as we shall see here-
after, that the ancient Egyptians, whose com-
plexion (as represented by their own artists)
seems to have been of a red copper or light
chocolate colour, were so closely allied to the
proper African nations, that the origin of both
must have been the same. — The complexion
of the African nations, then, wants that cha-
racter of uniformity, which is required to
distinguish it from that of other branches of
the human family ; and a marked tendency to
assimilation is exhibited in the hues of the
African and of the Semitic races inhabiting
similar localities, a fact whose full significance
will appear hereafter.

On instituting a similar comparison be-
tween the complexions of the various
branches and off-sets of the Mongolian race,
it will appear that, although an admixture
of yellow is one of its most constant cha-
racters, yet this may co-exist with other
shades, anti may even disappear altogether.
Thus, in the remains of the aboriginal tribes
of India still existing in the hilly regions of
the north, in the Dekhan, and especially in
Ceylon, all of which appear, from the charac-
ters of their language, their peculiar customs,
and their traditions, to be descendants of the
Mongolian rather than of the Japetic stock,
yye find a variety of shades of complexion,

and this within the limits of the same people.
For example, the Cinghalese are described by
Dr. Davy as varying in colour from light
brown to black ; the prevalent hue of their
hair and eyes is black, but hazel eyes and
brown hair are not very uncommon ; grey
eyes and red hair are occasionally, though
rarely, seen, and sometimes the light blue or
red eye, and light flaxen hair of the Albino.
Dr. Davy, in describing such a one, remarks
that her complexion would scarcely be con-
sidered peculiar in England, certainly not in
Norway ; for her eyes were light blue, and not
particularly weak, her hair of the colour that
usually accompanies such eyes, and her com-
plexion rather rosy. This tendency towards
a fair and even florid complexion, with light
eyes and bushy hair, can be traced in several
other nations of the same type, such as the
Mantchoos in China, and also among the
Chinese themselves. On the other hand, the
hardy Samoiedes, Tungusians, Kamschatdales,
and others, living on the borders of the Icy
Sea, have a dirty brown or swarthy com-
plexion.

If we pass on to the Oceanic races, we
find that any attempts to employ com-
plexion as a means of distinguishing them
from other primary stocks, must utterly fail,
so great and numerous are the diversities. In
almost every group of islands in the great
Oceanic area, the natives differ in complexion
from those of other groups ; thus the Malays
of the Eastern Archipelago, who resemble
the Chinese in features and general conforma-
tion, are of a darker colour, retaining, how-
ever, a yellow' tinge in their complexion ; this
tinge comes out very strongly in the natives
of the Caroline Islands, whose aspect is de-
cidedly Mongolian, and whose complexion is
of a citron hue, becoming brown by exposure;
the Tahitians and Marquesans, especially in
the families of their chiefs, which are secluded
from the wind and the sun, exhibit a clear
olive or brunette complexion, such as is
common among the nations of Southern
Europe ; the Hawaii, or Sandwich Islanders,
are somewhat darker; while of the new Zea-
landers and Ombai Islanders, some are com-
paratively fair, while others are dark or almost
black. Besides these, however, Australia,
New Guinea, and some of the neighbouring
islands are more or less exclusively peopled
by tribes bearing a close resemblance in com-
plexion and aspect to Negroes, whose precise
relation to the Malayo-Polynesian races it is
difficult to determine. There is, however,
such a complete transition from one type to
the other, presented by the natives of different
localities among whom there is no reason to
suppose that any intermixture has taken
place, and the differences are such between
the higher and lower castes of even the same
tribe, that all intelligent persons who have
long resided among the islands of the Pacific,
under circumstances favourable to accurate
investigation, appear to have come to the
conclusion,— that none of those characters on
which some observers have relied, as being

VARIETIES OF MANKIND. 1335

strongly marked in the individuals whom they
have happened to see in the course of their
brief visits to different localities, can be relied
on as general expressions of the attributes of
particular races. So that if colour be once
adopted as a test of separate origin, we must
suppose that tribes speaking the same lan-
guage, having the same customs and tradi-
tions, and closely allied in general conforma-
tion, sprang nevertheless from ancestors who
had no relation to one another ; and a distinct
pair must be assigned to almost every island
or group of islands, and, in some instances,
even two or more pairs to a single island.

Lastly, in regard to the American nations,
it is sufficient to remark, that the appel-
lation “ red men,” is by no means charac-
teristic of them as a whole ; for not only
are tribes elsewhere found at least equally
deserving of it, but it is not applicable to a
large proportion of the population of the
New Continent. For although some of the
North-American Indians are copper-coloured,
some are as fair as many Europeans ; others
are of a brown or yellow complexion ; and
others nearly, if not quite, as black as African
Negroes. Similar diversities exist among the
aborigines of South America. Here, also,
therefore, we should be forced into the sup-
position of a large number of primitive stocks
in near vicinity to each other, were so much
authority to be attributed to colour, as to
allow it to rank as a sufficiently distinctive
character for the specific discrimination of
any of the races of mankind.

We have now to examine if the peculiari-
ties of colour seen among different races can
be attributed with any considerable degree of
probability to external agencies ; and the evi-
dence bearing on this question may be con-
sidered under two heads, namely (I.) the
constancy of the relation between the habitual
operation of particular climatic influences and
particular shades of complexion ; and (2.)
the historical evidence of an actual change of
complexion, in races or tribes that are known
to have migrated from one locality to an-
other of a different character, or to have
changed their mode of life.

Now, the general relation between climate
and complexion is apparent on the most cur-
sory survey of the facts. It is only in the
intertropical regions, and in the countries
bordering on them, that we meet with the
greatest depth of colour in the skin ; and
all the nations inhabiting the level parts
of those regions exhibit a tendency towards
a very dark hue. On the other hand, the
colder temperate regions are the residence
of the fair races. And the intermediate coun-
tries exhibit the transition from one com-
plexion to the other, as we see on passing
from Central Africa, through Northern Africa
and Southern Europe, to Northern Eu-
rope. Now this, if we had no evidence
to the contrary, might fairly be held to
indicate that each race had been created
with especial reference to a particular cli-
mate ; the principal difficulty in the way of

such a supposition, being the great number of
different races whose separate origins it would
be necessary to assume, if it be held that
each has uniformly exhibited the complexion
which it now possesses. But it is most re-
markable that elevation above the sea-level is
found to have the same uniform relation to
the human complexion, that it has to vege-
tation. For as we find the plants of temperate
or even arctic regions on the sides of inter-
tropical mountains, so do we notice that high
mountains and table-lands of great elevation
are almost uniformly inhabited by people of
lighter hue than those of the surrounding
country, however close may be their affinity;
whilst low and level countries, especially
those which border on the sea, are as com-
monly tenanted by people of an unusually
dark colour. Thus the deepest hue among
the African races is to be found among the
negroes of the swampy plains of the Guinea
coast ; yet there are several instances, in
which nations residing at no great distance
from these, but at a higher level, are compa-
ratively light, although their ancestry is un-
doubtedly the same. In Northern India,
again, the lightness of complexion among the
inhabitants of the mountains and table-lands
is almost exactly in accordance with the
elevation at which the tribe has been accus-
tomed to dwell ; and some of these present
complexions of almost European fairness.
On the other hand, among the tribes that
wander along the shores of the Icy Sea, their
proximity to the ocean, together with their
habitual exposure, seem to compensate in
some degree for their distance from the
equator ; so that their hue is much swarthier
than that of the more civilised inhabitants of
Northern Europe. The influence of seclu-
sion from exposure, in lightening the hue of
the skin among the higher castes of various
tropical races, has been already remarked
upon ; and another indication of the import-
ance of this influence is derived from the
concurrent though independent observations
of M. D’Orbigny and Sir R. Schomburgh upon
the people of the New World, both having
remarked that those tribes which live under
the damp shade of dense and lofty forests,
are much fairer than those which are freely
exposed to solar light and heat in dry and
open spaces. The influence of continued
exposure to the solar rays is often strongly
marked in individuals of the lighter races ;
those who are naturally of a “ brunette ”
complexion becoming swarthy, whilst in those
who are naturally fair or “ blonde,” there is a
tendency either to a general reddening or
“ tanning” of the skin, or to the development
of “ freckles,” which are nothing else than
local collections of pigmentary matter, usually
of a reddish-yellow colour. In such cases,
the parts of the body which are habitually
kept covered retain their original fairness.

Seeing, then, that continued exposure to
the solar rays has such a marked effect upon
the complexion of individuals who are sub-
jected to it, we should be led to expect, upon

) 33(5

VARIETIES OF MANKIND.

the principles already laid down, that this
effect would be increased when the cause is
in continued operation for several genera-
tions. And we might with the more confi-
dence anticipate such a result, when we see
that a marked difference in complexion often
exists between parent and offspring, or be-
tween the children of the same parents.
Thus, it is a matter of familiar observation,
that of two members of the same family, the
one shall be a blonde, the other a brunette.
Further, it is not uncommon to find, in indi-
viduals of the fair races, large patches of the
surface almost as deeply coloured as the skin
of the negro. On the other hand, albinoism,
that is, the total absence of colouring matter
in the skin, is probably as common among
dark races as among fair. And Dr. Prichard
has collected evidence which shows that in
many of the individuals who have been de-
signated as “ white Negroes,” there has not
been mere albinoism (that is, an entire ab-
sence of colouring matter), but a positive de-
velopment of the colouring matter that cha-
racterises the xanthous variety, in which the
complexion is fair and ruddy. Such being
the tendency to variation presented by this
character, we might fairly anticipate that it
might undergo marked changes in the course
of a long succession of generations, especially
where the external conditions have been
altered ; and there is no deficiency of valid
historical evidence, that proves this to have
been the case. — Perhaps the most striking
example that could be cited, is that afforded
by the Jewish race; in which there is no ques-
tion that a general purity of descent has been
preserved through a long succession of gene-
tions, during which the scattered residence of
the race has subjected it to a great variety of
climatic influences. Now, although the de-
scendants of Abraham are still generally re-
cognizable by certain peculiarities of physiog-
nomy (so that they have often been quoted
as examples of the permanence and fixity of
the characters of races), yet a great variety of
complexion exists among them. Thus, among
the Jews whose families have been long settled
in this country, although a light brunette hue
with black hair is most common, yet a fair
complexion, with blue eyes, is not unfre-
quent. In Germany and Poland, the ordi-
nary complexion is more florid, and blue eyes
are more common. On the other hand, the
Jews of Portugal are almost invariably much
darker than those of Northern and Central
Europe, as are also those who still cling to
their ancient home in Palestine. Lastly, the
Jews that have been settled in India for a
long succession of generations, have become
nearly as black as the natives around them,
so that the people of a particular colony at
Mattacheri, in Cochin, in whom this change
has not yet taken place, are distinguished
by the appellation of“ white Jews.” Hence it
may be stated as a general proposition, that
the complexion of the Jewish race tends to as-
similate itself to that prevailing in any country
in which their residence has been sufficiently

prolonged ; and even admitting that a limited
admixture with the surrounding population
has taken place in arty or all of these in-
stances, still the introduction of a small quan-
tity of extraneous blood does not by any
means afford an adequate explanation of the
change, since it has not been sufficient to alter
any of the other characters of the race, and
(as already remarked) the immediate results of
such an occasional admixture are soon merged
in the general uniformity of the mass. It is
probable that, in races as in individuals, the
influence of a tropical climate in darkening
the complexion will be more decided, in pro-
portion to the previous condition of thechro-
matogenous function ; for example, that the
Jews, whose natural complexion is swarthy,
are more readily blackened than Saxons or
Celts would be, the pigmentary matter in
their epidermis being of a different character.

There are several other cases of the same
kind, in which the historical testimony is less
complete, but in which the deficiency is made
up by philological evidence. Thus, the Ba-
rabra or Berberines of the higher parts of the
Nile, appear, from the most careful researches
that have been made into their history, to be
the descendants of the Nobatae, who were
brought by Diocletian from an oasis in the
western country, fifteen centuries ago, to in-
habit the valley of the Nile. The particular
district out of which they issued was proba-
bly Kordofan, the inhabitants of which, true
Negroes, still preserve and speak the Barabra
language. In their habits of life, they show
a considerable advance in civilisation ; and
this has been accompanied by a considerable
change in complexion, their present physiog-
nomy and hue of skin presenting a marked
resemblance to that of the ancient Egyptians.
This alteration cannot be set down to any
intermixture with the Arabs, or other in-
habitants of the Nile Valley, from whom the
Berberines keep themselves distinct. — In like
manner, the Eunge, who made themselves
masters of Sennaar about three centuries ago,
although originally Negroes of the Shilukh
nation, no longer present the physiognomy or
complexion of that race, but much more
nearly approach the Berberines. There ap-
pears, in both cases, to be a special tendency
towards a red complexion, and even red hair;
and among the Funge, the individuals thus
distinguished are stated to form a separate
caste, being known under the name of “ El
Akmar,” or “the red people.” In Northern
India, again, there is no doubt that many of
the tribes of mountaineers, already alluded to
as distinguished by fair complexion and blue
eyes, are of the same stock with the inhabit-
ants of the low country ; their language, tra-
ditions, religious observances, &c., being es-
sentially the same. One of the most remark-
able of these tribes is the Siah-Posh,a people
of exquisite beauty, with regular Grecian
features, blue eyes, arched eyebrows, and a
fair complexion, having no resemblance to
the Affghan or Cashmerian people, near
whom they dwell; their language principally

1337

VARIETIES OF MANKIND.

consists of Sanscrit words, although Sanscrit
is no longer the spoken language of any part
of India ; and they are acquainted with only
the simplest form of Hindoo mythology ;
whence it may be fairly concluded, that they
separated from the common stock at a very
early period.

Titus, then, we have very strong evidence
that a certain relation exists between climate
and colour; and it is no valid objection to
the existence of such a relation, to say that it
is not perfectly uniform. For it is at least as
uniform as the relation between colour and
race, even where the climatic influences are
the same ; that is, the difference of shade
among people of different races that have
been exposed sufficiently long to the same
climatic influences, is not greater than that
which presents itself among individuals of the
very same nation. It would seem that, among
the most dark-skinned races, there is a greater
variety of complexion than is found in those
of fairer hue. Such has been already shown
to be the case among the Polynesian islanders ;
and the following extract from Bishop He-
ber’s Journal will serve to indicate the amount
of variety existing among the Hindoos. ‘‘ On
first landing,” he remarks, “ the great differ-
ence in colour between different natives
struck me much. Of the crowd by whom
we were surrounded, some were as black as
Negroes, others merely copper-coloured, and
others little darker than the Tunisines whom
I have seen in Liverpool. Mr. Mill, the
principal of the British College, who came
down to meet me, and who has seen more of
India than most men, tells me that he cannot
account for this difference, which is general
throughout the country, and every where
striking. It is not merely the difference of
exposure, since this variety is visible in the
fishermen, who are naked all alike. Nor
does it depend on caste, since very high-caste
Brahmins are sometimes black, while Pariahs
are comparatively fair. It seems, therefore,
to be an accidental difference, like that of
light and dark complexions in Europe ;
though, where so much of the body is exposed
to light, it becomes more striking here than
in our own country.” So among the in-
habitants of Central Europe, it appears that a
considerable modification in complexion has oc-
curred, which is not sufficiently accounted for
by the climatic change that has taken place
in it since the classical epoch. For the Ger-
manic nations were unanimously described by
ancient authors as exceedingly fair, possessing
yellow or red hair, and blue or grey eyes ; but
these characters are now far from being pre-
valent among them, and it is only amongst
the Scandinavian races that they are common
to the mass of the people.

On the whole, then, it must be concluded
that the Colour of the Skin is a character of
such variable nature, that no positive line of
demarcation can be drawn by its aid between
the different races of mankind ; and whilst it
must be freely admitted that we are far from
comprehending all the influences which ope-

rate to modify it, there seems ample evidence
that climatic variations, whose agency is ex-
erted for a sufficiently long period, are among
the most efficient. This statement is ob-
viously not invalidated by the fact, that Ne-
groes and other dark-skinned people, who
have lived for some time in temperate cli-
mates, have not lost their characteristic hue.
For there is no example on record, so far as
the author is aware, in which a Negro tribe
or set of families has maintained itself for even
three or four generations in a temperate
climate, without intermixture either with the
surrounding “ whites ” or with “ blacks ” of
more immediate tropical descent. And until
it shall have been shown that a continuous
descent of many generations has taken place,
in a group of Negroes completely isolated from
the parent stock, and exposed to the condi-
tions which are presumed to favour the pro-
duction of the xanthous variety, ivithout any
considerable departure from their present com-
plexion, there will be no negative evidence at
all equivalent in probative value to the facts
already cited on the affirmative side of the
question.

5. We have now to inquire into the cha-
racters furnished by the colour, texture, and
mode of growth of the Hair, which have been
much relied on by some writers, as more per-
manent and distinctive than those furnished
by the hue of the skin. Thus, the Negro is
usually characterised by his “ woolly ” hair ;
while the Mongolian races are affirmed to be
peculiar in the scantiness of their pilous
covering ; and the Hottentots are further
separated by its tufted arrangement, which
has been compared to the mode in which
the bristles are set in a scrubbing-brush. — Now
in regard to the colour of the hair, it is
scarcely necessary to remark that it cannot
be taken alone as a distinctive character of
races ; since it is liable to present the most
extreme variations within the limits of any
one. Among the xanthous Anglo-Saxons,
for example, jet-black hair is by no means
uncommon ; although various shades of brown
are most frequently met with. Among Ne-
groes, on the other hand, it is not at all rare
to meet with a more or less complete de-
parture from what may be freely admitted to
be the prevalent character of their race. In
the instances which have been already cited
as proving the want of constancy in the com-
plexion of the dark or melanic races, a corre-
sponding change manifests itself in the colour
of the hair, which often becomes of a reddish
brown, or even of a much lighter hue. These
may occur in individuals, or in whole tribes.
Thus, Dr. Pickering speaks of having seen
two children, in whom “the Negro aspect had
so entirely disappeared, that they might have
passed for the children of Europeans, but for
the remarkable appearance of the hair,” which
he could “ compare to nothing but a white
fleece.” * The (Singhalese, according to the
testimony of Dr. Davy, present as many va-

* The Races of Man (Bolin’s edition), p. 188

1338

VARIETIES OF MANKIND.

rieties of hair as they do of complexion ; its
hue ranging through black and brown to red
and even flaxen : and precisely the same is
true of the Tahitians and Marquesans among
the Oceanic race, as well as among many
other nations. The texture and mode of growth
of the hair, however, are characters on which
it would appear, at first sight, that more re-
liance may be placed. The pilous covering may
be described as “ woolly,” “ crisped” or “friz-
zled,” “flowing ” or “wavy,” and “straight.”
The African and Oceanic Negroes alone are
characterised by “woolly” hair ; the Austra-
lians, Abyssinians, and many African nations,
usually have the hair more or less “ crisped”
or “ frizzled among the Indo-Europeans,
the “flowing” or “ wavy” character prevails;
while a peculiar straightness most commonly
presents itself among nations of Mongolian
descent. It is obvious, however, that these
several terms express little more than differ-
ences in degree. For if “straight” hair has
a slight tendency to curl, it becomes “ wavy;”
if this tendency be increased, it is commonly
termed “ curly ; ” the “ crisped ” or “ friz-
zled” hair is little else than hair with a pecu-
liarly stiff and close curl ; and the “ woolly ”
covering of the head of the Negro is by no
means so different from the crisped hair of
other dark races, as the designation given to
it would imply, the chief difference consisting
in its closeness of texture and its tendency to
mat together. As Dr. Prichard has correctly
stated, it is clearly shown by microscopic ob-
servation that the hair of the Negro is not
really “ wool,” and it presents no constant
structural difference from the jet-black hair
which is not uncommon among Europeans.
It has lately been asserted, however, by
Dr. P. A. Browne, of Philadelphia, that the
following definite structural differences do
exist : — “ The hair of the white man presents
an oval section ; that of the Choctaw and
some other American Indians is cylindrical ;
that of the Negro is eccentrically elliptical or
flat. The hair of the white man, besides its
cortex and intermediate fibres, has a central
canal, vyhich contains the colouring matter,
when present. The wool of the Negro has
no central canal, and the colouring matter is
diffused, when present, either throughout the
cortex, or this and the intermediate fibres.
In hair the enveloping scales are comparatively
few, smooth of surface, rounded at their
points, and closely embrace the shaft ; in
wool they are numerous, rough, sharp-pointed,
and project from the shaft. Hence the hair
of the white man will not felt ; the wool of
the Negro will.”* Now, upon this it may be
remarked that neither of the characters speci-
fied by Dr. Browne will stand the test of
extensive observation. The form of the shaft,
as shown in transverse section, varies greatly
in the hairs of the same race, and even in
those of the same individual ; for not only is
it sometimes round, sometimes oval, and
(though more rarely) eccentrically elliptic or

* Transactions of the American Medical Associa-
tion, vol. iii. p. 62.

nearly flat ; but it may be even reniform, or
channelled on one side, a variety of which
Dr. Browne takes no notice, except as oc-
curring in the Hottentot. The central canal
of the hair, which is occupied by medullary
cells, is an extremely variable character ;
being often undistinguishable in the hair of
the white races. Moreover, the pigmentary
matter is sometimes almost exclusively con-
fined to the cells of the central canal ; some-
times it is equally diffused through the whole
fibrous substance forming the shaft of the
hair : and sometimes we have even seen it in
greatest abundance towards the periphery,
the centre being pale. Hence the elliptical
section, the absence of “ central canal,” and
the diffusion of pigmentary matter through
the hair, are not in the least degree peculiar
to the Negro, and cannot be regarded as
characteristic of his hair. So, again, the
writer takes upon himself to assert that there
is not a greater difference in the degree of
serration on the surface (which is due to the
imbricated arrangement of the scales forming
the cortical layer) between the hair of the
Negro and that of other races, than exists
among the individuals of any one race ; and
that the Negro’s hair does not approximate
more closely to wool in this respect, than the
Negro’s cranium does to that of the chim-
panzee. The only constant peculiarity of the
Negro’s hair is the tendency to a close curl ;
and this seems connected with its form. As
a general rule it may be stated that the
roundest hairs curl least, and that those which
show most flattening are the most disposed to
curvature in their growth. But that there is
something also in the nutrition of the hair
which influences its mode of growth, appears
from the following fact stated by Mr. Erasmus
Wilson as the result of extensive observa-
tions : — “I have collected several instances
in which the hair, naturally possessing a strong
curl, becomes lank and straight if its pos-
sessor be out of health ; the straightness of
the hair becoming as certain an index of a
disordered state of the economy, as a yellow
eye-ball or a white tongue.”*

Now if we attempt to apply the texture of
the hair to the discrimination of races, we
find that although it has a certain value as
affording a character of general applicability,
yet that this will not bear being carried too
minutely into particulars. Thus, among the
African nations, there are many whose affinity
to the Negro race cannot be questioned, and
which yet have merely “crisped” or “friz-
zled” hair, instead of a woolly covering; and
there are others which cannot be shown on
any other grounds to have a different descent,
among w'hom the hair is long and flowing.
On the other hand, we not unfrequently
meet with individuals among the Anglo-
Saxon race, in whom the hair is not merely
curly, but “ frizzled,” and almost “ woolly” in
its texture. Among the Oceanic races, again,
there is every gradation of the same kind ;

* On the Management of the Skin, 3d ed. p. 77.

1339

VARIETIES 01

and great varieties present themselves within
the limits of any one tribe. Here, too, the
influence of external conditions shows itself
in a very marked degree ; for it is among the
inhabitants of the lower levels bordering on
the sea, between the tropics, who are most
exposed to the vertical rays of the sun, their
climatic conditions being nearly allied to those
of the Negro, that the “woolly” character
most remarkably show's itself ; whilst in other
tribes of the same race, which are not less
prognathous, but live in higher and drier situa-
tions, the hair is only “ frizzled,” or even
becomes long and wavy. Even if, as Dr.
Prichard justly remarks, the hair of the Negro
were really analogous to wool, it would by no
means prove the Negro to be a peculiar and
separate stock, unless the peculiarity were
constantly presented by all the nations of
similar descent ; and were restricted to them
alone ; for, as already pointed out, there are
breeds of domesticated animals which bear
wool, whilst others of the same species, under
different climatic influences, are covered with
long straight hair. It is not unimportant to
notice, that wool is occasionally borne by the
dog, ox, and hog, to neither of which it is
natural ; whilst the sheep, whose ordinary
covering is composed of it, occasionally ex-
change it for long straight hair. These facts
so unequivocally prove that the texture of
the hair is peculiarly liable to be influenced
by external conditions, that it could only be
on the strictest proof of invariability, that such
a character could be properly adopted as a
basis for specific distinction.

As examples in which there is historical
evidence of alteration in the texture and mode
of growth of the hair, it will be sufficient to
refer to the case of the Barabras already
cited, whose hair, originally woolly, has be-
come longer and straighter, only retaining a
slight crispness ; and to that of the Western
Turks, whose chins are furnished with flowing
beards, in which their Eastern relatives are
almost entirely deficient.

The greatest peculiarity in the growth of
the hair is exhibited by the Hottentot race.
The following account of its appearance in a
young Bushman, who recently died in the
United States, is given by Dr. Parsons* : —
“ His hair lay in little distinct, compact, curly
tufts, twisted spirally ; and in the intervals of
these tufts, the skin was distinctly seen. The
filaments were very fine, some of them five
inches long, and black. They contained a
distinct cortex and granular medulla. The
transverse section of a filament resembled that
of the Negro’s, except in being concave on one
of the two longer sides of the ellipse,” or reni-
form. Thus, in the texture of the hair itself,
the Hottentot seems allied to the Negro,
whilst its sparseness reminds us of the scanti-
ness by which the Mongolian races are gene-
rally characterised. We shall hereafter see,
that there is strong reason for regarding the
Hottentot race as of kin to the Negro ; and

* Transactions of the American Medical Associa-
tion, vol. iii. p G2. '

MANKIND.

for attributing the modification which it has
undergone to the external conditions of its
existence. The peculiar character of the
chevelure of the Papuans, which will be no-
ticed in the account of that race, seems to be
chiefly due to its artificial treatment.

From the Anatomical portion of our inquiry,
then, we are led to the general conclusion,
first, that no such difference exists in the ex-
ternal conformation or internal structure of
the different Races of Men, as would justify
the assertion of their distinct origin ; and,
secondly, that although the comparison of the
structural characters of races does not furnish
any positive evidence of their descent from a
common stock, it proves that even if their
stocks were originally distinct, there could
have been no essential difference between
them, the descendants of any one such stock
being able to assume the characters of an-
other.

Of the next subject for investigation, the
Physiological conformity or diversity of the
several races of mankind, a much briefer sum-
mary will be sufficient. This part of the in-
quiry has been pursued with great diligence
and success by Dr. Prichard*, who lays it
down as a general axiom (the truth of which
must be admitted by all who are competent to
form an opinion on the subject, its validity
being confirmed by the careful study of those
races of domesticated animals which are re-
markable for the greatest amount of anatomi-
cal variation), that the great laws of the vital
functions, such as those expressing the periods
and duration of life, the economy of the sexes,
and the phenomena of parturition and repro-
duction, are, with slight deviations resulting
from external agencies, constant and uniform
in each particular species ; whilst there are
usually decided differences in regard to the
same peculiarities among races ofA animals,
which, though nearly resembling each other,
are yet specifically distinct.

Now, taking the average duration of life as
the first point of comparison, it has been
shown by Dr. Prichard, that, whilst there is a
marked difference in this respect between man
and the highest apes — the full term of exist-
ence of the chimpanzee being stated by M.
Lesson at not more than thirty years, and
that of inferior species being less, — there is
absolutely no difference among the several
races of mankind, the extreme age of the
Negro and American races being at least as
great as that of the European, with the same
average duration of life under the same cir-
cumstances as regards climate, mode of
life, &c.

The age at which the body attains its full
development, also, appears to be the same
amongst different races ; or, at any rate, does
not differ more than among the different indi-
viduals of the same race. The inquiry into
the epoch of the first menstruation has been
most industriously prosecuted by Mr. llo-

*

Physical History of Mankind, vol. i.

134-0

VARIETIES OF MANKIND.

berton ; and its results, published from time
to time, as they were obtained, have been
lately collected in a form which admits of easy
comparison.*' It appears, from the evidence
which he has brought together, that there is
no considerable difference either in the average
period of puberty, or in the earliest date of
menstruation, among the greater number of
tribes who are scattered over the whole of the
habitable globe, from the equatorial to the
polar regions , anil that neither has a cold
climate that influence in retarding it, nor a
warm one in accelerating it, which is popu-
larly attributed to these agencies respectively.
The only well-marked exception to this general
rule, occurs in the case of the Hindoo females,
among whom the first menstruation occurs on
the average about two years earlier than in
this country. But this only arises from the
fact, that a larger proportion of first menstru-
ations among Hindoo females, takes place in
the earlier years of that period, over which
the commencement of puberty is distributed
in European females, the distribution in the
latter being more equable, as will be seen by
the following table, furnished by Mr. Rober-
ton : —

Ages.

Hindustan.

England.

8

3

9

8

14

10

18

55

11

80

77

12

145

142

13

139

263

14

105

396

15

45

417

16

24

340

17

18

215

18

5

138

19

3

65

20

1

33

21

2

9

22

—

4

23

1

1

597

2169

For whilst the average age of puberty in
the Hindoo female is thirteen years, and in
the British, fourteen years eleven months, the
per-centage of menstruations under eleven
years is nearly the same in the two countries,
so that the current idea of the very early pu-
berty of Hindoo females is quite incorrect ;
and the difference in the average solely arises
from the fact, that the greatest number of first
menstruations occur among Hindoo females
in the twelfth, thirteenth, and fourteenth years,
whilst among the females of this country the
larger proportion presents itself in the four-
teenth. fifteenth, and sixteenth years. Now
this difference, as Mr. Roberton justly re-
marks, cannot be attributed to climate, for
Demerara and the West Indian Islands have
a higher mean annual temperature than Cal-

* Essays and Notes on the Physiology and Dis-
eases of Women, and on Practical Midwifery. 8vo.
London, 1851.

cutta and the Dekhan ; and yet we know that
the Negresses in these colonies are not earlier
than the peasant women in England. A more
probable cause, however, lies in the peculiar
habits of the natives of that country, which
tend, in more ways than one, to force forward
the period of puberty. “ It is the law of the
Shastras, that females shall be given in mar-
riage before the occurrence of menstruation,
and that, should consummation not take place
until after this event, the marriage is a sin.
Accordingly, it is the custom in Lower Ben-
gal to send the girl at the age of nine years to
the house of her husband, unless the latter he
so distant that it cannot he done ; and two
ancient Hindoo sages are of opinion, that if
the marriage is not consummated before the
first appearance of the catamenia, the girl
becomes ‘degraded in rank.’ At Bangalore it
would seem that this revolting custom does
not obtain, the husband refraining from taking
his wife to his own house till not less than
sixteen days have elapsed subsequently to
puberty.”* Now, it can scarcely be ques-
tioned that such a premature sexual excite-
ment will have a tendency to accelerate the
epoch of puberty ; and that, when this is con-
stantly acting through a long succession of
generations, an early puberty may come to be
a character of race. But besides this modus
operandi of the custom in question, the fol-
lowing has been pointed out by Mr. Ro-
berton : — “When it is recollected that the
consummation of marriage among the Hindoos
has taken place, at the latest, on the arrival
of puberty, during a lapse of more than three
thousand years, and that the practice is sanc-
tioned by ancient laws and consecrated by
custom, it is easy to conceive that those
females who were latest in reaching puberty,
would be the least sought after for wives, — that
such women would not be unlikely, in many in-
stances, to remain unmarried, — and that thus
(owing to the origination of a preference on
this ground in the selection of their wives,
operating through a long period of time)
Hindoo women would gradually come to con-
sist, in a proportion different from that in
Europe or elsewhere, of such as by constitu-
tion are early nubile. To me there seems no-
thing extravagant or far-fetched in this sup-
position. The production of a like state of
things in England, in any particular district, is
quite conceivable. Nothing is better esta-
blished, than that early (or late) puberty is
a family peculiarity. Let us, then, only sup-
pose families, possessing this kind of consti-
tution, to intermarry, and the peculiarity in
question would be propagated, extended, and
transmitted ; and so a race, distinguished by
it, would be produced.” f It is a justification
of this view, that the mean age of puberty
should differ in Bengal and the Dekhan, to
the extent of nearly a year, being twelve years
six months in the former province, and thirteen
3'ears five months in the latter, notwithstand-
ing its warmer latitude ; for, as just stated,

-j- Op. cit. p. 129.

Op. cit. p. 131.

1341

VARIETIES OF MANKIND.

although formal marriages take place at a very
early age throughout India, the custom is so
far modified in the Dekhan, that consummation
is not effected until after the first menstruation
has appeared.

The frequency of the catamenial flux, and
the epoch of life to which it extends, appear
from Mr. Roberton’s inquiries, to be no less
constant among different races. It is quite
true that the period of child-bearing is sooner
terminated among the women of many tribes,
especially in tropical climates, than it usually
is in this country ; but this is fairly attri-
butable to the earlier marriages, and the con-
sequently premature excitement of the gene-
rative power, of which its earlier decline is the
natural consequence. The same is continually
seen in this country. The marked difference
in this respect, that arises out of laws and
customs affecting the marriage state, is shown
by the fact, that in India the mean age for a
first parturition is 15£ years, whilst among
500 Manchester female operatives, tabulated
by Mr. Roberton, the mean age was found to
be 23 years. Some very curious evidence
has been collected by that gentleman, which
goes to prove that marriages nearly as pre-
mature as those of Hindoo females were for-
merly sanctioned by law and public opinion
in this country ; and that in Ireland they
have been by no means unfrequent within a
recent period.

The duration of pregnancy is well known to
be the same throughout all the races of man-
kind ; and this is a fact of peculiar importance,
as a difference in this respect is elsewhere
observable between species that are in other
respects closely allied.

The fertility of hybrid races, originating in
the intermixture of two races whose affinity
is most remote, is a fact of which there can
be no doubt whatever ; and there is strong
reason to believe that those hybrid races, the
parents of which are Europeans on one side,
and the aborigines of any country on the
other, are generally destined to become the
dominant population of those countries. For,
on the one hand, these “ half-castes ” very
commonly combine the best attributes of the
two races from whose admixture they sprang;
namely, the intelligence and mental activity of
the European, and the climatic adaptation of
the native.* And they are also in general
distinguished for their fertility, when paired
with each other, so that they are rapidly
rising into numerical importance. On the
other hand, this very intermixture, taking
place as it usually does between an European
father and a native mother, tends to di-
minish the number of the native population
in a very remarkable manner ; for there is
now a large amount of evidence, that when a
native female of the American or Polynesian
races has once been impregnated by an
European male, she thenceforth loses all
power of conception from intercourse with

* This is well seen in the case of the descendants
of the mutineers of the Bounty and of Tahitian
women, who now occupy Pitcairn’s Island.

the male of her own race. This was first
pointedly stated by that very intelligent tra-
veller, the Count de Strzelecki, who has
lived much among different races of abo-
rigines, the natives of Canada, of the United
States, of California, Mexico, the South
American Republics, the Marquesas, Sand-
wich. and Society Islands, New Zealand, and
Australia, and who affirms that in hundreds oj
cases of this kind into which he has inquired,
and of which he preserves memoranda, there
has not been a single exception.*

As regards Australia and New Zealand,
this statement, strange as it seems at first
sight, has been fully borne out by independent
evidence ; and it offers the most complete
explanation yet given, of the very rapid de-
crease in the native population of the various
islands of Oceania, in which European races
have been long established. Nothing pre-
cisely analogous is known in any other
case. Instances of the influence of the father
of a first offspring upon subsequent off-
spring by another father, are so frequent,
as to have given rise to a current be-
lief among the breeders of domesticated
animals, that such is the fact ; and the very
ingenious hypothesis has been suggested by
Mr. M'Gillivray, and ably advocated by Dr.
Harvey, that the female parent in such a case
becomes inoculated with the qualities of the
male, through the blood of the foetus, which
partakes of the latter. But there is no known
case, in which impregnation of a female by a
male of a different species or variety has ren-
dered her subsequently infertile to males of
her own ; on the contrary, the facts just re-
ferred to, as to the extension of the influence
of the first father over the subsequent progeny,
indicate that such is not the case. Hence
this peculiarity affords no ground whatever
for the establishment of a specific distinction
between the two races ; and the invalidity of
such a distinction is at once indicated by the
fact, that the peculiarity in question does not
hold good in regard to the African races, the
fertility of the Negro female with the male of
her own race not being apparently impaired
by previous fruitful intercourse with the
European male, a kind of intercourse which
is notoriously common in the West India
Islands, and in the slave-holding states of
North and South America. f

* See the Count de Strzelecki’s Physical Descrip-
tion of New South Wales and Van Dieman’s Land,
pp. 345 — 347. ; and Dr. Harvey’s Papers on the In-
oculation of the Maternal System with the Pecu-
liarities of the Paternal, through the Foetus in
Utero, in the Edinb. Monthly Journal for October,
1849, and October and November, 1850.

f It may he, as suggested by Dr. Harvey (loc.
cit.), that the final purpose of this curious provision
should be to replace the least improvable races by a
population of a much higher order ; the aboriginals
thus becoming extinct without violence, but in the
natural course of things ; and their places being oc-
cupied either by half-breeds or Europeans. And,
on the other hand, the immunity of the Negro may
be designed to preserve his tenure of those parts of
the earth, whether in subserviency to the European
or independently of him, where, by reason of the

1342

VARIETIES OF MANKIND.

The Psychical comparison of the various
races of mankind is really, in a practical point
of view, the most important department of
the whole investigation ; and yet it has been
the most neglected, until Dr. Prichard took up
the inquiry. Whilst the capaciousness of the
skulls of the Negro and European has been
measured and compared, but little account
has been taken of the workings of the brains
which they contained. The colour of the
skin, the flatness or projection of the nose,
the lankness or crispness of the hair, the
straightness or curvature of the limbs, have
been scrutinised and contrasted, as if these
alone constituted the proper description of
Man ; though it is surely in his mental cha-
racter and its manifestations, that the attri-
butes of humanity peculiarly consist.

The tests by which we recognise the claims
of the outcast and degraded of our own coun-
try to a common humanity, are surely the
same as those by which we should estimate
the true relation of the Negro, the Bushman,
or the Australian, to the cultivated European.
We must not judge of their capabilities solely
by their manner of life, however wretched
that may be ; since this is often, in great
degree, forced upon them by external circum-
stances. Nor have we any right to pronounce
them incapable of entertaining any particular
class of ideas, simply because we cannot find
the traces of these in their existing forms of
expression. It is only when such people have
been attentively studied — not by passing
travellers, who, though they may pick up a
little of their language, see little of their
inner life, — but by residents who have suc-
ceeded in gaining acquaintance with habits
which a jealous reserve would conceal, and
ideas which the imperfections of language
render most difficult of transmission *, that
we have any right to affirm what they are ;
and even this amount of information affords
little means of judging what they may be-
come.

It will be only when the effect of education,
intellectual, moral, and religious, has been
fairly tested, that we shall be entitled to speak
of any essential and constant psychical differ-
ence between ourselves and the most degraded
beings clothed in a human form. It will only
be when the influence of a perfect equality in
civilisation and social position has been in-
effectually brought to bear upon them for
several consecutive generations, that we shall
be entitled to say, of the Negro or of any other
race, that it is separated by an “ impassable
barrier” from those which arrogate to them-
selves an inalienable superiority in intellectual
and moral endowments. All our present
knowledge on this subject tends to show that

high temperature, the European cannot toil in the
way or to the degree which the cultivation of those
regions requires.

* A curious example of the difficulty of fully
comprehending the import of abstract terms, in a
language which has been so much studied, both by
linguists and by philologists, as the Chinese, will be
found in the Athenteum for March 1. 1851.

no such barrier exists, and that there is a
real community of psychical characters among
the different races of men ; the differences in
the degree of their positive and relative de-
velopment, not being greater than those which
exist in the successive or contemporaneous
varieties of our own race. And it may be
added, too, that in almost every instance, the
more we learn concerning any particular
nation or tribe reputed to possess the meanest
possible aspect of humanity, the more we
generally have to recede from the harshness
of our first impressions.

A very striking example of the near affinity
that may exist between the most degraded
“ outcasts of humanity,” and races consider-
ably advanced in civilisation and intelligence,
is presented by the relationship of the Bush-
men of the Cape of Good Hope to the Hot-
tentot population which tenanted that region
previously to the arrival of European colonists.
The following is a graphic account recently
given of them by one who has had ample
opportunities of observation : — “ The Dutch
Boer, the Griqua, the Bechuana, the Kaffir,
all entertain the same dread of, and aversion
to, these dwarfish hordes, who, armed with
their diminutive bows and poisoned arrows,
recklessly plunder and devastate, without
regard either to nation or colour, and are in
their turn hunted down and destroyed like
beasts of prey, which in many respects they so
nearly resemble. . . . Time, a knowledge

of, and an occasional intercourse with, people
more civilised than themselves, have made
little change in the habits and disposition of
this extraordinary race. The Bushman still
continues unrelentingly to plunder, and cruelly
to destroy, whenever the opportunity presents
itself. His residence is still amongst inacces-
sible hills, in the rude cave or cleft of the
rock — on the level karroo, in the shallow
burrow, scooped out with a stick, and shel-
tered with a frail mat. He still, with deadly
effect, draws his diminutive bow, and shoots
his poisoned arrows against man and beast.
Disdaining labour of any kind, he seizes when
he can on the farmers’ herds and flocks,
recklessly destroys what he cannot devour,
wallows for consecutive days with vultures
and jackals amidst the carcases of the slain,
and, when fully gorged to the throat, slumbers
in lethargic stupor like a wild beast, till,
aroused by hunger, he is compelled to wander
forth again in quest of prey. When he can-
not plunder cattle, he eagerly pursues the
denizens of the waste, feasts indifferently on
the lion or the hedgehog, and, failing such
dainty morsels, philosophically contents him-
self with roots, bulbs, locusts, ants, pieces of
hide steeped in water, or, as a last resource,
he tightens his ‘ girdle of famine,’ and, as
Pringle says, —

‘ lie lays him down, to sleep away,

In languid trance, the weary day.’

Whether this precarious mode of existence
may, or may not, have influenced the personal
appearance and stature of the Bushmen it is

VARIETIES OF MANKIND.

1343

difficult to say, but a more wretched-looking
set of beings cannot easily be imagined. The
average height of the men is considerably
under five feet, that of the women little ex-
ceeding four. Their shameless state of nearly
complete nudity, their brutalised habits of
voracity, filth, and cruelty of disposition, ap-
pear to place them completely on a level with
the brute creation, whilst the ‘ clicking ’ tones
of a language, composed of the most unpro-
nounceable and discordant noises, more re-
semble the jabbering of apes than sounds
uttered by human beings.”*

Now, there is ample evidence that the Cape
Bushmen are a degraded caste of the Hotten-
tot race. They agree with the Hottentots in
all the peculiarities of physiognomy, cranial
conformation, &c., by which the latter are cha-
racterised ; and a careful comparison of the
languages of the two races has shown that
there is an essential affinity between them.
It has been ascertained by Dr. Andrew Smith,
that many of the Bushman hordes vary their
speech designedly, by affecting a singular
mode of utterance (employing the peculiar
clapping or clicking of the tongue, which is
characteristic of the Hottentot language, so
incessantly, that they seem to be giving utter-
ance to a jargon consisting of an uninterrupted
succession of claps), and even adopting new
words, in order to make their meaning unin-
telligible to all but the members of their own
community. According to the same autho-
rity, nearly all the South African tribes who
have made any advances in civilisation, are
surrounded by more barbarous hordes, whose
abodes are in the wilderness and in the fast-
nesses of mountains and forests, and who con-
stantly recruit their numbers by such fugitives
as crime and destitution may have driven
from their own more honest and thriving
communities. In this manner it has happened
that within a comparatively recent period
many tribes of Hottentots have been de-
graded into Bushmen, through the oppres-
sions to which they have been subjected at
the hands of their more civilised neighbours.

Now, although of the Hottentots them-
selves we are accustomed to form a very low
estimate, — our ideas of them having been
chiefly derived from the intercourse of the
Cape settlers with the tribes which have been
their nearest neighbours, and which have un-
fortunately undergone that deterioration which
is so often found to be the first result of the
contact of civilised with comparatively savage
nations, — it appears from the accounts of
them given by Dutch writers at the time of
the first settlement of the Cape, that they
were a people considerably advanced in civi-
lisation, and possessed of many estimable
qualities. Their besetting sins seem to be
indolence and a love of drink (in this respect
strongly resembling the Irish); yet when they
can be induced to apply, they show no want
of capacity or vigour. The testimony of

* Lieut.-Colonel E. E. Napier’s Excursions in
Southern Africa.

Lieut.-Col. Napier is very strong as to their
merits as soldiers when officered by Euro-
peans ; “ and it has been,” he says, “ on the
Cape Mounted Rifles, composed chiefly of this
race, that many of the greatest hardships,
fatigues, and dangers of the last and former
Kaffir wars have principally fallen.” * It has
been frequently said that the Hottentots differ
from the higher races, in their incapacity to
form or to receive religious ideas. This is,
however, by no means true. The early Dutch
settlers describe them as having a definite
religion of their own ; and it was their obsti-
nate adhesion to this, which was the real ob-
stacle to the introduction of Christianity
among them. When the attempt was per-
severingly made and rightly directed, the
Hottentot nation lent a more willing ear than
any other race in a similar condition has done
to the preaching of Christianity ; and no
people has been more strikingly and speedily
improved by its reception.

Now, if we compare the condition of these
people with that of the lowest members of
the population of countries that claim to be
most advanced in civilisation, we find that the
difference is not so great as it might at first
appear. Unfortunately, there is scarcely a
civilised nation, in the very bosom of which
there does not exist an outcast population,
neither less reckless, nor less prone to the
indulgence of their worst passions, than the
miserable Bushmen, and only restrained from
breaking loose by external coercion. The
want of forethought and wild desire of re-
venge, which are said to be among the most
striking characteristics of the Bushmen, are
scarcely less characteristic of those classes
dangereuses, which, as often as the arm of the
law is paralysed, issue from the unknown
deserts of our great towns, and rival in their
excesses of wanton cruelty, the most terrible
exhibitions of barbarian inhumanity. So,
again, there is nothing in the inaptitude of
any barbarous tribe for religious impressions,
which surpasses that of the young heathens
of our own land, who, when first induced to
attend a “ ragged school,” are recorded to
have mingled “ Jim Crow” with the strains of
adoration in which they were invited to join,
and to have done their best, by grimaces and
gestures, to distract the attention of those
who were fixing their thoughts on the solemn
offering of prayer ; or of those who, after
having joined with apparent sincerity in reli-
gious worship, simultaneously took their de-
parture as the hour approached for the break-
ing up of the city congregations, in order that
they might “ go to work,” as they expressed
it ; that is, that they might exert their thievish
ingenuity upon the dispersing crowds. Now
if, on the one hand, we admit the influence
of want, ignorance, and neglect, in accounting
for the debasement of the savages of our own

* The conduct of this corps in the recent out-
break (March 20. 1851), is stated by the Governor
to have been most admirable. It was under its
escort alone, that he forced his "way through a
country entirely in possession of the Kaffirs.

1344-

VARIETIES OF MANKIND.

great towns, and yet cherish the belief that,
so far from being irreclaimable, they may at
least be brought up to the standard from
which they have degenerated ; on the other
hand, we cannot well doubt the operation of
the same causes on the outcasts of the Hot-
tentot races, or refuse to believe that even
the wretched Bushmen might be brought back
at least to the original condition of the people
from among whom they have been driven
forth.*

It may be freely admitted that the different
races of mankind exhibit very different degrees
of capacity for intellectual, moral, and social
improvement ; but this difference is not
greater than that which exists amongst indi-
viduals of the most favoured races, and cannot

* This parallel, suggested by the writer of this
article some time since (Edinburgh Review, Oct.
1848), has been recently followed up by the author
of “ London Labour and the London Poor ; ” who has
shown that a remarkable correspondence exists in
mental habitudes and mode of life, between the
sonquas or paupers of the Hottentot race, and the
wandering outcasts of our own, who possess nothing
but what they acquire by depredation from the in-
dustrious, provident, and civilised portion of the com-
munity. The latter, like the former, have a secret or
“ slang ” language of their own, adapted for the con-
cealment of their designs ; and, as already mentioned,
they are generally characterised by the great de-
velopment of the facial in proportion to that of the
cranial part of the skull. The one tribe of
“ nomads,” like the other, “ is distinguished from
civilised man, by his repugnance to regular and
continuous labour; by his want of providence in
laying up a store for the future ; by his inability to
perceive consequences ever so slightly removed
from immediate apprehension; by his passion for
stupifying herbs and roots, and, when possible, for
intoxicating fermented liquors ; by his extraordinary
powers of enduring pain ; by an immoderate love of
gaming, frequently risking his own personal liberty
upon a single cast ; by his love of libidinous dances ;
by the pleasure he experiences in witnessing the
suffering of sentient creatures; by his delight in
warfare and all perilous sports ; by his desire for
vengeance ; by the looseness of his notions as to
property; by the absence of chastity among his
women, and his disregard of female honour ; and
lastly, by his vague sense of religion, his rude idea
of a Creator, and utter absence of all appreciation of
the mercy of the Divine Spirit.” It is further re-
markable that the nomadic tribes seem to possess
(sometimes hereditarily, sometimes as an acquired
habit) such a constitutional adaptation to a wan-
dering life, that, despite its privations, its dangers,
and its hardships, they can rarely be induced to
abandon it. It is well known that among the many
instances in which the aborigines of Australia or of
North America have been brought up and educated
from an early age amongst Europeans, there are
few, if any, in which they have been satisfied to
to remain and to adopt the habits of civilised life.
On approaching manhood, they become restless, and
take the first opportunity of absconding to join
their brethren in “ the bush.” So, again, there are
numerous examples of white men adopting, by
their own choice, all the usages of the Indian
hunter or Australian bushman ; and these, having
once imbibed a fondness for the nomadic life, are as
irreclaimable as those who have grown up in it.
The same is the case, according to Mr. Mayhew,
with a large proportion of the “street-folk” of
London ; who will give up situations affording com-
forts and advantages of a far superior order, to
return to the indulgence of their wandering pro-
pensity.

for a moment be assumed as the basis for
specific distinctions between them. If the
Negro, for example, is at present far behind
the European standard, yet, under favourable
circumstances, the intellect and moral charac-
ter of individual Negroes have been elevated
to it; while, on the other hand, we have too
frequent proof that the intellect and moral
character of the European are capable, not
merely in individuals, but in families and
groups of people, of sinking even below the
average African standard. It is the observa-
tion of all who have had experience in the
education of the children of races reputed to
be inferior, such as Negroes, Hottentots, and
Australians, that their capacity is at least
equal to that of the lowest class of our own
youthful town population, and that their do-
cility is, if anything, greater. That this mental
development is generally checked at an early
age, and that the adults of these raees too
frequently remain through life in the condition
of “ children of a larger growth,” may be freely
conceded. But observation of the difference
in developmental power, between the mind of
the descendant of an educated ancestry, and
that of the descendant of an ignorant and
uncultivated peasantry, shows that within the
limits of the same race the same difference
may exist ; and nothing is more likely to main-
tain it, than the absence of any encourage-
ment to advancement, and the persistence, on
the part of society at large, in the doctrine
that the Negro never can be admitted within
the pale of white civilisation.

Looking to the fact already mentioned
(p. 1 341.), as to the'absence of that tendency
to extinction in the African races, by sexual
contamination from Europeans, which shows
itself so remarkably among other aborigines,
it is not a little interesting to observe, that
there are elements in the Negro character,
which have been deemed, by competent ob-
servers, capable of working a considerable
improvement in even Anglo-Saxon civilisa-
tion. Many intelligent thinkers have come to
the conclusion, that the boasted superiority of
the latter is, after all, more intellectual than
moral ; and that in purity and disinterested-
ness of the affections, in childlike simplicity
and gentleness of demeanour, in fact, in all
the milder graces of the Christian temper, we
may have even much to learn of the despised
Negro. “ I should expect,” says Channing,
“from the African race, if civilised, less
energy, less courage, less intellectual ori-
ginality than in ours ; but more amiableness,
tranquillity, gentleness, and content. They
might not rise to an equality in outward con-
dition, but would probably be a much happier
race.” And it is to be remembered that these
and similar remarks have been made respect-
ing the Negroes of the Guinea coast, or their
descendants, who are, as we shall presently
see, the most degraded of all the African
races, except those of the neighbourhood of
the Cape, whose degradation has been in great
measure the result of European oppression,
and the introduction of European vices. It

VARIETIES OF MANKIND.

is not a little remarkable that the earliest
civilisation of which we have an)' distinct
traces in the western portion of the Old
World, — perhaps the very earliest develop-
ment of the arts of life and of a spiritual phi-
losophy that man has witnessed — should have
presented itself in a race which was not only
African in its locality, but also in its affinities,
such being demonstrably the character of the
Ancient Egyptians, as will be seen hereafter.
Yet to this race the civilisation of Greece, of
Rome, and of Western Europe may be in
great measure ascribed ; and long after the
time when its power and intelligence had
gained their highest state of development, the
progenitors of the Anglo-Saxon race, both in
Britain and in Germany, were in a state of
barbaric ignorance and brutalism.

Referring, for the particulars of this part of
the enquiry, to the valuable collection of in-
formation brought together by Dr. Prichard
chiefly from the records of the Moravian mis-
sionaries who have planted themselves over
almost every portion of the habitable globe,
and who have gained a more intimate ac-
quaintance with the mental habits and feelings
of the people among whom they dwell, than
has been acquired by any other class of Eu-
ropean settlers; the following may be adopted
as its general results : — In all the races of
mankind, with which any adequate acquaint-
ance has been gained, unequivocal indi-
cations may be discerned of the same moral
and intellectual nature as that which the most
civilised tribes exhibit ; and these indications
become more obvious, the more complete is
our knowledge of their habits, not merely of
action, but of thought. We can trace, in
short, among all the tribes who are endowed
with the faculty of articulate speech, the same
rational, human nature; superior to that of
the highest brutes, not merely in the com-
plexity of the processes which it is capable of
performing, but in that capacity for generating
abstract ideas, and thus arriving at general
principles, which, so far as we have the means
of judgment, appears to be the distinguishing
attribute of man. So, again, we discover in
all of them the same elements of moral feeling;
the same sympathies and susceptibilities of
affection ; the same conscience, or internal
conviction of accountableness, more or less
fully developed ; the same sentiments of guilt
and self-condemnation, and the same desire
for expiation. These principles take very
different forms of expression, even in civilised
life ; much more, therefore, ought we to be
prepared for finding nothing more, even among
the best specimens of uncivilised barbarism,
than the mere rudiments of a higher under-
standing, and of a nobler moral nature, than
that which they have at present reached.
But the rudiments are there, though not
always in the same degree of forwardness for
being moulded to the institutions of a more
regular society, for the development of the
intellectual powers under a rational education,
and tor that growth of the moral and religious
sentiments which Christianity is pre-eminently

VOL. IV.

1345

fitted to promote in every mind that opens
itself to its benign influence.

The general conclusion, then, which we
seem entitled to draw from the Anatomical,
Physiological, and Psychological facts to which
reference has been made, is that all the
human races may have had a common origin ;
since they all possess the same constant cha-
racters, and differ only in those which can
be shown to vary from generation to genera-
tion.— We have now to inquire, lastly, into
the bearing of philological evidence upon the
same question ; and as this department of the
inquiry is more foreign than the preceding to
the character of the present work, a brief
notice of its chief results is all that can be
here admitted. These results, it may be re-
marked, are of extremely recent acquisition.
In fact, there is no department of ethnology
in which progress is at present so rapid, as it
is in the study of glottology.

Now it may be observed, in the first place,
that what has been just said of the com-
munity of psychical nature amongst the se-
veral races of mankind, is very strongly con-
firmed by the general fact of the universality
of spoken language, and of the power of trans-
lating from one language to another. Dogs
and monkeys may have languages of their
own ; but there is no such relation between
these and ours, as may enable us to com-
prehend them ; and where brute animals
have been taught to comprehend human lan-
guage, it has been only so far as to acquire
a mental association between the sounds of
certain words, and the material objects which
they represent. This is but the first and
simplest stage of the acquirement of language,
as every one must perceive, who watches the
development of the power of communication
by this means, in early childhood. A very
large part of all languages, but especially of
those employed by nations advanced in in-
tellectual culture, consists of terms expressive
of ideas and relations, rather than of material
objects ; and it is in the capacity for ex-
pressing the former, that the distinctive at-
tributes of human language appear specially to
consist. This capacity, though existing more
or less in all languages, will obviously vary
considerably in degree, according to the in-
tellectual culture of the people of whose
thoughts they are the habitual expression ;
and the power of fully rendering the thoughts
conveyed by one language into another
tongue, must of course depend in great part
upon the relative advancement of the two.
The abstractions of a German transcendental
philosopher do not always admit of being ef-
fectively conveyed, even in a tongue so nearly
related as the English to their original, far
less could they be translated into Hottentot
gibberish. So, again, the peculiar style of
eloquence cultivated in the East, does not
produce its adequate effect, when rendered in
Western tongues. But any two barbarous
languages, or any two which are highly cul-
tivated, are, on the whole, so pervaded by a

4 R

134G

VARIETIES OF MANKIND.

sameness of character, as to bear witness to
the similarity of their internal source.

The affinities between languages are sought
by philologists in two entirely different di-
rections ; namely, in their vocabularies, and
in their methods of grammatical construction.
In comparing the former, it is of course ne-
cessary to make due allowance for the pos-
sible influence of conquest, intermixture, or
frequent intercourse, in modifying the original
tongues ; but the experienced enquirer may
generally eliminate this source of error, by
placing his chief reliance on what are termed
•primary words, i. e. on words which serve to
represent the universal ideas of a people in
the most simple state of existence. Such are
the terms expressive of family relations ; the
names of the most striking objects of the
visible universe, the sun, moon, stars, trees,
rivers, &c. ; terms distinguishing the prin-
cipal parts of the body, as the head, eyes,
hands, and feet ; the numerals, up to five, ten,
or twenty ; and verbs descriptive of the most
common sensations and bodily acts, such as
seeing, hearing, eating, drinking, sleeping.
Such primary words are never wanting in the
language of any nation ; and it has been ascer-
tained by observation, that they are the last
to undergo change, either in the spontaneous
modifications which take place in the course
of time, or under the disturbing influence
of a foreign idiom ; so that a conformity in
primary words affords very strong evidence of
a community of origin among the nations
which exhibit it. — The evidence afforded by
conformity in grammatical construction, re-
quires a more intimate acquaintance than is
needed for the preceding, with what is some-
times called the genius of the language ; but
when it has been gained, it is frequently even
more important than that furnished by the
vocabularies. For there are many cases in
which the latter are so continually under-
going important changes (the want of written
records allowing them to possess no more
than a traditional permanence), that the diver-
gence of tongues becomes so great, in the
course of even a few generations, as to prevent
tribes descended from a common ancestry
from understanding one another ; and yet the
system of grammatical construction, which
depends more upon the grade of mental de-
velopment, and upon the habits of thought,
exhibits a remarkable permanence.

The following are the principal types of
construction, or “ methods by which the re-
lation between the different words that con-
stitute sentences is indicated,” according to a
very recent and distinguished authority.*

1. The Aptotic type, of which the Chinese
is an example. In this, there is a total ab-
sence of inflections ; and the words which, in
languages of the classical form, do the work of
the inflections, that is, express the relations
of the principal words to each other, are
themselves most commonly the names of

* Dr. R. G-. Latham, on the Natural History of
the Varieties of Man, p. 9.

objects and actions, i. e., nouns and verbs.

“ Thus if,” says Dr. Latham, “ instead of say-
ing, I go to London, Jigs come from Turkey,
the sun shines through the air, we said I go
end London, Jigs come origin Turkey, the sun
shines passage air, we should discourse after
the manner of the Chinese.” This is the
lowest grade of linguistic development.

2. The Agglutinate type, which is carried
to its fullest extent in the American lan-
guages. These possess inflexions, which can
be generally shown to have arisen out of the
juxta-position and composition of different
words, the incorporation not having been suf-
ficiently complete wholly to disguise the ori-
ginally independent and separate character of
the inflexional addition. This may be re-
garded as a decided advance in development.

3. The Amalgamate type, of which the
classical languages are the most perfect ex-
amples. These possess a very complete system
of inflexions, which express the relation be-
tween the fundamental idea denoted by the
term, and some other ; and these inflexions
are so completely incorporated with the root
with which they are conjoined, that their
existence as separate and independent words
cannot be demonstrated, and can only be sup-
ported upon the analogy of the agglutinate
languages. Thus, “ in a word like hominem,
there are two parts, homin, radical; em, in-
flexional. In the word te-tig-i, there are the
same. The power of these parts is clear.
The tig- and homin- denote the simple action
or the simple object. The te- denotes the
time in which it takes place ; the i, the agent.
In the proposition te-tig-i homin-em, the em
denotes the relation between the object (the
man touched) and the action (of touching).
Logically, there are two ideas, e. g. that of
the action or object, and that of the super-
added conditions in respect to time, agency,
and relation.”

4. The Anaptotic type, of which the English
is an example. This designation is given to
languages which were once inflexional, but
which have in great part ceased to be so.
In such we find that the auxiliary words
which do the work of the Greek and Latin
inflexions, are not names of objects and
actions like those of the Chinese language,
but possess (generally speaking) a purely
abstract value, having a meaning only when
in context with other words. Thus, where
the Roman said te-tig-i, we say, I have
touched ; where the Roman said patri, we say
to father; where a Roman said tangam, we
say, I will (or shall ) touch. In many of these
auxiliary words, however, an independent
meaning can be clearly seen ; thus have and
will are obviously verbs in their own right;
and the conjunction if is a corruption of the
Saxon gj/Xgive). Moreover, the inflexions are
seldom or never wholly disused; so that these
anaptotic languages always preserve relations
of affinity to those of the two preceding
types, of which they may be considered a
peculiar development.

To one or other of these types, or to tran-

VARIETIES OF MANKIND.

1347

sitional grades between them, it is believed
that all existing languages may be referred.
It is remarkable that the development of a
language should not by any means correspond
to the advance of civilisation, so far, at least,
as this is manifested by progress in the arts of
life. The Chinese, for instance, of all known
languages, most completely preserves, in a
fixed or stereotyped condition, that earliest
phase in the development of speech, in which
every word corresponded to, or represented,
a substantial object in the outward world ;
and it cannot be denied that a considerable
amount of intellectual development is to be
found amidst that people. And from what is
known of the ancient Egyptian language, this
appears to have been nearly in the same con-
dition. On the other hand, there are many
languages of comparatively barbarous nations,
even belonging to the same group with the
Chinese, which possess much greater flexi-
bility. The highest development of language
however, is undoubtedly to be found coinci-
dent with the highest intellectual cultivation ;
since this pre-eminently shows itself in the
Indo-European tongues, of which the Sanscrit
may be taken as the type, the Hellenic pre-
senting its highest development in the amalga-
mate form, and the English in the anaptotic.
In both these do we find that the general
plan of construction tends to give to every
single word a fixed and definite meaning, and
at the same time, to render it subservient to
the general idea that the sentence is to unfold,
which is obviously the great end and aim of
language; whilst in the Chinese, every spoken
word has an immense variety of meanings, and
its import being determined, partly by its
place in the sentence, partly by the tones or
accents with which it is pronounced, and in
the written language by an immense number
of conventional signs derived from figurative
sources, which are destined, not to express
sounds, but to suggest ideas, and thus to
assist the reader in guessing the meaning of
the word.

Now the most positive evidence which
philology is able to afford, in regard to the
affinities of two languages, is undoubtedly that
which is derived from their conformity both
in vocabulary and in grammar. But it fre-
quently happens that one of these kinds of
evidence is deficient ; and the degree of reli-
ance that can be placed upon the other, taken
alone, must depend greatly upon the circum-
stances of the individual case. Thus, if there
be evidence that the vocabulary of one of
these languages is in a state of continual
change, an entire difference of vocabularies is
no obstacle to the idea of the affinity between
two languages, when this is decidedly indi-
cated by a striking conformity in their systems
of construction. On the other hand, when
two languages or groups of languages differ
greatly in their construction, but present a
certain degree of verbal correspondence, full
weight may be attached to that correspond-
ence, if it can be proved that it has not been
the result of intercourse subsequently to the

divergence of the stock, and if it can be shown
to be probable that their separation took
place at a period when as yet the grammatical
development of both languages was in its in-
fancy. The first appears to be true of the
American languages, which seem, as a whole,
to be legitimately referable to a common
stock, notwithstanding their complete verbal
diversity. The second is the aspect under
which it appears likely that the Indo-European
or Japetic, and the Syro- Arabian or Semitic
groups of languages will come to present
themselves ; the results of the recent labours
of Rawlinson, Layard, Botta and others, on
Eastern Archaeology, tending decidedly in
this direction.

Philological inquiry, then, must be looked
to as the chief means of determining the
question of radiation from a single centre or
from multiple centres ; and although, in the
present state of this department of science it
would be unsafe to venture on a positive con-
clusion, yet the following may be considered
as the principal groups under which the
various languages hitherto studied may be
arranged.

1. The Indo-European, sometimes termed
Indo-German, frequently Japetic, and by late
writers Arian, or Iranian. This group com-
prehends nearly all the existing languages of
Europe, and those of a portion of South-
Western Asia.

2. The Syro- Arabian, often termed Semitic;
which are spoken by a large part of the popu-
lation of Syria, Arabia, and Northern and
Eastern Africa.

3. The Turanian, or Ugro-Tartarian; which
are spoken by the (Mongolian) people of
High Asia and of certain parts of Northern
Europe.

4. The Seriform, or Indo-Chinese ; which
are spoken by the people of South-Eastern
Asia.

5. The African ; which are spoken by the
people of Central and Southern Africa.

6. The Malay o- Polynesian ; which are
spoken by the inhabitants of the numerous
islands and island-continents of Oceania.

7. The American ; which are spoken by the
inhabitants of the New World, from the
Arctic Sea to Cape Horn.

Now it is not a little curious that the
linguistic affinity should often be strongest,
where the conformity in physical characters is
slightest, and w'eakest when this is strongest.
Thus among the Malayo-Polynesian and the
American races, as already remarked, there
are very striking differences in conformation,
features, complexion, &c. ; and yet the lin-
guistic affinity of the great mass of tribes
forming each group is not now doubted by
any philologist, though a doubt may still hang
over some particular cases. On the other
hand, the hiatus between the Turanian and
the Seriform languages is very wide ; but the
physical conformity is so strong between the
Chinese and the typical Mongolian nations,
that no ethnologist has ever thought of as-
4 r 2

1348

VARIETIES OF MANKIND.

signing to them a distinct origin. So, again,
there would seem to be no near relationship
between the American and the Turanian lan-
guages ; but the affinity of the two stocks
appears to be established by the transition-
link afforded by the Esquimaux, which are
Mongolian in their conformation and Ame-
rican in their language. The affinity of the
Semitic and Japetic languages, moreover, is
so deeply hidden, as to have, until recently,
almost defied discovery ; and yet the people
who speak them so far resemble one another
in physical characters, that they have been
almost invariably associated together under
the general designation of the Caucasian race.
The common origin of the inhabitants of the
continents of Europe, Asia, and America is
thus pointedly indicated by the combination
of these two sources of evidence. The por-
tion of the Malayo-Polynesian race, that is,
in nearest proximity with South-Eastern Asia,
presents such a striking' resemblance in phy-
sical characters to the inhabitants of the
neighbouring part of that great continent,
that their community of origin can scarcely
be doubted ; and when certain points of re-
semblance between some of the Oceanic and
Indian dialects are taken into account, this
inference receives strong confirmation. The
African nations have long been regarded as
the most isolated from the common centre
from which all the others appear to have
radiated ; but recent investigations have shown
that such isolation has no real existence.
For, on the one hand, there are tribes which
form (like the Esquimaux) a connecting link
between the Semitic and proper African fa-
milies, being African in their conformation,
but Semitic in their language ; and, on the
other, the study which has been recently be-
stowed on the proper African languages,
especially by Dr. Latham, has shown them to
have so much in common with the Semitic
tongues, that, with the additional evidence
derivable from community of certain usages,
extending through vast areas physically iso-
lated from each other, it now seems impos-
sible to believe but that the African nations
are nearly related to the Semitic, and are
through them, derivable from the great Asiatic
centre,

IV. General Survey of the frincifal
Families of Mankind.

In the summary view w hich will now be
presented, of the characters of the principal
varieties of the human race, it will be con-
venient, in the first instance, to arrange them
according to their existing geographical dis-
tribution, stating, under each head, the most
important peculiarities in physical conforma-
tion, in psychical character, and in language,
which tiiey may respectively present. A ge-
neral scheme of their probable relations of
affinity will be subsequently given.

I. European Nations. — The collective
body of European nations, with the excep-
tion of the Lapps, present a great uniformity

in physical characters ; for although minor
differences exist among their subordinate
groups, they all possess the elliptical cranium,
the symmetrical form, the xanthous com-
plexion, and the flowing hair, which cha-
racterise what is ordinarily designated as the
Caucasian variety. This group of nations,
however, must be primarily divided into those
of Arian or Lido- Median origin, and those
whose origin is probably or certainly Mon-
golian. Under the latter head may be ranked
(as already remarked) the Lapps and Finns
of Scandinavia ; the Magyars of Hungary ;
the Turks of Turkey ; not improbably the
Basques or Euskaldunes of Biscay and Na-
varre; and (possibly) the Albanians or moun-
taineers of ancient Illyria and Epirus.* The
European tribes of the Arian stock are con-
sidered by Dr. Latham as fundamentally di-
visible into the two great groups of Celts and
Indo-Germans. The former seem to have de-
tached themselves from the common stock, be-
fore the evolution of the language had pro-
ceeded to the formation of the cases of the
nouns, but after that of the persons of the verbs
had taken place f; and their language presents
obvious traces of agglutination, which, as
already shown, marks an early stage in lin-
guistic developemenf. The eastern origin of
the Celtic nations was first demonstrated by
Dr. Prichard j, and has been subsequently
more fully proved by Pictet. § The typical
Celts exhibit somewhat of that development
of the malar bones, which is carried to its
fullest extent in the pyramidal skull ; and in
their comparatively unprogressive psychical
character they contrast remarkably with the
Germanic group of nations. The Indo-Ger-
mans, on the other hand, seem to have de-
tached themselves from the common stock
after the evolution of the cases of nouns had
taken place ; and their language presents less
evidence of agglutination than does the Celtic.
The Eastern origin of this group of nations is
not now doubted by any competent ethno-
logist ; for their languages, in spite of their
diversity, constitute but one philological
group, being united alike by community in
many of the most important primary words, and
by general similarity of grammatical construc-
tion ; and being obviously all formed upon
the same base with the Sanscrit, if not upon
that language itself. Of all extant European
dialects, the Lettish and Lithuanian approach
most nearly to the ancient Sanscrit ; but a still
nearer approach seems to have been presented
by the old Prussian, a dialect now extinct,
which maintained, to the sixteenth century, a
very slightly changed form of the Zend or
Median language, which was an early deriva-
tion from the Sanscrit. Whilst every one of
the Indo-Germanic languages bears traits of

* See on this last point Dr. Latham’s “ Natural
History of the Varieties of Man,” p. 552.

f Op. cit. p. 529.

{ On the Eastern Origin of the Celtic Nations,
1831.

§ De l’Affinite' des Langues Celtiques avec le
Sanscrit; Paris, 1837.

VARIETIES OF MANKIND.

1349

affinity with every other, each has been mo-
dified by the introduction of extraneous
elements. Thus, in those of Western Eu-
rope, there is a considerable admixture of
Celtic ; whilst in others there are traces of
more barbaric tongues. In fact, there can be
little doubt, that Europe had an indigenous
population before the immigration of the Indo-
Gerinan or even of the Celtic tribes ; and of
this population it seems most probable that
the Lapps and Finns of Scandinavia, and the
Euskarians of the Bisca)an provinces, are the
remnant. There is evidence that the former
of these tribes once extended much further
south than at present ; and, on the other
hand, there is ample proof that the latter had
formerly a very extensive distribution through
Southern Europe. It has been clearly shown
by William Von Humboldt, that the Eusk-
arian language, so far from having been de-
rived (as some writers have supposed) from
the Celtic, must have been in existence long
anterior to the immigration of the Celtic
nations into Western Europe; and since that
time, it has been shown to have affinities with
the Fiunish tongue, and through this with
the languages of High Asia. It may be sur-
mised, then, that the advance of the Indo-
European tribes, from the south-east corner
into central Europe, separated that portion of
the aboriginal population, which they did not
destroy or absorb, into two great divisions ;
of which one was gradually pressed north-
ward and eastward, so as to be restricted to
Finland and Lapland ; and the other south-
ward and westward, so as to be confined at
the earliest historic period to a part of the
peninsula of Spain and the South of France,
gradually to be driven before the successive
irruptions of the Celts, Romans, Arabians,
and other nations, until their scanty remnant
found an enduring refuge in the fastnesses of
the Pyrenees.* It is curious that the Eusk-
arian language should carry out the principle
of agglutination to an extent which has no
parallel among the languages of the Old
World, and which is only surpassed by those
of America.

The Indo-Germanic race are unquestionably
those which are destined to acquire the greatest
predominance, not only in the Old World,
but in all those newly-found lands which have
been discovered by their enterprise. With
scarcely any exception, as Dr. Latham has
justly remarked, they present an encroaching
frontier ; there being no instance of their per-
manent displacement by any other race, save
in the case of the Arab dominion in Spain,

* This view, which was suggested by the Author
(British and Foreign Medical Review, Oct. 1847)
without the knowledge that it had been elsewhere
propounded, has been put forth with considerable
confidence by Dr. Latham (Varieties of Man,
p. 551.) as originating with Arndt, and adopted by
Rask, distinguished Scandinavian ethnologists. The
great antiquity of the_ Albanian tongue having been
fully proved, and the circumstances of the tribe
having been nearly the same, it is suggested by Dr.
La tham that this, too, may be a remnant of the abo-
riginal Turanian population.

which has long since ceased ; in that of the
Turkish dominion in Turkey and Asia Minor,
which is evidently destined to expire at no
distant period, being now upheld only by ex-
traneous influence ; and in that of the Magyars
in Hungary, who only maintain their ground
bj' their complete assimilation to the Indo-
Germanic character. It has been already
pointed out, however, that the rapid exten-
sion of this race is due, not merely to its
superior skill in the arts of war and diplomacy,
but to a physical cause which tends to ex-
tinguish the aboriginal population of many of
the inferior races, wherever sexual inter-
course takes place between them (p. 1341.).

II. Asiatic Nations. — Whilst in Eu-
rope the presence of the Arlan family is the
rule, and that of the Mongolian is the excep-
tion, we find in the vast continent of Asia,
that the reverse is the case ; the presence of
the Arian family being the exception, and
that of the Mongolian the rule. In fact,
although the Celtic and Indo-Germanic races
undoubtedly had their origin in Central or
Western Asia, yet the tribes which can, with
greatest probability, be regarded as the de-
scendants of the ancient stock, are extremely
few, and scarcely able to maintain their
ground. They are, according to Dr. Latham,
the Persians of Northern and Western Persia;
the Kurds , the Beluchi, the Affghans, the
Tajiks of Bokhara, and the Sia-posh. All
these speak languages which contain a large
proportion of Sanscrit words ; but whether
they are so far akin to the Sanscrit in gram-
matical structure, as to hold to it the same
relation as that which the European lan-
guages possess, is as yet uncertain. Whether
or not the Armenians belong to this group,
has not yet been ascertained.* It has been
generally considered, until recently, that the
nations of the great Indian peninsula for the
most part belonged to the same stock ; but
philological investigation has shown that such
a doctrine is certainly untrue with regard to
some, and is probably or possibly erroneous
with regard to others. The Tamulian, which
is the dominant language of Southern India,
is undoubtedly not Sanscritic in its origin,
although containing an infusion of Sanscritic
words, but more closely approximates to the
Seriform type. Many of the hill tribes, in
different parts of India, speak peculiar dia-
lects, which appear referable to the same
stock. And in Dr. Latham’s opinion, the
dialects spoken throughout Northern India
are to be regarded in a similar light, notwith-
standing the large infusion of Sanscritic
words which they contain. Viewed under this
aspect, the mass of the population of India is

* It is somewhat remarkable that greater atten
tion should not have been paid to the study of the
Armenian language ; as the facilities presented by
commercial intercourse are not small ; and the iso-
lated position of this nation is one which might
lead to the anticipation, that its language might
retain the Sanscritic type, with less alteration than
that of other nations, which have been more affected
by conquest and intermixture of races.

4b 3

1350

VARIETIES OF MANKIND.

not to be regarded as Arian, but as Mon-
golian ; and the introduction of the Sanscrit
language was accomplished by an invading
branch of the Arian stock, the only trace of
which is to be found in the distinctness of
the JBrahminical portion of the Hindoo popu-
lation, in whose religious and other writings
the Sanscrit language is still preserved.

In the Asiatic group of I ndo- Germanic
nations, the same general type of conforma-
tion presents itself as in the European : there
is, however, a much greater variety of com-
plexion. The mountaineers, even within the
tropics, are often as fair as Europeans ; whilst
those who live in the level plains, and are ex-
posed to the full heat of the torrid zone, may
be of a very deep brown or even black hue.
The variety of complexion shown among
the Hindoos, even in the Brahminical caste,
has been already adverted to. There is
but little to remind us of the Mongolian type
in the countenances of the Hindoos, which
are often remarkable for symmetrical beauty,
that only want a more intellectual expression
to render them extremely striking ; some traces
of it, however, may perhaps be found in the
rather prominent zygomatic arches (Jig. 828);

Fig. 828.

Hindoo Female of Pondicherry. (From a portrait
in M. Geringer’s “ L'Inde FrangaiseP)

but this is a character which not unfrequently
shows itself strongly in the Arian races (e. g.
the Celts) ; and the cranial part of the skull
presents no approach to the pyramidal type,
being often very regularly elliptical. Among
the southern inhabitants of the peninsula,
however, a much greater departure from the
Caucasian type presents itself ; for not only is

the colour darker, but the cheek bones are
more prominent, the hair coarse, scanty, and
straight, the nose flattened ; and sometimes
the lips are very thick, and the jaws project,
so that we have indications of a transition
towards both the pyramidal and the progna-
thous types.

The south-western portion of Asia is occu-
pied by the Arabs anil other Semitic races,
which, as will be presently explained, form the
transition between the proper Asiatic and pro-
per African nations.

The whole remainder of the vast Asiatic
continent is occupied by nations which present
a sufficiently close approximation to each
other, either in physical characters or in lan-
guage, or in both, to justify their association
in one extensive group, under the name of
Mongo/idoe. The typical character of this
great family of nations, as seen in a Mongolian
or a Tungus from Central Asia, consists in
the pyramidal form of the skull (fig. 811. et
seq.), with the broad flat face and prominent
cheek-bones, and its antero-posterior diameter
scarcely exceeding the parietal ; the nose is
flat, neither arched nor aquiline ; the eyes
drawn upwardsat their outer angle (fig. 8 14.);
the skin of a swarthy yellow ; the hair straight
and scanty, and the beard deficient ; and the
stature undersized. These characters are
softened down in many members of the group ;
and may even be entirely wanting, as for in-
stance, in the Circassians and Georgians, (p.

1 328.), termed by Dr. Latham the Dioscurian
Mongolidse. Still they are very extensively
distributed ; and there is by no means the same
amount of variation in complexion, under the
influence of temperature, that is seen in the
Indo- Germanic races. The following, accord-
ing to Dr. Latham, are the principal groups
into which the Asiatic nations may be ar-
ranged : — 1. The Scriform stock, distributed
over China, Thibet, the Indo-Chinese penin-
sula, and the base of the Himalayan range of
mountains ; their configuration is Mongolian,
softened down (fg. 829.) ; their languages

Fig. 829.

S/nttt of a Chinese Ladrone. (From a specimen in
the Museum of the Royal College of Surgeons.')

are aptotic, or with only the rudiments of an
inflexion ; and they thus preserve more than

1351

VARIETIES OF MANKIND.

any other race, the primitive condition of
human speech. In their mode of life, they
present the phenomenon of a civilization which
has attained a considerable degree of develop-
ment, remaining stationary through a very
long period of time, and isolating itself as jea-
lously as possible from the general current of
progress. In passing from China towards
India, there is a gradual transition in physical
and mental characters, between the Chinese
and the Hindoo ; thus the Burmese have
more hair and beard, more prominent features,
and darker complexions, than the Siamese and
Chinese ; and the darkness in complexion in-
creases towards the confines of Bengal. There
is, therefore, no such abrupt transition, as shall
make it difficult to admit the Seriform origin
of the bulk of the Hindoo population, if fur-
ther investigation of their language should
render this connection as probable as it has
already been shown to be in the case of the in-
habitants of the Dekhan and Ceylon. — 2. The
Turanian stock, including the proper Mongo-
lians of High Asia, the Tungusians, the Turks,
and the Ugrians. Among these, the con-
formity in physical characters is extremely
close, the only exception being in the case of
the offsets which have migrated into Europe,
and which have undergone transformation (as
explained at p. 1327.) into the Caucasian type
(fig.&XHet seq.). The languages of these people
are not monosyllabic, but have not undergone
any high development ; and they are spoken
with very little variation over extensive areas.
The general character of the country inhabited
by this group is remarkably uniform, being a
series of high table-lands or steppes, well
adapted for maintaining a nomadic pastoral
population. Such is the general habit of these
people, and such it has been from our earliest
knowledge of them. The Tungusians, how-
ever, advance to the Polar Sea, and adopt a
manner of life more resembling that of the
proper Hyperborean races. — 3. The Peninsular
Mongolidce, inhabiting the islands and penin-
sulas of the north-eastern coast of Asia, such
as Korea, Japan, and Kamschatka. These
are all Mongol in their conformation, but dif-
fer from the preceding in the character of
their languages, which seem to be, in some
cases, extremely po/y-syllabic, always showing
a strong tendency to agglutination, and thus
showing a transition to the American languages,
in which this peculiarity presents its highest
development. These tribes are separated from
each other, however, by considerable breaks
in geographical continuity; some of them lying
within the Arctic circle, and others as far
south as 26° N. L. And they are not less
distant in the two extremes of their social de-
velopment, one section of the group partaking
of the civilization of China, and another ex-
hibiting the rudeness of the Samoied. This
group is obviously not a typical, but a transi-
tional one. — 4. Hyperborean Mongolidce, in-
habiting the borders of the Icy Sea, especially
in the neighbourhood of the courses of the
large rivers, and subsisting especially by fishing
and fur-hunting. The area which they occupy

is not continuous ; the principal tribes, known
as the Samoiedes, the Yeniseians, and the Yu-
kahiri, being separated from each other by the
advance of the Northern Ugrians and Tungu-
sians. Their conformation is Mongolian ; but
their growth is stunted, and their complexion
swarthy ; and they bear a very close resem-
blance to the Laplanders and Esquimaux. It
is probable that they will be united when their
languages shall have been more fully studied,
either with the Turanian or with the Penin-
sular stocks.

Turning now to the Syro- Arabian or Semitic
nations, which occupy a considerable area in
the south-western part of Asia, we encounter
a very different type of physical conformation,
and a group of languages which is peculiar
alike in its structure and in its vocabulary.
Generally speaking, the people of this race ex-
hibit a remarkable symmetry of form, and per-
fection of cranial organisation {fig. 830) ; and it

Fig. 830.

Arab of the Guard Oj the Imaun of Muscat. ( From
a portrait taken by an officer of L’ Artemise.')

was remarked by Baron Larrey, who had ample
opportunities for observation during the Egyp-
tian expedition, that experience has proved
to him that their psychical character is con-
formable to this high standard, a great aptitude
for intellectual activity being combined with
extraordinary acuteness in the use of the or-
gans of sense. There can be no doubt what-
ever, that the Semitic races have exerted a
most important influence on the civilization
of the world ; and this not merely by their
own early progress in the arts of life (as shown
by the extraordinary history of the Assyrian
and Babylonian empires, on which so much
new light has recently been oast) ; but also
by having afforded the channel through which
Monotheism was transmitted from the patri-
4 r 4

1352

VARIETIES OF MANKIND.

archal times to that of Moses ; by having served
as the depository of the Mosaic dispensation,
by which that Monotheism was preserved and
organised in the Judaical system; and by
having been the centre whence has emanated
the fuller light of Christianity, which, in the
fulness of time, was exhibited among a people
blinded by their own prejudices and self-
esteem, to be the regenerator of the nations
that as yet knew not God. Scarcely less re-
markable is it that the third great Monotheistic
system — that of Mahommedanism — which' is
essentially a degraded mixture of Judaism
and Christianity, should have developed itself
amongst the same people, occupying the place,
on the one hand, of its Divine prototypes, and
on the other, of the various inferior religions
whose professors have been brought under
Arab sway, and forced to embrace the dogma
of their conquerors. Wherever this last
change has taken place, it has obviously been
for the better ; and there is no more striking
example of it, than the superior condition of
the African nations which have been thus
brought under Mahommedan influence. And
it can be scarcely doubted that it is the pur-
pose of Divine Providence, thus to spread and
to maintain a Monotheistic system, adapted
to the capacities of the people who receive it ;
until a higher intellectual and moral develop-
ment shall render them capable of appreciating
the purer light of Christianity.

The Semitic languages early attained a
considerable development ; but the forms it
took were not well adapted for further evolu-
tion ; and they present nearly the same type
at the present time, as that which is exhibited
in the earliest literature which the world pos-
sesses : namely, the sacred books of the He-
brew nation. Their alphabet was the earliest
in the world ; and their writing is peculiar in
passing in the direction contrary to that of
other languages, namely, from right to left.
“ Of the several nations,” remarks Dr.
Prichard *, “ who are connected by this com-
munity of language, some who were formerly
celebrated have become nearly extinct ; while
others have spread themselves, either as the
exiled followers of a persecuted faith, or as
the enduring apostles of a victorious one, over
the world, and seem destined, through the
energy of their invincible mind, to survive to
the end of time. The Syrian race scarcely
exists ; their language only survives in some
districts on the borders of Kurdistan ; every-
where they have been lost under the predomi-
nating Arabs. The Ilomerites in Arabia, if
they there exist, are little known ; the Abys-
sinian Homerites are the only inhabitants of
the province of Tigre, to the eastward of the
Tacazze, whose idiom still resembles the an-
cient Gheez. The Arabs, who spread Islam
by their victories from the Atlantic to the
Ganges, and the Jews, who are wanderers
over the whole world, are perhaps now more
numerous than were even their forefathers.”
Of the difference in complexion that manifests

itself among the Arabs of Arabia, mention
has already been made ; the greatest modifi-
cations of the ordinary type present them-
selves, however, among the African members
of the Semitic group, as will presently appear.

III. Afhican Nations. — Of the various
nations inhabiting the African continent, those
of the Negro type are usually regarded as the
most characteristic specimens. But, as Dr.
Latham has justly remarked, “ no fact is more
necessary to be remembered, than the differ-
ence between the Negro and African ; a fact
which is well verified by reference to the map.
Here the true Negro area, occupied by men
of the black skin, thick lip, depressed nose,
and woolly hair, is exceedingly small; as small
in proportion to the rest of the continent, as
the area of the district of the stunted Hyper-
boreans is in Asia, or that of the Lapps in
Europe.” When we have separated the
region north of the Great Desert, which is
mostly occupied by Semitic tribes ; the Great
Desert itself, whose scattered population is
far from being Negro in many of its features ;
the valley of the Nile, at least in its middle
and lower portions, including Egypt and Nu-
bia, and even Abyssinia ; and the Katfre and
Hottentot areas south of the equator ; there is
only left the western portion of the continent,
including the alluvial valleys of the Senegal,
the Gambia, and the Niger, with a narrow
strip of central Africa, passing eastwards to
the alluvial regions of the Upper Nile. Even
within this area, the true Negro type of con-
formation is by no means universally preva-
lent ; for many of the nations which inhabit
it must be ranked as sub-typical Negroes.
Our idea of the Negro character, in fact, is
almost exclusively founded upon that division
of the race which inhabits the low countries
near the Slave Coast ; such tribes, indolent
and degraded in an extreme degree, are dis-
tinguished alike by their extreme ugliness, and
by their brutal sensuality. The proper Negro
character consists in the combination of a
prognathous form of skull, with receding fore-
head and depressed nose, thick lips, woolly
hair, black unctuous skin, and crooked legs ;
the facial aspect being such as is represented
in figs. 803, 804. Similar characters are met
with, again, among the inhabitants of the al-
luvial regions around Lake Tchad, in the
interior ; and some of the tribes in the
lowest lands on the eastern side are but little
superior. On the other hand, in the imme-
diate neighbourhood of the typical Negroes,
but inhabiting higher levels, and presenting a
more advanced civilization, are found a num-
ber of tribes departing from the Negro type
in one or more of its distinctive characters.
Thus the race of Iolofs near the Senegal, and
the Guber in the interior of Sudan, have
woolly hair and deep black complexions,
but fine forms and regular features of the
European cast (fig. 831) ; the high parts
of Senegambia, where the temperature is
moderate and even cool at times, are inha-
bited by Fulahs of a light copper colour;
and on nearly the same parallel, but at the

Natural History of Man, p. 145.

VARIETIES OF MANKIND.

1353

Fig. 831.

Senegal Chief. ( From a portrait taken by an officer

in the expedition of Capt. Laplace.')

opposite sides of Africa, are the high plains of
Enarea and Kaffa, where the inhabitants are
said to be fairer than the natives of Southern
Europe. So, again, whenever we hear of a
Negro state, whose members have attained
any considerable degree of improvement in
their social condition, we constantly find that
their physical characters deviate considerably
from the strongly-marked or exaggerated type
of the Negro ; such are the Ashanti, the
Sulima, and the Dahomans of Western
Africa, of which last nation the king is de-
scribed by a recent visitor (Lieut. Forbes) as
many shades removed from black in his com-
plexion, as having quite an intellectual
expression of countenance, and as possess-
ing a remarkable symmetry of figure. It is
obvious, too, from the account given by the
same observer*, that a very complex social
system has developed itself among this people,
and that they have made considerable progress
in the arts of life, although this has hitherto
been only turned to account in furthering the
traffic in slaves, of which Dahomey is now the
centre, so far as the Slave Coast is concerned.
The highest civilization, and the greatest im-
provement in physical characters, are to be
found in those nations which have adopted
the Mohammedan religion. This was intro-
duced, three or four centuries since, into the
eastern portion of Central Africa ; and it
appears that the same people who were then
existing in the savage condition still exhibited

* Dahomey and the Dahomans, 1851.

by the pagan nations further south, have now
adopted many of the arts and institutions
of civilised society, subjecting themselves
to governments, practising agriculture, and
dwelling in towns of considerable extent,
some containing even as many as 30,000
inhabitants — a circumstance which implies a
considerable advancement in industry, and in
the resources of subsistence. The languages
of the Negro nations, so far as they are
known, seem to belong to one group ; although
there is a great difficulty in becoming ac-
quainted with them ; in consequence of the
entire deficiency of written records. The
same cause would of course give a want of
fixity to their vocabulary : and thus the dia-
lects of two nations descended from a com-
mon original, would be likely soon to diverge
from each other. Still they all present, so
far as is known, the same grade of develop-
ment, and the same grammatical forms ; and
various proofs of their affinity with the Semi-
tic tongues have been developed, these being
derived from similarity alike of roots and of
construction. The Semitic affinity of the
Negro nations is further indicated in a very
remarkable manner, by the existence of a
variety of superstitions and usages among the
Negroes of the Western Coast, which prevail
also among the Nilotic races whose Semitic
relations are most clear, as well as among
branches of the Semitic stock itself ; this is
especially the case with the rite of circum-
cision, which seems to be universally practised
throughout the Negro area.

The southern portion of the African con-
tinent is inhabited by a group of nations which
speak various dialects of the Kaffre tongue,
and which recede more or less decidedly from
the Negro type in physical characters. Our
acquaintance with them, however, is at pre-
sent very limited ; the interior of South Africa
having been as yet scarcely at all explored by
civilised man ; and the only people well
known to us being those of a few points on
the coast, such as Kongo on one side, and
Mozambique on the other ; and those of the
southernmost extremity, or the region of the
Cape. As we pass southwards from the
equatorial region, we find a gradual softening
down of the proper Negro characters ; and
this is greater according to the degree of civi-
lization, and the general improvement in ex-
ternal conditions. Thus, in the people of
Kongo {fig. 832), and in those of Mozam-
bique and its neighbourhood {figs. 833,
834), although the hair is woolly and
the colour black, yet the skulls are more
vaulted {fig. 833) and capacious anteriorly,
and have much less of the prognathous cha-
racter ; the nose is much more prominent, the
lips are less thick, and the general expression
is milder and more intellectual, than that of
the natives of Guinea. When we arrive at
the true Kaffres, the race of warlike nomadic
people which inhabits the eastern parts of
South Africa to the northward of the Hot-
tentots, so great a departure from the Negro
type presents itself, that many travellers have

1354

VARIETIES OF MANKIND.

Fig. 832.

Fig. 834.

Woman of Kongo. { After Rugendas.)

regarded them as having had a different origin.
The degree of this departure, however, varies
greatly in the different tribes ; for while some
of them are black, woolly-headed, decidedly
prognathous {Jig. 835), and obviously ap-
proaching the modified Negroes of Kongo in

Fig. 833.

Woman of the Mongolia tribe — near Mozambique.
{After Rugendas .)

Fig. 835.

Skull of Kaffre. {From a specimen in' the Museum
of the Royal College of Surgeons.')

Fig. 836.

Man from Mozambique. {After Rugendas.)

their features and general aspect, others recede
considerably both in complexion, features,
and form of head from the typical progna-
thous races, presenting a light brown colour,
high forehead, prominent nose, and tall robust
stature. The thick lips and frizzled hair are
generally retained, however; but the hair is
sometimes of a reddish colour, and becomes
flowing ; and the features may present a Eu-
ropean {Jig. 836) cast. Even among the
tribes which depart most widely from the
Negro-type, individuals are found who present
a return to it ; and it is interesting to remark.

Kaffre of the Amakosah tr ibe. {From a portrait by
Daniels. )

VARIETIES OF MANKIND.

1355

that the people of Delagoa Bay, though
of the Kaffre race, as indicated by their
language, being degraded by subjugation,
approach the people of Guinea in their phy-
sical characters. Generally speaking, the Kaf-
fres are a people very superior in vigour and
capacity to the destitute savages who occupy
the insulated regions of Negroland, and how
a considerable advance in civilization ; but
between the most elevated Kaffre and the
most degraded Negro, every possible gradation
is presented to us, as we pass northwards and
westwards from Kaffraria towards the Guinea
coast, so that no line of distinction between
them can be founded on physical characters.
So, on the eastern side, we pass up until we
meet with the same transition. The languages
of these people are distinguished by a set of
remarkable characters, which have been con-
sidered as isolating them from other African
tongues. According to Dr. Latham, how-
ever, these peculiarities are not so far without
precedent elsewhere, as to establish the very
decided line of demarcation which some have
attempted to draw ; and may be regarded, in
fact, as resulting from the fuller development
of tendencies, which manifest themselves in
other African languages.

The Hottentot race (including the Bush-
man) has, perhaps, so far as regards its phy-
sical characters, a better title to be considered
as forming a distinct species of the genus
Homo than any other ; for not only do these
characters present a combination which is not
found elsewhere, but that transitional grada-
tion is wanting, which usually presents itself
wherever there is a continuous population
that has long occupied the same locality. The
peculiarities of these people have been already
noticed separately; the following is a general
summary of them. The cranium is Mongoli-

form and brachycephalic, the cheek-bones pro-
minent, the jaws somewhat projecting, the eyes
oblique, the nose broad and flat, the lips thick,
the chin long and pointed; the complexion is
a mixture of black with yellow ochre; the hair
grows in little tufts ; the stature is low, and
the limbs are slight; the buttocks, however,
frequently present a steatomatous accumula-
tion. In their cranial characters there is,
therefore, an admixture of the Mongolian and
the Negro, the former being predominant ; and
this resemblance to the people of High Asia
is the more remarkable, when it is considered
that the physical conditions of the Hottentot
country bear a very close correspondence with
those of High Asia, the habitation of this
people being for the most part on karroos, or
elevated terraces and table-lands, over which the
vision extends with as piercing a gaze as that
of the Mongols. The buttock-hump, or stea-
topyga, is not by any means so characteristic
of this race as has been imagined ; for, as Mr.
Burehell has ascertained, it is only an indi-
vidual peculiarity, about as frequent as cor-
pulence among European nations; and it has
been met with in other tribes of Southern
Africa, as the Makuani of the Mozambique
coast. It cannot, therefore, be regarded as
affording the least indication of difference of
race, but would seem to result from the opera-
tion of the same local influences, whatever may
be their nature, as produce a similar accumula-
tion of fat in the rumps and tails of the sheep
inhabiting the same regions. The peculiar
relation of the Bushman tribe to the Hottentot
race, has been already explained ; among this
degraded people, the same general features
present themselves as those which have been
described as characteristic of the Hottentots
{figs. 837, 838.), but in stature, vigour, and
capacity, they are much inferior. A compari-

Bushman Female. ( From the “Atlas des Mammiferes of MM. Fred. Cuvier and Geoff. St. Hilaire.')

son of the cranium of a Bushman (figs. 839, already figured, will clearly indicate that the
810, and 841) with the three typical forms pyramidal skull is the one to which this bears

the greatest resemblance, especially in the
shortness of the antero-posterior diameter, as

Dahomey and the Dahomans, 1851.

1356

Fig. 839.

VARIETIES OF MANKIND.
Fig. 840.

Fig. 841.

Cranium of Bushman. ( From a specimen in the Museum of the Royal College of Surgeons.')

compared with the parietal, and in the breadth
and expansion of the malar bones.

The ethnological position of the Hottentot
race is not altogether clear. There is evidence
that it once occupied a more extensive area
than it does at present, and that this was
much encroached on by the Kaffres, previously
to the European colonisation of the Cape.
This fact lends weight to a suggestion offered
by Dr. Latham, in order to account for the
abruptness of the transition between the two
races : — “ Let two divisions of a certain class
pass into each other by imperceptible degrees,
and let one of the central portions of either
class spread itself at the expense of the parts
belonging to its circumference ; the effect which
follows is, that those portions of the area which
represent the phenomena of transition are
overlaid or overlapped ; and that, instead of
two populations coming into contact by im-
perceptible degrees, they meet as separate
classes, with as broad a line of demarcation
between their respective representatives, at the
peripheries of their respective areas, as there
was between their central or typical portions.
North-western America illustrates this. The
more southern A Igonkins have overlaid both
the Algonkins of their own section which ap-
proached the Esquimaux, and the Esquimaux
of the opposite section, which approached the
Algonkin. Hence the two populations meet
as widely-separated and broadly-distinguished
varieties of mankind.”* So, it may be sur-
mised, the bold and warlike Kaffres have over-
spread themselves through a region whose
aboriginal population exhibited a transition
betvveen the Hottentot and Kaffre types.
“ The language of the Llottentots,” says the
same learned ethnologist, “ can be shown not
to be more different from those of the world
in general, than they are from each other;” it
has not yet, however, been sufficiently studied
to enable its true affinities to be known, though
some philologists affirm that it is a degraded
Kaffre tongue.f

* Varieties of Mankind, p. 498.

t The author thinks it worth while still to repeat
a suggestion which he made some years since;
namely, that the Hottentot race is the remnant of
an earlier migration from High Asia, than that
which was the stock of the great bulk of African
nations ; and that it has been driven down into the
remotest corner of the continent, just asthe aboriginal
Turanian population of south-western Europe seems

Passing now to the valley of the Nile, we
find a group of nations whose physical charac-
ters and languages present a complete and
almost uninterrupted gradation from those of
the proper African tribes to those of the
Semitic group. Under the general designation
of Nilotic nations may be included the Gallas,
the Nubians, the Bishari, and many subordi-
nate groups. These come into close ap-
proximation, both locally and physically, with
the Eastern Negroes of the first division, and

Fig. 842.

Souahiny Chief, — Eastern Nubia. (From a portrait
given in “ Salt's Travels .”)

with the northern Kaffres of the second. The
colour of the Gallas varies from a deep black

to have been driven back by the Indo-European
immigration, and at last to have been limited to
the Basque provinces. For anything yet known to
the contrary, the structure of the Hottentot lan-
guage may, like their physical conformation, be
more closely related to that of the Turanian stock
than to the Semitic, with which the languages of
Northern Africa are obviously connected.

VARIETIES OF MANKIND.

1357

to a brownish yellow ; their stature is tall ;
their bodies spare, wiry, and muscular ; their
frontal profile vaulted, their nose straight or
even arched, their lips moderately full, their
hair often hanging over the neck in long twisted
plaits. Nearly the same description applies
to some of the Nubian tribes (fig. 842). of
which the resemblance to the Arab physiog-
nomy becomes very striking, although their
colour is jet-black ; and, ;as already shown,
there is distinct evidence of their Negro an-
cestry. The languages of these Nilotic people
present an intermediate gradation between the
proper Semitic and the proper African ; and
all that has been made known by the explora-
tions in these regions, which have been carried
on, more or less uninterruptedly, ever since
the French expedition into Egypt, tends to
break down the line of demarcation which was
supposed to separate the African nations from
all others. To a similar result have tended
all those Egyptological researches which have
been carried on with so much ardour during
the same period. For a careful examination
of the delineations of themselves left to us in
the paintings and sculptures of the ancient
Egyptians, and of the crania preserved in their
sepulchres, leaves no reasonable doubt, that in
their physiognomy and complexion they were
essentially African ; although very marked va-
rieties in cranial conformation, and in the hue
of their surface, appear to have existed amongst
them. The Copts, or existing natives of Egypt,
seem, on the whole, pretty nearly to represent
their physical characters, although in a condi-
tion of comparative degradation, owing to the
state of subjection to which they have been re-
duced ; and although the existing Coptic lan-

Fig. 813.

guage has been undoubtedly changed from its
original form by the successive colonizations
and conquests to which the country has been
subjected, yet it still shows a marked affinity
with the proper African languages in certain
peculiarities of its construction.

Lastly, the northern and north-western
portion of the African continent is occupied
by tribes whose Semitic origin is undoubted.
Several immigrations appear to have taken
place at different times from the Syro-Ara-
bian stock ; but that which has most claim
to the title of an aboriginal population, is
that of which the Berber races (from which
the north-west of Africa received the desig-
nation of Barbary) may be regarded as the
types ; the Kabyles of Algiers and Tunis (the
people of Abd-el-Kader), the Tuaryks of
Sahara, and the Shelahs or mountaineers of
Southern Morocco, being branches of the
same stock ; as were also, most probably,
the Guanches or ancient population of the
Canary Islands. These people all speak
dialects of a language, which has been shown
by Prof. Newman to be an offset from the
Semitic : and whilst the complexion, and even
the hair and physiognomy, of those which
approach the Negro area, present a remarkable
approximation to those characteristic of the
Negro, those of the northern and more ele-
vated districts retain the Caucasian type, and
some of them are quite fair in skin, and Euro-
pean in feature. But subsequently to the
settlement of these tribes in the regions they
still inhabit, there have been colonizations by
Phoenicians and true Arabs ; and these immi-
grants have for the most part remained distinct
from the aboriginal population (Jigs. 843,844;),

Fig. 8-1 k

Algerine Arabs of the Mozabite tribe. ( From portraits taken under the direction of Prof. Milne-Edwards.

their languages being divergent, and their
habits and grade of civilisation different. Such
were the sovereignties of Morocco, Algiers,
and Tunis, which brought the aboriginal tribes
under nominal subjection to themselves.

Notwithstanding its Semitic affinities, the
language of the North-African aborigines is
considered by Dr. Latham as having affinities
also with the proper African tongues, and as
having been isolated from them without suf-

1358

VARIETIES OF MANKIND.

ficient reason ; and if this be the case, another
link of transition exists, which, with those
previously named, brings the two groups into
such relations, that their separation cannot be
justified. By Dr. Latham, accordingly, the
Syro- Arabian or Semitic race is ranked with
the African under the general designation
Atlantidce.

IV. American Nations. — The aboriginal
inhabitants of America have been considered
by some ethnologists as a department of the
human family very distinct from the inhabit-
ants of the Old World; and attempts have
been frequently made to define them as a race
by physical characters. But these attempts
have been founded upon a very imperfect
acquaintance with the nations peopling this
vast continent ; for, taken in the aggregate,
they are by no means uniform either in phy-
sical qualities, in intellectual endowments,
moral character, or grade of civilisational
development ; nor is the line of distinction
between them and the rest of mankind nearly
so obvious or strongly marked as is usually
imagined. Thus the native Americans have
been described as “ red-men ; ” but there are
tribes equally red, and perhaps more deserv-
ing that epithet, in Africa and Polynesia; and
the American nations are by no means all of
a red or copper hue, some being as fair as
many European people, others being brown
or yellow, and others nearly, if not quite, as
black as the Negroes of Africa. Again, it
has been attempted by anatomists to dis-
tinguish the American races by a certain con-
figuration of skull and form of features ; and

Fig. 84-5.

Indian of the Oto tribe, — basin of the hpississippi.
( From the “ Alias du Voyage du Prince de Neu-
wied.”)

Notwithstanding this diversity in their phy-
sical characters, however, there is strong
evidence that the American nations constitute
one natural family, bound together by com-
munity of descent. This appears from the

even Dr. Morton, in his splendid work en-
titled “ Crania Americana,” has given his
authority in support of the opinion, that such
distinctive characters are to be found “ in the
squared or rounded head, the flattened and
vertical occiput, the high cheek-bones, the
ponderous maxillae, the large quadrangular
orbits, and the low receding forehead.”
Nevertheless, even he is obliged to admit that
very considerable diversities present them-
selves in the cranial conformation of the
American nations ; and he altogether ex-
cludes the Esquimaux, who, according to the
evidence of language, must be regarded as
being as truly an American people as any
other, in spite of their obvious conformity to
the Mongolian type of cranial configuration.
And it will be observed that many of the
characters just enumerated are those of the
Mongolian cranium ; a decided approximation
to which may be seen among several tribes,
whose dwelling is much further south than
that of the Esquimaux. The testimony of
travellers who have visited parts of the con-
tinent remote from each other, and who have
scrutinized with observant eyes the physi-
ognomy and form of head, not in individuals
only, but in nations, is very decided as to the
marked varieties in configuration which pre-
sent themselves among these ; thus, says that
eminent zoologist, M. D’Orbigny, “ A Peru-
vian is more different from a Patagonian, and
a Patagonian from a Guarani, than is a Greek
from an Ethiopian or a Mongolian.” The ac-
companying figures present examples of this
diversity (Jigs. 845 and 846).

Fig. 846.

South American of the Charruan tribe. ( From
a portrait by Werner, in the Museum of Paris.)

remarkable relationship which has been dis-
covered among their languages ; not, however,
in their words or even their roots, but in their
grammatical construction. In regard to vo-
cabulary, indeed, there are few parts of the

VARIETIES OF MANKIND.

Fie. 847. Ftg- 848-

1359

South American o f the Puri tribe, — interior of Brazil.

{After Rugendas.')

globe in which so many dialects, or even dis-
tinct languages, are spoken within such
limited areas ; and thus, if difference in this
respect be considered as a sufficient reason
for denying the mutual affinity of the races,
the number of separate stocks must be enor-
mously multiplied. On the other hand, the
mutual relationship just indicated, which con-
sists more particularly in the very remarkable
agglutination of words or portions of words,
has been found in all the American languages
which have been carefully examined, including
some of the most important dialects spoken
in parts of the continent very remote from
each other. And it is easily shown that this
practice, carried on without any regular sys-
tem, but according to the wants and caprices
of each detached community, will, in the
absence of such a literature as gives fixity to
a language, almost necessarily induce such
changes, that two offsets of the same stock,
developing themselves under different circum-
stances, shall cease in a few generations to be
mutually intelligible. There are other causes,
too, in the character of the people themselves,
and in the mode in which they employ lan-
guage, which tend to introduce such varia-
tions. Their speech is, for the most part,
rather an expression of their own ideas and
emotions, than a reflex of external things, —
much more subjective than objective ; and hence
their names for the most familiar objects, or
the simplest ideas, are long compound words
or epithets, which are in striking contrast with
the brief terms employed for the same pur-
poses by most other nations. This feature
in their phraseology seems common to all
the American languages ; and it is strikingly
indicative of a fundamental peculiarity in the
psychical character of the people, namely, a
predominance of the imaginative and rhetorical
disposition, over the mere sensuousness which
is observable among most nations that have

Soicth American of the Achagua tribe, — basin of the
Orinoco. ( From a portrait by M. Roulin. )

attained to a similar grade of material pro-
gress. Those, indeed, who are most familiar
with the psychical nature of the aborigines of
America, have been struck with the manifes-
tations they present of greater energy and
mental vigour, of a more reflective nature, of
greater fortitude, and of more consistent per-
severance in their various pursuits and enter-
prises, than are to be met with among any of
the aboriginal nations of the Old World ; and
these peculiarities are in great part due to the
intensity of their selfish emotions, which ex-
hibits itself in the sullen and unsocial cha-
racter, the proud apathetic endurance, the
intensity of hatred and revenge, the feeble
influence of the benevolent affections, and the
deep malice-concealing dissimulation, which
are so remarkable in the dwellers amid the dark
solitudes of the American forests. Among
many of the American nations, moreover,
traces have been observed of ancient institu-
tions, — complicated forms of government,
regulated despotisms or monarchies, privileged
orders, hierarchical and sacerdotal ordinances,
systematic laws (the result of reflection and a
settled purpose) connected with marriage, in-
heritance, family relationships, &c. and other
customs, — that mark a very early progress
in social development, the forms of which are
in great degree peculiar to them. Their
opinions, moreover, respecting a future state,
and the nature and attributes of invisible
agents, are strikingly different from those of
nations who have never emerged from primi-
tive barbarism. They have had in use, more-
over, from time immemorial, cultivated
plants and domestic animals, different from
those of the Old World; and their earliest
traditions refer the knowledge of these to
some fabulous person, who descended from
the gods, or who suddenly made his appear-
ance among their ancestors ; thus indicating
the remoteness of the era of their separation

13G0

VARIETIES OF MANKIND.

from the inhabitants of the Old World, who
have similar mythical legends in regard to the
introducers of their first arts and acquire-
ments.

Abundant evidence is afforded, by architec-
tural and other remains still existing, as well
as by the accounts of the early Spanish his-
torians, of the high degree of civilisation
which some of the nations of America had
attained, previously to the European immi-
gration, especially in the warmer regions of
that continent. Thus the natives of Mexico
had erected stupendous edifices, which rivalled
those of Egypt ; and although they did not
attain to the greatest of human inventions, —
that of symbols representing the sounds of
words, — they had long aspired after it, and
had contrived a method of recording events
and of handing down to memory the passages
of their ancient history. They had even made
great advances in science, and had a solar
year with intercalations on the principle of
the Roman calendar. They were diligent
cultivators of the ground, and also expert
miners and workers in metals ; even astonish-
ing the workmen of Europe with their skill in
setting gems. They appear, too, to have been
influenced by a deep sentiment of religion,
and to have had a very stately and majestic
ceremonial. Nevertheless, they do not seem
to have derived from these advances in civi-
lisation, any moral improvement, or any miti-
gation of that sullen malignity which seems
to be the general character of the native tribes
of the New World ; and their religion was
far from having an exalting influence, since
their gods had no attribute of clemency or
mercy, but were invested with the worst
forms of their own dark passions. In Peru,
also, we find remains of Cyclopean structures
erected during the government of the Incas,
which bear comparison with those of ancient
Egypt ; and the wonder is increased when it
is recollected, that no beast of burden save
the llama existed in Peru before the Spanish
invasion. At a time when there were no
public highways in Britain but such as were
relics of Roman greatness, there were roads
of 1500 miles in length in the empire of
Peru, carried over heights which overtop the
Peak of Teneriffe. The ancient Peruvians
were ignorant of the manner of forming an
arch ; but they had constructed suspension-
bridges over frightful ravines. They had no
implements of iron ; but they could move
blocks of stone as huge as the Sphinxes and
Memnons of Egypt.

Everything, then, seems to indicate one of
two things ; either that the American races are
descended from a stock originally distinct from
that of any part of the Old World, or that,
having had a common origin with the abori-
gines of Asia and Europe, they have existed
as a separate family of nations from a very
early period in the history of the race. This
question will be considered hereafter ; but it
must not here be left unnoticed, that several
of the tribes of the Western coast of America
present a striking physical resemblance to the

Peninsular Mongols ; and that there are in-
dications of communication between them, at
a comparatively late period.*

This brief account of the American races
would be incomplete, without a notice of one
of their most remarkable customs, — that of
altering the form of the skull by artificial
compression — which may be traced in dif-
ferent parts, both of the northern and southern
divisions of the continent. This flattening
was vertical in some instances, horizontal in
others. Of the former, Dr. Morton figures
examples, in his “ Crania Americana,” from
the tribe of Natchez Indians (which appears
to have been a branch of the Toltecan family)
that was exterminated by the French in the
year 1730. The compression was effected by
means of a bag of sand placed upon the fore-
head, whilst the occiput lay upon a sort of
mould, of which it gradually took the form
under the slow but constant influence of this
pressure. Some curious bas-reliefs, executed
by the Toltecans during their sojourn in
Mexico, show that the practice prevailed
amongst the most civilised portion of that
race. The horizontal flattening is practised
at the present time by the Chinooks and other
tribes inhabiting the neighbourhood of the
Columbia river ; the mode in which it is ac-
complished varying considerably in the differ-
ent tribes, but the general effect being the
same. So highly is this deformity valued by
them, that their slaves are not allowed to
practise it ; and yet the process by which it is
induced often gives rise to ulceration of the
scalp, and not unfrequently to death. In one
of the skulls figured by Dr. Morton, the ver-
tical diameter is reduced to little more than
four inches, the top of the cranium presents
a flattened arch not far removed from a hori-
zontal plane, and the face is protruded until
the facial angle is reduced to 60°, probably the
lowest grade ever observed in a human skull ;
the compression has also destroyed in a re-
markable degree the lateral symmetry. Yet
the capacity of the cranium is not altered by
the process ; and the “ flat-head ” Indians are
certainly not deficient in any of the mental
qualities of their race. Both kinds of flatten-
ing appear to have been practised by the
ancient Peruvians ; in whose sepulchres are
found vast numbers of crania, presenting such
different degrees of departure from what
seems to have been the normal form, that it is
not easy to find one which can be positively
affirmed to be unaltered. A characteristic
example of the effect produced by the process
of horizontal flattening is given in jigs. 849,
850, 851 ; which represents a skull closely
resembling that of a flat-head Indian of the
Columbia river. It seems not improbable
that the horizontal flattening was prac-
tised anteriorly to the advent of the Incas,
which may be dated at about the ycai
1100; and that the vertical flattening was
introduced by them. It seems to have been

* See Humboldt’s “Views of Nature ” (Bohn’s
edition), pp. 131 — 133.

varieties of mankind.

136!

Artificially- compressed Cranium from Titicaca. ( From a specimen in the Museum of the Royal College of

’ Surgeons.')

continued among the Peruvians for some
time after their conquest by the Spaniards ;
for the Ecclesiastical Court of Lima passed a
decree in the year 1.585, forbidding parents,
under certain specified penalties, to compress
or distort the heads of their children in the
various modes which were then in vogue.
The practice still exists among certain tribes
of South American Indians; and seems to be
regarded in much the same light with the
artificial compression of the foot by the
Chinese, or of the waist by the French and
English, — namely, as an artificial develop-
ment of a natural beauty.

V. Oceanic Nations. — The vast Oceanic
area, extending in longitude from Madagascar
on the one side, to Easter Island (half way be-
tween Asia and America) on the other; and in
latitude from Formosa to New Zealand, includ-
ing the numerous islands of the Indian and
Polynesian archipelagoes, and the great island-
continent of Australia, is peopled by tribes the
greater part of which are undoubtedly related
to each other very intimately, and have no near
affinities with those of any other region. The
only part of the mainland of Asia which is in-
habited by an Oceanic tribe, is the Peninsula
of Malacca ; and there is far more reason to
think that this tribe has migrated to that
locality from the neighbouring part of Oceania,
than that it represents the original stock and
line of migration of the Oceanic races. In the
physical characters of the Oceanic tribes, two
typical varieties present themselves ; and these
may be designated as the Malay o- Polynesian,
and the Negrito.

The Malayo-P.olynesians present a nearer
approach to the Mongolian type than to any
other ; but they must be compared rather with
the modified Mongols of the south-east por-
tion of the Asiatic continent, than with the
proper Turanian stock. Their complexion is
yellow, olive, brunette, or brown, rarely or
never darkening into black ; their hair, often
long, is usually black and straight ; the face is
usually somewhat flat, the cheek-bones high,
and the antero-posterior diameter of the skull
short ; but there is often a tendency to the

VOI.. IV.

prognathous character, such as is shown among
the inferior Hindoos. This division of the
Oceanic races occupies the greater part of the
Indian Archipelago, and the whole of the
Polynesian ; but it does not exist in New
Guinea, Australia, Tasmania, New Ireland, or
the islands between it anti New Caledonia,
which are peopled exclusively by Negritos.
That the tribes thus widely dispersed are all
descendants of one and the same stock, and
belong to the same race, seems distinctly
proved by the affinities of their languages ;
which, although presenting considerable modi-
fications (as might be naturally expected from
a prolonged isolation, and from the entire ab-
sence of a literature), yet accord, as has been
proved by William Humboldt, in many of their
primary words, and in their general plan of
construction. This mutual relationship is the
closest among the Malayan dialects of the
Indian Archipelago on the one hand, and
among the tongues spoken by the various Poly-
nesian islanders on the other; but these two
groups are also undoubtedly related to one
another, in such a manner as to constitute but
one family of languages. — The proper Malays
are, for the most part, a people of short and
slender stature, and small limbs, but well-
formed and vigorous; they have flat faces,
somewhat oblique eyes, and features resem-
bling the Chinese ; the hue of their com-
plexion, however, is considerably deeper, but
is not so dark as that of the Hindoos, yellow
being still a large ingredient. These cha-
racters, however, are far from being uniformly
exhibited by the whole Malayan branch ; and
in particular it is to be remarked that a ten-
dency to the prognathous type occasionally
shows itself, as in the skull of a Bugis of
Celebes, described by Blumenbach. — Between
the Malayan and the proper Polynesian area
is a small group, including the Pelew, Caroline,
and Marianne islands, the inhabitants of which
are even more conformable to the Mongo'ian
type than are either the true Malays or the
proper Polynesians ; these are termed by Dr.
Prichard, Micronesians. A consideration of
the probable lines of that migration which

4 s

362

VARIETIES OF MANKIND.

must be admitted to have taken place, unless
every island is supposed to have had its own
independent stock, has led Dr. Latham to the
conclusion that the Micronesian group was
peopled before the Polynesian area. — The
proper Polynesian branch presents such a wide
diversity in physical characters, that if it were
not for the unquestionable community of lan-
guage, usages, &c., it might be thought to con-
sist of several races, as distinct from each other
as they are from the Malayan branch. Thus
the Tahitians and Marquesans are tall and
well made ; their figures combine grace and
vigour ; the skulls are usually as symmetrical as
those of most Europeans ; and their physiog-
nomy presents much of the European cast,
there being only a slight flattening of the
nose, expansion of the nostrils, and thick-
ening of the lips, to indicate a degradation,
which is rather in the Negro than in the
Mongolian direction (fig. 850.). The com-
Fig. 850.

Tahitian Female. ( From a portrait by an officer of
“ L'Artemise”)

plexion, especially in the females of the higher
classes, who are sheltered from the wind and
sun, is of a clear olive, or brunette, such as is
common among the natives of Southern Eu-
rope ; and the hair, though generally black, is
sometimes brown or auburn, or even red or
flaxen. Among other tribes, as the Sandwich
Islanders, the New Zealanders, and the Tonga
and Friendly islanders, there are greater di-
versities of hue anti conformation (fig. 851.);
some being of a copper-brown colour; others,
nearly black; others, olive ; and others, almost

white ; the fairer races arc generally taller and
more vigorous, whilst the darker are inferior
in stature and figure. Many ot these varieties
present themselves in a single community,

Fig. 851.

Neiv Zealander. (From a portrait by Earle.')

such as that of New Zealand, and are so
strongly marked as to have led to the idea
that the difference is due to an intermixture of
races; but the unity of language, and the ab-
sence of any other indication, prevent such a
supposition from possessing the least claim to
reception. It is a most remarkable fact that
the Madecassians, or natives of Madagascar,
speak a language which is obviously derived
from the Malayan stock, being most nearly
allied to that of the Philippine Islands ; and
some of the multiform population of that
island bear a striking resemblance to Malays,
w hilst others seem more allied (as might be
expected) to the African nations of the main-
land. At present, the character and origin of
the Madecassian population is one of the
doubtful questions of ethnology.

The Negrito race presents a marked ap-
proximation to the physical characters of the
true Negro. The skull is of the prognathous
type ; the nose is flattened, the nostrils ex-
panded laterally, the lips thickened, and the
complexion a deep brown, or even black. The
character of the hair varies considerably ; for
in some cases it is long and straight ( fig. 827.);
and in others, crisp and frizzly ; and in others,
even woolly (figs. 805, 806.). By Dr. Prichard
and others a distinction was drawn between
those with straight, and those with woolly
hair; but the validity of this can scarcely be
maintained, since it appears that the very same
people may present one or the other kind
of hair, according, as it would seem, to
the climatic and other conditions under
which they exist. The Negrito race not only
inhabits the area which is more exclusively
its own, but is also believed to exist in

13G3

VARIETIES OF MANKIND.

the interior of many of the larger islands of
the Indian Archipelago ; it is not always cer-
tain, however, whether the people whose pre-
sence there is reported, are Negritoes or dark

Fig. 852.

Portrait of Ourou-Mare, an Australian Chief. ( From
the “ Allas du Voyage au Terns Australes.”')

Malays. There are many indications, indeed
that the Malayo-Polynesian and Negrito races
are not really so distinct, as the marked dis-
similarity of their respective physical types,
and the complete want of conformity between
their languages, would make it appear. For
as, on the one hand, some of the subdivisions
of the former present a decided tendency to-
wards the prognathous character, and the
depth of complexion, which are typical of the
latter, so among the latter we do find a lighter
shade of skin, a greater symmetry of skull, and
a considerable improvement in form and fea-
ture, not unfrequently displaying themselves ;
as is the case, lor example, with some of the
Papuans, or inhabitants of New Guinea, and
even occasionally with the Australian abori-
gines, notwithstanding that the physiognomy
of the latter generally exhibits a very manifest
degradation (Jig. 852.) The relations of the
language of the different branches of this race
to each other, and to other languages, have
not yet been clearly developed. They appear,
however, to possess a general community of
structure, with differences in the vocabulary;
anti such differences present themselves very
prominently among some of the languages of
Australian tribes, whose common origin can-
not be questioned. According to Dr. Latham,
they contain a considerable infusion of Malay
words ; but this is scarcely enough to establish
their community of origin with the languages
of the Malayo-Polynesian stock. Some other
affinities have been pointed out by Dr. Prich-
ard ; but these, it is remarkable, are not so
intimate as those which subsist between the
Australian and the Tamulian of Southern

India. Remote as the connection seems, this
circumstance adds weight to the idea, that the
native Australians are an offset from that
southern branch of the great nomadic stock
of Central Asia, which seems early to have
spread itself through the Indian and Indo-
Chinese peninsula.

It is commonly believed that there is no
people, excepting the most degraded of the
Negroes and the Bushmen of the Cape,
whose physical condition is so miserable,
or whose mental development is so low, as
that of the Australian aborigines ; but the
testimony of those who have visited them
in their native haunts, where as yet they
have been uncontaminated by contact with
Europeans, and have not suffered from the
deprivation of the land which affords them
the means of subsistence, is very decided in
regard to the exaggeration which has prevailed
on this point. In particular it may be re-
marked, that, although they have less suscepti-
bility than exists among many other rude
nations to religious impressions, yet it is cer-
tain that they are not destitute (as some have
represented them to be) of all idea of a God ;
they even seem to have a notion of a future
state, and a belief in good and evil angels.
They have likewise a superstitious belief in
magicians or sorcerers ; a belief which seems
to attain its highest point among the nations
of High Asia. Many complex and singular
institutions, especially relating to the tenure
of property, exist among them ; to which the
nearest approach elsewhere is presented by
the North American Indians.

Looking, then, to the great diversity which
exists among the subordinate groups of which
both these divisions consist, and their ten-
dency to mutual approximation, it cannot be
shown that any sufficient reason exists for
isolating them from each other ; and, as already
remarked, there seems no medium between the
supposition that each island had its aboriginal
pair or pairs, and the doctrine that the whole
of Oceania has been peopled from a common
stock. Looking, again, to the very marked
approximation which is presented by certain
Oceanic tribes to the Mongolian type, and this
in a locality which, on other grounds, might
be regarded as having received the first stream
of migration, the possibility, to say the least,
can scarcely be denied, that the main-land
furnished the original stock, which has under-
gone various transformations subsequently to
its first dispersion ; these having been the re-
sult of climatic influence and mode of life, and
having been chiefly influenced as to degree, by
the length of time during which the transform-
ing causes have been in operation. At any rate
it may be safely affirmed, that there is no
physical peculiarity which entitles the Oceanic
races to rank as a group, which must have ne-
cessarily had an original stock distinct from
that of the continental nations.

General Recapitulation.

On the whole then, the result of the ex-
tensive range of inquiries, of w hich an out-

4 s 2

1 364?

VARIETIES OF MANKIND.

line has now been given, may be stated as
follows : —

1. The extremest differences from each other,
or from a common stock, presented by the
races of Mankind, in regard alike to physical,
physiological, and psychological peculiarities,
are not greater in degree than those which
are known to arise amongst other species of
animals possessed of a similar adaptive capacity,
under the influence of changes in external con-
ditions ; and they differ only in degree, not in
kind, from those of whose origin in a change
of external conditions, in the case of mankind,
we have adequate evidence.

2. In whatever mode the types of the prin-
cipal varieties are selected, they are found to
be connected by intermediate or transitional
gradations; the descendants of each principal
stock exhibiting, in a greater or less degree,
a capability of approximation to the characters
of others.

3. There is nothing in these diversities,
therefore, to justify the erection of specific
distinctions among the different races of Man-
kind ; and, whilst a probability of the unity
of their original stock may consequently be
said to exist, all scientific evidence points to
the conclusion, that, if the original stocks were
multiple, they must have had attributes es-
sentially the same.

4. The supposition of a number of distinct
“ protoplasts,” one for each principal region
of the globe, is not required to account for the
extension of the human family over its area,
and it does not afford any assistance in ac-
counting for the phenomena of their existing
distribution ; since each principal geogra-
phical area contains races of very diversified
physical characters, the affinity of whose lan-
guages makes it next to certain that they must
have had a common descent.

5. The evidence of philological research
decidedly tends to the conclusion, that such
affinities exist between the earliest known
stocks of the principal groups of languages
now and heretofore in use, as can only be
reasonably accounted for on the hypothesis of
their common origin, and the consequent ra-
diation of the whole species from one centre.
What that centre is likely to have been, is a
legitimate object of inquiry ; and the follow-
ing, which have long been regarded by the
author as the most probable deductions from
modern Ethnographical research in relation to
this subject, are now submitted with additional
confidence, on account of the confirmation
w hich they have received from the most recent
investigations, and, in particular, from their
conformity with the arrangement which Dr.
Latham’s linguistic researches have led him
to adopt.

The stock from which the globe was ori-
ginally peopled, is probably more nearly repre-
sented at this time by the Turanians of High
Asia than by any other; and some part of
that region was probably their primary seat.
It is among the Mongols and their allies, that
that combination of physical attributes which
is best adapted to the exigencies of a nomadic

life, and that constitution which renders a
nomadic life a necessity of their nature, most
characteristically present themselves. The
bodily system of these people possesses a
vigour and adaptiveness, which enables it to
flourish under all the diversities of climate to
which their wandering propensities conduct
them ; and they can accommodate their mode
of life, without any great departure from their
characteristic nomadism, to a great variety of
external circumstances. Moreover, the geo-
graphical relations of High Asia make it the
most central spot on the whole globe, for the
radiation of Man to every corner of the ha-
bitable world; its connections with all other
lands are such as are possessed by no other
region ; while its climate is so intermediate
between that of the frigid and that of the
torrid zones, that the passage into either is
without any violent transition ; and, as a
matter of fact, we find that, while the Tungu-
sians and Ugrians have carried the Turanian
stock to the shores of the Polar Sea, a Tartar
tribe has made itself master of China, and
governs the whole of the south-east of Asia,
even to the Indian Ocean. This a prion ar-
gument, however, would be worth very little,
if w e did not find it in correspondence with
the very curious fact, that the most ancient
inhabitants of nearly every part of the globe
are connected with the nations of High Asia,
more or less closely, by affinity of language or
of physical characters. This we have seen to
be the case, not merely with the Seriform
stock of Southern Asia and the Hyperborean
and Peninsular Mongols of the north and
north-east, but also with the aboriginal people
of Northern and Southern Europe, with those
of the Caucasus, and with the first settlers of
the Indian Archipelago. Not less complete
is the transition to the American nations; for
whilst, on the one hand, the Esquimaux forms
the link of connection, agreeing in physical
character with the Hyperborean Mongols, and
in language with the mass of the proper Ame-
rican nations, increased acquaintance with the
languages of the latter, and w ith the languages
of the Northern Asiatics, has confirmed the
suggestion long since made, that they are con-
structed upon a plan essentially the same ;
the tendency to agglutination, which is less
manifested in the more immediate descendants
of the parent-stock, being most fully carried
out in its offsets, the Euskarian of the Basque
provinces, the languages of the Peninsular
Mongolidas, and the American tongues. The
only region regarding which there is not the
same amount of evidence, is Africa. But we
have seen reason to regard the whole group
of African nations as connected, through the
Semitic stock, with the Asiatic races ; and all
the knowledge recently acquired of the lan-
guage of Ancient Egypt*, together with all the
information gained by Major Rawlinson and

* See tlie memoir by the Chevalier Bunsen, “ On
the results of the recent Egyptian Researches in
reference to Asiatic and African Ethnology, and the
Classification of Languages,” in the Reports of the
British Association for 1847.

VARIETIES OF MANKIND.

1365

other decipherers of the most ancient inscrip-
tions in the south-west of Asia, tends towards
the conclusion, that the languages of the Afri-
can nations are derived from the same funda-
mental stock with those of the Arian and
Turanian, the separation having taken place
when they were as yet in that early stage of
development, which has remained stereotyped
(so to speak) in the Chinese and other Seri-
form tongues. Looking at the African popu-
lation under this aspect, we may fairly imagine
it to have been first derived from immigrants
by no means remote from the Turanian stock ;
these gradually spreading themselves over the
entire continent, became gradually modified
in their physical characters by the new cir-
cumstances in which they found themselves ;
and whilst the dwellers in the Nile valley ad-
vanced in civilization and in intellectual de-
velopment, and became assimilated in cranial
characters to the other races surrounding the
Mediterranean sea, those of Central, Western,
and Southern Africa underwent a degradation
into the prognathous type, similar to that
which has affected the earlier settlers in Oce-
ania, and to which some approach is seen in
Southern India. Viewed under this aspect,
the re-appearance of the Mongolian type of
conformation among the Hottentots of South-
ern Africa is extremely significant ; for, al-
though they are Africans by immediate de-
scent, yet the characters of their remoter
ancestry reappear, so soon as a correspondence
in physical conditions favours their repro-
duction.

In certain spots of the globe thus peopled
with races derived from a common centre,
varieties in physical conformation appear to
have sprung up, which, in a scanty and scat-
tered population, would have a far greater
tendency to perpetuation than is now any-
where exhibited (see p. 1312) ; new and more
refined languages were originated ; local de-
velopments of higher forms of civilization oc-
curred ; and subordinate centres were thus
formed, from which more limited radiations
have subsequently taken place, impressing
their own features of civilization upon the
countries through which they have spread.
Thus we have, at a very early period, indi-
cations of the Egyptian, the Syro-Arabian,
the Arian, the Indo-Chinese, the Mexican,
and the Peruvian races, preserved to us in
their architectural remains, or in their written
records ; and although some of these may
possibly have been mutually connected at
their origin, yet they seem to have been very
early separated, and to have attained their
fullest development independently of each
other. The subsequent migrations of certain
of these races, or of offsets from them, have en-
tirely changed their original distribution. The
Arab race has extended itself through North-
ern and even Central Africa, over Southern
Asia, and even into the Indian Archipelago.
But the Arian has displaced the aboriginal
population from almost every part of Europe,
and has there formed a secondary centre of

radiation, whilst its original stock has been
almost obliterated. It is obviously a stock
which attains its fullest development under
the influence of a moderate temperature ; and
only, therefore, when it exchanged its original
seat for the more favourable influences of
European climate, did it manifest its remark-
able capabilities. It can scarcely be doubted
that from this race, or from a mixed race de-
veloped between it and their aboriginal popu-
lations, America and Oceania are destined to
be re-peopled ; the destiny of Asia and Africa,
however, seems more obscure. In the former
country, the primitive races possess a con-
siderable amount of self-sustaining vigour ; and
in the latter, they exhibit an adaptiveness to
its peculiarities of climate, which will perhaps
never be acquired by Europeans. Moreover,
whilst the American and Oceanic races appear
doomed to extinction as pure races, wherever
they come into contact with Europeans, there
is no evidence that such is the case with those
of Mongolian or of African descent ; the latter,
indeed, hold their ground with remarkable
tenacity, and we may not improbably regard
them as destined, under the influence of Chris-
tian civilization, to bear an important part in
the future history of Mankind. (See p. 1344.)

Addendum. — [Since the former part of this
article has been in print, the statements of
Count Strzelecki, cited in p. 1341, have been
pointedly contradicted, as regards the abo-
riginal females of Australia, by Dr. T. R. H.
Thompson (surgeon, r.n.), who states as the
result of personal inquiries among several
different tribes, that for a native female to bear
children to a native male, after having borne
half-caste children to an European father, is
by no means an uncommon occurrence. He
admits that wherever European settlers are
commingled with the aborigines in Australia,
the native race disappears. This however, he
maintains, does not arise from “any deviation
of nature’s laws but because the European,
wherever he takes with him his civilization,
takes with him his vices also; so that drunken-
ness and syphilitic diseases, which soon be-
come rife among the neighbouring population,
speedily cause their decline. Dr. Brown
allows that the diminution is partly caused by
the comparative infecundity of the females who
have cohabited with Europeans ; but he ac-
counts for this by attributing it to the change
of life to which she is subjected.

“ From living in a state of nature, with irre-
gular and uncertain diet, exposed to every
vicissitude of climate, with no other protection
than a few kangaroo skins, or a roll of bark,
or of the ‘tulka,’ she enters on a more regular
life, partakes of regular meals, and sleeps no
longer exposed. But even with this a'teration
for the better, she does not bear to the w'hite
man more prolifically than to her native hus-
band ; on the contrary, her fecundity appears
to decrease, — for, on partaking of the white
man’s comforts, she is a recipient of his vices;
she passes much of her time in a half inebriated

4 s 3

1366

VARIETIES OF MANKIND.

state, smoking tobacco and drinking ardent
spirits whenever they can be procured. In-
deed, it is well known, that among the chief
inducements for the native female to remain
with a European, are the rum and tobacco
with which she is supplied ad libitum. Can
we then wonder, if, after some years spent in
a manner which must militate against her
capabilities for procreating, more than her
previous rude mode of life, she returns to her
tribe with a broken constitution, and probably
past the usual term of life for conception (they
seldom bear children after thirty years of age)
to prove in such instances sterile?”#

The same explanation is probably appli-
cable to the case of the other Aboriginal
races adverted to by Count Strzelecki ; and,
if it be the correct representation of facts, it
altogether destroys the force of any argument
which might be raised upon the infertility of
the native females after having borne children
to Europeans, in favour of the specific differ-
ence of the races.]

Bibliography. — For the facts of the latter "part
of this article, the author has relied in great part on
the learned and elaborate treatises of Dr. Prichard,
whose “ Researches into the Physical History of
Mankind” (3rd edit., London, 1836-184:7), will long
hold its rank as a most complete and masterly
treatise on Ethnology. His smaller work, “ The
Natural History of Man” (London, 1848), though
chiefly an abridgement of the preceding, contains in
its supplement some additional information of value.
The author has also derived much assistance from
Dr. Latham's more recent treatise, “Natural History
of the Varieties of Man,” (London, 1850). A large
part of the materials of the earlier portion of the
article, however, have been drawn direct from
original sources.

The Bibliography of the subject, to be complete,
must include a most extensive catalogue, not only
of special treatises in various departments of Eth-
nology, but also of Voyages and Travels, and of
Philological works and memoirs. The following are
selected as having the greatest claims to particular
mention : — Abel-Rtimusat, RecherchessurlesLangues
Tartares, Paris, 1820. Adelung, Mitbridates, Oder
allgemeine Sprachenkunde, Berlin, 1806 — 1817.
Balbi, Atlas Ethnologique, Paris, 1826. Barrow,
Travels in the interior of South Africa, Loudon,
1801 — 1804. Beechey, Voyage to the Pacific Ocean
and Behring’s Straits, London, 1831. Bennett,
Wanderings in New South Wales, &c., London,
1834. Blumenbach, Institutiones Physiologicaj,
Gottingen, 1787. De Generis humani Varietate
Nativa, Gottingen, 1795. Collectio Cl'aniorum di-
versarum Gentium, decades 1 — 7, Gottingen 1790 —
1828. Bopp, Vergleichende Grammatik, Berlin,
1833 — 1842. Bory de St. Vincent, Voyage dans
les quatre lies des Mers d’Afrique, Paris, 1803.
L’Homme, essai zoologique sur le genre humain.
Paris, 1827. Bruce, Travels to discover the Source
of the Nile, Edinburgh, 1790. Buffon, Histoire
Nat.urelle, gdndrale et particulifere, Paris, 1749 —
1804. Burchardt, Travels in Syria and the Holy
Land, London, 1822. Travels in Nubia, London,
1819. Burchett, Travels in Southern Africa, London,
1822 — 1824. Burnes, Travels into Bokhara, London,
1834. Camper, Dissertation Physique sur les Diffe-
rences re'elles que presentent les traits du Visage
chez les Homines de differens Pays, de differens Ages,
&c., Utrecht, 1791. Catlin, North American In-
dians, London, 1842. Chardin, Voyages en Perse,
et autre lieux de l’Orient, Paris, 1811. Choris,
Voyage Pittoresque autour du Monde, Paris

* Edinburgh Monthly Journal, October 1851.

1821 — 1822. Clapperton Sf Denham, Travels in

Northern & Central Africa, London, 1826. Cook,
Voyages around the World, London 1784 — 1785.
Craufurd, History of the Indian Archipelago, Edin-
burgh, 1820. Cuvier, Le Rbgne Animal distribue
d’apres son Organisation, Paris, 1817. Memoire sur
la Venus llottentote; in Mem. du Mus. d’Hist.
Nat. tom. v. Daniell, Medical Topography of the
Gulf of Guinea, London, 1849. Dauhenton, Memoire
sur les Differences de la Situation du grand Trou
occipital dans l’Homme et les Animaux; in Mem. de
l’Acad. des Sci. de Paris, 1764. Dr. J. Davy, An
Account of the Interior of Ceylon, London, 1821.
D'Azara, Voyages dans l’Amerique Meridionale,
Paris, 1809. Devon, Voyage en Egypte. De Salles,
Histoire Gdncrale des Races Humaines, Paris, 1849.
Desmoulins , Histoire Naturelle des Races Humaines,
Paris, 1826. Dieffenbach, Travels in New Zealand,
London, 1843. D'Orbigny, Sur les Variations que
presente la Couleur de la Peau chez les Races brunes
(Bull, de la Soc. Ethnol. 1846). L’Homme Ame'ricain
considere sous les Rapports physiologiques et mo-
raux, Paris, 1840. Du Ponceau, On the American
Languages, in the Transact, of the Amer. Philos.
Soc. vol. i. Earle, The Eastern Seas, or Voyages,
&c., in the Indian Archipelago, London, 1837.
TV. F. Edwards, Des Caractferes physiologiques des
Races humaines, conside'res dans leur rapports avec
l’histoire, Paris, 1829. Ellis, Polynesian Researches,
London, 1831. Ermann, Reise um die Erde, Berlin,
1833—1838. Gallatin, Various Papers on North
American Ethnology in the Archaeologia Americana,
and the Transactions of the Ethnological Society of
New York. Grey, Journal of Discoveries in Aus-
tralia, London, 1841 ; and on the Languages of
Australia, in Journal of Geogr. Soc. vol. xv. Hales,
Philology of the United States Exploring Expe-
dition. Hawkesworth, Voyages to the Southern
Hemisphere, London, 1773. Alex. Humboldt, Per-
sonal Narrative of Travels to the Equinoctial Re-
gions of the New Continent (transl.), London,
1814 — 1829. Researches concerning the Ancient
Inhabitants of America (transl.), London, 1815.
Kosmos (transl.) London, 1846—1851. TV. Von
Humboldt, Uber die Kawisprache, Berlin, 1836 —
1839. King and Fitzroy, Journal of the Voyage of
the Adventure and Beagle, London, 1840. Klaproth,
Asia Polyglotta, Sprachatlas, &c. Tableau his-
torique, &c. du Caucase, Paris, 1827. Knox, The
Races of Men, London, 1850. Lander , Journal

of an Expedition to explore the Course and Ter-
mination of the Niger, London, 1832. Larrey, Re-
marques sur la Constitution physique des Arabes ;
Comptes rendus, tom. vi. Latham, Man and his
Migrations, London, 1851. Ethnology of the Bri-
tish Colonies and Dependencies, London, 1851.
Lawrence, Lectures on Physiology, Zoology, and the
Natural History of Man, London, 1819. Lesson,
Voyage Medical autour du Monde, Paris, 1829.
Leyden, On the Languages and Literature of the
Indo-Chinese Nations, in Asiatic Researches, vol. x.
Marsden, History of Sumatra, London, 1811. Mor-
ton, Crania Americana, Philadelphia, 1839. Crania
Egyptiaca, Philad. 1844. Muller, Der Ugrische
Volkstamm. Pallas, Voyages en Russie, et dans
1’Asie Septentrionale (transl.), Paris, 1789—1793.
Parry, Arctic Voyages, London, 1821 — 1828. Peron,
Voyage de Ddcouvertes aux Terres Australes, Paris,
1807. P arouse, Voyage round the World (transl.),
London, 1798. Pickering, The Races of Man and
their Geographical Distribution, London, 1849.
Prichard, The Eastern Origin of the Celtic Nations,
London, 1831. Quetelet, Sur l’Homme et le Deve-
loppement de ses Facultes, Paris, 1835. Quoy et
Gaimard, Partie anthropologique du Voyage de
1’Astrolabe, Paris, 1829 — 1834. Bitter, Die Erd-
kunde im Verhaltniss zur Natur und zur Geschichte
der Menschen, oder allgemeine vergleichende Geo-
graphic, Berlin, 1832. Rugendas, Voyage dans le
Brezil, Paris, 1835. Ruppell , Reisen in Nubien und
Kordofan ; Frankfurt am Main, 1829. Sandifort,
Tabulae Craniorum diversarum Nationum, Lugd,

VEIN.

Batav. 1838 — 1843. SchomburgJi, On British Guiana,
&c. in the Transactions of the Philological, Ethno-
logical, & Geographical Societies. Scouler, On the
Languages of the North-West Coast of America, in
the journal of Geogr. Soe. 1842. Dr. Andrew Smith,
Report of the Expedition for Exploring Central
Africa from the Cape of Good Hope, Cape Town,
1836. Soemmering, Uber die Korperlich Vers-
chiedenheit desNegers vom Europeens, Mainz, 1784.
Sonnini, Travels in Egypt (transl.), London, 1799.
Sparrman, Voyage to the Cape of Good Hope and
round the World, Perth, 1789. Spix und Martins,
Reise durch Brasilien (transl.), Travels in Brazil,
London, 1824. Steedman, Adventures in the In-
terior of Southern Africa, London, 1845. Tiedemann,
Uber das Him des Negers, Heidelberg, 1837. Voter,
Continuation of Adelung’s Mithridates, Berlin, 1806
— 1817. Vergleichungstafeln der europaischen
Stamm-Sprachen, Berlin, 1822. Virey, Ilistoire
Naturelle du Genre Humain, Paris, 1824. Volney,
Voyage en Syrie et en Iigypte, Paris, 1787. Wilkes,
Account of the United States Exploring Expedition,
Boston, 1845. Winterhottom, Account of .the Native
Africans in the Neighbourhood of Sierra Leone
London, 1803.

W, B. Carpenter.

VEIN (4>\6r|/, Gr.; Vena, Lat. ; Verne, Fr ;
Blutader, Ger.; Vena, Ital.; Vena, Span.). — In
general anatomy the term vein, in the higher
animals, includes four sets of blood-vessels,
differing in so many respects from each other
as to renderit difficult to give a general defini-
tion which shall include all under one head,
either as it regards structure, course, or func-
tion : indeed, so unlike are the different S3S-
tems of veins, that the only remark which can
be said to apply to them all is, that they convey
blood in a direction towards the heart ; in this
respect, as well as in their want of uniformity
of character, being directly opposed to the
arteries.

The four systems of veins are the systemic,
the portal, the pulmonary , and certain veins
peculiar tojcetal life — the ductus venosus and
umbilical vein ; and it will be found, upon
contrasting them, that they differ much from
each other, considering that all enjoy the
common appellation vein. Thus, the systemic
veins, which correspond to the branches of
the aorta, excepting those of the abdominal
viscera, collect the blood from small and nu-
merous vessels into larger and fewer in its
progress towards the heart, constituting a
course of circulation of a truly venous cha-
racter ; while, on the other hand, that portion
of the blood, which is conveyed to the ab-
dominal viscera by the branches of the ab-
dominal aorta, is first collected from numerous
branches into one vessel — the vena porta —
thus far the circulation being venous, and is
then again broken up into smaller and re-
dividing vessels, after the manner of ar-
teries, and forming, as regards this particular,
an arterial circulation, though the vessels
are nevertheless veins. In both these in-
stances the blood conveyed by the vessels
in question has a similar quality, which is
characteristic of veins, and is called venous ;
it is blood saturated with carbon. In the
two other systems of venous circulation —
the pulmonary and umbilical — the current is

1367

venous while the fluid is arterial, these vessels
being channels by which the blood is returned
to the heart after it has left the arterialising
organs. Again, as regards the structure and
calibre of veins, our definition is necessarily
loose ; for, while veins are, in a general way,
thin, less elastic, and distensible, as contrasted
with arteries, they are nevertheless very
varied in these particulars in different regions,
and though, for the most part, the calibre of
veins is greater than that of the corresponding
arteries, still this is not always the case, as is
found upon contrasting the area of sections of
the pulmonary arteries and veins. It is there-
fore imj ossible to give a succinct, and, at the
same time, a comprehensive definition of
vein ; and the one which appears to me to be
most applicable and to include the members of
each venous system is this — that a vein is a
blood-vessel, neither artery nor capillary , convey-
ing blood in a direction toivards the heart, having
walls of greater tenuity and extensibility and, at
the same time , less elasticity than an artery.

The literary history of this subject is chiefly
interesting as referring to veins, in their rela-
tion to the general circulation. Until the
time of Harvey’s great discovery, the general
physiological relationship of the veins was
not understood, and the most discrepant
notions were entertained.

Hippocrates, in none of his writings, draws
distinction between arteries and veins. Plato,
in his Timeeus, describes the veins as con-
nected with the heart, and receiving blood
from it. He regards the veins as the messen-
gers, transmitting to the whole body the orders
coining from the soul : he attributes to them
the functions of sentient and motor nerves.
He considers that the veins have two centres
— the heart and the liver ; and he makes no
distinction between them and arteries. Praxa-
goras taught that the veins were blood-vessels,
in contradistinction to the arteries which he
considered air-vessels. Aristotle drew no
distinction between arteries and veins. Hero-
phi/us describes both arteries and veins as
blood-vessels : but he expresses himself in
doubt, as to whether the veins arise from the
heart or the liver, Erasistralus, holding the
same general doctrines as Praxagoras, further
described the texture of veins very minutely,
and, according to Marx, he noticed the ex-
istence of valves. Ce/sus and Aretceus made
no advance in this subject. Galen distin-
guished between arteries and veins - — both
blood-vessels : he also observed the anasto-
moses of each : he stated the origin of veins to
be from the liver, and of the arteries from the
heart, and that both were destitute of sensa-
tion. Avicenna described the veins “venae
quietas,” in contradistinction to the arteries,
which he styled “ venae pulsantes et audaces.”
According to Baulinus, Avicenna described
the valves of veins under the name of “ cel-
lules.”

The European anatomists of the 15th, 16th
and the early part of the 17th century, re-
mained in a state of great confusion and ig-

4 s 4

1368

VEIN.

norance, as to the bearing of the veins upon
the circulating system. Vesalius endeavoured
to establish the doctrine, that the vena cava
takes its origin from the heart, and not the
liver ; but in this he was opposed by Sylvius,
Columbus, Eustachius , and Fallopius.

While Ccesalpinus had occasional faint glim-
merings of the physiology of the veins, and
Fabricius, a remarkable knowledge of their
anatomy, it was still left to Harvey to indi-
cate their function and relation to the general
circulation.*

Veins are the necessary companions of
arteries, and are consequently found in all
animals possessing the latter vessels.

In the following remarks I shall, for the
purpose of examining the subject more com-
pletely, divide the consideration of vein into
these heads : —

J. Structure.

II. Phy sical and vital properties.

III. Origin, course, anastomoses, plexuses,
&c.

IV. Function.

V. Development.

My observations will be principally con-
fined to the consideration of these various
heads as applied to the veins of mammalia,
especially the human subject. The general
anatomy of this subject in invertebrate classes
has not, as yet, been sufficiently examined, and
does not appear to furnish many points for
generalisation, beyond those supplied in the
mere anatomical description given of the
venous system in the several invertebrate
classes, in the articles specially applied to them .

I. Structure. — There is scarcely any sub-
ject in structural anatomy, which has given
rise to so many varied and discrepant opinions,
and so much contradictory description as the
structure of veins ; the different writers upon
this point having been numerous, and with
scarcely any exception, each giving an ac-
count in some, and often important, respects,
contrary to those who have preceded him.
This circumstance may, to a certain extent, be
explained by the various observers having ex-
amined different veins, in different regions, and
in different animals ; and it must be remem-
bered that all microscopical observations
necessarily differ from those which are made
with the scalpel and the naked eye, and are
incompatible unless conjoined, compared and
interpreted by the same individual ; for, as we
shall presently find, structures which seem
reduced by dissection to their simplest ele-
ments, are found, when submitted to the mi-
croscope, to be compound ; this is especially
the case as it regards the internal tunic of
veins, as displayed by coarse anatomy and the
microscope respectively. All the discrepancies,
however, which have occurred cannot be
settled upon these grounds, and it must be

* For more elaborate details of literary history,
I would refer the reader to the article Circulation,
and to the learned “ Diatribe Anatomico-physio-
logica de structura et vita venarum,” by Marx.
See Bibliography.

granted that in some instances the writers
upon this subject have rather drawn upon
their imagination than depended entirely upon
anatomical demonstration. These conflicting
statements, however, serve to keep be'ore us
the fact that there is considerable difference
of structure in veins in certain regions.

The early anatomists who devoted their at-
tention to the investigation of the intimate
structure of organs, applied themselves to the
study of the minute texture of veins, and it
was indeed one point in their structure which
was greatly instrumental in leading Harvey
in his discoveries of the circulation.

Constantinus first described the structure of
veins as consisting of a “ tunica villosa.” Ve-
salius speaks of the membranous character of
veins, and of their being composed of three
sets of fibres, — a longitudinal, a circular, and
an oblique. Fallopius and Bartholini deny the
fibrous nature of the coats of veins, and
DiemebroecJc described veins as consisting of
one membranous tunic, and believes the state-
ment of the existence of three tunics to be
mere imagination. Willis, Nicolai, and Blan-
card describe veins as being composed of four
coats or tunics. Haller denies the existence
of transverse muscular fibres in the coats of
veins, which had been repeatedly mentioned
by other anatomists. Lieutaud states that the
veins are identical in structure with the ar-
teries, but simply attenuated. Prochaska does
not admit the existence of a fibrous tunic in
veins, whilst Scemmerring says it is to be found
only in the larger ones. Meckel, Autenrith,
and Bichat deny altogether the circular or
transverse coat of veins, and Senac says that
their tunics are composed simply of longitu-
dinal fibres.

To these might be added a long list of di-
verse descriptions, which are however of more
literary curiosity than anatomical value.

Veins, in the human subject and mammalia,
and I believe in vertebrata generally, are
membranous cylinders, consisting of various
fibrous coats, lined internally by an epithelium.
The walls of veins, which are sufficiently thick
to admit of coarse dissection, are with care
divisible by the scalpel into three layers, an
internal, middle, and external coat : but, when
submitted to microscopical scrutiny a still
further analysis is made; the internal layer
is found to have a compound character, and
the direction of the elementary fibres of the
several tunics is also shown ; the internal and
external coats are seen to be longitudinal,
while the middle is compound, partly circular
and partly longitudinal.

The relation of coarse and microscopical ana-
tomy will be best seen by the following table :

Coarse Dissection. Microscopical Examination.
f Epithelium.

Internal coat X Fenestrated membrane.

[ Longitudinal fibres.
Circular and longitudinal
fibres intermixed. Muscle.
Longitudinal fibres ; com-
pact areolar tissue.

Middle coat
External coat

VEIN.

1369

This may be taken as a tabular view of the
typical structure of veins of larger size, and
in the smaller vessels the same order of parts
is represented, but with less distinctness and
greater tenuity. There are certain regions,
however, where the venous texture, both in
quality and order, departs considerably from
the typical arrangement : these will be noticed
hereafter.

In the following observations, the several
coats of the veins will be described in succes-
sion, beginning with the innermost.

Epithelium . — It is difficult (as has been ob-
served by Henle), \n all cases, to make out a dis-
tinct epithelial layer lining the vascular cavity;
but, as far as my observations go, it is more
constant in arteries than in veins, and the
epithelium is more perfectly formed in the
former than in the latter. The anatomist will
frequently make search in vain for epithelium
on the inner surface of veins, and, when found,
a perfect epithelial cell is less common than
one imperfectly formed, the nucleus existing,
but the cell-wall either partially or wholly
absent.

Fig. 853.

Epithelium from the Vena Cava of a Sheep.

a, perfect epithelium ; b, common form ; c, epithe-
lium seen edgewise ; cl, nuclei of epithelium desti-
tute of cell-wall. (Magnified 200 diameters.)

The best method for examining the epithe-
lium is by scraping the inner surface of the
vessel, and placing the material removed on a
slip of glass ; or by viewing the free edge of a
valve under the microscope. Existing in its
most perfect form the epithelium is of a dia-
mond or rhotnboidal figure, containing a
nucleus, large in proportion to the cell, of a
granulai character, and lenticular or oval form.
The nucleus is distinct and well defined. The
cell itself is clear, pale, and watery to an ex-
tent that it is impossible to portray in a wood-
cut. Henle states that the longaxisoftherhom-
boid corresponds with that of the vessel in
which it exists. In the figure ( fig. 853. a), is re-
presented the most perfectly formed specimen
I have seen from a vein ; the rhotnboidal figure
being very marked : it was obtained from the
vena cava of a sheep. There is also seen
(Jig- 853. b), a more common form, where the

cell and nucleus are both present, but the
structure is less regular and more confused.
The epithelium is of the pavement or scaly
form, existing in a single layer : the cells are
flat, and either have no cavity, the opposed
sides being adherent, or the cavity is very
minute. This is displayed in the drawing
(Jig- 853. c), where some cells are seen edge-
wise : in this position the dimensions of the
nucleus are observed to bulge out the cell-
walls where it is placed, while the cell itself
forms a comparatively narrow line, or is even
reduced in appearance to a mere linear fila-
ment attached to the nucleus, sometimes at
one extremity and sometimes at both.

But the condition in which I have most
commonly found the epithelium is that re-
presented at d in the accompanying figure ;
the nucleus, the essential part of the cell,
being apparently all that is present, and re-
presenting the whole epithelial structure.
These lenticular corpuscles, the nuclei, are
scattered on the inner surface of the vein in
pretty much the same position and form as if
the cells were present, but the cell-walls are
not sketched out, or the nuclei are only here
and there partially invested by a cell. This
appearance 1 have observed in the freshest
specimens, and it may also be produced by
keeping those where the cell is distinct for a
short time, when the cell-wall liquefies, and
becomes invisible. From the fact that the
nuclei are in some instances pretty equally
separated from each other, and hold about the
same relative distances, whether the cell-wall
be present or not, it would seem not impro-
bable that, where not visible, the cell might
still exist in a state of imperfect and indistinct
formation,- — that the blastema may be present
in a mucilaginous condition, but of sufficient
density to retain the nuclei in their proper
relative position.

The nuclei may sometimes be seen thus
arranged on the surface of a valve near its
clear, thin edge, as is seen with unusual
distinctness in Jig. 865. a. These appear-
ances are generally destroyed by manipulation.
When a valve is placed for examination, the
nuclei are apt to float off' its surface in the
fluid with which the object is moistened, and
arrange themselves along the free margin of
the valve in the interval between its edge and
the glasses.

Henle has represented, in his matchless
work on general anatomy, the edge of a valve
magnified, in which the nuclei of epithelium
are arranged on a clear area, which rims the
margin of the valve; and this transparent,
structureless boundary he describes as the
epithelial cells, in which the nuclei, also
visible, are embedded. I have seen well de-
veloped epithelium at the edge of a valve, but
it did not present the appearance depicted by
Ilenle, the cell being a mere line as repre-
sented in Jig. 865. a. a, and scarcely formimr a
transparent edge. I have also occasionally
seen a structureless rim to a valve, and as
that was not changed by the washing and
brushing off' of the superimposed epithelium,

1370

VEIN.

I have given it a different interpretation: I
have indeed considered it as a reduplication
of the fenestrated membrane, existing there in
a state of great tenuity and destitute of fibrous
striations.

From the vena cava of the human subject
I have obtained epithelium, differing far from
the normal form. The specimen consisted
of flat, irregular cells, with a small bright
nucleus ; some cells distinct, others pale and
ill defined ; some densely granular, others
scarcely so at all.

In Birds (Loon — Colymbus septentnonalis ),
I have seen the epithelium diamond-shaped,
with a large, flat, bright nucleus.

In Balrachia (Frog — Rana temporaria),
the epithelium was large, pale, and irregular.

In Fish (Cod — Gadus morrhua ) the epi-
thelium was large, irregular, and granular.

Fenestrated membrane. — This structure,
which Henle has called the “ fenestrated,” or
“ striated ” membrane, is placed intermediately
between the epithelium and the fibro-vascular
elements of the vessels’ walls, and, from this
circumstance, as well as its physical proper-
ties, it bears a strong resemblance to the
basement or limitary membranes on the skin,
the serous and mucous surfaces.

This structure has been described and
figured by Henle, in a manner which exactly
coincides with my own observations. When
a portion of the membrane is stripped off the
inner surface of a vein (or artery, for it is the
same in either), and examined under the
microscope, it is found to consist of a thin,
continuous sheet, of a pellucid, structureless
membrane, to which are adherent some re-
ticulated fibres, having a longitudinal direc-
tion — hence it is “ striated.” It is also fre-
quently perforated with small holes, from
which circumstance it is called “ fenestrated.”
This homogeneous membrane has the remark-
able property of rolling itself up in the form
of a scroll, somewhat like the elastic laminae of
the cornea. According to Henle, it rolls
itself in the longitudinal direction, but I have
found the same tendency in the opposite
course. The apertures, or fenestrae, seen on
the membrane, all have more or less of a cir-
cular or oval form, and 1 have found that the
number and extent of these perforations de-
pend on the manipulation it has undergone.
Its physical properties are peculiar ; it is crisp
and somewhat elastic, and its inclination to roll
up in a scroll is so great, that it is never seen
in a flat form. The elasticity, which it pos-
sesses, is the reason, as it seems to me, why
the fenestrae are universally of a rounded
form ; for when any lesion is effected in it,
retraction occurs all round from the injury,
and thus makes the point or line of lesion the
axis of a circular or oval aperture, as the case
may be. In several specimens of this tissue,
in which no fenestrae at first existed, I have
produced them to any extent by pricking or
iacerating it with needles. The fenestrae in
the figure were thus produced.

The longitudinal striations appear to me to
be some fibres of the next tunic, — the in-

ternal longitudinal fibrous coat — accidentally
adherent to the homogeneous membrane.*

Fig. 854.

Fenestrated or Striated Membrane from the Ju-
gular Vein of the Red-throated Diver ( Colymbus
septentrionolis ).

a, Fenestra. (Magnified about 100 diameters.)

In the accompanying drawing (Jig. 854.) is
represented a portion of this membrane, from
the jugular vein of the red-throated diver
(Colymbus septentrionalis) . It was of a pale
pink tint, from contact with the blood in the
vessel, and, seen by transmitted light in the mi-
croscope, had a slight yellow cast. It was
marked by fine longitudinal threads on one
surface, which projected at some spots beyond
the torn edge of the membrane.

Purkinje and Rauschel consider this mem-
brane as similar to the middle coat of arteries.
Valentin describes it as a peculiar structure-
less membrane. Henle considers it as a tran-
sition from epithelium to fibrous tissue, in
which opinion he is supported by Schwann.

The fenestrated membrane has been found
on various parts of the internal surface of the
arteries and veins; but the best specimens 1
have seen have been from the principal veins
of large birds (goose, loon, gull), &c. At the

* Henle has made a singular speculation concern-
ing the nature of this structure : he believes it to be
an intermediate stage between the epithelium and
the longitudinal fibres next beneath it — that the
former is converted into the latter, and that this is
its intermediate condition. He believes that the
epithelium becomes fused into a continuous sheet,
and the nuclei absorbed, and that this subsequently
breaks up into fibres, — in short, that fibrous tissue
is formed from epithelium, and that the coats of the
vessels derive their density and increase from the
epithelial cells secreted on their interior.

VEIN.

1371

free margin of valves I have occasionally seen,
as noticed above, a clear, structureless rim,
which I have imagined to be this membrane
reduplicated, the membrane being extremely
thin, and the interposd fibrous lamina not
reaching quite to the margin.

It is said by Henle and others only to exist
in a few places, and certainly it is not always
to be found, though it is not perhaps right to
limit its existence to those spots only where
it has been recognised, as its extreme tenuity
and firm adhesion to the next coat might ac-
count for its not being generally seen.*

The tissue in question is best seen by slit-
ting up a vein and pinning it out on cork. The
inner surface is then scratched with a needle
after it has been moistened. The fenestrated
membrane retracts, and its edges may be
ruffled up and a small portion removed by
the points of very fine forceps, and thus ob-
tained for examination, which is best done
without any superimposed glass, as that flattens
the coils and folds, and it is impossible to
unravel them.

Fig. 855.

a

i

Transverse vertical Section of the Wall of the
Subclavian Vein of an Ox, exhibiting the relative
Thickness of the Three Coats.

a, internal coat ; b, middle coat ; c, the entire ex-
ternal coat. (Magnified 40 diameters.)

Internal tunic of longitudinal fibres. — The
internal tunic of longitudinal fibres is ex-
tremely thin, and occupies but a very small
amount of the thickness of the vessels’ walls.
This is well seen in Jig. 855. a, which is a trans-
verse section of the subclavian vein of an ox,
made vertical to the surface, and displaying

* It appears to me that there are sufficient
grounds to acknowledge the existence of a limitary
membrane beneath the epithelium in the blood-
vessels, and no sufficient reason to question its uni-
versal distribution. It must he recollected that
there are certain regions, even in the mucous mem-
brane (the nasal fossa, for instance), where no base-
ment membrane has been found, and I am not aware
that, in the skin, it has ever been separated from
the chorion, and yet in neither case is its existence
doubted. To exhibit the limitary membrane well,
some peculiar mechanical arrangements of the sur-
face is necessary, as papillreor crypts, and such are
not presented on the surface of blood-vessels. It is
not to be wondered at, therefore, that there is here
great difficulty in displaying the limitary mem-
brane.

the relative thickness of the three elementary
fibrous coats.

Specimens for displacing the profile views
of the walls of veins are best obtained by
slitting up the vessel, pinning it out upon
cork, and suffering it to get dry. Sec-
tions are then to be made vertical to the
surface, either parallel to, or at right angles
with, the axis of the vessel. Thin shavings
may then be removed with a very flat knife
(and for this purpose, a Beer’s cornea knife is
the best), anti when placed on a slip of glass,
moistened, and covered with a square of thin
glass, are ready for observation. The accom-
panying drawings were made from sections
thus obtained.

When a longitudinal section of the in-
ternal tunic is examined with a high power,
as in Jig. 856. a, it is seen to consist of very
fine yellow elastic tissue, which is peculiarly
pale and indistinct, having mainly a longi-
tudinal direction, but being much interlaced
and matted together, so that its longitudinal
course is, in many situations, obscure. This
coat is seen to be fine, and dense, and in
strong contrast to all the other structures,
from which it is separated by a distinct line of
demarcation. When thus viewed, the fibres
of this tunic are seen to present a succession
of waves, not unlike those of white fibrous
tissue, but finer and smaller : whether these
undulations are from its own inherent pro-

Fig. 856.

Longitudinal vertical^Section of Wall of Subclavian
Vein of an Ox.

a, internal coat rather thicker than common ; b, mid-
dle coat ; c, part of external coat. (Magnified 900
diameters.)

perties, or whether they are produced by its
adhesion to the next tunic, whose elastic con-
traction is greater than its own, thus throwing
it into folds and waves, I am unable to sa3'.
The identity of these fibres with yellow elastic
tissue is shown by the action of acetic acid
which does not destroy them, but renders
them even more distinct, while the contiguous

1372

VEIN.

masses of white fibrous tissue are obliterated.
When treated with this reagent the fibres of
this coat lose their wavy character to a cer-
tain extent, and present intersecting undula-
tions. (Fig. 857. a.) When the internal coat
is seen in transverse section, it presents a
granular, indistinct appearance, without fibres
of any determinate direction : in some places
it presents lines of a crumpled or corrugated as-
pect. In Jig. 858. a, this may be seen, as also
its distinctness from the next coat, from which
it is separated at one part by a slight interval.

This coat appears to exist in all the veins,
and in the smaller ones, and larger capillaries
when treated with acetic acid, as hereafter to
be described, its presence would seem to be
indicated by the internal longitudinal nuclei,
which are then displayed.

Middle coat of intermixed circular and lon-
gitudinal fibres. — This tunic occupies about
one-fourth of the entire thickness of the wall
of a vein. Its internal boundary is sharp and
distinct, where this coat is in contact with the
internal, but the outer boundary, where it gra-
dually merges into the external, is indefinite,
and indeed artificial.

In fig. 856. the middle coat is represented
at b, and is composed of intermixed fibres of
longitudinal and transverse yellow elastic
tissue embedded in a nidus of white fibre. As
this figure represents a longitudinal section,
the transverse fibres of the yellow element

Fig. 857.

Longitudinal vertical Section of Wall of Subclavian
Vein of Ox, treated with Acetic Acid.

a, internal coat ; b, middle coat ; c, part of external
coat. (Magnified 200 diameters.)

are seen cut across, and appear as small discs :
on the other hand, the longitudinal fibres
with which they are mingled, are seen in pro-
file, as interlacing and parallel rods : the

former gradually diminish, and the latter, in
the same proportion, increase, as viewed fur-
ther and further from the inner surface; and
that point where the discs entirely disappear
and the longitudinal fibres alone remain may
be considered as the external limit of the
middle coat. This limit is very clearly seen
in a specimen treated with acetic acid (fig.
857. b) ; when, as in fig. 858. b, the sec-
tion has been transverse, the discs and rods
of yellow elastic tissue occupy a position and
proportion the reverse of what has been de-
scribed. The discs are the most abundant on
the outer, and the rods on the inner part of
this coat, the former being seen in section, and
the latter in profile.

This middle coat is ver}' compact, especi-
ally near the inner surface, and it gradually
becomes less so in proceeding outwards.

It is difficult to tell what is the course and
direction of the nidus of white fibrous tissue
in which the yellow element is embedded, as
in the middle coat it forms a dense granular
compact mass*, when seen in situ, and its
true nature is only displayed by the action of
acetic acid. When, however, portions of the
tissue are picked abroad with needles, though
its direction is lost, its characters are ob-
vious.

As it regards the muscularity of this coat,
there can exist no doubt. The recent ob-
servations of Kblliker on the low form of
muscle, which he designates “ muscular,” or
“ contractile fibre-cells,” have placed this pre-
viously obscure subject in an intelligible and
satisfactory light, and have done much to ex-
plode the idea of non-muscular contraction, by
exhibiting the wide diffusion of this hitherto
unrecognised tissue.

Kblliker describes two forms of fibre-cells as
existing in blood-vessels, — one, consisting of
short, round, spindle-shaped, or rectangular
plates, like epithelium ; the other, of long
plates of irregular, rectangular, spindle, or club,
shape. The substance of these cells is soft,
light yellow, and homogeneous, and each con-
tains a peculiar, characteristic nucleus, whose
shape is constant, being that of a club or staff.
These fibre-cells are placed transversely as it
regards the vessel, and constitute a thin coat,
immediately external to the lining membrane,
intermixed with cellular tissue. These mus-
cular elements are clearly seen (as exhibited
by their nuclei) by the action of acetic acid
on small vessels. (Fig. 860.)

He further states that the great develop-
ment of the uterine veins during pregnancy is
principally from an increased size of the fibre-
cells existing in the middle coat, but partly
also from the inner and outer coat acquiring a
considerable quantity of smooth muscular fibre.
According to the same authority this mus-
cular element is not found in the veins of the
uterine portion of the placenta, the cerebral

* I would here observe, that when white fibrous
tissue is dried and re-moistened, as in these sec-
tions, it does not regain all its physical characters :
it has lost to a great degree its wavy lines, and
hence it is not so easily recognized.

VEIN.

1373

veins, the cerebral sinuses, Breschet’s veins of
the bones, and the venous cells of the corpora
cavernosa.

External coat of longitudinal fibres. — The ex-
ternal coat consists of a mass of areolar tissue,
adhering together with more or less compact-
ness, and running in a longitudinal direction.

This tunic occupies full two-thirds of the
entire thickness of the whole wall ol a vein.
Its internal boundary is irregular at the union
with the equally irregular outer limit of the
middle coat, and' its external boundary is the

Fig. 858.

Transverse vertical Section of Subclavian Vein
of Ox.

a, internal coat ; 6, middle coat ; c, part of external
coat. (Magnified 200 diameters.)

loose cellular tissue into which it degenerates,
and which constitutes the “sheath” of the
vessel. This coat, like the preceding, gradu-
ally diminishes in density and compactness as
it is examined further and further from its
inner limit, though its density is everywhere
inferior to that of the middle ; indeed, it may
be said that the tissue of which the vessel is
composed becomes looser and looser in pro-
ceeding outwards from the inner boundary of
the middle coat, — this quality passing gradu-
ally front one coat to the other.

The textural arrangement of this tunic
must be examined, like the preceding, from
longitudinal and transverse sections. In the
former it is seen that bundles of rods of yel-
low elastic tissue are disposed in alternate
lamina with white fibre, or rather, that the
former are embedded in a mass of the latter,
and that they are a continuation of the longi-
tudinal fibres of the middle coat, which gradu-
ally become arranged more and more in strata,
and at increasing distances. ( Fig. 856. c.)

The characters of the white fibrous tissue
between the bundles of yellow, become more
conspicuous as the laminae are wider apart.

The stratified arrangement of the fibres,
and their correspondence with the longitudinal
rods of the middle coat are very well seen in
the specimen treated with acetic {fig. 857.).

When this tunic is viewed in transverse
section, the relative thickness and proportion
of the lamella: are better seen than in a longi-
tudinal cut : the yellow element is seen to
occupy but a small relative thickness in com-
parison with the white.

When viewed w ith a high magnifying power
the divided extremities of the rods of yellow
fibrous tissue form undulating, and somewhat
imbricated lines of discs, while the white
fibrous tissue, cut across, shows slight, indis-
tinct, wavy indications. (Fig. 858. c.)

Seen with a low power, the ends of the
yellow fibrous tissue appear as series of dark
undulating dots on a field of white.

Minute veins. — When very small veins, a
few removes from capillaries, are examined
microscopically, they merely present faint stri-
ations in the longitudinal direction. When,
however, these vessels are treated with acetic
acid, nuclei and fibres are distinctly displayed,
w'hose long axis may be assumed to indicate
the direction of the tunic (or set of fibres)
which they represent, in which they are em-
bedded, and of which they form a part.

Henle was, I believe, the first to point out
this mode of textural dissection of vessels, and
nothing can be more satisfactory than the
analysis that it makes. By this means small
vessels alone can be examined, but the scru-
tiny may be carried up to those the third of a
line in diameter, which are sufficiently trans-
parent, when entire, to exhibit the nuclei.
Small vessels may be conveniently obtained
from the pia mater and mesentery ; they are
there free from other structures, and their
form is not interfered with.

I have foiind, however, that it is in the pia-
mater somewhat difficult to trace the small
veins; the arteries about them are more de-
finite and conspicuous, and less injured by
manipulation, and generally catch the atten-
tion of the observer. It has been more con-
venient to obtain isolated cerebral veins from
the surface of the ventricles of the brain ; the
small veins on the corpus striatum may be
raised and torn away with the points of fine
forceps, and sufficient capillaries will generally
be found attached to their extremities to ex-
hibit the structure of these vessels of all sizes.
The accompanying figures were made from
specimens thus obtained, about whose venous
character there could be no mistake.

Small veins vary in structure in different
regions, and according to their size ; some ap-
approach the structure of arteries *, w'hilst

* It may be convenient here to give a brief out-
line of the anatomy of capillary, and minute, arteries.
Their structure is more definite than that of veins ;
their walls are thicker and their cavity less in pro-
portion. The larger ones exhibit both a longitu-
dinal and a transverse striation. When treated
with acetic acid the nuclear corpuscles are numerous,
sharply defined, and obvious in their direction.

Capillaries, up to about l-16C0th of an inch in

1374-

VEIN.

others are far removed from them in com-
position.

Venous capillaries do not, that l am aware
of, differ from arterial. They consist of tubes
of homogeneous membrane, studded here and
there with nuclei of a more or less oval form,
and placed generally with their long axis cor-
responding with that of the vessel. In passing
to larger veins the change in structure of the
vessel (its increase and character) depends
upon the region from which it is obtained,
and whether or not it is endowed with muscle-
cells.

In the cerebral veins, which have no muscle,
in passing from small capillaries to larger
vessels, all that is observed is the superaddi-
tion of a tunic of areolar tissue, surrounding
the lining membrane ; and when this tissue is
treated with acetic acid, all that is observable
is a series of nuclei, oval, irregular, and longi-
tudinal, embedded in the substance of the
parietes, which have a perfect resemblance to
the external, or cellular coat of small arteries.
(Fig. 859. a.) In none of the microscopical
cerebral veins have I been able to discover
any nuclear or yellow fibres. In veins of
the -jtj to ta_ of an inch the vascular wall has
been composed of a tissue rendered trans-
parent by acetic acid, and displaying oval and
irregular nuclei having a longitudinal course,
without any admixture of elastic fibre. The
most internal of the nuclei appeared elongated,
but there was no appearance of fibres upon
the internal membrane, so as to produce a
striated membrane.

In those veins which are endowed with

diameter, consist of tubes of homogeneous mem-
brane, studded here and there with nuclei of an
oval form, whose long axis is that of the vessel,
except in the larger ones, where a few are placed
transversely. These corpuscles are elongated, and
more numerous, in the larger capillaries.

In arteries about 1 -600th of an inch, the walls
consist of a homogeneous tube, with the nuclei on
the outer surface still more elongated ; and external
to this, a set of nuclei, club-shaped and sharply
defined, placed at right angles to the former, and
representing the circular (muscular) tunic in which
they are embedded.

In larger arteries a cellular tissue, still more ex-
ternal, is seen, whose corpuscles — oval and irregu-
lar— are longitudinal. In such arteries (say, about
1 -300th of an inch in diameter), the tunics are,
1st. a homogeneous tube covered with elongated
longitudinal nuclei ; 2nd. a circular tunic, repre-
sented by the club-shaped transverse nuclei ; and
3rd. a longitudinal tunic of cellular tissue, in which
are imbedded oval and irregular nuclei. In passing
to larger vessels, the nuclei of the internal coat
elongate and disappear ; and the internal membrane
then consists of perfect striated membrane, the
homogeneous tube being covered with very fine
longitudinal fibres of elastic tissue. Such may be
seen in arteries of l-100th to 1-GOth of an inch in
diameter, and in some much smaller. Fibres make
their appearance shortly afterwards in the circular
tunic, intermixed with the club-shaped nuclei.

The proportion existing between the diameter
of an artery and the thickness of its walls is sub-
ject to considerable variety; and the same may be
said of the relative thickness of the several tunics
which compose the wall.

Henle has given good figures of the structure of
arteries.

muscular tissue, small club-shaped nuclei are
observed placed externally to the lining mem-

Fig. 859.

A, Minute Cerebral Vein ( about 1-200 th of an inch
diameter ), from Sheep, treated with Acetic Acid.

a, wall ; b, cavity.

B, Venous Capillaries (a, about 1 -16Q0t/t of an inch
b, about l-600t/t of an inch ) treated with Acetic
Acid.

In both these figures persistent nuclei of areolar
tissue and epithelial nuclei are alone visible. (Mag-
nified 200 diameters.)

brane, and transversely as it regards the ves-
sel ; these show themselves very distinctly on
the addition of acetic acid, and are character-
istic of the “ muscular fibre-cells” of Kblliker.
Such may be seen in the small veins of the
mesentery, which are more easily examined
than any other veins of this class. In these
vessels, two or three removes from capillaries,
the muscular nuclei make their appearance,
at first, few in number and irregular ; and in
still larger, but microscopical veins, these
nuclei are seen to be mixed up with, or
covered in by, more or less areolar tissue,
which at first is destitute of nuclear fibre, but
contains conspicuous nuclei, oval and irregular
in shape and longitudinal in direction. In
the accompanying drawing (fig. 860. b) is
a small vein from the mesentery of a rabbit,
measuring about of an inch in diameter,
and treated with acetic acid. On the lining
membrane are seen a few elongated nuclei
and longitudinal striations, constituting a sort
of incipient striated membrane. External to
this is a thin layer of muscular tissue, and
without that, again, is cellular tissue, which
constitutes the main bulk of the vascular wall.
The muscular coat is less distinct than in
arteries of the same si2e and thinner in pro-
portion to the areolar coat.

Such veins have, however, a strong resem-
blance to small arteries. Henle states that
the two systems of vessels are not to be dis-
tinguished in those measuring up to Tri_ of an
inch ; and he appears to consider thinness of
wall as the main characteristic in larger micro-
scopical veins. lie instances one vessel, which
he considers as venous, measuring flT of an
inch in entire diameter, having an annular
tunic and a cellular °f an inch- It
has appeared to me that the differences of
these vessels are principally these, — micro-
scopical veins have thinner walls ; the mus-

/

VEIN.

1375

cular tunic is less distinct, thinner than the
areolar, with which it is more or less mixed
up, and the latter is more abundant and more
developed than in small arteries.

In passing to vessels of larger size, the
fibrous tissue is seen to have a more conspi-
cuous development. The longitudinal stri-

j Fig. 860.

with Acetic Acid.

a, external longitudinal coat, exhibiting yellow
fibres and persistent nuclei of areolar tissue ; b,
middle circular tunic, showing nuclei of muscle
cells ; c, internal longitudinal coat (striated mem-
brane), the limit of the vessel’s cavity ; d. corre-
sponds to a small portion of the cavity of the vein.

B, Minute Vein from Mesentery of Babbit, exhibit-
ng the three Tunics less distinctly. (Magnified 200
diameters.)

ations and fibres on the lining membrane form
a perfect striated membrane, and, in still larger
vessels, increase so as to constitute a compact
coat of fibres, of more or less density — the
internal tunic of longitudinal fibres. In the
middle coat, the muscular element becomes
involved and mixed up with areolar tissue,
some fibres of which run parallel, and some at
right angles to the muscular nuclei. The
external tunic of areolar tissue becomes in-
creasingly developed, and yellow fibrous tissue
conspicuous and abundant.*

In fig. 860. A, is represented part of the
renal vein of a rabbit. The vessel is not cut
open or seen in section, but is simply 'laid
upon glass, treated with acetic acid, and a
small portion of the margin submitted to mi-
croscopical scrutiny. The internal membrane
is densely striated, and the other coats de-
veloped in proportion.

* In the comparative examination of small and
large blood vessels, there is much to confirm Ilenle’s
doctrine of nuclear and cell fibre. In the capillaries,
which are mere tubular cells, there is no fibre, and
the nucleus is persistent ; in larger vessels, where
fibrous tissue is developed, the nucleus disappears
and yellow fibre is found : but in those veins which
retain abundant persistent nuclei, as the cerebral
veins, even in those of larger size, no nuclear fibre
is detected.

There are certain regions in which the veins
undergo striking modifications in structure,
which require description ; and the remarkable
organs — valves — placed in their interior are
yet to be considered.

These points will be examined as follows : —

I. Veins, at their junction with the heart.

II. Cavse, passing through the diaphragm
and pericardium.

III. Cerebral sinuses.

IV. Umbilical vein.

V. Venous valves.

I. At the junction of the veins with the heart
there is a great alteration in their composition,
and this as it respects both cavce , and the pul-
monary veins : they assume a muscular cha-
racter, and become thicker and red, which
arises from a prolongation of the muscle of the
auricle into the fibrous structure of the vein.

This anatomical fact, as far as the cavae are
concerned, was described as early as 166h, by
Borelli ; subsequently (1700), by Bidloo, who
gave figures of it; and afterwards (1779), by
Gorter, who imagined that the muscle was
continued into the smaller vessels, and that it
there assumed a paler colour.

This muscular layer (though its existence
is denied by Cruveilhier) may be followed
upon the superior vena cava as far as the cla-
vicle, upon the inferior as far as the diaphragm,
and upon the pulmonary veins as far as the
division of the trunks into branches. (Hen/e.)
It exists on the superior cava in greater
amount than on the inferior, and it is there
best submitted to examination. When viewed
with the naked eye, the vena cava superior,
at its junction with the heart, is seen to be
red and muscular, and thicker than elsewhere.
In following this away from the heart, the
muscular character gradually diminishes, and
the ordinary fibrous tissue assumes the pre-
ponderance till the former is altogether lost.
At ten lines from the junction of the vessel
with the heart the mass was removed from
which the accompanying drawing was taken.

The cavae of some birds are sufficiently thin
and transparent to be viewed with transmitted
light when entire, and when slit up and held
to the light a beautiful arrangement of these
fibres is seen : they do not form one flat,
even, circular, covering, but are arranged in
numerous, successive, interrupted, rings, very
fine and red, gradually diminishing as they are
seen further from the heart. I have observed
this in the red-throated diver ( Co/ymbus sep-
lentrionalis), moor-hen ( Gal/inula ch/oropus ),
and various other birds. According to Cuvier,
in the ostrich, muscular fibres extend the
whole length of the posterior cava, and dis-
appear suddenly opposite the kidneys.

When a little mass of this structure is ex-
amined with the microscope, it is found to
consist of muscle of the same character as that
of the heart, — the fibres being small, striped
(though, perhaps, rather less distinctly so than
that of the auricle or ventricle), and, as far as
I have seen, destitute of sarcolemrna. There
is a good deal of wavy fibrous tissue, inter-
mixed with the muscle ; in this respect, con-

VEIN.

1376

trusting remarkably with that of the heart :
this exists in less amount in the immediate
vicinity of that organ.

There is yet another peculiarity in the
structure of the great veins near the heart, —
they have a partial investment of the serous
layer of the pericardium ; this, however, exists
only on the anterior surface ; and in the in-
ferior cava the amount of serous covering is
very small.

Fig. 861.

II. When the cavce pass through the peri-
cardium and diaphragm they contract an inti-
mate connection with those structures whose
fibrous tissue is more or less reflected upon
them and adds to their coats. Upon the su-
perior cava are to be seen (external to the
pericardium) white, glistening fibres, having a
longitudinal course, and traceable from the
pericardium directly upon the vein. The
pulmonary veins have a similar covering.

In the human subject, the inferior cava
passes through the pericardium and diaphragm
at once, and there forms so intimate an ad-
hesion to the margin of the aperture that I
have removed striped muscle (of the dia-
phragm) from the fibrous tissue of the vessel,
it having taken its origin from the outer tunic
of the vein.

In many of the lower animals (as in the
sheep, cat, and rabbit,) there is a considerable
interval between the diaphragm and pericar-
dium, in which the vena cava inferior is in-
vested with a covering of fibrous tissue con-
tributed from both these sources. It is white,

glistening, and strictly longitudinal, and ;s fur-
nished in largest amount by the pericardium.

III. Cerebral sinuses. — The cerebral sinuses
hold the place of large veins to the brain, but
are materially different from large veins in
structure. They consist of excavations or
tubes in the substance of the dura mater, —
the dura mater is, as it were, split into two
layers, and the interval is the cavity of the
sinus. Their form, which is very irregular —
triangular, quadrilateral, &c. — differs in dif-
ferent situations.

The internal or lining membrane of the
sinuses is stated by all anatomists to be iden-
tical with that of the veins ; but its exact
amount and nature I have not myself ascer-
tained. The continuity of the lining mem-
brane with that of the veins is seen where
the sinuses join the veins; thus, at the ca-
vernous sinus, where the ophthalmic vein and
circular sinus join it, the lining membrane
adheres to the inner wall of the sinus, but is
separated from the outer by the carotid artery
and certain nerves. The other element of the
walls of these peculiar veins is the white
fibrous tissue of the dura mater, arranged
without any regularity. The inner surface
of these vessels is smooth, but rendered ex-
tremely irregular by the occurrence of nu-
merous fibrous processes on bands projecting
into their cavity. In the superior longitudinal
sinus, the cavernous, and middle basilar, this is
most conspicuous. In the first mentioned
of these, the fibrous bands have been called
“ cordtz WillisiuncB " (after Willis, their first
describer). They are slips of white fibrous
tissue passing from the sides of the sinus, es-
pecially near the angles, attached at both
extremities, and either free or attached along
one side : these give the appearance as if the
inner surface were divided into cells ; into some
of these the probe enters and passes on into
the veins on the surface of the brain ; others are
blind, or lead to lesser sinuses, which not un-
frequently run parallel, for some length, to the
great sinus ; or the probe passes from one of
these cells to another. In the cavernous
sinus these fibrous bands are so numerous
that they look like a mass of areolar tissue,
whose areolae are distended with blood. The
cordae Willisianae are traversed by minute
arteries. ( Sir C. Bell.')

IV. The umbilical vein has a structure quite
peculiar to itself. The vessel may be best
examined by splitting it up with a director
and pinning it down on cork, with its inner
surface upwards. It is then seen to be smooth,
valveless, and whiter than other veins.

From the inner surface I have obtained
epithelium : the cells were flat, irregular in
outline, granular and fatty.

On making an incision, the membrane of
which it is composed retracts, so as to leave a
gap, and displays the dense fibrous mass which
forms the basis of the cord. It tears off in
irregular shreds, not showing a tendency to
tear in any particular direction. With care,
considerable portions of the membrane may
be stripped off. This structure is soft, elastic,

VEIN.

1377

and semi-pellucid. It appears structureless to
the naked eye, and looks almost like a thin film
of fecula jelly (arrow-root made with water), or
rather, perhaps, like the flaccid dull cornea of
an animal dead some days. When separated, it
coils up, and, where the surfaces have become
adherent, it is difficult to unfold it again : it
now looks and feels like thick mucus — it is
semitransparent and adhesive. When seen
under the microscope, it is found to he indis-
tinctly fibrous ; some masses appear as a dense
web of flat fibres, the fibres being strictly on
the same plane, with their sides adherent at
some points, and leaving intervals at others ;
in some places the interspaces are only small
specks on the surface of what appears to
be in other respects, an almost homogeneous
sheet ; there are also some indistinct longi-
tudinal striations, connecting these minute
interspaces and obscurely indicating the out-
line of fibres. The element of which this
coat is composed is singularly pellucid under
the microscope, scarcely refracting excepting
at its edges.

The fibrous mass of which the vein is com-
posed, in many places exhibits the appearance
as if the fibres were formed of spindle-shaped
cells strung together, with their ends over-
lapping ; and these cells may be occasionally
isolated, — they are spindle-shaped and have
an oval nucleus. They resemble those ob-
tained from the middle coat of the aorta of a
foetal pig, by Lehmann. (See his figure.)

Whether this condition is the result of im-
perfect maturation of the tissue of which the
vein is composed, or otherwise, I am unable
to say.

V. Valves. — The valves are membranous
folds on the inner surface of the veins, having
a definite form and regular arrangement with
regard to their object — the progress of the
venous blood to the heart , and obstruction to its
regurgitation. They are of peculiar interest
to the physiologist, as presenting a clear and
elegant specimen of animal mechanics; anil to
the literary anatomist they are not less inter-
esting, as having been one of the main objects
which suggested to Harvey his brilliant de-
duction of the circulation of the blood.

Cruveilhier states that the valves of veins
were first discovered by Etienne. Harvey
leaves the priority of discovery in doubt ; for
he writes, “ The celebrated Hieronymus Fa-
bricius of Aquapendente, a most skilful ana-
tomist and venerable old man ; or, as the
learned Riolan will have it, Jacobus Sylvius,
first gave representations of valves in the
veins.”* Fabricius himself lays claim to the
discovery, “ non solum nulla prorsus mentio
de ipsis facta sit, sed neque aliquis prius liaec
viderit, quam anno Domini septuagesimo
quarto, supra millesimum et quingentesimuin,
quo a me summa cum laetitia inter disse-
candum observata fuere.”f Marx, who ap-

* Harvey on the Motion of the Heart and Blood,
Sydenham Society’s Translation, chap. xiii.

t Fabricius, ab Aquapendente. Opera omnia Ana-
tomica, & c. Lips. 1687, p. 150. Fabricius calls the
valves by tire felicitous term, “ osteola,” little doors.

VOI.. IV.

pears to be profoundly versed in the literature
of this subject, says the discovery is due to
Erasistratus ; for he observes, “ Erasistratus
(30F n.c.), item clarus anatomus jam subtilius
in strueturam et usum venarum inquisivit,
valvulas jam observavit.”*

Harvey’s description of the valves is so
apposite and clear, as well as so interesting in
a literary point of view, that I shall quote it.
The valves, he observes, “ consist of raised
or loose portions of the inner membrane of
these vessels, of extreme delicacy, and a sig-
moid or semilunar shape. They are situated
at different distances from one another, and
diversely in different individuals ; they are
connate at the sides of the veins ; they are
directed upwards or towards the trunks of the
veins; the two — for there are, for the most
part, two together — regard each other, mu-
tually touch, and are so ready to come into
contact by their edges, that if any thing at-

Fig 862.

a, femoral vein ; b, saphena interna.

tempt to pass from the trunks into the branches
of the veins, or from the greater veins into
less, they completely prevent it ; they are
further so arranged, that the horns of those
that succeed are opposite the middle of the
convexity of those that precede, and so on,
alternately.” He further writes, “ In many
places two valves are so placed and fitted,
that, when raised, they come exactly together

* Marx. Diatribe Anatomico-physiologica cle
Struetura atque Vita Venarum. Carls. 1819, p. G.
j- Fabricius, Opera omnia, tab. iv. p. 157.

4, T

1378

VEIN.

in the middle of the vein, and are there
united by the contact of their margins ; and
so accurate is the adaptation, that neither by
the eye, nor by any other means, can the
slightest chink along the line of contact be
perceived. But if the probe be now intro-
duced from the extreme towards the more
central parts, the valves, like the flood-gates
of a liver, give way, and are most readily
pushed aside.”*

Valves exist in two different situations ;
namely, at the orifices of lesser veins where
they join the trunks which they supply, and
in the canals of veins, arranged at various
points.

Fig. 863.

Diagram, exhibiting different forms of Valves.

a, valve placed at the orifice of the renal vein in the
sheep, seen in face ; a', the same in ideal section ;
b, the ordinary semilunar valve from the tube of a
vein ; V , the same in section ; c, imperfect valve at
orifice of intercostal vein ; c1, section of imperfect
valve at orifice of hepatic vein ; d, the same in
face (the dotted lines in a, c and d correspond to the
orifices of the respective veins) ; e, very imperfect
valve ; d, the same in section ; f plan of double
valve at orifice of vein ; ft, the same in section ;
g, ideal section of small valve and sinus ; h, sec-
tion of sinus without a valve.

At the orifices of veins the valves are either
single or double: when single, the free margin
always looks towards the heart. In the canals
of veins the valves are usually double in the
larger, and single in the smaller. It is rare,
in the human subject, to find them in threes

* Loe. cit.

on the same plane, though it has been found
botli by Morgagni and Haller ; but in the great
vessels of the larger mammalia it is common.
There are none in the capillaries; but, accord-
ing to Ilenle, in veins of not more than half
a line in diameter, they make their appear-
ance.

For the purposes of anatomical description
a valve may be said to have a body, margins,
and cornua. The body of the valve has a
cardiac, concave, or proximal face and a convex
or distal face. The margins are,— the free,
or that which is unattached, and the attached
margin. The cornua are the angles formed by
the meeting of the two margins, and constitute
the extreme lateral boundaries of the valve.

Valves differ from each other very con-
siderably in form, varying from a mere linear
elevation on the inner surface, in which the
probe scarcely hitches as it is pushed along,
to others which almost form a long isosceles
triangle. The outline of the margins deter-
mines the form of a valve. Cruveilhier says
that the free margin is always straight ; but
this is not the fact, though it is always more
so than the attached.

In the first attempt at a valvular formation
there is merely a slight elevation of the inner
surface, and the free and attached margins
are nearly parallel : these scarcely constitute
valves. (Fig. 863. e, e'.)

Valves, still imperfect but of larger dimen-
sions, are found at the orifices of veins, as well
as in their canals. When existing in the former
situation (and this is applicable to all valves
thus placed), their attached margin corres-
ponds with the side of the orifice which is
furthest from the heart, and the outline of
this margin is determined by the form of the
vessel’s mouth. If the lesser vessel joins the
greater at right angles, the opening will be
circular, and the attached margin of the valve
a semicircle. If, however, the junction be ob-
lique, and an acute angle be formed by the
two vessels, then the margin attached will be
drawn out of the semicircle, so as to form a
sort of apex in the centre. The former of
these conditions is shown at fig. 863. c, taken
front a small valve at the orifice of an inter-
costal vein, joining the azygos; and the latter
is represented at d, which is a drawing made
from a valve at the orifice of an hepatic vein,
where it joins the vena cava: c' is an ideal
section of the same. The dotted line in a,c and
d represents, in conjunction with the line
of the attached margin of the valve, the orifice
of the tributary vein.

The next form, in order, and the one which
is the most common, is the semi-lunar* valve,
as it is ordinarily found in the tube of valved
veins,— the attached margin being nearly semi-
circular, and the free nearly straight (fig.
863. 1). It w'as probably of these valves that
Haller spoke when lie said that the attached
margin of valves constitutes a parabolic curve :
it may be applicable to some of the semi-lunar,

* Fabricius, not inaptly, described them as re-
sembling a finger nail, “ forma ostiolorum ea est,
ut indicia unguem imitentur.” — Loc. cit. p. 151.

VEIN. 1379

but it cannot be to valves in general : a para-
bola is a constant form, but the outline of the
valves is various. It appears to me that the
outline of a valve rather conforms to the
ellipse, the curve being sometimes very much
elongated, sometimes nearly approaching a
circle. An ellipse is obtained from a cylinder,
by an oblique section of it ; an oblique sec-
tion of a cylinder will only give an ellipse.
For the line of attachment, therefore, of a
valve with the cylindrical surface of a vein to
generate an elliptical curve, that line of attach-
ment must coincide with an oblique section
of the cylinder : and we see that this is fre-
quently the case, that is, when the valve is
viewed in profile, its attached margin forms a
right line at an angle, more or less acute, w ith
the wall of the vein, the acuteness of the
angle determining the elongation of the el-
lipse. This is represented in fig. 864. b, where
a shows the line of attachment seen in profile,
and a' the curve generated by that line when
seen in face. But sometimes the attached
margin does not form, when viewed laterally,
a straight line, but is more or less curved, as
seen at fig. b, b b', and then we necessarily get

Fig. 864.

Diagram exhibiting the Attachment and consequent
Forms of Valves.

A, section of valves in action, a, elongated ellip-

tical valve; b, broad semilunar valve.

B, exhibits tlie lines of attachment of, a, elliptical
valve in profile, and a', the resulting form ; b, the
attachment of parabolic valve in profile, and V,
the resulting form.

an aberration from the ellipse, and an approxi-
mation, more or less near, to the parabola.
Now, in such valves as are placed in pairs
in the canals of veins, with their convex faces
opposing and their cornua in contact, their
relative length and breadth depend upon the
obliquity of their attachment, — the require-
ments being constant, namely, that the op-
posed valves should meet by their free mar-
gins in aline across the centre of the vessel, —
for if the attachment be oblique and extend
more in the axis of the vessel, it will require
a much deeper valve to reach its fellow in the
centre, than if the attachment were more
across the tube, where a short, broad valve
wotdd accomplish the object. These tw o con-
ditions are represented in the figure (fig. 864.

a.), which is an ideal section of a vein, in which
both forms of valves are seenina state of action.

Valves in the canals of veins, though in
contact by their cornua, are sufficiently loose
and large to fall back fully upon the sides of
the vessels to allow the progressing current
to pass on uninterruptedly.

A valve the furthest removed in form from
those first mentioned, is represented in fig.
863. a , w hich is the drawing of a valve situated
at the orifice of the emulgent vein, where it joins
the inferior cava in the sheep. Its depth is very
considerable in proportion to its width, and
the centre of its attached margin is nearly an
acute angle, produced by the angle at which
the renal vein joins the cava.*

Structure of valves. — A venous valve con-
sists of a thin fibrous lamina, protruded into
the tube of the vessel.

If the attached margin be carefully cut front
the wall of a vein, and the organ be extended
upon a slip of glass, it is seen to be thin at
the free margin and thick at the attached ; if
it be viewed by transmitted light, with the
naked eye, it will be seen that the body of
the valve is divided, rather indistinctly, into
two portions, of which the free half is thinner
and bluish-white, while the other is much
thicker, and of a yellowish colour ; the line of
demarcation, between these, extending across
the body of the valve about parallel with the
free margin ; this however, does not exist, in
some valves.

The examination of a valve with the mi-
croscope requires that it should be completely
unfolded at its free margin, in the neighbour-
hood of which, in the larger valves, its struc-
ture can alone be successfully observed, on
account of the thickness and opacity of the
other parts of the valve. When removed
from a vein it should be placed upon a slip of
glass, moistened, and, the attached margin
being seized with forceps, it should be draw n
over the surface of the glass so as to unravel
any folds of the free margin, which are apt to
occur.

The epithelium cannot always be found on
the face of the valve, and to see it the body
must be very thin, and the focus of the in-
strument be thrown superficial to the fibrous
lamina, when their nuclei will sometimes be
viewed pretty distinctly. They are scattered
evenly over the surface, but the cell-wall is
extremely ill-defined, or not to be made out.
At the margin of the valve they are frequently
to be seen in one or two conditions, — free,
detached nuclei, accidentally adherent along
the margin ; or cells, seen edgewise, with con-
spicuous nuclei, as already described.

The fibrous lamina is the most conspicuous
element of the valve, and constitutes its bulk.
It consists almost entirely of white fibrous
tissue, extending front side to side of the
valve, running parallel with the free margin,
and continuous, apparently, with the circular
coat of the vein on each side of the attached

* The extreme depth of the valve here represented
is not constant ; it sometimes barely readies across
the orifice.

4 t 2

1380

VEIN.

margin of the valve. The fibres are singularly
regular, and present the most beautiful and
equal undulations, as if each fibre were of
exactly the same size and extent ; and the un-
dulations of all succeeding fibres are precisely
similar, as far as the tenuity of the structure
towards its attached margin is sufficient to
allow of its examination. These fibres may
be looked upon as a portion of the circular
coat protruded into the cavity of the vein.

Fig 865.

Small Portions of the Valves from a Sheep.

A, The valve showing a line of epithelial nuclei at
the extreme margin a o' ; a', detached nuclei ; b,
small portion of face of valve, exhibiting wavy
fibres, epithelium and muscle.

B, the same treated with acetic acid, a a, margin.
On the face of this valve are seen two sets of
nuclei ; and fine threads of elastic fibre. ( Mag-
nified 200 diameters .)

Running at right angles to these, and placed
upon a different plane, are to be seen fibres
or elongated corpuscles of a spindle shape,
and of very variable distinctness. These cor-
puscles are apparently muscular fibre-cells:
they are very conspicuous in some specimens,
and very indistinct in others ; whilst in others
they cannot be discovered at all.

On treating a valve with acetic acid, two
sets of nuclear corpuscles are to be discovered,
running at right angles to each other. Those
which are parallel with the wavy fibres of the
fibrous lamina are mainly oval', interspersed
with a few more elongated; and those, cutting
the former at right angles, and being parallel
with the muscular fibre-cells, are club-shaped
and spindle-shaped, having a strong resem-
blance to the nuclei of muscular fibre-cells.
The former, as it appears to me, are mainly
persistent nuclei of areolar tissue, and belong
to the wavy fibres, whilst the latter are evi-
dently muscular nuclei. Small threads of yel-
low fibre are occasionally seen. They are
very fine, detached and scattered ; and fre-
quently exhibit a spiral form. In examining
these structures it is necessary that, when
removed from the body, they should not be
allowed to dry before the observations are

completed ; for the characters both of the
fibrous lamina and nuclei are impaired per-
manently if they have once been dry.

Sinuses. — There is yet another item in the
valvular apparatus of venous canals, — the oc-
currence of sinuses in the walls of the veins.
These consist of small pouches or dilatations
in the walls of the veins immediately in front
of the valves. By these, the cylindrical form
of the vessel is lost at that spot, two bulgings
being apparent on it. These bulgings pro-
duce a certain amount of attenuation at
these points, the thinness being in direct
proportion to the increased area produced.
The sinuses vary in dimensions, anil do not
bear any exact proportion to the size of the
valve. Lateral dilatations maybe seen in the
walls of veins where no valves are present.
(See fig.' 863., b',g,e\ h.) When the valves are
in action, these distended sinuses present knots
along the course of the vessel ; an appear-
ance first described and figured by Fabricius:
he observes of them, “ non dissimilem for-
mant exterius pros se ferentes, ac nodi in plan-
tarum ramulis, el caule apparent.”*

The supply of valves in the venous system
is only partial, and is irregular. Valves
are only found (in the human subject) in
those veins which are subjected to muscular
pressure, and are, therefore, most abundant in
the veins of the limbs : and it has been well
laid down by Cruveilhier, “ that their pre-
sence and their number, their proximity and
their distance from each other are directly
influenced by the degree of opposition to the
onward progress of the blood in any set of
veins.” f

Of the veins of the head and neck, the ex-
ternal jugular is the only one with valves: it
possesses two, which however are not suffi-
ciently compact to oppose injection. There
are none in the cerebral sinuses or veins, and
none in the internal jugular. The veins of
the upper extremity are abundantly supplied
with valves, which appear to be somewhat
more numerous near the upper part of the
arm. There are valves in the axillary vein,
but none in the subclavian, vena innominata,
or superior cava. They are abundant in the
lower extremity, but most numerous at its
lower part ; in this respect differing from
the superior extremity. The branches of the
internal iliac vein are supplied with valves,
while the external and internal iliacs them-
selves, the common iliac, and the inferior cava,
have none. The spermatic veins (male) have
valves, while the ovarian (female) are desti-
tute of them. In the azygos veins, Cruveil-
hier denies the existence of valves, but they
are occasionally found in an imperfect state
of development.

The spinal veins are destitute of valves, as
are, also, those of the portal system, the he-
patic veins, those of the heart, kidney, uterus

* Loc. cit. For figures of these “ nodi,” see Fa-
bricius, Opera omnia, tab. II. p. 157. ; also Harvey,
De Motu Cordis et Sanguinis in Animalibus, Ana-
tomica Exereitatio. Lugd. Bat. 1639, p. 187.

f Cruveilhier. Anatomic Descriptive.

VEIN.

1381

and kings. Comparative anatomy and acci-
dental aberrations from nature furnish some
exceptions to the foregoing statements. Meyer
has found incomplete valves in the pulmonary
veins. Theile has found valves in the ova-
rian veins. E. H. Weber has observed them
in the portal veins of the horse ; and Cuvier,
in the same animal, has found them in the
splenic and mesenteric veins. Haller has dis-
covered valves in the pulmonary veins of the
dog and sheep.

Valves exist but sparingly in Birds and
Cetaceans-, and in It' pities and Fish are almost
wanting.

The office of valves is to prevent the blood
from effecting a retrograde course; “lest,
instead of advancing from the extreme to the
central parts of the body, the blood should
rather proceed along the veins from the
centre to the extremities ; but the delicate
valves, while they readily open in the right
direction, entirely prevent all such contrary
motion ; being so situated and arranged, that
if any thing escapes, or is less perfectly ob-
structed by the cornua of the one above, the
fluid, passing, as it were, by the chinks be-
tween the cornua, is immediately received
on the concavity of the one beneath, which is
placed transversely with reference to the
former, and so is effectually hindered from
getting any farther.”* This refers especially
to the valves in the venous canals. There is
a peculiarity about those placed at the orifices
of veins. I have already remarked that all
single valves placed at the mouths of veins
are attached to the distal margin of the orifice :
the free margin looks towards the heart, the
concave face obliquely towards the cavity of the
tributary, and the convex in the opposite direc-
tion. Now it is obvious from this arrange-
ment, that when the blood falls back upon
the concave surface of such a valve, it throws
it more or less across the area of the larger
trunk, and away from the orifice of the
smaller vessel, over which it forms no pro-
tection. The office of the single valve, thus
placed, appears to be not to guard the small
veins, or to prevent the retrocessant blood
from passing into it, but to oppose the blood
which it supplies from passing into that por-
tion of the recipient vein which is behind the
orifice of the tributary : the valve, as it were,
directs the blood into the onward track of
the great vein, and prevents it from taking an
opposite course.

The case, however, is different where the
valvular apparatus is double, for there a valve
is placed at the proximal, as well as at the
distal margin of the orifice : now the former
of these valves prevents the blood from pass-
ing behind the other into the smaller vein —
the two valves mutually assist each other, and
prevent the blood from passing behind either;
and the result is a complete obstruction to a1!
retrograde circulation into the smaller vessel.
The important object of exclusion of venous
blood from the thoracic duct is thus effected.

* Harvey, loc. cit.

Valves are essentially passive organs in the
circulation ; and they only avail when mo-
tion is given to the circulating fluid by other
means, — they determine what shall, and what
shall not, be the direction of the moving fluid.
The contraction of the muscles is one of the
great motor agents of the venous circulation.
When a muscle contiguous to a vein con-
tracts, the vessel is compressed and the blood
forced out of it ; and, were it not for the
valves placed at the distal side of the com-
pressed point, the blood would be sent as
much from, as towards, the heart. Autenrieth
has put this in a striking point of view;
he says, “Each swelling muscle becomes
thereby, for the neighbouring veins, a kind of
heart furnished with valves ; thus, while it
presses the vein, the valves prevent the blood
in the lower part of the same from being
driven backwards ; but, in the upper part,
opening valves are placed, from which the
blood, driven forth by the contracting muscle,
meets with no opposition in its direction to-
wards the heart. It is from this circumstance
that each violent movement of the body, which
consists in an alternate swelling up and sink-
ing down of the muscles, has so great a ten-
dency to accelerate the circulation ; naturally,
however, while the muscles are in a state of
repose, the valves cannot facilitate the move-
ment of the blood.’’*

The function of the sinuses is this, — to re-
ceive the valves when they are folded back,
during the onward current of the blood; and
to allow the blood to pass behind them and
to throw them across the area of the vessel
when that fluid regurgitates.

Vasa vasorum. — The coats of all blood ves-
sels, except those of very small size, are sup-
plied with arteries and veins especially devoted
to their nutrition, called “ vasa vasorum.”

According to Henle, vessels (veins and
arteries in common) receive vasa vasorum,
though themselves not larger than of an
inch in diameter, and sometimes even smaller.
The coats of capillaries and those of the
smallest vessels are not thus nourished by
a separate vascular supply.

The nutrient arteries of the venous coats
are derived from the small arterial trunks in
the vicinity of the vessel f ; they do not come
directly from larger arterial trunks, but from
smaller vessels; and the source of the vascular
supply is determined by the particular neigh-
bourhood of the vein — the same vessel having
vasa vasorum from different sources as it passes
along different regions ; thus, the vena azygos
is nourished by the intercostal, pericardial, and
oesophageal, arteries, according to its various
relations as it proceeds along its course. The
arteries supplying the tunics of a vein, appear
to go promiscuously to the vessel and the
adjacent tissues, sending some of its ramules
to the areolar tissue, nerves, fat, &c., in the
neighbourhood, and others to the walls of the
vessel. In the accompanying figure, repre-

* Autenrieth. Physiologie, §§ 388, 389.

f The artery usually has its vascular supply from
the same source as the vein which accompanies it.

4 t 3

I 382

VEIN.

seating a vein from the oesophagus of an eel,
magnified with low power, the vasa vasorum
are seen to supply, indiscriminately, the vessel’s
coats and some small pellets of adipose tissue
which were near it. The arteries, nourishing
a vein, ramify and divide principally upon, and
among, its cellular coat, and form an elaborate
plexus, with meshes having a general longi-
tudinal direction, as seen in the figure ; which.

Fig. 866.

Vasa Vasorum on external surface of a small Vein
from the oesophagus of eel. ( Anguilla acutirostHs.')

a a, vein; b h b, small arteries supplying indiscrimi-
nately the venous tunics and small masses of fat
around the vein ; c c c c c, granules of adipose
tissue. Natural injection. ( Magnified, about 18
diameters.)

though drawn from a fish, sufficiently indicates
the condition as found in man arid mammals.
The arrangement of these capillaries is, how-
ever, subject to variety : in the vena cava of
the cod, I have seen them long, straight, even,
and perfectly parallel, with scarcely any trans-
verse branching or anastomosis. The little
venous trunks of the vasa vasorum usually
open directly into the cavity of the vein,
among whose tunics they have previously
ramified, and their course is quite independent
of the corresponding arteries. ( Ilen/e.)

The vasa vasorum principally exist in the
areolar tunic, but Henle states that they are
to be found abundantly among the annular
fibres of the veins.* The internal longitu-
dinal coat is, in all cases, extra-vascular.

Nerves of veins. — As far as our knowledge
hitherto goes, veins differ remarkably from
arteries in rarely being made the support of

* In arteries, Weber has never found them in the
circular tunic. Burdaeh states that he has found
a few.

nerves, and in seldom receiving any distribu-
tion of them to their coats. It is a remark-
able circumstance that veins appear, with
slight exceptions, to be separated from nerves.
The exceptions to this rule are few and in-
considerable.

The inferior vena cava receives some small
filaments from the diaphragmatic ganglion of
the sympathetic, just below the diaphragm.
The vena porta supports and is entwined by
the branches of the hepatic plexus, which it
conducts to the liver. Pappenheim describes
some nerves as being distributed to the cere-
bral veins. Bidder states that he has traced
some filaments of the fourth cerebral nerve
to the lateral sinus : and Wrisberg describes
a nervous plexus as surrounding the facial
vein, which he ingeniously imagines may cause
contractions of the vein, and thereby pro-
duce that congestion of the face constituting
blushing.

In the cod-fish ( Gadus morrhua ), I have
traced nerves from the auricle down upon the
venous sinus immediately below it : these
formed loops in the walls of the sinus, and
appeared to return to the heart. The nerves
in question are doubtless a continuation of
the cardiac nerves ; and, in all probability,
bear the same relation to the rhythmical action
of this pulsating cavity, which the other car-
diac nerves do to the cavities of the heart
itself.

It is very probable that some such nervous
supply is furnished to those parts of the veins
of man and mammals, near the heart, in which
cardiac muscle is found.

It may, perhaps, be still a question whether
the almost complete non-nervous character
of veins is absolutely correct, and whether the
paucity or tenuity of the nerves, supplied to
veins in general, he not the reason why they
have as yet eluded observation ; for analogy
scarcely justifies the idea of organs possessing
muscular tissue and still being destitute of
nerves. This opinion is strengthened by the
fact that arteries, having the same sort of
muscularity as veins, though in larger amount,
are regularly supplied with nerves.

Comparative structure. — I am not aware
of any observations upon the comparative
structure of veins in birds and reptiles. Those
that I have myself made are principally in-
troduced under the heads, Fenestrated mem-
brane, Epithelium, Sfc.

In Birds, the venous walls are composed
principally of areolar tissue, external to the
lining membrane; and I have observed that
in the diving-birds, the vena cava posterior is
composed almost solely of elastic tissue-
There are no muscle-cells in the cerebral
veins of birds.

In Fishes, the venous parietes appear to be
formed of a sort of areolar tissue longitudi-
nally disposed. Embedded in the walls of
the veins there is an abundance of pigment,
which exists in greater quantity in the inter-
costal veins, and those tributary to the car-
dinal vein. This pigment is of the variety
called by Schwann “ stellate pigment -cells,”

VEIN.

1383

and consists of branched cells, of a black
colour, and various form. The body of the
cell is generally some modification of an oval
or oblong, and lies with its long axis corres-
ponding to that of the vessel ; and from its
extremities caudae project, of every imaginable
shape and proportion, of larger size than
those which project from its sides, which are
few and small. The body of each cell appears
to be occupied by its nucleus.

Fig 867.

A, vein from muscle of eel ( Anguilla acutirostris )
( Magnified, 50 diameters), b. vein from muscle of
sole ( Solea vulgaris) ( Magnified 100 diameters).
c, little mass from the external surface of the car-
dinal vein of the eel ( Magnified 200 diameters.)

In the accompanying figure, some of these
cells are represented from the eel ( Anguilla
acutirostris ), and sole ( So/ea vulgaris ), which
present considerable variety of form. They
also vary in the same individual in different
situations ; in the cardinal vein they are most
numerous and aggregated ; in smaller veins
they are less numerous and more distinct ;
and in those of minute size, they only occur
here and there at considerable intervals, and
at the spots where they are placed they
occupy nearly the whole face of the vessel.

When submitted to high microscopical
power, these cells are seen to be mixed up
with the tissue of the venous coats, and their
thin branched extremities have, in some places,
much the aspect of elastic tissue, in the uni-
formity of their dimensions and their dicho*
tomous divisions.

Caudal venous heart of eel. — Dr. Marshall
Hall, in 1831, first figured and described a
peculiar pulsating organ which exists in the tail
of the eel, calling it by the name of “caudal
heart ; ” and he considered it to be a muscular

ventricle, by whose contractions the blood is
propelled in the vein at the commencement of
which it is placed.

Rusconi has differently interpreted this
organ, and calls it a lymphatic heart, believing
that it is perfectly analogous to those pul-
sating sacs, which are found in certain parts
of the lymphatic systems of various reptiles.
And certainly the occurrence of a little pul-
sating organ, having the form, colour, and
general aspect of the lymphatic hearts in the
frog, situated in the vicinity of the venous
system, having an action independent of the
systemic heart, and existing in a cold-blooded
animal, is, from analogy, enough to suggest
the idea that Rusconi’s view is the correct
one. But this is not confirmed by anatomy,
for after repeated and numerous observations
of this heart, I am convinced that the original
description of it, given by Dr. Hall, is the
truth.

The caudal heart is to be found in eels of
all sizes, but is best seen in small individuals
a few inches in length, on account of their
clear skin, and the larger proportional size of
the organ in them. It may be seen by holding
the eel’s tail between the light and the eye of
the observer, either with a lens, or without the
aid of any magnifying power. It may be con-
veniently examined with the microscope by
wrapping the head of the animal in a wet cloth,
and then applying its tail to a slip of glass, and
placing it under the field of the instrument ; but
the extreme restlessness of the little fish some-
times renders it necessary that it should be
partially or completely stunned before it can
be viewed. The heart is then seen to be

Fig. 868.

G

Caudal Venous Heart o f Eel magnified about 25
diameters.

A and B represent two forms, a, the heart: b car-
dinal vein ; c sinus that receives the blood from
the capillaries ; d, minute veins from caudal fin.

placed near the extremity of the cardinal vein,
on the haemal aspect of the caudal vertebrae
at the end of the tail. It is of a yellowish
colour, chequered more or less with stellate
pigment, and of a form varying from a pear-
shape to a spindle-shape. (Fig. 868.) At
the distal extremity it is connected with a
small vein, which collects the blood from the
capillaries of the tail ; at its proximal ex-
tremity it is connected with the commenc-
ing cardinal vein ; or it may be said that on
4 t 1

VEIN.

1384

either side is the cardinal vein, and that the
heart is a muscular development on the coats
of that vessel. The action of this heart ap-
pears to be quite independent of the branchial
heart ; for, as Dr. Hall observes, “ whilst the
latter beats sixty, the former beats one hun-
dred and sixty times in a minute. It con-
tinues for a very long time after the influence
of the pulmonic heart is entirely removed.” *
I have never seen the action of the caudal
heart quite so rapid as is described by Dr.
Hall: in one individual, partly torpid from
cold, it contracted but sixty times in the
minute; but when this fish was warmed, the
number rose to one hundred and two, — the
beats of the branchial heart being less than
half the caudal.

The blood, which is deep red, appears to
flow into the extreme end of this organ in a
continuous stream, but is forced out at each
contraction from the other aperture in an
interrupted current. The absence of any re-
gurgitation, at the further end of the heart,
would suggest the presence of some valvular
apparatus there situate. The jet of blood,
sent forward at each contraction, may be
beautifully seen by holding up the tail of the
eel to the light ; it is seen as a regular, ar-
terial, per-saltum, jet, passing along the vessel
in front of the heart, which, in the intervals
of each contraction, is empty: as Dr. Hall
expresses it, the blood is “ propelled with
great velocity, at first with the appearance
of successive drops.” j- This per saltum cur-
rent only exists a short distance, and gradu-
ally degenerates into a continuous, venous,
stream. When the parts are submitted to
low magnifying power, I have observed that
at each systole of the heart the veins at
the distal extremity of the organ are vio-
lently tugged in the longitudinal direction
(produced by the shortening of the heart in
its contracted state), and this exists as far as
several ramifications from the heart (d' d').
A movement in the opposite direction takes
place at the diastole, which is doubtless as-
sisted by the elasticity of the vessels restoring
them to their former length. This circum-
stance, moreover, proves the complete con-
tinuity of structure of this organ with the
small vessels which furnish the blood upon
which it contracts.

I have seen this best when the tail has
been cut from the body, — the bloodless heart
still going on contracting.

I have failed altogether to find any lym-
phatics going to this pulsating organ ; and the
facts which I have already adduced, that it
receives blood from behind, and transmits it
forwards ; the large aggregate quantity of fluid
which it propels in a given time ; the rhyth-
mical tension of the capillary veins, attached
to the distal end, at each contraction, as well
as the apparent absence of lymphatics, seem
to prove that it is a blood, and not a lymph,
heart.

* Hall’s Essay on the Circulation, p. 172.

f Loc, eit-

II. Physical and Vital Properties. —
As it regards the physical properties of veins,
it may be remarked that their walls are thin
as contrasted with arteries of the same calibre,
those of the upper extremity being less than
those of the lower; they are somewhat looser
in texture, especially externally, and more
extensile in the transverse direction — are
distensible, and when distended they do not
readily return to their former dimensions ;
both circumstances being due, in a great
measure, to the general longitudinal direction
of their fibres : according to Soemmering
the resisting power of veins diminishes with
advancing age.

The walls of veins are elastic, though less
so than arteries, which pre-eminently exhibit
that quality.

The extreme thinness and slight physical
resistance of veins is the cause why they
collapse when empty.

An empty vein presents very fine longi-
tudinal rugEe on its inner surface.

The tissue of veins is less distinctly yellow
than arteries, and frequently is stained of a
pinkish colour by the blood in contact with it.

Though their physical properties are, for
the most part, of a negative character, they
nevertheless possess the property of tenacity
to a great degree, and are at least as strong as
arteries of the same capacity, though the
substance of the latter is so much more con-
siderable.

Ligature applied to a vein produces a longi-
tudinal folding of the walls, which is very ap-
parent when the vessel is laid open after it
lias been tied. An indentation is produced
across the inner surface of the vessel at the
line of ligature, caused by the complete or
partial rupture of its thin inner, longitudinal,
fibrous tunic. But the entire thickness of
the wall appears to have undergone a partial
cut, as though one element of the compound
mass of which it is composed had been divided
while the rest remained entire ; and it would
seem probable that a ligature applied tightly
around a vein would divide the crisp yellow
elastic tissue, while the tenacious white
fibrous element, with which it is mixed,
would remain entire. This probable expla-
nation I have found, upon microscopical ex-
amination, to be correct; the two parts, there-
fore, of a vein that has been ligatured, are
held together by the white fibrous tissue that
enters into the constitution of its walls.*

Vital Properties of Veins. — I am not aware
of any experiments which have been directed
to decide the amount of sensibility possessed
by veins : it is probably, judging from anato-
mical grounds, exceedingly low.

As regards vital contractility, it has been a
matter of dispute whether veins possess that
property or not. Soemmering held them to
possess it in an eminent degree, especially
under the influence of chemical stimuli, wh 1st

* For some beautiful illustrations of ligatured
veins, I would refer to Cooper and Travers’s Sur-
gical Essaj-s, vol.i. plate 12.

VEIN.

1385

Haller * denies that they are endowed with
irritability. It is now placed beyond all ques-
tion that veins are endowed with vital contrac-
tilityand that it exists in them in two distinct
and entirely separate forms — first, as a rhyth-
mical contraction, similar to what occurs in the
cardiac cavities ; and secondly, as that peculiar
slow and prolonged contraction which is known
as tonicity, and which in so striking a degree
exists, and exists alone, in arteries, — the
former occurring in a small portion of the
venous track, the latter pervading nearly the
entire venous system. To the establishment
of this last physiological fact, we are mainly
indebted to Professor Kolliker.

Venous rythmical contraction in man and
mammalia generally occurs only in the im-
mediate neighbourhood of the heart, but in
cold-blooded animals it extends a considerable
distance along the venous trunks. Flourensf
was the first to describe it in the frog, where
it has frequently been since witnessed ; and
Muller has observed that the venous trunks
of the frog continue to contract even after
the removal of the heart and the auricle.

Nysten has witnessed contraction of the
upper part of the vena cava in fish ; and
Wedemeyer has observed the same in other
cold-blooded animals. According to Muller
the rhythm of the veins in frogs occurs just
previous to that of the auricle, and the rhythm
of the auricle before that of the ventricle, and
the rhythm of the aortic bulb follows the
ventricular : there are four successive con-
tractions, of which that of the veins is the
first.

In mammalia the venous contraction is
almost synchronous with the auricular. I
have frequently witnessed it in vivisect
animals — rabbits, kittens, &c. ; and it exists
in the pulmonary veins as well as in the
cavae. It is only in the immediate neigh-
bourhood of the auricles that the veins
contract, doubtless just so far as the cardiac
muscle is prolonged into the venous tissues.
The rhythm appears to commence upon the
vein and pass forward upon the auricle.
This vascular rhy thm, existing in a high degree
in the lower vertebrata, and diminishing in
the higher, would appear, in man, to be the
last remnant of the tubular heart seen in the
in vertebrata.

It appears very probable that the contrac-
tion of the veins close to the auricles may be
of assistance in the economy ot the heart s
action. If it be recollected that the auriculo-
venous orifices are not guarded by valvular
apparatus, it will be difficult to explain how,
when the auricles contract, the blood is pre-
vented from flowing back into the patent
veins : may not this be prevented to a
certain extent by the contraction of the
veins, which thus constitute a sort of sphincter ?
This rhythmical action of the veins must in no
way be confounded with that peculiar venous

* Sec. Mem. sur les part, sensibles et irritables :
and Elem. Phys. lib. ii. p. 126. and lib. vi. p. 125.

f In Annales des Sciences Natur. tom. xxviii. p. 65.

pulsation which exists in certain forms of
disease. Venous tonicity has lately been esta-
blished by Kolliker*, and his physiological ex-
periments have been based upon and fortified
by the most conclusive anatomical discovery
— viz. the demonstration of unstriped muscu-
lar fibre in the walls of veins.

Professor Kolliker’s experiments were
made upon the veins of a leg immediately
after amputation ; and the agent of muscular
excitation was an electromagnetic apparatus.

“ The vena saphena minor was touched in
the fossa poplitea, on the lower part of the
leg and on the foot ; the vena saphena rnagna
on the lower part of the leg and dorsum
pedis. A few seconds after the application
of the wire, contraction took place ; at the
end of a minute the parts touched contracted
so much, that the blood that they contained
in large quantities was pressed out, until the
vessel had the appearance of a white cord.
On smaller veins of the skin, the effect was
not so rapid or so powerful.”

“ Three applications of the wire had no
effect on the vena poplitea, but it was already
very flaccid and empty before the experiment.
The vena tibialis postica was empty by con-
traction in a minute.”

The irritability endured in the veins for an
hour and fifteen minutes, being somewhat
longer than in the arteries and lymphatics,
and shorter than in the muscles.

This contractile power in veins is of that
peculiar character which has long been known
to exist in arteries : it is slow, gradual, and
persistent, and by it the vessel is braced up
and set at a given calibre. This contractility,
combined with the elasticity of the vessel’s
walls, is the antagonist to the distending
force of the blood within the vessel.

I have frequently noticed in animals ex-
amined during life, that the large venous
trunks are of greater calibre than when
viewed after death : that whilst the blood
flows on through the vessel, it is distended to
a larger size than when from exudation and
other causes the quantity of distending fluid
is diminished; just as at each jet of blood pass-
ing through an artery the tube is distended,
in opposition to its contracted state after
death, — the explanation being undoubtedly
this, that immediately after death the vein-
muscle becomes affected with cadaveric
rigidity, and this being unopposed by the
distending blood, contracts the vessel to a
calibre less than that which it could hold
whilst the contraction was opposed by the
distending force of the circulating fluid. The
same thing occurs more distinctly in arteries,
and, whilst the rigor mortis remains in ac-
tivity, forms a powerful opponent to injections.

III. General Remarks upon Veins

Origin ; Course ; Anastomoses ; Plex-
uses, &c. — General considerations of veins
are to be made principally in relation to arte-

* Kolliker and Siebold’s Zeitschrift. 1849.

1386

VEIN.

ries, in contrast with which the characteristics
of the former are most conspicuous.

The general, the pulmonary, and the portal
venous systems may be looked upon as the
roots of a tree, the trunks of which would
correspond with the auricles and the porta ;
or they may be viewed as three cones, the
bases of which are the capillaries of each
system, and the apices, the auricles, and the
porta. In either view, the veins are to be
examined, in their track intermediate between
these two points, as to their number, size,
relation, and modes of dividing and junction.
These observations will be carried solely as
far as they refer to the general circulation,
and that principally as it affects the human
subject ; the pulmonary and the portal sys-
tems being more properly considered in con-
junction with those viscera with which they
are connected.

The venous system is far more extensive
than the arterial, both as it regards size and
number of vessels.

Attempts have been made by different ana-
tomists to estimate the relative size of arteries
and veins, though it is difficult to see upon
what data any thing like an exact calculation
can be based ; nevertheless, Sauvages states
the capacity of veins, as compared with
arteries, to be as nine to four, Haller as
two to. one, and Borelli as four to one.
Though it may be impossible to say which
of these is the true estimate, it is ob-
vious that the disparity between the two sets
of vessels is very great. In the extremities
and head, indeed everywhere but in the vis-
cera, the veins form two distinct sets, the
superficial, subcutaneous, veins, and the deep
veins accompanying the arteries. These lat-
ter, which are called satellite veins ( venae
comites'), are almost always double — two veins
accompanying each artery of the same name.
“ This rule, however, has some exceptions; in
fact there is only one accompanying vein for
most of the great arterial trunks, and even for
some arteries of moderate size ; lastly, in some
few instances there is but one vein to two arte-
ries. Thus, there is only one superior and
one inferior mesenteric, one renal, and one
external iliac, vein, each of which corresponds
to the artery of the same name ; but there is
only one umbilical vein to two umbilical arte-
ries, and there are several suprarenal arteries,
but only one suprarenal vein.” ( Cruveilhiir .)
These exceptions, however, are not suffi-
ciently numerous to alter the dirt use and
branching character of veins. The following
apposite quotation upon this head is from
Meckel : — “ It is a universal law with veins,
that the branches or ramifications are larger
in comparison with the trunks than in the
arterial system ; the veins of a part, or even
of the whole body, never uniting themselves
to so small a number of stems as those out of
which the arteries take their origin. The
aorta and pulmonary artery originate as single
stems out of the respective cavities of the
heart; the systemic veins, on the contrary,
terminate in three trunks, the superior and

inferior cavas and the coronary vein ; more-
over, the superior cava receives, but just be-
fore its entrance into the heart, a fourth
trunk — the az3'gos vein. The pulmonary
veins terminate in four, five, or even six
trunks into the left auricle. Again, in the
extremities, — take the arm, for instance, —
where there is but a single artery, there are
four considerable venous trunks. Thus divi-
sion is the character of the arrangement of the
veins ; contratension that of the arrangement
of the arteries.” (Meckel, Handbuch der
menschlichen Anatomie, Band i. S. 201.)

Origin of Veins. — Veins originate, almost
without exception, by the capillaries uniting
■ — increasing in size, and diminishing in num-
ber. This fact has been known, and all but
universally received, since the days of Mal-
pighi, who (in 1661) demonstrated, by micro-
scopical research, that portion of Harvey’s
system of the circulation which had not been
displayed, — the passage of the blood inter-
mediately between the arteries and veins, —
the capillaries, — -and thereby explained the
origin of the veins. That veins originate only
by capillaries has also been generally ad-
mitted ; but Haller has described absorbent
veins as arising from all free surfaces ; and
Cruveilhier speaks of veins commencing with
open mouths on the surface of all mucous
membranes ; opinions long since refuted.
There appear, however, to be some excep-
tions to this general rule of capillary origin of
veins. Thus, the veins which return the
blood from certain portions of erectile tissue
would seem to commence as little venous
caverns or sacs, into which blood is poured
by arteries of a size much above capillary
vessels. ( Valentin : Muller.)

Mr. Paget has recently pointed out another
mode of venous origin as occurring in the
wing of the bat {Vesper lilio), where arteries
of comparatively considerable size pass at
once into veins without intermediate capil-
laries. Mr. Paget observes : “ Very gene-
rally the arteries of the second and third
order of branches pass into veins of corre-
sponding size without any intermedium of
capillaries. The capillaries are rather in the
position of offsets from the continuous chan-
nels of arterial and venous loops, than in their
more ordinary relation as intermediate canals
leading from arteries to veins.”* Further
research, especially in comparative anatomy,
will probably exhibit other instances of pecu-
liar venous origin.

Course, Anastomoses, Plexuses, lye. of Veins.
— In travelling from their commencement to
their termination, veins follow very various
courses, the most marked differences indi-
cating a division into those which accompany
their corresponding arteries, and those which
pursue an independent course; a division
which corresponds, with a few exceptions, to
the deep and the superficial veins.

In commencing, the veins form networks of

* Lectures on Inflammation, by James Paget,
F.R.G.S., in Medical Gazette, vol. xlv. p. U(38.

VEIN.

vessels, which unite and reunite till the}' form
venous trunks, which then take a more or
less direct route to the heart.

The deep veins accompany the correspond-
ing arteries, and pursue the same course as
these latter vessels, having similar relations
with the bones, muscles, nerves, and fascia; :
they are moreover surrounded by the same
sheath of condensed areolar tissue as the
arteries. It is remarkable, as has been ob-
served by Cruveilhier, that the relative posi-
tion of the two kinds of vessels, although
constant, does not seem to follow an}' general
rule ; all attempts to ascertain any law by
which the relations of the veins with the
arteries are regulated have been unsuccessful.

In some situations deep veins do not take
the same course as the corresponding arteries.
This is the case with those of the nervous
system (the cranial sinuses and spinal veins'),
the hepatic vein, the ophthalmic vein, the
azygos vein, &c.

The superficial or subcutaneous veins follow
an independent course, as respects arteries, and
accompany the cutaneous nerves and lympha-
tics in the interval between the muscular apo-
neuroses and the skin.

The anastomoses of veins, and the plexuses
formed thereby, are abundant and elaborate.
The inosculations are more numerous than
those of arteries, and occur by means of much
larger vessels. They take place “ by direct
inosculation, by lateral, transverse, or oblique,
communications, and anastomoses bv con-
vergence, which are found in every situation
and with all conceivable varieties. The
branches of the veins form lozenge-shaped
meshes ; and both the trunks and the branches
communicate freely with each other ; that is
to say, the superficial with the deep set,
the veins of the superficial set and those of
the deep set amongst each other, and the
vena cava superior with the vena cava infe-
rior : so that we may say that the whole ve-
nous system forms one vascular network ;
and it is by these free communications that
such obstacles as impede or completely inter-
cept the course of the blood in a given part
are rendered incapable of stopping it alto-
gether.” ( Cruveilhier .)

Idle anastomoses are so numerous and
complete, that it is almost impossible to inter-
cept the venous circulation by the interrup-
tion even of vessels of considerable size : if
even the superior cava with the venae innomi-
natce be interrupted, the blood will be re-
turned— finding its way back to the heart by
the anastomoses of the internal mammary, the
acromio-thoracic veins, &c. with the inter-
costal, azygos, and epigastric veins — so taking
the blood back by means of the inferior cava.
An obstruction of the inferior cava is com-
pensated for by the same set of vessels, the
blood going then in the other direction.*
Obstruction to the portal circulation does not
absolutely stop the blood : inosculations oc-
cur between the portal and general systems

* See Morbid Anatomy.

1387

of veins in the hmmorrhoidal plexus sufficient
to maintain the blood-current.

These are some of the special examples of
anastomoses ; the general method of inoscu-
lation also requires some explanation. For
example, a vein arises in conjunction with
another collateral vein, or takes its origin
from the latter, and after having pursued a
course of various length, again joins the prin-
cipal vein. Instances of this may be seen
in the various veins of the extremities.

A venous trunk may divide
into two of equal size, which
separate at a very acute angle,
and, after an elliptical interval,
again unite into one. Such may
frequently be observed in the
sapheena.

Cross anastomoses, by means
of large veins uniting those on
the opposite sides of the body,
are not unfrequent. Such are
the circular sinus and the basilar
sinus, in the skull, the azygos,
and the intercostal veins, &c.

A vein, just before its junction
with the trunk to which it is
tributary, divides into two, and
joins at different parts — an oc-
casional variety of the frontal
vein.

The plexuses of veins are
merely a high degree of anasto-
mosis : they are not subservient
to any laws in their formation
and arrangement, or susceptible
of any systematic division ; and
will probably be best under-
stood by describing and figur-
ing a few of the most charac-
teristic.

The simplest and most primi-
tive form of plexus is that which
is produced by the inosculations
and joinings of two vcnce comites
around and across an artery.

Such is exhibited in the accom-
panying figure : the anastomoses
are so numerous, that it is diffi-
cult to tell in parts whether
they are to be considered as
two vessels, or as one, with fre-
quent trivial interruptions of
cavity : at some points they run
a considerable distance without
conjunction, leaving an elongated
elliptical interval ; and at other
points their confluence is so
great that the intervals are re-
duced to small circular apertures
on the face of one broad vein.

A coarser and more compli-
cated form of plexus is exhibited
in the subcutaneous system of
veins, in the production of which „
several venous trunks combine, Spermatica.
and by their lateral branchings (after Breschet.)
and confluxes produce diamond-
shaped, rhomboidal, and triangular inter-

VEIN.

1388

spaces : — these anastomoses being all on
the same plane, excepting at a few points
here and there where a small channel dips
down to the deep veins. Such plexuses may
be seen on the dorsum of the hand and foot.

But the most elaborate and complex of all
the plexuses in the human* subject are
those formed around, about, and within,
the spinal canal : they are composed of nu-
merous trunks, which unite, divide, and re-

Fig. 870.

Plexuses connected with the Spinal Canal.

a, the great anterior spinal veins (the “grandes veinesrachidienn.es longitudinales anterieures" of Breschet) ;
b, ascending lumbar veins (the “ veines lombaires ascendantes ” of Breschet) ; c, veins uniting the above-
mentioned, through the intervertebral foramina (after Breschet).

unite, at every possible point, and in all con-
ceivable modes, by branches of all sizes,
lengths, and shapes, and leave intervals pre-
senting forms of endless variety. A portion
of these plexuses, seen in the accompanying
figure, from Breschet’s work on the veins,
conveys a better idea of them than any
lengthened description.

The diploic plexuses are the net-works of
veins which exist in and among the cancel-
lated tissue of the bones. In the flat bones
of the cranium, at the period of adult life,
they form large irregular meshes, by the mean-
derings of large, irregular, ampullated, veins.
These vessels are very unequal in size, are
subject to dilatations, and frequently end in
culs-de-sac. They are well represented in
Jigs. 187. and 188. Vol. I. But the most re-
markable peculiarity in these plexuses, is the
change they undergo during osseous de-
velopment. In early foetal life, when ossifi-

cation commences the cranial bones consist
of stellae of numerous ossific rays, the inter-
spaces between them being occupied by hosts
of small, almost straight, radiating, veins:
these veins are not covered in by osseous
structure, but are exposed on both surfaces
of the bone (Jig. 872.); they then gradually
become tortuous, and fuse into one another,
so as to diminish in number, and lose much
of their radiating character ; and after a time
they become covered by a thin plate of bone
on either surface. The process of fusion and
dilatation of the veins still goes on during
life, and ultmately leaves the diploic plexus,
consisting of a few large vessels. Diploic
vessels exist in all cancellated bone in various
plexiform combinations. In the loose texture

* In birds the intra-spinal plexuses are so large
and dense that it is with difficulty that the anato-
mist can make out that they are not extravasations.

VEIN.

1389

of the bodies of the vertebra remarkable
plexuses exist. {Fig. 87 1.)

Fig. 871.

Diploic Veins in a Vertebra,
a, great anterior spinal veins ; b, posterior spinal
veins ; c, transverse branches ; d, vense basis ver-
tebrarum ; e, vein on the surface of the body of
the vertebra. ( After Brescliet.')

Fig. 872.

IV. Function of Veins. — In function
veins may be considered as having a triple
office : they are passive organs of circulation;
they are diverticula or reservoirs for blood ;
and they are agents of absorption.

Circulation in the veins consists of the
passive and equable transmission of blood
along their tubes. “ When we consider the
great size of the veins, compared with the
arteries, we must conclude that the blood
flows but slowly in the venous system ; that,
from the narrowness of the trunks of the
veins near the heart, the blood must be ac-
celerated as it approaches the heart ; and
that receiving the impulse from the ventricle,
it must take a rapid course through the
arteries, until, again approaching the extreme
branches of the arteries, and passing into the
veins, its motion becomes more languid and
slow. In youth, as the size of the veins is
not in so great a proportion to the arteries
as in advanced life, the blood must be in
more rapid circulation : but in old age, owing
to the largeness of the veins and the accu-
mulation of blood in them, it moves slowly
through the venous system, and is almost
stagnant in the dilated veins and in the
sinuses.

“ There is no pulsation to be observed in
the veins, but what they receive from con-
tiguous arteries. There is no pulsation in the
veins because they are removed from the
heart ; because they do not receive the shock
of the heart’s action in their trunk, but only
by their widely-spread branches ; because the
contraction of the heart and of the arteries so
alternate with each other, as to keep up a
perpetual and uniform stream of blood into
the veins.” (Sir C. Bell’s Anatomy, vol. ii.
p. 284.)

As diverticula and reservoirs of blood the
veins must be considered as performing a most
important service in the oeconomy of the cir-
culation. There are numerous circumstances
both in health and disease which either tem-
porarily or permanently disturb the balance
of the circulation, and thereby displace and
choke up large quantities of blood ; and, were
it not for the reservoirs, diverticula, and lateral
compensating channels, which are afforded by
large, bulging, and dilatable veins, by the enor-
mous area of the common venous cavity, and
by the numerous and elaborate inosculations
and plexuses which these vessels every where
exhibit, such interruptions might lead to
consequences, permanent, irremediable and
destructive.

The whole subcutaneous system of veins
must be looked upon as a series of compen-
satory channels. The cavities of the deep
veins are quite sufficient to return the blood
that is sent to them by vessels of smaller
aggregate calibre. But during muscular ex-
ertion, &c., these deep vessels are impeded
by pressure, and then the blood finds a colla-
teral route by means of the subcutaneous veins.
So again, when from cold, or other causes, the
skin-muscle contracts and presses on the
cutaneous veins they are more or less emptied,
and their office is resumed by the deep veins :
they thus keep up a mutual reciprocation of
function.

The large internal veins of the body; the

1390

VEIN.

dilatations of the veins at the base of the
brain ; the large amount of veins in the
parenchymatous viscera ; the venous plexuses
of the spinal canal, together with the venous
cells and tubes in the cancellated tissue of all
bones, form a series of diverticula and reser-
voirs, equal to all emergencies*, where the
blood may slowly flow, or recede, or stagnate.
But the most striking examples of venous re-
servoirs are furnished by comparative anatomy.
All those animals which have diving habits
subject themselves to peculiar disturbance of
circulation. The prolonged stoppage of re-
spiration, but still more the immense pressure
of water to which they are exposed, when
deeply submerged, mechanically empties all the
superficial veins and produces much deep-
seated and visceral congestion. This is com-
pensated for by a special arrangement. In
diving birds there is great dilatation of the
posterior vena cava. In the Grebes and Divers
( Podiceps and Colymbus ) the posterior cava is
largely dilated in the liver and below, extend-
ing to opposite the kidneys. In the Cetacea,
which are subject to the same influence,
enormous dilatable venous plexuses, placed
within the abdominal cavity, perform the same
office.

Venous absorption probably occurs wherever
veins exist, but especially in the alimentary
canal, where, in conjunction with the lacteals,
they perform the important office of extracting
from the food the different materials which
enter the circulation and nourish the various
tissues of the body.

It is not my intention to enter upon any of
the elaborate arguments or disquisitions on the
evidence of venous absorption. I shall content
myself with a brief summary of the most im-
portant salient points.

That absorption by the veins takes place
independently of the lacteals has been proved
by a series of conclusive experiments conducted
by Tiedemann and Gmelinf, who administered
to a number of animals various substances of
distinct and easily recognisable physical and
chemical properties, and afterwards analysed
the venous blood, the secretions, and the
chyle. Substances having deep colours, such
as cochineal, indigo, litmus, gamboge ; sub-
stances having strong odours — turpentine,
assafcetida, garlic, musk — and saline sub
stances, such as sulphate of iron, chloride of
barium, ferro-cyanide and sulpho-cyanide of
potassium, were all in turn submitted to ex-
periment. Almost all of these matters were
found in the venous blood, several of them in
the urine, and a few only of the latter (the sa-
line substances) in the chyle. Therefore it ap-
pears that absorption did take place, in many
instances, independently of the lacteals, and

* Not literally equal to all emergencies : the
great deep-seated congestion caused in the cold
stage of an ague-fit has ruptured the vena cava :
the same has occurred in violent muscular exertion.

f Versuche fiber d. Wege auf welchem Sub-
stanzen aus dem Magen u. Darmkanal ins Blut
gelaugen. Heidelberg. 1820.

by the veins. This conclusion is fortified bv
other experiments conveying both positive
and negative evidence, which have been
performed by Majendie, Blake, Delille, Sega-
las, &c.

Majendie and Delide in conjunction per-
formed the following experiment. They
severed all the parts of the posterior
extremity of a dog, excepting the artery and
vein by which the circulation of the limb
was kept up. They then introduced some
upas poison into the foot; and in ten minutes
the animal died. It cannot be imagined here
that the lymphatics absorbed the poison, as
they were divided ; but it may be objected
that the matter was mechanically introduced
into the divided extremities of the vessels in
the wound. This difficulty has been over-
come in another experiment devised by Ma-
jendie. He found that death was caused by
the introduction of mix vomica into the intes-
tine of an animal in which the lacteals had
been tied, where the veins, by which alone
absorption could here take place, remained
entire. An experiment exactly the reverse
of the last was performed by Segalas, which
completely bore out the idea of venous ab-
sorption. Instead of tying the lacteals and
leaving the veins untied, Segalas tied the
veins, the lacteals remaining unimpaired. The
result was, that when poison was applied to
the intestine, no absorption took place, and
no result followed. It was further found by
Mr. Blake, that ligature of the vena porta
prevented the action of poisons introduced
into the stomach.

V. Development of Veins. — Are the
veins, large and small, originally developed as
capillaries, the succeeding changes by which
their texture and size are modified taking
place subsequently to their being permeable
sanguiferous channels ? Whether this is en-
tirely the case is doubtful ; that it is so to
some extent is certain; and therefore the
development of veins would involve two con-
siderations — first, the development of capil-
laries, and secondly, those after-changes by
which the vessels cease to be capillaries, and
become, in texture and volume, true veins.

The arguments in favour of the view that
veins are developed primarily as capillaries,
are — that veins, arteries, and capillaries con-
stitute one continuous system, which renders
a community of development antecedently
probable ; that arteries and veins are so
similar in structure as evidently to possess a
common development, which heightens the
probability of their development being the
same as their connecting link; that the part,
possessed by capillaries — basement mem-
brane — is that which we see in other parts
capable of giving rise to fresh structures ;
that we see all stages between the largest
veins and capillaries filled up without a gap;
that structures which in an early stage are
furnished only with capillaries, and vessels
a little removed from them, are found shortly

VEIN.

1391

to contain veins, and that the venous textures
become more strongly marked as the parts
become more mature ; and that veins but
little removed in size from capillaries, differ
from them by the addition of structures
exactly similar in nature to those which
larger veins possess in a greater amount.

The development of capillaries has been ob-
served, principally, by Schwann* in the tails
of young tadpoles, and the germinal mem-
brane of an incubated hen's egg, by Kollikerf,
in the tails of batrachian larvae generally, and
bv Paget J in the foetal membranes of sheep.
Their accounts, which my own observations
on the tails of batrachian larva; entirely con-
firm, all substantially agree.

On subjecting the tail of a very young tad-
pole to microscopical observation, and viewing
it with an object glass of a quarter of an inch
focal distance, it will_.be seen that the vessels
possess all the characteristics of veryfine capil-
laries, that is, they possess a delicate, perfectly
homogeneous membrane, with nuclei adhering
here and there to its internal surface. The
two great arterial and venous trunks are
elongated posteriorly, as the larvae grow, by
throwing out prolongations, which, by joining
the embryonic cells accumulated about the
extremity of the chorda dorsalis, inosculate
with them so as to form a continuous cavity.
The first lateral vessels of the tail, which
have the form of simple arcs going from artery
to vein, are formed by the junction of pro-
longations, from the caudal artery and vein,
with certain elongated or stellate cells in the
substance of the tail. From these vessels,
which constitute what may be called the pri-
mary arches, are thrown out projections which,
by inosculating in an exactly similar way with
neighbouring stellate cells, form secondary
capillary arches ; and thus the capillary net-
work continually extends itself in proportion
as the tail gets longer and broader, and at the
same time becomes more dense by the forma-
tion of new vessels between the primitive
meshes.

Such are the general appearances seen in
the tail of any of the batrachian larvae. These,
however, Schwann does not consider so con-
clusive as the appearances in the germinal
membrane of a hen’s egg. He says that when
the germinal membrane of a hen’s egg which
has been subjected to thirty- six hours’ incuba-
tion, is placed under the microscope, and the
area pellucida examined with a magnifying
power of 450, the capillary vessels are readily
distinguished in it. In some situations they
are perfect, and connected with the larger
vessel, some are of irregular calibre, having
bulgings here and there where two or three
channels meet, the intervening portions vary-
ing in size from that of a fibre of yellow
fibrous tis ue to the full capillary diameter,
and permeable to blood or not.

* Microscopical Researches, translated for the
Sydenham Society, by Henry Smith.

f Annales des Sciences Naturelles. August, 1846.

j Supplement to Muller's Elements of Physiology,
by Drs. Baly and Kirkes.

In addition to these capillaries, which form
a network of channels of irregular calibre,
and give off blind branches, some separate
irregular corpuscles are seen which are not
connected with the vascular network. These
bodies send off blind processes, of various
forms, in different directions ; in other words,
they are stellate cells. They have a reddish-
yellow colour, like that of the capillaries of
bone, which circumstance alone would be suf-
ficient to make it probable that they are the
primary cells of capillaries in process of forma-
tion ; and this probability becomes a certainty
when we perceive that some of these same
stellate cells are already connected with the
true capillaries, forming with them a common
cavity. This is Schwann’s description. Of
its correctness I cannot speak from my own
observation, but of the correctness and ex-
treme truthfulness of Kolliker’s account of
the same process in the tails of young batra-
chia I can, from my' own observations, con-
fidently speak : indeed he has left nothing to
be added.

Morbid Anatomy of Veins.

Veins are subject to a variety of morbid
changes, which are naturally incident to blood
vessels of their particular organisation and
functions, occasioning a remarkable contrast
in their pathology with that of arteries.

Thus veins are much more subject to diffuse
inflammation than arteries, and the products
of their inflammation being carried in the blood
to the heart, are conveyed all over the body ;
they moreover offer peculiar facilities for the
introduction of morbid materials into the cir-
culation, anil from both these circumstances
wide-spread and diffuse disease is the result —
conditions which have no parallel as the conse-
quence of arterial disease. Again, an injury to a
vein, such as a punctured wound, is followed by
cicatrization ; and any dilatation of its tube
interferes only partially with its functions;
whereas in an artery, from the vigorous and
pulsating character of the circulation in it, a
wound is only to be healed by obliteration of
the vessel, and any dilatation of it causes
an aneurism — a progressive and destructive
disease.

From the time of Hippocrates, some of the
diseases of veins — varix and haemorrhoids —
have been recognised ; but it was not till John
Hunter, in 1793, published his paper on the
diseases of veins in the “Transactions of a
Society for the Improvement of Medical and
Chirurgical Knowledge,” that any light was
thrown upon that most important of these
diseases — phlebitis.

Since then the subject has received a large
share of attention at the hands of some of out-
most distinguished pathologists : and Hodg-
son, Travers, Breschet, Bovillaud, Ribers, Ar-
nott, Lee, and hosts of others, have all added
their quota towards its elucidation.

The diseases of veins divide themselves into
phlebitis, with which may be considered the
effects of ivounds and ligatures; var'uc and

1392

VEIN.

hcemorrhoids ; rupture ; disease of valves ; ph/e-
bolites ; calcareous degeneration ; fatty tumours ;
entozoa.

Phlebitis. — Phlebitis may be conveniently
divided into plastic and suppurative. They,
however, frequently exist together, are pro-
duced by the same cause, or give rise to each
other.

Veins possess peculiar facilities for the pro-
duction of certain of their diseases, especially
inflammation of their lining membrane, caused
by the introduction of morbid materials into
their cavities ; which is a very general cause
of the disease now under consideration.
They are peculiarly subject to being opened,
on account of their superficial position, and
their being submitted to the surgical opera-
tion of venesection ; and it must be remem-
bered how large a superficies of the venous
cavity is exposed at every parturition to the
contact of those fluids which are secreted in the
healing of the placental wound. The veins si-
tuated in the osseous tissues present peculiar
facilities for the introduction of morbid mat-
ters into the circulation, on account of the
patency of their cut extremities, caused by the
adhesion of their walls to the unyielding tissue
in which they are embedded. Again, the di-
rection ofe th current of the circulation to-
wards the heart, is not likely to expel any
materials that are introduced into the vein,
but would rather tend to carry them on into
the mass of the circulating fluid.

The absorbing function of veins is often re-
ferred to as a cause of the introduction of
morbid matters into the circulation, and this
especially as it regards pus, but it cannot be
strictly said that pus is absorbed in cases of
purulent phlebitis ; and I apprehend that the
distinction laid down by Hunter*, on this
point, is perfectly correct. It appears to me
impossible for any one acquainted with the
structure of the coats of blood-vessels, and
the anatomy of a pus-cell, to imagine that pus,
as such, can be introduced within a vein by
any process analogous to absorption. It is
true that pus may enter a vein bodily, and as
pus ; and it is equally true that pus may be
absorbed ; but the former is by introduction
through some lesion in the vessel’s walls, and
in the latter the fluid is in some way altered be-
fore it can pass through the tunics of the vein,
if, indeed, a vein be here the agent of absorp-
tion. When pus is absorbed, as from a bubo,
or in empyema, it is attended with a different
series of symptoms and consequences from
those which arise when it is introduced bodily,
anil pus is, in these cases, not to be found in
the veins ; and it must be remembered that all
the circumstances — a wound secreting pus and
an open vein, or, what is tantamount to the
same, such inflammation of a vein as leads to
secretion of pus in its cavity, — are uniformly
present where the characteristic results of
phlebitis occur. The same thing is imitated by
injecting pus into the veins — with like results.

Plastic phlebitis bears the same relation to

* On the Blood, p 360.

suppurative, that the two forms of inflamma-
tion hold relatively to other organs. Plastic
phlebitis indicates a form of disease of milder
character, and consummated with results of
less severity. Suppurative phlebitis is more
or less mixed up with the plastic form, and is
generally secondary to it.

When a vein undergoes inflammation, the
affected portion throughout its entire thick-
ness becomes of a diffused red, which is not,
at this stage, to be distinguished from the red
stain produced by contact of the blood, ob-
servable, under certain circumstances, in both
arteries and veins ; this fades at the edges of
the inflamed portion. As the disease advances,
the part becomes irregularly mottled of all
shades, from purple to the natural colour of
the part ; with this appears, in the areolar tissue
of the veins, an effusion of sanious serum. The
effusion does not end in a serous exudation;
but, as the disease progresses, a plastic effusion
is exhibited, not only in the tissue of the vein,
but also within its cavity. Whether or not
the previously developed serous effusion also
escapes in part upon the free surface of the
lining membrane of the vein, is not easily de-
termined, but in the stage now under con-
sideration it probably does so, as in other
serous inflammation. At all events, at or im-
mediately after the time when such effusion
occurs, the tube of the vein becomes blocked
up with a coagulum of blood : this does not
occur at once, but progressively, beginning by
the deposition of fibrine upon the inflamed
surface, which deposition is increased by suc-
cessive layers, the original being for the most
part the most compact, until the entire tube is
blocked up. That part of this fibrinous product
is formed by the serous lining of the veins, —
secreted from the vasa vasorum, — is proved
beyond all question by the experiments of
Gendrin and Hope. Gendrin found that, by
securing a portion of a vein between two liga-
tures and removing all the blood it contained,
upon injecting some irritating substance into
it, plastic lymph was exuded in sufficient
quantity to fill the cavity of the insulated por-
tion.* In this experiment the fibrinous matter
was clearly true plastic lymph, in all respects
similar to the plastic effusion in other serous
cavities. Again, the experiments of Dr. Hope,
in which, by mechanical irritation, he pro-
duced warty excrescences on the valve of the
aorta, support the view I have taken. There
are many points in the formation of these
coagula in veins which are remarkable. That
they do, as already stated, consist both of
lymph-exudation and coagulated blood is more
than probable. But what determines the coagu-
lation of the blood in plastic phlebitis, is less
obvious. That the inherent power of coagu-
lation, which the blood in itself possesses, is
the cause, is not saying enough. There are

* The experiments were originally performed
upon arteries, but were repeated upon veins with
similar results. Dr. Hope’s were upon the aorta
near the heart : however, they prove the same fact
— effusion of lymph on the lining of the vascular
cavity.

VEIN.

1393

certain conditions which must occur before
coagulation can develop itself. While the
blood, itself in a state of health, remains in
contact with the lining membrane of healthy
blood vessels, coagulation is impossible ; but
under certain conditions of disease the blood
loses its fluidity, and these conditions may
either consist in some abnormality of the ves-
sel’s walls, or in some foreign matters becom-
ing mixed with the blood, — the former in-
fluence being passive, and the latter an active
agent in producing or hastening coagulation.

I would here urge the doctrine that the
vascular cavity, — the hollows of all the tubu-
lar vessels (veins, arteries, and lymphatics),
together with the ventricles and auricles of
the heart, — constitutes a true serous shut
sac, much complicated in form and modified
by its peculiar functions, it is true ; but pos-
sessing the same anatomical elements, — an
epithelial pavement placed upon a sheet of
limitary tissue, on the other side of which is
situated a nutrient vascular system. I would
here urge this view, because it applies with
much force to certain questions in venous
pathology, and to few more so than the one
under consideration, where arguments by
analogy are a desideratum. The lining mem-
brane of the veins then is a serous membrane.
On the surface of other serous membranes —
pleura, pericardium, &c. — plastic effusion con-
sists of sheets of lymph, and a certain amount
of serum. By analogy we, a priori, conclude
that lymph is effused in inflammation on the
lining surface of the veins, and this the experi-
ments of Gendriu and Hope have established
by indisputable proof. That the inflammatory
product consists partly of serum as well as
lymph is supported by analogy alone ; but
if admitted would explain the coagulation
of the blood to complete the clot, which is
known to be so much facilitated by the ad-
mixture of foreign or abnormal secretions.
Whatever may be the opinion of the forma-
tion of the coagulum, its characters are these :
— it consists of concentric lamina;, brownish,
yellowish, or white, of which the central are
the darkest and softest; and sometimes the
centre is nearly fluid blood. The density of the
entire clot is subject to much variety. The
coagulum is moulded to the cavity of the vein,
and sometimes present the exact impression of
the valves. Mr. Arnott has made an interesting
observation with respect to the coagulum,
that it extends along the affected vein usu-
ally to the next collateral branch, and there
abruptly ceases. The true explanation of
this circumstance is doubtless that given by
Mr. Henry Lee.# “ When any portion of
a vein is obstructed, the blood is kept at
rest between the obstruction and the next
collateral branch ; and, if disposed to coagu-
late, there is nothing to interfere with such
an action. But the case is different as soon
as one vein opens into another. A fresh cur-
rent of blood is then continually sweeping the

* On Phlebitis and Purulent Deposits, by Henry
Lee, Lond. 1850, p. 23.

VOL. IV.

orifice of the obstructed vessel ; and even
although the blood at this point should have
a tendency to coagulate, it is carried on in the
course of the circulation, before it can adhere
to the sides of the unobstructed vein.”

The coagulum thus extends towards the
heart, beyond the limits of the inflamed por-
tion, having a mere mechanical boundary. It
extends also at the distal end, but here it
becomes gradually attenuated : it often rami-
fies into many branches and subdivisions of
the veins that are tributary to the one ob-
structed, especially where they are not re-
lieved by collateral anastomoses. At those
points where inflammation has not occurred,
and the coagulation has been favoured by me-
chanical circumstances simply, the clot scarcely
adheres to the lining membrane of the vein.

But the plastic product is not always in the
form of a plug, moulded to the cavity of the
vein : it sometimes consists of shreds or
fringes of lymph, firmly attached to the lining
of the vein, and hanging into its cavity, either
from the walls or in festoons from the valves.*

The walls of the vein, at the same time,
undergo change, indicative of the same inflam-
matory phenomena, which consists mainly in
interstitial plastic deposit among the areolar
tissue of the tunics.

“ So soon as a fibrinous plug of this de-
scription is established, the red and violet
speckled colouring abates in intensity, and
the internal membrane, losing its smoothness
and polish, assumes a dull velvety or slightly
puckered appearance. The external mem-
brane appears thickened, turgid, and soon
becomes adherent to the cehular tissue, which
in its turn has been rendered firmer and paler
front the effusion of plastic lymph. Both
membranes are still readily distinguishable,
and even separable, from each other ; the con-
sistency of their texture is however impaired,
and they are easily torn. In this state of
things a vein, when cut asunder, does not col-
lapse, even after the plug has been removed ;
but, on the contrary, its calibre remains open
like that of an artery. This is more than ever
the case when the surrounding cellular tex-
ture has acquired firmness by the condensa-
tion of the inflammatory product infused into
it, or w hen it puts on a brawn-like character,
and intimately coalesces with the external
membrane of the vessel. j-

These phenomena may occur in veins of
any size ; and to any extent in ant particular
set of vessels. They occasion obstruction of
the circulation in all vessels tributary to the
one affected. Of such a condition Phlegmasia
alba dolens may be instanced as an example.

As regards the cause of plastic phlebitis,
or, indeed, of venous inflammation in general,
it may be the result either of spontaneous
action, or the circulation of poisoned blood —
the latter being infinitely the most common

* See Cooper and Travers’s Essays, Lond. 1818,
part i. plate 10.

t Hasse’s Pathological Anatomy, Sydenham So •
ciety’s translation, Lond. 1846, p. 13.

4 u

1394

VEIN.

cause. In the latter case the inflammation of
the vein is excited by contact of a coagu-
lum of vitiated blood with the lining of the
vessel. But the veins may, as well as other
tissues and organs, be the seat of spontaneous
inflammation. This is frequent in some forms
of varix ; especially in haemorrhoids, and usu-
ally, though not always, leads to the coagu-
lation of the contained blood. I have seen
acute inflammation of a varicose saphena
causing much interstitial plastic deposit, in
which no coagulum formed in the interior of
the vessel, whose canal was quite pervious.

Suppurative 'Phlebitis. — When phlebitis leads
to suppuration, it is generally, I believe always,
accompanied by plastic effusion also.

The question of pus formation within veins
is one of great importance and interest, and
difficult of solution. In a great proportion
of examples, purulent phlebitis is originally
lighted up by the mechanical introduction
of pus into the veins. In some few cases the
pus would seem to originate within the vein,
either from an ulceration of the inner surface,
or perhaps it is secreted free on the unbroken
lining membrane. One very remarkable point
is the enormous multiplication of the pus
within the vein. No absorption, or me-
chanical introduction, can at all explain the
immense increase; and it is obvious that there
exists within the vessel some source of this
pus generation. It was imagined by Gendrin
and Donne that the blood itself was the source
of the pus, and that it was developed by the
metamorphosis of blood globules into pus
cells ; and they imagined that the change of
form to a sphere, which the blood discs un-
dergo, when submitted to the action of certain
fluids, was an indication of the change. This
doctrine has, however, been long since ex-
ploded.

A more reasonable explanation, and one
founded upon analogy, is that the pus is se-
creted by the inner surface of the vein, by a
metamorphosis of epithelium. Vogel has long
since demonstrated, on the mucous mem-
branes, that pus is producible by a change of
epithelial cells, and this suggests an explana-
tion,— why, in an unbroken vessel, pus may
be produced in great abundance. Wherever
epithelium exists, it appears that pus cells may
be generated without lesion of surface; espe-
cially where the action is started by contact of
pus from some other source. This certainly
happens in serous cavities, — pleura, pericar-
dium, &c. ; and we may, from analogy, judge
that the same occurs in veins. This doctrine
is entertained by the high authority of Hasse ;
he observes, — “ In accordance with these
views, the puriform masses, generated within
the veins, would be developed as follows : —
First of all the cells of epithelium-lining dis-
covered by Henle, separate from the internal
membrane of the vein, so as to give the inner
surface of the vessel the dull appearance al-
ready described, and to render it more sus-
ceptible of a morbid tinge from imbibition. The
next change affects the passing blood cor-
puscles, which assume a spheroid or else a

gibbous appearance, advance with a slow re*
volving movement, or cling to one another,
parting with their serum and with their pig-
ment. The internal membrane of the vessel
generates new imperfect epithelium cells,
which mingle with the altered blood, and
finally actual pus-globules, which, when con-
gregated in sufficient number, completely ar-
rest the current of the blood, and affect the
blood-corpuscles in the manner already pointed
out. The simultaneous effusion of both fibrin
and albumen now serves to complete the
formation of a plug, which differs in external
characters according to its more or less rapid
development, and to the varying proportions of
its constituent parts. The plug, thus originat-
ing, afterwards undergoes further changes.”*
The actual changes that occur, and are ob-
vious to the naked eye, affect the plastic plug,
the fluid contents, and the parietes of the vein.
In suppurative as well as adhesive phlebitis,
plugs of lymph and coagula are formed, and
are partly the result of inflammatory action,
and partly they are the direct result of the
contact of fluid pus with the blood. f

The plugs that form in suppurative phle-
bitis are softer, more numerous, and vary in
form. They soon become broken down, and
exhibit disintegrated fibrin mixed with ge-
nuine pus. The coagula become softened,
first in the centre ; they loose their laminated
structure, and ultimately break up. These
coagula, in phlebitis the result of infected
blood, must not be considered as any indica-
tion of the locality in which the disease has
originated. In such cases the whole circu-
lating mass is infected : little portions of coagu-
lating fibrin, entangling pus-cells, are con-
tinually passing through the vessels, and here
and there attaching themselves to the lining
of the vessel, light up circumscribed regions
of inflammation. This coagulation is a re-
medial effort : by its means the materies morbi
is shut up and circumscribed by a harmless
coagulum : circulation in the affected vessel is
suspended and the poison cannot again mix
with the blood. Perhaps these coagula some-
times become absorbed, or organised and ob-
literate the vessel ; at other times they sup-
purate, and the walls of the vessel become
implicated and ultimately give way. “ The
formation of matter being brought about with-
in the inflamed vein, its membranes have like-
wise to undergo a further change. Their
colour now inclines to a greyish white ; they
become softened and thickened, are no longer
to be distinguished from one another, and
form, in con junction with the surrounding tex-
tures, a nearly uniform membranous layer of

* Ilasse’s Pathological Anatomy, p. 16.
f The influence of pus in causing coagulation of
the blood may be seen in the following experiment :

— “An abscess was opened in the groin, and a
quantity of pus received into a gallipot ; some blood
from the divided vessels w'as also received into the
same vessel ; they were then stirred together, and
in two minutes the mass coagulated. Some blood
taken from the same patient in the same manner,
but not mixed with pus, coagulated in eleven and a
half minutes.” — Lee on Phlebitis, &c. p. 27.

VEIN.

139,5

a lardaceoits aspect and character. By and
by a turbid puriform fluid is often found de-
posited at intervals in the cellular texture ; in
some instances where the suppuration is vi-
gorous in the vicinity of the vein, the latter
traverses the purulent channel for a consider-
able space, denuded of its entire circumfer-
ence. Here the membranes of the vein gra-
dually soften, and at length melt down, so to
speak, until no further vestige of their texture
is discernible within the common centre of
suppuration.”* If, however, this circumscrip-
tion of the pus by means of coagulum does not
occur, and it floats' through the vascular sys-
tem, it produces a variety of secondary effects
remarkable and important in their results.

The products of this secondary action are
known as “ purulent deposits,” or “lobular
abscesses.” Strictly speaking, they are not
deposits of pus; but the pus is “translated”
from one part to another, and there becomes
the originator and centre of a fresh abscess.

The actual mode of production of these lo-
bular abscesses has been the subject of much
discussion ; but the evidence upon the va-
rious points appears to resolve itself into the
following explanation. The pus-cells being
bodily introduced into a vein, or generated in
it, pass forward in the circulation till arrested
in the capillaries by their size being too great
to admit of their passage : they then excite
inflammation of the parenchyma of the affected
organ, which leads to condensation, and, sub-
sequently, to suppuration : the pus-cells being
the excitants of the inflammation, which is
suppurative, not only from its intensity, but
from the fact that pus germs are furnished by
the same body as originates the inflammation,
and thus more pus is generated.

Tire appearances of these local abscesses,
which are, strictly speaking, foreign to our
present subject, are determined by the cha-
racter of the organ in which they occur.

There appears to be some general laws as it
respects the development of these abscesses.
They occur in those organs which are most
vascular, and through which the largest quan-
tity of blood passes in the smallest space of
time; thus the lungs and liver are affected the
most abundantly. Again, after the blood has
been infected and the pus added to it, that
system of capillaries is first affected, through
which the fluid first passes; the capillaries, as
it were, filtering off the pus-cells and retaining
them. Thus, if pus gets into the systemic
veins, the capillaries of the lungs will be the
first to arrest their progress ; and when this
happens, as is generally the case, lobular ab-
scesses are most abundantly, or exclusively,
found in those organs, and when found else-
where also are most advanced in the lungs :
when, however, the portal system is the vehicle
of the pus, as occasionally happens after oper-
ations on the rectum, for example, we find the
abscesses in the liver. These laws are quite
correct in the main ; but there are some ex-
ceptions to them, and these exceptions are

* Hasse, loc. cit. p. 18.

quite explicable ; for though pus-cells are for
the most part too large to pass capillaries,
especially with their tendency to coagulate
blood, they may nevertheless pass through
some of the larger ones ; and it must be ad-
mitted that disintegrated pus globules may
pass through the smallest vessels : hence, in
some instances, the laws here suggested are
not exemplified.

The results of phlebitis are either suppura-
tion, resolution, or obstruction, the consequence
of organisation of the effused lymph. Upon
the latter subject some observations are ne-
cessary.

Obliteration of Veins. — Obliteration of veins,
the result of phlebitis, may be either incom-
plete or complete. Hasse mentions two forms
of partial obliteration of veins ; the first of
which has also been described by Carswell.
This form consists of a thickened and turgid
condition of the vessel’s walls, as if they had
been macerated ; at the same time they are
closely connected with the surrounding areo-
lar tissue. Within the vein, and intimately
connected with the lining membrane, is a hol-
low cylinder of fibrin, firm and whitish on its
exterior, and soft and dark-coloured within ;
the interior being bathed with the circulating
blood. Hr. Carswell’s explanation of this, in
which Hasse coincides, is that the soft centre
of the plug is carried away before the circu-
lating current, whilst the exterior becomes
organised and united with the interior of the
vein.

In the other form he describes the vein as
reduced to a whitish cord, and filled with an
organised plug. “ Betwixt this plug and the
thickened coats of the vessel, round about
the periphery of the former, were several little
canals, which, running along the whole extent
of the vein, had already begun to re-establish
the circulation. In all probability the impulse
of the blood below had, during the first period
of inflammation, here and there severed the
plastic plug from the parietes of the vessel ;
subsequently', the above plug being organised,
and the intervening blood absorbed, several
peripheral channels would form, instead of a
single central one.” *

In complete obliteration the vein diminishes
in size, shrinks nearly to a cord, and becomes
pale and soft. The plug also becomes reduced
in size and organised, and adheres firmly
to the lining of the vein. How the plug re-
ceives its vessels and communicates with the
vasa vasorum of the vein, I am not prepared
to state. But fibrin thus isolated probably
has the inherent power of generating vessels,
which ultimately communicate with those of
neighbouring textures. The secondary con-
sequences of obliteration of veins, — oedema,
Phlegmasia dolens, &c. cannot here be con-
sidered.

Healing of Wounds in Veins. — The condi-
tion of the wound and its mode of healing de-
pend upon the character and direction of the

* Hasse, loe. cit. p. 26. I beg to make abundant
acknowledgments to the very valuable writings of
this author, from whom I have drawn largely'.

4 u 2

1396 VEIN.

wound. If the wound be linear, and made
in the axis of the vessel or somewhat ob-
liquely, and there be not. much bleeding, its
lips will come together, adhere, and rapidly
form a linear cicatrix. If, however, it be
transverse, or if much bleeding occur from
it, a coagulum will form in and over the
aperture. “ An oval naked coagulum forms
the plug of the orifice, and a flattened co-
vered clot, which is an extravasation into
the cellular sheath, extends to some distance
around it.”* In twenty-four hours the lips
of the wound are found separated, the edges
are everted and adhere to the clot. At the
expiration of three days the internal margin
of the wound is elevated and rounded, and a
thin, narrow, membranous expansion, parti-
ally extending over the inner surface of the
clot, is seen to be continuous with the everted
edge of the internal tunic. The clot is more
compact and lamellated. At the fifth day the
membranous appearance extends over the
whole inner surface of the clot. Subsequently
the clot becomes more and more absorbed,
and the new membrane, extending from the
lips of the wound, becomes more organ-
ised. Vasa vasorum can be seen on it by
means of a lens from the twelfth to the six-
teenth day. “ On the twentieth day it is only
possible to distinguish the recent from former
wounds, by the tenuity, smoothness, and
transparency of the new membrane compared
with the old, which is dense, tough, and
wrinkled.” These dates, &c. refer to the
wounds made in ordinary bleeding operations;
in larger wounds the process is proportion-
ately longer. The wound is ever after indi-
cated by the peculiar thin, transparent, exten-
sile membrane with which it was repaired.

If a vein, having one of these cicatrices in it,
be injected with water, the new membrane
bulges out, on account of its elasticity, into
a pouch or bag.j- Mr. Travers is quite con-
vinced that this new membrane is continuous
with the internal membrane of the vein.

Effects of Ligatures on Feins. — The effects
of ligatures on veins are different from those
on arteries. The coats of the vein are, by the
ligature, thrown into longitudinal folds, which
are indicated when the vessel is slit up, and its
interior examined. The effect on the ele-
mentary coats of the veins is different from
that produced by ligature on the arteries :
instead of the deep cut through the inner
and middle coat, which occurs in the latter,
there is but a slight indentation, correspond-
ing to the ligature on the vein. This is
produced by the lesion of the thin internal
tunic, and that alone. As regards the rest
of the thickness of the vein’s walls, it ap-
pears that the outer or cellular tunic is di-
vided, leaving the middle condensed portion
of the venous wall uninjured. Upon a close
examination, however, it is found that one
element — namely, the yellow elastic tissue
— is divided throughout the entire thick-

* Travers, loc. cit. p. 24G.

t See the beautiful plates accompanying Mr. Tra-
vers’s essays before referred to.

ness of the outer and middle coats, leaving
the continuity of tube to be maintained by
the white fibrous element, which does not
suffer division ; and therefore that part of the
wall where the white fibrous element is most
condensed and abundant is that where least
impression is made by the ligature. A thin,
tightly tied, string produces the deepest im-
pression.

Accordingto Mr Travers, whenaligaturehas
been applied for a period of from twenty-four
hours to five days, it has produced the follow-
ing changes : — “The vein above and below
is thrown into longitudinal folds on either side
of the ligature. The portion next the heart is
perfectly empty and collapsed ; that next the
extremity is filled to distension by a long, and,
generally, firm, coagulum of blood, which is a
mould of the vessel, and bears the impression
of its semilunar valves. The coagulum ex-
tends for several inches; it is not always com-
pact and lamellated, and adhering to the in-
ternal tunic, being sometimes less consistent
and broken; but it always fills the calibre of
the vein. There is no blush upon the in-
ternal tunic, much less any sign of adhesive
inflammation, or thickening of the proper coats
of the vein, or agglutination of its contiguous
folds ; these folds being effaced on the re-
moval of the ligature ; but the cellular sheath
is thickened by a deposit of lymph in the vi-
cinity of the ligature.” * If two ligatures be
applied, and the vessel divided between them,
the ends retract about an inch. At the se-
venth day the interstitial deposit of lymph
among the areolar tissue around the vein is
very dense, and forms a hard fibrinous mass,
through which the ligature runs in a sort of
canal. According to Mr. Travers, ulceration
commences on the ninth day, and lasts from
fifteen to twenty-five days. “ The ulcerated
ends of the vein formed a crescentic sweep, and
were separated to the extent of an inch, and
fastened by adhesion to the cellular sheath,
which was much extended and thickened by
a subjacent deposition of lymph, so as to
form a smooth solid bed between the divided
ends of the vein. The internal membrane of
the superior portion of the vein had a thin
ragged edge, where it had been severed by
ulceration. The lower edge was smooth and
blended in with the bed of the wound. The
extremities had undergone no contraction but
that produced by the adhesion of the severed
extremity to the sheath. The portion of the
vein next the heart was empty. The upper f
was filled by a dark lamellated coagulum of
blood, adhering very strictly to the internal
tunic, which was discoloured by it. On care-
fully' separating the outer lamellae which
coated the interior of the vein, I could not
discover any thickening of the proper coats of
the vein, nor any appearance of inflammatory
action within its canal, nor was any such ap-
pearance indicated in the lower portion of
the vein.J

* Travers, loe. eit. p. 252.

f The jugular vein is referred to.

} Travers, loc. cit. p. 253.

ness of the outer and middle coats, leaving
the continuity of tube to be maintained by
the white fibrous element, which does not
suffer division ; and therefore that part of the
wall where the white fibrous element is most
condensed and abundant is that where least
impression is made by the ligature. A thin,
tightly tied, string produces the deepest im-
pression.

Accordingto Mr Travers, whenaligaturehas
been applied for a period of from twenty-four
hours to five days, it has produced the follow-
ing changes : — “The vein above and below
is thrown into longitudinal folds on either side
of the ligature. The portion next the heart is
perfectly empty and collapsed ; that next the
extremity is filled to distension by a long, and,
generally, firm, coagulum of blood, which is a
mould of the vessel, and bears the impression
of its semilunar valves. The coagulum ex-
tends for several inches; it is not always com-
pact and lamellated, and adhering to the in-
ternal tunic, being sometimes less consistent
and broken; but it always fills the calibre of
the vein. There is no blush upon the in-
ternal tunic, much less any sign of adhesive
inflammation, or thickening of the proper coats
of the vein, or agglutination of its contiguous
folds ; these folds being effaced on the re-
moval of the ligature ; but the cellular sheath
is thickened by a deposit of lymph in the vi-
cinity of the ligature.” * If two ligatures be
applied, and the vessel divided between them,
the ends retract about an inch. At the se-
venth day the interstitial deposit of lymph
among the areolar tissue around the vein is
very dense, and forms a hard fibrinous mass,
through which the ligature runs in a sort of
canal. According to Mr. Travers, ulceration
commences on the ninth day, and lasts from
fifteen to twenty-five days. “ The ulcerated
ends of the vein formed a crescentic sweep, and
were separated to the extent of an inch, and
fastened by adhesion to the cellular sheath,
which was much extended and thickened by
a subjacent deposition of lymph, so as to
form a smooth solid bed between the divided
ends of the vein. The internal membrane of
the superior portion of the vein had a thin
ragged edge, where it had been severed by
ulceration. The lower edge was smooth and
blended in with the bed of the wound. The
extremities had undergone no contraction but
that produced by the adhesion of the severed
extremity to the sheath. The portion of the
vein next the heart was empty. The upper f
was filled by a dark lamellated coagulum of
blood, adhering very strictly to the internal
tunic, which was discoloured by it. On care-
fully separating the outer lamellte which
coated the interior of the vein, I could not
discover any thickening of the proper coats of
the vein, nor any appearance of inflammatory
action within its canal, nor was any such ap-
pearance indicated in the lower portion of
the vein.J

* Travers, loc. eit. p. 252.

f The jugular vein is referred to.

} Travers, loc. eit. p. 253.

VEIN.

1397

Phlebectesis — Varix. — Dilatation of veins
is not only the commonest morbid change in
veins, but is the most frequent single patho-
logical condition that occurs in the human
body.

Varix is a condition of vein which occurs
in every possible variety of degree, and in va-
rious localities, and is generally developed by
the superaddition of some mechanical exciting
cause upon a constitutional predisposition, —
by the operation of some local physical in-
fluence upon veins, which, in common with
the other veins of the body, already' possessed
an abnormal laxity or softness of texture that
favours their dilatation.

The structure of veins, already described,
pre-eminently favours their dilatation: — a
structure consisting almost solely of longitu-
dinal fibres, with comparatively few in a cir-
cular direction to brace up its calibre, pre-
sents little to restrain its dilatation beyond
the lateral adhesion of the contiguous fibrous
rods and their matting together by a certain
amount of lateral branching. The coats of
veins moreover are very thin, and the amount
of distending force applied to them often very
considerable.

The anatomical relations of certain veins
give them, when in a state of varix, consider-
able peculiarities, and various distinctive ap-
pellations have been conferred upon such local
affections, — varicocele, hemorrhoids, & c.: their
pathological identity is, however, indisputable.

Though varicosity of the veins is, for the
most part, confined, in one individual, princi-
pally to one locality, it nevertheless appears to
depend upon a vice pervading the entire
venous system, the effects of which are more
particularly called out in one locality by the
existence of some mechanical excitant there
present. 1 cannot at all agree with Hasse
and Landouzy, “ that the full development of
this disposition in one locality prevents its out-
break in another.” This doctrine has, how-
ever, been supported by a show of argument.
Thus it may be truly said that haemorrhoids,
varicocele, and varicose subcutaneous veins
very seldom exist together in the same indivi-
dual : the concurrence of either two of them
is unusual, and much less frequent than their
solitary development ; and moreover the dif-
ferent forms are met with, as a rule, in different
classes of society : — thus hemorrhoids are
most frequent in the affluent, varicocele in the
sensual, and varix of the lower extremities in
the labouring classes. Again, the different
forms appear at different periods of life, —
varicocele aboutorsoon after puberty; hasntor-
rhoids and other varix usually about man-
hood. But all these arguments fail, when it
is recollected that in each of these suggested
instances there is some special circumstance,
which, acting as an excitant, superadded to a
previous constitutional disposition, might ac-
count for the particular locality in which the
disease makes its appearance, and the parti-
cular time at which it occurs. If in all these
instances obstruction to the circulation cannot
be made out, there is some cause of greater

vascular activity, which is also seen to be
efficient in the production of phlebectesis.
Haemorrhoids are most frequent in the af-
fluent, because their mode of life leads to
greater vascular activity in the alimentary
canal, and to frequent portal obstruction :
varicocele in the sensual, from the greater
stress of blood upon the spermatic veins ; at
puberty also, from the same cause : the la-
bouring classes likewise are afflicted with
saphenous varix on grounds similarly expli-
cable. It is because there is particular em-
phasis laid on one particular organ in each of
these cases that the specific form of phlebec-
tesis is assumed in the separate examples. And
where such influences have been compound,
other effects have followed, combining more
or fewer forms of varix. It cannot therefore
be said that one form of phlebectesis prevents
another, or even diminishes the chance of its
formation ; the truth is, that the same indivi-
dual is not liable to be exposed to the exciting
cause of more than one form, — that the pre-
disposing condition of the veins may be uni-
versal, but in one set alone is the morbid
change called forth.*

Phlebectesis may conveniently be divided
into several forms. Andral has made the fol-
lowing division : —

“ First species. Simple dilatation, unat-
tended by any other alteration, either affect-
ing the whole length of the vein, or existing
only at intervals.

“ Second species. Dilatation of the veins,
either uniform or at intervals, with thinning of
the parietes at the dilated points.

“ Third species. Uniform dilatation of the
veins with increased thickness of the parietes.

“ Fourth species. Dilatation of the veins at
intervals with thickening of the parietes at the
points where the dilatations exist.

“ In these two latter species, the vessel in-
creases in length as well as in breadth, and in
consequence becomes quite tortuous in its
course.

“ Fifth species. Dilatation of the veins, with
the development of septa or partitions, which
divide the interior of the vessel into small
compartments, that allow the blood to stag-
nate or to coagulate, &c.

“ Sixth species. Dilatation of the vein, its in-
terior being divided into a number of separate
compartments, as in the preceding species,
and in addition its parietes drilled by a number
of minute holes, which allow the blood to
pass from the vein into the surrounding cel-
lular tissue,” &c.

These include all the forms of phlebectesis
as far as systematic division is concerned.

* This may he very pointedly illustrated by in-
stancing the two spermatic veins in varicocele re-
spectively. It cannot be said that varix. of the left
prevents varix of the right spermatic vein ; for
both, not unfrequently, occur together. It cannot
be said that there is any difference in structure or
constitution between the two veins in the same in-
dividual. Then, why should the left, and the left
alone, be, in nine out of ten cases, affected ? Simply
because a strong mechanical influence operates on
one and not on the other vein.

4 u 3

1398

VEIN.

The first species simply includes a general
predominance of the venous system, — a dis-
proportionate size of the veins. It is of very
frequent occurrence, and is indicated by a
plethora or distinctness of the veins of the
subcutaneous system. This is often seen in
the veins of the back of the hand. It is not
to be considered strictly morbid, — it is in
many individuals an original conformation,
and in others merely temporary, the result
of warmth, strong exercise, pressure on a
venous trunk, &c. It is common, nay gene-
ral, in old people, though the healthiest. It
may be here observed that the capacity of
veins, as well as that of arteries, increases
with age.

The second species represents a condition
unquestionably morbid. It consists in a dila-
tation of the vein at the expense of its walls,
they becoming attenuated in proportion to the
increase of the vessel’s calibre. This appears
to consist essentially in a separating of the
longitudinal fibres of the outer coat, by which
the internal membrane is permitted to dilate
or protrude. The dilatation is seldom cy-
lindrical, it is usually unequal and in pouches.
These pouches are usually more or less globular
or oval ; sometimes, however, they are con-
stricted, or form pear-shaped, or even pedun-
culated, tumours.

The third and fourth species of Andral’s
division are mollifications of the same condi-
tion, and seem to be in many cases the direct
but gradual result of the first. Whether the
dilatation be general and equable, or partial
and irregular, the thickening is confined to
the dilated portion, and is doubtless a re-
parative condition, — an effort to resist by
increased strength of the vessel’s walls
any further stretching ; and it may be ob-
served that in this thickened form of phlebec-
tesis, those large, pouchy, and tumour-like,
dilatations do not occur. In these forms the
dilatation is more regular and cylindrical, or
increasing somewhat evenly in passing from
one part of the vein to another. In almost all
these cases there is increased length, some-
times very considerable, so as to make the
vein assume a serpentine or tortuous course;
in some instances the vein remains perfectly
straight. The increased thickness arises from
the superaddition of fibrous tissue in the ex-
ternal coat, probably developed from a sub-
inflammatory plastic exudation among the
normal tissue of the outer coat, itself an effect
of the stretching, in the dilatation of the vein.
The amount of thickening varies in different
cases: in those fully formed it is often very
considerable. The increased thickness of the
vessel’s walls prevents it from collapsing when
cut through : it remains patent like an artery.
The colour of its tissue differs, however, from
the arterial; it is reddish white, and pale, like
the normal venous tissue. Besides thickening
of the coats of the veins, they become inde-
finite and very hard ; the outer coat becomes
completely blended with the areolar tissue of
the sheath of the vessels ; by this means the
walls, which are often thicker than those of

an artery of the same size, are with difficulty
pressed together.

As regards the fifth species, I agree with
Hasse, that it more deserves to he considered
as a mere variety of the others than as itself
distinct. Tke septa are probably not new
formations.

The sixth species, whilst it evidently refers
to a particular form of venous dilatation, is
obviously misdescribed ; the minute holes
“ drilled in the sides of the veins” in this spe-
cies being in reality nothing more than the
mouths of small and dilated veins, wdiose di-
lated and attenuated walls are not easily re-
cognised, and thus the blood is thought to
escape into the cellular tissue.

To these may be added certain varieties of
erectile tumour, which consists essentially of
modified capillaries, but on which the venous
character is conspicuously impressed. In these
cases there are oval or spheroidal tumours of a
bluish or purple colour. They are composed
of dilated capillary veins, which are supplied
by enlarged arteries. The veins are stretched
into saccules and crypts, and the blood is re-
moved front them in veins disproportioned to
the size of the affected part, and often them-
selves varicose.

Having considered phlebectesis in general,
I may conveniently devote some remarks to a
few of the special forms of varix.

Varices of the Leg. — Varices of the lower
extremity usually occur after the commence-
ment of adult life. They are generally the
result of habitual toil in the erect posture;
they result also from obstruction to the cir-
culation ; and a not unfrequent source of ob-
struction has of late been displayed in the
fascia lata that forms the saphenous opening.
Briquet has shown that this affection is more
common amongst males than females. In 258
males examined by him 71 had varix of the
leg; in 485 females, 42 were affected.

There is another distinction in the disease as
it appears in the two sexes ; in man one trunk
is usually affected, or, at all events, the disease
is confined to vessels of larger size; whereas
in the female, the smaller cutaneous twigs are
generally the subject of the disease, and then
present an elaborate series of purple ramifica-
tions, very superficial and distinct ; and often
associated with the latter are circumscribed
local varices of greater size. This is the ge-
neral rule, hut it is liable to exceptions; each
form may occur in either sex, but the latter
is almost always confined to the female. This
circumstance was, I believe, first pointed out
by Hasse.

It is unusual for all the veins of the leg to
become varicose ; it is usually confined to one
branch of the internal saphena : the external
saphena may however likewise be affected, or
several branches of each. It is uncommon for
them to be affected symmetrically ; the right
leg, according to Briquet, is most generally
the subject of varix.

Varices of the leg are arranged in various
forms : in some cases they consist of packets
of folded and reduplicated tubes,- which, not a

VEIN. 139!)

little, resemble, when seen through the skin,
the vesiculae seminales ; in other examples the
varix is single, straight and prolonged. A re-
markable instance of this occurred under the
observation of the author not long since ; it
consisted in a varicose condition of the in-
ternal saphena on one side alone: the vessel
•formed one large, straight, uniform cylinder
from the saphenous opening to the inside of
the foot, measuring about two thirds of an
inch in diameter.

Phlebitis often occurs in varix of the leg.
The valves moreover are subject to peculiar
malposition, dependent upon the distension of
the vessel's tube : these conditions are no-
ticed elsewhere.

Varicocele, or varicose dilatation of the sper-
matic veins is another peculiar form of pble-
bectesis. In its general anatomy it differs in
no respect fiom the other forms of varix.

Varicocele appears to be dependent upon
sexual development, and occurs principally
about puberty^. Landouzy has demonstrated
this as follows : —

f 13 occurred between 9 & 1 5 yrs. of age.

In 41 cases-; 20 „ 15 & 25 „

(. 3 ,, 2o & So ,,

The influence of mechanical pressure in

causing this malady is very' strikingly shown
by the fact that the disease is almost confined
to the left side, on account of the long and
uninterrupted current of blood which bears
upon the left vein, by means of the high
juncture of the spermatic vein of that side
with the renal vein. Breschet found in 120
cases but one on the right side.

Haemorrhoids , in their relation to phlebecte-
sis, consist merely of dilated veins, situated in
the vicinity of the anus, and in which chronic
inflammation and thickening of the external
coat and surrounding areolar tissue is very
conspicuous. The dense covering of areolar
tissue, and the comparative smallness of the
enclosed vessel’s calibre, have given rise to
different explanations of the pathological
origin of piles.

Le Dran, Racamier, Delaroque, Cullen,
Chaussier, and others have considered them
as encysted coagula of extravasated blood.
Delpech and Cruveilhier describe them as
tumours of erectile tissue. But by far the
most numerous and reputed pathologists,
among whom may be mentioned Andral,
Stahl, Petit, Morgagni, Hodgson, Lobstein,
Froriep, and Brodie, concur in the now gene-
rally received doctrine of the origin of hae-
morrhoids in varicose veins.

Haemorrhoids consist of ova', ovoid, or
round masses with broad bases, situated either
just within, or just without, the sphincter ani.
On examining the texture of these tumours,
they are found to consist of cells or cavities
of various sizes, surrounded by layers of red,
dense, areolar tissue. These, which vary in
shape, are lined internally by the smooth
lining membrane of the vein, and are perfor-
ated here and there with the apertures of
small communicating and tributary veins.

The absolute continuity of these cells with
the venous cavity has been proved by Hasse
and Brodie, who have injected them from the
arteries ; the former has also injected them
by the veins.

They are very apt to inflame and become
lined with lymph, or stuffed with coagula.

Varices occur in all situations and in every
variety : instances are on record where they
have occurred in the veins of the oesopha-
gus, lips, eyelids, bladder, heart, &c. : indeed
there appears to be no region which is free
from the occasional development of this dis-
ease.

Rupture or Perforation of Veins — A number
of pathological examples, in which perforation
of the vessel’s walls is the conspicuous cha-
racter, may be conveniently, though, it must be
confessed, not very naturally, classed under
this head. Either with or without previous
change, and that change very various, the
lesion may occur, so that the only condition
common to these instances of morbid change
is a breach in the venous cylinder.

A rupture, without previous morbid change
in the vessel, and which may occur in any
case where the tissues of the vein are thin and
weak, may be produced by an unusual amount
of internal tension of the contained fluid. So
again, an attenuated or ulcerated state of vein
may yield before an amount of distension that
is neither excessive nor unusual : rupture is
the result in either case.

Destructive disease may, as well in veins as
elsewhere, attack the tissues of the organs in
question, — suppurative inflammation, ulcer-
ation both extrinsic and intrinsic, extension of
malignant disease, &c. : perforation is here
the issue.

In the rupture of a previously healthy vein
the change consists in a rent or tear of the
structure, the surrounding tissues being nor-
mal ; the rent is sharp, and more or less re-
gular. In perforation from ulceration, & c. the
aperture is rough, irregular, and jagged; the
parietes of the vessel are thinned down towards
the hole, are. much thickened more remotely,
and the orifice is ragged and shreddy.

Sudden or extreme obstruction to the cir-
culation, thus causing excessive distension,
has produced rupture of the healthy veins.
Bichat mentions instances of rupture of the
veins of the lower extremities during preg-
nancy ; Lee, those of the labia during labour.
Violent muscular exertion has ruptured veins,
by producing local congestions : Hodgson,
for example, has witnessed rupture of the
veins of the leg during cramp of the gastrocne-
mius ; I have three times seen rupture of a
vein on the dorsum of the foot during strong
exertion. Andral narrates an example where,
during a violent struggle, the vena cava in-
ferior was ruptured ; “ the borders of the
perforation seemed as if they had been torn
asunder, and the coats of the vein in the
neighbourhood were perfectly healthy.” The
peculiar bloodlessness of the surface, and con-
sequent deep-seated congestion which occurs
during rigors or the sudden application of cold
4 u 4

MOO

VEIN.

to the surface, has ruptured the large internal
veins. Portal tells us of a case of rupture of
the vena cava superior from a patient getting
into a cold bath : and Senac mentions the
rupture of the large internal veins as occurring
in the rigors of intermittents.

Rupture of the inferior cava from disease,
has been described by Dr. Squibb, in the Phi-
ladelphia Medical Examiner for 1847. “ The

vein at this point had been very much dilated,
and its coats much diseased and thinned : a
semiorganized mass or clot, which was con-
tained in the dilatation, was connected by its
surface to the softened coats of the expanded
vessel, and the rupture had occurred at the
junction of the edge of this mass with the side
of the vessel, and not at the projecting point
of the dilatation. The tumour was on the
anterior portion of the circumference of
the vessel, and was overlapped by the
edge of the liver, and by a portion of the
stomach.”

Morgagni mentions the rupture of a varicose
azygos vein, the result of extreme varicosity.
Perforation of veins from suppurative inflam-
mation or ulceration is not uncommon. The
cavities of the veins, especially in the stomach
and uterus, are often laid open by the exten-
sion of malignant disease. But the commonest
form of venous perforation is from the tegu-
mentary varicose ulcers of the leg, which is
originally extrinsic to the vein.

The following enumeration of ruptured or
perforated veins is from Andral. “ It has been
seen, first, in the superior cava, both within
and without the pericardium ; second, in the
inferior cava ; third, in the vena portae, both
within and without the liver ; fourth, in the
splenic vein ; fifth, in the jugular vein ; sixth,
in the subclavian vein ; seventh, in the veins
of the extremities ; eighth, in the veins that
run between the coats of the intestines.”

Affections of the Valves of Feins are partly
mechanical and partly dynamical. The most
frequent change they suffer from is the result
of the distension of the vein in which they
are placed ; but they are occasionally the sub-
ject of the same changes as occur in the vessel
itself. In varix the valves are not necessarily
damaged, though from the increased size of
the vessel in which they are placed they are
disproportioned to their office, and become
useless. Instances are mentioned by Stan-
ley, Lamrstaff, and Dr. R. Lee, where the
valves in varix were quite healthy, thin, and
transparent, but drawn aside and inadequate
to cross the vessel’s tube. The usual result
of varix is to injure the valves : they then be-
come torn in shreds or perforated ; or the
attached margin becomes detached, and the
valve is reduced to a membranous thread,
which stretches across the diameter of the
vessel. In other instances the valves are ren-
dered opaque and thick, — the result of chronic
inflammation. Whenever any affection of the
valves occurs, they are apt to become coated
with lymph ; and when a vein is the seat of
plastic inflammation, the valves usually be-
come ragged fringes of lymph.

Phlebolites. — The curious bodies called
p hlebolites, phlebolithes , or vein-stones, which
have excited much interest in the pathology
of veins, are true vascular calculi, — are cal-
culi or earth}' concretions deposited from the
blood in the veins ; and though their mode
ot formation differs considerably from those
other bodies which form in other hollow or-
gans, and which we call calculi, they are still
quite as much entitled etymologically to the
same designation. .

At a very early date, among the writings of
Realdus, Columbus, and Bartholin, phlebolites
were recognised and described ; but it was
not until Otto, Tiedemann, Cruveilhier, and
Carswell devoted their attention to them that
they excited much interest. Matured phle-
bolites are, for the most part, oval or round-
ish, bodies, sometimes irregular and flattened ;
they are sometimes prolonged and much at-
tenuated at one extremity, corresponding to
the distal end of the vein in which they are
embedded. They vary much in size, from a
grain of millet seed to a pea, or even to a
hazel nut ; their form also differs. Dr. Lee
describes a cylindrical vein stone, which was
found in the right common iliac vein of the
late Lord Liverpool ; it was an inch or more
in iength.

These concretions are of a yellowish or
white colour ; they are of varying density,
being sometimes of bony hardness, and at
others much softer, with a firmer nucleus,
which is always harder than the other parts of
the stone. When sections are made the cut
surface presents a series of concentric rings,
— there being at different distances from the
centre sufficient change of colour and density
to mark each annulus ; so that the calculus
is thus seen to be composed of successive
concentric laminae, hardest in the centre,
and gradually becoming softer in proceeding
outwards. They are frequently seen sur-
rounded externally by a layer of plastic mate-
rial, looking like a membranous investment ;
at other times they are firmly imbedded
in a dense coagulum ; but in the majority of
instances they are free from any covering.
The hardest stones, however, contain, inter-
mixed with the calcareous matter, much soft
animal material ; for, when desiccated, they
diminish in size ; and, unless the layers have
received equal proportions of earthy deposit,
they become irregular.

Phlebolites have been made the subject of
chemical analysis. According to Gmelin, the
following is their composition : —

Animal matter

- 27-5

Phosphate of lime

- 53-5

Carbonate of lime

- lo'o

Magnesia and loss

3-5

100-

This analysis has been repeated with the
same general results by Prout, Kemp, Hasse,
and Lehmann. They have since been sub-
mitted to another analysis by Schlossberger,

VEIN.

1401

who has given his results more in detail, as
follows : —

Phosphate of lime

- 50T

Phosphate of magnesia

- 13-7

Carbonate of lime

8-3

Organic matter

- 20T

Water -

6T

Loss -

1-4)

100'

These, then, are phlebulites completely ma-
tured. In those less completely developed
the phlebolite consists of an altered coagulum,
in the centre of which is earthy matter, sur-
rounded by white fibrinous concentric layers.
Cloquet has described one, which was not
fully formed, in which the calcification was
incomplete. It was taken from the inferior
cava, and consisted of a fibrinous mass, con-
taining a calcareous centre, from which a
number of rays of the same substance passed
through the fibrinous matter toward the cir-
cumference. Cloquet describes one of similar
structure, which be saw in Soemmering’s mu-
seum, and which was also taken from the inferior
cava. In a still more primitive condition these
calculi are recognisable. “ On drying the
coagula found within dilated veins, previously
to their having coalesced with the internal
membrane, they shrink together, grate under
the knife, and exhibit calcareous induration
at certain points, even in cases where it had
not been at all suspected.”*

As regards the origin and development of
phlebolites, only one opinion is now enter-
tained, namely, that they are developed from
modified coagula. Andral, however, gives the
following explanation. After speaking of cal-
careous degeneration of the coats of veins, he
goes on to say, “ these calcareous concretion*,
instead of lying between the coats of the
veins, sometimes push the internal membrane
before them, and project into the interior of
the vessel ; the membrane in such cases ge-
nerally contracts behind the concretion, and
forms a peduncle, which serves to attach it to
the side of the vein. It is probable that these
peduncles are sometimes ruptured or ab-
sorbed, and thus the concretion is completely
detached from its connection, and drops loose
into the vessel. This rationale may serve to
explain the origin of some of those calcareous
concretions which have been found in the
centre of the venous coagula.f

Hodgson imagined that phlebolites were
formed in the neighbouring textures, and
found their way into the veins by progressive
absorption.

Dr. Carswell has described and illustrated
the true method of their formation in detail,
exhibiting their successive changes in the pro-
gress of maturation. At first a coagulum of
blood is formed, which becomes condensed
and laminated in the centre ; the colouring
matter of the blood subsequently becomes ab-

* Hasse’s Pathological Anatomy.

t Andral, Precis, d’ Anatom. Pathol, tom. ii.

sorbed, and leaves ordinary yellow fibrin ; this
also becomes lamellated throughout. After
this calcification commences in the centre and
proceeds outwards till the whole is calcareous.

This mode of formation is maintained also
by Otto, Tiedemann, Lobstein, Cruveilhier.
Brrhman, Briquet, and Uasse.

The position of the phlebolite within the
vein, and the condition of the vein and phle-
bolite respectively, are subject to much variety.

In the dilated pouches, which sometimes
form in the sides of the veins, coagula are fre-
quently produced, which may terminate in
phlebolites. The pouch being filled, the walls
become atrophied, the inner surface becomes
rough and cellular, and closes firmly round
the calculus, sometimes making it appear ex-
ternal to the vein. At other times, not only
the pouch, but the entire calibre of the vein,
becomes implicated and stuffed with calcifying
coagulum ; in this case a portion of the tube
becomes obliterated. In other instances the
phlebolite is free in the cavity of the vein, is
loose and movable, and the vessel that con-
tains it is still permeable to the circulating
current. Such phlebolites, though loose anti
movable, are frequently surrounded by coagula
of blood ; sometimes by a layer of fibrin. They
have occasionally been surrounded by a thin
layer of fibrin, and attached at one point to the
side of the vein by a sort of peduncle, the rest
of the body hanging tree into the cavity of the
vessel. Tiedemann very naturally suggests that
in these cases the peduncle is produced by the
effusion of coagulable lymph, the result of
inflammation, caused by the presence of a
foreign body.

Phlebolites have been discovered in very
many of the veins : they have been found in
the vena cava inferior, the renal, the dorsal, the
common iliac, anterior and posterior tibial, the
saphena and other superficial veins of the
lower extremities, the hypogastric veins ; also
in the uterine, the vaginal, spermatic, vesical,
prostatic, and haemorrhoidal, veins. They have
likewise been seen in the splenic and mesen-
teric veins. Their most frequent and most
abundant position is in the veins of the pelvic
viscera. In number they vary considerably :
there are generally, though not always, more
than one. Tiedemann found thirty-six in the
spermatic veins of one individual, — fifteen in
one, and twenty-one in the other.

They occur almost always after middle age.
They produce no injury or inconvenience ;
nor is their presence known, except in a few
situations, during the life of the individual.

There are some general circumstances re-
lative to phlebolites which are striking and
curious. They always occur in veins below
the diaphragm, — in depending veins, — in
veins which circulate their blood against the
force of gravity.

According to Hasse, they always occur in
conjunction with phlebectesis.

They frequently, perhaps generally, occur in
veins returning the blood from diseased organs,
— from a diseased testicle or prostate, from
an ulcerated rectum, from an inflamed or

1 102

VEIN.

cancerous uterus, from an ulcerated leg, &c.
Examples of all these are on record.

What, then, determines their development?
This question it is not easy to answer ; all we
can say is, that those circumstances which fa-
cilitate mechanically the coagulation of the
blood, favour their production ; and it is not
improbable also that a vitiated state of blood
may predispose to and favour their develop-
ment: it is certainly probable that the pre-
disposing causes, whatever they are, may
be started into activity and be made efficient
for the production of these bodies, by some
temporary local disturbance of the circulation,
or by some slight subinflammatory condition,
which varicose veins readily take on, and
which, were it not for the existence of pre-
disposing circumstances, would soon be re-
solved.

Calcareous Degeneration of Veins. — The
transformation of the walls of veins into
earthy tubes, or calcareous deposition among
their tissues, is infinitely less common than in
arteries. It still however does occur, and
apparently in the same manner, by the same
progressive changes, and from the existence of
the same constitutional tendency, only in cir-
cumstances of greater intensity.

Occasionally patches of atheromatous de-
posit — consisting, as in arteries, of choles-
terine, oil, and phosphate of lime, — are seen
on the inner surface of veins, though they are
always much smaller, and less general than
those which are found in the arteries of the
same individual. They present a white opaque
appearance, and produce a slight elevation of
the surface where they are situate. This de-
posit becomes converted by degrees into bony
matter, as in arteries ; but instances where
this has existed to any considerable extent,
are very rare.

There are, however, some few on record.
Bailie has described ossification of the inferior
cava. Morgagni refers to a case observed by
Bonazolius and Stancarius, in which the cava
and emulgents were much dilated, and con-
verted partly into cartilage and partly into
bone. Beclard mentions an instance where
the femoral vein was calcified, and it was
lying in contact with a still more ossified fe-
moral artery. Horn noticed ossification of the
femoral and uterine veins. Mr. Hodgson re-
lates an instance of ossification of the saphena,
in which one calcareous patch measured an
inch in length; and l’hoebus states that he
saw in an anatomical museum an ossified sa-
phenous vein taken from a patient fifty-six
years of age, who died of cancer of the
stomach. By the calcareous deposit the vein
was rendered thick and inflexible ; but at the
points corresponding with the joints of the leg
the vein could be bent. The deposition was
between the coats of the vein, and was less
regular than that which is found in the coats
of arteries. The lining membrane was thick,
opaque, and nowhere broken. Microscopi-
cally, the deposit presented irregular projec-
tions and excavations. Furst and Bonetus
have found the coronary veins of the heart

converted into bone. Otto enumerates in-
stances of this change as also having occurred
in the splenic, portal, brachial, femoral, and
coronary veins.

A concretion of phosphate of lime, the size
of a nut, was. found by Andral in the parietes
of the external saphena. This might have
been an attached phlebojite.

Fatty Tumours. — Fatty tumours are occa-
sionally developed in the walls of veins around
the areolar tissue. Andral mentions one, —
“ I once saw a case of this description, in
which a tumour, presenting all the anatomical
characters of adipose tissue, was developed
between the coats of the vena porta;, near its
entrance into the liver. This tumour, which
was about the size of a walnut, projected into
the interior of the vein, and almost entirely
obliterated its cavity.*

Entozoa in Veins. — There is upon record
a unique example of acephalocysts being deve-
loped in the pulmonary veins of the human
subject, in which pouches were formed for their
reception. The observation was made by
Andral. I quote his description in extenso
from the “ Clinique Medicale.”

“ Several of these (acephalocysts) were
lodged in pouches with a smooth surface,
which at first seemed to be so many cysts.
Others of them empty, and rolled several
times on themselves, were contained in nar-
row canals, the elongated form of which they
assumed. The inner surface of these canals
was smooth, like that of the great pouches ;
they ramified like vessels. We soon ascer-
tained that at each pouch a vessel terminated
of small calibre, which, to form it, underwent
greater or less dilatation. We then dissected
the pulmonary veins, at their entrance into
the heart, and we traced them into the lungs :
when we had come to the;r almost capillary
divisions, we began to perceive several of them
present a considerable number of enlargements,
which were filled with hydatids. After being
thus dilated, the vein resumed its original ca-
libre; then, a little further on, it was again
dilated. The largest of the pouches might have
contained a large nut, and the smallest would
admit a pea. They existed equally in boih
lungs. The hydatids, which they contained,
hail all the characters of acephalocysts ; se-
veral presented small points of a dull white
colour in their substance ; others presented
on their inner surface a great number of
miliary granulations. Most of them were
bu rst.”f

Another entozoon, the Distoma hepaticum,
has been found in the (hepatic) veins. Several
examples have been recorded, but have again
been questioned. The matter has, however,
now been set at rest. In 1S30, M. Duval, at
Rennes, demonstrated to an anatomical class
several of these parasites in the hepatic veins
of a man. They were floating about in the
fluid blood. The vessels themselves were free
from any lesion. J

* Andral. toe. cit.

f Andral, Clinique Me'dicale, p. 555.

1 Duval, Gazette Medicale a Paris, 1842.

VENOUS SYSTEM.

140.3

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Prac., Paris, 1834. Dance, De la Phlebite, &c.
Archiv. de Med. Paris, 1828. Davis, Med. Chir.
Tr. Lond. 1823. Frank, De Plilebitide. Prax. Med.
Univ., Taurin. 1825. Hasse, Pathological Anatomy.
Syd. Soc. Translation, Lond. 1816. Hodgson, Trea-
tise on Dis. of Arteries and Veins. Lond. 1815.
Hunter, On the Inflammation of Veins, Ed. Med.
Comment., Edin. 1775 ; and Obs. on the Inflamma-
tion of the Internal Coats of Veins, Med. Chir. Tr.,
Lond. 1793. Langsvert, Theoria de Arter. et Yen.
Affect. Prag. 1764. Lee, Diseases of the Veins.
Cyc. of Med., Lond. 1834. Lee (Henry), On Phlebitis
and Purulent Deposits. Lond. 1856. Longuet, Sur
rinflammation des Veines. Paris, 1815. Phoebus, De
Concrementis Venarum Osseis et Calculosis. Berol.
1832. Puchelt, Der Venensystem, &e. Lips. 1818.
Ribes, Expose des Rech. sur la Phlebite. Rev.
Med., Paris, 1825.

(.S'. James LI. Salter.)

VENOUS SYSTEM (in descriptive hu-
man anatomy). — Under this head it is in-
tended to give a connected and concise ac-
count of the descriptive anatomy of the several
elements of the venous system, referring the
reader to those articles which treat of the
regional anatomy of the body, in which will

be found the application of the subject in its
practical bearings, in so far at least as the
large venous trunks are concerned.

The veins connect the capillary vessels with
the heart, one of their functions being, to
bring back to the central organ of the cir-
culation the blood which has been distributed
over all parts of the body: they are naturally
divided into two classes.

1. The veins which concur to form the two
vence cavce, and which thus communicate with
the right auricle of the heart ; these constitute
the systemic venous system: and

2. The veins which commence in the ca-
pillaries of the lungs, and finally discharge
their contents into the left auricle : these re-
present the pulmonary venous system.

These two classes of veins differ from each
other in the nature of their contents, no less
than in their modes of termination, for whilst
the systemic veins contain dark-coloured, and
essentially venous blood, the office of the
pulmonary veins is to convey red or arterial
blood from the pulmonary capillaries, where
it has been re-oxygenated, to the left auricle
of the heart. Valves are not found in the
veins of the pulmonary system, whilst they
are very abundant in many of the systemic
veins.

The cardiac veins constitute a small system
apart from that of the general venous system,
for not having any communication with the
venae cava? or with any of their branches, these
veins open by a separate orifice into the right
auricle of the heart.

Neither can the portal veins be included in
any general description of the venous system.
These veins emanate from the stomach, in-
testines, spleen, and pancreas, and unite to
form one large vessel, the vena portce, which
entering the liver, branches out in every di-
rection through that organ after the manner
of an artery, and thus constitutes the system
of the vena piortre.

From the capillaries of the portal vein in
the liver, another series of veins is derived,
which coalesce and form larger and larger
trunks, like the systemic veins generally, and
ultimately, to the number of three or four,
issue from the liver at its thick margin, and
join the inferior vena cava. These last-men-
tioned veins are termed hepatic veins, or venae
cavre hepaticas, and the function to which they
are subservient in the economy^ is that of re-
conveying into the general venous system, the
blood which has been diverted to the liver by
the ramifications of the portal vein.

1. The Pulmonary Veins.

These veins commence in the capillaries
of the pulmonary lobules, and by successive
junctions with adjacent branches enlarge in
size, whilst they diminish in number. They
traverse the lungs in company with the sub-
divisions of the bronchial tubes and of the pul-
monary arteries, the number of venous rami-
fications being identical withthatof the arterial,
and finally emerge from those organs, having
formed into trunks, each of which corresponds

1104.

VENOUS SYSTEM.

to a lobe of the lungs. There are consequently
three venous trunks for the right lung, and
two for the left. On the right side the branch
from the middle lobe unites with that from
the superior; and hence two pulmonary veins,
one superior to the other, are usually found in
the root of each lung, where on both sides
they are placed below but on a plane anterior
to the pulmonary artery and bronchial tube.
In the substance of the lungs the relative po-
sition of these parts is different, for there the
branches of the veins are behind, whilst those
of the artery are in front, the bronchus being
interposed between both.

The four pulmonary veins then perforate
the pericardium, and after a short course enter
the most posterior part of the left auricle,
those of the left side opening very close to-
gether, and not unfrequently by a common
orifice.

Within the pericardium these veins are in-
vested by its serous membrane, but on their
anterior surfaces only. In passing to their
destination, the right pulmonary veins lie
behind the right auricle of the heart.

II. The Systemic Veins.

The veins of this system will be described
in the following order.

a. The veins which form the vena cava
superior , and which are derived from the head,
face, neck, thorax, and upper extremities.

Amonst these the veins of the parieties of
the thorax (azygos veins'), and those of the
spinal column ( rachidian veins), are remarkable
as serving to connect the branches of the
superior with those of the inferior vena cava.

n. The veins which form the vena cava
inferior, and which convey the blood from the
lower extremities and from the pelvic and
abdominal cavities. The portal veins are an
adjunct to this system.

c. The proper veins of the heart ( cardiac
veins), which arise in the substance of that
organ, and open by a separate trunk into the
right auricle.

A. Tiie Veins which form the Vena
Cava Superior.

These are constituted by the veins, 1. Of
the head and face ; 2. Of the neck ; 3. OJ the
upper extremities ; 4. Of the thorax.

I . Veins of the head and face. * — The super-
ficial veins of the head and face unite to form
three principal trunks, which are placed on the
anterior, lateral, and posterior aspects of the
cranium ; anteriorly is seen the

Facial vein. — This vein originates in the

* The veins of the head may he divided into two
sets, those which ramify on its exterior and those
which occupy its interior ; the former will alone be
noticed in this place. The latter, which are repre-
sented by the cerebral veins and sinuses of the dura
mater, are described in Article Nervous Centres
(Dr. Todd), Yol. III. G31. Intermediate to these
two systems are the veins of the bones of the head
(the diploic veins), which, by their inosculations
with both, maintain a free communication between
the superficial and deeper seated veins. For a de-
scription of the diploic veins, see Art. Bone,
Yol. I. p. 436.

frontal region from numerous interlacing
branches, which usually give rise to one
large vein on each side (frontal vein), which is
joined by branches from the upper lid ( palpe-
bral') and root of the nose, and by the supra-
orbital vein ; sometimes there is but one frontal
vein placed in the mesial line, and dividing
into two branches, which descend one on
either side of the nose. The frontal vein
continues its course in the sulcus along the
inner margin of the orbit under the name of
angular vein, accompanying the artery of the
same name, and receives numerous branches
from the orbit, by which a close connexion
is maintained between the circulation on the
exterior of the cranium and that of the cere-
brum itself. At the lower margin of the orbit
the angular becomes the proper facial vein,
which passes downwards and outwards in an
almost direct course to the anterior edge of
the insertion of the masseter muscle.

The facial vein consequently has a much
shorter extent than its corresponding artery,
to the outer side of which it is invariably
placed ; it passes beneath the zygomatic mus-
cles, and lies on Steno’s duct, just where the
latter is about to penetrate between the fibres
of the buccinator muscle.

The facial vein receives the following branches.
Veins from the ate nasi, the coronary, buccal,
infra-orbital, and masseteric veins ; and also
several large communicating veins ( deep facial
or alveolar) from a venous plexus which is
lodged in the pterygoid space.

Having passed below the ramus of the jaw,
the facial vein enters the digastric space, which
it traverses from above downwards and back-
wards, and lies beneath the platysma myoides
and on the submaxillary gland (which con-
sequently is interposed between the facial vein
and artery) ; this vein next passes across the
external carotid artery to terminate in the
internal jugular vein, having been previously
joined by a large branch of communication
from the temporo-maxillary vein. In its
course through the digastric space the facial
vein receives (a), the ranine vein, which conics
from the inferior surface of the tongue, passes
backwards by the side of the fraenum, and
accompanies the hypoglossal nerve, between
the m)lo-hyoid and hyo-glossus muscles;
(b) , the satellite vein of the gustatory nerve,
which is derived from a plexus of superficial
veins on the dorsum of the tongue, and com-
municates freely with the preceding ( Cruvtil -
hier); (c), the submental vein, which arises in
the sublingual gland; and (d) several palatine
veins which are derived from a venous plexus
encircling the tonsil.

In many instances the facial vein unites
witli the proper lingual veins, and thus forms
a common trunk, which throws itself into the
internal jugular ; into this common trunk the
superior th_\roid, pharyngeal, and temporo-
maxillary veins, will in such a case be fre-
quently found to open.

On the lateral region of the head are placed
the trunks of the temporal and internal max-
illary veins.

VENOUS SYSTEM.

1405

The temporal vein is formed by the union of
two branches, which represent the superficial
and middle temporal arteries.

The superficial temporal veins form a wide-
spreading network of vessels on the lateral
aspect of the scalp, which communicates with
the frontal veins in front, with the occipital
behind, and with the temporal veins of the
opposite side across the vertex.

The middle temporal veins arise in the sub-
stance of the temporal muscle, where they
are joined, behind the external orbital process,
by branches from the orbit : these veins, by
their union, form a branch which is placed at
first between the temporal muscle and fascia,
but subsequently perforates the latter imme-
diately above the zygoma, and forms with the
superficial temporal vein a common trunk,
which enters the parotid gland, and unites
with the internal maxillary vein.

Internal maxillary vein. — In the pterygoid
space the branches of veins which correspond
to those given off’ in the same region by the
internal maxillary artery, viz. the inferior dental,
deep temporal, pterygoid, and (according to
Cruveilhier) the middle meningeal veins (pence
comites to the midtile meningeal artery, which
communicate in the cranium with the inferior
cerebral veins), unite to form a great venous
plexus placed between the pterygoid muscles,
which communicates freely, as has been men-
tioned, with the facial vein. Arising from
this plexus, the internal maxillary vein passes
backwards along with its artery, between the
ramus of the jaw and the internal lateral liga-
ment of the temporo-maxillary articulation,
and entering the parotid gland joins the tem-
poral vein ; by the union of these branches the
external jugular vein is formed. Many ana-
tomists give to the upper portion of the venous
trunk, formed in the manner which has just
been described, the name of temporo-max-
illary vein, by others it is designated posterior
facial, names which are applied to it until it
has emerged from the parotid gland, where,
according to these authorities, the proper
external jugular vein commences.

The temporo-maxillary vein (or that stage
of the external jugular vein which is contained
in the parotid gland) is joined by the branches
which accompany the transverse facial and
posterior aural arteries, and sends off' a large
communicating branch, which unites with the
facial vein.

The temporo-maxillary vein is situated more
superficially than the external carotid artery,
which it separates from the plexiform rami-
fications of the portio dura nerve.

On the posterior region of the head is found
the occipital vein. The ramifications of this
vein are spread over the posterior portion of
the scalp, and correspond very accurately to
the terminal branches of the occipital artery ;
the trunk which they form likewise accom-
panies that of the artery, passes with it beneath
the splenius and sterno-mastoid muscles, and
joins the internal jugular vein below the di-
gastric muscle ; less frequently it unites with
the external jugular vein. Opposite the mastoid

process, the occipital vein is joined by several
branches from the mastoid region, one of
which passes through a canal in the bone
(mastoid hole), and communicates directly
with the lateral sinus of the dura mater.

2. Veins of the neck. — The most remarkable
of these are the internal and external jugular,
and the vertebral veins.

External jugular vein. — This vessel is the
principal channel of the supcificial venous
circulation of the neck. Its direction is down-
wards and slightly outwards, and it extends
from the lower margin of the parotid gland to
the subclavian vein. Crossing the sterno-mas-
toid obliquely, the external jugular vein de-
scends parallel to the posterior edge of that
muscle, through the supra-clavicular space, and
lies on the deep cervical fascia, by which it is
separated from the omohyoid muscle, bra-
chial plexus, and subclavian artery. Finally,
the vein passes forwards through an opening
in the fascia cervicalis, and joins the subcla-
vian vein. Several of the nerves of the cer-
vical plexus are related to this vein ; many
of their branches cross it as they descend the
neck-; and the largest of the three ascending
branches of the plexus, the nervus auricularis
magnus, is parallel to the vein and to its outer
side, as it lies on the sterno-mastoid muscle.

Throughout the entire of its extent the ex-
ternal jugular vein is covered by the fibres of
the platysma myoides, which cross its direc-
tion obliquely forwards and inwards. This
vein is furnished with two sets of valves, one
of which is placed at its entrance into the sub-
clavian vein, and by this circumstance the ex-
ternal jugular is distinguished from all other
veins of the head 'or neck, in none of w hich
are valves found to exist.

The branches which the external jugular
vein receives are the following : first, several
large veins from the posterior region of the neck ;
one of these, which from its superior size, and
also from its position, may be distinguished by
the name of posterior jugular vein, descends
from beneath the trapezius muscle, through
the postero-superior triangle of the neck, and
joins the external jugular vein a little below
its centre. Lower down this latter vein re-
ceives, secondly, the “ venae comites” of the
superior and posterior scapular arteries. By
its anterior surface the external jugular vein
receives; thirdly, muscular branches ; fourthly,
a communicating branch, which passes be-
neath the sterno-mastoid muscle, and joins
the internal jugular vein ; and sometimes,
fifthly, the anterior jugular vein.

Anterior jugular vein. — This vein is but
seldom absent, although its size is subject to
much variety ; in general its development is
inversely as that of the external jugular
trunk, to which it is to be regarded as sup-
plemental. The branches of origin of the
anterior jugular vein are derived from several
small muscular and cutaneous veins of the
supra hyoid region, which generally communi-
cates with the facial veins. Thus formed, this
vein passes down by the side of the larynx
along the anterior margin of the sterno-

HOG

VENOUS SYSTEM.

mastoid muscle, beneath which it passes, a
little above the clavicle, to join the internal
jugular vein, close to the junction of the latter
with the subclavian vein.

The anterior jugular vein, in its course down
the neck, communicates freely with the inter-
nal and external jugular veins, and sometimes
terminates by opening into the latter.

It receives branches from the larynx, and
sometimes from the thyroid gland.

Not unfrequently the veins of opposite sides
are connected by a transverse b aneh, which
crosses the trachea immediately above the
sternum, and receives the terminations of some
of the inferior thyroid veins, and of one or
two subcutaneous veins from the thorax.

Internal jugular vein. — The blood which
has circulated through the brain and sinuses
of the dura mater, is returned by the great
lateral sinus to the internal jugular vein,
which extends from the posterior part of the
foramen lacerum posterius, to the root of the
neck, where on each side it forms the vena in-
nominata, by its union with the subclavian vein.

Its direction is strictly vertical.

At its commencement this vein presents an
oval dilatation (sinus, or gulph of the internal
jugular vein), which is lodged in the jugular
fossa, and into which the inferior petrosal sinus
of the dura mater opens. The internal ju-
gular vein is placed posterior, and external, to
the internal carotid artery, (the lingual, glosso-
pharyngeal, and pneumogastric nerves inter-
vening,) and rests upon the anterior surface of
the rectus capitis lateralis muscle ; but as the
vein is traced downwards, it will be found, a
little below the base of the skull, to lie parallel
with, and to the outer side of, the internal
carotid; the spinal accessory nerve here de-
scends upon the anterior surface of the vein.
Subsequently, the internal jugular vein enters
the sheath of the common carotid artery,
along with the vagus nerve, and preserves the
same relative position to that great vessel as
it did to its internal branch. At the root of
the neck the vein of the right side intersects,
at right angles, the front of the first stage of
the subclavian artery ; on the left side, the
vein, whilst it is anterior, is at the same time
parallel, to the thoracic stages of the sub-
clavian and carotid arteries.

Collateral branches of the internal jugular
vein. — Opposite the cornu of the os hyoides,the
internal jugular vein isjoined by (a) the facial
vein, and sometimes by (b) a large communi-
cating branch from the temporo-maxillary vein,
by which its size is sensibly augmented ; above
the os hyoides, it receives (c) the pharyngeal
vein, derived from a venous plexus on the sides
and back of the phanynx; (d), the proper lin-
gual veins, two in number, “ venae comites ”
of the lingual artery, the course of which they
accurately follow : the lingual veins, as has
been already stated, sometimes form a trunk
of considerable size, by uniting with the facial
vein * ; and (e), the occipital vein, wdiich has

* In considering the distribution of the veins of
the tongue, it may be observed that there are two

been described in the preceding page. Below
the level of the os hyoides, the internal jugular
vein receives (f) a laryngeal branch, which
escapes from the larynx through an opening
in the thyro-hyoid membrane ; (g), the supe-
rior thyroid veins, “ vena? comites ” of the
superior thyroid artery, and which emanate
from the superficial and upper portions of the
thyroid gland : these occasionally terminate
in the anterior jugular vein, or in the common
trunk of the facial and lingual veins when it is
present ; and (h) the middle thyroid veins,
which pass out from the lower part of the
lateral lobe of the gland, and join the most
inferior portion of the internal jugular vein.

The vertebral vein. — The vertebral vein
arises by muscular branches, which are
deeply placed at the base of the skull, in the
vicinity of the foramen magnum, and first
exists as a distinct trunk in the foramen of

the transverse process of the atlas, where it is
joined by two communicating branches, one
of which passes through the posterior condy-
loid foramen, and opens into the great lateral
sinus, whilst the other is derived from the oc-
cipital vein.

The course and relations of the vertebral
vein, from this to its termination, are iden-
tical with those of the cervical stage of its
corresponding artery, which it accompanies
through the foramina in the transverse pro-
cesses of the cervical vertebrae. On issuing
from the foramen of the sixth vertebra, it is
joined by the veins which accompany the ar-
teria cervicalis profunda and the arteria cer-
vicalis superficialis. Lastly, the vertebral vein
usually passes behind the subclavian artery on
the right side, and in front of that vessel, on
the left side, to terminate in the vena inno-
minate. Sometimes, though rarely, the ver-
tebral ends in the internal jugular vein.*

The vertebral veins anastomose very freely
with the spinal veins, as well with those which
are within the spinal canal, as with those
which are external to the vertebrae, by means
of small branches which enter the foramina,
by which the cervical spinal nerves issue.

3. Veins of the upper extremity. — These
veins are arranged in two series, a sitpcrfcialmd
a deep; both of which are provided with valves,
but the deep veins the most abundantly.

Superficial Veins. — In the fore-arm and
hand these veins are distributed with great
minuteness in the subcutaneous areolar tissue,
and anastomose freely with one another;
but their larger branches chiefly occupy the
radial and idnar (the lateral) aspects of the
fore-arm.

The radial or external superficial veins ema-
nate from numerous venules on the thumb
and dorsum of the fore-finger, and are joined

superficial or submucous veins, (the ranine vein, and
the satellite vein of the gustatory nerve') correspond-
ing to the subcutaneous veins in the limbs, by which
the blood is returned when the deep veins (proper
lingual) are compressed during the contractions of
the organ.

* Vide Art. Subclavian Arteby, Vol. IV.
pp. 815. and 822.

VENOUS SYSTEM.

1407

in the fore-arm by many cutaneous branches
from either side. Opposite the elbow joint
these tributaries have ended in one vessel of
considerable size, the cephalic vein, which,
being joined by a branch from the median
vein ( median cephalic), ascends between the
biceps and supinator longus muscles, follows
the outer margin of the biceps, traverses the
interspace between the pectoralis major and
the deltoid, and ultimately having arrived in
the subclavicular triangle, bends over the
upper edge of the pectoralis minor, penetrates
the thin expansion of the “fascia elavicularis”

( 'ligamentum bicorne), and enters the axillary
vein immediately beneath the clavicle. In
some instances a branch is continued upwards
from the cephalic vein, which passes over the
clavicle and communicates with the external
jugular vein.

The ulnar or internal superficial veins have
their origins from veins which ramify on the
dorsum of the hand anil of the two inner
fingers, one of which from the little finger has
been long known as the “ vena salvalella
others arise anteriorly from subcutaneous
veins on the front of the wrist. In the vici-
nity of the elbow both sets of branches unite
to form one principal trunk, the basilic vein,
which is reinforced almost at the moment of
its formation by the median basilic vein, a
branch of very considerable size from the
median.

The basilic vein, now much enlarged, as-
cends along the inner margin of the biceps
muscle, parallel to the brachial artery, but
more superficially than that vessel, (for the
deep fascia intervenes,) until it arrives oppo-
site the centre of the arm, when it pierces
the brachial aponeurosis, and joins one or
other of the vence comites of the brachial
artery. In a few instances the vein ascends
as high as the axilla, and entering that space
joins the trunk of the axillary vein. The
superficial veins in the front of the upper part
of the fore-arm unite to form a short trunk
termed median vein, which by its lateral
branches connects the radial and ulnar super-
ficial veins ; near the bend of the elbow the
median vein receives a large communicating
branch from the vena; comites of the brachial
artery, and terminates by dividing into two
very considerable veins, termed median basilic
and median cephalic veins respectively : the.
latter passes obliquely upwards and outwards,
over the tendon of the biceps, and joins the
cephalic vein ; the former, which is the
largest, inclines inwards, and in its course to
join the basilic trunk passes across the bra-
chial artery, separated from it only by the
“ semilunar fascia” of the biceps tendon.

The deep veins of the upper extremity ac-
company the ramifications of the larger arteries
chiefly, which in the lower as well as in the
•upper extremity, are invariably attended by
two veins, one on either side, hence called
vence comites; transverse branches at short
intervals maintain a free communication
between these vessels.

The vence comites of the ulmar artery are de-

rived from veins which correspond to the di-
gital arteries, and which form a superficial
palmar arch of veins, which at its outer ex-
tremity receives branches from the deep radial
veins, through which the venae comites of the
radial and ulnar arteries are brought into com-
munication with each other. The associate
veins of the interosseous artery unite with the
vena comites of the ulnar artery.

The vence comites of the radial artery com-
mence from the palmar interosseal veins, which
form a deep palmar arch across the heads of
the metacarpal bones, and are joined by veins
from the muscles of the thumb, and by branches
of the superficial arch which follow’ the course
of the arteria superficialis volae. The vena;
comites of both the radial and ulnar arteries
receive numerous tributaries from the veins
of the adjacent muscles, and ultimately unite
to form the

Satellite veins of the brachial artery. —
The brachial venae comites are joined by
veins which correspond to the branches
of the brachial artery in the arm (superior
and inferior profunda and anastomotica
magna), and aEo by the basilic vein. At
the lower part of the axilla, these veins, by
their union, form the axillary vein.

The axillary vein returns all the blood from
the upper limb : it is formed by the union of
the brachial venae comites (with one or other
of which, in the arm, the basilic vein is con-
tinuous), whilst the cephalic vein joins it near
its termination. Like its accompanying artery,
the axillary vein consists of three stages, and
its relations to surrounding parts are identical
with those of that vessel. The vein is placed
internal and anterior to the artery throughout
its entire course. When the arm is abducted,
the vein becomes inferior.

In addition to the cephalic vein, the axil-
lary trunk receives numerous branches which
correspond to those of the axillary artery,
viz., the circumflex and subscapular veins, the
alar, and the long, superior, and acromial
thoracic veins.

The axillary is the last vein of the upper
extremity, as we approach the heart, in which
valves exist : at the lower edge of the first
rib it becomes continuous with the subcla-
vian vein.

Subclavian vein.- — This great vessel extends
from the axillary vein to the inner margin of the
scalenus anticus muscle, where it unites^vvith
the internal jugular vein, to form the vena
innominata. The subclavian vein therefore
corresponds to the second and third stages
only of the subclavian artery ; and, as the
direction of the vein is nearly transverse,
whilst that of the artery describes an arch, it
necessarily follows that the former vessel is
much shorter than the latter. On both sides
of the neck the scalenus anticus muscle, and
the phrenic and pneumogastric nerves, are,
interposed between these associated vessels.
The subclavian vein is related anteriorly to
the subclavius and sterno-mastoid muscles, to
the clavicle, supra-scapular artery, platysma,
and superficial structures of the neck, and

1+08

VENOUS SYSTEM.

rests upon the first rib, the scaleni muscles,
and the phrenic nerve, which descends be-
tween the vein and the scalenus anticus mus-
cle. Contrary to what is observed in the
case of the axillary and of most other veins
of large size, the branches which join the
subclavian vein do not correspond to those
which are given off by the subclavian artery.
The collateral branches of the subclavian vein,
are the external and internal jugular veins ;
the former joins it on the outer, anti the latter
on the inner side of the sterno-mastoid mus-
cle. The subclavian vein not uncommonly
receives the vertebral also, although, as has
been stated, this vein is most frequently a
tributary of the brachio-cephalic trunk.

Brachio- cephalic veins. ( Vena innominatee,
Meckel.) — These veins, one on each side,
are formed by the union of the internal jugu-
lar with the subclavian vein ; they are appa-
rently of the same size, but are contrasted in
other essential particulars, as they are ex-
amined on the right and left side : thus they
will be found to differ from each other in
length and in direction, as well as in their
connexions with surrounding parts, as also in
the number of collateral branches which they
respectively receive.

The right vena innominata is comparatively
short, and nearly vertical in direction ; it is
placed behind the cartilage of the first rib,
and is related externally to the right pleura
and internally to its corresponding artery, the
arteria innominata ; the vein and artery how-
ever are not in close apposition, and the right
pneumogastric nerve is found in the interval
between them, but deeper than both ; fila-
ments of the cardiac nerves also are inter-
posed between them.*

The left vena innominata, more than twice
as long as the preceding, traverses the upper
part of the anterior mediastinum almost hori-
zontally from left to right, but at the same
time with an obliquity downwards and slightly
forwards. It is placed behind the first bone
of the sternum, from which it is separated by
the sterno-hyoid and sterno-thyroid muscles,
and by the thymus gland ; and bending across
the three primary branches of the aorta,
slightly overlaps the anterior surface of the
arch itself towards the right side. Imme-
diately below the cartilage of the first rib and
on the right side of the mesian line, the
innominate veins unite to form the superior
vena cava.

Collateral branches. — The vertebral is in
general the only vein which terminates in the
right vena innominata, for although it does
occasionally occur that the inferior thyroid
and internal mammary veins join the vena in-
nominata on their respective sides, yet in the
great majority of instances these veins ter-
minate differently on the right and left side :
on the left they almost invariably open into

* At the moment of its formation the right vena
innominata is placed anterior, and inferior, to the
first stage of the subclavian artery ; between them,
however, we find the mammary artery, and the
phrenic and pneumogastric nerves.

the corresponding vena innominata, whilst on
the right they as constantly open into the
vena cava superior. It is not very uncom-
mon for the left vena innominata to receive
all the inferior thyroid veins ; and the left
superior intercostal vein, which is usually
connected by a large collateral branch with
this vein, sometimes, but more rarely, termi-
nates directly in that vessel.

Inferior thyroid veins. — Although generally
described as consisting of two principal trunks,
one for each side, these veins very often con-
sist of as many as four or more branches,
which, arising from a plexus of veins in the
interior of the thyroid gland, emerge from its
lower bonier and descend on the (font of the
trachea, covered by the deep layer of fascia
and bv the infra-hyoid muscles, to open into
the left vena innominata. These veins lie in
a well-defined triangular space of much sur-
gical importance, which is bounded on the
one side by the innominata, and on the other
by the left carotid artery', whilst its third
side, which represents the base of the triangle,
is defined by the lower margin of the thyroid
body : the apex is constituted by the con-
vergence of the arteries which form its sides,
to the arch of the aorta ; and in this latter
direction, the space above described is some-
what encroached on by the left vena inno-
minata. Sometimes the thyroid veins of op-
posite sides unite to form an arch across the
trachea, ami in some few instances they open
into the transverse branch of communication
which sometimes unites the anterior jugular
veins of opposite sides.

Internal mammary veins. — These, which
constitute “venae comites” to the trunk of
each internal mammary artery, are formed by
branches which correspond with those which
emanate from that vessel. Very frequently
the two vessels unite in a single trunk, which
ends, as has been stated, in the vena inno-
minata on the left side, and in the vena cava
on the right.

Vena cava superior. — This great vein re-
ceives all the blood from the head and neck,
and from the upper extremities ; it is formed
by the union of the two brachio-cephabc
veins, and extends from the lower margin of
the cartilage of the first rib on the right of
the sternum, to the upper and posterior part
of the right auricle of the heart where it
terminates. Shortly after its formation, the
superior vena cava enters the pericardium
That portion of the vein which is without the
pericardium (and which is of very small extent)
is invested by a sheath of the fibrous layer
of that membrane, whilst its intra-pericardial
stage is completely invested by the serous
membrane, which it serves to convey to the
surface of the heart. In its entire course this
vein describes a curve, the convexity of which
is related to the right pleura with the inter-
vention of the pericardium, whilst the con-
cavity touches the aorta ; the pericardium is
anterior to it, and the pulmonary artery of
the right side passes behind it. The principal
collateral branch of the thoracic vena cava is

VENOUS SYSTEM.

1409

the great azygos vein, which joins that trunk
at the moment of its entrance into the cavity
of the pericardium.

Azygos veins.* — The azygos veins and their
tributaries (which are described by Cruveil-
hier amongst the superficial rachidian veins)
constitute a remarkable system which is of
great importance, as it assists in maintaining
the circulation through the spinal system of
veins, and at the same time connects the
branches of the superior with those of the
inferior vena cava.

The veins of the azygos system usually
consist of three principal trunks, the greater
and lesser azygos veins, and the left superior
intercostal vein.

The vena azygos major commences in the
lumbar region, by the union of several branches
from the upper lumbar veins, through which it
communicates with the inferior vena cava.
Sometimes the azygos vein receives a branch
directly from that vessel, and frequently another
from the renal vein.

After a very short stage in the abdomen,
the great azygos vein enters the thorax through
the aortic canal in the diaphragm, and ascends
on the vertebral column to the right of the
aorta, from which it is separated by the
thoracic duct. Having arrived at the third
dorsal vertebra, the vein now changes its di-
rection, and passing forwards and to the right
side, leaves the posterior mediastinum, arches
over the right bronchus, and descends to ter-
minate in the superior vena cava, where that
vessel is about to enter the pericardium.

The vena azygos major is joined by all the
intercostal veins of the right side, and by the
lesser azygos vein, through the medium of
which it communicates with the lower inter-
costal veins of the left side also. Two or
three of the middle intercostal veins of the
left side open directly into the great azygos
vein, it likewise communicates very freely with
the left superior intercostal vein.

The lesser azygos vein (or left or inferior
azygos vein), likewise has its origin in the
lumbar region, from some of the upper lnmbar
veins on the left side of the spine ; it anas-
tomoses with the neighbouring veins which
ramify on the surface of the vertebrae, and is
connected, more frequently even than the
greater azygos vein, with the corresponding
renal vein (Breschet). The lesser azygos
vein enters the thorax, either through the
aortic canal in the diaphragm, or by per-
forating its left crus along with the left
splanchnic nerve, ascends on the left side of
the spine, as high as the fifth or sixth dorsal
vertebra, where, crossing the front of the
spinal column, behind the aorta, to terminate
in the great azygos vein.

The veins from the five or six lower inter-

* As these veins have already been described in
an article specially devoted to the subject, they are
but briefly noticed in this place, and only in so far
as was necessary to carry out the design of giving-
a continuous description of the elements of the
venous system. Vide Art, Azygos (Dr. Harrison),
Vol. I. p. 3G4.

von. iv.

costal spaces terminate in this vessel. In
some instances there is no venous trunk cor-
responding to that above described, in which
case the left intercostal veins cross the spinal
column behind the thoracic aorta, to join the
great vein of the right side, which, under
these circumstances only, is appropriately
termed “ azygos.”

The left superior intercostal vein (left supe-
rior azygos vein) is formed by the union of the
three or four superior intercostal veins of the
left side. Its course is subject to some variety',
but it always serves to establish a connexion
between the azygos system and the deep veins
of the neck. In many instances this vein
passes upwards, and opens into the left vena
innominata, but more frequently it descends,
increasing in size as it approaches its termi-
nation in the great azygos vein. Sometimes
the left superior intercostal vein terminates in
the azygos minor.

There is sometimes a similar branch on the
right side, which corresponds to the right su-
perior intercostal artery ; this vein is always
inferior in size to that of the left side, and,
like it, terminates in the great azygos vein.

The bronchial veins are the “ venre comites ”
of the bronchial arteries, from the capillaries
of which they are derived, and which they'
accompany throughout the lungs. They leave
the root of the lung, having formed into two
or three trunks, and terminate, on the right
side, in the superior vena cava, or in the great
azy'gos vein, and on the left side in the left
superior intercostal vein, or in the azygos
minor.

In the pelvis the middle and lateral sacral
veins represent the azygos system ; they com-
municate freely with the veins in the sacral
canal, and with the vesical and haemorrhoidal
plexuses, and end in the common iliac veins.
The sacral veins thus establish a communi-
cation between the general venous system and
the system of the vena portae.

There are no valves in the azy'gos veins,
although they exist in great numbers in their
tributaries, the intercostal veins.

Veins of the spine.* ( Rachidian veins:

Breschet.) — These veins, imperfectly know'll
to Chaussier, were first accurately described
byDupuytren and Breschet f ; they have been
comprehensively' arranged by' Cruveilhier, who
includes, under the head of spinal veins, a
larger portion of the venous system than the
author first quoted. By Cruveilhier the veins
of the spinal system are divided into — -A. The
superficial or extra-spinal, and B., the deep or
intra-spinal veins.

A. The superficial veins of the spine are sub-
divided into the anterior and the posterior.

* Sudi of the veins of the spine as are situated in
the interior of the spinal canal, are described in the
Article Nekvotjs System (Dr. Todd), at page 629,
Vol. III. of this -work; any other than a brief
notice of the subject in this place is, therefore, un-
necessary.

t Essai sur les Veines du Raehis, 4to. Re-
cherches Anatomiques sur le Systhme Veineux, fol.
avec Planches.

4 x

H 10

VENOUS SYSTEM.

1. The anterior superficial spinal {or rachi-
dian) veins, include, according to this au-
thority, the vena azygos major, the vena azygos
minor, the trunk of the right and left superior
intercostal veins, the lumbar and ilio-lunibar
veins, and the lateral and middle sacral veins.

2. The posterior superficial spinal veins,
“ form an exceedingly complicated network,
the meshes of which surround the spinous
processes and lamina;, and the transverse and
articular processes of all the vertebrae.”

B. 'The deep or intra-spinal veins comprise
the following : —

1 . The veins of the bodies of the vertebrae ;

2. The great anterior longitudinal veins or
sinuses (Willis) ;

3. The posterior spinal veins and plexuses;
all these are external to the “ theca verte-
bralis and

4. The veins of the spinal cord itself ; in-
ternal to the theca vertebralis.

Superficial spinal veins. — The anterior super-
ficial spinal veins have been already described
as constituting a part of the azygos system.

The posterior superficial spinal veins (the
dorsi-spinal veins of Dupuytren and Breschet)
are derived from the muscles which fill the
vertebral grooves, and thus cover the laminae
and the spinous and transverse processes with
a series of anastomosing vessels. In the neck
they form a complicated plexus, from which
proceed two large veins ( posterior jugular,
Cruveilhier), which communicate freely with
the vertebral veins, and join the vense in-
nominatae.

From the numerous venous circles and
plexuses formed by the “ dorsi-spinal ” veins,
communicating branches are given off, which
perforate the ligamenta subflava, or pass
through the intervertebral foramina, and unite
freely with the deep spinal veins.

Deep spinal veins. — 1 . Veins of the bodies
of the vertebra: ( veines basi-vertebrales, Bres-
chet), [vide Fig. 36 1 . Vol. III. p. 630.], are
contained in bony canals in the bodies of all
the vertebra;, and are analogous to the diploic
veins of the cranium. The basi-vertebral
veins originate in the canallated tissue of the
bone, and form larger trunks, which converge
towards the posterior surfaces of the bodies
of the vertebrae, where the orifices of the
bony canals in which they are contained are
very apparent ; on emerging from the vertebrae
these veins form a plexus ( transverse plexus )
interposed between the bones and the pos-
terior common ligament of the spine, and
from which veins pass laterally to terminate
in the anterior longitudinal sinuses. Some of
the smaller venous canals pass forwards to
open on the anterior surface of the vertebral
column, where they anastomose with the su-
perficial veins.

2. The anterior longitudinal sinuses, Willis ;
(grandcs veines rachidiennes longitudinales an-
terieures, Breschet), [vide Fig. 360. p. 630.]
— These extend the entire length of the ver-
tebral column, under the form of two longi-
tudinal veins situated within the spinal canal,
along the external margins of the posterior

common ligament, and consequently between
the bodies of the vertebra; and the dura
mater, (hence sometimes termed meningo-
rachidian veins). Opposite every vertebra
these longitudinal vessels are connected to
each other by the transverse plexus of the
basi-vertebral veins, whilst externally they
communicate, by means of branches which
pass through the series of intervertebral fora-
mina, with the numerous veins which ramify
on the exterior of the spinal column, viz., the
vertebral, azygos, intercostal, lumbar, sacral,
&c. These longitudinal venous channels are
neither parallel to each other, nor are they of
uniform dimensions ; opposite the bodies of
the vertebras they are most closely approxi-
mated, whilst corresponding to the interver-
tebral foramina they are widely separated, as
if drawn outwards by the branches winch are
here connected with them. Each longitudinal
sinus, or “ venus plexus,” (for occasionally
two or more veins enter into the formation of
these channels on each side,) might therefore
be described as formed of “ a series of plexi-
form arches, which embrace the pedicles of
each vertebra, have their concavity directed
outwards and their convexity inwards, and
the extremities of which anastomose together
opposite the intervertebral foramina, where
they communicate with the branches on the
outside of the spine.”* According to Bres-
chet, interruptions occasionally occur in dif-
ferent parts of these longitudinal channels, a
circumstance which still further authorises
this description, in which each venous arch is
regarded as a separate trunk, communicating
with its fellows of the opposite side, and also
with similar branches above and below.

3. The posterior deep spinal veins (veines
longitudinales rachidiennes posterieures, Bres-
chet) are likewise situated in the interior of
the spinal canal, between the posterior sur-
face of the dura mater and the front of the
laminae. They there form a close interlace-
ment of vessels (posterior intra-spinal plexuses')
which is most remarkably developed in the
upper part of the canal. These veins and
plexuses are joined by the posterior superficial
spinal veins (dorsi-spinal veins'), and they com-
municate with the anterior longitudinal sinuses
by numerous small lateral branches.

4. The proper veins of the spinal cord ( me -
dul/i spina/es, Breschet) are small tortuous
vessels, which form an irregular plexus upon
both surfaces of the medulla spinalis between
the pia mater and the arachnoid membrane ;
they communicate through the foramen mag-
num with the petrosal sinuses or cerebellar
veins, and give of!' small branches which pass
through the foramina with the spinal nerves
to establish communications with the several
evr/ra-spinal veins. The veins of the spinal
cord are apparently the “ venae comites ” of
the proper spinal arteries.

“ The veins of the spine may be regarded, in
reference to the general circulation, as es-
tablishing an unbroken communication be-

* Cruveilhier’s Descriptive Anatomy, vol. ii.

p. 808.

VENOUS SYSTEM.

1411

tween the veins of all parts of the trunk, so
that we can suppose one of the venae cavae to
be obliterated without the venous circulation
being interrupted. The greater azygos itself,
which is generally regarded as the principal
means of conununicaiion between the two
venae cavae, is not, however, necessary, when
we consider the arrangement of the anterior
and posterior spinal plexuses. Thus, I have
sometimes seen the inferior, and sometimes
the superior vena cava, obliterated without
any apparent increase in the diameter of the
vena azygos, and, what will perhaps be thought
surprising, without oedema either of the
upper or lower extremities.

“ Supposing the vena cava ascendens to be
obstructed from the entrance of the hepatic
veins down to the renal veins, the blood
would then flow back by the lumbar veins into
the plexuses contained within the spinal canal ;
through these plexuses it would ascend to the
vertebro-costal (intercostal) veins, from thence
to the azygos veins, and through them into
the superior vena cava.

“ If all the jugular veins were obliterated,
the venous circulation in the head would still
continue, and would be carried on through
the spinal veins.” *

B. Veins which form the Inferior
Vena Cava.

The veins which unite to form the inferior
vena cava transmit the blood which is derived
from the lower extremities and from the vis-
cera of the pelvis and of the abdomen.

i. Veins of the lower extremities. — The
veins of the lower, like those of the upper
extremities, are divided into a deep and a
superficial set; they are likewise provided
with valves, which are most numerous in the
veins of the former class.

Superficial veins of the lower extremities. —
The small veins, which in great numbers
exist in the subcutaneous cellular tissue of the
dorsum of the foot, unite to form two prin-
cipal trunks termed saphenous. These are
placed, the one on the inner, and the other on
the posterior aspect of the leg.

Internal or long saphena vein. — This vein
first exists as a distinct vessel a little below
the ankle joint, in front of which it ascends
and passes along the inner surface of the leg,
at the distance of half an inch from the inner
margin of the tibia. At the knee it lies be-
hind the internal condyle, superficial to the
tendons of the sartorius, graciiis, and semi-
tendinosus muscles, and continuing to ascend
on the internal and anterior surface of the
thigh, gains the “ saphenic opening” in the
fascia lata, through which it passes backwards
to end in the femoral vein, at the distance of
about an inch below Poupart’s ligament.

In this long course the saphena vein re-
ceives many cutaneous branch , s , and also
several communicating veins from the deep
vessels. In the thigh, it is joined, near its
termination, by a large branch, which comes

Cruveilkier’s Descriptive Anatomy, vol. ii.

from the back of the limb, and by two or
three veins which are derived from the an-
terior and external surfaces of the thigh.
These latter pursue a direction upwards and
inwards, and thus cross anterior to the
femoral artery, so that they are liable to be
injured by the incisions made to expose that
artery. The trunk of the saphena vein itself
is seldom thus endangered, as it ascends on a
plane internal to the artery. Shortly before
its termination, the saphena vein is enveloped
in the meshes of the cribriform fascia, where
it is joined by three cutaneous veins from the
parieties of the abdomen, — viz. the superficial
pubic, the superficial circumflexa ilii, and the
superficial epigastric veins. When, from any
cause, the circulation through the inferior
vena cava is obstructed, those veins become
remarkably enlarged and tortuous.

The internal saphena vein is accompanied,
from the ankle to the knee, by the internal
saphena nerve. The valves , in its interior,
vary from two to six sets.

Communicating branches pass between this
vein and the deep veins of the leg and thigh ;
they are most numerous in the leg, where
they connect the saphena with the anterior
and posterior deep tibial veins.

Posterior or external saphena vein. — The
external saphena vein is formed by the union
of several branches from the outer side of the
foot, and ascends into the leg behind the
outer ankle. Inclining inwards and upwards,
it gains the centre of the back of the leg,
passes superficial to the groove between the
heads of the gastrocnemius muscle, and enters
the poplitaeal region. Opposite the line of
flexion of the knee-joint, this vein passes
through a small round opening in the popli-
taeal fascia, and joins the poplitaeal vein about
its centre. This vessel, sometimes called the
short saphena vein, is accompanied in part of
its course by the posterior saphena nerve. It
is usually furnished with two valves, which
are found near the termination of the vessel.
This vein communicates but rarely with the
deep veins of the leg.

Peep veins of the lower extremity. — In the
lower, as well as in the upper extremities, the
deep system of veins is represented by the
“ venae comites ” of the larger arteries. The
satellite veins of the posterior tibial artery are
derived from the deep plantar veins ( external
and internal). At the upper part of the leg
the posterior tibial veins are joined by the
satellite veins of the peroneal, and subse-
quently, at the lower edge of the poplitaeus
muscle, by those of the anterior tibial artery.
By the union of these is the trunk of the
poplitaeal vein formed.

The poplitceal vein. — This vein is of large
size, owing to the number and magnitude of
the branches which it receives; it is joined by
the tibial veins, by the external saphena, by the
articular, and, lastly, by muscular veins of large
size (sural) from the calf of the leg.

The poplitaeal vein is placed posterior to its
artery below, posterior and a little external to
that vessel, at the upper part of the poplitaeal
4x2

1412

VENOUS SYSTEM.

space. It is consequently situated between
the artery and the posterior tibial nerve.

The valves in this vein are four or five in
number. Its coats are stated by Cruveilhier
and others to be of more than ordinary thick-
ness.

Th e femoral vein is the continuation of the
poplitaeal, which latter vessel, having passed
through the tendinous opening in the adduc-
tor muscles, enters the thigh, and becomes
femoral. In the lower third of the thigh the
femoral vein anti artery (enclosed in a com-
mon sheath) are contained in “ Hunter's
canal,” the vein lying, as in the ham, posterior
and external to the artery. In the centre of
the thigh the vein is placed directly behind
the artery ; but throughout its upper third the
two vessels lie side by side, and in close con-
nection, the vein being the more internal.
A thin, fibrous septem derived from the sheath
which surrounds them passes backwards, and
separates these vessels at this part of their
course. The point of the aneurism needle is
apt to be entangled by this partition, in con-
veying a ligature round the femoral artery, if
care be not taken to keep the instrument on
its outer or arterial side, whilst at the same
time the sheath is kept tense. At the highest
point of its course, just where it is about to
pass beneath Poupart’s ligament, the femoral
vein constitutes the external boundary of
the crural ring, and would therefore neces-
sarily bear the same relation to the neck of
any hernial tumour which may have descended
through this aperture. In its course through
the thigh, the femoral vein is joined by nu-
merous muscular branches, also by the profunda
vein, about an inch and a half below the
crural arch, and, lastly, by the internal saphena
vein.

Its valves are from three to five in number.

Beneath Poupart’s ligament the femoral
becomes continuous with the external iliac
vein.

The external iliac vein, whilst it accom-
panies the external iliac artery, and holds the
same relation to surrounding parts as that
vessel, is nevertheless differently related to
its artery on the right and left side. As these
vessels lie on the horizontal ramus of the
pubis, their relative positions at both sides is
the same, the vein being placed internal to
the artery. On the left side this relation does
not alter, and the vein lies on the inner side
of the artery throughout its whole course ;
on the right side, however, the vein, in its
ascent, passes first behind the artery, and
then appears slightly to its outer side.

The internal circumflex ilii and the two
deep epigastric veins join the external iliac
vein at the commencement of its course im-
mediately above Poupart’s ligament. The
former holds a remarkable relation to the ex-
ternal iliac artery, for it crosses that vessel at
right angles to its anterior surface, and thus
separates the artery from the fascia transver-
salis.

The internal iliac vein is formed in the
cavity of the pelvis by the union of the veins

which correspond to the numerous divisions of
the internal iliac artery, — viz. by the glutceal,
sciatic, internal pudic, and obturator veins, all
of which arise external to the pelvis ; and by
numerous branches from the viscera contained
within the pelvis, and which are remarkable
for their plexiform arrangement. Of these, the
vesical veins form a plexus which surrounds
the neck of the bladder, and the prostate
gland ( vesico-prostatic plexus ), receives the
blood from the dorsal veins of the penis, and
communicates freely with the inferior hemor-
rhoidal veins. In the female a similar plexus
receives veins from the clitoris and the labia,
and in addition there are two others, still
more remarkable for their development, — the
vaginal plexus, which surrounds the vagina
near its commencement, and communicates
with the vesical plexus in front, and with the
haemorrhoidal veins behind, and the uterine
plexus, the veins of which are scarcely ap-
parent except during gestation, and which
communicate with the ovarian veins.

In both sexes the lower extremity of the
rectum is surrounded by the ramifications of
the haemorrhoidal plexus, the blood of which is
returned to the internal iliac vein by the
middle and inferior haemorrhoidal veins. This
plexus likewise communicates freely with the
superior licemorrhoidal veins, which unite with
the inferior meseraic veins, and so constitute
a part of the portal system.

In all these vessels valves exist in great
numbers, although none occur in the great
trunks in which they terminate.

The internal iliac vein on each side is in-
ternal to its corresponding artery.

The common iliac veins are formed by the
union of the external and internal iliac veins.
The junction takes place opposite the sacro-
iliac symphisis. These veins exhibit on each
side some interesting anatomical peculiarities.

The right common iliac vein, nearly vertical in
its direction, is placed posterior and external,
to its corresponding artery.

The left common iliac vein, larger than the
preceding, and nearly transverse in its direction,
lies internal, and inferior, to its corresponding
artery, and crosses behind the common iliac
artery of the right side.

The common iliac veins usually unite upon
the intervertebral substance between the fourth
and fifth lumbar vertebrae, to form ihe vena
cava inferior. The junction occurs to the
right of the mesial line, and inferior to, as well
as to the right of, the angle of bifurcation of
the aorta.*

The collateral branches of the common iliac
veins are the following : —

(a) The ilio-lumbar vein. — This vein arises in
the iliac fossa, by radiating branches, which

* The junction of the ven® innominat® to form
the superior vena cava, as well as that of the com-
mon iliac veins to form the inferior vena cava, oc-
curs on the right of the mesial line of the body.
In the former instance, the uniting veins are found
on a plane anterior to the arterial trunks which
they accompany ; whilst in the latter they lie be-
hind them.

VENOUS SYSTEM.

1413

correspond in their distribution to those of the
artery of the same name, and communicate
freely with the lower lumbar and sacral veins.

( b ) The middle sacral vein. ■ — A single trunk
placed on the sacrum in the middle line,
which communicates inferiorly with the vesi-
cal and haemorrhoidal plexuses, and on each
side with the adjacent lateral sacral veins. It
usually opens into the left common iliac vein,
but sometimes terminates more symmetrically,
by bifurcating and giving a branch to either
common iliac vein.

(c) The lateral sacral veins. — These ana-
stomose very freely with the middle sacral and
glutmal veins, and with veins in the sacral
canal, before terminating in the common iliac
veins.

Inferior vena cava. — (Vena cava ascen-
dens.)

This vein, the largest in the body, since
it returns to the heart all the blood which is
circulated below the diaphragm, is formed by
the junction of the common iliac veins, just
as the superior cava is constituted by that of
the venae innominatae. The abdominal vena
cava passes upwards in front of the lumbar
vertebrae, behind the liver and on the right side
of the aorta. At first the inferior vena cava
and the aorta are in close contact ; but as they
ascend, the vein inclines forwards and to the
right side, so that in the vicinity of the dia-
phragm these great blood-vessels become more
and more remotely related to each other, and
finally, the thoracic duct, the vena azjgos, the
right splanchnic and sympathetic nerves, the
right crus of the diaphragm and the Spigelian
lobe of the liver intervene between them. The
anterior relations of the inferior vena cava are
the following : the peritoneum, the mesentery,
the inferior portion of the duodenum, the
pancreas, the commencement of the vena
portae, and the liver, which latter sometimes
iorms a complete canal for the cava. Pos-
teriorly, the inferior cava corresponds to the
vertebrae, to the psoas muscle, and to the
right renal and right lumbar arteries : exter-
nal!}/, it is related to the right kidney.

The inferior vena cava is not uniform in its
dimensions, for it presents two remarkable
dilitations in its course, the first where it is
joined by the emulgent veins, and the second,
opposite to its junction with the venae cavae
hepaticae.

Having passed behind, or through, the liver,
the vena cava is transmitted through the
“ foramen quadratum ” of the diaphragm, and
at the same time penetrates the fibrous layer
of the pericardium, which is here intimately
connected with the cordiform tendon of the
diaphragm. Above the diaphragm the vena
cava bends abruptly to the left, and, after a
very short, and almost transverse course
within the pericardium, during which it is in-
vested on its anterior surface by the serous
membrane, terminates by entering the most
posterior and inferior portion of the right
auricle ; the axis of its opening is directed
upwards, backwards, and to the left side.
There are no valves in this vessel.

Collateral branches. — Besides the common
iliac veins, which are its formative roots, the
inferior vena cava receives the following, viz.,
the renal, spermatic, (ovarian in the female),
supra renal, lumbar, inferior phrenic , and
hepatic veins.

(a) The renal veins are of great size, and
pass transversely to join the cava ; the left is
the longest ; it passes in front of the aorta to
arrive at its destination, and is joined by the
left spermatic, vein.

Both renal veins arise in the cortical sub-
stance of the kidneys by small radicles, which
unite into larger vessels : these pass between
the “ pyramids,” and so gain the hilus, where
they lie in front of their accompanying arteries.

(li) The suprarenal, or capsular veins, are
more numerous than the arteries of the same
name ; there are usually three veins on each
side, and but one artei-}'. The veins are the
superior , which joins the inferior phrenic, a
middle, which unites directly with the vena
cava, and an inferior, which opens into the
renal vein of its own side.

(c) The spermatic veins originate in the
testis, and pass through the mediastinum
testis. On entering the cord they receive
veins from the epididymis, and assume a loose
plexiform arrangement (plexus pampiniformis).
The spermatic veins, now four or five in num-
ber, pass along the cord, and traverse the in-
guinal channel with the vas deferens and
spermatic arteries. At the internal abdomi-
nal ring the spermatic veins leave the vas
deferens and accompany their corresponding
arteries, lying behind the peritoneum and in
front of the psoas muscle. Continuing to
ascend, these veins cross the ureters external
to the common iliac arteries, approximate to
one another, and finally terminate, that of the
right side in the vena cava, and that of the
left side in the left renal vein.

In the abdomen there is either one sper-
matic vein, on each side, or two veins
which freely communicate by short transverse
branches, and unite in one common trunk
before terminating.

In the female these vessels are represented
by the

Ovarian veins, which form a plexus between
the layers of the broad ligament, and ter-
minate in the same manner as the spermatic
veins in the male.

(d) Lumbar veins (lumbo-vertebral veins). —
There are four or five pairs of lumbar veins
which are in every respect analogous to the
lumbar arteries from the aorta: they arise by
muscular branches in the lumbar region, and in
the parieties of the abdomen, W'here they are
connected with the epigastric veins, and on
both sides pass behind the psoae muscles to
open into the cava close to one another :
the veins of the left side cross the spine be-
hind the aorta. The lumbar veins commu-
nicate very freely with the venous system of
the spinal canal, with the ilio lumbar veins
below, and with the commencement of the
azygos veins superiorly.

(e) The inferior phrenic veins are derived

4x3

1414*

VENOUS SYSTEM.

from the diaphragm, and correspond accu-
rately to the phrenic arteries from the aorta.

The hepatic veins may be considered as
forming an adjunct to the portal venous
system, in connection with which they will be
briefly noticed.

Port al venous system. — One remarkable
class of the veins of the abdomen, those of
the chylopoietic viscera, do not terminate
directly in the vena cava, but unite to form a
large trunk — vena porta, which enters the
liver, and, branching out like an artery (hence
the name vena arferiosa ), forms a capillary
system in the substance of that organ.

The trunk of the vena porta is formed by
the coalescence of several large veins, which
return the blood from the stomach, spleen,
pancreas, and from the entire of the intes-
tinal tract, with the exception of the lower
part of the rectum, many of the veins of which
open into the internal iliac vein, as has been
already mentioned.

The veins which form the porta are the
following : — the superior and inferior mesen-
teric, the splenic, gastric, duodenal, and pan-
creatic, veins. All these are destitute of valves.

1. Inferior mesenteric vein.- — The veins of
the upper portion of the rectum (superior
hcemorrhoidal veins), sigmoid flexure of the
colon, and descending colon, unite to form
this vein, which ascends behind the inferior
transverse portion of the duodenum and the
pancreas, and opens into the splenic vein.
Bv means of the free communications which
exist between the inferior hasmorrhoidal veins
and the hasmorrhoidal and vesical plexuses,
the system of the vena portae is connected
with that of the general systemic circulation.

2. The splenic vein arises in the spleen, and,
accompanying the splenic artery (which lies
superior to the vein), follows a transverse
direction from left to right, and passes behind
the pancreas to unite with the superior me-
senteric vein.

Besides its proper splenic roots the splenic
vein receives the veins which correspond to
the “ vasa brevia,” as also the epiploic, pancre-
atic, and inferior mesenteric veins.

The gastric veins, of which the coronary
( coronaria ventricidi) is the most considerable,
likewise terminate in the splenic vein.

3. The superior mesenteric vein ( grande
mesara'ique, Cloquet ) receives the venous ca-
pillaries from the duodenum and all the small
intestines, also from the ascending and trans-
verse portions of the colon, and passes behind
the pancreas, where it unites with the splenic
vein. The superior mesenteric vein corre-
sponds to the artery of the same name, and is
placed anterior and to the right of it.

The trunk of the vena porta, formed by
the union of these two great veins (splenic
and superior mesenteric), is placed at first
behind the head of the pancreas, to the light
of the spinal column, and a little to the left
of the inferior vena cava : it next ascends,
with an obliquity backwards and to the right
side, between the layers of the gastro hepatic
omentum to the transverse fissure of the
liver ; after becoming slightly enlarged (sinus

of the vena portae), it there divides into two
branches, which pass horizontally into the
right and left hepatic lobes respectively. Its
principal anterior relations are the follow-
ing : the head of the pancreas and the duode-
num, the hepatic artery, and the ductus cho-
ledochus; to the two latter vessels it is
related, whilst traversing the gastro-hepatic
omentum ; it is surrounded by branches of
lymphatic vessels and of the hepatic plexus of
nerves.

The portal veins, and their subdivisions in
the liver, surrounded by a prolongation from
the capsule of Glisson, are contained within
the “ portal canals,” and are each accompanied
by a branch of the hepatic artery, and by a
branch of the hepatic duct. From these arise
the vaginal and interlobular branches, which, by*
their inosculations, form plexuses which are
similarly named. The interlobular veins sur-
round the lobules on their capsular surfaces,
and ultimately, having been joined by the
terminal branches of the hepatic artery, enter
the lobules (forming th e interlobular veins), and
terminate by inosculating with the intralobu-
lar (hepatic) veins: “this plexus interposed
between the interlobular portal veins and the
intralobular hepatic, vein constitutes the venous
part of the lobule, and may be called the
lobular venous plexus.” - — (Kiernan.)

“ The portal vein collects the venous blood
from the chylopoietic viscera, and then circu-
lates it through the lobules : it likewise re-
ceives the venous blood, which results from the
distribution of the hepatic artery to the struc-
tures of the liver: these two sources of supply
constitute the two origins of the portal vein,
the abdominal origin and the hepatic origin.”*

The blood conveyed to the liver by the
branches of the vena portae is conveyed back
again into the general circulation by the he-
patic veins.

Hepatic veins. — These veins arise in each
lobule, from the lobular venous plexus, by a
vein termed, from its position, intralobular .
The intralobular veins unite with others termed
sublobular, which, by their coalescence from
the venae cavae hepaticae, these latter, usually
four in number, leave the liver at its thick
margin, and open into the vena cava inferior,
where that vein passes between the Spigelian
and right lobes of the liver.

C. Cardiac Veins.

The proper veins of the heart form a sepa-
rate system of small extent, which communi-
cates with the right auricle of the heart by
the great cardiac vein. Their principal trunks
are thus distinguished :

1 . Great cardiac vein (anterior or great co-
ronary vein). — This vein commences on the
anterior surface of the heart, near its apex,
and ascends in the anterior interventricular
groove, as far as the base of the ventricles,
where, bending abruptly to the left, it gains
the hack of the heart by passing round the
left margin of the organ in the deep horizontal
groove between the left auricle and the left

* Vide Vol. III. p. 168., Art. Liver.

VESICULA PROSTATICA.

1415

ventricle. Still observing a transverse direc-
tion, the vein in its farther course, passes from
left to right, crosses the upper extremity of
the posterior interventricular groove, and
finally opens into the posterior surface of the
right auricle to the right of the mesial line.

Before its termination, the great coronary
vein presents a bulbous dilitation ( sinus of
the coronary vein). Its orifice in the right
auricle, which is protected by a special valve
( valve of Thebesius or lesser Eustachian valve),
is situated between the great Eustachian valve
and the right auriculo venticular opening.

Posterior cardiac vein ( posterior or lesser
coronary vein). — The lesser cardiac vein arises
near the apex of the heart, on its posterior
surface, and ascends in the posterior interven-
tricular groove, where it*xs joined by muscular
branches from either side. Finally, it ter-
minates in the great coronary vein when that
vessel forms its ampulla in the deep groove
above the base of the ventricles.

Several small veins, which belong exclu-
sively to the right ventricle, ascend along the
right border of the heart, and, curving round
in the groove between the right ventricle and
right auricle, likewise join the great coronary
vein — one of those which has long been dis-
tinguished by the name of the “ vein of Galen,”
is stated to communicate, frequently, by a
separate opening, with the right auricle.

Other veins of extreme minuteness ( vence
minhnce or veins of Thebesius) are described as
opening separately at various points into
either auricle. Their existence is denied by
some anatomists.

( B . Geo. M‘Dowel.)

VERTEBRAL COLUMN.— (See Sup-
plement.)

VESICULA PROSTATICA. (Syn. Si-
nus prostatce ; sinus pocularis ; utriculus pro-
staticus ; vesicula prostalica media seu spuria;
uterus masculinus ; Corpusculum Weberi-
anum.) The tubular structure indicated by
this name is a part of the male sexual ap-
paratus in Mammalia. It lies between the
lower ends of the seminal ducts, and opens
between them, by a special aperture, into the
commencement of the urino-genital canal : an
opening which has been usually, but not quite
correctly, viewed as an immediate process of
the urethra.

Tn Man, in whom alone it was recognised
until a few years ago, it is a little vesicle,
which is covered by the prostate. A si-
milar form and arrangement recurs in many
mammalia : but others exhibit very consider-
able deviations. Sometimes it is altogether
absent, or is but very rudimentary ; while in
other instances it is of considerable size. Its
relation to the prostate is equally variable ;
but even in man it is only superficial, being
solely due to its local arrangement.

On these grounds, the name “vesicula pro-
statica,” which at any rate merely applies
to its human anatomy, cannot always be used.
We prefer, therefore, to use that of “ the

Weberian organ or corpuscle,’* a name which
has been lately proposed in order constantly
to recall the great service which an eminent
anatomist has rendered to our knowledge of
this remarkable structure.

E. Id. Weber was the first who recognised
the great morphological import of this organ,
and who adduced proofs that in man and
the male mammalia it is the rudiment of an
organ which, by a great development in the
female individual, determines the form and
physiological relations of her generative ap-
paratus. Weber* explained the vesicula pro-
statica as the analogue of the uterus, and gave
it the name of the uterus masculinus.

We would willingly accept this denomi-
nation, if Weber’s view were quite correct..
But since we shall hereafter point out that
this never specifies the full morphological
value of the vesicula prostatica, but is, in
many cases, erroneous, we prefer the nomen-
clature already mentioned. Our examination
of the Weberian corpuscle is divisible into
three sections. The first regards its variations
of form ; while the second considers the ques-
tion of its possible functional import ; and the
third has for its object to determine the mor-
phological value of this structure.

I. Anatomy. — The Weberian corpuscle
occurs only in the class Mammalia, where
we meet with a greater complication of the
sexual apparatus than in any other group of
the Vertebrata. Thus the Mammalia are the
only vertebrate animals whose females possess
a real vagina and uterus. What we desig-
nate by this name in some other Vertebrata
cannot be regarded as morphological equi-
valents of the vagina and uterus of Mammalia.

Alan. — The Weberian corpuscle is a small
flask-shaped vesicle, with a rounded blind end
and a narrow neck directed downwards, placed
on the hinder wall of the urethra, under the
verumontanum, and covered by the prostate.
The middle lobe of this gland limits the upper
end of the corpuscle. The length varies, but is
commonly 3, 4 or 6 lines; the breadth at the
upper end is 2 lines, but it. sometimes attains a
more considerable size. Thus Adams-)- men-
tions an instance in which it had a length of
an inch, and by its upper end, which projected
free, was placed upon the dorsal surface of
the middle lobe of the prostate. And in the
hypospadian described by TheileJ; its size
was yet more considerable (1) inches).

The constricted neck sometimes forms half
of the whole corpuscle, and is, according to
HuschketJ, sometimes separated from the

* Amiot. anat. et physiol, zu Kretzschmar’s Diss.
inaug. circa lineam physiol, morbor. Lips. 1836.
Amtlicher Bericht iiber die V ersammlung Deutscher
Naturforscher in Braunschweig, 1842, p. 65. Z u-
siitze zur Lehre vom Bau und den Verrichtungen
der Geschlechts-organe (in den Abhandl. der
Fiirstlieh Jablonowskischen Gesellschaft), Leipzig,
1846.

■j- See article Prostate Gland, Vol. IV. p. 151.

j Muller’s Archiv fiir Physiologie, 1847, p. 23.
Tab. III. fig. 4., copied by Adams, loc. cit. fig. 106.

§ Soemmerring’s Lehre von den Eingeweiden.
Leipzig, 1844, S. 409.

4x4

1416

VESICULA PI10STATICA.

Perpendicular Section of the Weberian corpuscle in
Man ( copied from Weber's Zusdtzen.)
a. Urethra ; b, Weberian corpuscle; c, vas deferens,
with vesicula seminalis ; d, prostate.

Weberian corpuscle of Inuus Cynomolgus, as seen by a
perpendicular Section.

a, Urethra; 5, Weberian organ; c, vas defetens
with seminal vesicle ; d, prostate.

upper dilated part by a kind of constriction.
The under end opens by a small elongated
oval aperture (of £ to a line) on the anterior
declivity of the verumontanum. The orifices
of the two ejaculatory ducts* lie right and left
of the opening, at a very small distance from
it, usually somewhat higher, yet never quite
symmetrical : they are sometimes close to it,
or somewhat behind it. These ducts pass up
the sides of the Weberian organ, and receive
it between them, being bound up with it by
areolar tissue.

Fig. 873.

ducts. But at all events this is a rare ano-
maly, which has been since observed by Adams
only.* In a case mentioned by Hyrtif, there
was a simultaneous deficiency of both vesiculae
seminales, and the ejaculatory ducts descended
into the upper end of a single receptacle, which
was one inch long and seven lines broad.
But though Hyrtl and Theile regarded this
structure as certainly an uterus masculines,
and thus as a Weberian organ; yet the in-
sertion of the ejaculatory ducts at the upper
end is a circumstance which contradicts their
view. As we shall hereafter show, such a con-
nection is a morphological impossibility. Even
where an immediate communication between
the vasa deferentia and the Weberian cor-
puscle exists (as is normally the case in the
hare), it occurs only at the inferior extremity
of the latter organ.

Qusdrumarta. — In the Apes a Weberian

Fig. 874.

In the Weberian corpuscle of two new-
born infants, H. Meckel f found a special
variety of structure. It became thinner in its
ascent, so as to be only permeable by a hog’s
bristle, and ended as a solid thread, which
separated by bifurcating.

Morgagni | was the first who accurately
described the Weberian organ, which he also
probably discovered. Of fifteen human bodies
which he examined with this object, he found
it in fourteen. It is possible that in the
one remaining case he overlooked it, since
it sometimes happens that its mouth is but
small, or is even altogether deficient, as
Huschke has frequently ascertained it in
healthy and robust suicides. Nevertheless it
is not improbable that in some cases there is
a complete absence of the Weberian corpuscle;
the less so that we sometimes verify such- dif-
rences in other animals. In two of these
fifteen cases, Morgagni found that the utri-
culus, instead of opening by a special aperture,
communicated with one of the ejaculatory

* See Prostate, Vol. IV. fig. 103.

t Zur Morphologie der Ham- u. Geschlechts-
werkzeuge. Halle, 1848, S. 48. Tab. II. fig. 23.

I Advers. Amit. IV. Animadv. 3. Venet. 1762,

p. 110.

corpuscle appears very general. It here in-
closes a small, narrow and flat canal, which
above has a blind extremity, and scarcely
possesses a greater width than at its lower
end. Its length is about two lines. Its
moulh, in the uro-genital canal, is surrounded
as with a wall by an annular swelling, which
has some resemblance to a small os tinea?,
and in which one may also, generally, dis-
tinguish an anterior and posterior lip. Im-
mediately behind this opening are the mouths
of the ejaculatory ducts, the lower ends of
which are apposed to the hinder wall of the
corpuscle, and are covered by the prostate.

As far as my researches go J , the above
description will apply to the Weberian organ
in all Apes. At least I have found it thus in
Inuus Cynomo/gus (in whom it was formerly
described by BergmanntJ), in Inuus nemes-
trinus, Cynocephalus Maimon, and a species
of Harpale (Harpale Iacchus ? ) which, with
all the animals I examined, was placed at my

* Adams, loc. cit. p. 153.
t Oesterreiehe Medic. Wochenschrift, 1841, S. 45.
| Zur Anatomie u. Physiologie der Geschlechts-
organe. Gottingen, 1847, S. 99.

§ Wagner’s Handworterbuch der Physiologie,
Bd. III. Abth. 1. S. 130. Anmerkung.

VESICULA PROSTATTCA.

1417

disposal from the stores of the Physiological
Institute of this place.

Volitantia. — Among the Bats I have found
a Weberian organ hitherto only in Vespertilio
murinus. Here it is a small corpuscle, scarcely
one line in size, between the ejaculatory ducts.
It is covered by the prostate, and opens at
the usual place by a small and scarcely visible
aperture. In Flecotus auritiis I have sought
after it in vain. So also in G aleopitkecas
variegatus, where the points of opening of the
two seminal ducts are placed close together
upon a small and elongated verumontanum.

Insectivora. - — The Erinaceus Europceus
Talpa Europcea* , Sorex araucus, and Macro-
scelides Rozeti were examined : only in the
last is a Weberian organ present. It is a
roundish flask, which is proportionately of a
very considerable size, being fully one line
long, and quite as broad at the end. It opens,
by means of a short constricted neck, into
the uro-genital canal between the two seminal
ducts. The prostate, which consists, as in
the Sorex, of two compound gland-tubes, lies
in front of the utriculus, and close to it, but
without covering it. The thickened lower
ends of the seminal ducts receive it between
them, and are united to it by areolar tissue.

Ferce. — In the dog and the cat the Weberian
organ forms, as Weber has shown, a long
small bladder of some lines in size, which is,
for the most part, placed before the prostate
in a fold of peritoneum stretching between
the two ejaculatory ducts. There is no open-
ing into the urethra.

The description of Weberf certainly holds
good in many instances, yet not in all. I
have examined numerous dogs and cats, and
have very frequently found, instead of a vesi-
cular structure, a simple solid cylindrical cord,
which I have regarded as an obliterated ru-
diment of the organ. In many individuals
even this could not be detected. I also found
the Weberian organ as a solid cord in the
fox and leopard. The striped hycena, on
the contrary, possesses an elongated flask-
shaped Weberian corpuscle; but it, together
with the ends of the seminal ducts, is hidden
between the two kidney-shaped halves of the
large prostate.j: The latter are only fused

posteriorly ; in the larger anterior half they
are united by areolar tissue into a common
mass. There is no opening into the uro-
genital canal, and I have found none in any
of the beasts of prey examined.

The Weberian organ of the otter, which

* The commencement of the uro-genital canal
in the Eimacera and Talpa, forms in an anomalous
manner a spacious and defined cavity. Into this
cavity the urethra opens, as in the female mammalia,
by a narrow slit-shaped aperture. This was de-
scribed by me some time ago (zur Anatomie, &c.,
SS. 102. 105.) at which period I erroneously ex-
plained the cavity as a male vagina.

t Zusatze, &c. Tab. VII.

j The length of the prostate is fully one and
a half inches : its breadth is yet larger. Cowper’s
glands are also of considerable size, two inches long.
They have a longly clavate form, and a very thick
covering of striped muscular fibres.

Fig. 875.

Weberian Organ of the Hycena Striata (reduced to
half the natural size.')

a, Weberian organ ; b, b, vasa deferentia; c, e, pro-
state ; d, d, Cowper’s glands.

Leydig* has described, is of unusual form,
and much more considerable development.
It lies between the urinary bladder and
the two seminal ducts, and consists of a
body about six lines in length and propor-
tional breadth, the upper free end of which
is drawn out right and left into a long and
thin thread lying on the seminal duct. The
cavities and their openings could not be ex-
amined ; but without doubt both were pre-
sent. The Weberian organ is very similar in
the il Teles Taxus. It is a very considerable
cylinder, which measures about ten lines, and
rises to the hinder surface of the glandular
ends of the vasa deferentia, being very firmly
united to them by areolar tissue. The upper
end is folded into two horns, only the right
of which is permeable to a short distance.
The left is, from its root onwards, a solid
thin thread, which is closely attached to the

Fig. 876.

W eberian Organ of the Badger,
a, Weberian organ ; b, b, vasa deferentia ; c, thread-
shaped horns of the AVeberian organ.

* Zeitschrift fur Wissentschaftliche. Zoolog. von
Siebold u. Kolliker, Band II. S. 49.

1418

VESICUL A PROSTATICA.

corresponding vas deferens. Its cavity is
that of a canal, but not so wide a one as
might be guessed from the exterior thickness
of the body ; and it opens by a distinct aper-
ture on the verumontanum.

Pinnipedia. — The genitals of a young male
seal, probably Plwca vitulina, were examined
by me. Here I saw a scarcely visible linear
fold, which led to a longish Weberian organ
of about two lines in size. The fold lay close
behind a small ridge-shaped verumontanum,
on which were the orifices of the vasa defe-
rentia, situated close to each other. As in
the dog, the organ is situated partly in front
of, partly beneath, a prostate, which in form
and development also corresponds with that
gland in the dog.

Marsupialia. — In Didelphys Virginiana the
only animal of this order whose male genitals
I had, no trace of the Weberian corpuscle
was present.

Rodcntia. — The Weberian organ showed

maims, and Hypudeeus amphibius, I have
looked for it in vain. But certainly the My-
oxus Vitela , Dipus JEgyptiacus and Cricetus
vulgaris exhibited a single small longitudinally-
folded verumontanum, which, from its situa-
tion between the two orifices of the vasa de-
ferentia, must have been the opening of a
Weberian organ: but this structure isclf, on
account of its sheer minuteness and hidden
situation, eluded the further searches, which
were made in only a few individuals.

In Cavia cobaya the Weberian organ is, as
I described it some time since*, a small
roundish vesicle, scarcely a line in size, which
has a bilobed extremity, and, as in Macro -
scelidcs, a constricted neck, which opens into
the uro-genital canal between the two seminal
ducts. The Weberian organ of the rabbit
and hare is very much larger. It was formerly
known to the older zootomists under the name
of the azygous seminal vesicle f, and has only
received a more accurate description and ex-

Fig. 877.

JPeberian Organ of the Beaver ( after Welerf)\.
ct, a, Vasa deferentia; h, b, Weberian organ; c, c, prostate; d, d, seminal vesicles.

great variations in occurrence, size, and shape, planation through the researches of Htischke
In Sciurus vulgaris, Tamias striata *, Spermo- and Weber.

plains atillus, in MuS muscidus and decu- In the rabbit this organ attains a length of

from one to one and a half inches, so that it

* The Cowper’s glands of this animal are cylin-
drical structures of very considerable size (almost
half an inch long) : they have knot-shaped thicken-
ings at their end, and are rolled up in a coil around
this extremity. The prostate consists of two large
gland lobes which have the form of a hammer.

* Zur Anatomie, Sec. p. 104.
f See fig. 281. Art. Rodentia, Yol- IV. p. 393.
(Rymer Jones.)

j This engraving is copied from the “ Zusiitze,”
&c.

VESICULA PROSTATICA. 1419

projects very far, behind the urinary bladder. It
has the form of a flask, and in its anterior
half, which is compressed somewhat flat, it has
a breadth of five to six lines. Its base is bi-
lobed, as if drawn out into two lateral short
and rounded horns. Its mouth in the uro-
genital canal is wide (about one line), yet not
round or linear, but rather placed across, and
somewhat arched in shape, as if bent around
the swelling of the verumontanum. In new-
born individuals the organ is much smaller,
scarcely three lines long; but it is otherwise
exactly similar. In the male hare it is al-
ways smaller. In one example it measured
five lines, and was devoid of horns at the
base ; but these are sometimes little developed
in the rabbit also. But the most extraordi-
nary circumstance about the utriculus of these
animals is this, that it receives the ejaculatory
ducts. In all other instances, these open in-
dependently, by its sides, into the uro-genital
canal ; but here, departing from this rule,
they open into the undermost part of the
Weberian organ, at a short distance (in the
new-born rabbit half a line, in the adult two
lines) above its orifice previously described.
They occupy the anterior wall of the organ,
on which they course downwards, and each
terminates in a small papilla. In Lagomis
the same arrangement seems to occur. At
least Pallas* * * § states of the Lagomis ogstova
that the two ejaculatory ducts open together
by a common tube, which must doubtless be
regarded as a Weberian organ. f

Another very remarkable form of Weberian
organ is possessed by the beaver. The first
information concerning it we owe to Brandt
and RatzeburgJ, who compared this struc-
ture, on account of its form, to the uterus
bicornis of the female individual, yet without
recognising any nearer relation between the
two. They regarded it as a kind of sup-
plementary seminal vesicle. Its correct inter-
pretation is due to the acuteness of Weber.$

The Weberian organ is simple only at its
lower end, or that which usually opens be-
tween the orifices of the two vasa deferentia.
Very soon it is split into two horns, which
ascend in the peritoneal fold between the two
seminal ducts, and finally, after they have
dwindled to the form of threads, are apposed
to these. Brandt and Ratzeburg were able
to follow the terminal threads to the testicles ;
while in the example which Weber inves-
tigated, where the horns measured 24 inches,
they ceased much earlier. The lower half of
the horn is of very considerable thickness, as

* Xov. Spec, quadruped, e glirium ordine. Erlan-
gen, 1778, p. 67.

f According to Rymer Jones (loc. cit. p. 393.),
the two vasa deferentia in the Agouti also open by a
common duct into a cavity of tile verumontanum.
But since this at the same time receives the excre-
tory ducts of the seminal vesicles, it certainly is not
the cavity of the Weberian organ. Probably the
same structure is repeated here which I formerly
(loc. cit. p. 130.) described in the Cavia, and have
recently found in the Dipus.

+ Medizinisehe Zoologie. Band I. S. 137.

§ Amtlicher Bericht., &c., loc. cit.

much as four lines, and it encloses a spacious
cavity .

Edentata. — The sloth (Bradypus tridac-
tylus ), the only animal of this class of Mam-
malia whose genitals 1 was able to examine,
is completely devoid of this organ.

Pachydermata . — Duvernoy* mentions the
Weberian organ in the elephant as a deep,
blind sac, which lay concealed in the veru-
montanum. In the swine it has been de-
scribed by Weber. It consists here of a body,
which is nine lines in length and almost a line
in thickness, and which lies in the peritoneal
fold between the two ejaculatory ducts. At
its upper end it passes on either side into
a yet longer but thinner horn. Leydig, wdio
also mentions the opening of this body into
the uro-genital canal, states that, when in the
inflated condition, it has the thickness of a
goose quill.

In an adult boar with hypospadias, I found
this organ of yet larger size. The opening,
which lay between the points of aperture of
the two ejaculatory ducts, and had a length
of 1 ) lines, led into a cylindrical body, which,
gradually dilating to some extent as it passed
upwards, finally, after a course of fourteen
lines, split into two horns. These were placed
against the seminal ducts, and, as cords of
areolar tissue, could be followed with the cover-
ings of those tubes to the testicles. In other
instances the Weberian organ of the pig ex-
perienced a more considerable reduction.
Thus in a new-born individual whom I ex-
amined, I found only a single solid cord in
the middle line of the peritoneal fold between
the vasa deferentia; it had neither- cavity nor
opening into the uro-genital canal.

Soliditngula. — The Weberian organ of the
horse, which is generally of very considerable
size, was known to Cuvier -f-, who referred it
to the vesicula seminalis. It has also been fre-
quently described and figured by Gurlt J as a
median seminal vesicle. The first who re-
cognised its morphological importance was
Hausmann.§ With a reference to the older
researches of Weber upon the vesicula pro-
statica of man and the beaver, but before
this author had published his later observations
on the horse, he explained it as the male
uterus. And independently of him, Adams ||
was led to the same result.

The Weberian organ of the horse is a wide
tube, which opens into the uro-genital canal
by a large opening between the two vesiculae
seminales, the ejaculatory ducts of which it
receives by the constricted neck of its lower
extremity. In particular instances this open-
ing is, as Leydig observed, divided by a median
bridge into two apertures, which lie close to

* Cuvier, Lemons d’Anatomie comparee, nouv.
edit. t. viii. p. 210.

f Cuvier, Lecons dAnatomie eompare'e, nouv.
edit. t. viii. p. 176.

J Anatomie der Ilussaaugethieren, Berlin, 1834,
Th. II. S. 99. Anatom. Abbildungen der Haus-
saugethieren, Berlin, 1844, Tab. 69.

§ According to the communication of Bergmann.
Op. cit.

|1 Loo. cit. p. 152.

VESICULA PROSTATICA.

1420

each other ; or it is even, as Weber found it,
completely closed. In the same manner
Gurlt found that the Weberian organ, instead
of opening by a special aperture, sometimes
communicated with one or other of the eja-
culatory ducts. The lower end of the tube
is considerably dilated for a length of 1 to
3 inches. Above, this dilated part gene-
rally passes into a narrow cylinder, which

Ruminantia. — In the Llama, which pos-
sesses a heart-shaped parenchymatous pro-
state, I have been unable to find either a
median, single, opening into the commencement
of the uro-genital canal, or a Weberian organ.
But, on the other hand, one finds a very dis-
tinct rudiment in the new-born male deer.*
Here it courses as a single cord-like thread
in the peritoneal fold between the two eja-

Weberian Organ of the Ass (reduced in size.')
a, a, vasa deferentia, with the seminal vesicles, b, b ; c, Weberian organ.

sometimes attains a length of 5 to 7 inches,
and then divides into two short and usually
unequal horns. Not unfrequently this upper
part is, as was observed by Leydig and seen by
myself, a simple solid thread. In the instance
described by Weber the cavity was altogether
absent ; and an absence of the whole Webe-
rian organ has been observed by Leydig.

In the male ass I have also seen a very con-
derable Weberian organ {Jig. 878), the existence
of which I was first made aware of by Berg-
mann. It is here a straight canal, four and a
half inches long, which ascends in the peri-
toneal fold between the two ejaculatory ducts,
and divides at its extremity into two, much
wider, horns. These have blind ends, and a
length on the right side of 5, on the left of 9,
lines. There is no opening into the uro-
genital canal, but the lower end has a vesi-
cular dilatation of four lines in length, and
is separated by a longitudinal fold into two
blind sacs lying close behind each other.

culatory ducts until finally it bifurcates at
about an inch from the place of their inser-
tion. It is only during the earlier stage of
embryonic life that I have been able to find
a cavity and its opening : in the new-born in-
dividual the Weberian organ is already ob-
literated and solid. Some larger and smaller
hydatidous vesicles which are found in its
course, and especially at the site of its bifur-
cation, are the only relics of this its earlier
condition.

The same form of Weberian organ is re*
peated in the goat ; but its development seems
here to be very variable. I examined a large
number of genitals, which had been presen ed
some time in spirit. In all, the Weberian
organ was of considerable size and develop-
ment. Nevertheless I have reasons for the
conjecture that this is not the rule, and that

* See my description in the Gottingische Gelehrte
Anzeige, 1848, No. 174.

YESICULA PRQSTAT1CA.

1421

Fig. 879.

in the majority of lie-goats a less complete
development of the Weberian organ occurs.

According to my observations the organ
consists of a cylindrical body, which ascends
between the two seminal ducts, and is strongly
united to these by areolar tissue, especially
in its inferior half. After a course of an inch
and a half it splits into two horns, which are
apposed to the seminal ducts, and continue
with these to the testicles, where they pass
into the covering of the epididymis. In
two instances the lower third of the body
was dilated into a longish vesicle of about
three lines in diameter, while the part above
this measured scarcely one line. At the seat
of bifurcation it was again dilated, though
less considerably. In one individual the
middle portion was obliterated so as to form
a solid cord. The point of opening into the
uro-genital canal is a small linear fold, which is
separated by a short interval from the orifices
of the vasa deferentia, and is usually placed
below, but, in one instance, above them.

The genitals examined were those of either
new-born individuals, or of such as were
but a few weeks old. In two instances, which
were in no way distinguished by a special
development of the Weberian organ, the uro-
genital canal was wider and shorter than
normal, measuring from 2 to 2i inches long
only, instead of about 4< inches, while the
penis was smaller, and twisted into numerous
zigzags or spirals. But in other respects the
male organs were cjuite perfectly developed ;
the urethra opened at the extremity of the
penis, and the testicles had descended into
the scrotum.

In the sheep there is no Weberian organ.
Even in the new-born individual, neither its
opening nor any other indication of it can be

found. But in the bullock I found immediately
under the orifice of the vasa deferentia a small
and scarcely noticeable roundish aperture,
through which a probe penetrated about two
lines in depth, evidently into the tubular
cavity of a small Weberian organ, which was
covered by the heart-shaped mass of the pro-
state.

Fig. 881.

Weberian Organ of the Monodon.
a, verumont.anum ; b, b, orifices of the vasa de-
ferentia ; c, orifice of the Weberian body.

Cetacea. — Some time ago* I described the
Weberian organ in the narwhal and dolphin.
It lies in the prostate, beneath the conspicuous

* Zur Anatomie, &c., S. 100.

1122

VESICULA PEO STATIC A.

verumontanum, and possesses a flask-shaped
cavity of about one inch in depth. The open-
ing at the lower declivity of the verumon-
tanum is a fissure which has the shape of a
horse-shoe curved forwards, while a triangular
papilla, which arises from its posterior mar-
gin projects into it. In the Monodon the
latter is farther separated by a linear fissure.
In a dolphin ( De/phinus area ?) which I ex-
amined, the anterior extremity of this papilla
was united with the opposite margin ; so that
the opening was divided into two fissures
converging superiorly. In the same way
Leydig observed it in De/phinus p7ioc<sna ;
while in another individual of the same species
I have met with the condition previously de-
scribed. Possibly in younger individuals of the
Cetacea the Weberian organ has a yet greater
development. At least Eschricht, who was not
aware of the structure just described, states*
that, in a male embryo of the Plerobalcena,
the inferior extremity of both vasa deferentia
was connected with a transverse fold, of which
the free margins exhibited the appearance of
an obliterated cord. From its situation this
would about correspond to the lateral horns
of an uterus.

II. Physiology . — We, now, proceed to
enquire what is the use of this structure, the
occurrence and variable forms of which we
have hitherto been treating of. It is a general
law that the physiological import of an organ
stands in a direct relation with its anatomical
development. If we regard the Weberian
organ in this point of view, we shall soon be
convinced, from its absence in many Mam-
malia, and from the varieties of its develop-
ment in particular individuals, that its in-
fluence upon life cannot be very important.

When Morgagni first discovered the human
Weberian organ, he thought that it was con-
nected with the prostate. Its situation made
him think it possible that some tubes of the
prostate emptied themselves into it, and that
it was in a certain manner, like the gall-
bladder, a saccular dilatation of the excretory
duct of the prostate. But anatomical research
soon convinced him that his conjecture was
necessarily erroneous. A communication be-
tween the prostate and the Weberian organ
never exists, and is indeed rendered impossible
by an arrangement like that which obtains in
the horse, the goat, and the beaver.

According to other views, the Weberian
organ has the function of a seminal receptacle.
Thus it has received the name of a vesicula
seminalis. But we know how prone the
earlier anatomists were to this designation,
and how they indicated in this manner all
those accessories of the male genitals of
Mammalia which opened near, or together
with, the ejaculatory ducts, without any closer
acquaintance with their structure and import.
More recent researches f have corrected us
on this point. They have shown us that the

* Untersuehungen Uber die nordischen Wallthiere,
Liepzig, 1849, S. 102.

t Leydig, 1. c.

dependent structures known as the dual se-
minal vesicles of the vasa deferentia almost
always possess a glandular texture, and never,
or only occasionally (as in man), contain
spermatozoa. It is true that the flask-shaped
seminal vesicles of the horse and ass are
genuine reservoirs of sperm, — as we may
conclude from the fact, that the vasa defe-
rentia open into them, — but as a rule exactly
the reverse relation obtains.

But the same anatomical arrangement as
that of the vesicula seminalis in the horse
may be seen in the Weberian organ* of the
hare previously mentioned. On this ground
only one might conclude a similar functional
import. And the microscope really brings
proof that the contents of the Weberian organ
are, in this instance, sperm.

But the connection of the excretory duct
and the Weberian organ is limited to the
hare and lagomys. In all the other Mammalia
the two structures open near to each other
without any communication. Now if, in spite
of this, the Weberian organ has the function
of a seminal receptacle, this can only happen
by the sperm, which has been previously
poured into the urethra, being discharged
through the lower aperture of the Weberian
organ into its interior.

We will not quite deny the possibility of
such an occurrence ; but the probability of it
seems but small. At any rate a contraction
of the muscular layer around the urethra
would be necessary thereto; but, without offer-
ing any new hypothesis, it would scarcely be
possible to perceive why the sperm should
thus be sent upwards rather than downwards.
The verumontanum alone would not be able
to prevent this.

Such considerations would be silenced by
direct observation ; but hitherto no one has
ever met with real semen in the Weberian
organ, except in the hare. Morgagni states,
that on pressing the human vesiculas seminales,
he has seen sperm exude from the prostatic
utricle. But the correctness of this state-
ment is rendered very doubtful by the fact,
that the examination was made at a time
when the accurate diagnosis of semen was net
yet understood. A fluid may certainly have
exuded from the Webe’ian organ, but that
it was sperm is very doubtful. It might easily
form the contents of the Weberian organ,
where, as is sometimes the case, this has an
abnormal communication with one or the
other vas deferens.

I will not bring forward further argumen
against the import of the Weberian organ as
a seminal vesicle, such as its little capacity in
many instances, &c. They would only prove
that such a function is sometimes impossible.

A third theory of the function of the vesi-
cula prostatica has been lately suggested
by Weber. According to this view it is a
kind of valvular ventricle, by which the urine

* As has been also remarked bjr Leydig. H. Meckel,
on a priori grounds, wrongly denies this connection
in the hare.

VESICULA PROSTATICA.

1423

is hindered from penetrating the vasa defe-
rentia. In order to this, the urine must, like
the semen in the previous view, enter into
the vesicle, which, distended by it, must by
its own pressure close the ejaculatory canals.
Hence the same difficulties recur as in the
first case. Since the urethra contains urine
only during the act of micturition, and is at
other times empty and collapsed, this fluid
must, even in its passage through the tube
by which it is discharged, pass into the vesi-
cula : a fact which is the less supposable,
inasmuch as to this end a backward move-
ment of the urine would be necessary. Be-
sides in many cases the situation of the
Weberian organ is such that, even if distended
by a fluid, it could not possibly operate in
such a way. And moreover, even where it
might perhaps be possible, it seems unneces-
sary, since the tumid or papillary margins
of the orifices of the vasa deferentia are suf-
ficiently closed by the passage of the urine
itself.

One other conjecture of the physiologi-
cal value of the Weberian organ still remains
to us, — viz. that it is a secretory appa-
ratus. It was found by the older anatomists
that here and there, for instance in the
horse, it was filled with a thick fluid,
mostly of a yellow tint. As was previously
remarked, this can only be secreted by the
coats of the Weberian organ. Morgagni
mentioned that the inner clothing of the organ
was a mucous membrane, and possessed a
glandular texture ; and the later researches
of Huschke and Leydig have succeeded in
verifying a number of small glands therein.
These glandules have a different form in the
different animals ; for instance, in the rabbit
they are simply spherical ; in the boar they
are elongated tubes provided with buds and
processes.

Whether such glandules always exist in the
Weberian organ must be verified by further
careful researches. Leydig could not find them
in the dolphin, nor could I in the dog. At
any rate they are absent where, as in the
deer, &c., the cavity has disappeared.

Exteriorly to this mucous membrane, which
possesses a layer of cylindrical cells as an
epithelium, there is a layer of smooth mus-
cular fibres, which take the longitudinal di-
rection. In the hare only, in whom they
form a considerable layer, especially at the
lower end, they are more twisted together.
It is evident that this latter arrangement is
connected with the import of their Weberian
organ as a seminal vesicle. At all events
they are thus susceptible of more powerful
contractions, which one may produce in the
recently dead animal by galvanic and other
stimuli for a considerable time. Together
with these muscular fibres there is a quantity
of areolar tissue with white and yellow fibres.
This sometimes predominates, and where the
cavity disappears, it seems to occur alone.

It can no longer be doubted that the
I Weberian organ, at least where it is com-
pletely developed, and possesses an internal

cavity and an opening, may prepare a secre-
tion ; but the nature and physiological import
of the secretion are as yet unknown to us.
H. Meckel* states, that he once found a
clear vitreous mass in the Weberian organ
of the rabbit, which from its re-actions was
gelatine. Nevertheless it is very improbable
that the secretion always consists of this sub-
stance, at least if I can judge from its external
physical properties.

This secretion may easily be carried away
from time to time with the urine or the sperm.
Whether it plays any further part — whether
it is possibly, like the secretion of the prostate,
subservient to the dilution of the semen (as
may be conjectured from the arrangement
of the Weberian organ in the hare) or to
other purposes, we know not. After all,
however, the function of the secretion can
scarcely be an important one.

III. Morphology. — It is impossible that
we should be quite satisfied with what we
have learnt above concerning the physiological
value of the Weberian organ. Granting that,
in some instances, it serves as a seminal re-
ceptacle, that in others it delivers up the pro-
duct of secretion, still its essential import is
certainly not thus exhausted. It seems that
the application of the Weberian organ to
this or that end is but a casual result of its
general situation, rather than that it constitutes
a sufficient reason for its presence. We are
constrained to adopt such a view by the cir-
cumstance, that the Weberian organ is fre-
quently devoid of all connection with other
structures, and is even sometimes reduced to
a ligamentous thread, the functional value of
which one cannot imagine.

Thus the Weberian organ takes a rank
amongst that class of structures which possess
not so much a prominent functional value,
as a morphological import ; which are neces-
sitated not so much by the actual require-
ments of life as by the general typical plan
of the structure. Should any one deny the
existence of such a class of structures, it
would only be necessary to remind him of
the wing-stumps of many apterous insects,
of the bony girdle for the extremities of the
blind worm, of the embryonal teeth in the
bearded whale. All these are parts which
are of scarcely any physiological value to the
animals named, although under different cir-
cumstances, and in other animals they fulfil
the most important functions : they are simply
morphological rudiments, which, according to
the common architectonic law, are repeated
even where they are useless.

But such parts are found, not merely in
particular animals and groups, but also es-
pecially in the different sexes. Of what use
to the male individual are the milk-glands
and teats '? of what use to the female the well-
known rudimentary penis called the clitoris?
Are they not the plainest indications that the
male and female organs are constructed after
a common type, and that it is only by different
developments of the same elements that they
* Op. Cit. p. 49.

1 124.

VESICULA PRGSTATICA.

take their different forms, and with these
their different destinies ? Careful contem-
plation leads us to regard the Weberian organ
as one of this class of structures. As was
previously mentioned, Weber had pointed out,
that by its situation and connection with the
uro-genital canal, and very frequently (as in
the beaver) by its form, it corresponds so
completely to the uterus of the female mam-
malia, that there is every reason for regarding
it as its morphological equivalent in the male
individual.

According to this view, the difference be-
tween the Weberian organ and the uterus is
limited to that of a lesser or greater degree
of development. In the female individual it
becomes the receptacle of the embryo. The
physiological task which it thereby under-
takes demands a complete development, while
in the male individual, in whom it has not
such an important functional import, and is
only occasionally applied to this or that sub-
ordinate purpose, it undergoes a check, or
even retrogrades in development. The dif-
ferent degree of this checked or retrograde
metamorphosis, depending on its different
application, conditionates the difference of its
anatomical development. In many male in-
dividuals it completely disappears ; in others
it remains an useless relic of a rudimentary
character, while in others it assumes a more
considerable size and development.

The form of the receptacle of the embryo,
which, despite many varieties, is in general
very constant, is connected with its functional
import. But the Weberian organ is devoid
of so specific an object. What wonder, then,
that we find it more freely submitted to the
play of the formative process, and that its
form and development are even subject to
manifold varieties in particular individuals ?

The theory of Weber at once gives us a
sufficient explanation of the different anato-
mical circumstances of this notable organ ;
and in like manner it affords a new and secure
basis for the efforts of anatomists to deter-
mine the analogy — i. e. the common plan of
structure — of the male and female organs.

Ever since Aristotle and Galen, vain at-
tempts have been made to discover an indica-
tion of the uterus in the male of the Mam-
malia; and sometimes this structure, sometimes
that — now the vesicula seminalis, and now
the prostate — has been thus regarded. The
explanation given by Weber offers the first
satisfactory adjustment, and at the same time
promises a sufficient interpretation of the nu-
merous hermaphrodite misdevelopments, or of
androgyny. Weber even hints at this (and in-
dependently of him Bergmann also), while he
subjects the well-known case of Ackermann*
to a morphological analysis f, although only
with the immediate intention of further sup-
porting his explanation of the vesicula pro-
statica. He came to the conclusion that the

* Infantis androgyni historia et iconographia,
Jenae, 1805. See also Art. Hermaphroditism,
Vol. II. p. 709.

A Zusatze, loc. cit. S. 13.

part described by Ackermann as a cystoid
uterus, the opening of which into the uro-
genital canal was situated close to the efferent
apertures of the vasa deferentia, was due
solely to a disproportionate enlargement of
the vesicula prostatiea.

Under such circumstances it is easily ex-
plicable why the theory of Weber has re-
ceived a very general assent. Huschke, Theile,
Hausmann, Bergmann, Leydig, and the author
in Germany, Duvernoy in France, and Adams
in England, have all accepted it, and have
sought to give it further stability by new re-
searches. And Leydig* has further shown
that the type of the glands imbedded in the
wall of the Weberian body completely cor-
responds with that of the uterine glands in
the respective female animals.

FI. Meckel -j- only has expressed himself
against the interpretation of Weber, although
he so far agrees with it as also to see in the
vesicula prostatiea a rudimentary structure of
chiefly morphological import ; but he explains
it as being the analogue, not of the uterus,
but rather of the vagina. The chief support
which he adduces of this theory is the relation
of the Weberian organ to the vasa deferentia
and the urethra.

It is well known that the older anatomists
regarded the vasa deferentia as the structures
which, in the female individual, discharge the
functions of the Fallopian tubes. Even Weber
partook of this opinion, although Muller J
had already shown the morphological differ-
ences of the two in birds, and Rathke§ in
snakes. That this holds good of Mammalia
was first maintained by Bergmann || and the
author of this article If, on the ground of their
comparative researches; and it was afterwards
reduced to certainty by the observations of
Kobelt** on the development of the genitals
in the human subject. As Muller and Rathke
had previously found, Kobelt showed that,
at an early date of embryonic life, tubes and
seminal ducts exist simultaneously in all in-
dividuals, but that, in the different sexes,
only one of these canals attained a complete
development.

If the seminal and Fallopian tubes were
identical structures, the Weberian theory of
the morphological nature of the vesicula pro-
statica could not possibly be correct; for, in
that case, the former of these must constantly
open into the upper end of the vesicular, or
into its two cornua respectively, which is
never the case. But now that we know the
difference of these two canals, the anatomical
arrangement of the vasa deferentia and
Weberian organ no longer constitutes an ob-
jection against the explanation of the latter
as the uterus.

* Opus cit. S. 49.

| Zur Morphologic, See., S. 47.

% Bildungsgeschiebte der Genitalien. Bonn, 1830.

§ Entwickelungsgeschichte der Natter, S. 212.
Kiinigsberg, 1839.

|| Op. cit. in Wagner’s Handworterbuch.

Zur Anatomie, & c., S. 90.

** Der Nebeneierstock des Weibes. Heidelberg,
1847.

VESICULA PRO STATIC A.

1425

But it is not on this that Meckel chiefly
relies. He conspicuously brings forward an-
other argument. He states that, if with Weber
we regard the vesicula prostatica as the
uterus, and its opening as the os tine®, we
must in consequence consider as the vagina
the beginning of the uro-genital sinus, into
which open, beside the vesicula, the ejacu-
latory ducts and the urethra; a view which
has often occurred to the author of this
article. But, in the female Mammalia, the
vagina never receives the urethra. This is
always inserted at the outer border of the
vagina, where it passes into the short and
sinus-like dilatation of the uro-genital canal
( vestibulnm , atrium vagince), so that the vagina
always lies internally to the aperture of the
urethra.

Its relation to the vasa deferentia is exactly
similar, as the history of their development
proves that they are originally the efferent
ducts of the Wolffian bodies. It is true that
these latter generally disappear in the female
mammal, but here and there some relics of
them are left. This is especially the case in
the female ruminant and pig, where they are
known under the name of Gartner’s canals.
Here also they open, never into the vagina,
but into the ductus uro-genitalis, together with
the urethra. So that in all cases, after the
points of opening of the urethra and vasa
deferentia, the vagina comes next interiorly.
And in the male mammalian the Weberian
organ has this situation : it is therefore, con-
cludes Meckel, the vagina, and not the uterus.

While I allow the correctness of the facts
brought forward by Meckel, and while, —
against my own earlier opinion, — I have some
scruples as to the unconditional accuracy of
Weber’s explanation, yet 1 cannot approve
of Meckel’s conclusion. The form of the
Weberian organ, the bifurcation at its upper
end, which occurs in so many instances, even
its being imbedded in a transverse fold of
peritoneum (corresponding to the broad liga-
ments of the uterus) remind one too closely
of the female uterus to admit of the analogy
being mistaken.

Now, in order to reconcile this circum-
stance with the facts brought forward by
Meckel, there remains but two expedients ;
either to suppose a complete deficiency of
the vagina in the male mammal (in which
case the explanation of Weber would be pre-
served entire), or to set forth the Weberian
organ as the morphological equivalent of the
vagina and uterus together.

The latter of these two acceptations, which
I have already defended against Meckel in
another place*, finds its full confirmation in
the observations on its normal and abnormal
development. On these grounds it may be
advisable to review them briefly in this place.

From the exposition which Rathkef has
given us of the development of the vagina

* Gottingische Gelehvte Anzeigen, loc. cit.

t Abhandlungen zur Bildungs- und Entwicke-
lungsgeschichte, Leipzig, 1832, S. 60.

VOL. IV.

and uterus, it becomes evident that these two
structures at first present the appearance of
a common or inseparable tube, the genital
canal, which is only afterwards divided into
an upper and under section by a different
development of its coats, being connected with
a transverse dismemberment. One of these is
developed into the vagina; the other forms
the uterus. At its first formation the uterus
is simple : its cornua only begin later, when
the tubes enter its cavity.

Now, if this genital canal sustained a check
of development prior to the separation of the
uterus and vagina, it would remain as a simple
tube, the horns of which would be either not
at all or but imperfectly developed : in short,
it would be a Weberian organ.

In this way the observations on the normal
development of the genitals do not in the least
contradict the explanation of the Weberian
organ as a genital canal (uterus plus vagina).
It is true that we can scercely thence deduce
an absolute proof. We find it, however, in
the evidence afforded by the pathological his-
tory of its development, since we observe that
the Weberian organ is there metamorphosed
into both of these parts.

I have already mentioned above, that a
knowledge of the Weberian organ is of the
greatest importance in the study of herma-
phrodism — a study which now requires a
fundamental revision in connection with the
recent observations on the morphology of the
genitals — and especially since the numerous *
instances of androgyny for the most part de-
pend upon an excessive development of this
structure in the male individual, — associated
with some other abnormal occurrences in the
development of the uro-genital canal and the
penis, which appear at the same time, accord-
ing to the law of coexistence.

I have now a number of such androgyny
before me. They are all goats, in whom this
deformity of the genitals is proportionately
very frequent. The exterior segments of the
genitals (uro-genital sinus and penis) are, in
different degrees of development, formed after
the female type, i e. they are checked in their
development to male parts ; and so also is
the Weberian organ; while instead of ovaries,
testicles with epididymes and seminal ducts
are present.

In one of these, a new-born animal, the
Weberian organ forms a very considerable
tubular dependency, which opens by an oval
and fissured aperture of about 14 lines in
length, close beneath the two vasa deferentia,
in the commencement of the short and wide
uro-genital canal. (Fig. 882.) From thence the
Weberian organ ascends for about two inches
as a short and wide cylinder, to split at its
extremity into two horns of an inch in length.
The left horn is hollow in its whole course,
but the right only in its lower half. The

* Another smaller number of androgyni includes
female individuals, with excessive development of
the Wolffian bodies and their efferent duets (Epi-
didymis and vasa deferentia). Vide Simpson, loc,
cit., p. 707.

4 v

1426 VESICULA PROSTATICA.

vasa deferentia coarse along the anterior
surface of the Weberian organ, and are con-
nected thereto by areolar tissue. Subse-
quently to the splitting they run along the

Fig. 882.

Internal Genitals of a Male hermaphrodite Goat.

a, a, testicles with epididymis b, h ; c, guber-
naculum testis ; d, d, vasa deferentia with the
seminal vesicles; e, vagina; ff, cornua of the
uterus.

lower border of the cornua, between the two
lamellae of the ala magna, but soon become
continuous with the canal of the epididymis.
The testicles have not descended into the
scrotum. They lie at the ends of the cornua,
the outer coverings of which pass into the
sheath of the epididymis. If the vasa defe-
rentia (which are somewhat thickened at
their lower extremities, and, at about six lines
from their apertures, possess a pair of seminal
vesicles which lie more deeply), be removed
from the Weberian organ, it will be seen that
the lower end of the latter (e) is wider in an
extent of nine lines than the segment which
lies above it, and is distinguished therefrom
by a constriction. By a further examination
of the interior at this point, 1 find a transverse
fold by which the two segments are still more
separated from each other. Although this
fold is not a complete os tineas, yet it cannot
be doubted that the two segments of the
Weberian organ, which are limited thereby,
are the uterus and vagina ; the less so
that they possess different developments of
the muscular and mucous membranes, which,
in appearance and structure, exactly corre-
spond with these membranes in the uterus and
vagina of a new-born female goat.

In a second individual 1 remark a very
similar form and development of the Webe-

rian organ : excepting that there is a much
more considerable size and capacity, which is
due to the adult age at which the animal was
killed. But here there is no separation into
vagina* and uterus. But, in spite of this, by
a comparison with the normal female genitals
of an individual of the same age, one will
easily be convinced, that the Weberian organ
in this instance corresponds to the uterus with
the vagina, and not to the former of these
only.

But this may best be seen in a third herma-
phrodite now lying before me (fig. 88.3.). Here
the Weberian organ is so completely separated
into uterus and vagina by the development of

Fig. 883.

Internal Genitals of a Male hermaphrodite Goat,
a to/, as in. fig. 8S3. ; g, g, Fallopian tubes; h, ure-
thra; i, uro-genital canal.

a formal os tincai, that it might almost be
thought, from the simultaneous presence o1'
the Fallopian tubes f, from the very consider-

* The hermaphrodite goat figured by Gnrlt (Path.
Anat. Tab. 22. fig. 3, 4.), and copied by Simpson
(loc. cit. p. 300.), exactly resembles this; only the
horns of the uterus were here produced for a great
length, because the testicles had descended through
the inguinal canals into the scrotum.

+ The presence of real tubes in the so called An-
drogyni is very rare, and has perhaps hitherto beci
observed with certainty only by Mascagni in the
bull. (Atti di Siena, vol. vii. p. 201.) What are
usually thus called are only the longly produced
horns of the uterus. All that lies between the body
of the uterus and the Hunterian ligament belongs,
to the cornu of the uterus. The tubes always lie, as
H. Meckel lias pointed out (1. c. S. 43.), on the
other side of the Hunterian or round ligament, as
is represented in my case by the figure above. At
the end of the tubes in this ease, there is a small,
almost cup-shaped, nodosity at the inner border of
the epididymis, which is apparently the imperfectly
developed fimbria.

VESICULA PROSTATICA.

1427

able width of the vaginal orifice, and the
almost female uro-genital canal, that we had a
true female before us. The testicles (a a),
which remain in the abdominal cavity, possess
a true ala vespertilionis, and also exhibit a
more solid parenchyma than usual, although
they consist of spermatic gland-canals. Only
the epididymis and vas deferens are distinctly
male in character. The latter (cl cl) takes the
same course as in the instance previously de-
scribed, except that the lower ends are com-
pletely buried in the anterior wall of the body
of the uterus and the vagina (like the Gart-
ner’s ducts), and the seminal vesicles are much
smaller.

In this way we acquire a conviction that the
Weberian organ, by a further development, is
formed — not into a uterus only, nor yet into
a vagina only’’ — but, at least as a rule, into
both these structures simultaneously. Hence
we need not scruple to regard it as the mor-
phological equivalent of both. So that the We-
berian organ is the male sinus genitalis, which in
the female animal undergoes a further develop-
ment into the vagina and the uterus.

It is certainly an important guarantee for
the correctness of this theory, which had been
casually expressed for some time by Bim-
baum *, and is now — from a communication to
me by letter — shared in by my friend H.
Meckel, that it had been applied by E. H.
Weber f himself, to the vesicula prostatica of
the rabbit. From a comparison with the
female organs, he came to the conviction, that
it represented the uterus with the vagina ;
but unfortunately he neglected to extend this
view, and in the other Mammalia he regards
the vesicula prostatica as only a masculine
uterus.

We have mentioned above that the lower
part of the Weberian organ is occasionally
contrasted with the upper, either by an annular
constriction, in man, or by a singular width,
as in the horse : or that the contrast may be
limited to particular individuals, as in the
goat. It is evident that this can only be
explained as a transverse severance into
uterus and vagina, a condition which cer-
tainly is never normally completed in the
male animal.

And when, as sometimes happens in the
horse, the upper section altogether disappears,
we need have no scruples in regarding the
lower remaining part as the vagina only. J In
such instances the theory of Meckel holds
good : a theory which was but too widely ap-
plied by its founder.

lienee it may be laid down as a law, that
the upper part of the Weberian organ, which
corresponds to the uterus, and which also
shows such great variations in the develop-

* Besclireibung und Kritik einer eigentkumlicke
Bildungshemmung. Giessen, 1848, S. 15.

f Zusatze, &c„ S. 8.

I In some pathological instances a vagina exists
without an uterus ; as was detailed by llicco (Cenno
Stor. su di un neutro uomo), and quoted by Simp-
son (1. c. p. 703.).

ment of its horns, is less persistent than the
under part of the vagina. Thus the question
may arise whether the Weberian organ, when
it is devoid of cornua, still possesses an upper
or uterine part. In order to decide this with
certainty, every such instance would require
a careful analysis, assisted by the history of
its normal and abnormal development. But
as a rule we are justified in supposing that the
Weberian organ is, as was stated above, and as
is constantly rendered indubitable by the pre-
sence of cornua, both vagina and uterus.

I have here, without further discussion,
passed over the question, whether a com-
plete absence of the vagina may not obtain in
the male mammalia ; a supposition which is
required by the unconditional reception of
Weber’s theory. And this has been done
because an assumption of this kind only leads
to doubtful morphological hypotheses ; the
necessity of which seems very inconceivable
after the positive results we have already
obtained. Wherever the female individual
possesses a vagina the Weberian organ is, at
least in part, vagina also ; even where, as in
the beaver, the exterior appearances speak by
no means strongly in its favour.

But it is certainly otherwise in the case of
those Mammalia whose females lack the vagina.
Here I do not so much refer to the mono-
tremata, who, in the development of their
genitals, approach much more closely to the
birds than to the other Mammalia, and per-
haps are devoid of a proper uterus : but rather
to the elephant, in the female of which, as
Mayer has lately shown *, the orifice of the
urethra is only separated by a very small fold
from the external orifice of the uterus, and the
vagina is absent. The whole genital canal is
here metamorphosed into uterus. In like
manner the Weberian organ of the young male
certainly corresponds to the uterus solely.
In any case, such instances constitute but
rare exceptions, and do not affect the general
interpretation of the Weberian organ.

After all that we have now learnt concern-
ing the morphological import of the Weberian
organ, it is scarcely necessary to state, that
it, — or rather the embryonic part out of
which it is developed in the male animal, —
is present in all mammalia up to a certain
period of foetal life. Where it is afterwards
absent it must be attributed to a retrograde
process of development ; which to some ex-
tent appears to occur very earl}', as in the
sheep. The date and degree of this retro-
gression is shewn by the anatomical de-
velopment of the Weberian organ. In some
instances it preserves both its embryonal
form and size ; in others it continues to in-
crease even after birth, as was especially men-
tioned of the rabbit.

I recur once more to this animal, because
it, with its congeners, is not only conspicuous
on account of the described connection be-

* Beitrage zur Anatomie der Elephanten ; in den
Nov. Act. Leopold, t. xxii. P. II. S. 38.

2 Y 2

VESICULA PROSTATICA.

1428

tween the Weberian organ and the vasa de-
ferentia, but also on account of its seeming
to constitute an exception to the alleged
morphological law that the efferent ducts
of the Wolffian glands never open into the
vagina, but always into the point of its tran-
sition into the uro-genital canal. Accord-
ing to my observations in the embryo of the
rabbit, even here the ordinary relation is
originally present: the Weberian organ opens
close behind the vasa deferentia into the uro-
genital canal. But very soon a transverse
fold arises behind the points of opening of the
seminal ducts, and by its continual enlarge-
ment, even after birth, it as constantly pro-
trudes these openings outwards into the neck
of the Weberian organ. Even in the fully de-
veloped condition this fold may be recognised
in the anterior swollen margin of the opening
of the Weberian organ.

Addendum. — A considerable period having
elapsed since the MS. of the preceding article
was placed in the Editor’s hands, I have
availed myself, during that time, of many op-
portunities both of confirming and extending
my observations on the phenomena con-
nected with the Weberian corpuscle. My
esteemed friend and colleague, the eminent
embryologist, (J H. Bischoff, has, with great
liberality, handed over to me a large number
of rare preparations, from the collection of
the Giessen University, for comparative ex-
amination.

From another source also an important
addition to the knowledge of this organ has
been afforded us ; and this I hail with the
greater pleasure, as it shows how great an
interest attaches itself to this subject in other
countries. The treatise to which 1 allude is
the Inaugural Dissertation by Wahlgren, pub-
lished at Lund.*

I therefore now find myself in a position
to fill up many deficiencies in the foregoing
paper. For this purpose I prefer the form of
a supplement, and hope that the reader will
excuse whatever degree of inconvenience at-
taches itself to it, on account of the circum-
stances under which a foreign contributor is
situated.

Quadrumana. — I formerly conjectured that
the true Apes, without exception, possessed
the Weberian organ (p. 1416.) ; in confirma-
tion of this, 1 can now add, that it occurs
both in the species mentioned (/ oc . cit.), and
in Pitheem troglodytes and Cynocephalus por-
carius. Wahlgren observed it likewise in an
undescribed species of Ape. It appears, how-
ever, not to occur throughout the group in an
equal manner. In the Lemur alkifrons, I ob-
served on the colliculus seminalis a fine longi-
tudinal fissure, between the apertures of the
seminal ducts (a fine capillary canal entered
it a short distance — but this may have been

* Bidrag till Generations-Organernas Anatomi
ocli Pliysiologi hos Menniskan och Daggdjuren,
1849. Translated by Peters into German, in J. Mul-
ler’s Archiv fur Anatomie and Physiologic, 1849,
S. 686., etseq.

made in mounting the preparation): in Stenops
tardigradus I have, however, convinced myself
of the absence of the organ.

Force. — Wahlgren describes the Weberian
corpuscle in Fells lynx as an oval cavity, three
lines in length, and opening by a fissure-hke
aperture into the uro-genital canal on the mid-
dle of the verumontanum. In the Brown
Bear it is similar, but much larger (5"'), pear-
shaped, and with a considerable aperture.
Nasua fused, also, according to Wahlgren,
possesses a similar gland. In the Otter, I
have now observed this organ in two speci-
mens. It is disposed as the foregoing, and; as
was conjectured, has a considerable central
cavity, with a small aperture. The cornua
are solid ligamentous cords.

Marsupialia. — The marsupial animals ap-
pear to be very generally destitute of this
organ. In Halmafurus giganteus, Phascolomys
wombatus, and Sarcophilus ursinus, I found no
more traces of it than previously in Didelphys
virginiana. Wahlgren also found it absent in
Hcdmaturus giganteus.

Rodentia. — The remarkable structure of
this organ in Rabbits and Hares might well
belong to the whole group of the Leporince .
In Lepus borealis it is the least, catens paribus,
according to Wahlgren. Yet here it attains
even the colossal size of three inches, with a
proportionate breadth (up to i" 10"'). With
the Palmipedia, on the contrary, it is other-
wise. Distinct as it is in the Beaver (p.
1418.), it is but little developed in the nearly
related Myopotamus coypus, in which Wahlgren
found a mere rudiment, consisting of two
thread-like cords. The two agreed in their
position with the Weberian corpuscle of the
beaver, and enclose a small cavity, with an
opening on the colliculus seminalis. With re-
gard to Sciurus, Wahlgren confirmed the ab-
sence of the organ : nor was it observed in
Lemnus. Hystrix cristata and Hydrochccrus
capybara are likewise without it, according to
my own observations. In the last, however,
as in the closely allied Agouti and Cavia, the
two seminal ducts have a common, cavernous,
wide aperture.

Edentata. — Besides the Bradypus tridac-
tylus, I have lately examined Cholcepus dulac-
tylus, also Dasypus octosus, and Ornithorhyncus
paradoxus. In none of these is the organ
present. Wahlgren also states the same of
Ornithorh yncus.

Runiinantia. — The Weberian organ appears
to be generally present in the Cervina. That of
the deer is above described (p. 1420.). It is ffir
more considerable in the Hart and the Reindeer,
where it ascends between the seminal ducts
in the firm of a cylinder, about two inches
long, which in the former is distinctly bi-cicft
at the extremity. There is an internal cavity,
which in the Hart is continued into the
cornua, and opens on the verumontanum.
In the Goat there are numerous individual
varieties in the development of this organ,
as I have before mentioned (p. 1420.). In
many instances it is altogether wanting, as
I have now convinced myself. In one case I

VESICULiE SEMIN ALES.

1429

saw it in the form of a single longish body
(3'"), between the vasa deferentia; in another
it continued upwards as a long solid cord,
which adhered by its bifurcate extremity to
the seminal ducts. In both cases it had a
distinct opening. The wide differences in the
development of the organ above mentioned,
are of rare occurrence.

As regards the Sheep, the absence of the
Weberian corpuscle in the perfect form has
been already stated. According to Wahlgren,
however, such is the case (as in the Goat) in
isolated individuals only ; whilst in others, on
the contrary, a small purse-shaped body repre-
sents this organ.

Wahlgren describes this organ as occurring
in the Bullock in the form of a flask-shaped
sac, 6-T" long. That here also many va-
rieties occur (as pointed out by my observa-
tions), is evident, for in another (castrated)
animal it was present as a short uniform canal.

Cetacea. — In a young specimen of Delphinus
delphis (so labelled), I now find, as already
stated in regard to other species, two thick, cleft-
shaped, closely approximate pseudo-repre-
sentations of this organ. The examination of
the Halicore dugong was of particular interest
to me. This animal, belonging to the group
of herbivorous whales, possesses a Weberian
organ, having a small roundish (and bordered)
opening on the colliculus seminalis. Its form
and size cannot be accurately determined on
account of the condition of the preparation ;
it appears, however, to be about an inch in
length, and in shape like a wide longish bottle.

A peculiar structure here distinguishes the
commencing portion of the uro-genital canal.
Instead of exhibiting a direct continuation of
the urethra, it begins with a peculiarly wide
cavity, which is bent outwards like the bellv
of a retort, and receives the urethra (under
wh'ch the large colliculus seminalis rises pro-
minently) on its hinder wall. I know of only'
one mate mammal that presents a similar
structure, viz. the Hedgehog; nor in this case
is the disposition of parts so remarkable.
When, therefore, Wahlgren asserts that this
cavity at the commencement of the uro-genital
canal in the Hedgehog is the Weberian organ,
he is in error ; as is proved by the co-exist-
ence of both of these peculiarities of struc-
ture in the Dugong.

In reference to the morphological significa-
tion of the organ in question, Wahlgren com-
pletely agrees with me. Tie also views it as
the representation of the whole femaie sinus,
that is, the uterus and vagina taken together.*
We must not forget that, as we have already
observed, the latter of these two parts finds

* Still more recently, on the contrary, Van Decn
affirms (Zeitschrift fiir wissenschaftl. Zoologie v.
Siebold und Kolliker, 1849, S. 268.), also Betz (Mul-
ler’s Archiv, 1850, S. 65.), that the Weberian organ
is exclusively the “ uterus masculinus.” We do
not here again enter into a critique of this view, and
must refer our readers to our former remarks. We
must mention, however, that the first of these arti-
cles contains very numerous errors, and many' odd
hypotheses!

a complete and general representation in this
organ. This especially applies to the simple
form of this organ, when it occurs as a mere
oval body without upward continuations of
the cornua ; and among others, to the human
utriculus, which, on that account, in the case
of an abnormal enlargement, becomes merely
a vagina. Steglehner has already remarked*
on this subject, that the so-called uterus cys-
todes of Ackermann’s well-known hermaphro-
dite case (Art. Hermaphroditism, Vol. II.
p. 7G9.), answered, not to the uterus, but the
vagina. I have been led to the same results
by the examination of a great number of
human hypospadiacs and hermaphrodites. A
true uterus, as in the single case of Mayer j-,
is indeed only seldom found on such a va-
gina. The vasa deferentia pass constantly
on the anterior wall of this vagina, and open
near it in the uro-genital canal, like Gart-
ner’s canals in the Ruminantia. They are
never connected with the vagina itself, as
Hyrtl has observed.

( Rud . Deuel: art.)

VESICUL.E SEMIN ALES. — These
are a pair of sacculated organs, peculiar to
the male, situated behind the bladder, be-
tween it and the rectum. In man they ap-
pear, externally, as multilocular cysts about
two inches in length and three quarters
of an inch in their greatest breadth. Their
shape is fusiform ; their larger ends diverging
from one another, and their smaller ends con-
verging so as almost to meet. These smaller
ends are surrounded by the prostate, and are
directed slantingly forwards, as well as down-
wards and inwards. Along their inner sides
pass the vasa deferentia, with which they
join, by a narrow outlet, at the base of the
prostate.

The vesiculce are invested by a fascia de-
rived from the prostate, which can be removed
by careful dissection, and then they are found
to consist of a blind tube of about the calibre
of a small goose quill doubled upon itself
again and again, all the gyrations being held
together by cellular tissue, so as to give
the appearance of fusiform multilocular sacs.
A little careful maceration will enable the
anatomist to unravel these gyrations, when
each vesicula will sometimes be found to
be one simple caecal tube about six or eight
inches long, or, more frequently, there will be
three or four caecal diverticular appendages to
the main tube, in which case the greatest
length (that of the central main tube) will be
very much less. This tube has a very much
smaller calibre for a short distance from its
junction with the vas deferens than else-
where. The narrow portion is straight, and
is commonly called the duct of the vesiculae
seminales.

These vesicles are found to contain a
synovia-like brownish mucus, the nature of

* De Hermaphroditorum Natura. Bambergas,
1817, p. 97.

f Yol. II. Art. Hermaphroditism, fig. 303.

4 y 3

1430

VESICUL.E SEM1NALES.

which we shall have to inquire into presently,
when we treat of their function.

The fascia that invests the mass of gyra-
tions, like a fusiform bag, contains a great
proportion of involuntary muscular fibre, and
there is also a large admixture of involuntary
fibre in the proper parietes of the tube. It is,
of course, lined throughout with a mucous
surface, which has a faint reticular marking,
like that of the stomach in some animals,
and is evidently glandular, or secreting.

Comparative Anatomy. — Some consider-
able difficulty has been experienced by com-
parative anatomists in identifying the vesiculse
seminales in different animals. This has
given rise to much discrepancy as to their
existence, or non-existence, in certain species.
In the Ruminantia, for instance, the prostate
assumes the very singular form of two organs,
each having a large central cavity opening
into the urethra by a single duct ; and these
organs, very naturally, have been regarded by
some as vesiculse seminales. Who, indeed,
can undertake to say, with certainty, that
they are not? It is far from improbable that
they are both the one and the other — pros-
tate and vesienla at once.

There are two very distinct kinds of com-
parative anatomical identity — functional iden-
tity and homological identity. Instances are
very numerous of homologically identical parts
being very diverse in function ; the function of
the (homological) hand, for instance, is to
seize with in man, to walk with in the horse,
to fly with in the bat, and to swim with in the
whale. And there are not wanting many in-
stances of parts functionally identical, and
homologically diverse ; a striking instance of
which is furnished by the urinary bladder in
Mammalia, compared with the reservoir of
urine sometimes met with in Ovipara. In
the case now before us, the function is in
question, and the homology by no means
jrrononce ; no wonder then that identification
should be difficult and uncertain. We pro-
ceed, however, to notice the various forms
of certain sacs met with in brute animals,
posited in close relation to the vasa defe-
rentia, and impressing one somehow', perhaps
homologically, with a notion that the}' are
identical with the human vesicular seminales.

Such vesiculae are exclusively confined to
the ‘placental division of the Mammalia. They
are not met with in the Marsupialia nor
Monotremata, nor in the other vertebrate
classes, — Aves, Reptilia, nor Pisces. In
some of these, Aves for instance, there are
undoubted reservoirs of semen, formed by di-
latations of the vasa deferentia ; these, how-
ever, are manifestly not the organs in question.

Reservoirs of semen are also met with in
some Invertebrata, but since, as I have else-
where noticed (Art. Symmetry, Vol. IV.,
p. 850.), homological identity of parts can in
no instance be established in animals belonging
to different sub-kingdoms, the only identity
being in all cases merely that of function,
these have no title to be described in an
article on the vesiculae seminales, from which

by function they are, as will be seen here-
after, for certain diverse.

They are indubitably present in all the
Quadruviana, the Cheiroptera, and the Insecti-
vora. They are wanting in the Carnivora.
Present in the Rodcntia, and Pachydermata ,
and in the Manatee. In the other Cetacea
they are absent. In the Ruminantia, the ques-
tionable organs, mentioned above as hollow
prostates, occur.

In the higher Quadrumana they much re-
semble those of man ; and their ducts join
the vasa deferentia much in the same manner
as in the human subject. In most of the
lower monkeys they have not the convoluted
form, but occur as simple sacs, and the outlets,
at the side of the verumontanum, alone are
common to their ducts and the vasa deferentia.
In Galeopithecus they are remarkably small.

In the hedgehog their size is enormous —
twice that of thevesiculae in man — and they
have a very interesting form. They consist
each of a small central duct, from which ramify
very numerous convoluted caeca of much
greater calibre. The central duct terminates
on the verumontanum, near the vas deferens.

In the Rodentia they are, mostly, very large.
In the rabbit and hare they are, apparently,
fused together, and form a single mesial sac,
the upper end of which is somewhat square,
thick and glandular. This sac opens by a
mesial orifice, which receives the vasa defe-
rentia, upon the verumontanum. It is, how-
ever, very improbable that this really (homo-
logically) represents the vesiculae seminales ;
its mesial position, between the vasa deferentia,
is essentially different from that of the vesiculas,
which is always external to those ducts. It is
most probably the utriculus prostaticus. In the
other Rodents they are double ; — long, simple,
and bi-fusiform in the guinea pig; serrated in
tY\erat ; having small ramifications mtheagonti;
and convoluted in the beaver. In the squfrrel
they consist of a small tube with glandular
parietes, and much convoluted. In the Alpine
marmot they are but slightly developed, very
convoluted, and have glandular parietes. In
all these their outlets are quite distinct from,
though near to, those of the vasa deferentia.

In the Pachydermata they assume very-
various forms. In the genus Equus they re-
semble two small urinary bladders, and have
two distinct muscular coats. They are thicker
at their fundus than elsewhere; the thickening
consisting of a glandular substance. The
orifice of their ducts is in common with those
of the vasa deferentia. There is also, in this
genus, a third vesicular organ, situated me-
sially between the vasa deferentia, of a long
eylindical form, with a rounded fundus, and
secreting a substance of the consistence and
colour of honey. This is, undoubtedly', the ho-
mologue of the utriculus prostaticus. In the
Hyrax they are very large and convoluted. In
the Rhinoceros they consist of two large irre-
gular sacs, whose excretory ducts join the vasa
deferentia. They are very large in the elephant,
of an oval figure, with a constriction at their
upper end. Their internal surface is divided by

VESiCULiE SEMINALES.

1431

irregular columns and grooves, more marked
in their upper part, and deficient at the lower.
On their outer and anterior aspect is a pe-
culiar muscle, arising from their neck and
middle portion, and spreading out over their
upper part, which can contract their cavity
and expel t heir contents. Their ducts join
the vasa deferentia beneath their ampuliated
portion noticed below. In the boar they each
consist of a great number of lobes and lobules
arranged around, and communicating with, a
small central canal, which opens on the veru-
montanum, near the vas deferens.

It may not be out of place here to mention
several remarkable peculiarities in the structure
of the vasa deferentia, when they arrive at the
back of the bladder, in several animals. In man
this part of them is dilated and sinuous, and
generally contains a fluid very similar to that
found in the vesiculae. In the horse this
part of the ducts is extremely thickened by
the occurrence of numerous glandular cellules
in its walls. These cellules contain a thick
mucus. Much the same condition is met
with in the bull. In the elephant each vas
deferens, when it arrives at this part, enlarges
into a very large cavity, which it is evident
may readily, and no doubt does really, fulfil
the function indicated by the words vesiculae
seminales.

Function. — With regard to the function
of these organs, I am able to come to little
more than a confimation of the negative con-
clusion of Hunter, that they are not reservoirs of
semen. Hunter's positive conclusion that they
form part of the generative apparatus, is pretty
clearly proved. I proceed to offer the evi-
dence from which these two conclusions are
arrived at.

1st. They are not reservoirs of semen. That
they were receptacles into which the semen
might regurgitate and be stored up ready for
emission, was doubtless suggested by their con-
nection with the vasa deferentia in the human
subject, so like the relation of the gall bladder
to the hepatic duct. A very obvious objection
to this is that, as we have seen, the same relation
does not occur in the majority of animals ;
but the difficulty of proving the identity of
the sacs called vesiculae in other animals,
diminishes very much the force of this ob-
jection ; and even if a homological identity
were proved, still numerous caveats warn us
not therefrom to infer their functional identity.
It is moreover extremely easy to conceive the
possibility of the regurgitation of semen into
the vesiculae, where the two ducts have an out-
let, though merely an outlet, in common. (In
such cases they join just in the act, so to
speak, of debouching.) And it is far from
impossible to conceive the regurgitation of
semen even when the outlets are distinct,
especially in some instances. In the guinea-
pig, for example, the outlets of the vasa defe-
rentia, vesiculae seminales, and prostatic ducts,
are surrounded by — occur in the bottom of—
a little spout, of about a line in diameter,
which projects about half a line into the ure-
thra, slanting towards the outlet. Another

objection to their being reservoirs of semen
is that the fluid found in them is extremely
different from that found in the vasa de-
ferentia, as observed by Hunter, in colour,
consistence, and smell ; but that they should
secrete a mucus of their own, is only pa-
rallel with w'hat we know to be the case in
the gall bladder ; and that admixture with
this mucus should considerably alter the
character of the semen, is extremely pro-
bable. To a microscopic examination of the
contents of the vesiculs, we naturally look
for a solution of this question, now that we
know the extremely characteristic microscopic
appearance of semen — Are ^spermatozoa found
in it?

Muller says “ That the vesiculae seminales
are really receptacles of semen, is beyond a
doubt, since spermatic animalcules have been
discovered in their contents in the human
subject after death.” * To the fact, that
spermatozoa are occasionally found in the
contents of the vesiculae, I can add my
testimony ; but I am compelled by other
facts to dissent from the conclusion at which
Muller arrives.- To infer that the proper
function of the vesiculae is to serve as re-
servoirs of semen, because spermatozoa “have
been” found in them after death, is a non
sequitur. Spermatozoa may often be found
in the urethra, and I have found them in the
urinary bladder. These restless little entities
often wriggle themselves into organs where
their presence is far from usual or normal.
Even after death they may be forced into the
the vesiculae by the violence unavoidable
in removing the [tarts for examination. The
question is, are they usually found in the
contents ot the vesiculae, and that in large
numbers? To answer this question I thank-
fully avail myself of the more extensive obser-
vations of my friend, Mr. J. Quekett, who
carefully examined the subject some years
ago. He tells me that the presence of sper-
matozoa in the human vesiculae is not very
frequent, even when the sacs are very dis-
tended by their contents ; and that when
they are present, it is in sparing numbers —
in fact, as a few stray ones. This accords per-
fectly with the results of my own researches.

When I find the vesiculae seminales full to
distension with a mucous fluid, and discover, by
a microscopic examination, only a few solitary
spermatozoa in it, and when I compare this
with the crowds of spermatozoa seen in the
fluid squeezed from the vas deferens, I cannot
believe, even allowing a reasonably broad
margin for dilution with mucus, that 1 am ex-
amining stored semen. In the lower animals
I have never observed a single spermatozoon
in the contents of their vesiculae seminales,
although I have carefully examined it taken
from individuals that had been purposely sub-
jected to prolonged sexual excitement un-
gratified. My observations, however, have been
entirely confined to those brute animals the
ducts of whose vesiculae do not join the vasa

* Physiology. Translation by Baly, p. 8-184.

4 y 4

1432

VESICUL/E SEMINALES.

deferentia, which, as may be seen by reference
to the comparative anatomy cited above, is
the case with all the lower animals readily
procurable, alive, and in functional activity, in
this country. The best evidence that com-
parative anatomy affords on the subject is,
that, in the elephant, vesiculce seminales, join-
ing the vas deferens just as in man, coexist
with unmistakeable seminal reservoirs. If the
vesicular were merely receptacles of semen
their presence here would be quite superero-
gatory, and contrary to Nature’s usual fashion.
It adds to the signification of this fact, that
the junction of the ducts occurs below the
enormous ampulla, that is, between it and the
urethra ; so that the ampulla must be filled
before any semen could be regurgitated into
the vesiculae.

Still, as spermatozoa are occasionally found
in the human vesiculae seminales, microscopic
evidence, of itself, is not able to give us that
complete negation of the old and widely spread
view of the functions of the vesiculce which
I have ventured upon above. And here the
acute observations, unaided by the microscope,
of the immortal Hunter, of themselves suf-
ficient to prove this negation almost to a
certainty, afford such an accession of proof as
cannot fail to be convincing. He examined
the vesiculae in several subjects in which one
testicle had been extirpated a long time before
death, and he found in every case that the
vesicu/a of the castrated side was as full as that
of the other. One of the cases examined by
him was a married man in whom he had ex-
tirpated the left testicle a year before his death.
“ On examining the body, the vesiculae were
both found nearly full, more especially that
on the left side, which might have been acci-
dental.” To remark that the vesicula of the
castrated side was fuller than the other seems
to be proving too much (he observed the
same in one other case) ; but the rest of his
cases show clearly that this was, as he says,
accidental. These invaluable observations of
Hunter, together with his comparison of the
thick brownish mucus found in the vesiculae,
with the extremely different, milky, slightly
viscid semen in the vas deferens of the same
subject, and the contrast observable in the
two fluids by aid of the microscope, — a few
scattered spermatozoa or none at all in the
one, crowded myriads in the other, — lead
irresistibly to the conclusion that the vesiculae
seminales are not reservoirs of semen.

2dly, They form part of the generative ap-
paratus. This is pretty clearly ’ proved by
Hunter, by observations made on those animals
that have periods of rut or sexual excitement
alternating with periods of sexual quiescence
or impotency, such as the stag, the mole, and
the land-mouse. In these animals the vesiculae
seminales, in common with the testicles, pro-
state gland, &c., are exceedingly small during
the period of impotence, and enlarge enor-
mously and rapidly for the season of rut. In the
mole they are hardly discernible in winter, but
becomeenormously largein spring. Conclusive,
ho weyer, as this proof appears, primd facie,

to be, it is somewhat weakened by the fact
that much the same thing happens, in various
animals, to other parts which would scarcely
be enumerated as belonging to the generative
apparatus, such as the horns of the stag, the
comb of the cock, &c. Yet, adding to the
fact of this periodic enlargement and diminu-
tion the anatomical position and connections
of the vesiculce, together with their absence
in the female, there is constituted a very
satisfactory proof that they form part of the
male generative apparatus.

These conclusions, however, merely bring
us two steps nearer to a definite knowledge of
the exact office fulfilled by the organs in ques-
tion. I now proceed to adduce such other ob-
servations as I have been able to make, or
have found upon record, as may aid in forming
an hypothesis as to their positive function,
or may appear interesting.

The mucus found in the vesiculce is, as will
readily be admitted from what has been said
above, undoubtedly secreted by their glandular
parietes. This is still better proved by a case
of Hunter’s, where, as a congenital defect,
they had no outlet (nor inlet), and yet were
full of mucus. This case shows also that
they have the power of re-absorbing their
secretion, or at least renders it highly probable.
A mucus in all respects similar is usually
found in the part of the vas deferens imme-
diately contiguous to the junction of the duct
of the vesiculae. This is very probably se-
creted by the walls of this part of the vas —
in the horse there is no doubt of it. The mu-
cus of the vesiculce is very thick and viscid in
all animals, but more so in some than in others.
I have examined it carefully in the guinea-
pig, in which animal it is remarkably thick ;
but there is a difference, in this respect, be-
tween that which is near the outlet and that
which is at the fundus, it being thickest in the
former position and gradually thinner towards
the latter. It is transparent, granular, and
has a faint opaline blue colour. I found
that it rapidly solidified upon being squeezed
out of the vesiculce, and that too even when
not exposed to the air and w'hen not subjected
to any remarkable diminution of temperature,
when lying, in fact, in the urethra of the
animal just killed. The mucus contained in the
vesiculae also solidified more though slowly —
that in the fundus most slowly, and tire rest
in gradual progression up to that near the
outlet. In opening the abdomen of a guinea-
pig, it is almost impossible to avoid com-
pressing the vesiculce, and probably from
this cause a considerable quantity of the
mucus is forced into the urethra, where I
always found it forming a solid mass as hard
and elastic as the cartilage of a ray-fish,
and moulded to the shape of the urethra : this
within a few minutes after the death of the
animal. Now, this is just the contrary to
w'hat, according to Hunter, is the case with
emitted semen, which becomes more and
more fluid under exposure. I was, however,
highly interested to observe that if the vasa
deferentia and vesiculce be compressed at the

1433

VESICULiE SEMIN ALES.

same moment, so that the mucus and semen
shall mix in the act of escaping into the
urethra, and they do mix in a remarkably per-
fect manner in the little spout-like verumon-
tanum of the guinea-pig, then the immediate
solidification of the mucus dots not occur.
Whether this curious effect of their mixing is
due to the mechanical whipping of the sperma-
tozoa or to a specific solvent power for mucus
in the semen, must remain undetermined at
present.

The degree of liquefaction produced seems
to be much greater than what would be due
to simple admixture, that is to say, it is much
greater than would be produced by adding a
drop of water equally small to a mass of gum,
for instance, equally thick and equally large.
This throws fresh light on some observations
of Hunter’s, made upon guinea-pigs. He
killed a male (which, by the way, he had
castrated on one side six months before),
immediately after it had copulated, and he
found the vesiculae of both sides full. Ha
also killed a female immediately after she had
received the male and “examined with atten-
tion what was contained in the vagina and
uterus; in neither,” he remarks, “could I
find any of the mucus of the vesiculae, which
from its firmness must have been easily de-
tected.” He regards these facts as proof
that the contents of the vesiculae are not
emitted in copulation ; but that part of the
proof based on the non-detection of thick
mucus in the vagina and uterus is, of course,
much weakened by the fact of the liquefying
property of the semen. The other part of
his proof, derived from the fullness of the
vesiculae immediately alter coitus, is, perhaps,
answered by the following observations. The
vesiculae are never found empty — except when
they are diminished during the periodic rut
in certain animals — in fact they seem to all
appearance equally full at all times, but here
no doubt appearances are dectitful ; they
contract and expand according to the volume
of their contents, so that they are never flaccid,
and always appear to be as full as they can
be. I have observed them exceedingly full
and large in an animal just killed, and have
watched them contracting under the stimulus
of exposure to cold air, and when nearly the
whole of their contents have been expelled by
the contraction, they have still appeared to be
quite full, — I should have considered them to
be so if I had not actually seen them expel"
their contents. It is evident that the whole
contents of the vesiculae are not emitted in
one copulation, but there is strong reason to
believe that a part is.

The semen which can be squeezed from
the vas deferens is milk white and has very
little if any viscosity. Now Hunter de-
scribing emitted semen says, “ the semen first
discharged from the living body is of a bluish
white colour, in consistence like cream, and
similar to what is found in the vasa deferentia
after death (?); while that which follows is
somewhat like the common mucus of the
nose but less viscid. The semen becomes

more fluid upon exposure to the air, particu-
larly that first thrown out.” Here then is a
mucus, which very probably is from the
vesiculae. I am convinced that it does not
exist in the semen of the vas deferens.

The mucus of the vesiculae, examined in
the guinea-pig, is not soluble in water. The
urine of the animal seems to solidify it in an
extreme degree, for if a little of it gets into
the urinary bladder it becomes as hard as
spermaceti. Boiled in water it shrivels up
slightly, but is not in the least degree dis-
solved. I dissolved it by repeated boiling in
solution of potash, by which means I pro-
cured a perfect^ limpid, colourless solution.
This yielded no precipitate on the addition of
acetic acid. In neither of these respects,
therefore, does it differ much from the ordi-
nary varieties of mucus. (See Art. Mucus,
Vol. III. p. 482.) Submitted to microscopic
examination, 1 have found it to consist of a
very sparing quantity of fluid, in which are
suspended little conglomerated masses of trans-
parent solid, just visible b}T the naked eye.
The majority of these are of a pretty uniform
volume, and appear, when magnified fifty dia-
meters, about the size of duck shot, there are,
however, much larger ones and much smaller.
Their general contour, whether they be large
or small, is spherical, and they have a nodulated,
mulberry-like surface, asif composed of smaller
bails. The smaller component balls have also
an irregular, granular surface, and neither they
nor the large conglomerate spheres show any
distinct trace of being enclosed in a cell-mem-
brane. I have, however, sometimes observed
numerous nucleated cells in a portion taken
from the fundus of the organ. But often I
have sought for these in vain. I have never
found them when the vesiculae have been ex-
ceedingly full and distended, in which circum-
stances, most probably, secretion would be
arrested, and perhaps even absorption going
on. These cells are about the size of the
smaller (component) spheres. I am tempted
by these observations to conclude that the
cells I met with were the secreting epithelia
of the vesiculae, and that becoming fiiled with
inspissated mucus (?) they conglomerate them-
selves into larger spheres. 1 found it con-
venient in making these examinations some-
times to add a little white of egg, which pro-
duces no alteration in the appearances beyond
a greater isolation of the spheres. When
water is added, the outlines of the spheres
become much more distinct, showing a greater
difference of refraction of light, and there be-
come percept. ble very numerous insoluble
globules, which have a great tendency to
coalesce, and appear very much like oil ; their
refractive power is, however, less, and there
are other reasons for doubting that they are
really globules of oil. When semen is mixed
with this secretion of the vesiculae, the spheres
are still visible, and the spermatozoa are seen
disporting in the fluid between them. No
solution of them is clearly detectable. This,
however, it should be observed, is when the
mixture is exposed to cold, &c. in examination ;

1434 VESICULvE SEMIN ALES.

it might be different when it is lodged in the
uterus or vagina of the female.

For reasons given hereafter, I am led to
believe that the quantity of actual seinen
from the testicles emitted at each copulation,
is most probably very small, perhaps only
three or four drops, at all events not more
than tile vas deferens is capable of containing.
Such an extremely small quantity would be
lost in the capacious canal of the urethra, or
still more in the enormously capacious canal
of the vagina, in the uterus, and in the Fallo-
pian tubes. Some dilution, some addition
to the volume, seems necessary in order to
obtain an efficient injection of the life-giving
fluid. And the quantity actually emitted
by a rnnn amounts, by all accounts, to two
or three drachms. There has been an ad-
dition somewhere. The prostate has doubt-
less contributed its share, the tiny glands of
Cowper theirs, the urethra has given its mite
of mucus, more mucus is awaiting in the va-
gina, and I believe that the vesiculae are not
behind in adding a portion of their hoard of
ready-formed mucus to the general stock.
The spermatozoa huddled and crowded in
countless millions in the vas deferens are now
able to disport themselves at ease in the con-
genial medium ; and the number contained in
a few drops of pure semen would be sufficient
to people abundantly several drachms of fluid.

I am induced by these considerations to
form the hypothesis that the office of the
vesiculae is to secrete, and keep in store, a
mucus of such a nature as is congenial to
spermatozoa ; which answers the simple
purpose of diluting the semen secreted in
sparing quantities by the testicles. By di-
luting I mean merely increasing the volume,
not liquefying; for the mixed fluid is more
viscid than pure semen. This hypothesis I
would, however, have regarded as only pro-
visional until more satisfactory evidence is
obtained. It is the only one which the facts
at present known warrant. One is much
inclined to doubt that so singular an organ as
the vesiculae is devoted to so simple a pur-
pose. The prostate is generally believed to
perform an exactly similar office ; and one is
still more loth to believe that two organs so
different in appearance as the prostate and
vesiculae have an identical function. But as I
have- advanced this hypothesis I proceed to
defend it on these and other points.

That organs, having the air of being very
important, are sometimes engaged in per-
forming a very simple and subordinate func-
tion, is instanced by the salivary glands, which
afford also an example of several distinct
organs fulfilling exactly the same purpose : —
the parotid, the submaxillary, the sublingual,
and the numerous little buccal glands, all
engaged in secreting a moistening and diluting
fluid, which is not indispensably necessary.
All these salivary glands are, however, very
much alike in appearance and structure,
whilst the vesiculae seminales do not in any
way resemble the prostate. In reference to
the human subject this remark is true, but

not as regards many brute animals. In the
guinea-pig the prostate is composed of nu-
merous ramified caeca, but loosely bound
together, and not very small in calibre, and
the vesiculae really appear as though they
were merely a couple of the prostatic caeca
gigantically developed. The secretion of these
prostatic coeca is also exactly similar to that
of the vesiculae. Objections to the iden-
tity of the functions of two organs, based
on the difference of their appearance, are
completely answered by observing the enor-
mous difference of appearance of the liver, -
for example, in vertebrata, compared with the
liver of a crab or lobster ; or, what is more
similar to the case under consideration, the
large and remarkable gland that secretes the
egg-shell in the ray-fish, compared with the
part which secretes the egg-shell in birds,
which is nothing more than just a peculiar
villosity of one portion of the oviduct. It is
not now my task to enquire into the function
of the prostate, I am merely combatting an
objection that may be raised to the hypothesis
which I am advocating.

The question very naturally suggests itself,
how is it that the vesiculae are absent in
several animals of the mammalian class ? In
birds and reptiles there is no urethra, no
vagina, no uterus for the semen to be lost in :
the orifices of the vasa deferentia are brought
into immediate apposition with those of the
oviducts in the act of copulation ; but in the
carnivora, where the vesiculae are indubitably
absent, the seinen has to find its way,
meandering through all those labyrinths; and
in the kangaroo, the wombat, &c., the males
of which have no vesiculae, the vaginae of the
females are remarkably long, double, and sin-
gularly crooked (see Yol. Hi., fig. 138,).
The answer to this is, the males of these
animals possess a great number of glands (loc.
cit. figs. 135, 136. and Vol. IV. fig. 875.),
pouring their secretion into the urethra,
which secretion, not improbably, serves the
same purpose of dilution.

With respect to the difference of the con-
tents of the vesiculae in different animals, so
obvious, for instance, in respect of their con-
sistence or viscosity, it should be remembered
that we have evidence of a specific relation
between the spermatozoa of a given species
and the medium in which they are destined to
float after their exit from the spermatic ap-
paratus. I allude to the fact noticed in the
article Semen (Vol. IV. p. 504.), that the
spermatozoa of amarine non-copulating species
continue their movements in sea water, but
become instantly motionless and dead when
treated with fresh water, which has no inju-
rious effect on the spermatozoa of freshwater
species. This may, perhaps, also throw light
upon the function of other accessory seminal
glands. Every copulating species is probably
able to supply, from one or several glands, a
medium congenial to its own spermatozoa.

There is then no special reservoir for semen
in the human subject, nor in the great ma-
jority of mammalian animals. What then

VESICULAR SEMINALES. 1435

becomes of the secretion of the testicles
when it is not used ? Another question also
requires to be answered. The semen, as will
be seen by referring to Art. Semen, seems to
be a highly elaborated secretion. There is
none amongst the various secretions of the
body that seems to require so much time for
its elaboration. Not only have cells to be
formed and thrown off, as in the case of other
secretions, but, after they are liberated in the
tubules of' the testis, nuclei have to divide,
nucleoli to multiply, and each division of the
nucleoli to become, through a gradual adoles-
cence, an adult spermatozoon. This surely
requires time ; how can such a fluid be im-
provised at any moment when copulation may
take place ?

To the first of these questions I would
answer, the testicles do not go on continually
secreting, but stop when there is no occasion
for their action ; as 1 have convinced myself
by observing, that the vas deferens is gene-
rally found empty in men who have been
long removed from the society ot women.
Hunter arrives at the conclusion, that the vas
deferens and testicles can and do reabsorb the
unused semen, and that conclusion it is im-
possible to avoid, because there are many
instances on record of the vasa deferentia
being imperforate in a subject whose testicles
were in full functional activity. But involun-
tary emissions in sleep are most probably the
usual and natural means whereby the burden
of unappropriated secretion is got lid of.

The answer to the second question is as
follows. There is strong reason to believe
that man, in common with brutes, is subject
to a periodic rut, an alternation of sexual
excitement and quiescence, occurring at short
intervals. During the period of excitement
spermatozoa are becoming rapidly adult, the
testicles and their ducts are full of semen, the
individual is in the condition of a fish with a
full milt, or a bird or stag with enlarged tes-
ticles. He now instintively seeks the society
of women (these things are not so mucjj mat-
ters of chance as is generally imagined, and the
testicles may be blameable for much of what
is usually ascribed to the heart). Lascivious
dalliance increases his excitement, and all is
ready for the copulative act. There is reason
to believe that one vas deferens alone furnishes
the semen for one copulation, the other vas
supplies another emission ; but after a few
encounters, some of them perhaps without
effect, a period of rest is required to secrete
and perfect a fresh store of semen. The
duct of the testicle is the only reservoir, and
for that reason, combined with the unlikeli-
hood of the impromptu secretion of semen, I
formed the opinion cited above, that the
quantity of actual secretion of the testicles
emitted in one copulation is probably so small
as to require augmentation by some congenial
fluid.

Hunter remarks,- — “ We have a presump-
tive proof that the semen can be absorbed in
the body of the testicle and in the epididydi-
mis, and that the vesiculae secrete a mucus

which they are capable of absorbing when it
cannot be made use of. We may likewise
infer from what has been said, that the se-
men is not retained in reservoirs after it is
secreted, and kept there till it is used, but
that it is secreted at the time, in consequence
of certain affections of the mind stimulating
the testicles to this action ; for we find that
if lascivious ideas are excited in the mind,
and the paroxysm is afterwards prevented
from coming on, the testicles become pain-
ful and swelled, from, we may suppose, the
quantity of semen secreted, and the in-
creased action of the vessels, which pain and
swelling is removed immediately upon the
paroxysm being brought on and the semen
evacuated ; but, if that does not take place,
the action of the vessels will still be kept up,
and the pain in the testicles in general conti-
nue till the paroxysm and evacuation of the
semen is brought on, to render the act com-
plete; without which a stop cannot be so
quickly put to the action of the vessels that
produce the secretion, nor the parts be al-
lowed so easily to resume their natural state.
There is at this time no sensation of any kind
felt in the seat of the vesiculae seminales,
which shows that the action is in the testicles,
and in them alone. The pain in the testicles,
in consequence of being filled with semen and,'
of the action being incomplete, is sometimes
so considerable as to make it necessary to
produce an evacuation of the semen to relieve
the patient.” Hunter was not aware of the
highly elaborated character of the seminal
fluid, or he would probably not have so readily
accepted the idea of the semen being secreted
“ at the time.” The “ lascivious ideas ” which
he mentions are probably an effect or conco-
mitant of seminal repletion rather than a cause,
yet becoming, perhaps, an additional cause in
their turn.

Many interesting arguments in relation
to this subject might doubtless he derived
from the manner of copulation of different
animals ; but this is an occurrence in the
natural history of species which authors
have entirely left unnoticed, probably from
feelings of delicacy. This want is felt as a
great desideratum by the comparative anato-
mist, in investigating any of the accessory
parts of generation, where the manner of
coition unavoidably forces itself upon our
consideration, malgre the delicacy, which
everybody feels, but which the physiologist is
bound to suppress when he handles such sub-
jects. As a sample of such arguments I may
adduce the following. The prolonged coition
of the dog, which is destitute of vesiculae, was
formerly much dwelt upon in support of the
pre-Hunterian view of tne receptacle-function
of these sacs. But is the act prolonged in
every animal destitute of vesiculae ? I have
been told that the copulation of cats is very
quickly completed ; and cats are as destitute
of vesiculae as dogs. On the other hand, the
boar is very long in coition, although his vesi-
culae are very large and complicated. Such
reasonings on thefacts of comparative anatomy

1136

VISION.

are, indeed, very unsafe, unless the number of
facts observed is very great, and that is not
the present condition of our knowledge of the
copulative act. For that reason I have not
dwelt upon this, prima facie so obvious, line
of argument.

Our knowledge of the function of the ve-
siculae seminales is, therefore, nearly in the
same condition as it was left by the great
Hunter, whose concise paper on this subject
is a master piece of reasoning and scientific
acumen. I have been able to add to this, be-
sides confirmation, little more than some few
observations tending to render it more pro-
bable that the secretion of the vesiculaeis used
in copulation. I have, further, ventured on
an hypothesis which, 1 suppose, has suggested
itself to many before, and with which 1 am by
no means satisfied. So great, however, are
the difficulties surrounding the subject, that
in this unsatisfactory state — the positive func-
tion still hypothetical — I am compelled re-
luctantly to leave it.

(S. R. Pittard .)

VISION. — ( Fr. vision, from Latin visio, from
video, visits, sight.) — The faculty of seeing is one
of the chief means by which living creatures are
brought into relation with the world around,
and is the especial means by which they are
enabled to appreciate the wonderful pheno-
mena which flow directly and indirectly from
the creation of light. When in obedience to
the Divine command, “ There was light,”
there were organs created for its perception ;
and it is interesting to observe that the re-
storation of this gift of perception, when lost,
was among the most frequent, and certainly
not the least striking of the manifestations of
miraculous power displayed by the Saviour of
mankind. The vastness of the field over
which the faculty of vision gives us command,
the precision and permanence of this class
of our percepions, the variety and accuracy
of the information it conveys, and the delight
it affords, lead us irresistibly to regard it as
the most perfect of our senses. In the in-
vestigation of this subject a train of minute
adaptation and wonderful contrivance is dis-
closed to us, in which are combined the ex-
tremes of grandeur and of delicacy. There
is no department of science that possesses
a more absorbing interest than the laws of
optics when applied to the eye, and certainly
none which points with a steadier hand to the
wisdom of an omnipotent Creator.

Very curious and unexpected information
respecting the early condition of the surface of
this planet and the ancient atmosphere has been
afforded by an investigation into the structure
of the organs of vision with which the earliest
marine animals were supplied. In the eloquent
language of Dr. Buckland, “ with respect to
the waters wherein the Trilobites maintained
their existence throughout the entire period
of the transition formation, we conclude that
there could not have been that imaginary tur-
bid and chaotic fluid, from the precipitate of
which some geologists have supposed the ma-

terials of the surface of the earth to be de-
rived : because the structure of the eyes of
these animals is such, that any kind of fluid
in which they could have been submerged at
the bottom must have been pure and itrans-
parent enough to allow the passage of light to
organs of vision, the nature of which is so
fully disclosed by the state of perfection in
which they. are preserved. With regard to
the atmosphere also, we may infer that had it
differed materially from its actual condition,
it might have so affected the rays of light,
that a corresponding difference from the eyes
of existing Crustaceans would have been found
in the organs on which the impressions of
such were then received. Regarding light it-
self, also, we learn, from the resemblance of
these most ancient organizations to existing
eyes, that the mutual relations of light to the
eye and of the eye to light, were the same at
the time when Crustaceans endowed with the
faculty of vision were first placed at the bot-
tom of primaeval seas as at the present mo-
ment.”

Light. — To the opinions of the ancients on
the subject of light but little allusion need be
made, as they were but crude and vague con-
jectures. One, for instance, supposed that the
eyes emitted emanations of some sort by which
objects were, as it were, felt. Others ima-
gined that visible objects were constantly
throwing out from them spectral resemblances
of themselves, which, when received by the
eye, produced an impression of those objects ;
but in these fanciful notions there is little
satisfaction, and we proceed at once to the
hypothesis of our illustrious countryman, Sir
Isaac Newton. According to his theory,
light was an imponderable substance, whose
inconceivably minute particles produced the
sensation of light by their action on the eye :
moving with immense velocity, they were
nevertheless acted on by attractive and repul-
sive forces residing in all material bodies, and
by these forces were liable either to be turned
aside from their natural straight course, re-
flected by the repulsive force, or penetrating
between the particles of bodies, to take a
direction on quitting them finally determined
by the position of the surface at which they
emerged. About the same time, however, a
very different hypothesis was advanced by
Huyghens, to the effect that all space is filled
with an extremely elastic and rare ether, and
that light is the result of the undulatory
movements communicated to this ether by
self-luminous bodies, which movements being
transmitted to the optic nerve, give rise to
the sensation of light. The beautiful experi-
ments of Dr. Thomas Young strongly con-
firmed the truth of this theory', which is based
upon the supposition that light acts by vibra-
tions upon the retina, in the same manner as
the undulations of the air striking upon the
tympanum excite the sensation of sound.

The velocity of the luminous undulations
deduced by Romer from the eclipses of the
satellites of Jupiter, is proved to be about
192,500 miles in a second: in other words,

VISION.

1437

light travels a distance equal to eight times
the circumference of the earth, between two
beats of a clock.

That white light was supposed by Newton
to be composed of seven colours is too well
known to need description here ; but the
proportion of each colour, according to the
observations of Newton and Fraunhofer, is

as follows : —

Newton.

Fraunhofer.

Red -

- 45 -

- 56

Orange

- 27 -

- 27

Yellow

- 40 -

- 27

Green

- 60 -

- 46

Blue

- GO -

- 48

Indigo

- 48 -

- 47

Violet

- 80 -

- 109

360

360

It is to Sir David Brewster that we are in-
debted for our knowledge of the fact, that
the solar spectrum in reality consists of only
three primary colours, red, yellow, and blue ;
each of which exists throughout the whole of
the spectrum ; and that the super-position of
these in different degrees of intensity in dif-
ferent parts produces the seven huesr. The
proportion in which the primary colours com-
bine to form white light, is : —

Yellow, three parts.

Red, five parts.

Blue, eight parts.

All the seven hues are possessed of different
degrees of refrangibility ; the red being least
refrangible, the violet the most. It appears
from Sir John Hersehell’s experiments that
just beyond the violet there exists a band
of coloured light of still greater refrangibility,
which he has denominated the lavender band.
The same great philosopher has also proved
that the coloured rajs in the spectrum differ
materially in the length and rapidity of their
undulations.

Coloured rays.

Length of
luminous
rays in parts
of an inch.

Number
of undu-
lations in
an inch.

Number
tions in a

of undula-
second.

Extreme red

0'000(K6fl

37640

4'8 Mill, of Mill.

Red

*0000256

30 ISO

477

intermediate

•0000246

40720

495

Orange •

•0000240

41610

506

Intermediate

•0000235

42510

517

Yellow

•0000227

44000

535

Intermediate

•0000219

45500

555

Green

*0000211

47460

577

Intermediate

*0000203

49320

(SCO

Blue

•0000196

51110

622

,,

Intermediate

•0OO0189

52910

644

Indigo

•0000185

54070

658

,,

Intermediate

•0000131

55210

672

,,

Violet

•0000174

57490

699

Extreme Violet -

■0000167

59750

7‘/7

”

From this table it will be seen that the sen-
sibility of the eve is confined within much
narrower limits than that of the ear, the ratio
of the extreme vibrations being nearly T58 : 1,
therefore less than an octave, and equal to a
minor sixth.

Sir William Herschell discovered that there
are rays in the solar spectrum which give rise
to the sensation of heat, independently of

those of light, and these calorific rays are
most abundant a little beyond the red ex-
tremity of the spectrum, and gradually di-
minish towards the violet, beyond which they
are imperceptible ; an important practical fact
has recently been discovered in relation to
these rays. It is well known that plants
growing in stove houses often suffer from the
scorching influence of the calorific rays, and
when the great palm-house at Kew was about
to be erected, an elaborate series of experi-
ments was undertaken by Mr. R. Hunt, to
ascertain whether it would not be possible to
cut them off by means of a tinted glass. In
this he was fully successful, and discovered
that a glass tinted of a very pale yellow-green
colour by oxide of copper completely pre-
vented the permeation of all that class of
heat rays which exists below, and in the point
fixed at that of maximum calorific action ; as it
is to this class of rays that the scorching in-
fluenced due, the use of theglass described has
effectually protected the plants. The absence
of oxide of manganese commonly employed
in all sheet glass, is insisted on, it having been
found that such glass will, after exposure for
some time to intense sun-light, assume a
pinky hue, which is highly7 objectionable.

To Dr. Wollaston we owe the discovery of
the existence beyond the extreme violet of
chemical rays, which are known to us solely by
their effects. It is to their action that the
fading of vegetable colours, and the blackening
of nitrate of silver, is due. The influence of
these chemical rays extends throughout the
spectrum, and to it the term actinism has been
applied. From the experiments of Mr. Hunt it
appears that actinism exercises an important
influence on the vegetable world, exciting the
germination of seeds, and being essential to the
formation of the colouring matter of leaves.
The actinic principle is most energetic in spring,
when its stimulus is required to rouse dormant
vegetation from the repose of winter : as soon
as this is effected, the luminous rays, with the
advance of the sun, become more active, and
the formation of woody fibre proceeds under
their particular agency ; but in autumn, the
actinic power having performed its part, is
no longer required, the whole energy of ve-
getation being concentrated under the in-
fluence of the calorific rays in the ripening
of fruits and perfecting of seeds. It has
been long known that the calorific and lumi-
nous rays were capable of extinction by means
of polarisation, but it has only been very re-
cently ascertained by Professor Wartmann
that the chemical rays are equally amenable
to polarisation under similar conditions.

Those diversified colours which render the
floral world so attractive, w'hich impart such
beauty to the feathered tribes and the legions
of butterflies, and in brilliant pigments re-
ward the labours of the chemist, are not pro-
perties inherent in matter itself, but arise
from the action of matter upon light, whereby
certain of the coloured rays which form white
light are reflected, whilst others are absorbed
or transmitted. Scarlet cloth, for instance

1139

VISION.

absorbs almost all colours except red, which
it reflects ; but those substances which reflect
all the rays appear white ; those which ab-
sorb all are black. The brilliancy of tints
is greatly increased when viewed in light of
their own colour, as may be proved by throw-
ing the red rays from a prism upon any scarlet
object, or the green rays upon a green leaf.
The colour of transparent substances depends
upon their property of absorbing some of the
colours of white light, and transmitting others.
The blue tint of the atmosphere in reflected
light, and its red morning and evening tinge,
are to be ascribed to this cause.

Dyes anti paints are substances which,
when applied to bodies, so change their sur-
faces, that when seen in white light, they re-
flect only the particular colour of the dye or
paint. There are several modes by which
white light can be reproduced, of which a
simple one is, the rapid rotation of a disk
painted in stripes, with the prismatic colours
in the correct proportions. In this case, the
eve receives the impression at the same time,
and in the same place, of a red circle, an
orange, a yellow circle, and so on, and conse-
quently a white circle, since the sensation of
white is but the simultaneous sensation of all
these colours.

As in the production of white light, it is
necessary that all the simple colours should
exist in their due proportions; so it is evident
that by suppressing or increasing one the
harmony will be destroyed, and the light will
be no longer white. Thus, for instance, by
suppressing red, we obtain a blueish green,
which, compounded with red, would form
white light. Whenever two colours, simple
or compound, fulfil this condition, they are
said to be complementary one to the other.
They are as follows : —

Colour.

Complementary.

Red -

-

- Blueish-green.

Orange

-

- Blue.

Yellow

-

- Indigo.

Green -

-

Violet-reddish.

Blue -

-

Orange-red.

Indigo -

-

Orange-yellow.

Violet -

-

Yellow-green.

Black -

-

- White.

White -

-

- Black.

With respect to the production of light,
bodies are divided into luminous and non-
luminous ; among natural bodies some pos-
sess in themselves the property of exciting
in our eyes the sensation of brightness, or
light, as the sun and other heavenly bodies
which shine by their own light. There is
also chemical light, or that produced by com-
bustion, electric light, phosphorescent light, et
cetera. Non- luminous bodies are such as
become visible only when light falls upon
them from some luminous source.

Bodies are also divided into transparent
and opaque, in reference to their capacity for
transmitting light through their substance,
though this property depends, not merely on

their absolute transparency, but also on the
density of the medium through which the
light passes. There is no perfectly opaque
or perfectly transparent substance known.
Diamond is nothing more than charcoal in a
different state of molecular aggregation, and
gold can be made pervious to light. On the
other hand, the purest air or clearest water
gradually extinguishes by absorption the rays
transmitted through them. According "to
Bouguer the purest sea water loses all its
transparency at a depth of 730 feet, and the
reason that more stars are visible from the
summit of a lofty mountain than from the
level of the sea is, because the light from the
more distant stars becomes so much enfeebled
during its passage through the lower strata of
the atmosphere, that it has not sufficient
power to affect the sight.

If a pencil of rays diverging from a lumi-
nous point fall upon the surface of a convex
lens, they will not all be equally refracted.
The ray which passes through the axis of the
lens will not be changed in its course, but the
remainder of the rays will be more and more
refracted in proportion as they recede from
the optical centre of the lens. When the
rays pass out from a bi-convex lens into air
they are refracted from a line perpendicular
to the point of emergence : the effect is to
cause them all to converge towards the cen-
tral ray to a point at which they meet, called
the focus. The distance between the focus
and the refracting surface is the focal dis-
tance or focal length, and is influenced by the
refracting power of the lens, the amount of
its curvature, and the distance of the lumi-
nous body.

Parallel rays entering any plano-convex or
double convex lens at an equal distance from
its axis, are concentrated to the same focal
point, but as the peripheral rays are more
refracted than the central rays, they are sooner
brought to a focus ; hence the image formed
at the focus of the lens is somewhat indistinct
at its edges. This imperfection is due to
what is termed spherical aberration, and is
counteracted either by shutting out the peri-
pheral rays, or by such a combination of lenses
as will establish a just proportion between the
refraction of the central and peripheral rays.
Such lenses are made of crown glass, com-
posed of flint and alkali only, and flint glass,
in which oxide of lead is added to the other
materials. The latter possesses a much higher
dispersive power than the crown glass; but
the refraction of the rays is nearly the same
in both, and when combined, achromatic lenses
are obtained. This term is applied from their
utility in obviating another source of con-
fusion, chromatic aberration, which is caused
by the unequal refrangibility of the prismatic
rays when transmitted through an ordinary
lens, whereby the images are fringed with
colours, and are rendered even more indis-
tinct than by spherical aberration. Newton
supposed that an achromatic lens was an im-
possibility ; but in 1757 Dollond completely
succeeded in overcoming the difficulty by the

VISION.

1439

combination of crown and flint glass. He
supposed the mean refractive power of flint
glass, as compared to crown glass, to be 158
to 153 ; Fraunhofer states it to be 164 to
153. The prismatic dispersion in English
flint glass is times, but in Fraunhofer’s, it
is twice as great as in crown glass.

Such are the chief facts concerning light,
which bear reference to vision: to the con-
sideration of the physiology of which we now
proceed.

Phenomena of Vision. — The special function
with which the retina is endowed being the
perception of light, a marvellous range of
phenomena is open to the inquirer. It is
indeed a wonderful thing to have ascertained
beyond doubt, that in perceiving the tint of
the scarlet geranium our eyes are affected by
undulations recurring four hundred and eighty-
two millions of millions of times in a second ;
that before we can appreciate the tint of the
yellow blossoms of the gorse or laburnum,
five hundred and forty-two millions of mil-
lions of vibrations must have taken place ;
and that to discriminate the colour of the
violet, not less than seven hundred and seven
millions of millions of movements must have
been communicated to the fibrillae of our re-
tinae ! Whilst such facts almost transcend
the powers of human conception, their esta-
blishment is a striking triumph of human in-
tellect. But how great ought to be our
admiration of that Omnipotence which has
endowed the eye with the gift, not merely of
appreciating one colour, but of distinguishing,
in all their shades, the inexpressibly compli-
cated vibrations which mark the hues of a
parterre of flowers, and characterise the gor-
geous plumage of the birds which give anima-
tion to a tropical forest. The sense of sight,
in its ordinary acceptation, may be defined as
the recognition by the mind of certain im-
pressions made upon the retina, and commu-
nicated through the medium of the optic
nerve to the encephalon ; a sound condition
ol each and all of these parts (which may be
considered as the media of communication, so
far as one sense is concerned, between the
external world and the mind) is indispensable
for perfect vision. Light may fall upon the
retina, and the images of objects may be there
depicted, but should the optic nerve be un-
sound, or certain portions of the brain be
disorganised, no responsive image is called up
before the mind ; the eye may gaze upon the
noonday sun, but all is dark within.

The natural stimulus of the retina is the
luminous rays : the appreciation of light and
colour its active condition ; and its state of
repose suggests the appearance of darkness :
but besides light, any other excitement ap-
plied to the retina or optic nerve gives rise to
the same result, — the production ofluminous
appearances. Pressure upon the eym-ball, the
electric current, or vascular congestion, all
excite this special phenomenon. Occasion-
ally, too, irritation of the brain has the same
effect ; and many are the waves and corrus-
cations, the fiery clouds and flaming spectra,

which haunt the amaurotic when certain
morbid complications exist. The phantasms
of fever, and the illusions of the dying, are
to be placed in the same category with the
above.

For visual purposes, a certain amount of
stimulation of the retina is necessary ; hence
it is both difficult and painful to discern ob-
jects in very faint light : but in this respect
the retina is endowed with great powers of
accommodation. It is well known that per-
sons long immured in dungeons profoundly
dark to ordinary eyes, have acquired the
power of discerning the most minute objects.
On the other hand, excessive light is in-
jurious, for by it vision may be instantane-
ously extinguished, as happens by a stroke of
lightning. The accommodation to various
amounts of light is, however, gradual, as is
proved by passing from a dark room into sun-
light, or into a brilliantly lighted apartment.
In this case the pupil has been widely dilated
to admit the greatest possible quantity of light
into the eye. For the first second or two
after arriving in the light, all is confusion ; and
there is even pain, from the flood of light
which thus breaks in on the retina through
the widely dilated pupil, and takes it, as it
were, unawares. On the other hand, a per-
son entering a moderately dark room from
full sunlight, sees nothing for a time, because
the strongly contracted pupil admits so little
light, that no sensation is produced. After a
while the pupil dilates, and vision gradually
becomes complete. In order that a clear idea
may be formed of the mode in which images
are depicted upon the retina, and also of the
causes of myopia and presbyopia, it is neces-
sary that the mode of action of convex lenses
should be described.

Fig. 884.

Let c d be a biconvex lens, and a b an ob-
ject on one side of it, but further removed
than the focal point f. Every point of
the object will send forth rays in all direc-
tions, but to avoid confusion, we will only
consider those flowing from the extremities
ab. The rays emitted from a undergo re-
fraction, are altered in their direction, and
are united at a' upon the secondary axes
drawn from a through g, the centre of the
lens. The rays from b are in like manner
united at b'; consequently, a'b' is the image
of the object ab, but inverted. Seen from
the middle of the lens, the image and object
appear at the same angle, for the angle b'ga'
is equal to the angle bga, being angles at the
vertex. The relative size of the object or the
image depends upon the relative distance of

1440

VISION.

each from the lens. If the object lie twice
as far as the focal distance from the lens, the
image will be formed on the other side at an
equal distance, consequently the image and
the object are equal in size. But if the object
approach nearer to the glass, the imave will
recede, becoming larger. We thus obtain in-
verted and enlarged images of objects stand-
ing further from the lens than the focal dis-
tance, yet not so far as twice that distance.
Thus the image a'u' is larger than the object
ad. If the object be further removed from
the glass than twice the focal distance, the
image will be nearer ; we therefore obtain in-
verted diminished images of distant objects.

Dioptric phenomena. — Krause has described
the anterior surface of the cornea as being
spherical, the posterior parabolic. We re-
cently had an opportunity of examining a
human cornea in less than an hour after the eye
had been extirpated from the living subject,
and satisfied ourselves that, in that case at
least, the two surfaces were perfectly parallel.
According to Chossat the figure of the cornea
is an elhpsoid of revolution about the major
axis, which axis determines the axis of the
eye. The ratio of the semi-axis of this cdlipse
to the excentrieity he determines at 1 '3 ; and
this being nearly the same with the index of
refraction, parallel rays incident on the cornea
in the direction of its axis will be made to
converge, with great exactness, to a focus si-
tuated behind it, the aberration, which would
have existed had the external surface been
of a spherical figure, being almost completely
destroyed. The form of the crystalline lens
is that of a solid of revolution, having its
anterior surface much less curved than its
posterior: by some authorities both surfaces
are described as being ellipsoids of revolution
about their lesser axes ; but Krause found the
posterior surface to have a parabolic curve,
whose parameter was from 34;'" to W" . He
found also that the elliptical curve of the an-
terior surface of the lens varied as regards its
long axis, in different cases from 4'" to 5-jV" ;
its short axis also varying from If'" to 2
Dr. Albert de Graefe informs us that he has
repeated these observations, and ascertained
them to be correct. Valee states that he has
found by a comparison of Krauss’s measure-
ments of the dimensions of the eye, that the
exterior convex surfaces have exactly that
geometrical form which produces foci free
from deviations. He calls them optoidal sur-
faces, and also finds that the posterior convex
surfaces are at least so far optoidal, as the
pencils of light penetrating into the eye in-
fringe upon them. The axes of the two sur-
faces of the lens arc not exactly coincident in
direction with each other, nor with that of the
cornea.

The refractive index of the surface of the
lens is, according to Brewster, 1 '3767 ; of
the centre r.3990, the mean being F3839 :
that of the vitreous humour is B3394; thus
the refractive density of the lens being greater
than that of either the aqueous or vitreous
humour, it exercises an important influence

on the converging rays incident on it from
the cornea. The effect of its elliptic figure
is probably to correct the aberration of ob-
lique pencils, and general aberration is still
further obviated by the peculiar and varying
density of its substance. By Professor James
Forbes the variable density is supposed to
alter the figure of the lens under pressure, and
so to assist in focal adjustment.

As the rays refracted by the aqueous hu-
mour pass into the crystalline, and those from
the crystalline into the vitreous humour, the
indices of refraction of the separating sur-
face of these humours will be, according to
Brewster : —

From aqueous humour to outer layer

of crystalline - P0466

From ditto to crystalline, using the

mean index - P0353

From vitreous to crystalline outer

layer P0445

From ditto to ditto, using the mean

index - - - - - P0332

Suppose, then, the eye to be directed to-
wards an object, the rays of light proceeding
from that object are thus disposed of. Those
which strike the cornea very obliquely are
reflected, as are those which impinge upon
the sclerotic; a large proportion of the rays,
however, pass through the cornea, being power-
fully refracted by it, and the aqueous mem-
brane, and less by the aqueous humour
behind : proceeding onwards, many of the
rays are arrested by the iris, some being ab-
sorbed, others reflected, conveying the colours
and brilliancy characteristic of that membrane.
The more central rays pass through the pupil
and the crystalline lens. The layers of this
body, increasing in density from the circum-
ference to the centre, resemble in their effect
upon the rays the atmosphere of this earth,
which causes a gradual bending of the rats
flowing from the heavenly bodies ; so the crys-
talline lens by its form and structure gradually
but powerfully increasestheconvergenceof the
rays which penetrate it, both on their entrance
and their exit. They then traverse the vitreous
humour, — the chief use of which appears to
be to afford support to the expanded retina,
— and ore brought in a perfectly natural eye,
to foci upon the retina, forming there an
exact but inverted picture of the object. If
the eye of a white rabbit or any other aibino
be carefully cleansed, the flame of a taper held
before the cornea may be seen inverted at the
back of the eye, increasing in size as the taper
is brought near, diminishing if it retires, and
ever moving in the direction opposite to that
given to the flame.

Such, in general terms, are the phenomena
attending the formation of images in the eye;
and they are strictly in accordance with the
mode of action of convex lenses, of which
the rule is, that an image formed by a convex
lens is inverted, and its position relatively to
the position of the object and its magnitude,
are to that of the object as its distance from
the lens is to the distance of the object from
the lens. The rays composing a pencil falling

VISION.

1441

upon the cornea, are refracted by the trans-
parent media of the eye in proportion to the
difference between the density of these media,
and that of the air, and in proportion to the
curves presented by their several surfaces. It
is of course the central ray only, or that
which passes through the axis of the eye,
that is not refracted ; all the other rays un-
dergo refraction, and are approximated to the
central ray. The prime rays have been termed
rays of direction, because every prime or axial
ray determines the direction of the other rays.
As every object emits rays, from every point,
in all directions, which rays then proceed in
straight lines, it necessarily follows that, un-
dergoing these refractions, there must be some
point in the eye at which the axial raj's of
the different pencils, proceeding from the ob-
ject, cross ; and this appears to be very near
the centre of the eye, somewhat behind the
crystalline. Sir D. Brewster places it in the
geometric, centre of the e\ e-ball, consequently
a little within the crystalline lens ; and Volk-
mann has described the point of intersection
as being 3'" 97 behind the cornea, O'" 43 before
the posterior surface of the crystalline, and
6/// 23 in front of the retina. Other and very
careful observers, however, place it at a very
short distance behind the crystalline lens. It is
called the focal centre, and the angle formed
by the intersecting axial rays from two points
is the visual angle. This focal centre seems,
according to the researches of Ruete, to be
of importance in another way. In the steady
contemplation of objects, we have to bring
them into the focal centre of the produced
visual axis ; and in the motion by which this
is accomplished, it would appear that ihe eye
revolves accurately round a point, which point
of revolution is the focal centre of the eye.
In vision, the muscles of the two eyes act
under the influence of the will, with a remark-
able and admirable sympathy ; and it is on
this harmonious consent, as it were, of op-
posing muscles, that vision in its most perfect
form depends.

Vision under water is attended with some
curious consequences, the result of what is
termed “ internal ” reflection. An eye placed
under perfectly Stillwater, as for instance, the
eye ot a diver, will see external objects only
through a circular aperture (as it were) of
96° 55' 20" in diameter overhead. But aii
objects down to the horizon will be visible in
this space; those near the horizon being much
distorted and contracted in dimensions, espe-
cially in height. Beyond the limits of this
circle will be seen the bottom of the water,
and ali subaqueous objects reflected and as
vividly depicted, as by direct vision ; and in
addition, the circular space above mentioned
will appear surrounded with a rainbow of faint
but delicate colours. In the eyes of fishes, the
humours being nearly of the refractive density
of the medium in which they live, the action
ol bringing the rays to a focus on the retina is
almost entirely performed by the crystalline
lens, which is nearly spherical and of small
radius in comparison with the whole diameter

VOL. IV.

of the eye ; there is also a very great in-
crease of density towards the centre, whereby
spherical aberration is obviated, the corneal
refraction having little influence.

When speaking of light we have mentioned
spherical and chromatic aberrations ; and it is
necessary that they should be again alluded to
in reference to the eye. Spherical aberration is
beautifully counteracted by the figure and vary-
ing density of the crystalline lens ; which, in-
creasing in refractive power towards the centre,
refracts the central rays in each pencil, to the
same point as its external rays; but an important
agent in obviating this aberration is the iris,
which is, as it were, perpetually on the watch
to limit the rays entering the eye to those
which produce a perfect image, cutting off
others which, by their obliquity of incidence,
might occasion the imperfection in question.
Opticians endeavour to obtain the same effect
in their instruments by the employment of an
opaque screen or diaphragm ; but no device
of human art can equal the ever changing
pupil of the living eye.

Sir David Brewster, and some other autho-
rities, deny that the eye is perfectly free from
chromatic aberration : and it is certain that
when the pupil is dilated bv belladonna, and
the lateral rays freely admitted, coloured
fringes are perceptible, as we have ourselves
experienced ; on the other hand, the forms
and relative densities of the humours of the
eye closely imitate the achromatic combina-
tion of lenses, for the two menisci, formed by
the aqueous and vitreous humours, having
the double convex crystalline lens, of greater
density than either, placed between them,
fulfil these conditions very happily, and can
hardly fail to obviate, in a material degree,
chromatic aberration. The coloured fringes
we have spoken of, as being produced by the
dilatation of the pupil, must not be confounded
with the chromatic images, which depend on
certain conditions of the retina. The former
are always connected with refraction, and
they attach particularly to two conditions,
namely, the falling of a light close to a shadow,
and the projection of the limits of either on
the retina, in such a way that all sharpness of
outline is lost. The transition from light to
shade — the blending of the light and darkness
thus produced — gives rise to coloured fringes.
This may be shown by taking up a position,
at the end of a room, before a brightly illu-
minated window, and holding up any small
object, such as a pencil, before the eye, which
must be steadily fixed upon the window-
sash. Presently prismatic colours appear on
either side of the bars as well as of the
pencil. Goethe explained all chromatic phe-
nomena on the sole ground of modifications
in light and shade. In the light seen through
dull media, according to his theory, yellow
is first perceived, then in succession, red,
pale blue, blue, violet, black blue, and black ;
and he explains dioptrically-formed coloured
margins from the subjective side, by a mutual
encroachmentof the light and dark, the shadow
before the light being perceived as blue and

4 z

]i42

VISION.

violet, and the light before the shadow as red
and yellow.

Distinct vision. — Dugald Stewart, in his
“ Philosophy of the Human Mind,” proposes
this question : Suppose the eye to be fixed in
a particular position, and the picture of an
object to be painted on the retina, does the
mind perceive the complete figure of the ob-
ject at once, or is this perception the result of
the various perceptions we have of the dif-
ferent points in the outline ? He arrives at
the conclusion that the mind does at one and
the same time perceive every point in the
outline of the object, for perception, like con-
sciousness, is an involuntary operation : as no
two points, however, of the outline are in the
same direction, every point by itself constitutes
a distinct object of attention to the mind ; but
these acts of attention are performed with
such rapidity, that the effect is the same as if
the perception were instantaneous. When
the eye is directed to any point of a land-
scape, it sees with perfect distinctness only
that image of it which is directly in the axis
of the eye ; but the extreme mobility of the
eve, together with the duration of the impres-
sions upon the retina, enable us 'to take in
every part of the view with equal distinctness.
In all probability, it is only in the axis of the
eye, corresponding with the yellow spot, that
vision is perfect; the posterior part of the
retina is certainly better adapted to receive
images than the anterior, where the grey
nervous layer becomes thinner and thinner
towards the border. Dr. Young calculated
that the range of motion in the eye-ball is
55° in every direction, so that the head being
fixed, a single eye may have perfect vision of
any point within a range of 110°. He fur-
ther ascertained, by fixing the eye in the
most natural direction, namely, forwards, and
a little downwards, and by then moving a
luminous object before it in various direc-
tions, that the range of vision upwards was
t>0°, downwards 70°, inwards 60°, and out-
wards 90°, giving an entire horizontal play of
150°, and a total vertical play of 120°.

The small portion of retina corresponding
to the extremity of the optic nerve, is insen-
sible to visual impressions. Volkmann states
that he has satisfied himself by calculation
that the small insensible spot corresponds
exactly with the dimensions of the central
artery. Dr. Young determined that the dis-
tance of the centre of the optic nerve from
the visual axis is of an inch, and that the
diameter of the most insensible part of the
retina is ^ of an inch. It is to be borne in
mind that the fibrous lamina of the grey
nervous layer of the retina is at this point
evolving itself from the nerve, and is not yet
invested with the vesicular or other laminae.
Mr. Bowman has well remarked that this in-
capacity of vision at the entrance of the optic
nerve seems to be essential to the mode of
junction of the retina with the nerve, since it
appears to have been the chief reason why
the nerve was not made to enter in the axis
of the eye. If the blind spot had been situated

in the axis, a blank space would have always
existed in the centre of the field of vision,
since the axis of the eyes in vision are made
to correspond. But as it is, the blind spot3
do not correspond when the eyes are directed
to the same object ; and hence the blank
which one eye would present, is filled up by
the opposite eye. Mariotte, was the first who
described the existence of these blind spots,
and they may be discovered by the following
simple experiment: — Let two black dots be
placed one inch apart on a sheet of white
paper: if the left eye be closed, and the dots
are regarded at the usual distance for distinct
vision, the attention, however, being particu-
larly directed to that on the right hand, the
other dot will be found to disappear the
moment the pencil of rays proceeding from it
falls upon the centre of the entrance of the
optic nerve.

It has been already stated, that when the
rays from an object meet in foci on the retina,
a distinct image is formed : should the focus,
however, be before or beyond the retina, it is
evident that some indistinctness must be
caused, for each point of the retina would
then receive rays from several points of the
object. It is to be borne in mind, that the
nearer the object to the eye, the greater is
the divergency of the incident rays; and the
greater their divergency, the more distant is
their focus. When the retina corresponds,
or nearly corresponds, to the points of con-
vergence of the several pencils of light, dis-
tinct vision is obtained, the usual distance
being from eight to ten inches, at which dis-
tance, reading or writing is naturally per-
formed. If, when writing, for instance, we
removed the head further, or approached it
nearer, and no alteration took place in the
eye, vision would become indistinct, because
the focus would be altered, and would either
fall short of, or be thrown beyond, the re-
tina : should the rays, however, very nearly
unite upon the retina, vision, of large ob-
jects especially, may prove sufficiently dis-
tinct, though not perfectly clear. A just
distinction was, therefore, drawn by Jurin
between perfect vision and distinct vision, the
perfection of vision depending on the distance
alone of objects, whilst their distinctness
would be regulated not less by their size, than
bv their distance from the eye.

The pupil of the eye performs an important
part in enabling us to see objects distinctly.
When looking intently at a near object, the
pupil contracts, thereby limiting the rays
which pass through it to the most central,
and stopping the progress of those more di-
vergent rays which, not converging to foci on
the retina, would cause circles of dissipation :
upon the same principle, vision of near objects
is assisted by a pin-hole aperture. Let a per-
son thrust a pin through a card, and make
a clean hole ; then let him hold a book so
close to his eyes that the type becomes con- ;
fused ; if he now looks through the pin-hole,
he will again see it distinctly, because the
card answers the same purpose as a further

VISION.

1-143

•contraction of the pupil, arresting the progress
of those rays which are too divergent, and
limiting those entering the eye to the central
rays, which, from their trifling divergence,
unite correctly on the retina. The same ad-
vantage is gained by a near-sighted, and by a
presbyopic eye. In the one case vision is im-
proved by the card stopping the rays, which
would converge to foci in front of the retina ;
in the other, by its arresting those which tend
to foci behind the retina. So that this simple
experiment frequently makes a difference of
several inches in the vision of myopic and
presbyopic persons.

A curious experiment devised by Father
Schemer, has reference to this point. If we
make in a card two small orifices with a
needle, at a less distance from each other
than the diameter of the pupil, and hold
these openings close to the eye, a double
image of a small object held within the
visual distance, — a pin’s head, for instance —
will be seen. From the pin’s head there pass
two very minute pencils of rays through the
apertures into the eye. These rays converge
towards a point lying behind the retina, and
fall upon the retina at two different points.
These are two isolated points of the circle of
dispersion, which would exist upon the retina,
if the other rays were not intercepted by the
card. If we now withdraw the pin’s head more
and more, the images will approach, because
the rays, falling upon the eye through the
apertures, will diverge less, and will conse-
quently be refracted towards a point lying
nearer to the retina. If the object be re-
moved from the eye to the distance of distinct
vision, the two images will perfectly coincide,
since all rays passing from one point, lying
exactly at the distance of distinct vision, will
be concentrated at one point of the retina. It
may be asked, what are the conditions of
adaptation necessary for an eye in looking
through a fine aperture? In its normal con-
dition, for the maintenance of which no effort
is necessary, the eye is in the state necessary
for seeing objects which lie at the distance of
distinct vision. If a distant object be re-
garded through the small apertures, the rays
passing through them into the eye must evi-
dently meet at one point before the retina, as
the condition of each adaptation does not
change in the eye: but the two pencils di-
verge again behind the point of intersection,
striking the retina at two different points,
when, consequently, distant objects will be
seen double ; therefore, we only see a small
object single, through two small apertures,
when it lies at the distance of distinct vision.

This experiment of Scheiner led Dr. Porter-
field to invent an instrument called an op-
iometer, for the determination of the focal
distance of the eye ; and Dr. Young sub-
sequently greatly improved upon it, his in-
strument being simple in construction, and
both convenient and accurate in its applica-
tion.

The greatest distance of human vision is
so variable, that no arbitrary limits can be as-

signed to it. Uncivilised tribes, as the North
American Indians, the inhabitants of the im-
mense Asiatic steppes, and the New Zealan-
ders, possess powers of sight which are
almost incredible. It is interesting, however,
to remark, that the mean degree of capability
of vision was the same among the ancient
Greeks and Romans as at the present day.
The Pleiades furnish the proof of this, showing
that some thousand years ago, as now, stars
which astronomers call of the seventh mag-
nitude, were not visible to the naked eye in
persons of ordinary powers of vision. Even
among civilised nations, however, instances
are occasionally met with of extraordinarily
keen sight. General Drinkwater, in his
*• History of the Siege of Gibraltar,” mentions
that there were two boys in the garrison pos-
sessed of such uncommon quickness of sight,
that they could see the shots fired by the
enemy almost immediately after they had
quitted the guns, and were constantly em-
ployed to look out and give warning to the
soldiers of the approach of these missiles.

From the experiments of Harris, it seems
that a simple object, as a black square on a
white ground, or a white square on a black
ground, can be seen under a less angle than
the equal parts of a compound object, as the
squares of a chequered figure, and that their
least, or minimum visible angle cannot be less
than 40" : others, however, say 30". If it is
40", the size of the image on the retina will
be -j-o’oo inch. At a medium, Harris thinks it
not less than 2'. He remarks that the diffi-
culty of keeping the eye perfectly steady, may
be one cause why a single object can be dis-
cerned under a less angle than the parts of a
complex one ; and that it is natural to sup-
pose that the fewer objects we contemplate,
and the more they differ in colour, the easier
we can distinguish their several impressions on
the retina. The result of repeated and very
careful experiments by Hueck, tends to show
that white objects on a black ground are seen
at a greater distance than black objects on a
white ground *, and this is fully corroborated
by an instance mentioned by Humboldt. This
distinguished traveller was with Bonpland, at

* The following facts, deduced from extensive
and very careful experiments, conducted by Lieut. -
Colonel Hamilton Smith, are of great practical im-
portance. The object was to ascertain the liability
of different colours to be hit as marks, under pre-
cisely similar circumstances, as to men engaged, size
of target, weather, &c. The result showed the
proportion to be as follows . —

Red, 12. Rifle-green, 7. Austrian blueish-grey, 5.

Colonel Derinzy, who was actively engaged in
the Peninsular War, has given much attention to
the effect of different coloured uniforms on the
chances of being hit. The day before the battle of
Vittoria, his Portuguese rifle company, dressed in
earthy-brown, and a company of British Fusileers,
of equal strength, dressed in red, had to dislodge the
French from a bridge. They were equally exposed
during the rvhole of the skirmish, and after it was
over, Colonel Derinzy compared notes with his
Fusileer comrade, and found that the relative losses
were precisely one to two ! This fact (for which we
are indebted to Captain Nelson, r.e.) strikingly
4 z 2

I 14 I

VISION.

Ohillo, near Quito, in South America, from
whence the long extended ridge of the volcano
of Pichincha is visible. Bonpland had pro-
ceeded on an expedition to the volcano,
and Humboldt, with others, was somewhat
anxiously looking out for him. The Indians
of the party recognised the traveller as a
white point moving along the face of a black
basaltic precipice, before he was discovered by
Humboldt and others, who were looking out
for him with telescopes (a proof, by the way,
of their excellent vision) ; but in a short time
the Europeans also were able to distinguish
the white moving figure with the naked eye.
The weather was clear, and the distance 1P8
geographical miles. A small object in motion,
however, is more easily discerned than if at
rest : by the gradual motion of the image over
the retina, the impression upon each part con-
tinuing for some time, the effect is the same
as if a linear image were formed.

Duration of impressions. — A beautiful pro-
vision to insure uninterrupted vision, is
afforded by the duration of impressions upon
the retina, whereby we never lose sight of an
object we are viewing, during the necessary
winking of the eyelids. M. D’Arcy found
that the light of a live coal, moving in a circle,
at the distance of 165 feet, maintained its
impression upon the retina somewhat more
than the seventh part of a second. From the
observations of Plateau, it seems that the
interval of time, during which the impression
retains the same intensity, is more consider-
able in proportion as the light is moderated ;
the mean duration of the impression excited
by all the colours from the instant of their
maximum intensity till their entire disap-
pearance, being one-third of a second in a
dark room, and one-sixth of a second in a
light room. If two or more impressions suc-
ceed each other at such short intervals that
the first has not faded away before the next
commences, they run one into another, the
eye seeming to receive but a single impression ;
as, for example, the appearance of a circle of
fire from a revolving burning stick — when it
is in reality the combination of many indi-
vidual impressions succeeding each other with
rapidity : upon this depends many of the most
beautiful examples of the pyrotechnic art ;
from the same cause a flash of lightning ap-
pears as a continuous line of light, because
the light emitted at any point of the line
remains upon the retina until the cause of the
light passes over the succeeding points. In
order that an object may become visible, it is
necessary that the retina should be exposed to
its influence for an appreciable time, a fact
first pointed out bv Lord Bacon, who observes,
that notwithstanding the rapidity of the act of
vision, a certain time is required for its ex-
ercise, which is proved by certain objects, as,
for instance, a musket-ball, being invisible on

corroborates Colonel Smith’s results : hence it ap •

7_i_5

pears that the liability of brown is — =6, and

that red is by far the most fatal colour, green next,
.then brown, and Austrian grey the least.

account of the velocity of their motion ; for
the flight of the ball, he remarks, is too swift
to allow an impression of its figure to be con-
veyed to the sight. This subject has been
recently investigated with much success by
Mr. William Swan*, who arrives at the fol-
lowing conclusions.

When the eye receives a succession of
flashes of equal duration from a light of con-
stant intensity, which succeed each other so
rapidly as to produce a uniform impression,
the intensity of this aggregate impression will
also be constant, provided the number of
flashes in a given time varies inversely with
the duration of each. The brightness of the
impression produced by flashes of light of a
given intensity, which succeed each other so
rapidly as to produce a uniform impression
on the eye, is proportional to the number of
flashes in a given time.

When light of a given intensity acts on the
eye lor a short space of time, the brightness
of the luminous impression on the retina is
exactly proportional to the time during which
the light continues to act. This law has been
proved to be true for impressions lasting iroin
to aV of a second.

The intensity of the impression produced
by light, which acts on the eye for of a
second, is almost exactly y^th of the apparent
brightness of the light when seen by uninter-
rupted vision ; and the time required for light
to produce its full effect on the eye seems to
be about ^ of a second. Lights of different
intensities produce their complete impressions
on the eye in equal times, so that the light ol
the sun requires the same time as common
artificial light to produce its impression on
the eye. The brightness of an impression on
the eye increases with a rapidity exactly pro-
portional to that of the light by which it is
produced.

Rays of different refrangibility act on the
eye with equal rapidity. The apparent bright-
ness of the spark produced by electricity ot
high tension is only about TooWo vvl|at
its apparent brightness would become if its
duration were prolonged to of a second
and the brightness of electric light increastf
with the tension of the electricity.

The wonderful rapidity of the electric light is
shown by the following experiments: — Viewed
by the illumination of an electric spark, the
spokes of a wheel in the most rapid rotation
appear stationary, vibrating cords seem to he
in a state of repose, and a succession ot drops,
which generally appear to the eye as a con-
nected stream, is seen to be but a succession
of drops, because the impression of each
image lasts for so short a time that the posi-
tion of the moving bodies is not altered. The
light of electricity of high tension has a less
duration than the millionth part of a second.

When on the subject of light, we have
alluded to the reproduction of the impression
of white light by the rapid revolution of a disk

* Transactions of the Royal Society of Edinburgh,
vol. xvi. p. 581.

VISION.

1443

painted with the prismatic colours ; and Pla-
teau describes an experiment which leads to a
singular result. He takes two disks of exactly
the same size, made of thick white paper, and
divides one into eight equal sectors, of which
two and two, corresponding and opposite ones,
are coloured red, white, blue, and black. The
second disk is coloured entirely black, two
sections lying opposite to one another, and
rather shorter and narrower than those of the
first disk, being cut out. Both disks are then
attached to rollers which are as much equal to
one another as possible. They are placed
vertically behind one another, so that the
axes of rotation coincide, and the rollers are
set in motion by cords which pass over two
wheels, as nearly as possible equal to one
another. The posterior coloured disk, which
is rendered transparent by varnish, is well
lighted from behind by a lamp. On rotation of
the disks the whole field at first appears black,
but, by gradual transitions, it passes into red,
then white, and lastly into blue.

The stimulus of vivid light produces an
effect upon the retina which is stronger and
lasts longer, in proportion to the intensity of
the primitive effect. The after-images of light
objects will be light, and those of dark objects
dark, if the eye be withdrawn from all subse-
quent action of light. If, for instance, we
look long through a window towards the clear
sky, and, turning suddenly away, close the
eye, we shall see the light intervening spaces
bounded by the dark window frames ; but if,
on the contrary, the eye be turned towards a
white wall, the after-image of the frame will
appear light, and the intervening spaces dark.
The reason is, that if the eye, already dazzled,
be turned towards the white surface, the parts
of the retina previously affected by the bright
light will be less sensitive to the white light of
the wall, than those parts on which the image
of the dark window frames has fallen, and
which has therefore not been unduly stimu-
lated. If the bright sun, or the intense light
resulting from the combustion of lime in
oxygen, be gazed upon, the spectrum continues
for a long period, and if the eye be closed, it
passes through a series of colours until it dis-
appears. The white is followed by yellow,
orange, red, green, violet, and finally black,
one after the other in regular succession. Sir
Isaac Newton experimented upon this subject,
and ran a great risk of blinding himself thereby,
as is described by him in a letter to John
Locke, dated June 30th, 1691. After detail-
ing the various steps of his experiment of
gazing on the sun, and observing the subse-
quent phantasm, he says, — “ At length by
repeating this, without looking any more on
the sun, I made such an impression on my
eye, that if I looked upon the clouds, or book,
or any bright object, I saw before it a round
bright spot like the sun; and, which is still
stranger, though I looked upon the sun with
my right eye only, and not with my left, yet
my fancy began to make an impression upon
my left eye as well as upon my right. For if
I shut my right eye and looked upon a book

or a cloud with my left eye, I could see the
spectrum of the same almost as plain as with-
out my right eye if I did but intend my fancy
a little while upon it : for at first if I shut
my right eye, and looked with my left, the
spectrum of the sun did not appear till I in-
tended my fancy upon it ; but by repeating
this it appeared every time more easily. And
now in a few hours’ time I had brought my
eyes to such a pass, that I could look on no
bright object with either eye, but I saw the sun
before me, so that I durst neither write nor read ;
but to recover the use of my eyes, shut myself
up in my chamber made dark for three days
together, and used all means to direct my
imagination from the sun ; for if I thought
upon him, I presently saw his picture, though
I was in the dark: but by keeping in the dark,
and employing my mind upon other things, I
began in three or four days to have some use
of my eyes again, and by forbearing to look
upon bright objects, recovered them pretty
weil, though not so well but that, for some
months after, the spectrum of the sun began
to return as often as 1 began to meditate on
the phenomena, even though I lay in bed at
midnight with my curtains drawn.”

Dimensions of Objects. — With the represen-
tation of external things by means of the organ
of vision, the mind combines its knowledge of
their size and distance. We infer the real
magnitude of an object from its apparent mag-
nitude, or from the angle under which its rays
intersect each other in the eye ; our know-
ledge of its actual distance from us is merely a
deduction of our judgment arrived at through
the sensations excited in the eye according to
the different positions of objects, and such
sensations are regulated by the angle of vision.
For instance, we infer the increased distance
of an object of known size, as a man, from the
decrease of the visual angle. The angle of
parallax, or that angle which the axis of the
eyes when directed towards an object forms
with it at the point of contact, is also to be
taken into account, for it becomes greater in
proportion to the nearness of the object. We
are further aided by the position of the object
relatively to other known objects, but here, in
forming our conception of true dimensions, we
are largely assisted by the lessons of experi-
ence. The infant will grasp at the moon ; and
it is by degrees that it acquires such experi-
ence and judgment that the original percep-
tions of sight become signs of the tangible
qualities of external objects, and the distances
at which they are placed. In determining the
relative distances of objects one to another,
we are principally guided by the angle of vision;
yet what an exercise of judgment is implied,
founded on a comparison of a variety of dif-
ferent circumstances, and involving a complex
mental operation, when a magnificent prospect
is displayed to our view, and by an instanta-
neous act of the mind we become aware of
the various distances at which all the com-
ponent parts are placed, the size of each indi-
vidual part, and the relation held by each to
the others. Here however, clearness of at-
4 z .3

1-146

VISION.

mosphere and a sufficient amount of light are not being seen reversed, according to the
of importance, for everyone must be aware position in which they are depicted on the
how deceptive is the estimate of the size of an retina; but it would appear that by many
object when seen through a fog, or looming a sufficient distinction has not been drawn
large in the gloom of the evening. between seeing the image and seeing by

Some persons are gifted, as it were, intui- means of it. A little reflection shows that
tively with the power of judging correctly of the actual perception of the object takes
the true dimensions of objects. Napoleon place in the sensorium, and that the image on
possessed this in an eminent degree. He the retina is only a necessary step in the pro-
could tell at a glance the number of men com- cess. In truth, we have no notion of upright

posing a distant mass of troops, and the space
of ground they would cover when deployed.
In doing this a mental computation must have
taken place unconsciously, rapid as thought,
and based on a combination of great powers of
calculation, long experience, and profound
knowledge of the subject.

For the production of a distinct image on
the retina it is necessary that it be of a certain
magnitude, which will depend on the suscep-
tibility of the eye. We may here observe that
the apparent magnitude of an object must not
be confounded with its apparent superficial
magnitude, the term being applied to its linear
magnitude. The apparent superficial magni-
tude varies in proportion to the squares of the
apparent magnitude. The image of an object
moderately illuminated must be 0 001 of an
inch long, or the extreme rays of light must
form an angle of half a minute in the eye at a
minimum ; whence it follows that an object
of mean illuminating power will be visible if
its distance is not greater than 68,000 or 69,000
times its greatest length. Strongly luminous
bodies, as the fixed stars, are visible at infi-
nitely small visual angles. They excite in the
eye merely a sensation of light, without creat-
ing any impression as to their apparent mag-
nitude. The disk of the moon subtends a
visual angle of half a degree, the diameter
of its picture on the retina will be of
an inch, and the entire superficial magnitude
of the image the -jjJ^g-th of a square inch ;
yet forms of light and shade are perceptible
whose linear dimensions occupy upon the re-
tina a space whose diameter does not exceed the
6000000 of a square inch. The eye in a healthy
condition is capable of reading print in the
light of the full moon, and that of the noon-
day sun, their intensities being to each other as
1 to 300,000. Plateau asserts that white may
be distinctly seen in the light of the sun at an
angle of 12", yellow at an angle of 13", red at
23", and blue at 26", but that in ordinary day-
light these angles must be half as large again.

In estimating the motions of objects, we are
guided by the movement of their images on
the retina; anti unless a body moves in such
a manner that the line of vision shall describe
at least one degree in each minute of time, its
motion will not be perceptible ; for which
reason we are not conscious of the move-
ments of the heavenly bodies. The more
nearly at right angles to the line of vision the
direction of the motion is, the greater will be
the apparent motion produced by any real
movement of an object.

Erect I'ision. — A variety of explanations
have been offered to account for objects

or inverted, except that which is founded on
experience. A man is upright whose head is
upwards, and his feet downwards. Whatever
be our standard of up or down, the sensible
representation of up will always be an image
moving on the retina towards the lower side,
and the sensible representation of down will
be a motion towards the upper side. . The
head of the man’s image is towards the image
of the sky ; its feet are towards the image ot
the ground ; and consequently it cannot, ap-
pear otherwise than upright. So, as all objects
are inverted on our retinas, they do not change
their relation one with another, and our only
knowledge of position is from relative rela-
tion, therefore we may truly say that we do
not see the image on the retina, but by means
of it. For every image ou the retina, we sub-
stitute an object, and seek in a definite direc-
tion for the object corresponding to a definite
image on the retina. In this we are assisted
by other perceptions of sense, there existing
the greatest harmony between such percep-
tions in respect to locality.

Dr. Alison, in an able paper*, advances the
opinion, that the harmony between the inti-
mations acquired by sight and by touch, as to
the relative position of objects or their parts,
notwithstanding that the impressions made
by them on the external organs of sight and
of touch are arranged inversely in regard to
one another, arises from the course ot the
optic nerves and tractus optici, whereby im-
pressions on the upper part ot the retina are
in fact impressions ot the lower part ot the op-
tic lobes — that is to say, of the sensorium—
and impressions on the outer part ot the retina
are, in like manner, on the inner part of the
sensorium. This theory was first suggested by
Mr. Dick, a veterinary surgeon ; but though
ingenious, can hardly be considered satisfac-
tory, as it implies the necessity for con-
ditions which cannot always be (ulfilled : and
truly the question is of a nature not to be
decided merely by anatomical inquiry.

Kepler’s explanation of objects appearing
erect to us is, that the mind, perceiving the
impulse of a ray on the lower part ot the re-
tina, conceives this ray to be directed from a
higher part of the object, and vice versa. For-
terfield argues that the mind never sees any
picture painted on the retina, and consequent!)
never judges of the object from what it ob-
serves in the picture ; and that in seeing any

* On Single and Correct Vision, by means of
Double and Inverted linages on the Retins, lrans"
actions of the Royal Society of Edinburgh, vol. xiii.
p. 472.

VISION.

1447

object the mind, by virtue of a connate immu-
table law, traces back its own sensation from
the sensorium to the retina, and from thence
outwards, along right lines drawn perpen-
dicularly from every point of the retina on
which any impression is made by the rays
forming the picture, towards the object itself,
by which means the mind always sees every
point of the object, not in the sensorium or
retina, but without the eye, in these perpen-
dicular lines. But these lines nearly coincide
with the axes of the several pencils of rays
that flow to the eye from the several points of
the object ; and since the mind has also a
power of judging rightly of the distance of
objects, it follows that every point of the
object must appear and be seen in the place
wheie it is, and consequently the object must
appear in its true erect position, notwithstand-
ing its picture on the retina is inverted. This
theory of lines of visible direction Reid regards
as a law of nature, of which our seeing objects
erect, from inverted images, is a necessary
consequence. Sir David Brewster too believes
that erect vision results from the lines of
visible direction being in all cases perpen-
dicular to the impressed part of the retina ;
but Muller offers the following objections: —
“ The hypothesis that erect vision is the re-
sult of our perceiving, not the image on the
retina, but the direction of the rays of light
which produce it, involves an impossibility,
since each point of the image is not formed by
rajs having one determinate direction, but by
an entire cone of rays. And, moreover, vision
can consist only in the perception of the state
of the retina itself, and not of any thing lying
in front of it in the external world. The
hypothesis also that the retina has an outward
action, and that objects are seen in the direc-
tion of decussating lines, that is to say, in the
direction of the perpendicular of each point of
the concavity of the retina, is a perfectly arbi-
trary assumption ; since there is no apparent
reason why one direction should have the pre-
ference rather than another, and each ultimate
sensitive division of the retina, if it had the
power of action beyond itself, would act in as
many directions, as radii might be drawn from
it towards the exterior world.” * Notwith-
standing these objections, the law of visible
direction affords the most satisfactory expla-
nation of the phenonmena of erect vision ; all,
however, we know positively is, that in the or-
dinary exercise of vision, the mind infers the
positions of objects from an impression made
upon the retina, and that it as certainly draws
the right conclusion therefrom.

This, however, is not more wonderful than
that the undulations of the luminous particles
should excite the sensation of light in the
retina, or that vibrations acting on the auditory
nerve should give rise to sound. We may
heap conjecture on conjecture as to the final
cause of these phenomena, but we must stop
at the limits to the boundaries of human
knowledge. The profound resources of the

* Elements of Physiology, by Balj’, p. 1171.

Divine Intelligence excite our wonder and
exalt our thoughts, but there are a thousand
things abstractedly possible which set at
nought our comprehension.

It is curious that such an acute mind as
that of the late eminent metaphysician. Dr.
Brown, should have been so satisfied that the
perception of the number and position of
visible objects is acquired only by association
or custom, that he dismissed the subject thus
curtly: — “In the single vision of the erect
object from a double image of the object in-
verted, there is nothing at all mysterious to
any one who has learnt to consider how much
of the visual perception is referable to associa-
tion. If the light reflected from a single ob-
ject touched by us had produced, not two
merely, but two thousand, separate images in
our eyes, erect or inverted, or in any inter-
mediate degree of inclination, the visual feel-
ing thus excited would still have accompanied
the touch of a single object ; and if only it had
accompanied it uniformly, the single object
would have been suggested by it, precisely in
the same manner as it is now suggested by
the particular visual feeling that now attends
the double inverted image.”* It has been
justly remarked by Dr. Alison, that if it were
only by experience and association with the
perceptions of touch that we learned that any
object placed before the eyes, and seen by
two images, is nevertheless single, we might
reasonably conclude that we should never see
an object double which we know by touch to
be single ; whereas we all know, that if by
pressure on the ball of one eye, or by any
other means we direct the axes of the two
eyes to different points in an object, we imme-
diately see it double, and cannot by any means
avoid seeing it double so long as that con-
dition of the eyes continues, notwithstanding
the full conviction, derived from touch, of its
being single. This tangible theory (if the ex-
pression may be used) has found little favour,
but having met with the support of so able a
man as Dr. Brown, it could not be passed over
in silence.

Single Vision. — When both eyes, acting
simultaneously, are directed to an object, a
single image only is seen. A variety of opinions
have existed with reference to this interesting
point, some of them sufficiently singular.
Gassendi, Du Tour, Porta, and Gall, for in-
stance, asserted that we do not make use of
more than one of our eyes at a time, the other
being relaxed, and inattentive to objects. Dr.
Briggs supposed that single vision was owing
to the equal tension of the corresponding parts
of the optic nerves, whereby they vibrated in
a synchronous manner ; and Dr. Reid was of
opinion that the correspondence of the two
eyes, on which single vision depends, arose
from some natural constitution of the eye and
mind. Porterfield says that the true cause
why objects do not appear double, depends on
the faculty we have of seeing things in the
place where they are, every point of an object

* Lecture 29.

4 z 4

1 448

VISION:

being seen nearly in a straight line drawn per-
pendicularly to the retina from that point of
it where its image falls and this law of visible
direction may be regarded as exercising an
important influence on the production of
single vision.

In reference to this phenomenon, it is ne-
cessary to advert to the remarkable structure
of the commissure of the optic nerve. The
chiasma results from the junction of the optic
tracts, in front of and inferior to the tuber
cinereum. The fibres which constitute the
inner margin of each tract, b, are continued

Fig. 885.

across from one side of the brain to the other,
forming no connection with the optic nerves,
and existing where those nerves do not exist,
as in the mole. These fibres may be con-
sidered as commissural between the thalami of
opposite sides. The remaining fibres of the
tracts go to form the optic nerves, the cen-
tral passing across to the nerve of the oppo-
site side, and the outermost, c c, passing to
the optic nerve of the same side. Besides
these, the two retina are brought into direct
connection by the fibres, a, which form the
anterior border of the chiasma. From this
arrangement it appears that corresponding
parts of the two retinae are brought into
relation one to the other, in the same manner
as corresponding parts of the cerebral con-
volutions are linked together by the various
commissures : the right side of each retina
appears also to be continuous with the right
optic tract, and the left side of each with the
left ;thus each side of the central apparatus
is brought into communication with its- own
side of both retinal images, which may be
supposed to favour their conception as one.

The learned Arabian Alhazen supposed
that when corresponding points of the two
retinas are affected, the mind perceives one
image ; this opinion has found favour ; but Dr.
Todd and Mr. Bowman, and also Dr. Alison
have especially pointed out the importance of
the decussation of the commissural fibres.
Dr. Alison arrives at the conclusions : first,
that certainly in some, and probably in all
animals, the structure of the optic nerve
brings the impressions which form inverted
images on the retina into the same order on
the sensorium as those which might result
from the touch of the same objects ; secondly,
that in those animals which can direct both
eyes to one point, the partial decussation of
the optic nerves, generally if not universally
present, enables the images produced by an
object on the corresponding parts of the
retinae of the two eyes to co-operate in pro-

ducing one impression on the sensorium, and
one sensation in the mind; and lastly, that
the decussation which takes place in the cor-
pora pyramidalia affords correct information
as to objects of sight from impressions made
on them simultaneously in both optic lobes,
— that is to say, on both sides of the senso-
rium,— notwithstanding that the impression
on each side of the sensorium comes from
the opposite side of the object in view. Thus
it will be seen that Dr. Alison refers the con-
nection of sight with touch to the decussation
of the corpora pyramidalia. We may fairly
conclude that there must be some structural
provision in the organisation of the cerebral
portion of the visual apparatus, which favours
the perception of a single image from a double
impression, and keeps in perfect harmony the
important senses in question : how far the
corpora pyramidalia may be concerned, is
matter of speculation. The precise action of
the mind, by which the single image only is
appreciated, is of course unknown to us, but
an additional argument in favour of the part
performed by the chiasma is afforded by the
occurrence of cases where only half an object
or word is seen when both eyes are directed
to it. Thus, as has been humorously illustrated
by Dr. Hull, the word patriot becomes riot;
ami o( matrimony, only mony is seen. Such
phenomena are (as remarked by Dr. Todd and
Mr. Bowman) readily explained by supposing
the anatomical arrangement of the sides of the
retina, with regard to the optic tracts, to be
such as has been described, since any derange-
ment of one optic tract w'ould then affect the
same part of both optic images.

For the production of single vision, it is
necessary that the muscles which move both
eyes should act in perfect concert. The
effect of this is, that the axes of the eyes
converge towards the object to which they
are adjusted, and the image falls on corre-

Fig. 886.

sponding parts of the two retinas. Let a b
be the two eyes, and c any object before
them. Then a c, b c are their axes, which
meet in c. An image is consequently pro-
duced in each eye which will correspond with
the perspective projection of the object from
the points a and b. If the two images are un-
synrmetrieally placed, so that the axes meet
either before or behind the object, a double
sensation is excited, as happens in strabismus,
and the double vision of intoxication. The
upper sides of both retinae correspond, as dotlie
lower ; and the outer side of each corresponds
with the innerside of the other ; but theobjects
and corresponding points of the retinae should

VISION.

1419

lie in a certain circle, designated (he horopter ;
a circle which passes at once through the
point of coincidence, l, of the visual axes, la,
l b, and the points of decussation, c c', of
these axes with the lines of direction.

Fig. 887.

Let c c' be the centres of the eyes a b, l
the point regarded, l c F the horopter, a and
b the points of the retina on which the axes
of the eyes terminate ; and let m be a second
point in the horopter. The point l appears
upon the axial points a and b, the point m at

0 and pi a line betwixt l m will form the
chord of the arc of the horopter lying between
/ and in; and as all triangles drawn upon the
arc of a circle have equal peripheral angles,
so is the angle l c m equal to the angle l c' in.
Both are farther equal to the opposite angles
oca, p c' b. Moreover o c is equal to pc,
and a c to b c', as radii proceeding from the
centres c and c' of the retinal circles, which
in each eye have an equal circumference.
Consequently o is just as far from the axial
point a, as p is from the axial point b ; and so
identical or corresponding points of the retina
are affected by the rays proceeding from both

1 and in. It is, however, to be borne in mind,
that though impressions made on non-cor-
responding points of the middle portions of
the two retinae are perceived as two, impres-
sions made on non-corresponding points of
the circumferential parts are not so perceived,
the distance between such points being within
certain limits.

When an object is viewed at so great a
distance that the optic axes of both eyes are
sensibly parallel when directed towards it, the
perspective projections of it seen by' each eye
separately are similar, and the appearance to
the two eyes is precisely the same as when
the object is seen by one eye only. But this
similarity no longer exists when the object
is placed so near the eyes that to view it the
optic axes must converge : under these con-
ditions a different perspective projection of it
] is seen by each eye ; and these perspectives

are more dissimilar as the convergence of the
optic axes become sgreater. Fig. 888. repre-
sents the two perspective projections of a
cube, b is that seen by the right eye, and a
that presented to the left eye, the figure being
supposed to be placed about seven inches im-
mediately before the spectator and viewed
with each eye alternately, the other being
closed, and the head kept perfectly steady.

„ Fig. 888.

Mr. Wheatstone has shown that the single
sensation excited by these two images is that
of a third image different front them both, but
excitable only by both of them at once, and
attended with the notion of solidity or projec-
tion in relief. This he has illustrated by a
most ingenious instrument called the stereo-
scope. Accurate representations are drawn
of the appearance presented by an object of
three dimensions, when viewed by each eye
at a short distance. These drawings are then
placed symmetrically in the right and left
compartments of a small box, so as to be
reflected by sloping mirrors to the eyes
of the observer, who must place them as near
as possible to these mirrors ; then, by moving
sliding panels to or from him, he will find
a position, and one only, in which the bin-
ocular image will be seen single, of its proper
magnitude, and without fatigue to the eye,
because in this position only the ordinary re-
lation between the magnitude of the pictures
on the retina, the inclination of the optic
axes, and the adaptation of the eye to distinct
vision at different distances, are preserved. It
being thus shown that there is an essential
difference in the appearance of objects when
seen with both eyes, and when only one eye is
employed; and that the most vivid belief of
the solidity of an object of three dimensions
arises from two different perspective projec-
tions being simultaneously presented to the
mind, the question arises, how is it that per-
sons who see with only one eye form correct
notions of solid objects, and never mistake
them for pictures ? and how happens it that
a person having the perfect use of both eyes
perceives no difference in objects around him
when he shuts one of them? To explain
these apparent difficulties, says Mr. Wheat-
stone, it must be kept in mind that, although
the simultaneous vision of two dissimilar pic-
tures suggests the relief of objects in the most
vivid manner, yet there are other signs which
suggest the same ideas to the mind, and are
less liable to lead the judgment astray in pro-
portion to the extent of our previous expe-
rience. The vividness of relief arising from
the projection of two dissimilar pictures, one

VISION.

lidO

on each retina, becomes less and less as the
object is seen at a greater distance from the
eyes, and entirely ceases when it is so distant
that the optic axes are parallel while regarding
it. We see, with both eyes, all objects beyond
this distance precisely as we see near objects
with a single eye ; for the pictures on the two
retinae are then exactly similar, and the mind
appreciates no difference, whether two iden-
tical pictures fall on corresponding parts of
the two retinae, or whether one eye is im-
pressed with only one of these pictures. A
person deprived of the sight of one eye sees
therefore all external objects, near and remote,
as a person with both eyes sees remote objects
only : but that vivid effect, arising from the
binocular vision of near objects, is not per-
ceived by the former, who, to supply the
deficiency, resorts to other means of acquiring
more accurate information ; and of these the
motion of the head is the principal.

Mr. Wheatstone has also shown that, if
similar images, differing only in magnitude,
are presented to analogous parts of the retinas,
the resultant idea is that of an image appa-
rently intermediate in size between them.*

Foucault and I. Regnault have employed
the stereoscope to determine whether com-
plementary retinal images produce the im-
pression of white on corresponding points of
both eyes. Two complementary rays, ob-
tained by chromatic polarisation, were thrown
in a horizontal direction on the mirrors of
a stereoscope, and reflected from them on the
screens attached at the sides, so that two
small disks of paper were coloured by them.
At first one or other complementary colour
was alternately seen : after a time, however,
the two impressions united to form white ;
and when the eyes had once become accus-
tomed to this, a whole series of complemen-
tary colours could be introduced successively,
and nothing but white was seen during the
entire experiment.

From the following interesting experiments
by Sir David Brewster, it appears that we
give solidity and relief to plane figures by a
suitable application of colour to parts that are
placed at different distances from the eye. If
we look with both eyes through a lens about
two and a half inches in diameter, at an ob-
ject having colours of different refrangibilities,
as a red rose among green leaves, the two
colours will appear at different distances from
the eye of the observer. In this experiment
we are looking through the margin of two
semi-lenses, or virtual prisms, by which the
more refrangible rays are more refracted than
the less refrangible rays. The doubly coloured
object is thus divided into two, as it were,
and the distance between the two blue por-
tions is as much greater than the distance
between the two red portions (red and blue
being supposed to be the colours) as twice

* Sir David Brewster disputes this and several
other deductions of Mr. Wheatstone, in an able paper,
“On the Law of Visible Position in Single and
Binocular Vision,” Transactions of the Royal So-
ciety of Edinburgh, vol. xv.

the deviation produced by the virtual prism,
if we use a large lens or two semi-lenses, or
by the real prisms if we use prisms. The
images of different colours being thus sepa-
rated, the eyes unite them, as in the stereo-
scope, and the red image takes its place
nearer the observer than the blue, in the same
manner as the two nearest portions of the dis-
similar stereoscopic figures stand up in relief
at a distance from their more remote por-
tions. The reverse of this will take place, if
a concave lens be used, or if the refracting
angles of the two prisms be turned inwards.
The modified stereoscope has very recently
been applied to photographic purposes with
the happiest results.

Adaptation to distance. — On no subject
connected with the physiology of the eye
has there been a greater diversity of opinion
than on the mode in which adjustment to
distance is performed. That such adjustment is
necessary, is proved by the simple experiment
of looking between the fingers held about
eight inches from the eye, at a distant object.
When the distant object is seen distinctly, the
fingers will be seen indistinctly; and if we
look at the fingers so as to see them quite
distinctly, the distant object will be indis-
tinct. Our space will not admit of our doing
more than glancing rapidly at the theories
which have been advanced, anti eagerly sup-
ported, to account for this alteration in the
focus of the eye. By Bayle, Rohault, Home,
Others, and Schroeder Vanderkolk, alteration
in the form of the eye by means of the ex-
ternal muscles was supposed to be the medium
of adjustment. The movements of the iris
have had their supporters, of whom the prin-
cipal were Mile and Pouillet. Ramsden and
Sir Everard Home regarded a change in the
convexity of the cornea as the medium of
adjustment. By John Hunter and Dr. Young
(who devoted much time to the inquiry),
elongation and shortening of the axis of the
lens, through a contractile power inherent in
the lens itself, were supposed to be the cause;
and lastly, it was referred by many authori-
ties, including Kepler, Scheiner, Camper, and
Porterfield, to the movement of the lens by
means of the ciliary processes. Porterfield
was probably the first who hit upon the true
explanation, by referring the adjustment to
the'action of the ciliary body upon the crys-
talline, and by distinctly asserting the mus-
cularity of the ciliary body. In reply to the
arguments of De la Hire (who maintained
that at whatever distance objects were placed,
the eyes never altered their focus), Porter-
field acutely observes : “ This author main-
tains that it is impossible the crystalline can
change its situation, because the ciliary liga-
ment is not muscular, and consequently has
no power of contraction : and of this opinion
are likewise a great many anatomists, and in
particular llovius : but it appears that all of
them have been led into this mistake by an
unjust notion they have entertained about the
colour of muscles. Every body knows that
our muscles are generally of a red colour; but

1451

VISION.

it does not from thence follow that what is not
red is not musculous. The muscular fibres of
the guts and stomach have scarce anything of
redness in their colour ; and it is also certain
that the pupil does contract and dilate itself
according as objects are more or less lumi-
nous, and yet noneof the fibres which perform
that action are in the least red. Whence it
follows that the fibres of the ligamentum ciliare
are not to be deprived of a power of con-
traction because of a colour different from
what generally obtains in other muscles ; nor
are we to be surprised that so many accurate
anatomists, after a careful examination of this
process, have not scrupled to affirm it to be
truly muscular.”

Mons. Pouillet h as advanced the hypothesis
that, by the peculiar conformation of the lens,
near objects are seen through the medium of
the rays passing through its centre, and distant
objects by means of the circumferential rays.
He describes the crystalline lens as made up of
strata, differing in curvature and density, so
that its section exhibits a series of concen-
trical ellipses having varying excentricities,
the internal strata being more curved and
more dense than the external ; whence the
rays which pass from the latter converge to a
more distant point than those from the former.
According to this theory, the crystalline lens
has many different foci, and the effect should be,
that when a pencil of rays falls upon it, those
rays which are near the axis of the pencil,
and therefore near the centre of the lens, are
brought to a shorter focus than those which
are near the border ; whence near objects
would, says M. Pouillet, be seen by means of
the central rays, and distant objects by means
of those rays which fall near the borders of
the crystalline lens.

It has been observed that De la Hire de-
nied that there is an alteration in the focus,
whether we look at a near or distant object.
He regarded the whole adjustment as a simple
enlargement and diminution of the pupil. At
first sight this may appear absurd, but there
are facts which give some colour to his theory.
That a change in the size of the pupil has a
considerable influence upon the distinctness
of objects at different distances, is known,
and it the eye be turned to a near object, as
a book, after it has been gazing at a distant
ship, the illumination of both being equal,
the pupil is observed to contract. Dr.
Mackenzie says, it is an error not unfre-
quently adopted, that if the rays which pass
into the eye from a distant object, and those
from a near object, have the same divergence,
a circumstance which may depend on a mere
change in the size of the pupil, they will be
collected on the same point of the retina
without any change in the refractive media of
the eye. That this cannot be the case, is evi-
dent from the fact that the rays from a dis-
tant object, and those from a near object,
although they may have the same divergence,
fall on the cornea at different angles of inci-
dence, and must necessarily meet the axis of
the eye at different points after refraction.

Now the whole effect of the alteration in the
size of the pupil is, as explained elsewhere,
to increase the distinctness of objects by
cutting off those rays which would cause cir-
cles of dispersion on the retina. On the one
hand, an enlargement of the pupil gives dis-
tinctness to distant objects, by allowing a
greater quantity of light to enter the eye, and
on the other, its contraction assists in render-
ing near objects distinct by cutting off the
lateral rays which are not duly refracted, and
would cause confusion of the image on the
retina. If, however, a proof were required to
show that something more than a mere alter-
ation in the form of the pupil is necessary
to the perfection of vision at all distances, it
would be afforded by the change termed pres-
byopia. The eye, in what may be called its
state of perfect indolent vision, is adapted
only to see distant objects, the adjustment to
the near focus requiring an effort : the power
to make the effort in question is partially or
entirely lost by the presbyopic eye, yet the
pupil may act as vigorously as ever. Though
it is not unusual to find a degree of sluggish-
ness in the actions of the pupil in elderly
persons, yet we have repeatedly seen instances
in which the iris acted with great vigour, and
where a book was obliged to be held at arm’s
length for the type to be distinctly seen.

Wagner and Dr. Clay Wallace of New
York follow Porterfield in attributing the ad-
justment to the action of the corpus ciliare ;
the latter considering that, “ by the graduat-
ing power of the ciliary processes and ciliary
muscles, together with the elasticity of the
membranes of the vitreous body, the crystalline
may be drawn not only backwards and for-
wards, but its inclination may be changed so as
to throw the image on another part of the re-
retina and the modus operandi he explains byr
supposing “ the outer ciliary muscle to contract
the vessels returning from the ciliary pro-
cesses ; the ciliary processes which are at-
tached by the filaments of Ammon to the
ciliary zone and crystalline capsule, to become
erect and to draw forward the crystalline
body ; and the inner ciliary muscle, aided by
the elasticity of the membranes of the vitreous
humour, to draw it backwards.”

The opinion, however, which appears most
satisfactory, is that advanced by Mr. Bow'-
man, who has clearly proved the muscular
nature of the ciliary body. “ It has (says
he) the arrangement of a muscle, very much
the structure of a muscle, and is largely sup-
plied with nerves, which are in great part
derived from a motor source — the third
pair. This muscle arises, or has its most
fixed attachment, at the junction of the scle-
rotica and cornea, as much in front of the lens
as is possible, consistently with the preserva-
tion of the transparency of the cornea. That
it may act more free!}’, a canal, the circular
sinus, is interposed between its origin and the
portion of the sclerotica which it lies against.
Beyond this point it is hardly at all attached
to the sclerotica, over which its fibres may be
supposed to move in contraction ; but it

1452

VISION.

covers, and is inserted into, the anterior one-
eighth of an inch of the choroid membrane,
which is in this part tougher and firmer than
elsewhere, and united in a very special manner
to the lens by the ciliary processes, through
the medium of a firm tough membrane, and
of a strong elastic fibrous membrane proceed-
ing from it to the margin of the lens, and yet
not quite to its margin, for an elegant arrange-
ment exists, the canal of Petit, by which
traction is made, not on the vitreous around
the lens, nor on the edge of the lens itself, so
much as on its anterior surface. I confess it
seems to me very difficult to doubt that this
complicated system ot parts is intended to
advance the lens towards the cornea, so as to
bring forward, up to the retina, the focus of
a near object, which would otherwise fall be-
hind the nervous sheet. It is possible also, I
think, from the peculiar direction taken by the
ciliary muscle, that it may compress the front
of the vitreous, and thus help to throw for-
ward the lens.” *

An ingenious theory has been suggested by
Sturm, and supported by Matteuci, founded
on the results of Chossat’s measurement of
the eye of an ox, to the effect that in place
of comparing the optical apparatus of the eye
to a system of spherical lenses whose axes are
blended, we ought to consider the organ as
composed of several refracting media, sepa-
rated by surfaces which are neither exactly
spherical, nor even of revolution or symme-
trical about a common axis. Reasoning from
this, he argues that a peculiar refraction of
the rays of light takes place, whereby tne
retina is placed in what he terms a focal in-
terval, which focal interval will change its
position according as the external luminous
point recedes from, or approaches to, the eye
and that the retina will be always met by the
concentrated fasciculus around the axis in the
focal interval ; the surface of intersection of
this fasciculus and of the retina being very
slightly modified, in order that the impression
may not be sensibly altered, or the perception
rendered indistinct. This theory is, however,
decidedly open to objection, and is rendered
unnecessary by that ot Mr. Bowman.

Magnifying lens. — It has been already
stated that the apparent magnitude of an ob-
ject depends upon that of the angle of vision
under which it is seen, and this increases in
proportion as the object is brought nearer to
the eye ; but the magnitude of the angle of
vision being limited, we are obliged to resort
to artificial means to enlarge it further than,
in its natural condition, is admitted of. The
pin-hole aperture affords some assistance, but
the convex lens more. The following is the
mode in which it acts : —

Let cd be a convex lens, and ab an object
lying within the focal length of the glass, then
all the rays passing from a point of the object
ab will diverge after their passage through
the lens, exactly as if they came from the
corresponding point of the image ab ; an eye

* Lectures on the Parts concerned in the Opera-
tions on the Eye, p. 60.

Fig. 889.

a

behind the lens would be able to see the ob-
ject distinctly through the lens if the image
ab were at the distance of distinct vision. In
this case, however, the object being much
nearer the eye, it could not be seen without
the lens. The magnifying power of the lens
therefore depends essentially on the means it
gives us of bringing the object very near the
eye, and thus increasing the angle of vision.

Abnormal Vision.

In the consideration of abnormal vision, we
propose to divide the subject into

f. Abnormal Vision resulting from defec-
tive action of the retina or sensorium ; as
Achromatopsy , Hyperchromatopsy, and
Anorthopia.

2. Abnormal Vision arising from faulty con-
figuration of the eye, or from changes in
the refractive media ; as Myopia, Pres-
byopia, and Cylindrical Eye.

Amaurosis, Chrupsia, and other morbid
conditions, do not fall within the scope of this
article.

Achromatopsy (a not, colour, the

eye), or insensibility of the eye to colours, is
an affection which has been recognised nearly
two hundred years; but, although cases have
been from time to time published in the Phi-
losophical Transactions and other scientific
works, our knowledge of the phenomena of
this singular condition is of recent date, and
is chiefly due to the labours of Wartmann,
Seebeck, Szokalski, Purkinje, Himly, &c.

Various names have been proposed for this
imperfection of vision ; but the majority are
exceedingly unmanageable. By Sommer and
Szokalski the term chromato-pseudopsis has
been employed ; Goethe proposed to call it
ahyano-blepsis, whilst Purkinje divided the
disorder into four varieties, — achromatopsia,
chromato-dysopsis, ahyano-blepsis, and anery-
thro-blepsis ; others again have been satisfied
with the simple term chroviato-metablepsis.
Jiingken employs indifferently the denomina-
tions of achromatopsy , chromatopseudopsy, and
chromatometablepsy . Many writers, however,
have adopted the term Daltonism, proposed by
Prevost, and supported by Wartmann ; and,
although objectionable as perpetuating the in-
firmity of an individual, it has the merit of
simplicity and easy inflection. The term
achromatopsy is, perhaps, that most usually
employed, although, strictly speaking, it is
only applicable to one class. Still, being ex-
tensively recognised, we shall adopt it to de-
signate this imperfection of vision ; occasion-

VISION.

1453

ally the expression “ Daltonian” may be used It has been remarked by Wartmann as a
for the sake of brevity. curious fact, that in no ancient author is there

Modifications of insensibility to colours any passage which can be referred to the
exist in every degree, and in the minor shades subject of achromatopsy, and that the riume-
are so frequent as to be almost proverbial rous travellers who have traversed the old and
with reference to the male sex ; indeed, if new world are equally silent in this respect,
twelve men, taken at random, were shown a As to the relative frequency of achroma-
numner of ribands of the more delicate topsy, Seebeck states that five out of forty
colours, a diversity of opinion would almost youths who composed the two upper classes
certainly arise as to the appropriate names, in a gymnasium at Berlin, were affected with

The number of persons who cannot distinguish it, and Prevost has declared that the pro-
certain colours is considerable ; but the defect portion of this imperfect vision to perfect
is seldom known to others, those who are con- vision, is as one to twenty. It is true that
scious of their imperfection being desirous of Chelius and Chevreul entertain a very op-
concealino- it, and some perhaps, not being posite opinion, but the balance of authority is
aware of It till accident leads to its discovery, decidedly against them.

In every case that has fallen under our notice,
there has been reluctance to submit to ex-
amination, from the fear ot ridicule ; and
indeed it is difficult to repress a smile when a
person is seen to match green and scarlet to-
gether, or crimson and dark blue, and earnestly
protest that the colours are absolutely iden-
tical. The nearest approach to this condition
in the healthy eye, and a test by which the
embarrasment of Daltonians may be judged of,
is the difficulty of distinguishing between blue
and green by candlelight ; a difficulty which
every one must have experienced. Analogous
to this defect of the organ ot vision, is that
better known, because more evident, insensi-
bility of the organ of hearing, whereby many
persons are utterly unable to detect the differ-
ences between musical notes, or, as pointed
out by Dr. Wollaston, their ears maybe abso-
lutely insensible to sounds at one extremity of
the scale. Sir David Brewster remarks# that,
although his own hearing is perfect and each
ear equally acute for all ordinary sounds, yet
one of them is absolutely deaf to the chirp of
the cricket, while the other hears it distinctly.
Dr. Pliny Earle has published t a remarkable
illustration of the imperfection of the two
senses in conjunction. “ The whole family
(says he) of which the chart has been ex-
hibited, is probably no less generally charac-
terised by a defective musical ear than an
imperfect appreciation of colours. Several ot
the individuals comprised in it are utterly inca-
pable of distinguishing one tune from another.
* * A gentleman who has the general defect

under discussion, and whose case is included
in the thirty-one herein mentioned, is a well-
known professor in one of the Metropolitan
Medical Schools of the United States. In
him the total inability to discriminate between
musical sounds is coexistent with the defec-
tive perception of colour * * Another

of the gentlemen xvhose case of defective per-
ception of colours is herein noticed, is gene-
rally acknowledged as one of the first and
greatest of American poets now living. He
also is unable to distinguish one tune from
another; yet his poetry is not deficient in the
requisites of perfect cadence, harmony, and
rhythm.”

* Philosoph. Mag. vol. xxv. p. 13G.

f American Journal of Medical Sciences, vol. 35.
p. 347.

This affection is often hereditary, and is
found in some families to a remarkable extent.
It sometimes occurs in successive generations,
of which a remarkable instance has been pub-
lished by M. Cunier *, and at other times it ap-
pears in alternate generations, descending far
more frequently on the maternal side than the
paternal. In the case of Mr. Milne, recorded
by Dr. Combej-, the maternal grandfather was
affected with Daltonism, also his two brothers
and a second cousin. In that of a child related
by Dr. NichollJ the maternal grandfather and
several of his brothers were similarly affected ;
such was also the case with two young men
mentioned by Dr. Cornaz $ They were the
offspring of the same mother but by different
fathers, and in both, achromatopsy existed to
a marked degree. But the most striking
illustration of the hereditary character of this
defect has been recorded by Dr. Pliny Earle ||,
and it is so remarkable that we give it in
his own words. “ My maternal grandfather
and two of his brothers were characterised
by it, and among the descendants of the first
mentioned, there are seventeen persons in
whom it is found. I have not been able to
extend my inquiries among the collateral
branches of the family, but have heard of one
individual, a female, in one of them, who
was similarly affected.* * * Nothing is known
of the first generation (of five) in regard to
the power of perception of colours. In the
second, of a family consisting of seven
brothers and eight sisters, three of the
brothers, one of whom, as before mentioned,
was the grandfather of the writer, had the
defect in question. In the third generation,
consisting of the children of the grandfather
aforesaid, of three brothers and four sisteis,
there was no one whose ability to distinguish
colours was imperfect. In the fourth genera-
tion, the first family includes five brothers
and four sisters, of whom two of the former
have the defect. In the second family there
was but one child, whose vision was normal.
In the third there were seven brothers, of
whom four had the defect. In the filth, seven
sisters and three brothers, of all of whom the

* Annales d’Oculistique, tom. i. p. 417.

t Transactions of Phrenological Society, p. 222

t Med. Chir. Trans, vol. vii. p. 477.

^ Annales d’Oculistique, tom. xxiii. p. 43.

|| Op. cit. p. 349.

1154.

VISION.

vision is perfect in regard to colour. In the
sixth, four brothers and five sisters, of whom
two of each sex have the defect. In the
seventh, two brothers and three sisters, both
of the former having the defect. In the
eighth, there was no issue, and in the ninth
there a e two sisters, both of them capable of
appreciating colours.” Of the fifth genera-
tion “ the defective perception has hitherto
been detected in but two of the families. In
one of them, consisting of three brothers and
three sisters, one of the brothers has the
defect, and in the other, a male, an only child,
is similarly affected.”

Sex exercises a considerable influence on
the occurrence of achromatopsy; of the
thirty-one cases mentioned by Dr. Earle,
twenty-seven were males and four females,
and the result of upwards of two hundred
cases shows that as a general rule the propor-
tion of males is nine tenths of the whole. A
very remarkable instance has however been
published by M. Cunier*, where achroma-
topsy occurred in five generations of one
family, there being thirteen cases, and all
females ; but this stands alone as a notable
exception to the general rule. If it be true
that the works of the needle are the means
of perfecting a delicacy in the judgment of
tints, and in women the organ of colour is
more developed than in men (as asserted by
Gall), these very works ought to lead daily to
the detection of achromatopsy if it existed ;
and we may reasonably conclude that as cases
are not discovered they do not exist.

According to the observations of Szokalski,
this defect of vision especially obtains among
nations having a Germanic origin, as the
Germans, English, Swiss and Belgians; the
French, Italians, and Spaniards being com-
paratively free : it seems to be common in
the United Slates, but this does not militate
against the proposition, the Americans being
descendants of the old British stock. How
far this peculiarity may be attributable to
the greater sensibility of the inhabitants of
southern climes, where the more brilliant sun-
shine develops colours in a degree unknown
in the northern latitudes, is a question which
cannot be decided in the present state of
our knowledge: nor can we affirm with con-
fidence, as stated by the same writer, that
achromatopsy occurs most frequently in ro-
bust constitutions, combined with a bilious
and melancholic temperament. A difference
of opinion exists as to whether achromatopsy
is indicated by any visible signs ; Szokalski,
Ruete, and Himly affirm that there is no
diagnostic mark, and Rau considers that a
yellowish tinge of the iris, which has been
considered by some to be indicative of it, is
far too common to be so regarded. Professor
Wartmann has in his first memoir drawn
attention to a peculiar golden lustre of the
eyes, which presents itself in cases of achro-
matopsy, where the iris is hazel. Miss Sedg-
wick f says of the historian Sismondi, that he

* Op. cit.

f Letters from Abroad, vol. i. p. 250.

had brilliant hazel eyes ; he was a Daltonian.
At least five other cases are known to have
presented the same peculiarity, but the num-
ber is yet too small to admit of this being
regarded otherwise than as a coincidence, for
in truth there appears to be as many Dalto-
nians with blue, black, and grey eyes, as with
hazel, and as many eyes without a yellow
pupillary margin as with it.

There is sufficient evidence before us to
warrant our considering achromatopsy under
two distinct forms: congenital and non-con-
genital. The former is always persistent: the
latter may be divided into permanent and tem-
porary.

Writers have classified the defect according
to degree; but the simplest and most practical
arrangement is that of Wartmann, who recog-
nises two classes only: the Dichromatic and the
Polychromatic. This we think advantageous,
as avoiding unnecessary sub-classification, the
varieties of the defect being endless.

Congenital Achromatopsy. — This form is
most common, and the majority of recorded
cases of insensibility of the eye to colour
are examples of it. It presents the best
marked illustrations of both varieties, which
we shall proceed to consider.

Class I. ( Dichromatic Daltonism of Wart-
mann). — Black, white, and the intermediate
shades of grey are the only tints recognized by
patients of this class. Such persons dis-
tinguish with facility the forms of objects and
the gradations of light and shade, but to them
all the charms of nature and of art, as ex-
pressed by colour, are unknown ; their retinae
are rather sensitive than otherwise, and they
not only see objects at a great distance, but
can read with facility in an obscurity amount-
ing to darkness.

The first of these cases on record was pub-
lished by Dr. Dawbeny Tubervile, an oculist of
Salisbury,* being that of a young woman who
consulted him about her sight, which, though
excellent in every other respect, incapacitated
her from distinguishing any other hues than
black and white ; it is especially mentioned
that she could read “ for nearly a quarter of
an hour in the greatest darkness.” The next,
best marked case has been recorded by M. U.

Hombres Firmas.j- M. , of Anduze, of a

bilious and melancholic temperament, but lead-
ing a very active life, had arrived at an ad-
vanced age without its being known, except
to a very few individuals, that there was any-
thing uncommon in his sight; but all colours
appeared to him as tints of grey, between black
and white. Like several others having this
infirmity, he was fond of painting, and had
painted in his apartment two friezes and a
pannel between tiie windows: of these he was
proud; but some of his visitors inquired why
he had represented the ground, the trees,
houses, and persons all blue? He replied that
he wished them to match the furniture, lie

* Phil. Trans. No. 164. p. 736. and Lowtliorp’s
Abridgement, vol. iii. part i. p. 40.

•f Ann. d’Oculistique, tom. xxii. p. 72.

VISION.

H55

being quite unconscious that this was red.
He had a collection of engravings, some
coloured and others plain, but the only dif-
ference he could perceive was, that some
were clearer than others. When criticising a
picture he would discuss the composition of
the design, the light, shade, and perspective ;
but, as to the colours, he was silent. When
walking with others in a garden, he affected to
speak of the beauty and size of the dowers,
their regularity and perfume, but to his eyes
the)', like the pictures, were all grey. The case
of a shoemaker named Harris, described in
the Philosophical Transactions,* * * § has been ge-
nerally quoted as a well-marked example of
this form of achromatopsy, but on carefully
considering the remarks made upon it by Dr.
Dalton f , we are doubtful whether it really
was as supposed, and are inclined rather to
refer it to the second class.

The case of M. Collardeau J has been
described as of this nature. This gentleman
was an amateur artist, but the imperfection
of his vision gave rise to the strangest pro-
ductions. So long as he confined himself
to the pencil, or to sketching in one colour,
he designed with much skill, but his paintings
in colours were the reverse of happy. For in-
stance, wishing to work up a scene in which
he had drawn a dog, he unfortunately mistook
the colour, and painted red all those parts
which should have been deep blue. He has
been known to confound on the canvass yel-
low with blue, and red with green, regarding
his work with the complaisance of a man who
felt that he had achieved success.

The following interesting cases are of a
character forming a connecting link between
the two classes of achromatopsy. The first
is related by D’Hombres Firmas.$ Count

• of Alais, aged thirty -eight, married,

and the father of a family, possessed excellent
vision in every repeet, except the perception
of colours ; but yellow, and the shades be-
tween black and white, were the only tints
he could recognise. On a number of dif-
ferent roses being placed in his hands, he
merely saw that white flowers were brighter
than purple; yellow flowers he distinguished,
but red, blue, violet, and white blossoms all
appeared more or less dark though he dis-
tinguished the yellow centres. This gen-
tleman was fond of geology, but found it im-
possible to judge of the colours which marked
various formations in the map of M. Dumas.
Lacustrine formations and the lias were the
only ones which he distinguished, all the
others appearing to him tinted in grey; and
he would have confounded them together,
if his excellent sight had not enabled him to
follow the dotted lines and letters by which
they were indicated. He drew with taste in
crayon, Indian ink, and sepia ; but only on

* Phil. Trans, vol. lxvii. p. 260.

t Memoirs of the Literary and Philosophical So-
ciety of Manchester, vol. v. part i. p. 38.

I Observations sur la Physique et l’Histoire Na-
turelle, vol. xiii. p. 87.

§ Op. cit. p. 73.

one occasion attempted a scene in colours, of
a peasant and a bouquet of flowers. The re-
sult was so very unsatisfactory to ordinary
eyes, that he was not tempted to repeat the
experiment.

The second case has been recorded by Dr.
Deconde.* A soldier applying for his discharge
on the ground of the formation of cataract,
attracted particular attention on account of
the cyanic colour of his sclerotica ; and on
investigating his power of distinguishing co-
lours, it was found that all those of the spec-
trum were confounded in two fundamental
hues, yellow and blue. Dark red, bright
red, rose, orange, yellow, green in which yel-
low predominated, and greyr white, all ap-
peared as different shades of yellow : whilst
blue, green, and white with a blueish shade,
were perceived as blue. All the very deep
colours were regarded as black, and all the
very light ones had a whitish appearance,
though the man did not seem to have cogni-
zance of white, properly so called. Light, de-
composed by a prism, appeared to him of uni-
form blue. His sight was feeble and easily
fatigued. Numerous trials always led to the
above results.

Class II. ( Polychromatic Daltonism of
Wartmann .) — This form includes the vast ma-
jority of cases of insensibility' to colours, and
presents a very remarkable diversity' of phe-
nomena. The colour, w hich, of all others, is
the stumbling-block, is lilac, and next to it
rose, indigo, and violet; on the other hand,
yellow and blue are most commonly recog-
nised. A very general form is that first de-
scribed by the illustrious Dalton f, who has
given his name to the affection ; and the
following are the chief features of his case.
He was not conscious of any peculiarity of
vision until the age of tw enty-six, when, a dis-
cussion arising as to the colour of the flower
o {'Geranium zonale, it was discovered that he
and his brother differed materially from other
people in their ideas upon the point. About
two years afterwards he entered upon an in-
vestigation of the subject, and the following
are the principal results at which he arrived.
The solar spectrum appeared composed of
three colours, yellow, bine, and purple, the
red being little more than a shade or defect
of light. Orange, yellow, and green were
shades of yellow, whilst green and blue were
strongly contrasted. Of ordinary' colours,
crimson and dark blue were identical ; the
colour of a florid complexion being a dull
opaque blackish blue, upon a white ground ;
blood seemed bottle green ; the face of a
laurel leaf was a good match fora stick of
sealing wax ; and the back of the leaf an-
swered to the lighter red of wafers. Green
baize appeared a dark brownish red : and a
light drab was not to be distinguished from
a light green ; browns were very diversified,
some having a great affinity for green, others

* Annales d’Oculistique, tom. xx. p. 52.

J Mem. of tlie Lit. and Phil. Society of Man-
chester, vol. v. part i.

1450

VISION.

for red; pink appeared sky blue by daylight,
bat assumed an orange or yellowish appear-
ance by candle light. Dalton believed that
the peculiarity in his vision was caused by the
vitreous humour of his eyes having a blue
tint : to this point reference will hereafter be
made.

According to Professor Wartmann, the
following are the most common confusions of
colour, ranged in order of their frequency : —

1. Deep red with deep blue.

Indigo with violet.

Deep blue with violet.

Bright orange with bright yellow.

5. Deep brown with deep green.

Dark blue with indigo.

Bright brown with bright green.

Dark red with dark green.

Rose with bright blue.

10. Dark orange with dark yellow.

Bright red with bright green.

Deep yellow with dark green.

Dark brown with black.

Bright red with bright blue.

15. Bright yellow with bright green.

Bright red with bright yellow.

Dark red with black.

Dark red with dark brown.

Dark green with violet.

20. Dark red with dark yellow.

Dark red with violet.

Bright yellow with bright brown.

Bright blue with violet.

25. Dark red with dark grey.

Dark red with indigo.

Rose with violet.

Dark blue with dark grey.

Dark green with indigo.

30. Rose with dark blue.

Rose with indigo.

Dark green with dark grey.

Bright orange with bright green.

White with faint green.

Putting aside the differences in the bril-
liancy of the tints, it is found that the follow-
ing numbers express how many times each of
those tints is proportionally seen without
error.

Red -

- 37

Blue

- 100

Orange -

- 12

Indigo -

0

Yellow -

- 100

Violet -

- 0

Green -

- 59

Wartmann has given* a very interesting
account of his experiments on the vision of
Louis D . This individual did not per-

ceive any great difference between the colour
of the leaf and that of the ripe fruit of the
cherry ; he confounded that of a sea-green
paper with the scarlet of a riband placed close
to it. The flower of the rose seemed to him
greenish blue, and he called the ash colour
of quick lime light green. The appearances
presented by a solar spectrum were as follows,
— the coloured bands, brilliant and distinct,

extended a length of about 0,102/. D

perceived four colours only, blue, green, yel-
low and red. He limited the blue part exactly
to the space occupied by the violet, indigo and
blue : he called the green and yellow bands,
less an interval of 0-002' towards the orange,
green ; he called that band of 0 002', and a
fraction of the red 0'012' in breadth, yellow ;

lastly, the remaining 0 00S/ of red appeared to
him of a red difficult to define. By refracted
light the results were nearly the same, thirty-
seven plates of glass exhibiting only four
different colours in various intensities.

When examined by polarized light, it seems
that on the one hand he did not appreciate
the equality ofintensity of two complementary
colours as did ordinary vision ; but lie found
a total and abrupt difference when colours
passed at once from the finest red to very
rich deep blue, a distinction far from being
marked to others.

Ilis visual organ was unable to perceive the
different mixtures of red which accompany
blue to make it pass into purplish violet.
This precise circumscription of the consti-
tutive domain of a colour is a fact which, in
the opinion of Professor Wartmann, was new
and worthy of being remarked.

Whilst a series of these experiments with
polarised light were going on, the sun, which
had been obscured, suddenly shone out, and
D- declared that the colours imme-

diately assumed a different tint to his sight,
all reddening in a sensible manner, so that
he called red that which he had before named
green and ill-defined blue, whereas the Pro-
fessor saw no other change in the colours
than an increase of their brilliancy and strength.

Wartmann then submitted the patient to
experiments to ascertain his perception of the
complementary colours, and the result showed
that although his eyes were not insensible to
them, the colours which appeared to him
complementary were not the same as those so
regarded by the normal eye. The Professor
then painted a human head, giving to each
part a complementary colour. Thus the hair
and eyebrows were white, the flesh brownish,
the sclerotica black, the lips and checks green.
When asked what he thought of the head,
D replied that it appeared to him na-

tural, that the hair was covered with a white
cap little marked, and that the carnation of the
cheeks was that of a person heated by a long

walk.

There are a certain number of cases of in-
sensibility to colours which have been quoted
by all writers on the subject. We shall there-
fore content ourselves with merely referring
to them*, describing a few well marked and
uncommon instances less generally known.

Dr. Boys de Loury f has published the

particulars of a M. H , who was obliged,

on account of his defective sight, to aban-
don the profession of a dyer. His principal
colour was yellow. The brilliant yellow of
the apricot and deep brown of the chesnut
were only distinguished as varieties of shade.
All dark hues were called black; scarlet ap-

* Cases of achromatopsy are detailed as follows:
— Phil. Trans, vol. Ixvii. p. 260, vol. lxviii. p. 611;
Edinb. Phil. Trans, vol. x. 253 ; Spurzheim Phren-
ology, Sited, p.276; Combe’s Syst, of Phrenology ;
Trans. Phren. Society, p. 222 ; Trans. Med. Chir.
Society, vol. vii. p. 477, vol. ix. p. 359 ; Glasgow
Med. journal, vol. ii. p. 12; Edinb. Phil. Journal,
vol. vi. p. 135.

f Revue Medicale, Nov. 1843.

Taylor’s Scientific Memoirs, vol. iv. p. 173.

VISION. 1457

peared as a blue grey, rose colour dirty white ;
orange, pure yellow ; apple green, yellow ;
lilac, blue ; violet, grey. There was no un-
usual appearance in his eyes, but he saw most
perfectly in the evening.

Dr. Sommer* has described his own case
thus. Blue can always be distinguished from
yellow, bright blue from green, and deep red
from black, but green and dark blue are
often confounded. Yellow, black, and de-
cided blue are the fundamental colours. If
he holds a leaf of a tree and a stick of red
sealing-wax side by side he recognises dis-
tinctly the difference in intensity between
the two colours, but cannot affirm which is
green or which red : rather decided blue
and rather intense red bear a great re-
semblance; blue is confounded with red,
green with brown, brown and orange with
bright brown. As to crimson, lilac, purple
and deep scarlet, they are colours of which
he cannot form even an idea. He one day
met a lady wearing a blue bonnet ornamented
with red roses, but could scarcely distin-
guish any difference between the two. On
another occasion wdien walking out it began
to rain. “ Then (says he) a crowd of red um-
brellas displayed themselves, and I compared
the colour to the azure of the sky.” The
rainbow appeared to him composed of blue
and yellow ; he knew that there were shades,
but could not satisfactorily discern them.

The case of the late Mr. Troughton was
examined by Sir John Iderschell and Sir D.
Brewster, and it was ascertained that he saw
the red space yellow ; hence according to the
views of Sir D. Brewster, he saw a space con-
taining much yellow, and little blue, the red
light being as it were absorbed in consequence
of the retina being insensible to its action. Sir
D. Brewster goes on to say f. “ If this be the
case there must have been a diminution of light
in the red space seen by Mr. Troughton, and I
am persuaded from the experiments I made
upon his eyes that this was the case ; but whe-
ther it was to the extent of the total defalcation
of the red rays, I will not venture to assert.
But it is not necessary that it should be so ;
the defective perception of red light may be
accompanied with a more acute perception of
the other colours, in a manner analogous to
what takes place in the chemical spectrum,
where the removal of the red rays produces
an increased action of the rays that are left.”
Sir D. Brewster, adds that he has long been
of opinion that the retina receives a more
powerful luminous impression Irom yellow
light than from the pure white light of which
this yellow forms but a part.

Persons affected with achromatopsy not
only see well in deep gloom, but their vision
of distant objects is particularly sharp, from
the azure blue of the atmosphere presenting
the strongest possible contrast to black. One
intelligent person says J, “So much is this the

* Graefe und Walthers, Journal fur Chirurgie, Bd.
v. Heft i. S. 135.
t Phil. Mag. vol. xxv. p. 139.

. t Glasgow Medical Journal, vol. ii. p. 12,

VOT.. IV.

case with me when viewing a distant object
as to overcome the effect of perspective ; and
the shading in the form and garments of
persons at a distance is often so predominant
as to overcome the effect of diminution in
size; and although, I see the object most dis-
tinctly, I am unable to tell whether it be a
child near me or a full-grown person at a
distance.”

Daltonians endeavour to obviate the an-
noyances arising from their infirmity by
taking some standard colours or shades as
points of comparison, as for instance the
green of grass ; they also bring the sense of
touch to their assistance, and are enabled by
these means, united with close attention, to
avoid many errors ; but nevertheless they feel
repugnance to express an opinion upon colours
Non- congenital Achromatopsy . — This though
quite distinct from Chntpsia, is generally a
morbid symptom, and might easily be con-
founded with it. It is to be borne in mind
that in certain cases of chrupsia objects ap-
pear tinged with colours foreign to them ;
a general officer for instance saw all white
objects of a deep orange colour at certain
times of the day, and to a lady they appeared
of a bright blue*; but in such cases all
objects are tinged with a prevailing tint or
it is confined to those which are white,
coloured objects being properly recognised.
In achromatopsy one or more colours are
effaced, and the individual is no longer cog-
nizant of them.

Permanent Achromatopsy. — A bootmaker
in Paris-]-, was attacked with amaurotic
amblyopia, which followed suppression of the
cutaneous exhalation. It was accompanied
with rheumatic pains, and there was at first
irritation of the retina, but this subsided,
leaving the sieht imperfect. The patient,
however, assured M. Szokalski that he had
possessed a full perception of colours until
after a copious bleeding from the arm. From
that time he could only discern white, black,
and grey, and could not distinguish an engrav-
ing from a coloured print. He one day bought
a pieee of yellow morocco leather by mistake
for a white piece, and when examined by M.
Szokalski, he cotdd not distinguish any co-
loured patterns which were exhibited to him.

Dr. Mackenzie thus writes : “ I always con-
sidered this affection as a congenital one, till I
was consulted by a man who had gradually
become subject to it. He was by trade an
ornamental painter, and could judge at one
time perfectly of colours. His right eye was
affected with mydriasis when he called upon
me, and there was incomplete amaurosis of
both eyes, so that he could no longer read a
common type. On trying him I found he
mistook red and green. The use of spirits
and tobacco was probably the cause of the
affection of sight in this individual.”^;

* Collections from the unpublished medical writ-
ings of C. H. Parry, M.D. vol. i.

t Ann. d’Oculistique, tom. iii. p. 200.
j Practical Treatise on Diseases of the Ey^e, 3rd
edition, p. 799.

5 A

1458

VISION.

Wartmann* has related a case supposed
not to have been congenital; this, however, is
uncertain; the particulars are interesting, es-
pecially as valuable information, to which we
have referred, was obtained from this patient.

M. Louis D was the eldest of seven

brothers and four sisters, who were assorted
in a very singular category. The first set had
red hair, and their vision was perfect ; the
others had fair hair, and all were unable to

distinguish colours. Louis D belonged

to the latter, as regards external appearances,
but according to his own recollection, and the
evidence of his mother, he perceived colours
during his infancy, in the usual manner. At
the age of nine years his skull was fractured,
after which his perception of colours appears
to have become defective. The fact however
of his brothers, who resembled him in ap-
pearance, being similarly affected from birth,
weakens the chain of evidence on this point.
His infirmity was for some time unknown,
and his father endeavoured, by repeated cor-
poral punishment, to put a stop to what he
called a perverse pretence, and a severe cor-
rection was administered by his master, a
bookbinder, because he used red paper, in-
stead of green, for the covers of some books.

Temporary Achromatopsy. — This form ap-
pears to us not to have received the attention
it merits, having been passed over in silence,
or only cursorily alluded to, by the great
majority of writers. The exciting causes are
congestion, hepatic derangement, and dys-
pepsia, and it may exist in conjunction with
more or less amaurosis, or by' itself, as a
simple derangement of vision.

The first case we shall relate is highly in-
teresting from the marked manner in which
the insensibility to colours existed, its dura-
tion and satisfactory disappearance as restora-
tion to health proceeded. It occurred in the
practice of that very able physician, Dr. Hays.-f-

Mary Bishop, cetat. twenty, was admitted
into the Wills Hospital, Feb. 9, 1839. She
was of short, robust stature, full habit, very-
dark complexion, black hair, and hazel hides,
flushed face, colour of her cheeks at times
almost of a purplish hue; catamenia sup-
pressed. In 1837 and 1838 she had suffered
from two attacks of cerebral disease ; after
the first attack, objects appeared double. The
second attack left her entirely blind, in which
condition she continued for four months.
After this her sight began to return, and at
the period of her admission into the hospital,
she could read large print. When she came
under the notice of Dr. Hays, in May, 1839,
she had been largely depleted, and had taken
remedies for the restoration of the catamenia,
under which treatment her sight had im-
proved. At this time it was discovered that
she was unable to distinguish colours, yellow
and blue being the only ones she could name
with certainty. Nearly all others she termed
brown, or hesitated to name, designating how-

* Op. cit.

t American Journ. of Medical Sciences, vol. xxvi.
p. 277.

ever their shades, or intensity of colour accu
rately. Thus she called a deep red, dark
brow n ; a bright green, light brown ; and
very pale pink, very light shade of brown
The patient was not sensible at first that
she laboured under any particular defect in
distinguishing colours. She had noticed, that
grass and roses did not appear as formerly, and
she remembered that as her sight began to re-
turn, the first colour she perceived was yel-
low. The usual treatment for amenorrhea was
adopted, and on the 29th of May the catamenia
returned copiously, but continued only for a
single day. It was followed, however, by a
very marked improvement in vision. Roses
now appeared to her of their natural colour,
and she could distinguish the difference be-
tween the colour of the rose and that of the
leaves, which she had not previously been
able to do. By the middle of June she was
able to see the eye of a needle and the end of
a thread, but could not thread the needle from
inability to see both at the same time. At
this period she was again examined with the
prismatic spectrum, and distinguished pretty
accurately the yellow, blue, green, and red,
but was doubtful as to the orange. On the
30th of November it is stated that her sight
was good, notwithstanding another attack of
congestion and suppression of the menses.
She distinguished all the primitive colours
readily, and named most of the secondary
ones as correctly as could be expected, with
the exception of violet, which she was at a loss
to name.

A gentleman, aged 36, librarian to one of
our medical colleges, has communicated to me
the particulars of his own case in the follow-
ing words : “ A few years ago I noticed that
on getting out of bed, and looking at a new
carpet which had been laid down but a short
time, I was unable to distinguish the colours,
though I could clearly make out the pattern,
which appeared simply black and white. I
felt rather alarmed, and asked my wife if it
was the same carpet. She assured me it was,
and inquired mv reason for putting the ques-
tion. On telling her, she at once suspected
I had taken some had wine at a public dinner
I hail attended over-night. I may add that I
have invariably experienced the same effects
after dining out, more especially if I take more
than one kind of wine ; and of this I take hut
little, in consequence of the severe illness I
experience on the following morning. If 1
take grog or punch, the symptoms, including
the loss of power of seeing colours, are
more severe.”

Simple congestion of the head and eyes,
especially when accompanied with fatigue,
is also an exciting cause of achromatopsy.
Ruete states, that a girl suddenly lost the
faculty of distinguishing colours as a conse-
quence of congestion ; and we have known
instances produced by exhaustion.

A clergyman, 45 years of age, of full habit,
but enjoying good health, was performing Di-
vine service in the month of June, 1851, anil
felt fatigued and oppressed by heat and the

VISION.

1459

close atmosphere of the church. At the con-
clusion of the service, on rising from the
kneeling posture, he was alarmed at finding
that the crimson velvet cushion and hangings
of the pulpit appeared of a dark violet hue,
and that other familiar objects which he knew
to be red, had likewise changed to bluish
green ; there was at the same time some gid-
diness and discomfort in the head. Having
rested in the vestry about ten minutes, the
symptoms gradually passed away, the crimson
objects becoming less and less blue, and the
red objects gradually resuming their proper
colour. Aperient medicine, &c., was pre-
scribed, and we are not aware of any other
attack having been experienced.

Another case occurred during the great
Exhibition in Hyde Park. A stout plethoric
farmer, aged 52, visited London, and had
undergone much fatigue and excitement in
seeing the various objects of interest. On the
third day, after spending some hours in the
exhibition, he felt giddy and oppressed, and
remarked that the crimson hangings appeared
of a dull brownish green. This led him to
notice other objects, and he ascertained that
he could no longer discern the difference be-
tween reds and greens generally, though yel-
lows and blues retained them proper colour.
On his leaving the building, the uniform of
the footguards and the colour of the foliage
of the trees, nearly assimilated. When he
reached home, he slept for three hours ; and
on awaking, was much relieved at finding
that the power of discerning colours had re-
turned.

The extraordinary variety and glare of co-
lours at the exhibition was singularly dis-
tressing to the eyes, and numerous persons
suffered from congestion of the choroid in
consequence.

According to M. Cunier, temporary achro-
matopsy almost always constitutes one of the
symptoms of congestive amblyopia in per-
sons affected with hemorrhoids and venous
congestion of the abdomen. The confusion
between the sensations of red and blue, takes
place every time that the encephalo-ocular
turgescence is augmented by the effect of a
lively emotion, anger, a rapid walk, too great
application of the eyes, &cA That eminent
oculist relates the following case. He was
consulted by an officer of artillery, who suffered
-in a slight degree from congestive amblyopia.
Every time that he performed manoeuvres,
and fatigue increased the cerebro-ocular con-
gestion, the men appeared dressed entirely
in blue ; the white waistbelts he distinguished,
but the red worsted epaulets, the red tuft of
the shako, the facings of the coat and red
stripes down the trowsers, appeared blue.
He could see that the shako and trowsers
were of black cloth. A brief repose, with
cold water to the eyes and forehead, soon re-
stored natural vision.

An interesting example of temporary achro-
matopsy, doubtless the effect of congestion,

is related by Professor Wartmann. M Thury,
an ex-professor of botany in the academy of
Lausanne, had walked during the night from
Geneva to Nyon to witness a magnificent
aurora borealis, which shone on the night of
the 17th and 18th of November, 1848. To
his great surprise and disappointment, he
could not discern any difference between the
blue of the sky and the magnificent blood
colour of the aurora, which was viewed with
rapture by all around. Singular to say, another
lady of Geneva, a septuagenarian, presented
precisely the same peculiarity, though both
she and the professor hud distinctly seen
manv previous auroras.

The following case, which occurred under
our own observation, is an example of tem-
porary achromatopsy caused by vitiated blood
circulating through the brain and retina, and
disturbing the functions of those organs: —

Mr. H., a solicitor aged 37, of a spare
make and melancholic temperament, is fre-
quently subject to attacks of congestion of
the liver followed by vomiting and purging of
bile. These attacks are ushered in by dull
pam in the head and tenderness of the eye-
balls, rendering motion of them distressing.
At such times he is quite incapable of dis-
tinguishing colours, all objects being simply
divided into two classes, black and white
with their intermediate shades of grey. The
vision of objects continues perfectly distinct,
but it is not until the portal system has been
relieved that the perception of colours is
recovered, and then yellow is the first dis-
tinguished. If however he takes five grains
of calomel, the attack is cut short and the
power of discriminating colours at once re-
stored. There is nothing whatever unusual
about his eyes, and under ordinary circum-
stances he possesses perfectly natural vision.

Achromatopsy may be the result ofinjury,as
in the following case related by Dr. Boys de
Loury.* An individual was struck by a pistol
ball which entered his mouth without touch-
ing the tongue and broke through the hard
palate and base of the orbit. After his re-
cover}' from the wound, the injured eye re-
tained but little sight ; only a small spot of
the retina was sensible to light, and to use
this, the eye was obliged to be thrown con-
siderably to one side. Then objects were
seen distinctly but without colour. This
person described a palette spread with co-
lours, as a plate with many holes, and con-
founded the thumb opening with the spots
where the colours were placed.

Various explanations, differing widely, have
been offered to account for the insensibility
of the eyes to colour ; and we may re-
mark that the subjects of this affection have
in several instances been men of intellectual
eminence. As for example, the metaphy-
sician Dugald Stewart, Dr. Dalton the illus-
trious chemist, Mr. Troughton the eminent
optician. Dr. Sommers, Dr. Unzer, of Al-
tona, and Professor Brandis. The opinion

Op. cit. p. 49.

Eevue Medicale, Nov. 1843.

5 a 2

3460

VISION.

advanced by Dalton and supported with the
ability for which he was remarkable, was
this : “ It appears therefore almost beyond
a doubt that one of the humours of my eye
and of the eyes of my fellows, is a coloured
medium, probably some modification of blue.

I suppose it must be the vitreous humour :
otherwise I apprehend it might be discovered
by inspection, which has not been done.”*
Before his death, the great chemist had re-
quested his friend Dr. Kansome to examine
his eyes after his demise : this was done most
carefully, and it was ascertained that though
the crystalline lens had tile slight yellow tinge
common in old persons, the vitreous humour
of both eyes was absolutely colourless.
Nevertheless the hypothesis has been revived
by Dr. Trinchinettif, who considers that the
defect is produced by a coloration of one or
more of the transparent media of the eye, and
probably of the crystalline lens, and even goes
so far as to advise depression or extraction
of the lens as a means of radical cure !

Goethe f; attributed the confusion of colours
to an insensibility to blue ; whereas Szokalski
expressly states) that among more than sixty
cases of achromatopsy, of which he had notes,
there was not one in which there was abso-
lute deficiency of the perception of blue.
Others again have supposed that the retina
itself has a blueish tinge in such cases, whilst
Dr. Thomas Young j| attributed achromatopsy
to the absence or paralysis of those fibres of
the retina which are calculated to perceive
red.

The able metaphysician Dugald Stewart ^T,
has viewed the subject from a different point.

“ In the power (says he) of conceiving colours,
too, there are striking differences among
individuals. Ami indeed 1 am inclined to
suspect that in the greater number of in-
stances the supposed defects of sight in this
respect ought to be ascribed rather to a
defect in the power of conception. One
thing is certain, that we often see men who
are perfectly sensible of the difference be-
tween two colours when they are presented
to them, who cannot give names to these
colours with confidence when they see them
apart, and are perhaps apt to confound the
one with the other. Such men, it should
seem, feel the sensation of colour like other
men when the object is present, but are
incapable (probably in consequence of some
early habit of inattention) to conceive the
sensation distinctly when the object is re-
moved.”

This explanation would have weight sup-
posing persons had rare opportunities of
contrasting colours, for then their memory

* Mem. of the Literary and Phil. Soc. of Man-
chester, p. 43.

j- Atti della sesta Riunione degli Scienziati Itali-
ani, p. 712.

J Zur Farbenlehre, §§ 111 to 113.

§ Annales d’Oculistique, tom. iii. p. 7.

|| Phil. Trans, vol. lxxvi. p. 344. m

*|f Elements of the Philosophy of the Human
Mind, p. 73.

might fail them, and they might feel uncer-
tainty as to the proper appellation to be
given to a tint ; but if there be one sense
more than another which enjoys unbounded
licence, it is that of sight ; not an hour
passes that the property of distinguishing
colours is not called into exercise, and in this
age of high civilisation it is in perpetual ac-
tivity. Nevertheless Dr. Hinily has adopted
the same view. It is on record however
that intelligent persons have expressly de-
clared that their infirmity arose from no care-
lessness on their part, as they had made
many earnest endeavours to correct it.*

By phrenologists, achromatopsy has been
attributed to imperfect development of the
organ of colour ; Szokalski, though believ-
ing that there exists in the brain a portion
which presides over the function of vision, and
that this portion is diminished in volume in
persons affected with achromatopsy, adds,

“ We know well that phrenologists place the
organ of colour in the middle of the super-
ciliary arch ; we have, however, examined
scrupulously and with great pains many
persons who have presented very decided
depressions of this arch ; but despite of the
best wishes in the world, we could never
discover in them any trace of chromatop-
seudopsy.” j-

Neither does our own experience support
the theory of the phrenologists; in two well-
marked Daltonians examined by us, the whole
superciliary region was remarkably well de-
veloped.

The vision of the late Mr. Troughton was I
carefully investigated by Sir John Herschel,
who instituted a series of ingenious experi-
ments for the purpose of ascertaining, if
possible, the cause of the imperfection.
The result at which he arrived was, “ that
all the prismatic rays have the power of
exciting and affecting the eyes with the sensa- 1
tion of light, and producing distinct vision,
so that the defect arises from no insensibility
of the retina to rays of any particular refran-
gibility, nor to any colouring matter in the
humours of the eyes preventing certain rays
from reaching the retina, but from a defect
in the sensorium by which it is rendered in-
capable of appreciating exactly those dif-
ferences between rays on which their colour
depends. J

Hartmann) is of opinion that it is by ana-
lysis that we arrive at a knowledge of ob-
jects which present themselves to our notice ;
he supposes that we do not perceive them
instantly, but little by little and only by exa-
mination of their distance, form and colour,
which scrutiny rests on a series of changes
operating on the retina, ciliary nerves,
and motor ocular nerves : we do not easily
recognize objects unless this succession of
modifications has become habitual and takes

* See GlasgowMedical Journal, vol. ii. p. 17 ; Op.
it. p. 100.

+ Op. cit. p. 100.

X Encyclopaedia Metropolitana, article “ Light.”

§ Der Geist des Menschen, S. 152. 1820.

VISION.

14GL

place easily, hence achromatopsy results
from a certain state of torpor and indolence
of the retina and motor muscles of the eye!

Professor Wartmann, the most recent au-
thority upon this subject, stated in his first
Memoir that achromatopsy (or Daltonism)
has its origin in a defect of the sensorium.
In his second Memoir he enters at length
into a somewhat different explanation of the
phenomena. “ I admit (says he) with Harvey,
Young, Jungken, Miiller, and others that its
seat is in the retina, and [ think that it is
produced by an abnormal state of the nervous
expansion, in such sort that it reacts equally
under two or more differently coloured vi-
brations. If the vibration caused by a ray of
red is identical with that engendered by a
green ray, there will be confusion of these
colours. This theory is independent of all
systems destined to explain light. * * * The
theory which explains Daltonism by an ab-
normal elasticity of the retina has the ad-
vantage of substituting a reasonable physical
condition for a vague notion of the sensorium :
besides, it is supported by facts, because the
injuries which alter the ordinary constitution
of the visual organ are capable of exciting,
permanently or temporarily, a false perception
of colours. Lastly it appears to be confirmed
by the circumstance that with many Daltonians
the eye sees less distinctly the red rays than
those of which the refrangibility is greater.*

The actual seat of the phenomena of achro-
matopsy must, after all, remain matter of
speculation, as it is one of those things in-
capable of demonstration. D'Alembert says :
“ It is very plain that the word colour does
not designate any property of body, hut
merely a modification of our mind : that, for
instance, whiteness and redness exist only
in us, and by no means in the bodies to which
we refer them by a habit in force from in-
fancy.” The knowledge that we possess of
the existence of colours is derived from the
evidence afforded by the thousands of persons
endowed with the power of distinguishing
them, and therefore we conclude that they
do exist. But supposing we were all like
Dalton and many others whose visual organs
never appreciate red any more than the gene-
rality of eyes distinguish the calorific or ac-
tinic rays, we should then not he aware
of the existence of the colour called red, which
plays so conspicuous a part in the adornment
of the universe ; or if some few eyes gifted
with superior powers discerned it, the majority
would have to admit its existence on the
evidence of others, not from knowledge de-
rived from their own eyes

As regards remedial measures, Wartmann
and Seebeck recommend the employment
of coloured glasses of a certain known tint ;
suppose this tint red, the impression of a
green body and of a red body at first the

* Deuxieme Memoire, p. 46. Dr. Wartmann
enters at length into the discussion of this subject,
but our space will not admit of our extracting his
ingenious arguments.

same to the naked eye will be distinguished
by the use of the transparent screen.
Wartmann, however, admits that this me-
thod only remedies mistakes in the specific
nature of colours, and not those which apply
to the shades of one and the same tint.
Jiingken and Chelius have recommended the
use of coloured bands, bearing the name of
their colour, and Szokalski has suggested that
sensations of the various shades may be ex-
cited by fixing the eyes on different coloured
patterns, and then on a black or white
surface. But this proceeding is scarcely
so likely to be productive of benefit as that
recommended by Professor Wartmann.

Should the achromatopsy result from con-
gestion, such means should be adopted as
are best calculated to subdue it; as depletion,
purgatives, and low diet. If it arises from
menstrual suppression, it will be proper to pre-
scribe emmenagogues, with mustard pediluvia,
hip baths, and such other means as are likely
to restore the catamenia. Should derange-
ment of the hepatic system be the exciting
cause, a dose of calomel, followed by a black
draught, will often be sufficient to remove it ;
but it will be proper to follow such a pre-
scription with alterative doses of mercurials
and saline aperients, of which the Pullna and
Marienbad waters are very serviceable : ta-
raxacum with or without the nitro-muriatic
acid may also be advisable.

Dyspepsia is too protean a disorder for us
to attempt more than to suggest the pro-
priety of carefully investigating the parti-
culars of cases where the insensibility to
colour can be traced to this cause, and of
laying down such a plan of treatment, medical
and general, as seems best adapted to tile
exigencies of each individual case.

Hifperchromatopsy {virep, beyond ;
colour; caps, vision). — Our knowledge of
this condition of the vision which may be
regarded as the opposite to achromatopsy, is
at present very limited, and is chiefly derived
from the publications of Dr. Sachs * and Dr
Cornaz.) As we have never had an op-
portunity of investigating a case of the sort,
we can only draw our information from these
and some other sources.

Dr. Sachs is, we believe, an albino, and is
in addition affected with hyperchromatopsy.
The first account of this very singular anomaly
of vision was published by him, and other
instances have since been discovered. Pro-
fessor Wartmann, of Geneva, in a communi-
cation with which he recently favoured us,
thus writes : — “ Quant a l’Hyperchromatopsie,
c’est une affection qui n’est probablement pas
extremement rare. Je connais deux personnes
qui rn’ont dit en etre atteintes, et j’espere etre
un jour en etat de publier quelques recherches
sur ce sujet. Get etat n’est point necessaire-
ment lie a Falbinisine.”

* Histori® Naturalis duorum Leucuethiopum Par-
tial!* du®. Erlangen, 1812.

+ De l’Hyperchromatopsie, par le Dr. E. tornaz.
Bruxelles, 1851.

HG3 VISION.

The characteristic of Hyperchromatopsy is
that of attaching colours not merely to objects
which, according to ordinary vision, possess
them, but also to other objects which have no
pretensions to them, and this to an extent
scarcely credible.

It does not appear that the same colours
always attach to the same objects with different
individuals ; on this point there is considerable
diversity, hut as the account published by
Dr. Sachs of his own perceptions is the most
minute which has appeared, we shall take it
as the ground of the following description : —

The objects to which colours especially
connect themselves in this condition of vision
are, figures, dates, the days of the week, the
letters of the alphabet, and musical notes.
These colours are not all equally distinct :
the clearest are yellow, different shades of
pure white and blueish white ; the less clear
are orange, red, dull white, dark blue, brown
and green. Black only attaches itself to one
of the letters of the alphabet. This morbid
sensibility to colours thus displays itself : —
A and E are red, but the first has more of the
vermillion tint, the second most of the rose.
I is white, O orange, U black, and is the only
example of black ; UE or U is white, so is
M and N. C is of a pale ash colour. D is
yellow. F of a dull white. H a blueish ash
colour. K approaches deep green. S is of
deep blue, and W is brown.

Musical notes indicated by the names of

the letters p0 et caetera, present gene-

rally the same colours as these ; however
whilst in the alphabet, B and G appear almost
colourless, the Si fiat appears of an ash grey,
and the Sol of an uncertain green.

Of figures, 0 is almost transparent, of a
pale and uncertain yellow, 1 of an undecided
white, 2 of an uncertain tint, 3 almost ash
coloured, 4 minium red, 5 yellow, 6 indigo, 7
blueish white, 8 brown, 9 almost deep green.
The numbers composed of several figures
take the colours of the last forming them. 0
does not change the colours of the figures to
which it is joined, but gives to them a certain
appearance, whilst a figure often repeated in
the same number causes the colour proper to
it to increase in intensity. 10, II, 100, 110
and 111 are white; the first of them re-
sembles white glass, the second is milk-colour,
the third semi-transparent white ; the two
last perfect white. 14, 24, 40, 44, 400 and 440
are red, but 15, 25, 50, 55, 500, 555 and 1000
are yellow; why the 1000 is yellow whilst 100
is white we do not understand, as the addi-
tional 0 does not account for it

Sunday, is to the eyes of this conscientious
observer, white slightly tinged with yellow.
Monday , another shade of white ; the co-
lour of Tuesday is obscure and undecided.
Wednesday is yellow ; Thursday is of a
yellowish green, verging towards orange.
Friday of a dull white, and Saturday is of a
blueish ash colour.

It is stated that the abnormal sensations
of colour are so intimately connected with

these objects, that some can only be seen
without them by a strong mental effort, and
that in the case of others this does not
suffice.

In the present state of our knowledge we
are not in a position to offer any satisfactory
explanation of this singular anomaly of vision.
That its seat is not in the eye but in the
sensorium is however most probable, and in
this opinion Dr. Wartmann concurs. More
extended opportunities for observations will
doubtless throw additional light on what must
be regarded as a very curious subject.

Anorthopia (a, not; opBbs, straight; vtpis, vi-
sion).— This is a condition of vision far from
uncommon, and is characterised by the in-
dividuals subject to it being unable to discern
when objects are not parallel one to the other,
and is often accompanied by a want of ability
to distinguish whether objects are symme-
trical. Such persons are incapable of drawing
objects correctly; a house will be sketched
with its proportions wrong and leaning on
one side, and a figure will be equally unna-
tural, yet the artist wi 1 be sublimely un-
conscious of any defects. They are unable
to discern whether pictures are straight on
the walls, or blinds drawn parallel with the
window frame ; Negroes are very subject
to this peculiarity of vision. Nothing is
more common than to see them, when mark-
ing out the ground-plan of a house, path,
or boundary wall, draw the lines as awry as
possible, and yet persist that they are quite
straight, nor can they be convinced to the
contrary. It has appeared to us that the
persons in whom this condition of vision
existed in a marked degree, were charac-
terised by unsymmetrical heads and faces, but
this may have been a coincidence merely.

In children who show evidences of anor-
thopia, pains should be taken to overcome it
by practice and tuition. They should write
upon ruled paper at first, and when subse-
quently writing on ordinary paper, should
always be made to place it straight before
them and to write across it by the hand
moving on the wrist v\ hich should be a fixed
point, and seldom moved. In drawing, the
correctness of the lines should be ascer-
tained by admeasurement ; and the study of
geometry, perspective, and all other branches
requiring attention to symmetry are calculated
to be of service.

Myopia {yva , I shut ; the eye), commonly
called near sight, is an affection almost, if not
entirely, confined to civilization.

Every eye, when in a state of repose, is
adapted by its size, figure, and the refrac-
tive powers of its media, to the formation of
a distinct image of an object presented before
it, at one particular distance. This differs in
different individuals; but from 12 to 20 inches
may be regarded as the distance at which
ordinary print is legible, the shortest distance
at which it can be seen clearly and without
exertion being from 6 to 8 inches. A person
who brings small objects nearer to the eyes
than G inches is considered myopic.

VISION.

1463

It is commonly supposed that a certain
visible conformation of the eye exists in con-
nection with, and characterises myopia ; that
the eye is full, the cornea prominent, the an-
terior chamber large, &c. : but this is by no
means necessarily the case; for it may happen
that of two individuals in whom the apparent
configuration of the eyes is the same, one will
be myopic, the other presbyopic. It is also a
popular belief that near-sight decreases with
age ; such does not accord with our experi-
ence. We have repeatedly seen persons above
sixty years of age as near-sighted as in their
youth, and are acquainted with a lady of
eighty-five, who has certainly never fatigued
her eyes with work or reading, and who still
uses, and has used for many years, a No. 7.
myopic glass.

Myopia may arise from imperfection in the
form, consistence, or relation of some of the
refractive media ; or it may result from the
loss of adjusting power. The first description
may be induced by too great convexity either
of the cornea or lens, or both ; by an undue
density of any of the refractive media ; by a
too great distance between the cornea and
retina, &c. The effect is always the same,
namely, to cause the rays of light to be so
much refracted that, in place of being concen-
trated to a focus exactly on the retina— a
point essential to distinct vision — they are
brought to a focus before reaching it. It is a
law in optics that the nearer an object is
brought to the eye, the more divergent are
the rays proceeding from it, and consequently
the greater the distance at which they will be
collected in a focus by refractive media. For
this reason it is that near-sighted persons
habitually hold objects very close to their
eyes, as by that means the image is thrown
back upon the retina. One of the causes of
imperfect vision in such persons, is the circle
ol dissipation formed on the retina by the rays
after they have crossed at the focal point.
This is principally produced by the circum-
ferential rays ; and if these can be excluded,
vision is rendered much more distinct. Thus
it is that great assistance is afforded by look-
ing through a pin-hole in a card, and even
by holding to the eye a hollow roll of paper,
or the hand partially closed. The habit of
half shutting the lids which has given the
name to the affection, has reference to the
same object — the exclusion of the circum-
ferential rays.

In connection with this point, we may
mention that the reason stars are seen
earlier in the evening twilight with the assist-
ance of tubes than without, is, as pointed
out by Arago, that the tube cuts off a
large portion of the disturbing diffused light
of the atmospheric strata which intervene
between the star and the eye. In like
manner a tube is useful even in a dark
night in preventing the lateral impression of
the faint light which the particles of air re-
ceive from all the other stars in the sky, and
thereby increases the intensity of the lumi-
nous image and the apparent size of the star.

Distant objects appear large to near-sighted
persons, because a distinct picture is formed
only at the point of intersection of the
rays proceeding from an object ; as this point
falls short of the retina in such persons, the
retina receives the rays beyond the point of
intersection, and they are consequently more
extended. Myopes also read with more ease
in partial darkness than those whose sight is
perfect. The quantity of rays from an object
is always in an inverse ratio to the square of
the distance ; and as these persons naturally
bring the object close to the eye, they receive
the full benefit of all the light proceeding from
it ; whereas other persons are obliged under
similar circumstances to close the lids and
contract the pupils to see distinctly, whereby
much less light enters their eyes than those
of myopic, individuals ; hence they see with
greater effort and less distinctness.

In congenital myopia the pupils are fre-
quently large, and do not contract fully. To
compensate for this the persons acquire the
habit of knitting the brow's and half closing
the lids, which gives them a characteristic
appearance. The handwriting of near-sighted
persons is generally small and cramped, the
proximity of the letters to the eyes increasng
the visual angle subtended by them, thus
increasing their apparent size.

Among the exciting causes of acquired
myopia are, overwork of the eyes at the focus
for near objects, the indiscreet use of glasses,
and the necessity of working in obscure light.
The first and last may be c'assed together,
and apply especially to engravers, watch-
makers, jewellers, and other artificers, the
nature of whose work requires close inspec-
tion. But there is yet another class espe-
cially subject to this impairment of vision,
namely, literary men. The public are little
aware of the extent to which the studious and
those who live by the exercise of their intel-
lect, suffer from imperfection of sight. Many
instances have fallen under our notice of poor
students and writers, whose poverty compelled
them to pursue their literary avocations in
the gloom of dusky apartments, or by the aid
of a dim candle, and wrho have become myopic
and amblyopic in consequence. And scarcely
less numerous are those who are visited
with this affliction though pursuing their la-
bours under more favourable circumstances.
It would appear that even the study of oph-
thalmic science may cause the same penalty
to be paid; for M. Desinarres informs us
that one of his pupils became very myopic by
exerting his eyes too much in the diagnosis
of diseases of the eye ; a sad result of most
rare industry.

A common cause of myopia is the improper
use of eye glasses. In this country they are
often worn from affectation ; but in France
glasses are used by the young men who wish
to escape the conscription, for the deliberate
purpose of rendering themselves near-sighted,
that constituting a ground for exemption
During the years 1831, 1832, and 1833, 7 '.3
per 1000 of the conscripts examined in

Hoi Vision.

France were rejected on the score of short
sight.

Oculo-cerebral congestion may give rise
to myopia ; a case alluded to by Smith was
probably of this nature, — that of a person
who suddenly became myopic on coming out
of a cold bath. And Revielle-Parise men-
tions an officer who was similarly attacked
at the end of a troublesome ague. Local con-
gestion is said to produce the same effect.
Desmarres relates a remarkable instance of a
lady excessively presbyopic, who became near-
sighted during a severe attack of conjunc-
tivitis, the former condition of vision returning
after the attack had subsided. Mr. Tyrrell also
mentions a lady who had long suffered from
granular lids, which were eventually cured,
but she afterwards required the aid of concave
glasses, from the cornea having become un-
usually convex during the continuance of
the chronic disease. In each of these cases,
there may have been some change, either
in the quantity or quality of the aqueous
humour, or in the consistence of the cornea.

Itis very common to meet with eyes differing
in their focal length, and in such cases one
usually falls into disuse ; it is also occasion-
ally found that one eye will be myopic and
the other presbyopic, a condition of vision
embarrassing to the patient and the sur-
geon ; but the nature of which may easily be
ascertained by careful trial with glasses. D -.
Serre, in a memoir on the application of
phosphenes, or the luminous spectra excited by
compression of the eye *, states that these as-
sist in the diagnosis of myopia. He says that,
in such cases the nasal and orbital phos-
phenes appear equal to the temporal in con-
stancy, brilliancy, and sometimes in size ; but
he cautions us against concluding that the re-
tinae of myopes are more sensitive than those
of persons having normal vision, ascribing the
above appearances to the greater prominence
of the eyes, which facilitates compression, and
admits of its application to the deeper parts of
the eye. These results he adds, are at com-
plete variance with the opinion of M. Steeber
of Strasburg, who thinks that the proximal
cause of myopia may sometimes be a peculiar
alteration of the retina admitting of a compli-
cation of myopia with amblyopia, or com-
mencing amaurosis ; for that if the retina be
essentially affected, the orbital, and sometimes
the nasal phosphenes are scarcely appreciable,
or they may be entirely wanting. Dr. Serre
further asserts that which is certainly con-
trary to received opinions, and (we may
add), to our own experience, that when the
foci of two myopic eyes differ, the retina of
the eye with the shortest focus being that
least used, is absolutely stronger and more
active than the retina of the other eye.

Myopia may be symptomatic of hydro-
phthalmia, and of conical cornea. In the former
case it will be accompanied with enlargement,
and symptoms indicating some inflammation
of the eye. In the latter, the change of form

* Annales d’Oculistique, tom. xxiv. p. 161.

in the cornea will be apparent on close exa-
mination.* Instances have also come under
our notice of congenital cataract having been
mistaken for myopia, f In such cases the
patients have dull vision, and are unable to
see small objects distinctly even with the
aid of glasses. On careful examination a
greyish hue may be detected in the pupils ;
and if these be dilated by atropine, the
nature of the case is at once displayed by
the semi-opaque or slightly turbid lenses be-
coming visible.

The progress of myopia depends very much
upon the line of conduct pursued by the indi-
vidual. If that be judicious from the com-
mencement, the defect may not increase, or if
acquired, may diminish ; but its march is too
often as follows : — A person who is occupied
for months together in reading small type (for
example), finds that he discerns distant objects
less and less distinctly, and at once jumps to
the conclusion that spectacles are required ;
lie goes to an optician, tries a pair, sees
better, purchases them, and proceeds with
his labour. After a time he finds that these
glasses do not afford the same amount of
assistance they did at first ; they -are care-
fully wiped, but still are not satisfactory, and
therefore a pair of a higher power are
purchased ; with these he sees sharply at
first, though they do diminish a little ; but
they in time are laid aside, and the individual
goes on and on, until the whole scale has been
run through, and he is halt blinded for the
remainder of his life. In the progress of such
a case other symptoms often develop them-
selves ; not only is the sight rapidly shortened,
but it is weakened ; the eyes ache, and are
speedily fatigued by application ; there is op-
pression about the brow, and often headach;
he is teased with muscae volitantes, and the
sight is obscured from time to time by a mist.

The case now assumes the character of
impaired vision from overwork, and unless
judicious treatment be adopted, amaurosis
may be the result.

It is important to know that near sight
may be acquired in childhood by the common,
practice that children have, of approaching
their eyes very close to any object on which
their attention may be engaged. When learn-
ing to read or write, or draw, they almost
invariably hold their faces sideways, nearly
touching the slate or paper. This should at all
times be discouraged. In like manner infants
should not have very small toys given them,
or such as require to be looked at closely, for
not only may they be rendered short-sighted,
but strabismus may be caused, for as the visual
axes naturally converge when objects are held
very near the eyes, the frequent repetition of
this may occasion a squint. For the same
reason there is sound judgment in printing
children’s books in good bold type, and it is
well to encourage young people to observe
distant objects, and to describe what they

* See Practical Remarks on Near Sight, pp. 47. 50.

+ London Journal of Medicine, vol. i. p> 507.

VISION.

1163

see in trees, landscapes, the exterior of houses,
&c. As a general rule glasses are not ad-
missible for young persons, for if worn there
is scarcely any hope c f amendment ; but it is
sometimes necessary to allow them during
music lessons, in which case they should be
of the lowest power that enables the child to
see the notes, and their use should be re-
stricted to that pursuit.

Myopic persons, generally, should remove
objects they are regarding as far from them
as possible, and should avoid small type,
minute writing, and microscopical inves-
tigations. The use of a high desk is very
important, not merely as tending to prevent
oculo-cerebral congestion, but also pain in
the chest, which is often caused by stooping ;
and as a general rule, all near-sighted persons,
of whatever age, should exercise the eyes,
when in the open air, by' endeavouring to
make out distant objects.

There is a simple plan which persons who
write or read much should adopt as being
highly serviceable in preserving the powers of
their vision. It is that of raising their eyes
from their work at short intervals, and fixing
them upon the cornice of the ceiling at the
further end of the room, and if there be a
pattern, making it out. This exercises the
eyes at the focus for distant objects ; and,
simple as it is, is of great use in preventing
nearsight.

There is a form of myopia of which we
have seen several examples, and which is
deserving of attention. It occurs in young
persons, and leads to unmerited punish-
ment. The youth does not hold his book so
near the eyes as to attract attention, and reads
fluently at perhaps eight or ten inches ; but he
cannot see objects distinctly at twenty feet.
Such young persons have been brought to us
under the impression that they were “ sham-
ming;” but careful investigation convinced us
that such was not the case. Great responsi-
bility attaches to the advice given in a case of
this description, as on it depends much of the
comfort of the individual during life. He
should by' no means be allowed glasses, as
they would most assuredly confirm the mis-
chief. His books should be of large type ; he
should frequently rest his eyes when study-
ing ; should be much in the open air ; and
the eyes should be often bathed with cold
spring water.

Presbyopia (irpzcrgvs, old ; the eye) is that
condition of vision in which objects are not
distinctly perceived unless they are at some
distance from the eye. Although not neces-
sarily confined to advanced years, it is one of
the changes which warn the individual that
the prime of life is past, as it usually com-
mences about the age of forty.

To a person in whom presbyopia is com-
mencing, distant objects appear as clear and
sharply defined as ever ; but reading, writing,
and working, especially by candlelight, be-
come irksome and distressing. The eyes feel
strained, and there is uneasiness over the
brow sometimes amounting to headach ; the

page of a book appears misty, the type con-
fused at the ordinary reading distance, and a
strong light is indispensable. The person
therefore draws the candle to him, and holds
the book close to it nearly at arm’s length,
throwing his head back to increase the dis-
tance.

These symptoms are the result of changes
in the eye which cause the converging rays of
light to be brought to a focus beyond the
retina, upon which a confused and imperfect
image is consequently depicted. They may be
the result either of flattening of the cornea or
the crystalline lens, diminution in the density
of the humors, or diminished curvature of the
retina. Absence of the crystalline lens pro-
duces the same effect in an extreme degree.

The explanation of the feelings of dis-
comfort, and other presbyopic symptoms, is
simply this — the object being removed to a
greater distance than is natural, the visual
angle is reduced in size, the picture on the
retina diminished, and the quantity of light
becomes less: hence the retina, with its some-
what impaired sensibility is unable to appre-
ciate the object without effort, and a con-
siderable increase of light.

The necessity for this increased quantity of
light is a frequent cause of amblyopia super-
vening upon presbyopia, for a very large
number of work-people pursue their avoca-
tions in densely crowded and ill lighted rooms,
and they are obliged to struggle on despite of
their failing sight. Dr. Sichel states that one
of the causes which renders amblyopia in
connection with presbyopia so common in the
conciergeries of Paris is, that the majority of
persons are tailors and shoemakers, who
almost without exception inhabit confined
rooms called loges, into which light and air can
scarcely penetrate. Presbyopia may be con-
genital, and it is frequently excited in persons
under thirty, by the injurious habit of wearing
convex glasses, miscalled “preservers.” Among
the lower and even the middle classes the
belief is general that if from any cause the
sight is weakened, such glasses are beneficial,
an impression most fallacious. It however
answers the purpose of some advertising op-
ticians to encourage the idea, regardless of
the consequences to their victims.

M. Desmarres states* that country people
are almost all attacked with presbyopia at an
early age, because their sight is much exer-
cised on distant objects, and very little on
near objects, whereas the dwellers in towns
are attacked later in life. It may be so in
France, but is certainly not the case in Eng-
land. The same writer affirms that this im-
perfection in sight is rife in countries where
the light is very bright.

The first indications of presbyopia are
always perceived in the evening, and it is im-
portant that they should be distinctly borne
in mind. During the day, persons past the
meridian of life, accustomed to read, write, or
work can do so without inconvenience, but as

* Traite des Maladies des Yeux, p. 809.

1166

VISION.

the shades of evening draw in and lights are
introduced, they find that they cannot fix
their eyes upon their work as before, without
fatigue; if they persist, this fatigue increases,
and after a time amounts to headaeh ; but if
they put on convex glasses of a low power, all
discomfort vanishes, and their sight is at once
restored, and they can pursue their occupa-
tions with perfect ease. If however they
persist in abstaining from glasses, and by in-
creasing the light endeavour to improve their
sight, the retina will be over stimulated, and
in addition to presbyopia, they will acquire
dull and imperfect vision of all objects, far as
well as near.

There are persons whose sight, never par-
ticularly good, but who from easy circum-
stances have used it little, become alarmed at
finding, about the age of fifty, that their eyes
appear to have suddenly failed, and they
think they are becoming blind. Many such
cases have fallen under our observation.
The facts are simply these : presbyopia has
advanced so slowly and gently, and the eyes
have been used so little, that until the defect
has become confirmed, the parties are uncon-
scious of its existence. Some accidental cir-
cumstance, as an attempt to read a news-
paper in the evening, reveals the imperfection :
proper glasses are alone required to restore
the vision.

Belladonna and atropine produce temporary
presbyopia by suspending the power of ad-
justment, the eye being fixed at the focus for
distant objects. Mydriasis also renders the
individual more or less presbyopic. Presby-
opia may be converted into myopia, and vice
versa, of which cases are related by various
writers.*

Dr. Sichel lias justly pointed out that neu-
ralgia of the eye-ball is by no means infre-
quent in connection with presbyopia. We
have seen several instances, and generally
traced it to overstraining the eyes in efforts
to read or work without glasses. The pain
is at first transient, but if the exciting cause
be continued, it becomes more severe and per-
sistent, extending from the eye to the neigh-
bouring parts and not readily yielding to
treatment. In such a case, rest to the eyes
is all important in the first instance, and
suitable glasses are indispensable.

The chief remedial measures for presbyopia
are comprised in the early and judicious
use of suitable glasses, but the means of
prolonging natural sight and of staying the
progress of presbyopia are as follows : —
Persons habitually engaged in minute work
should ascertain by experiment the greatest
distance at which they can clearly and with-
out effort see their work, and always endea-
vour to maintain that distance ; they should
raise their eyes from time to time, and direct
them to some object at the opposite end of
the room to alter the focus: but when en-
gaged in lighter pursuits they may if agree-

* See Practical Remarks on Near Sight, &c.
pp. 9U — 95.

able read at less than their working distance.
In reading or writing just that amount and
quality of light is proper which thoroughly
illuminates the object, and yet feels grateful
and pleasant to the eyes. - It is injurious to
face the light ; the best position when reading
is with the light rather behind and on one
side ; the eyes are thus protected from all
heat and glare, while the object is fully illu-
minated. When this arrangement is "incon-
venient, a screen or shade may be used with
advantage. Reading by twilight and firelight
is highly injurious to feeble eyes. Stooping
over work should be avoided as one great
cause of congestion of the eyes; for which
reason a high desk is useful. Whenever the
ey es feel fatigued, a few minutes’ rest and
bathing with cold water will be refreshing
and beneficial. There are two descriptions of
lenses jin common use for spectacles, the dou-
ble concave for short sight, the double convex
for long or aged sight ; plano-convexes and
piano-concaves are scarcely ever employed.
It sometimes happens however that the cur-
vatures of the surfaces are unequal; for in-
stance, a ten-inch lens may be required, but the
optician may not have what is technically
called the “tool” of the proper curve, and
therefore selects two tools, the numbers of
which combined make ten — as one of seven
and the other of three inches — and the lens
produced by these, though with surfaces of
very unequal curvature, answers the purpose
perfectly. Periscopic glasses were invented
by Dr. Wollaston, but are seldom employed,
and there are others with attractive names
but not deserving of particular notice.

A common prejudice exists in favour of
pebbles, but it is erroneous, for whilst on the
one hand their chief merit consists in extreme
hardness so that they are not easily scratched,
that very hardness renders them difficult to
cut and grind, many being broken in the
process. They are expensive from this cir-
cumstance, and the difficulty of meeting with
crystal of sufficent size which is pure and
without flaw. Crown glass is now made of
such excellent quality and so colourless that
lenses made, from it possess every qualifica-
tion that can be desired. Among the many
singular things characteristic of the Chinese
is their spectacles. Without knowing any-
thing of the theory of the convergence and
divergence of light by means of lenses, both
convex and concave lenses are used all over
the empire, and of such a singular size and
shape that there can be little doubt of their
being original inventions. They are made
of rock crystal ground with the powder of
corundum and are of immense size, being re-
tained in their position on the face by means
of silken cords with weights attached, which
are slung over the ears.

Frames, of whatever material they may be
formed (and blue or bronze steel is the best),
should possess the following qualifications.
The rims should accurately fit the form of
the lenses, and be sufficiently strong to re-
tain them: the connectin'! arch or bridge

VISION.

must ba of such width and shape that it will
fit the nose accurately, and maintain the
centre of each glass in front o( the axis ot
the corresponding eye. This is a point of
great importance, otherwise the eyes will
not have the full 'assistance of the lenses.
The necessity for the bridge being adapted
correctly was proved by a case that re-
cently came under our notice, where a wart
on the side of the nose had degenerated into
a scirrhous growth from the friction of an
ill fitting spectacle frame which constantly
pressed upon, and irritated that point. The
lateral branches of the frame should he suffi-
ciently strong and elastic to retain it in its
place, firmly and immoveably under all move-
ments of the head ; and they should he of
such a shape and size that no undue pressure
can be caused on the temples or sides of the
head. Besides the injury to the eyes from
ill-fitting frames, persons acquire the habit of
grimacing in their efforts to see through them.
Hand glasses and those retained on the
nose by a spring are objectionable ; the latter,
when clipping the nose, almost invariably
throw the centres of the glasses out of the
axial lines of the eyes, and both are deficient
in that steadiness which is indispensable to
perfect and comfortable vision.

The power of bi-convex glasses is indicated
by their numbers, and these numbers signify
the inches of the focal length.

The numbering of the French glasses,
whether presbyopic or myopic, has a much
more extensive range than the British, as will
be seen by the following lists.

Presbyopic (French). 80, 72, 60.48, 36, 30,
2d, 20, 18, 72, 60, 48, 36, 30, 24, 20, 18, 16,
15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 44, 4,
3j-, 3, 2-t, 2, If, If, 1.

Myopic (French). 60, 30, 20, 18, 16, 15, 14,

13, 12, 11, 10, 9, 8, 7, 6, 5, 44, 4, 3f, 34, 3,
2f, 2i, 2, If, If, If, 1.

Presbyopic (British). 48, 36, 30, 24, 20, 18,

14, 12, ‘l0, 9, 8, 7, 6, 5f, 5, 4f, 4, 3®, 2f, 2f,
2_l, 2_2_ 2 la 14.

Myopic (British). 00, 0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,20.

The numbers of the double convex glasses
below 5 in both scales are confined to patients
who have undergone the operation for cataract.

The golden rule in the selection of spec-
tacles, whether for myopia or presbyopia, is to
choose the lowest power that is productive of
distinct vision : and so long as these afford
the necessary assistance the party should rest
contented, for if he begins with too high a
number or rashly increases the power, it will
be found not only difficult to go back, but
equally so to subdue the inclination for
further increase.

A myopic person should therefore select
glasses which will enable him to distinguish
the outlines of objects distinctly at about
forty-five feet, without diminishing them in
the slightest degree ; anil with these he
should be satisfied, not changing them for a
higher power unless absolutely obliged.

It frequently happens that the eyes of

1467

myopic persons are of different focal length,
in which case great care should be taken by
diligent trial to determine the powers which
will bring the eyes to perfect equality, and
with these lenses the frames should be fitted;
but there is another condition of vision which
is sometimes embarrassing ; it is when one
eye is myopic and the other presbyopic.
This can only be ascertained by careful trial
of each eye with convex and concave lenses,
and the results are sometimes quite unex-
pected ; if therefore a person using glasses
complains of faulty vision with one eye, which
cannot be satisfactory accounted for, it is
proper to try the eye with a different descrip-
tion of lens, which will frequently show the
nature of the case at once. Eyes thus faulty
require a double convex and a double concave
lens fitted into the same frame, and the same
rules apply to their selection, as to glasses
generally.

In England the lowest power in use for
presbyopia is a glass of 48 inch focus; in France
it is otherwise, as will be seen by reference to
the table already given. M. Sichel commences
with a 72 inch, and in some cases with a 96 inch;
Mr. A. Ross, however, who has had an im-
mense amount of experience as an optician,
informs us that he has met with but one per-
son who could perceive any sensible difference
between these two powers, as far as assistance
to the sight was concerned. It is quite pos-
sible that in the early stage of presbyopia a
72 inch glass may be sufficient, and if found to
be so, it should by all means be preferred to
a higher number ; but, practically speaking, a
48 inch is that most usually required, because
persons in this country seldom seek assistance
until the presbyopia lias advanced beyond the
aid of a 72 inch glass. It has been recom-
mended to calculate the requirements of the
eye by the age of the individual, but this is
fallacious, as ey es differ much in their natural
powers of vision, and not less in the amount
of assistance they need. The only true mode
of obtaining suitable spectacles is by absolute
trial.

Persons should not be satisfied with a
hasty trial of glasses in an optician’s shop, for
the eyes soon become excited and confused,
rendering it impossible to arrive at a correct
decision. It is far better to select two or
three pairs of spectacles which are near the
mark, and to test them leisurely at home.
Those to be selected should simply gil>e black-
ness and distinctness to the letters of a book,
and enable a person to read or work at the
natural distance with perfect comfort ; such
glasses supply to the eyes precisely that
amount of refractive power in which they are
deficient.

Cylindrical Fye. — This peculiarity of the
organ of vision was first investigated and ex-
plained by the present Astronomer Royal. It
depends on the curvature of the cornea being
greater in the vertical plane than the hori-
zontal, whereby the rays are refracted to a
nearer focus in a vertical than in a horizontal
plane ; this gives rise to much confusion of

1108

VISION.

vision, a point appearing a line, a circle an
oval, and a square a parallelogram. In an in-
teresting case related by Dr. Robert Hamil-
ton*, the patient, when looking at a clock, was
unable to distinguish the hands if they pointed
perpendicularly, as at six o’clock, but if hori-
zontally he had no difficulty: so when looking
at a wheel at a little distance, the horizontal
spokes only could be seen. The patient was
a coach painter by trade, and this peculiarity
of vision greatly interfered with his business,
for he could not draw vertical lines with any
degree of correctness, and unwittingly made
them slanting, a serious fault in heraldic de-
vices ; horizontal lines he drew with perfect
precision. ITis method of correcting the per-
ceptions of perpendicular lines was to bend
his head at right angles with his body, where-
upon upright bodies became distinct and accu-
rately represented. This man also practised
a manoeuvre which forcibly reminds us of an
act common to persons having conical corneae,
that of placing the fore-finger at the outer
angle of the eyelids and drawing them out-
wards whereby vision is improved.

To remedy the defect under which he
laboured, Professor Airey made a pin-hole in
a blackened card, which he caused to slide on
a graduated scale ; then strongly illuminating
a sheet of paper and holding the card between
it and the eye, he had a lucid [joint on which
he could make observations with ease and
exactness. Then resting the end of the scale
on the cheek bone he found that the point at
the distance of 6 inches appeared a very well-
defined line inclined to the vertical about 35°
and subtending an angle of 2°. Again, at the
distance of inches, it appeared a well-defined
line at right angles with the former, and of the
same apparent length. It was therefore neces-
sary to make a lens which, when the parallel
rays were incident, should cause them to
diverge in one plane from the distance of St-
and in the other plane from the distance of
6 inches. The professor obtained a lens of
which the radius of the spherical surface was
3£ inches, of the cylindrical 4£ inches, and with
this he was able to read the smallest print.

In Dr. Hamilton’s patient the relation of the
horizontal to the vertical focus appeared to be
as 5Jf inches to 6A- inches, and on trying him
with plano-concave cylindrical lenses, it was
found that a lens of 24 inches focal length,
the cylindrical surface being made to act ho-
rizontally, operated very beneficially. Besides
this irregular refraction the man was myopic,
but the lenses in question fitted as spectacles,
enabled him to see well.

The defect of the cylindrical eye may be de-
tected by making a small pinhole in a card
which is to be moved from close to the eye to
arm’s length, the eye meanwhile being directed
to the sky, or any bright object of sufficient
size. With ordinary eyes the indistinct image of
the hole remains circular at all distances, but
to an eye having this peculiar defect it be-
comes elongated, and when the card is at a

* Monthly Journal of Medical Science, June 1847.

certain distance passes into a straight line.
On further removing the card the image be-
comes elongated in the perpendicular direc-
tion, and finally if the eye be not too
long-sighted, passes into a straight line per-
pendicular to the former.

Professor Stokes has invented a highly
ingenious instrument for determining the
nature of the required lens, and the following
is the proposition on which it is based.

Conceive a lens ground with two cylindrical
surfaces of equal radius, one concave and the
other convex, with their axes crossed at right
angles ; call such a lens an astigmatic lens :
let the reciprocal of its focal length in one of
the principal planes be called its power, and a
line parallel to the axis of the convex surface
its astigmatic axis. Then if two thin astig-
matic lenses be combined with their axes
inclined at any angle, they will be equivalent
to a third astigmatic lens determined by the
following construction.

From any point draw two straight lines
representing in magnitude the powers of the
respective lenses, and inclined to a fixed line
drawn arbitrarily in a direction perpendicular
to the axis of vision at angles equal to twice
the inclinations of their astigmatic axes, and
complete the parallelogram. Then the two
lenses will be equivalent to a single astigmatic
lens represented by the diagonal of the pa-
rallelogram in the same way in which the
single lenses are represented by the sides.
A piano-cylindrical or spherico-cylindrical
lens is equivalent to a common lens, the
power of which is equal to the semi-sum of
the reciprocals of the focal lengths in the two
principal planes, combined with an astigmatic
lens, the power of which is equal to their
semi -difference. If two piano -cylindrical
lenses of equal radius, one concave and the
other convex, be fixed one in the lid and the
other in the body of a small round wooden
box, with a hole in the top and bottom, so as
to be as nearly as possible in contact, the
lenses will neutralise each other when the
axes of the surfaces are parallel ; and by
merely turning the lid round, an astigmatic
lens may be formed of a power varying con-
tinuously from zero to twice the astigmatic
power of cither lens. When a person who
has the defect in question has turned the lid
till the power suits his eye, an extremely
simple numerical calculation, the data of
which are furnished by the chord of double
the angle through which the lid has been
turned, enables him to calculate the curva-
ture of the cylindrical surface of a lens for
a pair of spectacles which will correct the
defect in his eye.*

A curious case is related in the Annales
d’Oculistique f , of an anomaly of vision,
which was probably the consequence of a
defect in the form of the cornea, such as
that under consideration. M. Schnyder, the
Pastor of Menzberg in the Canton of Lucerne,

* Report of the British Association, vol. xviii.

t Tom. xxi. p. 222.

VITAL STATISTICS.

1469

was presbyopic for horizontal lines and
myopic for vertical. This he remedied by
wearing spectacles the glasses of which were
cylindric bi-convexes, with rectilinear, hori-
zontal and similar axes. These glasses obvi-
ated the presbyopia relative to the horizontal
lines, and they were combined with sphero-
biconcave lenses to get riel of the myopia for
vertical lines. Each of the glasses was made
moveable for facility of cleaning.

The following means are recommended to
ascertain if an eye has the defect now de-
scribed. The person should attentively con-
template for some time and with attention a
cross, three or four lines in size, made of line
wire and fixed in a frame. It affected, he
will see the horizontal lines differ in thickness
and blackness of tint from the vertical.

To determine the focal length which the
lenses should have, a person whose sight is
presbyopic in one direction should take bi-
sphero-convex lenses which enable him to see
distinctly at the ordinary distance the lines
which otherwise appear indistinct: he can
deduce the focal distance of the cylindrico-
convex glasses. A person myopic in one
direction should do the same with regard to
bi-sphero-concave lenses. The convex glasses
should be chosen of one or two numbers
stronger.

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(The subject of Vision is more or less treated of in
works on Optics and Natural Philosophy ; papers
on its physiology and pathology are very numerous,
and are to be found in Philosophical Transactions
and Journals, in the Annales d’Oculistique, &c.)

(IE. White Cooper .)

VITAL STATISTICS.— The duration of
human life, with a consideration of the princi-
pal causes by which it may be lengthened or
curtailed, is a subject which evidently belongs
both to the domain of physiology and to that
of statistics. It belongs to physiology, in-
asmuch as the duration of human life is the
final effect of the operation of natural causes
brought to bear on the healthy human frame ;
and it belongs to statistics, whether we use
that term in the’ less exact sense of a branch
of human knowledge largely indebted to the
use of numbers, or in the more accurate sense
of a department of science, having an im-
portant bearing on the interests of the public.*

In this place it is proposed to take oidy
a limited view of the subject of Vital Sta-
tistics, and to examine the scientific methods
which have been suggested and employed for
determining the true duration of human life in
communities and classes of men ; in other

* For some remarks on the true meaning of the
term “Statistics,” see Statistics, Medical, note,
p. 803.

1 170

VITAL STATISTICS.

words, to do for this important branch of
statistics what has been done elsewhere for
the statistical or numerical method.* Having
already insisted on the precautions to be ob-
served in the use of numbers as a scientific
instrument, it remains to determine the pre-
cise value of those measures of the duration
of life which are in common use for scientific
and practical purposes.

On a superficial view of the subject, it
might seem sufficient, in order to determine
the mean age attained by a given class of
persons exposed to a given class of influences,
to collect the ages, at death, of a certain
number of persons belonging to that class, to
add those ages together, and to divide the sum
by the number of persons. But it must be
evident, on further consideration, that an
average so obtained may furnish a very im-
perfect measure of the longevity of the class,
and of the force of the influences brought to
bear upon the individuals of whom it is com-
posed.

In order to build up a science of Vita!
Statistics — in other words, in order to deter-
mine the true influence of external agents on
the duration of human life, we must make
use of such materials as happen to be ready
to our hands. These materials do not always
present themselves in the same shape, nor do
they all possess the same value. Sometimes
they are simple averages ; at other times they
are complex calculations based upon the same,
or similar facts, but moulded into new forms
by means of certain necessary corrections. A
few preliminary observations on these mate-
rials will be found to answer several useful
purposes. They will serve, at one and the
same time, as a test of the value of the prin-
ciples sought to be established, and as a
check to the tendency with which the statist
is often reproached to exaggerate the value of
inferences drawn from numerical data.

Several methods are in use for measuring
the duration of human life. Of these, the
best known and most commonly employed
are the following: —

1. The mean age at death ; 2. The rate of
mortality; 3. The expectation of life ; 4. The
mean duration of life ; and 5. The probable
duration of life. Other terms, such as the
specific intensity of life, and other methods,
such as the ages of the living, are occasionally
employed.

]. The mean age at death. — The mean, or
average age at death, is the sum of the ages
at death, divided by the number of deaths.
Thus, if five persons die at the respective ages
of 20, 30, 40, 50, and 60, their mean, or

, , • 20 + 30 + 40 + 50+60,

average age at death is ! :

bo 5

or 40 years ; and if a second group of five
persons die at the respective ages of 20,
35, 50, 65, and 80, their mean age at death is

20+35 + 50 + 65 + 80 , ... --

1 ' i ’ or 50 years. Mow, d

5

these two groups of five persons were each
exposed during their lives to a peculiar set of

* See Statistics, Medical, p. 801.

influences, the nTean age which they respec-
tively attained would be a measure of the
force of those influences. But such a mea-
sure would be open to the serious objection
that the number of facts from which the
averages are calculated is insufficient. Let
us, however, suppose this objection to be set
aside by increasing the number of deaths in
each case to several hundreds or thousands,
so as to embrace either the entire number of
deaths of the classes submitted to comparison,
or such a considerable proportion of deaths
taken without selection as would give satis-
factory results in accordance with the strictest
requirements of the numerical method, the
question still presents itself. Is the mean age
at death a safe measure and standard of com-
parison ? The answer to this question must
be in the negative. The mean age at death is
not always a safe and sound standard. Its
employment would often lead to very erro-
neous inferences. It will therefore be neces-
sary to discriminate between those cases in
which it may be employed with safety, and
those in which its use would lead to fallacious
results.

The mean age at death can be employed
with safety as a true test or measure only in
those cases in which the calculation purport-
ing to embrace an entire class of persons,
every member of that class is included, or in
which the calculations embracing only a sec-
tion of an entire class, the class in question is
retained in a state of perfect uniformity during
the whole time comprised in the calculation.
According to the first supposition, we take a
given number (say 100,000) of children born
in a given year, and trace them through life
till they are all dead, summing up their ages
at death, and dividing by the number of deaths.
According to the second supposition, we ex-
tract from some register of deaths the ages of
ali who die during some term of years, having
ascertained, by referring to the census, that
the population has continued stationary (that
is to say, constantly gaining as many by fresh
births as it loses by death), during the time
over which the calculations extend. The
same reasoning will be found to apply to the :
mean age at death, taken as a measure of the
true duration of life of the members of any
handicraft, trade, or profession. It can only
be a true measure so long as the blanks
caused by death are filled by new recruits,
entering at the same age as the age of entrance
of the deceased. In all other cases but those
now specified, the mean age at death is a
more or less fallacious measure of the true
duration of life. j

As the mean age at death has been lately
revived as a measure of the duration of human
life, and a test of the sanitary condition of
the population, though its fallaciousness was
long since recognised and pointed out by the
early constructors of life-tables, it may be
well to devote some space to a statement of
the cases in which the proposed test is most
open to objection.

a. The mean age at death has been employed
as a test of the sanitary condition of a nation,

1 4-7 1

VITAL STATISTICS.

and as a measure of that condition when com-
pared with another nation, or with the same
nation at another time, in ignorance or for-
getfulness of the well-ascertained fact that the
living population ot one nation may diflti
verywidely in its composition from the living
population of another, and that the elements
of the population of the same nation may
undergo very extensive changes even in a
short term of years.

In illustration of the first of these state-
ments, it will suffice to instance the strongly-
contrasted populations of England and Ame-
rica, of which the first has 46 and the second
54 in the hundred under 20 years of age, the
number above 20 being, of course, reversed.
In the two populations ot Denmark and Sar-
dinia, on the other hand, the relative pro-
portions at different ages are very nearly the
same ; and, when expressed in round numbers,
for long intervals of age, identical. As a
general rule, however, there is considerable
difference between one population and another
in the proportion of persons living at the
same ages. In support of the second ot these
statements, the change which took place in
the population of England in the interval
from 1821 to 1841 may be adduced. At the
former period, the persons living under 20
years of age were 49 per cent, ot the whole
population, but in 1811 they had fallen to 46
per cent.

There is no room for doubt, therefore, that
different populations vary in their composition,
and that the same population may, in course
of time, undergo considerable changes, and
exhibit very striking contrasts in the number
of persons 'living at different ages.

Such being the case, it will not be difficult
to prove that the differences in question do so
materially affect the mean age at death as to
rob it of its alleged value as a test or measure
of the sanitary condition of nations. We
have only to suppose the young population of
America transferred to England, and exposed
to the same causes of death as determine the
duration of life of its own inhabitants, in
order to be full}' convinced of the fallacious-
ness of this test. Now, according to the
rate of mortality prevailing in England, little
more than half its inhabitants die before com-
pleting their 20th year, and somewhat less
than half after that age. If the mean age of all
who die under 20 years of age be taken at 5
years, and of all who die above 20 at 60 years,
the mean age at death of fifty persons dying
out of the respective populations of England
and America, will be about 34 and 30 years.
These numbers, however, though correctly
calculated from the rough data just assumed,
diverge much less widely than the true re-
sults, for the actual mean age at death, which
is 29 years in England, is only 20 years in
America.* * So that two populations, subject
to the same law of mortality, and losing the
same number of persons at the same ages, in

* See an essay by F. G. P. Neison, Esq. in the < th
volume of the Journal of the Statistical Society.

consequence of the different constitution of
their respective popidations, may have a
widely different mean age at death. Similar
results to those obtained by comparing Eng-
land and America are arrived at if we compare
England in 1821 with England in 1841. The
mean age at death, which in 1821 was 25
years, became in 1841, owing to the change in
the population already referred to, 29 years.*
If any further illustration of the fallacy of the
mean age at death, when used as a test of the
sanitary state of nations, were required, it might
be found in its failure when applied to coun-
tries of which the true position in the sanitary-
scale has been ascertained by the application
of unexceptionable tests. The three nations,
England, France, and Sweden, for example,
occupy the following relative position
1. England. 2. France. 3. Sweden.

But if the mean age at death were taken as
our guide, they would rank as follows : —

1. France. 2. Sweden. 3. England.

The mean age at death being 34 for France,
31 for Sweden, and only 29 for England, t
b. The mean age at death has been em-
ployed as a measure of the relative sanitary
condition of English counties, cities, and
towns, of town and country, and of the several
districts of large cities. To show the fallacy
of the method as so applied, it will suffice to
prove that the populations thus compared are
composed of different elements. Taking, as
before, the number living below 20 years of
age as an illustration, it appears that while
there are 47 in the hundred under 20 in
Essex and Suffolk, there are only 44 in the
hundred under 20 in Staffordshire ; that for
47 in the hundred in Leeds, 46 in Sheffield
and Birmingham, and 44 in Manchester,
there are only 42 in Liverpool, 41 in Exeter,
and 40 in London ; and, lastly, that the popu-
lation under 20 years of age, which amounts
to 47 per cent, in Bethnal Green falls as low
as 41 in Clerkenwell, 40 in Kensington, 36 in
St. Giles's and Marylebone, and 31 in St.
George’s, Hanover Square. The effect of
this variable distribution of the population on
the mean age at death is very well marked,
and is placed in a very striking light by sup-
posing the population of the metropolis to be
transferred to some of these counties and
cities, and to be exposed to the influences for
good or evil w'hich are brought to bear on the
duration of life of their actual populations.
Thus, if the population of London, of which
40 per cent, are under 20 years of age, were
to be transferred to the county of Hereford,

The exact age, deduced from the rough data as-
sumed in the text, will be as follows : —

^ 4.

England, x 5 +‘*x60=115+1620=1735, which, di-
vided by 50, gives 3+7 as the average age.

America, 5ix 5 +il’x60 =135 + 1380=1515, which, di-
2 2

vided by 50, gives 30 3 as the average age.

* For the facts on which these comparisons are
founded, see an essay in the 6th vol. of the Journal
of the Statistical Society. By G. R. Porter, Esq.

+ See the Gth annual Report of the Registrar
General, p. 572.

1472

VITAL STATISTICS'.

where the average age at death is nearly 38-’-
years, the mean age at death would become
30i years, or a year anil a half in excess of
the mean age at death of the existing inhabit-
ants of London. The advantage, therefore,
which the county of Hereford enjoys over the
metropolis, in a sanitary point of view, instead
of being represented by the difference between
38 x, and 29 years, or 94 years, is really not
more than a year and a half. Again, the
average age at death in the metropolis is 29
years, and in Sheffield 23 years ; but if the
population of the metropolis were transferred
to Sheffield, the average age at death would
be 28 years. So that the difference of 6
years, which, according to this test of the
mean age at death, marks the sanitary su-
periority of London over Sheffield, dwindles,
under this very obvious correction, to one
year. If we apply the same correction to the
several districts of the metropolis, we obtain
similar results. Bethnal Green is the district
in which the mean age at death is lowest,
while in Kensington it attains its maximum.
In Bethnal Green the mean age at death is
26, in Kensington 32. But the population of
Bethnal Green transferred to Kensington,
would have a mean age at death of 27 years;
so that in this case also a difference of six
years in favour of the more aristocratic
quarter dwindles down to one year. In some
cases the use of this corrective actually re-
verses the position of the two populations
submitted to comparison. Thus, the mean
age at death in the united parishes of St.
(files’s and St. George’s Bloomsbury is 28
years, and in Bethnal Green, as has just been
stated, 26 ; but transfer the population of
Bethnal Green to St. Giles’s, and the mean age
at death becomes 24 years. The application,
therefore, of this correction completely alters
the relative position of the two parishes, so
that the parish which, when tested by the mean
age at death, seemed the healthiest, proves to
be the most unhealthy. Serious errors and
exaggerations have also been committed in
comparing the smaller districts of our large
towns with each other. The meanest and
most squalid districts are as naturally the
resort of those who marry early, and of those
who are sunk into poverty by the burden of
large families of young children, as better
districts are the abodes of the more prudent
and least encumbered members of society.
The lowest districts of the large towns of
England are also the resort of that part of
our population which indulges most habitually
in intemperance, and in all the habits that
engender poverty, misery, and disease. It is,
therefore, inevitable that in comparing the
worst districts with those of a somewhat
better class, we should be comparing popula-
tions containing a large proportion of persons
liable to a high mortality for reasons other
than the insalubrity of the districts themselves
with those containing a smaller proportion.

c. The mean age at death has also been
used to test the sanitary condition of different
classes of persons inhabiting the same town

or town district. A very extensive series of
tables, for instance, has been compiled, in
which the mean age at death of the gentry,
tradesmen, artisans, and paupers of the several
parishes of the metropolis is represented, and
used as a measure of their sanitary condition.*
The parish of St. James’s, Westminster, in
which the class termed gentry is more likely
to be appropriately named than in the poorer
and less fashionable parishes, may be con-
veniently taken as an example. In this parish
the average age at death, children included,
is 42 for gentry, 26 for tradesmen, 21 for
artisans, &c., and 49 for paupers. The differ-
ences are here so extraordinary, as only to
admit of explanation on the supposition of a
vast disproportion between the numbers living
at the same ages in the several classes. If
the element of age in the living is disregarded
in comparing the gentry with the artisans out
of the workhouse, it must equally be dis-
regarded in contrasting the gentry with the
paupers in the workhouse, who are drawn
chiefly from the artisan class. The difference
between 49 (the mean age at death of paupers),
and 42 (the mean age at death of the gentry)
is obviously due to the greater average age of
the inmates of the workhouse, as the differ-
ence between 42 (the mean age at death of
the gentry), and 21 (the mean age at death of
artisans), is traceable mainly, if not wholly, to
the great disparity in the ages of the living,
members of the two classes. Unfortunately
we are not yet in a condition to apply to the
mean age at death of these classes of the
population, the same correction which, when
applied to counties, cities, and city districts,
served in so striking a manner to equalize the
results. The ages of the living members of
the several classes of society is still an impor-
tant desideratum. The tables under consider-
ation also give the mean age at death of gentry,
tradesmen, artisans, and paupers dying after
21 years of age. In the parish of St. James’s,
Westminster, the mean ages at death of these
classes are 57, 51, 46, and 58 respectively.

The differences, though less considerable, are
still at total variance with the results of the
most accurate inquiries into the value of life
of the same classes of society f, and only
admit of explanation by supposing a great
disparity in the ages of their living members,
together with an erroneous method of se-
lection and classification.

d. The mean age at death has also been I
employed to test the sanitary state of different

* These Tables are published in the same volume
(vol. vii.) of the Journal of the Statistical Society,
which contains Mr. Neison’s valuable essay just
quoted. They form part of a paper by Mr. Chad- ■
wick, “ On the best Modes of representing accu-
rately by Statistical Returns the Duration of Life,
and the Pressure and Progress of the Causes of
Mortality among different Classes of the Commu-
nity, and amongst the Populations of different I
Districts and Countries.

j- See especially, Contributions to Vital Statistics,
by F. G. P.Neison, in which the artisan class is shown
to occupy a much more favourable position in the
sanitary scale, than had previously been supposed.

VITAL STATISTICS. 1473

classes of society, and of the members of
different professions, without reference to
their place of residence. But little objection
can be made to this test when applied with
ordinary precaution. If the earliest age ad-
mitted into the tabular abstracts, from which
the averages are calculated, is the same in all
the classes submitted to comparison ; if during
the time over which the observations extend
the classes compared with each other have
received no rapid accession of numbers ; and
if the deaths are those of the whole body of
the profession or trade (or, if of a section
only, then of a similar section in every case),
the mean age at death will constitute a fail-
measure of the relative sanitary condition of
the several classes in question. But if, on
the other hand, two professions or occupations
are compared, in which the age at entry is not
the same; or the one is stationary in point of
numbers, while the other is rapidly increasing;
or if the whole body is taken in the one case,
and only the senior or junior members in
the other, the results will be quite unworthy
of confidence.

Some of the greatest misapprehensions
existing with respect to the duration of life of
certain classes of the community, are traceable
to the selection of the senior members of a
class to represent the entire class to which
they belong. Nothing is more common, for
instance, than to hear royal families, or the
members of the aristocracy, or the clergy, or
the army, spoken of as long-lived, on the
strength of the advanced ages attained by
kings, [leers, archbishops, or general officers.
In making a selection of the more conspicuous
members of the class, the significant fact is
overlooked that they are also the oldest
members, and that they do not attain their
exalted rank till a period of life greatly in
advance of that at which they entered their
several professions. The mean age, at death,
for example, of archbishops and bishops of
the established church, is upwards of 71
years, but the mean age at death of the whole
body of the clergy is about 64 years. A
similar disparity would be found to exist be-
tween the [leers and the whole body of the
aristocracy, and between general officers in
the army, and admirals in the navy, and the
whole body of officers in the tw o branches of
the public service.

The tables already referred to as comparing
the four classes of gentry, tradesmen, artisans,
and paupers in the several districts of the
metropolis, supply analogous examples of
erroneous selection and classification. In the
great majority of the metropolitan parishes, for
instance, there is no class of gentry properly
so called ; but this class consists, with the
exception of a few professional men not im-
properly mixed up with it, of tradesmen who
have retired from business long enough to be
entered in the mortuary registers as gentle-
men. On the other hand, the pauper class
is very largely recruited from the ranks of
the artisans and labourers, and contains a
very considerable proportion of old persons

who, being no longer able to earn their liveli-
hood, have come upon the public for support.

The mean age of the living has been occa-
sionally resorted to as a test or measure of
salubrity. It has been assumed that a low
average age of the living members of a class,
when compared with the average age of ano-
ther class, arises, cceteris paribus, from a high
mortality leading to a quick addition of young
members. This assumption is justified only
in those cases in which the addition of young
members can be shown not to arise from any
other cause, such as an increased demand for
members of the class in question. It is there-
fore a test to be employed with great caution;
and it will also be necessary to show that the
age of admission of the classes subject to com-
parison is the same, or open only to very
slight variation.

2. The rate of mortality . — The mortality, or
rate of mortality, is the number of deaths
which takes place in a given population, in a
given space of time. The calculation is gene-
rally made for a year, so that the ratio comes
to express the number of the living out of
which one will die annually. The ratio is
sometimes stated as a fraction, and sometimes
as a percentage proportion. If, for in-
stance, out of a living population of 100,000,
two thousand deaths take place every year,
TTre.rnrco °r 35> or '2 Per cent, is the mortality,
or rate of mortality, to which that population
is exposed.

In estimating the value of this test, it is
necessary to bear in mind that the rate of
mortality varies for every year of life. It
follows, therefore, as a natural consequence,
that the rate of mortality, like the mean age
at death, must be materially influenced by
the ages of the living population. In a po-
pulation containing a large proportion of
young children, subject to a very high mor-
tality, the aggregate rate of mortality for the
entire population will be necessarily higher
than in a population abounding in older per-
sons and having a comparatively small number
of children. But a very cursory examination
of tables of mortality will convince us that
the error attaching to the rate of mortality
as a test or measure of the sanitary condition
of a population is much less than that which
is inherent in the mean age at death ; for not
only do the extremes of life approximate much
more closely to each other in their respective
rates of mortality than in the mean ages at
death, but ages which, though less widely
separated, are far enough apart to affect the
mean age at death, are exhibited as subject
to a mortality very nearly identical. From
5 to 10 years of age, for example, the rate of
mortality, in the male population of England,
is ’970 per cent., and from 20 to 30 years
of age -974 per cent. ; so that, while out of
100,000 persons dying at the respective ages of
5 — 10 and 20 — 30, 970 and 974 persons would
die in the year, their age at death would count
in the one case as something between 5 and
10, and in the other at some age between 25
and 30. The difference in the rate of mor-

5 B

1474- VITAL STATISTICS.

tality would be almost nothing, while the dif- at length for any year of life from birth to 95

ference in the age would amount to about
20 years. So also if we compare individual
years instead of terms of years. The mor-
tality at 10 years is -791 per cent., at 20 years
•784 per cent. ; at 1 1 years it is '702 per cent.,
at 18 years .709 per cent. The rate of mor-
tality differs very slightly in the ages brought
under comparison, while the mean age at
death differs by 10 and 7 years respectively.

These a priori reasonings are fully borne
out by the results of actual comparison. In
one of the reports of the Registrar General*
the expectation of life (which will be presently
shown to be the true test or measure of the
sanitary state of a population), the mortality,
and the mean age at death, for six different
populations, are compared with each other,
with what result the following table will show.

Expectation of life, in pears : — Surrey, 45 ;
England, 41 ; France, 40; Sweden, 39; Metro-
polis, 37 ; Liverpool, 26.

Rate of mortality , or one death in — Surrey,
52; England, 41; France, 42; Sweden, 41;
Metropolis, 39 ; Liverpool, 30.

Mean age at death, in years : — Surrey, 34;
France, 34; Sweden, 31 ; England, 29; Me-
tropolis, 29; Liverpool, 21.

The rate of mortality, then, keeps pace
with the expectation of life, to such an extent,
at least, as to place the six communities in
the same relative position ; while, according
to the mean age at death, the nations which
stand third, fourth, and fifth on the list suffer
transposition, France and Sweden taking
rank before England in the scale of salubrity,
and England, which holds, of right, the second
place immediately after her own county of
Surrey, is made to descend to the fourth rank.
When compared, therefore, with an accurate
measure of the duration of human life, the
rate of mortality shows itself more worthy of
confidence than the mean age at death.
Nevertheless, for reasons already assigned, it
must not be looked upon as altogether free
from objection, and must, in every case, be
regarded as of inferior value to the test next
to be considered, namely, —

3. The expectation of life. — The expectation
of life, or the mean future life-time, is the
mean number of years which, at any given
age, the members of a community, taken one
with another, may expect to live. This ex-
pectation is embodied in those series of cal-
culations which are technically known as life-
tables, and which are so largely in use in the
important operations of life-assurance. When
correctly calculated, they are based on the
two concurrent series of facts, the numbers
and ages of the living and the numbers and
ages of the dying, and they therefore comprise
the two elements necessary to perfect ac-
curacy. When based upon the ages of the
dying alone, they are open to nearly the same
objection as those which apply to the mean
age at death.

The following is an abbreviation of the
English life-table, which will be found given
* Sixth Annual Report, p. 572.

years of age in the fifth annual report of the
Registrar Genera!.*

Age.

Males.

Females.

o-

40'19

42-18

1-

46-71

47-55

2-

48'82

49-57

3-

49-52

50-29

4'

49-74

50-48

5-

49-64

50-38

10'

47-08

47-81

15'

43'35

4413

20'

39-88

40-81

25-

36-47

37-52

30-

33-13

34-25

40-

26'56

27"72

50'

20-02

21-07

60-

13-59

14-40

70-

8-51

9-03

80-

4-92

5-20

90-

2-68

2-77

95-

2’22

2-06

The table is read thus : — At birth the ex-
pectation of a male child is 40T9 years, of a
female child 42' 18 years; at 5 years of age
the expectation is 49'64 years for a boy and
50'38 years for a girl ; at 20 years of age,
males one with another may expect to live
39"88 years, and females 40"8 1 years ; at 30
the expectation has fallen to 33' 13 for men
and 34-25 for women.

4. 'The mean duration of life, the mean life,
the mean life-time, or vie moyenne, is found
by adding the age to the expectation of life.
Thus the mean duration of life at 5 years of
age is 5 + 49 '64 for boys, and 5+50'38 for
girls, or 54'64 for boys and 55'38 for girls ;
at 10 years of age the mean duration of life
is, for boys and girls respectively, ! 0 + 47 '08
and 10 + 47'81, or 57'08 and 57-81; and at
30 years of age 30 + 33' 13 or 63' 13, and
30 + 34*25 or 6+25. The mean duration of life
differs from the mean age at death, inasmuch
as the one is a calculation based on all the
deaths taking place, after a given age, in the
members of a community traced through life,
while the other is founded upon such deaths
as happen to be noted in a community which
has been undergoing continual disturbance by
births, immigration, and emigration.

5. The probable duration of life, probable
life-time, equation of life, or vie probable, is
the age at which a number of children born
into the world will be reduced one-half, so
that the chance is equal of their dying before
or after that age. Thus it has been ascertained
that, out of 51,274 males and 48,726 females
(making up together the number of 100,090
infants) at birth, 25,637 males will die between
the 45th and 46th year, or at about 45J years
of age, and 24,363 females between the 47th
and 48th year, or at about 47i years ; so that
the equation of life or probable life-time of
males at birth is 45£ years, and of females

* Report, p. xix.

1475

VITAL STATISTICS.

47i years. The same terms (probable life-
time, equation of life, or vie probable') are also
employed in speaking of persons who have
attained more or less advanced ages. Thus
the probable duration of life of a female at 25
years of age is about 41 years, being her actual
age added to the number of years required to
reduce the females living at that age to one
half. In like manner the probable duration
of life of a male aged 60 years is 73 years,
being his age added to the 13 years required
to reduce himself and his contemporaries to
one half their number.

The term “specific intensity” has also
been used as a measure of the value of life.
It represents the number living at any given
age, divided by the number dying at that
age. For example, if, at the age of 44, 72,709
male survivors of the population of Eng-
land and Wales, out of 100,000 born into
the world, lose by death 990, the specific
intensity is 7§7ga or 73475, while for the
number of 72,190 female survivors losing 923
of their number, the specific intensity is
or 78M09. Females, therefore, have a higher
intensity of life at 43 years of age than males ;
in other words, they suffer from a less mor-
tality.*

Such are some of the principal methods
which have been recommended or employed
for ascertaining the true duration of human
life, — a branch of statistical inquiry which
has received large contributions of late years,
many of which, however, are unfortunately
rendered altogether valueless by the omission
from the calculations of some elements ne-
cessary to precision, but not yet obtainable.

Bibliography. — 1. The fifth and sixth annual
Reports of the Registrar General. — 2. Contributions
to Vital Statistics. By F. G. P. Nason, Esq. — 3.
Quarterly Journal of the Statistical Society, vol. vii.
Essays by Edwin Chadwick, Esq. and F. G. P.
Neison, Esq. at pp. 1. and 40. On the subject of
the Construction, Properties, and Applications of
Life Tables, which is intimately connected with
Vital Statistics, many interesting details and full
references to authorities will be found in Mr. Farr’s
letters to the Registrar General in the fifth and
sixth Annual Reports.

(IV. A. Gup.)

V OICE.f — ( Syn. Gr. <po» rj ; Lat. Vox ; F r.
Vole ; Germ. Stimme ; It. Voce; Span. Voz.)
This term is usually applied to those sounds
which animals produce by means of the
air traversing their organs of voice, such as
we observe in mammalia, birds, reptiles, and
in some insects.

The human voice is susceptible of several
modifications, such as timbre or quality, in-
tensity, and pitch ; including those successive
transitions of tone from one pitch to another
which constitute melody. The organs ot
voice comprise the thorax with the muscles

* See Contributions to Vital Statistics. By
F. G. P. Neison, F. L. S. &c., p. 5.

t [It was intended that this article should have
comprehended Voice and Speech. It is now found
necessary to defer the latter subject to the Supple-
ment. Ed.]

of respiration, the lungs, trachea, larynx,
pharynx, mouth, tongue, nasal cavities, nerves,
ami blood-vessels. Of these, the thorax and
Jungs may be considered an air-chest or
bellows, the trachea a porte-vent or air-pipe,
and the glottis a complex reed. The trachea
varies in length and diameter with the age
and sex of individuals, until they arrive at the
adult period of life. By its structure the
trachea is endowed with elasticity, together
with the power of longitudinal extension and
relaxation, and of increasing or diminishing in
diameter : the acoustic effect of these pro-
perties will presently be investigated.

The sum of the areas of the two
bronchi is greater than that of the trachea ;
by which adaptation the latter is more readily
supplied witli air during the vocalization of
the breath. In all mammalia, birds, and
reptiles, the axes of the bronchi are inclined
to that of the trachea at a greater or less
angle. With reference to the voice, the
larynx is the most important organ in the
whole apparatus. The mouth, fauces, tongue,
and nasal organs are not necessary to the
production of voice ; nevertheless they exer-
cise a considerable influence on its quality, and
are indispensable for the production of arti-
culate language. The thorax is sufficiently
capacious to contain as much air after a
full inspiration as will sustain the glottis in a
state of vibration, when the tone is of mo-
derate intensity, during the space of fifteen
seconds, which will enable a person to pro-
nounce in rapid succession from thirty to forty
monosyllables at one expiration.*

The phenomena of the voice of animals
must at a very early period have afforded to
physiologists proof of the susceptibility of
membranous structures to enter into a state
of vibration; and it is now generally known
that membranes, whether twisted into a cord
like the string of a violin, or in the form of a
parallelogram stretched in one direction as
the vocal ligaments, or in that of discs
stretched all round as the head of a drum,
are all capable of producing musical sounds
when properly excited.

The theory of the vibratory movements of
stretched membranous surfaces has occupied
the attention of many of the most celebrated
mathematicians, such as Euler, Bernoulli,
Riccati, Biot, Poisson, Sir John Herschel,
and others. It is a subject requiring the most
profound analysis, and the solution of pro-
blems of much greater complexity than those
either of strings or bars ; but in order to bring
the theory of vibrating membranes within the
reach of computation, the membranes are
supposed to lie homogeneous and of equal
thickness and elasticity. Now this hypo-
thesis will not satisfy the conditions of the
vibratory movements of the vocal organs,
such as the windpipe for example, which is
composed of tissues of variable thickness,
density, and elasticity; it would therefore be

* For the anatomy of the Iranian larynx, reference
is made to the article Larynx.

5 b 2

] 176

VOICE.

futile in the present state of the science of
acoustics to attempt any mathematical solu-
tion of the laws of the equilibrium and move-
ments of the heterogeneous masses of the
vocal tube. When, however, a membrane is
stretched in one direction only, it obeys the
same laws as a string.

Fig. 890.

An outline of the transverse section of the Human
Larynx. ( Outline o f Jig. 18, Vol. III. p. 100, in
which the different parts are indicated.')

x, x, the plane of the vibrating position of the vocal
cord; y,yy,y, the plane of the respiratory posi-
tion.

Having adapted two laminae of India rubber
to a pipe connected with the bellows of an
organ, M. Biot caused a current of air to
pass over their free edges, by which means
he obtained with facility sounds of different
pitch. Professor Willis made similar expe-
riments with leather and caoutchouc, but
could not produce with these substances so
great a range of tones as the glottis will
yield, and therefore concluded that the vocal
ligaments possess greater elasticity. Mr.
Willis has also investigated the position in
which it is necessary that membranous laminae
should be placed, in order that they may be
excited and sustained in a state of vibration.
He has likewise given a satisfactory explana-
tion of the mode of action of the air on reeds,
such as those of the organ pipe, which applies
also to free reeds, and every other case where
a vibratory motion is maintained by a current
of air.

The experiments and theory of Mr. Willis

are exceedingly important, for he has shown
that in ordinary breathing the vocal cords
remain inclined to each other, at an angle
which prevents any vibratory motion ; whereas
when their surfaces lie in the same plane, the
breath immediately excites them into a state
of vibration ; the natural position of the vocal
cords in these two states is seen in (fig. 890).
Muller also made some experiments on
stretched membranous bands, both isolated,
and in connection with a tube ; from which he
concludes that the force of the current of air
influences the pitch of the note produced; so
that a strong current will produce a more
acute tone than a weak one, and vice versa ;
but the author has not found this to be the
case in any of the experiments which he has
made. To obtain a pure quality of tone
when two membranous bands are stretched
across a tube, it is necessary that they should
be of equal weight and length, and subjected
to equal tension, otherwise they cannot
vibrate freely in equal periods of time. Ac-
cording to Cagniard De la Tour, if two mem-
branous laminae of equal length and weight
be stretched by unequal forces, so that there
is an interval of a fifth between the notes
they yield separately, the note resulting from
their combined action is the intervening third.
Midler is disposed to doubt the accuracy of De
La Tour, but his own views do not differ ma-
terially from those of the latter, as he says that
when one tongue is most readily thrown into
vibrations bv the current of air, the sound is
emitted by it alone, but if the blast is such
that it throws them both into motion, they
may both vibrate together, and by reciproca-
tion produce a simple sound intermediate
between the fundamental note of the two
vibrating separately ; they may also emit two
distinct sounds, or the blast being modified,
the two sounds may be produced in suc-
cession. From these researches it appears,
that membranous laminae, stretched in imi-
tation of the thyro-arytenoid ligaments, will
not only vibrate readily, but produce a range
of musical tones. It has been remarked that
sounds are most readily produced when the
two laminae are stretched in the same plane,
and that a smaller volume of air is required
the nearer the edges of the laminae approach
each other, and a still smaller one when their
edges actually touch. De Kempelen states,
that to produce sound, the edges of the
glottis must be approximated to within
or at least TV, of an inch. These experi-
ments upon artificial vibrating tongues per-
fectly agree with those the author has made
on the larynxes of animals. Owing to the
nature of the articulation of the thyroid with
the cricoid cartilage, and the manner in which
the crico-thyroid muscles act, an equal ten-
sion of both the thyro-arytenoid ligaments is
simultaneously secured, supposing the aryte-
noid cartilages to be at the same time in
corresponding positions, which is a necessary
condition for the production of a synchronous
vibratory motion in the two lips of the
glottis.

VOICE.

1477

If the larynx of an animal be dissected out,
and the vocal cords be stretched, they will
vibrate like a piece of caoutchouc or leather
in a current of air. In conducting these ex-
periments, it is necessary to secure the same
conditions as those which are required in the
lamina above mentioned ; for instance, the
inner edges of the glottis must be turned
towards each other till they are in the same
plane and parallel to one another before they
will produce any sound ; hence we infer, that
when the tension of the arytenoid ligaments
takes place in the living animal, they turn upon
their axes till their planes (which in the state
of relaxation are inclined to the axis of the
vocal tube) become perpendicular to it, and as
the edges of the glottis approximate, and its
chink is nearly or entirely closed up, they
acquire the true vibrating position. The
production of the most simple tones of voice
requires the associated actions of a most
extensive range of organs ; and it is calculated
that in the ordinary modulation of the voice,
more than one hundred muscles are brought
into action at the same time.

The lungs having been first supplied with
air by the act of inspiration, and the air in
the chest and trachea having subsequently
been condensed by the muscles of expiration,
a portion of the edges of the glottis yields to
its pressure, and is curved upwards, so as to
form an angle with the axis cf the vocal
tube, leaving between them a narrow aperture
through which the air escapes. The tension
and elasticity of the vocal ligaments tend to
restore them to the plane of the vibrating
position ; the air having been rarefied below
the glottis during their elevation, becomes
condensed on their depression, and the ne-
cessary force is again accumulated to re-
elevate the vocal ligaments, and thus an oscilla-
ting movement, consisting of a partial opening
and closing of the glottis, takes place, which
being communicated to the contiguous air,
the sounds of the voice are produced.

The relative length of the vibrating edge of
the glottis is regulated by the pressure of the
column of air in the trachea, and the resistance
of the vocal ligaments. The intensity of the
voice in the same medium, and under similar
collateral circumstances, depends on the
pressure of the column of air in the trachea,
and the range of motion performed by the
vibrating edges of the glottis. The vocal
ligaments do not vary the pitch of the voice
by their tension alone, but by their variations
in length and tension conjointly. The author
has learnt this from his own experiments on
the vocal functions of the larynx, which have
been confirmed both by Majendie and Mayo ;
the former having observed in the larynx of a
dog that a longer portion of the ligaments of
the glottis vibrated during the utterance of
grave tones, and that the length was dimi-
nished as the tones became acute. The latter
had an opportunity of inspecting the move-
ments of the glottis in a man who had made
an attempt to destroy himself by cutting bis

Fig. 891.

The Head and Focal Organs prepared for experi-
ments. (After Muller.)

The cervical vertebrae are removed, and the oeso-
phagus opened behind the arytenoid cartilages,
which are fixed together by a strong pin and
ligature ; the latter is brought through the open-
ing, which is then firmly sewed together, and the
lower opening of the oesophagus is also closed up.
The larynx is laid bare, and the superior portion of
the thyroid cartilage carefully removed so as not
to injure the mucous membrane of the larynx.
The parts thus prepared are firmly fixed against
the column, to which the arytenoid cartilages are
also attached by the cord which binds them to-
gether. The trachea is connected with a pipe
and bellows for the supply of air.
a, the trachea; b, the os hyoides; c, the cricoid
cartilage ; d, portion of the thyroid cartilage re-
maining for the attachment of the cords e, by
means of which the vocal cords may be extended ;
f, apparatus for compression.

Fig. 892.

The apparatus used for the lateral compression of the
vocal cords, as seen in fig. 891 f.

5 B 3

1478

VOICE.

throat. In this case the larynx was divided
immediately above the vocal cords, and in
consequence of the oblique direction of the
wound, the arytenoid cartilage and the vocal
cord on one side were injured. During
respiration the glottis was observed to assume
a triangular form, but when a sound was
uttered, the chord® vocales became nearly
parallel, and the rima glottidis of a linear
form. The posterior part of the aperture
did not appear to be closed. In a second
case of this kind, he observed that the aryte-
noid cartilages, as long as the vocalization of
the breath continued, maintained the position
which they had assumed when the glottis
was closed entirely.* * * § The vibrations of the
thyro-arytenoid ligaments are considered by
Ferrein f to be analogous to those of strings ;
hence he denominated these ligaments (though
improperly) chordae vocales. He imagined
that the longitudinal tension of these cords
alone governed the pitch of the voice. Mr.
Willis); has embraced the hypothesis of
Ferrein ; he observes, that to obtain the
various notes of the glottis, it is only ne-
cessary to vary its longitudinal tension after
the ligaments have been placed in the proper
position j but M. Biot § remarks, “ Qn’y
a-t-il en effet dans la glotte qui ressemble a
une corde vibrante? Comment pourroit-on
en tirer jamais des sons d’un volume com-
parable a ceux que Phomme produit ? Les
plus simples notions d’acoustiques suffisent
pour faire rejeter cette etrange opinion.”

On inspecting the larynx from above, we
see two very nearly rectangular-shaped la-
minae, one on each side of the chink of the
glottis, but nothing resembling an isolated
cord. The mucous membrane which lines
the thyro-arytenoid ligaments (to which it
closely adheres), as well as the rest of the
vocal tube, must be considered as forming a
part of the weight of the vibrating surface
upon which the air acts ; the thyro-arytenoid
ligaments confer on this membrane the re-
quisite tension and resistance during vocaliza-
tion, and it is this membrane which gives the
sides of the glottis their laminated figure.
The vocal ligaments, with their lining mem-
brane, are stretched by the thyro-cricoid
muscles, not all round like a drum, but in
one direction only, namely, in that of their
length, being attached on three sides, leaving
one only free to vibrate. The vocal cords
are, as has been seen, rectangular-shaped
membranes, and from experiments made on
the larynx after death by Ferrein, Muller,
and others (which the author has repeatedly
verified), are found to vibrate like cylindrical
cords ; we will therefore apply to the former
the well-known formulae which regulate the
vibrations of the latter.

In cords composed of the same material,

* Mayo, Outlines of Physiology, p. 991.

t M (: moires de l’Academie. 1741. p. 400.

J Cambridge Philosophical Transactions, vol. iv.

§ Precis Elem. de Phys. tom. i. p. 398.

and of uniform thickness, the time of a com-
plete musical vibration, or double oscillation, is

where l is the length of the cord, p its weight,
P the force with which it is stretched, and
g— 1 bTl7 feet.

In order to apply this formula to the vocal
ligaments, let a be their depth, b their breadth.

Fig. 893.

The apparatus employed for mailing experiments on
the Human Larynx. (After Mtiller.)

N, shaft or column for the attachment of the larynx ,
f the forceps for compressing the larynx late
rally ; u, the bellows pipe ; v, the manometer con-
nected with the tube u, for estimating the tension
of the air used in the experiments. M, o, columns
for the attachments of the pulleys x1 and if ; .r,
a line by means of which the vocal cords are ex-
tended in the direction of their length ; it passes
over the pulley x' ; y, a line passing over the
pulley y', by means of which the vocal cords may
be relaxed and reduced to their minimum length,
thus performing the office of the crico-thyroid
muscle ; z, a line by means of which the vocal
cords may be extended by drawing them down-
wards and forwards.

VOICE.

1179

and $ their specific gravity ; then p will be
equal to ablS, and equation (1.) becomes

‘=2V

abS
2s P

- (20

and the number of such vibrations in 1" will be

N=

'/2g\>

2 1'J abS

- - (3)

We observe, in the first place, that if all
other things remain the same, the number of
vibrations varies inversely as the length of
the cord ; hence, if the vocal ligaments were
divided by nodes into n ventral segments,
each segment might be considered a separate
vibrating ligament, whose length would be
•jtb of the vocal cord, and consequently the
number of its vibrations in a given time would
be n times as many as that of the whole cord.

Owing to the elasticity of the thyro-aryte-
noid ligaments, their lengths, when in a state
of repose, differ considerably from those which
they present under the greatest tension. They

differ also in the two sexes. In a series of
experiments by Muller, the differences of
length were observed to be as represented in
the following table, the figures of which are
in inches and decimals of an inch. From these
experiments it appears that the lengths of the
male and female vocal cords in repose are
nearly as 7 to 5, and in tension as 3 to 2. In
boys at the age of fourteen, the length is to
that of females after puberty as 6‘25 to 7, so
that the pitch of the voice is nearly the same.
These experiments afford an idea, although an
imperfect one, of the elasticity of the vocal
ligaments. It has always been a subject of
surprise, if the thyroarytenoid ligaments obey
the laws of strings, how such short and narrow
laminae should produce such very grave tones
as many bass singers are capable of uttering ;
and this struck M. Biot as one of the circum-
stances which in his opinion prove their mode
of vibration to be unlike that of strings. He
asks, “ Ou pourroit-on trouver la place ne-
cessaire pour donner a cette corde la longueur
qu’exigent les sons les plus graves ?”

Subjects of Experiment.

Number of Experiments-

1.

2.

3.

4.

5.

6.

Male in a state of re- j

pose - - - J

0-7087

0-63

0-63

0-83

0-748

0-748

Male in the state of j
greatest tension - J

0-83

0-83

0-984

1-0236

0-9055

0-9055

Female in a state ofl
repose - - J

0-47244

0-47244

0-551

Bov of 14 in repose.

6*414

Female in the state of!
greatest tension - J

0-63

0-59

0-63

Boy of 14 grea

0*571

test tension.

Mean length in male -

In repose.
0-72834

Greatest tensi
0*912070

on.

Mean length in female

0-4986S

0-61679

The author is acquainted with some bass
singers who can produce the note C which
results from sixty- four musical vibrations.
Let us now investigate this phenomenon more
closely, and endeavour to explain how such
grave tones are produced by such extremely
short membranes. Muller has contrived
several ingenious pieces of mechanism, seen in
figs. 891, 892, and 893, by means of which
he was enabled to estimate the amount of
tension, lateral compression, and atmospheric
pressure on the vocal cords, during the pro-
duction of sound. In order to find the
variations in the amount of condensation of
air in the vocal organs in the production of
sounds differing in pitch and intensity, the
apparatus was furnished with a manometer
{fig- 893, v). From that portion of the ex-
periment which was confined to the investiga-
tion of the effects produced by tension of the

vocal, compared with that of musical cords,
he obtained results which are recorded in the
following table.

Number

ofExperi-

Weights employed.

ments.

4 loths.*

16 loths.

61 loths.

i

c

A'

G"-u

2

C ft

B1

A2 It , A2

3

G'tt

C2Jt

C3

4

A1

D2

C3

5

Alt

F‘ff

G2

C

Alt

G'Jt

G3

7

D'

C2

A2

8

DU

B1

A2

9

G

G1

f G2 both octaves
\ imperfect.

* A loth = 225-5531 grs. English.

5 b 4

14S0

VOICE.

In the above table C1 answers to 256 vibra-
tions. Muller states that the numbers of vibra-
tions in these experiments are not exactly in the
direct ratio of the square roots of the stretch-
ing forces, and that the weights 4, 16, 64, did
not produce the octaves, but generally from a
semitone to two or three tones lower. Now
this result should have been anticipated ; but
it does not seem to have occurred to him that
whilst he increased the tension he at the
same time increased the length, and we know
(eq. 3.) that the number of vibrations in this

v tension ,

case varies as and conse-

■v/length of cord

quently the numbers actually produced by the
weights above mentioned ought (agreeably to
Muller’s experiments) to be less than those
which correspond with octaves. We see by
the first experiment in the above table that
the tension sufficient to produce 818 musical
vibrations is 64 loths, or very nearly 33 ozs.
If, therefore, we take the mean length of the
vocal ligaments under the greatest tension at
•91 of an inch, and substitute in equation (3.)
their values for all known quantities, remem-
bering that P represents the tension of one
vocal cord, we shall find the weight of each
ligament, viz.

ablS — ^IL=],144 grs. - (4.)

In an adult male I found that the two vocal
ligaments, when divested of mucous mem-
brane, weigh one grain, which is scarcely one-
half their weight by theory; hence it appears
that a considerable portion of mucous mem-
brane is connected with the vocal cord in the
production of sound, which agrees with the
anatomy of these parts.

It is now necessary to offer some explana-
tion respecting the vital state of the vocal
ligaments. The state of repose is the ordi-
nary condition of the vocal ligament in the
living subject, when the voice is not exercised ;
but we must not therefore conclude it to be
incapable of further contraction. In fact, the
state of repose during life is a state of tension,
for the ligaments being connected with the
thyro-arytenoid muscles, not in a few points,
but continuously throughout their whole
length, must obey the motion of these muscles,
which, like all other muscles, are in a state of
tension during repose. We also know by
experience that when we produce a sound
lower than the usual pitch of our voice, the
crico-thyroid chink is opened principally by
the contraction of the same muscles, and the
ligaments must therefore at the same time lie
relaxed. It appears, then, both from the
anatomy and physiology of the human larynx,
that the ordinary state of the vocal cords is
one of considerable tension, which admits of
being lessened, and thereby produces the range
of lower notes. If we suppose the glottis
to be partially closed when we are talking,
that is, at the ordinary pitch of our voice,
and to be more opened as the tones become
graver, this of course will co-operate with

the relaxation of the vocal cords. In the
production of the higher notes, the crico-
thyroid chink closes, and the thyro-arytenoid
muscles, and consequently the ligaments, are
elongated. Since, therefore, the vocal liga-
ments have been proved to extend and con-
tract for acute and grave tones respectively,
and after death vibrate in a great measure
like musical strings, we think it may be
fairly inferred that they likewise obey, to a
certain extent, during life, the laws of the
vibrations of such strings, and that the con-
clusions which we have derived from the
foregoing formulas are not far removed from
the truth. A further confirmation of these
views may be derived from the following con-
siderations. The length of a cord of invariable
weight varies directly as the tension, and in-
versely as the square of the number of vibra-
tions. Now, if we assume the length of the
vocal cord, which gave G2$ under a tension
of 32 loths to be -91 inch, which is the mean
length of the male vocal cord in its greatest
tension, according to the first table, and which
gave the notes A1 C1, under the tension
8 and 2 loths respectively, the corresponding
lengths of that cord, according to the formula,
will be '83 inch and '58 inch*; but '58 inch
is less than the least length in repose in the
table. This result is, however, quite consis-
tent with the theory here proposed ; because
after death the thyro-arytenoid muscle be-
comes of itself elongated, and consequently
the vocal ligament attached to it, and there-
fore the length of the ligament must lie greater
in this state than when it is in that which we
have defined to be the state of repose before
it has lost its vitality.

In experiments made on the larynx by
stretching the vocal ligaments with given
weights, and by forcing a current of air through
the glottis, care must be taken to keep the
organs moist, and of the same temperature
as they possess during life. The amount of
condensation of the air in the vocal tube has
been ascertained by Cagniard De la Tour, and
Muller, the former in the living, and the latter
in the dead subject. In a person who had an
opening in the windpipe after the operation of
tracheotomy, Cagniard De la Tour found that
the tension of the air in the vocal tube, while
blowing the clarionet, was equal to a column of
water of thirty centimetresjn height, and that
to produce a simple vocal sound in the same
person a tension of sixteen centimetres was
necessary. Muller found that he could pro-
duce sound in a larynx artificially by a tension
of 3'4 centimetres; but for very loud sounds
an increased tension was requisite. The dis-
crepancy between the experiments of Cag-
niard De la Tour and Muller may be ascribed
to the circumstance that the one operated on

\/p p

* N varies as I varies as then '91 inch

1 1\*

• length of cord for A1 ; ; — ; — § — , the length

b (818)2 (427/

of the cord for A1 = ‘83 inch ; and the length for
Cl = -58 inch.

^ mtmm***

VOICE.

1481

the living vocal organs, but in a state of dis-
ease, the other on the organs after death.

Variations in the hygrometric and thermo -
metric states of the air exert very powerful
influence on the pitch of the voice ; during
the prevalence of a cold moist state of the
atmosphere, especially in England, the voices
of singers become lower by two or three notes,
and regain their usual pitch when the air be-
comes dry.* In thus tracing out the analogy be-
tween the laws of stretched cords and those of
the vocal ligaments, it is not intended that those
ligaments should be considered as stringed
instruments, but only that this analogy is
accurate as far as relates to the velocity with
which an impulse is propagated along them.
Dodart f supposed the tension of the vocal
cords to be merely subservient to an altera-
tion in the size of the aperture of the glottis,
and that the difference of ^ of a fibre of silk,
or 3!^ of a hair in the dimensions of that
aperture, was sufficient to alter the pitch of
the voice ; but this has been so completely
refuted by more recent physiologists, and is
so directly at variance with acoustic prin-
ciples, that we need not give illustrations of
its fallacy. M. Savart considered that the
action of the air in its passage through
the ventricles of the larynx, between the su-
perior and inferior ligaments, is really the
source of sound, and analogous to the me-
chanism of the bird-call or dog-whistle. J
There is certainly a great resemblance in the
structure of that instrument to the space
above mentioned in many of the higher ani-
mals, which might easily have led to this in-
genious hypothesis ; but, as we find neither
superior ligaments nor ventricles of Morgagni
in many of the order Ruminantia, in which
the voice is very sonorous, this theory (as
Muller remarks) is untenable.

We next come to the consideration of the
alleged analogy between the action of the
vocal ligaments and that of the reeds of mu-
sical instruments. This opinion is maintained
by MM. Biot, (Jagniard De la Tour, Majendie,
Malgaigne, Muller, and several other distin-
guished scientific men. lt'is opposed prin-
cipally by M. Savart, who observes that the
essential principle of the action of reeds con-
sists in the periodical opening and shutting of
the orifice through which the stream of air
passes, but that this is wanting in the glottis ;
and that were the latter a reed, the edges of
the thyro-ar} tenoid ligaments which form the
sides of the chink would be alternately forced
asunder by the column of air in the larynx, and
brought together by their tension ; whereas
he found by experiment that air blown through

* When Grassini came to this country, owing to
the change from the air of Italy to that of England,
her voice became one octave lower: after singing
for two or three seasons, her natural voice returned,
but it had lost its attractions with the low tones
which had obtained her the greatest applause.
Transactions London Medical Society, New Series,
vol. i. 184(i ; art. Aphonia, p. 36.

t Mem. de l’Acacl. des Sciences, 1700. 1701.

j See fg. 890.

the glottis produced sound although its edges
were from one-sixth to one-fourth of an inch
asunder. M. Savart has however clearly mis-
taken the circumstance wherein the essential
principle of reeds consists, since those of the
clarionet, bassoon, hautboy, &c. do not en-
tirely close the apertures through which the
breath passes ; and this is likewise the case
with the natural reed formed by the lips of
players on the flute and horn. There is in
all probability a double action of the vocal
cords in the production of sound ; the one
being a vibratory motion throughout their
length similar to that of a musical string, and
the otlyer an oscillation like that of a reed,
forming a partial opening and closing of the
glottis. The author is led to adopt this view
of the functions of the vocal organs from
considering that every circumstance which
he has established in his previous investiga-
tion of their action when treated as cords, is
perfectly consistent with the hypothesis of
their vibrating like the tongues of reeds ; for
let us now suppose them to be simply mem-
branous tongues. In this case the axis of
motion is the edge of the ligament attached
to the thyro-arytenoid muscle; the vibrations
take place in a plane perpendicular to the
axis of that muscle, and the length of the
tongue is the breadth of the ligament. The
author has observed in repeated experiments
on the larynx after death, that the chink of
the glottis was partially opened and closed in
the production of sound, and Muller found
that by decreasing the breadth of the liga-
ment he rendered the note more acute ; but
as this breadth is so small, being in its ordi-
nary state in an adult generally less than one-
tenth of an inch, it is extremely difficult to
measure the variations corresponding with
different notes ; and the author cannot learn
that any one has yet succeeded in determin-
ing these varying lengths with sufficient ac-
curacy to form data for the application of the
mathematical formulae of elastic vibrating
tongues.* We know that the number of vi-
brations made by the same tongue in a given
time varies inversely as the square of its
length. If, therefore, a tongue whose length
is only -1 inch give any note, the length ne-
cessary to produce the octave will be '07
inch, that is, the variation will be only '03
inch ; we see then how minute must be the
changes answering to the intermediate notes,
and consequently how much more difficult it
is to determine them in the vocal ligament
when considered as a tongue than as a
stretched membrane or cord. It is moreover
observable that the extension and relaxation

* The formula of Giordano Eiccati is
U _n2D /2pE,

"FV G

where N is the number of vibrations, D the thickness,
and L the length of the tongue or rod, E its rigidity,
G its specific gravity, g the space through which a
body falls by gravity in 1", and n a number ’constant
for each mode of vibration, depending on the num-
ber of nodes.

1482

VOICE.

of the vocal cord, which, as we have seen,
are analogous to those of a musical string,
produce a corresponding shortening and elon-
gation of its axis, regarded as a tongue ; and
lastly, since one tone only is produced at a
time, the vibrations resulting from the double
action which appears to exist in the vocal
apparatus must be synchronous.

We have seen how nearly, when we take
into account the delicacy and difficulty of the
experiments, their results agree with the
theory that the vocal cords are subject to the
same laws as other stretched laminae, and it
would be highly interesting to compare these
results with the simultaneous variations which
they undergo transversely, and thus discover
how far the laws of vibrating elastic tongues
may be applied to them. It might possibly
be objected to the idea of this twofold action,
that the production of sound by the vocal
cords is sufficiently accounted for by suppos-
ing them to vibrate merely as elastic tongues ;
but then it is found by experiment, that by
artificially dividing their length into two ven-
tral segments, there results the octave of the
fundamental note, which proves that at all
events they vibrate as cords. In conclusion,
we must ever bear in mind the vast difference
between natural and artificial mechanism, and
however complicated a problem it may be to
determine that constitution of the vocal ap-
paratus, by which the thyro-arytenoid liga-
ments may simultaneously obey the laws of
cords and tongues, yet to a physiologist who
is accustomed to meet with the most admir-
able contrivances and combinations in the
animal frame, the difficulty of finding a strictly
mathematical solution is, in such a case, no
objection to its truth, when the facts, as far
as they have been observed, are decidedly
favourable to its reality. Were the move-
ments of the glottis independent of any tube
or column of air, the study of the functions
of the vocal organs would be much more
simple ; but we find it situated nearly in the
centre of the vocal tube of which the trachea
and bronchi are the inferior, and the upper
part of the larynx, pharynx, nose and mouth,
the superior portion ; we have therefore to
consider the influence of this tube, and of its
inclosed column of air in the production of
voice.

In order to investigate the mutual relations
between a reed and a pipe, two methods
may be adopted : one of these is to vary the
pitch of the reed while the length of the pipe
remains constant, and the other to vary the
length of the pipe with a reed sounding one
tone only when detached from the tube. In
the construction of reeded pipes for musical
purposes, it is incumbent on the mechanician
to adjust the length of the tube to the pitch
of the reed. When a free reed is used on
the principle of Kratzenstein or Grenie, it is
found that, if the pipe be not in perfect unison
with the reed, the purity of the tone de-
creases within certain limits, as the discord-
ance between the reed and pipe increases.
The researches of MM. Biot, Weber, Willis

and Muller have greatly enlarged our know-
ledge on this subject. We learn from their ex-
periments how great an influence is mutually
exerted between a pipe and its reed, when
the pitch of the one is made to vary while
the other remains constant, and we may con-
clude that analogous effects are produced
between the vocal tube and the glottis. The
slightest knowledge of acoustics is sufficient
to inform us that the pitch of any pipe, such '
as the organ, the flute, the trumpet, in short
of all musical tubes vibrating in a similar
manner, depends on the velocity of an im- j
pulse propagated in the air within, and is ji
determined by the length of the pipe. As j
long as the tubes of musical instruments re- |
main rigid, the nature of the materials which
compose them does not affect the pitch of j
the sound, but merely influences the quality |
of the tone, and it is indifferent whether we [
employ metal, wood, or paper in their con- |
struction ; each of these substances will yield
a tone of a particular timbre, or quality, de- ji
pending on the nature of the motions pro- |
duced among its particles by the friction of j
the air on its surface; but the pitch will be j
the same in each, if the lengths of the pipes j;
be equal, proving that the air itself is the jj
source of sound. When, however, the sides |
of the tube are composed of flexible mem- I
branes, the inclosed air has a vibratory mo- 11
tion, conjointly with, and subordinate to, that ji
of the parietes of the tube, w-hereby the pitch
of the sound is affected, as well as its quality.

M. Savart* found that by taking tubes com- t
posed of layers of paper of constant length, l!
but varying in thickness, graver sounds were
produced as the parietes became thinner, and
that the gravity of the sound was increased j
by moistening and relaxing the sides of the j|
tubes. We shall presently see the application
of these facts to the vocal apparatus.

We find the flexibility of the trachea and ji
bronchi capable of being varied by the opera- j
tion of two forces, the one longitudinal or
parallel to the axis of the tube, the other j!
transverse. The first of these comprises the j
muscles which elevate and depress the larynx;
the latter, the cartilaginous segments of rings ji
perpendicular to the axis of the tube hating jj
muscular fibres attached to their posterior
extremities, the contraction and elongation of
which regulate the diameter of the trachea.
The pharynx, mouth and nasal cavities, which I
form the superior extremity of the vocal tube,
are also provided with muscles to modify the
tension of that part of the tube so that it
may vibrate synchronously with the | rest.
The necessity for this change in the dimen-
sions of the tube, in order that it may vibrate
in unison with the glottis, is in accordance, S
not only with the joint system of pipe and
reed above described, but also with what \
actually takes place in the vocal organs of
living animals. When the voice is raised in
the scale from grave to acute, a corresponding
elevation takes place in the larynx towards

* Annales de Cliemie et de Physique, tom. xxxii.

VOICE.

1483

the base of the cranium. By placing the
finger on the pomum Adami this motion can
be easily felt, and at the same time the thyroid
cartilage is drawn up within the os-hyoides,
and presses on the epiglottis; the small space
between the thyroid and cricoid closes, the
pharynx is contracted, the velum palati is de-
pressed and curved forward, and the tonsils
approach each other : the reverse of these
phenomena takes place during the descent of
the voice. These are the principal pheno-
mena common to most mammalia which can
be recognised by external observation ; the
other changes being, on account of their situ-
ation, invisible.

The effects of these variations on the tone
of the voice have been hitherto little under-
stood. It has always appeared incomprehen-
sible why the vocal tube should apparently
increase in length in the production of the
acute tones, and shorten in the grave ; a cir-
cumstance which theoretically presents an
acoustic paradox. Dodart and many others
have conceived the elevation of the larynx to
be merely for the purpose of shortening the
vocal tube in the supra- laryngeal cavity, and
have considered the trachea as producing no
effect on the pitch of the tone. Majendie
has also pointed out the shortening of this
part of the tube. In order to ascertain the
effect of these changes, the following experi-
ments were made on the dead body. Having
laid bare the vocal organs of an adult male,
1 raised the larynx to the position it would
occupy by the elevation of the voice to an
octave, being about half an inch, and at the
same time minutely observed the position of
the lowest ring of the trachea with reference
to the sternum. By this operation I found the
trachea was raised out of the chest, nearly
to the same extent as the larynx had been
elevated towards the base of the skull. The
next step was to examine whether any change
had taken place in the diameter of the tube.
For this purpose, having measured the diame-
ter of the trachea in its natural position, the
larynx was again elevated to the same extent
as before, when the diameter was found
diminished one-third. These experiments
prove that, contrary to the general precon-
ception, the elevation of the larynx shortens
the tube independently of the contraction
between the thyroid cartilage and os-hyoides,
and at the same time lessens its diameter.
The same effects may easily be detected dur-
ing life by placing the finger on the trachea
immediately above the sternum during the
elevation of the larynx, when the trachea is
} found to ascend out of the chest, and after-
wards to return to its former position ; a
movement in which the lungs and bronchi
participate. The alteration of the tube in
diameter may also be perceived by grasping
the trachea with the finger and thumb during
the elevation and depression of the larynx.*
These movements are so striking as to lead

! * Essays by the author, in the London and Edin-

! burgh Philosophical Magazine, for September, Oc-
tober, and November, 1836.

irresistibly to the conclusion, that there exists
a constant -adaptation between the tension
and the vibrating length of the thyro-arytenoid
ligaments and the walls of the vocal tube, in
the production of tones of the ordinary re-
gister ; for we have seen that the variations
of the vocal cords, at least as far as relates
to the modulation of sound, are perfectly in-
dependent of the length of the vocal tube,
and consequently the changes in its length
which we have just described are not at all
necessary for that purpose. Again, the vocal
tube is so short, that, as has been ascertained
by Weber and others, it could not, were it
rigid, affect the pitch of the note produced by
the glottis. As however this tube is com-
posed of flexible materials, its effects are
similar to those observed in M. Savart’s ex-
periments ; that is, the relaxed state of the
parietes compensates for its want of length,
and enables it to vibrate synchronously, and
therefore to give forth sounds equally grave
with those of the glottis, thereby reinforcing
the tone which would indeed be produced,
though with much less intensity, without this
aid.

The Falsetto, or voce di testa, has always been
considered a most embarrassing subject of re-
search, and its peculiar quality has excited the
attention both of the physiologist and of the
musician. Its most remarkable characteristic
consists in its being less reedy in tone, and
partaking nearly of the quality of the har-
monic sounds of stringed and wind instru-
ments. The change produced in the voice
when passing from the falsetto into the com-
mon tone, or the reverse, is in some persons
very sensible to the ear, whilst in others it is
almost imperceptible. Some individuals, more-
over, have the faculty of producing in the same
pitch as many as eight or ten tones, possessing
either the falsetto or the common character.
The falsetto has been generally ascribed to
some particular adaptation of the upper liga-
ments of the larynx. Dodart* has attempted
to prove that it is a supra-laryngeal function,
and that the nose becomes the principal tube
of sound instead of the cavity of the mouth.
Bennati + also considered these tones as being
modulated by the supra-laryngeal cavity alone.
This hypothesis, however, is untenable, since
it supposes the column of air not to be in-
fluenced by the trachea, which is contrary to
experience. In order to detect some of the
movements of the larynx while the voice is
passing from the first to the second, or falsetto
register, it is only necessary to place the point
of the finger in the crico-thyroid chink, when
it is found that at the moment the transition
from the primary to the secondary register
takes place, this chink, which was closed dur-
ing the production of the highest note of the
ordinary register, suddenly opens on the pro-
duction of the first note of the falsetto register,
and consequently the thyro-arytenoid liga-
ments are relaxed at the same moment the

* Mem. de l’Acad. 1707.

f Recherches sur le Me'chanisme de la Yoix
humaine.

!

'I

U84

VOICE.

larynx falls, and the vocal tube is lengthened,
although during these changes the tones become
more acute. As soon as this has taken place,
the larynx again rises as the voice becomes
more acute. In a mezzo-soprano voice en-
dowed with a double falsetto, or third register
consisting of several tones of each register,
with the power of producing tones of the
same pitch either of the ordinary or the fal-
setto quality, we observed that the larynx fell
at the commencement of each register, and
that the thyro-arytenoid ligaments were twice
relaxed, but in a much smaller degree. These
observations have since been verified by many
musical persons.

In order to explain the phenomena as con-
nected with the production of falsetto tones,
we must remember that at the highest note
of the primary register the crico-thyroid mus-
cles are contracted as much as possible in
closing the crico-thyroid chink, and therefore
that no further tension of the vocal cords can
take place. In this state of things, the thyro-
arytenoid muscles are at their maximum of
elongation, and their transverse section is a
minimum; consequently neither can a higher
note be produced by an extension of the liga-
ments, nor are these muscles in a condition to
affect the dimensions of the glottis ; hence the
necessity of some alteration in the state of the
larynx in order to effect the scale of the fal-
setto, which is an octave above the ordinary
register, and to prevent the mere repetition of
the same series of sounds. This alteration
might be produced in two ways ; one of these
is a partial closing of the aperture of the glottis
caused by the action of the thyro-arytenoid
muscles when they have returned to their
ordinary condition, and are in a favourable
state to produce that effect under the influence
of the laryngeal nerves. For, let us suppose
the larynx to be in the same state as at the
commencement of the primary register, except
that the chink of the glottis is half closed ;
the consequence will be that as only half the
length of the ligaments can be made to vibrate,
the octave of the lowest note in that register
will result from the same tension which pro-
duced that note, and this will manifestly be
repeated in consecutive notes of the range of
the falsetto. This range is limited in general
to a few notes, owing probably to the chink
being soon completely closed by the stretching
of the vocal cords. It is also owing to this
partial closing of the glottis that a much less
quantity of air is required for the falsetto than
for the ordinary scale, which is proved by our
being able to sustain a given note in the fal-
setto to a much longer time than we can sus-
tain the corresponding note in the primary
register. The partial closing of the glottis was
observed by Majendie in his experiments on
the dog, and by Mayo in the human subject.
Another explanation was suggested by Gott-
fried Weber, namely, that the falsetto range
is caused by a nodal division of the vocal cords
producing harmonics of the fundamental notes,
by which means the glottis acquires the same
pitch as if it were half closed. If we consider

the glottis as a reed, it is evident that since
the number of vibrations must in this case be
the same for the same note as when we sup-
pose the ligaments to obey the laws of cords,
the axis of vibration or the breadth of the liga-
ment must be duly diminished, which may be
brought about by the rotation of the thyro-
arytenoid muscle on its axis.

Having thus considered how the glottis rnay '
act in the falsetto range, let us now examine
in what way the vocal tube contributes to its
formation. We have seen that this tube gra- j
dually shortens during the ascent of the pri-
mary register, suddenly falls to its original
length when the falsetto commences, and again
diminishes during the secondary register. Now
it appears from Savart’s experiments that,
notwithstanding the shortness of this tube,
the wave length of a column of air vibrating !
within it is the same as that of a rigid pipe of
much greater length, and we have therefore
strong grounds for believing that the notes of
the primary register are reinforced in con-
sequence of the vibrations of the glottis being
always in unison with the fundamental pitch
of the walls of the tube ; hence in the falsetto,
when the vocal apparatus has resumed its
original condition, there will be less reinforce-
ment of the sound, since the parietes of the
vocal pipe are no longer in unison with the
glottis, but give its grave octaves. We have
found, by numerous experiments, that a flex-
ible disc will vibrate to almost any pitch, but
will reinforce the sound in a trifling degree
only, unless the pitch be in unison with its
fundamental note ; and on the same principle
we may suppose the intensity of the notes in
the second register to be diminished, and their
quality to be modified by the forced vibration
of the walls of the tube, while in the primary
all things concur in augmenting the effects
produced by the glottis. Muller agrees with
Lehfeldt in opinion, that the falsetto notes are
produced by the vibrations of the inner por-
tion of the borders of the vocal ligaments, and
the variation of the pitch by their tension ;
and, although he does not mention by what
mechanism this is effected, he seems to attri-
bute it chiefly to the agency of the thyro-
arytenoid muscles. The author’s explanation
is in many points coincident with that of
Muller, but he has taken into account one or
two circumstances which appear to have
escaped Muller’s attention. The natural key
or pitch of the vocal organs may be found by
sounding the voice, without either elevating
or depressing the larynx. The grave octave
of that note will be the fundamental sound
of the vocal ligaments vibrating in their most
relaxed state, with the glottis entirely open.
Any tones of a graver pitch, produced by an
unusually relaxed state of the vocal cords, lose
both their quality and intensity, and cannot
be included in the compass natural to the
voice. According to the preceding principles,
the pitch of the voice being usually an octave,
or a fifth graver than the length of a column
of air within the vocal pipe, we see the cause
why a falsetto quality of sound cannot be

VOICE.

1485

obtained except during the production of acute
tones. In many persons the speaking pitch is
an entire octave graver than corresponds to
the length of a tube, which would enable a
column of air to produce the same sound ;
and in such persons the falsetto can seldom
be effected. In consequence of the pitch of
the vocal organs thus occupying a middle or
central position between the acute and grave
notes, a great facility is afforded to their action
in modulating the voice. The vocal tube,
like any other tube open at both ends, is said
to be capable of producing the harmonics of
its fundamental tone in the ratio of the series
of natural numbers, 1, 2, 3, 4. These harmonic
sounds have been described by Knecht of
Leipsic, and by Dr. Young. I have occasion-
ally thought that I have heard them during
the forcible expiration which attends the bois-
terous laughter of children. The density of
the air inspired is said to affect the pitch of
the voice as in rigid tubes.

The influence of the epiglottis on the voice
has been the subject of divers hypotheses.
MM. Biot, Majendie, and Mayo have inferred,
from the experiments of Grenie, that the epi-
glottis prevents the tones from becoming more
acute when they increase in intensity. Lis-
covius, on the other hand, states that neither
its depression, elevation, nor even its entire
removal has any effect on the voice. * Haller
appears to have deduced the same opinion
from the circumstance of birds being destitute
of this organ. “ Epiglottis equidem nihil facit
ad vocem, cum ea (vox) nata sit et perfecta
quamprimum aer ex glottidis rirna prodit, et
absque epiglottide aves suavissime canant.”f
According to Muller, the influence of this
organ on the pitch of the voice is exercised
during its depression only, rendering the tones
graver, and at the same time duller. He thinks
we evidently employ it in this way during the
production of very deep tones ; and observes

that, by introducing the finger at the side of
the mouth, the epiglottis will be found to
maintain the same position during the utter-
ance of musical notes, whether they be of the
falsetto character, or of the ordinary scale. I
am disposed to ascribe to the functions of the
epiglottis much the same value as Muller ;
since it is clear that its presence is not essen-
tial to the mere formation of voice, for it may be
removed, together with the superior ligaments
of the glottis, the ventricles of the larynx, and
the capitula laryngis of Santorini, without im-
peding the vibratory movements of the glottis.

The art of singing consists in the applica-
tion of the vocal organs to produce a certain
succession of tones in some determinate order,
which constitutes melody. This can be ac-
complished with precision by those only who
can accurately discern with the ear, and imi-
tate with the voice, the variations of the pitch
of a musical instrument, or other sounding body'.
In many persons the perception of sound is
defective; so that, whatever may be the purity
and intensity of their notes as single uncon-
nected musical sounds, they can never be
used for musical purposes, that is, for sounds
succeeding each other at regular intervals,
governed by fixed rules. Many persons can
imitate the voices of birds and beasts, and
diversify the character of their tones to an in-
definite extent. These performances illustrate
the perfection of the human voice, but the
artifices by which they are effected have no
reference to the subject under investigation.
The musical varieties of the human voice are
classed according to their pi'ch, or the middle
note of their primary register, which depends
on the dimensions and physical constitution
of the vocal ligaments. These varieties are,
the Bass, the Tenor, the Contralto, and the
Soprano * ; the usual compass of each kind
in the adult is represented in the annexed
table.

[ I

| Contralto. | Soprano. |

C D E F G A B C' D1 E' F< G' A' B' C 2 D2 E2 F2 G5 A2 B2 C3 D3 E3 F3 G3 A3 B3 C3

I BaSS~ I ! Tenor. I

In addition to these characteristic and prin-
cipal divisions of the voice, there are certain
others, called the Baritone, the Mezzo-soprano,
and the Soprano-sfogato, which are subdivisions
of the foregoing, and the place of either of
which in the scale is indicated by its name.
We see by this table what an extensive variety
of harmonious sounds may be produced by the
combinations of the different kinds of voice.
In ordinary singers the range seldom exceeds
two octaves, except in those endowed with a
falsetto. There have been some celebrated
singers, such as Catalani, Malibran, and others,
whose compass has even exceeded three
octaves, but such instances are rare. The

* Theorie der Stimme. Leips. 1814.

t Physiology, lib. ix. p. 372.

voices in both male and female are nearly of
the same pitch until the age of puberty, at
which period the voice of males sinks an
octave. This change of pitch is owing to a
sudden enlargement of the larynx, the antero-
posterior diameter of which is augmented by
from one-fourth to one-third, with a simul-
taneous lengthening of the vocal ligaments.
During this process the voice is hoarse, and
there is a temporary inability to regulate it.
Eunuchs do not undergo this change. Ben-
nati is of opinion that the voice should not be

* The first two of these belong to the male sex,
and the last two to the female. In this table C is
the pitch of the 8-feet, organ pipe, or the funda-
mental of the fourth string of the violoncello ; the
ciphers denote the octaves, that is, C1, C2, &c. are
the first and second octave of C.

1486 VOICE.

exercised at this time of life, and in support
of his views he cited the cases of Donzelli
and Donizetti, of whom the latter lost his
voice by singing, whilst the former retained it
by abstaining from singrng at that period.
There are, however, many examples of per-
sons possessing fine voices, who never paid
the least attention to this rule.

The oral, nasal, and pharyngeal cavities
exercise an important influence on the quality
of sounds after their production by the larynx.
Further effects are ascribed by Bennati to
the arches of the palate, the uvula, and velum,
all of which appear to contract with the acute,
and relax with the grave tones, and are in
constant motion during the modulation of the
voice. The contraction of these parts during
the production of acute sounds has also been
observed by Fabricius ab Aquapendente,
Meyer, Gerdy , and Dzondi. Bennati con-
ceived, as has been already mentioned, that
the falsetto notes, which he calls notes “ sur-
laryngiennes,” are produced exclusively in the
superior part of the vocal tube ; but it has
been shown that this hypothesis is contrary to
acoustic principles, and that the same motions
of the palate are also equally observable during
the production of acute tones of the ordinary
register. Muller also states that the arches of
the palate may be touched by the finger with-
out a]tering the pitch, which could not be the
case on the hypothesis of Bennati. It is to
be remarked that neither Muller nor Bennati
mentions the opening of the crico-thyroid chink
on sounding the first note in the falsetto re-
gister ; neither do they mention the simul-
taneous falling of the larynx, and they deny
the existence of a third register. According
to the hypothesis of Lehfeldt and Muller, any
increased intensity of vocal sound ought to
raise the pitch of the voice ; but if this were
the case, the performance of prolonged vocal
sounds on the same note, but of variable in-
tensity, would be rendered impossible without
a simultaneous adjustment between the tension
of the vocal ligaments and the current of air ;
whereas, by examining the state of the crico-
thyroid chink during the utterance of these
sounds, it is found that no such adjustment
takes place. The exquisite quality of the
sounds of the larynx, when modified by the
oral and nasal cavities, renders the human
voice far superior to any artificial musical in-
strument ; since its tones glide through all
the en-harmonic intervals between successive
notes, an effect which no such instrument can
perfectly imitate. Dodart estimates the num-
ber of tones which can be produced by the
voice and appreciated by the ear in the com-
pass of an octave, at three hundred : a striking
proof of the complete control exercised by
the laryngeal nerves over the vocal apparatus.

The action of the vocal organs in producing
speech is a distinct branch of the physiology
of voice, which the author has elsewhere in-
vestigated.* It is well known that the vowel
sounds have been imitated by Krat/en stein,

* Vide “ On Articulate Sounds, and on the Causes
and Cure of Impediments of Speech. London. 1851.”

De Kempelen, and Willis, by means of me-
chanism, and that the principles on which
they depend have been successfully analysed
by the latter : but this is a subject which
would require a very lengthened examination
to render it the justice which its importance
demands.

Having now completed the investigation of
the physiological character of the human
organs of voice, and having for the sake of
simplicity considered them in three distinct
lights, namely, as membranous ligaments obey-
ing the laws of musical strings, as a reeded
instrument, and as a membranous pipe with
a column of air vibrating within it, the results
of the various experiments which have been
noticed would certainly seem to warrant the
conclusion that each of these views is cor-
rect ; for it cannot be denied that these ex-
periments clearly show the vocal apparatus to
be influenced by the air expelled from the
chest in precisely the same way as if it were
a stretched cord, a reed, or a vibrating tube.
Why then should we hesitate to adopt the J
obvious conclusion that the vocal organs do in
fact combine the properties of these various
instruments, and are themselves the perfect
types of which these instruments are only im-
perfect imitations ? The error of those who j
have preceded the author in this inquiry
seems to consist in viewing the organs of
voice, not as a complex, but as a simple ap-
paratus; with some the favourite hypothesis (
has accordingly been that of musical strings,
with others that of a reed, while experiments
are equally in favour of both.

It cannot be expected that in this brief jj
treatise, a subject, wherein, notwithstanding
the attention hitherto bestowed on it for many
years by men of the highest philosophical I
talent, so little comparatively has been effected,
should be at once exhausted, and all its diffi-
culties removed ; hut the inductive method,
the only satisfactory mode of reasoning on
such subjects, has been most scrupulously j
pursued; and whatever explanations have been t
offered of the phenomena of the voice are at
least founded on facts which are inconiro- j
vertibly established.

Comparative Anatomy and Physiology j|
of the Organs of Voice. — Having given
an outline of the structure and functions of
the vocal organs in man, and stated our
views of the principles on which the produc-
tion of voice depends, we shall now proceed to
the investigation of the physiology of voice in
the lower animals.

Mammalia. — In the various orders of mam-
malia the organs of voice present different 1
grades of development and complexity of
structure, producing in each case some pecu-
liarity of timbre, or quality of tone, by which
we are enabled to distinguish them from one
another. Some species are mute, such as the
giraffe, armadillo, and others, whilst some jj
possess voices of greater or less intensity.

The organs of voice in the lower mammalia,
as well as in man, are composed of lungs, which,
considered in an acoustic point of view, act : j

VOICE.

1487

merely as bellows, the trachea or pipe, and
the larynx* * * § or reed. The nervous and mus-
cular systems are similar to those of man, and
do not require to be treated in detail. The
acoustic principles of the first section will
generally be applicable to the lower orders of
Mammalia, so that when the structure is given
the functions will be understood.

In the account of the anatomy of the vocal
organs given by Cuvier, Vicq d’Azyr, Brandt,
Wolff, Henle, and others, no estimate is made
of the relative dimensions of the larynx in the
various classes of animals ; therefore, in order
that the reader may form an idea of their
magnitude in Mammalia, compared with that of
man, f it will only be necessary, in those which
have a similarity of figure, to give the linear
value of one of their dimensions, namely, that
of the mean height of the superior margin of
the thyroid, above the plane of the base of the
cricoid, since their respective magnitudes will
be as the cubes of those heights. J Also the
lengths of the inferior thyro-arytenoid liga-
ments, when devoid of tension, are given. The
letters H and L will be used to represent the
heights and lengths respectively.

Quadrumana. — The vocal organs of the
Quadrumana have already engaged the atten-
tion of several distinguished anatomists, such
as Vicq d’Azyr, Camper, Hunter, Cuvier,
Brandt, and others ; and a condensed view of
this part of the subject will be now given.

Chimpanzee. — Os hyoides : base concave,
where a sac b {fig. 894) is lodged. Larynx, H.
08 in. Thyroid : margins, superior and in-
ferior, nearly parallel. Cornua short ; supe-
rior inclined upwards and backwards, inferior
inclined downwards and forwards. Cricoid
elliptical : margins, superior triangular, notch
in front; inferior parallel to the first ring of
the trachea, except in front, where it is de-
pressed. Arytenoids small. Cuneiform curved,
and in contact with the anterior margin of
the arytenoids. Cart. Santorini — inferior
thyro-arytenoid ligaments prominent. L.
0'5 in. to O'G in., superior thyro-arytenoid
ligament not prominent. Ventricles of Mor-
gagni oval, deep, leading to sac {a, a), lying
between the epiglottis and arytenoid carti-
lage ; right sac anterior to the left, convo-
luted, terminating in the concavity of os hy-
oides (c). Epiglottis : apex obtuse, trachea
16 rings. Voice more acute than in women ;
quality inferior: cause, sacculated larynx, &c.*

* In the following description, the axis of the
vocal tube is supposed to be perpendicular to the
horizon, and not parallel or oblique, as is generally
the case in the living animal.

t In man, we may assume the mean of H=
T5 in. and L=0-72834.

J In most Mammalia the figures of the larynges
are similar; but in some orders they are dissimilar.
For instance, in the Cervus, amongst the Ruminantia,
the thyroid bulges out considerably in front, and in
the Sus scrof a, amongst the Pachydermata, it is ex-
tremely narrow. In the Cetacea the whole larynx
differs from those of all the other orders.

§ These measures relate to an animal not quite
full grown, and are rather too small for an adult
chimpanzee.

Orang-outang. — - Larynx : volume equal to
chimpanzee. Thyroid : wings united at an
obtuse angle : margins, superior notched in
mesial line. Cornua short. Cricoid ellipti-
cal : margins, superior and inferior, depressed
in front ; the latter connected with the first
ring of the trachea. Crico-thyroid chink
large. Arytenoids small. Cuneiform large
and curved. Cart. Santorini : vocal ligaments,

Fig. 894.

Lateral vieiv of the Larynx of the Chimpanzee,
a, a, sac connected with the lateral ventricles ; b,

os hyoides ; c, sac protruding at the base of os

hyoides; d, thyroid ; e, trachea ; f cricoid.

inferior prominent ; L. less than in woman.
Ventricles oval, furnished with a canal pene-
trating the thyro-hyoid membrane. Sacs
large, lie on each side the larynx. Ventricles
valvular, rendering the inflation of the sacs
under the control of the animal. Epiglottis
broad, apex obtuse.*

Gibbotis. — Os hyoides : base not excavated.
Larynx, volume nearly equal that in orang;
ventricles deep, communicating with a sac in
Hylobates agilis, which lies in front on the
thyro-hyoid membrane. Voice acute. Cry,
bow wow.

Monkeys of the old continent. — Os hyoides :
base excavated {fig. 895, b). Sim. Hamadryas,
larynx destitute of sac.f Larynges perfo-
rated, sacs in the thyro-hyoid space. S. cyno-
cephalus, S.mona, S.cercopithecus(y?g.895,A),
S. Malbrouch, S./Ethiops, S. rubra, S. Veter j,

* According to Camper, the laryngeal sacs in the
orangs disqualify them from applying the vocal
organs to the use of articulate language ; but this
hypothesis is rmtenable, because language is in-
dependent of the quality, intensity, or pitch of the
laiyngeal sounds.

f Cuvier states that 5. Patras has no sac or
aperture in the larynx ; this is, however, an error.

J Cuvier.

14-88

VOICE.

and S. Inuus *, two sacs. Laryngeal aperture
situated at the base of the epiglottis, oval or
circular. Voice acute ; quality hoarse : cause,
laryngeal sacs.

Fig. 805.

A

Larynx of 8. Cercopithecus.

A. a, epiglottis ; b, os liyoides ; c, sac ; e, trachea.
b. f cavity of the os liyoides.

Albino Baboon. — Os hyoides : base, b

(Jig- 896.) excavated, inclosing a sac, c;.
Larynx: H. '75 in.; Thyroid: upper margin
concave, lower irregular ; Cricoid : a vertical

Fig. 896.

Larynx of an Albino Baboon,
b, section of the os hyoides, showing the inclosed
sac c ; d, thyroid ; f, crico-thyroid space ; e, trachea.

ridge rising from the posterior surface, the
cartilage tapering towards the anterior surface
* Ludwig.

which is very narrow; Crico-thyroid space:
large ; Epiglottis : apex obtuse.

in the monkeys of America, some species
have sacs appended to the larynx, the most
complicated form of which is observed in

Simla Seniculus, or Bed 'Howling Monkey. —
Os hyoides, base excavated ; opening quad-
rangular. Thyroid, volume three times that
of man * Cricoid elliptical, nearly osseous.
Pomum large and excavated, into which pris-
matico-oval sacs open ; sacs also communi-
cating with the larynx by a semilunar open-
ing at the base of the epiglottis. Arytenoids
small. Cuneiform absent ; instead of them,
prominence. f Vocal ligaments: superior im-
bedded in tendino -cartilaginous masses J ; in-
ferior inserted at base of pomum. Ventricles
passing on each side of epiglottis, which is
connected with an infundibuliform sac, po-
mum, and oval pharyngo-laryngeal sacs, (i
Voice intense ; howl discordant.

S. Appella and S. Capucina. — Os hyoides
not excavated. Thyroid, cricoid, and aryte-
noid, like man. Cart. Santorini large, and
curved backwards. Cuneiform absent ; their
place supplied by fatty tendino-cartilaginous
masses meeting each other to form a channel
for the passage of air: in shape like the letter
S. || Voice: quality like a Hute, hence called
Whistling Apes ; expression, a plaintive me-
lody, from which they are also called Weeping I
Apes.

S. Bosalia. Larynx perforated at the
thyro-cricoid ligament, below the thyro-aryte-
noid ligament ; aperture circular, sac small.

8. Coaita. Larynx like the Sapajous. Tra-
chea dilated behind the cricoid cartilage.

S. Ateles arachnoides. — Os hyoides : base j
quadrangular, excavated. Larynx: cartilages
of Santorini with masses substituted for cunei-
form cartilage. Vocal ligaments : superior
give rise to the cuneiform masses ; inferior
lie over the superior IT at their insertion.**
Epiglottis : apex notched and connected with
the cuneiform fibro-cartilaginous masses.
Voice acute ; quality hoarse ; melody, a
plaintive cry.

Lemur. L. gracilis. — Os hyoides : base
not excavated. Larynx : no sac. H. 0'33 in.
Thyroid : wings united at an obtuse angle ;
margins, superior oblique, inferior parallel to
superior. Cricoid elliptical ; margins, supe-
rior and inferior depressed. Crico-thyroid:
chink large, rhomboidal. Epiglottis rounded;
at its base a pit. L. O' 1 33 in.

L. tardigradus. Cornua elongated and
united with first ring of trachea.ff In Lem.
Mongoz and L. Catta are processes running
from the epiglottis to os hyoides. Voice in
Mongoz, a peevish kind of cry when irritated.

Cheiroptera. Phyllostoma Spectrum. — Os
hyoides like that of Lemurs. Laiynx : II.
0'5 in. Thyroid like the Lemurs; notch, su-
perior absent; prominence small; margins, J

* Brandt. f Ibid. J Ibid.

§ Humboldt describes six laryngeal sacs. Cam-
per one. Yicq. d’Azyr, Cuvier, and Brandt more
than one.

|| Cuvier. Brandt. If Cuvier.

** Brandt. ft Ibid.

VOICE.

1489

inferior a notch ascending to middle of carti-
lage. Cricoid like that of Lemurs ; margins,
a notch in front, and a foramen on the right

Fig. 897.

Larynx of S. JEth'wps.

d, tongue ; b, epiglottis ; c, opening to sac ; e,
superior vocal cords ; f inferior vocal cords ; a,
ventricles of Morgagni ; g, a vertical furrow ;
h, trachea.

side. Arytenoids as in L. Mongoz. Cuneiform
cart, absent. Sesamoid oblong b (Jig. 898).
C. ol Santorini triangular. Interarticular cart.

Fig. 898.

Posterior view of the Larynx of the Phyllostoma
Spectrum.

a, epiglottis ; b, sesamoid ; d, junction of the
cart, of Santorini ; f interarticular cart. ; g,
raised margins of cricoid cart. ; c, surface of cri-
coid ; e, trachea.

size of a millet seed, oblong (/). Vocal liga-
ments : superior not prominent ; inferior nar-

VOL. IV.

row. * L. 0,m2 in. Ventricles short. Epi-
glottisf rounded, with pointed projection on
each side. Voice very acute, with a plaintive
cry. Trachea 34 rings.

Insectivora. Erinaceus Europceus. — La-
rynx : H. 0‘45 in. Thyroid : wings united in a
short point. Cricoid a posterior vertical fur-
row c (Jig. 899). Crico-thyroid : chink triangu-
lar. Epiglottis s apex acute ; base divided by
a fissure into two lobes, into which the vocal
ligaments are inserted. Cart, of Santorini in-
clined forwards, having the interarticular cart. |
between them b. Vocal ligaments : infe-
rior strong. L. 0T76. Ventricles deep,
leading to a sac$ situated between the epi-
glottis and os hyoides. Voice generally mute.

Fig. 899.

Larynx of Erinacea Europeea.
a, epiglottis ; b, prominences of cartilages of San-
torini ; f interarticular cartilage ; c, furrow of
cricoid cart.

Carnivora. Ursus Malayanus. Larynx :
H. 1'55. Thyroid: wings unite at an obtuse
angle; tubercle in mesial plane a (Jig- 900), to
which the epiglottis is attached ; margins,
superior ascending upwards, inferior ex-
cavated in front as far as the tubercles b
(Jig. 900). Cornua : superior short ; inferior
very long. Cricoid ; superior margin inclined
upwards, with a notch in front, by which the
body is nearly cut through ; inferior con-
cave in front ; lateral parietes held together
by a transverse ligament. Arytenoids rhom-
boidal, between which are the sesamoids, d d,
furnished with small muscles to approximate
them. Cart. Cuneiform and C. Santorini pre-
sent. || Epiglottis broad ; apex obtuse. Vo-
cal ligaments : inferior inclined upwards to
the place of the superior, separated by a
transverse groove. L. 0’833, or nearly equal
those of man.

Ursus Arctos. See Wolff.

Syriac Bear. See Brandt.

Viverra Kasua. — Thyroid : wings united
at an obtuse angle. Cricoid semitransparent.

* Vicq. d’Azyr states that the vocal ligaments
are absent, but this is denied by Brandt.

f He is also in error in stating that the epiglottis
is absent in the common bat.

J Brandt thinks that the interarticular cart, of
Mammalia is represented by the Cricoid of Birds ;
but, as Henle observes, there seems to be little
foundation for this opinion.

§ Wolff.

|| These cartilages have been confounded with
each other by Cuvier and Wolff.

5 c

1490

VOICE.

Epiglottis broad. L. 0 375 in. Voice more
acute than in woman.

Meles Europcea. — Thyroid: margins notched
in front. Crico-thyroid chink triangular. Ary-

Fig. 900.

Anterior view of the Larynx of Ursus Malayanus.
a, tubercle ; b, notch of thyroid cart. ; c, notch of
cricoid cart.

Showing the Sesamoid Cart, d d, of Ursus Ma-
layanus.

tenoids small. Epiglottis triangular. Ven-
tricles deep, leading to two sacs, one of which
lies under the root of the tongue, the other
between the thyroid and cricoid cartilages.*

Musle/a Furo. See Wolff. Ventricles lead
to sacs.

Lutra Vulgaris. — Thyroid : superior and in-
ferior margins parallel and inclined upwards,
superior terminating in a round apex, in-
ferior hollowed out in front b {Jig. 901.), and
protuberant ; Cricoid, (c) inferior margin, so
widely separated in front, as only to be slightly
united at the inferior margin of the thyroid.

* Cuvier was of opinion that the posterior part of
the vocal ligaments produced the vocal sounds.

Epiglottis, oval but not large. Cart, of San-
torini absent.

Fig 901.

a

Oblique view of the Larynx of Lutra Vulgaris,
a, epiglottis ; b, thyroid ; c, c, cricoid.

Cards familiaris. Thyroid : margins inclined
upwards ; wings unite at an obtuse angle.
Cornua: superior furnished with a transverse
ligament running to the thyroid as in the
hyaena. Cricoid : superior margin depressed in
front. Arytenoids curved, and inclined from
each other. Cart. Santorini and C. Cuneiform
present. Ventricles deep. Epiglottis trian-
gular, having a vertical furrow at its base. L.
(and consequently the pitch of the voice)
varies in almost every species; modulation
expressive of emotion.

Felts Leo. — Larynx : II. 3’ 14 in. Thyroid :
margins parallel, and inclined forwards and
upwards; wings united at an obtuse angle;
notch large below the pomum. Cricoid el-
liptical, ridge of Galen prominent. Crico-
thyroid : space large, rhomboidal, traversed in
front by muscular fibres. Arytenoids rhom-
boidal. Cart. Santorini absent. Vocal liga-
ments : superior prominent. Ventricles deep,
forming a sac between the vocal ligaments.
Epiglottis : apex obtuse. Trachea 59 rings.*
Voice grave, very intense ; roar terrific.

F. Tigris. — H. l-8 in. L. 1 in. The
superior ligament very prominent. In other
respects the larynx resembles that of the lion.
Voice more acute than the lion. Purrs like
the cat.

F. Leopardus and Catus. — Larynges differ
only in magnitude. The whole of the Feline
order are remarkable for the prominence of
the superior ligaments, by which the purring
is most probably produced. c {fig. 902.)+
Voice a mewing, which is well known ; also a
melancholy cry by night.

* Vicq. D’Azyr and Cuvier state that the rings
of the trachea are not entire. Perrault, on the con-
trary, describes them to be complete circles; but
this is an error.

t Vicq. d’Azyr ascribed the purring of the cat to
two thin membranes situated beneath the inferior
ligaments ; but we were unable to detect them : nor
could Cuvier, Wolff, Casserius, and others, succeed
in finding them,

VOICE.

1491

Phoca vitulma, or Common Seal . — Larynx! Marsupialia, Kangaroo. — Thyroid! mar-

H. 1-2 in. Thiroid : wings united by a small gins, superior a notch in front. 'Arytenoids
cartilaginous plate ; cornua parallel to axis of large. Cuneiform Cart., ventricles and su-

Fig. 902.

Larynx, Tongue, and Trachea of the Cat.
a, tongue ; b, epiglottis ; c, superior vocal cords ; d,
infinferior vocal cords.

vocal tube. Cricoid : depth of anterior to pos-
terior surface as 2 to 5. Crico-thyroid chink
rhomboidal. Epiglottis triangular, fixed to the
thyroid by cartilage. L. 0’675in. Trachea 78
rings.* Voice, nearly the pitch of a soprano;
melody, a melancholy moaning.

* According to Wolff, the first twelve rings are
complete circles, the rest overlap each other.

perior ligament absent. Vocal cords mem-
branous, fold upon themselves, so that they
cannot be stretched* by tbe arytenoids.
Voice, when in pain, moans piteously, f

Phalanger. J — Vocal cords: membranes sub-
stituted for vocal ligaments, but, as in the
kangaroo, do not fold on themselves. Com-
mon Phalanger : vocal ligaments absent.

Didelpkis Opossum. — ( Fit!. 903.) Larynx : H.
0288 in. Superior ligament absent. Ventricles

Fig. 903.

i. 2.

1. A lateral view of the Larynx of Didelphis
Opossum.

a , thyroid cart. ; b, cricoid ; r, crico-thyroid
ligament ; d, trachea.

2. A posterior view of the same,
c, cricoid cart. ; e, laryngo-tracheal ligament ; d,
trachea.

very small. Inferior ligament: L. 0 176 in.
Voice consequently acute; purrs like the cat. §
Trachea 20 rings.

Rodent ia. Paca. — Epiglottis nearly semi-
circular ; at its base a blind sac. Ventricles
not deep. Vocal cords but little salient.

Cavia capybara. Larynx similar to that of
the paca. Voice grunts like a pig.

Lepus cuniculus. The Rabbit. — ( Fig. 904.)
Larynx: H. 0'4 in. Thyroid: wings united at
an obtuse angle; margins oblique and parallel.
Crico-thyroid chink large. Arytenoids small,
pyramidal. Cuneiform cart, curved. Vocal
cords: superior thin and delicate ; inferior pro-
minent. L. 0'26 in. Epiglottis a obtuse ; apex
slightly notched, at the base of which are 4
conical cartilaginous bodies or tubercles in-
clined towards each other : between them,
b b, is a triangular space ; and a vertical
groove passes between the insertion of the
vocal ligaments from b to c. On each side
a ligamentous filament descends, which acts
on the tubercles above mentioned. The infe-
rior tubercles give attachments to superior
vocal ligaments and roof of the ventricles.
Office of tubercles — to open the ventricles,
stretch the superior ligaments, and give free-

* Cuvier.

f Bennett’s Wanderings in New Soutli Wales.

| The Phalanger of Cook.

§ Cuvier describes two small vibrating mem-
branes at the base of the epiglottis, which is denied
by Wolff.

5 c 2

1492

VOICE.

dom of motion to inferior ligaments. Voice
acute.

Fig. 904.

]. 2.

1. Larynx of the Babbit laid open.

2. Side view of the same, externally,
a, epiglottis ; b, thyroid; d, cricoid; c, crico -thy-
roid ligament ; e, trachea.

Ilystrix cristata. Porcupine. — Vocal liga-
ments absent. Ventricles of Morgagni none.
Voice mute.

Castor Fiber. The Beaver. — Larynx : fl.
045 in. Epiglottis triangular, having a vertical
raphe upon its posterior surface terminating
in a sac bordered by the vocal ligaments.
Arytenoids small anil conical. Vocal cords:
L. 025 in. Trachea 22 rings. Voice acute.

Mus Raltus. See details by WoltF.

Edentata. O rnithorynchus paradoxus. —

( Fig. 905.) Larynx : H. '(> in. Thyroid : wings
united at an obtuse angle ; body partly cartila-
ginous, and partly osseous ; supports laterally
two transverse osseous processes f f at the
bases of which are two curved cartilaginous
appendices. Cricoid elliptical. Arytenoid
triangular. Ventricles not deep. A sulcus,
d d, lies between superior ligament and cri-
coid cartilage.-* Epiglottis : apex acute, a.
Trachea 15 rings.

Armadillo. — Epiglottis bilobed. Voice mute.

Bradypus tridactylus or Sloth. — Larynx :
Cart, of Santorini and superior vocal cords
absent. Ventricles a mere impression. Infe-
rior vocal ligaments free. Trachea convoluted.
Voice a plaintive melody, consisting of an
ascending and descending scale of the hexa-
chord.f

Pachydermata. Equus. — H. P85. Thy-
roid : wings united at an acute angle, and
notched below to the pomum. Cricoid :
margins, superior deflected inwards. Cricothy-
roid chink inclined both vertically and horizon-
tally. Arytenoids large ; bases deflected from
each other, by which the glottis is always kept
open. Cart, of Santorini curved or hook-like

* This is described by Blainville, but Meckel
seems not to have observed it.

t Bingley, An. Biog.

bases fixed to the arytenoids. L. 2 in. Supe-
rior vocal ligaments not prominent. Ventricles
ot Morgagni oval, deep, cc{fig. 906) Epiglottis

Fig. 905.

A. view of the internal mechanism of the Larynx oj j1
Ornithorynchus paradoxus.

a, epiglottis ; b, superior vocal cords ; c, inferior {
vocal cords ; d, sulcus ; /, -transverse osseous |
processes; g, spines of transverse processes; e, |
trachea.

triangular, a; at the base two processes * con-
nect it with the arytenoids. Between the com-
missure of vocal ligaments and epiglottis there
is an oval cavity, c ; and on the posterior sur-
face of the epiglottis a groove, furnished at its
base with a semilunar membrane. \ Trachea
52 rings. Voice, the neigh, which is well
known, but not easily described. Herrissant
has exaggerated, as Cuvier states, the office of
the semilunar membrane in the production of
this singular sound.

Asinus vulgaris. — Larynx : H. 1-95 in. Thy- |j
roid : wings united at an obtuse angle. Cricoid
elliptical. Crico-thyroid chink not large. Epi-
glottis : apex obtuse a {fig. 906.) ; at its base an
arched cavity, b , in which the vocal ligaments
are inserted. On each side of this cavity c, e,
are two circular apertures, which lead to two
large sacs situated behind the mucous mem-
brane between the vocal ligaments and inter-
nal surface of the thyroid. L. P275 in. Tra-
chea: rings spiral. Voice : quality discordant;
range about 5 tones. The bray is well known. J
Mule. — Laryngeal cavities similar to those
in the ass. Voice, a species of bray resem-
bling the voice of the ass, rather than that of
the horse.

* These are the boms of the epiglottis of Casse- f
rius.

t The semilunar membrane of Herrissant.
j According to Herrissant, the edge of the arched
cavity causes the peculiar timbre of the voice of the
ass, and acts like the semilunar membrane in the
neigh of the horse ; both these hypotheses, how-
ever, are extremely doubtful ; the sac mentioned in
the text doubtless contributes largely to the produc-
tion of the braying of the ass. During the bray an
acute sound accompanies the inspiratory movement
of the thorax. i

VOICE.

1+93

Quagga. — Larynx somewhat like the horse,

Fig. 906.

Larynx of the Horse laid open.

a, epiglottis ; b, semilunar membrane ; e, aperture at
the base of the epiglottis ; d, sulcus ; e, ventri-
cles ; f arytenoids ; g, inferior vocal cords ; h,
trachea.

Fig. 907.

The Larynx of the Ass laid open.

a, epiglottis; b, arched cavity; e, apertures; d,
aiytenoids and vocal cords ; e, trachea.

but destitute of semilunar membrane. * Voice
resembling the bark of a dog; hence its name.

Tapir Americanus. — Larynx : LI. & L. less
than in the horse. Thyroid : pomum absent.
Forthe Cart.of Santorini and Cart. Cuneiform,
are substituted fibro-cartilaginous masses, f
Vocal ligaments : superior short and indis-
tinct ; inferior strong. Ventricles elongated
into an oval blind sac. A semilunar opening
in the base of the epiglottis, leads to a curved
cavity on each side of it.J Voice, a species of
whistle. <)

Sits scrofa. — Larynx; H. 1*55 in. Thyroid;
wings united at an acute angle, become more
acute below ; superior cornua absent. Cricoid

Fig. 908.

Mesial section of the Larynx of the Pig ( Sus
scrofa).

a, sac; 6, superior ligament; e, inferior ligament;
d, sacculus laryngis-;. e, left arytenoid c. ; f cri-
coid c. ; g, trachea..

an eccentric ellipsoid. Arytenoids locked
to each other at the apex of their superior
prominence by a cartilage. || Vocal cords
directed obliquely downwards to form, with
the axis of the vocal tube, an angle of 30°, and
are inserted at -§- the height of the thyroid
from its lower margin. L. 0*9 in. Ventricle d
( fig. 908.) an oblong chink leading, by a groove
inclined backwards, to a sac, a. Voice a
grunting, discordant sound.

Rhinoceros. — Larynx : H. 5 in. ; Thyroid :
cornua none, figure rbomboidal. Cricoid :

* Cuvier. f Brandt.

X Brandt. § Bingley, An. Biog.

|| This cart, is peculiar to the pig.

*j[ The larynx of this animal has been described by
Casserius, Herrissant, Cuvier, Wolff, and Gurlt ; the
former first noticed the sacs in these words, ‘ Fora-
mina duorum ventrium per quae aer ingreditur, ad
grunnitum in porcis efiiciendum.” Herrissant sup-
posed the sacs to be the principal organs in the
production of the voice of the pig, but we cannot
concur in this opinion, they merely affect the quality
of the sound.

5 c 3

VOICE.

1 494

nearly thrice as deep behind as in front ; Crico-
thyroid space very large ; Ventricles of Mor-
gagni large and deep ; superior vocal cords
prominent. L. 1-75 in.

Elephant. — Larynx : H. 4'83 in. Thyroid :
wings united at an obtuse angle ; surface ex-
ternally convex ; cornua, superior short ; mar-
gins of inferior notched in front. Poraum a
distinct cartilage. Cricoid elliptical ; inferior
margin concave ; body deep, posteriorly pass-
ing over the first three rings of the trachea.
Vocal ligaments : superior indistinct ; infe-
rior strong. L. 3'75. Trachea, 30 rings,
which are often partially subdivided. Voice
intense, of a grave pitch, aided by the pro-
boscis.

Ruminantia. Camelus Bactrianus. — H.
3 in. Thyroid : wings united at an obtuse
angle. Cricoid elliptical. Arytenoids trian-
gular. Ventricles oval. Epiglottis : apex

the epiglottis leading to a sac. A. gutturosa,
pomum very large.*

Cervus. C. Farandus or Rein Deer. — La-
rynx has a laryngeal opening at the base of
the epiglottis +, leading to a large sac.

C. Alcan. H. 2’5 in. Thyroid : wings
united at an obtuse angle ; cornua long; po-
mum large, and concave within. Cricoid :
posterior deep, shielding the five first rings of
the trachea ; anterior narrow. Crico-thyroid
chink c (Jig. 910) broad ; crico-thyroid liga-
ment strengthened by additional perpendicular
fibres d ; its superior ligament absent, inferior
inserted into the concavity of the pomum.
L. I -8 in. Voice grave.

Fig. 910

Fig. 909

Larynx of Cervus Alcas.
a, thyroid c. ; b, cricoid ; d, crico-thyroid ligament.

The Larynx of the Camel laid open.

a, epiglottis; b, superior vocal cords; c, inferior;

d, arytenoid cartilages ; e, vertical ridge ; h, tu-
bercle ; f trachea.

obtuse, posterior surface furnished with a tu-
bercle. Vocal ligaments : superior rather
broad bb (Jig. 909); inferior strong cc. L. T5
in. Voice grave, but seldom exercised.

Llama. — Larynx similar to the camel. Vo-
cal ligaments, superior and inferior, present.

Giraffe. — Vocal ligaments said to be ab-
sent.

Bos . — Larynx: wings of thyroid nearly
equilateral, united at an obtuse angle. Cricoid
massive, elliptical. Vocal cords : superior
absent ; inferior strong. L. 085 in. Trachea
52 rings. Voice sonorous, intense, pitched in
C = 256 vib. in

Ovis Ammon. — Larynx differs from Bos only
in dimensions. Voice guttural, pitched in F
= 341 vib. in 1".

Antelope. A. Dorcas, and A. Corinna. — La-
rynx perforated by an aperture at the base of

C. Capreolus. — Larynx: LI. 1'85 in. — Thv-
roid : wings united at an obtuse angle. Cor-
nua : superior long, inferior shorter, curved ;
pomum large, concave within. Cricoid, ec-
centric ellipse. Body : posterior deep, ante-
rior narrow. Crico-thyroid chink large. L.
1'26 in. Voice grave.

Cetacea. Balcenoptera rostrata. — H. 10 in.
Thyroid : wings united at a very obtuse

angle |, the superior margins being nearly
straight ; inferior excavated by a triangular
notch near the centre. Cornua : superior ab-
sent; inferior very large, straight, but curved
in the dolphin. Cricoid : deep behind, absent
in front, where it opens into a large sac §

* See Pallas, Spicil. Zoolog. fasc. xii. fig. 16.

t See Camper, Naturges. des Orang-outang, &c.

j Indeed the wings spread open almost into a !
straight line.

§ This sac has been described by Hunter and
Sandifoot. In the dolphin and porpoise the cricoid
is imperfect in front.

VOICE.

1495

lying in front of the larynx. Tracheal
length 4 in. ; posterior cartilaginous, an-
terior membranous at its laryngeal extre-
mity. Arytenoids : superior prominences

elongated, flattened, and inclined forwards —
their inner margins lie in contact; the inferior

Fig. 911.

Section of the Tongue , Pharynx and Larynx of the
Porpoise.

a, pyramidal position of larynx; c, pharynx; d,
laryngeal cavities laid open, and a bristle is passed
though the glottis, f.

prominences short, but strong. Epiglottis :
base springs from the superior margin of the
thyroid, to which it is fixed by a cartilaginous
union. It is flattened and directed back-
wards to unite with the superior prominence
ol the arytenoids, with which it completes the
aryteno-epiglottic portion of the vocal
tube. The diameter of this portion is nar-
rower than the rest of the tube, which crosses
the fauces, enters the posterior nares, and
terminates in the olfactory organs. In its
passage it is grasped by a strong sphincter
muscle of the fauces, as in the porpoise, e e
CAg'SH)- Vocal ligaments absent. Aper-
ture of the vocal tube, in those which have
but one opening, as the spermaceti and
bottle-nose whales, grampus, dolphin, and
porpoise, transverse ; but in those which
have two apertures*, as in the great whale-

* Hunter remarks that the cartilages of the
larynx are much smaller in the bottle-nosed whale
of twenty-four feet, than in the piked whale of fif-
teen feet. He is also of opinion that the absence of
the vocal cord, co-existing with that of the thyroid
gland, tends to show that the functions of the

bone whale, it is longitudinal. Thyroid gland
absent. Voice absent, or reduced to a single
lowing. Trachea, in Ralcenoptera rostrata,
length 4 in.; posterior cartilaginous, anterior
membranous at its laryngeal extremity.

Birds. — The vocal organs of birds differ
from every other class of animals by the con-
stitution of the superior, and by the addition
of an inferior larynx. The same acoustics
apply, with few exceptions, to all Mammalia,
but in birds is required an additional investi-
gation.

The superior larynx of birds is situated
immediately below the os-hyoides, to which it
is connected by the thyroid membrane, and
hyo-aryngeal muscles. Its figure and struc-
ture are more uniform than those of the
inferior larynx. It is partly cartilaginous, and
partly osseous.

The thyroid cartilage forms the anterior,
and part of the lateral boundary of the larynx,
and rests upon the first ring of the trachea.
Wings, superior margin ascending forwards
and upwards, meet each other in the mesial
line, where the cartilage terminates in either a
pointed, rounded, or flattened projection; in-
ferior margin usually horizontal, corresponding
to the first ring of the trachea, as in Palmi-
pedes, but are excavated in Scansores. The
posterior margins terminate in two quad-
rangular bones, with which the thyroid carti-
lage is frequently ossified (and these then
become portions of the wings of the thyroid ;
the quadrilateral bones, being also oblique
angled, are shaped to form a union with the
posterior margin of the thyroid, and present
horizontal edges above and below, leaving a
small triangular space for the cricoid cartilage
posteriorly. The cricoid is a small triangular
bone, lying on the inside of the posterior edges
of the two quadrangular bones ; it supports
the two arytenoid cartilages, as in Mammalia;
and although it forms a very small portion of a
ring, it is yet necessary for the completion of
it. These four bony or cartilaginous pieces
are most distinct in young birds, and amongst
old ones are quite distinct in the Anas do-
mesticus and Ana-s motlisshnus, but are con-
solidated into one in the Scansores, ostrich,
and many others. The arytenoid cartilages
are long and tapering upwards and forwards,
and form by their inner margins laterally the
rima glottidis : they are generally ossified.
Their external margins are bounded by the
thyroid cartilage, and their inner margins
form the rima glottidis.

Epiglottis. — In most birds the epiglottis is
situated on the internal surface of the thyroid ;
it is rudimentary, and is termed the processus
epiglotticus : it is generally osseous, but ac-
cording to Henle it is leaf-like in the stork
and heron ; and in some of the Gallinacese, as
in Sterna, Rallus, and Lams, it is thin, flat, and
flexible, as in Mammalia.

Rima glottidis. — The form of this chink
in a state of repose is triangular, the apex
being directed backwards: it is bounded an-

latter are in some manner associated with those of
the former.

5 c 4

1496

VOICE.

teriorly by the thyroid, laterally by the ary-
tenoids, and posteriorly by the cricoid carti-
lage, but is destitute of salient membranous
laminas. *

Muscles. — The superior larynx is raised
by the hyo-thyroideus and the thyro-tra-
chealis muscles, and depressed by the hypsilo
and sterno-trachealis. The glottis is opened
by the thyro-arytenoideus posticus, and closed
by the thyro-arytenoideus lateralis, as in the
higher order of reptiles.

The superior larynx is supplied by the
superior laryngeal nerve alone, the inferior
laryngeal terminating in the inferior larynx
and trachea.

The inferior larynx. — This organ is pecu-
liar to birds. It is exceedingly diversified in
form and structure. It is always found except
in the condor, and other vultures. If vve make
a section of the lower larynx of birds in the
mesial plane, its lateral segments, if viewed
separately, present a double organ of sound ;
the exceptions to this rule are, the parrot,
perroquet, and cockatoo. The inferior larynx
of birds is often a very complex structure, and
may be considered a double reed furnished
with a pipe. It is symmetrical in most orders
of birds except the Palmipedes, and is situated
between the last ring of the trachea and first
of the bronchi; it lies upon the oesophagus pos-
teriorly, where there is generally a triangular
space for the passage of that tube.

The frame-work of the inferior larynx is
formed by the developement of several lower
rings of the trachea, which take diversified
forms in different orders of birds, and some-
times in the sub-genera of the same order, as
in Mergus and Anas among the Palmipedes.
In those birds which have a pure quality of
voice, and whose instinct excites them to pro-
duce a continuous succession of tones, con-
stituting some defined melody, we find the

* Although anatomists are generally agreed respect-
ing the position and figure of the several pieces which
enter into the formation of the superior larynx of
birds, they differ widely in reference to the parts
which they represent when compared with man.
Cuvier conceives that the posterior cartilage, which
Humboldt1 calls sockel, represents the cricoid of
Mammalia, and that birds are destitute of epiglottis,
thyroid, and arytenoid cartilages. Fabricius 2 * con-
siders it best to divide the pieces into three parts,
viz. two arytenoids and an os-innominatum. Tiede-
mann5 thinks the anterior piece represents the
thyroid, the quadrangular pieces the cricoid, and
the triangular the arytenoid cartilages of Mamma-
lia. Meckel4, on the contrary, considers the trian-
gular pieces to be the cricoid divided. Carus6
supposes the quadrangular pieces to be arytenoids,
and the triangular the cartilages of Santorini.
Wagner6 unites the single with the quadrilateral
pieces for a cricoid, and the triangular for the
arytenoids.

1 Observations de Zoologie.

2 De Larynge. P. i. cap. vii. In op. omnia. Lips.
1687, p. 273.

5 Zoologie, b. ii. p. 644.

4 Archiv. fur Anat. imd Physiol. 1832, p. 324.

5 Lehrbuch der Vergleichenden Zootomie, b. i.
p. 1 95.

6 Lehrbuch der Vergleichenden Anatomie, p. 242.

inferior larynx not only better adapted to pro-
duce a purer quality of tone, but it is pro-
vided with a greater number of muscles for
modulating the voice.

Among the Insessores, the Corvidae and
Sylviadae have the external walls of the infe-
rior larynx composed on each side of three
semilunar bones which are developed from
the inferior portion ot the trachea. The larynx
is bounded internally by a bone, which tra-
verses the lower end of the trachea, the verti-
cal longitudinal section of which coincides with
the plane of the mesial section i (Jig. 912):
this os transversale, after stretching across
the tube, divides at each end into two lamina;,
which diverge laterally from the axis of the
bone to meet the two first external bones of
the larynx, thus strengthening and complet-
ing its solid framework. The superior part
of the os transversale is concave, and fur-
nished with a very thin delicate membrane,
rising vertically from the bone li {fig. 912):
this is called by Savart the membrana semi-
lunaris.

Fig. 912.

Section of the lower Larynx,
h, membrana semilunaris ; i, os transversale ; g,
membrana -ty mpan iform i s.

This membrane is most developed in sing-
ing birds, and is considered by Savart to be
one of the most essential organs of voice in the
inferior larynges of the nightingales, thrushes,
linnets, finches, and other singing birds, as
well as in speaking birds, such as the pies,
jays, &c. The inferior edge of the os trans-
versale gives attachment to the membrana tym-
paniformis.

Bones of the inferior larynx. — The first
bone a {fig. 913) is flattened and curved,
being convex externally, and concave inter-
nally: it forms the boundary of the internal
lateral face of the larynx.

The second hone b {fig. 913) presents nearly
the same form as the first, but it possesses
greater mobility, the muscles which are in-
serted into it drawing it upwards and out-

VOICE.

J 497

wards perpendicularly to the axis of the
bonchus of the same side, by which means
the area of the latter is varied.

The third bone is but very slightly curved
(c). It is separated from the second bone by a
triangular membrane; having its extremities
articulated to the second bone by ligaments
which permit of an extensive freedom of mo-
tion, particularly of a rotatory movement on
its axis, and it is an important agent, accord-
ing to Savart, in modulating the voice. The
internal surface of this bone is lined with a
fibrous cord which forms the external lip of
the glottis. The posterior extremities of
these three bones are not united, but have a
triangular space between them for the passage
of the oesophagus.

Fig. 913.

Inferior Larynx of the Raven,

Shewing the three bones, a, b, c.

The Membrana tympaniformis. — This is a
thin transparent membrane, extending from
the os transversale to the extremities of the
bronchial half-rings g {figs. 912 and 914) : it
forms the internal surface of the larynx and
bronchi, and is a continuation of the semilunar
membrane; so that the tympaniform and
semilunar membranes are stretched simul-
taneously, and the latter is acted upon through
the instrumentality of the former.

The Arytenoid Cartilage. — This is a small
body situated at the head of the second bone :
it is described by Savart as being of a lozenge
shape in the starling, but very short in the
nightingale. This form of larynx in the Cor-
vidae and Sylviadae is provided with six pairs
of muscles.* (See fig. 914.)

Palmipedes. — In the genera Anas and
Mergus the inferior larynges of the males only
are unsymmetrical, and composed of bony ca-
vities. In the Anas domesticus, the inferior
larynx presents osseous cavities formed by

* These muscles are given in detail by Savart,
Memoire sur la Voix des Oiseaux, in the Ann. de Chem.
et de Physique, vol. xxxii., also Cuvier, in the Regne
Animal, vol. iv. There are five pairs of muscles as-
signed to the inferior larynx of the singing birds by
Cuvier, Mr. Yarrell, Professors Grant and Owen, but
six can be made out in the Corvidae, as stated by
Savartj and seen in the figure of the Raven.

the developement and union of the last six or
seven rings of the trachea. It is divided
within into two unequal cavities by the os

Fig. 914.

2. 1.

1. The inferior Larynx of the Raven,

Shewing the six muscles, a, b, c, d, e, f which mo-
dulate the voice on one side.

2. Anterior view of the same,

Shewing the membrana tympaniformis, g.

transversale, of which the left is always the
largest. The figure of the os transversale is
very similar to that of the arytenoid cartilage
in the human larynx, consisting of prominences,
ridges, and base : the superior prominence of
this bone projects high into the tube of the
trachea, and completely divides the larynx at
its base. The ridge on its left side is fur-
nished with a salient lamina, corresponding to
a thin transparent semilunar lamina, situated
opposite to it : the latter is placed at the en-
trance of a small osseous cavity at the infe-
rior boundary of the left larynx; a still larger
osseous cavity lies obliquely above the semi-
lunar membrane. The air sets this membrane
in motion as it circulates in the left chambers
of the larynx, and contributes to the produc-
tion of the well-known peculiar character of
voice in this bird. On the right side the
cavity of the larynx is of smaller dimensions,
of less irregular form, and destitute of those
prominent ridges and salient laminae within.
There appears to be a small tj'mpanic mem-
brane attached to the first few rings of the
bronchus on the right side.

In the Mergus serrator the inferior larynx
is partly osseous, and partly membranous : it
consists of two irregular cavities. The os
transversale, i (fig- 915), which has an exten-
sive union along its posterior edge and base
with the bony boundaries of the larynx, divides
this tube into two parts, except at its superior
prominence, where it leaves a channel b
for the air from the right bronchus fi to pe-
netrate the trachea. On the right lateral
surface of the larynx, a large oval membrane

1498

VOICE.

forms the boundary : the rest of this cavity is
composed of bone. On the left side the
larynx is furnished with four membranes, of
unequal dimensions, which are inclined to each
other at different angles ; of these membranes
three are lateral, and the fourth forms the
base. The internal lateral membrane b lies
almost parallel to the superior promontory of
the os transversale i, from which it is separated
by a channel, leading from the left to the right
larynx.# Through this channel the air from the
left bronchus must pass to reach the trachea.

The internal lateral membranehasafree salient
edge interiorly, over which the air brushes in
its passage from the lungs to the trachea, j-
The posterior, anterior, and lateral mem-

branes are supported by bony rings, of which
the anterior is the largest. The membrane
forming the base is penetrated by the left
bronchial tube, and is connected with several
of the bronchial i ings through the medium of
the membrana tympaniformis. Thus the air
from the lungs throws into vibration one
large membrane in the right, and four in the
left larynx, all of unequal dimensions, and con-
stituting a very complex piece of mechanism.

In the M. Merganser or Goosander the
inferior larynx is most developed on the
left side li (Jig. 91G), which is chiefly mem-
branous, while the other side d is composed
principally of bone. On the left side there
are four irregular membranes, ct,b, c, supported

Fig. 915.

Two views of the Inferior Larynx of the Mergus Serrator.

by bones, and that on the external ring h.
The os transversale is very small and does
not reach the free edge of the internal mem-
brane b, which is similar to that of the
Mergus serrator, thus leaving a communi-
cation open between the right and left side of
the cavity of the larynx, through which the
air from the left lung must pass to reach the
tube of the trachea, which terminates on the
superior part of the right side of the larynx.
The right side is chiefly surrounded by bone
externally, having a very small oval membrane
anteriorly, and is furnished with a small
tympanic membrane at its junction with the
bronchus. The salient portions of these
membranes, and the small membrana tym-
paniformis are best adapted for putting the
air into a state of vibration, reinforced by

* The area of this channel is increased by an
osseous cavity which is formed by the posterior con-
cave surface of the ridge g, lying externally in
front of the larynx.

f Beneath the inferior point of attachment of the
internal lateral membrane, the above-mentioned
conical osseous cavity passes vertically downwards c
terminating between the bronchi in a kind of cul
de sac.

the chambers of which the larynx is com-
posed.

Fig. 916

Inferior Larynx of the 31. flerganser.

VOICE

1499

In the female the larynx is of a much
simpler structure, the external wall is com-
posed of several consolidated rings, those situ-
ated below the os transversale terminating in
the membrana tympaniformis between the last
bone of the larynx and first of the bronchus.

In the Anas clangula we find another variety'
in the structure of the vocal organs. The
inferior larynx is nearly of a semilunar form,
with its convex surface directed exteriorly ;
it is situated obliquely' to the axis of the
trachea. It is partly bony, and partly mem-
branous, and divided into several cavities.
A large semilunar bone forms the principal
framework of the whole larynx. On the left
side there are two cavities, one of which is
situated above the other. The superior cavity
is formed by a groove in the semilunar bone
by which it is bounded both externally and in-
ternally, but is furnished with a membrane
above. At the posterior extremity of the
bone forming the floor of this cavity, there is
a perforation by which the air in the inferior
cavity from the left bronchus is admitted.
The inferior cavity lies at the base of the
larynx, and is connected with both bronchial
and tracheal apertures ; it is bounded an-
teriorly by the semilunar bone, and inferiorly
by the basilar membrane.

On the right side the semilunar bone forms
externally a protuberance, which is concave
within, forming the anterior and lateral bound-
ary of a large cavity which lies between the
bronchial and tracheal apertures. This cavity
is subdivided by bone and membranes into
two irregularly formed cul de sacs, which are
nearly parallel to the axis of the trachea.

The os transversale is a very irregularly
formed bone, as in the Mergansers, dividing the
larynx into two unequal and unsymmetrical
parts ; its superior prominence, which is
conical, penetrates the trachea nearly one-
eighth of the entire length of that tube. The
rings of the trachea here are no longer entire
but divided anteriorly and posteriorly by a
dense membrane, and in some places by os-
seous interposed substances, the whole being
supported within by the os transversale. A
basilar membrane supported by the semilunar
bone, forms the floor of the larynx. This
membrane is perforated by the bronchial tubes,
and is connected with the bronchi by means
of the membrana tympani. In the female,
the left side of the larynx lies above the right,
as does that of the male, and the base is like-
wise oblique to the axis of the trachea. The
trachea of the male has an enlargement occu-
pying about one-fourth of its length, its size
being regulated by an additional pair of mus-
cles, which draws the rings of that part either
into an oblique, or into a nearly horizontal
position.

The whole of this complicated mechanism
is concerned in producing the tones peculiar
to the A. clangula.

The A.rtrfina, or red-breasted whistling duck,
presents another instance of laryngeal struc-
ture peculiar to itself ; but our limits will not
admit our giving its anatomy in detail : let it

suffice therefore to mention, that its left cavity,
which is largest, is chiefly membranous, whilst
the right is almost entirely osseous, and some-
what resembles in external form the larynx of
Mergus Merganser. A. muscatus , A. Penelope ,
or widgeon, and A. JEgyptiaca , have also bony
enlargements of the inferior larynx ; but the
Anser domesticus, and the Lams, and Ardea,
with some others amongst the Grallatores, are
destitute of these enlarged cavities common
in the order Anas. The organs of voice in
the Palmipedes are, with a few exceptions,
only provided with one pair of muscles.*

In the Gallinaceae the structure of the in-
ferior larynx is more uniform, simple, and
symmetrical than in the Palmipedes. In the
male Phasianus gallus, the common cock, this
larynx is composed externally of two or three
of the lower half rings of the trachea, con-
nected in the inside with the os transversale
both anteriorly and posteriorly, through the
interposition of two triangular laminas given
off by it, which are also connected with the
bronchi. Between the rings of the larynx
there is interposed a membrane which forms
the side of the glottis externally. The
inferior portion of the trachea is much com-
pressed laterally. The inferior larynx of the
pheasant does not differ materially in structure
from that of the cock. In the partridge
the os transversale is attached immediately
to the last half ring of the larynx. In the
Gallinaceae, owing to the os transversale lying
below the last semilunar rings of the larynx,
the membranes on each side arc immediately
opposite to each other, so as to form the two
sides of the glottis, and the larynx is not en-
tirely a double reed as in the Sylviadae, in
which the membrana semilunaris forms with
the membrana tympani the interior lips of the
glottis, and divides the larynx into a double
organ of voice. In this respect the structure
of the larynx in the Gallinacete is intermediate
between the parrots and the singing birds. The
trachea being compressed laterally, and the
glottis very straight, these, according to
Cuvier, may be considered the causes of the
acute sounds which these birds produce.
They are provided with one pair of muscles.
In the Indian pigeon, however, the sterno-
tracheal muscles divide, and send a few fibres
to the inferior larynx.

In the Falcons, the larynx being provided
with but one pair of muscles, viz. the sterno-
tracheal, its structure is much more simple
than in the singing birds. The membrana
tympani is however large, but does not appear
to give off any semilunar membrane. The
bronchial rings are distant from each other,
and bound together by thin membranes ; the
rings of the larynx are almost in juxtaposition,
leaving no vibratile membranous space be-
tween them ; consequently the membrana
tympani is the chief vibrating tissue. The
order also has one pair of vocal muscles.

Scansores.— In the parrots the inferior

* The exceptions in this order are the Velvet
duck, the Golden Eye, the Red Breasted 3Ieryanser,
and Ganet, in which there are two pairs.

1500

VOICE.

larynx differs in structure from that of any other
order of birds. They have no os transversale
dividing the vocal organs, which is conse-
quently a single larynx. The segments of
the rings in which the lower end of the trachea
terminates are consolidated together on each
side. The last two of these segments are of
a crescent-like or semilunar form, with its
axis nearly perpendicular to the axes of the
ring of the trachea ; they are concave to
each other, and their extremities articulated
together, forming an elliptical space which is
furnished with a thin vibratile membrane, as
seen in Jig. 917. At their junction is the
joint or axis on which they revolve upon each
other, and by which the tension of the mem-
brane of the glottis is capable of being varied.

Fig. 917.

Inferior Larynx of the Parrot,
a, h, tensors of the glottis ; c, laxator of glottis.

The glottis is formed on each side by the
elastic membranes that fill the space between
the semilunar bones|; these membranes leave
a narrow chink between them through which
the air from the lungs passes, and puts them
in a state of vibration whenever the bird
draws them sufficiently tense ; for this pur-
pose they are provided with three pairs of
muscles, of which two a, h, are tensors, and
one c laxator of the glottis.

The trachea of birds comprehends that
portion of the vocal tube which lies between
the superior and inferior larynx ; its diameter
and length generally depend on the length of
the neck of the bird. In the common crane,
the trachea after making its exit from the
thorax, penetrates the sterno-tracheal space,
and then making four turns upon itself in the
same plane, it leaves the breast bone to
follow its course into the neck : by this ar-
rangement the vocal tube is greatly lengthened
for the purposes of voice, and the surface of
the sternum increased for the attachment of
the great pectoral muscles without adding
materially to the weight of the bird. The
voice of the crane is very sonorous, and may
be heard at a great distance.

In Bewick’s swan (Jig. 9 18), the manner in
which a considerable additional length is
given to the trachea by its convolutions, will
be evident upon an inspection of the figure.

The spoonbill presents another remark-
able instance of convoluted trachea, doubling
twice upon itself. Other examples of con-

voluted trachea are found in the Gal-
linacese ; as in the Rhynchcea Australis, and
Phasianus Pun-aqua. In the singing birds
the trachea is a cylindrical tube; the rings
which are at first cartilaginous become ossi-
fied with age. The tracheal rings, which are
entire in the adult state, being connected by
elastic membranes, are at a sufficient distance
from each other to allow of all the movements
of the neck.

Fig. 918.

Inferior Larynx and convoluted Trachea in Bewick's
Swan, from Yarrell.

The diameter of the trachea in singing
birds is nearly uniform and proportional to
its length ; but among the Palmipedes, the
Mergansers, and some species of Anas, as the
A. fusca and A. rujina, there are tracheal en-
largements with additional muscles, to control
their dimensions. The number of rings in the
trachea of some birds is very great, sur-
passing that of any other class of animals.
In the Phccnieoqtterus, according to Dr. Grant,
there are at least 350 rings.

Physiology of the Voice of Birds. —
The vocal apparatus of birds consists of the
lungs, larynx, and trachea, representing a wind
chest, reed, and pipe. The inferior larynx
has been proved by Cuvier to be the organ in
which the sounds are generated. To ascertain
this fact, he divided the trachea of a black-
bird about the middle of its length, thus pre-
venting the passage of the air through the
superior orifice ; the bird notwithstanding con-
tinued to sing, though the tones were more
feeble than before. In a second experiment
on the pie, performed in the same manner, the
bird cried with as great intensity of tone, and
with the same acuteness as before the opera-
tion, for the space of about ten minutes
when the blood from the wound being drawn
into the larynx suffocated the animal. These
experiments, however, were sufficient to prove
that the sound did not arise from the superior
larynx ; and when we view the structure of
that organ, and, find it destitute of vocal
ligaments, or any salient membranous lamina?,
and bounded by cartilaginous or osseous
matter, and compare it with the complex
organization of the inferior larynx, we might

VOICE.

1501

without experiments conclude the latter to be
the organ of sound.

The superior larynx nevertheless performs
an important office, both preventing the passage
of the food into the wind-pipe, and modifying
the sound of the voice. It can be opened
and closed with rapidity, in singing birds ;
and is actively employed in the production of
melody : we can easily witness its simultaneous
movements with the mouth, in the song of
the canary, linnets, and others. Its influence
on the pitch is according to Savart, but little,
not amounting to more than a semitone. The
inferior larynx may be considered a reed
prefixed to a tube. The salient laminae of
the membrana tympaniformis, and the mem-
brana semilunaris are especially adapted to
produce a series of vibrations, when a current
of air is forced into the bronchi. It is indeed
only necessary to dissect out the vocal tube of
a bird, (such as that of the goose for example),
and blow into it by the mouth, to elicit
sounds. In the singing birds, which have the
lower larynx furnished with the most elaborate
muscular apparatus, the tension of the vibra-
tile membrane of the glottis can be regulated
with precision, so as to enable them to effect the
varied melodies which nature or art dictates.
In order to prove the duplex structure of the
inferior larynx, Savart divided the recurrent
nerve on one side in the living bird, after
which it continued to sing with all the modi-
fications of its melody as before. We agree as
to the duplex office of the lower larynx in
singing birds ; but in them the semilunar
membrane appears common to both sides, as
is also the os transversale. Savart considered
the semilunar membrane to be chiefly de-
veloped in those birds which have the most
reedy quality of voice, the speaking birds for
instance, such as the jays, pies, &c., but that,
in the production of the flute tones in singing
birds, it is more relaxed, and the glottis more
open. He observes that, in making a trans-
verse section of the trachea in the living bird,
which also cuts the recurrent nerve, and pro-
duces a relaxed state of the glottis, the
sounds become less ‘ criard,' and less ‘ sourd ’ ;
but, as birds thus maltreated suffer greatly, he
recommends the section of the recurrent nerve
only. It is one of the most difficult subjects
in acoustics to determine theoretically the
sound which many of the maleNatatores ought
to produce, such, for example, as the Anas
domesticus, A. clangula, Mergus serrator, and
M. merganser, the structure of whose la-
rynges has been briefly described ; and, when
we consider that these larynges are composed
of chambers of varied dimensions, bounded by
walls partly membranous and partly osseous,
the membranes being of unequal area, and
perhaps unequal tension, we may have some
notion of the extreme difficulty of the inquiry,
when some of the greatest mathematicians of
the past and present age have as yet been un-
able to determine analytically the law of the
vibration of a single piece of stretched parch-
ment, like the drum.

Experiment shows that asingle membranous

stretched disc will produce many other, be-
sides its fundamental and harmonic sounds ;
we need not, therefore, be surprised at the
discordant tones which many of theNatatores
are well known to produce. The reason why
short tubes, such as the tracheas of many
small birds, produce tones of a very grave
pitch, has already been satisfactorily explained
by Savart. We observe, however, that, in those
birds in which the trachea is shortest, the
diameter smallest, and the walls very elastic,
the voice is most acute. The muscles
which vary the tension of the walls of the
vocal pipe are in continual action during the
modulation of the voice, in order to adjust the
tube of the trachea to the pitch of the glottis;
but the number of vibrations is doubtless
determined by the glottis, and reinforced by
the walls of the pipe, as in Mammalia. The
cavities in the trachea of some of the Natatores
must certainly influence the timbre, or qua-
lity of the voice of those birds. In the com-
mon crane, and other birds which have a con-
voluted trachea, the tones ought to be grave
in proportion to its length, if the number of
vibrations is determined by the length, as in
musical instruments.

The voice of birds, as of other animals, is
always in a minor key ; but to describe the
melody of each bird would be foreign to our
subject. The range of notes is generally within
an octave, though they can greatly exceed it.
In the parrots, which have a voice of great
power, the inferior larynx is single. The two
membranes of the larynx leave a narrow chink
between them, through which the air is forced
from the lungs. These membranes, vibrating
in all their dimensions, produce that harsh and
disagreeable quality of sound peculiar to them.
They can also whistle, during which the glottis
is probably silent, and the column of air
vibrates as in a flute, when a vibratory move-
ment being communicated by the air, traverses
the elastic walls of the tube. Besides the
power of speech possessed by some birds,
many can imitate almost every sound they
hear. The blackbird has been known to imi-
tate the song of the nightingale, the crowing of
the common cock, and the cackle of the hen ;
the jay is said to mock the notes of the green-
finch and the neighing of the horse so closely,
that it was scarcely believed to be a bird by
those who heard it; also the calling of fowls to
their food, and the barking of the house dog.

The sounds uttered by birds are so various
that to describe them physiologically in detail
would occupy a volume ; let it therefore suf-
fice, in concluding this section of our article,
to mention that the voice of birds has been
made the theme not only of the naturalist, but
also of numerous eminent writers both in
prose and verse.

Voice of Reptiles. — The mechanism of
the vocal organs in reptiles presents very diver-
sified forms. The larynx varies considerably
in structure, not only in different orders, but
in different genera of the same family. It
would therefore be impossible to compress
within the limits assigned to this article the

1502

VOICE.

minute anatomy of the several species ; they
have been recently investigated and detailed
in a monograph by Henle.

Sauria. — In the Crocodile the larynx is com-
posed of three cartilages, namely, the thy-
roid and cricoid consolidated into one ring-
formed cartilage, called the thyro-cricoid, and
the two arytenoid cartilages. The basi-hyoid
element of the hyoid bone is expanded into a
disc; and lies in front of the larynx, which it
protects ami supports. The arytenoid car-
tilages are connected with the superior margin
of the thyro-cricoid by a membranous suture,
but nothing approaching to a joint furnished
with ligaments and synovial membrane is ob-
servable. The mucous membrane of the
larynx is reflected over the inferior margins
of the arytenoid cartilages, and forms a deep
pouch beneath them, leaving a free fold with
a margin on each side; so that, when these
cartilages are brought near each other, this
fold forms the vocal cord, and produces the
tones peculiar to the Alligators In the Ca-
meleon the larynx is provided with a sac in
front, similar to that observed in some of the
Quadrumana. The air passes to and from
this sac by means of an opening, lying between
the lower margin of the larynx and the first
ring of the trachea. The larynx of this ani-
mal has been very minutely described by
Treviranus.

Some reptiles have a membrane at the base
of the tongue, which answers to the epiglottis ;
others have a cartilaginous epiglottis ; others
again a mere bony or cartilaginous processus
epiglottieus, as in birds. “ But,” observes
Henle, “ the presence of this process does
not imply that there is no epiglottis, or con-
versely, the presence of an epiglottis that there
is no processus epiglottieus.” Cuvier de-
scribed five cartilages in the larynx of the
crocodile, but it is now generally admitted
that he was mistaken.

The vocal cords are more perfectly deve-
loped in the Gecko, and thecanieleon, than in the
crocodile. They are broad membranous folds
passing from the bases of the arytenoid car-
tilages to the innersurface of the crico-thyroid.

In the Lacerta a very thin membranous fold
is found passing from the bases of these car-
tilages in the position of the vocal ligaments ;
but Henle is of opinion that the acute chirp-
ing tone of the lizard depends rather on the
vibration of the margins of the glottis, than
on these folds, which are incapable of being
approximated to each other, or brought into
a state of tension.

Chelonia. — The vocal organs of the Chelonia
are not adapted for perfect intonation of the
breath, being destitute of vocal cords. The
superior portion of the larynx is surrounded
by, and connected with the basi-hyoid element
of the os hyoides as in the Sauria. In the
Emys, and the Testudo, the thyroid cartilage is
annular, and distinct from the cricoid ; the
arytenoids are triangular, and the internal
surface is much enlarged, owing to the very
concave form of the larynx. In the Midas,
the aditus laryngis is furnished with a fold of

mucous membrane, which serves for the pro-
duction of certain sounds. In the great tor-
toise of Madagascar, Cuvier describes a tri
angular membranous crest attached to the
base of the larynx which, ascending to its
opening, divides it into two parts, and is
analogous to what is found in the superior
larynx of some birds. Meckel found the same
kind of crest in T. tahulala, but it is absent
in T. Grceca and several other species. The
muscles of the larynx are the constrictor, and
the dilator aditus laryngis.

Ophidia. — In this class the larynx i< very
little developed, with regard either to volume
or to mechanism. The upper rings of the
trachea are consolidated into a crico-thyroid
cartilage, to which the arytenoids are attached.
In some species these are sessile, mere pro-
cesses of the crico-thyroid ; and in others, they
are divided from it by a suture, but in the
pythons and boas they are free. The processus
epiglottieus is nearly quadrangular in the
Boa: the vocal cords are absent, and therefore
the voice is reduced to a mere hissing sound,
which is produced by the breath passing over
tlie edges of the aditus laryngis. The muscles
of the larynx are the elevator, depressor, di-
lator, and compressor laryngis.

Batrachia. — In the Batrachia the two
arytenoid cartilages form a considerable por-
tion of the frame of the larynx, and the cri-
coid, with a few exceptions, is a complete
ring. The arytenoids are triangular, and their
apices being upwards form the superior lateral
boundaries of the larynx. The vocal cords
pass from end to end of the bases of the
triangles. According to Henle, the wholeof the
tailless Batrachia, except the Pipa and the Dac-
tylethro, have vocal cords. In Bufo there are
two pairs of vocal cords (y?g. 9 19), correspond-
ing to the inferior vocal cords in Mammalia.

Fig. 919.

Bufo.

a, and b, semilunar folds of the superior vocal
cord ; c. inferior vocal cord ; d, lung.

Above and below the vocal cords there are sacs
lined with mucous membrane, and bounded by
the arytenoid cartilages. Between the vocal
cords a small cartilage is sometimes found.

VOICE.

1503

In Bombinator igncus, Hyla vetrucosa, and
others, the arytenoid cartilages are regular
obtuse-angled, and nearly equilateral triangles.
In B. cinereus they are more acute-angled, and
directed backwards. The vocal cords in bufo
are very thin elastic membranes, sucli as might
be expected to produce the croaking deep
tones of these batrachia.

In Pipa the larynx is a very peculiar piece
of mechanism ; tiie arytenoid cartilages being
convex externally and concave internally, so
that when the entrance to the larynx is closed
they form a dome over the windpipe, which
Cuvier has compared to a kettle-drum.

In Rana temporaria, R. esculenta, and Hyla, the
males are provided with two sacs, which open
by a straight canal into the larynx. These sacs
are situated on each side of the lower jaw,
and are capable of considerable distension,
when filled with air during the cry of the
animal. Cuvier, Roesel, and Blumenbach,
describe only one sac in Hyla ; but Meckel,
as well as Henle and myself, found two sacs,
as in the other frogs. These sacs doubt-
less exert a powerful influence on the quality
of the sounds which frogs utter, analogous
to the influence of similar sacs which exist in
many of the higher animals.

Fig. 920.

Rana temporaria.

a, tongue ; b, os hyoides ; c, superior vocal cords ;
d, inferior vocal cords ; e, pharynx ; f right
bronchus.

The muscles acting on the larynx in Batra-
chia are the dilator aditus laryngis and the
constrictor aditus. Besides these, there is
found in the tailless Batrachia a third muscle,
the compressor glottidis, which in Bi ito arises
from the columella*, and is inserted into the
posterior point of the arytenoid cartilage. Its
use is to compress the larynx, to bend the
posterior angle of the arytenoid outwards, and
to expand the vocal ligament. It is the most
important muscle connected with the voice in
the tailless Batrachia. Its course varies in
different species, and is absent altogether in
Pipa.

* One of the inferior processes of the os hyoides.

In Proteus anguinus the most simple form
of cartilaginous larynx is found, consisting of
lateral cartilaginous strips, divided in two on
each side ; the superior portion answering to
the arytenoid cartilage of the higher orders of
animals, the inferior to the laryngo-trachealis
cartilages.

In the Triton, and Salamander, the larynx
consists of a membranous sac, which is kept
open by the lateral cartilages of the vocal tube.
Hence we learn that the arytenoid cartilages
do not wholly disappear, until the larynx be-
comes entirely membranous.

Insecta. — A large number of insects are
mute; some produce their sounds merely by
friction, and others by the passage of the air
through the thoracic spiracles. The sounds
produced by friction are denominated stridu-
lation ; those by the air from the tracheae,
buzzing, or humming (bourdonnement), &c.
Organs adapted to produce stridulation are
found in the Orthoptera, Omoptera, and some
of the Coleoptera.

Gryl/i. — In the Gryllus camjiestris (Jig. 921)
the elytrum is composed of dry, thin, trans-
lucent membranes, forming two planes, united
and strengthened at their junction by four
longitudinal and parallel nervures ; one of
these planes lies on the back, and the other
on the side of the insect. The former
of these planes is divided by a series of
regularly curved nervures, into a number
of areoles. The musical apparatus may
be divided into two systems, the first com-
posed of four oblique nervures, which ter-
minate in a strong nervure, serrated like a
file (a) ; this may be considered as the bow.
The second is formed of three nervures, which
take their origin in a remarkable point in the
internal border of the elytrum, furnished with
a tuft of short still' hairs, or brush (5); above
this point is found a firm, transparent, and
nearly triangular disc or sounding plate *,
surrounded by a nervure. When the insect
cries, the wings are crossed, and the bow
rubbed rapidly across the whole length of the
Fig. 921.

1. 2.

Elytra of Gryllus campestris.
disc or sounding plate, whereby the whole of
both elytra are put in a state of vibration, and
the stridnlous sounds peculiar to these grylli
result. The pitch of the sound of the house
cricket is very acute, being equivalent to about
409(3 vibrations in a second.

Cicada ?, Cigales. — The Cicadas have their
musical instruments inclosed in the interior
of the abdomen. Reaumur gives a detailed
description, illustrated by drawings, by which
they may readily be recognised. These in-
struments, he says, are contained in the abdo-

* Termed by M. Goureau the “chanterelle.”

loOT

VOICE.

minal cavity, divided into two cells by a scaly
partition of a triangular form, covered by two
cartilaginous plates, acting as shutters or
opercula. When viewed from the abdominal
surface, each cell presents exteriorly a white
folded membrane with radiated reflections,
which he terms the mirror. On opening from
the upper surface the part of the abdomen
corresponding to the cavity, we perceive on
each side a plaited membrane, dry and sono-
rous, which is moved by a powerful muscle,
composed of straight parallel fibres springing
from the scaly partition ; this membrane is the
tymbal. In order to bring into play an instru-
ment so complicated, Reaumur states that the
insect alternately contracts and relaxes the
muscle attached to the tymbal, and by this
means produces the sound. He believes that
“ this sound is augmented in the drum, and
that this portion of the vocal organ has no
other use than to give it brilliancy.” He also
imagines “ that the trochanter of the haunch
performs the office of a curb, and prevents
the operculum from being too much elevated
during the song. Some doubts have arisen
with regard to this simple explanation of the
song of the Cicadas, and entomologists have
concluded that the air performs an important
part in the formation of the voice, and that
it is due, at least in a great measure, to a rapid
current issuing from the stigmata of the meta-
thorax, which resounds within the organs
above described.”

The humming, or buzzing or Insects. —
It has been supposed by some entomologists
that the hum of insects is produced by the os-
cillations of their wings during flight, and this
supposition is strengthened by the fact that
the tones are altered during the suspension
of the insects in the air, and that the sound
becomes more acute when the tips of the wings
are removed. This hypothesis will not, how-
ever, bear the test of rigid investigation.

It was observed by John Hunter, “ that in-
sects emitted sounds after their wings were
cut off.* De Geerf, finding that after he had
cut off the wings, winglets, and poisers, the
buzzing continued, placed the insect under a
microscope, and observing that the stumps of
the wings were in rapid motion, he pulled
them off by the roots, on which the buzzing
ceased ; and hence he inferred that the sound
was produced by the vibrations of the wings.
But it is not surprising that insects, after such
mutilation cease to emit any sound. Bur-
meister| is of opinion that the sounds of some
Diptera, such as Tabanus bovinus, are produced
by a stream of air rapidly transmitted through
the thoracic air-holes during flight. He has
described and figured the mechanism of the
thorax and the air-holes of the Eristalis ienax,
which is as follows: — The aperture of the
hinder air-hole is provided with a sphincter
muscle, perpendicular to the inner surface of
which are sixteen or eighteen horny lamellae, of
the same breadth as the muscle, and connected in

* Phil. Trans. 1792. t Vol. “• P- 13-

X Art xvi. p 377. Taylor’s Scientific Memoirs.

the middle by another longitudinal horny band.
The sphincter muscle is lined with a membrane
clothed with feathery hairs, which cover the
air-hole like a sieve, and exclude foreign bodies.
He leaves it to naturalists to decide whether
or not this mechanism contributes to the form-
ation of the sound ; adding that either way
it is of little consequence, as many insects
have no such lamellae. He observes that when
the insect sits or crawls it breathes through
the air-holes of the abdomen, but during flight
through those of the thorax. He considers
the hum of insects to be in reality a whistle.
The pitch of this hum is hitherto unexplained,
although it is quite certain that it does not
depend upon the number of the vibrations of
the wings, for in a favourable light the motion
of the wings of many insects, whose hum is of
a high pitch, can be clearly detected ; but, if
that pitch were owing to the vibrations of the
wings, their number would necessarily be so
great as to render the motion imperceptible.*
The author has recently examined, with
Professor Queekett, the spiracles of other
insects, such as the blue-bottle fly, and the
humble bee, and has discovered in them a
beautifully organised valvular opening, capable
of producing the sounds which these insects
emit during flight, f In Jig. 922. is shown
one of the large thoracic spiracles of a blow
fly ( Musca vomitoria) ; it consists of two
valves, one much larger than the other, each

Fig. 922.

Thoracic spiracle of the blow-fly, Musca vomitoria.

being provided with numerous branching
horny filaments or hairs which serve as a
support to the thin membrane forming the
valve ; a somewhat similar form of spiracle
occurs in the humble bee, (jig. 923). The
valves are nearly of equal size, and the
branching hairs are much stronger and more
numerous than those in the blow fly. j

* Those who wish to pursue the subject further
may consult the second note to p. 425. art. Motion.,
f The pitch of the blue-bottle fly ranges, in
different species, from 288 to 341 vibrations in a
second.

WRIST-JOINT

Besides stridulation, and humming, some
insects, such as bees, emit a cry, or, as the
French entomologists term it, piaulement.
M. Goureau supposes this variety of voice to
be used, when bees swarm preparatory to their
emigration. He remarks that those insects
which produce the sound by friction are not
singers, but musicians ; and that insects in
general make use of their voices to communi-
cate certain ideas and sensations.

Fig. 923.

Thoracic spiracle of the Humble Bee (Bombas
terrestris).

In insects we find a great diversity of beau-
tifully contrived mechanism for the modula-
tion of sound, all answering the same end in
the economy of these countless myriads of
minute beings.

Bibliography . — J. Casserii Placent. Be Vocis
Organis, Ferrar, 1600, fol. Hieron Fabricii, Oper.
omn. Lips. 1637,. fol. Aristotle, tom. ii. p. 281.
Galen, tom. iv. chap xi. Dodart, M€m. de I’ Acad,
de Paris, 1700, 1706, 1707. Wallis (J.), Be Lo-
quela, 1740. Ferrein, ibid, 1741. Bertin, Notiveanx
Sys. de laVoix, 1745. Herrissant, Mem. del’Acad.
de Paris, 1753. Steller, Beschreibung von Sonder-
baren Meerthieren, Halle, 1753. Busch, Be Mecha-
nismoOrgani Vocis, Groning. 1770. Pallas, Spicilegia
Zoolog. Berolini, 1777, 1778. Vicq-D’Azyr, Mem.
de 1’Acad., 1779. Camper, Phil. Trans., 1779. Vogel
(B. A.), Be Laiynge Humana; et Haller, Element.
Physiol. tom. iii. vol. ii., 1787. Amman (J. C.),
1790. Humboldt and Bonpland, Kecueil d’Observ. de
Zool., Paris, 1805, fol. Blumenbach, Handbuch der
Vergleichenden Anat. Gottingen, 1805. Dutrochet,
Essai d’une Nouvelle Theorie de la Voix ILumaine.
Paris, 1806. Young (Dr. T.) Lectures on Natural
Philosophy, vol. iv., 1807. Yarrell, Linn. Trans,
vol. xvi. Gocliel, Be Voce Animal. Mix. Acad. Nat.
Cur. Wolff, Biss. Anat. de Organo Vocis Mam-
malium. Berol. 1812. Savart, Annal. etdeChemie
de Physique, tom. 24. 26. 29. 32. IJscovius, Theorie
der Stimme. Leipz. 1814. Magendie, Prdcis Ele-
ment. de Phys. Perrault, Mem. pour servir a
l’Histoire des Anim. tom. iii. Biot, Precis Element,
de Physique, Paris, 1824. Chladni, in Gilbert’s Ann.
76. p. 187. Bennati, Recherch.es sur le Me'canisme
de la Voix Humaine. Paris, 1832. Willis, Trans.
Phil. Soc. Cambridge, 1832. Sir C. Bell, Phil. Trans.
1836. Gurlt,~Ver gl. Anat. der Hanssaugethiere, 1836.
Goureau, Essai sur la Stridulation des Insectes. Ann.
de la Societe Entomologique. Paris, 1837. Burmeister
(H.), On the Cause of the Sound produced by

VOL. IV.

(Normal Anatomy). 1505

Insects in Plying, Taylor's Scientific Memoirs,
vol. i. 1837. Meckei, Anat. Comparee, tome dixieme.
Paris, 1838. Henle, Bes Kehlkopfs der Reptilien.
Leipzig, 1839. Cams, Lehrbuch der Vercliliehenden
Zootomie, Bd. 1. Wagner, Lehrbuch der Ver-
chleichenden Anat. Treviranus, Erscheinungen und
Gesetze Organischen. Bd. 2. Cuvier, Anat. Com-
paree, tom. viii. Paris. 1846. Mayo, Outlines of
Physiol. Lehfeldt, Biss, de Vocis Formatione, Berol.
Muller, Elements of Physiol, by Baly, p. 1002.

(John Bishop.)

WORMIAN A OSSA ( vide Cranium).

WRIST-JOINT ( Radio-carpal Articula-
tion), Normal Anatomy of the. — The ar-
ticulation of the wrist results from the union
of the bones of the fore-arm with those of the
hand, and is constituted by the contact of the
lower surfaces of the radius and of the trian-
gular interarticular cartilage with the sca-
phoid, lunar, and cuneiform bones of the
carpus. The radius and the triangular fibro-
cartilage accordingly present a uniformly
smooth and slightly concave surface, whilst
the first three bones of the carpus afford a
surface which is as uniformly convex. The
transverse measurement of these articular
surfaces is greater than the antero-posterior,
since the former averages one inch and a half
in the adult male, whilst the latter scarcely
exceeds three quarters of an inch.

In this joint are found all the anatomical
dispositions which characterize other arthro-
dial articulations : the hones are invested with
cartilage, lined by a synovial membrane, and
present smooth surfaces which deviate but
slightly from being planiform ; and lastly, the
ligaments connecting the osseous surfaces are
so disposed, as to admit of all the free gliding
motions which are indispensable to the hand
as an organ of touch and of prehension.

It is proposed in this article to describe,
seriatim, the different structures which enter
into the composition of the radio-carpal
articulation, with their relative anatomy, but
for a detailed account of the surgical anatomy
of the region of the wrist, the reader is re-
ferred to the article Hand, where this subject
has been fully entered into.

I. The Bones which constitute the wrist-joint.

a. The Radius. — The lower end of the
radius, which is of a quadrilateral form, is
curved so as to present a concavity ante-
riorly, and a convexity in the opposite
direction. On its different aspects various
objects of interest present themselves to view,
which maybe thus enumerated: — Anteriorly
is seen a smooth surface, to which the ten-
dons of the flexor muscles, surrounded by
their synovial sheath, are applied ; posteriorly ,
a series of depressions and irregular elevations
are observable, the former of which indicate
the course of different tendons passing to the
hand. Of these depressions the most ex-
ternal is a broad but shallow groove, which
lodges the tendons of the radial extensors of
the carpus : to its inner side, but separated
from it by a well-marked ridge, is a narrow
deep groove, which runs obliquely down-
wards and outwards, and transmits in this

5 D

1506

WRIST-JOINT (Normal Anatomy).

direction the tendon of the extensor secundi
internodii pollicis. The remainder of the
dorsal aspect of the radius is subjacent to the
tendons of the m. extensor digitorum com-
munis and the extensor indicis. The outer
surface of the lower extremity of the radius is
the least extensive, and is furnished with a
shallow groove, which affords insertion to the
tendon of the supinator longus, and gives
passage to the tendons of two of the extensor
muscles of the thumb, viz., the extensor ossis
metacarpi pollicis and extensor primi inter-
nodii pollicis. This surface is terminated
inferiorly by the styloid process , which lies on
a plane a little posterior to the last-mentioned
groove : lastly, the inner surface of this por-
tion of the bone presents a smooth concave
surface of oval form, its long axis directed
from before backwards, which serves for arti-
culation with the head of the ulna, and enters
into the formation of the inferior radio-ulnar
articulation. By its inferior surface, the radius
is adapted for articulation with the carpus. The
aspect of the surface, owing to the curvature
of the radius already indicated, is downwards
and forwards, whilst at the same time it is
directed slightly inwards, from its external
boundary passing lower than the internal.

The inferior surface of the radius presents
a triangular outline, the apex of which is
placed externally at the styloid process, whilst
the base, in the opposite direction, is consti-
tuted by the sharp margin separating the
inferior from the internal articular surface on
tlie radius, and serving for the attachment of
the broad extremity of the radio-ulnar inter-
articular cartilage ( triangular fibro cartilage').
The two margins which border this inferior
articulating surface of the radius serve for the
attachment of ligaments, and of these the
anterior is the most prominent. Lastly, the
carpal surface of the radius is divided into
two portions by a ridge, which traverses it
from before backwards : the external of these
articular “facettes” is triangular in shape,
and adapted to the scaphoid bone, whilst
the more internal of the two is quadrilateral,
and articulates with the semilunar carpal bone.

It has been mentioned that the radius at
its lower extremity undergoes a change of
form, and that from being cylindrical higher
up, it becomes here quadrilateral. This ex-
pansion of its surface takes place at the
expense of its solidity, for a section of the
bone shows that inferiorly the compact tissue
is extremely thin, whilst the cancellated tissue
is in proportion more abundant.

This circumstance is adduced, as in some
measure explaining the frequency of fracture
in this situation, an accident notoriously
common.

The ulna is excluded from the articulation
of the wrist by the triangular fibro-cartilage,
which stretches across transversely between
the head of the ulna above and the carpus
inferiorly, and presents a surface concave in
each direction.

The inferior surface of this fibro-cartilage
is on the same plane with the inferior surface

of the radius, and constitutes with it the
superior articulating surface of the wrist-joint.
The entire of this conjoint surface is some-
what oval (or diamond-shaped), and is limited
externally and internally by the styloid pro-
cesses of the radius and ulna respectively.

b. The Scaphoid, Semilunar, and Cuneiform
Bones of the Carpus. — The Carpus, superiorly,
presents a surface which is pretty uniformly
convex. That convexity, however, is slightly
interrupted by the undulating lines resulting
from the lateral articulations between the
bones which compose it.

The convexity of the upper surface of the
scaphoid bone is triangular in form, and articu-
lates with the outer facette on the inferior
surface of the radius; the semilunar bone is
quadrilateral in conformity with the shape of
the inner facette of the radius, whilst the
cuneiform bone presents a surface of a trian-
gular form, by which it comes accurately into
apposition with the inferior surface of the
radio-ulnar interarticular cartilage. The aspect
of the radial or upper conjoint surface of
those three bones is directed upwards and
slightly backwards.

II. The Ligaments. — These are placed on
each of the several aspects of the wrist, and
are usually designated from their position, —
the anterior, the posterior, and the lateral
radio-carpal ligaments. But whilst the wrist-
joint is thus protected on its different aspects
by ligamentous bands, it is to be observed
that no distinct intervals naturally separate
these ligaments from one another, so that it
might with strict propriety be said that the
articulation of the wrist is defended by a
ligamentous envelope of a capsular form, j
strengthened in particular parts, but more
especially laterally by other superimposed and
superadded fibres.

a. Anterior Radio-carpal Ligament. — The
fibres of this ligament are connected superiorly
to the anterior margin of the lower end of the
radius and of its styloid process, and to the
“ triangular ligament,” from whence they
radiate to their insertion into the anterior
surfaces of the scaphoid, semilunar, and cunei-
form bones. Below, they are partly con-
tinuous with the fibrous fasciculi ( interosseous
ligament), which connect the two rows of
carpal bones.

The fibres of the anterior radio-carpal
ligament pursue a direction for the most part
downwards and inwards.

By its anterior surface this ligament is in
relation with the tendons of the deep flexor
muscles, anti also (but more remotely), with
those of the superficial flexor, and with the
median nerve, the entire surrounded by an
extensive and complicated synovial apparatus.
Beneath these structures, and immediately in
front of the ligament, is the anastomosis,
between the anterior radial and the anterior
ulnar carpal arteries, which also receive tribu-
taries from the descending branches of the
interosseal, and the ascending of the deep
palmar arch of arteries.

b. Posterior Radio-carpal Ligament. — This

WRIST-JOINT. (Normal Anatomy). 1507

ligament much resembles the one last de-
scribed. Arising from the posterior edge of
the carpal end of the radius, its fibres pass
downwards and inwards to the back of the
carpus, where they expand and take an ex-
tensive attachment to the three inner bones
of the first range. The tendons of the ex-
tensor muscles of the fingers are related to
the superficial surface of this ligament, which
has also in contact with it the posterior carpal
arteries from the radial and ulnar trunks.

The anterior and posterior ligaments are
connected, both externally and internally, with
the lateral ligaments, so that no portion of
the periphery of the articulation is devoid of
ligamentous covering

c. External Lateral Ligament of the Wrist-
Joint. — The external lateral ligament is funi-
cular in form, and connects the styloid process
of the radius with the scaphoid and trapezium,
the two most external of the carpal bones.
The direction of its fibres is downwards and
backwards. The radial artery crosses ob-
liquely over the external surface of this liga-
ment, and separates it from the tendons of
the extensor ossis metacarpi and the extensor
primi internodii pollicis. The synovial mem-
brane lines its inner surface. When the hand
is fully adducted, this ligament is put upon
the stretch.

d. The internal lateral ligament. — This li-
gament is larger and longer than the pre-
ceding ; for, notwithstanding the greater
length of its styloid process, the ulna is more
widely separated from the carpus than is the
radius. This ligament connects the styloid
process of the ulna with the cuneiform hone,
giving a fasciculus to the fusiform bone and
to the anterior annular ligament. The tendon
of the extensor carpi ulnaris is posterior and
parallel to this ligament. The internal lateral
ligament limits abduction, so as to render it
the least extensive of all the motions enjoyed
by the wrist joint.

III. Synovial Membrane. — The synovial
membrane of the wrist joint is very extensive,
and contains a large quantity of synovia. Its
anatomical disposition is so simple as not to
require any special notice ; but it may be of
practical importance to remember the prox-
imity of this structure to the synovial sacs
between the lateral articulations of the carpal
bones, and also its contiguity to the articula-
tion between the trapezium and the first
metacarpal bone. The former circumstance
explains the facility with which acute inflam-
mation, occurring in the smaller carpal articu-
lations as the result of imparonychia, may be
propagated to the contiguous wrist joint,
where, too frequently, the morbid action thus
excited proves destructive to the articulation.
The latter circumstance demands our atten-
tion, since it teaches that, in amputating at
the first carpo-metacarpal articulation a care-
less use of the knife may inflict a wound upon
the wrist joint itself, from which the most
serious consequences may accrue.

The synovial membrane of the wrist joint is
separated from that of the inferior radio-

ulnar articulation by the triangular interarti-
cular cartilage. In amputating at the wrist
joint, if care be taken to leave the inter-
articular cartilage uninjured, the motions of
pronation and of supination will be left to the
forearm, and may therefore be communicated
to the artificial substitute for the amputated
hand. In this respect, the amputation
through the joint offers an advantage which
is sacrificed when amputation is performed
through the continuity of the bones of the
forearm.

IV. Mechanical Functions. — The wrist-
joint enjoys every variety of motion included
under the head of gliding motions (Bichat) ;
thus it is capable of flexion, extension, adduc-
tion, abduction, and circumduction. In the
motions of flexion and of extension, the carpus
rolls either forwards or backwards on the
lower articular surface of the radius. Flexion
is limited, not only by the posterior ligament,
but also by the lateral ligaments which are
attached behind the centre of motion of the
articulation. Extension is limited by the an-
terior ligament only. In adduction and abduc-
tion the carpal bones glide from side to side
on the surface opposed to them. Of these
motions abduction is the more limited, be-
cause, probably, the styloid process oftheradius
and the trapezium come sooner into mutual
contact than the corresponding parts at the
inner side of the joint do. In circumduction
(a motion compounded of all the preceding
ones), the hand moves through a circle re-
presenting the base of a hollow cone, the
apex of which is at the joint. The free gliding
of the carpal bones on each other causes this
movement to appear more extensive than it is
in reality, whilst it gives ail that ease and
grace to the movements of the wrist which
are in so especial a manner its characteristics.

The wrist joint thus constituted would not,
a priori, be supposed to enjoy that remarkable
immunity from accidental luxation which
must be conceded to it. In truth, this articu-
lation owes its remarkable strength and its
freedom from accidental displacements to the
mass of tendons which occupy its anterior
and posterior surfaces principally, not to its
ligamentous connections, nor to the form of its
osseous surfaces. Those tendons, like so
many vital ligaments kept tense as well by the
tonic as by the active contraction of their
muscles, and bound down by the annular liga-
ments, hear off', in a great degree, all violent
shocks from the joint itself, whilst, by their
antagonistic resistance to each other, they at
the same time maintain the bones in accurate
contact.

But whilst, owing to these circumstances,
the impetus of shocks applied to the hand are
borne oft' from the articulation of the wrist,
they fall in many instances with resistless
force upon the lower end of the radius,
which, owing to the thinness of its compact
tissue, is ill adapted for opposing an effectual
resistance. It has already been shown that
the ulna is but indirectly connected with the
carpus ; and that a layer of highly-elastic tissue
5 d 2

1508

WRIST-JOINT (Abnormal Anatomy).

intervenes between the carpus and that bone.
These circumstances taken in connection with
the remarkable mobility of the lower radio-
ulnar articulation sufficiently explain why the
ulna so frequently escapes injury from forces
which act on the hand, and which suffice to
fracture the radius. At the same time it is to
be observed, that displacements of the lower
extremity of the ulna are by no means unfre-
quent accompaniments of fractures of the
radius.

(Benjamin Geo. M‘Dowel.')

WRIST, Abnormal Conditions of. —
In the following account of the abnormal con-
dition of the different structures which enter
into the composition of the wrist, we shall
consider this region as formed not only by the
lower extremities of the bones of the forearm
and the wrist-joint, properly so called, but
also by the carpus surrounded by its fibrous
and fibro-synovial tissues.

The abnormal condition of the different
structures of this region may be arranged un-
der those which we can refer — 1st, to conge-
nital malformation; 2nd, to accident; and 3rd,
to disease.

Congenital. — Congenital dislocation of
the bones which constitute the radio-carpal
articulation may be considered rare; never-
theless, I have seen within these few years
thirteen examples of this malformation. One,
in which the bones of the forearm were
thrown forwards and the carpus backwards.
In the remaining twelve cases, the bones of
the forearm were placed on the dorsum of the
carpus, which they overlapped.

The history of congenital luxations of the
wrist-joint is modern. Cruveilhier, in his
Pathological Anatomy (liv. ix., 1833), ' has
published an example of this deformity, al-
though he was not himself aware of the true
nature of the case. The example he adduces
is that of an adult female, concerning whose
history, unfortunately, he could learn nothing.
In this case the forearm was preternaturally
short, and it formed a right-angle with the
hand, which besides was inclined to the
radial side of the forearm; extension was im-
possible; flexion, to a certain degree, was per-
mitted ; the inferior extremities of the radius
and ulna were dislocated backwards, and
formed a very considerable prominence be-
neath the skin posteriorly.

The extremity of the radius was less salient,
and descended much less than that of the ulna.
The superior extremity of the carpus could be
felt on a [Jane which was superior and ante-
rior to that of the inferior extremity of the
bones of the forearm.

Dissection. — The bones of the carpus were
found on dissection to be in a state of atrophy,
and more or less malformed ; the radius, short-
ened and deformed, scarcely measured five
inches; the deformity principally affected its
lower extremity, which was large and deeply
grooved posteriorly for the reception of the
tendons of the extensor muscles; the articular
surface for the carpus was placed on the an-

terior aspect of the bone; the ulna was only
six inches and a half in length, its lower ex -
tremity, much smaller than normal, descended
half an inch below the carpal extremity of the
radius.

Fig. 924.

The carpus was much deformed, particu-
larly as to the first row, which was merely, we
may say, in a rudimentary state. The pisi-
form was the only bone of this first range that
was normal. The bones of the second or
metacarpal row participated in the deformity.
The head of the os magnum was altogether
absent, and the unciform was imperfect.

Cruveilhier published the foregoing case,
erroneously supposing it an example of dislo-
cation of the wrist-joint, the result of accident.
Dupuytren and Marjolin disagreed with Cru-
veilhier, but equally mistook the true nature
of this case ; they, doubting the possibility of
an accidental luxation of the wrist-joint, con-
sidered that all the phenomena which the
post-mortem examination of the limb presented
in Cruveilhier’s example, might be accounted
for by supposing the case to have been one of
fracture of the radius, and consecutive dis-
placement of the ulna.

It must ever appear as a matter of surprise
that Cruveilhier could have supposed that this
case just adduced was an old accidental luxa-
tion left unreduced, because, according to such
an hypothesis, neither the arrest of develop-
ment as to the length of the forearm (which
only measured six inches and a half), nor the
abnormal appearances observed in the bones
of the carpus, could have been satisfactorily
accounted for, or explained.

It is equally difficult to imagine how it was
that Dupuytren, who had his attention so
much alive to the subject of congenital luxa-
tions, should have overlooked the true nature
of Cruveilhier’s case, and referred the pheno-
mena it presented to the circumstance of the
radius having been broken through its lower
epiphy sis ; no one ever heard of shortening ot
the radius to this amount as the result of frac-
ture ; besides, the bones on the carpus were in
a state of atrophy, and the ulna, which Du-

1503

WRIST-JOINT (Abnormal Anatomy).

puytren did not suppose had been fractured,
was deformed, and only six inches and a half
long.

At the period when this case, the subject of
so much difference of opinion between two
such eminent pathologists, attracted the atten-
tion of the profession in Dublin, the writer
had under his care, in the House of Industry,
a patient who was born with deformity of
both her wrist-joints and forearms, but whose
right wrist-joint presented appearances closely
resembling those described as characterising
the deformity of the wrist and forearm in
Cruveilhier’s case. As the history of this
woman’s case was known from her birth, it
was calculated to throw light on the subject
in dispute. It seemed on this and other ac-
counts so interesting, that on the loth of De-
cember, 1838, 1 laid it before the Pathological
Society in Dublin. It was as follows : —

Case II. — Deborah O’Neil, aged thirty,
has been an inmate of the House of Industry,

for the last seventeen years. She is liable to
occasional attacks of epilepsy. She cannot
be said to be insane, but she is wayward and
refractory, and will not submit to any rational
control. Yet she is very industrious. Her
upper arms and hands bear in size and length
a just proportion to the rest of her stature,
which is about the middle size, but her fore-
arms appear scarcely more than half their
normal length.

Her left forearm is dislocated forward at
the radio-carpal joint, while the right forearm
is dislocated, as in the preceding figure, back-
ward on the dorsum of the carpus.

The lower extremities of the bones of the
right forearm could be seen and felt on the
dorsum of the carpus, where they formed a
very remarkable projection. The lowest ex-
tremity of the ulna could be seen to descend
below the level of the lowest extremity of the
dislocated radius, and when the hand of the
patient was flexed could be made very promj-

Fig. 925.

Right Forearm, dislocated at Wrist. Case of O'Neil.

nently to distend the skin posteriorly. When
the surgeon introduced his fingers in front of
the wrist-joint, and made a slight extension of
the hand, the superior extremity of the carpus
could be felt to be placed superiorly and ante-
riorly to the lowest extremities of the bones
of the forearm. The hand inclined to the
radial side, it could be extended on the fore-
arm freely, but flexion was incomplete.

The left wrist-joint presented an unique
example of dislocation of the bones of the

forearm exactly in the opposite direction to
those already described. The forearm was
thrown forwards, and the carpus with the hand
on the back of the radius and ulna(y?g. 926.).

This woman presented a very grotesque ap-
pearance in consequence of the remarkable
shortness of both her forearms (Jigs. 926. and
927.) ; still she had a very good use of her
hands, and showed admirable dexterity and
skill in cutting out minute patterns on paper
with her scissors.

5 d 3

1510 WRIST-JOINT (Abnormal Anatomy).

As to this case of Deborah O’Neil, no am- been for many years previously, an inmate in
biguity existed. At the time the writer thus the House of Industry, under the constant
laid her case before the meeting, accompanied observation ot the whole medical staff of the
by casts of her forearms, she was, and had institution. The history of her life was known.

Left Forearm. Case of O'Neil.

It was stated that she never met with any of December, 1843, Mr. Smith exhibited be-
accident, and that the peculiar deformity fore a meeting of the Dublin Pathological
observable in each forearm and wrist-joint Society, the skeleton of the limb in this case,
had existed from her birth. The right extremity presented an example

The writer, in continuation, observed, that of luxation of the carpus forwards, while in
while congenital malformation was known very the left was afforded an instance of displace-
frequently to affect simultaneously both sides of ment of the carpus backwards.
the body, yet it would, on the other hand, be Right Extremity. — The upper arm and
very difficult for any one to suggest what pro- hand, as already mentioned, bore a just pro-
bable accidental causes could be imagined portion to each other, and to the stature of
capable of dislocating the bones of both wrist- the individual, but the forearms were scarcely^
joints, in opposite directions, as in the case of one half the usual length. The first range ot
O’Neil: besides, the mere displacement of the the carpus was articulated with the anterior
bones of both forearms at the wrist-joint, con- aspect of the radius, which bone was only
stituted only a part of the abnormal state of
things noticed, because both of the forearms
were so short as to measure only hall' the length
of the arm, and did not exceed in length the
measurement of the long axis of the hand.

The history of her case, then, from her birth- — -
the negative evidence as to the existence of
any previous accidental cause adequate to ac-
count for the appearances, and the actual
abnormal condition of both the upper extre-
mities of O’Neil — all taken together, suffi-
ciently proved her case to offer a curious spe-
cimen of congenital malformation of both
wrist-joints and forearms.”

When the writer presented this case to the
meeting of the Pathological Society, he laid
before the members two casts of the mal-
formed extremities of the patient, and when
the drawing of Cruveilhier’s case ( pi. 2.
liv. ix.), was placed along side of the cast of
the right forearm of O’Neil, every one pre-
sent agreed in the opinion that the cast pre-
sented an exact counter-part of Cruveilhier’s
drawing (fig. 924.).

Deborah O'Neil, five years subsequently to
this date, died suddenly of apoplexy, in the
Government Asylum, Island Bridge. Dr. R
W. Smith, the surgeon of the institution, made
a p ost mortem examination of the affected arti-
culations. The result fully proved, as had
been anticipated, that her right wrist-joint in
every respect resembled the remarkable case four inches and a half in length (Jig. 927.).
brought forward by Cruveilhier. The ulna, six inches in length, was prolonged

Post Mortem Examination. — Upon the 15th below the radius nearly half an inch, its lower

Fig. 927.

Skeleton of Right Forearm. Case of O'Neil.
( After Smith.)

151 1

WRIST-JOINT (Abnormal A’natomv).

extremity was destitute of the rounded head,
which in the normal state is received into the
concavity of the radius, and was carried for-
wards outwards and upwards (see Jig. 927.).
About half an inch above the level of its
lower extremity it was in contact with the
radius by a very small surface which was
destitute of cartilage. An anterior and pos-
terior ligament connected the two bones in
this situation, and permitted a very slight
degree of motion between them. The lower
extremity of the radius was totally destitute
of articulating surface, and was represented
by a rounded and blunt margin.

The surface for articulation with the carpus
was placed altogether on the anterior aspect
of the bone. It consisted of a deep excava-
tion of an oblong form, and its longest diame-
ter running somewhat transversely ; it was
tolerably smooth, though not invested with
cartilage.

The radius and ulna were not only remark-
ably short, but likewise atrophied, both as to
breadth and thickness.

Their superior extremities, with the excep-
tion of being unusually small, presented no
abnormal appearance.

The bones of the first row of the carpus
were in a state of atrophy, especially the
semi-lunar bone. When the hand was flexed
at a right angle with the forearm, the lower
end of the ulna formed a most conspicuous
projection, while during extension, two pro-
minences were seen ; one, in front, caused
by the carpus, the other posteriorly, mark-
ing the position of the lower extremities of
the bones of the forearm. The hand was
inclined to the radial side of the forearm ;
it admitted of being flexed to a right angle,
and could be extended perfectly. The ex-
tensor tendons in their passage from the
forearm to the hand were lodged in deep and
narrow grooves, or channels, formed on the
dorsal aspect of the radius.

Upon the left side the deformity was equally
remarkable, although the reverse of that no-
ticed on the right side. The carpus was re-
ceived into a socket formed for it by the
radius and ulna. This socket was not at the

lowest extremity of the bones of the forearm
but near to it, and on the dorsal aspect of
the bones, and it presented somewhat a
glenoid shape, the longest diameter of which
was directed obliquely downwards and in-
wards. With respect to the carpus, there was
neither a scaphoid nor semi-lunar bone. The
hand placed in the state of extension formed
a right angle with the forearm, but the patient
had the power of bringing it to a straight
line with the latter, in which position two
prominences were seen ; but, contrary to what
was observed on the opposite side, the dorsal
projection was here formed by the carpus,
the extremities of the radius and ulna con-
stituting the palmar eminences (see Jig. 927.).
In this left extremity, the carpus and forearm,
including the elbow joint, were malformed,
as well as the wrist-joint, but the rest of the
skeleton, with the exception of the right
wrist-joint and forearm, was quite normal.

Case III. — Case of congenital luxation of
the wrist-joint of both bones of the left fore-
arm backwards.

The writer exhibited to a meeting of the
Surgical Society of Dublin, on March 20th,
1847, the cast of the left forearm of an adult
female, who had been born with a luxation of
the carpal extremity of both the bones of
the left forearm backwards. The lower ex-
tremities of the radius and ulna were placed
completely on the dorsum of the carpus,
while the hand was, consequently, situated in
the front of these bones.

This remarkable cast of congenital luxa-
tion of the wrist-joint was sent across the
Atlantic by Dr. R. MacDonnell, now holding,
as a surgeon of the Montreal Hospital, a
distinguished place in British America.

We observe that in the casts ( figs. 928. and
929., the representations of Dr. R. MacDon-
nell’s case), the hand is well formed, but that
the forearm is much shorter than it should be,
being very little longer than the hand ; the
whole length of the forearm is not eight inches,
while that of the hand, measured in its greatest
length, amounts to six inches and one half.
The forearm in its upper part is round and
muscular; as we examine it towards the hand.

Fig. 928.

Congenital dislocation of both Bones of the Forearm backwards.

it assumes a well marked quadrilateral form,
and we observe a projection on the dorsum of
the carpus posteriori}', obviously formed by
the lower extremities of the radius and ulna,
which are dislocated backwards. The lower
extremity of the forearm at the wrist here
exhibits a very oblique termination, the ulna

having passed, by fully an inch, the carpal ex-
tremity of the radius.

When we place the forearm on its palmar
aspect, as on a table, and view the ulnar side
of it, we notice that the ulna rides conspi-
cuously on the back of the carpus, being
above its level about an inch ; and at the
5 d 4

1512

WRIST-JOINT (Abnormal Anatomy).

same time that the ulna has passed so far
downwards on the back of the carpus as to
reach even to the upper extremity of the
metacarpal bone of the little finger (see fig.

929.). The radius at its lowest part, besides
being thus shorter than the ulna, is much less
salient on the dorsum of the carpus.

The upper extremity of the carpus and the

Fie. 929.

hand are placed, as has been mentioned, an-
teriorly to, and somewhat above, the lowest
extremity of the radius and ulna, and conse-
quently the measurement of the antero-pos-
terior diameter of the wrist is much increased ;
the whole forearm is somewhat bowed, pre-
senting on its anterior aspect a concavity in
the longitudinal direction. Near the wrist-
joint the tendons of the flexor carpi ulnaris
on the inner side, and of the Hexor carpi ra-
dialis on the outer, or radial side, are thrown
into strong relief, and thus contribute to give
the quadrilateral form to the wrist above
alluded to.

Since the writer made this communication
to the Surgical Society of Dublin, he has
seen other cases of congenital luxation at the
wrist-joint of both the bones of the forearm
backwards on the dorsum of the carpus.
They so strongly resembled the cases just
now adduced, that he refrains from entering
into particulars. From all these last men-
tioned, the individuals practically suffered little
from the defect.

From the cases the writer has seen or in-
vestigated, he may draw the following conclu-
sions : —

1st. That the case of D. O’Neil, brought
before the Pathological Society of Dublin,
Dec. 15th, 1838, by the writer, was the first
example laid before the profession with the
intention of proving that such a lesion as a
congenital luxation of the wrist-joint existed.

2nd. That Cruveilhier’s case, adduced five
years previously, as a case of an old unreduced
luxation of the wrist-joint, and considered
by Dupuytren as a fracture of the radius and
dislocation of the ulna, and since misinter-
preted by others, must hereafter be looked
upon as an excellent example of congenital
luxation of both the bones of the forearm
backwards at the wrist-joint.

3rd. That the case sent to Dublin by Dr.
MacDonnell of Montreal, is another exam-
ple of a congenital luxation of the bones of
the fore-arm at the wrist-joint backwards.

4th. In these three the humerus and hand
seem to have borne, as to length and size, a
normal proportion to the stature of the indi-
viduals; but the forearms in all three were so
much shortened, as not to exceed by one
inch the measurement of the long axis of the
hand.

5th. The lower extremity of the ulna iri
the three cases, instead of being on a level
with the lower extremity of the radius, as it
normally is, had passed lower down on the
dorsum of the carpus from half an inch to
one inch.

Besides these three cases of congenital
luxation of the bones of the forearm back-
ward at the wrist-joint, Dr. R. Smith has, in
his valuable work recently published, referred
to two more specimens of the same malform-
ation. A cast of one of these specimens was
preserved in the Museum of the Bristol In-
firmary, in August, 1836, when the writer and
Dr. Smith visited that hospital, and the bones
of the other specimen have been preserved
in the Museum of the Richmond Hospital.

The case of O’Neil presented in her lett
forearm the only example of which we have-
heard of congenital luxation of the bones of
the forearm forwards (fig. 926.). In this case,
also, it is to be remarked, that the forearm was
preternaturally short.

Since the above observations were written
I have seen other examples of congenital
luxations of the wrist, in which the bones of
the forearm were displaced backwards, and
the carpus forwards, as in figs. 924. and 925.
Sometimes the defect was single, or only a(-
feeted one forearm ; in others, the defect, if
the paradoxical language be allowed, was sym-
metrical, affecting both wrists alike. A case
of this last description was shown to me
lately in the Downpatrick Infirmary, by the
surgeon of the institution, Mr. Brabazon,
who was kind enough to present me with a
cast, which I have in my possession* This
healthy young woman is the mother of many
well-formed children, and feels but little in-
convenience from the malformation.

When speaking of the congenital defects
of the elbow-joint, we noticed that the up-
per extremity of the radius often exceeded
its normal length, so as to reach as high as
the level of the olecranon process. (See
Elbow, Abnormal Condition of.) We may |
here remark, that the ulna as the result ot
congenital malformation, in almost all the
specimens we have examined, of the congenital

* This cast so much resembles that of fig- 929.,
that they could scarcely be supposed to have been
taken from two different individuals.

1513

WRIST-JOINT (Abnormal Anatomy).

luxation of the wrist, has been at least half
an inch lower down than the level of the
carpal extremity of the radius. The reverse,
however, of this I have lately seen, in a case
of congenital luxation of the wrist, under
Dr. M' Dowel's care, in the Whitworth Hos-
pital. In this case, of which Dr. Gordon has
been kind enough to present me with a cast,
the radius has, at its lower extremity, passed
half an inch lower down on the back of the
carpus than the ulna ; varieties have been also
noticed as to the carpus; in some cases the
bones of the carpus were not only malformed,
but deficient in number ; in one case nine
bones were found.

There are other congenital malformations of
the wrist-joint which demand some attention
from the physician and surgeon, such as
affections of the wrist analogous to valgus,
and cases of the foot and ankle, but we do
not consider this the place to discuss these
cases.

We may make the same remark as to those
congenital defects of the hand with deformity
of the wrist, which have been noticed to co-
incide with a deficiency in the brain on the
side opposite to the deformity.

Accident. — The principal lesions which
the structure that compose the region of the
wrist are liable to, are : —

1st. Dislocations of the wrist and neigh-
bouring radio-ulnar articulations.

2nd. Dislocations of the bones of the carpus.

3rd. Fractures of the lower extremities of
the bones of the forearm, in the immediate
vicinity of the wrist-joint.

1st. Dislocations. — Dislocations and frac-
tures of the bones entering into the com-
position of the wrist-joint are two kinds
of lesions, which for a long time have
been confounded together, or mistaken for
each other. Even in modern times authors
have stated the wrist-joint to be liable to
numerous luxations. Thus, Boyer, Petit, Mr.
Samuel Cooper, &c. &c., entered into a de-
scription of the different dislocations of the
wrist, as forwards, backwards, inwards, and
outwards, complete and incomplete, just as
Hippocrates and others, down to Celsus, had
done.

Nevertheless, some moderns, at the head
of whom we would place Dr. Colles of Dublin,
Dupuytren, and Sir Benjamin Brodie, main-
tained that luxations of the wrist-joint from
accident were either impossible, or, at all events,
exceedingly rare, and expressed their opinion
that authors had, under the erroneous name
of didocation, really described an accident
now pretty generally believed to be a frac-
ture of the radius in the immediate vicinity
of the wrist-joint, with displacement back-
wards of the carpus and hand.

Velpeau followed these, and not only de-
nied the reality of such an accident as simple
dislocation of the wrist, but gave his reasons
why he believed that no such accident could
occur, observing, that the strong tendons of
the flexor muscles of the forearm, bound
down by the anterior annular ligament of the

carpus, must render impossible any luxation
of the bones of the forearm forwards at the
wrist-joint, during any forcible bending back-
wards of the hand, such as might, for example,
be produced by a fall on the palm ; and, 2nd!y,
that the common and radial extensor (re-
strained as they are by the posterior annular
ligament), oppose any luxation of the bones
of the forearm backwards at the wrist during
a movement which should produce an extreme
flexion of the hand forwards.

Velpeau, however, admitted, that from ex-
periments he had made on the dead subject,
he had learned that efforts of a different order,
such as a forcible pulling, accompanied with
a simultaneous bending of the hand, whether
backwards or forwards, inwards or outwards,
might break every tissue, and produce a lux-
ation without any fracture of the radius. Such
cases, he says, he believes will always be ac-
companied with a wound of the integuments,
and are not to be looked upon as the simple
dislocations we are now considering, nor
should they, in his opinion, enter into the
same category with them.

In support of the doctrine, that most, if
not all, of the simple dislocations of the
wrist, of the authors already alluded to, were
really fractures of the lower extremity of the
radius, we confess that one observation of
Velpeau appears particularly strong, viz., that
for the last thirty or forty years in which the
question has been discussed, and the reality
of the luxation disputed, no one has brought
forward one instance which, rigidly examined,
he would look upon as an incontestable exam-
ple of a simple luxation of the wrist-joint.
He admits that the solitary case adduced by
Voillemier is a very notable one, and de-
serving of attention, but that in his opinion,
the question is still open as to whether a sim-
ple luxation of the wrist-joint can occur,
without there being at the same time any
lesion of the edges of the articular surfaces,
or of the integuments.

We think we cannot do better than here
give an abstract of this remarkable case, given
by Voillemier.*

“ Levillain Louis, ast. 27, of a vigorous con-
stitution, on the 28th Sept. 1839, was ad-
mitted under the care of M. le Noris, into
the Hopital des Cliniques (Paris) ; at the
moment of admission he was in a hopeless
state, completely insensible ; the pupils largely
dilated, the respiration stertorous. Amongst
other lesions from which the patient had suf-
fered, in consequence of his having fallen into
a court-yard from a window three stories high,
to the ground, it was noticed specially t/iat
the left wrist-joint presented a very remarkable
deformity, and of such a nature that Voille-
mier, prejudiced as he said he felt he was,
that a luxation of the wrist was a great rarity,
if not an impossibility, could not help saying
to his colleague, M. Dumeril, present at the
examination of the patient, that the case be-

* See Archives Generates de Medecine, Decemb.
1839, p. 400.

1514

WRIST-JOUSTT (Abnormal Anatomy).

fore them was one of dislocation of the wrist.
Four hours after the admission of the patient
into hospital he died.

“ The forearm was semi-flexed as well as the
hand. The bony plane represented by the
metacarpus and the carpus was almost parallel
to that of the forearm. The hand was neither
adducted nor abduced, but had suffered a dis-
placement “de totalite” towards the internal
side. At the posterior and inferior part of
the forearm there was a saliency formed by
the displaced carpus. A line drawn from the
summit of this saliency to the phalangeal ex-
tremity of the metacarpal bone to the middle
finger, measured three inches and seven lines,
the same length which the uninjured carpus and
metacarpus of the opposite side presented. At
the inferior and anterior part of the forearm
a, there existed a transverse eminence, situ-
ated about eight lines nearer to the extreme
point of the fingers, than the posterior sali-
ency b, while it projected anteriorly beyond
the plane of the palmar surface of the hand,
fully seven lines. The radii on both sides
measured alike. The skin was abraded, and
a wound about an inch long existed on the
dorsal surface of the radius near the wrist,
at about the level of the superior border of
the pronator quadratus.

Ligaments. — The external lateral ligament
and the posterior ligament were lacerated ;
the anterior completely torn from the border
of the radius. Some remnants of this struc-
ture lay on the front of the carpus. The in-
ternal lateral ligament was not torn, but the
styloid process of the ulna, maintained by this
ligament, and at the same time by the attach-
ment of the sheath of the flexor carpi ulnaris,
had been detached from the body of the bone.
Thus all the means of union of the articu-
lations had been completely severed, and the
bones of the forearm were only held to the
carpus by some bundles of fibres, which passed
posteriorly from the triangular ligament to
the internal side of the carpus.

Bones. — -The radius did not present any
trace of fracture ; the body of the ulna was
also unbroken, but its styloid process was
torn from the rest of the bone, although still
held by ligament and tendon, as above men-
tioned. In the new position which the bones
of the forearm had accidentally assumed, re-
latively to the carpus, they concealed and lay
in front of the whole first range of carpal
bones, and had been arrested in their descent
only by the true annular ligament, and the
tendons of those flexor muscles which pass
behind this ligament.”*

Let us suppose now a transverse fracture
of the radius, situated near to the wrist-joint,
with the displacement backwards of the in-
ferior fragment. This kind of accident will
most simulate a luxation of the wrist, such as
the foregoing case, in consequence of the
size of the two eminences, the one placed
anteriorly, the other posteriorly ; but in frac-

* Archives Generates de Medeeine, Decemb. 1839,
p. 401.

ture the anterior and posterior saliency, in
general, are not very conspicuous ; while in
luxation the posterior formed by the carpus,
and the anterior by the bones of the forearm,
have each a thickness of more than half an inch.

It is very true that we have seen cases
(see fig. 933., for example) of fractures through
the junction of the lower epiphyses of the
radius, with fracture also of the ulna, which
even in this amount of saliency of the anterior
and posterior prominency, much resembled
the case of a dislocation ; but the saliency pos-
teriorly in the case of the dislocation is formed
only by the rounded summit of the carpus, and
the measurement from this point to the ulti-
mate extremity of the middle finger gives
only the normal length of the hand ; whereas,
if the deformity at the back of the forearm
resulted from a fracture of the radius with
displacement backwards of the lower frag-
ment surmounting the carpus, a measurement
taken from the summit of the dorsal pro-
minence to the end of the middle finger would
show an increase of at least half an inch over
the normal length of the whole hand, because
to the summit of the carpus in the case of
fracture with displacement is superadded the
amount of the depth of the lower fragment
of the radius. By this test of measurement,
therefore, we might settle our diagnosis be-
tween these two accidents which so much
resemble each other.

The styloid process, too, of the radius can
be felt still holding its normal relation to
the carpus in cases of fracture, and to move
with the hand when any motion is communi-
cated to it ; whereas, in the rare dislocation
of the wrist-joint, which we are here consi-
dering, the lower extremity of the radius and
ulna will be found placed in front of the
carpus, and here, too, form an abrupt swell-
ing, just above the superior margin of the
annular ligament of the wrist.

Dislocation of the bones of the forearm baclc-
ivards with displacement forwards of the carpus.

— It is said that this dislocation, which is the
reverse of the foregoing case of Voillemier,
may occur as the result of accident.* Upon
this head all we have to say is, that this dis-
location of the bones of the forearm back-
wards at the wrist-joint, as the result of acci-
dent, must be exceedingly rare ; but that, on the
other hand, this is the very displacement of
the bones which so usually exists in almost
all cases of congenital dislocation of the wrist-
joint (figs. 924. and 925.).

Luxations of the lower extremity of the ulna.

— There are two species of this luxation of
the lower extremity of the ulna. In one, the
ulna escapes from the sigmoid cavity of the
radius in passing backwards ; in the other, it
is by the anterior part of the articulation that
the displacement occurs. Luxation of the
inferior extremity of the ulna backwards is the
more frequent of the two ; that forwards must
be rare, says Boyer, for 1 have seen but one

* See Nelaton, Ele'mens de Patbologie, vol. ii.
p. 408.

WRIST-JOINT (Abnormal Anatomy). 1515

example of it, and Dupuytren mentions that
he has met with but two. Sir A. Cooper
refers to only one case of dislocation of the
lower extremity of the ulna. In this case the
bone was thrown backwards.

Luxation of the lower extremity of the ulna
at the wrist-joint, backwards. — Desault has
published the history of a washerwoman who
had a luxation of the inferior extremity of the
ulna backwards, in consequence of the violent
and sudden pronation in which the wrist hail
been forced into while she was in the act of
wringing clothes.

In this luxation, backwards, the forearm and
hand are in a state of forced pronation, and
the two bones are strongly crossed, forming
with each other a very acute angle of decus-
sation ; the inferior part of the forearm is
much narrower than in the normal state ; the
forearm, the hand, and the fingers, are main-
tained in a state of moderate flexion, but
fixed ; the tendons of the flexor muscles of
the finger are, as it were, matted together into
a single fasciculus, displaced inwards, and
form a sensible saliency upon the ulnar border
of the radius.

What strikes one most, in looking at the
back part of the wrist, is the very manifest
projection on the dorsum of the region, formed
by the lower extremity of the ulna, which
rises so much above the level of the back of
the hand.

Luxation forwards. — Desault, Boyer, and
Dupuytren have each adverted to this dislo-
cation, in which we observe an oblique cross-
ing of the bones of the forearm; the fingers
are semiflexed, and there is a remarkable
narrowness of the inferior part of the limb.
The forearm and hand are fixed into a state
of supination, the saliency of the ulna is per-
ceived in front, the tendons of the flexor
muscles are pushed outwards towards the
radius, and the inferior part of the ulna,
instead of being parallel to that of the radius,
as in the normal state, is oblique from above
downwards, from within outwards, and from
behind forwards.

Boyer gives the following remarkable ex-
ample of this accident. In 1791, a woman
of a strong constitution, and of a spare, though
muscular frame, while in a state of intoxica-
tion, looking at two persons playing “domino”
in a cafe, in Paris, foolishly ventured some
advice to the players, who besought her not
to interrupt them. She, however, thought
proper to persist in giving her gratuitous
advice, until at last one of the players, a
strong and vigorous man, got up in a very
angry mood, seized her violently by the right
hand and endeavoured to push her out of the
room. In this movement her hand and fore-
arm were carried suddenly into a state of
preternatural supination. Immediately the
woman experienced the most acute pain,
and cried out that her wrist was broken.
The pain, the deformity, and the impossi-
bility she experienced of executing the or-
dinary movements of the forearm, made

her fear that she was most seriously injured”
“I was called in,” says Boyer, “instantly,
and I found the patient complaining of most
acute suffering, having the forearm flexed, the
hand fixed in a forced state of supination.
The least effort to communicate a movement
of pronation caused the patient the most acute
aggravation of her sufferings. The ulna
formed a very sensible prominence anteriorly,
and this bone, instead of being parallel to the
radius, formed with it an acute angle, crossing
its direction somewhat, and passing down-
wards, forwards, and outwards.” All these
symptoms taken together left no doubt on
the mind of Boyer, but that the case he had
to deal with was one of luxation forwards of
the lower extremity of the ulna. It was not
until after having tried thrice unsuccessfully
that at length he succeeded in reducing the
dislocation.

Luxations of the inferior extremity of the
ulna forwards from the scaphoid cavity of the
radius are, according to the opinion also of
Dupuytren, excessively rare, at least, “ in
the course of my long practice,” he says, “ I
have met with but two cases of this accident.”
One of these cases he gives us a detail of, as
follows ; — Case. M. Blot, an officer of the
gendarmerie, aet. 32, of a sanguine tempera-
ment and athletic constitution ; while on duty
during the night, the horse upon which he was
mounted took fright, reared up, and fell back
with his rider. The latter was happy enough
during the fall to disengage himself nearly
from the animal, with the exception that his
right arm was placed between the head of the
horse and the ground, and thus received a
violent shock. M. Blot, considering his fore-
arm broken, applied to two surgeons, who,
each in succession, recognised a dislocation
of the ulna at the wrist, and each, also, failed
in reducing the dislocation. M. Blot came to
Paris, suffering much, and applied at the
Hotel Dieu to Dupuytren, on 25th November.
He then laboured under the following symp-
toms : — The forearm was much swollen ; the
hand was in a median position between pro-
nation and supination ; the inferior part of the
forearm was deformed, rounded or rendered
cylindrical near the wrist-joint by the diminu-
tion of its bilateral diameter — a remarkable
saliency existed within and in front, formed
by the lower extremity of the ulna thrown
forwards towards the palmar aspect — behind,
a remarkable depression replaced the ac-
customed prominency formed by the lower
extremity of the ulna (la malleole interne) ;
indeed, behind, a depression existed instead
of the saliency ordinarily formed by the head
of the ulna. If we followed with the fin-
gers the ulna, from the elbow even to the
hand, we perceived that this bone directed
itself obliquely forwards and outwards in
crossing and passing over the inferior part
of the radius. The luxation of the radius
forwards became then evident. There was
no crepitation. The movements of pronation
and supination were completely lost. Du-

1516

WRIST-JOINT (Abnormal Anatomy).

puytren having failed at the first attempt, he
succeeded in reducing the luxation by inclin-
ing the hand forcibly to the radial side, and
pushing with his two thumbs, united the dis-
placed extremity of the ulna inwards and
backwards. By this process the reduction
was affected. The patient cried out at once,
“ I am well.” All deformity had disappeared,
and the motion of pronation and supination
were restored. (Gazette Medical, Malgaigne.)

Such cases as these, says Dupuytren, ought
to be recorded by every surgeon when he
meets with them, in consequence of their
rarity and importance.

Luxation of the bones of the carpus. — The
bones of the carpus are united to each other
so solidly, and their movements are so limited,
that without experience, we should be dis-
posed to pronounce luxation of any of these
bones impossible. Nevertheless, the head of
the os magnum may be dislocated from the
cavity formed for it by the scaphoid and semi-
lunar bones. The first range of the bones of
the carpus is articulated with the bones of the
second range in such a manner that slight
gliding movements of flexion and extension of
the hand are permitted, which augment a little
the movements of flexion aud extension of
the hand upon the forearm, and add some-
what, as Cruveilhier says, to the grace of the
movements of this portion of the upper ex-
tremity. In flexion, the head of the os mag-
num, which is somewhat inclined backwards,
raises up the thin capsule which surrounds
its articulation, and if this movement be
carried very far, the capsule and accessory
fibres which support the bone posteriorly are
broken, and the os magnum escapes from the
cavity in which it is naturally placed ; the dis-
location cannot be called complete, yet^ the
os magnum passes somewhat the level of the
posterior surface of the other bones of the
carpus.

The accident is more common in women
than in men, no doubt because the ligaments
are weaker and the bones enjoy greater
motion in the former, than in the latter. The
luxation backwards of the os magnum, the
only one which can occur, is always the result
of a forced and violent flexion of the wrist,
such, for example, as a fall on the back of the
hand would produce. We recognise the lux-
ation of the os magnum by the history of the
accident, and by the deformity produced. We
perceive a hard, circumscribed tumour, which
has suddenly appeared on the back of the
hand, in the situation which corresponds to
the head of the bone. This tumour becomes
more prominent when the hand is flexed, and
diminishes when it is extended : we can make
it disappear entirely by a slight compression.
This luxation causes but little inconvenience ;
but the head of the os magnum always remains
more salient when the hand is flexed, and
forms a tumour, more or less marked, accord-
ing to the extent of the displacement.

We can easily reduce this luxation by ex-
tending the hand, or by exercising a slight
pressure on the head of the os magnum ; but,

although it is easy to make the bone resume
its position in the cavity formed for it by the
scaphoid and semi-lunar bones, it is very dif-
ficult to maintain it there, and the incon-
venience and deformity resulting from the
luxation are so trivial, that few persons will
submit with patience to the means usually
recommended.

Fractures of the lower extremity of the radius
in the immediate vicinity of the wrist-joint. —
We believe that the first important effort to
direct attention to the peculiarities which the
fracture of the lower extremity of the radius
presents, was made by the late professor of
surgery, of the College of Surgeons, in Dublin,
Dr. A. Colies, in the year 1814.* Subse-
quently, we find Sir A. Cooper, in London,
and Dupuytren, in Paris, each pointing out
the importance, in a practical point of view,
of our studying this accident, and distin-
guishing the case of fracture of the radius
with displacement backwards of the carpus,
from true dislocation backwards of the hand
at the wrist-joint.

Velpeau followed these, concurring with
them in the opinion that a transverse frac-
ture of the lower extremity of the radius
was a very common injury, and frequently
mistaken for a dislocation. He seemed to be
even more positive than his predecessors in
maintaining the doctrine that no accidental
luxation of the wrist-joint could occur with-
out a fracture of some of the bony processes,
or laceration of the integuments.

This fracture is rarely attributable to any
direct cause; it appears, however, that Hub-
lier communicated to the Academy of Medi-
cine the case of a young girl, who having had
the wrist caught between the pole of a car-
riage and a wall, had gotten a transverse frac-
ture of the lower extremity of the radius. In
this case there was combined with the above
mentioned transverse fracture, another vertical
one at right angles with it, dividing into two
the lower fragment, constituting what in
other articulations we have elsewhere in this
book (vide Knee, Elbow) denominated a
T fracture. This species of fracture by direct
violence, corresponds much to the cases de-
scribed by Dupuytren as ‘‘Fracture par ecrase-
ment.” Fractures of the radius may be caused
by falls on the back of the hand, but by far
the most frequent sources of the fracture in
question are falls on the palm.

Malgaigne asks, by what mechanism are
these fractures of the lower extremity of the
radius specially produced. In reply he ad-
duces the following experiment by Nelaton : —
The latter amputated the forearm of a dead
body at the elbow, and cut off the olecronon
at a level with the head of the radius. He
then applied the palm of the hand of the sub-
ject on a solid plane, the forearm being at
the same time directed vertically; he now
with a mallet struck a heavy blow directly on
the superior extremity of the two bones of

* Vide Edinb. Med. and Surgical Journal, vol. x.
1814.

1517

WRIST-JOINT (Abnormal Anatomy),

the forearm. The wrist broke and became
immediately deformed. The dissection re-
vealed a simple and transverse fracture of the
carpal extremity of the radius, with a dis-
placement backwards of the lower fragment,
as with ordinary cases of fracture of the
radius in the immediate vicinity of the wrist-
joint, a species of injury, which in this city is
known by the name of “ Colles’ fracture.”

It would also appear to Malgaigne, Bouchet,
and Voillemier, that this fracture may be the
result of a sudden and violent flexion of the
hand without the patient having had any fall.
This fact was first established by Bouchet,
who, in endeavouring to produce dislocation
of the wrist on the dead body, only caused in
his experiments fractures of the inferior ex-
tremity of the radius ; sometimes with other
disorders, and more particularly with a simul-
taneous fracture of the styloid process of the
ulna.

Symptoms. — If Codes’ fracture of the
radius be produced by a fall, the patient will,

Fig.

sometimes, be able to say that at the moment
of the accident he felt a sensation of some-
thing having given way near to the wrist-joint.
The inferior extremity of the forearm and
the hand swell ; the fingers are semi-flexed,
and the patient experiences the greatest diffi-
culty in performing the ordinary movements
of the hand, or forearm. He usually pre-
sents himself to us with the hand of the
injured forearm resting on its ulnar margin,
and supported by the other hand, and in a
middle state between pronation and supina-
tion.

The posterior surface of the forearm usually
represents a considerable deformity ; for a
depression is seen to exist about one inch
above the line of the wrist-joint, whilst a con-
siderable swelling occupies the wrist itself and
metacarpus ; indeed, the carpus and base of
the metacarpus, appear to be thrown back-
wards so much, as at first view to excite a
suspicion that the radius had been dislocated
forwards, and the carpus and hand back-

930.

“ Colles ’ Fracture

wards ( Jig. 930.). On viewing the anterior sur-
face of the limb we observe a considerable
fulness, as if caused by the flexor tendons
being thrown forwards ; this fulness extends
upwards, to about one-third of the length of
the forearm, and terminates below at the
upper edge of the annular ligament of the
wrist.

The inferior fragment of the radius being
salient posteriorly, while the superior is
thrown forwards,' the injured forearm, viewed
side-ways, resembles, in the undulating direc-
tion of its long axis, the outline, according
to Velpeau’s idea, of a silver dinner-fork.
Besides presenting this very striking de-
formity, in this fracture we find the hand oc-
casionally thrown outwards, or towards the
radial side, and then the carpal extremity of
the ulna presents a strong saliency internally.
The degree, however, in which this projec-
tion towards the inner edge of the wrist takes
place, will be found to vary.

The patient is unwilling to attempt to pro-
nate or supinate his hand, and if we endea-
vour to communicate such movements, much
pain is produced. There is considerable pain
felt by the patient when we press firmly with
the point of the finger in the exact situation
of the fracture.

The internal lateral ligament of the wrist-

joint is generally put upon the stretch, and
the patient usually complains of much distress
here ; but this pain, which some patients feel
about the lower extremity of the ulna, does
not always arise simply from a sprain coin-
cident with the fracture or from a rupture of
the internal lateral ligament of the articula-
tion of the carpus with the forearm, but we
believe sometimes is owing to a fracture of
the root of the styloid process of the ulna.

It is in this last case more particularly that
the hand “ par un mouvement de totalite,” is
carried outwards, and that the ulna seems very
salient, internally (Jig. 931.).

A narrowing of the region of the wrist, in
the transverse direction, has been much ad-
verted to by Dupuytren, as a symptom of the
fracture we are now considering, but we
believe this narrowing is, in general, more ap-
parent than real. We rather concur with
Velpeau, who says, “ Many observations have
induced me to believe that Dupuytren, and
others, have been deceived as to the supposed
narrowing of the wrist.” He adds, an in-
terosseous space, in reality', does not exist
near to the wrist joint; indeed, there is scarcely
any open interval to be seen between the
lower extremity of the radius and ulna for the
space of one inch above the line of the radio-
carpal articulation. Now, fractures ordinarily

1518

WRIST-JOINT (Abnormal Anatomy).

take place at a point which is below the level
of this line, and any displacement, the result
of fracture, cannot readily affect the breadth
of the interosseous space, placed above the
line of the fracture.

Fig. 931.

It is only in cases where the fracture is
situated so high as an inch and a half, or
more, above the joint, that any abnormal ap-
proximation of the bones towards each other,
and ultimate obliteration of the interosseous
interval is to be dreaded.

Although therefore, as a result of Colies’
fracture, we observe the forearm assume, near
the wrist-joint, a cylindroidal form, there may
be no real narrowing whatever, but the ap-
pearance of it may be attributed rather to an
increase, in the antero-posterior diameter of
the region of the wrist, than to any real
diminution which occurs transversely.

Malgaigne has, however, adduced an example
to explain how, in certain rare cases, a diminu-
tion of the transverse diameter of the forearm
may occasionally take place, and by the
action of the pronator quadratus not on the
inferior, but on the upper fragment of the
radius. (Jig. 932.)

It is said by some, that crepitation, caused
by the movements of the fragments of the
broken radius on each other, can always be
elicited, and that this sign is diagnostic of
fracture ; moreover, that the deformity is
easy to reduce by extension, but liable to
return when the extending force is removed.
Such observations, no doubt, may sometimes
be made with truth. For our own parts, we
do not think that crepitation can, except in a
very few cases, be elicited in Colles’ fracture
of the radius. We have found it to be an
injury attended with a deformity which can,
it is true, be removed by extension, but our
experience corresponds with that of Sir A.

Cooper, who asserts that in this fracture a
very powerful extension is required to brine
the broken ends of the radius into apposition.

Fig. 932.

After Malgaigne.

Diagnosis. — In many cases, a fracture of the
radius in the immediate vicinity of the wrist-
joint is attended with so much deformity, and
accompanied with such characteristic appear-
ances, that the observation of Pouteau appears
well founded, that it can be recognised at the
first “ coup d’oeil but on the other hand,
there are some cases in which very little ex-
ternal evidence of any fracture can, without
careful examination, be detected. The un-
dulating curve, which has been compared to
that represented by a silver fork, cannot exist
without fracture, and the elevation from the
level of the back part of the radius of the
common extensor tendons is another feature,
which we believe with Velpeau to be peculiar
to fracture ; we know that in the normal
state the tendons of the extensor carpi radialis
longior and brevior remain applied as longi-
tudinal bands, lying flat on the posterior
surface of the radius, and no interval whatever
exists between these two bands and the back
part of this bone near to the wrist. Now,
when there is a fracture of the radius here,
this bone is rendered somewhat concave on its
posterior surface, and these tendons must, of
necessity, abandon the bony surface, and be
raised up several lines from it, so as to repre-
sent a cord, more or less tense, but easy
to depress. If, for example, the hand of
the patient being a little flexed, the surgeon j
in examining these cases, places his finger or
thumb three or four lines above the level of
the wrist-joint, on the posterior surface, arid
near to the external border of the radius, he
will, if fracture exist, recognise beneath the

WRIST-JOINT (Abnormal Anatomy''. 1519

skin the tense cord, and perceive that it can
be depressed even to the posterior surface of
the radius, from which it had been manifestly
elevated. This last is a test upon which
Velpeau specially relies.

Upon the subject of Diagnosis of this
fracture of the carpal end of the radius,
Dr. Colles remarks, — “ the facility with which
the surgeon can move the ulna backwards
and forwards, does not furnish him with any
useful help in his diagnosis as to the true
notion of the injury. Moreover, when he
moves his fingers along the anterior surface of
the radius, he finds it more full and prominent
than is natural ; a similar examination of the
posterior surface of this bone, induces him to
think that a depression exists about an inch
and one half above its carpal extremity. He
now may expect to find satisfactory proofs of
a fracture of the radius at this spot. For
this purpose he attempts to move the broken
pieces of the bone in opposite directions, but,
the patient is by this examination subjected
to considerable pain, yet neither crepitus, nor
a yielding of the bone at the seat of fracture,
nor any other positive evidence of the ex-
istence of such an injury is thereby obtained.
At last,” adds Dr. Colles, “ after many un-
successful trials, I hit upon the following
simple method of examination, by which I
was enabled to ascertain that the symptoms
above enumerated actually arose from a frac-
ture of the lower extremity of the radius •
— let the surgeon apply the fingers of one
hand to the seat of the suspected fracture,
and locking the other hand in that of the
patient, make a moderate extension, until he
observes the limb restored to its natural form.
As soon as this is affected, let him move the
patient’s hand backward and forward, and he
will, at every such attempt, be sensible to a
yielding of the fractured end of the bone, and
this to such a degree as to remove all doubt
from his mind.”

I have already stated that sometimes the
fracture may exist without being accompanied
by any appreciable displacement of the bones.
The patient complains of a severe pain in the
region of the wrist, when pressure is made
on the broken part, and also when the fore-
arm is moved. These are the only symptoms
which exist, (if we except a slight swelling,
particularly observable on the anterior surface
of the wrist,) so that one would be tempted
to believe that there was only a simple sprain
existing. If, however, we make pressure on
the line of the articulation, we do not cause
the patient any pain, which we should do, if
the symptoms arose from a sprain, while if
the same degree of pressure be made a few
lines above the joint, the pain is very severely
felt. Now, if we place a thumb on the radius
behind, in the presumed seat of fracture, and
make the effort to bend the wrist at this part,
so as it were to make the forearm here form
an angle on itself, salient anteriorly ; if the
angle be thus formed, we hereby obtain a
pathognomonic sign of the fracture ; and a
comparison of the two wrists submitted

equally to this experiment, puts the matter
beyond all doubt.*

Fractures of the lower extremity of the
radius are generally looked upon as serious
injuries. If this fracture has been mistaken
for a sprain, or luxation, or abandoned to
nature, according to Dupuytren, very serious
changes ensue. “ The forearm, in the region
of the wrist, instead of presenting a surface
flattened anteriorly, will assume a cylindroidal
form. The movement of pronation and
supination will be lost, an oedematous swell-
ing of the soft parts will continue ; the arti-
culation remains immovable for a consi-
derable time, and, if a rupture of the lateral
ligament of the inferior radio-cubital articula-
tion, or fracture of the styloid process of the
ulna be superadded to the fracture of the
lower extremity of the radius, we may see
continue for life the abnormal mobility of the
two bones on each other.” Mr. Diday, of
Paris, has gone further, and asserted that
these consequences of fracture of the radius,
above alluded to, are often observed, in spite
of all kinds of treatment, and of bandages,
which modern surgery has suggested.

In making an estimate, as to the amount of
evil resulting from the fracture of the lower
extremity of the radius and its usual con-
sequences, we find authors differ. Velpeau
would seem to attribute many of the evils
alluded to by Dupuytren rather to improper
bandages, and the manner of treating the
injury, than to anything in the nature of the
accident itself.

Although written so many years ago, the
opinion of Dr. Colles, as to the prognosis in
these cases, seems to us nearer the truth than
any of the above mentioned conflicting ob-
servations of the authors alluded to.

Dr. Colles remarks, “ that should the case
be treated as a case of sprain, and the fracture
left unreduced, the practitioner will find, after
a lapse of time, sufficient for removing similar
swellings, that the deformity is undiminished.
By such mistakes the patient is doomed to en-
dure for many months considerable stiffness,
and lameness of the limb, accompanied by
severe pains, in attempting to bend the hand
and fingers ; one consolation only' remains, the
limb will, at some future period, again enjoy
perfect freedom in all its motions, and be
completely exempt from pain, the deformity
will, however, remain undiminished through
life.”

Upon the whole, then, we may safely say,
that when the fracture we have been describing
has nothing unusual in it, and is only accom-
panied with the ordinary displacement back-
wards of the inferior fragment, that the case
generally proceeds favourably.

If the true nature of the accident has been
early recognised, and proper and sufficient
extension made of the forearm, the peculiar
characteristic curve disappears, not to return ;
the fingers are found to be much more free
in their movements, and can be more fully

* See Colles and Malgaigne.

1520

WRIST-JOINT (Abnormal Anatomy).

extended than before ; the pain disappears,
and in about a month after the fracture has
occured, if judicious treatment be adopted, the
union of the fragments is so perfect, that the
passive motion to restore the joints to their
primitive suppleness may be commenced.

Notwithstanding, therefore, the opinions of
Dupuytren, Biday, &c., &c., we think that, as
a general rule, in the case of Colics’ fracture
the prognosis is favourable.

It may be otherwise, if the styloid process
of the radius be elevated much above its
natural level, if the hand has quitted, par-
tially, the lower end of the ulna, so as to
be carried “ par un mouvement de totalite ”

outwards, and if the case has not been early
recognised.

Anatomical characters of the Fracture — On
dissection, it will be found that the hard
swelling which occupies the back part of the
hand and wrist, is caused by the displacement
backwards of the lower fragment of the radius
and the carpus carried with it in this direction.
As a consequence of the altered direction of
the radius, we find that the aspect of the
carpal articular surface of this bone is altered
and instead of being directed, as it normally
is *, downwards and somewhat forwards, it is
now directed downwards and backwards (fg,
933.) ; the carpus and metacarpus retaining

their connexion with the broken radius must
always thus follow this bone in its derange-
ments, and cause the characteristic dorsal
convexity above alluded to. The change of
direction of the articular surface of the radius
is well shown by measuring the length of the
broken radius in these cases, both on the
palmar and dorsal aspect of this bone longi-
tudinally, when it will be found that in Colies’
fracture, the posterior measurement is several
lines less than the anterior, which is exactly
the reverse of what this measurement normally
should be.

We dwell upon this abnormal ob'iquity of
the lower articular surface of the radius, for
in the treatment of this injury it should be
our principal aim to remedy this obliquity,
and, as it were, reverse it, and thus make the
aspect of the articular surface look as it
should normally do, downwards and forwards.

The change of direction of the articular
surface is caused by the extensor muscles
of the carpus, and of the thumb, and by
their tendons, which pass along the posterior
surface of the radius in sheaths, firmly con-
nected with the inferior extremity of this
bone, to which deviation in the direction of
the lower fragment the action of the supinator
longus muscle and its tendons may also some-
what contribute.

Professor Smith, who has investigated labo-
riously the anatomy of the bones in this injury,
says he has discovered nothing to invalidate
the truth of the general proposition first main-
tained by Voillemier, namely, that when the
radius is broken within an inch of its lower
extremity, the direction of the fracture is
usually transverse ; but we find that he differs
entirely from this last-named author upon the
doctrine of the fracture of the radius in ques-
tion, being one by impaction. It is very true,
he says, that in every instance of the ordinary

fracture of the carpal extremity of the radius,
which he had an opportunity of examining
anatomically long after the occurrence of the
injury, he found upon making a section of the
bone, from before backwards, a line of com
pact tissue continuous with the posterior wall
of the shaft, extending to a greater or less dis-
tance into the reticular texture of the lower
fragment ; but he cannot agree with Voillemier,
that this appearance affords evidence of im-
paction of the upper fragment into the lower.
In the only recent specimen Mr. Smith had an
opportunity of examining, the lower fragment
was displaced backwards, the superior pro-
jecting one-eighth of an inch in front of it.
There was no impaction whatever in this re-
cent specimen, of either fragment into the
other, nor any line of compact structure pene-
trating the reticular tissue of the lower frag-
ment.

If the doctrine of impaction were true, the
shortening of the radius in cases of fracture of
its lower extremity, should be much greater
than it ever is, for there is a second cause of
shortening in operation, i. e. the alteration in
the direction of the articulating surface, m
consequence of which the posterior surface of
the radius (naturally longer than the anterior)
becomes the shorter of the tw'o. Now', if to
the degree of shortening produced by this
cause we add that arising from impaction, we
should have an amount of shortening much
greater than ever occurs in the case of Colics’
fracture ; indeed, alter adducing other argu-

ments against the theory of Voillemier, as to
this being a case of fracture by “ penetration
Mr. Smith further remarks, that as long as the
ulna remains unbroken and the ligamentous
connexion between the two bones uninjured,
it is scarcely possible for either fragment to

* We always take it as understood that the
patient is in the erect posture.

WRIST-JOINT (Abnormal Anatomy). 1521

penetrate the other, even to the extent of half
an inch.

We agree with Velpeau, Smith, &c., in
thinking that in this injury, Colles’ fracture,
there is scarcely any diminution of the trans-
verse diameter of the forearm. The cylin-
droidal form which the arm acquires being
owing partly to an effusion among the flexor
tendons, but principally to the increase of the
antero-posterior diameter of the forearm at the
seat of the fracture, consequent on the back-
ward displacement of the lower fragment.

I have never seen the case, spoken of by
many, of transverse fracture of the radius, with
displacement forwards of the hand and lower
fragment, which accident is said to be pro-
duced by a fall on the back of the hand.

Fracture of the lower extremity of the Ulna.
— A fracture of the lower extremity of the
ulna is rather a rare accident, because, per-
haps, of the great elasticity of this long and
slender bone, and the mobility of its lower
end, by which it, as it were, eludes the force
which might otherwise cause its fracture. In-
deed the ulna, it will be recollected, is not
directly connected with the hand as the
radius, the “ manubrium manus,” is : and
hence, when a patient falls on the palm of the
hand, the whole force of the weight and im-
pulse are sustained by the radius ; but if this
last bone gives way, and a transverse fracture
occurs, with displacement backwards of the
hand and lower fragment, then, as a secondary
consequence, a fracture of the ulna, near the
wrist-joint, may follow. In the vast majority
of cases, however, of fracture of the radius
close to the wrist, which occur, for example, in
Colies’ fracture, the ulna remains unbroken.

Fracture of the lower extremity of the ulna
may also be the effect of direct violence.

When the ulna is broken alone, without
being accompanied by any simultaneous frac-
ture of the radius, it may be recognised by the
pain felt by the patient when direct pressure
is made on the broken part of the ulna, and by
the difficulty he experiences whenever he
attempts to pronate or supinate the forearm.
When the surgeon takes hold of the lower
fragment of the ulna, and moves it backwards
and forwards, crepitation can be felt.

Fracture of the lower extremity of the ulna
is an accident which requires much attention
from the surgeon, as sometimes, if the sepa-
rated fragment be small, as, for example, con-
sisting merely of the styloid process of the
ulna, no union may occur, and permanent
weakness of the wrist-joint may follow.

Disjunction of the lower Epiphysis of the
Radius. — This must be considered rather a
rare accident ; it is, however, occasionally to
be met with ; and the history of the art of
surgery furnishes us with well-marked ex-
amples of it, as the three following cases
sufficiently prove : —

Case 1. — “I have,” says Cloquet, “ ob-
served one case of the disjunction of the
lower epiphysis of the radius, in a young lad
twelve years of age, who Cell from a consi-
derable height from a tree to the ground.

VOL. IV.

Besides the injury done to the radius, he
received, at the time of the fall, a wound of
the head which in three days proved fatal to
him.”

Dissection. — The epiphysis of the right
radius was entirely separated, and a great
quantity of blood was effused in the deeper
palmar region, behind the tendons of the deep
flexor muscles of the fingers (Diction, de
Medecine, 1824).

Case 2. — Rognetta has adduced a similar
case of a lad at fifteen years (Gazette Medi-
cate, 1834.).

Case 3. — In December 15th, 1838, the
writer laid a case before the Pathological
Society of Dublin, which was a true speci-
men of a disjunction of the lower epiphysis of
the radius.

The patient, having been above eighteen
years of age, had attained to a more mature
time of life than any other example of this
special injury affecting the wrist hitherto
recorded ; a representation of the external
appearance which the lower part of the fore-
arm and carpus presented in this case have
been preserved by a plaster cast ; and after
the death of the patient, the actual condition
of the parts having been ascertained anato-
mically, these circumstances, in the writer’s
opinion, make this case valuable.

A. B., aet. eighteen, a mason, fell from a scaf-
fold which was attached to the front of a lofty
house at its third story. By the fall he re-
ceived a severe injury of the head, which
rendered him immediately insensible, and in
this condition was admitted into the Richmond
Hospital. Besides the injury of the head, we
noticed in this case a remarkable lesion ; the
right wrist had suffered a derangement, accom-
panied with a deformity that at first sight we
might suppose would be produced by a dislo-
cation of the carpus and hand backwards on
the dorsum of the forearm (Jig. 931.). The
plane of the hand and carpus were placed fully
three quarters of an inch behind the plane of
the rest of the forearm ; and from the external
appearances there seemed no doubt but that
there was an abrupt transverse solution of
continuity of the forearm, close to the wrist-
joint, which equally affected both radius and
ulna.

On viewing the limb laterally, the peculiar
curve which Velpeau compared to the back of
a silver dinner fork, was exaggerated beyond
what we noticed in the ordinary fracture of the
radius in this situation; and the tendons of the
extensors, particularly those of the extensor
carpi, were thrown remarkably into relief.
The anterior, or palmar surface of the fore-
arm presented a longer and more uniform
curve than the posterior ; the depth of the
antero-posterior diameter of the wrist in the
seat of injury was much increased : so that
this and the bilateral measurement seemed
equal.

Thus the accident presented many of the
appearances of the dislocation, backwards, of
the hand and carpus ; but the longitudinal
measurement, taken from the highest part of

5 e

1522 WRIS-TJ01NT (Abnormal Anatomy).

the dorsal prominence to the root of the in- inch over that of the opposite hand. This
dex finger ( from A to B fig. 934.), on the in- excess of length was manifestly caused by
jured side, gave an excess of length of half an the presence of the disjoined epiphysis, which

Fig. 934.

Disjunction of the Epiphysis of the Radius , with displacement backwards of the Hand and Carpus.

— Author’s Collection.

had been superadded to the summit of the
carpus, and was carried back with it, the
wrist-joint itself remaining perfect.

This simple test of the comparative measure-
ment proved the case was not one of mere
dislocation of the hand ; but we may also add,
that, although there was considerable swelling
and projection forwards of the palmar surface
of the region of the wrist, there were not
those hard protuberances to be felt in front of
the carpus which the extremity of the radius
and ulna, with their styloid processes, should
have presented had the dislocation above
alluded to occurred.

The man died, in a few hours after admis-
sion, from the injuries he received, particularly
of the head.

It had not been deemed advisable to reduce
the fracture, as the man seemed to be in a
dying state.

Dissection. — With the assistance of my
friend, Dr. Power (now Professor of Anatomy
of the Royal College of Surgeons, Dublin), I
removed the greater part of the forearm, that
we might the more carefully examine the
true nature of the lesion, the external ap-
pearances of which we have above described.

On making, then, the anatomical examina-
tion of the parts composing the region of the
wrist in this case the radius was found to
have suffered a transverse interruption of con-
tinuity in the line of junction of its inferior
epiphysis, and the lower fragment was dis-
placed directly backwards, so far as nearly to
have passed the extremity of the upper frag-
ment {fig. 935.). The lower extremity of the
ulna was broken a short distance above the line
of junction with its epiphysis. This fracture
was oblique. The extremities of the two frag-
ments of the ulna formed with each other an
angle salient in front. The ligaments and the
radio-carpal articulation also remained unin-
jured, and the carpus (of course) accompanied
the lower fragment of the radius in its dis-
placement backwards.

Case 4. — A boy, set. eleven, was admitted
into the Richmond Hospital on the 2nd of
September, 1840, under the care of Dr. Mac-
donnell. Upon the Sunday previous to his

admission he had been thrown from a horse
with great violence. The lower extremity of
the left radius was broken, and he sustained a

Fig. 935.

Disjunction of the Lower Epiphysis of the Radius,
with fracture of the Ulna, and displacement ba, to-
wards of the Carpus and Hand. — Museum of the
Richmond Hospital.

concussion of the brain, under the influence
of which he remained insensible for three
quarters of an hour. The accident occurred
at some distance from town. Before an hour
elapsed the boy was visited by a surgeon, who,
it is said, forcibly extended the limb, and then
applied a narrow roller tightly round the wrist.
On the following day (Monday) the patient

1523

WRIST-JOINT (Abnormal Anatomy).

complained of intense pain in the limb ; the
hand became cold and discoloured ; the roller
was not removed nor relaxed. On Tuesday,
dark coloured vesicles formed ; constitutional
symptoms of the gangrene showed themselves;
the pulse 159, feeble; countenance anxious.
The gangrene increased for two days more,
and reached within two inches of the elbow-
joint. On the sixth day a line of separation
showed itself ; and on the twenty-fourth day
the bones were sawn through, and the wound
soon healed.

Dissection of amputated Forearm. — The
radius was found to have been completely
broken through in the line of junction with its
lower epiphysis. The ulna was entire. The
preparation of the disjoined epiphysis and
gangrened hand is preserved in the Museum
of the Richmond Hospital.

The causes which have been known to pro-
duce a disjunction of the epiphysis are said to
be similar to those which produce a transverse
fracture of the bone close to the wrist-joint:
but why in one case we should have a fracture,
and in another a disjunction of the epiphysis,
we cannot say. All my own observation has,
as yet, taught me relative to this subject from
the cases I have seen and inquired into, has
been that the cause producing the disjunction
in question has always been a violent one.

When a patient has suffered a disjunction
of the lower epiphysis of the radius, there is,
in general, much deformity observable in the
region of the wrist. The hand, carpus, and
lower fragment are carried backwards, and
form together a plane which is from half an
inch to three quarters of an inch behind the
plane of the back part of the rest of the fore-
arm ; the transverse line of elevation of the
lower fragment above the level of the dorsum
of the upper fragment of the radius is very
abrupt and obvious ; and the first impression
on the mind is, that a dislocation backwards
of the carpus and hand is the accident which
has occurred. This abrupt transverse ridge
and depression are crossed vertically by the
extensor tendons of the carpus; and pressure
with the fingers discovers these longitudinal
tendinous bands to be on the stretch, having
been forcibly' elevated from the back part of
the radius as they pass to their grooves formed
in the lower fragment.

The palmar surface of the forearm is un-
usually convex from above downwards, and
does not present a salient angle in front, such
as we might expect from the abrupt depression
we noticed on the dorsum of the wrist and
forearm. This convexity of the forearm in
front, however, abruptly terminates in a trans-
verse narrow sulcus which marks the situation
ot the upper margin of the anterior annular
ligament. The radial margin of the forearm is
concave, and the ulnar margin presents a cor-
responding convexity. The patient complains
much of pain, and has the same inability to
move the forearm and hand as in cases of
fracture.

By the above-mentioned signs we become
informed that a solution of continuity in or

near to the transverse line of junction of the
lower epiphysis of the radius exists : but
without having had any' opportunity' of insti-
tuting an anatomical examination, we believe
it would be difficult for any one to affirm
whether the case were one of fracture, or
disjunction of the epiphysis. Some writers
seem to think that the case of disjunction
of the epiphysis may be recognised by the
circumstance, that, although there is an evi-
dent solution of continuity in the line of the
radius, the crepitus of an ordinary fracture
cannot be produced. To which we reply',
that the absence of crepitation is not by any
means unusual in cases of fracture of the ra-
dius in the region of the wrist; and, therefore,
from this observation no useful inference can
be deduced to aid our diagnosis.

In the examples of disjunction we have
seen, we have always noticed a fixed condi-
tion, as it were, from the interlocking with
each other of the portions of the disjoined
radius ; so that it seemed quite vain to seek
for crepitus ; — indeed we found it invariably
demanded a considerable force in these cases
to restore the limb to its original form.

We believe it is impossible to make a dif-
ferential diagnosis entirely to be relied on in
these cases ; but we may, we think, conjec-
ture that the disjunction in question exists
rather than a fracture, when the age of the
patient is under eighteen or nineteen years,
and the situation of the solution of con-
tinuity is in the exact transverse line of the
junction of the epiphy sis to the shaft of the
bone. If, however, the diagnosis be difficult,
we have practically little to regret this cir-
cumstance, because the prognosis and the-
treatment will be the same in both cases.

Section 111. Disease. — In describing
the alterations, the result of disease as it af-
fects the other articulations, the abnormal
anatomy of which we have already adverted
to in this work, we have classed these morbid
changes into those which are the consequence,

1st. Of Acute Arthritis.

2nd. Of Strumous Arthritis ; that is to say,
“ a scrofulous disease of the joints, having
its origin in the cancellous structure of the
bones.”

3rd. Of Chronic Rheumatic Arthritis.

Here we may adopt a similar arrangement,
but shall find it necessary to add, —

4thly. A few observations on Synovial Tu-
mours of the Region of the Wrist.

Acute Arthritis of the radio-carpal , and of
the inter-carpal articulations, may be the con-
sequence of a contusion or a wound, or it
may originate in some internal cause, such as
an acute rheumatic, or a diffuse inflammation.

Acute arthritis of any or all the joints which
enter into the composition of the region of the
wrist may be the consequence of a sprain or
wound, or the inflammatory action may have
been communicated to these joints by having
extended along an injured tendon of the fin-
ger, or the inflammation, suddenly showing it-
self in the joints, may have originated in some
unknown internal causes, such as those which

5 e 2

1524? WRIST-JOINT (Abnormal Anatomy).

preside over the development of an attack of
an acute rheumatic arthritis, or of diffuse in-
flammation.

Whatever may have been the specific nature
of the acute inflammation, there is soon no-
ticed, besides the pain felt through the carpal
region and the heat, that there is considerable
swelling. This last is more particularly ob-
served on the dorsum of the wrist and carpus
than elsewhere. An effusion, whether of
serum or pus, very soon takes place into the
interior of the synovial sac, which will always
have a tendency to distend this sac in all di-
rections ; but there can appear but little
swelling at the anterior part of the arti-
culation, because here a large fasciculus
of flexor tendons of the fingers passes, and
supports the synovial membrane. On the
lateral aspect of the wrist-joint, the tume-
faction, although sensible, is still limited by
the resistance which the lateral ligaments op-
pose to the distension of the capsule. Behind,
on the contrary, where the synovial membrane
is unsupported and but superficially covered,
the swelling, the result of the inflammation,
soon becomes much more manifest, and fluc-
tuation evident.

We are not aware of any case recorded in
which complete dislocation of the hand, on
the back part of the forearm or of this last
forwards, had occurred as the result of acute
inflammation. The only luxation, the result
of acute arthritis in the region of the wrist,
which has been noticed hitherto, has been
that of the ulna backwards.

This luxation is not an uncommon result
of an attack of acute arthritis of the wrist, by
which the ligament which connects the ulna
to the cuneiform bone becomes softened and
lengthened, and permits of the ulna being dis-
located partially or completely backwards.
Bonnet has commented on the frequency of
this backward displacement of the ulna, and
looks upon it as the simultaneous effect of
the facility with which the ligamentous ties of
this bone become softened and elongated, and
of the faulty position in which the hand is
kept by the patient, who remains usually
in bed during these acute attacks, and pre-
serves the forearm and hand in a state of
complete pronation, — a position which favours
the displacement of ihe ulna backwards.

We have stated that acute arthritis of
the wrist and carpal joints may be the result
of inflammatory action, propagated from a
wounded tendon of one of the fingers. The
following is one of a few of those cases which
had been admitted into the Richmond Hospital
within a short period.

Case. — John Murphy, a labourer, ret.
thirty-eight, while engaged in a fight with
another labourer, received from him a bite in
the little finger. The inflammation which fol-
lowed involved the tendons and their sheaths,
and spreading up the forearm, implicated in
its passage the carpal and meta-carpal joints
as well as the wrist and radio-ulnar articula-
tion, all of which became ultimately disorgan-
ised. The amputation of the forearm, below

the elbow-joint, became necessary. On making
an anatomical examination it was found that
there was complete disorganisation of the wrist-
joint. All the bones of the carpus were loose
and bathed in purulent matter.

Chronic Strumous Arthritis of the Wrist, or
White Swelling. — This is a disease which is
generally considered to have its origin in the
cancellous structure of the bones. It is fa-
miliarly designated by many English writers
by the well-known but somewhat equivocal
name of “ white swelling."

When we take into consideration that the
bones and the joints which compose the region
of the wrist are very superficially placed, and
that they are frequently subjected to sprains
and concussions from falls on the palm of the
hand, we need not be surprised to find that
these numerous injuries become so many de-
termining causes, giving rise to a chronic in-
flammation of the bones and articular textures
of the wrist, which frequently assumes the
strumous character.

As to the symptoms of this disease, we
have to observe that the patient complains of
pain, sometimes in one point of the wrist,
sometimes in another, which is increased on
the slightest motion. Soon a swelling ap-
pears on the dorsum of the carpus, and the
hand, from day to day, becomes more flexed
on the forearm. After a time the region of
the wrist assumes a globular form. The fore-
arm, when compared with that of the opposite
side, has an emaciated and wasted appearance.
The patient usually has the hand supported
on its palm, in the prone position, on some
flat surface; the whole hand has a most
helpless aspect ; the fingers are swollen at
their bases, and seem elongated and tapering
towards their extremities : they are straight
and motionless, and it is always with diffi-
culty and pain that the patient moves them, —
a circumstance we can easily account for, by
recollecting that the inflammatory irritation
which affects the wrist-joint is readily propa-
gated to the tendons of the fingers which pass
so immediately in front of it.

The synovial membrane in these cases is
early distended by an increased secretion into
the interior of the sac, and a fluctuating swell-,
ing may be occasionally perceived posteriorly,
as in the case of acute arthritis ; but in the
case of white swelling, instead of true fluctua-
tion, there is in general nothing but a decep-
tive feeling of it, from the infiltration of the
tissues in the region of the wrist, by a glairy
gelatiniform structure, similar to that which
constitutes the chief bulk of white swellings in
general.

During the second period of the disease,
the degree of flexion of the hand and of the
wrist-joint becomes increased, and the lower
extremity of the bones of the forearm, parti-
cularly of the ulna, becomes very salient pos-
teriorly. As the disease goes on, the bones
of the carpus become more deeply carious ;
chronic symptomatic abscesses form, and their
contents make their way to the surface, which
is frequently studded over, in advanced cases.

1525

WRIST-JOINT (Abnormal Anatomy).

with the fistulous orifices of canals, which con-
duct purulent matter from the centres of some
of the carious bones, and from the interstices
between them. At this period of the disease we
can, by holding the lower part of the forearm
with one hand, and grasping the metacarpus
with the other, move these parts laterally in
opposite directions, clearly ascertaining that
all the bones are loose and carious, and in an
irrecoverable state of disorganisation. The
constitution of the patient invariably sympa-
thises deeply with this state of things ; and
the wasting effects of hectic fever are found
usually coinciding with the disease of the
wrist and carpus ; and, if amputation be not
performed, the life of the patient may be sa-
crificed. This operation, however, almost in-
variably succeeds in arresting altogether the
hectical symptoms, and the patient is restored
to health.

The scrofulous disease of the cancellous
structure of the bones of the carpus, and of
the carpal extremity of the radius, does not
always proceed thus unfavourably. Occasion-
ally, instead of suppuration, a resolution of the
inflammatory action may ensue, or anchylo-
sis, with partial displacement backwards of
the bones of the forearm at the wrist-joint,
may be established. This last, however, may
be looked upon rather as an arrest of the
morbid action than as a cure, because the
patient is not only deprived of the use of the
wrist, and sometimes of the medio-carpal
joints, but also of the use of the fingers ; in-
flammatory action in these cases having been
communicated to the flexor tendons and their
sheaths, rigidity of the ligaments, or even
anchylosis of the joints of the fingers, too
generally follows as a natural consequence.

It may here be asked, whether, in the pro-
gress of this disease, the wrist-joint is liable
to those spontaneous displacements of the
bones which other articulations affected with
white swelling seem to be. To which we
reply', If we except the partial displacement
backwards of the ulna, previously mentioned,
these displacements must be considered as rare.
Bonnet of Lyons, who has had much expe-
rience, says he has not himself met with any
case of spontaneous luxation of the hand,
whether backwards or forwards, the result of
disease ; nor has he read of any such recorded.
Nelaton relates, however, that Richet showed
him a preparation found in the dead-room, in
which it was observed that the bones of the
carpus had lost their usual relation to the
radius, the inferior extremity of which was
carried into the palm of the hand, while the
bones of the carpus were carried back-
wards on the dorsal surface of the forearm.
Numerous fistulous orifices were seen, which
evidently had, up to the period of the pa-
tient’s death, furnished a purulent discharge,
so that the disease had not been completely
cured, although it was manifest that the liga-
ments had resumed their firmness and solidity,
and that the luxation had taken place a long
time previous to death.

Here, then, is a reply in the affirmative to

the quaere, whether spontaneous dislocation
of the wrist-joint occur ; and an unquestion-
able example of dislocation of the bones of
the forearm forwards adduced, on the respect-
able authorities of Nelaton and Richet. To
this observation we may add the following,
showing that complete dislocation backwards
of both the bones of the forearm may occur
at the wrist (s eefig. 936.) ; and here the testi-
mony as to this fact rests also on the produc-
tion of a specimen found in the dissecting
room*; its history is unknown. By examin-

Fig. 936.

ing this preparation, in which the dislocation
backwards of both the bones of the forearm
had evidently taken place, we can observe
much overlapping of these bones on the dor-
sum of the carpus, so that the styloid process
of the dislocated radius quite overhangs the
trapezium, even so far as the root of the
meta-carpal bone of the thumb, and the ulna
lies in contact with the back of the cuneiform
bone, so that the articular extremity of the
radius has passed down for more than an inch
below its ordinary situation ; the anterior sur-
face of the bones of the forearm, when they
lie on the dorsum of the carpal bones, are
solidly united to them. (See jig. 936.)

Anatomical Characters of Chronic Strumous

* This specimen formerly belonged to the Mu-
seum in Park Street, Dublin, where I saw it. It
now is to be found, I presume, in the Museum of the
Queen’s College, Belfast.

5 E 3

1526

WRIST-JOINT (Abnormal Anatomy).

Arthritis , or White Swelling , of the Wrist. —
When we remove the integuments from the
wrist, in one of those advanced cases of
chronic strumous disease of the radio-carpal
and inter-carpal articulations, we encoun-
ter the usual appearance of a gelatiniform
effusion, of a yellowish-green colour ; we
observe the tendons and nerves somewhat
swelled, as if infiltrated ; the ligaments all
softened ; purulent matter occupying the in-
terstices of the articular surfaces ; the bones
easily yielding to pressure, hollow and carious
in the centre of their cancillated tissue; and
leading from these carious bones, are seen
fistulous canals opening extensively by nu-
merous orifices on the cutaneous surface of
the wrist.

In the Museum of the College of Surgeons
of Dublin we find a preparation, which is
truly designated as an instructive one, show-
ing the effects of scrofulous disease on the
bones and other structures of the wrist. To
save the patient’s life, it became necessary to
perform an amputation of the forearm. The
hand has been preserved in spirits, and the
back of the carpus has been laid open to
view. The wrist is semi-flexed ; the palm and
fingers are swollen, and the front of the joint
is studded with fistulous orifices. One soli-
tary fistulous orifice appears in the centre of
the palm. The bones of the carpus, deprived
of their synovial membranes and ligaments,
are loose and disjointed ; and to use the words
of the donor, the late Professor Todd, “ they
felt during life like a bag of marbles.”

There is also another preparation, styled
“ scrofulous disease of the carpus, meta-car-
pus, and extremity of the radius,” presented
by Professor Porter. The bones are re-
remarkably soft, light, and porous. The na-
tural shape of each is considerably altered,
by loss of substance in some parts, and de-
posits of new osseous matter in others : the
latter, wherever it exists, has a peculiar spi-
culated appearance; some of the bones are
increased in size, others diminished ; the car-
tilages have, for the most part, disappeared ;
the synovial membrane of the smaller joints
had been completely destroyed ; that of the
radio-carpal articulation was hypertrophied,
soft, and pulpy. The ligaments were not
recognizable, and the bones lay almost loose
in a quantity of purulent matter, with which
a fistulous orifice, in the front of the joint,
communicated. The skin, the cellular tissue,
and the sheaths of the tendons were infil-
trated with a thin gelatinous fluid ; the median
and ulnar nerves were remarkably enlarged.

The scrofulous disease, commencing in the
centre of the cancellous structure of the
bones of the carpus and carpal extremity of
the radius, does not always proceed thus un-
favourably. Anchylosis, with partial displace-
ment of the forearm at the wrist-joint, may,
as already stated, be established, as the result
of the morbid action we are here treating of.

In the Museum of Anatomy in Leyden
there is a preparation of the bones of the
wrist, in which the carpal extremity of the

radius and ulna are much enlarged and remark-
ably scabrous on their surface ; the radius
and ulna are anchylosed firmly with each
other near to the carpus ; the os lunare was I
united to both radius and ulna; the os sca-
phoides, cuneiform and magnum, had totally
disappeared ; the trapezium was also firmly
united to the meta-carpal bone of the thumb
and with that of the index finger.

In the above-mentioned Museum at Ley- ;
den there is also another preparation, ex- j!
hibiting anchylosis of the bones of the forearm,
and of the carpus, at the wrist-joint, after the
disease, which had arisen, we are told, from a
scrofulous cause, had happily been cured.

In concluding, then, the account of the
anatomical characters of the scrofulous caries j
of the bones which compose the region of the
wrist, we may observe, that, as a result of this
disease, some of the carpal bones are di- j
minished in size ir. many cases, while in others
they are enlarged. We have noticed some
specimens in which two or three of the carpal
bones have disappeared altogether, while
others have had additional bony growths
attached to them. The lower extremities of
the bones of the forearm, in almost all the
cases, were found rough and scabrous, and
increased in bulk, particularly close to the
wrist-joint. Wp, also, after our own examina-
tion of the bones of the region of the wrist,
have to make the same observation that
Sandiford has made relative to the specimens
he has preserved in the Anatomical Museum
of Leyden, of which he says, — “ Omnia hoec
ossa levissima sunt.”*

Chronic Rheumatic Arthritis of the Wrist. —
The wrist-joints, together with the joints of
the carpus, are very frequently affected with
the disease we have elsewhere, in this work,
called “ Chronic Rheumatic Arthritis,” or
rheumatic gout.

When the joints which enter into the region
of the wrist are engaged, the fingers are all
more or less distorted, and their joints en-
larged, as already described. (See Hand.)

Females are more liable to have their wrist-
joints affected with chronic rheumatic arth-
ritis than males, and elderly persons mo;e
commonly than those who are young; but
this disease is to be seen, occasionally, in
young persons of both sexes. The disease,
when it appears in the wrist-joint, will, in
general, be found to affect, symmetrically, the
right and left wrist of the patient. The cause
of the disease is generally referred to rheu-
matic fever, and the other articulations of the
patient are usually more or less implicated.
The patient complains of pain in the joints,
particularly at night, of stiffness and rigidity,
and of a crackling sensation in them when
they are moved. When we come to examine
the wrist, it is remarked to present a preter-
natural convexity on its dorsal aspect, arising
from an inordinate quantity of fluid poured
out into the synovial sac of the joint. The

* Museum Anatomicum, Sandiford, p. 244.
vol. iii.

1527

WRIST- JOINT (Abnormal Anatomy).

bursae of the extensor tendons, as they pass
over the carpus, also become distended : these
softer fluctuating swellings after a time sub-
side, and the lower extremity of the radius
and ulna, where they enter into the formation
of the wrist-joint, enlarge; longitudinal ridges
of bone can be felt on the back of the radius
close to the wrist-joint. The ulna, besides
being much hypertrophied at its lowest point,
rises abnormally above the level of the dorsum
of the carpus. When the disease has been of
long duration, the region of the wrist becomes
contracted, the back of the carpus and hand
presents an attenuated appearance, showing
the course of the tendons, and allowing the
ridges and prominences of the bone to become
visible.

Anatomical Characters. — When we remove
the fibrous covering of the tendons which
pass by the back part of the wrist-joint and
carpus, we find that these tendons are gene-
rally deeply imbedded in bony sulci, or grooves.
The capsular ligament and other fibrous struc-
tures, both on the palmar and dorsal aspect
of the joint, seem to be denser and stronger
than natural.

On examining the interior of the wrist-
joint, we notice that all the articular carti-
lages of encrustation have been removed from
the ends both of the radius and ulna, and
that the inter-articular fibro-cartilage, which
intervenes between the lower extremity of
the ulna and cuneiform bone of the carpus, is
removed. In general, at the usual period we
are afforded opportunities for making our ana-
tomical examinations, we find but little left of
the synovial membrane by which we can judge;
but in some cases we have found red synovial
fimbriae exist in the wrist-joint, just as we
have noticed this same vascular condition of
the synovial tissues to co-exist with the other
anatomical characters of the chronic rheu-
matic arthritis, as they have shown them-
selves in other articulations which had been
affected with this peculiar disease.

Radius. — The lower extremity of the radius
is usually somewhat enlarged, and the surface
of the bone is scabrous from small exostotic
growth. We find the grooves on the back
of the radius for the passage of the extensor
tendons are preternaturally deepened.

The articular surface of the lower extremity
of the radius, where formed for the reception
of the summit of the carpus, is usually much
hollowed out, and polished from porcellanoid
deposition. The outline of the carpal sur-
face of the altered radius is usually studded
round with bony granules, or vegetations.
When we look to the ulnar side of the
lower extremity of the radius, we find the
lesser synovial cavity for the reception of
the carpal end of the ulna much enlarged,
particularly in its antero-posterior diameter.
This scaphoid cavity we find also presenting
an eburnated surface, and on it fine parallel
ridges and grooves are distinctly seen to run
in the direction of the rotation of the ulna
on the radius in pronation and supination.
Where the lower extremity of the ulna con-

fronts the cuneiform bone (the inter-articular
fibro-cartilage having been removed), it pre-
sents a smooth and polished surface.

Ulna. — The carpal extremity of the ulna
is frequently much enlarged, and furnished
with exuberant bony growths ; its lowest ex-
tremity, where it confronts the cuneiform
bone of the carpus (without the intervention
of cartilage), is smooth. The part of the ex-
tremity destined for rotation on the radius is
convex, and oval from before backwards, and
of a form, of course, adapted to that of the
little scaphoid cavity in the latter, and which
is deprived of cartilage, eburnated, and simi-
larly marked with corresponding parallel ridges
and grooves.

Carpus. — In our anatomical investigations
into the state of the hands of those who have
long laboured under chronic rheumatic ar-
thritis, we have found the bones of the carpus
to be much altered by this disease : in general,
the region which these bones constitute will
be found to have all its dimensions contracted
within a smaller compass then natural. The
form of each individual bone is so much
changed, that, if found detached, it could
scarcely be recognised as a carpal bone. The
cartilaginous structure naturally intervening
between all the bones is always absorbed.

Cruveilhier has said that, in the anatomi-
cal examination of one of his cases of this
disease, he found the bones of the carpus
confounded together into an irregular mass,
so that it was difficult to say the part which
each took in the construction of the carpal
region.

On examining, anatomically, the bones of
the region of the wrist of a patient who had
been ten years labouring under this disease,
and was under our own immediate observation
for almost the whole of this period, we found
the bones of the carpus were exceedingly
rough on their non-articular surfaces ; each
individual bone was found much altered from
its normal figure ; some were enlarged beyond
their usual size, others diminished : the true
annular ligament of the carpus, which con-
nected the small bones together on their
palmar aspect, and contributed to maintain
the arched form of this region, was much
shorter than usual.

When we examined each bone, we found
that the scaphoid was eburnated on its su-
perior articular surface, where it corresponded
to a similar surface on the carpal end of the
radius. Below, the scaphoid, instead of con-
tributing, with the head of the os magnum, to
form part of the medio-carpal articulation,
was really united to the head of the os mag-
num by true bony anchylosis. The semi-
lunar and cuneiform of the first range were
much enlarged. The os lunare, where, by its
lower concave surface, it corresponded to
half of the head of the magnum, was not, like
the scaphoid, united to this last bone, but, on
the contrary, both surfaces of the magnum

* Vide a work on Chronic Rheumatic Arthritis,
by the author, shortly to be published.

5 E 4

1528

WRIST-JOINT (Abnormal Anatomy).

and lunar bones, which confronted each other,
were covered with an ivory-like polish. The
trapezium, where it supported the first phalanx
of the thumb, was polished on its pulley-like
articular surface. The trapezoides was much
diminished in size, and solidly anchylosed with
the first phalanx of the index finger. The
transverse diameter of the magnum was not
one quarter of an inch ; and the loss of breadth
to this degree accounted somewhat for the
abnormal narrowing of the carpus already
noticed. The cuneiform was normal, as well
as the pisiform. The junction, then, of the
magnum with the scaphoid, and the equally
solid bony union of the trapezoides with the
meta-carpal bone of the index finger, were the
only articulations of this region, or, indeed, of
the whole skeleton of this individual, which
presented specimens of true bony anchylosis.
The cause of the eburnation of the surfaces
of some of the carpal bones might have been
that these bones bore occasionally much of
the weight of the man in progression, because
he had been much disabled in his lower limbs,
and habitually used crutches.

Synovial Tumours of the Region of the Wrist.
- — Synovial tumours generally present them-
selves around the joints of the extremities ;
and the wrist seems especially liable to them.
By the term synovial tumours of the wrist, we
do not mean those formed by an increased
effusion into the proper synovial sac of the
radio-carpal articulation, but enlargements
constituted by bursae in this region.

Synovial cysts, called ganglions, are fre-
quently seen on the back of the wrist and
carpus. They are of a globular form, and, as
to size, vary from that of a hazel-nut to that
of a walnut- They are usually situated at the
level of the medio-carpal articulation in the
course of the extensor tendons as they pass
to the carpus. These tumours are slightly
moveable, indolent, and painless, without any
alteration in the colour of the skin which
covers them from that which is natural. The
contents of these little swellings are found to
be synovia of a variable consistency : some-
times it is serous and limpid ; occasionally
the contents are constituted by a thick trans-
parent jelly. The cyst seems to be formed
by the reticular tissue which immediately
covers the sheath of the extensor tendons.
The part of the cyst which corresponds to
the skin is united to it by a layer of very thin
cellular tissue, but loose enough to allow of
the skin being easily raised up. The part, on
the contrary, which is deeply situated reposes
in the sheath of the tendons, or the capsular
ligament of the wrist, and is firmly connected
to them. This union is sometimes so inti-
mate that it is impossible to take away the
cyst without interfering with the tendon or
the articular capsule.

The thickness of this cyst varies much.
Sometimes it is thin and translucent, and it
breaks when subjected to but little pressure ;
at other times its thickness and its texture are
such that the most violent efforts cannot rup-
ture it.

W e have usually seen this disease in fe-

males more than in males ; and the cause of
the origin of these little tumours in the wrists
of the former appeared to us frequently attri-
butable to over-exertion, such as prolonged
play ing on some musical instruments, such,
for example, as the harp or piano.

Whatever may have been the cause for the
origin of these encysted tumours, once formed,
they for a time increase in a gradual manner ;
and when they have attained a moderate size,
they cease to grow. They sometimes, though
rarely, subside spontaneously.

The interior of the membranous sac, in the
distention of which, by a glairy fluid, the tu-
mour consists, is smooth and polished. The
interior of these cysts generally have no com-
munication whatever either with the medio-
carpal or wrist-joint itself; but Velpeau says
he has seen two cases in which he could
easily press the liquid contained in the cyst
into the articulation of the wrist if he at the
same time gave certain movements to the
joint, lie adds, that twice he had an oppor-
tunity, in the dead body, to show that these
cysts communicated with the interior of the
joint.

Morbid Condition of the Synovial Burses of
the Flexor Tendons. — The swellings which
these enlarged bursae constitute, do not pre-
sent the same regularity of form that gan-
glions do.

The cause of their origin may generally be
referred to some great exertion — to a fall or
other external violence. I have known, in
one case, one of these swellings appear with-
out having been produced by any injury. The
constitution of this patient was very decidedly
of the rheumatic character.

The species of swelling we are now refer-
ring to commences in the synovial bursa
which envelopes the flexor tendons of the
fingers as they pass beneath the anterior an-
nular ligament of the wrist : the swelling con-
sists of an increased quantity of synovial fluid
effused into the cavity of the little sac the
bursa constitutes. At first the effusion is
small, and the bursa keeps within its normal
boundary, behind the anterior annular liga-
ment ; but the accumulation of synovia in-
creases by degrees ; and then the swelling
appears divided into two parts, which are
separated from each other by the annular
ligament, which seems to form a transverse
band which constricts the sac, leaving a tu-
mour above the annular ligament in front of
the wrist, and another beneath the level of
this ligament in the palm. Pressure on the
portion of the sac above makes the synovial
fluid pass down into the part of the bursal
sac beneath. In these cases the skin pre-
serves its colour and normal mobility, the fin-
gers become somewhat flexed, and there is
some difficulty experienced in fully extending
them. The patient suffers no^iain, but only
complains of a numbness and weakness in the
fingers, hand, and wrist.

On compressing one of the extremities of
this tumour (as, for example, that placed

*

Dictionnaire de Mddecine, tom. 25, pi. 294.

1529

WRIST- JOINT (Abnormal Anatomy).

above the annular ligament), while the fingers
of the opposite hand are placed on the other
extremity, which ' is placed beneath this
fibrous band, we readily perceive a “ frotte -
ment” which is quite peculiar. This “frotte-
ment” is caused by the passage to and fro,
under the true annular ligament of the wrist,
of small foreign bodies which are not unlike
barley grains or those of boiled rice. Their
forms are exceedingly variable. They are
usually of a white colour, and have a polished
surface. They are found in vast numbers in
the same cyst, mixed with a more or less con-
siderable quantity of glairy synovial liquid.
They are ordinarily free from all adhesions to
the parietes of the bursa.

Many theories have been formed as to the
origin of these little bodies found loose in the
bursa, about the wrist, and elsewhere.

Dupuytren thought he had established the
theory that they were hydatids. Laennec and
Raspail agreed" with him in this view ; but
Bose, to whom Dupuytren referred, dissented.
The last-mentioned naturalist looked upon
them as concretions of lymph of an adipo-
cerous nature. He says, “ They are not to
be considered as ‘ hydatids,’ because they
have not given any sign of life on escaping
from the cyst.” On dividing these bodies, he
found them uniform throughout, whilst that
of hydatids are always hollow ; and again,
because submitted to a strong lens, they have
appeared to him to be nothing else than an
inorganic mass, whether he examined them
when recent or dried.”

Sir Benjamin Brodie’s opinion now seems
generally to prevail. It is adopted by
Nelaton * and other French physiologists : —
“ There seems to be no doubt but that these
loose bodies have their origin in the coagu-
lated lymph which was effused in the early
stages of the disease ; and I had opportuni-
ties, by the examination of several cases, to
trace the steps of their gradual formation. At
first the coagulated lymph forms irregular
masses of no determined shape, which after-
wards, by the motion and pressure of the
contiguous parts, are broken down into small
portions. These by degrees become of a
regular form, and assume a firmer consist-
ence, and at last are converted into the oval
bodies above alluded to.”f

Examples of these have been seen in the
synovial sheaths of the radial extensors as
well as on the back of the wrist in the course
of the extensors of the fingers. But it is,
nevertheless, certain that the bursa of the
flexor tendons, situated in front of the wrist
and carpus, and behind the true annular liga-
ment of this region, is the special locality in
which these foreign bodies are most frequently
found.

Painful Crepitation of Tendons around the
Wrist. — We notice, sometimes, around the
carpus and in the inferior extremity of the

* En 1819 M. Brodie donna une interpretation
satisfaisante de leur etiologie en les rattacliant aux
epancliemens sero-albumeux. (Nelaton, Pathclogie
Chirurgicale.)

t Brodie on the Diseases of the Joints.

forearm, a swelling which is peculiar in this,
that, whenever the tendons around which the
swelling forms are moved, there is thereby
elicited a very peculiar crepitation.

This crepitation is noticed along the course
of the extensor carpi radialis longior and
brevior, and in that of the long abductor and
short extensor of the thumb. This swelling
is not globular, nor is it so well defined as a
ganglion, but may be said to represent in its
form a portion of a spiral which, parting from
the dorsal surface of the forearm, soon turns
round the external part of the radius to gain
the root of the first metacarpal bone.

This swelling seems to be of an inflamma-
tory nature, and is occasionally accompanied
with a superficial redness of the skin ; and
pressure on this part becomes painful to the
patient. If the surgeon places his thumb or
fingers on the postero-external surface of the
forearm, near to the wrist-joint, where the ob-
long swelling exists, and at the same time de-
sires the patient to move the hand by flexing
and 'extending the wrist-joint, or exert the
muscles, the peculiar crepitation which cha-
racterises this lesion is soon perceived.

It is not very easy to convey an idea of this
crepitation ; but it has been compared by
many to that produced by the crushing to-
gether, with our fingers, portions of finely
powdered starch, or to the effect which we
feel produced when we walk over snow.
When once recognised, it is perceived to be
quite different from that crepitation which is
produced by the movement on each other of
the fragments of broken bones or the rubbing
together of roughened articular surfaces.
This disease has for its anatomical seat the
fibro-synovial sheaths of the tendons already
mentioned. These extensor tendons, namely,
the two extensor radialis longior and brevior,
as well as those of the long abductor and short
extensor of the thumb; cross each other, each
in special sheaths or canals formed on the back
part and external edge of the lower extremity
of the radius ; and if inflammation attack the
lining membrane of these fibro-synovial
sheaths, it is plain that, in this anatomical
arrangement, there may be seen many circum-
stances to favour the development of this
crepitation.

This affection has not, we believe, ever
been observed to have come on sponta-
neously, but generally to have arisen from
some violent and continued efforts of the
wrist and hand.

It has been noticed in soldiers and masons,
and in those who are in the habit of twisting
the forearm, as in the act of forced pronation
of the forearm of washerwomen in wringing
clothes. The tumefaction, the swelling, pain
and heat, and the crepitation also, once com-
menced, augment generally for four, six, or
eight days ; and if the patient be guilty of
any imprudence, the evil is maintained to the
same degree even to the twelfth or fourteenth
day, after which it ordinarily terminates in
resolution.

( Robert Adams.)

Addendum to the Article Urethra.

Injustice to a distinguished anatomist and surgeon, Mr. Henry Hancock, whose claims
to priority of the discovery of unstriped muscular fibres in the urethra were over-
looked by the author of the article Urethra, the Editor thinks it right, with the as- |j
sent of the author of that article, to insert the following paragraph, drawn up by I
Mr. Hancock, as an addendum to it : —

The urethra itself is a membranous tube,
consisting of mucous membrane, presenting
villi on its free surface for the most part
arranged in rows, some being conical, others
tuberculated, covered by epithelial scales.
The outer surface of the urethra is closely
invested by cellular tissue, external to which
is found a layer of organic muscular fibres,
similar to, and in fact continuous with, the
muscular coat of the bladder. This last-
named structure consists of two layers, an
internal and an external ; the external passes
forwards on the outside of the prostate
gland ; the internal, on the contrary, accom-
panies the mucous lining of the bladder, when
it becomes urethral through the prostate
gland, forming a covering of involuntary
muscular fibre to the canal in its passage
through the gland. In front of the prostate,
the two layers of muscular fibre unite and
invest the membranous portion of the urethra,
where they may easily be distinguished from
the voluntary muscles of the part. Reaching
the bulb they again separate into an internal
and an external layer ; the internal continues
forwards to the orifice of the urethra, lying
between that canal and the corpus spongio-
sum ; the external passes on the outer sur-
face of the corpus spongiosum, separating

it from its fibrous investment, to which the
fibres adhere pretty closely. These latter,
like the internal, are continued forward to
the orifice of the urethra, and in their course
they invest the spongy portion of the bulb,
the urethra, and the glans penis, entering
very largely into the formation of the peculiar
structure found at the orifice of the urethra,
and which appears to consist almost entirely
of involuntary muscle anil cellular tissue.
Hence, the corpus spongiosum urethra lies
between two layers of involuntary muscle,
the one separating it from the urethra, the
other from its fibrous investment; and this
arrangement obtains wherever the corpus
spongiosum exists, whether the quantity
thereof be small or great. On the under and
lateral portion of the urethra, where the quan-
tity is abundant, the corpus spongiosum lies
between two layers of involuntary muscular
fibre. On the upper surface of the urethra,
where the quantity is comparatively small,
the same arrangement may be observed, whilst
at the glans, which is not formed merely by
increased development of the spongy tissue,
but also by a folding back, as it were, of the
spongy tissue over the corpora cavernosa, we
find these muscular layers multiplied.

ANALYTICAL INDEX

TO THE

F 0

URTH Y 0 L U M E.

PLEURA , 1.

mediastinum, 1.
ligamentum latum pulmonis, 2.
pleura pulmonalis, 2,
pleura costalis, 2.
pleura diaphragmatica, 2.

Polygastria, class of microscopic animalcules, 2.
their division into families by Elirenberg, 3.
locomotion of animalcules, 5.
nutritive system, 14.
dental system, 15.
muscular system, 15.
nervous system and organs of sense, 16.
secretions, 16.
reproduction, 16.
fissiparous generation, 16.
gemmiparous reproduction, 17.
sporiferous reproduction, 17.

Polypifera, class of zoophytes, 18.
division into families, 19.
hydra described, 20.

extensors of the tentacula, 22.
alcyonidze described, 24.

nutrition of the alcyonidee, 27.
corallidce or cortical polypes, 30.
corallium rubrum, 31.
isis hippuris, 32.

madreporid<e, madrephyllida?, 33.

their fung'ra, 33.
pennatulidie, 38.
actiniadse, 38.
aulozoa : tubularidce, 40.
tentacular apparatus, 41.
digestive system, 41.
circulation, 42.
reproduction, 42.
mode of propagation, 42.
sertularidae, 48.
bryozoa, 50.

muscular system, 52.
alimentary system, 54.
reproduction, 55.

Popliteal Region , and Popliteal Artery , 60.
varieties, 63.

branches of the popliteal artery, 64.
operative relations, 64.

Porifera , or sponges, 64.

division into families by Blainville, 65.
skeleton, 66.
gelatinous cortex, 67.
irritability, 67.
circulation of water, 67*
reproduction, 69.

Products , Adventitious , 71.

[The term applied to the substances which, either pro-
duced by or developed in connexion with the animal
frame, neither form a natural constituent element, nor a
natural secretive product, of the structure amid which it
is evolved.]

calculi : urinary calculi, 74.
uric acid calculus, 77.
urate of ammonia calculus, 78.
oxalate of lime calculus, 78.
cystin or cystic oxide calculus, 79.
phosphate of ammonia and magnesia calculus,
80.

neutral phosphate of lime calculus, 80.
mixed phosphates, 80.

neutral phosphate of ammonia and magnesia, 80.
xanthic oxide calculus, 80.
carbonate of lime calculus, 80.

Products , Adventitious ( continued ).
carbonate of magnesia, 81.
urate of magnesia, 81.
urates of soda, potassa, and lime, 81.
phosphate of magnesia, 81.
chloride of sodium, 81.
renal calculi, 81.
calculi of the prostate gland, 82.
praputial calculi, 82.
lachrymal calculi, 82.
nasal calculi, 82.
calculi of frontal sinus, 82.
calculi of mouth, 32.
salivary calculi, 83.
the tonsils, 83.
pharynx and oesophagus, 83.
gastro-intestinal calculi, 83.
biliary calculi, 85.
pancreatic calculi, 86.
seminal calculi, 86.
mammary calculi, 86.
vaginal and pudendal, 86.
uterine, 86.
pseudo-calculi, 86.
elementary cell, 86.
foetal, 87.
placental, 87.

vascular j arteries, parietal, 87.
veins, parietal, 89.
central, 89.

lymphatic and lacteal, 89.

serous and synovial cavities, 90.

fibrous membranes, 90.

cerebral, 90.

uterine, 90.

fallopian tubes, 90.

pulmonary concretions, 90.

arthritic, 90.

cutaneous, 91.

ein compounds, 91.

albumen, 91.

fibrin, 93.

casein, 94.

globulin, 94.

fat ; fatty substances, 94.
in the liver, 94.

pancreas, 95.
mamma, 95.
kidney, 95.
testicle, 96.
lungs, 96.
arteries, 96.
muscles, 96.
tendon, 96.
nerves, 96.
bones, 96.

adventitious products, 97.

fatty matters excreted in the semi-fluid or fluid
state, 97.
in the urine, 97.
fasces, 97.
saliva, 97.
sweat, 97.
encysted fats, 97.
cholesteric fats, 98.
tumours, 98.
granules, 98.
patches, 98.
scales, 98.
sugar, 99.

saccharine diabetes, 99.

1532

ANALYTICAL INDEX.

Products , Adventitious ( continued ).
blastemal formations, 100.

their potential qualities, 102.
deposits : typhous deposit, 103.
tuberculous deposit, 104.
purulent deposit or pus, 110.
mucus, 114.
softened fibrin, 114.
epithelial fluid, 115.
melanic deposit, 116.
stagnation, 117.
extravasatcd blood, 117.
chemical action, 117.

introduction of black coloured substances from
without, 1 17.
diphtheritic deposit, 118.

white thrush, 118.
growths, cells, 118.
granules, lly.
nuclei, 119.
fibrils, 119.

enlargement of growths, 120.
their decay, 121.
their removal, 121.
cicatrisation, 121.
vital effects, 122.
localisation. 122.

inocul ability, 124.
ha?matoma, 125.
sarcoma, 126.
cystoma, 127.
angeiectoma, 127.
melanoma, '128.
of fat basis; lipoma, 129.
steatoma, 130.

cholesteatoma. See Cholesteric Fats , p. 98.
of gelatin basis ; fibroma, 130.
enchondroma, 132.
osteoma, 134.

in unnatural sites, 134.
in the natural tissues, 134.
undetermined basis : colloma, 135.
infiltrating growths : cancer, 136.
pseudo tissues, 138.
induration matter, 138.
simulating the natural tissues, 139.
extra-vascular tissues, 159.

nail. See Toothy 142.
cartilage, 139.

simple vascular tissues : cellular tissue, 140.
serous tissue, 140.

fibrous and elastic pseudo-tissues, 141.
osseous pseudo-tissue, 141.
nervous pseudo- tissue, 141.
blood-vessel, 141.
erectile tissue, 142.
lymph vessel, 142.
fibrous and spongy cartilage, 142.
hair, 142.
tooth, 142.
cutaneous, 143.
mucous, 143.
glandular, 143
muscle, 143.
unstriped fibres, 143.
germ formations ; parasites, 143.
liquid adventitious products, 144-
gaseous adventitious products, 145.

Prostate Gland , 146.

form, position, and adjacent viscera, 146.
levator prostata?, 147.

ligamenta pubo-prostatica media et lateralia, 147.

uvula vesica?, 149.

intimate structure, 149.

liquor prostaticus, 150.

sinus pocularis, 151.

uterus cystoides, 151.

development of the prostate and vesicula pros-
tatica, 153.

function of the prostate gland, 153.
morbid anatomy, 154.
hypertrophy, 154.
atrophy, 156.
inflammation, 156.
abscess, 156.
ulceration, 156.
tubercles, 157.
cancer, 157.
fibrous tumours, 157.
cystic prostate, 157.
prostatic concretions, 158.
prostatic calculi, 159.

described by Vogel, and analysis by Las-
saigne, 159.

comparative anatomy, 160.

prostate in mammalia, 160.
in the ape, 160.
in the tarsier, 163.
in the galeopitheci, 160.
in the roussette, 160.
in the dormouse, 160.
in the hedgehog, 160.
in the mole, 160.

Prostate Gland {continued) .

in the hear, 160.

in the otter, weasel, and marten, 170.

in the ichneumon, 160.

in the dog and cat, 160.

in the hyena, 160.

in the marmot, 160.

in the rabbit, 160.

in the squirrel, 160.

in the rat, 160.

in the agouti, 161.

in the guinea-pig, 161.

in the elephant, 161.

in the wild boar, 161.

in solipedes, 161.

in ruminants, 161.

in the stag, axis, and buffalo, 161.

in the chamois, 161.

in the seal, 161.

in the cetacea, 161.

in the marsupial sub-class, as the kangaroo,
161.

in the opossum, 161.
in the wombat (doubtful) 161.
among amphibious reptiles are found glands
analogous to the prostate, 161.

Protein , the basis of the greater portion of the bodies of all
animals, 162.

analysis of fibrin, albumen, and casein, 162.
tritoxide of protein, 163.
binoxide of protein, '163. 1
third oxide of protein, 163.
protein and chlorine, 163.
and nitric acid, 164.
and sulphuric acid, 164.
and hydrochloric acid, 164.
and potash, 164.
erythroprotid and protid, 164.
fibrin, average proportions in animal products, 165.
fibrin and sulphuric acid, 166.
and nitric acid, 166.
and acetic acid, 166.
and hydrochloric acid, 166.
and potash, 166.

albumen, proportion in animal products, 167.
casein, proportion in the milk of animals, 168.
vegetable fibrin, 169.
vegetable albumen, 169.
vegetable casein, 169.

Pteropocla, an order of mollusca, 170,

organisation of this class of marine animals, 170.
their habits described by M, d’Orbignv, 171.
integument of the clio, 171.
muscular system, 172.
locomotive apparatus, 173.
respiration and circulation, 173.
nervous system, 173.
eyes, 174.

head-cowls and tentacula, 174.
conical appendages to the head, 175.
mouth of the clio, 176.
generative system, 177.
ovary, 178.

Pulse , 181.

age, infancy, 182.

pulse at different periods of life, 182.
sex, 183.

temperament, 185.
stature, 185.
posture, 185.

cause of difference of pulse in different positions,
187.

exercise, 189.

diurnal variations of the pulse, 189.
in rest, 191.
in sleep, 191.
food, 192.

mental emotions, 192.

temperature of the body, 192.

density of the air, 192.

relation of the pulse to the respiration, 192.

Quadrumana, 194.

their division into simia? and lemurina?, 195.

osteology : the.chimpanzee, orangoutan, siamang.

mandrill, 187.
myology, 205.
neurology, 206.
angeiology, 208.
splanchnology, 208.
second group of simia? described, 210.
lemurina?, or second family of quadrumana, 214.
osteology, 216.
myology, 218.
neurology, 219.

Radial and Ulnar Arteries , 221.
radial artery, its relations, 222.
in the forearm, 222.
in the wrist, ^22.
in the palm, 223.

branches of the radial arlery, 223.
arteria radialis recurrens, 223.
arteria superficialis vola?, 223.
arteria anterior carpi radialis, 223.

ANALYTICAL INDEX. 1533

Radial and Ulnar Arteries ( continued ).

arteria dorsalis carpi radialis, 22 3.
arteria dorsalis pollicis, 223.
arteria magna seu princeps pollicis, 224.
arteria radialis indicis, 224.
ulnar artery, 224.

its relations in the forearm, 224.

in the hand, 224.
branches of the ulnar artery, 225.
arteria interossea, 225.
arteria* carpi ulnaris, 225.
communicans ulna?, 226.
digital arteries, 226.

varieties of the radial and ulnar arteries, 226.
varieties of origin, 226.
high origin of the radial, 226.

varities in its distribution, 226.
high origin of the ulnar, 227.
its course, 227.
size, 227.

diseases and injuries of the radial and ulnar arteries,
228.

aneurism, 228.
false aneurism, 228.

Radio-ulnar Articulations , 228.

upper radio-ulnar articulation, 228.
round head of the radius, 228.
sigmoid cavity of the ulna, 229.
annular or orbicular ligament, 229.
synovial membrane, 229.
movement, 229.

lower radio-ulnar articulation, 229-
lower extremity of the radius, 229.
lower end or head of the ulna, 229.
triangular fibro cartilage, 230.
synovial membrane, 230.
movement, 230.
pronation and supination, 230.
dislocations of the joints, 231.

Ren*, or the Kidney , 231.

renal organs in the lower animals, 232.
in insects, 232.
in the arachnida, 232.
in the lamellibranchiata, 232.
in the gasteropoda, 232.
among the cephalopoda, 232.
in fishes, 232
in reptiles, 233.
in birds, 233.

kidneys of mammalia, 233.
human kidney, 234.
form, 234.

dimensions and weight, 234.
position and relations, 234.
anterior surface, 234.
posterior surface. 235.
circumference, 235.
extremities, 235.
ureter or excretory duct, 235.
its direction, 235.
and relations, 235.
blood-vessels of the kidney, 235.
emulgent or renal arteries, 235.
emulgent or renal vein, 236.
lymphatics, 236.
nerves, 236.

structure of the kidney, 236.
cortical substance, 236.
medullary substance, 237.
capsule, 238.

calices, infundibula, and pelvis, 238.
minute structure, 239.

fibro-cellular matrix, 239.

tabuli uriniferi, 241.

mode of injecting the tubes, 241.

course and termination of the tubes, 242.

structure of the tubes, 242.

malpighian bodies, 243.

two distinct systems of capillary vessels in kidneys,
249.

portal system of the kidney, 250.
comparison between the hepatic and renal portal
circulation, 251.
epithelium of the kidney, 252.
ciliary motion cf the tubes, 253.
epithelium of the pelvis and ureter, 254.
function of the malpighian bodies and uriniferous
tubes, 254.

pathology of the kidney, 256.

disease of the kidney from retention of urine, 256.
disease of the kidney from renal calculi, 256.
disease of the kidney from external violence, 257.
extension of disease from other organs to the kid-
ney, 257.

diseases resulting from a constitutional cause, 257.

acute suppurative nephritis, 257.

acute desquamative nephritis, 257.

chronic desquamative nephritis, 258.

renal haemorrhage, 261.

fatly degeneration of the kidney, 262.

* See note to this article, page 231.

Ren , or the Kidney {continued) .

hydatids in the kidney, 263.
cancer of the kidney, 263.

Reptilia , class of vertebrate animals, 264.
division into families, 265.
osteology cf chelonian reptiles, 265.
plastrum or ventral cuirass, 266.
pelvis, 267.

borres of the carpus, 267.
feet, 268.
tarsus, 270.

osteology of ophidians, 272.
myology of chelonian reptiles, 273..

muscles of the neck and head, 27 5.
of the shoulder, 275.
of the arm, 27 6.
of the forearm, 278.
of the hand, 279.
of the thigh, 279.
of the leg, 280.

myology of ophidian reptiles, 281.
muscles of the spine, 281.
of the ribs, 281.
of the head, 282.
anterior temporal, 282.
middle temporal, 282.
posterior temporal, 283.
muscles of the head of the rattlesnake, 283.
muscles of the throat, 284.
myology of the salamander, 285.
muscles of the head, 285.

of the trunk, 285.
of the extremities, 286.
teeth of reptiles, 287.
of the crocodile, 288.
of the lizard, 288.
of the boa constrictor, 289.
poison fang of serpents, 290.
poison apparatus of the viper, 291.
tongue of reptiles, 292.
digestive system, 294.
stomach, 296.
viscera, 297.
lymphatic system, ,300.
lymphatic hearts, 302.
venous system, 303.
arterial system, 303.
organs of respiration, 306.
circulation of the blood, 307.
the heart, 307.
nervous system, 309.
the brain, 309.
sympathetic system, 312.
organ of hearing, 313.
organ of vision, 314.
appendages to the eye, 314.
lachrymal apparatus, 316.
urinary apparatus, 316.

the kidneys, 316.
male organs of generation, 317.
female organs of generation, 321.
the oviducts, 321.
development of the embryo, 322.
tegumentary system, 324.
musk gland of the crocodile, 325.
anal glands, 325.

Respiration , 325.

respiration of plants, 328.
respiration of animals, 329.
respiratory membrane, 330.
giils or branchiae, 331.
trachea?, 331.
lungs, 331.

in birds, 331.

man : apparatus for renewing the air in the lungs of
the human species, 333.

frequency of the respiratory muscular movements,

338.

quantity of air drawn into, and expelled from, the
lungs, 339.

quickened or forced inspiration, 340.

changes upon the atmospheric air in respiration,

342.

animal matters exhaled from the lungs, 314.
quantity of carbonic acid gas in the expired air,
345.

period of the day, 346.
digestion. 346.
fasting 347.
alcohol, 347.

conditions of the mind, 348.
exercise, 348.
temperature, 348.
effect of the seasons, 349.
barometric pressure, 349.
age, sex, and constitution, 350.
influence of the respiratory movements upon the
evolution of carbonic acid from the lungs, 351.
frequency of the respiratory movements, 351.
bulk of the air expelled, 352.

stoppage of the respiratory movements for a time,
352.

quantity of oxygen absorbed at the lungs, 354.

ANALYTICAL INDEX.

1534

Respiration ( continued ).

differences between arterial and venous blood, 356.
free gases in the blood, 358.
theory of respiration, 361.

intermixture of air in the upper and lower ap-
paratus, 362. l

actions between the blood and the atmospheric air,

362.

causes of the change of colour in the blood, 365.

Rodentia , an Order of mammiferous vertebrata, 368.
bones of the cranium, 369.
in the hare, 369.
in the rabbit, 370.
in the marmot, 370.
in the squirrel, 370.
in the beaver, 370.
in the cape mole, 370.
in the ondatra and water voles, 370.
in the rat and rat moles, 371.
in the gerbilles, 371.
in the hamster, 371.
in the dormouse, 371.
in the rhyzomys, 371.
in the jerboa, 371.
in the helamys, 372.
in the echimys, 372.
in the capromys, 372.
in the porcupine, 372.
in the cosndou, 372.
in the paca, 372.
in the guinea-pig, 372.
in the couia, 373.
in the agouti, 373.
in the capybara, 373.
in the viscache, 373.
in the kerodons, 373.
in the chinchilla, 373.

bones of the face of various animals of this order, 374
to 379. 1

bones of the carpus, 379.
clavicle, 380. '
femur, 380.
fibula, 381.
teeth, 382.

organs of digestion, 385.
stomach, 386.
intestinal canal, 389.
liver, pancreas, spleen, 390.
lympathic system, 390.
arterial system, 390.
venous system, 391.
nervous system, 391.
organs of the senses, 392.
male organs of generation, 392.
female organs of generation, 396.

Rot if era, or Rotatoria , class of invertebrate animals, 396.
division into families by Ehrenberg, 400.
tegumental system, 409.
motory system, 411.
digestive system, 411.
the teeth, 412.

vascular and respiratory systems, 413.
nervous system and organs of the senses, 414.
reproductive system, 414.

Ruminantia. See Supplement.

Saliva , 415.

quantity of saliva secreted during the day, 415.
physical qualities, 415.
specific gravity, 416.
chemistry, 416.
saliva of children, 417.
male and female saliva, 417.
general properties, 418.
saliva of animals, 418.
saliva in disease, 419.
salivary calculi, 419.
ranula, 420.
hydrophobia, 420.
infection, 420.
syphilis, 420.
mercurial salivation, 420.
various kinds of diseased saliva analysed, 421.
spontaneous saliva, 421.
gelatinous saliva, 422.
milky saliva, 422.
urinary saliva, 422.

Salivary Glands , -122.

parotid gland, 423.
submaxillary gland, 424.
sublingual gland, 424.
subsidiary salivary glands, 425.
labial glands, 426.
buccal glands, 426.
molar glands, 426.
palatine glands, 426.
anterior lingual glands, 426.
posterior lingual glands, 426.
minute structure, 427.
vascular supply, 428.
nervous supply, 428.
lymphatics, 428.
saliva of mastication, 429.
saliva of deglutition, 429.

Salivary Glands ( continued ).
morbid anatomy, 430.
salivary fistula?, 431.
nature of ranula, 431.
comparative anatomy, 431.

salivary apparatus of entozoa, 431.
among enchinodermata, 431.
in myriapoda, 431.
in the insecta, 431.
in cirrhopoda, 432.
among pteropoda, 432.
in cephalopoda, 432.
among reptiles, 432.
in aves, 432.
in mammalia, 433.
in the ruminantia, 433.
among edentata, 433.
in carnivora, 433.

Scapular Region , 433.
the muscles, 433.

supra-scapular nerve, 434.
supra-scapular artery, 435.
supra-spinal branch, 435.
infra-spinal branch, 435.
below the spine of the scapula, 435.
deltoid muscle, 435.

trapezius and latissimus dorsi muscles, 435.
infra-spinatus muscle, 436.
teres minor muscle, 436.
teres major, 436.
triangular compartment, 436.
quadrilateral compartment, 436.
posterior scapular artery, 436.
veins of the scapular region, 437.
lymphatics of this region, 437.
uses of the scapula, 437-
furuncular inflammation, 438.
chronic abscesses, 4j8.
fractures, 438.
ablation, 438.

Scrotum , 438.

skin of the scrotum, 438.
areolar tissue, 438.
vessels of the scrotum, 439.
nerves, 439.

Secretion , 439.

excrementitious and recrementitious secretions, 439.

organs of secretion, 441.

development of cells, 441.

excretory organs of animals, 443.

absorbent system, 444.

biliary apparatus in various animals, 445.

biliary ducts in mammalia, 450.

hepatic cells in various animals, 452.

sources of the demand for secreting function, 455.

existence of the elements of secretions in the blood,

459.

presence of urea in the blood, 459.

pre-existence of uric acid in the blood, 460.

hippuric acid detected in the blood by Dr. Garrod,

460.

kreatine and kreatinine, 460.
metastasis of secretion, 461.
secretion of milk, 463.
menstrual flux, 463.

influence of the nervous system on the secreting pro-
cess, 464.

mammary secretion influenced by the state of the
mind, 464.

quantity and quality of the milk changed by mental
emotions, 465.

remarkable instances produced by excitement, 465.
phenomena produced over the secreting processes by
mental states, 466.

changes in the state of nutrition arising from injured
nerves, 468.

Semen. 472.

histological elements of the semen, 472.
periodical development of the spermatozoa and tes-
ticles, 473.

form and history of development of the spermatozoa,
474.

spermatozoa in man, 474.
in mammalia, 475.
in aves, 477.
in reptilia, 480.
in fishes, 483.
in mollusca, 484.
in insecta, 488.
in Crustacea, 493.

morphology and development of the spermatozoa, 499.
organisation of the spermatozoa, 502.
motions of the spermatozoa, 502.
chemical composition of the semen, 505.
physiological office of the semen, 507.

Sensation ; perception of the mind, 508.

sensation distinguished as common and special, 509.
objective and subjective sensations, 510.
reflex sensations, 510.

Sensibility , like sensation, involves the power of affecting
the mind through the body, 510.
the word also applied to nerves, to signify their power
of evolving the nervous force, 511.

ANALYTICAL INDEX.

1535

Serous and Synovial Membranes , 511.
white fibrous tissue, 512.
yellow fibrous tissue, 512.
areolar tissue, 513. 524.
burs®, 513.

subcutaneous burs®, 514.

the internal surface covered by a cell-growth, 514-.
character of the cells, 515.
arrangement of the cells, 515.
subtendinous burs®, 516.
cartilage corpuscles, 517.
synovial membranes, 518.

epithelium of these structures, 519.
vessels of the synovial membrane, 519.
serous membranes, 522.

epithelium of these membranes, 523.
basement membrane, 523.

subserous cellular tissue, 524.
nerves, 525.

choroid plexus, 525.
development of serous membranes, 526
development in the human fcetus, 526.
development by friction, 526.
physiology of the serous and synovial membranes, 527.
contrast of serous and synovial membranes, 528.
subcutaneous and subtendinous burs®, 530.
morbid anatomy, 530.

serous and dropsical effusions, 530.
physical and chemical properties found in the
fluid, 531.

inflammatory or fibrinous effusions, 532.

composition of the fluid, 533.

organisation of the effusion, 535.

suppurative inflammation, 535.

chronic inflammation, 536.

events of inflammation, 535.

tubercle, 537.

cancer of the tissues, 537.

ossification, 537.

cysts, 538.

subserous areolar tissue, 538.
loose cartilages, 5 38.

Sesamoid bones, 541 .

in the human subject, 541.

of the thumb and great toe, 541.
structure, 541.
development, 542.
disease and injury, 542.
other sesamoid bones, 542.
comparative anatomy, 543.
use of sesamoid bones, 543.

Seventh Pair of Nerves, 543.
facial and auditory nerves : the auditory nerve, 543
its apparent origin, 544.
facial nerve, 544.

description of the facial nerve, 544.
in the cranium, 545.
portio intermedia, 545.
in the temporal bone, 545.

superficial petrosal nerve, connected with the fa-
cial, 545.

branch from the facial to the membrane which closes
the fanestra ovalis, 546.
filament to the stapendius muscle, 546.
the chorda tympani, 546.

connexion of the facial and vagus nerves, 546.

external to the cranium, 546.

posterior auricular, 546.

digastric branch, 547.

stylo-hyoid branch, 547.

tempora-facial division, 547.

orbicular or supra-orbital branches, 547.

infra-orbital filaments, 547.

the buccal branches, 547.

cervico-facial division, 548.

supra-maxillary part, 548.

infra-maxillary, 548.

the portio intermedia in the human subject, 548.
general results of examinations in comparative ana-
tomy, 550.

physiology of the seventh nerve, 551.
the facial nerve distributed almost exclusively to mus-
cular structures, 551.

the portio dura termed by Bell the respiratory nerve of
the face, 552.

the section of the facial nerve indirectly affects the
sense of smell, 552.

effect of division of the portio dura on the eye, 552.
influence of the facial nerve on the sense of taste, 553.
the facial nerve a nerve of motion, 554.

Shell; the term applied to the envelopes in which the
bodies and members of many animals belonging to
the radiated, molluscous, and articulated sub-king-
doms are enclosed, 556.
shells of the mollusca, 557.
of the echinodermata, 566.
of Crustacea, 569.

[The diversities in the subordinate divisions of the
various groups and classes will be found under their re-
spective heads in the article.]

Shoulder Joint : Normal Anatomy, 571.
deltoid muscle, 571.

Shoulder Joint : Normal Anatomy ( continued ).
scapulo-humeral articulation, 572.
the bones : glenoid cavity of the scapula, 573.
head of the humerus, 573.
the tuberosities, 573.

structures which facilitate motion in the joint, 573.

cartilage of incrustation, 573.

connecting media ; capsular ligament, 574.

long tendon of the biceps, 575.
synovial membrane, 575.

mechanical functions: motion of fluxion, 57 6.
of extension, 576.
of adduction, 576.
of abduction, 576.
of circumduction, 577.
of rotation, 577.

Shoulder Joint : Abnormal conditions of, 577.
disease : acute arthritis of the shoulder, 577.
symptoms of acute inflammation, 577.
anatomical characters of arthritis, 577.
chronic arthritis of the shoulder, 577.
simple chronic arthritis, 578.
symptoms, 578.
cases, 578.

anatomical characters of chronic arthritis, 580.
cases, 581.

chronic rheumatic arthritis, 58-i.
symptoms, 584.
diagnosis, 585.
anatomical characters, 585.
cases, 588.

fractures : fracture of the acromion process, 600.
of the coracoid process, 600.
of the neck of the scapula, 601.
of the superior extremity of the humerus, 601.
intra-scapular fracture of the humerus, 601.
extra-scapular fracture through the tubercles, 602.
fracture of the superior extremity of the humerus
through the line of junction of the epiphylis with the
shaft of the bone, 603.

fracture of the surgical neck of the humerus below the
tuberosities and junction of the epiphylis, 605.
dislocations, 605.

dislocation downwards and inwards into the axilla, 606.
symptoms, 606.

anatomical characters of the dislocation into the
axilla, 607.

dislocation forwards, 609.

dislocation backwards of the head of the humerus on the
dorsum of the scapula, the result of accident, 611.
case, 611.

diagnosis between the fractures of the superior ex-
tremity of the humerus and dislocations of the
shoulder-joint, 613.

dislocation of the head of the humerus sometimes
combined with a fracture of the arm, 614.
dislocation of the head of the humerus accompanied
with a fracture of the neck of the humerus, 614.
muscles : laceration of the tendon of the subscapularis
muscle, 615.

eedematous swelling, 615.

paralysis of the muscles of the arm, 615.

alterations of the nerves, 616.

luxations of the head of the humerus complicated
with a lesion of the axillary artery, 616.
case, 616.

congenital malformation of the shoulder-joint, 617.
anatomical characters of congenital malformation with
displacement of the head of the humerus inwards,
618.

cases,. 618.

congenital malformation with displacement of the head
of the humerus on the dorsum of the scapula, 619.
case, 620.

Sixth Pair of Nerves, 621.

visible origin of the nerve, 621.
connected with the sympathetic nerve, 621.
physiology of the sixth nerve, 622.

Skeleton, 622.

law of unity in variety, 622.
vertebr® are unequal quantities, 624.
even the one vertebra is not of equal quantity in all
individuals of the same species, 625.
all vertebr® contain a greater or less amount of certain
known elemental pieces, 625.
the dorsal vertebra of human anatomy is an artificial
figure, 625.

the cervical vertebra developes the costal appendages,
626.

all the cervical vertebr® develope costal appendages,
627.

the lumbar vertebra developes the costal appendages,
627.

all the lumbar vertebr® develope costal appendages, 628.
the sacral vertebr® develope costal appendages, 628.
the coccygeal vertebr® are deprived of their costal ap-
pendages, 629.

the first seven thoracic costo-vertebral figures are whole
or plus quantities, 629.

the five asternal costo-vertebral forms are propor-
tionals metamorphosed from five sternal costo-verte-
bral plus quantities, 630.

1536

ANALYTICAL INDEX

Skeleton ( continued ).

the five lumbar vertebra? are proportionals metamor-
phosed from five sternal costo-vertebral archetypes,

630.

the sacro-coccygeal series of vertebra? are proportionals
degraded from sternal costo-vertebral circles, 631.
the seven cervical vertebra? are proportionals degraded
from seven sterno-costo- vertebral whole quantities,

631.

the mammalian spinal axis consists of a series of seg-
mental quantities, whose only variety or specific dis-
tinction depends upon proportioning from the whole
thoracic quantities, 631.

uniformity of structure is a condition proper to the plus
thoracic originals of the spinal axis of the mamma-
lian body, 632.

every spinal segment which is lesser refers to every
spinal segment which is greater, and all lesser seg-
ments refer to that which is greatest, 633.
structural uniformity cannot characterise such spinal
segments as are proportionally or quantitatively va-
rious, 633.

specific variety is none other than proportional variety,

633.

the knowledge of the differential quantity between all
spinal segments renders them exactly uniform in
idea, 633.

without knowing the full dimensions of whole or uni-
form quantities, we can never rightly understand the
real character of lesser and special forms, and there-
fore can never otherwise understand the law of
formation, 634.

the mammalian cervix is not limited to the fixed num-
ber of seven cervical vertebra?, 634.
the number of ce. vical vertebra? in the mammal cervix
depends upon the number of archetypal costo-ver-
tebral figures which have suffered metamorphosis,
635.

the presence of cervical ribs subtracts from the number
of cervical vertebra?, and adds to the number of
thoracic archetypes, 636.

the length of the thorax depends upon the number of
persistent costo-vertebral archetypes, 636.
the numerical length of the lumbar spinal region de-
pends upon the number of archetypes subjected to
metamorphosis, 637.

the numerical length of the sacral and coccygeal series
is not fixed, and this is owing to the same fact of
archetypes undergoing metamorphosis, 637.
a comparison of the same numerical vertebra? in all
human spinal axes will prove the truth of the pre-
sent interpretation of the law which governs the
development of al! vertebral forms, not only in the
same spine, but all other spines, 637.
the anomaly is a link in the chain of form, 638.
all the spinal segments of all classes and species of ver-
tebrated animals are only as the variable propor-
tionals of sterno-costo-vertebral archetypes, 638.
the hyoid apparatus occurs opposite to the cervical
spinal region, where we know costal quantity to be
lost ; the hyoid apparatus refers to the cervical ver-
tebra?, and consists of their ribs metamorphosed, 640.
the ventral apparatus occurs opposite to the lumbar
spinal region, where we understand that costal quan-
tity is lost; the ventral apparatus refers to the lumbar
vertebra?, and consists of their ribs metamorphosed,

643.

clavicles, coracoid bones, and ribs are identical parts of
the costo-vertebral whole quantities or archetypes,

644.

marsupial bones, pubic and ischiadic bones and ribs,
are identical parts of the costo-vertebral whole
quantities or archetypes, 648.
chevron bones and ribs are identical parts of the costo-
vertebral whole quantities or archetypes, 650.
the sternal med an line ranges from the maxilla to the
pubic bones of the abstract archetypal skelatal fabric,
651.

every fossil skeletal species of extinct animals, as well
as every recent existing species of skeleton, are forms
created of the archetypal skeleton, 655.
the cranio-facial apparatus consists, like the thoracic
apparatus, of variable proportionals of the sterno-
costo-vertebral quantities, 655
the scapulary or fore-limbs of all the vertebrated ani-
mals are homologous to one another ; the variety
among these organs occurs by a metamorphosis or
omission of elementary quantity, 661.
the scapulary and pelvic members are homologous,
654.

the sterno-costo-vertebral quantity is a proportional of
the dorso-ventral quantity, 667.
the scapulary and pelvic pairs of limbs are proportional
quantities metamorphosed from the dorso-ventral
archetypes, 669.

the cranio-facial apparatus of segments are propor-
tionals of the dorso-ventral archetypes, 673.
the cranio-facial apparatus is the origin of the dorso-
ventral archetypal series, and the caudal apparatus
is its termination, 673.

the uniform archetypal series undergoes a graduated
metamorphosis of its quantities for the production of
all varieties of skeletal species, 674.

Sleep : necessity for, and nature of sleep, 677.
medulla oblongata, 677.
ganglia of sensation, 677.
hemispheric ganglia, 677.
the cerebellum, 677.
sleep of plants ; of leaves, 678.

* of flowers, 679.
periodicity of sleep, 679.
causes of sleep, 680.
phenomena of ordinary sleep, 682.
access of sleep, 683.

power of being aroused by impressions made upon the
organs of sense, 683.
amount of sleep required by man, 695.
as age advances, 685.
temperament, 685.
habit, 686.

previous exhaustion, 686
entire absence of sleep, 686.
deficiency of sleep, 686.
protraction of sleep, 687.

dreaming : entire absence of voluntary control, 687.

peculiarities of the state of dreaming, 689.
somnambulism, 691.

readiness with which the train of thought may be |
guided during the state of somnambulism, 694.
causes of somnambulism, 695..
mesmerism, phenomena of mesmerism, 696.

Smell , 697.

general structure of the organ of smell, 698.
the olfactive organ in other air-breathing vertebrata i
corresponds with that of man, 699.
insects possess the olfactive power, 700.
nerve of smell, 700.

conditions of the exercise of the sense, 701.
purposes of the sense, 701.

in the air-breathing vertebrata the sense of smell is,
as it were, the sentinel of the respiratory organs, 702.
in man, the sense of smell is not, ordinarily, so acute as
it is in many of the lower animals, 702.

Softening and Induration , 703.
softening of the brain, 706.
softening of the spinal cord, 706.
induration of the brain, 706.
induration of the spinal cord, 707.
softening of the heart, 707.
induration of the heart, 707.
softening of the lungs, 707.
induration of the lungs, 707.
mucous, serous, and articular membranes, 70S.
lining membrane of the heart, 708.
internal membrane of arteries, 708.

softening of the arachnoid, peritoneum, and pleura, 708. jj
softening of mucous membranes, 708.
softening of the skin, 710.
appendages of the skin, 710.
induration of mucous membranes, 710.
indurated and thickened state of the membranes of the
brain, pericardium, and pleura, 711.
softening of the liver, 711.
induration of the liver, 711.
softening of the spleen, 711.
induration of the spleen, 711.
softening of the kidney, 712.
induration of the kidney, 712.
induration and softening of the uterus, 712.
prostate gland, testicle, and epididymus, 712.
osseous framework of the body, 712.
softening of cartilage, 712.
fibrous tissue becomes indurated, 713.
softening of the muscular structures, 713.
softening of cellular tissue, 713.
induration of cellular tissue, 713.

Sulipeda, group of herbivorous quadrupeds, 713.
genus equus : equus caballus, equus hemionus, equus J
asinus, equus zebra, equus quaccha, and equus mon-
tanus, 714.
osteology, 715.

cervical vertebra?, 716.
dorsal vertebra?, 717.

vertebree of the loins, 718. 1

cudal vertebra?, 718.
thorax, 718.
ribs, 718.

anterior extremity, 718.
scapula, 718.
humerus, 718.
forearm, 718.
carpus, 718.
metacarpal bones, 719.
posterior extremity, 719.
pelvis, 719.
leg, 720.
fibula, 720.

bones of the tarsus, in the horse, 721. j

of the metatarsus, 721.
myology, 721.

panniculus carnosis, 721.
proper muscles of the spine, 722.
the tail ; muscles which raise or strengthen the |
tail, 753.

muscles which depress the tail, 723.
muscles adapted to move the tail laterally, 724.

ANALYTICAL INDEX. 1537

Solipeda ( continued ).

muscles derived from the spinal column which
serve immediately for the movements of the
cranium, 724.

muscles arising from other cervical vertebra?, 724.
muscles of the ribs and sternum, 724.
walls of the abdomen, 725.
anterior extremity ; muscles of the shoulder, 72 5.
muscles inserted in the humerus, 726.
muscles of the forearm, 727.
extensors, 727.

muscles of the carpus and metacarpus, 727-
muscles of the hand (extensor communis digit-
orum), 728.

posterior extremity ; muscles of the pelvis, 729.
muscles inserted in the os femoris, 729.
flexor muscles of the leg, 729.
extensor muscles of the thigh, 729.
muscles implanted into the foot, 730.
muscles implanted into the digit, 730.
flexor muscles, 731.
extensor muscles of the toes, 731.
muscles which act immediately upon the lower
jaw, 731.

muscles of the os hyoides, 731.
muscles of the tongue, of the palate, and of the
larynx, 732.

muscles of the face, 732.
depressor of the lower eye-lid, 732.
long dilator of the nostril, and elevator of the
upper lip, 732.

alimentary apparatus ; teeth, 732.
salivary glands, 734.
parotid glands, 734.
submaxillary glands, 734.
sublingual glands, 734.
pharynx, 734.
stomach, 735.
liver, 736.
spleen, 736.
pancreas, 737.
circulatory apparatus, 737.
structure of the horse’s foot, 737.
horny hoof, 737.
the sole, 739.

cartilages of the foot, 740.
soft parts of the foot, 741.
nervous system and organs of the senses, 741.
organs of generation ; male organs, 742.
scrotum and penis, 742.
testicles, 742.

female organs of generation, 743.
urinary bladder, 743.
orifice of the uterus, 743.
ovaria and fallopian tubes, 743.
gravid uterus, 743.
the hippomanes, 744.
mammary glands, 744.

Spinal Accessory Nerve , 745.
internal branch, 748.
external branch, 748.

comparative anatomy of the spinal accessory, 748.
physiology of this nerve, 749.

Spinal Nerves , 750.

posterior branch of the first cervical or sub-occipital
nerve, 750.

posterior branch of the second cervical nerve, 750.
posterior branch of the third cervical, 751.
horizontal branch. 751.

posterior root of the fourth cervical nerve, 751.
posterior branches of the fifth, sixth, seventh, and
eighth cervical nerves, 751.
posterior branches of the seventh and eighth cer-
vical nerves, 751.

posterior branches of the dorsal (thoracic) nerves, 751.
external or muscular branches of the eight superior.
751.

the internal branches, 751.
external branches of the four inferior, 751.
internal branches of the four inferior, 751.
posterior branches of the lumbar nerves, 752.
external branches, 752.
posterior branches of the sacral nerves, 752.
anterior branches of the spinal nerves, 752.
anterior branch of the first cervical nerve, 752.
anterior branch of the second cervical nerve, 752.
anterior branch of the third cervical nerve, 752.
anterior branch of the fourth cervical nerve, 752.
cervical plexus, 752.
superficialis colli, 753.

the ascending branch, 753.
the descending branch, 753.
the auricularis magnus, 7 53.
superficial branch, 753.
deep branch, 7 53.
the occipitalis minor, 753.
supra-clavicular and acromial nerves, 753.
acromial nerves, 753.

communicating branches, 753.
internal descending cervical, 753.
phrenic nerve, 754.

right phrenic, and the left, 754.

VOL. IV.

Spinal Nerves ( continued ).

anterior branches of the four inferior cervical and first
dorsal nerves, 754.
the brachial plexus (axillary), 754.
nerve for the rhomboideus, 755.
nerve to the serratus magnus, 755.
nerve for the subclavius, 755.
supra-scapular nerve, 755.
subscapular nerves, 755.
nerves for the subscapularis, 755.
internal cutaneous, 755.

external terminal branch, 755.
internal branch, 756.

cutaneous nerve of Wrisberg (the accessory nerve of
the internal cutaneous), 756.
external cutaneous, 756.
branches to the biceps, 756.
branches for the brachialis anticus, 756.
median nerve, 756.
muscular branches, 756.
anterior interosseous nerve, 756.
palmer cutaneous branch, 757.
terminal digital branches of the median, 757.
first digital nerve, 757.
second digital nerve, 757.
third digital nerve, 757.
fourth digital nerve, 757.
the ulnar nerve, 757.

superficial external, 758.
deep branch, 758.
musculo spiral nerve (radial), 758.
internal cutaneous, 759.

branch for the internal head of the triceps, 759.
branch for the outer head of the triceps and anco-
neus, 759.

external cutaneous branch, 759.
anterior terminal branch, 759.
internal branch, 759.
deep terminal branch, 759.
circumflex nerve (axiliary), 759.
anterior branches of the dorsal (intercostal) nerves, 760.

intercostal branches, 760.
first dorsal nerve, 760.
second dorsal nerve, 760.
cutaneous branch of the third dorsal, 760.
cutaneous branches of the fourth and fifth dorsal
nerves, 760.

twelfth dorsal nerve, 761.

anterior branches of the lumbar nerves, 761.

the lumbar or lumbo-abdominal plexus, 761.

upper musculo cutaneous, 761.

lower musculo cutaneous, 762.

genito-crural nerve, 762.

crural nerve (femoral), 762.

internal cutaneous nerve, 762.

accessory saphaenus nerve, 763.

middle cutaneous nerve, 763.

nerve to the femoral vessels, 763.

branch for the vastus interims, 763.
branch for the crura?us, 763.
branch for the rectus, 763.
branch for the vastus externus, 763.
saphaenus nerve, 764.
obturator nerve, 764.

anterior branches of the sacral nerves, 765.
sacral plexus, 765.

nerve for the obturator internus, 766.
internal pudic nerve, 766.

superior branch (dorsal nerve) of the penis, 766.
inferior branch (perinasal), 766.
pudic nerve, 766.
superior gluta?al nerve, 766.
inferior gluta?al nerve (lesser sciatic), 766.

cutaneous branch to the back of the thigh and
upper part of the leg, 767.
nerve for the pyriformis, 767.
nerves for the gemelli and quadratus femoris, 767.
great sciatic nerve, 767.
nerve for the semi-tendinous, 767.
semi-membranosus, 761.
peroneal nerve (external popliteal), 768.
peroneal cutaneous, 768.
peroneal saphaenus, 768.
superior external articular, 768.
inferior external articular, 768.
anterior tibial nerve, 768.
musculo-cutaneous nerve, 769.
tibial nerve, 769.

terminal branches, 770.
internal plantar nerve, 770.
external plantar nerve, 771.

Spleen: situation and form, 771.
varieties of the spleen, 771.
size and weight, 771.
consistence, 772.
structure, 772.

serous membrane, 772.
fibrous coat, 772.
trabecular tissue, 773.
splenic or malpighian corpuscles, 775.
red spleen substance ; the spleen-pulp ; parenchyma
of the spleen, 780.

5 F

ANALYTICAL INDEX.

1538

Spleen ( continued ).

cells of the spleen-pulp, 780.
the blood effused in the spleen-pulp, 781.
cells in mammals, 783.
in birds, 783.
in reptilia, 783.
in fishes, 784.

blood-vessels of the spleen ; splenic artery, 787.
splenic vein, 788.
lymphatics of the spleen, 793.
nerves, 794.

function of the spleen, 796.
morbid anatomy, 800.
enlargement, 800.
inflammation, 801.

Statistics , Medical, 801.

of facts considered as the elements of statistical in-
quiries, 804.

of the average and extreme results deduced from
observation, 806.

of extreme values derived from observation, 813.
Statistics, Vital. See Vital Statistics.

Stomach and Intestinal Canal. See Supplement.

Subclavian Arteries , 814.
subclavian vein, 815.

first stage of the right subclavian artery, 815.

anterior relations, 815.
first stage of the left subclavian artery, 816.
differences between the right and the left subclavian
arteries in their first stage, 816.
relations of the left artery, 816.
subclavian arteries in their second stage, 8 17.
subclavian artery in its third stage, 817.
anomalies in the origin of the subclavian arteries, 818.
brandies of the subclavian arteries, 819.
vertebral artery, 819.

relations, 820.
basilar artery, 820.
branches of the basilar artery, 821.

inferior (or posterior) cerebellar artery, 821.
superior (or anterior), 821.
posterior artery of the cerebrum, 821.
varieties occasionally observable in the vertebral ar-
teries, 822.
vertebral vein, 822.
internal mammary artery, 822.
branches of the mammary artery, 822.
varieties, 823.
inferior thyroid artery, 823.
relations, 823.
branches, 824.
supra-scapular artery, 824.
arteria transversalis colli, 824.
arteria cervicalis profunda, 824.
superior intercostal artery, 824.
operative proceedings, 825.

Supra- Renal Capsules , 827.
in man, 827-

in mammalia, birds, reptiles, and other vertebrata.

828.

minute structure, 830.
cortical substance, in man, 841.
medullary substance, 832.
accessory supra-renal capsules, 832.
supra-renal blood-vessels in the human subject,
833.

the veins, 833.
lymphatics, 833.
nerves, 833.
in mammalia, 833.
in birds, 834.
in reptilia, 834.
in fishes, 835.
development, 836.
physiology, 837.

Sweat , 841.

in the healthy human subject, 841.
observations made by Linings in the climate of South
Carolina, 842.

experiments made by Mr. Cruikshank and by Mr.
Abernethy, 842.
by Lavoisier and Seguin, 842.
gases which pass off from the body by insensible
perspiration, 842.
experiment by Simon, 843.

sweat analysed by Berzelius and by Anselmino, 843.
sweat in disease, 844.

Symmetry , an anatomical signification that one half of
an animal is usually an exact reversed copy of the
other, 845.

lateral repetition, 845.

in man, exceptions are offered by the heart, great
blood-vessels, lungs, bowels, liver, spleen, &c., 846.
abnormal deviations from symmetry, 848.
comparative anatomy, 848.
in all mammalia, 848.
in birds, 848.
in reptiles, 848.
in fishes, 849.
in articulata, 849.

in mollusca and other animals, 850.
antero-posterior symmetry, 851.

Symmetry ( continued ).

symmetry of disease, 851.
plants, 852.
crystals, 852.

Sympathetic Nerve. See Supplement.

Sympathy , the assumption by different individuals, or by
different parts of the same individual, of the same or an
analogous physiological or pathological state at the same
time, or in rapid succession, 852.
sympathetic sensations, 853.

movements excited by a stimulus applied at a dis-
tance, 853.

sympathetic phenomena. 854.
continuous and contiguous sympathy, 855.

Synovia , the fluid that exists within the membrane lining
joints to assist motion by lubrication, 856.
synovia chemically examined, 856.

Taste, the sense by which we distinguish the sapid pro-
perties of bodies, 856.
seat of the sense, 857.
conditions of the sense, 857.
nerves of taste, 858.
speciality of the nervous fibres, 859.
gustative papilla?, 860.
conical and filiform papilla?, 860.
exercise of the sense, 861.

influence of habit in blunting the sensibility to par-
ticular tastes, 862.

sense of taste affected by illness, 862.
purpose of the sense, 863.

Teeth ; comparative Anatomy , 864.
dentine tissue, 865.
crusta petrosa, or cement, 865.
enamel tissue, 86 5.

characteristic examples in the teeth of various
animals, 865.

the dental system of fishes, 873.
number and form, 873.
situation, 875.
substance, 877.
development, 880.
dental system of reptiles, 882.

situation and attachment, 883.
substance and structure, 884.
development, 885.
poisonous serpents, 887.
crocodilia, 895.

dental system of mammals, 898.
tusk of the elephant, 923.

Temperament ; a term (of ancient date) referable to pecu-
liarities in the constitution of an individual, 935.
sanguine temperament, 936.
melancholic temperament, 936.
nervous temperament, 936.

Temporo- Maxillary Articulation , 937.
in the human subject, 937.
bones, 937.

interarticular fibro cartilage, 937.
synovial bursa?, 937.
ligaments; external lateral, 937.
internal lateral, 938.
stylo maxillary, 938.
muscles, 938.
motions of the joint, 938.
of the jaw, 938.

abnormal conditions of the temporo-maxillary joint ;
accidents, 938.

when both of the condyles are dislocated, 938.
when one condyle only is dislocated, 939.
congenital malformation, 939.
disease; chronic rheumatic arthritis, 939.

anchylosis, 939.
comparative anatomy, 940.
in aves, 941.
reptilia, 941.
pisces, 941.

homology of the joint, 941.

Teratology ; doctrine of congenital deformities, 942.
original malformation of the germ, 942.
cause in the mother, 942.
in the father, 942.

deformity of the originally well-formed germ, 942.

cyclopia, 944. 967.
malformation of the ovum, 946.

mola botryoides or hydatica, 946.
separation of the placenta into lobes, 946.
vessels of the umbilical cord separated near the
placenta, 947.

umbilical cord too long, 947.
umbilical cord too short, 947.
absence of one of the umbilical arteries, 947.
increased number of the vessels of the cord, 948.
persistence of the umbilical vesicle, 948.
constriction of the umbilical cord, 948.
umbilical cord too thick, 948.
malformations of the foetus, 948.

non. closure of the anterior part of the body, 948.

fissure of the whole anterior wall of the body, 949.

fissure of the thorax, 949.

ectopia of the heart, 949.

fissure of the anterior abdominal wall, 950.

complete ectopia of the abdominal viscera, 950.

ANALYTICAL INDEX.

1539

Teratology {continued.').

congenital umbilical hernia, 950.
congenital ventral hernia, 950.
acquired umbilical hernia, 950.
fissure of the pubic and hypogastric regions, 950.
formation of a cloaca, 950.
congenital fissure of the urinary bladder, 951.
ectopia vesicas urinariae, 952.
inversio vesicas urinarias, 952.
cervical fissure, 953.
fissure of the face, 953.
complete fissure of the face, 953.
hare-lip, double, 953.
single, 953.

fissure of the palate without a hare-lip, 953.
fissure of the under lip, 954.
fissure of the skull, 954.

want of the brain and exposure of the basis of the
skull, 954.

denuded surface of the basis cranii occupied by a
spongy substance, instead of brain, 955.
surface of the basis cranii only partially denuded,

955.

skull flat, more evolved, but having an opening,
through which the brain [protrudes as a hernia,

956.

fissure of the back part of the body, 957.
hydrocephalus congenitus. 958.
hydrocephalus extemus, 960.
acephali, or foetus without a head, 960.
acephali in the form of a rounded mass without
extremities, 960.

acephali in same form, with indication of feet,
960.

acephali in which the trunk is more developed,
without a head and thoracic extremities, 961.
acephali without a thorax and without superior
limbs, and composed of an abdomen, genital
organs, and inferior limbs, 961.
acephali in which the trunk is more developed,
with an imperfect thorax, 961.
acephali with a trunk composed of a thorax and an
abdomen, with superior and inferior limbs, 962.
acephali in which some cranial bones are found,
962.

body and extremities perfectly developed, having a
neck surmounted by the ears, 962.
acephali composed of the trunk only, without in-
dication of limbs, 962.

want, and defective formation, of the trunk, 963.
sympodia, 964.

original defective formation of the pelvis, 965.
defective development of the spinal column, 965.
defective formation of the extremities, 965.
want of all the extremities, 965.
want of the intermediate parts in the extremities,
966

limbs too short, 966.
limbs which seem to be truncated, 966.
diminished number of fingers and toes, 966.
coalesced fingers and toes, 966.
deficiency of the under jaw, 967.
total defect of the opening of the mouth, 967.
opening of the mouth represented by a fissure of
the face, 967.

too short an under jaw, 967.

fcetus in foetu : a fcetus more or less perfect contained
in the cavity of the body of its twin brother, or
sister, 967.

the more or less developed rudiments of a fcetus
adhering, in the form of a tumour, to the external
surface of a second body, 968.
double monsters, in which one of the foetuses is
more or less perfect, and the other merely an
appendix to it, 968.

double monsters : anterior duplicity, 969.
lateral duplicity, 970.
inferior duplicity, 972.
posterior duplicity, 972.
superior duplicity, 972.

Testicle ( Human Anatomy), 976.
protective parts or tunics, 97 6.
tunica albuginea, 977.
glandular or secreting structure, 977.
tubuli seminiferi, 978.
rete testis, 979.
excretory paits, 979.
vasculum aberrans, 980.
vas deferens, 980.

vessels and nerves ; spermatic vessels, 981.
absorbents, 982.
nerves, 982.

testicle in the fcetus, and its passage into the scro-
tum, 982.

functions of the testicle, 984.

influence of the testicles and brain upon each other, 985.

envelopes of the testicle, 986.

superficial or external spermatic fascia, 986.

cremaster muscle, 986.

deep spermatic fascia, 986.

spermatic cord, 986.

[For Comparative Anatomy , see the article Organs of
Generation.']

Abnormal Anatomy oj the Testicle, 986.

congenital imperfections and mal-formations ; nume-
rical excesses and defects, 986.
instances of monorchides, 987.

deficiencies and imperfections of the vas deferens, 987.

imperfect transition, 988.

passage of the testicle into the perineum, 990

passage of the testicle through the Curling ring, 990.

inversion of the testicle, 991.

atrophy of the testicle, 991.

arrest of development, 991.

wasting, 992.

all those causes which produce decay in other parts
likewise occasion wasting of the testicle, 992.
inflammation of the tunica vaginalis, or acute hydro-
cele, 994.

hydrocele of the tunica vaginalis, 995.
multilocular hydrocele, 996.

hydrocele, generally single, sometimes occurs on both
sides, 996.

congenital hydrocele, 996
encysted hydrocele of the testicle, 997.
encysted hydrocele of the tunica vaginalis, 998.
spermatozoa in connexion with encysted hydrocele of
the testicle, 998.

diffused hydrocele of the spermatic cord, 999.
encysted hydrocele of the spermatic cord, 1000.
complications of hydrocele, 1001.
hsematocele, 1002.

encysted hematocele of the testicle, 1003.

hematocele of the spermatic cord, 1003.

encysted hematocele of the spermatic cord, 1003.

orchitis, 1004.

acute orchitis, 1004.

chronic orchitis, 1006.

syphilitic orchitis, 1008.

tubercular disease, 1008.

carcinoma ; scirrhous disease of the testicle, 1009.

^ encephaloid cancer, 1009.
colloid and melanosis^cancer, 1010.
cystic disease, 1010.
ossific deposits in the testicle, 1011.
loose bodies in the tunica vaginalis, 1011.
foetal remains in the testicle, lull,
varicocele, 1011.
adipose tumours, 1012.
morbid anatomy of the scrotum, 1013.
elephantiasis, 1013.
hypertrophy, 1014.

cancer scroti, or chimney-sweeper’s cancer, 1014.
melanosis, 1016.
fibrous tumours, 1017.

Thorax , 1017.

classification of the respiratory movements in animals,
1018.

first kind of respiratory movements ; infusoria, 1018.
second species of respiration ; insects, 1019.
third species; fishes, 1019.
fourth species; amphibia, 1020.
fifth species; birds, 1021.
sixth species; mammalia, 1021.
of the thorax in man ; anatomy of the frame-work of the
thorax, 1022.
dorsal vertebra?, 1022.
inter-vertebral disks, 1022.
sternum, 1022.

anterior or cutaneous surface of the sternum, 1023.
posterior surface, 1022.
borders of the sternum, 1023.
clavicular extremity, 1023.
inferior extremity of the sternum, 1023.
structure of the sternum, 1023.
development or ossification of the sternum, 1023.
ossification of the body, or the second, third, fourth,
and fifth pieces, 1024.

union of the points of ossification of the body of the
sternum, 1024.

ossification of the appendix, 1024.
of the ribs, 1024.
classification of the ribs, 1025.
general character of the ribs, 1025.
surfaces, 1025.
borders, 1025.
extremities, 1026.
body, 1026.
curve, 1026.

arch or general bend of the ribs, 1026.
curves of torsion of the ribs, 1026.
articulations of the ribs, 1027.
position of the ribs, 1027..
structure, 1027.
development, 1027.
special characters of the ribs, 1027.
length, 1028.
weight, 1029.

torsion (special characters), 1029.
surfaces (special characters), 1030.
specific differences of the extremities of the ribs,
1030.

head, 1030.
neck, 1030.
tubercle, 1031.
angle, 1031.

5 F 2

ANALYTICAL INDEX.

1510

Thorax ( continued ).

groove, 1031."
costal cartilages, 1031.

general characters of the costal cartilages, 1031 .
differential characters, 1031.
liability of the costal cartilages to ossify, 1031.
ligaments of the ribs, 1032.

with the bodies of the vertebra?, 1032.
with the transverse processes of vertebra?, 1032.
characters peculiar to certain costo-vertebral
articulations, 1032.
with the sternum, 1032.

characters peculiar to chondro or costo-sternal
articulations, 1032.

connexion of the ribs with their cartilages,1033.
articulations of the costal cartilages one with
the other, 1033.

ligaments of the sternum, 1033.
of the thorax in general, 1033.

boundaries of the thoracic cavity, 1034.
contents of the thorax, 1035.
shape of the thorax, 1035.
external thorax, 1035.

anterior or sternal region, 1035.
posterior or vertebral region, 1035.
lateral or costal region, 1035.
internal conformation of the thorax, 1036.
anterior region, 1036.
posterior region, 1037.
lateral region, 1037-

conformation as affected by age and sex, 1037.
conformation as affected by disease and occupa-
tion, 1038.

pigeon or chicken breast, 1039.
dimensions of the thorax, 1040.
external measurement, 1040.
internal measurement, 1040.
of the respiratory muscles, 1042.
intercostal muscles, 1042.

intercostales externi, 1043.
intercostales interni, 1043.
action of the intercostal muscles, 1044.
movement of the levers, 1047.

effect of tensions, oblique, perpendicular, and de-
cussating, between the moveable levers or ribs,
1050.

of the degree of obliquity of a tension, 1052.
of the obliquity of the ribs or bars with reference
to the spine, 1053.

of oblique tensions in contrary directions, 1053.
of tenisons at different parts of the bars or ribs,
1054.

action of the intercostal muscles (resumed), 1055.
levatores costarum, 1055.
triangularis stcrni, 1055.
infra-costales, 1056.
of the elasticity of the ribs, 1056.
of the elastic power of the lungs, 1058.
of the muscular contractility of the lungs, 1060.'
of respiratory muscular power, 1060.
of the respiratory volumes, 1064.
residual air, 1065, 1066.
reserve volume, 1067.
breathing volume, 1067.
complemental volume, 1067.
vital capacity volume, 1067.
vital capacity, 1068.

effect of height, 1070.
affected by position of the body, 1073.
affected by weight, 1073.
relation of vital capacity to the circumference
of the thorax, 1077.
vital capacity affected by age, 1077.
affected by disease, 1078.
of the respiratory movements, 1079.
ordinary breathing, 1080.
deep inspiratory, 1081.
deep expiratory, 1082.

change of position by extreme breathing, 1082.
of ordinary breathing, 1082.
extraordinary breathing in both sexes, 1082.
pathological respiratory movements, 1083.
limited breathing movement, 1084.
non-symmetrical breathing, 1084.
reversed breathing, 1084.
massive breathing, 1084.
interrupted breathing, 1084.
partial breathing, 1084.
quick and slow breathing, 1085.
irregular breathing, 1085.
double breathing, 1085.

of the number of respirations in a given time,
1085

relative velocity of the breathing and the
pulse, 1085.

sudden change in atmospheric pressure, 1086.
of the sounds of respiration, 1086.

Thymus Gland , 1087.

human anatomy, 1087.

relative situation, 1088.
development, 1090.
mature structure of the gland, 1090.
contents of the thymic cavities, 1093.

Thymus Gland ( continued ).

early development, 1094.
development of size, 1095.
comparative anatomy, 1095.
mammalia, 1095.
cheiroptera, 1095.
insectivora, 1096.
carnivora, 1096.
marsupialia, 1096.
among rodents, 1096.
in edentata, 1097.
monotremata, 1097.
pachydermata, 1097.
ruminantia, 1097.
aves, 1097.
reptilia, 1098.
pisces, 1099.
physiology, 1099.

morbid anatomy: absence of the gland, 1101.
inflammation, 1102.
atrophy, 1102.
hypertrophy, 1102.

Thyroid Gland , 1102.

size, 1102.
form, 1102.

situations and relations, 1103.
colour, 1103.
structure, 1104.
contents of the cavities, 1105,
vessels: arteries, 1106.
capillary plexus, 1107.
lymphatics, 1107.
nerves, 1107.
development, 1107 !
comparative anatomy, 1108.
birds, 1108.
reptiles, 1 108.
fishes, 1109.
morphology, 1111.
morbid anatomy, 1114.

inflammation, 1114.
alterations of structure, 1114.
melicerous degeneration, 1114
adventitious formations, 1116.
carcinomatous growths, 1116.
encephaloid or scirrhus, 1116.
enlargement of the vessels, 1116.
history of investigations, 1117.

Tibio-fibular Articulations , 1117.

superior tibio-fibular articulation, 1118.
ligaments, 1118.

anterior ligament, 1118.
posterior ligament, 1118.
tendon of the biceps, 1118.
synovial membrane, 1118.
inferior tibio-fibular articulation, 1119.
anterior ligament, 1119.
posterior ligament, 1119.
interosseous ligament, 1119.
mechanism of the articulations, 1119.
dislocation of the fibula at the upper tibio-fibular
articulation, 1119.

Tongue, 1120.

human anatomy, 1120.
size, 1120.
direction, 1120.
shape, 1120.

general description, 1120.
superior surface, 1121.
inferior surface, 1122.
anterior extremity, apex, or point, 1122.
posterior extremity or base, 1122.
the basis or framework of the tongue, 1123.
hyoid bone, 1123.

hyoglossal membrane or ligament, 1124.
median fibrous septum, 1124.
investments, 1124.
muscular system, 1125.
intrinsic muscles, 1125.

transverse lingual, 1126.
vertical lingual, 1126.
superior lingual, 1126.
lateral lingual, 1 126.
inferior lingual, 1126.

mode of termination of the intrinsic fibres, 1131.
extrinsic muscles, 1132.
palatoglossus, 1132.
styloglossus, 1132.
hyoglossus, 1133.
genioglossus, 1133.
accessory extrinsic muscles, 1134.
movements of the tongue, 1134.

as affecting its length, 1134.
as affecting its direction, 1134.
tegumentary system, 1135.
cutis, 1135.

basement membrane, 1135.
epithelium, 1135.

papillary structure of the tongue, 1136.
circumvallate papillae. 1136.
fungiform papillae, 1137.
conical or filiform papillae, 1138.
simple papillae, 1139.

ANALYTICAL INDEX.

1541

Tongue (continued).

functions of the different papilla?, 1 140.
mucous glands, 1 140.
vessels of the tongue 1 141.
nerves of the tongue, 1141.

comparative anatomy, 1 141.
mollusca, 1 142.
cephalopoda, 1143.
vertebrata, 1143.;
hyoid apparatus, 1144.
in fish, 1144.
in birds, 1145.
in mammalia, 1146.
pisces, 1146.
reptilia, 1146.
aves, 1150.
mammalia, 1151.

the functions of the tongue, 1151.
prehension, 1151.
mastication, 1152.
insalivation, .1152.

" deglutition, 1152.

speech, 1153.

morbid anatomy of the tongue, 1153.
inflammation, 1153.
suppurative glossitis, 1153.
erectile glossitis, 1153.
mercurial glossitis, 1154.
ulceration of the tongue, 1154.
dyspeptic ulceration, 1154.
aphthous ulceration, 1155.
indurated non-malignant ulceration, 1155.
gangrenous ulceration, 1156.
syphilitic ulceration, 1156.
rhagades or fissures, 1156.
glossy tubercle, 1156.
phageda?nic syphilitic ulcers, 1156.
cancer of the tongue, 1157.
tumours of the tongue, 1157.
fatty tumours, 1157.
encysted tumours, 1157.
mulberry-like tumour, 1158.
polypus-like tumour, 1158.
hypertrophy and prolapsus of the tongue, 1158.
atrophy of the tongue, 1159.
diseases of the papilla?, 1159.
hypertrophy of papilla?, 1159.
atrophy of the papilla?, 1160.
effusions into papilla?, 1161.
lymph, 1161 .
denuded papilla?, 1161.
fur, 1161.
tongue-tie, 1162.
tongue swallowing, 1162.
adhesions of the tongue, 1162.
necrosis of the hyoid bone, 1162.

Touch , 1163.

general sensibility, 1163.
special organs of touch, 1165.
conditions of the sense, 1167.
tactile discrimination, 1168.
sense of temperature, 1171.
muscular sense, 1172.
sense of weight, 1175.
sense of direction, 1175.

mental phenomena connected with the sense, 1176.
improvability of the sense of touch, 1177.
morbid conditions of the sense, 1182.
ana?sthesia, 1182.
hypera?sthesia, 1184.
depravation, 1184.

Tunicata , 1185.

divisions and subdivisions into families and genera,

1186.

anatomy and physiology of the tunicata, 1193.
anatomy of the asciadiata?, 1200.

of the clavellinidae, 1213.
of the botryllida?, 1218.
of pyrosoma, 1227.
of salpae, 1230.
of pelonaia, 1239.
locomotion of the tunicata, 1240.
affinities of the tunicata, 1241.

Urethra , 1244.
in the male, 1244.

direction, 1244.
length, 1244.
diameter, 1245.
prostatic portion, 1246.
membranous portion, 1247.
triangular ligament, 1247.
spongy portion, 1248.
bulb, 1248.

mucous membrane, 1249.

Jacun® ; lacuna magnus, 1250.
structure, 1250.

Cowper’s glands, 1252.

comparative anatomy, 1253^
blood-vessels of the urethra, 1254.
arteries, veins, 1254.
nerves, 1254.
lymphatics, 1254.
function, 1254.

Urethra ( continued ).

development, 1255.
pathology, 1256.

congenital malformations, 1256.
epispadias, 1256.
hypospadias, 1256.
deviations.in diameter, 1256.
diseases and accidents, 1256.

the urethra deviates frequently from its nor-
mal direction, 1257.
solutions of continuity, 1257.
inflammation, 1257.
ulceration, 1259.
abscesses, 1259.
tubercles, 1259.
spasmodic stricture, 1260.
permanent stricture, 1260.
varieties of permanent stricture, 1260.
false passages, 1261.
fistula? in perina?o, 1261.
causes of stricture, 1262.
co-existence of stone with stricture, 1262.
diseased lacuna?, 1262.
obstructions from other causes, 1262.
irritable urethra, 1263.
neuralgia of the urethra, 1263.
in the female, 1263.

meatus urinarius, 1264.
organisation, 1264.
prostate gland, 1265.
pathology, 1265.
comparative anatomy, 1267.

Urine , 1268.

urea, 1269.

extractive matters of urine, 1269.

animal extractive soluble in water only, 1269.

colouring matter, 1270.

mucus. See article Mucus.

uric or lithic acid, 1270.

hippuric acid, 1270.

lactic acid, 1271.

quantitative composition of healthy urine, 1271.
urine of animals, 1279.

lion, tiger, and leopard, 1279.

horses, 1279.

oxen, cow, 1280.

camel, 1280.

pigs, 1280.

goat, 1280.

beaver, 1280.

rabbits and guinea-pigs, 1281.
birds, 1281.
rattle-snake, 1281.
bull-frog, 1281.
land-tortoise, 1281.

urine in disease ; human subject, 1281.
lithic acid deposit, 1282.
deposit cf lithates, 1282.
deposit of earthy phosphates, 1283.
deposit of oxalate of lime, 1283.
deposit of cystine, 1283.
carbonate of lime deposit, 1283.
hippuric acid, 1283.
calculi : lithic acid calculi, 1287.

mulberry or oxalate oflime calculi, 1287.
cystic oxide calculi, 1287.
phosphatic calculi, 1287.
alternating calculi, 1288.
mixed or compound calculi, 1288.
diseased condition of urine, 1289.
febrile urine, 1289.
anaemic urine, 1289.
alkaline urine, 1289.
urine nearly normal, 1289.
diseases: phlebitis uterina, 1291.
meningitis, 1291.
encephalitis, 1291.
delirium tremens, 1291.
myelitis, 1291.
bronchitis, 1291.
pneumonia, 1291.
pleuritis, 1291.
empyema, 1291.
hepatitis 1291.
nephritis, 1291.

chronic nephritis, albuminous nephritis, mor-
bus brightii, 1291.
cystitis, 1292.
typhus. 1292.
intermittent fever, 1292.
cholera, 1292.
rheumatism. 1293.
phthisis, 1293.
struma, 1293.
diabetes mellitus, 1293.
diabetes insipidus, 1293.
diabetes chylosus, 1293.
jaundice, 1293.
urine of pregnancy, 1294.
foreign substances in the urine, 1294.

Varieties of Mankind, 1294.

distinctive characteristics of man, 1294.
his two hands, 1294.

ANALYTICAL INDEX.

1542

Varieties of Mankind ( continued ).

erect attitude, 1295.
cranium, 1295.
position of the fade, 1296.
vertebral column, 1296.
length of lower extremities, 1296.
biped progression, 1279.
knee joint, 1279.
arched form of the foot, 1297.
form of the trunk, 1297.
visceral apparatus, 1297.
conformation of the brain, 1299.
man’s senses subordinated to his intelligence,
1300.

capacity for intellectual progress, 1300.
species and varieties, zoologically considered, 1301.
diversities of age have led to the establishment
of species which have no existence in nature,
1302.

influence of external conditions in modifying the
conformations both of plants and animals, 1303.
tendency to spontaneous variation exists in many
races, 1304.

general survey of the diversities, in physical and psychi-
cal characters, presented by different races of man-
kind, 1315.

anatomical differences by which the several races of
mankind are distinguished from each other, 1319.
conformation of the cranium, 1319.
prognathous type, 1321.
pyramidal type, 1322.
oval or elliptical type, 1323.
conformation of the pelvis, 1331.
conformation of the other parts of the skeleton
1331.

colour of the skin, 1333.

colour, 'texture, and mode of growth of the
hair, 1337.

physiological conformity or diversity of the several
races, 1339.

average duration of life, 1339.
epoch of the first menstruation, 1339.
frequency of the catamenial flux and the epoch
of life to which it extends, 1341.
duration of pregnancy, 1341.
fertility of hybrid races, 1341.
psychical comparison of the various races of mankind,
1342.

philological evidence of a common origin, in language,
1345.

aptotic type, 1346.
agglutinate type, 1346.
amalgamate type, 1346.
anaptotic type, 1346.

principal groups of various languages, 1347.
general survey of the principal families of mankind,
1348.

European nations, 1348.

Asiatic nations, 1348.

African nations, 1352.

American nations, 1358.

Oceanic nations, 1361.
addendum, 1365.

Vein, 1367.

literary history, 1367.
structure, 1368.

epithelium, 1369.
fenestrated membrane, 1370.
internal tunic of longitudinal fibres, 137 1 -
middle coat of intermixed circular and longitudinal
fibres, 1372.

external coat of longitudinal fibres, 1373.
minute veins, 1373.

veins at their junction with the heart, 1375.
cavae, passing through the diaphragm and pericar-
dium, 1376.
cerebral sinuses, 1376.
umbilical vein, 1376.
venous valves, 1377.
structure of valves, 1379*
fibrous lamina, 1379.
sinuses in the walls of the veins, i380.
office of valves, 1381.
vasa vasorum, 1381.
nerves of veins, 1382.
comparative structure, 1382.
caudal venous heart of eel, 1383.
physical and vital properties, 1384.
vital contractility, 1384.
venous tonicity, 1385.

general remarks upon veins : origin, course, anasto-
moses, plexuses, &c., 1385.
origin of veins, 1386.
course, anastomoses, plexuses, 1386.
function of veins, 1389.

circulation in the veins, 1389.
as diverticula and reservoirs of blood, 1389.
venous ab>orption, 1390.
development of veins, 1390
as capillaries, 1390.
morbid anatomy of veins, 1391.
phlebitis, 1392.

Vein ( continued ).

suppurative phlebitis, 1394.
obliteration of veins, 1395.
healing of wounds in veins, 1395.
effects of ligatures on veins, 1396.
phlebectesis ; varix, 1397.
varices of the leg, 1398.
varicocele, 1399.
haemorrhoids, 1399.
rupture or perforation of veins, 1399.
affections of the valves of veins, 1400.
phlebolites, 1400.

calcareous degeneration of veins, 1402.
fatty tumours, 1402.
entozoa in veins, 1402\
distoma hepaticum, 1402*

Vcnoiis System , 1403. .

pulmonary veins, 1403.
systemic veins, 1404.

veins which form the vena cava superior. 1404.
facial vein, 1404.
temporal vein, 1405.
superficial temporal veins, 1405.
middle temporal veins, 1405.
internal maxillary vein, 1405.
temporo-maxillary, 1405.
occipital vein, 1405.

veins of the neck; external jugular vein, 1405.

anterior jugular vein, 1405.

internal jugular vein, 1406.

collateral branches, 1406.

vertebral vein, 1406.

spinal veins, 1406.

veins of the upper extremity, 1406.

superficial veins, 1406.

radial or external superficial veins, 1406.

ulnar or internal superficial, 1407.

basilic vein, 1407.

deep veins of the upper extremity, 1407 ._
satellite veins of the brachial artery, 1407.
subclavian vein, 1407.
brachio-cephalic veins. 1408.
collateral branches, 1408.
inferior thyroid veins, 1408.
internal mammary veins, 1408.
vena cava superior, 1408.
azygos veiris, 1409.
veins of the spine, 1409.
superficial spinal veins, 1410.
deep spinal veins, 1410.

veins which form the inferior vena cava, 1411.
veins of the lower extremities, 1411.
superficial veins, 1411.
internal or long saphena vein, 1411
posterior or external saphena vein, 1411.
deep veins of the lower extremity, 1411.
femoral vein, 1412.
external iliac vein, 1412. *
internal iliac vein, 1412.
collateral branches, 1413.
inferior vena cava, 1413.
collateral branches, 1413.
ovarian veins, 1413.
lumbar veins, 1413.
portal venous system, 1414.

inferior mesenteric vein, 1414.
splenic vein, 1414.
superior mesenteric vein, 1414.
hepatic veins, 1414.
cardiac veins, 1414.

Vertebral Column . See Sujyplement.

Vesicula Prostatica , 1415.
anatomy, 1415.
man, 1415.
quadrumana, 1416.
volitantia, 1417.
insectivora, 1417.
ferae, 1417.
pinnipedia, 1418.
marsupialia, 1418.
rodentia, 1418.
cavia cobaya, 1418.
edentata, 1419.
pachydermata, 1419.
solidungula, 1419.
niminantia, 1420.
cetacea, 1421.
physiology, 1422.
morphology, 1423.
addendum, 1428.

Vesicula; Se?nina/esi 1429.

comparative anatomy, 1430.
function, 1431.

they are not reservoirs of semen, 1431.

they form part of the generative apparatus* 1432.

Vision , 1436.
light, 1436.

diversified colours arise from the action of matter
upon light, 1437.

bodies divided into transparent and opaque, 1438.
spherical and chromatic aberration, 1438.
phenomena of vision, 1439.

ANALYTICAL INDEX. 1543

Vision ( continued ),

dioptric phenomena, 1440.
vision under water, 1441.
distinct vision, 1442.
duration of impressions, 1444.
rapidity of electric light, 1444,
dimensions of objects, 1445.
magnitude of an object, 1446,
erect vision, 1446.
single vision, 1447.
adaptation to distance, 1450.
magnifying lens, 1452.

abnormal vision, 1452.
achromatopsy, 1452.
congenital achromatopsy, 1454.
dichromatic, 1454.
polychromatic, 1454.

confusions of colour ranged in the order of
their frequency, according toWartmann,1456.
non-congenital achromatopsy, 1457.
permanent achromatopsy, 1457.
temporary achromatopsy, 1458.

remarkable cases, 1458.
hyper-chromatopsy, 1461.
anorthopia, 1462.
myopia or near sight, 1462.

exciting causes, 1463.
presbyopia, 1465.

use of suitable glasses, 1466,
cylindrical eye, 1467.

Vital Statistics , 1469.

mean age at death, 14-70.
rate of mortality, 1473.
expectation of life, 1474.
mean duration of life, 1474.
probable duration of life, 1474.

Voice, 1475.

physiological character of the human voice ; vibratory
movements of the vocal organs ; experiments, 1475.
falsetto, or voce di testa, 1483.
art of singing, 1485.

comparative anatomy and physiology of the organs of
voice, I486,
mammalia, 1486.
quadrumana. 1487.
chiroptera, 1488.
insectivora, 1489.
carnivora, 1489,
marsupialia, 1491.
rodentia, 1491 .
edentata, 1492.
pachydermata, 1492.
ruminantia 1494.

Voice ( continued ).

cetacea, 1494.
birds, 1495.

physiology of the voice of birds, 1500.
voice of reptiles, 1501.
insecta, 1503.

humming or buzzing of insects, 1501.

Wrist -Joint, 1505.

bones which constitute the wrist-joint, 1505.
radius, 1505.

scaphoid, semilunar, and cuneiform bones of the
carpus, 1506.
ligaments, 1506.

anterior radio- carpal, 1506.
posterior radio carpal, 1506.
external lateral ligament of the wrist, 1507.
internal lateral ligament, 1507.
synovial membrane, 1507.
mechanical functions, 1507.
abnormal condition of the wrist, 1508.
congenital, 1508.

cases, 1508.
accident, 1513.

dislocations of the wrist, and neighbouring radio-ulnar
articulations, 1513.

dislocation of the bones of the forearm backwards,
with displacement forwards of the carpus, 1514.
luxations of the lower extremity of the ulna, 1514.
luxation of the lower extremity of the ulna at the
wrist-joint, backwards, 1515.
luxation forwards, 1515.
luxations of the bones of the carpus, 1516.
fractures of the lower extremity of the radius, in the
immediate vicinity of the wrist-joint, 1516.
symptoms, 1517.
diagnosis, 1518.

anatomical character of the fracture, 1520.
fracture of the lower extremity of the ulna, 1521.
disjunction of the lower epiphysis of the radius, 1521.
cases, 1521.

disease : acute arthritis of the radio-carpal and of the
inter-carpal articulations, 1523.
case, 1524.

chronic strumous arthritis of the wrist, or white swel-
ling, 1524.

anatomical characters of chronic strumous arthritis or
white swelling of the wrist, 1525.
chronic rheumatic arthritis of the wrist, 1526.
anatomical characters, 1527.
synovial tumours of the region of the wrist, 1528.
morbid condition of the synovial bursas of the flexor
tendons, 1528.

painful crepitation of tendons around the wrista 1529,

THE END.

London :

Spottiswoodes and Sha’

New-street-Square.

V 1

Todd

v.4,pt.2

18J+9-52