PAPERS, 
CHIEFLY ANATOMICAL, 
PRESENTED AT THE 
PORTLAND MEETING 
OF THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT 
OF SCIENCE, 
AUGUST, 1873. 
By BURT G. WTT.mr.B_—\r r> 
PROFESSOR OF COMP. ANATOMV AND ZOOLOGY, CORNELL UNIVERSITY, 
ITHACA, N. Y. 
SALEM, MASS. 
SALEM Pi: ESS, CORN EH OE LIBERTY AND DERBY STREETS. 
1874. PAP E R S, 
CHIEFLY ANATOMICAL, 
PRESENTED AT THE 
PORTLAND MEETING 
OF THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT 
OF SCIENCE, 
AUG-TJST, 1873. 
By BURT G. WILDER, M.D., 
PROFESSOR OF COMP. ANATOMY AND ZOOLOGY, CORNELL UNIVERSITY, 
ITHACA, N. Y. 
BULLETIN OF THE CORNELL UNIVERSITY, 
Vol. I. SCIENCE. No. 3. 
SALEM, MASS. 
SALEM PRESS, CORNER OF LIBERTY AND DERBY STREETS. 
1874. CONTENTS . 
The Outer Cerebral fissures of Mammalia, especially the Carnivora, 
AND THE LIMITS OF THEIR HOMOLOGIES . . . . . .214 
Cerebral variation in domestic dogs and its bearing upon scientific 
PHRENOLOGY .......... 234 
Lateral asymmetry in the brains of a double human monster . . 250 
The papillary representation of two arms in a double human monster 251 
The habits and parasites of epeira riparia . . . . .257 
The nets of epeira, nephila and hyptiotes (mithras) . ... 264 
The need of a uniform position for anatomical figures ; with a recom- 
mendation THAT THE HEAD BE ALWAYS TURNED TOWARD THE LEFT . 274 
Lateral position of the vent in amphioxus, and in certain batrachian 
LARVAE ........... 275 
Composition of the carpus in dogs ....... 301 
Present aspect of the question of intermembral homologies . . 303 
Variation in the condition of the sense organs in fcetal pigs of the 
SAME LITTER . . . . . . . . .303 
The pectoral muscles of mammalia ....... 305 
VARIATION IN THE PECTORAL MUSCLES OF DOMESTIC DOGS . . . .308 The outer Cerebral Fissures of Mammalia (especially the 
Carnivora) and the Limits of their Homology. By 
Burt G. Wilder, of Ithaca, N. Y. 
Naturally, human brains have been most extensively studied, 
and chiefly those of adults ; some have compared foetal brains with 
those of Quadrumana but the existing doubt and disagreement,* 
with the lack of any generally recognized basis for the determina- 
tion of fissural homologies, suggest the need of a different method 
of study; and as the main object of tins and the next paper is to 
throw doubts upon the value of current opinions respecting brains, 
it is proper to state the materials upon which my opinions are 
based. It will be understood therefore that, unless otherwise 
stated, my present generalizations are based upon these materials 
only, and are subject to revision when a larger number of speci- 
mens is at my disposal. 
Where but a single drawing or diagram was made, it generally 
represents the outer surface of the left side ; the second usually 
the right side, or the upper (dorsal) surface ; and the mesial and 
ventral surfaces were added if their peculiarities required and time 
permitted. All of these drawings and diagrams were made by 
myself, and most of them were exhibited at the meeting. 
The varieties of dogs’ brains will be given in the next paper. 
On the following page I give a list of original preparations and 
drawings of mammalian brains made since July, 1871, and forming 
the basis of this and the following paper. 
* A good example of this is stated by Ecker who includes the anterior central lobe 
with the frontal, while Gratiolet and Bischoff include it with the parietal. 
This note, with some other matter which delay in publication has permitted me to in- 
sert, should bear date of December, 1873. B. NATURAL HISTORY. 
SCIENTIFIC NAME. 
POPULAR NAME. 
NU 
IND 
to 
c 
9 
MBER 
IVIDU 
9 
Z 
to 
O 
OF 
AL8. 
H 
to 
to 
to 
TOTAL. 
DRAWINGS. 
GO 
s 
< 
3 
< 
to 
5 
i 
6 
8 
3 
i 
1 
i 
1 
2 
5 
5 
6 
23 
29 
58 
22 
3 
3 
1 
1 
2 
2 
2 
2 
Felis catus, var. domesticus... 
Domestic Cat ( 
5 
17 
20 
42 
4 
4 
1? T 1 . 
1 
1 
1 
1 
1 
5 
1 
1 
1 
3 
1 
TT , . 
1 
1 
2 
1 
3 
3 
2 
2 
1 
1 
1 
1 
19 
4 
1 
24 
2 
1 
1 
5 
7 
Mule 
1 
1 
jy 
7 
8 
5 
20 
1 
10 
8 
18 
2 
1 
1 
2 
2 
Capi a segagi v(iv 
f, . ... 
2 
1 
1 
4 
1 
1 
2 
2 
2 
2 
1 
1 
2 
. . 
1 
i 
1 
i 
* 
Cynomys Lndovicianus 
Prairie Dog 
1 
i 
1 
1 
i 
, , ., .. 
1 
i 
1 
2 
3 
— 
Genera, 28; Sp., 32; Yar., 40-45. 
Total . . 
48 
88 
189 
87 
45 216 
B. NATURAL HISTORY. 
These specimens form part of a collection to illustrate the neu- 
rology and embryology of domesticated animals, which Professor 
Agassiz* authorized me to make for, and at the expense of, the 
Museum of Comparative Zoology in Cambridge.! 
It will be seen that the above list of one hundred and eighty- 
nine individuals includes about twenty-eight genera, represented 
by about thirty-two species, and about forty-five varieties, the 
numbers varying according to differing estimate of the taxonomic 
relations of the individuals. 
The size of human brains, the expense of their preservation in 
numbers, the rarity of apes’ brains, and especially of foetal speci- 
mens, together with the complexity of the fissural pattern which 
man and Quadrumana have in common with herbivorous mammals, 
are additional reasons for selecting other subjects. A simpler fis- 
sural pattern exists with the Carnivora. Among these the wild 
Canidce (fox, wolf and fennec) occupy a position midway between 
the Viverridoe and Mustelidce on the one hand, and the domestic 
dogs, the Felidae, Ursidce and Ilycenidai, on the other. That is, 
all the main fissures found in Carnivora are present in the fox, 
but uncomplicated by contortions and by secondary fissures. 
Method of Preparation.]:—The present paper treats only of 
those cerebral fissures which are visible from the outer side of a 
brain properly prepared. Heretofore all brains have been har- 
* Since this paper was written, he who inspired it has,finished his work in this world. 
As his student, his assistant and fellow-teacher, I cannot refrain from expressing my 
sense of bereavement. To me he was not only a great naturalist; hevvas the wisest of 
teachers and the kindest of friends; whose criticism was a healthy stimulus and his 
praise a sweet reward. 
f Those who bear in mind that not a single brain was preserved from an entire 
menagerie which was suffocated in Boston about thirteen years ago, and that no simi- 
lar collection exists in this country on account of its great cost in time, alcohol and 
means of displaying, will appreciate the extent of interest which Prof. Agassiz felt in 
this special undertaking; and while, as Professor in one institution, I must regret that 
the result of any of my work should leave it for another, yet as it must be years before 
my own or any other museum can command the means required for such a special col- 
lection, I am really grateful for the opportunity of using this material as it came for 
the instruction of my students, and by this kind of work, avoiding for a season, the 
outside drudgery in the way of popular writing and lecturing, to which the existing 
financial condition and policy of the average American University compel its Profes- 
sors continually to resort, whether ready or not, to the impairment of their powers, and 
the detriment of the interests of the institution to which they would rather devote all 
their time, their energies and their enthusiasm. 
X It may seem that these remarks might be omitted or placed at the end of the paper; 
but I have become so impressed with the often repeated dictum of Prof. Agassiz that 
“ the method affects the result,” that I wish to submit mine at the outset. NATURAL HISTORY. 
217 
dened while resting upon their base. They become unnaturally 
flattened, and are then generally figured from above only. Like so 
many other methods borrowed from anthropotomy, the common 
manner of extracting the human brain is seldom applicable to those 
of animals; the skull, as well as the brain, is more useful if ver- 
tically bisected, and this seems to be the only way of insuring the 
safety of the olfactory lobes and the appendicular lobule of the 
cerebellum ; the former are rarely figured of their full size (as, for 
example, in the cat and cheetah. Trans. Zool. Soc., vol. i, pi. xx), 
while the very existence of the latter seems often unsuspected 
even in those animals where, by extracting the brain after bisecting 
the skull, I have found it of great size. In a future communica- 
tion, I intend to illustrate this peculiar organ and make some 
remarks upon its connections, mode of formation, function and 
zoological significance. It is particularly large in the bear but 
small or wanting in the lion and in cats ; being often bulbous at 
its extremity, the utmost care must be exercised to avoid breaking 
the pedicel, and I have found it easier to effect the dislodgment 
by throwing air behind it with a small blow-pipe. Figure 1 rep- 
resents from below the left appendicular lobule (A L) of a 
Chinese dog ;* it seems to be a protrusion of a portion of one of 
the horizontal series of convolutions. 
I am inclined to think that in most cases, the way to preserve 
the entire brain in its natural form is to bisect it either before or 
after extraction, and to place each half upon its mesial surface in 
a flat-bottomed vessel of alcohol. As it rapidly loses weight in 
alcoholf and gains in water, and as handling out of these fluids 
is apt to distort it, I would recommend weighing each half of the 
head before and after extraction ; the difference gives the exact 
weight of the brain; but as the apparatus which I employ (a sort 
of adjustable “Mitre-box”) does not as yet enable me to insure 
bisection on the middle line exactly, I have not felt justified in 
comparing the two halves of brains together. If both hemispheres 
are to be preserved entire, the section should go rather to the left 
than the right of the middle line, in order to leave the mesial sur- 
face of the right hemisphere uninjured ; but if the right is to be 
* This and the other figures will be found at the end of next paper. 
fThe extent of this loss may he seen from the following cases; a brain weighing 
,085. lost one-sixth of its weight in eighteen hours, and one-third in four days; a brain 
weighing ,125. lost one twenty-fifth in sixteen hours and one-half its weight in two 
months; of course the rapidity of the loss will vary with the size of the brain, the 
amount and strength of the spirit and the frequency of its renewal. 218 
B. NATURAL HISTORY. 
dissected, then the mesial surface of the left should be saved by 
carrying the section a little to the right; of course, however, if 
there is certainty of the saw going just between the two, so much 
the better. 
The pia mater should be removed before drawing; this is best 
accomplished after the brain has shrunken a little in spirit, using 
a pair of fine forceps and fine curved scissors. 
If possible, both sides of a brain should be drawn; but if only 
one, the left; and with all Carnivora (although not with all Her- 
bivora), all the outer fissures may be seen in such a view; while 
this is not the case in the view from above, even when the brain is 
flattened. In drawing, each half should rest upon a slip ruled in 
square centimetres ;* if the brain is larger than that of a cat, the 
slip may be pinned upon a sheet of cork, and two or more threads 
stretched over the brain, coinciding with the lines hidden by it; 
then the drawing may be made upon another ruled slip, with great 
accuracy; the mesial, upper and lower surfaces of the brain may 
be drawn in like manner, though less easily ; and large diagrams 
may be accurately reproduced, by ruling cloth in squares ten, fif- 
teen or twenty times the diameter of the original drawing ; the 
homologous fissures may be uniformly colored as in the diagrams 
exhibited ; Gratiolet, Owen and Bischoff have colored homologous 
folds, but it is obvious that the same end is more readily attained 
by coloring the fissures ; and that alterations are also more prac- 
ticable. 
It would certainly be an advantage to possess a cast of the cra- 
nial cavity for comparison with the brain ; and all comparative 
measurements and weights should take into account the shrinkage 
of brains, and their loss of weight.f 
* [ am happy to state that Mr. Geo. Woolworth Colton, the well known map-maker, 
and a member of this Association, has offered to prepare ruled paper of a size and 
quality suited to this and other natural history purposes. 
It will be noted that the perspective is ignored in drawings made by the above method; 
each iissiue is represented as if at a point on a line perpendicular to the surface on 
which the brain rests: a drawing in which this line should be perpendicular to the 
convex surface of the hemisphere would produce the effect seen in fig. 5, plate la. 
f When a brain is once thoroughly hardened in alcohol it may be kept in weaker 
spirit or clear water during examination; it rapidly shrinks still more in the air; I am 
conducting experiments to show how well and how long, hardened brains can be pre- 
served in a mixture of equal parts glycerine and water; which does not evaporate like 
spirit and, by its greater specific gravity, avoids injurious pressure of the specimens 
upon each other or upon the vessel; the best w'ay of keeping many brains for study is 
in a wdde tin box two or three inches deep and cased in wood, with a glass cover; if 
each half of a brain is kept on its mesial surface, no injury can result. B. NATURAL HISTORY. 
219 
The Cerebral Fissures.— More attention has been given to 
the folds (gyri, convolutions, or anfractuosities) than to the fis- 
sures (furrows or sulci). But, whatever may be the manner of 
their formation, the latter really represent the location of the 
augmented gray, ganglionic or dynamic tissue more than the for- 
mer ; for, as a rule (the only exceptions being the points of oblique 
junction of two fissures), the contiguous walls of a fissure are 
nearer together than the two sides of either of the folds which it 
separates ; a line representing the fissure, therefore, indicates the 
location of a much larger bulk of gray matter than a line of equal 
width representing any part of the surface of the fold. 
Practically too the fissures are by much the easier to describe 
and designate, and it would be as hard to designate folds without 
first identifying fissures as to describe the countries of Europe 
without mentioning its rivers. The sides of a fissure are usually 
near together and parallel, so that the fissure may be described or 
figured as a single line of certain direction; but the opposite 
borders of any one fold are rarely parallel throughout their whole 
extent. 
Moreover, the surface, wdiich in one brain forms two folds, with 
an intervening fissure, may in another be one continuous fold. 
What shall it be called ? Relatively, at least, the surface of a con- 
voluted brain is the same as it was before the fissures appeared ; 
while the fissures are gradually introduced and are to a certain 
extent capable of identification ; and although they ma}r be wholly 
due to a vertical elevation of the contiguous folds, yet it is the 
fissures and not the folds which can be said to increase, to connect, 
or to remain separate. Granting, then, that folds are the ulti- 
mate object of our study, fissures are first to be so thoroughly 
identified in all animals that when one of them or one of the folds 
is mentioned, there can be no doubt of its being recognized by all. 
Fissures may be studied in four ways: 
First: As to their general nature. 
Second: Singly, as to their special peculiarities. 
Third: As evidences of zoological affinities. 
Fourth: As indications of intellectual power. 
The last view will be considered in the next paper. According 
to the first view, we may at once separate three of Owen’s fissures 
from the rest. The rhinal is the line of separation between the 
olfactory crus or tract and the cerebrum proper. The median or 220 
B. NATURAL HISTORY. 
inter-hemi spheral fissure divides the two cerebral hemispheres ; 
and although in most Carnivora the true fissures seem to be ar- 
ranged with some reference to it, and although it has clearly defined 
borders, yet neither of these features exists with Herbivora. The 
sylvian fissure marks the location of a kind of mound of cerebral 
substance, the “Island of Reil,” and its manner of formation is 
somewhat peculiar, as shown hereafter. 
Formation of Fissures. — No one doubts that all brains, even 
the most deeply furrowed, were smooth at an earlier stage of 
development. This transformation, so far as the result is con- 
cerned, might be compared with the segmentation of an undivided 
yolk; but probably the process is more often comparable with 
the formation of the primitive furrow ; and although they look 
like clefts or depressions in the brain mass, it is probable that the 
fissures are the result of a difference in the rapidity of growth of 
different parts; certain points or lines remaining relatively sta- 
tionary, and becoming the bottoms of depressions or fissures. 
Still I cannot rid myself wholly of the idea that shallow fissures, 
at least, may be formed by direct depression; •and if Ecker is 
rightly translated he seems to have this view respecting all of 
them ; “Actual convolutions are formed in these districts only 
with the further progress of the formation of fissures (p. 14). 
The formation of the convolutions is, of course, entirely depend- 
ent on the development of the fissures; and in the region of the 
temporal lobe, in which the latter are most variable, the convolu- 
tions are so too” (p. 65). ' 
But on page fifteen, in contrasting the sylvian with other fissures 
he says that the latter “originate simply from depressions or folds 
of the cerebral cortex.” (The italics are mine). 
Now, as regards the aspect of the cerebral surface in the adult, 
it makes perhaps no great difference whether we speak of the fis- 
sures as depressions or the folds as elevations ; and the former is 
more natural on account of the greater extent of the elevated sur- 
faces ; so too in conversation it is easier to sajr that the sun rises 
and sets than that the earth revolves upon its orbit; but in sci- 
entific language it would seem proper to speak according to the 
fact rather than the appearance. 
Undoubtedly one source of confusion is the indiscriminate use 
of terms signifying the transformations themselves and the condi- tions reached thereby; and we might avoid it by discriminating 
between appearance and aspect, formation and conformation, 
development and presence or existence, etc. 
As a single example of the looseness of our present expressions, 
on account of lack of definite information, Huxley (Comp. 
Anat. of Vertebrates, p. 492) enumerates among the distinctive 
features of the human brain, “the filling up of the occipito tempo- 
ral fissure,” as compared with that of apes ; in its most literal 
sense this would imply that something filled a existing 
fissure ; a little less literally, that the bottom of the fissure grew 
up to the surface of the adjoining folds, so that a foetal fissure did 
not exist in the adult; and still again, and this would be a per- 
fectly legitimate interpretation, it might indicate the fact, that a 
fissure which exists in apes did not exist in man in any stage ; 
but even this would be capable of at least two meanings, according 
as the readers believed, or not, in actual evolution. 
The formation of fissures seems to proceed very rapidly.* I 
have traced it in kittens of the same litter, killed at short intervals 
beginning at birth ; and even allowing for individual and sexual 
differences, it would appear that during the first week, a change 
may occur perceptible within six hours ; the most favorable fissure 
for this purpose is the frontal. 
The large superficial cerebral vessels often lie in the fissures; 
but that this is merely a coincidence, and not a cause, is indicated 
by the frequent departure of these blood-pipes from their trenches ; 
the slight furrow which marks the course of a large vessel across 
a fold has generally a more regular form with better defined bor- 
ders. Where the folds are much contorted as in man and most 
herbivora, as compared with their simplicity at an earlier stage, 
one can hardly avoid the conjecture that the folds are formed 
under pressure, and that the brain behaves much as would a piece 
of thick cloth crowded into a cavity. Still more suggestive of 
this idea is the lateral contortion of the median lobe of the cere- 
bellum in cats; in the newly born kitten (Fig. 2, K), this is ver- 
tical in direction and presents few folds ; in all but one of the 
adult cats that I have examined, the median lobe appears, as in 
Fig. 2, C, laterally contorted ; the progress of these remarkable 
changes will be fully illustrated on another occasion.f 
B. NATURAL HISTORY. 
221 
* As does the yolk segmentation with Turtles (Agassiz, Cont. Nat. Hist. U.S.2,523). 
fEcker speaks (p. 10) of the “ formation of convolutions as a necessary consequence 
of certain mechanical processes of the brain and skull,” but it is not clear bow much 
influence is attributed to the latter by this expression. 222 
B. NATURAL HISTORY. 
Yet while we may recognize a sort of correlation between the 
existence of fissures and the need of enclosing a certain amount 
of gray matter within a space which is represented by the cranial 
cavity, it by no means follows that osseous walls are the imme- 
diate and direct cause of the convolution ; much less does it follow 
that the particular direction of the fissures is occasioned by the 
ridges upon the inner cranial surface with which they coincide. In 
short, we may regard the size of skull and of brain as concomi- 
tants of the degree and character of fissuration without attempting, 
as yet, to assign to them the relation of cause and effect. It may 
not be proper to compare cerebral fissuration with the primitive 
formation of the encephalic lobes, but it is certain that this latter 
takes place independently of cranial circumscription, especially in 
many fishes where the cranial cavity far exceeds the brain mass ; 
and it would be interesting to ascertain whether this interspace 
exists in any of those fishes which, like Elacate, present some cere- 
bral fissuration. At present the matter must be regarded as un- 
decided ; and the way to elucidate our own lack of information is 
to ask ourselves whether, in total absence of cranial walls, any 
cerebral convolution would be developed in the higher Mammalia. 
Fissural Homologies.—In order to describe the variations of 
fissures in different brains, they must first be identified. Although 
Owen has (Comp. Anat. of Vertebrates, vol. iii, pp. 114 to 143) 
undertaken to homologize the fissures of the higher mammalia 
(Gyrencephala) throughout, and has rarely admitted the liability 
of error (as on p. 117), yet the very completeness of his determi- 
nations throws doubt upon them in view of the lack of reference 
to individual peculiarities, and the renunciation of development as 
a guide to homology ; and it will be safer to keep in view the con- 
clusion of Gratiolet. (Mem. sur les plis cerebraux de l’homme, 
p. 10.) 
“ It is sufficient to compare the brain of an ape with that of a carnivore 
or ruminant in order to show that in the different mammalian orders, the 
cerebral folds present very different arrangements. 
These differences are such that it would be imprudent to establish par- 
allel divisions and to search for homologies. In fact that search has no 
certain basis, and we do not hope to accomplish it in a moment.” 
Criteria of homology.—Having no true structural features, 
they present, as tests of homology: 1. Position in relation to B. NATURAL HISTORY. 
223 
internal structure (as the rhinal and sylvian). 2. Position in 
relation to other fissures so determined. In connection with this 
latter test, we must ascertain whether anything like transposition 
is possible; this question will be raised in respect to special fis- 
sures. Their connections, branches, length, and general direction 
are probably of less value. Great aid is always to be had by 
comparison with simpler brains of allied species, or with the brains 
of young of the same species. The extent of variation in length, 
direction and connections, which may exist without invalidating 
their homology, is most readily seen by comparing the corres- 
ponding fissures upon the two halves of one brain (plate 3, figs. 
12, 13) ; it appears that a long fissure may be represented by 
several short and disconnected ones ; that branches may or may 
not exist at either end (these branches are almost invariably 
dichotomous) ; that two fissures wholly separate in the foetus, and 
in other species ■ may unite either directly or by a branch. Good 
examples of this are the lateral and coronal fissures, which are 
perfectly distinct in the foetus/in some adults, and on one side only 
of others, but which show a tendency to unite ; a marked con- 
stancy in the location and direction of a branch may, as in this 
case, indicate the point of union. Finally, with respect to several 
fissures, we must either deny a homology which would be other- 
wise unquestioned, or admit that in one species or on one side, its 
manner of formation may greatly differ. This will be exemplified 
in connection with the special fissures in this and the following 
paper ; for example the presylvian, and the ectosylvian. While 
insisting, however, upon the provisional nature of many of the 
names which authors have given to the cerebral fissures of mam- 
mals, it is necessary to adopt some nomenclature in order to be 
understood, and in the present paper the names given by Owen 
will be employed with some modifications. 
Special Fissures. The Sylvian.—This is the most constant 
of all fissures ; there is no question respecting its existence or its 
name in all brains which are fissured at all.* 
Its length, direction, branches and connections vary consider- 
*0n this account I have not hesitated to mark this Assure ivpon all the Agures, s; 
hut since there is some doubt respecting the name or the nature of all other Assures, 
the letters designating them are placed outside of the Agure, in order to allow revision ; 
most of the Agures are shown white on a dark ground; this will allow futm e alteration 
in the relative width of Assures in order to indicate their depth or relative constancy. 224 
B. NATURAL HISTORY. 
ably, but, as a rule, in the adult it forms a nearly straight fissure 
directed dorsad and backward, never reaching the dorsal margin of 
the hemisphere, and rarely if ever inclining forward, though gener- 
ally nearly vertical in Herbivora. Its manner of formation is very 
peculiar, and may be readily traced in new born or foetal kittens 
and puppies ; in these and also in the foetal wolf (fig. 6), there 
appears, where in the adult the sylvian is to join the rhinal, a 
rounded elevation (which is probabty homologous with the Insula 
or Island of Reil, of bounded above and behind by a 
shallow trench ; in front this island is apparently continuous with 
a narrow area of cerebral substance which still more anteriorly 
broadens into that part which lies just behind the olfactory lobe ; 
the primitive sylvian fissure is therefore an depressed 
line whose posterior end joins the rhinal, and whose anterior end 
is turned upward ; by the gradual projection of the cerebral mass 
above this line, it overhangs the depressed tract, so that the ven- 
tral part of the curve reaches the rhinal fissure and coincides with 
it for a certain distance ; this portion I have ventured to call the 
basisylvian (Bs) ; by the growth of the mass before and behind 
the semicircular area now left, and the final approximation of the 
walls, the Insula is at length wholly concealed, and the semicir- 
cular trench becomes a single fissure ; strictly speaking therefore, 
the sylvian is an arched fissure like those which surround it (ecto- 
sylvian, supersylvian and lateral).* 
Presylvian (Ps.).—The anterior and ascending (dorsad) extrem- 
ity of the primitive sylvian seems to correspond with the “ascending 
*From a translation (Cerebral Convolutions of Man) which has just come into my 
hands, I find that Ecker of Freiburg, four years ago, observed the formation of the 
sylvian fissure, and that some of his conclusions upon this and other points are nearly 
like my own. I am sure that Ecker will be only glad that another has reached similar 
results from different materials, for he employed human brains exclusively, while I 
have purposely discarded them for the simpler brains of Carnivora. Certainly he and 
all other honorable scientific men would accept the collections and drawings made by 
me as evidence of my entire independence in the work; but for the satisfaction of 
others, including the writer of an editorial in “ The New York Evening Post ” for Aug- 
30, which directly charges me with unacknowledged borrowing from Ecker, I am com- 
pelled to state that to-day, Sept. 8, 1873, for the first time, have I learned the contents of 
Ecker’s work. 
Moreover, while not questioning the correctness of Ecker’s statement that in man 
“ the whole hemisphere curves itself in an arch, concave below, around the place of en. 
trance of the cerebral peduncle ” (p. 15), it is proper to say that the brains of kittens and 
puppies examined by me do not confirm it; nor is it easy to see how so long a fissure 
as that of the bear could be formed in that way; it is evident that for the elucidation of 
this and many other points, we need a very extended series of observations upon the 
developing brain of many animals. B. NATURAL HISTORY. 
225 
branch” (Ecker, fig. 1, S") in its manner of formation, and 
in its relation to the sylvian; but the intervening space in all 
brains I have examined is so much larger than the “operculum” of 
anthropotomy that I hesitate to affirm it before observing its forma- 
tion in many intermediate species. Moreover, in a lion (fig. 18), 
there is a small fissure between the sylvian and what I take to be 
the presylvian, which in some respects more nearly resembles the 
“ascending branch” in man ; while in a bear (fig. 10) and raccoon 
(fig. 11) there is a similar one in front of the presylvian, which 
may be only a continuation of the slight upward curve at this 
point which the rhinal presents in many dogs. I would suggest the 
name presylvian, at least for the fissure already described in Car- 
nivora. It is evidently the same which Flower refers to as super- 
orbital (Anat. of Proteles; Proc. Zool. Soc., 1869, p. 479), but there 
seem good reasons for regarding it as ideally, at least, a dismem- 
berment of the sylvian. I say ideally, for although generally so in 
fact, yet occasionally there is no connection whatever, and that 
which would in respect to position be called presylvian is an 
isolated fissure. This is the case on both sides of a raccoon 
(fig. 11),* and on the left of an impure tan terrier clog; of the 
right of this brain I have no drawing, but think the union is as 
usual. This is certainly a point which should be clearly under- 
stood before we can be sure of the value of our determination; at 
present I am not prepared to explain it. It will be noted also that 
in most dogs and in the lion, the presylvian is not only very long, 
but apparently double, as if a special and independent fissure had 
become connected with its dorsal end; whether this is the case 
can probably be decided by sections, for there is reason to think 
that an independent fissure is always deepest at its middle where 
it may generally be supposed to commence ; and if the fissure in 
question is shallower at the point of suspected junction we majr 
fairly conclude that it is really a compound fissure. 
FRONTALf (F.). This fissure is very characteristic of Carnivora, 
being absent, so far as I know, only in Paradoxurus figured by 
Gervais. (Nouv. Arch, du Museum, tome vi, pi. 9, fig. 2.) 
*But in another specimen the connection seems to exist as usual, 
fl have adopted Owen’s name as applied originally to the brain of cat and cheetah; 
but am not sure that it is homologous with that so called by him in the human brain. 
Flower has called it crucial. P. Z. S., p. 479. 
A. A. A. S. VOL. XXII. B. (15) 226 
B. NATURAL HISTORY. 
The frontal appears from without as a cleft in the mesial mar- 
gin ; in kittens it begins as a mere shallow depression which 
rapidly deepens and narrows ; it is nearly as much a mesial as an 
outer fissure, and in some cases joins one of the mesial fissures 
so as to appear a continuation of it; as seen from above the 
fi’ontal extends outward and sometimes forward (as in fox). As 
a whole I have seen it take a backward course, only in a black 
bear, both sides, and a skye terrier, right side, although when 
curved, its outer end may turn slightly backward. It rarely 
branches, or if so but very slightly as on the right of a St. 
Bernard (524) ; in some cases, as in right of bull terrier (514) ; 
an apparent bifurcation is merely the union with it of a small 
secondary fissure. But even such junction is very rare ; on right 
of bear (502, fig. 10), it joins another at right angles, but on 
left a considerable space intervenes. 
Supersylvian (Ss.). Next in independence, in constancy, and in 
order of formation seems to come that semicircular fissure which 
Owen calls supersylvian; perhaps it should precede the frontal in 
the above respects, but like so many other points, my present ma- 
terial does not enable me to determine this. I am quite certain, 
however, that Owen’s table (C. A. V., iii, p. 136) does not in all 
respects (as its author admits) represent the relative rank of all 
the cerebral fissures. It generally divides the surface of the hem- 
isphere into two subequal portions; its usual relation to the 
other fissures is seen in the fox (fig. 3) and the foetal wolf (fig. 
6). In this, it forms a nearly regular curve with no branches or 
connections ; and whichever we may conclude to be its representa- 
tive, in the young terrier (fig. 7) it would appear to begin as a 
longitudinal groove about midway of its final extent and nearly 
over the sylvian. This is also the case in cats ; but in most brains 
its hinder end either branches or joins some small fissure, while, as 
a rule, its anterior end bifurcates, the longer arm reaching forward 
and ventral often with a slight dorsal turn at the extremity, while 
the shorter points obliquely forward and dorsal and often enters 
the lateral fissure just outside (as in hyaena, fig. 9). This little 
branch so closely resembles the one which is given off at the junc- 
tion of the lateral and coronal in nearly all cases as to suggest 
that it is, like it, due to a union of two independent fissures ; but 
of this there is no evidence. The fact that a similar branch some- B. NATURAL HISTORY. 
227 
times leaves the ectosylvian, as in fox (figs. 3 and 4), suggests a 
like constitution for this latter fissure, or else a serial arrangement 
of cerebral foldings which is not as yet accounted for upon any 
theory of correlation between mind and brain. 
In a lion (fig. 18) the Ss is irregular, with branches and junc- 
tions with other fissures. In a bear (fig. 10) and raccoon (fig. 11) 
we have a peculiar arrangement, the explanation of which I for- 
bear to suggest until I see foetal brains of these species. The 
weasel presents only two fissures where most Carnivora have three, 
and it is not easy to say which they are; a similar doubt is ad- 
mitted by Owen (C. A. V., iii, p. 117) in comparing the brain of 
Coati (Nasua) with that of the stoat; and I ask no better evi- 
dence of the fact that our knowledge of the zoological value of 
fissures is as yet incomplete than the comparison between my fig- 
ure of the weasel’s brain (fig. 8) and Ow’en’s figure of the stoat’s ; 
for the animals are similar species of closely allied genera, if not, 
indeed, members of the same genus (Allen, Bull. Mus. Comp. Zool., 
No. 8, p. 167), or varieties of the same species (Gray, Proc. Zool. 
Soc., 1865) ; yet my figure shows two fissures outside of the syl- 
vian, while Owen’s has but one which he calls supersylvian. 
Lateral (L.). This is usually a curved furrow which divides 
the space between the mesial border and the super sylvian into two 
nearly equal parts.* The name was given by Owen, probably in 
reference to its approximate parallelism with the mesial border, 
which is often quite striking, as in the lion and hyaena; but its 
anterior extremity is inclined to connect with another fissure, the 
coronal, so constantly and so smoothly that but for occasional ex- 
ceptions and observations of foetal brains, one would incline to 
regard the whole as a single fissure with a branch, mesiad, resem- 
bling that of the supersylvian; but a careful comparison indicates 
that the lateral generally bifurcates anteriorly, and that the ventral 
arm is joined by the coronal; occasionally they miss connection, 
as on left side of terrier (fig. 12), shepherd (512), and of another 
small dog (540), on right of pointer-shepherd (fig. 14), and on 
both sides of skye terrier (503) and young tan terrier (534), on 
*This division of the cerebral snrface into subequal areas by the fissures will be 
mentioned in the next paper; of course, as the hemisphere is convex, no figure can 
represent the true relative distances of the fissures unless the surface is projected upon 
a plane (as is done with a fox’s brain, fig. 5); it would appear, however, upon a series 
of transverse sections, which I hope to show upon another occasion. 228 
B. NATURAL HISTORY. 
left side of lion, and in cats generally ; the weasel has no coronal; 
the bear and raccoon are peculiar in this as in other respects. In 
the young terrier (fig. 7) the lateral is very short and the union has 
not taken place. The Coronal (C) may be passed over with what 
has been said in connection with the lateral. But there are two 
secondary fissures which are associated with the hinder end of the 
lateral; one of them, which generally occurs in cats, has been 
called medilateral by Owen ; it lies mesiad of and usually behind 
the lateral and often joins it, but seems to be an independent 
fissure. When there is any fissure mesiad of the lateral in dogs, it 
lies farther forward, and is generally interrupted, so that I am not 
certain of the homology; but in some cats (fig. 15) the true medi- 
lateral seems to coexist with an anterior fissure mesiad of the lat- 
eral; while in some dogs, greyhound (fig. 16), the lateral' is 
prolonged backward, as if by a medilateral, while a separate fis- 
sure, apparently a true Ml, lies between it and the mesial border, 
and another, El, lies outside between it and the super sylvian. This 
last, which has not so far as I know received a name, may be 
called the ectolateral. Flower evidently alludes to its constancy 
i*n Canidce (P. Z. S., p. 482), as occasioning the bifurcation of 
the posterior limb of the third gyrus (the value of his general- 
ization will be discussed farther on). 
Ectosylvian (Es.). This fissure is in some respects the most pe- 
culiar of all, for it presents differences not only of adult condition, 
but also of manner of formation, which lead us to doubt the value 
of this character. Its simplest, and what may be regarded as its 
normal, aspect is presented in the young terrier and foetal wolf, and 
in the adult fox, where it forms a curved line of greater or less ex- 
tent between the sylvian and the super sylvian (it is probably want- 
ing in the weasel, fig. 8) ; this regular form occurs also in some dogs, 
as a setter (10) (left side), and St. Bernard (524) (right), where, 
however, there are two or more small offshoots from the convexity, 
like the single and apparently normal anterior one of the fox ; but 
while the above instances would suggest that the ectosylvian is a 
simple arched fissure commencing at a point just above the tip 
of the sylvian, and increasing at both ends, many others would 
incline us to describe it as composed of three independent pieces, 
one in front, and one behind the sylvian, and the third connecting 
those above it; as, for example, in the terrier (fig. 25). B. NATURAL HISTORY. 
229 
And that this is a not impossible view of its formation is 
shown by the fact that in several dogs, as right terrier (511) 
(fig. 13), and left greyhound (fig. 16) and St. Bernard, this top 
piece is apparently wanting altogether, leaving the front and hind 
posts of the door unconnected. This is apparently the normal con- 
dition of things in all Felidae (fig. 17), although the ends may 
branch, and, even as in lion, join other fissures. In many dogs, as 
the Pomeranian (fig. 20), the posterior upright may be in great part 
wanting, or abbreviated and joined with the sylvian; finally, in 
Hyaena (fig. 9), the anterior upright seems to be transferred behind 
the sylvian; but this involves a very grave general question of 
homology which there is no means of solving at present. 
It will be understood that the foregoing are by no means offered 
as full accounts of the outer fissures, even with respect to my 
present materials ; but rather as hints for monographic work upon 
them when a larger number of specimens or accurate drawings 
shall be available. Let me suggest in this connection, however, 
that to be useful, the original drawings should be made by the anat- 
omist, and that the transfers should be made under his eye ; an 
abbreviation or extension of a fissure, which would appear trifling 
to the most conscientious artist, might involve a contradiction of 
important generalizations respecting its connections. 
But before any final work can be done in respect to fissures, we 
need a complete account of the brain of some one mammal, giving 
its appearance from all sides, sections and dissections of all parts, 
and demonstrations of the relations wdiich may exist between the 
fissural pattern and the internal structure; then a full series of 
figures representing*all the stages of development, both of the 
brain as a whole and of its parts; on some accounts the fox 
would be the most useful species, but as it is not to be had in 
large numbers, and as dogs are ineligible as a standard, from the 
breed differences as well as from the usual complexity of the fis- 
sural pattern, w*e shall probably find the cat most available for 
this purpose ; such a work would form a fitting continuation of 
Straus-Durckheim’s magnificent monograph of the Osteology and 
Myology of that animal.* 
Taxonomic Value of the Fissural Pattern. Upon this point 
Gratiolet speaks as follows (op. cit. p. iii) :— 
*It is one of the tasks which I wish to accomplish, hut trust this will not deter 
others from undertaking it. 230 
B. NATURAL HISTORY. 
“Iii like manner there is a particular type of cerebral folding in 
the makis, the bears, the cats, the dogs, etc.; in short, in all the 
families of mammalia (d’animaux). Each of these lias its own 
character, its norm, and in each of these groups the species can 
be easily combined according to the sole consideration of cerebral 
folds.” 
Gervais* concludes that we may recognize order, family, genus 
and even species by the brain (Nouvelles Archives clu Museum, 
7, vi, p. 152). 
Flower says {op. cit. p. 480) : “For working out all the modifications of 
the brain convolutions of the Carnivora, a larger number of specimens 
would be required than are at present accessible; but the series in the 
museum of the College of Surgeons is sufficiently extensive to show that 
they will furnish important indications of affinity, and that these indica- 
tions correspond remarkably with the evidence afforded by the cranium, 
digestive and reproductive organs.” 
While admitting the probability that such a family norm of fis- 
suration does exist and may hereafter be designated, yet the care- 
ful study of an amount of material greater in some respects, at 
least, than previous writers seem to have had, only makes me urge 
the importance of Gratiolet’s remark, that “ the value of any con- 
clusions respecting ideal unities has a necessary condition, that of 
resting upon a sufficient number of exact observations” {op. cit., 
p. iii). The need of this may be seen by an examination of Flower’s 
generalization, respecting the very groups which we can best illus- 
trate {op. cit. p. 482). 
“The dogs (Cynoidea — Canidce) are very uniform in their 
cerebral characters having always four distinct and regular gyri 
surrounding the fissure of Sylvius, which is short and approaching 
a vertical direction. The first and second arched gyri have the 
anterior and posterior limbs equal, the third has the posterior 
limb broad and bifurcated.”f 
“All the other Carnivora have only three arched gyri on the outer 
surface, the first or lower one of the dogs being either wanting or 
concealed beneath the second within the fissure of sylvians. In the 
hyaena.its hinder limb is partly exposed.” 
“In the Arctoidce {—Ursidai, Procyonidce, Mustelidce, Ailuridcc, 
* But although this author figures the brains of eighteen species of Carnivora (and 
casts of the cranial cavities of these and other species) he seems to ignore the existence 
of individual differences, and gives hut a single brain for each species and none what- 
ever from dogs (excepting casts). 
| By what I have called the ectosylvian fissure. B. NATURAL HISTORY. 
231 
Lutra and Enhydra), the fissure of Sylvius is rather long and slopes 
backwards; the inferior gyrus has the limbs long, corresponding 
with the length of the sylvian fissure ; the anterior rather narrower 
than the posterior (especially with the true bears) ; the middle 
gyrus is moderate and equal-limbed ; the upper one large, very 
broad in front and distinctly marked off from the second poste- 
riorly, as far as near the lower border of the temporal lobe ; except 
in the smaller members of the genus Mustela where the sulcus sep- 
arating the superior from the middle gyrus is less produced pos- 
teriorly than in others of the group. In Galictis vittata, however, 
the brain is quite a miniature of that of a bear; but the middle 
convolution is united with the upper one at its superior anterior 
angle.” 
“ In the JEluroidea (including all other Carnivora excepting the 
Pinnepedia), the sylvian fissure is moderate and nearer to the ver- 
tical than in the last group. The gyrus which immediately sur- 
rounds it is wide, especially the posterior limb which is generally 
twice the width of the anterior and is divided by a vertical fissure,* 
well marked in the cats and hyaenas. In the cats the anterior limb 
is also partially divided. In the civet both limbs are simple, the 
second gyrus is moderate and simple. The superior gyrus is 
wide in front but small posteriorly, the sulcus which separates it 
from the second not extending quite to the hinder apex of the 
hemisphere (the suricate agrees with the hyaenas rather than 
with the civets in the general character of its brain convolutions).” 
Of the Arctoidea, Prof. Flower may have had more material than 
I, but in the absence of exact enumeration, his characterization of 
the fissural pattern seems to me insufficient at least; if by dogs, 
Prof. Flower includes only the feral Canidce, his generalization 
may be not far from correct; although the backward slant of the 
sylvian, in both my own and Gervais’ drawings, is generally greater 
than in hyaena and weasel, and equal to that of cat and lion. 
But if the domestic dogs are included the definition would not 
apply to many of them; for the bifurcation of the third gyrus is 
often so complete as to constitute two equal gyri, as on left of 
terrier (fig. 12), and the outer or fourth gyrus may be likewise 
bifurcated, as in left of greyhound (fig. 16), while the first and 
second gyri are, as a rule, rendered irregular by the peculiarities of 
the ectosylvian ; moreover, the generalization respecting all other 
* Which I believe to be the hinder upright of the ectosylvian. 232 
B. NATURAL HISTORY. 
Carnivora involves a denial of the homology of the complete 
ectosylvian of the fox with the incomplete one of the cat, yet this last 
is very nearly like those on the left of the terrier (fig. 12) and 
greyhound (fig. 16).* 
Other discrepancies might be pointed out, if it were possible to 
present, in this paper, figures of all the brains which I have pre- 
pared ; but so long as Prof. Flower makes no reference to the dif- 
ferences of individuals of the same species, to variations of age 
and sex, or to differences between the right and left sides of the 
same brain, I shall be obliged to doubt the value of the general- 
izations. 
Lateral Variation. I wish it had been possible to offer here 
drawings of both sides of all the brains of the feral, as well as 
domestic Carnivora. I do not recall a case in which this lateral 
variation has amounted to the total absence of a main fissure upon 
one side ; it consists rather in a difference of length, depth, branches 
and connection, or of nearness to other fissures ; the minor fissures, 
however, present very great lateral variations as to presence and 
location. Since most of the examples given are from domesticated 
dogs, I do not wish to lay too much stress upon the fact of lateral 
variation, but in no work have I seen both sides of an animal’s 
brain figured or described ; and since no two brains of different 
species can be so nearly related as the two halves of the same 
brain, it is evident that a careful study of lateral variation 
will furnish a test of the value of the differences observed among 
brains (see plate 3). 
Lateral Compensation. Lateral variation is often compensa- 
tory. For instance, a long fissure of one side may be repre- 
sented by several short ones upon the other, the aggregate length 
being equal to the single one; a straight fissure may represent a 
curved one ; or a single one may have as counterpart a shorter one 
with a branch ; in one case, the total length of a bifurcated sylvian 
fissure is just that of the longer but undivided fissure of the oppo- 
site side. 
* The foregoing certainly raises the question whether we can rightly look for tax- 
onomic assistance among the organs of domesticated animals: hut meantime it seems 
proper to include our canine varieties in any generalization respecting the group of 
Cynoidea. B. NATURAL HISTORY. 
233 
The functional significance of this will be alluded to in the next 
paper. 
Conclusion. The foregoing is far from a satisfactory view of 
the subject; but it is all I can offer at present. My chief object 
has been to point out the defects of our methods of preparing and 
drawing brains, and the insufficiency of material for making any 
generalization respecting that mammalian order whose brains are 
most readily obtained and whose fissural pattern is comparatively 
simple. With a single specimen or figure of the brain of Felis, 
Canis, Hyaena, Ursus, Mustela, one might make generalizations 
as to specific, generic and family fissural patterns which would be 
quite as true to nature as many which are annually published upon 
this or other departments of Comparative Anatomy, but they 
might be controverted by other specimens or even by the other 
halves of the same. The greater complexity, both from secondary 
fissures and from contortions of the primary fissures, which pre- 
vails with the brains of most Herbivora, is an a fortiori argument 
against making the attempt to determine their fissural patterns 
before the Carnivora are disposed of. After a pretty careful study 
of the specimens and works at my command, I feel justified in 
asserting that we cannot as yet characterize the fissural pattern 
of any mammalian order, family, genus or even species without 
the risk that the next specimen will invalidate our conclusion ; 
that our studies in this direction should be based upon the careful 
comparison of accurate drawings of a much larger number of spec- 
imens than now exist in any museum; that nearly allied forms 
of Carnivora should be compared ; and that the most satisfactory 
results are obtainable from large series of foetal and jmung brains 
of the same species, and, if possible, family and sex, in order to 
eliminate minor differences. 
Addendum on the Lion’s Brain. The kindness of Mr. Lee 
Powell* has just enabled me to prepare the brain of a young 
African lion, seven and one-half months old; the left hem- 
isphere is here figured (fig. 19) for comparison with the Asiatic. 
The most striking difference is in the great development of the 
temporal lobe (the postsylvian region), which not only projects 
laterally more than in the other, but also forward over the region 
* Of Robinson’s Circus and Menagerie, Utica, N. Y. 234 
B. NATURAL HISTORY. 
just in front, so as partly to cover it and make the ventral portion 
of the sylvian coincide with the ventral branch of the ectosylvian, 
(Es) ; the frontal region is less prominent, and the outline of the 
cerebellum is quite different. In the Asiatic lion the left coronal 
is wholly independent; likewise the right coronal of the Af- 
rican ; but the right of the former joins the lateral, which is the 
usual arrangement, while the left of the latter joins the supersyl- 
vian in a similar fashion. Other differences might be pointed out 
both between the two brains and the two halves of each; but it 
seems to me that these alone are enough to make us hesitate from 
basing a diagram of the fissural pattern of this species upon any 
such number of specimens as are likely7- to be found in any museum ; 
while the same peculiarities present almost insuperable obstacles 
to a recognition of particular folds as organs of special mental 
faculties separated by certain fissures. 
[The figures illustrating this paper are given in the plates, be- 
tween pages 248 and 249, and their explanation will be found on 
page 249.] 
Cerebral Variation in Domestic Dogs, and its Bearing upon 
Scientific Phrenology. By Burt G. Wilder, of Ithaca, 
N. Y. 
The following observations are based upon the careful study of 
thirty-two dogs’ brains, representing fifteen to twenty breeds. 
There were four of the same family, a mother and three children 
of different ages ; two others nearly related to them, and two pair 
of brothers of different ages; the others are not known to be re- 
lated ; most of them are supposed to be of pure breeds.* 
*The figures referred to in this paper are included with those of the preceding 
paper in the plates placed between pages 248 and 219. B. NATURAL HISTORY. 
235 
LIST or DOGS’ BKAINS PREPARED AND DRAWN BY ME, AND FORMING THE 
MATERIAL UPON WHICH THIS PAPER IS BASED. 
M.C.Z.* 
Weight 
Weight 
GO 
o'o5 
Fig. 
No. 
Breed. 
Age. 
Sex 
Body, in 
grams.t 
ot 
Brain. 
’-w pC T3 
Kb « 
1 
Pomeranian or Spitz. 
adult. 
$ 
8,837. 
,068 
.007 
20 
3 
“ I children of 
5 weeks. 
? 
1,316. 
,047 
.035 
21 
| No. 1, by the 
2 
“ }• same father, 
4j “ 
$ 
1,006. 
,041 
, .040 
22 
1 bnt of 2 sepa- 
4 
“ j rate litters. 
54 hrs. 
a 
,132. 
,008 
.060 
23 
215 
a "1 later children 
! of mother of 
3 days. 
$ 
,213. 
,010 
.047 
24 
216 
u {father above 
J mentioned. 
3 days. 
? 
,217. 
,011 
.044 
25 
Eng. rat terrier (small 
at birth. 
$ 
,092. 
,005 
.054 
blk. and tan). 
522 
Eng, rat terrier brother 
24 hours. 
cT 
,081. 
,008 
.099 
of above. 
Spaniel J pure. 
at birth. 
? 
,221 
,007 
.030 
511 
Eng. blk. and tan ter- 
6 mos. 
? 
1,320. 
,038 
.028 
12,13 
rier(small). 
512 
Shepherd. 
young. 
a 
1,952. 
,055 
.028 
540 
Shep. cur (pt. terrier ?) 
6 weeks. 
? 
2,228. 
,058 
.021 
• 
541 
Mexican (Chihuahua). 
17 years 8 mos. 
a 
2,436. 
,050 
.020 
6 
Eng. terrier) 
9 mos. 
a 
5,300. 
,074 
.014 
> brothers. 
25 
7 
“ ) 
3£ yrs. 
a 
5,300. 
,069 
.013 
526 
Italian greyhound. 
1 yr. 
a 
6,074. 
,067 
.011 
8 
Ital. greyh’nd impure. 
adult. 
a 
4,367. 
,065 
.010 
520 
Spaniel (large impure). 
adult. 
a 
6,158. 
,082 
.010 
536 
Chinese (hairless). 
9 mos. 
a 
7,026. 
,074 
.010 
1 
503 
/ 
Skye terrier. 
15 yrs. 
a 
7,800. 
,072 . 
.009 
578 
Hound. 
20 yrs. 
a 
22,450. 
,108 
.005 
9 
Setter (large). 
12 yrs. 
a 
25,400. 
,106 
.004 
Newfoundland. 
adult. 
a 
38,345. 
,120 
.003 
26 
13 
Bull and cur. 
12 yrs. • 
<ft 
40,570. 
,125 
.003 
St. Bernard. 
old. 
$ 
40,820. 
,098 
.002 
25 
With seven others the re 
cord of which is r 
nore 
or less im 
perfect. 
No. 7 was not weighed; he was slighter in form than No. 6, 
but the weights are assumed to be equal; the “fresh wfcight” of 
the brain is computed by forming a proportion with another brain 
* This is the number on the Catalogue of preparations of Domesticated Animals in 
the Museum Comp. Zool. 
t Castrated at about six years old. 
t For uniformity, a full stop is placed after the number of grains (the unit of weight), 
and a comma after the number of kilograms (1000 grams). 236 
B. NATURAL HISTORY. 
of nearly equal weight when hardened, hut the fresh weight of 
which was also known: as to the weight being greater than that 
of the older brother’s brain, I can only adduce the greater mental 
and physical activity which it displayed. 
The brains of dogs are by no means common in museums, and 
figures of them are even more rare, partly, perhaps because the 
very commonness of the species induces delay in its examination,* 
but partly, I am inclined to think, from a notion that since they 
are all called dogs, there can be no great anatomical differences 
between them. Yet aside from any question of their origin from 
different specific forms of feral Canidce, the fact is patent that our 
various breeds of dogs differ among themselves in respect to size, 
color, form and habit far more than would be required for the dis- 
crimination of species among wild animals; and there have not 
been, so far as I am aware, any investigations to show whether, or 
not, these external distinctions coexist with structural peculiarities. 
It had long been my wish to undertake such an inquiry; and 
the liberality of Prof. Agassiz, in authorizing me to make for the 
Museum of Comp. Zoology a collection to illustrate the neurology 
and embryology of domesticated animals, has afforded me the 
means of commencing the investigation. 
The table of absolute weights of brain and its ratio in thou- 
sandths to the whole body is mainly confirmatory of the general 
rule that young mammals have proportionally larger brains, and 
that the smaller species and varieties in like manner excel the 
larger; but the difference between, for instance, a little tan terrier 
and a Newfoundland is something prodigious, as seen by the fol- 
lowing selected table, where the large dogs are represented by the 
Newfoundland, the medium sized by the English terrier (common 
size) and the small and young dogs by the small terrier and young- 
est Pomeranian. 
No. 
Variety. 
Age. 
Body. 
Brain. 
Ratio. 
4 
Pomeranian. 
54 hrs. 
,132. 
GO 
O 
O 
.0G0 
8 
Eng. terrier (small). 
6 mos. 
1,320.. 
,038. 
.028 
7 
“ “ (large). 
yrs. 
5,300. 
,0GS). 
.013 
Newfoundland. 
adult. 
38,315. 
,120. 
.003 
*As the house fly and mosquito are seldom among the first captures of the entomol- 
ogist. B. NATURAL HISTORY. 
237 
Generalizations like the above, and others which might be made 
respecting the ratios at different ages, in the two sexes and in 
various breeds, are evidently provisional until we have a much 
larger mass of material. 
I would add that measurements were taken of the intestines; 
the capacity of the stomach and coecum was recorded and all 
viscera were weighed, so that I shall at some future day be able to 
present some statistics respecting them, and also respecting the 
degree of variation in the form of the stomach and coecum, of 
which many specimens are preserved, inflated, either at Ithaca or 
in Cambridge. This is the case also with all the other mammals 
here mentioned. 
TABLE SHOWING THE RATIO OF BRAIN AND BODT WEIGHTS OF A FEW 
MAMMALS, CHIEFLY CARNIVORA. 
M.C.Z.I 
Scientific 
name. 
Common 
name. 
Age. 
X 
o 
H 
Weight 
of body. 
Brain 
Ratio. 
• 
o 
* H 
o 
577 
Maoacus ? 
White faced. 
5 yrs. 
d 
2,939. 
,082.5 
.028 
Yulpes fulvus. 
Red fox. 
adult. 
? 
2,918. 
,047. 
.016 
.073 
530 
Canis lupus. 
Gray wolf. 
4 days a. p. 
,460. 
,009. 
.019 
Canis familiaris. 
See special 
table. 
Felis catus dom. 
See special 
table. 
average of 
6 adults. 
2,847. 
,027. 
.009 
552 
Felis leo. 
African lion. 
7j mos. 
d 
11,230. 
,162. 
.014 
.117 
12 
Hyaena vulgaris. 
Striped hyaena. 
old. 
$ 
33,770. 
,110. 
.003 
.800 
502 
Ursns America- 
nus. 
Black bear. 
1 yr. 
$ 
,240. 
.550 
577 
Procyon lotor. 
Raccoon. 
adult. 
d 
5,540. 
,044. 
.008 
.040 
628 
Putorius Nove- 
boracensis. 
Weasel. 
nearly 
grown. 
,100. 
,005. 
.050 
188 
Equus caballus. 
Mare. 
14 yrs. 
$ 
,684. 
379 
it it 
ti 
adult. 
$ 
,597. 
175 
u a 
Horse. 
adult. 
d 
Ol 
CO 
o 
347 
ti et 
Colt. 
at term. 
d 
,361. 
354 
u <( 
ti 
? 
15,938. 
,190. 
.012 
325 
Bos taurus. 
Durham bull. 
2 yrs. 
d 
590,000. 
,337. 
.0008 
537 
Camelus bactria- 
nus. 
Camel. ■ 
? 
? 
299,813.' 
,615. 
.0025 
1.247 
In comparing the weight of the brain with that of the flexors of 
the lower jaw (temporals and masseters) we find, for instance, that 238 
B. NATURAL HISTORY. 
the jaw muscles are about eight times heavier in a liytena, four 
times in a Newfoundland, twice in a bear, a fox, and camel, but 
the same weight in a tan terrier, while in the young lion (552) 
they are only about two-thirds the weight of the brain, although 
this ratio must alter greatly as the animal grows older. 
M.C.Z. 
Variety. 
Age. 
Sex. 
Body. 
Brain. 
Ratio. 
220 
Common ? 1 
17 days. 
d 
,180. 
,013. 
.072 
219 
“ ,• same litter. 
C< 
d 
,262. 
,013. 
.049 
218 
“ J 
« 
9 
,250. 
,013. 
.052 
222 
(( 
5 days. 
? 
,128. 
,018. 
.063 
40 
il 
3 days. 
? 
,080. 
,004. 
.050 
38 
U 
at birth. 
? 
,110. 
,005.5 
.050 
39 
“ (sister of 37). 
36 hrs. 
? 
,075. 
,003.5 
.047 
37 
<< 
12 hrs. 
d 
,092. 
,003.5 
.038 
542 
Maltese. 
? 
d 
,560. 
,022. 
.037 
48 
23 days. 
d 
,359. 
,014. 
.039 
25 
“ (in part). 
? 
$ 
,648. 
,021.5 
.033 
24 
a u u 
2 mos. • 
? 
,800. 
,025. 
.031 
34 
Common. 
3 days. 
¥ 
,099. 
,003. 
.030 
510 
Maltese (in part). 
? 
$ 
,963. 
,023. 
.024 
26 
a 
? 
? 
1,770. 
,026. 
.015 
32 
Common. 
adult. 
¥ 
1,882. 
,025. 
.013 
<( 
t i 
d 
2,591. 
,031. 
.012 
20 
“ (striped gray). 
young. 
¥ 
1,912. 
,023. 
.012 
30 
Common. 
? 
¥ 
2,276. 
,027. 
.012 
23 
“ 
adult. 
¥ 
• 2,370. 
,028. 
.012 
28 
it 
U 
¥ 
2,978. 
,027. 
.009 
22 
Maltese (in part). 
U 
d 
4,550. 
,031. 
-007 
21 
U ii (6 
66 
d 
2,712.' 
,025. 
.007 
TABLE OP TWENTY-THREE DOMESTIC CATS, 
The following inferences may be drawn, provisionally, from the 
foregoing table. 
1. The ratio of.brain to body, in the adult cat, is about the same 
as in the adult dogs of the medium sized breeds: namely, .007 to 
.015. B. NATURAL HISTORY. 
239 
2. In kittens of the same litter (as 218, 219, 220 and 37, 39) 
the brain weights are' more uniform than the body weights, and 
the latter causes a variation in the ratio. 
3. Although the increase of the body weight is much more rapid 
than that of brain weight, when the whole period of growth is con- 
sidered, yet a comparison of 38, 39, 37, 34 with 218, 219, 220, 222, 
48, shows that the brain must grow very rapidly during the first 
two or three weeks after birth concomitantly with the increase in 
bodily powers and the use of the senses. 
A comparison of 2 and 4, among dogs, looks the same way; 
and in both cats and dogs, it will be remembered that the forma- 
tion of fissures proceeds very rapidly during the earlier days. 
With pigs, calves and colts, on the other hand, I have found the 
fissures already deep and numerous long before birth, and it will 
be interesting to contrast the relative increase of bi'ain and body 
weights in the Carnivora and Primates which are born helpless, 
and the Herbivora, which are in fuller possession of their faculties 
at birth. 
General Form.—Some dogs’ brains are high and rounded, while 
others are low, long and narrow in front; of the latter type are 
those of setters, Newfoundlands (Fig. 26), St. Bernards, shepherds 
and bull dogs ; in all of these the olfactoiy lobes are visible for 
about half their extent when the brain is seen from above but they 
are wholly concealed by the hemispheres in the Pomeranians (Fig. 
20), greyhound (Fig. 16) and terriers (black and tan, Fig 12), the 
Chinese and Chihauhau dogs ; and between the two groups come 
the bull terrier and skye terrier. 
In the fox and wolf the brain is narrow and low in front, but 
in the lion it is rather high ; while in the domestic cat, though low, 
the frontal region is very broad ; evidently, however, it is not easy 
to discriminate between the effect of large size of a certain region 
and the l'elatively small size of an adjoining one, and it must be 
remembered that in all very young dogs’ brains the olfactory lobes 
are hidden, but this is probably from their own undeveloped con- 
dition. 
The greater prolongation of the olfactory lobes and of the ad- 
joining region of the cerebrum, in front of the presylvian, which 
generally prevails in the larger dogs at least, as compared with 
the Felidae, might be held to indicate their superior power of scent; 
but this proves nothing respecting any mental faculty. 240 
B. NATURAL HISTORY. 
M.C.Z. 
Animals. 
Fig. 
Length of 
Hemisphere 
in millimeters.* 
In front 
of frontal. 
Ratio. 
33 
Bull and Cur. 
.009, 
.023, 
.333 
7 
Tan terrier. 
25 
.053, 
.010, 
.188 
14 
Pointer and shepherd. 
14 
.045, 
.013, 
.288 
Cat. 
17 
.032, 
.003, 
.094 
510 
Lion. 
18 
.071, 
.013, 
.183 
The above table is in no way intended as an index of the zoo- 
logical or psychological relations of the several animals, but as a 
single proof of the impossibility of basing generalizations respect- 
ing groups upon one or even several individuals ; for in respect to 
an element of brain form which might naturally be noted in any 
attempt at characterization, there is nearly as much difference 
between two dog varieties as between two Feline species, or be- 
tween the cat and the terrier. 
Fissural Complexity.— There must be, of course, a limit to 
the depth of fissures (or to the elevation of folds), although we 
have, as yet, no means of ascertaining the nature of the limitation, 
nor whether it is uniform in all brains; but supposing it to be 
equal in two given cases, it is evident that a larger number, or 
length, whether of branches or secondary fissures, indicates a cor- 
respondingly larger amount of grajr matter; and this, supposing 
its quality to be equal in the two cases, indicates a greater amount* 
of brain power. 
1. Now the cerebral mass is capable of expending nerve force 
in three directions, which are ideally distinct, at least in their 
purpose, but practically linked together in most cases. 
1. 1 hysical, ) Qr }ncpvisual. 
2. Mental, J 
3. Sexual, for the species. 
At present we have no way of ascertaining from the brain alone, 
whether its peculiarities relate to greater mental, physical, or 
sexual power. 
We would naturally account for the more numerous fissures 
of dogs, as compared with the feral Canidce, upon the ground of 
*A full stop is placed after the place for the number of meters (the unit of measure), 
and a comma after the millimeters (thousandths of a meter.) B. NATURAL HISTORY. 
241 
their higher mental capacity ; and upon this ground must he ex- 
plained the somewhat remarkable.fact that the brain of an adult 
Pomeranian female (Fig. 20) has fewer fissures than that of her live 
weeks old pup (Fig. 21) ; for the father was a trained dog, while 
the mother was comparatively unintelligent. 
But the wolf, according to Gervais’ figure, has more secondary 
fissures than the fox, and this must be accounted for by its greater 
physical power. 
Perhaps this is also the explanation of the great fissural com- 
plexity of the young lion, as compared with the adult cats or even 
most dogs ; but Professor Agassiz has suggested to me that the 
greater power indicated by’' the condition of the lion’s cerebrum 
may be connected with its prodigious.virility, the complete sexual 
act having been performed nine times in an hour, under his obser- 
vation, and the same rate having been maintained during at least 
two successive nights. 
In a young lion’s brain (Fig. 19) the depth of the supersylvian 
fissure is at least one-lialf the thickness of the hemisphere at that 
point and in its plane; while in an adult cat’s brain the depth 
was only one-fourth, and in a dog’s about one-third ; all the other 
fissures were very deep in the lion, and the layer of gray matter 
very thick. 
I hope to make a careful measurement of several dog’s brains, 
according to the method adopted by Wagner, with such suggestive 
results. 
2. There are individual variations among the adults which do 
not affect the presence or relative position of main fissures, but 
their length, direction, branches, connections and continuity, and, 
by inference, the manner of their formation; these variations 
enable us to recognize any brain and may in some cases approxi- 
mate them to other carnivorous families.* 
3. The two sides of the same brain present just such variations 
as those above described between different individuals. 
The few instances cited show to what extent this variation may 
exist; so great is it, indeed, that I do not think it possible to 
“mate” two hemispheres by their fissural pattern alone, without 
taking into account the similarity of size, or general form. 
* The resemblance of the ectosylvian flssurj of certain dogs to that of the cats is re- 
ferred to in the preceding paper. 
The number of specimens is not yet large enough to justify any inference respect- 
ing the sexual peculiarities of brains. 
A. A. A. S. VOL. XXII. B. (16) 242 
B. NATURAL HISTORY. 
4. There are resemblances between brains of the same breed, 
which lead us to suspect the existence of a uniform modification 
of the general pattern for different breeds. 
This is noticeable in the Pomeranian series; but in the first 
place some other brains show the same tendency of the ecito sylvian 
to join flie sylvian, and in the second place the near relation- 
ship of all the younger dogs to the single adult prevents our 
knowing how far the resemblance is one of family and how far of 
breed, in general. 
The same doubt exists respecting two tan terrier brothers 
(6 and 7) whose brains are similar, especially since they do 
not particularly resemble those of others of the same breed. 
5. All of these dogs’ brains are comparable in respect to the 
fissural pattern, both among themselves and with the feral Canidce. 
There is something which leads even the child to call all dogs 
by that name, whether they be terriers or St. Bernards, grey- 
hounds or bull-dogs, poodles or mastiffs; just what this feature 
is, has not, so far as I am aware, been scientifically described ; 
nor have I any suggestion to make; the case seems to be similar 
with their brains; I do not think I should mistake the brain 
of a dog for that of any other animal, but I cannot yet say upon 
what grounds, and am by no means sure that my diagnosis would 
be correct in all cases. 
But it is evident that in order to ascertain whether or not there 
is any peculiar dog pattern, and if so, what it is, a much greater 
amount of material is required than is now accessible. 
If nothing else, I have at least shown that no fissural pattern 
involving several fissures can be correctly known from the exam- 
ination of a single brain, much less one side of such brain. The 
collection at Cambridge is very large as compared with that of 
most museums, but far too small for any final conclusions. I 
merely venture to express the hope that when we are able to com- 
pare say twenty-five brains of the same breed of dog, wre may 
be reasonably sure what are its cerebral characteristics, and prob- 
ably several hundred specimens will be required to demonstrate 
the essential features of the dog’s fissural pattern as contradis- 
tinguished from all other Canidai. 
The immense cost of such a collection raises the question of 
the value of the result, and this is only part of a general question 
not sufficiently considered when scientific inquiries are begun. B. NATURAL HISTORY. 
243 
If a thing is to be done at all, it can be accomplished far more 
completely and economically by one person or one institution 
than by several working separately or at different periods. I 
would therefore ask members of the Association to bear me in 
mind when they have or know of a dog of pure blood and well 
known character, which has outlived its usefulness; a careful 
transportation and death by chloroform will obviate distress on 
the part of both the animal and its master. 
The relation of these variations to Scientific Piirenol- 
qgy.*—In using the phrase “ scientific phrenology ” I place myself 
between two fires ; for the professional phrenologist claims that 
all phrenology is scientific, while many scientists deny the com- 
patibility Of the terms. Let it be understood then, that I use 
phrenology in a general sense, and to avoid coining a new word, 
to indicate the study of the brain as an organ of the mind ; and, 
further, that I am not in the least biased by the views of others, 
but am trying to learn the truth by a new method of investiga- 
tion. In justice to myself also, it is right to state that I speak 
as an anatomist and not as a physiologist, much less as a psy- 
chologist. With all due respect for the latter classes of investi- 
gators, I believe that they have been hitherto building upon very 
slight foundations, and that an immense deal of hard work in the 
way of anatomical comparison must be done before they can be 
sure of the grounds upon which their experiments and conclusions 
can be based. Further, I hold that most of the facts already at 
hand are not of the right sort; and that we have begun at the 
wrong end and in the wrong way in our efforts to correlate brain 
and mind. 
Mental associations of parts of the Brain mass.— Four 
methods may be employed in order to ascertain the mental associ- 
ations of parts of the brain mass : 
1. The Phrenological. The skull was accepted as an index of 
the form of the brain, and a certain number of cases of corres- 
pondence between cranial forms and marked characters was held 
to demonstrate the locality of mental faculties and propensities. 
♦This phrase is used by Gei'vais (Nonvelles Archives du Museum, tome vi, PI. 9, 
Fig. 2). This author gives admirable lithographs of many brains and moulds of 
tire cranial cavity. and suggests the value of a comparison of carnivorous brains, for 
the advancement of “ scientific phrenology.” B. NATURAL HISTORY. 
That this method is not satisfactory appears from the following 
considerations. 
a. No definite and constant correspondence whatever exists be- 
tween folds and fissures of the brain and the outer cranial surface. 
b. Several important faculties are located over the frontal air 
sinuses, as pointed out by Dr. Cleland, from whom the accom- 
panying figure (Fig. 27) is copied.* 
c. No phrenologist has ventured to draw the accepted map of 
mental faculties upon the surface of the brain itself; and, from 
what we have learned, it is certain that what would fit one side 
would not fit the other. 
d. No allowance is made for the extensive sheet of gray matter 
which covers the mesial surfaces of the hemispheres, and which, 
so far as has been shown, differs in no way from the rest. 
e. To all appearance, the gray matter forms a continuous sheet, 
which may be more or less folded in the adult but was perfectly 
even at an earlier stage.f 
/. By the failure (in several cases, though one is enough) on the 
part of the most expert phrenologist to determine correctly the 
character of an individual by examination of the liead.J 
2. The Pathological. By comparing cerebral lesions with men- 
tal manifestations observed during the life of the individual. 
This is at present unsatisfactory, because : 
*The lingering admirers of Phrenology. Popular Science Review, 
t This is perhaps not so conclusive an objection as might at first appear; for tho 
present non-recognition of lines of demarcation is no proof of their non-existence; 
and the experiments of terrier and others seem to demonstrate something like a locali- 
zation of power in respect to muscular action; this, however, would not seem to re- 
quire the same circumscription of area as in the case of distinct mental faculties. 
X My views in respect to phrenology are given in “ The Tribune Extra,” No. 3, and 
my personal experience in “ The Ithaca (N. Y.) Democrat” for Jan. 29,1873. They will 
shortly appear in a republication of the lecture above referred to in the “ Half-Hour” 
series of Messrs. Estes and Lauriat. B. NATURAL HISTORY. 
245 
a. It lias failed of absolute demonstration in respect to an ap- 
parently single organ, the cerebellum, for Dr. Hammond accepts 
neither the view of Flourens that it coordinates muscular action, 
nor that of Spurzheim that it is connected with sexual feeling, 
and concludes that it has no special function.* 
b. The large number of cases in which aphasia coexisted with 
lesions of a tolerably definite region of the left hemisphere has 
not yet convinced the highest authorities that the mental faculty 
of language is there situated. 
c. There is reason to suppose that peculiar mental conditions 
may exist when no cerebral lesion is recognizable, and that lesions 
may exist w ithout mental disturbance. 
d. Finally, Brown-Sequard concludes “from the study of every 
symptom of brain disease, that all parts of the brain may, under 
irritation, act on any of its other parts, modifying their activity, 
so as to destroy or diminish, or to increase and morbidly to 
alter it.”f 
3. The Experimental. This has been introduced by Fritsch and 
IIitzig, Beaunis and Nothnagel,| who, by galvanic or chemical irri- 
tation or destruction of certain cerebral regions of dogs, have 
demonstrated the existence therein of centres of action for dif- 
ferent sets of muscles. This method promises great results, but, 
it may involve injury and abnormal action, and thus far has 
* Quart. Journ. of Psychological Medicine, April, 1859. 
f On the mechanism of production of symptoms of diseases of the brain, Archives of 
Scientific and Practical Medicine, vol. i, p. 117. 
In this connection the following conclusions of Brown-Sequard (which I have but 
lately seen in the original, Feb., 1874) are of great significance: “An immense variety 
of symptoms in different individuals may be caused by a lesion in one and the same 
part of the brain; and the same symptoms may result from the most various lesions.” 
Archives of Scientific and Practical Medicine. March, 1873, p. 259. 
The above, together with the decided disbelief in the correctness of the generally 
accepted views of nervous physiology, which are elsewhere in the same journal ex- 
pressed by the same high authority, should lead us to be cautious in our deductions 
from any single series of observations. 
J Fkitsch and IIitzig.—Ueber die electrische Erregbarkeit des Grosshirns. Archiv 
fur Anatomie, Physiologie und wissenschaftliche Medicin, 1870, p. 300. 
IIitzig.—Ueber die beim Galvanisiren des Kopfes entstehenden Siorungen der Mus- 
kelinnervation. Archiv fur Anat. Physiol, und wissenschaftliche Medicin, 1871, p. 710. 
Weitere Un ter such ungen zur Physiologie des Gehirns. Do., 1871, p. 771. 
Beaunis.—Note sur l’application des injections interstitielles a l’etude des fonctions 
des centres nerveux. Gazette Medicate de Paris, 1873, Nos. 30-31. 
Nothnagel.—Interstitielle Injectionen in die Hirnsubstanz. Centralblatt fiir die 
med. 'VVissenschaften. 1872. page 705. 
Experimentelle Untersuchungen fiber die Functionem des Gehirns. Virchow’s 
Archiv, 1873, p. 181. 
The above references are taken from Prof. II. P. Bowditch’s excellent report on 
Physiology, Boston Med. and Surg. Journal, July 17, 1873, p. 79. 246 
B. NATURAL HISTORY. 
shown only a connection between cerebral substance and muscular 
organs, not of brain and mind. 
The above method has been later employed by Ferrier,* who, 
however, used faradic instead of galvanic electricity. 
Dr. Ferrier’s results are interesting in the highest degree, and 
it is only to be regretted that he has not at once published a dia- 
gram of a brain, so that all may know to what parts he refers in 
his description. 
It is worthy of note that in the following expression he jumps 
at no conclusions respecting the localization of mental faculties. 
“ There is reason to believe that, when different parts of the 
brain are stimulated, ideas are excited, but it is difficult to say 
what the ideas are. There is, no doubt, a close relation between 
certain muscular movements and certain ideas.” 
But the results of such experiments can hardly be accepted as 
indicative of the localization of mental faculties in the human 
brain, or that of any animal than the one experimented upon, 
until it is shown that homologous folds exist in both ; and even 
then the fact that the same faculty, for instance, combativeness, 
is manifested by a dog with its jaws, by a horse with his hind 
legs, by a bull with his horns, and by human beings, with hand or 
foot, or only with tongue, renders the practical phrenological ap- 
plication a very difficult one. The following suggestion was made 
by me a year ago (lecture on the brain above referred to). 
“To apply galvanic stimulus to the supposed organs of promi- 
nent and distinct faculties, either indirectly, through the skull, or 
directly, in cases of accident; perhaps it is not too much to sug- 
gest that the experimentum crucis could be tried, if an enthusiastic 
believer would allow himself to be trephined, through a few pro- 
tuberances. We could then witness the manifestation of friend- 
ship or combativencss, as the subject clasped the operator in his 
arms or planted a blow between his eyes. 
It cannot be denied that trephining is one of the perilous opera- 
tions, but a healthy man would have a fair chance ; a criminal 
would do well to accept the risk in case of possible slow strangu- 
lation, and should he die during the operation, it would merely 
anticipate by a score of years the method of execution, namely, 
*Fereier.—“ Experimental Researches in Cerebral Physiology and Pathology.” 
British Medical Journal, April 2fi, 1872. Also: “A new method with the brain;” read 
before British Association for Advancement of Science, 1873, and printed in “Nature,” 
and in “Popular Science Monthly” for Dec., 1873. B. NATURAL HISTORY. 
247 
by an overdose of chloroform, to which I believe vve shall be com- 
pelled to resort, in the interests of decency, humanity, and even 
artistic effect.” 
But while convinced that this method of investigation will 
throw great light upon the question of the correlation of bi’ain 
and mind, I am by no means confident that it will demonstrate 
the localization of m ntal faculties in certain cerebral folds. On 
the contrary, although satisfied that my present-material is too 
small for final conclusion, I am more and more inclined to think 
that a cerebral hemisphere acts as a unit, either singly or with its 
fellow ; that, other things being equal, a greater number and depth 
of fissures indicate a greater mental or bodily power, and that the 
actual number of the fissures has only a general functional signifi- 
cance, analogous to coils of intestine, or corrugations of mucous 
membranes; but that like these, or like the peculiar turns of horns 
and the arrangement of turbinated bones, their arrangement in 
what is called the fissural pattern may be fairly accepted as indi- 
cations of zoological relationship, more and less remote. The ex- 
tent of their value in this regard must be ascertained by much 
more extensive comparison than has been made. 
4. Cyno-phrenology. The method here advocated is, in theory, 
that of the phrenologists, but its practice differs therefrom in two 
important respects: a. In employing the brain itself for com- 
parison, in using large numbers, in comparing the two sides, and 
in keeping the brains for such study as is impossible from figures. 
b. In employing not human, but canine brains, upon the grounds 
of their simpler fissural pattern, their smaller size, and conse- 
quent easier preservation in large number, and the possibility of 
an accurate acquaintance with the mental characteristics of the 
dogs. At present we are well acquainted with the natures of our 
family, our friends, and of public men; their brains are rarely at 
our disposal for scientific investigation ; so we study the brains of 
paupers and uncultivated persons whose characters are known to 
us either not at all or very imperfectly. With dogs, the brain and 
the mind of the same individual are at our disposal; while lateral, 
epochal, individual and sexual variations, together with those ap- 
pertaining to families and breeds, may be more easily observed 
and separated. 
I have records of the habits and disposition and mental attain- 
ments of several dogs, but the material is far too slight for 248 
B. NATURAL HISTORY. 
anything like a scientific deduction. I even hesitate to associate 
the great width of the supersylvian fold of a bulldog, with his 
fighting powers, for his disposition was gentle enough. 
Even Distribution of Fissures.—I cannot help thinking that 
at least one of the elements of the fissural pattern is the sub- 
division of the surface into approximately equal areas. This is 
best demonstrated by projecting the surface of a hemisphere upon 
a plane. But the only brain on which I have as yet done this 
is less satisfactory than I expected ; and I shall hope hereafter to 
offer sections of the hemispheres which will better indicate both 
the distance between the fissures and their depth. 
If particular folds are the organs of either mental faculties or 
distinct groups of muscles, and if as such organs they are circum- 
scribed by the intervening fissures, then how can we explain the 
following facts? 
1. That these folds are generally continuous around the ends of 
the intervening main fissures. 
2. That even where “islands” are formed by the extension of 
branches or by secondary fissures, there was a time when these 
surfaces were continuous upon the same level. 
3. That no one has }ret demonstrated any structural lines of 
demarcation corresponding to the fissures. 
4. That there may be differences between the two halves of the 
same brain equal to or even greater than those which distinguish 
individuals or even species. 
The zoologist and comparative anatomist would not hesitate to 
call attention to the greater or less width of a certain fold, and 
would regard it as of possible taxonomic value ; but the cautious 
physiologist would certainly shrink from the inference that this 
was conclusive proof of the greater or less power of certain mus- 
cles or mental faculties ; and he would be yet more loath to infer 
that the apparent obliteration in many dogs of the posterior leg 
of the front or lowest fold (which in fox intervenes between the 
sylvian and ectosylvian) indicated the absence of either the mus- 
cles or the faculties which the fox exercises through it; or even to 
infer that the apparent transfer of the anterior leg of this fold in 
hyaena, to behind the sylvian fissure indicated a real transfer of a 
mental or muscular “ organ although, should the fissural ar- 
rangement prove constant, it would be unhesitatingly accepted as 
of great taxonomic value. Plate 1. 
Formation and Nomenclature of Fissures in Carnivora. 
Fig. 6. Foetal Wolf {Canis occulentalis): 
four days before birth. (530.) 
Fig. 3. Fox, V. fulvus. $ adult. 
Fig. 7. English Terrier: one day. $ (532.) 
Fig. 8. Weasel. Putorius Noveboracemis. 
Nearly grown. (528.) 
Fig. 4. Fox, V. fulvus. $ (513.) 
Fig. 1. Appendicular lobule of Cere- 
bellum, left side, of Chinese dog. (p. 217.) 
Fig. 2. Median lobe of Cerebellum of 
Kitten (K) and Cat (C), showing contortion 
during growth, (page 221.) 
Fig. 5. Fox. Same as 4, projected on a plane. 
(See page 21S, note.) Brains of Hyaena, Bear and Raccoon. 
Plate 2. 
Fig. 9. Hycsna vulgaris, ? old. (12.) (p. 229.) 
Fig. 10. Bear: Ursus Americanua. $ one year. (502.) (p. 231.) 
Fig. 11. Raccoon: Procyon lotor. Adult. (577.) (p. 225.) 
(I am in doubt respecting most of the Assures in Ursus and Procyon.) Plate 3. 
Lateral Variation in Dogs and Cats. 
Fig. 12. Small bl’k and tan Terrier, $ (left side) 
six months. (511.) 
Fig. 14. Young Pointer and Shepherd. <f (14.) 
Fig. 15. Cat. Half grown, $ (20. .- 
Fig. 13. Same as tig. 12 (right side reversed). 
Fig. 17. Cat, adult, (p. 232.) 
Fig. 1(J. Greyhound, one year, (520.) (p. 229.) Lions. 
Plate 4. 
Fig. 18. Lion. Felix Leo, var. Asiaticus: seventeen months. Cerebellar lobes 
shown in part. (510.) p. 233. 
Fig. 19. I.ion. Felix Leo, var. Africanus, seven ami one-ball' months. 
Cerebellum in outline only. (552.) p. 233. Plate 5. 
Varieties of Dogs. 
Fig. 20. Pomeranian dog, 9 adult (1). (Mother of 21, 22, 23.) 
Fig. 24. (41 and 42) Pomeranian pups, 
2 three days. 
Fig. 21. Pomeranian pup, $ five weeks. (3) 
Fig. 22. Pomeranian pup, 9 four and 
one-half weeks. (2) 
Fig. 23. Pomeranian pup, fifty-four hours. f4) 
Fig. 26. Newfoundland, J adult. 
Olf. lobe exposed. 
Fig. 25. English terrier, oil. lobe hidden; three and 
one-half years. (7) (p. 228.) Double Human Monster. 
Plate 6. 
Fig. 3. Right brain, left hemisphere (the dotted line indicates 
a part of the frontal lobe which was destroyed): weight, ,190. 
Fig. 1. Left brain, left hemisphere: weight, ,182. 
Weight of right brain, ,39(5. 
Weight of left brain, ,372. 
Fig. 4. Right brain, right hemisphere (drawn after drying): 
weight, ,200. 
Fig. 2. Left brain, right hemisphere: weight, ,190. (drawn 
after drying.) See page 250. B. NATURAL HISTORY. 
249 
All the facts indicate that while it is not impossible or even im- 
probable that different areas of the cerebral surface may be in 
functional relation to either movements or mental operations or 
both, yet these areas are not always, if ever, circumscribed by the 
fissures; that the fissures merely increase the amount of gray 
matter wherever they are ; their signification being rather quanti- 
tative than qualitative. 
This question might be decided by Dr. Ferrier’s method, explor- 
ing not only the free surface of the folds but also the hidden walls 
of the fissures. 
Explanations of Figures.*—With two exceptions (Figs. 10 
and 13) the brains are shown from the left side, and all the 
drawings are made from specimens hardened, and thereby 
shrunken, in spirit. The olfactory lobe is given in outline ; also 
the cerebellum and medulla oblongata: but neither the nerve 
roots, nor the cerebellar convolutions are indicated. As stated 
on page 218, note, each fissure is drawn as it appears to the 
eye placed over it perpendicularly to the surface on which the 
brain rests. 
Figures 3, 4, 20, 22, 25, showing the fissures dark on a white 
ground, have been kindly loaned to me by the “ N. Y. Tribune,” from 
those which illustrated the report of my lecture on “The Brain, 
and the present scientific aspect of Phrenology,” printed in the 
“Tribune” Extra, No. 3 : a few inaccuracies which could hardly 
be avoided in the hasty preparation for the press, have been since 
corrected. 
The remaining figures, in which the fissures are shown white on 
a dark ground, have been drawn on wood and cut by Mr. Philip 
Barnard of Chicago (now a student in Cornell Univ.), to whose 
patience and accuracy I gladly bear witness. All the drawings 
were made by me from specimens which I had prepared. 
The fissures are lettered uniformly throughout. 
S—Sylvian. 
Bs — Basisylvian. 
I*s— Presylvian. 
It — Rhinal. • 
Er— Ectorhinal. 
P — Frontal. 
C — Coronal. 
Es—Ectosylvian. 
Es’—Its posterior branch. 
Esv— Its ventral branch. 
S* — Supersylvian. 
Ss'—■ Its medial branch. 
L — Lateral. 
L'—Its medial branch. 
El—Ectolateral. 
Ml— Medilateral. 
* The numbers in parenthesis refer to the Catalogue of the Neurology and Embry- 
ology of Domesticated animals at the Museum of Comparative Zoology. 
A. A. A. S. YOL. XXII. B. (16*) 250 
B. NATURAL HISTORY. 
Lateral Asymmetry in the Brains of a Double Human Mon- 
ster. By Burt G. Wilder, of Ithaca, N. Y. 
[The figures form plate 6 at the end of the preceding paper.] 
It is generally known that the right and left hemispheres often 
present considerable differences in the details of the cerebral pat- 
tern ; but very rarely do we find figures or detailed descriptions 
which indicate the extent of this lateral variation, although its ex- 
istence would seem a serious difficulty in respect to phrenology. 
As remarked in a previous paper no brains of different individuals 
can be so closely allied as those of the same individual, and a study 
of these must serve to check our estimates of the zoological value 
of fissural variation between species; next in value for this pur- 
pose would usually be ranked the brains of twins or, with animals, 
brothers and sisters of the same litter; but an intermediate stage 
of relationship is presented by double monsters, like the one de- 
scribed in the next paper, and as their brains are rarely preserved 
or figured, I have thought them worth recording.* 
The brains were bisected soon after extraction; each was 
weighed and each cerebral hemisphere placed in spirit upon its 
mesial surface ; being quite soft, they became unnaturally flattened 
in the process ; they were drawn after hardening and the two 
right hemispheres shrank while drawing, from evaporation of the 
spirit, so as to lessen their area and to expose the island of Reil to 
an unnatural extent, as appears in figures 2 and 4. This prevents 
the otherwise interesting comparison of the four hemispheres in 
respect to the length of the fissures, without reference to their 
depth; and in respect to the total area of the outer surface of 
the hemispheres. 
But the fissures themselves and their connections are unchanged, 
and certainly present some striking differences whether the two 
brains are compared together, or the two halves of the same brain. 
I have lettered only the sylvian (S'), its ascending branch (S"), the 
first temporal (t;) ; and the fissure of Rolando or centralis (C). 
The temporal (k) of the right brain, left hemisphere, is in two 
portions, the separation occurring at a point corresponding with a 
transverse fissure in the other hemisphere ; and although Ecker 
* I hope on a future occasion to present a detailed comparison of the four hemi- 
spheres of several double-headed calves and pigs, which are now in the Museum of 
the Cornell University. B. NATURAL HISTORY. 
251 
says nothing of it (op. cit. 62), yet some foetal brains in my pos- 
session indicate that there may here be two fissures which origi- 
nate separately but usually unite ; the case ma}" be compared with 
that of the lateral and coronal in carnivora. (See page 227.) 
I do not feel sufficiently sure of the correctness of the generally 
received designations of the other fissures to compare them indi- 
vidually, but it is evident that all the fissures differ greatly as to 
length, direction, branches and connections, and that the smaller 
fissures vary considerably in number, giving an appearance of fis- 
sural complexity in the following order. 1. Left brain, left hem- 
isphere ; 2. Left brain, right hemisphere; 3. Right brain, right 
hemisphere ; 4. Right brain, left hemisphere. 
It is worth noting that, excepting with the left brain, right hem- 
isphere, this order is inversely to that of the weights, as if by 
way of compensation; also that the two hemispheres of the left 
brain present the two extremes of fissural complexity, while the 
intermediate conditions are seen in the right brain. 
Furthermore, it may not be too much to associate the greater 
weight (,024. grams) of the whole left brain over the right, with the 
fact that the corresponding part of the double body is larger than 
the right, and the median third leg is thrown over toward the right 
side, as if it were more fully a right leg of the left child than a 
left leg of the right child. 
The combined weight of the two brains is ,768. which is to that 
of the bodies, 5,000. about as 1 to which is the average ratio 
in females at birth, according to Tiedeman ; that in the male being, 
according to the same authority as 1 to 5’85 ; as quoted in Quain’s 
Human Anatomy, ii, 570. This monster is apparently of the male 
sex. 
The Papillary Representative of Two Arms of a Double 
Human Monster, with a Note on a Mummied Double 
Monster from Peru. By Burt G. Wilder, of Ithaca, N. Y. 
The double monster here referred to was still-born, at term, 
in March, 1873 ; aside from the malformation it was of good size 
and appearance ; the left spine was found to be fractured, and 252 
B. NATURAL HISTORY. 
it may have died during parturition which was long and difficult, 
although the mother recovered without trouble. 
Having preserved all the viscera (including the brains, which 
were described in the previous paper), it is my intention to pre- 
pare a detailed account of the case in connection with several 
other double monsters in my possession, so I will merely men- 
tion that it weighed about 5,000. grams (about eleven pounds), 
and measured about twenty-two inches when the legs were 
extended. 
There are two stomachs, symmetrically disposed, as usual in 
such cases; the small intestines continue independently to near 
the caecum; this, the colon and rectum are single, the latter ter- 
minating at an imperforate anus, just above (behind) the genitals ; 
there are two hearts, and two pairs of lungs ; four kidneys and two 
bladders; the sex is apparently male, but the testes have not 
entered the scrotum, and I have not yet looked for them among 
the viscera. 
As seen in the figure, its heads are separate and complete, 
the right larger then the left, as with the corresponding brains ; 
the opposite limbs and sides of the compound body are some- 
what unsymmetrical, the right child seeming to constitute more 
than half of the whole ; the hands and feet are quite well formed 
but there is an extra right pollex; further details will be given 
hereafter. 
So far this specimen nearly resembles that so wrell described 
and figured by Professor Jeffries Wyman in the “Boston Medical 
and Surgical Journal” for March 29, 1866.* 
There is also a third and median and morphologically symmet- 
rical leg coming off from the pelvis, and possessing a partly 
double foot with a median primus (great toe) bearing a nail upon 
each side, and seven other toes of which four seem to belong to 
the right, and three to the left, moiety ; but this left foot belongs 
of course to the right child, and the right belongs to the left child 
which thus claims four and a half of the eight toes. 
The leg and foot are less regular and symmetrical than in 
Wyman’s case, and the whole limb is swung out towai'd the 
left as if more under the control of the right child, concomi- 
♦The figure is reproduced in Dr. S. J. Fisher’s essay upon Diptoteratology, p. 72, and 
figs. 53 and 54, the description is there quoted in part, and in full in Prof. J. B. S. Jack- 
son’s Catalogue of the Warren Anat. Mus. of Harvard University. B. NATURAL HISTORY. 
253 
tantly with the greater bulk of the right brain (see preceding 
paper). 
The point to which I wish to call particular attention is the ex- 
istence of a minute papillary representative of the missing arms, 
corresponding to the legs which are represented by the fused and 
median limb ; this is a papilla about *005, in length and slightly 
constricted at the base ; the surface is slightly wrinkled and a 
few short hairs spring from the tip ; it is wholly tegumentary, and 
its cavity contains only loose connective tissue. 
Fig. 1. Dioephalous Monster, from behind; 1-6 of natural length. 
Its nipple-like appearance, and its location upon the line of 
junction of the shoulder regions of the two individuals, suggested 
its being the result of a fusion of the left nipple of the right child 
and the right nipple of the left child (the other two occupying 
their normal positions upon the pectoral regions), but it is im- 
perforate; and what is conclusive, the real nipples, though small 
and hardly projecting from the surface, occupy places upon the 
sides of the junction-line, the right one (left of right child) being 254 
B. NATURAL HISTORY. 
•030, and the left (right of left child) *025, behind the median 
papilla, and at a distance of *025 apart; an elongated mammary 
gland underlies the left nipple as indicated by the slight elevation 
in fig. 2, A, but no such is apparent under the other. 
Fig. 2. A. Integument bearing the papillary limb P, and the two nipples N, N'. 
B. Median scapula and clavicle from above. 
C. The same from the side, the scapula divided near the middle line; all of 
natural size. 
Immediately beneath the integument upon the line of junction 
are two bones whose position in reference to the papilla is approx- 
imately shown by the dotted outline in fig. 1; while their forms 
and connections are shown in fig. 2, B and C. The longer bone 
is evidently a median and nearly symmetrical clavicle; it is 
about -045, in length, is wholly ossified, and presents at its hinder 
extremity an appearance of epiphysis, ’which is attached to the 
anterior slope of the scapular elevation by ligaments, without 
any synovial capsule; its anterior extremity gives oflf a slender 
tendon which bifurcates at a distance of *005, into the tendons of 
the two sterno-mastoid (?) muscles; into each side are inserted 
two muscles, the deido-mastoid occupying the anterior, and the 
trapezius the posterior half. The enclosed spaces C M and T B. NATURAL HISTORY. 
255 
indicate the attached ends of the cleido-mcistoid and trapezius mus- 
cles of the right individual; the clavicle is strongly curved toward 
the left individual, as seen from behind, but as seen from the side 
its outline is nearly straight, fig. 2, C. 
The scapula is a nearly symmetrical disk of bone with a carti- 
laginous border which is narrow in front, projects as an angle 
upon each side, and is broader behind where it is closely connected 
with a transverse bar of cartilage, excepting an elongated gap 
upon the middle line; the scapular disk is convex upon its dorsal 
surface, rising near the anterior border into a decided elevation or 
tubercle corresponding with a deep pit P, upon the concave deep 
surface, as shown in the section C. 
I am not prepared to express a decided opinion as to the nature 
of the cartilaginous bar ; but have no doubt that the disk represents 
the fusion of the inner or vertebral or proximal moieties of the left 
scapula of the right child, and the right scapula of the left child, 
at a point proximad of the glenoid cavities so as to leave only por- 
tions of the acromial spines to unite and form the elevation against 
which the clavicle abuts ; to the various borders of the scapula 
are attached muscles, which seem to represent the two rhomboidei, 
the serratus magnus, the levator anguli scapidce, and the omohyoid ; 
but as I am still in some doubt respecting the pectoralis major, 
and the attachments of the teres major and latissimus dorsi, I will 
defer an account of them to another occasion ; when, too, the 
absence of a sternum and the apparent anomalous direction of the 
clavicle can be accounted for. 
In general, however, it is evident that the condition of things is 
like that in Prof. Wyman’s case, excepting that the separation of 
the two individuals at the shoulders is less complete ; or the union 
is more so. 
The result is to reduce so far the median and third arm, that 
instead of being obviously and unmistakably such it is a mere 
papilla which but for its position and its relation to the underlying 
bones would never be regarded as a limb, much less as two arms ; 
yet it is evident that it is just as much so, morphologically, as is the 
earliest pad-like rudiment of a limb in the developing foetus; for 
it is possible to conceive of a complete series of intermediate 
conditions with Wyman’s case at one extreme and this at the 
other. 
It would seem therefore that, in any such system of classifiea- 256 
B. NATURAL HISTORY. 
tion of monsters as that proposed by Dr. Fisher, our monster 
should rank as Dicephalus, tribrachus tripus; op. eit., p. 71. 
But the question arises whether the name could be retained in 
case of a still further reduction, so as to leave no external evi- 
dence of a median limb; and while this may be of less practical 
importance in respect to monsters, yet it is akin to the general 
problem “what constitutes a digit or dactyle” briefly indicated by 
me.* 
Note on a Mummied Dicephalus from Peru. — Dr. Chas. 
S. Swazey of New Bedford has kindly allowed me to bring some 
photographs of Peruvian relics, and among them is one of a 
human dicephalus, closely resembling our specimen ; but as it 
is in a sitting posture and shown from in front, the existence 
of median limbs is merely to be inferred, the left foot is partly 
hidden by the right, and the three tibial (inner) toes of the right 
are turned down. It seems, from this, that monsters occurred 
among the ancient Peruvians, and that they were not consigned 
to scientific investigation, but duly mummified.f 
*Intermembral Homologies, p.63; Proc. Bost.. Soc. Nat. Hist., vol. 14,1871. 
fit is stated in Spencer’s “Descriptive Sociology” that the “ Huacas,” or sacred 
objects of the Peruvians included twins and monsters. B. NATURAL HISTORY. 
257 
The Habits and Parasites of Epeira riparia, with a Note on 
the Moulting of Nephila plumipes. By B. G. Wilder, of 
Ithaca, N. Y. 
The large garden spider with black and yellow abdomen, which 
is very common in certain parts of the south, and less abundant 
at the north, was first, so far as I know, described and figured only 
b}r Hentz.* 
Although that author’s description is very brief, the spider is 
readily identified, and it may be better to defer a fuller description 
until a male is secured ; at present there are some points in its 
economy worthy of investigation, and I will here indicate them, 
first quoting in full Hentz’s account of the species. 
“ Description.— Black, ceplialo-thorax covered with silvery-white 
hairs ; abdomen barred with bright jmllow spots and dots ; thighs 
usually brightwufous at base, except the first pair. Of a large 
size, seldom small. 
Observations.— This remarkable species usually dwells on the' 
margin of waters where it makes a web of strong threads, in which 
large Libellulce and Melolonthce are often caught. The abdomen 
of the female is flat in the early part of the season, and it is not 
till August that, being distended with eggs, it assumes the ovi- 
form shape. Its cocoon is conical, as large as a small plum, like 
a pear hanging down. Whenever opened it was found full of young 
spiders instead of eggs. Is it viviparous ? 
Habitat.— The United States.” 
During the war I had the opportunity of studying certain 
features in the economy of this species, which at the time, I 
imagined to be wholly undescribed, and in “Harper’s Monthly” 
for March, 1867, under the title of “200,000 spiders,” I gave 
’descriptions and figures of the female E. riparia, of her net and 
of the cocoon; also of presumed ichneumonidian and chalcidian 
parasites found therein. And as nothing has since appeared 
respecting it, I will here give an abstract of the above mentioned 
paper, together with some additional observations respecting the 
escape of the young from the cocoon. 
* Boston Journal of Natural History, 1847, v, 4(58, pi. xxx, fig. 5, under the name of 
E. ripuri t. 
A. A. A.S. VOL. XXII. B. (17) 258 
B. NATURAL HISTORY. 
On the 21st of March, 1865, on James Island, just south from 
Charleston, South Carolina, I found suspended in a bush a pear- 
shaped cocoon (fig. 1), like that described by Hentz. Between 
Fig. 1. Cocoon of Epeira riparia; nat. size. 
the above date and April 2d, I found in the same locality, and 
chiefly near a ditch, two hundred and five similar cocoons. 
Fig. 2. A. Vertical transverse section of cocoon of Epeira riparia, containing 
only the eggs of the spider. 
B. The same showing the cocoons of the ichneumon, which destroyed 
the eggs, and which are themselves destroyed by chalcidians. 
C. Cocoon of ichneumon from which the insect has escaped. 
1. Outer, and usually glazed, coat of the cocoon. 2, 3, 4. Second, third and 
fourth, or inner coats, separated from each other. 5. The pedicel. 6. Looser 
interior of pedicel. 7. Thickened base of pedicel. 8. Suspensory of the 
egg-cover. 9. The egg-cover. 10. The eggs partly exposed by separating 
the cover from the cup. 11. The cup. 12. Loose silk surrounding the cup. 
13. Hole made by escaping ichneumon. 14. Ichneumon cocoon. 15. Holes in 
the ichneumon cocoons made by the chalcidians. 16. Corresponding holes 
in the spider’s cocoon. 259 
The cocoon is usually pear-shaped, ranging from -015,(15 milli- 
meters) to -022, in transverse diameter, and from -025, to '032, in 
length. The wall averages -000,5 Q millimeter) in thickness, and 
usually consists of four concentric and closely united coats or 
layers of silk, which are nearly equal in thickness and compact- 
ness, the outer one (l), however, being usually smoothly glazed 
without, so as to crackle like thin paper ; sometimes there are but 
three coats, and in some of these cases, the outer one is not glazed 
but soft and velvety; the coats thin out over the pedicel, but not 
by well-defined edges'. 
At the top of the cocoon is a pedicel or stem (5), hollow and loose 
in texture (6) above, but broader and denser below, where it is 
concealed by the body of the cocoon, and having its lower surface 
or base very firm, like a silken disk (7). 
The contents of the cocoon are a mass of loose* reddish silk (12) 
attached above, about the base of the pedicel and apparently also 
to the inner coat (a special portion of this loose silk, like a 
cushion (8) attached to the base of the pedicel); a kind of saucer 
(9) of very delicate silk, which is inverted, and suspended by the 
cushion above mentioned; a cup (11) of the same delicate silk 
suspended to the lower border of the saucer (which thus forms its 
cover) by a few fibres of loose silk; a mass of eggs (10), from 
five hundred to two thousand two hundred in number, enclosed 
within the cup (at the time these were found, these eggs had 
evidently hatched, for in their place were found large numbers 
of little fragments of broken shells) ; many little round bodied 
spiders, never, in the earlier weeks, less than five hundred in 
number ; which, when the cocoon was opened, came tumbling out, 
each swinging by its own little thread, and “ looking like so many 
chickens hung by their tails” (Harper’s Magazine, 1866, p. 452, 
and fig. 12). 
I have never witnessed the making of a cocoon ; a spider after- 
ward taken near Boston, Mass., was just finishing her work at 
6 a.m. of Sept. 26, by attaching lines from the cocoon to sur- 
rounding objects. But it may be inferred that the pedicel is first 
formed, and firmly secured by strong lines in all directions ex- 
cepting downward ; that to its lower surface the spider affixes the 
cushion of loose silk; and to this the inverted saucer; the eggs 
are now expressed upward into this, while the spider hangs back 
downward below it; the cup is now formed under and about the 
eggs ; and then around the whole is spun the loose mesh of silk 
B. NATURAL HISTORY. 260 
which serves the double purpose of protection to the eggs and the 
spiders, and as a primary habitation for the latter before they es- 
cape and make nets of their 'own ; finally, the outer wall is formed 
in three or four consecutive layers, and the cocoon is braced by 
strong lines passing to the surrounding twigs. 
From the above account it appears that the cocoon must be 
formed and the eggs laid in the previous summer; and that in 
South Carolina, the eggs are hatched as early as the 21 st of March; 
but although by opening a cocoon every day or two, I satisfied 
myself that each of them did really contain from five hundred to 
two thousand living spiders, and although they "were kept exposed 
to the sun and occasionally sprinkled with water, yet during all 
the time I kept them, namely, until June 15, not one of the 
entire cocoons was opened by the inmates. On and after the 10th 
of May, however,- they sometimes came out of holes cut in the 
cocoons, or through openings, hereafter to be described. But first 
it is important to state that from a single entire cocoon found at 
Ithaca, N. Y., the spiders escaped through a hole made by them- 
selves near the base of the pedicel, on the 14th of June, 1873 ; so 
perhaps, but for an accident which destroyed them, those at the 
south would soon have made their way out. 
The fact, however, remains that the young of Epeira riparia 
live together for many weeks in a confined space, and with no 
food excepting one another.* That they do eat each other is cer- 
tain ; first, because in cocoons opened later in the season, the 
spiders were found to be fewer in number, but larger in size ; and 
second, because they were seen to do it, even when out of the 
cocoon and supplied with other food (as blood) which they seemed 
to relish. There never was any fighting, however ; the smaller 
and weaker seemed to understand that for the good of the species 
(pro bono publico) they must be devoured by the larger and 
stronger, who performed their part “ doucement et sans cliolere.” 
It is evident that here is an opportunity for noting the working 
of “ natural selection,” upon a large scale ; for out of the five 
hundred young who are hatched, comparatively few can reach 
maturity, else the country would soon be overrun with them; the 
fact being that although the species is widely distributed, yet I 
B. NATURAL HISTORY. 
* Three cocoons of this species were brought to me Feb. 26,1874; and the young 
spiders are hatched; without speculating as to the time that may have already elapsed 
since the hatching, this gives us nearly four months during which the young remain 
confined; and it will appear that the cocoon itself must keep out the cold as efficiently 
as the egg shells, pupa cases and cocoons of insects which appear later in the season. B. NATURAL HISTORY. 
261 
never found them in such abundance in other parts of the south, 
and saw only eight cocoons between Charleston and Eutaw Springs, 
South Carolina, searching the woods bordering the road both going 
and returning. 
Of the four hundred and six cocoons obtained on James Island 
in the spring of 1865, only one hundred and thirty-four were en- 
tire, and presented no opening whatever. My notes state that 
one hundred and ninety of the others were pierced, but by what 
is not mentioned and I do not now venture to conjecture ; but no 
spiders came out of these before May 10, although the openings 
were certainly similar to those made by the spiders in the cocoon 
mentioned on page 260. 
Of the remaining eighty-two cocoons, fifty-nine were torn, in 
one or more places, and through the rents projected loose silk; 
having once “ seen a little bird about the size of a sparrow, fly at 
a cocoon hanging in a tree, make one or two quick pulls and then 
retreat,” I am inclined to think all these rents were so caused ; 
and as these attacks would usually open the cocoon without in- 
juring the inmates, I drew the inference that this might be a pro- 
vision of Nature, like the fertilization of flowers by insects, by 
which the invasion of the cocoon should really permit the contin- 
uance of the species; that this is not the only means of egress 
has been since shown in the case mentioned upon page 260. 
Parasites.—The remaining twenty-three cocoons presented 
openings of one, and usually of two sizes; the larger about -001, 
and the smaller ’000,3 in diameter. Some of these cocoons con- 
tained a few spiders, but usually only empty shells ; while the origi- 
nal contents were in all cases crowded to one side and upward by 
a mass of small oblong cocoons (14) of a whitish silk, and more or 
less firmly united by threads. In one spider’s cocoon, some of the 
smaller cocoons were empty with a hole in one end corresponding 
in size and location with the larger holes in the spider’s cocoon 
(13) ; three were entire and each contained fragments of a single 
insect, apparently an ichneumon, of which I have at present no 
fragments which can be specifically identified. The small cocoons 
in all the other twenty-two cocoons in this series presented no 
large holes but instead, many small holes like pin-pricks (15) 
corresponding to the smaller holes in the spider’s cocoons (16) ; 
and in all these pierced cocoons were fifteen to twenty little black 
insects, some motionless (pupae), others crawling actively about 262 
B. NATURAL HISTORY. 
(imagines), which are undoubtedly chalcidians, but as yet unde- 
termined ; all such cocoons contained also the empty pupa skins 
of the ichneumons, which, having destroyed the spiders before or 
after hatching, had been themselves devoured by the chalcidians. 
The chalcidians range from -001, to *002, in length. The ich- 
neumons range from *005, to *006, in length. Their pupa skins 
from *006, to *008, and their cocoons from *007, to *010, in length 
and -003, to *004, in diameter. 
In the article above quoted, are given figures and descriptions 
of these parasites and some suggestions as to the manner of their 
entrance to the cocoon ; but it is evident that a careful investi- 
gation will be needed in order to elucidate fully the history of 
this spider and its enemies. 
Note upon the Moulting of Nephila plumipes.—Mr. Black- 
wall* has clearly described the moulting of Epeira calophylla, and 
Tigs. 3, 4. Moulting of Nephila plumipes, 
called attention to the fact that the first separation of the integ- 
ument occurs along the border of the cephalo-tliorax and not upon 
the median line. Having witnessed this very often with Nepliila 
* Trans. Linn. Soc., vol. xvi, p. 473, and spiders of Gr. Br., p. 7. B. NATURAL HISTORY. 
plumipes, I am able to confirm his description ; and as no illus- 
trations of the process are known to me, I offer here two repre- 
sentations of Nephila drawn by me from the same individual, while 
partly extricated (fig. 3), and while hanging and drying prepara- 
tory to mounting to her net (fig. 4) ; the position must assist the 
flow of fluid from the abdomen into the limbs and cephalo-thorax. 
I have “biographies” of several individuals of this species which 
were isolated and watched for a greater or less length of time, in 
a few cases from soon after hatching to the adult condition; and I 
have observed remarkable differences of disposition and habit, 
quite comparable to those commonly ascribed only to human 
beings and the higher animals ; there seem to be truly psycholog- 
ical individualities even among spiders. 
Fig. 5. Nephila plumipes, a few days old; natural size and enlarged.* 
Fig. 6. Cocoon of Nephila plumipes, or loose silk attached to the lower surface 
of a leaf. 
*This, with figs. 3, 4 and 6, and fig. 1 of the following paper, are electrotypes of cuts 
in my article “ Memoirs of a Cripple,” in “Our Young Folks ” for Sept., 1806, furnished 
me at cost by Messrs. J. R. Osgood & Co. 264 
B. NATURAL HISTORY. 
The Nets of Epeira, Nephila and IIyptiotes (Mithras). By 
B. G. Wilder, of Ithaca, N. Y. 
Most Epeiridce (“garden” spiders or “geometrical” spiders) 
construct a net in the form of a nearly circular disk which is sus- 
pended at various angles, but probably never quite vertical or 
horizontal, although the former position is generally predicated 
of the ordinary species, and the latter of Tetragnatha and some 
species of Epeira. The net consists of a spiral viscid line laid 
upon a framework of dry radii which converge to a point which 
apparently coincides with the centre of the disk, but may vary a 
little therefrom, and, according to Emerton,* is usually nearer 
the top than the bottom. In some cases, and perhaps in all, the 
radii are first connected by a primary spiral dry line at greater 
intervals than the secondary viscid line ; this is begun at the 
centre and completed at the periphery, and according to Emerton 
(op. cit., 479) is removed as the viscid line is laid on (it is per- 
manent in Nepliila) ; the viscid line is begun at the periphery and 
completed near the centre ; the spider takes position at the centre 
upon the lower surface of the net, and always with its head down- 
ward. The net of E. vulgaris is figured by Emerton (Am. Nat., 
vol. ii, PI. 2), that of E. riparia by me (Harpers’ Magazine, 
March, 1867, p. 463), and those of several British species by 
Black wall, in his great work, “Spiders of Great Britain and 
Ireland.” The net of Nepliila plumipes f consists wholly and in- 
variably of a series of looped viscid lines, laid upon radii which 
gradually increase in length from the upper to the lower region 
of the net so that the “centre of radiation” is very much nearer 
the upper than the lower margin, and is, in fact, more nearly 
in the upper of the two foci of the elliptical net; the radii are 
very numerous and closely set; secondary radii are placed in the 
wider intervals commencing at various distances from the centre ; 
and the primary dry line is looped like the viscid line, and is re- 
tained; the necessity for this extra support being evident from 
the great size of the nets, which range from one to four feet in 
diameter, and are strong enough to hold a light straw hat. 
The free radii are in the same plane with the others, are always 
‘American Naturalist, 18G8, p. 478. 
f As described and figured by me in “ How our new Acquaintances Spin,” Atlantic 
Monthly, August, 18G6, from which fig. 1 is taken. B. NATURAL HISTORY. 
265 
in the upper region of the net, and occupy about of its area; 
they are more irregular than the others, and crossed by irregular 
lines so as to merge gradually into the outer scaffolding, and are 
crossed by neither the dry nor the viscid looped lines. 
Fig. 1. Net of Nephila plumipes, made in a wire frame, and photographed 
upon wood; reduced. 
In nature, the free radii, as above described, occupy about of 
the area; but the web of which a figure is given was made upon 
a wire frame ; the limits of which seem to have interfered with the 
extension of the loops above the level of the centre of radiation. 
Hyptiotes (of Ithaca, N, Y.).— The spider, whose web will 
now be described, no doubt belongs to the genus Hyptiotes 
Walck. (afterward and more generally called Mithras) ; of which 
there have been described at least two species, H. paradoxus 
and II. Jiavidus, from Europe, the former having been lately 
found in Ck-eat Britain.* 
I refrain from giving a specific name, because if there prove to 
be only one species in the limited states, we may have to retain 
the name cavata which Hentz applied to the species found by him 
in Alabama, and to which he gave a new generic name Cyllopodia ;f 
Hentz, however, states decidedly that it has but six eyes (whereas 
* It is my intention to publish shortly a full description of the spider, with refer- 
ences to the synonymy kindly furnished me by Messrs. Blackwall and Cambridge of 
England, and Wm. Holden of Marietta, Ohio, 
t Bost. Journ. of Nat. Ant. 1847, vol. v, p. 466. 266 
B. NATURAL HISTORY. 
my specimens have eight), and his descriptions, both generic and 
specific, are hardly full enough for identification : he knew nothing 
of the net. Mr. Emerton has a few specimens of both sexes, taken 
in Massachusetts, which I have not yet examined critically, but I 
have not heard of its discovery in other parts of the country. 
I have not been able to find specimens of Hyptiotes earlier than 
the middle of September, and they seem to disappear about the 
middle of November; I have never seen young specimens, but 
certain little cocoons are very numerous in the same localities, 
so I suspect them to be made by them. 
These cocoons sometimes contain about a dozen egg-shells ; 
in which case the spiders have evidently escaped by pushing up 
the base of one of the guy lines, which seems fitted like a trap 
door; sometimes the cocoon is empty, and then the outlet is a 
ragged hole at one side; and in one I found remains of some 
winged insect, dipterous or hymenopterous, evidently a parasite 
as with the Epeira riparia (see preceding paper), which may 
account for the ragged the other specimens. 
In some cocoons there are eggs as yet unhatched, and I may 
succeed in rearing the young. 
The cocoons are about *002, in diameter; and those which 
contain entire eggs include also some loose silk. 
It will be seen that the habits of Hyptiotes, and the form of its 
net, with its mode of construction, are sufficiently peculiar to ob- 
viate any danger of confounding it with other genera; I have not 
yet seen the work of Ausserer in which Mr. Holden thinks the 
net of the European species is referred to, and do not think any 
extract from it has appeared in this country, so that a full des- 
cription of the net may not be out of place. 
Specimens of Hyptiotes were first found by me in the woods 
bordering Cascadilla Creek in Ithaca, N. Y., in the latter part of 
September, 1870 ;* their dull color, their small size (about -003,5 
in length) and their habits of remaining fixed against the hemlock 
twig, to which the net is attached, may account for their having 
escaped observation during the two previous years when I col- 
lected in that locality. 
This species seems usually to construct its net just before day- 
break, and I have only twice observed the process ; on the 4th of 
* Of about fifty specimens then taken, all proved to be females, nor did I find any 
males until the 28th of Sept. 1873; these are smaller and fewer in number and make no 
net, being generally found near that of some female. In this as in previous papers I 
have added notes since the time of presentation. B. NATURAL HISTORY. 
267 
October, 1870, I saw the last cross4ine (that nearest the apex) 
finished, and four years later, Sept. 28, 1873, I witnessed the 
formations of the fine lesser lines: as the process was identical 
in the two cases, there seems good reason to regard it as normal. 
Some account of this and of the habits of the spider was given at 
a meeting of the Cornell Univ. Nat. Hist. Soc., for Oct. 10, 1870, 
when also specimens of the female were shown. The male was 
exhibited on the 10th of Oct., 1873, at a meeting of the same 
society. 
, Fig. 2. Net of Hyptiotes “ upon the stretch.” 
BB, hase line. A, apex. 
O, origin of apex line. B,' the four radii. 
A. L., apex line. V’ " etc., vi’scid lines. 
S' " "" Points of attachment of the viscid lines upon the 
radii; forming little steps upon the latter. 
SI. Slack-line between the first and fourth legs. 
This is better shown in the enlarged lower figure, where only the legs of the right 
side are represented. In the upper figure the spider is shown rather large and the net 
rather small; the base-line should also be more extended before attaching to the branch 
at either end. 
The net is triangular in form, and consists of four radii, never 
more or fewer, crossed by several (6 to 10) independent viscid 
lines ; the centre of radiation is prolonged into a single nearly 268 
horizontal strong and short line which is attached to a branch or 
twig ; the outer ends of the radii are attached to a second strong 
line more or less nearly vertical and nearly at right angles with 
the first. 
The radii and base line probably involve no unusual process ; 
but the entire independence of the viscid lines contrasts strongly 
with the spiral or looped lines of Epeira and Nepliila. 
At the time of the second observation above mentioned, the 
spider had completed the base line, B.B., the four radii (B/ " 111 
"*), and the four viscid lines nearest the base V' " 111 iv), she was 
just then passing along the upper radius (R/) from the direction 
of the apex (A) ; having reached the viscid line (iv) last com- 
pleted it turned about, seemed to make some rough measure- 
ments of distance with its body, and then, by drawing its spin- 
ners along the radius for a short distance (about .002,) formed 
thereon the same kind of 'attachment of a new line which I 
have described and figured in the net of Nephila, and which, 
though not alluded to by authors, is perhaps generally adopted 
as much more secure than contact at a single point. The spider 
then allowed her abdomen to fall away from the radius, hang- 
ing therefrom by the first and second pair of legs, and braced 
away from it by the third pair, she began to move the fourth 
pair simultaneously to and from the mammulae, so as to ex- 
tract therefrom a very viscid and elastic line which had a faint 
yellowish tinge; doing this, she at the same time moved slowly 
toward the apex, to a point where the interradial spaces were 
narrow enough to permit her to cross to the second; this she did, 
ceasing at the same time to draw out the line, which, as she now 
returned toward the fourth viscid line, contracted considerably, 
so that it was nearly of the proper length when she attached it 
to the second radius at a point about as far from the fourth vis- 
cid line, as it had been begun upon the first radius ; again turning 
and making the extended attachment as before she repeated the 
drawing process so as to carry the viscid line to the third radius, 
and from this to the fourth. 
She then ceased drawing the line, and returned to the first 
radius by way of the crossing (C), began a sixth viscid line, and 
afterward a seventh, eighth and ninth, all in the same way and at 
about the same distances apart. 
The rapidity of movement of the fourth pair of feet is very 
B. NATURAL HISTORY. B. NATURAL HISTORY. 
269 
great; by considerable effort I could move one hand at about the 
same rate, and found it to average, at least, five times in a second, 
or three hundred in a minute ; about ten minutes were required to 
complete these five viscid lines, the time spent in returning being 
very short; and as the other four and longer lines must have 
taken at least fifteen minutes, our spider may be estimated to 
move her hind legs definitely and nearly without cessation about 
7500 times in less than half an hour; an estimate which is cer- 
tainly far within the facts. 
I have not yet satisfied myself respecting the exact nature of 
this viscid line,* beyond the exceeding viscidity and elasticity al- 
ready alluded to ; but I do not think that it is “curled” like that 
of the CinifloniclcB, as described by Blackwall (op. cit., p. 139), 
and figured by Miss Stavely (op. cit., p. 114). 
[For the rest of the description the present tense is applicable, 
since it applies to the often witnessed proceedings of many differ- 
ent individuals.] 
As soon as the net is completed, the spider takes her position 
on the apex line (AL) at about an inch from the point of attach- 
ment (O) with her head toward the net; seizing the line between 
the first and second pair of feet, she walks slowly backward, “foot 
over foot” with the fourth pair, until she reaches the point of at- 
tachment (O) ; into which, or into the line near it, she fixes the 
fourth pair of feet; this proceeding puts the whole net upon the 
stretch, draws the second and third radii toward the apex, and thus 
alters the direction of the base line ; the slack line (SI.), which has 
now accumulated between the points upon the line grasped by the 
first and second, and the fourth pair of feet, is held away from the 
body by the third pair, as seen in the lower figure (only the legs 
of the right side are shown). 
I have not yet measured the strain put upon the net, but it 
is evidently considerable, yet these spiders remain immovable 
for hours, like a set spring; so motionless are they, and so com- 
pactly placed are the legs, that they look more like projections 
of the wood than living creatures, and no insect would ever mis- 
trust danger from them. But when the web is struck by an 
insect, the spider shows that though quiet she is watchful; loosing 
her fourth feet, the strain is relaxed and the whole net regains its 
original condition with a sharp snap, which causes the elastic 
*An account of this and of the parts concerned in its production will be given 
hereafter. 270 
B. NATURAL HISTORY. 
lines to vibrate in all directions and generally entangles two or 
more of them upon the insect; should this first attempt fail, the 
spider, which has been carried sharply forward with the line, but 
which has retained her equilibrium by means of the third pair, 
again walks backward and again lets go; this is sometimes 
repeated six times in quick succession; when satisfied that her 
prey is entangled, she advances a few steps at a time, apparently 
feeling her way (as do the Epeiridse generally), and approaches 
the quarry by the nearest radius; the subsequent operations are 
essentially those of the Epeiridae, and need not be here described ; 
but in some cases, while advancing toward the prey, she cuts the 
line with her jaws between her front and hind legs, which allows 
the net to collapse somewhat; the spider, however, has attached 
a new line in her rear, so that the continuity is not wholly broken ; 
by repeating this, and cutting all the radii, she is enabled at last 
to gather the entire net within her front legs and to throw it, like 
a blanket, upon the struggling prey, which is thereby hopelessly 
entangled ; in such cases, therefore, and, in fact, generally, an 
entire net is destroyed in making a single capture. 
Farther account of its habits would be here out of place, but 
there are some points to be noted in respect to the plan of the net 
and the mode of its formation. 
1. Unlike both Epeira and Nephila the number of radii is con- 
stant; in the hundred or more nets which I have examined, there 
have been always four radii. 
2. But the distances between them, the number of viscid lines 
and their intervals, like the several dimensions of the net, vary 
considerably, as shown by the following table. 
TABLE OF DIMENSIONS OF THE NET OF HYPTIOTES IN MILLIMETERS; 
TAKEN FROM TEN NETS. 
Maximum 
Mean 
Minimum 
.150, 
.035, 
.010, 
Length of 
apex line 
(excluding slack). 
.210, 
.150, 
.100, 
Length of 
net from 
apex to 
base line. 
.180, 
.110, 
.140, 
Width of net 
at longest 
viscid line. 
.150, 
.110, 
.075, 
Length of space 
included by 
viscid line. 
12 
10 
7 
Number of 
viscid lines. In fact, the net of the spider, like the cell of the bee, as demon- 
strated by Wyman, is never the model of geometrical precision 
which we have been led to believe by superficial examination. I 
have never yet seen the net of any spider in which the eye alone, 
unaided by instruments, could not discover irregularities, which, 
if they existed upon a like scale in human workmanship, would 
be regarded as serious imperfections. But when it is remembered 
that insects measure spaces in much the same wTay that we do, by 
the eye or the limbs, the only wonder is that metaphysicians and 
theologians ever ascribed to their work an exactness which men 
attain only through exceeding care and delicate mensuration. 
3. Like the nets of Epeira and Nephila, and probably all others, 
the net of Hyptiotes is not vertical but inclined at an angle which 
varies greatly but is generally more than 45°. 
4. So too, the inclination of the longitudinal axis of the net 
varies greatly. I have never seen the apex-line inclined upward 
from its origin, but have occasionally seen it slope downward at 
about 45°; usually the angle is between this and the horizontal. 
5. The independence of the viscid lines is very striking, but it 
is evident that the “drawing out” method of this spider would 
not permit the formation of viscid lines from below upward, with- 
out risk of entanglement. 
° » 
6. The “ drawing-out” may impart to the viscid line an elas- 
ticity which enables it to shrink to the proper length, after having 
been long enough to enable the spider to pass from one radius to 
the next near the apex; it being forced to do this on account of 
its small size as compared with the interradial spaces ; the alter- 
natives would be either—1. To make a larger number of radii, 
which, however, would increase the resistance to the strain, and 
lessen the vibrations of the viscid lines: 2. To spin a series of 
primary cross-lines, not viscid, equal in number to the secondary 
viscid lines, and to use the former as means of crossing while 
spinning the latter in the ordinary way, then cutting them away 
as described by some Epeiridce; at present we may hardly conjec- 
ture the causes which led to the exclusion of these hypothetical 
methods, but meanwhile it is to be noted : — 
7. That the series of viscid lines must be commenced at the 
larger and concluded at the smaller extreme, because otherwise 
either—1. Each succeeding line would have to be engineered by 
its predecessor which would be between it and the crossing: or, 
B. NATURAL HISTORY. 
271 272 
B. NATURAL HISTORY. 
2. If the spider chose to effect her crossing at the base line, then 
the shorter lines would' have to be carried and stretched the 
greater distance, and vice versa; whereas now, that distance de- 
creases with the length of the viscid lines themselves. 
8. The net is triangular, the section of a circle, unlike that of 
any other genus ; and, in idea at least, may be regarded as filling 
the vacant space in the net of Nephila as compared to that of 
Epeira; so that we may say in mathematical language, Nephila-\- 
Hyptiotes — Epeira; in more homely phrase the net Epeira is a 
whole pie, that of Nephila is a pie lacking one-sixth, while that 
of Hyptiotes supplies the missing piece. 
Fig. 2. Diagram representing the forms of nets of Nephila Ar., Ilyptiotes 
II., and Epeira E. 
Zoological relations.—The above comparison of the. net- 
patterns of Epeira, Nephila and Hyptiotes is suggestive, but by no 
means conclusive ; and we need to know much more concerning 
all of them, especially their embryology, before venturing an opin- 
ion respecting their zoological relations: particularly since*our 
highest authority is now inclined to place Ilyptiotes among the 
Cinflionidce (Blackwall Ann. and Mag. of Nat. Hist. 1864, p. 436). 
It is worth noting, however, that the gap between the continuous 
spiral net of Epeira and the returning loops of Nephila may be 
regarded as lessened by the following considerations. 
1. Mr. Blackwall states that E. calophylla “usually employs a 
radius as a means of communication between its net and a small 
tubular cell of white silk which constitutes its retreat. and 
on reaching this radius it retraces its steps until it reaches a point 
on the opposite side of the radius, and by repetition of this the 
net is made to consist of a series of looped-lines, “ arcs of circles 
it does not appear that this “free radius” is always in the same 
region of the net, although it is probably one of the upper series, 
as seen in the figure by Miss Stavely (British spiders, p. 246). 
2. In several nets of a small species which is common in Ithaca, 
N. Y., I have (Sept. 28, 1873) seen the addition of four looped 
lines (like those of Nephila) to the lower border of the net; and 
in May, 1871, I found a deserted net built in an angle which 273 
B. NATURAL HISTORY. 
consisted of fourteen turns of the spiral line which formed the limit 
of the net upon the side toward a fence post, but on the other 
three sides (the top, the bottom, and the right side), the was 
extended by ten looped lines : this augmentation of the lower 
region of the net would leave the centre of radiation above the 
geometrical centre, as Emerton states to be the case (Am. Nat., 
II, 478) with E. vulgaris, but without explaining whether it is due 
to the addition of independent lines or of loops or the increase of 
the spaces between the spiral lines. 
Now since all these spiders hang from the lower surface of the 
inclined net, and always head downward, it is evident that, for 
the larger ones especially, it must be very much easier to reach 
even a distant point below their level, or even at one side, than to 
turn and ascend ; and if it shall prove, upon closer scrutiny than 
has been given, that the true Epeiridce may, upon occasion, 
and under any circumstances, construct a part of their nets of 
looped lines, it might be conjectured that a habit thus formed would 
become confirmed, intensified and transmissible ; Nepliila might in 
this way b| regarded as a derivative from Epeira.* 
The simple triangular net of Ilyptiotes, with its uniform number 
of radii and small number of cross lines, might be regarded per- 
haps as a further specialization from that of Nephila, the circle of 
the Epeira being now reduced from five-sixths to one-sixth of its 
area, and the dry space above the centre in the net of Nephila, 
represented by a single radius, the apex line ; but in some respects 
it is easier to compare the net of Ilyptiotes with that of Epeira 
calophylla; the apex line would then represent the single free 
radius. The ordinary Epeiridce, as well as Nephila, are accustomed 
to vibrate their nets, when touched by insects, and this habit may 
be the basis of the remarkable method by which Ilyptiotes en- 
tangles its prey. 
Repair of nets. — It is known that the Epeiridce renew the entire 
net occasionally, and they have been seen to chew it, for the pur- 
pose, apparently, of extracting the gum. In most cases, the 
Nephila renews only one-half of its net, which varies from one to 
* A comparison of their forms looks the. same way; for the young Nephila is round 
bodied like the Theridion, and makes at first a similarly irregular net of lines crossing 
in all directions; later it passes through the more elongated form of the ordinary Epeira 
and finally attains the almost cylindrical outline proper to its genus. See previous 
paper. 
A. A. A. 8. VOL. XXII. B. (18) 274 
B. NATURAL HISTORY. 
three feet in diameter ; it cuts the net in two vertically, and stuffs 
the mingled silk, gum and dust between its jaws, chewing it for sev- 
eral flours, and finally rejecting a black and very hard pellet which 
seems to consist almost entirely of dust; the half of the net thus 
destroyed is then renewed by looped lines necessarily; the next 
day, the other half may be renewed in like manner. 
It would appear that most Epeiridce renew the entire net at once ; 
but it will be worth while to notice whether the larger species do 
not, like Nephila, renew only one-half at a time, for if so, they 
must employ looped lines instead of a continuous spiral. 
As stated above, the entire net of Hyptiotes is usually destroyed 
in the capture of a single insect; and as the rejected pellet is 
quite dry, we may infer that the spider appropriates the viscid 
portion of the net enveloping the prey. 
I shall probably propose the name Americanus for this spicies 
of Hyptiotes; for although this may be the species referred to by 
Ilents as Cyllopodia cavata, yet his description and figure are in- 
sufficient for identification. 
The Need of a Uniform Position for Anatomical Figures. 
By Burt Gr. Wilder, of Ithaca, N. Y. 
The convenience of a uniform position for anatomical figures is 
sufficiently evident to all; and the neglect of such uniformity is a 
source of delay and even misinformation to beginners. The posi- 
tion with head to the left is advocated partly because it is more 
natural, in dissection and drawing ; partly because the only author, 
Professor Agassiz, whose figures are uniformly placed, many years 
ago chose that position, as may be seen in the “Poissons fossiles.” 
The figures in Huxley’s and in Owen’s Comparative Anatomy of 
Vertebrates are often scarcely intelligible, on account of reversed 
positions, and the larger number of authors seem to regard the 
matter as of no importance whatever. B. NATURAL HISTORY. 
275 
Lateral Position of the Vent in Amphioxus and in the Larva; 
of Rana Pipiens. By Burt G. Wilder, of Ithaca, N. Y. 
The posterior opening of the alimentary canal in Amphioxus 
lanceolatus has been so variously described and figured that a brief 
historical sketch is here given.* 
Historical sketch.—It does not appear that Pallas or Costa or 
Yarrell remarked any peculiarity in the cloacal region, and I have 
not seen the earlier papers by Retzius and Muller. Couch (4 
(1838) 382) merely states that “the vent is at the length of one- 
third of the body from the tail,” but as in all my specimens the 
* The following list probably includes all the important original papers upon this 
genus; in the text they will be referred to by their numbers as here arranged; the last 
number will indicate the page and the middle one, when it occurs, the volume; the list 
of general works in which Amphioxus is mentioned occurs upon page 278. 
Bibliography (special papers). 
1. Pallas, Spicilegia zoologica, fasc., xt, p. 19, fig. 11., t. 
2. Costa, Annuario zoologico, 1834. 
3. Yarrell, History of British Fishes, 1836, p. 468 (2nd ed. ii, p. 618, 3rd ed. i, p. 1.) 
4. Couch, Mag. of Nat. Hist. 1838, p. 381. 
5. Couch, Fishes of Brit. Islands, p. 415, pi. 248. (date ?). 
6. Costa, Fauna del regno di Napoli, 1839. 
7. Retzius, Monatsbericht der Academie der Wissenchaften, 1839, p. 197. 
8. Rathke, Bemerkungen fiber den Ban des a. L, 1841. 
9. Sundevall and Loven, Forhandl. Skand. Naturf. 2nd mode, Kjobenh. 1841, p. 280. 
10. Goodsir, Trans. Roy. Soc. Edinburg, xv, p. 1 and Ann. of Nat. Hist, vii, 346,1841: 
also Anatomical Memoirs, vol. 1. 
11. Mfiller, Ueber den Bau und die Lebenserscheinungen des a. 1. Abhandl. Ak. Wiss. 
Berlin, 1842, pp. 79-116, Taf. 1-5. 
12. Kolliker, Ueber das Geruchsorgan von A. Archiv ffir Anat. 1843, pp. 32-35, Taf. 
11, Fig. 5. 
13. Quatrefages, Comptes rendus xxi, p. 519,1845. 
14. Quatrefages, Sur 1’ Amphioxus, Ann. des Sciences Nat. 1845, pp. 197-248, PI. x-xiii. 
15. Gray, A. belcheri, Proc. Zool. Soc. 1847, p. 35. 
16. Mfiller, Monats. Akad. Wissen. Berlin 1851, p. 474. 
17. Sundevall (Branchiostoma elongatum) Oefuers, Vet. Ak. Forhandl. 1852, p. 147. 
18. Sundevall (B.caribeeum) Op. cit., 1853, p. 11. 
19. Max Schultze, Verhandl. Naturhist. Vereins preuss. Rheinl., xix. Sitzungsber. 
p. 197. Also in Siebold’s andKolliker’s Zeitschrift iv, 1852, p. 416, taf. 13, figs. 5 and 6. 
20. Kroyer, Danm. Fisk, iii, p. 1,087 (date ?}. 
21. Steenstrup, Oefuers. Dansk. vid. Selsk. Forhandl. (1863) 1864, p. 238. 
22. J., Comptes rendus, 1864, pp. 479-483. Also in Ann. and Mag. of N. H., 
1864, xiv, pp. 151 and 319. Also in Rev. et Mag. Zool. 1864, xvi, p. 79. 
23. Kowalewsky, Mem. Ac. Sc. St. Petersb., 1867, xi, No. iv, pp. 16, 3 pi. abstract of 
same in Bibl. Univ. Art. 25, 1866, Bull. Sci. pp. 193-195, transl. in Ann. and Mag. of Nat. 
Hist. 1867, p. 69. 
24. Bert, Comptes Rendu 1867, p. 364 or Ann. and Mag. of N. H., xx, p. 302. 
25. Owsjannikow, Bull, de la Ac. Impe. des Sci. de St. Petersb., tome xiii, No. 4. pp. 
287-302, 1868. 
26. Moreau, Obs. sur la struct, de lacorde dors. Comptes rendus, May, 1870, p. 1006. 
27. Moreau, Note sur la region cranienne, Comptes rendus, May, 1870, p. 1189. 276 
B. NATURAL HISTORY. 
post ventic region forms only f or | of the whole length, Couch 
probably referred to the “abdominal pore.” It is worthy of note, 
however, that Couch’s figure, though rude and in some respects 
inaccurate, rightly indicates the fact, apparently overlooked by all 
other observers before and since, that the ventral border of the 
left muscular mass retreats a little at the cloacal region (as shown 
in my figures) so as to expose the mesial surface of the right 
muscular mass or the cloaca itself when distended. 
Goodsir (10 (1841) 382) says “The anus is in the form of a 
longitudinal slit,” as appears also in all his figures, one of which 
is reproduced herewith (Fig. 1. G). These figures have the loca- 
tion of the vent nearly correct in proportion to the length of the 
body, but the author states that the “ anal fin is interrupted at the 
anus,” 375, whereas it is usually, if not always, widest at that 
point. It must be remembered, however, that Goodsir’s observa- 
tions were confined to two individuals, and his dissections to but 
one of these, and while correcting his errors, we are more inclined 
to wonder at the amount of new information which he obtained 
from so scanty material. 
Fig. 1. G. Hinderpart of Amphioxus, from below; copied from Goodsir, PI. 1. Fig. 4. 
M. The same, from the left side; copied from MUller, 11. Taf. 1. Fig. 1. 
Q. The same, from the left side; copied from Quatrefages, PI. xiii, Fig. 1. 
From his second paper (11, 1842) it appears that Muller had 
plenty of material; he rightly locates the vent opposite the broad 
part of the caudal fin (as seen in Fig. 1, M) making the intestine 
project slightly as a narrow tube with oval orifice ; his description 
is as follows (translated): “The vent lies on the left side of 
the abdominal fin ; this anomalous position of the vent upon one 
side of the anal fin recalls a similar peculiarity with Lepidosiren 
both figure and description show therefore that Muller supposed 
the vent of Amphioxus to differ from that of most vertebrates, 
merely in its lateral position, and no allusion is made to the pecul- 
iarity in the concluding general remarks. 
* It will be seen hereafter that in this genus the condition of things is quite unlike 
that in Amphioxus. B. NATURAL HISTORY. 
277 
In the somewhat extended paper of Quatrefages (14) it is not 
easy to separate his own observations from his summary of pre- 
ceding ones; as seen in Fig. 1, Q, the vent is the oval orifice of a 
simple tube which opens far in advance of the expanded caudal fin, 
which also is shown rather shorter than is natural; as in Muller’s 
figure, however, the vent is correctly shown to -the left of the 
“abdominal segmented canal.” 
Quatrefages’description (translated) is as follows : “The anus 
lies at a point where the membranous border enlarges into a lancet 
form, it opens upon the left side of the abdominal surface of the 
body, close to (tout aupres) a membrane which occupies the 
median line.” p. 201. 
Later observers seem to have overlooked the “ anomalous loca- 
tion of the vent,” referred to by Muller and Quatrefages. 
The formation of the anus, by a gradual constriction of the 
borders of the “secondary cavity” is described b}r Kowalewsky 
(23, pages 3, 4, 5, 7) ; the figures of the earlier stages indicate that 
the anus is median; some of the later ones show it as if on the 
left and others as if on the right side ; but the text nowhere refers 
to any unsymmetrical position, which is the more noteworthy be- 
cause attention is called (10) to the unsymmetrical character of 
the oral aperture. 
We may conclude that our author, while no doubt well aware of 
the general opinion respecting the vent of the adult, did not under- 
Fig. 2. (copied from Kowalewsky. Entwick. des Amphioxus; the caudal region of 
the embi-yos shown in Fig. 22, 23 and 28, corresponding to A, B and C, i-espectively. 
A. An embryo of sixteen hours, seen from above, showing the outline of the intes- 
tine which narrows and opens at the anus a apparently upon the dorsal region of the 
body, with a single series of ciliated epithelial cells behind it. 
The letters R and L are added better to designate the relative position of parts. 
B. An embryo of twenty-four hours, seen from the right; a, the anus which appears 
to open on the right side of the body. 
C. An older embryo seen from the left, on which side the anus appears to open; and 
this is the more confusing from the considerable backward extension of the caudal 
region. 
No reference is made in the text to the exact position of the orifice. 278 
B. NATURAL HISTORY. 
take to elucidate the manner in which this condition was reached ; 
although, had he so chosen, his opportunities and the skill else- 
where displayed, would have enabled him to clear up the obscurity 
which now rests upon it. 
Most systematic works and zoological text-books* published 
since the discovery of Amphioxus include more or less complete 
accounts of its structure ; but as their authors have not published 
separate papers upon the subject, one can only conjecture the 
extent of originality in their descriptions. 
The recent and very complete work of Claus (51) states that 
the “vent is somewhat laterally placed;” and further (p. 830) 
that the development (according to Kowalewsky) involves “strik- 
ing asymmetry with respect to the mouth, vent,” etc. 
Schmarda (52, 302, fig. 501) gives a somewhat altered copy of 
the figure from Quatrefages, but no reference to the vent. 
Huxley (55, p. 117) says that the “anal aperture is a little to 
the left of the median line,” yet his figure, apparently copied from 
Muller, is reversed so as to bring the vent upon the right of the 
anal fin. 
Troschel (59, 284) says that “the fin passes to the right of the 
vent.” 
Owen (56, 1, 31, fig. 23) gives a purely diagrammatic figure of 
the organs of Amphioxus, in which the intestine opens on the 
median line, and the text contains no allusion to a peculiarity in 
that region. 
Clark (60, fig. 226) copies Owen’s diagram without comment; 
and Gegenbauer (53, 788), in like manner, copies Quatrefages, 
merely saying (p. 799), “Die Cloaken bildung fehlt bei Am- 
phioxus.” 
Ilieckel offers a figure (61, Taf. xiii), which mainly resembles 
* systematic WORKS (arranged in no special order). 
51. Claus, Grundzuge der Zoologie, 1872, 828. 
52. Schmarda, Zoologie, 302, fig. 501. 
53. Gegenbauer, Yergl. Anat., 1870, 778, fig. 256. 
54. Rolleston, Forms of Animal Life, 1870, lxxxiv. 
55. Huxley, Anat. of vert, animals, 1871,116, figs. 28 and 29. 
56. Owen, Comp. Anat. and Phys. of Vert. 1, 31, fig. 23. 
57. Agassiz and Gould, Principles of Zoology, 1848,181, fig. 153. (Shows correctly 
the position of vent.) 
58. Vander IToeven, Hand book of Zoology, 56,185S. 
59. Troschel, Handbuch der Zoologie, 1871. 
60. Clark, II. J., Mind in Nature, 1865. 
61. Haeckel, Natiirliche Schopfungsgeschite, 1872. 
62. Gunther, Catalogue of Fishes in the British Museum, vol. viii. B. NATURAL HISTORY. 
279 
that of Quatrefages ; and Gunther (62, 513) enumerates, among 
the generic characters, “ a low rajdess fin runs past the vent 
so far as I know the point is not alluded to by other S3'stematic 
writers. 
9 It appears therefore that to many the lateral position of a nor- 
mally median primary opening seems to require no mention, and 
that when the asymmetry is alluded to, it is not certain whether 
the vent is lateral and the fin median, or the reverse. 
The reception of a large number (about one hundred and fifty) 
of specimens, well preserved in spirit,* and the subsequent oppor- 
tunity of examining sixty specimens from the coast of Florida, 
belonging to the Museum of Comparative Zoology,f have enabled 
me to investigate this point quite fully. 
Nothing of the exact structure of the ventj can be made out 
with the naked eye ; in addition to the dissection of many indi- 
viduals under the lens, I have made about two hundred micro- 
scopic sections of the cloacal region ; and the following account 
is based upon their careful and prolonged comparison. 
It would be more amusing than instructive to enumerate the 
many and different opinions successively formed in the course of 
this investigation before the present conclusion was reached, and 
while admitting the possibility that the true condition of things is 
not yet known, I shall ask of the critic to state the amount of 
material upon which his contrary opinion is based. I am well 
aware of the insufficiency of both figures and description, espec- 
ially in respect to the minute anatomy of the tissues ; upon some of 
these points I have nearly made up my mind; but as all of them 
are more or less involved in the general structure, and some of 
them are quite differently represented by different authors, it seems 
♦Collected at Naples and sent by mail by my friend and former student, W. S. Bar- 
nard, S. B., Ph. D. 
f Just as this paper is going to press, Prof. Putnam has kindly loaned me two speci- 
mens from the Florida coast which agree so entirely with the specimens belonging to 
the Mns. of Comp. Zoology, and are so immediately distinguishable from the Naples 
specimens, in form and in the proportions of the regions, that I feel almost assured of 
the specific distinctness of the Amphioxus from the two localities; but, as will be ex- 
plained farther on, no conclusion upon this point can be regarded as reliable unless 
based upon the accurate measurement of many specimens, and the enumeration of 
the segments composing their different regions: this will take time, but will be done 
as soon as possible. 
JThe terms cloaca and vent are here used provisionally; at present, notwithstanding 
all that is known of the different morphological and physiological relations of the ali- 
mentary, urinary and generative outlets in vertebrates, as briefly stated by Huxley, 
109, 131,138, the above terms are not clearly discriminated from rectum and anus. 280 
B. NATURAL HISTORY. 
better to defer a discussion of them until the completion of the 
study which I am now making of the entire organization of this 
lowest, and in most respects, anomalous vertebrate. This paper 
may be regarded as a preliminary notice of a single part of the 
subject. 
Fig. 3. A. Amphioxus; seen from the left, natural size; V, the vent; 
A P. The abdominal pore. 
B, C, D. Transverse sections at middle of body to show different condi- 
tions of ventral wall in different individuals. 
B. A cross-section of the body at the middle of its length, showing the 
“abdominal groove.” 
C. The same of a Florida specimen, in which the abdomen is flat, or but 
slightly convex. 
D. The same of a Naples specimen, full of eggs, in which the abdominal 
groove is obliterated. 
The simplest presentation of the subject will be an explanation 
of the figures. 
Fig. 3 shows an Amphioxus (from Naples) of the natural size, 
head to the left; no details of structure are given, but there is no 
question respecting the existence of an expanded vertical fin around 
both ends of the body; the notch V indicates the location of the 
vent, and the notch AP the location of the abdominal pore. 
Most of the Naples’ specimens present the abdominal groove 
described and figured by Muller as formed by two lateral folds of 
the integument extending from the mouth to the abdominal pore 
(Fig. 3, B) ;* a specimen sent from Naples by Prof. Panciri to the 
Museum of Comparative Zoology is distended by the enlarged re- 
productive organs, and these folds are wholly obliterated, together 
with of course, the groove (Fig. 3, D) ; and most of the Florida 
specimens (taken in May), in which the reproductive organs are 
less bulk}7, have loose ventral parietes, as if regaining the grooved 
condition during the gradual discharge of the reproductive pro- 
ducts (Fig. 3, C) ; so it is quite possible that the folds and grooves 
are periodical appearances for the accommodation of the repro- 
ductive development. 
Position of the Vent.—The position of the vent with respect 
to the fin and length of entire body is very differently represented 
*A similar groove exists in the male pipe-fish (Syngnathus) but is located behind, 
the vent. B. NATURAL HISTORY. 
281 
by Muller and Quatrefages ; in all my Naples specimens the vent 
is as in Muller’s figure opposite that part of the fin which first 
gains its greatest depth, passing from before backward or just 
before it begins to decrease in depth, passing from behind for- 
ward.* 
In one of the larger specimens from Naples .045, in length 
(about two inches) the vent is .005, from the tip of the tail, and 
the abdominal pore .009, in front of it, or .014, from the tip ; the 
latter opening is therefore about one-third of the length from 
the tip and the former one-ninth. Or, assuming the length of 
the body to be 100, the post poral region is .31 and the post 
cloacal region .11. 
Muller’s figure yields the following ratio, post poral region .13, 
post cloacal region 4, while according to Quatrefages’ figure the 
post poral region is .41 and the post cloacal .23. But as one of 
the Florida specimens, .043 in length, gives the same regions as 
.25 and .9 respectively, we may infer the existence of considerable 
variation. It is my intention to present a large series of accurate 
measurements of specimens from various localities as one element 
in the determination of specific or variety differences. 
TABLE OF PROPORTIONS OF AMPHIOXUS, AS DERIVED FROM SPECIMENS 
FROM NAPLES AND FLORIDAND FROM THE FIGURES OF 
MOLLER AND QUATREFAGES (IN MILLIMETERS). 
Naples 
Florida 
Miiller 
Quatrefages 
.045, 
.043, 
Total length. 
o 
o 
From vent to 
tip of tail. 
.11 
.09 
.04 
.23 
Ratio to 
whole length. 
8 
O 
From abdom. 
pore to tip 
of tail. 
» 
V H lo « 
M CO t-* 
Ratio to 
whole length. 
The vent and the fin.—Leaving out of view for the present 
the absolute position of the vent with respect to the median line, 
*In many alcoholic specimens, especially those from Naples, the fin is carried to the 
left and as it were wrapped over the entire cloacal region (as indicated in the Fig. 6 C) 
and this in connection with the peculiarly protected orifice of the vent, the sharpness 
of the tail, and the suspected existence of a caudal sense organ suggests the possibil. 
ity of occasional retrograde locomotion. 282 
B. NATURAL HISTORY. 
it is desirable to confirm the general opinion that it lies to the left 
of the abdominal (caudal or anal) fin. 
I first selected, at random, fifty specimens from the Naples lot, 
and carefully introduced a black bristle into the vent. The naked 
eye can hardly detect a difference between the two sides of the 
cloacal region, but the bristle would never enter the right side, 
while, by a little preliminary movement to the right (the necessity 
for which will appear farther on), it readily entered upon the left 
side of the fin.* 
Forty more of the same lot were examined in other ways either 
by section or dissection, with the same result. All of the sixty 
Florida specimens were afterwards examined, and the vent found 
to open always upon the left of the fin.j 
Fig. 4. Hinder extremity of Amphioxus, magnified about ten diameters. (For fuller 
explanation, see the text and the explanation of the lettering upon the next page ) 
I' We may fairly conclude from these one hundred and fifty speci- 
mens, that in the Amphioxus of the Mediterranean and of the 
Florida coast, the vent opens to the left of the abdominal fin ; 
and that exceptions will probably be as few as are the cases 
of transposition of viscera with men, and not to be compared 
with the exceptions to the rules as to “blind sides” among 
Pleuronectidoe. 
*In order to avoid some errors into which I was led, I would add that specimens so 
treated, however carefully, are not fitted for sections or for minute examination of the 
cloacal region; the cloacal valve is apt to he ruptured or distorted, and the pressure of 
the bristle unnaturally prolongs the cloacal notch. 
f These specimens are less well preserved than the others, and either from this cause, 
or from a difference in the natural width of the body (into which I shall inquire with a 
view to possible specific difference), it is easier to see the parts with the naked eye or 
a feeble lens. B. NATURAL HISTORY, 
283 
The following explanation of the lettering applies to all the 
figures of Amphioxus. 
Ao — Aorta. 
AC — Abdominal cavity. 
AF — Abd. fin (anterior to caudal expan- 
sion). 
AFo — Abd. folds. 
AG — Abd. groove. 
AL — Abd. lamina (lateral). 
AMS—Abd. median septum. 
AR—Abd. ridge. 
AS— Abd. segmented canal. 
AP — Abd. pore. 
B —Basement membrane. 
Cl — Cloaca. 
C1R—Cloacal ridge. 
C1N — Cloacal notch. 
CIS — Cloacal sinus. 
CIV — Cloacal valve. 
CIA — Cloacal aperture or vent. 
CF— Caudal fin. 
CR —Caudal fin rays (only three shown 
above and below). 
CNe — Caudal nerves. 
CC — Central canal of spinal cord. 
Ci — Cilia. 
DF — Dorsal fin (anterior to caudal expan- 
sion). 
DR — Dorsal ridge. 
DFi—Dorsal (posterior) fissure of spinal 
cord. 
DS —Dorsal segmented canal. 
F— Faeces. 
HNA—Hyperneural arch. 
HNC — Hyperneural canal. 
I — Intestine. 
IC — Inner (mucous ?) coat of intestine. 
IS — Intermuscular septum. 
ICC —Inner (mucous ?) coat cells. 
M — Mesentery. 
MC — Middle (muscular ?) coat of intestine. 
My— Muscular mass. 
N —Notochord (the thick wall of the tube). 
NS — Notochordal sheath (of connective 
tissue). 
NL — Notochordal laminae (contents). 
N A — Neural arch. 
NC — Neural canal. 
Nu —Nucleus. 
P — Peritoneum, lining abd. cavity*and 
covering intestine. 
PG— Pigment granules of cord. 
PC — Posterior aspect of cloaca. 
SC — Spinal cord. 
SM — Sphincter muscle of cloacal valve. 
T — Integument. 
T C — Tegumentary cells. 
V—Vent or cloacal aperture. 
Z — Supposed caudal sense organ. 
1, 2, 3, 4, 5, etc. Caudal myocommata or muscular segments beginning with that 
which first abuts upon the cloaca. 
Fig. 4 represents the caudal region magnified about ten diam- 
eters ; it is in part diagrammatic, so as to include more features 
than could be really seen upon a single specimen without dissec- 
tion. The Notochord (NN) is shown in its whole length, tapering 
gradually backward. Only the hinder end of the spinal cord (SC) 
is shown, but its course is indicated by the pigment granules (PG) ; 
which form a double row upon the sides of the median line 
throughout the whole length of the body excepting near the head 
(as shown by Muller and Owsjannikow) and near the posterior 
extremity; none of mv specimens show them beyond the point 
where the muscular segments seem to cease, mainly about .000,5 
from the tip of the cord ; as shown by Owsjannikow, the granules 
are not generally opposite each other, or at regular intervals, in 
my specimens.* 
Three spinal nerves are shown (CNe) of which the most anterior 
*The cord is shown ending in a simple and free manner but I have several prepara- 
tions which indicate some connection between its extremity and what appears to be a 
funnel-shaped canal leading from the surface at the point Z. I shall make this a matter 
of special investigation hereafter; Quatrefages describes the tip of the cord as enlarged, 
but is not certain of the constancy of that peculiarity. 
The precise histology of this, as of all other parts, can only be determined and illus- 
trated by very numerous preparations in different aspects and by much enlarged 
figures. 284 
B. NATURAL HISTORY. 
has a ventral as well as a dorsal division. (Compare Quatref., 14, 
pi. xii, fig. 1). 
Excepting in very small specimens, the nerves can be seen only 
after carefully stripping off the integument, and the same is nec- 
essary in order to see the caudal Jin rays (CFR). 
Caudal fin rays.—I am quite sure, from numerous observations 
upon small specimens from which the skin was removed, that the 
rays whose cut ends appear upon vertical section of the caudal 
region arise in a continuous series along the dorsal and ventral 
borders of the body, at least as far forward as the vent and run 
forward almost horizontally. Several short rays are represented by 
Muller (11, Taf. 1, Fig. 3 and p. 88) rising near the tip of the 
tail and inclining slightly forward. I am certain that these rays 
continue uninterrupted, and without branching over several seg- 
ments ; but I have not yet assured myself of their precise distri- 
bution, nor in what way they are accommodated in the narrower 
fin in front of the vent: I venture therefore to show only three 
rays above and below. 
As represented by all authors, the myocommata (muscular seg- 
ments) incline backward at their dorsal and ventral extremities 
so as to form a prett}'- regular curve the greatest convexity of 
which lies just opposite the notochord ; the ventral moiet}T is the 
longer (excepting near the tip of the tail) and seems to extend 
farther back than the dorsal; but there seems to be no secondary 
dorsal and ventral curve as in ordinary fishes. 
But there are dorsal and ventral longitudinal structures, which 
have been so variously described that, at present, I prefer to des- 
ignate them merely as the dorsal ridge (DR) and abdominal ridge 
(AR) and their cavities as dorsal and abdominal segmented canal 
(DSC and ASC). 
Whatever may be the precise nature and functions of this struc- 
ture, however, it is in direct relation with the root of the fins and 
will form an element in the question of the position of the fins 
and the vent in respect to the median line. The dorsal ridge 
extends backward upon the median line almost to the final myo- 
comma (this is shown in any lateral view, but I have not yet car- 
ried sections into that region). The abdominal ridge, in like 
manner, is median from the abdominal pore (not shown) backward 
upon the median line, to where the abdominal fin expands into the B. NATURAL HISTORY. 
285 
caudal; here it decreases in size more rapidly than the dorsal 
ridge does at a corresponding point (although the interspaces are 
not shorter) and wholly disappears from the lateral view at the 
commencement of the cloacal region (its continuation will be seen 
in the sections) nor does it appear again in the post cloacal region, 
contrary to the figures of all authors. 
The cloacal region.— As first figured by Couch (4. p. 381), 
though not described and apparently not understood bjr him, and 
overlooked by ail subsequent observers, the cloacal region is dis- 
tinctly marked upon the left side by the failure of three or four 
myocommata to reach the level indicated by the corresponding 
myocommata of the right side. 
In most of the specimens examined by me, the condition of 
things is represented in Fig. 4.* 
The ventral extremity of the myocomma marked (1) is very 
slender and just fails to gain the level of the myocomma next in 
front; its successor (2) ceases at a still higher level and the next 
two (3 and 4) at higher and higher so that their ventral borders 
form an oblique outline from below, backward and upward ; the 
greatest height of the space so uncovered being about .000,3 from 
the normal level, or about one-seventh of the depth of the body 
at that point ; this line forms the antero-dorsal boundary of the 
cloacal region ; the corresponding postero-dorsal boundary is 
formed by the antero-ventral border of the next myocomma (5) 
which reaches its normal level, as do its successors; the back- 
ground of this space is formed by the mesial surface of the corre- 
sponding right myocommata, and its ventral outline is a pretty 
definite ridge (C1R), the nature of which will appear upon the 
sections. 
The posterior fourth of the cloacal region is vacant and may be 
called the cloacal notch (C1N) ; (it is this which is liable to unnat- 
* There is considerable discrepancy in the number of muscular segments (myocom- 
mata) both for the whole body and for separate regions; in the specimen figured (Fig. 4) 
I find that the ventral ends of four segments abut upon the cloaca, the most anterior 
very slightly, the fifth segment passes the cloaca and forms the dorsal and posterior 
boundary of the notch and there are sixteen more caudal segments, but in other speci- 
mens from Naples and also from Florida, there seem to be no more than fifteen post 
cloacal segments; there is reason to believe that the number varies with age but it is 
quite possible that the comparison of a large number from various localities may indi- 
cate a constant numerical difference serving to distinguish geographical varieties, 
and even, perhaps species; there is certainly a considerable difference in the height and 
tlrckness of the body, between the specimens from Naples and from Florida. 286 
B. NATURAL HISTORY. 
9 
ural extension backward by the introduction of the bristle, as 
mentioned on page 282). The remaining three-fourths is usually 
occupied by the cloaca (Cl) excepting a slight interval between it 
and the background and ridge, which may be called the cloacal 
sinus (Cl S). 
The Cloaca.—In most small specimens and many of the larger 
ones from Naples, all which are strongly contracted by the spirit, 
the elongated triangular space (cloacal region) above described is 
empty; but the tegumentary cells may easily be traced over the 
rounded borders and also upon the deeper level of the background, 
from the surface of the fin, which is here connected wholly with the 
right half of the body. 
But in other of the Naples specimens, and in all of those from 
the Florida coast, which, so far as this region is concerned, seem 
to be in a more nearly normal 
condition, the anterior three- 
fourths of the space presents a 
semi-cylindrical elevation of in- 
tegument with a curved posterior 
outline. Its suiface is continu- 
ous dorsally wdth the slightly 
overhanging margin of the my- 
ocommata; posteriorly with the 
contiguous surfaces of the clo- 
acal notch; wdiile the ventral 
.surface is slightly separated 
from the underlying cloacal 
ridge, and extends across the 
middle line as will be shown 
in Fig. 5. It will be noted that 
this surface is smooth and pre- 
sents no orifice whatever, and 
that we cannot therefore admit 
that the vent opens toward 
the left side of the body; this 
however by no means contradicts 
the statement that it opens to 
the left of the abdominal fin. 
Fig. 5. Diagrammatic views of cloacal region from below (A, B and C) and from 
right side D; all more or less enlarged. B. NATURAL HISTORY. 
287 
Fig. 5, A. View of the cloacal region from below, and still more 
enlarged than in Fig. 2. The caudal fin (CF) is turned over 
toward the right, but not distorted; its base is upon the median 
line, as seen at both ends of the section, and its exposed border 
therefore lies a little to the left of that line; the hidden border of 
course, to the right; upon each side of the anterior section is seen 
the abdominal ridge (AR) which is soon hidden upon the right, 
by the deflected fin, but continues backward upon the left to the 
cloaca where it seems to cease, but, in reality (as seen in B and in 
Fig. 4), is only narrowed and deflected dextrad of the median line 
so as to pass the cloacal region ; the five cloacal myocommata are 
numbered 1-5, and the succeeding one 6. 
It will be noted that owing to the fact that the base of the 
caudal fin preserves its true longitudinal course over the cloacal 
region, a little less than one-lialf of the latter is visible; the curved 
dotted line indicates the location of the vent; which is really 
dextrad of the median line, although practically, the outlet or 
pseudo-vent is a little sinistrad of that line, namely around the 
border of the base of the fin. 
Fig. 5, B, is the same as A, excepting that the caudal fin is 
removed down to its attachment, so as to expose nearly the whole 
cloacal region ; the attachment itself is deflected like the abdom- 
inal ridge, but remains visible around and behind the cloaca, 
where it again comes upon the median line; the cloacal notch is 
shown as a triangular black spot at the posterior extremity of 
the cloacal region, and the vent itself as a dark line upon the 
right posterior border, somewhat oblique, so as to be nearer the 
median line behind, but not reachinq it. 
In C, the cloacal region is still farther enlarged so as to show 
the relation of the parts to the median line; the dotted line 
indicates the limits of the exposed portion of the end of the 
intestine; the posterior extremity is seen to be rounded and the 
vent is a valvular aperture. 
D shows the same from the right side, and diagrammatically; 
the border of the valve should be represented as slightly thick- 
ened and rounded. 
I hope at some future time to give more detailed figures of 
this region, but these sufficiently indicate the morphological rela- 
tions. 288 
B. NATURAL HISTORY. 
In figure 6 are given enlarged diagrammatic representations of 
transverse sections made at seven different points as indicated by 
the corresponding capital letters upon Fig. 4 ; all are as viewed 
from behind. As already stated, these figures indicate the results 
of a careful and prolonged comparison of several hundred sec- 
tions made upon man}' specimens between the points A and G. 
Fig. 6. Sections of cloacal region (ventral half of the body) as seen from behind. 
A is just in front of the cloaca and G just behind it; the others at intermediate points 
indicated by the lines in Fig. 4. 
A is just in front of the cloaeal region and G is just behind it; 
both of these are, therefore (or should be), symmetrical figures; 
all the others are more or less asymmetrical on account of the 
deflection of the abdominal ridge, and the attachment of the tin, 
and the location of the vent itself upon the right aspect of the 
cloaca. 
The sections of course included the whole animal, but as the 
present paper concerns only the cloacal region, and several parts 
of the general anatomy of the dorsal region are in doubt, I pre- 
fer to show only what I am pretty certain of. 
The lettering is uniform and explained elsewhere (p. 2*3). 
The general arrangement is best seen in A. The lower half only 
of the notochord (N) is shown, and its contents are omitted from B. NATURAL HISTORY. 
289 
doubt of their exact nature ; as in Petromyzon, etc., the noto- 
chord is surrounded by a sheath of connective tissue (NS) from 
which are given off the various intermuscular septa (I S) which 
separate the myocommata (My), and the abdominal lamince (AL) 
which line the abdominal parietes. The aorta (A) lies between 
two laminae ; below the abdominal cavity the laminae join the con- 
nective tissue walls of the abdominal segmented canal (AS) which 
constitutes the abdominal ridge; to the sides of the latter also, 
are joined the corresponding subcutaneous fascia (S F) which 
envelops the tegumentary surface of the muscular masses; to the* 
lower border of the abdominal segmented canal also are attached 
the subcutaneous fasciae of the caudal fin, which are only partly 
shown in the series A-G-, but much enlarged in A'. The fin 
itself is wholly shown only in A, where its depth is slight; but 
its relative depth in the other sections may be judged by compar- 
ison with Fig. 2, which is magnified only half as many diameters. 
In this too are shown the cut ends of the caudal fin-rays (CFR), 
already described; they seem to be usually oval in section, and 
sometimes composed of two lateral pieces; but their structure 
must be more minutely investigated. 
Within the abdominal cavity is seen the cut end of the intestine, 
which, at A, contains a faecal mass F. All authors state that the 
alimentary canal is ciliated throughout, but give no figures of 
either the cilia or the cells to which they are attached and leave us 
to suppose that no muscular or peritoneal coats exist. 
As all these are points of minute anatomy which can be best 
determined upon living or fresh specimens, I hesitate to offer a 
description or figure of the parts, and must ask that both be re- 
garded as provisional. As might be expected, so delicate a tissue 
as the peritoneum was rarely left uninjured in a section, but I 
think it exists in several specimens in the relation which is nor- 
mal with vertebrates, and which is diagrammatically indicated in 
the figures (P), of course the parietal and visceral layers are 
really in contact with each other,,above (forming the mesentery M) 
and with the connective tissue and alimentary canal elsewhere. 
The existence of an inner or mucous or epithelial coat is cer- 
tain, also that, in the intestinal region, at least, it consists of 
columnar cells which give a striated aspect to the section; these 
cells are from .001 to .002 of an inch in length, and seem to be 
longer in the anterior than in the posterior part of the intestine, 
A. A. A. S. VOL. XXII. B. (19) 290 
B. NATURAL HISTORY. 
giving a, corresponding variation in the thickness of the mucous 
membrane (1C) ; traces of cilia appear in several of the sections, 
but I do not feel sufficiently sure of their uniform presence or 
their character to include them in the figure. 
As said above, no muscular coat is assigned to Ampliioxus by 
previous describers, nor have I seen any structure answering to it 
in the anterior part of the intestine, but in its posterior part and 
especially in the cloacal region, so constant is the appearance of 
a second coat outside of the mucous coat that I venture to insert 
it, provisionally, in the figure ; very often it is somewhat separated 
from the mucous coat; its thickness is about the same but its 
structure is granular and not at all striated ; prior to the investi- 
gation of this point upon fresh specimens, I would only suggest 
that perhaps the muscular coat is needed near the cloaca for the 
periodical expulsion of the feces which are brought back by the 
constant action, of the cilia, which may possibly exist only in the 
anterior (branchial) region of the alimentary canal. 
B presents nearly the same appearances, but as it is a section 
just at the anterior angle of the cloacal region, it presents an in- 
dentation upon the left side of the base of the caudal fin, while 
the abdominal segmented canal (AS) is deeper in position and 
thrown to the right of the median line, like the fin attachment. 
In C this change is more marked, the section being through the 
middle of the length of the cloaca, the AS is thrown far to the 
right and the base or attachment of the fin likewise, but the lat- 
ter soon regains its normal position upon the median line, giving 
rise to two important features of this region the ridge and the 
sinus. 
The cloacal riclge (CR) is the sudden angle formed by the verti- 
cal and median blade of the fin with its deflected basal part; it 
forms the outline shown as a single line in fig. 2 and appears in 
fig. 3 A as the sinister border of the fin. 
The cloacal sinus (CS) is the space between the sinister surface 
of the deflected basal part of the fin and the ventral surface of 
the cloaca itself. The dotted line represents the fin in the condi- 
tion already alluded to (p. 286) as thrown across and upward upon 
the left side so as to enclose and protect the cloacal sinus and the 
already concealed vent. 
In D we have a section directly through the vent and exhibiting 
its peculiar features. As might be inferred from the other figures B. NATURAL HISTORY. 
291 
(4 and 6 C) the integument may be traced from the left surface 
of the body upon the ventral surface and across the median line 
to a point where, in C, it becomes continuous with the integument 
of the fin-base, but in D it remains distinct and presently returns 
upon itself so as to form the mucous lining of the cloaca and the 
inner surface of the clocical valve (CIV) which itself is merely the 
ventral wall of the cloaca, free upon its right border for the 
extent of the vent. 
I have not represented the muscular and peritoneal coats in this 
section for I am not quite certain as to their points of commence- 
ment ; neither a peculiar striated structure which appears in this 
part of the valve and which may be a special muscle for opening 
or closing the vent. 
At E the section is made just behind the cloaca, so as to present 
its posterior rounded surface (PCI) which is continuous with the 
integument in all directions. The height of the cloacal cavity, 
which had somewhat decreased in D, is here little more than half 
what it was in A and the sub-aortic union of the abdominal lami- 
nae here forms an abdominal median septum (AMS) the connections 
of which are as in all excepting A somewhat asymmetrical. The 
AS is rather larger and nearer the median line ; the sinus and 
ridge occupy their usual places. 
At F the section is through the vacant space, or notch (C1N) 
already described in fig. 2 and fig. 3, B, C, D, as a trihedral de- 
pression from the left side at the base of the fin ; the median 
septum is still deeper, and the A S C nearer the median line. 
In G, we find a return to the symmetrical arrangement of parts, 
but with the absence of the alimentary canal; the septum is 
median and its connections regular. In fact, in some respects it is 
easier to describe and study the sections in the reverse order be- 
ginning with G ; which presents the simplest structure. 
But although the arrangement above described may be required 
for protection of the cloacal outlet, especially during backward 
locomotion, yet it is quite possible that in order to avoid such 
circuitous exit for the faeces, the animal may flex its body strongly 
ventrad, to such an extent as to allow the deflected basal part of 
the fin to hang more directly from its attachment, and so expose 
the true vent at the moment of deflection ; this must be determined 
by observation of living individuals. But this does not affect the 
morphological position of the vent upon the right of the median 292 
B. NATURAL HISTORY. 
line, but to the left of the abdominal fin, whose basal part is here 
deflected and attached wholly to the right half of the body. 
I foresee one possible exception to the above interpretation of 
the morphological relations of the vent; upon the ground that the 
abdominal ridge and the fin are normally median organs like the 
similar dorsal structures, it may be urged that since the cloaca 
lies to the left of them, it is lateral in position, and to the left of 
the median line, and that perhaps the vent itself, if distortion were 
removed, might perhaps be regarded as median in its position, or 
nearly so. 
This view would be strengthened by reference to the manner 
in which the abdominal median septum (AMS) maintains its con- 
nection with the abdominal segmented canal (ASC), as it is 
traced in the series of sections from G to A. 
For a long time, while studying the sections under the micro- 
scope, I felt anxious to see that the median septum consisted of 
two lateral sheets which separated below so as to receive the ali- 
mentary canal; but there is no good evidence of this, any more 
than in the other fishes, where this septum consists of fibres inter- 
laced in all directions, with no reference to a median division ; and 
in F and E the septum seems to be deflected from the median line 
and to pass wholly to the right, leaving only a branch to go to the 
left. 
But to this must be said — 1. That the various septa form a 
continuous sheet of connective tissue, which is thicker in some 
places and thinner in others; that naturally the larger part of the 
median septum would retain its connection with the fin and the 
abdominal segmented canal which is evidently associated there- 
with : and, 2. That although the septum, and the abdominal seg- 
mented canal and the fin are all normally median organs, yet the 
latter two are peripheral parts, and hardly entitled to serve as 
criteria for determining the morpliical position of a comparatively 
central or axial canal like the intestine ; and although the septum 
consists of sclerous tissue, and might be ossified, and so become 
a part of the skeleton, to which all other organs are generally 
referred for their location, yet it must be remembered that the 
morphological value of the spinal axis arises not from its being of 
osseous or sclerous tissue, but from its primary appearance upon 
the line of the primitive furrow; in like manner the spinal cord 
and aorta and alimentary canal are all median and primary and B. NATURAL HISTORY. 
293 
permanent organs ; and their right to be so considered is not to 
be denied on account of the appearances presented by accessory 
prolongations of connective tissue, or by peripheral and transitory 
organs like the fins.* 
Recapitulation.— 1. The abdominal folds and the furrow be- 
tween them extending from the oral aperture to the abdominal pore 
are periodical appearances, according to the condition of the 
reproductive organs. 
2. The cloaca is usually about one-ninth (or .11) of the total 
length from the tip of the tail, and, including the four myocom- 
mata which abut upon it, there are 20-25 myocommata behind it; 
both the ratio and the number, however, are probably variable. 
3. The caudal fin contains very long and delicate anteverted fin 
rays. 
4. The caudal fin is continuous with the dorsal and abdominal 
fins; and the cloaca lies opposite the point where the greatest 
depth of the fin is acquired, passing from before backward. 
5. On the left side three or four myocommata fail to reach the 
general level of the ventral border of the body and so expose the 
cloaca. 
6. The dorsal ridge is always median and is visible to.near the tip 
of the tail; but the abdominal ridge is deflected to the right of 
the cloaca, and does not reappear behind it, although it regains 
the median line. 
7. The abdominal fin likewise loses its connection with the left 
myocommata and is attached wholly to the right side, but regains 
its median attachment behind the cloaca. 
8. Nevertheless the blade of the fin always occupies the median 
line, and, at its junction with the deflected basal part, presents a 
distinct ridge, which forms the abdominal margin of the pseudo- 
vent. 
9. The true (or morphological) vent is an oblique elongated 
opening upon the right side of the cloaca and considerably to the 
right of the median line. 
10. But the basal part of the fin underlies this orifice and extends 
downwards to and slightly across the median line so as to bring 
*For a brief discussion of the question as to the morphical values of parts and char- 
acters, see my paper,—Intermembral Homologies, Proe. Bot. Soc. Nat. Hist., 1871, vol. 
xiv. 294 
B. NATURAL HISTORY. 
the blade upon that line, and therefore, although the vent is to 
the left of the fin, yet, 
11. Not only is the true vent invisible from either the right or 
left side, but the faeces in order wholly to leave the body, must 
pass to the left from the true vent and escape at a point which is 
really upon the left of the median line. 
12. This complex protection of the vent, in connection with 
other appearances, suggests that backward progression of the 
animal is Often resorted to. 
But we must conclude, wTith Goodsir, that to “complete the his- 
tory of the lancelet, an examination of it when alive in' seawater 
must be undertaken. In this way only can certain points in its 
structure be explained and light be thrown on the economy of one 
of the most anomalous of the vertebrated animals.” 
rig. 7. Cloacal region of Protopterus annectens; natural size; drawn from a spec- 
imen in the Museum of Comp. Zoology, L the left side; R the right side; CG the 
caudal groove, a furrow upon the median line which divides the edge of the fin into 
two thin laminae. 
The vent in Protopterus and Lepidosiren.—Muller’s refer- 
ence to the asymmetrical position of the vent in Lepidosiren 
(Protopterus) annectens has been quoted (page 276) ; Quatrefages 
follows Muller in comparing it with Ampliioxus, but as shown in 
the above figure (which does not differ essentially from the figures 
and description of other authors),* the structural arrangements 
are quite unlike, for in Lepidosiren and Protopterus the vent is a 
distinct circular orifice wholly upon one side of the median line 
opening upon a sort of fusiform papilla or raised surface which, 
however, projects less from the surface of the body than the thick- 
*Owen, Linn. Trans, xviii; Bischoff, Ann. Des. Sci. Nat. 3rd series, 14, Peters. 
Muller’s Archiv fur Anatomie, 1845; Vander 'Hoven, Handbook of Zoology, and Gun- 
ther’s Catalogue of Fishes. B. NATURAL HISTORY. 
295 
ened fin-base ; this latter extends forward to between the roots of 
the skelea (hinder legs) ; for some distance behind the vent (in the 
specimen here figured) the thin border of the fin is in two laminae 
with a groove between. The side of the fin-base opposite to the 
vent projects somewhat like the vent papilla, and all authors agree 
that the vent opens sometimes upon one and sometimes upon the 
other side. Without sections of the body at this region and the 
study of the embryonic condition of the parts one cannot be sure of 
what is their morphological relation, but they appear as if the 
vent, a normally median organ, opened itself upon one or the other 
side of the fin-base and that the two mutually crowded each other 
a little from the median line ; perhaps the blade of the fin is deeper 
in the young individuals. 
In Ceratodus.—In a large specimen of Ceratodus Forsteri at 
the Museum of Comparative Zoology the fin ceases considerably 
behind the vent, and this is apparently a median opening, although 
slightly asymmetrical in form, perhaps on account of distortion in 
the spirit. Gunther makes no mention of a peculiarity of this 
region. 
The vent in Myzontes (marsipobranchii).—Whatever maybe 
their precise zoological relationship,* there is no doubt that the 
Myzontes are the group of vertebrates next above Amphioxus, and 
it is therefore desirable to ascertain the character of the vent in 
the three genera now constituting the group. 
In Myxime glutinosa the vent is a longitudinal median slit be- 
tween what might at first seem to be the divided moities of an 
abdominal fin. I have not as yet made the sections which would 
probably decide the matter, but am inclined to think that the true 
fin lies wholly behind the vent, and the slight cutaneous fold which 
lies in front of and behind it is not in the strictest sense a fin 
like that which exists in Amphioxus. 
* Of late years the opinion has gained ground that the peculiarities of Amphioxus 
are such as to entitle it to the rank of a sub-class or class or even sub-kingdom; with 
this, however, I have never sympathized. I hesitate to express a contrary opinion 
without more extensive knowledge than I now possess, but it may not be improper to 
state that last summer (at the Anderson school of Nat. Hist. Penikese Id., Aug., 1873), 
after a lecture in which 1 contrasted diagrammatic views of the branchial apparatus in 
Amphioxus, Myzine, Bdellostoma and Petromyzon, Prof. Agassiz announced his belief 
that these four genera would prove to be the representatives of four groups which he 
would regard as orders of the class Myzontes (or marsipobranclis). This opinion 
might and will hereafter, be confirmed by many other considerations which I now 
refrain from presenting. 296 
B. NATURAL HISTORY. 
In Bdellostoma polytrema the body is deeper in front of than 
behind the vent, which is thus caused to look backward as well as 
ventrad, between two folds which seem to be equal or if unequal, 
not so in any uniform manner ; all the specimens examined by me, 
(from the Mus. Comp. Zool.) are in poor condition. 
In Petromyzon.—It so happened that the three representatives 
of this genus first examined by me were a large P. Americanus 9 , 
and two small specimens from Cayuga Lake of a species which I 
do not yet regard as satisfactorily determined ; the first named 
presented a sort of notch in the right half of the body just at the 
vent, which gave the latter a decided sinister aspect; the two 
smaller specimens were a 9 and $ ; and in one the vent looked 
to the right, in the other to the left; and I imagined this peculi- 
arity might relate to convenience in copulation; but of seventeen 
specimens of P. Americanus since examined, no such condition of 
things exists ; a much larger number of specimens must be exam- 
ined before any generalization can be made. I am inclined to 
think, however, that the very early larvae of the Myzontes may 
present an Amphioxus-like structure of the cloaca. 
The vent in the larvae of Rana pipiens.—An examination of 
fifteen larvae of Rana pipiens, taken in the same stream in June, 
1873, showed that in every case there was a decided asymmetry in 
the cloacal region. The median caudal fin is continuous from the 
tip of the tail to the abdominal integument. In the specimens 
with small skelea (hind-legs) the connection between the abdomi- 
Fig. 8. A larva of Rana pipiens, partly dissected, seen from below; B, the persistent 
left branchial orifice; most of the intestinal coil has been removed, I being the cut end 
of the pyloric portion, and C the cut end of the last coil; 11 the rectum lying close 
against the left side of the abdomen, before crossing to the median line to open at V 
the vent between the two moieties of the fin (A), of which the right is much thinner; 
S, the left skelos or hindleg. B. NATURAL HISTORY. 
297 
nal skin and the fin proper is a broad fold, which becomes reduced, 
apparently by absorption, as the skelea increase, until in those 
farthest advanced it forms a mere ridge upon the middle line. 
Fig. 9. A transverse section oij the root of the tail of the same larva of Rana pipiens 
made in a plane indicated by the line S in fig. 8. S, the cut end of the left skelos; L, 
the thicker left moiety of the flti which is continuous with the caudal tin; the thinner 
right moiety ceasing at a point just behind the section. 
Now the vent seems to divide this into two laminae of which the 
left is always the larger and thicker, while that upon the right of 
the orifice is thinner and in the specimens with largest skelea, has 
nearly disappeared; the vent must therefore be described as 
wholly or in part on the right of the median fin in these larvae. 
But the fact that the vent is to the right of the caudal fin, and 
that the latter is not as is usual among vertebrates, wholly inter- 
rupted by it, does not necessarily enable us to say that the vent is 
dexlrad of the median line; on the contrary, I am inclined to think 
that the vent is really upon the median line, in the larva as in the 
adult, and that the laminae of the anal fin are divaricated unequally 
according to their different thickness, giving the apparently lateral 
position of the opening as already described. 
We ought perhaps to discriminate between the real vent as it 
exists in both stages of growth and the orifice of the short tube* 
between the deciduous laminae, which orifice certainly looks to- 
ward the right. 
It is obvious that a more extended examination should be made 
of the larvae of different Batrachians ; and the purpose of thip 
paper is mainly to call attention to a peculiarity which, so far as I 
am aware, has not before been observed. 
The condition of things is more like that of Bdellostoma than 
Amphioxus ; and a curious contrast exists, from the fact that while 
* Alluded to by Owen (C. A. V., vol. i, 623) as the “ tegumentary and transitory clo- 
acal canal at the fore-part of the subcaudal fin.” 298 
B. NATURAL HISTORY. 
the latter form gains a caudal prolongation beyond the vent, Bana 
loses the tail in the course of development; and the adult cloacal 
aspect is not unlike that figured by Kowalewsky in the Amphioxus 
of sixteen hours. 
WEIGHTS AND MEASUREMENTS (IN GRAMS AND MILLIMETERS) OP LARVAE 
OP RANA PIPIENS, MADE WHILE SPECIMENS WERE PRESH, 
JUNE 16, 1873. 
No. 
Weight. 
Length of 
Skelea 
(hind 
legs). 
Body (muzzle 
to vent). 
Tail 
(from 
vent). 
Total 
length. 
Alimentary 
canal from 
mouth to bight 
of intestine. 
Prom bight 
to vent. 
Total. 
1 
,013. 
.003,5 
.041, 
.076, 
.117, 
2 
,013. 
.001, 
.041, 
.074, 
.115, 
3 
,015. 
.004, 
.037, 
.076, 
.113, 
,413, 
,350, 
.763, 
4 
,016. 
.004, 
.042, 
.076, 
.118, 
,500, 
,365. 
.865, 
5 
,015. 
.005, 
.042, 
.078, 
.120, 
6 
,013. 
.006, 
.041, 
.076, 
.117, 
7 
,014. 
.008, 
.041, 
.080, 
.121, 
8 
,020. 
.012, 
.046, 
.086, 
.132, 
9 
,019. 
.013, 
.043, 
.087, 
.130, 
,465, 
,380, 
.845, 
10 
,022. 
.037, 
.045, 
.097, 
.142, 
11 
,021. 
.038, 
.048, 
.098, 
.146, 
12 
,020. 
.040, 
.046, 
.098, 
.144, 
13 
,026. 
.042, 
.047, 
.089, 
.136, 
,760, 
,513, 
1.273, 
14 
,028. 
.046, 
.045, 
.100, 
.145, 
15 
,025. 
.051, 
.046, 
.091, 
.137, 
Having arranged the specimens according to the increase in 
length of the skelea, we see : 
1. A general increase in the wreight and total length ; and, with 
the four measurements given, in the length of the alimentary canal; 
but none of these increments are constant. 
2. The skelea of 10 are nearly three times as long as those of 
9 ; but the increments of length and weight of body are gradual. 
3. The comparison of 13 with 9 indicates that the shortening 
of the alimentary canal, which is said to occur at a later stage,* 
has not yet commenced. 
*Owen, C. A. Y., i, 624. 299 
B. NATURAL HISTORY. 
Addendum.—Through the kindness of Prof. Theodore Grill I 
have to-day (April 29, 1874) received a copy of Stieda’s “ Studien 
uber Amphioxus lanceolatus,” read before l’Academie imp. des 
Sciences de St. Petersbourg, Sept. 5,1872, and published in March, 
1873 ; its presentation and publication thus antedating those of 
my paper by about a year.* 
Although the foregoing paper was already in type, room was 
kindly made for the present note respecting Stieda’s paper. It is 
chiefly histological, with historical and critical remarks ; embrac- 
ing only seventy pages, and yet touching upon the whole structure 
it is necessarily very brief in many respects. 
Of the twenty-five figures, seven are magnified sections of the 
entire animal, at the following points : in front of the mouth, 
through the mouth, through the anterior part of the respiratory 
cavity, through its posterior part, at the vent and behind the vent. 
A review of most of the points of general structure must be de- 
ferred to another occasion ; in some respects my observations con- 
firm his, in others I am not prepared to make a positive assertion, 
but in a few I am sure he is incorrect. The only reference to the 
position of the vent is on page 5 :—“Hinter dem Porus abdomi- 
nalis, im Bereich der eigentlichen Afterflosse, befindet sich, an der 
linken Seite, die nur kleine afteroffnung.” (Behind the abdominal 
pore, in the region (line ?) of the true anal fin, lies the very small 
anal opening). 
I give a copy of the lower half of his figure representing the 
section at the vent; it is reversed for convenience of comparison 
with my own, since his is as if viewed from in front, while all 
mine are as if viewed from behind. 
With regard to the minute structure of thd intestine which he 
describes as presenting in addition to the peritoneum, an outer 
thinner coat, a middle or thicker coat, and an inner or epithelial 
layer which, at the vent, gradually merges into the ordinary cuticle, 
Prof. Stieda’s reputation as an histologist deters me from positive 
counterstatement at this time; but as to the morphological rela- 
tions of parts to each other and to the middle line, I am obliged 
* Foreign scientists will hardly be able to believe that a memoir upon so interesting 
a subject, and in a periodical which doubtless is at once received in every university 
library of Europe, should so long be unknown to a worker in the same Held here and 
even then be first learned of through the “scientific record” of a popular magazine, 
“Harpers’ Monthly;” but my American brethren will understand the case, for they 
know that, excepting only at Boston, New York, Philadelphia and Washington, they 
are always liable to do over what has been already done a year or more before, and to 
rediscover things which are already familiar. 300 
B. NATURAL HISTORY. 
to differ with him, and trust that he will, upon reception of my 
paper, reexamine this point, as I shall this and others in the light 
of his researches. 
I am enabled to offer the following additions to the bibliography 
from the complete list of works at the end of Stieda’s paper. 
Costa, Cenni zoologici ossia descrizione sommaria di talune specie nuove di animali. 
Napoli, 1834. 
Notice sur le Branchiostome, comptes rendus T., xiii, p. 873,1841. 
Notice sur le Branchiostome, L’Institut, I, Sect, ix, No. 407, p. 345,1841. 
Frammenti di Anatomia com par at a, Fascic. I, Sporia e Notomia del Branchios- 
tomum lubricum. Napoli, 1843 fol. 
Ueber Branchiostoma, Isis, p. 708,1846. 
Gervais et van Beneden, Zoologie medicale, T. I, p. 287,1859. 
Goodsir, An. Nat. Hist, vii, p. 346. 
Iloven, Verzameling van berigten over Amphioxus 1. Tijdschrift voor natiirl. Geschie- 
denis, D. viii (2 Afd.), p. 73,1841. 
Harting, Leerboek van de Gronbeginselen der Dierkunde, II, D. I. Afd. 4, Visschen, 
Tiel, H. E. A. Campagne, 1805. 
Huxley, Examination of the Corpuscles of the Blood of Amphioxus, Trans. Brit. 
Assoc., p. 95,1847. 
“ KOBaNeBCKiNj, NCTOpig pa3NTiji,” Amphioxus 1., 1865. 
Lindsay, On Amphioxus 1. An. Nat. Hist., 2 Ser., vol. 23, p. 339,1857. 
Leuckart und Pagensteclier, Untersuch, ueber nied Seethiere Amphioxus 1. Muller’s 
Arcliiv, 1858, p. 568. 
Martino, Sull’ anatomia del Branchiostoma 1. Giornale dell Instituto Lombard, T. vii, 
p. 172, 95, Milano, 1846. 
Wilh. Muller, Beobacht, des pathol. Instituts zu Jena, Spec. Th., Reike I. Ueber den 
Bau der Chorda dorsalis. In der Jenaischen Zeitschril't f. Med. vr. Naturw. Bd. 
vi, p. 287,1867. 
Reichert, zur Anat. des Branchiostoma 1, Reichert’s Archiv, 1870, p. 755. 
Fig. 10 (copied from Stieda, Taf. 2, fig. 9; reversed, and cut light on a dark ground.) 
This is to be compared with my figure D, fig. 6. B. NATURAL HISTORY. 
301 
On the Composition of the Carpus in Dogs. By B. G. 
Wilder, of Ithaca, N. Y. 
In a paper “On the composition of the carpus of the dog,”* 
Prof. Flower describes and figures the right carpus of a dog about 
six weeks old in which the “so-called scapho-lunar bone, though 
well ossified consists not only of a perfectly distinct scaphoid and 
lunar but also of a third piece, evidently corresponding to the os 
centrale of the typical carpus,” p. 64 ; and regards this as “proving 
that in the dog at least neither the radiale (scaphoid), intermedium 
(lunar), nor the centrale are suppressed, but they are all developed 
independently and afterwards coalesce to form the so-called 
scapho-lunar bone.” 
Pig. 1. The right carpus of an Asiatic lion, seven months old (largest figure), of a 
shepherd pup, and of a new-born English black and tan rat terrier (smallest figure); 
all are drawn from above and of natural size. The lettering is uniform. P. Pollex; 
I, Index; M, Medius; A, Annularis; Ml, Minimus, p, pisiform; x, radial sesamoid, 
a cartilaginous nodule attached to the radial border of the scaphoid; sc, scaphoid or 
radiale; l, lunar or intermedium; ce, centrale; c, cuneiform or uinare; tm, trape- 
zium; td, trapezoid; m, magnum; u, unciform. 
Wishing to confirm the above statements upon other specimens 
1 examined the parts in question upon two young dogs and a young 
Asiatic lion, carefully removing thin slices of the cartilaginous 
carpi; the figures show that: 
1. In this lion seven months old, the scapho-lunar is a single carti- 
lage, containing three centres of ossification, which undoubtedly 
♦Read at the British Association Aug. 7, 1871, a#d published in the Journal of 
Anatomy and Physiology, Nbv., 1871, page 62. 302 
B. NATURAL HISTORY. 
correspond to the three elements, scaphoid, lunar and centrale 
and which would probably, at a later age, coalesce into one bone. 
2. In the shepherd pup (age unknown) the single scapho-lunar 
cartilage contains but two ossifications ; the radial one, however, 
is so large as to allow the supposition that it represents the already 
coalesced scaphoid and centrale. 
3. In the new-born terrier, the cartilage presents no trace of 
ossific deposit, though sections were made in all directions ; it is 
moreover single and undivided, as in the other cases, but as it ar- 
ticulates with the cuneiform and unciform on the one side, with the 
trapezium on the other, and with the magnum and trapezoid by its 
distal border, it must be held to represent the scapho-lunar just as 
much as do the partly ossified cartilages in the other two cases. 
A similar appearance is presented in a foetal gray wolf the 
mother of which died four days before the expected time of birth, 
and in a young red fox, whose eyes were just opening. 
From the above facts we may conclude that: 
1. The carpal element centrale which Gegenbaur holds to enter 
into the composition of the typical carpus, but which he found 
distinct only in Quadrumana and in some Rodentia and Insectiv- 
ora,* exists as a separate centre of ossification in a young lion, 
and is probably represented in the young shepherd dog and the 
terrier ; as in the young dog described by Flower. 
2. But in the three cases described by me the cartilages of these 
three elements are probably connate, and the osseous formations 
coalesce; while in Flower’s example there seems to have been 
neither connascence nor coalescence of either cartilage or bone; 
for even if we suppose that in that case a single cartilage after- 
ward divided, yet it is certain that no such change occurs in the 
lion ; and since the shepherd pup presents only two ossifications, 
we must either conclude, as above that a coalescence of centrale 
with scaphoid has occurred, or that in this kind of dog the centrale 
is wanting. 
3. It is easier to imagine that the Carnivora may vary among 
themselves and that the dogs in particular, which in so many other 
respects present striking differences, may vary in regard to the 
manner of formation of carpal elements and even perhaps as to 
their existence. 
4. It is evident that any generalization respecting dogs should 
specify the breed, age and sex. 
* Carpus und Tarsus, p. 50. B. NATURAL HISTORY. 
303 
Present Aspect of the Question of Intermembral Homolo- 
gies. By B. G. Wilder, of Ithaca, N. Y. 
Attention is called to the apparent unconsciousness of English 
and Continental anatomists that there exists, chiefly in the United 
States, an opinion respecting the homology of the anterior and 
posterior limbs, totally at variance with their own; and it is sug- 
gested that if each party will yield a part of its present position, 
a reconciliation may be effected. I hope, by means of embryology 
and the study of Amphioxus to demonstrate the existence of a 
true “meketropy” (antero-posterior symmetry) within the verte- 
brate branch. I hold that if the same methods of comparison and 
of deduction which are employed in studying the limbs of different 
animals are used in comparing the anterior and posterior limbs of 
the same animal, there can be no escape from the conclusion that 
the anterior digit (thumb) is the true homologue of the posterior 
dactyl (little toe) ; and that the little finger is in like manner the 
true homologue of fhe great toe. To this opinion are now in- 
clined the following anatomists: Wyman, Agassiz, Dana, Coues, 
Foltz, and the w'riter ; all others now living, and those who have 
written on the subject since 1774, hold the contrary opinion.* 
Variation in the Condition of the External Sense Organs 
in Fietal Pigs of the same Litter. By Burt G-. Wilder, 
of Ithaca, N. Y. 
In comparing foetal mammals of unknown age, it is natural to 
estimate their relative age, partly according to the degree of 
closure of the lids, and the direction of the pinnte; since it is 
known that the former are at first mere folds above and below 
the uncovered balls, which are gradually covered by them ; and 
that the pinnae are first formed as little triangular folds behind 
the meatus, which at first project directly forward, and then, as 
* A historical sketch of the question, with a full bibliography is given in a paper 
lately published by me, Intermembral Homologies; Proc. Bost. Soc. Nat. Hist., 1871. 304 
B. NATURAL HISTORY. 
they increase in size, gradually rise to the erect position, and only 
later are retroverted upon the neck. 
While forming a collection of foetal pigs at the large abattoir 
of J. P. Squiers in East Cambridge, Mass., during the summer 
of 1872, I compared the individuals of the same litter, carefulty 
avoiding any artificial displacement of the parts. 
Fig. 1. A. Head and series of pinnae from foetal pigs (Nos. 296 to 300, M. C. Z.) 
of the same litter. 
B. Head and series of eyes Irom foetal pigs of the same litter (Nos. 303 
to 309). 
In the five pigs of the same litter * having an average length 
from vertex to anus of ‘067, mm. and an average weight of ,017-5 
grams, the direction of the pinna ranges from a slight but decided 
anteversion, to an almost complete retroversion. Figure 1, A. 
In the seven pigs of another litter f averaging -040, in length, 
the lids range from folds covering slightly the upper and lower 
margins of the ball, to complete closure. The sizes and degrees 
of closure do not exactly coincide. It would be interesting in 
both these cases to know the relative position of the individuals 
in the mother’s uterine cornua; but these facts indicate the need 
of far more extended comparisons than have been made. 
I have also observed some striking changes in the form of the 
nostril in foetal pigs ; it is in its earliest condition a notch, whose 
lower margins then come together forming a hole; this elongates 
laterally and is indented above so as to become more and more 
crescentic; but at or before birth the circular form is regained 
and retained through life; illustrations of these changes will be 
presented upon another occasion. 
♦Marked 296 to 300 on the Catalogue of Neurology and Embryology of Domesticated 
Animals at the Museum of Comparative Zoology, Cambridge, Mass, 
t Marked 303 to 309 in the same catalogue. B. NATURAL HISTORY. 
305 
The Pectoral Muscles of Mammalia. B;> Burt G. Wilder, 
of Ithaca, N. Y. 
The following is a provisional abstract of results based upon 
the dissection of the pectoral group of muscles of twenty-two 
genera of mammals, representing all of-the usually recognized 
orders, excepting the Solipedia, Hyracoidea, Cetacea and Sirenia. 
Beford publishing in detail and with figures from the drawings* 
which I have made of all the dissections, I wish to examine sev- 
eral other genera (particularly Lutra, Phoca, Delpliinus) and also 
other individuals or species of the species and genera here 
enumerated. 
Homo, Man. 
Troglodytes Chimpanzee. 
Pithecus, Orang. 
Macacus, Monkey. 
Galago, Lemur. 
Felis catus, Cat. 
Felis leo, Lfon. 
Cams occidentalis, Gray wolf. 
Canis familiaris (see next paper), .... Dog. 
Ursus, ...... Bear. 
Procyon, Raccoon. 
Putorius, . . . <• Weasel. 
Mephitis, Skunk. 
Scalops, Mole. 
Condylura, Star-nosed mole. 
Pteropus, Bat. 
Bradypus, Sloth. 
Myrmecophaga, Ant-eater. 
Cyclothurus, Little ant-eater. 
Dasypus, Armadillo. 
Mus, Rat. 
Arctomys, Woodchuck. 
Bos, Cow. 
Cervus, Deer. 
A. A. A. S. VOL. XXXI. B. 
* These drawings were shown at the meeting. 306 
B. NATURAL HISTORY. 
The investigation began in an effort to reconcile conflicting 
statements respecting the existence of the Pectoralis minor in the 
cat and some other Mammalia. Strauss-Durckheim denies its 
presence in the cat; and Cuvier and Meckel in some other carni- 
vora; while others (Haughton), mention its presence without 
comment. 
In nearly all Mammalia the main pectoral mass is naturally 
separable into an outer and an inner layer; these are respectively 
homologous with the Pectoralis major and P. minor of man; for 
convenience and in order to avoid the ascription of less constant 
attributes than relative position, they may be called respectively 
ectopectoralis and entopectoralis; as the buttock muscles are now 
called ecto-, meso- and ento-glutceus. 
The usual origin of the ectopectoralis is the middle line of the 
sternum, and a median raphe anterior to it; its insertion is into 
the outer tuberosity of the humerus, and distad therefrom upon 
the same bone; the usual origin of the entopectoralis is from the 
anterior angles of the costal cartilages and sternum, and from 
the contiguous borders of these parts; its insertion is upon the 
outer humeral tuberosity and outer margin of the bicipital groove, 
covered more or less by the insertion of the ectopectoral. But 
there is nearly always a small but distinct tendon which is at- 
tached to the coracoid process or to the tubercle representing it 
in many quadrupeds; this is interesting in view of the fact that 
in Quadrumana often, and in man usually (but by no means so 
generally as is supposed), the entire attachment upon one or both 
sides is upon the coracoid process. 
This coracoid insertion is perfectly distinct in all the Canidce 
and Felidae dissected by me; but Strauss-Durckheim, not recog- 
nizing the entopectoral as such on account of its great size, 
describes the tendon of the sterno-trochiterien in the cat (which 
he regarded as a dismemberment of the P. major, as sending a 
slip to the supra spinatus; teleologically it might as well be so, 
but morphologically there is every reason for its attachment to 
the rudimentary coracoid. The above, by the way, is the only 
error in description which I have found in that admirable mono- 
graph ; but errors of homological interpretation are by no means 
uncommon. 
The ectopectoralis tends to separate, especially anteriorly, into 
superimposed laminae ; while the entopectoralis tends to form fasci- B. NATURAL HISTORY. 
307 
culi, corresponding to the number of costo-sternal articulations 
involved in its origin. 
The ectopectoralis has generally an outward direction, and acts 
therefore as an adductor humeri; the entopectoralis has an oblique 
direction from within, forward and outward, and acts chiefly as a 
retractor omou (retractor of the shoulder). The entopectoralis is 
generally much the larger, the exceptions being man, the higher 
quadrumana, the bear, the skunk and the bat. 
I* addition to the main pectoral mass, there are generally 
found one, two or more smaller muscular elements, whose rela- 
tions are variable with the thorax and armus, with the main pec- 
toral mass, and with certain other muscles (latissimus dorsi, 
dermo humeralis, rectus abdominus and obliquus externus. It is 
probable that these are differentiated portions of the main pec- 
toral mass, but a more extended comparison is needed. 
There is need of more accuracy in the dissection, delineation 
and description of muscles; since at present there is great con- 
fusion respecting the nature of true muscular integers, and the 
basis of muscular homologies ; as a provisional opinion, it may 
be stated that size, form and function are much less reliable than 
origin, relative position and insertion, and that origin is the most 
reliable basis for muscular homology. 
The most profitable work will be the careful comparison of 
nearly allied species and genera. At present, so little are we 
agreed upon the basis of arrangement that each new “myology” 
is in great part useless in the present and a burden upon the 
future; in fact, we should do well to avoid publication of dissec- 
tions made of a single specimen of a species, and a single species 
of a genus ; and of all dissections by beginners. My own experi- 
ence has proved the risk of fallacies resulting from the too sparing 
or too persistent use of the knife, and the overlooking of points 
which may have no teleological importance, but great morpho- 
logical significance. 308 
B. NATURAL HISTORY. 
Variation in the Pectoral Muscles of Domestic Dogs. By 
Burt G. Wilder, of Ithaca, N. Y. 
ABSTRACT. 
I have made drawings* of my own dissections of the pectoral 
muscles in nine breeds of domestic dogs (Cants familiaris), as 
follows: English terrier, skye terrier, spaniel, greyhound, spitz 
or Pomeranian, setter, Newfoundland, St. Bernard and shepherd. 
Like that upon the brains of dogs, this investigation was begun 
in order to ascertain whether among our domestic dogs there exist 
internal and structural differences comparable with those of habit 
and external appearance, which are greater than would be held to 
characterize distinct species of wild animals.f 
Deferring publication in full until a greater number of breeds 
have been examined, j and until the general homology of the pec- 
torales is determined, I would say here that so far there has been 
great uniformity in the main pectoral muscles, ectopectoral and 
entopectoral; certainly no such differences as might be inferred 
from the external appearances of the breeds. Among the minor 
outlying members of the group referred to in the preceding paper, 
there is some variation, but usually not more than might be attrib- 
uted to mere individual peculiarity. 
The stomachs and caeca of these and several other dogs are pre- 
served, inflated, in either Ithaca or Cambridge. I hope at some 
time to present superposed outlines of these for exact comparison. 
* These were shown at the meeting. 
t Yet as remarked on-page 242, even the child recognizes them all as dogs. 
t A Chinese dog and a Mexican (Chihuahua) dog are among the specimens awaiting 
dissection.