336 
Kneeland on the Skeleton of the Great Chimpanzee. 
Art. XXI.— On the Skeleton of the Great Chimpanzee, Tro- 
glodytes gorilla. Read before the Boston Society of 
Natural History, April 21st, 1852. By S. Kneeland, Jr., 
M. D. Boston. 
The Society has recently received a most valuable addition 
to its Cabinet, in a nearly complete skeleton of the Troglo- 
dytes gorilla, presented by the American Board of Commis- 
sioners for Foreign Missions. It consists of a fine skull, with 
lower jaw, with the teeth complete ; all the vertebrae except 
the atlas; the pelvis complete; both scapulre and clavicles; 
the entire humerus, radius, and ulna of left side, the ulna of 
the right side with the humerus and radius broken; the femur 
and tibia of right side, and the head and upper portion of 
shaft of the left femur; all the ribs, a few bones of the hand, 
and the manubrium of the sternum. 
The cranium is of great size and strength ; the internal 
capacity is only twenty-seven cubic inches, while that of 
another specimen belonging to the Society is thirty-five cubic 
inches. Prof. Wyman gave the measurement of the last as half 
an inch less; this trifling difference may be owing to my using 
smaller shot, and perhaps pressing them down a little more 
closely. From the capacity, from the great development of 
the sagittal and lateral crests, and the massive character of 
all the bones, this is undoubtedly a male; the appearance of 
the jaws, the complete development and worn surfaces of the 
teeth indicate an adult, if not an old animal. The sutures 
are hardly discernible, as usual; the superciliary ridges and 
crests are exceedingly well developed. The specific characters 
pointed out by Professor Agassiz, in the decreasing depth of 
the infra-orbitar canal from before backwards, and the pro- 
jection outwardly of the inner walls of the orbits, are well 
seen on this specimen. There are two infra-orbitar foramina 
on each side. The nasal bones are united together, in the 
lower half presenting traces of a median suture, in the upper 
half a prominent ridge ; the portion of the bone between the Kneeland on the Skeleton of the Great Chimpanzee. 
337 
inner orbitar angles of the frontals seems to confirm Dr. Wy- 
man’s opinion, that it is an independent piece, having its own 
centre of ossification; the foramen existing midway between 
the incisive foramen of each side and the edge of the alveo- 
lus, on the left side is replaced by two, as in the Chimpanzee. 
The zygomatic arches are exceedingly strong, much more so 
than in our other specimen, inclosing temporal muscles which 
might easily account for the tremendous strength of the jaws. 
The other anatomical peculiarities of the cranium and face 
have been sufficiently detailed by Dr. J. Wyman in the fifth 
volume of the Society’s Journal, (p. 426.) The following 
points are interesting : — The dental formula is the same as in 
man ; the median upper incisors are twice the size of the 
lateral, the reverse of which is the case in the lower jaw ; they 
are also respectively longer, giving to the upper incisors a 
convex edge, and to the lower a concave one ; in the upper 
jaw there is an interval of two or three lines between the 
incisors and canines, and no interval between the latter and 
the premolars, the reverse being the case in the lower jaw, in 
which, however, the interval is less ; the upper canines extend 
from the alveolus one inch and a half, the part within the 
alveolus being at least two inches ; they are an inch broad 
and three fourths of an inch thick ; the upper canines are 
worn anteriorly by the lower, and posteriorly by the first 
lower premolar, giving to the tooth a triangular shape, with 
an anterior, a posterior, and an internal cutting edge ; the 
action of the lower premolar on the upper canine, and of the 
latter on the lower canine, produces a distinct talon, or heel, 
at the base of these teeth; the two grooves, mentioned by 
Dr. Wyman as occurring on the inner face, are not seen in 
these canines, probably from the extent of the worn surface ; 
there is the lower portion of a single groove, however, which 
is lost in the worn surface beyond. To produce these sur- 
faces there must be some lateral motion of the jaw, which 
would not be expected from the great length of these teeth. 
The premolars and molars agree with Owen’s description in 
JOURNAL, B. S. N. H. 44 JUNE, 1852. 338 
Kneeland on the Skeleton of the Great Chimpanzee. 
the Cyclopedia of Anatomy and Physiology (Art. Teeth) ; in 
the upper molars the anterior inner cusp is seen to be united 
to the posterior outer cusp by an oblique ridge ; the first 
lower premolar is much larger than the second, the anterior 
cusp being so strongly developed that the tooth resembles an 
enlarged human canine; all the lower molars have three 
cusps on the outside and two on the inside. The lower jaw, 
as will be seen by the measurements, is of great size and 
strength ; the ramus being at right angles with the body of 
the bone; the condyle is one inch and three fourths wide, 
and five eighths of an inch thick, projecting much internally ; 
the coronoid process is higher than the condyle. The exter- 
nal face of the ramus is deeply concave for the masseter 
muscle, which is nearly three inches wide ; the ramus inclines 
very much outwardly at its lower portion, and is grooved 
internally for the internal pterygoid muscle. The body of the 
jaw is one and three fourths inches high, and nearly an inch 
thick; the height at the symphysis, and width is two inches; 
the thickness one and one fourth inches; the chin is convex 
and retreating, its convexity measuring three and one fourth 
inches. 
Trunk. Of the vertebrae, only the atlas is wanting. The 
odontoid process of the axis, instead of being almost perpen- 
dicular as in man, inclines backwards at an angle of about 
50°; the spinous process is an inch long, spreading at its 
apex to nearly the same width, with an evident disposition to 
fork as in the human type ; it is also somewhat concave at the 
end of its under surface. The bodies of all the cervical ver- 
tebras are higher, but narrower than in man, and received 
deeply one in the other. The spinous processes are hori- 
zontal, long, and, excepting the third, which is sharp-pointed, 
are swelled or club-shaped at the end; the fourth is the 
longest, the third the shortest; their lengths are, from the 
posterior face of the spinal canal, as follows: — the third, two 
and one eighth inches ; the fourth, three and three fourths 
inches ; the fifth, three and five eighths inches ; the sixth, Kneeland on the Skeleton of the Great Chimpanzee. 
339 
three and one eighth inches ; the seventh, three and one fourth 
inches. The use of these long spinous processes is sufficiently 
obvious, being required for the attachment of the ligamen- 
tum nuchae, which must be very strong in these creatures; 
from the posterior situation of the occipital foramen, the head 
must have a great tendency to fall forward, and its immense 
weight requires a corresponding strength in this ligament. 
The transverse processes are very long, the posterior an inch 
in length ; the anterior, or cervical ribs, begin to be seen at 
the fourth, increasing to the sixth and seventh, which last are 
of equal size ; there being, as a general rule, no cervical ribs to 
the seventh vertebra of the mammal neck. All the cervical 
vertebrae are pierced for the vertebral artery on each side ; 
the transverse processes are directed obliquely downwards. 
The dorsal vertebrae are fourteen in number, (as in the 
Chimpanzee, according to Cuvier) ; they much resemble the 
human in shape and size; the last two are rather larger, and 
more like the human lumbar vertebrae ; the spinous and trans- 
verse processes are much more developed ; the spinous pro- 
cess of the first is like the cervical, and two and seven eighths 
inches long; the spinal canal is less in this and the remainder 
of the column; the spinous processes of the second and third 
dorsals are compressed laterally at the end, and are two and 
a half inches long. At the fourth, the spinous processes 
begin to descend, as in man, to the ninth ; below this they re- 
semble the lumbar spines, though pointing more downwards. 
The last dorsal has its rib on the right side firmly anchylosed 
to the body. 
The lumbar vertebrae are only three in number, fewer than in 
any of the higher Mammals; the bodies are larger and thicker 
than in man; the vertical diameter is less anteriorly than 
posteriorly, making this region concave anteriorly, and show- 
ing that the erect position is as unnatural for it as for the 
other Quadrumana. Possibly one of the lumbar vertebrae may 
be missing; though from the manner in which they fit into each 
other, and into the last dorsal and first sacral, it seems hardly 340 
Kneeland on the Skeleton of the Great Chimpanzee. 
probable ; adding the fourteen dorsals, the whole number is 
the same as in man. 
The sacrum, which has a slight lateral devialion to the left, 
consists of eight bones, firmly joined together, the interverte- 
bral spaces being obliterated, excepting between the first and 
second. The first bone resembles very much a lumbar ver- 
tebra, and on one side its transverse process, though bearing 
the upper portion of the articulating surface for the right 
ilium, is not connected with tire lateral portion of the sacral 
wing below ; on the left side, the bony union is complete, 
and the spinous process is continuous without interruption or 
foramen with the median sacral crest; this crest, at its upper 
portion, is two inches in height, gradually decreasing, and 
lost entirely on the sixth bone, where also the sacral canal 
terminates. The sacrum is long and narrow, having a very 
decided concavity anteriorly. The articulating surface for 
the ilium is confined to the first three vertebrae. Whether or 
not any coccygeal vertebras are anchylosed in the sacrum, it is 
not easy to say; from the uncommonly large number of 
sacral vertebrae, namely, eight, it would seem probable that 
these also include the coccyx ; the terminal bone ends in a 
rounded projection, which has somewhat the appearance of 
an articulating surface.1 
The bodies of the second and third cervical vertebrae 
incline backwards; the direction becomes perpendicular in 
the fourth, and in the last three a little inclined forwards ; at 
the upper dorsal region the spine is slightly convex, in the 
lower dorsals and lumbar concave ; at the last lumbar and 
first sacral it is again convex, and in the lowest portion again 
concave. The whole number of vertebrae is thirty-two, and 
possibly thirty-three ; the length of the cervical, dorsal, and 
lumbar vertebrae is twenty-two inches; from this it would 
appear that the spinal column is very nearly as long as the 
1 In Dr. W. Lewis’s description of a Gibbon (Yol. I. of this Journal, p. 35,) 
it is stated that the coccyx consisted of one bone ; in our specimen this single 
rudimentary coccyx may have been attached to the sacral terminal surface. Kneeland on the Skeleton of the Great Chimpanzee. 
341 
human, to which it also comes nearer, in its curves, than to 
that of any of the Quadrumana. 
The pelvis of the T. gorilla departs widely from that of the 
Chimpanzee and Orang, and approaches that of man in the 
greater spread of the ilium, — its deep anterior cavity, and 
corresponding posterior convexity, on which a well-marked 
longitudinal ridge indicates the origin of the glutseus maxi- 
mus, — and a fainter semicircular line, extending from the 
sciatic notch to near the rudimentary anterior inferior spinous 
process, about two and a half inches above the acetabulum, 
the probable origin of the glutseus minimus; the anterior 
superior spinous processes are fully six inches in advance of 
the plane of the sacrum. The sacrum extends only to the 
spine of the ischium, about four inches from the tuberosities 
of this bone, so that the pelvis has somewhat of the length- 
ened narrow form peculiar to the Quadrumana, though it 
projects far more from the line of the spine than in the other 
members of the group. The superior aperture has not the 
narrow, elongated shape of the Orang’s, the antero-posterior 
diameter being only half an inch greater than the transverse, 
these being respectively six and a half and six inches ; in the 
female, according to Dr. Wyman’s measurements, the dif- 
ference is greater, being three inches. The tuberosities of 
the ischia are very thick and broad, and the rami of the 
pubes very wide; the whole lower portion indicates great 
strength and solidity. It is the portion of the pelvis between 
the acetabulum and the lower edge of the sacro-iliac articula- 
tion, which is so much shorter in this animal than in the 
Chimpanzee, and which gives to the pelvis its more human 
aspect. 
At first sight the scapula has the appearance of the human, 
having very much its shape, but somewhat enlarged; the 
measurements given at the end of the article show it to have 
belonged to a larger specimen than the one described by 
Dr. Wyman. It more nearly resembles that of the Orang 
than that of the Chimpanzee, but is more like that of Man 342 
Kneeland on the Skeleton of the Great Chimpanzee. 
than either, in its more equilateral form. The spine is placed 
nearly in the middle of the bone, making the supra spinous 
nearly equal to the infra spinous fossa; after about one third 
of its length it ceases to have the broad thick edge of the 
human spine, reaching nearly to the posterior border, but is 
continued by a sharp well-marked ridge quite to the edge, as 
in the Orang; the spine is also more perpendicular to the 
plane of the dorsum than in man, and its direction more that 
of the axis of the trunk. The acromion process is longer, 
and less curved than in man, and wants the strong angle on 
its posterior surface a little in advance of the plane of the 
glenoid cavity ; its arch over this cavity belongs also to a 
much larger circle. The coracoid process has a greater in- 
clination downwards than in man and the Chimpanzee ; this 
direction, in the Orang, Vrolik considers a sign of inferiority. 
The glenoid cavity is much the same as in man, the upper 
half being less narrow in proportion. The subscapular fossa 
is very deep, and divided by prominent ridges into five or six 
smaller depressions. There is no deep supra-scapular notch 
as in the human scapula; but there is a decided concavity at 
the base of the coracoid process, without the narrowness of a 
notch, contrasting strongly with the nearly straight line of the 
upper border of the bone in the Orang. 
The clavicles are shorter and stronger than in man, and 
less curved ; the edges are more angular; their length, in a 
straight line, is six and one fourth inches; their circumference 
in the middle two inches, thence increasing to each end ; the 
subclavian ridge is well marked. 
The sternum, at its upper portion, is four inches wide, and 
about half an inch thick ; there is a decided semilunar notch, 
but less than in man ; the lower portions are wanting. There 
is no sign of division into lateral halves in this upper portion, 
which is three and three fourths inches long. The articular 
surface for the clavicles is less curved and more horizontal 
than in man. 
The ribs are fourteen pairs; of these two are wanting on Kneeland on the Skeleton of the Great Chimpanzee. 
343 
the left side, at about the middle of the series. They much 
resemble those of man, and form a very capacious thorax; 
they are, however, longer and thicker, and the curves less 
complicated. Some of them, like other bones, bear marks of 
old injuries. The angles of the ribs are extremely well 
marked; even the last is united both to the body and to the 
transverse process of a single vertebra. 
The humerus is about three inches longer than that of man, 
and two inches greater in circumference at the middle, the 
latter measurement being five inches ; around the middle of 
the head, horizontally, eight and one fourth inches ; greatest 
width at lower extremity four and one fourth inches. The 
bone is of very compact structure, and very heavy. It re- 
sembles that of man, but it is less twisted on itself; the bici- 
pital groove is quite deep and wide, having on its sides very 
large tuberosities for the insertion of the powerful muscles 
indicated by the immense scapular surface of origin; the 
ridges for the attachment of the pectoralis major, latissimus 
dorsi, and teres major attest also the great strength of these mus- 
cles ; unlike those of Dr. Wyman’s specimen, these bones have 
the deltoid insertion well marked, and the anterior face rather 
convex than concave, even more so than in man. Both the 
condyles, and the condyloid ridges are more developed than 
in man ; the trochlear portion is less excavated, and the 
internal ridge less prominent; there is a deep groove between 
the trochlea and the surface for the head of the radius, which 
is very slight in man. The lower extremity is perforated in the 
right humeris, but not in the left; the cavity for the olecra- 
non is an inch in width and half an inch deep, while that for 
the coronoid process on the anterior surface is hardly sunk 
beneath the level of the bone; this difference is much less 
in man. 
The ulna is more curved than in man, as is also the radius ; 
they curve in opposite directions, inclosing a wide space be- 
tween them ; the curve of the radius begins at the tubercle, 
while the ulna is curved its whole length. The articulating 344 
Kneeland on the Skeleton oj the Great Chimpanzee. 
surface for the humerus, on account of the less prominence 
of the inner ridge of the trochlea, differs from that of man in 
being proportionally wider, and in having a deep concave 
inner wall, which in the human ulna is not only wanting, but 
the edge of this border of the joint is worn into a deep notch 
corresponding with the long inner ridge of the human tro- 
chlea; at the bottom of this cavity is an irregular long bone, 
apparently wedged in, and perhaps having a separate centre 
of ossification ; if the olecranon process were taken off through 
the suture here left open, the head of the ulna would very 
much resemble the head of the tibia, to which it corresponds 
in the lower extremity ; this is seen on both sides. The 
articulating surface for the head of the radius is less perpen- 
dicular than in man ; the coronoid process is also less promi- 
nent, in conformity with the small anterior concavity on the 
humerus; the styloid process, and the accompanying groove, 
occupy a greater proportion of the lower extremity. With 
the exception of stronger ridges, and sharper angles, the 
remaining portions of the ulna and radius resemble much the 
same bones in man, on a large scale. The proportion between 
the humerus and ulna brings this animal nearer to man than 
the Chimpanzee or Orang. 
The femur, in its head and neck, is much like the human; 
it has a roughness, hardly a depression, for the ligamentum 
teres ; the neck of the bone is proportionally shorter, and 
placed more obliquely with respect to the shaft; the trochan- 
ters, especially the great, are much stronger ; the lesser tro- 
chanter also stands out enormously to receive the internal 
iliac muscle, situated in the immense iliac fossa, and princi- 
pally concerned in flexing the thigh on the pelvis, as in the 
act of climbing ; the space between the great trochanter and 
the head of the bone is less, and the concavity much deeper 
than in man ; the neck of the bone is also more flattened and 
less round, supporting, as it does, less proportional weight. 
The whole bone is flatter, especially just above the condyles, 
and its shaft more curved. Though the inner condyle is so Kneeland on the Skeleton of the Great Chimpanzee. 
345 
much longer than the external as to give the lower part of 
the shaft an inclination outwards, as in man, the curve of the 
middle and upper portions restores its general direction nearly 
to the vertical, as in the Chimpanzee. The femur is about 
two inches shorter than the humerus; in this respect the T. 
gorilla recedes from the human type, while he approaches it 
in the relative lengths of the ulna and humerus. 
The tibia also is considerably shorter than the human, 
and more curved both laterally and anteriorly, producing 
consequently a large .interosseous space. The upper articu- 
lating surfaces, as observed by Dr. Wyman, are on different 
planes; the internal one being the lowest and concave, the 
outer one convex; as the lowest surface answers to the long- 
est condyle of the femur, the axes of the bones are nearly in 
the same line. The right astragalus is preserved, somewhat 
resembling the human, but flatter and longer ; the articular 
surface for the tibia is less convex, and narrower posteriorly ; 
the surface for the scaphoid is more prominent, flatter, and 
with a better-marked constricted portion or neck ; the lateral 
surface for the tibia is more quadrilateral and less vertical ; 
the surface for the fibula is less triangular; the posterior por- 
tion is wider, with a less deep groove for the flexor longus 
pollicis ; the surfaces for the os calcis, with the deep groove, 
are very much as in man. There are also some carpal, meta- 
carpal, and phalangeal bones of the hand, and a few pha- 
langes of the toes ; the metacarpal bones are long and curved 
inwards, with large lower articulating surfaces; the bones of 
the fingers have their edges much turned under on the ante- 
rior surface, for the protection of the vessels, nerves, and ten- 
dons, as they grasp the limbs of trees in their usual swinging 
mode of progression ; they may also serve for the insertion of 
the strong ligaments. 
All the bones are exceedingly solid and heavy, indicating 
very great muscular force ; many of them bear marks of frac- 
ture and bony growths, which indicate that this was a vetera* 
male, who had seen many a hard fight; the skull, the lower 
JOURNAL B. S. N. H. 45 JUNE, 1852. 346 
Kneeland on the Skeleton of the Great Chimpanzee. 
jaw, and many of the long bones show by their broken condi- 
tion that he was killed only after a severe struggle, and with 
many a wound both from bullet and cutting instrument. 
The height of this specimen must have been nearly five 
and a half feet, and the breadth of his shoulders, judging 
from the scapulae and libs, over two feet; the hands extend a 
little below the knees ; the abdomen, judging from the iliac 
fossae, must be nearly two feet wide ; the lower extremities 
are strongly bowed. If we clothe this immense skeleton with 
its powerful muscles and its coarse covering, we may 
have an idea of a monster which it would be more pleasant 
to read about and describe than to meet. 
A table of measurements (in inches) has been added, com- 
paring this specimen with those of Dr. Wyman ; those be- 
longing to the former occupying the first column, and the 
latter the other two. 
Head. 
Male. 
Male. 
Female. 
From the posterior plane of the occiput to mar- > 
gin of incisors, ..... J 
Greatest lateral diameter of cranium at post- } 
auditory ridges, ..... J 
13.5 
12. 
9.1 
6. 
6.1 
5.2 
Smallest lateral diameter of cranium behind orbits 
Diameter of face across zygomata, 
Diameter of face outside of orbits, 
From posterior plane of occiput to fronto-nasal ) 
2.5 
6.75 
5.3 
7.5 
2.5 
6.5 
4.9 
7.3 
2.5 
5.5 
4.3 
6.5 
suture, ....... £ 
From fronto-nasal suture to margin of incisors, 
6.5 
4.8 
4.5 
Breadth of zygomatic fossa, . 
2. 
1.7 
1.4 
lnter-orbitar space, ..... 
1.3 
1.1 
1. 
Lateral diameter of orbit, .... 
1.6 
1.5 
1.4 
Vertical diameter of orbit, .... 
1.75 
1.6 
1.4 
Length of bony palate, .... 
3.5 
3.7 
3.4 
Lower Jaw. 
Length from condyle to symphysis, . • 
7.5 
7. 
6.5 
Length from angle to symphysis, (outside,) 
6. 
From angle to condyle, .... 
Breadth between angles, (inside,) . • . 
5. 
5. 
Breadth of ramus, ..... 
2.9 
2.9 
2.45 
Height of ramus, ..... 
5. 
4.6 
4.3 
Upper Extremity. 
Length of scapula along base, 
10. 
9. 
liroadest part of scapula, .... 
7.25 
6.5 Kneeland on the Skeleton of the Great Chimpanzee 
347 
Posterior extremity of spine from upper angle, 
Male. 
5.3 
Male. 
4.5 
Femal e. 
Humerus, ....... 
16.5 
17. 
Radius, 
13.5 
13.5 
Ulna, 
14.3 
14.2 
Pelvis. 
Length of sacrum, 
6.5 
6. 
Breadth of sacrum, 
Breadth of pelvis between spinous processes of ilia, 
4. 
3.7 
3.2 
16.5 
15. 
15. 
Breadth of ilium, 
0. 
8. 
7.5 
Length of os innominatum, .... 
14.5 
14. 
12. 
Antero-posterior diameter of pelvis 
6.5 
8. 
Transverse diameter of pelvis, 
6. 
5.1 
Length of symphysis, ..... 
Long diameter of obturator foramen, 
3.2 
3. 
2 3 
2.2 
2.1 
2.2 
Outside of one tuber ischii to the other . 
7.15 
5.8 
Lower Extremity. 
Femur, . 
14.3 
14. 
Tibia, 
11.5 
11.5 
Vertebra. Last Dorsal. 
Transverse diameter, ..... 
1.7 
1.75 
Antero-posterior diameter, .... 
1.25 
1. 
Vertical diameter of anterior face, . 
1.1 
.8 
“ “ posterior face, 
1.15 
Second Lumbar. 
Antero-posterior diameter, .... 
1.3 
1.15 
Transverse diameter, ..... 
2. 
1.7 
Vertical “ anterior face, 
1. 
1. 
“ “ posterior face, 
1.4 
1. 
Second Dorsal. 
Antero-posterior diameter, .... 
.65 
Transverse diameter, . 
1. 
Vertical “ anterior face, 
.6 
“ “ posterior face, 
.75 
Fourth Cervical. 
Antero-posterior diameter, .... 
.7 
Transverse diameter, 
.8