272 CONTRIBUTIONS TO COMPARATIVE PATHOLOGY. 
of the human being than does that of the latter ; and, in fact, 
that the chimpanzee occupies the first step next to man in the 
descending series of beings. For the short sketch of the bony 
structure of these animals which follows, I am chiefly indebted 
to that paper. 
The surface of the skull is smooth and convex, on the coro- 
nal portion of it, in the chimpanzee, in distinction from the fron- 
tal and sagittal crests, which give so strong a carnivorous cha- 
racter to the orang. There is a far greater proportion of brain 
behind the meatus auditorius externus. The cranial sutures re- 
main in the adult animal. The facial angle in the chimpanzee 
is 35° in the orang it is but 30°. In the young chimpanzee the 
cranial portion of the skull preponderates over the facial, and, 
as in the infant, the development of the brain is great compared 
with that of the frame. As the animal grows, the brain grows 
too, although not in the proportion in which it does in man ; 
but in the orang, although the cranium seems to enlarge with the 
growth of the animal, it is only a thickening of the walls, and a 
development of the frontal and sagittal crests, and a development 
of the temporal muscles, while the cavity of the cranium is 
scarcely enlarged at all. 
The projecting nasal bone — the aquiline nose — of the chim- 
panzee, compared with the flattened elongated bone of the orang, 
is a startling approximation to the anthropoid character. 
The smaller development of the canine teeth in the chim- 
panzee, compared with the corresponding formidable weapons 
of destruction possessed by the orang, and the situation of the 
teeth approaching to the unbroken proximity of those of man, 
are very striking resemblances of structure. 
The clavicle of the simia troglodytes is longer and stronger, 
keeping the shoulders more widely apart than those of the simia 
pithecus or orang, and has the same curve as that of man. The 
humerus closely resembles that of man. The peculiar twist of 
it is very evident, while the distal articulating surface allows 
much variety and freedom of action. The radius and ulna are 
more curved than in man, leaving room for greater muscular 
development, and for muscular attachments to greater mecha- 
nical advantage, but not so curved as in the orang. The upper 
extremities, although longer than those of the human being, are, 
compared with those of the orang, short : they reach only to the 
knee in the chimpanzee, while they extend as low as the ancle in 
the orang. The carpal bones are smaller in the chimpanzee. The 
thumb reaches to the end of the metacarpal bone of the fore 
finger, but in the orang it does not reach so far. 
In the hind extremities the chimpanzee differs from the orang 
