COMPARISONS OF THE GREAT APES. 
8<T 
an Ape as large as a man, but which resembled the Hylobates, were found there, and named Dryo- 
pithecus , in strata of Mid-Tertiary age. 
In concluding this part of the subject, which relates especially to the man-shaped Apes, some 
very obvious reflections occur. There is something very interesting as well as instructive and suggestive 
in the study of the proportions of the limbs to each other and to the body in the larger Apes, of which 
The fingers in 
knee ; in the 
man hang down to below the 
Chimpanzee they reach below 
JAW OF THE GIBBON. 
the Gorilla is the highest in the scale, and in man. 
middle of the thigh ; in the Gorilla they attain the 
the knee ; in the Orang they touch the ankle ; in 
the Siamang they reach the sole; and in some 
Gibbons the whole palm may be applied to the 
ground without the trunk being bent forward 
beyond its natural position on the legs. It is also 
found that in man the arm-bone exceeds in length 
each of the bones of the fore-arm in a marked 
maimer, and in the Gorilla and Chimpanzee it does 
so but slightly ; the bones are equal in the Orangs, 
and very unequal in the Gibbons, those of the 
fore-arm being the longest. When the length of 
the arms down to the wrist is compared with that 
of the body, omitting the legs, there is not much 
difference between man and the Gorilla, but it increases in the Chimpanzee, Orang, and in the Siamang. 
The lower limbs are short in the Gorilla, and this is characteristic — they offer but a poor support to- 
the huge body — and the resemblance to the symmetrical proportion of the legs to the body in man is 
scanty indeed. This disproportion is greater in the Chimpanzee and Orangs, in which the lower limbs 
are pigmies. 
Consider the hand in the same manner. Man’s perfect hand, writes Owen, is one of his peculiar 
physical characters, and that perfection is mainly due to the differences of the first and the other four 
fingers, and the ability of this first to be opposed to them, as a perfect thumb. A partially opposable 
thumb, that is to say, one which can be brought over the palm, more or less, is present in the hand of 
the great Apes. It is large in the Gorilla, so far as Apes are concerned, and it reaches, when it and 
the fingers are stretched out, to just a 
little beyond the first joint of the first 
finger, or rather of its first movable part. 
But in the Chimpanzee and Orang it 
does not reach to the joint, and it is 
longest and strongest in proportion in 
the Gibbons (Hylobates). In the Gorilla 
and the Chimpanzee, the wrist-bones are 
in number, but there are nine in 
BACK OF JAW OF THE AGILE GIBBON. 
eight 
the Orangs and Gibbons. 
of the length 
The toe-tliumb is about five-twelfths 
of the whole foot in the Gorilla, and it is slightly longer in the Chimpanzee and 
Hylobates, but it is not more than a fourth of the length of the foot in Orangs. 
The nails of all the fingers and toes of the great Apes are flattened, except in the Hylobates, 
whose thumb and toe-thumb nails only are so ; the rest are more claw-like. 
Finally, as regards the brain and nervous system. In the man-shaped Apes the brain is smaller as 
compared with the nerves which proceed from it than in man ; and the brain proper is smaller relatively 
to the cerebellum than in man. The convolutions, the fissures, and eminences of the brain are 
generally less complex, and those of the two sides or hemispheres of the brain are more symmetrical 
than in man. The sides of the brain or the hemispheres are rounder and deeper in man, and the' 
proportions of their lobes to one another are different. Some convolutions and fissures present in man 
are less perfectly formed, but still exist in the Apes, and the cerebellum is not covered entirely in the- 
Hylobates but it is in the other Anthropomorplia. 
