572 EXTERNAL CHARACTERS OF GORILLA CHAP. 
and it is a curious fact that the Siamang, which has a large 
laryngeal pouch, is not excelled in this respect by species in 
which this sac is not developed. 
, 
Fic. 273.—Cerebrum of the Gibbon (ylobates). (Lateral aspect.) c.c’, e.c’’, Anterior 
and posterior central convolution ; %, interparietal fissure; fv, frontal lobe ; 
Js, Sylvian fissure ; 0c, occipital lobe ; pa, parietal lobe ; s.c, fissure of Rolando ; 
tp, temporal lobe; *, fronto-orbital fissure. (From Wiedersheim’s Structure of 
Man.) 
Of Gorillas, genus Gorilla, there is but one species, which must 
apparently and rather unfortunately be called Gorilla gorilla. 
The misfortune is double: in the first place the repetition of 
the same word as both generic and specific appellation is tiresome 
to the ears and barbarous in its suggestion ; in the second place 
it is now well known that the “ Gorilla ” of Hanno, observed by that 
Carthaginian voyager on an island off the African coast, was not 
a Gorilla at all as the word is now understood, but probably a 
Baboon. The external aspect of this great Anthropoid is familiar 
from many reproductions. The male, as is usual, is larger than 
the female, and his characters are more pronounced. 
The face is naked and black, and the skin generally is deep 
black, even at birth. The ear is comparatively small, and is 
adpressed to the side of the head; it is altogether more human 
in form than that of the Chimpanzee, and this statement applies 
also to the rudimentary condition of the muscles of the ear, 
which are more rudimentary than in the Chimpanzee. The nose 
has an obvious median ridge, and is thus pronounced as an external 
feature; the nostrils are very wide. ‘The hands and feet are 
short, thick, and broad; the digits are webbed. In the foot the 
heel is more apparent than in other Anthropoids. It is not, 
