736 PRIMATES 
number of the dorso-lumbar vertebrxe, the present and following 
genus resemble man; although they both differ in having thirteen 
in place of twelve pairs of ribs. 
The brain of the Gorilla, according to Dr. Hartmann, resembles 
that of the Orang in the complexity of its convolutions, and is 
thereby distinguished from that of the Chimpanzee. In form it is 
of the long oval characteristic of Man; the brain of the Chimpanzee 
and Orang being more rounded. 
Gorillas live in family parties in the depths of the dense forests 
of Western Equatorial Africa, seeking their food during the day, 
while at night it is said that the female and young ascend a tree 
at the foot of which the male sleeps. They walk with the backs 
of their closed hands and the flat soles of the feet placed on the 
ground. Although there has been much exaggeration on this 
point, it appears certain that the male Gorilla is an extremely 
ferocious and dangerous animal when brought to bay, but the 
statements as to its making unprovoked assaults on men do not 
appear authentic. They utter deep guttural sounds, which on 
some occasions may be described as grunts and at others as a 
roar. 
Anthropopithecus1—One of the most important differences of 
this genus from the preceding is the absence of any marked 
disparity between the two sexes, either in the size or the con- 
formation of the skull, although the male can always be dis- 
tinguished by the larger size of the canine teeth. The mandibular 
symphysis is also much shorter. Differences in the characters of 
the teeth are described below. The genus is confined at the present 
day to the Ethiopian region. 
The Chimpanzees (Fig. 357) inhabit Western and Central 
Equatorial Africa; and there has been much discussion whether 
they should all be included under one specific name (d. troglodytes), or 
whether there are really two or more species. A female specimen 
now living in the London Zoological Gardens, characterised among 
other distinctive features by the nearly bald head, clearly indicates, 
however, a second species, which probably corresponds to the 
imperfectly defined .f. calrus of Du Chaillu. 
The region inhabited by the Chimpanzees extends from the 
Gambia to the Benguela, reaching as far inland as 28° E. long. 
The Common Chimpanzee is a smaller animal than the Gorilla, its 
height not exceeding 5 feet. In colour it is darker than the 
latter, and the ears are relatively larger. In the upright position 
1 De Blainville, Lecons Orules (1839). The Chimpanzees have been very 
generally described under the name of Zroglodytes, but since this name is 
preoccupied for a genus of birds, it is incumbent to follow the strict rule, and 
adopt the name Anthropopitheens, although both the present witers have 
elsewhere expressed the opposite opinion. 
