Chaptek X1\ 



TROGLODYTES NIGER, THE CHIMPANZEE, ITS BRAIN 



AND BEHAVIOR 



//,s- Posiliu)} umani: the Pnmaics; Mvasurcincnls and Bruin Indices; Surface 

 Appearance of the Brain; Inter7\al Structure of the Brain Stem in Cross Section 



~^11I{ thimpanzff, although usuall\ iftcrrccl to tlu- f^i'iiiis ol l-*an, is 

 sdim'tinu's clrscribc'cl as Simia, w hicli appears to l)c' an oIcKt clfsigna- 

 _ tioii. It occiipirs a position amon^ tlu' <j:;rcat antliro[K)icl apes inlcr- 

 mcduitc bclwecn the gorilla and the orang-outang. 



Appearance of the Chimpanzee 



In point ol si/e it is somewhat hirger than tlu' orang, hut smaller than the 

 gorilla. Depending upon its speeies, tiie animal \aries m height Irom some- 

 thing o\er thrt-e feet to a littk- o\ t'r lour k'ct. In eolor it is a ljlaekish-i)ro\\ n 

 with rather thiek hair o\er the entire bod\ exeept the laee and brow . In some 

 species the scalp is bald. Ilu' ehimi)an7.ee i:>ossesses great strength and 

 agility. In spite of its rc'lati\el\ short stature, it is more than a match e\-en 

 for the strongest man. Its bod\ is short, usuall\ with a protuberant abdomen. 

 Tke legs are also short, and compared w ith tin- ii|)per extremity, the\' appear 

 even shortt-r. The foot is short with a great toe which is thick and opposable. 

 The otiur toes ari' united b\ a wt'b near tlu'ir basi's. The arms are long, reach- 

 ing for a considerable distance bilow the kiu't's w hen the animal stands erect. 

 The hands are broad; the thumb is short and tlu' lingers are united by a web 

 at their bases, as in the case of the toes. The middle linger is the longest. 

 Callosities dcxt'lop on the dorsal surkicc' of the lingers in consequence of 

 "knuckle" walking and running w hich the animal dues mostly upon all lours, 



545 



