THE CHIMPANZEES. IQl 



The vertebral cobimn begins to show the S-shaped 

 flexure, characteristic of Man's back-bone ; it presents also 

 a human character in the form of its second neck vertebrae, 

 and there are thirteen pairs of ribs, as in Man. The hind- 

 most vertebras "give the impression of a rudimentary tail." 

 {JIartjnan?t) 



The humerus is nearly equal in length to the fore-arm ; the 

 wrist {carpus) has only eight bones (the central bone being 

 absent), agreeing, therefore, with the number in Man. 



All the ridges and grooves seen in the human brain are 

 present in that of the Chimpanzee, but " they are simpler and 

 more symmetrical, and larger in proportion to the brain." 

 {Huxley.) The cerebellum, and the nerves also, are larger in 

 proportion to the cerebrum than in Man; and certain structures 

 (the corpora trapezoided) which exist in the brains in the lower 

 Mammalia are absent. These prominences, which are situated 

 in that portion of the brain known as the medulla oblongata^ at 

 the summit of the spinal cord, disappear, as we have seen, in 

 all the genera of higher rank than the Cebidce, one of the 

 lowest families of the Anthropoidea. The brain in its convo- 

 lutions and in many other respects conforms to that of the 

 Orang. This is especially the case in A. calvus. 



The uvula, which is absent in the throat of the Orang, is 

 pendulous in the Chimpanzees, as in Man. Large air-sacs 

 are also present, and the hyoid bone is excavated posteriorly, 

 suggesting the conformation of the same bone in Alouatta (the 

 South American Howlers). The stomach is very similar to 

 that of Man, and so are the digestive and reproductive organs. 

 The round ligament, attaching the head of the thigh-bone 

 into its pelvic socket, is present, and restricts the flexibility 

 of the hind-limb of the Chimpanzees, compared with that of 



