THE ORIGIN OF THE HUMAN BODY 271 



which have their strength concentrated in the hind-limbs, 

 e.g. reptiles like the dinosaurs. In the last place come the 

 prosthenic vertebrates, whose strength is concentrated in the 

 fore-limbs, e.g. the carnivora and apes. Now man belongs to 

 the merosthenic type, and his mode of progression, therefore, 

 is more primitive than that of apes, which are prosthenic, all 

 anthropoid apes, such as the gorilla, the chimpanzee, the orang- 

 utan and the gibbon having longer fore-limbs than hind-limbs. 

 The striking anatomical differences between apes and men, 

 though not of suflBcient importance to exclude the possibility 

 of collateral relationship, are so many solid arguments against 

 the theory of direct descent. We will content ourselves with 

 a mere enumeration of these differences. In the ape, the 

 cranium has a protruding muzzle and powerful jaws equipped 

 with projecting canine teeth, but the brain-case is compara- 

 tively small; in man, on the contrary, the facial development 

 is insignificant and the teeth are small and vertical, while the 

 brain-case is enormous in size, having at least twice the 

 capacity of that of an ape. "The face of man," to quote 

 Ranke, "slides, as it were, down from the forehead and appears 

 as an appendix to the front half of the skull. But the gorilla's 

 face, on the contrary, protrudes from the skull, which in turn 

 slides almost entirely backward from the face. By a cross-cut 

 one may sever the whole face from the skull, except a very 

 small part near the sockets, without being forced to open up 

 the interior of the skull. It is only on account of its protrud- 

 ing, strongly developed lower parts that the skull-cap of the 

 animal can simulate a kind of human face." ("Der Mensch," 

 vol. II, p. 401.) These differences may be summarized by 

 saying that the head of the ape is specialized for mastication 

 and defense, whereas the head of man is specialized for 

 psychic functions. Again, as we have seen, the fore-limbs of 

 the ape are long, and its hind-limbs short, the extremities of 

 both the latter and the former being specialized primarily 

 for prehension and only secondarily for progression. This is 

 due to the ape's adaptation to arboreal life. In man, however. 



