702 THE HIGHER ANTHROPOIDS 



these great anthropoids unlit tluin tor an circctual ficct posture and thus 

 impose upon thrni all alike a limitation w hieli prohibits the ultimate eulmina- 

 tion ol manual diii'erentiation. Neither the hand nor the foot is exclusivclv 

 sueh in the great anthropoids. Each partakes of characters of the other; the 

 foot in many respects being hand-like, while tin' hand is much used as a foot. 

 The plannnetric coefficients of the pyramichil systems in orang, ehim])anzce 



and gorilla are given m the tollowing tabulation 



Pi_JiNiMETRic Coefficients of the Pyramidal System in Higher Anthropoids 



COMPARISON OF THE PYRAMIDAL SYSTEM IN THE GREAT ANTHROPOIDS AND 



THE INTERMEDIATE PRIMATES 



The general relation of the pyramidal system in the higher anthro- 

 poids to that of the intermediate primates is of even greater interest. W hat- 

 ever slight differences exist among the great apes in this respect, the variation 

 between these and the intermediate group is so striking as to ieave no doubt 

 concerning a dehiiite advance in neokinetic organization. The i)yramidal 

 system III the higher antliropoids is much greater than in the intermediate 

 primates. The gibbon stands fow est in the scak'. Reasons lor its more limited 

 neokinetic activity ha\c' alreadx been ascribed to the restrictions imposed 

 upon It by its extreme arboreal specialization and its im|)erfect development 

 of the lower extrt-mity. Macacus, on the other hand, stands nearest to the 

 higher anthropoids, although the interxal between it and them is impressive. 

 This approximation may, perhaj^s, be explained b\ tlie fact that the macaque 

 has developed an ellien-nt manual organ which only lags behind that ol the 

 higher anthropoids because of tlu' animal's cxtensi\e specialization for an 

 essentially arl^oreal tyjx' of life. . 



