THE BONES 77 



The prototype of the carnivora (arctocyon) like the pro- 

 totype of the ungulates (phenacodus) had a hand which 

 closely resembled that of the prosimiae and primates of the 

 present day. When the human hand is compared with the 

 hand of an anthropoid many points of difference may be 

 observed. Man alone possesses a perfect hand fitted for the 

 most delicate uses. The hand of the highest anthropoid, the 

 gorilla, is broad and clumsy, and, in the opinion of R. Hartmann, 

 is more like a lion's paw. The length of the palm is considerable, 

 but the fingers only become independent from the middle of 

 the first phalanx ; between the third and fourth fingers the skin 

 is continued almost to the second phalanx. The dorsal surface 

 of all the fingers is convex. 1 In the chimpanzee also the four 

 fingers are connected with each other by a membrane which 

 sometimes extends as far as the joints between the first and 

 second phalanges. As in the gorilla, the horny skin of the 

 palm is furrowed with countless wrinkles, and the gorilla has 

 numerous small callosities deeply imbedded in the lines of the 

 hand. 



Another of the typical features of man is the thumb, sur- 

 passing as it does in length and anatomical structure the thumb 

 of even the highest anthropoids. In man the thumb extends as 

 far as, or even past, the middle of the first phalanx of the index 

 finger. In the gorilla it reaches but a short way beyond the 

 base of the first phalanx of the index finger, while in the 

 chimpanzee and other anthropoids it is still shorter. The 

 human thumb alone has remained stationary throughout the 

 ages and has thus not increased in perfection. In all the apes, 

 without exception, the thumb has undergone retrograde changes, 

 so that the hand, even of the gorilla and the gibbon, is no longer 

 a perfect organ of prehension. In all apes the index finger is 

 shorter than the third finger, though, it must be admitted, 

 cases are sometimes found in man betraying very similar ape- 

 like conditions. 



Distinctively human is the power of bending the hand so as 

 to form a kind of scoop, and the power of completely encircling 

 a ball (suited to the size of the hand) with the curved fingers 

 (A. Ecker). In his book Ranke 2 advances several points, of 



1 Ranke, loc. cit., ii., pp. 15, 24. z lbid., p. 7. 



