530 THE EVOLUTION OF THE HUMAN FOOT. 



beeau.se of the very fact that he is ai-boreal to a supreme deg-ree, pos- 

 sesses a reduced g-leuoid cavity; in man the primitive arrangement, 

 that is to say, the one which is analogous to that of the arboreal animals 

 is again found, as may 1)6 supposed, in negroes and the greater number 

 of negritos, and the arrangement adtii)ted to plantigrade locomotion 

 belongs to the European. 



It is strange to lind that this peculiarity of the European foot, dis- 

 tinguishing it from that of the negro, recurs in certain rodents and 

 marsupiids of a primitive type. This nuist doubtless have piqued the 

 curiosity of M. Volkov; he has, it seems to us, completely solved the 

 enigma. The animals of primitive types have an extra bone, the 

 external tibial, which in primates is fused with the scaphoid and forms 

 its tuberosity. This explains the greater transverse dimensions which 

 the scaphoid, has in apes. In man, because of adaptation to walking, 

 the scaphoid is reduced, and though it still possesses, coossitied with 

 it, the external tibial, it has assumed the reduced dimensions and the 

 appearance of the autonomous scaphoid of primitive manuuals. 



1 shall content myself with this too rapid and incomplete examina 

 tion of these three most important elements of the human foot, and 

 hasten on to a consideration of the foot as a whole, the real synthetic 

 portion of M. Volkov's work. 



Considering- as a whole the foot, not merely of man alone but of all 

 animals that walk upon their soles, such as the bear, for example, and 

 one of a very remote class, the armadillo, we see that it is greatly 

 differentiated from that of animals who use it but seldom, or not at 

 all, for walking. Among the latter the skeleton of the tarsus is 

 greatly lacking in solidity, the ligaments are relaxed, and the bones 

 have rounded articular facets denoting movements of considerable 

 amplitude. On the contrar}', the tarsus of a plantigrade, such as man, 

 is formed of angular bones with nearly ilat articular surfaces, bound 

 together by powerful ligaments, an arrangement indicating that its 

 movements are very restricted. 



It is the same with the toes. In arboreal monkeys they are very 

 movable, the first is even opposable, while, in man, they remain bound 

 together. 



In the most arboreal monkeys, as is remarkably well shown in the 

 orang, the metatarsals and the phalanges are bent, presenting a con- 

 cave surface on the plantar aspect, an arrangement adapted for 

 grasping branches; in man they are almost straight. Besides these 

 characters, the foot of man has another important peculiarity which 

 also assists in giving it the solidity required for plantigrade walking; 

 that is, its arched condition. 



The monkeys not adapted for walking have a flattened foot, and, as 

 is well known, support themselves upon its outer border whenever 

 they attempt: to progress along the ground. 



