18 PHYSICAL BASIS OF CIVILIZATION 



from hands by having the hallux unopposable, 

 owing to the altered shape of the entocuneiform 

 bone. The hallux is long enough to serve as a ful- 

 crum, standing or walking. This, in connection 

 with the position of the occipital foramen magnum, 

 a little back of the center of the base of the skull, 

 is the essential condition on which the erect attitude 

 depends. 



Most scientists continue to call the posterior 

 extremities of apes and anthropoids hands, and all 

 apes quadrumana. This view has been adhered 

 to in these essays. 



There is, however, good anatomical reason for 

 classifying these extremities, with Huxley, as feet. 

 But since functionally they are hands, almost to the 

 same extent as the anterior pair, and since the 

 anthropoids, according to some observers, usually 

 walk on the knuckles of these members, and accord- 

 ing to others on the inside edges, it seems more 

 rational to retain the former classification in these 

 essays at least. 



A foot form fit to support the body in the upright 

 attitude could never have emerged from the pos- 

 terior extremities of any of the typical quadrupeds. 

 They have no proper heels. From the back ends 

 of their feet to where the toes or claws touch the 

 ground the distance is too short. To secure a 

 stable equilibrium in this position requires a long 

 axis from heel to toe. The differences between a 

 human and a quadrupedal foot are so enormous, that 



