THE PAST EVOLUTION OF MAN G9 



briuin conditioned by the characteristic curvature of 

 the adult human spine, there has been developed, on 

 the front aspect of each hip-joint, an exceedingly 

 powerful ligament — by far the strongest in the 

 body — whose function it is to prevent the whole of 

 the body above that level from rolling backwards in 

 obedience to the law of gravitation. Hence the 

 exceptional development of these " Y-shaped liga- 

 ments " comes to be a characteristic of the human 

 anatomy. 



" Man the erect " is thus, as Stevenson calls him, 

 " Man the erected." Let us observe some conse- 

 quences of this attainment of the erect attitude. 

 The hands being freed for grasping, it becomes no 

 longer necessary that the feet should retain this 

 power. It is much better that they should concen- 

 trate their attention — so to speak — on the completest 

 possible adaptation of the sole function of support 

 and progression. Hence we find that the great toe 

 of the human foot cannot be opposed to the other 

 digits as can the thumb, and as can the great toes 

 of certain of the apes. Not even in the tell-tale 

 baby can the great toe be opposed, but no one who 

 has observed a baby can have failed to notice the 

 facility and frequency with which it bends all the 

 toes together towards the sole of the foot. And 

 though it soon loses this tendency as it learns to 

 use the foot for its special purpose, no one can 

 doubt that the human foot is descended from a 

 prehensile organ. Various " armless men " have 

 shown its latent possibilities in this direction. 

 Furthermore, there exists in every human foot — 

 though civilised man never employs them — a com- 



