FORCING INTELLIGENCE 71 



even those much larger than man, habitually carry 

 these sense organs. 



Excepting possibly the giraffe, the largest quad- 

 rupeds which habitually carry their eyes higher than 

 man are yet at a disadvantage compared with him, 

 because in looking backwards or sideways his head 

 pivots easily on the erect vertebral column. They, 

 on the contrary, in executing these movements, have 

 to curve or even double the joints in the backbone 

 horizontally. Thus has the upright attitude direct- 

 ly caused man's erect ancestry to survey a wider 

 field of vision, sound, and odor, and therefore to per- 

 ceive a greater variety of phenomena in his environ- 

 ment than do any of his competitors. This constant 

 influx of a much greater variety of experiences culti- 

 vates activity and energy of the mental processes, 

 and educates the mind to greater knowledge of the 

 relations and connections between phenomena, and 

 thus the upright attitude becomes a constant incen- 

 tive to the use of the mental faculties. 



For a race not possessing any of the usual physical 

 adaptations to their environment, for a race afflicted, 

 as heretofore shown, with many extraordinary in- 

 firmities and defects of structure, for a race which 

 at the same time possessed an organism which, by 

 the upright attitude with hands above and feet 

 below, was especially adapted to an infinite variety 

 of compound concerted movements, for a race which, 

 for the reasons above given, was exclusively de- 

 pendent on the conduct of its individuals for escape 



