90 ARE THE EFFECTS OF USE INHERITED? 



inheritance of ancestral stages of evolution, of 

 which the embryo presents a condensed epitome. 

 While the relative thinness of the infant's sole 

 might be pointed to as the effect of disuse during a 

 long series of generations, its thickness is rather an 

 illustration of atavism still resisting the effects of 

 long-continued disuse. There is nothing to show 

 that the inheritable portion of the full original 

 thickness was not gained by natural selection 

 rather than by the directly inherited effect of use ; 

 and the latter, being cumulative and indiscrimina- 

 tive in its action, would apparently have made 

 the sole very much thicker and harder than it 

 is. If natural selection were not supreme in such 

 cases, how could we account for the effects of 

 pressure resulting in hard hoofs in some cases and 

 only soft pads in others ? 



