144 Heredity and Social Progress 



be seen that associations cover a much larger 

 field than the field of bodily activity. Our 

 ability and capacity to think is far greater 

 than our ability and capacity to act. The 

 inner mechanism is, therefore, much more 

 varied and complex than the outer, a condi- 

 tion which may be explained by assuming 

 that the earlier organs of expression in ante- 

 cedent life have been less completely dis- 

 placed by evolution than have the outer 

 organs of expression. 



Our assumption, if true, is of importance 

 in connection with a vital biologic problem. 

 Acquired characters cannot be inherited, but 

 they can appropriate the disused inner motor 

 organs not yet displaced by the stress of evo- 

 lution. Primitive organs are so closely linked 

 by associations to present activities which 

 yield acquired characters that they are able 

 to find a new method of external expression 

 through the newly acquired activities with 

 which they are united. Associations thus 

 give to acquired activities a motor basis that 

 they cannot create for themselves. 



One of the most obvious of these agents of 



