HUMAN AND ANIMAL EVOLUTION CONTRASTED 29 



heredity is certainly not new. Of course it has long 

 heen recognized that what the parents themselves 

 learn they are likely to impart to their children. To 

 call this by the name of heredity may be somewhat 

 new, but the idea is old. But in former years this 

 idea was not clearly separated from heredity in the 

 more common use of the term. It was somewhat 

 unclearly thought that one generation passed on its 

 characteristics to the next by a combination of meth- 

 ods. It was supposed that each generation inherited 

 at birth certain powers {congenital characters), and 

 then by the experiences of life developed these pow- 

 ers, consciously or unconsciously, transmitting to 

 the next generation an inheritance different from 

 that which it had itself received, which was still 

 further modified by the next generation. The whole 

 process was looked upon as heredity without any 

 very definite attempt to separate the different fac- 

 tors. Later, especially after Weismann had thrown 

 so much light ui)on the process of transference of 

 characters by organic heredity, the complex ideas 

 of earlier days began to get cleared up. As a result 

 the term "heredity" has been retained as apply- 

 ing only to the ])rocess of transference from one 

 generation to the next by the germinal substance 

 in the sex cells. The intense interest which was then 

 aroused over the process of organic inheritance drew 

 attention to this phenomenon. As it became more 

 and more evident that acquired characters are not 

 inherited by organic inheritance, they came soon to 

 be slightingly spoken of and looked upon as not hav- 

 ing any influence in the evolution process. Further, 

 it is a fact that among animals the phenomenon of 

 social heredity has little influence, and inasmuch as 



