306 SOCIAL HEREDITY AND SOCIAL EVOLUTION 



principles wherein human evolution stands apart, 

 principles which to a large extent so modify the prog- 

 ress of evolution as to vitiate all comparison be- 

 tween human development and that of animals. 



The Inheritance of Acquired Characters 



The fundamental distinction between acquired and 

 congenital characters was not sharply recognized 

 until Weismann threw such a clear light upon meth- 

 ods of heredity by his theories advanced thirty years 

 ago. A distinction between those characters which 

 had been received by inheritance and those that 

 were acquired during life had been indeed recognized 

 before ; but it was reserved for Weismann to distin- 

 guish them sharply as having totally different rela- 

 tions to the problem of inheritance and development. 

 From that time biologists have been coming to place 

 less and less reliance upon acquired characters as 

 affecting the evolutionary process, until to-day they 

 are practically excluded from the discussion. In 

 modern discussion of evolutionary methods it has 

 come about that to show that any character has 

 been acquired during the life of an animal has been 

 regarded as sufficient to exclude it from playing any 

 part in the evolutionary process. Acquired char- 

 acters have thus been slightingly thrown to one side. 



From our study of the evolution of human society, 

 we are forced to restore to acquired characters an 

 immense significance. The first striking feature that 

 we find wherein the evolution of mankind differs 

 from that of animals is that here acquired characters 

 are transmitted to posterity, and do count emphat- 

 ically in evolution. To be sure, they are not trans- 

 mitted by the same laws as are congenital characters, 



