26 SOCIAL HEREDITY AND SOCIAL EVOLUTION 



sessions which each generation may enjoy and may 

 make use of; but in no case do these possessions 

 become part of the individual so as to enter into the 

 structure of the germinal substance, and therefore 

 they do not become a part of organic inheritance. 



Social heredity is thus simply the handing from 

 generation to generation of the accumulations that 

 have been heaped up by the past, wholly outside of 

 the innate nature of the individual. 



The laws controlling these two different types of 

 heredity are diametrically opposite. Organic hered- 

 ity concerns the germinal substance in the egg and 

 sperm. It is fixed and determined by the mixture of 

 the germinal substance of the two parents in sex 

 union. It is not capable of being modified by any 

 action of the individual and is unmodified by any 

 kind of acquired variations. It is controlled by very 

 definite laws, as has been shown by the studies of 

 recent years. It is organic heredity that has been 

 almost wholly concerned in producing the animal 

 and vegetable kingdoms as they exist in the world 

 to-day, and it is this which has been subjected to the 

 severe scrutiny of the last thirty years. It is 

 organic heredity that has been chiefly concerned in 

 the development of what we have spoken of as the 

 human animal, and it is this type of heredity that is 

 kept ever in mind by our eugenic friends in their 

 endeavors to emphasize the primary importance of 

 a control of marriage and of thus securing a better 

 inheritance for mankind. 



In sharp contrast to this stands social heredity. 

 This does not at all concern the germinal substance 

 in the egg and is not fixed by the union of germ sub- 

 stances in sex union. It is capable of being modified 



