HUMAN AND ANIMAL EVOLUTION CONTRASTED 25 



the common sense of that term. But nevertheless 

 it is perfectly evident that these characteristics 

 which constitute civilization are handed on from gen- 

 eration to generation. There is never any failure of 

 one generation to receive them from its parents, and 

 thus they are transmitted from generation to gen- 

 eration just as truly as are the color of the eyes and 

 the complexion of the skin. It thus becomes clear 

 that there is a kind of transmission of attributes 

 from parent to child that is totally distinct from that 

 which our students of heredity have been studying. 

 Our parents may directly give us some of their pos- 

 sessions, so that we as well as they may use them, 

 and yet these need not become a part of our organic 

 nature and never be transmitted by the ordinary 

 processes of reproduction. This kind of inheritance 

 may be distinctively called social heredity in distinc- 

 tion from organic heredity, which latter term we will 

 retain for heredity as it has been commonly under- 

 stood. 



By the term '* social heredity" is meant thus the 

 power of handing on to the offsi^ring the various 

 accumulated possessions of the parents. These pos- 

 sessions may be material, as when one generation of 

 man receives the various structures which previous 

 generations have built. They may be purely mental, 

 as when one generation teaches to the next the facts 

 that have been taught it by the previous generation, 

 or the facts that it has itself discovered anew. They 

 may be even more intangible than this, as when one 

 generation quite unconsciously learns the customs, 

 habits, and even the mental methods of thinking of 

 the last. In all cases, however, the things handed on 

 to the next generation may be looked upon as pos- 



