AS THE BIOLOGIST SEES IT 



further consideration in connection with 

 our present consideration of the problem 

 of war as the biologist faces it. 



An essential thing to keep in mind in 

 this connection is that man differs mark- 

 edly from other animal kinds in having 

 two kinds of inheritance often confused 

 because of the use of the common term, 

 inheritance, for both kinds. He has a bi- 

 ological inheritance this is real heredity, 

 inherent in him and responsible for much 

 of his physical and mental condition, and 

 for that instinctive behavior, partly in- 

 dispensable for the actual maintenance 

 of his life and health, as in the obvious 

 cases of the suckling of babes and the 

 winking of the eyelids and the less no- 

 ticed actions of his internal organs, 

 but partly no longer indispensable, in 

 his present stage of evolution, as in the 

 cases of various brute performances, once 

 necessary to his self-preservation. He 

 has also a social inheritance, not a part of 

 his heredity, but playing a very important 

 and conspicuous role in his life, especially 

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