LEE BARKER WALTON 131 



Modern genetics throws light on the distribution but 

 not on the origin of the character producing genes or 

 factors. These units have in general long been in exist- 

 ence. It is to some such principle as the one suggested that 

 we must look for evidence sufficiently definite to over- 

 come the prejudice which has arisen against the old ac- 

 quired character ideas as to the fundamental origin of 

 characters. 



There is need of studying, in this connection, the be- 

 havior of microorganisms near the equator as well as in 

 the southern hemisphere, particularly in an experimental 

 way, before definite conclusions may be drawn. 



