WHAT EVOLUTION IS 93 



as an instance, may have been inborn 

 traits in this animal which were 

 simply called into evidence by the 

 changed environment rather than 

 produced by it? Certainly such as- 

 pects of the problem should be tested 

 before a final conclusion can be ar- 

 rived at, and in so crucial an experi- 

 ment as the one described, it is 

 extremely desirable that independent 

 evidence on the same point from 

 other investigators should be at hand 

 before a final decision is reached. 



Other students of this general 

 problem have also carried out ex- 

 tended series of experimental studies 

 reaching over many generations. 

 Thus the Americans Guyer and Smith 

 have advanced evidence to show 

 that eye defects produced in one 

 generation of rabbits are inherited 

 by the descendent stock. But here 

 the defects produced and those as- 



