150 THE AMERICAN NATURALIST [Vol. XLVI 



multiplication of such cases will not help the matter. 

 Personally, I believe that the experimental work now so 

 extensively carried on in the study of genetics is throw- 

 ing a flood of light on all biological questions and that 

 systematists not only may but must make use of the 

 demonstrated results of such study, in attacking their 

 own special problems, if they are really in earnest in the 

 purpose to solve them. 



