46 



THE AMERICAN NATURALIST 



[Vol. LI 



ity are due to specific factors which display consistent 

 Mendelian behavior has been demonstrated by Bateson 

 and Punnett (1908) and others and has been suggested by 

 Correns (1913) for cases which are concerned with the 

 specific category of normal self-sterility in Cardamine 

 pratensis. It appears, nevertheless, as East (1915) in 

 principle has suggested, that many cases in which sterility 

 has followed rather wide crossing would seem to be sus- 

 ceptible of a more logical treatment from the standpoint 

 of non-specific disturbances in the reaction systems 

 involved. 



