SCOPE OF GENETICS 41 



we have had proof of the occurrence of a 

 similar repulsion in the case of the two 

 factors in the Sweet Pea. 



If the case of this moth stood alone it 

 would be interesting", but its importance is 

 greatly increased by the fact that we know- 

 two cases in birds which are closely compar- 

 able. The simpler case to w hich alone I shall 

 refer has been observed in the Canary. Like 

 the Currant moth it has a kind of albino, 

 called Cinnamon, and males of this variety 

 when mated with ordinary dark green hen 

 canaries produce dark males and Cinnamons 

 which are always hens ; while the green male 

 and the Cinnamon hen produce nothing but 

 greens of both sexes. This case, which has 

 been experimentally studied by Miss Durham, 

 offers a certain complication, but in its main 

 outlines it is exactly like that of the moth, 

 and the same interpretation is applicable to 

 both. 



