378 



GENES MODIFYING NOTCH. 



some question as to the virginity of the mother, yet makes that inter- 

 pretation unHkely. It seems to me more probable that in these three 

 cases the father carried a modifier for Notch. Excluding, likewise 

 No. 9 on the same grounds, it is evident from this table that the ata- 

 vistic types predominate. 



Fio. 99. 



As I stated the yellow prune forked stock crossed to short Notch had 

 given in Fi so many intermediate flies that the experiment undertaken, 

 to locate the short-Notch factor in the sex chromosome had to be 

 abandoned. A year later the forked flies had disappeared from this 



