CORRESPONDING GENES IN DROSOPHILA. 



59 



has been determined with respect to minute, which is very close 

 to it. 



TABLE II. 



+ HA + 



st + + p 



9 Xst + + pd". 



Minute (which is dominant) sometimes overlaps wild-type in 

 appearance; accordingly only the minute offspring have been 

 recorded in Table III. In the experiment reported in Table IV. 



TABLE III. 



_L -L _L -L 



9 X st + p + c?. 



stApM 



TABLE IV. 



+ A + M 



st + ca + 



9 X st +ca + c?. 



this overlapping seemed to be slight, so all the offspring are 

 recorded. It is possible, however, that the two M-ca cross- 

 overs may be due to such overlapping. More extensive counts 

 from M/ca females, in experiments in which no other loci were 

 studied, have not given any crossing over. There is an un- 

 usually low scarlet delta crossover value shown in Table IV., 

 but the count is so small that no special significance is to be 

 attached to this fact. 



There can now be no doubt that one half or more of the right 



