No. 580] INFERTILITY OF DBOSOPH1LA 



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One hundred and two rudimentary females were tested 

 in these ways. In only three cases were rudimentary 

 males produced. One female produced two; one female 

 produced four, and another female produced one male. 

 It is evident, therefore, that the scarcity of rudimentary 

 sons can not, in general, be ascribed entirely to the condi- 

 tions of the food. 



As pointed out above, red bar daughters might appear 

 in the foregoing tests and such females might have either 

 of the two parentages specified. Most of the females of 

 this kind would bo expected to come from white bar fe- 

 males by rudimentary males, since the converse case would 

 rarely be realized. Seven females, that appeared, were 

 tested by breeding to white bar males and gave the results 

 in the first of the two following tables. Four others were 

 tested by breeding to rudimentary males with the result 

 shown in Table la. The results confirm the expectation 



