FERTILITY AND STERILITY IN DROSOPHILA 



359 



TABLE 3 



Control: Showing the result of testing the grandparental stock, truncate by truncate 



Per cent of eggs which complete development 22.6. 



It is true that the extracted truncates vary somewhat in the 

 length of wing. Moreover, they appear in about the ratio of 1 

 truncate wing to 14 of the long wings. In all cases I selected the 

 most typically truncate forms, and if low fertility is an accom- 

 paniment of the truncate wing as such, I should have discovered 

 the fact in this experiment. This does not exclude the possibility, 

 however, that some of the low fertility here may be concomi- 

 tant to the truncate wing, for a comparison of the fertility of their 

 long winged brothers and sisters shows that the fertility of the 

 extracted longs is higher (see table 7). 



In Part II it has been demonstrated by numerous experiments 

 that the truncate stock is deficient in egg production. A compari- 

 son of the egg production of the extracted truncates together with 

 that of the truncates used in control and also with that of the 

 truncates given in Part II makes it absolutely certain that these 

 extracted truncates have been benefited also in regard to egg 

 productivity as a result of crossing and extracting from a wild 

 stock. The evidence is conclusive that fertility can be trans- 

 ferred to the truncates. 



THE JOURNAL Ot EXPERIMKNT.U. ZOOLOGY, VOL. 17 , NO. 3 



