Drosophihi Mchinofiastrr. 311 



Table XVI II. F^ gouoralion Iroiu curved 9 by l)Iaclv, i)uri)k' curved d*. 



4. Black purple curved 9 by curved o^. 



The F, from the reciprocal cross to that in 3 gave 202 gray red eyed 

 curved sons and 231 gray red eyed curved daughters. These inbred gave in 

 F„ the different classes in table XIX. 



Table XIX. F.- generation from black, purple, curved 9 by curved cf . 



The fact that all the flies in the F, and F. are curved shows that the two 

 mutants are identical. The last two tables give data on the linkage of pur- 

 ple and black. There are 184 cross overs in a total of 287S a linkage of 12.8. 



5. The Black, purple vestigial was crossed to a new wild stock from 

 Arlington, Md. Over 500 sons and daughters were like the wild type. Since 

 crossing over does not take place in the males, Fi females whose composition 

 was (b p V B 1' V) were back crossed to black purple vestigial (b p v). The 



