98 T. H. MORGAN AND ELETH CATTELL 



SRBYX - SRByX - LWBYX - LWByX \ 



Gametes LRBYX - LRByX - SWBYX - SWBy^ / ^^ 

 of Fi 



SRBYX - SRByX - . . .bY - ...by Sperm 



SRN 9 6 SRN d" 3" 



LRN 9 6 LRN d^ 3 



SRB 9 2 LWN d" 3 



LRB 9 2 SWN c? 3 



^^ SRB d^ 1 



LRB d^ 1 



LWB c? 1 



SWB d^ 1 



There was no evidence of crossing of color factors in 1937 males, 

 and none are expected, since both Black and Normal carry the 

 black factor; and the yellow factor that distinguishes them is 

 not sex-hnked. In wing characters SRN d^ = 572, while LRN 

 c^ = 316, SRB cf = 198, while LRB cf = 94. On the other 

 hand, LWN d' = 410, while SWN d^ = 166; LWB cf = 130, 

 while SWB d' = 51. The sum of the 'straight' males is 1310 

 and the cross-overs 627, nearly 2 to 1. 



The reciprocal cross is as follows: 



SRB d' by LWN 9 



„ LRN 9 514 



' LWN d' 404 



LRN 9 = 831 



LRN d^ = 312 



LRB 9 = 278 



LRB d" = 78 



LWN 9 = 661 



LWN cf = 616 



LWB 9 = 189 



LWB d' = 184 



SRN d" = 282 



SRB d^ = 146 



SWN c^ = 244 



SWB d^ = 89 



(SWN 9=5) (in one bottle) 



