82 T. H. MORGAN AND ELETH CATTELL 



ybBrX - YbBrX - yBBrX - YBBrX Eggs 

 C^ametes J^i ^j^g^.^ _ YbBrX - ybBrX - YbBr Sperm 



Summary of F2 



The results agree again fairly well with the expectation. The 

 numbers of gray males and females are quite close. This corre- 

 spondence between the sexes holds throughout, although the 

 females exceed the males in the grays and blacks, while the males 

 are in excess in the yellows and browns. 



In the next case also the same two characters are involved, 

 viz., yellow and black, but combined with short (miniature) 

 wings and white eyes. The analysis is the same as in the last 

 case, and need not be repeated: 



SWB 9 by SWY d" 



SWN 9 = 78 

 ^1 SWN d^ = 62 



The reciprocal cross was also made: 



SWY 9 by SWB cf 



SWY c? = 



^^ SWN 9 = 



SWN 9 = 68 



SWN d^ = 71 



SWB 9 = 10 



SWB d^ = 11 



*^* SWY 9 = 38 



SWY c^ = 64 



SWBr 9 = 12 



SWBr c^ = 11 



