HEREDITY AND SEX 



these four sorts are formed by females of the 

 origin described is as follows : When such a 

 female is mated with a long- winged, white-eyed 

 male, there are obtained female offspring, all 

 of which are long- winged, but half of them are 

 red-eyed, half white-eyed. The male offspring, 

 however, are of four sorts, viz. red short, white 

 long, red long, and white short. This result 

 harmonizes with the hypothesis advanced. For 

 if the gametes of the female are X-R, X-L, 

 X-R-L, and X, and those of the male are X-L 

 and , then the following combinations should 

 result : 



X-L' X-R, red long female, 

 X-L' X-L, white long female 

 X-L' X-R-L, red long female, 

 X-L' X , white long female, 



X-R, red short male, 



X-L, white long male, 



X-R-L, red long male, 



X , white short male. 



This expected result accords with that ac- 

 tually obtained by Morgan. 



Color-blindness in man is a sex-limited char- 

 acter, the inheritance of which resembles that 



179 



