66 



HEREDITY AND SEX 



A male with short or miniature wings appeared in 

 my cultures (Fig. 38). Mated to long-winged females 

 only long-winged offspring were produced. When 

 these were mated to each other, there were produced 



X 



X 



X 



X 



Fig. 37. — Upper series, back cross of Fi 9 to white ^ . Lower series 

 back cross of Fi red-eyed $ to white 9 . 



long-winged females (50%), long-winged males (25%) 

 and miniature-winged males (25%). 



It is possible to produce, in the way described for 

 eye color, miniature-winged females. 



When such miniature-winged females are mated to 

 long-winged males, all the daughters have long wings, 

 and all the sons have miniature wings (Fig. 39). If 



