THE MECHANISM OF SEX-DETERMINATION 67 



these are now mated, they produce, in equal numbers, 

 long-winged males and females and miniature-winged 

 males and females. 



The same relations may again be illustrated by body 

 color. 



XX 



XXXIX 



Fig. 38. — Sex-linked inheritance of short (" miniature") and long wings 

 in Drosophila. Parents, short-winged $ , long-winged 9 . Fi long-winged 

 $ and 9 . F2 long-winged 9 and $ and short-winged $ . Sex chromo- 

 somes to right. Open X carries short wings. 



A male appeared with yellow wings and body. Mated 

 to wild gray females he produced gray males and 

 females. These mated to each other gave gray females 

 (50%), gray males (25%), and yellow males (25%). 



As before, yellow females were made up. Mated to 

 gray males they gave gray females and yellow males. 



