SEX-LINKED INHERITANCE IN DROSOPHILA 35 



dominant characters (C and R). The number of cross-overs is 

 relatively high. The converse cross gave 1 to 97 (see Jour. 

 Exp. Zool., p. 91, vol. 13, 1912). 



Of the cross-overs there were 14 in one direction to 6 in the 

 opposite. Moreover, it is the short, red, browns and yellows, 

 often assumed to be the less viable combination, that give the 

 larger number. 



Short, red, yellow by long, white, black 



The two crosses recorded under this heading, both absent from 

 the preceding paper, were Nos. 3, and 4 of the series (page 89). 



When the female LWB is crossed to the male SRY all the 

 female offspring are long, red, gray and all the males long, white, 

 gray. The numerical results follow: 



SRY d" by LWB 9 



Fi 



LRN 9 = 80 



LW^N cf = 78 



The analysis follows: 



LWByBrX — LWByBrX 

 SRbYBrX — SWbYBr 



^ LWByBrX — SRbYBrX 



' LWByBrX — SWbYBr 



