A Modification o{ tlie Sex Ratio, and of other Ratios, etc. 33? 



( rMX — rmX 

 Gametes of fi . . ■; 



' 1 rMX — rm 



( rMXrMX Miniature 9 

 I rmXrJIX „ 9 



" riMXrm „ <J 



\ rmXrra Rudimentary-miniature (J 



When rudimentary-miniature females are crossed to long-winged 

 males, the female offspring have long wings and the males rudimentary- 

 miniature wings: 



rm 9 by RM ^ = 



In addition, another mass culture gave as expected 32 long- 

 winged females and three rudimentary-miniature males, but in addition 

 one miniature female. The occurrence of the one miniature female can 

 not be accounted for except by mutation. Even if one of the rm 

 females had been Rm there should be no females of this class. 



Four of the long females in this last cross were mated with 

 miniature males and gave: 



L 9 114 ^ (S 77 M 9 90 ^I c5 15 Rud.-min. d 5 



The expectation (see gametes below i)) calls for fewer long males 

 than long females (about 1/5 less) and much fewer miniature males 

 than miniature females. 



Six of the long females were mated to two of their rudimentary 

 brothers and gave: 



L 9 115 L (5 113 -M (5 5 R 9 10 R (5 12 Rud.-min. (J 4 



The analysis follows: 



Rud.-min. 9 • • • ""mX rmX 

 Long (5 RMX rm 



I rmXRMX Long 9 

 ' I nnXrm Rud.-min. (J 



Gametes RmX — rmX — RMX — rMX 



of Fj rmX — rm 



1) RmX — rmX — RMX — rMX (Eggs (F, Long $)) 

 rMX — rm (Sperm (Min. (J)) 



