SEX-LINKED CHARACTERS IN DROSOPHILA. 



I8 7 



The table shows that in the FI generation there should be 

 only NR females and YW males. My studies completely bore 

 out this conclusion. 



As in the previous experiment, the females of the FI generation 

 should produce four classes of eggs, representing the various 

 combinations of the factors concerned. The males should pro- 

 duce two classes of sperms. The union of these gametes should 

 produce in the F 2 generation equal numbers of males and females 

 of the four classes, NR, YW, YR, NW. 



Complete coupling would give only two classes of eggs and 

 hence only two classes of males and females, viz., NR and YW. 

 Table IV. shows the results actually obtained. From 24 

 bottles there hatched 9,626 flies, distributed as follows: NR fe- 

 males, 2,761; NR males, 2,462; YR females, 30; YR males, 29; 

 N W females, 2 1 ; NW males, 24; YW females, 2,204; Females, 

 2,095. 



Here again the coupling occurs, and again the coupling is not 

 complete. We find also the deficiency of males and of mutants 



TABLE IV. 



GIVING RESULTS OF EXPERIMENT II. 



