480 



GENETICS 



Zygotes from 

 which Pi 

 developed 



Gametes of Pj 



Zygotes of Fj 

 that give rise 

 to long-winged, 

 gray-bodied flies 



Zygotes of Fj 



9 long-winged, 

 gray-bodied 



3 long-winged, 

 ebony-bodied 



3 vestigial-winged, 

 gray-bodied 



1 vestigial-winged, 

 ebony- bodied 



Fig. 256. — Diagram illustrating independent segregation and possible recom- 

 binations of two pairs of chromosomes and two pairs of genes in a case of di- 

 hybridization between a vestigial-winged, gray-bodied fly (Drosophila) and a 

 long-winged, ebony-bodied fly {cf. Fig. 247). 



E, gene for gray body; e, gene for ebony body; V, gene for long wing; v, gene for 

 vestigial wing. 



