LINKAGE 



49 



with the normal allelomorphs of these factors. After 

 maturation one or the other of these chromosomes 



Blaok veatlglal 



Oray long 



Gaaetes of Hale 



Gametes of Penal e 



mn c 



mn ( ■) CUD C 



3 



Blaok vestigial 



CTTD c 



3 



CXE3 CXZD 



BLACK VESTIGIAL GRAT LONG 



Fig. 21. — Diagram to illustrate non-crossing over in the male and 

 crossing over in the female in a cross between black vestigial by gray long 

 (coupling experiment). The Fi male was backcrossed to black vestigial 

 females with the results shown to the left; and the Fi female was back- 

 crossed to black vestigial males, with the results shown to the right. 



will be left in each egg and each sperm. The gametes 

 will consequently contain the same combinations of 



