84 



SEX INHERITANCE 



wild type A. grossulariata is crossed to the rare mu- 

 tant type A. lacticolor. 



LACTICOLOR $ 



CROSSULARIATA rf 



FIG. 30. Abraxas lacticolor female by A. grossulariata male. The sex 

 chromosomes are represented by the circles in the center of the diagram, 

 and the letters contained in them stand for the factors that each carries. 

 The W chromosome, confined to the female line, is represented without 

 either G or L; for it, Like the Y chromosome in Drosophila, carries no sex 

 linked factors. 



