INDEPENDENT MENDEL1AN INHERITANCE 



75 



our shorthand notation they will all be (WX). On the other hand, 

 the white-eyed male will produce sperm cells half of which have an X- 

 chromosome and half a F-chromosome. The X-chromosome of the sperm 

 cells carries a factor w for white eyes, but the F-chromosome does not bear 



F, 



FIG. 35. Inheritance of white eye color in Drosophila. Red-eyed female mated to 

 white-eyed male. Solid lines indicate history of chromosomes of female; dotted and 

 gray lines, of the male. (Adapted from Morgan.) 



this factor. In the shorthand notation these two kinds of sperm are rep- 

 resented by (wX) and F respectively. The F-chromosome is drawn in 

 black to indicate its unknown constitution with respect to the factors it 

 contains. When an egg-cell (WX) of the red-eyed female is fertilized 

 by a (wX~) sperm cell, a female is produced of the genetic constitution 



