PRINCIPLES OF HEREDITY 



379 



RED 



Fig. 112. — Sex-Linkage. White-eyed female by red-eyed male. 

 The symbols used are the same as in the last figure. The results 

 are somewhat different although the principles involved are identical. 

 The first generation females are red-eyed because they receive a 

 red gene from their father. The males are white-eyed because they 

 receive a white gene from the mother and only an inactive Y-chro- 

 mosome from the father. The results in the second generation are 

 explained in the same way. 



Morgan, Sturtevant, Muller, Bridges, Mechanism of Mendelian 

 Heredity. 



