12 



MENDELIAN SEGREGATION 



Similarly, a sperm bearing the factor for vestigial 

 fertilizing an egg bearing the factor for long produces 

 a hybrid, or heterozygote, with long wings; a sperm 

 bearing the factor for vestigial fertilizing an egg 



Fig. 6. — Diagram to illustrate how by the random meeting of two kinds 

 of sperm and two kinds of eggs the typical 3 : 1 ratio results. 



bearing the same factor produces a homozygote, 

 having the recessive character vestigial wings. 



Since the sperm and the eggs meet at random 

 there should be 1 long VV, to 2 long Vv, to 1 vestigial 

 vv; or, putting together all flies with long wings, 

 3 long to 1 vestigial. Three to one is the character- 



