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 
Fic. 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- 
