MENDELIAN SEGREGATION 



23 



The two pairs of chromosomes " assort" on the 

 spindle in either one of the two ways shown in the 

 diagram; resulting in four and only four kinds of 

 gametes. 



EGGS 



SPERM 





FIG. 12. Diagram to show the 16 possible kinds of permutations of 

 the four kinds of gametes of Fig. 11. Along the top line are four kinds 

 of eggs ; along the left side are four kinds of sperm ; in the squares are the 

 combinations formed by the meeting of each kind of egg with each kind 

 of sperm, giving 9 long gray; 3 long ebony; 3 vestigial gray; 1 vestigial 

 ebony. 



The process just described takes place both in the 

 male and in the female. Consequently there will 

 be four kinds of eggs and four kinds of spermatozoa. 



