THE MECHANISM OF HEBBDITY 



59 



equal quantities in both the egg cells and the pollen cells, 

 as is shown by the accompanying diagram. 



I n 



Fig. 19i — Diagram to illustrate gamete formation in a dihybrid,in independent inheritance. 



It is clear that if this process occurs in both male and 

 female germ cells, and these germ cells unite by chance, 

 the result is that obtained in the breeding experiments. 

 The posssible matings can be shown graphically as follows : 



Sperms 



A B 



A b 



Eggs 



a B 



a b 



A B 



A b 



B 



