THE MECHANISM OF HEREDITY 



59 



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

 as is shown by the accompanying diagram. 



i n 



FIQ. 19. 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 ma tings can be shown graphically as follows : 



A B 



SPERMS 

 A b a B 



A B 



A b 



Egga 



a B 



