MENDEL'S LAW OF HEREDITY 



ingly difficult thing it is to fix types obtained by 

 crossing, if the number of dominant characters 



OamctOR 



Zygut* 



Gametes 



FIG. 34. Diagram to show the gametic combinations and 

 segregations involved in a cross between guinea-pigs differ- 

 ing in three unit-characters. L stands for long hair, S for 

 short hair, W for white hair, and D for dark hair; R for 

 rough, and Sm for smooth coat. Compare Figs. 22 and 32. 



in the selected type increases. On the theory of 

 unit-characters the gametic combinations and 

 segregations involved in this cross are as shown 



49 



