44 THEORY OF EVOLUTION 



bearing. Chance combinations at fertilization 

 give the three classes of individuals of the sec- 

 ond generation. 



The white flowering plants should forever 

 breed true, as in fact they do. The red flowering 



PARENTS 



" 







FIG. 14. Diagram illustrating the history of the factors in 

 the germ cells of the cross shown in Fig. 13. 



plants also breed true. The pink flowering 

 plants, having the same composition as the hy- 

 brids of the first generation, should give the 

 same kind of result. They do, indeed, give this 

 result i.e. one white to two pink to one red 

 flowered offspring. 



