74 



Outline of Genetics 



when crossed with the pure white strain, yielded Fi 

 hybrids of an intermediate degree of redness as before. 



Fig. io. — Diagram illustrating Nillson-Ehle's explanation of 

 15: 1 ratio obtained in F2 generation from cross between red-grained and 

 white-grained wheat. 



The F2 generation, however, showed a different situation. 

 Reds and whites were obtained in the proportion of 

 63 : 1 ; the 63 reds as before falhng naturally into differ- 



