64 



Plant Genetics 



ratio of IS : I ; but in addition to this, among the 15 reds 

 there could be distinguished varying degrees of redness. 

 Nilsson-Ehle suspected that 15:1 meant a dihybrid 



Fig. 14. — Diagram illustrating Nilsson-Ehle's explanation of 15 : i 

 ratio obtained in Fj generation from cross between red-grained and 

 white-grained wheat. 



ratio, 16 individuals being necessary to give the ratio, 

 so that he constructed the tentative scheme shown in 

 fig. 14. 



