CLASSIFICATION AND INHERITANCE OF SMALL GRAINS 101 



with very low fruitfulness in FI and a ratio indicating one main 

 factor difference in F 2 . 



FIG. 24. Individual spikes of F 2 generation of cross of Svanhals X Manchuria 

 representing the phenotypic progeny classes in which lateral florets bear awns. 

 From left to right: Low fertility awned plant which will give all classes of 

 segregates in F 3 as in Fz; high fertility awned which will segregate into inter- 

 medium, high fertility awned and six-rowed in FS; six-rowed which will breed 

 true in Fa. (After Harlan and Hayes, 1920.) 



Biff en (1907b) found the sexless condition dominant in a cross 

 between deficiens and two-rowed. Results from an F% generation 

 of a similar cross grown at the Minnesota station indicate that 

 it is almost impossible to separate deficiens r two-rowed, and inter- 



