Wheat Investigations. 45 



and for which a very considerable degree of homogeneity may 

 safely be assumed, lends particular significance to these differ- 

 ences. For one of these characters, viz, the crude protein con- 

 tent, whose behavior alone could be studied from one year to 

 the next, it was shown that these differences are not mere fluc- 

 tuations but the result of inherent tendencies as evidenced by 

 the coefficient of correlation between the values of one year and 

 those of the next. Of the physical characteristics the kernel 

 weight, the hardness as measured by the percentage of yellow 

 berries, and the color show marked differences. Even in the 

 nursery rows where the strains grew side by side the degree of 

 hardness of the different lines was so marked that out of the 

 original 259 strains 158 were discarded as being soft and opaque. 

 This character while very susceptible to the environment is 

 regarded by Freeman (Loc. cit. 1918) as being controlled by ge- 

 netic factors which determine the greater or less sensitivity of 

 this character to the environment. Leith, 26 who also studied the 

 inheritance of the yellow berry, found that while there is no dif- 

 ference between the yellow and hard berry of the same pure 

 line in the production of yellow berry in their progeny, there is 

 a very considerable difference between pure lines in their ten- 

 dency to reproduce hard berries. 



No less pronounced are the differences between the indi- 

 vidual lines with respect to the chemical characteristics as will 

 be seen from Tables 5 and 7. The average protein content for 

 all strains in 1917 was higher than in 1918. But in spite of the 

 seasonal variation of the environment affecting the absolute 

 quantity of the protein the fact remains that the individual strains 

 tended to retain their relative protein rank regardless of the 

 seasonal average for this character. 



From the close association between protein and gluten it 

 may be inferred that there is a tendency for the pure strains 

 to retain also their gluten rank, though there has been no oppor- 

 tunity yet to study the behavior of this character from year to 

 year. 



Perhaps the most pronounced differences between the pure 

 lines are reflected in the quality of their glutens and in the size 

 of bread loaf baked from their flours, as shown in Tables 

 9 and 10. While the present data do not convey any informa- 



8 B. D. Leith, Loc. cit. 



