1913] Shaw: Studies on Influences Affecting Protein Content of Wheat 69 



THE CONSTANCY OF CHANGE TOWARD STARCHINESS IN WHEAT 



KERNELS 



The phase presented in this portion of the study has to do 

 with the tendency of varieties toward a constancy of change 

 from the type seeded. The central idea was that if there really 

 existed a strong tendency toward the development of a distinctly 

 starchy nature, under the conditions which here obtain, not only 

 would the progeny of perfectly typical glutenous kernels show 

 a considerable number of more or less starchy kernels and a 

 lower protein (gluten) content, but spotted kernels would show 

 a similar change in their progeny; and the entirely changed 

 kernels, carrying 100 per cent of starchy kernels in the original, 

 would show a still lower percent of typical kernels and a verj' 

 low protein content in the progeny, remaining, in fact, essentially 

 starchy. 



The plan of the experiment which extended over the seasons 

 of 1906-08, inclusive, was to grow a number of varieties of wheat 

 at several points in the state, the physical and chemical con- 

 dition of the originals used being first determined, and to follow 

 the changes in the progeny in each instance during the season 

 and th(' total period of the trials. 



The experiments were conducted in the fields at Modesto, 

 Ceres, and Tulare as typical of San Joaquin Valley conditions, 

 and at Yuba City and Davis as representative of Sacramento 

 Valley conditions. In order to follow better such changes as 

 occurred, by the eye as well as by analysis, such varieties of 

 wheat were selected as had typical kernels of distinctive ap- 

 pearance. 



THE NITROGEN OF TYPICAL vs. SPOTTED WHEAT KERNELS 



OF THE SAME VARIETY 



At the outset a number of varieties of wheat were hand- 

 separated into three primary lots or groups, based upon the 

 physical appearance of the kernels, as follows : 



Group I, consisting entirely of perfectly typical (glutenous) 

 kernels : 



Group II, consisting of kernels of the same varieties of wheat 



