1913] Shaw: Studies 07i Influences Afecting Protein Content of Wheat 109 



one-half sunshine. The samples under two-thirds sunshine aver- 

 aged .52 per cent more protein than those under one-half sunshine, 

 and .28 per cent more than those under one-third sunshine. 

 There was, then, a drop in the full sunshine sample to about the 

 same protein content as those receiving one-half sunshine. 



The results for 1909 at Davis came in the same order as those 

 of 1908. The samples under one-third sunshine average higher 

 in protein than those under one-half sunshine by .23 per cent. 

 The samples under two-thirds sunshine averaged higher than 

 those under one-half by .6 per cent, and than those under one- 

 third sunshine by .37 per cent, while the average of the samples 

 grown under full sunshine is nearl}" the same as of those grow^n 

 under one-half sunshine. 



These results certainly show that the protein content does not 

 vary inversely with the amount of sunshine which the plants 

 receive. On the other hand, the experiments at Davis and those 

 of the year 1909 at Tulare tend to show that there is a happy 

 medium under which the maximum amount of protein is stored. 

 This optimum condition seems to be at a point somewhat below 

 the normal sunshine. If, however, the amount of sunshine falls 

 below that medium then again there is a decrease in the amount 

 of protein stored. Just why this should be the case is still a 

 matter of conjecture. It is quite probable, however, that it is 

 due to a disturbed condition of the physiological functions within 

 the plant brought about by the abnormally low sunshine. This 

 fact can only be determined by a closer study of the formation 

 and transformation of the various compounds in the plant. 



The giiadin content of the samples in this experiment seems 

 to bear even less relation to the sunshine than did the total 

 protein. In fact, there was no regularity whatever in the results 

 those obtained at Tulare being just opposite from those obtained 

 at Davis. 



A comparison of the two years at the two stations shows that 

 there was a marked difference in the protein content of the samples 

 in different seasons. At Davis we find that the samples averaged 

 a higher percentage of gluten in 1909 than in 1908 by over 2 per 

 cent. 



