126 University of California Publications in Agricultural Sciences [Vol. 1 



Fourth — In wheats 100 per cent of which are entirely starchy 

 there may be a reversion to an entirely glutenous condition in 

 a single season, or the reverse may occur, dependent upon the 

 seasonal condition. 



Fifth — Allowing the grain to stand on the straw in the field 

 until fully ripe does not materially affect the protein content. 



Sixth — The protein content of wheat is affected by the time 

 of seeding, the product of late seeded grain having a higher 

 percent of protein than that of early seeded grain. 



Seventh — The protein content of wheat is very largely influ- 

 enced by the water content of the soil in the later period of its 

 growth, and the effect of either irrigation or rainfall during this 

 period is to lower its protein content. 



Eighth — The percentage of sunshine which the grain receives 

 during its period of growth has a somewhat direct bearing upon 

 its protein content, but other seasonal conditions are more im- 

 portant. 



Ninth — Retarding the growth through cooling the atmosphere 

 has a tendencj^ to increase the protein content. 



Tenth — The quantity of available nitrogen in the soil either 

 alone or in the presence of other available plant foods, provided 

 there be sufficient to supply normal growth, appear to have little, 

 if any, influence upon the protein content. 



Eleventh — The low gluten content of wheats grown in Cali- 

 fornia is not due to soil exhaustion, but rather to the following 

 causes: (1) To climatic factors which allow a long growing 

 period; (2) to relatively early seeding; (3) to the use of varieties 

 inherently low in gluten; (4) to a lack of selecting highly glu- 

 tenous seed. 



Acknoivledgements : The author is greatly indebted for valu- 

 able assistance rendered in the prosecution of various parts of 

 the routine analytical w'ork which furnishes the basis for this 

 paper to IMiss Rachel Corr and Messrs. J. D. Rose, B. A. Madson, 

 and E. H. Walters, and also to Messrs. A. J. Gaumnitz, H. F, 

 Blanchard and J. T. Bearss for the careful attention to the field 

 production of the samples. 



Transmitted January 24, 1913. 



