Mar. i8, 1918 



Respiration of Stored Wheat 



697 



it follows that there is approximately twice the enzymic activity per 

 unit of mass than that shown by normal wheat. The normal spring 

 wheat used by the writers weighed 24.62 gm, per 1,000 average kernels. 

 A shriveled sample of the same type of wheat was obtained which weighed 

 11.73 g™- per 1,000 kernels, or less than half the weight of the normal. 

 The rate of respiration of these two lots was compared, and, as shown 

 in figure 3, the respiratory activity of the shriveled sample decidedly 

 exceeded that of the normal, or plump wheat. Thus the quantity of 

 carbon dioxid respired by the latter when it contained 14.5 per cent of 

 moisture was respired by the shriveled wheat used when it contained 

 only 12.8 per cent of moisture. The curves tend to converge at moisture 

 contents slightly below 12 per cent. 



The respiration data for the shriveled sample are given in Table VI, 

 while in Table VII is shown the interpolated quantity of carbon dioxid 

 respired by the normal and shriveled wheats at even percentages of 

 moisture. 



Table VI. — Respiration of shriveled spring wheat, '^ incubated at 27-8° C . for four days 



a Weight per bushel of sample, 47M pounds. Weight per 1,000 kernels, 11.73 gm. Nitrogen on dry 

 basis, 2.03 per cent. 



Table VII. — Interpolated quantity of carbon dioxid respired per unit of time and material 

 at even percentages of moisture 



SOUNDNESS OF THE WHEAT KERNEL IN ITS RELATION TO THE RATE 



OF RESPIRATION. 



A form of unsoundness recognized as such by the grain trade and 

 frequently occurring in spring wheat is the frosted condition. This 

 results from the freezing of the plants before the grain is matured and 

 desiccated. The plants usually thaw later, and, vv^hile the protoplasm 



