Mar. i8, 1918 



Respiration of Stored Wheat 



705 



lively small, no intermediate temperatures were employed. Regular 

 increases in the temperature of the thermostat by lo-degree intervals 

 were then made until the respired carbon dioxid showed a marked 

 diminution. 



The data in Table XV and the graph in figure 6 show that the rate of 

 respiration increased to a maximum at 55° C. This is therefore the tem- 

 perature at which the most rapid evolution of heat would occur. A dis- 

 coloration of the seed coat of the wheat kernel begins to show on some 

 kernels at about 35° C, while at 55° the whole mass is of a mahogany 

 color. At 65° the respiratory enzyms have been ' partially but not 



/s 



2'S 35 '^S .5i5 



es 



7^ 



Fig. 6. — Graph showing the relation of temperature to the rate of respiration. 



wholly inactivated, while at 75° this inactivation has proceeded still 

 further, and some roasting of the grain has occurred. 



Table XV. — Respiration of hard spring wheat at different temperatures 



"A part of this carbon dioxid may have resulted from roasting the grain. 



