144 Journal of Agricultural Research voi. xvii, no. 4 



present would not be the same in the two ears. This was proved experi- 

 mentally. 



In considering the rate of the counter reaction in connection with the 

 problem at hand — namely, the possibility of expressing the experi- 

 mental results in curves all starting from the same point — it must be 

 borne in mind that it becomes appreciable only near the point of equi- 

 librium, and even then it would affect the proportionality between 

 the sugar present and the sugar lost in different ears at the same tem- 

 perature only when the percentage of sugar in the ears at the beginning 

 of storage varied considerably. 



A decrease in the quantity of active enzymes present would produce a 

 steady fall in the values of the velocity constants; this would cause a 

 decreasing rate of actual sugar loss. There is no evidence that this 

 occurs up to 30° C. 



In view of the foregoing facts, together with the fact that the ears 

 selected for the final calculations were all in practically the same stage 

 of maturity and therefore contained nearly the same percentage of 

 original sugar, the following procedure in preparing the data for con- 

 struction of curves all starting from the same point seemed justified. 

 The sugar lost during each 24-hour period of storage was calculated as 

 proportions of the sugar present in the ears at the beginning of each 

 period. The percentages of sugar found in the ears analyzed at the 

 beginning of each experiment were then averaged. Ten ears with not 

 less than 80 per cent water were included in the final average. 



Taking this mean as the starting point for all temperatures and apply- 

 ing the proportions of sugar lost during each succeeding 24-hour period, 

 calculated from the experimental data, a new set of proportions was 

 obtained, based upon the same original sugar content in all cases. A 

 single concrete case may serve to clarify the foregoing procedure. The 

 total sugar in all the ears analyzed at the beginning of each experiment 

 averaged 5.766 per cent. During the first 24 hours of storage at 30° C. 

 the average loss of total sugar in three ears was 50.28 per cent of the 

 initial sugar present; that is, the total sugar in the com was 50.28 

 per cent less than at the beginning of storage. Applying this propor- 

 tion to an initial sugar content of 5.766 per cent, we obtain, after 

 the first 24-hour period of storage at 30°, a total sugar content of 

 2.867 per cent. Making use of all the experimental proportions in the 

 same manner, the percentage of total sugar present at the end of each 

 24-hour period of storage was calculated, assuming that the sugar con- 

 tent at the beginning of storage was 5.766 per cent. Each calculated 

 percentage was then substracted from 5.766, the initial sugar present. 

 The sugar loss, expressed as percentages of the initial sugar, could then 

 be calculated for the following storage periods: 24, 48, 72, and 96 hours. 

 The same procedure was followed for all the sugars at all the tempera- 

 tures, with the results shown in Table III. 



