MISCELLANEOUS 



411 



parable pairs of samples were taken: one to show the change taking place 

 from evening until early in the night; another to show the change taking 

 place from evening until late in the night; and a third to show the changes 

 occurring during the whole night. In the first column under each method 

 of calculation is shown the percentage loss in total carbohydrate (starch 

 by acid hydrolysis method plus soluble sugars) and in the second column 

 the loss in soluble sugars. One will see by following along the several lines 

 that the three methods of calculation give comparable results both as to 

 the total carbohydrate and soluble sugars. Followmg down the columns 

 for each kind of plant makes it evident that the percentage of loss in both 

 total carbohydrates and sugars increases as the night progresses. If one 

 compares the two beans with the peanut, he will see that in the beans a 

 much larger percentage of both constituents is lost during the night than 

 in the peanut. An examination of the original analytical data, not here 

 given, shows that the starch in the several leaves in the evening exceeds 

 by five- to ten-fold the amount of soluble sugars, and that peanut leaves 

 are richer in both starch and sugar than the bean leaves. All these leaves 

 are starch storers. In leaves that do not store starch, as is the case with 

 onion, the change, of course, is in the sugars. 



in 



V) 



o 



\- 

 z 

 u 

 u 

 q: 

 ui 

 Q. 



10 - 



20 - 



30 - 



40 • 



50 



60 



70 



6 



PM. 



10 II 12 



TIME 



3 



A.M. 



Figure 163. Per cent loss of polysaccharides (alcohol insoluble acid hydrolyzable 

 substances, including starch) of peanuts and beans at intervals from night to morning; 

 percentage computed on the basis of the amount present in the initial sample taken in 

 the evening. 



Fig. 163 shows the percentage loss in the polysaccharides in the bean 

 and the peanut leaves during the three periods of the night, and Fig. 164 

 shows the amount of total carbohydrates in the same leaves at various times 

 during the night calculated on the basis of residual dry weight and total 

 nitrogen. 



