22 



P. M. on the 29 tl1 of May, 1913. They were dried at 7OC., and 

 analysed with the following results I- 

 Table 18. Carbohydrates in Leaves. (Expressed 

 as percentage of dry matter). 



We have no direct proofs which enable us to decide positively, 

 whether the main cause of the reduction in the percentages of sugars 

 in the morning, is their transformation into higher compounds, or their 

 migration from the leaves. The leaves collected in the evening and 

 on the following morning proved that the weight of dry matter in the 

 leaves is always greater in the evening than in the morning ; this 

 means that the migration of soluble nutrients must be more .actively 

 performed in the night. Therefore, perhaps, the main cause of the 

 diminution in the percentage of these carbohydrates in the morning is 

 their translocation from the leaves. Assuming this is the case, then 

 during the day the formation of glucose, saccharose and starch in 

 the leaves, exceeds the amount transferred, and this results in the 

 accumulation of these sugars towards evening. The percentage of 

 pentosanc is lower at 4:00 P.M., probably owing to a. greater increase 

 of organic matter other than pentosane. More samples were col- 

 lected at 5:00 A.M. and at 4:00 P.M., when the rice plant was 



fairly mature. Sugars in the fresh leaves were extracted repeatedly 



i 

 by means of warm alcohol, and then inverted into reducing sugars. 



The results of analysis are given below:- 



