35 



present in the plant, as is sometimes the case, it exerts a consider- 

 able influence on the analytical estimates of dextrine, because, what 

 we call dextrine, in this paper, represents non-reducing carbohydrates 

 which are insoluble in alcohol of 90 % but soluble in cold water. 

 Hence it would appear that, from this point of view, the amount 

 of the so-called dextrine may vary in proportion to the amount 

 of soluble starch in the parts of rice plant. 



The percentage of protein has a gradual decrease throughout 

 the plant's life, as is shown in Table 17, under the heading "Protein". 

 On the other hand, the percentage of insoluble starch in the entire 

 plant rises with the increase of dry matter, and the most active 

 production of starch takes place in the maturing grain. In the leaves 

 there is an increasing percentage of starch throughout the plant's life ; 

 while the percentage of starch in the stems rises rathar rapidly after 

 the period of tillering, owing to the vigorous formation of starch in 

 the stems during the period of vegetative growth, - and declines 

 during maturation. The roots resemble the stems with respect to 

 the fluctuations in their percentage of starch. 



The absolute quantities of starch contained in the various parts 

 of the rice plant gradually and steadily increase during the period 

 of tillering. But afterwards a rapid increase takes place in ths stems 

 until the flowering stage, while at the same time in the leaves and 

 roots there is only a slow increase. A large amount of starch dis- 

 appears in the stems after the time of flowering, at which period the 

 highest amount of starch is contained in those organs. It is, therefore, 

 believed that the stems of the rice plant store starch to furnish 

 carbohydrates for the formation of grain. But the leaves do not 

 seem to perform a similar physiological function, at any rate to such 

 a degree that there is a great reduction in the amount of starch in 

 the results given by analysis. Thus, while a decreasing amount of 

 starch is found in the stems during maturation, a conspicuous loss c f 

 protein takes place in the leaves, as previously stated. 



