43 



The total amount of nitrogen in the plant increases up to 

 maturity, analysis does not show a loss at any stage of growth, as 

 some investigators have maintained. . The leaves contain a large 

 amount of nitrogen until the time of the third collection, which was 

 carried out just before heading out ; and after this stage the stems 

 also become rich in nitrogen. Thus it is found that there is not a 

 similar variation in the amounts of nitrogen in these parts of the rice 

 plant, the highest quantity of nitrogen being reached earlier in the 

 leaves than in the stems. Accordingly, it can be asserted that a more 

 active movement of nitrogen from the leaves begins before any large 

 amount of this ingredient in the stems migrates into the panicles. 

 The nitrogen in the grain increases very rapidly during the maturing 

 process, reaching about 60 % of the total amount of nitrogen in the 

 plant ; and in the same period the leaves and stems lose a large 

 amount of nitrogen, as described before A greater decrease of 

 nitrogen is noticed in the leaves than in the stems in the period of 

 maturation. Therefore it is very probable that the leaves transmit 

 a much greater amount of nitrogen to the stems, than the latter 

 organs supply to the grain. The roots do not appear to play 

 an important role in the matter of translocation of the reserved 

 nitrogen. 



The percentage of phosphoric acid at each stage of growth is 

 always found to be smaller than that of the nitrogen in the corres- 

 ponding part of the rice plant. Usually there is a decreasing 

 percentage of phosphoric acid in all parts of the plant throughout its 

 life. The percentage of phosphoric acid is a little greater in the 

 stems than in the leaves until the time of flowering, while a greater 

 percentage of nitrogen is contained in the leaves than in the stems. 

 However, at maturity the leaves retain a slightly higher percentage 

 fo phosphoric acid than the stems, owing to the fact that, during 

 maturation, less phosphoric acid migrates from the leaves. The 

 roots contain a much lower percentage of phosphoric acid than of 



