6l 



contained in those organs increases towards maturity, though at this 

 same stage nitrogen and phosphoric acid decrease in amount, owing 

 to their migration to the grain. It does not seem that the lime in 

 the vegetative tissues migrates much to, or takes any very active 

 part in, the formation of the grain, for this latter is very poor in 

 lime. Twelve seimples of grain taken from other experimental plats, 

 each of which had been supplied with a different amount of lime, 

 were analyzed, and the differences in percentage of lime contained 

 in the grain from the various plats were found to be very small, and 

 the average percentage of lime was 0.078. 



The percentage of magnesia in the entire plant is, in this case, 

 practically constant throughout the plant's life, as shown in Table 

 55. However, another experiment proved that the entire plant had 

 a decreasing percentage of magnesia throughout its life, dependent 

 upon the production of dry matter in the plant's body. The per- 

 centage of magnesia in the leaves has a sudden rise at maturity, 

 owing to the fact that the dry matter of the leaves decreases while 

 the actual amount of magnesia increase during maturation. The 

 stems have a gradual decrease in the percentage of magnesis, which 

 latter migrates to the grain to a greater extent than the lime does. 

 And there occurs a reduction in the amount of magnesia in the stems 

 at maturity. A fair amount of magnesia is deposited in the grain, 

 as is often found to be the case among the gramineae. The plants 

 which developed better on plat B absorbed smaller quantities of soda, 

 lime, magnesia and potash than those on plat At while the nitrogen 

 and phosphoric acid in the plants from both plats were abont the 

 same. It might thus seem that the surplus of potash present in the 

 rice plants from plat A, accelerates the absorption of soda, lime and 

 magnesia. Yet this is very doubtful, for no such phenomenon 

 occurred in a similar experiment with the same variety of spring 

 crop, as may be seen from the following figures : (v. p. 50) 



