the period of vigorous growth, and absorbs a great deal of water 

 through the roots. Yet it must be borne in mind that a good 

 quantity of water is produced by dehydration which occurs in the 

 synthetic process of the higher carbohydrates and protein substances. 

 Leaves also contain the maximum amount of water at the time of 

 flowering, and a remarkable decrease of water takes place in them 

 when the crop is mature. However, it is not certain whether this 

 marked reduction in the amount of water is due to the more active 

 evaporation from the surface of the live leaves during maturation, or 

 to the fact that withered leaves are more abundant in the later part 

 of the plant's life. The amount of water contained in the stems is 

 always much greater than that in the leaves, especially at maturity, 

 for the structure of the stem is such that it retains much water in 

 its tissues, and prevents rapid evaporation. Both when the grain 

 is at an early and at a mature stage, the amount of water does not 

 vary a great deal. Rapid evaporation from the glumes of grain 

 may take place in the early period of maturation, and on the other 

 hand the stems may supply sufficient water to compensate for this 

 loss. In the course of maturation the glumes become hardened, and 

 this hinders rapid evaporation ; but at the same time the upper 

 portion of the stems withers to some extent, and thus the transport- 

 ation of water to the grain is partly checked. Furthermore, the 

 vigorous synthesis, in the grain, of starch and protain from simpler 

 compounds results in the production of water. Hence the reason 

 for there being a fairly constant weight of water in the grain in its 

 early and in its mature stages becomes clear. The quantities of 

 water in 10 bundles of rice plants are shown in the following list: 



