320 



BOTANICAL GAZETTE 



[NOVEMBER 



to many causes. In the leaves protein synthesis is going on con- 

 tinuously in the presence of soluble carbohydrates. There is also 

 synthesis of other organic nitrogen compounds, such as chlorophyll, 



Fig. i. -Relation of soil nitrification and nitrate intake by green plant organs; 

 nitrate in soil expressed in parts per million; all other data calculated as percentage 

 on drv weight basis. 



