76 Science of Plant Life 



U. S. Dept. of AgriculUtre 



Fig. 46. An orchard in California. The excess food of the trees is 

 accumulated in the fruits. 



bage, food is stored in the cluster of leaves at the top of the 

 stem. In corn and cereals, the excess food finally accumu- 

 lates in the grain. In the century plant, a considerable part 

 of the excess food is stored in the thick, fleshy leaves ; 'the 

 process of accumulation may go on from 20 to 30 years, and 

 the total quantity of food stored may amount to many pounds. 

 In nature such accvimulated foods are used for another season's 

 growth of the plant or in starting the growth of its offspring. 

 Before insoluble foods are transferred in the plant, they are 

 digested or made soluble by enzymes. When these soluble 

 substances accumulate in the cells of storage organs, they fre- 

 quently are transformed again into an insoluble form. For 

 example, starch formed in potato leaves is transferred through 

 the plant to the underground tubers in the form of glucose, 



