Digestion, Transfer, and Accumulation of Foods 77 



U. S. Dept. of Agriculture (E. L. Adams) 



FIG. 47. A field of shocked rice in California. The surplus food of the rice plant 

 accumulates in the seeds. These are more used than any other one article of diet 

 by man. 



and there it accumulates in the cells in the form of starch. It 

 is believed that the same enzymes which change the starch to 

 glucose, under suitable conditions change the glucose back 

 again to starch, and that, in general, the enzymes that digest 

 foods are the agents that build them up again into the more 

 complex insoluble forms. 



Kinds of food accumulated. In any given plant in which 

 food is accumulated, protein, carbohydrate, and fat are all 

 present. Depending on the plant, however, the amount of 

 any one of these may be very great or it may be so small as 

 to be practically negligible. In the sugar cane and sugar beet 

 the excess food occurs mainly in the form of cane sugar (su- 

 crose). In the potato it is almost wholly starch. The grains 

 of wheat, oats, and rice contain mostly starch, but also some 

 protein. In sweet corn there are both sugar and starch; in 

 field corn there is mostly starch. In both kinds of corn there 

 are measurable quantities of protein and oil. In the soy bean 



