IO4 Field, Forest, and Wayside Flowers 



air causes some of this water to evaporate from 

 the foliage. More comes up to supply the loss, 



FIG. 19. Starch-grains of the potato (a) and of wheat (b). 



(Much magnified.) 

 (From the Vegetable World.} 



and this also dries out slowly through the sunlit 

 hours. As the water evaporates the mineral sub- 



