EXPOSURE TO LIGHT 



239 



The leaves of Corn and other Grasses are good examples of the 

 alternate arrangement. In Corn, for example, the second leaf 

 appears at the next node above and on the opposite side of the 

 stem from the first leaf, and the third leaf appears at the third 

 node and almost directly over the first leaf. Usually on account 

 of a slight twisting of the stem, the leaf blades do not occur 



FIG. 221. Tobacco, a plant with the alternate arrangement of leaves. 



After Hayes. 



directly over each other, but extend in slightly different direc- 

 tions, so that the lower leaves are not directly in the shade of the 

 upper ones. In fruit trees and many other plants having the alter- 

 nate arrangement, the second leaf is not quite on the opposite 

 side from the first and neither is the third leaf usually over the 

 first. (Fig. 221 .) The leaves are so arranged that no large open 

 spaces appear in looking in from the end of the twig as shown in 



