ECOLOGr OF LEAVES 



111 



A B 



Fig. 78. Leaves standing nearly Vertical in Compass-Plant 

 (Silphium laciniatum). 



A, view from east or west ; B, from north or south. 



139. Movements of Leaves and Stems toward or away 

 from Light (Heliotropic Movements). — The student doubt- 

 less learned from his experiments with seedling plants 

 that their stems tend to seek light. The whole plant 



