100 ELEMENTS OF BOTANY. 
nearly upright, with their edges approximately north and 
south, Fig. 86, so that the rays of the midsummer sun will 
during every bright day first strike the leaf-surfaces at right 
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« Fic. 86. — Leaves standing nearly Vertical in Compass-Plant 
(Silphiwm laciniatum). 
angles, then be nearly parallel to them, and again toward 
sunset strike them at right angles. | 
126. Movements of Leaves and Stems toward Light. — The 
student doubtless learned from his experiments with seedling 
