PERSONALITY OF PLANTS 
reverse their direction they go backward like 
a ferryboat. 
The ancients as far back as Aristotle recog- 
nized the sensitiveness of plants to light and 
their eager use of its life-giving properties. In 
fact, one has only to watch the Sun-F lower fol- 
low the orb of day across the heavens to realize 
that there must be something vital in sunlight 
for the plants. What interests us is that they 
have the instinct or the knowledge to so present 
their surfaces to the light that they receive a 
maximum benefit from its influences. From the 
aristocratic indoor potted plant to the wild 
trees and shrubs on the edge of a thicket, we 
notice a vigorous straining toward the light. 
Each leaf is tilted at just the right angle to re- 
ceive the largest possible share of energy, for 
the leaves are starch factories for which the 
sun furnishes the motive power. 
Botanists tell us that this heliotropism or 
turning motion toward the light is due to the 
tendency of most leaves to arrange themselves 
perpendicularly to the sun’s rays. Tendrils 
may be apheliotropic or tend to turn away from 
the light. Morning Glories or Wistaria, which 
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