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MANUAL OF NATURE STUDY. 
11. Study measurements of leaves, tendrils, etc. 
Have a sensitive plant, Mimosa pudica , if possible, 
brought in the school-room, and let the children 
touch the leaflets and observe them to immediately 
close together, and after a time regain their original 
position. Why does the plant behave in that way? 
This explanation of leaf movement, either from 
touch or influence of light or darkness, rain or sun¬ 
shine, is too difficult for a work of this kind. For 
full explanation of plant movement, the teacher is 
referred to pages 532-539, vol. I, of Kerner and 
Oliver’s Natural History of Plants; also vol. II, 
Goodale’s Physiological Botany, pages 397-424. 
See another chapter of this book for sleep move¬ 
ment of plants. Darwin says that all growing parts 
of a plant are in constant movement around one 
common center from right to left, or the opposite 
direction, from left to right. The tendril and 
twiner are only exaggerations of this common 
movement. Encourage the children to observe 
direction of grape tendril, pea climber, bean, wista¬ 
ria, hop vine, morning glory or any other vine in 
the vicinity, and report. 
Can a plant bore its roots into the ground any 
easier by this worming process than by straight 
pushing? Try to push a tender sprout or tender 
twig straight into the ground. Now try to work it 
back and forth. Which is the most successful way? 
