HOW PLANTS BEHAVE, 



CHAPTER I. 



HOW PLANTS MOVE, CLIMB, AND TAKE POSITIONS. 



1. Two plants — one of them common in cultivation, and the other rarer, but 

 almost as easy to raise — are looked upon as vegetable wonders, namely, the 

 Sensitive Plant and Desmodium gyrans. They are striking examples of 



2. Plants that move their leaves freely and rapidly. In the well-known Sensitive 



Plant {Mimosa pudica) the foliage quickly changes its position when touched, 

 appearing to shrink away from the hand. Fig. 1 represents 

 a piece of stem with two (compound) leaves ; the lower one 

 expanded, as it is in sunshine and when untouched : the 

 upper leaf shows the position which is taken, by quick move- 

 ments, when roughly brushed by the hand. It makes three 

 movements. First, the numerous leaflets close in pairs, 

 bringing their upper faces together and also inclining for- 

 wards; then the four branches of the leafstalk, which were 

 outspread like the rays of a fan, approach each other; at 

 the same time the main leafstalk 

 turns downward, bending at its joint 

 with the stem. So the leaf (for it is 

 all one compound leaf) closes and 

 seemingly collapses at the touch. 

 In a short time, if left to itself, 

 it slowly recovers the former out- 

 spreading position. 



3. The second plant, Desmodium Fig. 1. SenBitive Plant. 



gyrans (we have no common name for it), also belongs to the great Pulse Family, 

 and flourishes in warm climates. It inhabits the warmer parts of India, but is 



