AND TAKE POSITIONS. 11 



discerned by the eye. Lifeless things may be moved or acted on ; living beings 

 move and act, — plants less conspicuously, but no less really, than animals. In 

 sharing the mysterious gift of life, they share some of its simpler powers. 



6. The Sleep of Plants, as Linnseus fancifully termed it, — that is, the different 

 position which leaves and leaflets take at nightfall, — is a familiar case of free 

 movement, only the motion is too slow to be seen by the eye. The Sensitive 

 Plant is a good instance of this. Its leaves slowly assume the same posture at 

 or before sunset that they rapidly do when disturbed by a touch or jar, and they 

 remain so until the light of morning. Most other plants of the Pulse Family 

 (the Locusts, for instance), and many of other families, take a very different posi- 

 tion by night from that of day. The end-leaflet of Desmodium gyrans hangs 

 down as soon as the light of day begins to wane, but rises and turns its upper 

 face to the sun again in the morning. 



7. The Turning of Green Shoots to the light, which we observe when house-plants 

 are kept in our windows, and the turning of the upper face of most leaves 

 towards the lighted side, are similar cases of slow movement or bending. Many 

 people suppose that the green shoot grows towards the light, whereas it only bends 

 towards it. One has only to notice the behavior of the slender stemlet of a seed- 

 ling Radish, or of any similar plant, when set in a window, and see it bending 

 towards the lighted side in a few minutes, before it has had time to grow percep- 

 tibly, to be convinced that the growth and the bending are different acts. 



8. The eontrary Directions of Stem and Root when springing from the seed are of 

 this kind. Read the brief account given in ' How Plants Grow,' paragraphs 28 

 and 29, and watch the operation in j'^oung seedlings. Note how one end of the 

 embryo plantlet rises out of the soil and into the light, and, if need be, turns 

 quite round to ^o so, while the other turns from the light and strikes deeper into 

 the ground. This shows that it is the plant itself which acts in taking these direc- 

 tions, and that these positions are the result of real movements, however slow. 



9. Climbing Plants afford some of the most curious and most varied illustrations 

 of the movements which plants perform ; and in these it is easy to see what 

 the movements are for. The advantage which a plant gains by climbing is, that 

 it may thereby rise higher and get a fuller exposure to the light than it could 

 with the same amount of material if it stood independently. Compare the 

 amount of wood or other material in a tree with that of any climber which has 

 ascended it and made a support of its topmost branches. Plants climb in 

 several ways. Some are 



