118 ME. DARWIN' OX CLIMBING P1.A.XTS. 



be said that plants acquire and display this power only when it is 

 of some advantage to them ; but that this is of comparatively rare 

 occurrence, as they are affixed to the ground, and food is brought 

 to them by the wind and rain. We see how high in the scale of 

 organization a plant may rise, when we look at one of the more 

 perfect tendril-bearers. It first places its tendrils ready for action, 

 as a polypus places its tentacula. If the tendril be displaced, 

 it is acted on by the force of gravity and rights itself It is acted 

 on by the light, and bends towards or from it, or disregards it, 

 whichever may be most advantageous. During several days the 

 tendril or iuternodes, or both, spontaneously revolve with a steady 

 motion. The tendril strikes some object, and quickly curls round 

 and firmly grasps it. In the course of some hours it contracts 

 into a spire, dragging up the stem, and forming an excellent 

 spring. All movements now cease. By growth the tissues soon 

 become wonderfully strong and durable. The tendril has done its 

 work, and done it in an admirable manner. 



