CLIMBING PLANTS 



may be difficult to see the main stem, for it is quite thin, 

 though as strong as a piece of steel wire. It often happens, 

 when hurrying through a rather open part of the forest 

 after game, that one's leg suddenly catches in a thin, spiny, 

 wiry stem of Smilax or some such creeper. The first that 

 one knows of the creeper is when a quarter of an inch of the 

 spine is buried in one's flesh. 



Away up amongst the branches and foliage far above one's 

 head, leaves and flowers are developed on numerous branches 

 which have vigorously pushed out as soon as they got near 

 the sunlight, this tough, spiny, thread-like stem being 

 their only connexion with the ground. 



The development of these climbing plants is probably 

 connected with the dense shade of forests. In such places 

 a young stem growing up will become long and drawn out ; 

 its tip will droop over and hang downwards. But there is a 

 curious peculiarity in the growth of all stems. The stem 

 generally grows more rapidly at any one time on one side, 

 say on the north, and therefore bends over to the opposite 

 side. After a time it will be growing most rapidly on the 

 eastern side and then its head points westwards, and so on. 

 The result is that the tip of the stem swings in an irregular 

 circle round the stem itself. Its head turns to every point 

 of the compass in succession. Supposing a stone is tied to 

 the end of a piece of string, and one swings the stone 

 horizontally in a circle, then, if an upright stick is put in 

 the ground and the string comes against it, the string will 

 coil itself round the stick because the stone goes on swinging 

 horizontally. 



Our young climbing plant in the shade of the forest acts 

 in exactly the same way. If there is any trunk of a suitable 

 size, it will in the course of its revolving or sweeping round 



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