Climbing Plants 235 



rocks, or the trunks of large trees. The English- 

 ivy, the poison-ivy, and the climbing-fig all 

 clamber by this expedient, and their grip upon 

 their supports is amazingly tenacious. 



Darwin observed that the rootlets of the climb- 

 ing-fig, when they were a few days old, began to 

 emit minute drops of a clear, viscid fluid. This 

 fig is a first cousin to the plant which produces 

 the india-rubber of commerce, and, like all 

 members of the family, it abounds in caoutchouc. 

 So the liquid which glues its rootlets to the wall 

 is fluid india-rubber, and with time and exposure 

 to the air this substance becomes converted into a 

 brittle, resinous matter, very similar to shellac. 

 " Whether other plants which climb by their root- 

 lets emit any cement," says Darwin, " I do not 

 know; but the rootlets of the ivy, placed against 

 glass, barely adhered to it, yet secreted a little 

 yellowish matter." 



But hook- and root-climbers, however lovely and 

 pleasant to the landscape-gardener, have little in- 

 terest for the student of plant habits. His at- 

 tention is given rather to the twiners and tendril- 

 bearers, whose movements seem instinct with life, 

 akin to that of the animal world ; for every tender 

 tip of every growing twiner sweeps around and 



