CLIMBING PLANTS 



111 



strength, for instance, Ampelopsis which has tendrils provided with 

 peculiar discs, maintains its hold. 



Induce a shoot to grow on to a stone or some movable object. 



Cut off the shoot from the plant, and by means of weights on a 

 spring balance the force necessary to pull the tendrils from the stone 

 can be ascertained, though as a matter of fact, it generally happens 

 that the tendril is torn rather than the discs detached. 



Again, the method of attachment of the ordinary Virginia creeper 

 should be noted and cases examined in which the tendrils have not 

 come into contact with a solid surface. The effect on the structure 

 of the tendril is striking. 



Photograph by Wilfred Mark Webb 



FIGURE 223. A Bryony Tendril. 



