Climbing Plants 243 



tremities partly-grown or imperfectly formed leaves. 

 Those of the grape and the Virginia creeper are 

 altered flower-stalks, and occasionally reveal their 

 origin by developing into what are known as 

 "flower-tendrils." These, like Bottom the weaver, 

 undertake all roles, bearing a bunch of flowers 

 midway, and having coiling, sensitive tips. And 

 among those borne by the grape the vine-dresser 

 finds every gradation, from the tendril with a soli- 

 tary blossom half-way along its length to the bunch 

 of flowers or grapes ending in a tendril coil. But 

 whether they are leaf-stems or flower-stems by na- 

 ture the conduct of all tendrils is much the same. 

 "Both kinds spontaneously revolve," says Darwin, 

 "and at about the same rate. Both, when touched, 

 bend quickly toward the touched side. And both 

 kinds soon after grasping a support contract spirally, 

 and then increase greatly in thickness and strength." 

 A vigorous grape-tendril is often several inches 

 in length, and forks once or twice. Its branches 

 move independently of one another, and in bright 

 July days they traverse their circle in from two to 

 three hours. After a tendril has revolved for a 

 time it bends toward the dark, so that if a grape- 

 vine be planted against a wall the tendrils reach 

 toward it, and in a vineyard they generally point 



