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 rdéles, 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, 
‘Cand 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 
