HOW PLANTS CLIMB. 



17 



26. There is great variety in the behavior of different tendrils. Those of the 

 Grapevine do not make sweeps, but stretch out away from the light, or in the 

 direction from which least light comes, — an instinct which is apt to lead them 

 to a support, — and the two forks diverge, as if feeling for something to lay hold 

 of. When they reach anything that can be surrounded, one fork commonly grasps 

 from one side, the other from the opposite side, somewhat as an object would be 

 grasped by a thumb and finger. 



27. The more branching tendrils of the Virginia Creeper equally turn from the 

 light, and therefore towards the wall or trunk, which this climber delights to 

 occupy and cover. 

 When their tips 

 reach the wall they 

 expand into a disk 

 or flat plate, which 

 adheres firmly to 

 the surface. This 

 particularly adapts 

 the Virginia Creeper 

 to ascending walls 

 or other flat sur- 

 faces. The tendrils 

 which do not attach 

 themselves remain 

 slender, and in a 



week or two shrink and wither away. Those that do usually spread their branches 

 widely apart, like fingers of an outstretched hand, form their disks and fix them 

 fast to the wall ; then they contract more or less into coils, and at length grow 

 stronger and more rigid ; so that they last for years, and endure a pretty heavy 

 strain without breaking or parting from the wall. It is most interesting to see 

 how the strain is divided by these five or six separate attachments, by the coiling 

 of each branch to give elasticity, so that the pull shall come upon all at once, and 

 to note the strengthening of the whole by the formation of more woody fibre. 

 The strain is distributed among the branches, and the whole combination is so 

 strong that it is rarely torn away by wind or storm. 



28. In revolving tendrils the most wonderful thing to remark is the way in 



2 



Fig. 7. Virginia Creeper : tendril beginning to form its disks or hold&sts. 

 branclies with full-formed disks. 



8. Older 



