During
the following winter it ceases to live, but adheres firmly in a dead
state both to its own stem and to the surface of attachment. In the
accompanying diagram (fig. 11.) we see the difference between a
tendril (B) some weeks after its attachment to a wall, with one (A)
from the same plant fully grown but unattached. That the change in
the nature of the tissues, as well as the spiral contraction, are
consequent on the formation of the discs, is well shown by any
lateral branches which have not become attached; for these in a week
or two wither and drop off, in the same manner as does the whole
tendril if unattached. The gain in strength and durability in a
tendril after its attachment is something wonderful. There are
tendrils now adhering to my house which are still strong, and have
been exposed to the weather in a dead state for fourteen or fifteen
years. One single lateral branchlet of a tendril, estimated to be at
least ten years old, was still elastic and supported a weight of
exactly two pounds. The whole tendril had five disc-bearing branches
of equal thickness and apparently of equal strength; so that after
having been exposed during ten years to the weather, it would
probably have resisted a strain of ten pounds!
SAPINDACEAE.
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