On a tendril which was eleven inches
long I counted ninety-four of these beautifully constructed little
hooks. They readily catch soft wood, or gloves, or the skin of the
naked hand. With the exception of these hardened hooks, and of the
basal part of the central stem, every part of every branchlet is
highly sensitive on all sides to a slight touch, and bends in a few
minutes towards the touched side. By lightly rubbing several sub-
branches on opposite sides, the whole tendril rapidly assumed an
extraordinarily crooked shape. These movements from contact do not
interfere with the ordinary revolving movement. The branches, after
becoming greatly curved from being touched, straighten themselves at
a quicker rate than in almost any other tendril seen by me, namely,
in between half an hour and an hour. After the tendril has caught
any object, spiral contraction likewise begins after an unusually
short interval of time, namely, in about twelve hours.
Before the tendril is mature, the terminal branchlets cohere, and the
hooks are curled closely inwards. At this period no part is
sensitive to a touch; but as soon as the branches diverge and the
hooks stand out, full sensitiveness is acquired.
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