In a plant placed in the hot-
house and growing vigorously, a tendril revolved for not longer than
36 hours, counting from the period when it first became sensitive;
but during this period it probably made at least 27 revolutions.
When a revolving tendril strikes against a stick, the branches
quickly bend round and clasp it. The little hooks here play an
important part, as they prevent the branches from being dragged away
by the rapid revolving movement, before they have had time to clasp
the stick securely. This is especially the case when only the
extremity of a branch has caught hold of a support. As soon as a
tendril has bent a smooth stick or a thick rugged post, or has come
into contact with planed wood (for it can adhere temporarily even to
so smooth a surface as this), the same peculiar movements may be
observed as those described under Bignonia capreolata and
Eccremocarpus. The branches repeatedly lift themselves up and down;
those which have their hooks already directed downwards remaining in
this position and securing the tendril, whilst the others twist about
until they succeed in arranging themselves in conformity with every
irregularity of the surface, and in bringing their hooks into contact
with the wood.
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