In this
latter case, whilst the tendril was slowly and quite insensibly
crawling onwards, I observed several times through a lens that the
whole surface was not in close contact with the stick; and I can
understand the onward progress only by supposing that the movement is
slightly undulatory or vermicular, and that the tip alternately
straightens itself a little and then again curls inwards. It thus
drags itself onwards by an insensibly slow, alternate movement, which
may be compared to that of a strong man suspended by the ends of his
fingers to a horizontal pole, who works his fingers onwards until he
can grasp the pole with the palm of his hand. However this may be,
the fact is certain that a tendril which has caught a round stick
with its extreme point, can work itself onwards until it has passed
twice or even thrice round the stick, and has permanently grasped it.
Hanburya Mexicana.--The young internodes and tendrils of this
anomalous member of the family, revolve in the same manner and at
about the same rate as those of the Echinocystis. The stem does not
twine, but can ascend an upright stick by the aid of its tendrils.
The concave tip of the tendril is very sensitive; after it had become
rapidly coiled into a ring owing to a single touch, it straightened
itself in 50 m.
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