The tendril,
though so sensitive, does not move very quickly after a touch, no
conspicuous movement being observable until 5 or 10 m. had elapsed.
The convex side of the tip is not sensitive to a touch or to a
suspended loop of thread. On one occasion I observed a tendril
revolving with the convex side of the tip forwards, and in
consequence it was not able to clasp a stick, against which it
scraped; whereas tendrils revolving with the concave side forward,
promptly seize any object in their path.
Passiflora quadrangularis.--This is a very distinct species. The
tendrils are thick, long, and stiff; they are sensitive to a touch
only on the concave surface towards the extremity. When a stick was
placed so that the middle of the tendril came into contact with it,
no curvature ensued. In the hothouse a tendril made two revolutions,
each in 2 hrs. 22 m.; in a cool room one was completed in 3 hrs., and
a second in 4 hrs. The internodes do not revolve; nor do those of
the hybrid P. floribunda.
Tacsonia manicata.--Here again the internodes do not revolve. The
tendrils are moderately thin and long; one made a narrow ellipse in 5
hrs. 20 m., and the next day a broad ellipse in 5 hrs.
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