12 m.; in a second plant the same course was followed, and
the two circles were completed in 3 hrs. 41 m.; in a third plant, the
internodes followed the sun and made two circles in 3 hrs. 47 m. The
average rate of these six revolutions was 1 hr. 46 m. The stem shows
no tendency to twine spirally round a support; but the allied
tendril-bearing genus Paullinia is said (Mohl, p. 4) to be a twiner.
The flower-peduncles, which stand up above the end of the shoot, are
carried round and round by the revolving movement of the internodes;
and when the stem is securely tied, the long and thin flower-
peduncles themselves are seen to be in continued and sometimes rapid
movement from side to side. They sweep a wide space, but only
occasionally revolve in a regular elliptical course. By the combined
movements of the internodes and peduncles, one of the two short
hooked tendrils, sooner or later, catches hold of some twig or
branch, and then it curls round and securely grasps it. These
tendrils are, however, but slightly sensitive; for by rubbing their
under surface only a slight movement is slowly produced. I hooked a
tendril on to a twig; and in 1 hr. 45 m. it was curved considerably
inwards; in 2 hrs.
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