microphylla.
Clematis calycina.--The young shoots are thin and flexible: one
revolved, describing a broad oval, in 5 hrs. 30 m., and another in 6
hrs. 12 m. They followed the course of the sun; but the course, if
observed long enough, would probably be found to vary in this
species, as well as in all the others of the genus. It is a rather
better twiner than the two last species: the stem sometimes made two
spiral turns round a thin stick, if free from twigs; it then ran
straight up for a space, and reversing its course took one or two
turns in an opposite direction. This reversal of the spire occurred
in all the foregoing species. The leaves are so small compared with
those of most of the other species, that the petioles at first seem
ill-adapted for clasping. Nevertheless, the main service of the
revolving movement is to bring them into contact with surrounding
objects, which are slowly but securely seized. The young petioles,
which alone are sensitive, have their ends bowed a little downwards,
so as to be in a slight degree hooked; ultimately the whole leaf, if
it catches nothing, becomes level. I gently rubbed with a thin twig
the lower surfaces of two young petioles; and in 2 hrs.
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