I could detect no spontaneous movement in the petioles of
the leaves.
Whilst the tendrils are revolving more or less regularly, another
remarkable movement takes place, namely, a slow inclination from the
light towards the darkest side of the house. I repeatedly changed
the position of my plants, and some little time after the revolving
movement had ceased, the successively formed tendrils always ended by
pointing to the darkest side. When I placed a thick post near a
tendril, between it and the light, the tendril pointed in that
direction. In two instances a pair of leaves stood so that one of
the two tendrils was directed towards the light and the other to the
darkest side of the house; the latter did not move, but the opposite
one bent itself first upwards and then right over its fellow, so that
the two became parallel, one above the other, both pointing to the
dark: I then turned the plant half round; and the tendril which had
turned over recovered its original position, and the opposite one
which had not before moved, now turned over to the dark side.
Lastly, on another plant, three pairs of tendrils were produced at
the same time by three shoots, and all happened to be differently
directed: I placed the pot in a box open only on one side, and
obliquely facing the light; in two days all six tendrils pointed with
unerring truth to the darkest corner of the box, though to do this
each had to bend in a different manner.
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