shoot revolved in a course opposed to the sun, at an average rate,
judging from three revolutions, of 1 hr. 23 m.; but no doubt the
direction of the revolving movement is variable. When the plants
have grown tall and are branched, all the many lateral shoots
revolve. The stem, whilst young, twines regularly round a thin
vertical stick, and in one case I counted eight spiral turns in the
same direction; but when grown older, the stem often runs straight up
for a space, and, being arrested by the clasping petioles, makes one
or two spires in a reversed direction. Until the plant grows to a
height of two or three feet, requiring about a month from the time
when the first shoot appears above ground, no true leaves are
produced, but, in their place, filaments coloured like the stem. The
extremities of these filaments are pointed, a little flattened, and
furrowed on the upper surface. They never become developed into
leaves. As the plant grows in height new filaments are produced with
slightly enlarged tips; then others, bearing on each side of the
enlarged medial tip a rudimentary segment of a leaf; soon other
segments appear, and at last a perfect leaf is formed, with seven
deep segments. So that on the same plant we may see every step, from
tendril-like clasping filaments to perfect leaves with clasping
petioles. After the plant has grown to a considerable height, and is
secured to its support by the petioles of the true leaves, the
clasping filaments on the lower part of the stem wither and drop off;
so that they perform only a temporary service.

These filaments or rudimentary leaves, as well as the petioles of the
perfect leaves, whilst young, are highly sensitive on all sides to a
touch. The slightest rub caused them to curve towards the rubbed
side in about three minutes, and one bent itself into a ring in six
minutes; they subsequently became straight. When, however, they have