main petiole carries three leaflets; but their short, sub-petioles
are not sensitive. A young, inclined shoot (the plant being in the
greenhouse) made a large circle opposed to the course of the sun in 4
hrs. 20 m., but the next day, being very cold, the time was 5 hrs. 10
m. A stick placed near a revolving stem was soon struck by the
petioles which stand out at right angles, and the revolving movement
was thus arrested. The petioles then began, being excited by the
contact, to slowly wind round the stick. When the stick was thin, a
petiole sometimes wound twice round it. The opposite leaf was in no
way affected. The attitude assumed by the stem after the petiole had
clasped the stick, was that of a man standing by a column, who throws
his arm horizontally round it. With respect to the stem's power of
twining, some remarks will be made under C. calycina.

Clematis Sieboldi.--A shoot made three revolutions against the sun at
an average rate of 3 hrs. 11 m. The power of twining is like that of
the last species. Its leaves are nearly similar in structure and in
function, excepting that the sub-petioles of the lateral and terminal
leaflets are sensitive. A loop of thread, weighing one-eighth of a
grain, acted on the main petiole, but not until two or three days had
elapsed. The leaves have the remarkable habit of spontaneously
revolving, generally in vertical ellipses, in the same manner, but in
a less degree, as will be described under C. 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