g spontaneous movements the most singular are those of
Desmodium gyrans of India, sometimes called Telegraph-plant, which is
cultivated on account of this action. Of its three leaflets, the larger
(terminal) one moves only by drooping at nightfall and rising with the
dawn. But its two small lateral leaflets, when in a congenial high
temperature, by day and by night move upward and downward in a
succession of jerks, stopping occasionally, as if to recover from
exhaustion. In most plant-movements some obviously useful purpose is
subserved: this of Desmodium gyrans is a riddle.

475. =Movements in Flowers= are very various. The most remarkable are in
some way connected with fertilization (Sect. XIII.). Some occur under
irritation: the stamens of Barberry start forward when touched at the
base inside: those of many polyandrous flowers (of Sparmannia very
strikingly) spread outwardly when lightly brushed: the two lips or lobes
of the stigma in Mimulus close after a touch. Some are automatic and
are connected with dichogamy (339): the style of Sabbatia and of
large-flowered species of Epilobium bends over strongly to one side or
turns downward when the blossom opens, but slowly erects itself a day or
two later.

476. =Extraordinary Movements connected with Capture of Insects.= The
most striking cases are those of Drosera and Dionaea; for an account of
which see "How Plants Behave," and Goodale's "Physiological Botany."

477. The upper face of the leaves of the common species of Drosera, or
Sundew, is beset with stout bristles, having a glandular tip. This tip
secretes a drop of a clear but very viscid liquid, which glistens like a
dew-drop in the sun; whence the popular name. When a fly or other small
insect, attracted by the liquid, alights upon the leaf, the viscid drops
are so tenacious that they hold it fast. In struggling it only becomes
more completely entangled. Now the neighboring bristles, which have not
been touched, slowly bend inward from all sides toward the captured
insect, and bring their sticky apex against its body, thus increasing
the number of bonds. Moreover, the blade of the leaf commonly aids in
the capture by becoming concave, its sides or edges turning inward,
which brings still more of the gland-tipped bristles into contact with
the captive's body. The insect perishes; the clear liquid disappears,
apparently by absorption into the tissue of the leaf. It is thought that
the absorbed secretion takes w