support with surprising security. The tendrils are thus brought into
action, if the stem twines round a thin vertical stick; and in this
respect the present species differs from the last. Both species use
their tendrils in the same manner when passing through a thicket.
This plant is one of the most efficient climbers which I have
observed; and it probably could ascend a polished stem incessantly
tossed by heavy storms. To show how important vigorous health is for
the action of all the parts, I may mention that when I first examined
a plant which was growing moderately well, though not vigorously, I
concluded that the tendrils acted only like the hooks on a bramble,
and that it was the most feeble and inefficient of all climbers!

Bignonia Tweedyana.--This species is closely allied to the last, and
behaves in the same manner; but perhaps twines rather better round a
vertical stick. On the same plant, one branch twined in one
direction and another in an opposite direction. The internodes in
one case made two circles, each in 2 hrs. 33 m. I was enabled to
observe the spontaneous movements of the petioles better in this than
in the two preceding species: one petiole described three small
vertical ellipses in the course of 11 hrs., whilst another moved in
an irregular spire. Some little time after a stem has twined round
an upright stick, and is securely fastened to it by the clasping
petioles and tendrils, it emits aerial roots from the bases of its
leaves; and these roots curve partly round and adhere to the stick.
This species of Bignonia, therefore, combines four different methods
of climbing generally characteristic of distinct plants, namely,
twining, leaf-climbing, tendril-climbing, and root-climbing.

In the three foregoing species, when the foot-like tendril has caught
an object, it continues to grow and thicken, and ultimately becomes