Cuap. III, BIGNONIACEA, 89 
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, aud 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. 383m. 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 aérial roots from the bases of its 
leaves; and these roots curve partly round and adhere 
to the stick. This species of Bignonia, therefore, com- 
bines 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 
5 
