twiners, and some root-climbers. The tendrils always consist of
modified leaves. Nine species of Bignonia, selected by hazard, are
here described, in order to show what diversity of structure and
action there may be within the same genus, and to show what
remarkable powers some tendrils possess. The species, taken
together, afford connecting links between twiners, leaf-climbers,
tendril-bearers, and root-climbers.

Bignonia (an unnamed species from Kew, closely allied to B. unguis,
but with smaller and rather broader leaves).--A young shoot from a
cut-down plant made three revolutions against the sun, at an average
rate of 2 hrs. 6m. The stem is thin and flexible; it twined round a
slender vertical stick, ascending from left to right, as perfectly
and as regularly as any true twining-plant. When thus ascending, it
makes no use of its tendrils or petioles; but when it twined round a
rather thick stick, and its petioles were brought into contact with
it, these curved round the stick, showing that they have some degree
of irritability. The petioles also exhibit a slight degree of
spontaneous movement; for in one case they certainly described
minute, irregular, vertical ellipses. The tendrils apparently curve
themselves spontaneously to the same side with the petioles; but from
various causes, it was difficult to observe the movement of either
the tendrils or petioles, in this and the two following species. The
tendrils are so closely similar in all respects to those of B.
unguis, that one description will suffice.

Bignonia unguis.--The young shoots revolve, but less regularly and
less quickly than those of the last species. The stem twines
imperfectly round a vertical stick, sometimes reversing its
direction, in the same manner as described in so many leaf-climbers;