I have given one
remarkable instance, namely that of the Maurandia semperflorens, the
young flower-peduncles of which spontaneously revolve in very small
circles, and bend when gently rubbed to the touched side; yet this
plant certainly does not profit by these two feebly developed powers.
A rigorous examination of other young plants would probably show
slight spontaneous movements in their stems, petioles or peduncles,
as well as sensitiveness to a touch. {45} We see at least that the
Maurandia might, by a little augmentation of the powers which it
already possesses, come first to grasp a support by its flower-
peduncles, and then, by the abortion of some of its flowers (as with
Vitis or Cardiospermum), acquire perfect tendrils.
There is one other interesting point which deserves notice. We have
seen that some tendrils owe their origin to modified leaves, and
others to modified flower-peduncles; so that some are foliar and
others axial in their nature. It might therefore have been expected
that they would have presented some difference in function. This is
not the case. On the contrary, they present the most complete
identity in their several characteristic powers.
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