70 LEAF-CLIMBERS. Cuap. IT. 
the power of movement has been transferred to the 
flower-peduncles from the young internodes, and sensi- 
tiveness from the young petioles. But to whatever 
cause these capacities are due, the case is interest- 
ing; for, by a little increase in power through natural 
selection, they might easily have been rendered as 
useful to the plant in climbing, as are the flower- 
peduncles (hereafter to be described) of Vitis or 
Cardiospermum. 
Rhodochiton volubile—A long flexible shoot swept a 
large circle, following the sun, in 5 hrs. 30 m. ; and, as 
the day became warmer, a second circle was completed 
in4hrs. 10m. The shoots sometimes make a whole 
or a half spire round a vertical stick, they then run 
straight up for a space, and afterwards turn spirally in 
an opposite direction. The petioles of very young 
leaves about one-tenth of their full size, are highly 
sensitive, and bend towards the side which is touched ; 
but they do not move quickly. One was perceptibly 
curved in 1 hr. 10 m., after being lightly rubbed, and 
became considerably curved in 5 hrs. 40 m.; some 
others were scarcely curved in 5 hrs. 30 m., but dis- 
tinctly so in 6 hrs. 30 m. A curvature was perceptible 
in one petiole in between 4 hrs. 830 m. and 5 hrs., 
after the suspension of a little loop of string. A 
loop of fine cotton thread, weighing one sixteenth of a 
grain (4:05 mg.), not only caused a petiole slowly to 
bend, but was ultimately so firmly clasped that it 
could be withdrawn only by some little force. The 
petioles, when coming into contact with a stick, take 
