114 TENDRIL-BEARERS, Ouap. IIL. 
secured the internodes; when this was done, I could 
never detect any movement in the petiole, except to 
and from the hght. 
The tendrils, on the other hand, when the internodes 
and petioles are secured, describe irregular spires or 
regular ellipses, exactly like those made by the inter- 
nodes. A young tendril, only 1} inch in length, 
revolved. Dutrochet has shown that when a plant is 
placed in a room, so that the light enters laterally, the 
internodes travel much quicker to the light than from 
it: on the other hand, he asserts that the tendril itself 
moves from the light towards the dark side of the 
room. With due deference to this great observer, I 
think he was mistaken, owing to his not having 
secured the internodes. I took a young plant with 
highly sensitive tendrils, and tied the petiole so that 
the tendril alone could move; it completed a perfect 
ellipse in 1 hr. 30 m.; I then turned the plant partly 
round, but this made no change in the direction 
of the succeeding ellipse. The next day I watched a 
plant similarly secured until the tendril (which was 
highly sensitive) made an ellipse in a line exactly to 
and from the light; the movement was so great that 
the tendril at the two ends of its elliptical course 
bent itself a little beneath the horizon, thus travelling 
more than 180 degrees; but the curvature was fully 
as great towards the light as towards the dark side 
of the room. I believe Dutrochet was misled by not 
having secured the internodes, and by having observed 
a plant of which the internodes and tendrils no longer 
