CuAl". III. FUMAElACE^ai. 125 



metamorphosis of the tenninal leaflets is complete, 

 and they are converted into perfect tendrils. Whilst 

 the plant is young, the tendrils appear like modified 

 branches, and a distinguished botanist thought that 

 they were of this nature; but in a full-gro^n plant 

 there can ha no doubt, as I am assured by Dr. Hooker, 

 that they are modified leaves. When of full size, they 

 are above 5 inches in length; they bifurcate twice, 

 thrice, or even four times; their extremities are 

 hooked and blunt. All the branches of the tendrils 

 are sensitive on all sides, but the basal portion of the 

 main stem is only slightly so. The terminal branches 

 when lightly riibbed with a twig became curved in 

 the course of from 30 m. to 42 m., and straightened 

 themselves in between 10 hrs. and 20 hrs. A loop 

 of thread weighing one-eighth of a grain plainly 

 caused the thinner branches to bend, as did occasion- 

 ally a loop weighing one-sixteenth of a grain; but 

 this latter weight, though left suspended, was not 

 sufficient to cause a permanent flexure. The whole 

 leaf with its tendril, as well as the young upper inter- 

 nodes, revolves vigorously and quickly, though irregu- 

 larly, and thus sweeps a wide space. The figure traced 

 on a beU-glass was either an irregular spire or a 

 zigzag line. The nearest approach to an ellipse was an 

 elongated figure of 8, with one end a little open, and 

 this was completed in 1 hr. 53 m. During a period 

 of 6 hrs. 17 m. another shoot made a complex figure, 

 apparently representing three and a half ellipses. 

 When the lower part of the petiole bearing the leaflets 



