GO :MR. DARWIN ON CLIMBING PLANTS. 



quite still for 12 li. or 18 h., and tlien recommence revolving ; such 

 strongly marked interruptions in the movements I have observed 



in no other plant. 



The leaves bear four leaflets, themselves subdivided, and termi- 

 nate in a much-branched tendril. The main petiole of the leaf, 

 whilst young, moves spontaneously by curving itself, and follows 

 nearly the same irregular course, and at about the same rate, with 

 the iiiternodes. The movement to and from the stem is naturally 

 the most conspicuous, and I have seen the chord of the curved 

 petiole forming an angle of 59° witli tlie stem, and an hour after- 

 wards an angle of lOG^. The two opposite petioles do not move 

 together, and one is sometimes raised so mucli as to stand close to 

 the stem whilst the other is not far from horizontal. The basal part 

 of the petiole moves less than the distal part. The tendrils, be- 

 sides being carried by the moving petioles and internodes, them- 

 selves move spontaneously, and the opposite tendrils occasionally 

 move in opposite directions. By these several movements of the 

 young internodes, of the petioles, and of the tendrils^ all acting 

 together, a wider space is swept for a support. 



In young plants, the tendrils are about three inches in length : 

 they bear two lateral and tw^o terminal branches ; and each branch 

 bifurcates twice, with the tips forming blunt double hooks, having 

 both points directed to the same side. All the branches are sen- 

 sitive on all sides ; and after being lightly rubbed, or after coming 

 into contact with a stick, they bend in about 10 m. One that be- 

 came, after a light rub, curved in 10 m., continued bending for 

 between 3 h. and 4 h., but subsequently in 8 h. or 9 h. became 

 straight again. Tendrils, which have caught nothing, ultimately 

 contract into an irregular spire, as they do also, only much more 

 quickly, after clasping a support. In both cases the petiole bear- 

 ing tlie leaflets, which at first is straight and inclined a little 

 upwards, moves downw^ards and abruptly bends itself in the middle 

 into a right angle ; but this is more plainly seen in I^, miniatus 

 than in E. scaler. The action of the tendrils in the Eccremo- 

 carpm is in some respects analogous to that of the tendrils of 

 Bignonia capreolafa\ but the w^hole tendril does not move from 

 the light, nor do the hooked tips become enlarged into cellular 

 disks. After the tendrils have come into contact with moderately 

 thick cylindrical sticks or with rugged bark, the several branches 

 may be observed slow^ly to lift themselves up, change their posi- 

 tion, and again come into contact with them. The object of these 



