TENDRTL-BEARERS. Gl 



movements is that the double hooks at the extremities of the 

 branches, which naturally face in all directions, may be brought 

 into contact with the wood. I have watched a tendril, which had 

 bent itself at right angles abruptly round the sharp corner of a 

 post,neatly bring every single hook into contact with both surfaces. 

 The appearance suggested the belief, that though the whole tendril 

 is not sensitive to light, yet that the tips are so, and that they 

 turn and t wist themselves towards any opaque surface. Ultimately 

 the branches arrange and fit themselves very neatly to all the irre- 

 gularities of the most rugged bark, so that they resemble in 

 their irregular course a river with its branches, as engraved on 

 a map. But when a tendril has thus arranged itself round a 

 rather thick smooth stick, the subsequent spiral contraction 

 generally spoils the neat arrangement, and draws the tendril 

 from its support. So it is, but not in quite so marked a manner, 

 when a tendril has spread itself over the rugged bark of a thick 

 trunk ; for in this case the spiral contraction of the opposite 

 branches sometimes draws the opposed hooks firmly to their 

 supports. Hence we may conclude that these tendrils are not 

 perfectly adapted to seize smooth moderately thick sticks or rug- 

 ged bark. AYHien a thin stick or twig is placed near a tendril, 

 its terminal branches wind quite round it and seize their own 

 lower branches or main stem ; and the stick is thus firmly, but 

 not neatly, grasped. The extremities of the branches, close to the 

 little double hooks, have a strong tendency to curl inwards, and 

 are excited to this movement by contact with the thinnest objects. 

 This accounts for the tendrils apparently preferring such objects 

 as excessively thin culms of a grass, or the long flexible bristles 

 of a brush, or the thin rigid leaves of an Asparagus, all which 

 objects they seized in an admirable manner ; for the tips of 

 each sub-branch seized one, two, or three of the bristles, for in- 

 stance, and then the spiral contraction of the several branches 

 brought all these little parcels close together, so that thirty or 

 forty bristles were drawn into a single bundle, and afforded an 

 excellent support. 



Polemoxiace.e. — Cobaa scandens — This is an admirably con- 

 structed climber. The terminal portion of the petiole, which 

 forms the tendril, was in one very fine specimen eleven inches in 

 length, with the basal part bearing two pairs of leaflets, only two 

 and a half inches in length. The tendril of the Cobaca revolves more 

 rapidly and vigorously than in any other plant observed by me, 

 with the exception of one Passijlora. It made three fine large, nearly 



