TENDEIL-UEAllEUS. 55 



tliem ; but these objects were not well seized. The tendrils, after 

 clasping au upright sticky repeatedly loosed it again ; often 

 they would not seize it at all, or their extremities did not coil 

 closely round it. I have observed hundreds of tendrils in Cucur- 

 bitaceous, Passifloraceous, and Leguminous plants, and never saw 

 one behave in this manner. When, however, my plant had grown 

 to a lieight of eight or nine feet, the tendrils acted much better ; 

 and one or both regularly seized an adjoining, thin, upright stick, 

 not high up as with the three previous species, but in a nearly 

 horizontal plane ; thus the non-twining stem was enabled to 

 ascend the stick. 



The simple undivided tendril ends in an almost straight, sharj), 

 uncoloured point. The whole terminal part exhibits one odd 

 habit, which in an animal would be called an instinct ; for it con- 

 tinually searches for any little dark hole into which to insert 

 itself. I had two young plants ; and, after having observed this 

 habit, I placed near them posts, which either had been bored by 

 beetles, or which had become fissured in drying. The tendrils, by 

 their own tiovement and by that of the internodes, slowly travelled 

 over the surface of the wood, and when the apex came to a hole 

 or fissure it inserted itself; for this purpose the terminal part, 

 half or quarter of an inch in length, often bent itself at right 

 angles to the basal part, I have watched this process between 

 twenty and thirty times. The same tendril would frequently 

 withdraw^ from one hole and insert its point into a second one. I 

 have seen a tendril keep its point in one instance for 20 h. and 

 in another instance for 36 h. in a minute hole, and then with- 

 draw it. 



Whilst the point of a tendril is thus temporarily inserted, the 

 opposite tendril goes on revolving. The whole length of a tendril 

 often fits itself closely to the surface of the wood with which 

 it is in contact ; and I have seen a tendril bend at right angles 



and place itself in a wide and deep fissure, Avith the apex again 



abruptly bent and inserted into a minute lateral hole. After a 

 tendril has clasped a stick, it contracts spirally ; if it catches 

 nothing, it does not contract. When it has adapted itself to the 

 inequalities of a thick post, though it has clasped nothing, or 

 when it has inserted its apex into some little fissure, the stimulus 

 suffices to induce spiral contraction; and this contraction always 

 draws the tendril away from the post. So that in every case the 

 above described nicely adapted movements were absolutely use- 

 less, excepting once when the tip became jammed in a naiTow 



