Chap. in. BIGNONIACE^I. 95 



their behaviour : I repeatedly placed close to them, 

 thick and thin, rough and smooth sticks and posts, as 

 well as string suspended vertically, but none of these 

 objects were well seized. After clasping an upright 

 stick, they repeatedly loosed it again, and often would 

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

 closely round. I have observed hundreds of tendrils 

 belonging to various Cucurbitaceous, Passifloraceous, 

 and Leguminous plants, and never saw one behave in 

 this manner. When, however, my plant had grown 

 to a height of eight or nine feet, the tendrils acted 

 much better. They now seized a thin, upright stick 

 horizontally, that is, at a point on their own level, and 

 not some way up the stick as in the case of all the 

 previous species. Nevertheless, the non-twining stem 

 was enabled by this means to ascend the stick. 



The extremity of the tendril is almost straight and 

 sharp. The whole terminal portion exhibits a singular 

 habit, which in an animal would be called an instinct ; 

 for it continually searches for any little crevice or hole 

 into which to insert itself. I had two young plants ; 

 and, after having observed this habit, I placed near 

 them posts, which had been bored by beetles, or had 

 become fissured by drying. The tendrils, by their 

 own movement 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; in 

 order to effect this the extremity for a length of half 

 or quarter of an inch, would often bend itself at right 

 angles to the basal part. I have watched this process 



