56 MR. DAIIWIN ON CLIMBING PLANTS. 



fissure. I fully expected, from the analogy of B. caprcolata and 

 B. littoral is, that the tip would have developed itself into an 

 adhesive disk ; but I could never detect even a trace of this 

 process. Improbable as the view may be, I am led to suspect that 

 this habit in the tendril of inserting its tip into dark holes and 

 crevices has been inherited by the plant after having lost the power 

 of forming adhesive disks. 



Bignonia picta.—-1\\\s species closely resembles the last in the 

 structure and movements of its tendrils. I casually examined a 

 fine growing plant of the allied B. Lindlcyi, and this apparently 

 behaves in all respects in the same manner. 



Bignonia capreolata. — "We now come to a species having ten- 

 drils of a different type : but first for the internodes. A young 

 shoot made three large revolutions, following the sun, at an 

 average rate of 2 h. 23 m. The stem is thin and flexible, and I ha\ e 

 seen one make four regular spiral turns round a thin upright st irk, 

 ascending, of course, from right to left, and therefore in a reversed 

 direction compared with the first-described species; but after- 

 wards, from the interference of the tendrils, it ascended either 

 straight up the stick or in an irregular spire. These tendrils are 

 highly remarkable. In a young plant they were about 1\ inches 

 in length, and much branched, the five chief branches apparently 

 representing two pairs of leaflets and a terminal one ; each branch 

 is bifid or more commonly trifid toward its extremity, with all the 

 points blunt but distinctly hooked. A tendril when lightly rub- 

 bed bends to that side, and subsequently becomes straight again ; 

 but a loop of thread weighing \\\\ of a grain produced no effect. 

 The terminal branches of a tendril twice became in 10 m. slightly 

 curved when touching a stick ; and in 30 m. the tips curled quite 

 round the stick : the basal part is less sensitive. The tendrils 

 revolve in an apparently capricious manner, sometimes not at all, 

 or very slightly, but at other times they describe large regular 

 ellipses. I could detect no spontaneous movement in the pel ioles. 



At the same time that the tendrils are revolving more or less 

 regularly, another remarkable movement first begins ; the tendrils 

 slowly begin to bend from the light towards the darkest side of the 

 house. I repeatedly changed the position of my plants, and the 

 successively formed tendrils always ended by pointing, some little 

 time after the revolving movement had quite ceased, to the darkest 

 side. But when I placed a thick post near a tendril, and between 

 it and the light, the tendril pointed in that direction, In two in- 

 stances a pair of leaves stood so that one tendril was directed to- 



