HABITS OF CLIMBING PLANTS. 177 



This tendril had five disk-bearing branches, of equal thickness 

 and apparently equal strength ; so that this one tendril, after 

 having been exposed during ten years to the weather, would 

 have resisted a strain of ten pounds." 



Our space will not allow even . an abstract of Darwin's 

 account of the admirable adaptations and curious behavior of 

 various tendrils, even of some very common plants ; as for 

 instance of the familiar Cohcea scandens, in which (the stem 

 and the petioles being motionless) the great compound tendril 

 borne at the summit of the leaf executes large circular sweeps 

 with remarkable rapidity, carrying round an elaborate flexible 

 grapnel, consisting of its five subdivisions, from 50 to 100 

 in number, which are very sensitive even to a slight touch, 

 bending in a few minutes toward the touched side, so that 

 they clasp twigs very promptly, and aU tipped with minute, 

 double or sometimes single, sharp hooks, which catch in little 

 inequalities, and may prevent the tendi'il branchlets from 

 being dragged away by the rapid revolving movement before 

 their irritability has time to act, while the still free ones pro- 

 ceed to arrange themselves, by various queer and complicated 

 movements, so as to secure the most advantageous hold ; then 

 contracting spirally so as to bring other portions up within 

 reach of the support, until all are inextricably knotted and 

 fastened, and finally growing stouter, rigid and strong, bind- 

 ing the plant firmly to its support. 



We cannot omit all mention of Bignonia capreolata, a not 

 uncommon climber of our Southern States, of which we espe- 

 cially wish to obtain fresh seeds or young plants, that we may 

 ourselves observe the remarkable behavior of its tendrils which 

 Mr. Darwin describes. These are said to turn from the light, 

 as in many other cases ; they will clasp smooth sticks, but soon 

 lose their hold and straighten themselves again. A rough, 

 fissured, or porous surface alone satisfies them ; their young 

 tij)S seek and crawl into dark holes and crevices, in the man- 

 ner of roots ; then they develop their hooked extremity, and, 

 especially when they meet with any fibrous matter, the hook 

 swells into irregular balls of cellular tissue, which first adhere 

 to the fibres by a viscid cement, and then grow so as to de- 



