IS 



NATURAL HISTORY READER. 



enlarged ends, then with rudimentary or dwarfed leaves, 

 and finally with full-sized leaves ; when these are developed 

 they clasp with their leaf-stalks, and then the first-formed 

 filaments wither and die off ; thus the plant, which in its 

 youth was a tendril-climber, gradually develops into a true 

 leaf-climber. During the transition, every gradation be- 

 tween a leaf and a tendril may be seen on the same plant. 



(I. The family of the Bignonias is one of the most inter- 

 esting of the class of tendril-climbers, on account of the 

 variety of adaptation which is found 

 among them. In one species the leaf 

 bears a pair of leaflets, and ends in a 

 tendril having three branches. The 

 main tendril may be compared to a 

 bird's leg with three toes, each bear- 



ing a small claw. And this compari- 

 son seems apt enough, for, when the 

 tendril comes against a twig, the three 

 Tendril Books. toes curl round it like those of a perch- 



ing bird. Besides the toes or tendrils, 

 the leaf-stalk is sensitive, and acts like that of a regular 

 leaf-climber, wrapping itself round a neighboring object. 



7. In some cases the young leaves have no tendrils at 

 their tips, but clasp with their stalks, and this is a case ex- 

 actly the reverse of Tropceolum — a tendril-climber whose 

 young leaves have no tendrils, instead of a leaf-climber 

 whose young climbing organs arc not leaves. Thus the 

 close relationship that exists between leaf- and tendril- 

 climbers is again illustrated. This plant also combines the 

 qualities of another class of climbers, namely, twiners, for 

 it can wind spirally round a support as well as a hop or any 

 other true twiner. Another species also helps to support 

 itself by putting out roots from its stems, which adhere 

 to the stick up which the plant is climbing. So that here 

 are four different methods of climbing — twining, leaf, ten- 



