MIXED CEOP OF UNIFORM AGE. 81 



tween the climbing plants themselves, considered as an integral por- 

 tion of the forest crop, and the trees on which they climb. 



Plants with a climbing habit rise up into and spread over the 

 crowns of their supports either (i) by means of adventitious roots, 

 which enter into the very smallest crevices in the bark, and attach 

 themselves firmly thereto, e, g., ivy, Fines scandens, Ac.; or (ii) by 

 means of tendrils, which grasp- by merely curling up round any 

 sufficiently thin body with which they come into contact, e ,g.> the 

 whole genus Vitis, Bauhinia Vahlii, many rattans, &c. ; or (iii) by 

 means of tendrils which, when unable to meet a plant part sufficiently 

 thin to be grasped by curling up round it, may nevertheless often 

 fix themselves to any, even moderately, rough, surface with tha 

 help of their free extremity, which at once- swells up into a sucker- 

 like disc that grows into and completely fills up the minutest cre- 

 vices and sinuosities, and becomes adherent thereto, after the 

 manner of adventitious ro.o ts, e. g., the vines ;. or (iv) by means 

 of hooked spines, e. g.,. many rattans, Cap parts, horrida, &c. ; or 

 (v) by twining round the stems and branches of their supports, 

 at first generally in a loose coil, and then with a tight grasp, e.g\. 

 MilletticL auriculata,, Spatholobus. Roxlurghii^ Bauhinia TW<///, 

 Butea superba, the vines, Celastru& senegcdens-is, Combeetum decan- 

 drum and a host of other climbers; or (vi) and lastly,by interlacing 

 branches with, or simply resting up against or on the stems and 

 branches of, their supports, e.g., Dalbergia volubilis, Acacia pennata, 

 Cudrania javanensis, &c. From the few examples just given it 

 will be observed tliat the same climber may employ more than ono 

 mode of ascension. Thus the vines twine as well as possess tendrils, 

 which themselves can grasp both by curling up and by attaching 

 themselves like adventitious aerial roots; Bauhinia Valil'd not only 

 has tendrils, which after the disarticulation of the curled-up portion, 

 are reduced to mere hooks, but also twines and scrambles up; the 

 rattans twine and also possess tendrils, and moreover, to a certain 

 extent, scramble up, in which mode of ascension they are assisted 

 by their numerous prickles ; the climbing figs twine as well as creep 

 up by means of adventitious roots; and so on. 



Whichever the mode of ascension followed, the result is always 

 the invasion and overspreading of the crowns of the supports by 

 the dense foliage of the climber. The least harm done is impeded 

 growth and a sickly condition of the support. Moreover, when 

 the climber ascends by twining, the steins and branches of the sup- 

 ports get constricted, the increasing pressure on the bark, following 

 the entire circumference of the stem, prevents the free vertical 



