202 CONCLUDING BEMAEKS, Chap. V, 



primordially a twiner ; this then became a leaf-climber, 

 the leaves being afterwards converted by degrees into 

 tendrils, with the stipules greatly increased in size 

 through the law of compensation,* After a time the 

 tendrils lost their branches and became simple ; they 

 then lost their revolving-power (in which state they 

 would have resembled the tendrils of the existing 

 L. aphaca), and afterwards losing their prehensile 

 power and becoming foliaceous would no longer be 

 thus designated. In this last stage (that of the exist- 

 ing L. nissoUa) the former tendrils would reassume 

 their original function of leaves, and the stipules which 

 were recently much developed being no longer wanted, 

 would decrease in size. If species become modified in 

 the course of ages, as almost all naturalists now admit, 

 we may conclude that L. nissolia has passed through a 

 series of changes, in some degree like those here 

 indicated. 



The most interesting point in the natural history of 

 climbing plants is the various kinds of movement 

 which they display in manifest relation to their wants. 

 The most diflferent organs — stems, branches, flower- 

 peduncles, petioles, mid-ribs of the leaf and leaflets, 

 and apparently aerial roots — all possess this power. 



The first action of a tendril is to place itself in a 

 proper position. For instance, the tendril of Cobaea 



" Moquin-Tandon (£llements de this nature was suddenly effected ; 



Teratologie, 1841, p. 156) gives for the leaves completely dis- 



Ihe case of a monstrous bean, in appeared and the stipules grew to 



which a case of compensation of an enormous size. 



