OF TENDRILS. 2G7 



CHAPTER II. 



OF TENDRILS. 



Under the name of Tendrils (cirrhi), are designated 

 those soft, cylindrical prolongations, which are capable 

 of twisting or twining round bodies they meet with ; they 

 are found in different parts of plants, and generally 

 serve to support those which are unable to do so of them- 

 selves. 



The origin of tendrils is perfectly analogous to that 

 of spines ; they are not organs properly so called, but 

 degenerations or modes of prolongation of which almost 

 all the organs are susceptible, and they only differ from 

 spines in their softness, flexibility, and in their usually 

 greater length. 



We call those Petiolary which are produced by the 

 prolongation of common petioles into flexible filaments ; 

 this is frequent in the simply winged leaves of the Le- 

 guminosge, among the Vicieac, and is met with, though 

 more rarely, in bipinnate leaves, as in Entada. In this 

 last case, the common petiole is prolonged into an elon- 

 gated tendril, and the partial ones either do not lengthen 

 at all, or only present a small, scarcely apparent point. 

 We also find tendrils analogous to simple leaves, but 

 with the segments so distinct that they resemble winged 

 leaves, as in Mutisia, and especially in Cobcea. Petiolary 

 tendrils are sometimes simple, sometimes branched : — 

 simple, when they are formed by the unbranching pro- 



