108 TENDRILS.— RAMIFICATION 
formed of hardened parenchyma, arising immediately from, and 
in connexion only with, the epidermal tissue and layer of cells 
beneath. 
Another irregularly developed branch is the tendril or cir- 
rhus : this term is applied to a thread-like leafless branch, which 
is twisted ina spiral direction, as in the Passion-flower (jig. 213, 
v, v). It is one of those contrivances of nature by means of 
which weak plants are enabled to rise into the air by attaching 
themselves to neighbouring bodies for support. Tendrils may 
be also observed in the Vine (fig. 214, v, v, v), where they are 
regarded by many botanists as the terminations of separate axes, 
or as transformed terminal buds. 
Eres 2s: Fic. 214. 
Fig. 213. Aportion of the stem of Passifiora quadrangularis. v, v. Tendrils, 
— Fig. 214. Part of the stem of the Vine. », v, v. Tendrils, 
Both spines and tendrils are occasionally produced from 
leaves and some other organs of the plant ; these peculiarities 
will be referred to hereafter, in the description of those organs 
of which they are respectively modifications. 
B. RamiricaTIon oR Brancuine.—In the same way as 
branches are produced from buds placed on the main axis or 
stem, so in like manner from the axils of the leaves of these 
branches other buds and branches are formed ; these again will 
form a third series, to which will succeed a fourth, fifth, and so 
on. The main divisions of the stem are called branches, while 
the smaller divisions of these are commonly termed twigs. 
The general arrangement and modifications to which these are 
liable are commonly described under the name of ramification 
or branching, which may be defined as the lateral development 
