GHAP. II. 
HAIRS. 
45 
The surface of the cuticle is either perfectly smooth, or fur- 
nished with numerous processes, consisting of cellular tissue in 
different states of combination, which may be arranged under 
the heads of hairs, scales, glands, and prickles. All these ori- 
ginate either directly from the ^uticle, or from the cellular 
substance beneath it ; never having any communication with 
the vascular or ligneous system. 
In Nepenthes the cuticle in the inside of the pitchers is 
pierced by a great number of holes, each of which is closed 
up by a firm thick disk of small cellular tissue, deep brown in 
colour, and connected with the cavernous parenchyma of the 
pitcher. Besides these, Nepenthes has also stomates, the cu- 
rious structure of which has been already described. 
a Of Hairs. 
These {figAb.) are minute, 
transparent, filiform, acute 
processes, composed of cel- 
lular tissue more or less elon- 
gated, and arranged in a single row. They are found occa- 
sionally upon every part of a plant, even in the cavities of the 
petiole and stem, as in Nymphaea and other aquatic plants. 
In the Cotton Plant (Gossypiam herbaceum, &c.) they form 
the substance which envelopes the seeds, and is wrought into 
linen; in the Cowhage (Mucuna urens and pruriens), it is 
they that produce the itching ; and in the Palm tribe they are 
the long, entangled, soft, strangulated filaments that are used 
for tinder. They vary extremely in length, density, rigidity, 
and other particulars ; on which account they have given the 
following names to the surface on which they grow : — 
Down or Pubescence (pubes, adj. pubescens), when they form 
a short soft stratum, which only partially covers the cuticle, 
as in Geranium molle. 
Hairiness (hirsuties, adj. hirsutus), when they are rather 
longer and more rigid, as in Galeopsis Tetrahit. 
Pilosity, when they are long, soft, and erect, as in Daucus 
Carota. 
