CHAP. ir. HAIRS. 45 



The surface of the cuticle is either perfectly smooth, or fur- 

 nished with niuuerous 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 cuticle, 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 bi'own 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. 



3. Of Hairs. 



These {Jig.lb.)ave minute, 

 transparent, filiform, acute 

 processes, composed of cel- 

 lular tissue mo''e 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 Nymphasa and other aquatic plants. 

 In the Cotton Plant (Gossypium 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 {picbes, adj. jmbescens), 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. 



