SCALES, HAIRS, PRICKLES, AND THORNS. 39 



bark. They are not found on roots, or on parts that 

 grow under water. They are often like simple threads, 

 but frequently also like cells, stretched out lengthwise, 

 and threaded on each other ; having often, instead of 

 a sharp point at the tip, a minute nipple or vesicle, 

 which gives out an oily or sticky fluid, sometimes 

 coloured. Examples may be found in the clammy 

 groundsel, the moss-rose, the sun dew, and the fly bush 

 of the Cape of Good Hope. In the chick pea, the hairs 

 on the leaves are tipped, as Deyeux has described, 

 with little transparent globules, if the plant be in the 

 sunshine ; which, when wiped away, are speedily re- 

 newed ; but at night and in dull damp weather, they 

 disappear till the sunshine returns. 



According to the aspect of what has here been called 

 by the general name of hair, plants are said to be 

 downy 1 , cottony 2 , silky 3 , woolly 4 , or bristly 5 , and a 

 number of distinctions, even still more minute, have 

 been made; when the hairs are in rows, they are 

 termed fringes 6 . 



The hairs of some plants, such as mullein or shep- 

 herd's club, make the leaves look like thick flannel, or 

 the felt of a hat, intended, it should seem, to prevent 

 too rapid evaporation, and in Alpine plants to protect 

 them from cold. At the Cape of Good Hope, advan- 

 tage is taken of this to form wearing apparel. 



Hairs and bristles on plants are sometimes simple 



(1) In Latin, Pubens. 



(2) In Latin, Tomentosus. (3) In Latin, Sericeus. 



(4) In Latin, Lanatus. (5) In Latin, Hispidus. 



(6) In Latin, Ciliee, whence Ciliatus. 



