STRUCTURE OF SKIN — SEBACEOUS FOLLICLES. 



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destitute of it as some other animals ; for in Tartary, 

 the eastern parts of India, China, and some parts of 

 Africa, a hair of varying quaUty forms their sole 

 covering- ; and Sir Joseph Banks imported three from 

 Spain, which were smooth, sleek, and as short-haired 

 as a horse. 



(25.) Structure of the Shin. — The skin is composed 

 of three coats, or layers ; the outermost, the cuticle or 

 scarf-skin, is a thin delicate membrane, devoid of feel- 

 ing, and of a scaly texture, pierced by innumerable 

 small holes, for the passage of the hairs, and perspira- 

 tion, and covering the next, or mucous coat, so named 

 from its pulpy appearance. In this resides the colour- 

 ing matter, which imparts its peculiar tints to the hair, 

 and which can only be satisfactorily demonstrated in 

 the dark races. The existence of this coat has been 

 by some denied ; but it is probable that, though present 

 in all, it can only be exhibited in such as have depth 

 of tint, to admit of the display. It is here that sensa- 

 tion principally resides ; the nerves, or rather their ter- 

 minations, ramifying minutely in its substance, at which 

 they have arrived by piercing the third tunic, or true 

 skin, a dense firm elastic membrane, in which the 

 roots of the hairs are imbedded, and from which, in 

 fact, they take their origin. 



(2G.) Sebaceous Follicles. — The skin is studded 

 over by small glands, or what, in anatomical language, 

 would be called sebaceous follicles, which vary in num- 

 ber in different breeds, and different parts of the body, 

 being most numerous on the breast and shoulders, and 

 secreting a peculiar unctuous semi-solid matter, which, 

 as we shall immediately see, possesses alkaline properties. 



