TEGUMENTAL SYSTEM. 407 



Colon?'. — The colour of the cuticle is the same in all horses, 

 be they black or grey, chestnut or bay : although the surface of 

 the skin appears (when the hair is shorn off) to correspond in 

 hue with the colour of the hair, the infiltration of serum from a 

 blister underneath the cuticle shews that this appearance is de- 

 ceptive. 



Extent. — In most parts of the body the cuticle is thickly clad 

 with hair; but there are places (which were pointed out before) 

 where we find it nearly or quite bare. Every part of the cutis is 

 covered by cuticle ; and it not only insinuates itself into perspi- 

 ratory pores and follicular passages, but lines to a considerable 

 extent some of the outlets of the body. Cuticle passes into the 

 mouth and pharynx, and therein becomes continuous with the 

 membrane covering those parts ; it likewise may be traced into 

 the anus, and, indeed, some have imagined, through the entire 

 alimentary canal. The nature of the parts, however, by no means 

 bears such a character : although we must acknowledge, that, 

 so indetectible is the line of termination or separation, we are un- 

 able to say precisely where the skin ends and the membrane be- 

 gins. It may, demonstrably, be traced into the meatus audito- 

 rius externus. Bichat, indeed, is of opinion that not only the 

 cuticle, but the cutis also, lines these cavities in man. " All 

 authors," says he, " have admitted an epidermis upon mucous 

 membranes. But it would appear that most of them believed 

 that only this part of the skin entered the cavities and lined 

 them. Haller, in particular, is of this way of thinking. But 

 a slight inspection will suffice to remark, that here, as upon the 

 true skin, it forms but a superficial covering to the papillary sur- 

 face and to the corion. Boiling water, which detaches it from 

 the palate, tongue, and pharynx even, exposes to naked view the 

 tico other strata of skin*." 



Pores. — The cuticle is everywhere pierced with holes, corre- 

 sponding in size, situation, and number, to those of the cutis. 

 First, there are the pores for the hairs ; secondly, the perspiratory 

 or exhalent pores ; thirdly, the absorbent or inhalent pores ; and, 

 fourthly, pores of a larger size, thrcHigh which unctuous secre- 

 tions, in various parts, are emitted. 



Production. — At one time it was believed that the cuticle was 

 formed out of the crystallization of a fluid effused from the sur- 

 face of the cutis : but the simple fact of the foetus in utero (where- 

 in it is surrounded by liquid) having a cuticle, is a refutation of 

 this opinion. That it is, however, a deposition or secretion from 

 the cutis, the same as the hoof is from the sensitive parts of the 



* Anatomie Generale, toni. iv, page 469. 



