80 A MANUAL ON THE HOG. 



or exterior of these is, the cuticle or scarf skin, which 

 covers the whole surface of the body, and protects the 

 tjie more sensitive parts from the injuries which might re- 

 sult to them from immediate contact with external agents. 

 It is a thin, tough, callous texture, perforated with innu- 

 merable holes, or pores, through which pass the hairs, and 

 bristles, and whence exude those transpirations by means 

 of which the body throws off all vapors injurious to the 

 system. Chemical analysis has proved it to be chiefly com- 

 posed of gelatine, and consequently insoluble in water of 

 common temperature. This layer is considerably tougher 

 and denser, in the hog, and other of the pachydermata, 

 than it is in the horse, ox, and most of our domesticated 

 animals, 



" Beneath this is the rete mucosum, a soft expansion of tis- 

 sue which overspreads, and can, with difficulty, be separated 

 from the layer below it. Its purpose appears to be to pro- 

 tect the terminations of the blood vessels, and nerves of 

 the skin, which it, in a manner, envelops, or covers. This 

 layer determines the color of the body, and of the hair. 



, The third, and undermost part, is the cutis vera, or true 

 skin, an elastic texture, composed of innumerable minute 

 fibres, crossing each other in all directions, fitting closely to 

 every part of the frame, yielding by its elasticity to all the 

 motions of the body, and interposing its dense, firm struc- 

 ture between the more vital parts of the system, and ex- 

 ternal injuries. Innumerable blood vessels, and nerves 

 pass through it, and appear upon its surface, in the form of 

 papillae ; it is in fact far more sensitive than the muscles, or 

 flesh. 



" The skin varies in density in different breeds of swine. 

 In some of the large, old breeds, it is thick, coarse, and 

 tough ; while in many of our smaller breeds, and particu- 

 larly in those which have a considerable admixture of 

 Asiatic blood, and in the Chinese pigs themselves, it is soft, 



