CHAPTER X. 



THE SKIN. 



It is obvious that one important function the skin performs 

 is that of affording cover to the delicate parts beneath, and 

 wherever the chance of injury is the greatest we generally 

 find the skin is the thickest, whilst in those parts where 

 sensibility is most required the skin is thinnest. The skin 

 of the back, quarters, and limbs are good examples of the 

 first type; on the back especially we have a protective 

 covering which, in some horses, is as much as a quarter of 

 an inch in thickness. The face and muzzle is a good example 

 of the latter variety, the skin in some parts being as thin as 

 paper. In those parts not exposed to violence we also find 

 the skin thin, as on the inside of the arms and thighs. 



According to Colin, the surface of the horse's skin is equal 

 to from 50 to 60 square feet. 



The skin as an organ of touch is of great importance. 

 All animals appear most sensitive to slight skin irritation ; 

 Hies will cause horses to go nearly mad with irritation, and 

 the elephant, with his thick hide, is quite as sensitive to 

 these tormentors as a highly-bred horse. 



The skin is highly endowed with sensory nerves, par- T 

 ticularly in those parts connected with the organs of pre- 

 hension, where also the long hairs growing from the part 

 are brought into contact with distinct nerve-endings. 



The skin is a bad conductor of heat, and this is con- 

 siderably assisted by the layers of fat found beneath it or 

 at no great distance from it, as in the abdominal region, 

 where the subperitoneal fat protects the viscera of animals 

 living in the open and lying in wet places. 



