408 NAVIN 0^■ THE HORSE. 



mentioned. It is also penetrated by the hair-bulbs, or roots. 

 The true skin is attached to the body by means of the cel- 

 lukxr tissue, described under its name elsewhere. Over a great 

 part of the body it is attached to a muscle peculiar to quadru- 

 peds, called the ^^panniculus camosus,^' and which enables the 

 animal to shake flies and other offending objects off the body. 



The rcte miicosum, or middle layer of the skin, is a thin, soft, 

 web-like structure, which, in different animals, and sometimes 

 in different parts of the same animal, is of different colors, and 

 which Q'ives the color to the animal. This is one of the most 

 curious things in nature. The pores, \vhich have their origin 

 in the true skin, pass through the rete mucosum on their way 

 out^tard. 



The scarf-skin, or outer layer of the skin, called the cuticle, 

 is a tough, thin, transparent membrane covering the other two 

 layers of the skin. It is without sensibility, and serves as a 

 protection to those parts of the skin which are sensitive. But 

 for its presence the slightest touch would cause much pain. It 

 is the cuticle which is raised in drawing a blister. It is com- 

 posed of an infinite number of small scales, somewhat resem- 

 bling the scales of a fish, and similarly arranged. The direc- 

 tion in which these scales lie determines the direction of the 

 hair on the different parts of the animal. The cuticle is pro- 

 duced by the true skin, and is perforated by all the pores 

 which arise from it, and w^hich are its means of attachment to 

 the true skin. The dandruff, or scurf, which gathers on the 

 horse's hide, is only the worn-out scales of the cuticle. 



The nerves of the skin do not enter the scarf-skin, but their 

 fine extremities are, perhaps, in contact with its under surface. 



GLANDS AND PORES OF THE SKIN. 



These have already been spoken of, and their origin in the 

 cutis, or true skin, pointed out ; but their importance demands 

 a more careful consideration of their structure and uses. 



In the true skin there are found many little glands, each 



