68 THE SKIN. 



violently to contract when any parasite or other object irri- 

 tates the skin. There is also a deep layer of fat, panniculus 

 adiposus, deepest in young animals, which raises the skin, 



Fig. 166. (MttLLER.) Section o f horse's skin enlarged 30 diam. a, Epidermis; b, 

 Rete mucosum, containing the pigment; c, Papillae; d, True skin; e, Connective tissue, 

 containing fat ; /, Stem of hair ; g, Hair-follicle ; h, Hair-bulb with papilla ; I, Oil or 

 sebaceous glands ; mm, Sweat glands ; n, Duct of a sweat-gland. 



and is the cause of the rounded forms so much admired. 

 The skin varies in thickness in different animals and in 

 different parts of the same animal. It is thin and elastic 

 over the belly, thick and less yielding on the back. Where 

 the skin has to cover unyielding structures, it is tightly 

 bound down, but over the greater part of the body it is loose, 

 and in parts thrown into folds. In a healthy animal, even a 

 thick skin is supple and yielding. It is loose and elastic in 

 the young ox that is laying on flesh without difficulty; but 

 in the horse, ox, or other animal out of condition, or suffer- 



