3 88 VETERINARY LECTURES 



are thus stimulated in their circulation, animal heat sustained, and 

 the internal organs kept free from congestive disorders. From this 

 it will be seen that clipping acts as a splendid tonic, fully equal — in 

 fact, superior — to an extra feed of corn per day. 



660. Hoofs, Horns, and Claws are appendages pertaining to 

 the skin. The hoof, or horny box, protects and shields the 

 sensitive parts of the foot, and is secreted by the coronary band 

 {pars. 167 and 168). Horns, seen on the sides of the forehead of 

 many animals, are modifications of the skin ; they differ very 

 much in shape, size, and colour. A horn has a base, body, and point, 

 and is secreted by a fine vascular membrane, which covers the horn 

 core, and forms a circular pad in connexion with the skin at the 

 base. The rings formed at the base of the cow's horn are looked 

 upon by many as an indication of the age of the animal. The first 

 ring is supposed to make its appearance about the age of three 

 years, a new ring being formed each succeeding year. These rings 

 are often rasped out, and rubbed down with sand-paper and oil, to 

 give the animal a more youthful appearance. The bony projection, 

 or horn core, is made up internally of cavities, interspersed with 

 thin beams of bone, which give to it both strength and lightness. 

 Claws are formed in a manner analogous to that in which hoofs 

 and horns are produced. 



661. Skin Diseases are numerous, and of great variety, and 

 may be classed under three heads : 



1. Inflammatory. 



2. Non-inflammatory. 



3. Parasitic. 



INFLAMMATORY DISEASES OF THE SKIN. 



662. Variola Equina, or Horse-Pox, is a specific, vesicular, 

 eruptive, febrile disease of the inflammatory type, happily of rare 

 occurrence in country practice, and, although of a constitutional 

 character, manifestations of the malady are made through the agency 



