40 



HORSESHOEING. 



like layer, without blood-vessels or nerves. It extends over the 

 entire surface of the body, and protects the underlying, very sen- 

 sitive middle layer from external influences. The oldest cell- 

 layers lie on the outer surface, and are being continuously brushed 

 off in patches or scales, while new ones are constantly being 

 formed on the outer surface of the middle layer. 



2. The middle layer, leather-shin or dermis, is composed of 

 solid, fibrous, and elastic tissues, and contains many blood-ves- 

 sels, small nerves, sweat- and oil-glands, and hair folhcles from 

 which the hair grows. The hair upon the posterior surface of 

 the fetlock-joint is usually long and coarse, forming a tuft known 



as the "footlock," which 

 encloses a horny spur, 

 called the ergot. Common 

 bred horses have, as a rule, 

 larger and coarser foot- 

 locks than thoroughbreds. 

 The derm or leather-skin, 

 which produces the hair 

 and epiderm, is the thick- 

 est and most important 

 layer of the skin. 



3. The inner layer, or 

 subcutaneous tissue, unites 



Foot from which the near half of the homy wall and i\,c^ mirlrllo lavov iiri+Vi 

 a greater part of the so-called aeshy wall have been i^uuie idyei Wlin 



removed, in order to show the relation of the lateral the mUScleS, teudoUS, liga- 

 cartilage to adjacent structures : o, vertical section of 

 the skin prolonged downward through the pododerm 

 (foot-skin) to show clearly that the latter is hut a con- 

 tinuation of the former ; a', hairless place on the skin ; 

 6, perioplic hand ; V, line indicating the upper border 

 of the same ; &", surface of section of the periople, or 

 perioplic horn-hand; c, coronary cushion; C, (left) 

 line which marks the upper border of the coronary 

 cushion ; c", section of wall at the toe ; d, podophyl- 

 lous tissue (sensitive laminse) ; e, homy sole ; /, white 

 line ; g, homy frog ; h, fleshy flrog ; t, lateral cartilage. 



ments, bones, or other 

 structures. It is that loose 

 fibrous mesh or net-work 

 through which the butcher 

 cuts in removing the hide 

 from the carcass. 



(6) The hoof-skin (Figs. 

 23 and 24, b, c, d ), or po- 

 doderm, is completely enclosed by the hoof. Although it is only 



