DISEASES OF HORSES AND CATTLE. 235 



CHAPTER XX. 



DISEASES OF THE FEET. 



A better idea of the diseases of the foot can be 

 had by some knowledge of the substances which 

 enter into its construction. The soft parts of the 

 foot are protected by a horny box called the hoof. 

 The hoof is divided into three parts, viz., the wall, 

 sole, and frog. Each of these has a separate func- 

 tion to perform, but all unite in protecting the sen- 

 sitive parts of the foot. The wall is composed of a 

 multitude of fibers which run from the top of the 

 hoof to the sole, with which it unites. The external 

 layer is hard and covered by a cement substance, 

 which prevents the escape of moisture; also pre- 

 vents moisture from penetrating into it. The next 

 layer is a little softer, while the internal surface is 

 composed of a great number of plates called the 

 horny laminae, which correspond to the sensitive 

 laminae. The wall receives the substance, which 

 develops it from the coronary band or ligament, 

 which is situated at the top of the wall in the same 

 manner as our nails. Anything which interferes 

 with the health of this band prevents the healthy 

 growth of the wall, hence a dry, brittle hoof. The 

 horny sole resembles the wall, only instead of 

 fibers it is composed of plates in layers. These 

 plates are developed from the sensitive sole. They 



