THE ar:\iy jiokse. 45 



this covering some part of the hoof is secreted or formed. The 

 divisions of this hiyer of fiesh are called the sensitive parts or 

 structures of the foot. They are the coronary hand,, sensitive 

 hunina', sensitive sole, sensitive frog, and the coronary frog 

 hand. 



The coronary hand is a tnick convex band of toug'h flesh, 

 about f inch Avide, and extends entirely arovnid the top of the 

 hoof from one bull) of the heel to the other; in front it is 

 attached to the extensor pedis tendon, and on the sides to liga- 

 ments of the coffin joint, to the lower end of the os corona?, and 

 to the lateral cartilages. The surface of the coronary band is 

 covered with small pointed projections or villi. The coronary 

 band secretes or forms the principal part (middle la^^er) of the 

 wall of the hoof. 



The sensitive lamina? (fleshy leaves) cover and are firmly 

 attached to the anterior or wall surface of the os pedis and to 

 the lower part of the outer surface of the lateral cartilages. 

 These delicate leaves of the flesh dovetail into the horny 

 lamina^ and, with them, serve to fasten the wall of the hoof to 

 the os pedis and to the lateral cartilages. 



The sensitive sole covers the sole surface of the os pedis, is 

 covered with villi, and secretes the horny sole. 



The sensitive frog covers the lower face of the plantar 

 cushion, and from its villi the horny frog is secreted. 



The coronary frog hand or perioplic ring is a narrow l)and 

 of flesh running around just above the coronary band and sepa- 

 rated from it by a faint groove. From the fine villi on the 

 surface of this ring the delicate fibers grow which form the 

 periople. 



The hoof. 



The l)OX or case of horn, called the hoof, which incloses and 

 protects the other structures of the foot, is divided into three 

 parts — wall, sole, and frog. In a healtlw foot these parts are 

 solidly united. 



The wall is the part seen when the foot is on the ground ; it 

 extends from the edge of the hair to the ground and is divided 

 into the toe, quarters, heels, and hai's,- it has an internal surface, 

 an external surface, and an upper and a loAver border. 



The toe is the front part of the wall. It is steeper in the 

 hind foot than in the fore. The quarters extend backward 

 from the toe to the heels. The heel or buttress is that part of 



