426 NAVIN ox THE HORSE. 



strong ligament attaclied along the lower half of the forward 

 border, and to the coffin-bone in front of it. Two ligaments, 

 one attached at each end of the shuttle-bone, pass up and are 

 attached to the sides of the coronal, or lower pastern-bone. 



The Coronary Siihstance. — I shall now proceed to the expla- 

 nation of this important and extraordinary structure. It is 

 generally called the coronary ligament, but very inapproj^ri- 

 ately, as it has none of the characteristics of those parts which 

 are called ligaments. 



The situation of the coronary substance, as has been before 

 pointed out, is in the hollowed out or shaved out upper border 

 of the wall of the hoof, lying directly behind the coronary 

 ring. It is the main cause of the prominence around the 

 upper border of the crust, called the coronet. It is broadest 

 and thickest around the front part of the wall, becoming 

 narrower and thinner around the quarters and heels, and 

 posteriorly being joined to and lost in the substance of the 

 heels of the sensitive frog. 



The connection with the wall is formed by the little tubes 

 called villi, which secrete the horn. Its inner side, in front, is 

 connected with the coffin-bone and the extensor tendon ; at the 

 sides with the cartilages which rise up from the sides and wings 

 of the coffin-bone. It is united to these by what is called 

 cellular tissue. The superior, or upper, border of the coronary 

 substarice appears to be a continuation of the true skin. But 

 this is not the case. The anatomist finds a plain line of 

 separation between them, and its structure demonstrates or 

 proves its different character. Its lower border, as it passes, 

 down on the coffin-bone, becomes thin and gathered into numer- 

 ous little points, from which are formed the sensitive lamellae. 



Three different parts are found in the coronary substance. 

 A cartilaginous net-work, which is the base or frame-work of 

 the structure, and the office of which seems to be to accommo- 

 date it to the motions of the parts, and to afford j^rotection 

 to the glandular structure. The next part is a net-v/ork of 



