374 THE BARS. 



than the outer. While it is thin to yield to the shock, its increased surface 

 gives it sufficient strength. 



On account of its thinness, and the additional weight which it bears, the 

 inner heel wears away quicker than the outer ; a circumstance that should 

 never be forgotten by the smith. His object is to give a plane and level bearing 

 to the whole of the crust. To accomplish this, it will be often scarcely necessary 

 to remove anything from the inner heel, for this has already been done by the 

 wear of the foot. If he forgets this, as he too often seems to do, and cuts away 

 with his knife or his buttress an equal portion all round, he leaves the inner 

 and weaker quarter lower than the outer ; he throws an uneven bearing upon 

 it ; and produces corns and sandcracks and splints, which a little care and 

 common sense might have avoided. 



THE CORONARY RING. 



The crust does not vary much in thickness (see A, page 372, and 6, in the 

 accompanying cut), until near the top, at the coronet, or union of the horn of 

 the foot with the skin of the pasterns, where (w, page 345), 

 it rapidly gets thin. It is in a manner scooped and hollowed 

 out. It likewise changes its colour and consistence, and seems 

 almost like a continuation of the skin, but easily separable 

 from it by maceration or disease. This thin part is called 

 the coronary ring, #, p. 345. It extends round the upper 

 portion of the hoofs, and receives, within it, or covers, a 

 thickened and bulbous prolongation of the skin, called the 

 coronary ligament (see 6, in the accompanying cut). This 

 prolongation of the skin it is nothing more is thickly supplied with blood- 

 vessels. It is almost a mesh of blood-vessels connected together by fibrous 

 texture, and many of them are employed in secreting or forming the crust or 

 wall of the foot. Nature has enabled the sensible laminae of the coffin bone, 

 c, which will be presently described, to secrete a certain quantity of horn, in 

 order to afford an immediate defence for itself when the crust is wounded or 

 taken away. Of this there is proof when in sand-crack or quittor it is neces- 

 sary to remove a portion of the crust. A pellicle of horn, or of firm hard sub- 

 stance resembling it, soon covers the wound; but the crust is principally formed 

 from this coronary ligament. Hence it is, that in sand-crack, quittor, and other 

 diseases in which strips of the crust are destroyed, it is so long in being renewed, 

 or growing down. It must proceed from the coronary ligament, and so gradually 

 creep down the foot with the natural growth or lengthening of the horn, of 

 which, as in the human nail, a supply is slowly given to answer to the wear 

 and tear of the part. 



Below the coronary ligament is a thin strip of horny matter, which has 

 been traced to the frog, and has been supposed by some to be connected with 

 the support or action of that body, but which is evidently intended to add to 

 the security of the part on which it is found, and to bind together those various 

 substances which are collected at the coronet. It resembles, more than any- 

 thing else, the strip of skin that surrounds the root of the human nail, and 

 which is placed there to strengthen the union of the nail with the substance 

 from which it proceeds. 



THE BARS. 



At the back part of the foot the wall of the hoof, instead of continuing round 

 and forming a circle, is suddenly bent in as in the small cut, in page 372, where 

 d represents the base of the crust, and e its inflection or bending at the heel. The 

 bars are, in fact, a continuation of the crust, forming an acute angle, and meet- 

 ing at a point at the toe of the frog see ff, 6, and c, in the smaller cuts and 



