THE CORONARY RING.— THE BARS. 397 



often scarcely necessary to remove anything from the inner heel, for this 

 has ah'eady 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 sand-cracks and splints, which a little care and common sense might 

 have avoided. 



THE COEONARY RING. 



The crust does not vary much in thickness (see A, page 305, and h, 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, Avhere it 

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

 out. It likewise changes its colou.r 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. It extends round the 

 upper portion of the hoofs, and receives, Avithin it, or 

 covers, a thickened and bulbous prolongation of the skin, 

 called the coronary ligament (see b, in the accompanying 

 cut) This prolongation of the skin — it is nothing more — 

 is thickly supplied Avith 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 Avail of the foot. Nature has enabled 

 the sensitive laminte of the coffin-bone, c, Avhich Avill be presently described, 

 to secrete a cei-tain quantity of horn, in order to alTord an immediate 

 defence for itself Avhen the crust is Avounded or taken aAvay. Of this there 

 is proof Avhen in sand-crack or quittor it is necessary to remoA'e a portion 

 of the crust. A pellicle of horn, or of firm hard substance resembling it, 

 soon coA'ers the Avound ; but the crust is principally formed from this 

 coronary ligament. Hence it is, that in sand-crack, quitfoi-, and other 

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

 I'enewed, or growing doivn. It must proceed from the coi-onary ligament, 

 and so gradually creep doA\aa the foot Avith the natural groAvth or lengthen- 

 ing of the horn, of which, as in the human nail, a supply is sloAvly given 

 to ansAver to the Avear and tear of the part. 



BeloAV the coronary ligament is a thin strip of horny matter, Avhich has 

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

 Avith the support or action of that body, but Avhich is evidently intended 

 to add to the security of the part on Avhich it is found, and to bind together 

 those A'arious substances which are collected at the coronet. It resembles, 

 more than anything else, the strip of skin that sui'rounds the root of the 

 human nail, and which is placed there to strengthen the union of the nail 

 Avith the substance from Avbich 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 at each heel on itself as in 

 the small cut, in page 395, Avhere 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 meeting at a point at the toe of 

 the frog — see a, h, and c, in the sinaller exits — and the inside of the bars, 

 like the inside of the crust — see the first and larger cut — presents a 

 continuance of the horny leaves, shoAving that it is a part of the same 

 substance, and helping to discharge the same office. 



It needs only the slightest consideration of the cut, or of the natural 



