36 THE ANATOMY OF THE HOR8E. 



provided that has been executed. The following is a preferable method 

 of procedure : Procure a foot severed a few inches above the fetlock, 

 and inject the arteries and veins from the metacarpal vessels. When 

 the injection has solidified, roll the foot in a piece, of wet cloth, and 

 bury it in a fermenting heap of stable manure. Decomposition will 

 speedily set in, and after a week the preparation should be examined 

 at intervals of two or three days, the metacarpal bone being fixed in a 

 vice while forcible attempts are made to pull off the hoof. Wheu this 

 has been effected, the foot and removed hoof should be immersed for 

 a day in a saturated solution of carbolic acid in water, to which a little 

 methylated spirit may be added. This will speedily remove all odour 

 of decomposition, and dissection may then be proceed with. 



The Hoof (Plate 10, Figs. 4 and 6). This is made up of the wall, 

 the bars, the sole, and the frog. 



The Wall is that part of the hoof which is exposed when the foot 

 rests in its natural position on a flat surface. It is divided, tihough 

 not by any well-defined boundaries, into toe, quarters, and heels. The 

 toe includes an area on each side of the middle line of the wall in 

 front ; and it passes on each side into the quarter, which comprises 

 the lateral region of the wall. Behind the quarter on each side of 

 the hoof is the heel, which, when the foot rests on the ground, 

 appears to be the terminal part of the wall. In reality, however, 

 the wall does not stop at the heel, but is reflected inwards and 

 forwards, and it is this concealed continuation that is termed the 

 bar. In a well-formed fore-hoof . the wall in the region of the toe 

 slopes at an angle of about 45°, and in a hind-hoof at about 50°. 



The External Surface of the wall is, in a state of nature, covered by <a 

 kind of epithelial varnish termed the periople, which is thickest at the 

 top of the wall, just under the hair, and is secreted by the so-called 

 perioplic ring. This is a natural varnish provided to check evaporation 

 and consequent cracking of the subjacent horn, and it ought not to 

 be rasped away in shoeing. The periople is most conspicuous after 

 maceration of the foot in water, and it may be traced all round the top 

 of the hoof just under the hair, as a band of soft elastic horn. At 

 the back of the foot it is blended with the horny frog. The internal 

 surface of the wall is traversed in a vertical direction by the series of 

 horny laminw. These number about five or six hundred ; and before 

 separation of the hoof they were interleaved with the sensitive laminae 

 to be .presently described. The superior border of the wall shows a 

 kind of gutter, termed the coronary or cutigeral groove, which is the 

 mould left by the coronary cushion. The floor of this groove has 

 a closely punctated appearance, each minute perforation being the 

 upper end of one of the horn tubes of the wall, and lodging, in the 

 natural state, one of the papillae of the coronary cushion. The 



