THE LIMBS 



187 



up in front by a flat or rather concave plate of a 

 crescentic shape, called the 6 sole ' (7), composed of 

 softer and less fibrous material than the wall. Its ante- 

 rior and lateral borders, where it comes in contact with 

 the inner surface of the toe and quarters of the wall, form 

 nearly two-thirds of a circle. Its posterior concave border 

 is bounded on each side by the bars, and in the middle 

 it is deeply notched to receive the point of the frog. 



Lastly, all the posterior part of the foot which comes 

 to the ground is formed by the frog (8, 9 and 10) and 

 its posterior prolongations, called the c branches ' and 

 i glomes/ covered by a thick, callous, but not very horny 

 epidermis, and which corresponds in form with that of 

 the under surface of the ' plantar ' cushion previously 

 described. We can distinguish a pyramidal median 

 prominence (s), pointed in front where it reaches the 

 centre of the sole, with a groove on each side separating 

 it from the bars, called the c lateral lacuna ' (11 and 12) ; 

 a deeper groove in the middle line farther back, the 

 6 median lacuna' (13), on each side of which are the 

 branches of the frog, which posteriorly are swollen out 

 into the glomes, rounded prominences forming the 

 lower part of the heels (14), and continued round on 

 each side of the hoof into the coronary cushion. 



The terminal portions of the horse's four limbs are 

 remarkably alike both in external appearance and inter- 

 nal structure, more so than are those of any other animal ; 



