MANUAL FOR ARMY HORSESHOERS. 41 



is on the ground. It is divided into the toe, quarters, buttresses, or 

 heels, and the bars. The toe is the front part of the wall. It is 

 steeper in the hind foot than in the fore. The quarter extends on 

 each side from the toe to the buttress, or heel. The buttress is that 

 part of the wall where it bends abruptly inward and from which it 

 extends forward and forms the bar. The bar extends inward and 

 forward from the buttress along the frog to within about an inch of 

 the point of the frog. The hoof is thus made stronger^ by the ends 

 of the wall being extended inward. The I^ars are weight carriers, 

 and the}^ also act directly on the wall to produce expansion when 

 weight is placed on the frog. 



The wall has two surfaces and two borders. The external surface 

 is smooth and is covered with a coat of fine horn called the per io pie. 



The internal surface is covered with from 500 to 600 laminx . These 

 are thin plates of horn running downward and forward. Between^ 

 them are fissures into which dovetail the corresponding laminte of 

 the corium. The laminae and the corresponding laminae of the ' 

 corium are firmly united, and this union (a) binds the wall of the 

 hoof to the third phalanx and its cartilages; (6) suspends the weight 

 of the horse from the wall as in a sling; and (c) thus pre^'ents the 

 bones from descending on the sole. 



The upper border of the wall has a deep groove in which lies tlie 

 coronary corium. or band. The loAver border is known as the bearing 

 surface, or spread. It is the part that comes in contact with the 

 ground in the unshod foot and to which the shoe is fitted in the 

 shod foot. 



The sole is a thick plate of horn, somewhat half -moon shaped. 

 The upper surface is convex. The lower surface is concave and 

 is covered with scales or crusts of dead horn, which gradually loosen 

 and fall off. The outer border of the sole is joined to the lower part 

 of the inner surface of the wall by a ring of soft horn called the 

 white line. The inner border is V-shaped, and is in union with the 

 bars except at the apex of the angle, where the sole joins the point 

 of the frog. The sole protects the sensitive parts above, and i t should 

 not bear weight, except a very narrow ship on its border along the 

 white line,_ an eighth or a tenth of an inch iii width. 



The frog is a wedge-shaped mass filling the V-shaped space between 

 the bars and sole and extending downward, more or less below the 

 bars and sole. The lower surface has two prominent ridges, separated 

 behind by a cavity called the cleft, and joining in front at the point 



