56 



HORSESHOEING. 



scales of dead horn. Behind, the sole presents a triangular 

 opening whose borders lie partly in contact with the horny frog 

 and partly with the bars. This opening or re-entering angle 

 divides the sole into a tody (Fig. 31, /) and two \vings or 

 branches (Fig. 31, /'). The outer border of the sole unites 

 through the medium of the white line with the lower part of 

 the inner surface of the wall, — that is, with the keraphyllous 



Fig. 37. 



Vertical section of the horny sole magnified: a, Horny frog, with the posterior portion of 

 funnel-shaped openings which contain the horn- the perioplic horn-band and the periople 

 producing villi of the fleshy sole; they are of which covers the quarters removed from 

 various sizes; b, horn-tubes; c, intertubular the hoof as one piece by maceration: a, 

 jjQPjj trough-shaped depression of upper surface, 



which is divided posteriorly into the two 



layer of the wall. This white :!^: t^:^':,T^!^^^ ^^ l^^^f^ 

 line (Figs. 31, g^ and 35, h), of ZrZi^^V^lZS^lT.i^^^^^^^ 



so much importance to the horse- frog;d, lateral surface of homy frog which, 



. in its upper part, adheres to the bar, but 



Shoer, is formed by the horn- below, at d', lies free; e. point or suminlt of 



1 1 1 ii 1.1 the frog; /, perioplic horn-band; /', peri- 



leaves, and by those short plugs opie of the quarters, 

 of tubular horn which are se- 

 creted by the villi that are always found at the lower ends of 

 the fleshy leaves. The w^hite line may be said to exist wherever 

 the horn-leaves can be discerned upon the plantar surface of 

 the hoof. It not only passes around the circumference of the 

 sole from heel to heel, but may be followed forward from the 

 buttTe'sses along the bars almost to the summit of the frog. 

 The horn of the white line is soft, unpigmented (white), and 



