50 



HORSESHOEING. 



partly in contact with the horny frog and partly with the bars. 

 This opening or re-entering angle divides the sole into a body 

 (Fig. 27, /) and two wings or branches (Fig. 27,/). The outer 

 border of the sole unites through the medium of the white line 



Fig. 31. 



Fig. 32. 



/ fW\ f -^—^ 



Vertical section of the iiomy sole magnified : a, Homy frog, with the posterior portion of 

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

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

 various sizes ; 6, horn-tubes ; e, Intertuhular horn, hoof as one piece by maceration : a, trough- 

 shaped depression of upper surface, which 

 is divided posteriorly into the two upper 

 with the lower part of the inner channels of the frog by 6, the frog-stay; c, 

 surface of the wall,— that is, with part of the frog that is joined to the bar and 



the keraphyllous layer of the 

 wall. This white line (Figs. 27, 

 gr, and 29, ^), of so much impor- 

 tance to the horseshoer, is formed 

 by the horn-leaves, and by those 



short plugs of tubular horn which are secreted by the villi that are 

 always found at the lower ends of the fleshy leaves. The white 

 line may be said to exist wherever the horn-leaves can be dis- 

 cerned 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 buttresses along the bars almost 

 to the summit of the frog. The horn of the white line is soft, 

 unpigmented (white), and possesses so very httle resistance 

 (strength) that it is often found crumbling or even absent in 



forms the lateral wall of the depression 

 (channels) on upper surface of frog ; d, lat- 

 eral surface of horny frog which, in its 

 upper part, adheres to the bar, but below, at 

 d', lies free ; e, point or summit of the frog ; /, 

 perioplic horn-band ; /, periople of the quar- 

 tere. 



