12 



THE ART OF HORSE-SHOEING. 



border, tlie sides remaining free and separate. Thus on. 

 each side is formed a deep fissure which permits the frog 

 to expand laterally when compressed, without such force 

 being continued to the sides of the foot. The frog is 

 elastic, and wlieu pressed upon must expand slightly. 

 If these spaces between frog and bars did not exist, the 

 foot would be injured when the frog was compressed by 

 the weight of the horse — either the sensitive parts within 

 would be bruised or the heels would be forced apart. 



Tlie centre of the frog presents a depression or 

 "cleft," caused by the doubling in of the horn. Few 

 shod feet exhibit it of natural appearance, and the term 

 cleft, by implying a narrow deep fissure, keeps up the 

 false notion. The cleft should be shallow and rounded. 

 It serves two purposes — it increases the mobility of the 

 frog, and by breaking the regularity of surface affords a 

 secure foot-hold on level grouiid. 



FiQ. 9.— Section of Foot at cleft. 



Fig. 10.— Section of Foot at cleft. 



The prominence of the frog might lead a su])erricial 

 ■observer to consider it a thick solid mass; and I believe 

 this mistake is the cause of its too frequent mutilation. 

 It is merely a layer of horn following the outline ot the 



