ART OF SHOEING. 541 



several published papers, the hoof does not bulge, widen, or 

 expand, when exerted on the ground, but the opposite action 

 is going on ; the horse's foot is most relaxed or dilated at the 

 instant when the limb is arriving at its full extension, then it 

 is that the more passive structures are being brought to act, 

 and though, as we Lave shown, there is no such motion going 

 on as was supposed, we can demonstrate the existence of 

 other movements, better defined, and more constantly going 

 on than those supposed to prevail. By the action which fol- 

 lows the alighting of the foot on the ground, pliable structures 

 are drawn upwards while pressure is being exerted down- 

 wards as the several bones revolve, and this folbws upon the 

 resilient function which results when the foot is implanted, 

 and which goes on through the whole structure during its 

 instant action. 



The annexed illustrations represent the arches of the pedal 

 bone, and the sole, of a fore and hind foot. The drawings 

 were executed from transverse sections through the pedal 

 bones, so as to show the arch most distinctly ; the section of 

 the whole hoof was made in the same way, transversely from 

 the upper margin of the wall, down throughout its extent, 

 including sole and frog below. 



Figs. 222 and 223 showthe pedal bone andhoof of a fore foot. 



Figs. 224 and 225 show the same parts of the hind foot. 



On examining these structures, the somewhat different 

 functions of fore and hind feet become more apparent to us ; 

 corresponding with the external character, and what may be 

 observed in the action of the horse. The fore foot sustains 

 most weight, covers a larger surface than the hind, and the 

 arch, both of sole and bone, is scarcely so high in the fore as 

 in the hind foot, whilst its breadth and sustaining power is 

 greater. In the hind, again, as we endeavour to interpret 

 its action, we are aided by observing the structures, which 



