FAEMERS' INSTITUTES. 389 



hind foot, where the duty of supporting the hinder parts alone is distributed 

 over the quarters and heels of both sides of the foot. 



The bars are continuations of the wall, reflected at the heels towards the 

 center of the foot, where they meet in a point, leaving a triangular space 

 between them for the frog. 



The whole inner surface of the horny crust, from the center of the toe to the 

 point where the bars meet, is everywhere lined with innumerable narrow, thin, 

 and projecting horny plates, which extend in a slanting direction from the upper 

 edge of the wall to the line of junction between it and the sole, and possess 

 great elasticity. These projecting plates are the means of greatly extending 

 the surface of attachment of the hoof to the coffin-bone, which is likewise cov- 

 ered by a similar arrangement of projecting plates, but of a highly vascular and 

 sensitive character, and these, dove-tailing with the bony projections above 

 named, constitute a union combining strength and elasticity in a wonderful 

 degree. 



The horny sole covers the whole inferior surface of the foot, excepting the 

 frog. In a well formed foot it presents an arched appearance and possesses 

 considerable elasticity, by virtue of which it ascends and descends, as the weight 

 above is either suddenly removed from it or forcibly applied to it. This descend- 

 ing property of the sole calls for our especial consideration in directing the form 

 of the shoe, for, if the shoe be so formed that the horny sole rests upon it, it 

 cannot descend lower ; and the sensible sole above, becoming squeezed between 

 the edges of the coffin-bone and the horn, produces inflammation, and perhaps 

 abscess. The effect of this squeezing of the sensible sole is most commonly 

 witnessed at the angle of the inner heel, where the descending heel of the coffin- 

 bone, forcibly pressing the vascular sole upon the horny sole, ruptures a small 

 blood-vessel, and produces what is called a corn, but which is, in fact, a bruise. 



The horny frog occupies the greater part of the triangular space between the 

 bars, and extends from the hindermost part of the foot to the center of the sole, 

 just over the point where the bars meet, but is united to them only at their 

 upper edge; the sides remain unattached and separate. 



The frog is evidently designed for very important uses, but as our object is 

 purely practical, and not speculative, we will not stop to inquire whether its 

 chief office is to expand the foot and prevent contraction or not, but proceed to 

 consider it in a point of view bearing more usefully on our subject, viz., as the 

 part which offers us the best criterion whereby to judge of the effect of our shoe- 

 ing upon the foot generally, for no part undergoes so much change from bad 

 shoeing, or exhibits it so soon as the frog. If we carefully observe the form 

 and size of the frog in the foot of a colt of from four to five years old, at its 

 first shoeing, and then note the changes which it undergoes as the shoeings are 

 repeated, we shall soon be convinced that a visible departure from a state of 

 health and nature is taking place. At first it Avill be found large and full, with 

 considerable elasticity ; the cleft, oval in form, open and expanding, with a con- 

 siderable elasticity ; the cleft, oval in form, open and expanding, with a contin- 

 uous, well defined and somewhat elevated boundary, the bulbs at the heels fully 

 developed, plump and rounded, and the whole mass occupying about one-sixth 

 of the circumference of the foot. By degrees the fullness and elasticity will be 

 observed to have diminished, the bulbs at the heels will shrink and lose their 

 plumpness, the cleft will become narrower, its oval form disappearing, the back 

 part of its boundary give way, and it will dwindle into a narrow crack extend- 

 ing back betw^een the wasted, or perhaps obliterated bulbs, presenting only the 



