178 COMPENDIUM OF THE YETEIilNARY ATIT. 



the horse,. is in motion, and then the back 

 part of til e sole descends a little, being some- 

 \Vhat elastic, and suffers the laminie to elon- 

 gate in a small degree, so as to prevent any 

 painful concussion. 



The bottom of the hoof is formed by the 

 SOLE, the FROG, and the bars. 



The sole is rather concave or hollow on its 

 external surface, and consists of a different 

 kind of horn from that which forms the crnst, 

 being of a scaly texture^ and sometimes soft 

 and pulverable on its exterior surface : its use 

 is to defend the sensible sole, that lies imme- 

 diately luider it. From its concave form the 

 horse is enabled to tread more firmly on the 

 ground, and the sensible parts are less ex- 

 posed to blows or pressure than they would be 

 had it been made either fiat or convex; and 

 being: somewhat flexible and elastic toward 

 the heels, it assists in the action of those cu- 

 rious springs we have just described. 



The frog is a very important part, and re- 

 quires to be particularly considered. It is in- 

 timately united with the sole, but is composed 

 cf a touixher and more elastic kind of horn. It 

 lesembies a wedge in its form ; but towards* 

 the heel, wheie it becomes wide and ex- 



