THE HOOF. 23 



support and protection of the tendons that flex the foot, 

 to facilitate the springy movements of these creatures, 

 and for the prevention of jar and injury to the limbs. 



In the horse's foot, the presence of this thick, com- 

 pressible, and supple mass of horn at the back of the 

 hoof, its being in a healthy unmutilated condition, and 

 permitted to reach the ground while the animal is stand- 

 ing or moving, are absolutely essential to the well-being 

 of that organ, more especially should speed, in addition 

 to weight-carrying, be exacted. 



The fro sr, like the sole, exfoliates or becomes reduced 

 in thickness at a certain stage of its growth ; the flakes 

 are more cohesive than those of the sole. 



It must be remarked, however, that this exfoliation of 

 the sole and frog only takes place when the more re- 

 cently-formed horn beneath has acquired sufficient hard- 

 ness and density to sustain contact with the ground, and 

 exposure to the effects of heat, dryness, and moisture. 



The " Coronary Frog-Band" or " Periople" is a con- 

 tinuation of the more superficial layer of the skin around 

 the coronet and heels, in the form of a thin, light-colored 

 band that descends to a variable depth on the outer sur- 

 face of the wall, and at the back part of the hoof becomes 

 consolidated with the frog, with which it is identical in 

 structure and texture. It can be readily perceived in the 

 hoof that has not been mutilated by the farrier's rasp, 

 extending from the coronet, where the hair ceases, to 

 some distance down the hoof; it is thickest at the com- 

 mencement of the wall, and gradually thins away into 

 the finest imaginable film as it approaches the lower cir- 

 cumference of this part. When wet it swells and softens. 

 and on being dried shrinks, sometimes cracks in its more 

 dependent parts, or becomes scaly. 



The fibres composing it are very fine and wavy, as in 

 the frog; they likewise spring from villi which project 



