THE PRACTICAL HORSESHOER. 35 



heels, between which is interposed a soft, elastic substance 

 known as the frog". 



The parts within the hoof known as the laminae, or leaves, 

 articulate with each other, and the extent of their articula- 

 tion corresponds with the contraction and expansion of the 

 hoof, modified, of course, under the influence of partial or 

 complete pressure while traveling-. Now, in order to favor 

 this physiological action of the foot the nails must not be 

 inserted any nearer the heels than the safety of the shoe 

 requires ; for should the shoe be nailed all around, as the 

 saving- is, the hoof, at its solar border, is fettered ; hence 

 the action of articulation cannot occur, and the horse soon 

 becomes lame. If possible the frog" should be allowed to 

 come in contact with the g"round, for it acts as a pad and 

 very much lessens the jar or concussion which otherwise 

 must necessarih^ occur. The nature of the g-round over 

 which the animal travels determines the form, character, 

 and endurance of the frog". Thus in the unshod colt we 

 usually, in a healthy^foot, find the frog' well formed, promi- 

 nent, and callous ; this is the result of the stimulating hard 

 knocks it receives when traveling-. On the other hand, 

 should Ave examine some horses' feet after the^^ have been 

 long" submitted to the evils of domestication (which include 

 faulty shoeing"), we shall find that the frog" is often imperfect, 

 both in function and structure. I would not have an}^ one 

 infer from these remarks that the blacksmith is always 

 blamable for the loss of the frog", etc., for in the winter, 

 when the roads are a mass of sleet and ice, calks seem to be 

 necessaiw, and, under such circumstances, it is almost im- 

 possible to bring" the frog" in contact with the ground ; hence 

 it may deteriorate. 



Then, again, there are various diseases of the foot which 

 interfere with the integrity of the frog as well as that of 

 other parts which enter into the composition of a horse's 

 foot. It is the custom of some shoers to cut away the frog. 



