CHAPTER II. 



FROG PRESSURE. 



THAT portion of the hoof called the " frog," 

 performs the most important visible 

 function in the economy of the movement 

 of the horse. It is intensely vital and 

 vigorous. The greater its exposure and the 

 severer its exertion, the more strenuous is the 

 action of nature to renew it. It is the spring 

 at the immediate base of the leg, relieving 

 the nervous system and joints from the shock 

 of the concussion when the Race Horse thun- 

 ders over the course, seeming in his powerful 

 stride to shake the solid earth itself, and it 

 gives the Trotter the elastic motion with 

 which he svv^eeps over the ground noiseless 

 upon its yielding spring, but, if shod with 

 heavy iron, so that the frog does not reach 

 the ground to perform its function, his hoofs 

 beat the earth with a force like the hammers 

 of the Cyclops. 



With the facility to error characteristic of 



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