INSTANTANEOUS PHOTOGRAPHS. 55 



yielding takes place, owing to the pressure on the 

 frog, which is forced upwards, causing the ultimate 

 expansion of the walls of the hoof, &c. 



' (2) On the middle part of the foot, when the 

 bones bear the weight of the body, the flexors and 

 extensors being for the instant in a state of quietude 

 — i.e. neither of them are extending or contracting. 



* (3) In the toe, when the animal gives a push, 

 by which an impetus is given to send the body 

 forward.' 



These words were written as long ago as 1858, 

 and have since received exact corroboration in the 

 instantaneous photographs of the horse's action, with 

 which we are now so familiar. 



It may seem to some persons a matter of little or 

 no consequence whether the heel or toe should first 

 come to the ground during progression. In reality, 

 it is of the very last importance, and, as we shall see 

 in a future page, does not only affect the hoof, but is 

 intimately connected with the whole of the muscles 

 which the horse uses in progression, and with the 

 nerves which supply these muscles with energy. 



The reader is requested to bear in mind that the 

 hoof only expands laterally, and that on and near the 

 toe the expansion is so trifling, that it may be practi- 

 cally disregarded. Reference will again be made to 

 this fact. 



