THE SHOULDEE. 39 



Stead of stretching under the action of the muscles, 

 they are sure to move the bones to -which they are at- 

 tached, and they thus become a most useful instrument 

 in the act of progression. 



The fibres, or threads, of which the muscles are 

 composed, are so aiTanged that they can contract upon 

 themselves to such an extent as to shorten the distance 

 between theii* extremities by one-third of their whole 

 length (Bostock). This is a fact which must be kept 

 steadily in view, as the action of the animal is greatly 

 influenced by the length of its muscles. For example, 

 if the muscles which move the leg in one horse are 

 double the length of those which perfonn the same 

 duty in another horse — and if in each case they contract 

 or shorten themselves by exactly one-third of then* own 

 length — it must follow that the horse with the long 

 muscles will cover double the space, at each stride, that 

 his opponent can do. The advantage of attending to 

 this point will be fully illustrated as I proceed. 



THE SHOULDER. 



There is no part of the horse receives so much at- 

 tention from the public as the shoulder, and yet I fear 

 the views which are entertained regarding it are not 

 generally coiTect. The fact that it should vary in 

 shape according to the pm'pose to which the horse is to 

 be applied, is too often overlooked. The carter and 



