THE LEGS. 



47 



more or less almost in every individual: one horse is said to have 

 shoulders oblique, another to have them straight, depending on 

 the more or less inclined position of the blade-bones; and the 

 former is valued as a riding-horse, and justly so, while the other 

 is condemned and rejected. The reason of this will appear evi- 

 dent when we come to learn that every time the shoulder is put 

 in motion the scapula makes a sort of partial revolution on its 

 own centre or axis, which at first slightly depresses, but instantly 

 afterwards elevates and advances its base or upper part, while its 

 lower part or obtruncated apex, which was at the commencement of 

 the movement advanced, recedes until the scapula has nearly or 

 quite revolved into a straight or upright position. The more ob- 

 lique the original position of the scapula the greater will be its 

 revolving sweep, and the more free and extensive the action of the 

 shoulder, as will appear evident from the following diagram : — 

 c 



FIG. IV. 



Taking the graduated quadrant A B to represent the arc the 

 scapula describes in its imperfect revolution, it is manifest that, 

 setting the limit of its motion forward at the figure 1, its sphere of 

 revolution will be increased in proportion as its inclination or 

 obliquity is greater at the commencement : a scapula whose base 

 inclines to number 7 in the scale will have two degrees of extent 

 of action more than one which only reaches number 5, and two less 

 than one whose base descends so low as the 9th degree. 



The first movements of the shoulder-bones, those that lift the 

 limb off the ground and advance it, consist in a limited revolution 



