THE HORSE. 



We will not say that the form of the spnng' was borrowed from this 

 construction of the limbs of the horse, but the effect of the carriage-spring 

 beautifully illustrates the connexion of the different bones in the extremi- 

 ties of this quadruped. 



The obliquity or slanting direction of the shoulder effects another very 

 useful purpose. That the stride in the gallop, or the space passed over in 

 the trot, may be extensive, it is necessary that the fore part of the animal 

 should be considerably elevated. The shoulder, by means of the muscles 

 which extend from it to the inferior part of the limb, is the grand agent in 

 effecting this. The slightest inspection of the last cut, or of that at p. 63, 

 will show that, just in proportion as the point of the shoulder is brought 

 forward and elevated, will be the forward action and elevation of the limb, 

 or the space passed over at every effort. At each contraction of the muscles 

 which extend from G to J, or from the shoulder-blade to the bone of the 

 arm, will the point of the shoulder be projected and elevated. In the 

 upright shoulder it can scarcely be carried beyond the point at which it is 

 placed in these cuts. In the oblique or slanting shoulder it commences 

 its action from that point; therefore it is that a slanting shoulder is indis- 

 pensable in a horse from which good action and considerable speed are 

 required. 



The slanting shoulder accomplishes another very useful object. The mus- 

 cles extending from the shoulder-blade to the lower bone of the shoulder are 

 the powers by which motion is given to the whole of the limb. The extent 

 and energy of that motion depend much on the force exerted or the 

 strength of the muscle ; but there are circumstances in the relative situa- 

 tions of the different bones which have far greater influence. Let us 

 suppose that by means of a lever we are endeavouring to raise a certain 

 weight. 



