228 THE HORSE. 



We begin with the fore extremity, and with its upper part tiic shoulder 

 It IS seen at G, page 63. 



THE SHOULDER. 



The scapula, or slioulder-bhxdc, situated forward on the side of the 

 chest, is a bone of a somewhat triangular shape, with its apex or point 

 downward, and its base or broad part upward. Tlie point lies between 

 tiie first and second ribs; the hinder part of the base reaches as far back 

 as the seventh rib ; it therefore extends obliquely along the chest. It is 

 divided externally, into two unequal portions by a ridge or spine running 

 through almost the whole of its extent, and designed, as we shall pre- 

 sently siiow, for the attachment of important muscles. The broad or 

 upper part, having no muscles of any consequence attached to it, is termi- 

 nated by cartilage. 



We iiave stated that the muscles of the hinder legs are principally con- 

 cerned in the motion of the horse. They impel the machine forward, and 

 the main uses of tlie fore extremities are to lift the fore part of the horse 

 from the ground, that it may be thus impelled to throw forward the legs as 

 far as possible, that they receive this weight at a due distance, and to sup- 

 port the force and shock of that weight when it reaches the ground. We 

 will inquire as we proceed how far one or all of these objects are accom- 

 plished. 



The shoulder-blade is united to the chest by muscle alone. There is 

 a large muscle, with very remarkable tendinous fibres, and of immense 

 strength (the serralus major, greater saw-shaped muscle), attached to the 

 chest, and to the extensive smooth internal surface of the shoulder-blade, 

 and by which, assisted, or rather strengthened, by the muscles of the 

 breast, the weight of the body is supported, and the shock of the widest 

 leap, or the most rapid motion, sustained. Had there been a bony union 

 between the shoulder and the body, the vital parts contained in the chest 

 could not have endured the dreadful shock which they would occasionally 

 have experienced; nor could any bone have long remained whole, if 

 exposed to such violence. The muscles witliin the shoulder-blade act as 

 powerful and safe springs. They yield, as far as necessary, to the force 

 impressed upon them; by their gradual yielding they destroy the violence 

 of the shock, and then, by their elastic power, immediately regain their 

 former situation. 



SPRAIN OF THE SHOULDER. 



In some violent and unexpected shock, these muscles are occasionally 

 injured. Although we do not believe that, in one case in twenty, the farrier 

 is right when he talks of his shoulder-lameness, yet it cannot be denied, 

 that the muscles of the shoulder are occasionally sprained. This is effected 

 oftener by a slip or a side fall, than by fair, although violent exertion. It 

 is of considerable importance to be able to distinguish this shoulder-lame- 

 ness from injuries of other parts of the fore extremity. We shall look in 

 vain for much tenderness, or heat, or swelling: it is a sprain of muscles 

 deeply seated, and v.'here these symptoms of injury cannot possibly exist. 

 If, on standing before the horse, and looking at the size of the two shoulders, 

 or rather their points, one should appear evidently larger than the other, 

 we must not consider this as indicative of sprain of the muscles of tne 

 shoulder. It probably arises from bruise of the point of the shouldei 

 which a slight examination will determine ; or the whole of the limb, this 



