THE WITHERS. — MUSCLES OF THE BACK. 173 



THE WITHERS. 



The spinous or upright processes of the dorsal vertebrae, or bones of the back, above 

 tne upper part of the shoulder, are as remarkable for their length as are the transverse 

 or side processes of the bones of the loins. They are flattened and terminated by 

 rough blunted extremities. The elevated ridge which they form is called the withers. 

 It will be seen in the cuts (pp. 63 and 167), that the spine of the first bone of the 

 back has but little elevation, and is sharp and upright. The second is longer and 

 inclined backward ; the third and fourth increases in length, and the fifth is the 

 longest; — they then gradually shorten until the twelfth or thirteenth, which becomes 

 level with the bones of the loins. 



High withers have been always, in the mind of the judge of the horse, associated 

 with good action, and generally with speed. The reason is plain enough: — they 

 afford larger surface for the attachment of the muscles of the back ; and in proportion 

 to the elevation of the withers, these muscles act with greater advantage. The rising 

 of the fore parts of the horse, even in the trot, and more especially in the gallop, 

 depends not merely on the action of the muscles of the legs and shoulders, but on 

 those of the loins, inserted into the spinous processes of these bones of the back, and 

 acting with greater power in proportion as these processes, constituting the withers, 

 are lengthened. The arm of the lever to which the power is applied will be longer; 

 and in proportion to the length of this arm will be the ease and the height to which 

 a weight is raised. Therefore good and high action will depend much on elevated 

 withers. 



It is not difficult to understand how speed will likewise be promoted by the same 

 conformation. The power of the horse is in his hinder quarters. In them lies the 

 main spring of the frame, and the fore-quarters are chiefly elevated and thrown for- 

 ward to receive the weight forced on them by the action of the hinder quarters. In 

 proportion, however, as the fore-quarters are elevated, will they be thrown farther 

 forward, or, in other words, will the stride of the horse be lengthened. Yet many 

 racers have the forehand low. The unrivalled Eclipse was a remarkable instance of 

 this ; but the ample and finely proportioned quarters, and the muscularity of the thigh 

 and fore-arm, rendered the aid to be derived from the v/ilhers perfectly unnecessary. 

 The hea\'y draught-horse does not require elevated withers. His utility depends 

 on the power of depressing his fore-quarters, and throwing their weight fully into 

 the collar ; but for common work in the hackney, in the farmer's horse, and in the 

 hunter, well-formed withers will be an essential advantage, as contributing to good 

 and safe action, and. likewise to speed. 



MUSCLES OF THE BACK. 



The most important muscles which belong to this part of the frame are principally 

 those which extend from the continuation of the ligament of the neck, along the whole 

 of the back and loins ; and likewise from the last cervical bone; — the svpe.rJidaKs and 

 transversalis rnsfarum, or superficial and transverse muscles of the ribs, going from 

 this ligament to the upper part of the ribs to elevate them, and to assist in the expan- 

 sion of the chest; also the large inass of muscle, the Idiigis.siinus dnrsi, or longest mus- 

 cle of the back, from the spinous and transverse processes of the vertebrae to the ribs, 

 and by w^hich all the motions of the spine, and back, and loins, to which allusion has 

 been made, are principally produced; by which the fore-quarters are raised upon the 

 hind ones, or the hind up'm the fore ones, according as either of them is the fixed 

 point. This is the principal agent in rearing and kicking. 



Tlie last muscle to be noticed is the spinnlh dorsi, the s])inal muscle of the hack, 

 from the spinous processes of some of the last bones of the back to those of the fore 

 part; — thick and strong about the withers, and broadly attached to them; and more 

 powerfully attached, and more strongly acting in pr^^portion to the elevation of the 

 withers ; and proceeding on to the three lowest bones nf the neck, and therefore mainly 

 concerned, as already described, in elevating the fore-quarters, and producing high 

 and safe action, and contributing to speed. 



Before the roof of tlie chest is left,some accidents or diseases to which it is exposed 

 must be mentioned. The first is cf a very serious nature. 

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