226 THE SPINE AND BACK. 



ranks among these, and foremost among them. The closeness with which thp 

 roller is buckled on in the stable must be a serious inconvenience to the horse ; 

 and the partially depriving these muscles of their power of action, for so many 

 hours in every day, must indispose them for labour when quicker and fuller 

 respiration is required. At all events, a tight girth, though an almost neces- 

 sary nuisance, is a very considerable one, when all the exertion of which he is 

 capable is required from the horse. Who has not perceived the address with 

 which, by bellying out the chest, the old horse renders every attempt to girth 

 him tight comparatively useless ; and when a horse is blown, what immediate 

 relief has ungirthing him afforded, by permitting the intercostals to act with 

 greater power ? 



A point of consequence regarding the capacity of the chest, is the length or 

 shortness of the carcase ; or the extent of the ribs from the elbow backward. 

 Some horses are what is called ribbed home ; there is but little space (see cuts 

 pp. 108 and 221) between the last rib and the hip-bone. In others the distance 

 is considerably greater, and is plainly evident by the falling in of the flank. The 

 question then is, what service is required from the horse ? If he has to carry 

 a heavy weight, and has much work to do, he should be ribbed home, — the 

 last rib and the hip-bone should .not be far from each other. There is more 

 capacity of chest and of belly — there is less distance between the points of 

 support — and greater strength and endurance. A hackney (and we would 

 almost say a hunter) can scarcely be too well ribbed home. 



If speed, however, is required, there must be room for the full action of the 

 hinder limbs ; and this can only exist where there is sufficient space between 

 the last rib and the hip-bone. The owner of the horse must make up his mind 

 as to what he wants from him, and be satisfied if he obtains that ; for, let 

 him be assured that he cannot have everything, for this would require those 

 differences of conformation that cannot possibly exist in the same animal. 



The thorax, or chest, is formed by the spine/, above (p. 241) ; the ribs e, on 

 either side ; and the sternum, or breast-bone, c, beneath. 



THE SPINE AND BACK. 



The spine, or back, consists of a chain of bones from the poll to the 

 extremity of the tail. It is made up of twenty-three bones from the neck to 

 the haunch; eighteen, called dorsal vertebra, composing the back; and five 

 lumbar vertebra, occupying the loins. On this part of the animal the weight 

 or burden is laid, and there are two things to be principally considered, easiness 

 of carriage and strength. If the back were composed of unyielding materials — 

 if it resembled a bar of wood or iron, much jarring or jolting, in the rapid motion 

 of the animal, could not possibly be endured. In order to avoid this, as well as 

 to assist in turning, the back is divided into numerous bones ; and between each 

 pair of bones there is interposed a cartilaginous substance, most highly elastic, 

 that will yield and give way to every jar, not so much as to occasion insecurity 

 between the bones, or to permit considerable motion between any one pair, but 

 forming altogether an aggregate mass of such perfect elasticity, that the rider 

 sits almost undisturbed, however high may be the action, or however rapid the 

 pace. 



Strength is as important as ease ; therefore these bones are united together 

 with peculiar firmness. The round head of one is exactly fitted to the cup or 

 cavity of that immediately before it ; and between them is placed the elastic 

 ligamentous substance, which has been just described, so strong, that in endea- 

 vouring to separate the bones of the back, they will break before this sub- 

 stance will give way. In addition to this there are ligaments running along tho 

 broad under surface of these bones— ligaments between each of the transverse 



