74 THE ANATOMY OF THE HORSE. 



parts, on account of the varieties they possess ; but thej'- 

 have some characteristics in common, each being composed 

 of a spongy body, and parts protruded therefrom, called joro- 

 cesses. These processes often unite to form a hollow, through 

 which the spinal marrow is transmitted : they also furnish 

 surfaces of articulation with each other, as well as by their 

 bodies anteriorly and posteriorly ; by their means the sur- 

 faces of attachment are increased, and the strength of the 

 spinal chain is thereby rendered very great. Though but 

 little motion is allowed between any two of these bones ; yet 

 the flexibility of the whole spine is considerable ; by which 

 wise contrivance the spinal marrow, nerves, and blood- 

 vessels, are not liable to compression. 



The neck bones, or cervical vertebrae (see Skel. C, C) are 

 the largest of the spinal chain. Their spinous, or upward 

 projecting processes {Skel. s, s, s, s, s) are indistinct ; but on 

 each side of the body a considerable prominence branches 

 out into two transverse processes (Skel. u, u, u, u, u) : at the 

 common base of these is seen a foramen for the passage of 

 the vertebral arteries and veins. Each vertebra likewise is 

 indented posteriorly, into which hollow, the most forward 

 part of the body, the next vertebra fits ; and from the sides of 

 each bone, before and behind, a piece is wanting, which defi- 

 ciency is termed the notch; and when the bones are together 

 these notches in one, meet those of another bone, and thus 

 is formed a circular hole, or foramen, through which the spinal 

 nerves emerge. The bones are united together by articular 

 cartilages, dense capsular ligaments, and all the appendages 

 of a joint. Above the arch, where the spinal marrow is 

 protected, are several oblique articulating processes {Skel. 

 r, r, r, r, r). It will be evident, from the strong means 

 employed for the articulation of the bones of the neck, not 

 only by the round head and corresponding cavity, but more 

 particularly by their oblique processes, that no dislocation 

 can easily take place between any of these vertebrae ; for 

 when such an accident does occur the animal inevitably dies 

 from the compression of the spinal marrow, which accident 

 is usually called breaking the neck. 



The back, or dorsal vcrtehrre, are eighteen {Skel. I to the 

 last 3). These bones do not essentially differ from each 

 other except in the length of their spinous processes, which 



