70 OSTEOLOGY OF THE HORSE. 



In the ordinary movements of the head, all the cervical ver- 

 tebrae, more or less, participate: it is only in the nodding motion, 

 or sudden chuck of it, that the occipital joint is especially called 

 into action. When the nose is carried to one side, the odontoid 

 process revolves upon its own axis within the cavity of the atlas. 



Common articulations of the vertebra. — All the ver- 

 tebrae, excepting the atlas and last lunsbar, articulate one with 

 another, before and behind, through the apposition of their 

 bodies, and the adaptation of their articulatory processes. They 

 are bound together by — 1st, The inferior vertebral ligament, con- 

 sisting of bands of ligamentous fibres running obliquely along the 

 inferior surfaces of the bodies of the vetebrae, expanding as they 

 approach, and taking root in each intervertebral substance ; 2d, 

 The superior vertebral ligament, situated within the vertebral ca- 

 nal*. It pursues the same course along the inner surfaces of the 

 upper portions of the rings which the inferior ligament does be- 

 low, maintaining the whole more firmly together; 3d, Inter- 

 transverse ligaments, binding together the transverse processes ; 

 4th, Inter-spinous ligaments, between the spinous processes, but 

 found only in the back and loins ; 5th, Capsular tnembranes, in- 

 closing the smooth cartilaginous surfaces of the articulatory pro- 

 cesses; 6th, The intervertebral Jibro-cartil ages, forming the prin- 

 cipal bond of union between the vertebrae (so strong a one, that 

 rather than this substance will part from its attachments, the 

 bone itself will give way), consist of so many dense, concentric, 

 fibrous substances, interposed between the bodies of the vertebrae, 

 to the surfaces of which they are most firmly and inseparably in- 

 herent. In form, they correspond to the bones, but in thickness 

 and volume they differ in each vertebral region. The fibres are 

 found to cross and intercross one another, and to be so disposed 

 as to leave in the centre spaces, which are filled with a soft, pulpy, 

 elastic tissue, which adds to facility of motion; 7th, Ligamentum 

 Nucha vel Subjiavum, an elastic ligamentous substance, reaching 

 from the occiput to ihe coccyx. It arises from the occipital tu- 

 berosity, and there consists of a cylindrical chord. It is conti- 

 nued backward along the superior border of the neck, and 

 stretches broader and broader as it proceeds, in order to reach 

 down to the spinous processes, to all of which (with the exception 

 of the first) it is fixed. It is broadest at the dip made by the 

 spine in front of the withers. As it approaches the tallest dorsal 

 spine, it narrows, and, after having passed the sixth or seventh, again 

 becomes a chord, or rather a band, whose greatest breadth is cross- 



* It cannot be demonstrated without sawing tlu-oiigh the bony arches. 



