LIGAMENTS OF THE SPINE. 267 



experiment will succeed remarkably well in the loins; from 

 which it is evident, that this mass is a soft and elastic ball, on 

 which the bodies of the vertebrae play. 



The pulpy matter is proportionately much more abundant in 

 infancy than in the subsequent periods of life; it is also much 

 softer, whiter, and more transparent. In advanced life there is 

 great diminution of its volume, as well as of its elasticity, 

 which accounts, in some measure, for the comparative stiffness 

 of the spine in old people. The fibrous part in them is always 

 more abundant, and is much disposed to ossify. When the 

 trunk is kept erect for several hours in succession, it becomes 

 shorter, from its weight bearing upon the inter-vertebral mass; 

 but a short period of rest in the horizontal position, restores if, 

 to its original length. 



2. Anterior Vertebral Ligament, (Fascia Longitudinalis An- 

 terior, Ligament Vertebral Anterior.) This ligament is placed 

 on the front part of the spine, and extends from the second 

 vertebra of the neck to the first bone of the sacrum, inclusively. 

 It increases gradually in breadth, from its commencement to 

 its termination, but is not every where of the same thickness; 

 for it is thin on the neck, thicker in the thorax, and again be- 

 comes thin in the loins: in the latter, however, it is strengthened 

 by an accession of fibres from the tendinous crura of the dia- 

 phragm. 



This ligament adheres very closely to the inter-vertebral 

 substance, and to the projecting margins of the bodies of the 

 vertebra, but less closely to the middle or concave parts of the 

 latter. Its fibres do not run out its whole length, for the more 

 superficial extend from one vertebra or inter- vertebral substance, 

 to the fourth or fifth below: the middle ones extend to the se- 

 cond or third below ; and the deepest seated are applied be- 

 tween the proximat'e vertebra? only. In general, more of the 

 fibres are inserted into, and arise from the fibro-cartilaginous 

 matter than the bones. In several parts, but particularly in the 

 neck, small slips are sent off obliquely to the vertebra below. 

 The laminae of this ligament leave intervals between them for 

 the passage of blood vessels. 



Beneath the anterior vertebral ligament are found a great 

 many short and insulated ligamentous fibres, extended oblique- 



