266 SKELETON. 



CHAPTER V. 



OF THE LIGAMENTS OF THE SPINE. 

 Ligaments of the Bodies of the Vertebrce. 



1. Inter -vertebral Substance, (Ligamenta Interverlebralia, 

 Ligamens Jntervertebraux.) The bodies of the true vertebrae 

 are united by a substance blending the nature of ligament and 

 that of cartilage, and, therefore, called fibro or ligamento-carti- 

 laginous matter. It occupies all the space between the conti- 

 guous bodies of the vertebra, and adheres most closely to their 

 substance. This inter-vertebral matter increases successively 

 in thickness, as it is placed lower down on the spine, whereby 

 the lumbar vertebrae are mutually at a much greater distance 

 than any others. The curvatures of the spine, as formerly 

 stated, depend considerably upon the arrangement of this sub- 

 stance: between the vertebras of the neck it is thicker at its 

 .anterior margin than at the posterior; on the contrary, between 

 the dorsal vertebree it is thinner in front. In the loins, it is 

 again much thicker in front than behind, and this feature is un- 

 usually marked between the last lumbar vertebra and the sa- 

 crum. 



This inter-vertebral matter is formed of concentric lamellae, 

 the texture of which is ligamentous. These lamellae are more 

 abundant anteriorly and laterally than behind. Their fibres 

 cross in every direction, leaving between them interstices or 

 cells, filled with a soft, pulpy substance: this substance is not 

 very obvious near the circumference, but in approaching the 

 centre, it becomes more and more abundant, as the interstices 

 are larger, until the centre seems to be constituted almost -en- 

 tirely by it. The pulpy mass in the centre is in a state of con- 

 siderable compression, which may be proved by separating the 

 bodies of adjoining vertebrae, or by making a vertical section 

 through them; in which case the pulpy mass will be freed from 

 compression, and will rise up into the form of a cone. This 



