LIGAMENTS OF THE SPINE. 273 



by him as coming from the neck of the process. There is some 

 cellular tissue at the front, in which the process revolves. 



The Middle Straight Ligament, (Lig. Medium Rectum, Liga- 

 ment droit Moyen,) or Occipito-Dentate, arises from all that 

 part of the summit of the processus dentatus anteriorly which 

 is between the moderator ligaments, and is inserted into all that 

 part of the interior circumference of the foramen magnum be- 

 tween the insertion of the moderator ligaments. It is a thin 

 ligamentous membrane, disposed to form in its middle a verti- 

 cal fissure, separating its two halves. It cannot be seen well, 

 unless the whole membrana annuli anterioris be dissected away, 

 and the anterior bridge of the first vertebra sawed off; it will 

 then be found immediately behind the bursa of the processus 

 dentatus. It is separated from the superior appendix of the 

 transverse ligament by a layer of condensed fatty substance. 

 This ligament should not be confounded with the superior ap- 

 pendix of the transverse ligament, nor with the beginning of the 

 posterior vertebral ligament, as has been done by Bichat and 

 others. The difference is well established by Caldani, as it lies 

 deeper than either of them when viewed from the vertebral 

 cavity; though, from the close connexion of the fibres of the 

 ligaments among themselves, as well as with others, the mistake 

 may readily occur.* 



The Articulation between the oblique process of the first and 

 of the second cervical vertebra is very moveable, as the atlas 

 is permitted to revolve around the processus dentatus to the 

 amount of one-fourth of a circle at least. This articulation has 

 a synovial capsule which is strengthened by an anterior and by 

 a posterior ligament. 



The anterior ligament of the articulation between the oblique 

 processes arises from the inferior margin of the atlas and from 

 its anterior tubercle, and is inserted into the base of the pro- 

 cessus dentatus, and into the front of the body of the second 

 vertebra. The fibres of the latter insertion are long and fre- 

 quently distinct from the first. 



* Its existence is, however, scarcely to be considered uniform, as it is often 

 wanting where the processus dentatus is very long, for example when it reaches 

 the anterior part of the foramen magnum and forms a joint there, as it sometimes 

 does. 



