LIGAMENTS OF THE FIRST TWO VERTEBRA. 75 



The ligaments constituting the OCCIPITO-AXOIDEAN ARTI- 

 CULATION are peculiar in arrangement, and maintain the 

 relation of the bones during rotatory and nodding move- 

 ments. 



The occipito-axoid ligament, or the apparatus ligamento- 

 colli, is attached above by a broad expansion to the 

 isilar process of the occipital bone, in front of the fora- 

 icn magnum ; below it is continuous with the posterior 

 common ligament of the vertebral column ; its deeper 

 >res, however, have a special insertion into the posterior 

 irt of the body of the axis, and into the superior border 

 >f the transverse ligament. 



The occipito-axoid ligament is to be removed in such a way as to 

 leave the portion which is inserted into the transverse ligament. 



The odontoid ligaments are two strong bands extending 

 from the sides of the apex of the odontoid process to a 

 depression on the inner surface of the condyles of the occi- 

 pital bone. A third band extends from the tip of the odon- 

 toid process to the anterior edge of the foramen magnum ; 

 it bears the name of ligamentum suspensorium. As these 

 ligaments control the movements of the cranium in rotation 

 they are sometimes called the check ligaments. 



The transverse ligament extends across the odontoid 

 process from a tubercle on the inner surface of one articu- 

 lar process of the atlas to a similar point on the other ; its 

 upper border receives a part of the occipito-axoid ligament, 

 and its inferior border sends some fibres downward to the 

 base of the odontoid process ; from this arrangement of its 

 fibres it is sometimes called the crucial ligament. 



The removal of the odontoid and transverse ligaments 

 will show an articulating surface in front of the odontoid 

 process, where it rests against the atlas, and another be-' 

 hind, where it comes in contact with the transverse liga- 

 ment ; these are both provided with synovial membranes. 



DISSECTION XII. 



ANATOMY OF THE EYE. 



The structure of the eye is best studied upon that of some animal. 

 The market-house will almost always furnish those of an ox, calf, or 



