ARTHHOLOGY. 103 



laminal margin of the atlas. The superior spinous process 

 of the dentata is connected to the upper surface of the 

 laminae of the atlas by yellow elastic hands lying together 

 along the middle line expanded in becoming blended with 

 the interlaminal ligament outwardly. The superior surface 

 of the synovial membrane is in contact with the odontoid 

 lig^aments, three in number : — The hroad ligament runs 

 from the transverse ridge on the upper surface of the 

 odontoid process, the two small ligaments are beneath 

 this just visible, one on either side, running from the 

 depressions on the upper surface of the odontoid process. 

 The three run to the roughened surface at the antero- 

 superior part of the body of the atlas. This is a specimen 

 of an axonoides articulation ; it allows motion of the head 

 from side to side, whereby the muzzle may be made to 

 describe a circle. 



Vertebral articulations. 



The rest of the vertebral articulations have many 

 characters in common. The anterior convex surface of the 

 body is united to the posterior concavity of the body in 

 front of it, through the medium of an intervertebral disc of 

 cartilage, which is soft and cartilaginous centrally, hard 

 and fibrous externally. Inferiorly its fibres in some cases 

 take a marked direction from before backwards along the 

 central line, forming the inferior vertebral ligament, most 

 marked in the lumbar region, where it affords attachment 

 to the crura of the diaphragm. The superior vertebral 

 ligament serves to strengthen this union superiorly, for it 

 runs along the floor of the spinal canal, its whole length 

 consisting of a series of bands attached to the roughened 

 upper surfaces of the vertebral centra, widest in becoming 

 attached to the intervertebral discs, growing narrow oj^po- 

 site the centres of the vertebral bodies, in forming a small 

 band passing over the transverse groove for a venous 

 sinus. 



The anterior oblique processes of the vertebrae are 

 united to the posterior oblique processes of the vertebrae 

 in front, each by means of a synovial membrane with a 

 strengthening capsular ligament. This articulation is ar^Aro- 

 dial, and is separated inferiorly by the intervertebral gap 

 from the amphiarthrodial union of the bodies, supero-inter- 

 nally from its fellow by the interlaminal ligaments which, 



