26 



(1) The absence of a centrum. 



(2) The large canal divided into two parts by a transverse 



ligament. 



(3) The broad horizontal transverse processes. 



(4) The anterior articular facets deeply concave for articulating 



with the condyles of the skull. 



(c) Examine the second vertebrae or axis, and note— 



(1) The centrum bearing the odontoid process (body of first 



vertebra). ' 



(2) The spinous process, large and bifid. 



(3) The small transverse processes. 



(d) Examine the five remaining cervical vertebrae, noting — 



(1) The form of the centra, and the facets upon the posterior 



end of the centrum of the seventh vertebra for the heads 

 of the first pair of ribs. 



(2) The small spinous processes, except in the seventh vertebra. 



(3) The broad inferior lamellae of the transverse processes, except 



in the seventh. 



2. The thoracic vertebrae. 



(a) Examine the vertebrse of the thoracic region, twelve, sometimes 

 thirteen, in number, and note — 



(1) The long slender spinous processes. 



(2) On the centra, anteriorly and posteriorly, except in the case 



of last three or four vertebrae, the facets for the heads 

 of the ribs. 



(3) The transverse processes, with articular facets on their under 



surfaces for the tubercles of the ribs, except in the last 

 three or four vertebrae. 



(4) The hypapophyses, beginning at the ninth thoracic vertebra, 



and increasing in size from the vertebra backwards. 



(5) The notches, forming the foramina for the spinal nerves. 



3. The lumbar vertebrae, usually seven in number. (See above, I.) 

 Note in addition — 



(a) Their large size relative to the other vertebrae. 



(b) The strongly developed processes, especially the transverse 



processes. 



(c) The short stout centrum of the last vertebra. 



4. The sacral vertebrae. Note — 



(a) That these are four in number, and are fused. 



(b) That only the first of these directly supports the pelvis by its 



large broad expansion. 



5. The caudal vertebrae. Note — 



(a) These are about sixteen in number. 



(6) Their processes and arches become reduced posteriorly till 



the last vertebrae are represented only by centra. 



