THE VERTEBRAL COLUMN. 19 



ordinary vertebra, except that the transverse processes are directed 

 somewhat downwards. 



3. The transverse processes of the third vertebra are longer than 

 those of the second : each is directed do^v^lwards, is broader at its 

 extremity than at its base, and bears a hammer-shaped cartilaginous 

 epiphysis larger than those of the remaining transverse processes. 



4. The transverse processes of the fourth vertebra are the 

 longest : each is broader at its free end than at its base, is 

 directed upwards and backwards, and provided with a cartilaginous 

 epiphysis, 



5. 6, 7. The transverse processes of the fifth, sixth, and seventh 

 vertebrae are smaller, contracted towards their free extremities, and 

 directed upwards. 



8. The eighth vertebra is distinguished from the rest by its 

 body possessing no articular head. It presents, at each end, a con- 

 cave articular depression. The transverse processes resemble those 

 of the seventh. 



9. The ninth vertebra unites the vertebral column with the hip- 

 bones, and is hence to be regarded as a sacrum. The body bears 

 on its anterior surface an articular head for articulation Avith the 

 eighth vertebra : on its posterior surface are two small rounded 

 and closely approximated processes (Figs. 4 and 5 sc) for articulation 

 with the urostyle. The transverse processes are strong, broader at 

 the free ends than at their origin, directed upwards and backwards, 

 and provided with cartilaginous epiphyses. 



III. Articulations of the Vertebrae, 



The articular heads and depressions of the vertebral bodies, 

 together with the joint surfaces of the articular processes, are 

 covered with hyaline cartilage. The periosteum of the bodies, as 

 also that of the articular processes, forms true capsular joint liga- 

 ments. The articulations of the vertebrae are still further strength- 

 ened by longitudinal fibres, which extend along the anterior and 

 posterior surf aces of the vertebrae, and correspond to the Jigamenhvm 

 vertébrale comimme ant'icum et posticum of man. Between the 

 vertebral arches are membranes which represent the ligamenta 

 intercniraUa. Between the spinous processes are bands of connective 

 tissue which form ligamenta interspinalia, (For the articulation of 

 the atlas with the occiput, see page 24.) 



c 2 



