DORSAL VERTEBRJE. 



45 



above, the other below. These are covered with cartilage in the recent state; 

 and, when articulated with the adjoining vertebrae, form oval surfaces for the 

 reception of the heads of the corresponding ribs. The pedicles are directed 

 backwards, and the inferior intervertebral notches are of large size, and deeper 

 than in any other region of the spine. The laminse are broad and thick, and 

 the spinal foramen small, and of a circular form. The articular processes are flat, 

 nearly "vertical in direction, and project from the upper and lower part of the 

 pedicles, the superior being directed backwards and a little outwards and upwards, 

 the inferior forwards and a little inwards and downwards. The transverse pro- 

 cesses arise from the same parts of the arch as the posterior roots of the trans- 

 verse processes in the neck ; they are thick, strong, and of great length, directed 

 obliquely backwards and outwards, presenting a clubbed extremity, lipped on its 

 anterior part by a small concave surface, for articulation with the tubercle of a 

 rib. Besides the articular facet for the rib, two indistinct tubercles may be seen 

 rising from the extremity of the transverse processes, one' near the upper, the 

 other near the lower border. In many they are comparatively of small size, and 

 serve only for the attachment of muscles. But in some animals, they attain con- 

 siderable magnitude either for the purpose of more closely connecting the seg- 

 ments of this portion of the spine, or for muscular and ligamentous attachment. 

 The spinous processes are long, triangular in form, directed obliquely downwards, 

 and terminate by a tubercular margin. They overlap one another from the fifth 

 to the eighth, but are less oblique in direction above and below. 



Fig. 5. A Dorsal Vertebra. 



Superior Ai-tiC. 1'roccss 



Demi. facet for lit'acl cj IZiT> 



Demijacetfarlifa.di ofRll 



Infer. Artie .Proc. 



The peculiar dorsal vertebras are the first, ninth, tenth, eleventh, and twelfth 

 (fig- 6). 



The First Dorsal Vertebra presents, on each side of the body, a single entire 

 articular facet for the head of the first rib, and a half facet for the upper half of 

 the second. The upper surface of the body is like that of a cervical vertebra, 

 being broad transversely, concave, and lipped on each side. The articular sur- 

 faces are oblique, and the spinous process thick, long, and almost horizontal. 



The Ninth Dorsal has no demi-facet below. In some subjects, the ninth has 

 two de mi -facets on each side ; then the tenth has a demi-facet at the upper part, 

 none below. 



The Tenth Dorsal has an entire articular facet on each side above ; no demi 

 facet below. 



