TEE VERTEBRA. 39 



The transverse processes incline very much forward and downward ; they become longer from 

 the first to the second-last bone ; in the latter they become contracted, and in the seventh 

 vertebra they are still more diminislied, and terminate in au obtuse point. The tubercle of the 

 anterior articular process is extremely prominent, and the posterior notches are surmounted bv 

 a small, very acute prolongation, directed backwards, which becomes more developed towards 

 the anterior vertebrae. This small prolongation exactly represents the transverse process of the 

 dorsal vertebrae. 



E. Rabbit.— They are stronger than those of the Cat, and the first three have on the lower 

 surface of their bodies a very salient crest, which simulates a real inferior spine ; the others 

 have a median crest which gradually decreases towards the last bone. The tubercle surmount- 



Fig. 24. 



LUMBAR VERTEBRA OF THE CAT AND RABBIT. 



A, Second, third, and fourth lumbar vertebrcB of the Cat (inferior face}. 1, 1, 1, 

 TraDsverse processes ; 2, 2, 2, crest on the inferior face of the body; 3, articular 

 tubercles of the first vertebra. 



B, Second, third, and fourth lumbar vertebra of the Babbit (inferior face}. 1, 2, 

 Same signification as in preceding. 



C, Third lumbar vertebra of the Cat (lateral face}. 

 prolongation; 2, ditto posterior prolongation; 3, 

 4, 4, posterior ditto; 5, spinous process. 



D, Third hcmbar vertebra of the Babbit (lateral face}. 

 prolongation ; 2, ditto posterior prolongation ; 



1, Transverse process, anterior 

 I, anterior articular tubercles; 



1, Transverse process, anterior 

 , anterior articular tubercle : 



4, 4, posterior articular tubercles : 5, spinous process. 



ing the posterior notches is more developed than in the Cat. The spinous process is prolonged 

 backward by a translucent bony plate, wliich disappears in the last two. The anterior articular 

 tubercles are more developed, more erect, and nearer the median line, than in the Caruivora. 

 Lastly, the transverse processes are relatively longer, and those of the first are remarkable for 

 the notched enlargement they offer at their free extremities. 



4. Sacrum (Fig. 25). 



The sacrum results, as already stated, from the consolidation of five vertebrse. 

 This single bone articulates, in front, with the last lumbar vertebra ; behind, 

 with the first coccygeal bone, and on the sides with the ossa innominata. It is 

 triangular, flattened above and below, and from before to behind describes a 

 slight curve upwards. It offers for study a superior and an inferior face, two 

 borders, a base, a summit, and a central canal — the extension of the spinal canal. 



Faces. — The superior face presents, on its middle, the spinous processes of the 



