292 THE SKELETON OF THE BABBIT. 



The characters of a typical lumbar vertebra have 

 already been described : as a group they are charac- 

 terised by their large size, and the great development 

 of their processes, especially the transverse pro- 

 cesses. They increase in size from before backwards, 

 the last but one being the largest. The first two 

 have hypapophyses : the last one has a short stout 

 centrum, and a stout crest-like neural spine. 



5. The sacral vertebrae. 



Strictly speaking, the sacral vertebra are those 

 of which the expanded ribs directly support the 

 pelvis ; and of these the rabbit has only one, or at 

 most two. A certain number of the succeeding ver- 

 tebrae , which are fused with one another and with the 

 last true sacral .vertebra, are, however, commonly 

 included under the same name, the whole fused mass 

 being spoken of as the sacrum. Beckoned in this 

 way the rabbit has three or more sacral vertebra, the 

 lines of boundary between which can easily be made 

 out in spite of their fusion. 



a. The first sacral vertebra is much the largest, and is 



produced laterally into a pair of large wing-hke 

 expansions which support the pelvis, and are 

 probably modified ribs fused with the vertebra. 

 The neural spine is large and nearly vertical. 



b. The hinder sacral vertebrae are much smaller, and 



decrease in size from before backwards. Their 

 number is variable, increasing with age through 

 fusion with the anterior caudal vertebras. 



The anterior outer border of the second sacral 



vertebra just touches the pelvis, but it is doubtful 



whether any true costal element is present in it. 



6. The caudal vertebrae. 



These are about sixteen in number : they decrease 

 in size from before backwards, gradually losing all 

 their processes, and ultimately the neural arches as 



