PELVIC VERTEBRA. 451 



of all the true vertebrse. The bodies are deeper FIG. 129. 

 before than behind, and broad transversely. 

 The superior and inferior surfaces are flat and 

 oval, having projecting and hard edges. The 

 intervertebral notches are very large, especial- 

 ly the lower the spinal foramen is triangular 

 or oval, and larger than in the dorsal. The spinous pro- 

 cess is broad, thick, and short, ending in a rough border. 

 The oblique processes are vertical the superior being con- 

 cave and looking inward the inferior convex and looking 

 outward and forward. The transverse are long, slender, and 

 stand at right angles. The fifth or last lumbar vertebra 

 is somewhat peculiar in having its body of greater size, 

 deeper generally in front than behind, so as to give some- 

 thing of the wedge shape ; in its transverse processes being 

 thick, short, and round, and in the spinal foramen being 

 larger. 



The false or pelvic vertebrce consist of the sacrum and 

 coccyx. 



The sacrum is situated at the lower part of the true ver- 

 tebrae, occupying the posterior and superior portion of the 

 pelvis. Its form is triangular, and its position is like that 

 of a wedge, its base being above, and apex below having 

 the innominata laterally the lumbar vertebra upon its 

 superior, and the coccyx on its inferior portion. This bone, 

 in the adult consisting of one piece, in the child forms five 

 pieces. Its surfaces are the anterior, posterior, and two 

 lateral. 



The anterior surface is concave from above downward, 

 and marked by four transverse lines, showing the original 

 divisions of the bone into five pieces. At the outer extrem- 

 ity of these lines four foramina are observed, called the 

 anterior sacral foramina, for transmitting the anterior sa- 

 cral nerves. The two superior of these foramina are quite 

 large the rest diminish in size as they descend ; they are 



FIG. 129 represents the upper surface of a lumbar vertebra. 1 Spinous pro- 

 cess. 2 Lateral lamina. 3 Superior articular process. 4 Transverse process. 

 6 7 Body. 8 Vertebral foramen. 



