70 



THE HUMAN BODY. 



surface of the body of the fifth lumbar vertebra. On its 

 sides are large surfaces to which the arch bearing the lower 



Pa s 



Fsa 



FIG. 22. The last lumbar vertebra and the sacrum seen from the ventral side. 

 Fsa, anterior sacral foramina. 



limbs is attached (see Fig. 13). Its ventral surface is con- 

 cave and smooth and presents four pairs of anterior sacral 

 foramina, Fsa, which communicate with 

 the neural canal. Its dorsal surface, convex 

 and roughened, has four similar pairs of pos- 

 terior sacral foramina. 



The coccyx (Fig. 23) calls for no special 

 remark. The four bones which grow togeth- 

 er, or ankylose, to form it represent only the 

 bodies of vertebrae, and even that imperfectly. 

 It is in reality a short tail, although not visi- 

 ble as such from the exterior. 

 The Spinal Column as a Whole. The vertebral column 



FIG. 23. The 

 coccyx. 



