THE SUPPORTING TISSUES. 



79 



drawn downward. This latter arrangement is better adapted 

 for the attachment of the heavy muscles of the body. The 

 lumbar vertebrae have proportionately a much larger body, 

 and the processes relatively much shorter and thicker. The 

 sacrum consists in reality of five fused vertebrae, the indi- 

 vidual ones being still clearly traceable on it. This fusion 



SUP. ARTIE. PHOC. 



Fig. 25. THE SACRUM, FRONT VIEW. 



aids materially in giving strength to that portion of the col- 

 umn where it is connected with the hip bone. The coccyx 

 consists of from two to four or five very much reduced verte- 

 brae and serves as far as we know no special function. The 

 individual vertebrae are separated by pads of elastic carti- 

 lage which give them a certain amount of lateral motion, 

 and which also serve as cushions to break the jars. The 

 double curvature of the entire column still further serves to 

 reduce this to a minimum. 



BIBS. 



Attached to the dorsal vertebrae are twelve pairs of ribs, 

 which extend slightly downward, then upward, and enclose 

 the organs of the chest. With the exception of two on each 

 side, called the floating ribs, they are attached to the ster- 

 num, or breast bone, by means of elastic cartilages, which 

 permit a slight movement at these points. 



