THE SKELETON. 9 



The bones of the body serve several 

 important purposes. 1. They give the 

 body its general shape. 2. They sup- 

 port the softer material of the body within and 

 around them. 3. They protect delicate and impor- 

 tant parts against injury from without, as, for exam- 

 ple, the brain, lungs and heart. 4. They serve as 

 levers, to be moved by the muscles in the various 

 movements of the body, as we shall learn more 

 clearly, somewhat later. 



^ the figure of the skeleton 



of the we perceive that the bones are grouped 



Skeleton. . , - , ,. . . , 1 



into four natural divisions, namely: 1. 

 The bones of the head. 2. Those of the main body, 

 or trunk. 3. Those of the upper extremities, or 

 arms. 4. Those of the lower extremities, or legs. 



We have now learned about the number, shapes, 

 material, union, uses and groups of the bones of the 

 skeleton. We are now ready to study the more 

 important bones of each group more closely. 



