8 STRUCTURE OF THE HUMAN BODY. SKELETON. 



of the skull. This canal contains the spinal marrow, which is con- 

 nected with the brain 

 through the hole in 

 the skull. Ail the 

 vertebra} are very 

 firmly joined toge- 

 ther. Nevertheless 

 it is always very 

 wrong to lift children 

 by the head, as is 

 sometimes done ; for 

 they are liable to be 

 killed on the spot. 



At the level of the 

 cnest, the vertebra? 

 form a support for 

 the ribs, which ex- 

 tend forward, and 

 meet against a bone 

 placed under the 

 skin, and called the 

 sternum or breast- 

 bone. There are 

 twelve ribs on each 

 side. Man and wo- 

 man have therefore 

 twenty-four. 



The hips are formed 

 by a kind of com- 

 plete bony girdle 

 which is called the 

 pelvis. The shoulder 

 is formed of two 

 bones, the clavicle, or 

 collar-lone in front, 



