22 



PHYSIOLOGY AND TEMPERANCE. 



In infancy, the skull is made up of several distinct bones. 

 The child, when learning to walk, stumbles about and bumps 

 his head without doing serious harm, the bones being more 

 elastic and freer to move. As the brain enlarges, these bones 

 grow, and when fully formed they are dovetailed into each 

 other, something after the manner in which 

 a carpenter joins his pieces in making a 

 box. The only bone which remains separate 

 is the lower jaw. 



There are a number of small openings in 

 the skull for the passage of nerves and ves- 

 sels. There is one large one at the under 

 part or base of the skull, through which 

 the spinal cord is connected with the brain. 



11. The Bones of the Trunk. In 

 classifying the bones, we mentioned one 

 belonging to the trunk, called the hyoid. 

 This is a small bone shaped like a much 

 l>ent bo.w with the arch in front, and placed 

 high up in the neck, to support the tongue 

 and give a firm point of attachment to its 

 numerous muscles. In addition to this bone, 

 the trunk comprises the bones of the spine, 

 the ribs, the breastbone, and two very irreg- 

 ular bones which extend forward from the 

 base of the spinal column, spreading out on 

 the sides to form the hips, and meeting 

 again in the front of the body. They form, 

 with the spine, a complete basin, called the 

 pelvis. On the lower and under surface of 

 the hip bone is a deep socket, for the head 

 of the large bone of the thigh. 



12. The Spine. Of all the wonderful 

 FIG. 6. Th Spine, arrangements of bones in the human frame, 



