PHYSIOLOG-Y, 



AND 



HYGIENE. 



CHAPTER I. 

 THE FRAMEWORK OF THE BODY. 



Tlie Bones Their Form and Composition The Properties of Bone 

 Tlie Skeleton Tlie Joints The Spinal Column The Growth of 

 Bone The Repair of Bone. 



1. The Bones. The framework which sustains the 

 human body is composed of the Bones. The superstructure 

 consists of the various organs on which the processes of 

 life depend. These organs are soft and delicately formed, 

 and, if unprotected, would, in most cases, rapidly be de- 

 stroyed when subjected to violence, however slight. The 

 bones, having great strength and power of resistance, afford 

 the protection required. 



2. The more delicate the organ, the more completely does 

 Nature shield it. For example : the brain, which is soft in 

 structure, is enclosed on all sides by a complete box of bone ; 

 the eye, though it must be near the surface of the body 

 to command an extensive view, is sheltered from injury 

 within a deep recess of bone; the lungs, requiring freedom 

 of motion as well as protection, are surrounded by a large 

 case of bone and muscle. The bones serve other useful 

 purposes. They give permanence of form to the body, by 



1 . The framework of the body ? The superstructure ? Softness and delicacy 

 of the organs ? How protected ? 



2. The more delicate the organ ? Example in relation to the brain ? The eye ? 

 The lungs ? The services performed by the bones ? 



