A CHAPTER FOR BOYS 375 



In order that an individual human being may live 

 and develop, it is necessary that he should eat, drink, 

 digest, and assimilate, and that he shouM be able to 

 move about, to perceive ; that is, to hear, see, feel, smell, 

 taste, determine weight, and distinguish temperature, 

 to think, and to express ideas in language. In order to 

 keep his vital machinery in order, it is necessary that 

 the body should also be able to repair injuries which 

 may occur in consequence of wear or accident, and to 

 remove worn-out material which would otherwise ob- 

 struct the working of the delicate machinery of which 

 his body is constructed. Each of these functions re- 

 quires special organs and apparatuses to carry on the 

 work, as described in a previous chapter and illustrated 

 by the colored chart. They may be more briefly re- 

 viewed as follows: 



The Nutritive Apparatus.— This consists of or- 

 gans for the purpose of taking in food or nourishment, 

 digesting it, and distributing it throughout the body 

 wherever it is needed. These are chiefly the mouth and 

 teeth for receiving and chewing the food, the stomach 

 and intestines for digesting and absorbing it, and the 

 heart and blood vessels for distributing it to the body. 



The Moving Apparatus.— For the purpose of pro- 

 ducing motion, we have the muscles and the bones, by 

 which the food is received, masticated, and swallowed, 

 the blood circulated, the body moved about from place 

 to place, and speech, expression, respiration, and many 

 other important functions performed. 



The Thinking and Feeling Apparatus. —The 

 brain and nerves afford the means of thinking and feel- 

 ing, also giving rise to all the activities of the body by 

 the production of nerve force. To aid the brain and 

 nerves, we have special organs provided, termed the 



