100 THE HUMAN BODY. 



or gullet; then to the stomach, which lies at the lower 

 border of the ribs, in front ; then to the small intestine, 

 which is twenty feet long, coiled in the lower part of the 

 abdomen ; then to the large intestine, which is five feet 

 long, and ends the tube. 



DIVISIONS OP THE ALIMENTARY CANAL. 



1. MOUTH. 4. STOMACH. 



2. PHARYNX (Throat). 5. SMALL INTESTINE. 

 8. (ESOPHAGUS (Gullet). 6. LARGE INTESTINE. 



8, Each of these divisions of the canal has its own 

 peculiarities, and each has its own part of the work of the 

 whole to do. This work is called digestion. 



9, By digestion, we mean the changes that take place in 

 the food, as it passes through the alimentary canal, by 

 which it is fitted to be taken into the blood. 



10, The need of such changes is very plain. We could 

 not imagine that the food, in the condition in which it is 

 eaten, could be taken into the blood. There are no open- 

 ings from the canal into the blood-vessels. Nothing can 

 get out of it into the rest of the body, unless it can soak 

 through its walls, as water would soak out of the finger 

 of a glove if it were poured into it. To do this, the food 

 must be dissolved. 



11, A lump of sugar or salt will dissolve in water; but 

 a piece of meat, or a cooked egg, or oatmeal, or many other 

 articles of food, will not. All such articles must be changed 

 in the alimentary canal, so that they will dissolve in water. 



12, We find, accordingly, that from the walls of the 

 canal, and from certain organs called glands which lie 

 just outside of the canal, and communicate with it by 



