10!) THE II UMAX ]}() fir. 



in one large tube, which is called the duct of the gland. 

 The duct of the parotid gland opens on the inside of the 

 cheek. The ducts of the submaxillary and sublingual 

 glands open under the tongue. 



27, These glands make the saliva from the blood which 

 passes through them. The saliva moistens and softens 

 the mouthful of food, coats it over, so that it will slip 

 down the canal, and to some extent dissolves it. When 

 the mouth is absolutely dry, it is almost impossible to 

 chew or swallow any thing. 



THE STOMACH. 



28, The stomach is a portion of the alimentary canal 

 about twelve inches long, expanded into a pouch. It 

 lies at the lower border of the ribs in front, more on 

 the left side than on the right. When it is empty, it 

 collapses, like any other bag. When it is full, it ex- 

 tends down below the ribs ; and, as it lies directly under 

 the heart, it sometimes presses up, and makes the heart 

 feel crowded. 



29, This pouch, like the rest of the alimentary canal, is 

 lined with mucous membrane, somewhat like the lining 

 of the mouth. If this membrane is examined with a lens, 

 innumerable little holes appear: so small, and so close 

 together, are they, that it has been estimated that there 

 are five millions of them in all. These are the mouths 

 of little pits that dip down in the membrane. Some of 

 these pits are shaped like the finger of a glove: others 

 have side-branches, like several glove-fingers opening into 

 one central finger. These are the glands of the stomach, 

 which make the gastric juice. When food enters the 

 stomach, this juice wells up from the pits until a drop 



