THE DIGESTION' 2OQ 



contraction of upright muscles, called the pillars of the 

 fauces, which connect the posterior part of the soft pal- 

 ate and the base of the tongue. These muscles come to- 

 gether in the middle like sliding doors. There are two of 

 them on each side, and the tonsils lie between them. The 

 tip of the soft palate hangs down between the pillars, 

 and is called the uvula. By looking into a mirror with 

 the mouth very wide open and the tongue flattened, you 

 can see the palates, the pillars, the uvula, and perhaps the 

 tonsils. 



371. The Tonsils ( Fig. 165 ) resemble the lymphatic 

 glands. They are oval in shape, and lymph cells, resem- 

 bling white blood corpuscles, are formed in them by mul- 

 tiplication, and pass out of the tonsils into the saliva as 

 salivary corpuscles. They are supposed to be germicidal 

 and protective. Sometimes the tonsils swell, and by press- 

 ing the soft palate backward and upward, cut off the pas- 

 sage from the upper pharynx and nose, necessitating 

 mouth breathing. They are often partly or entirely re- 

 moved by the surgeon without noticeable injury to the 

 health. 



372. The use of tobacco is a common cause of diseases ' 

 of the throat. It causes a dryness and thirst, and fre- 

 quently leads those who use it to take alcoholic drinks. 

 Often the habit of smoking produces a troublesome disease 

 called smokers sore throat, which can be cured only after 

 smoking has been discontinued. The heat of smoking 

 is very trying to the organs, although not so injurious to 

 them as the poison of the tobacco. A still more dreadful 

 disease which can be traced to the same cause is that of 

 tobacco cancer. Persons dying of tobacco cancer lose their 

 voices in the advanced stage of the disease. This disease 

 is practically incurable. 



373. The Esophagus, or gullet (Fig. 166), opens from the 

 lower part of the pharynx. It is about nine inches 



p 



