BACTERIOLOGY IN A NUTSHELL. 



face of the nose which are kept in motion as 

 we breath in the bacteria-laden air. The 

 curves in the nasal cavity also catch dust laden 

 with bacteria and deposit it in the moist sur- 

 face of its walls where it is imbedded in mucous 

 and thrown off by the nose blowing process, if 

 our bodies are in a normal condition. 



The Thirty 9r more dififerent micro-organisms 



°" ■ are said to be normally present in the mouth; 



among these are found some that are patho- 

 genic. The diplococcus pneumonia and the 

 diphtheria bacillus are among the number, 

 Yet in a condition of healthfulness these are 

 expelled through the action of the saliva and 

 the desquamating of the epidermis due to tht 

 process of mastication. While saliva is not a 

 germicide, we are taught that it exerts some 

 influence over disease-producing germs where- 

 by their growth and virulence are lessened. 



The In the passage of disease germs to the vital 



""^^' portions of the lungs, we have seen that the 



surfaces of the nose and mouth play an im- 

 portant part in reducing their harmfulness 

 The surfaces of the walls of the bronchi also 

 serve as an impediment to their progress, 

 Here they are imbedded in a coating of mucous 

 to be, as a general rule, coughed up and ex- 

 pectorated unless the system is in a condition 

 to favor the development of bronchitis, pneu- 



S4 



