LUNGS AND STOMACH. 141 



there are greater opportunities for germs to come 

 in contact with the bronchial walls where they 

 become imbedded in mucus with which they may 

 be expelled by coughing and the action of the 

 ciliated epithelium. Both the alveolar epithelial 

 cells and the leucocytes which enter the air sacs 

 and bronchioles have been shown to take up bac- 

 teria. The conditions in the lungs which favor 

 the development of infections, as bronchitis, pneu- 

 monia^ influenza, tuberculosis, are by no means 

 clearly understood. Variations in individual 

 resistance, here as in other parts of the body, such 

 as may be caused by exposure to cold, are certainly 

 of great importance. It is probable that the lung 

 is the infection atrium for a number of our acute 

 infectious diseases. It has been demonstrated that 

 systemic infections, as with anthrax bacilli, may 

 be caused by the inhalation of the micro-organisms. 



The gastric juice, through the hydrochloric stomach. 

 acid it contains, is able to kill anthrax, typhoid, 

 tubercle bacilli, cholera vibrio and other organ- 

 isms. Clinical and experimental evidence shows 

 that this power is often inadequate, virulent 

 micro-organisms reaching the intestines in spite 

 of it (typhoid, cholera, dysentery, tuberculosis, 

 etc.). It is probable that bacteria in the stomach 

 are often protected against the action of the gas- 

 tric juice to some extent by being imbedded in 

 solid particles of food. Certain acidophilic germs, 

 as well as yeasts and torulae, seem to flourish in the 

 gastric secretions; these are largely non-patho- 

 genic, but the regularity with which peritonitis 

 follows perforating wounds of the stomach indi- 

 cates that it probably always contains pathogenic 

 bacteria, though it may be only their temporary 



