INFECTIONS OF THE DIGESTIVE TRACT 31 



that in the course of chronic gastric affections, the 

 number of anaerobic microorganisms in the stomach is 

 seldom great. 



We are able to form an opinion as to the bacterial con- 

 ditions that prevail in the stomach because this organ is 

 readily accessible through the aid of the stomach-tube. 

 Of the conditions of bacterial life in the small intestine 

 we know really very little, because of the inaccessibility 

 of the contents of this portion of the digestive tract 

 during life. It is, of course, well established that the 

 duodenum and jejunum contain few bacteria and that 

 these are usually not of the kind that produce pathogenic 

 effects or induce putrefaction. For example, Gushing 

 and Livingston * found that in gunshot wounds of the 

 upper part of the small intestine, the bacteria which 

 escaped into the peritoneal cavity did little or no harm 

 -a result in sharp contrast with what happens after 

 injuries at lower levels of the digestive tract. Again, if 

 we take the intestinal contents from the jejunal or duo- 

 denal level of the gut of a person recently dead of an 

 acute disease not especially implicating the digestive 

 tract (e.g. pneumonia), it will be found that the bacteria, 

 while acting readily on sugars, owing to the presence of 

 B. lactis aerogenes, do not induce putrefactive decompo- 

 sition on proteid media. There are exceptions to this 



1 " Experimental and Surgical Notes upon the Bacteriology of 

 the Upper Portion of the Alimentary Canal, with Observations 

 on the Establishment there of an Amicrobic State as a Preliminary 

 to the Operative Procedures on the Stomach and Small Intestine," 

 "Contributions to the Science of Medicine by the pupils of 

 William Welch," p. 543, 1900. 



