EPIDEMIOLOGY OF INFLUENZA 503 



New York Department of Health seem to indicate that the Koch- 

 Weeks bacillus may be merely a variety of the true influenza bacillus. 



BACILLUS OF PLEURO-PNEUMONIA OF RABBITS. This is a small Gram- 

 negative bacillus, described by Beck, not unlike that of influenza. These 

 microorganisms are slightly larger than the Pfeiffer bacilli and grow upon 

 ordinary media even without animal sera or hemoglobin. 



BACILLUS MURISEPTICUS AND BACILLUS RHUSIOPATHI^E. While mor- 

 phologically similar to the microorganisms of this group, these bacilli are 

 culturally easily separated because of their luxuriant growth on simple media. 

 The last two microorganisms are more closely related to the groups of the 

 bacilli of hemcrrhagic septicemia. 



