1. Six cases of epidemic influenza in various stages of disease were investigated.
2. Suspicious cultures of bodies resembling Bacterium pneumosintes were obtained in three cases, twice from the lung filtrates of inoculated animals and once from the filtrate of nasopharyngeal washings direct.
3. In these instances material was obtained within 36 hours of the acute onset, thus confirming the observations of Olitsky and Gates.
4. Macroscopic and microscopic findings in the lungs of inoculated animals were uniformly negative.