Filter-passing Virus in Epidemic Influenza

In view of the extensive investigations carried on by Olitsky and Gates'' with reference to the causative agent in epidemic influenza, and particularly in view of the fact that the claims of these observers regarding the demonstration in material and cultures from influenzal patients of a filter-passing microorganism have been more or less confirmed by the reports of Gordon a in England, and Lister' 4 in South Africa, it seemed to us that the epidemic experienced in Toronto during the past winter should not be allowed to pass without an attempt being made to duplicate some of the experiments of these workers. Attempts to culture a filterable virus were made in this laboratory by Maitland, Cowan, and Detweiler'5 during the epidemic in the winter of 1920. These were unsuccessful, but the work as far as cultures were concerned, was admittedly not exhaustive. The ani-