IN JANUARY 1907, I contributed  an article to the Special Influenza Number of The Practitioner. In 1919 it must be admitted that for actual control over influenza we are practically no further advanced than in 1907. Nor are we much further advanced in our knowledge of the bacteriology of influenza. We have no knowledge whether the pandemics of the past mean the excitation in microbes always with us, or increased pathogenicity and greater striking-power, or the introduction of an equally mysterious virus from some unknown centre or centres.