possibly influenza is the fact that as shown by present day findings these men were all of the age in which the mortality is highest, and were living under sanitary conditions which predispose to high incidence and high mortality. According to Parkes, in 827 A.D., an attack of “cough” which spread like the plague was recorded. In 876, Italy and later the whole of Europe was attacked, and the army of Charlemagne, returning from Italy, suffered greatly. “Dogs and birds were attacked at this time.” In 976 the whole of France and Germany was attacked by a fever whose principal symptom was cough. There is also record of diseases which may have been influenza which were seen in Germany and France in 927 and in England in 996 and 997. All of these records are indefinite and from their nature unconvincing to a critical student. Several investigators have gone over these past records up to 1889 with the idea of determining definitely what plagues were, and which were not, true influenza. The criteria used by the various investigators have differed slightly in some instances. For instance, one chooses to use the record of low mortality in widespread epidemics as the chief characteristic of pandemic influenza, while another emphasizes principally the complications. The experience of recent years has amply demonstrated that influenza may be characterized by a high mortality or a low mortality; that pneumonia may be prevalent or relatively rare during an epidemic. These features are not truly characteristic of influenza itself. They are phenomena which depend chiefly for their existence on secondary invasion with organisms other than the causative agent of influenza. It may be that the influenza virus itself is capable of producing pneumonia, but it is generally accepted that an overwhelming majority of the complicating pneumonias are due to secondary infections. One perusing the former literature today would hesitate to state that an ancient epidemic was not influenza merely because it was accompanied by high mortality, nor would he wish to say that it was not this disease because there was no mention of a high incidence of pneumonia. We have had both types within the last few years, as in March and April, 1918, when the disease appears to have been accompanied by a very low mortality and a low incidence of pneumonia, and in October of the same year when the pneumonia incidence and the death rate were both relatively much higher.