Attention should be called to a certain inaccuracy which has appeared in the literature and which has resulted in some instances in a misunderstanding of the entire history of influenza. Finkler says: “According to August Hirsch the first influenza epidemic occurred in 1173 and he places it in his work as the first out of eighty.” This has given the impression to some that influenza was unknown previous to that date. Leichtenstern has quoted Hirsch more accurately and thereby given an entirely different meaning to the statement. “August Hirsch says that the first epidemic that can be definitely said to be influenza occurred in 1173.” Jordan also conveys the latter impression. He remarks that the first extensive, well described epidemic of influenza occurred in 1510. Hirsch places the first authoritative influenza epidemic in the year 1173; Zeviani in 1293; Gluge in 1323; Schweich, Biermer and Ripperger in 1387; while Saillant, Thompson, Zuelzer and Leichtenstern accept nothing prior to the first pandemic of 1510 as being unquestionably influenza. It should be remarked here that opinion is not unanimous in every case as to the identity of all epidemics following 1510. Hirsch concluded that there have been about eighty epidemics since that of 1173. Parkes states that in the fourteenth century there were six epidemics, in the fifteenth seven, in the sixteenth eleven, in the seventeenth sixteen, in the eighteenth eighteen, while in the first half of the nineteenth ten epidemics are on record. Table I shows in brief review the occurrence of the more important epidemics since the year 1173. Like all similar summaries given in tabular form it possesses the disadvantage of telling only parts of the entire story, and those in only a very general way, but it will suffice as a resumé and for the emphasis of certain phenomena to which attention will be later directed. Concerning the epidemic of 1889, it is usually stated that it had its origin in Bokhara in May of that year. As will be seen from the table influenza was present also in Greenland and the Hudson Bay territory in the spring of 1889. The possibility of simultaneous origin in at least two localities in that year will be discussed later. The epidemic remained in Bokhara until August of the same year, after which time it slowly traveled to Siberia where at Tomsk traces of the disease were observed with certainty in October. At that time it was also observed in the Caucasus and in European Russia. It appeared in Petrograd in October, 1889, and remained epidemic until December of that year. The spread of this epidemic throughout the world is indicated in the following table adopted from Leichtenstern: _Spread of Influenza in 1889–90._