“It appears, then, that the origin of the summer epidemic must be explained upon such epidemiological principles as will account for the primary wave of 1889–90, that the current outbreak is in pari materia with that of 1891, its excessive mortality being mainly due to the accident of season, aided by the special circumstances of overcrowding and fuel shortage which are due to the war. In a word, this is not essentially a war epidemic.” Wutzdorff found that in some towns, particularly in North Germany, the 1891–1892 wave was almost as extensive as that of 1889–90 had been in other places, but that in general the morbidity in Germany was much lower. He bases these conclusions on a study of the extent of crowding in the hospitals in the two years, on statistics of government physicians, etc. In Europe the recurrent epidemics of 1891 increased as a rule very gradually, developed slowly, reached their high point frequently after many weeks, and as gradually decreased. The epidemic duration in the winter of 1891–92 lasted four or five months. The morbidity in spite of the longer duration was decidedly less. This is very different from the explosive appearance of 1889 when the peak was reached in fourteen days and the whole epidemic had been completed in six to eight weeks. There were some exceptions to this rule, as in Yorkshire, England, where the epidemic broke out suddenly between the 11th and 13th of April, 1891, had reached its peak after ten days, and for another twenty days declined. Especially interesting was Sheffield, where the first spread began gradually and ran a slow course, while the second epidemic of 1891 began explosively, lasted a short time and declined rapidly, but showed a significantly greater mortality than that of 1889. The experiences in various communities in the United States have been not unlike those described for European cities. Abbott in describing the successive epidemics in Massachusetts remarked that the 1889–90 spread manifested itself by a sudden rise in the mortality from influenza and pneumonia, beginning about December 20th and culminating in the middle week of January, thereafter falling off quite suddenly in February to about the usual rate for these diseases. The second epidemic two years later began with a more gradual rise in October and November and then increased sharply in December, continued for nearly three weeks at its maximum in January, and declined nearly as sharply as in the previous epidemic two years before. Winslow and Rogers who have studied the 1918 epidemic as it affected the various towns of Connecticut observed that the outbreak in a given community generally occupied a period of from six to eight weeks, and was steep and abrupt in communities which were badly hit, flatter and more gently sloping in those which escaped lightly. Also the outbreak was more severe in communities receiving the infection early than in those later affected.