At the time of the coming of the epidemic there were stationed at Pittsburgh two military camps, comprising about 7,000 men. It was with the presence of the disease among these men that our investigations were chiefly concerned. The men at their respective camps (on the campus of the University of Pittsburgh and at the Carnegie School of Technology) were housed in barracks which had been erected only a short time previously. These barracks contained large dormitories, in which the individuals freely mingled with each other. In them there was no opportunity of complete isolation, and by this means of housing good opportunity was available for the propagation of any communicable infectious disease. The ordinary sanitary arrangements for these groups were well provided. The first cases of recognized influenza made their appearance on October 2. On this day two men were found with the disease and were isolated. On the following day there were four, and on the third day eight. It was soon recognized that the increasing number of the infected cases was growing so rapidly that definite arrangements for their segregation and care had to be undertaken. This was provided for on October 4, when the Elizabeth Steel Magee Hospital was in part taken over by the military authorities and wards were rapidly adapted for the coming epidemic. For the foresight in making the adequate arrangements for its control and management we shall always remain indebted to Major E. W. Day. His indefatigable work in the early days of the epidemic will always be remembered, and the fact that the epidemic was kept within reasonable bounds of control was the result of his stringent quarantine regulations along with the organization of his medical forces. Working under his direction, Capt. H. H. Hendershott undertook the management of the hospital and rendered most efficient service. The capacity of the hospital was soon overburdened, so that from a normal 150–bed institution it was on the sixth day of its conversion into an emergency hospital carrying more than 300 cases of influenza. This hospital in itself was unable to accommodate all of the cases falling ill, and provision for these had to be made in some of the municipal institutions. On October 5, 1918, the Medical School of the University of Pittsburgh undertook to provide the laboratory facilities for the emergency Military Hospital. It was at first intended to equip only those laboratory departments which were deemed essential for the clinical care of the patients in the wards. Inasmuch, however, as the epidemic of influenza was spreading with alarming rapidity throughout the city, it was deemed advisable to close the Medical School and to place at the disposal of the Military Hospital all the laboratory facilities which could in any way be of use in the care and study of the influenza patients. This permitted the establishment of departments in pathology, bacteriology, physiology, physiological-chemistry and