It was hoped that it would be possible to follow selected cases over considerable time periods, observation to compromise coordinated clinical as well as laboratory data, but the exigencies of the situation rendered this impossible. Unfortunately, this limits the value of the studies. But since similar observations were made on cases ranging from normal to the gravest severity—in fact, preceding death but a few hours in some instances—and from the nature of the findings, certain conclusions are clearly warranted. It is regrettable that the data on certain points is not more extensive, and particularly that other methods of observation were not employed. As an example of the latter, measurements and analyses of expired air may be given, as this was planned from the beginning and unsuccessful efforts made to provide the required apparatus. In view, however, of the circumstances of the investigation, it is felt that the studies made are, on the whole, reasonably comprehensive and complete. And it is only fair here to acknowledge that this was rendered possible by the cordial and practical support of the Medical School, the military authorities, the director of the laboratories, clinical colleagues, particularly Dr. W. W. G. Maclachlan, and last, but not of less importance, of the members of the department who made the studies. In presenting the results, it is deemed most expedient and practical to omit extensive tabulations and to summarize the data under each subject. From the report it will be obvious that certain studies were in preliminary stages at the termination of the investigation. This was due in certain instances to the lateness of their undertaking, or time consumed in providing essential equipment and methods; or to disappearance of suitable cases due to waning of the epidemic. RESULTS _Circulation_ For the most part, cases showing marked clinical symptoms were studied. The pulse in severe cases frequently was weak and rapid but regular. In some cases it was less rapid than the clinical state would seem to indicate. _Arterial Blood Pressure_ was low; systolic pressure in severe cases ranging downward from 95, and diastolic down to 40 or under. In patients in early stages of convalescence the pressure showed a marked advance toward normal levels. Arterial blood pressure seemed a reliable general index of the condition of the patient. _Venous Blood Pressure._—The observations included patients who a few hours later expired. The Von Recklinghausen method was used. No marked abnormality was observed, so other methods of observation were deemed superfluous. _Respiration_ In severe cases, frequently it was rapid and of shallow character; but, like the pulse, often it was less rapid than the clinical state would seem to indicate.