Gastrointestinal symptoms were insignificant: 8 patients complained of nausea early in the disease and 6 of them vomited. Diarrhea occurred in only 1 case, constipation being the rule. The spleen was palpable in 21 cases, but this is of doubtful significance, since nearly all the patients came from malarial regions. Jaundice was not noted. Aside from the profound depression, sometimes amounting to stupor, mental symptoms were not noted except in 1 case which showed a mild delirium. Influenza, although _per se_ a self-limited disease of short duration, frequently leads to the development of serious complications, the most important of which are pneumonia and purulent bronchitis with a varying degree of bronchiectasis. In the group of 100 cases of influenza studied, purulent bronchitis developed in 36 instances, pneumonia in 15; in 3 cases there was lobar pneumonia, in 12 bronchopneumonia. Further discussion of these complications is reserved for the sections dealing with them in detail. Other complications were relatively rare. Otitis media occurred in one case and frontal sinusitis in one. No fatalities were observed among cases of uncomplicated influenza, the deaths that occurred being invariably associated with a secondary pneumonia due in nearly all instances to secondary infection with pneumococci or hemolytic streptococci. Purulent Bronchitis It has been stated that a considerable number of cases of influenza developed a more or less extensive purulent bronchitis. This term is used as descriptive of a group of cases showing clinically evidence of a diffuse bronchitis as manifested by numerous medium and fine moist râles scattered throughout the chest and evidence of a definitely purulent inflammatory reaction as indicated by the expectoration of fairly copious amounts of mucopurulent or frankly purulent sputum. This condition is regarded as quite distinct, on the one hand, from the common type of mucoid bronchitis frequently associated with “common colds” and a fairly common feature of uncomplicated cases of influenza, in which physical examination of the chest reveals only transient sibilant and musical râles without evidence of extension to finer bronchi, and, on the other hand, from bronchopneumonia. =Bacteriology.=—Thirteen cases of purulent bronchitis following influenza in none of which was there any evidence of pneumonia at the time cultures of the sputum were made nor later were subjected to careful bacteriologic study. Specimens of bronchial sputum were collected in sterile Petri dishes and selected portions thoroughly washed to remove surface contaminations before bacteriologic examinations were made. The results are shown in Table XIII. TABLE XIII BACTERIOLOGY OF THE SPUTUM IN CASES OF PURULENT BRONCHITIS FOLLOWING INFLUENZA