This group of autopsies confirms the view that the red confluent lobular pneumonia is caused by pneumococci in association with B. influenzæ. Hemolytic streptococci may invade secondarily. In Autopsy 297 a few hemolytic streptococci were found in the bronchus but apparently had not entered the lungs. In the absence of histologic examination it is not possible to determine if the invasion of hemolytic streptococcus (in Autopsy 364) has caused necrosis of the pneumonic tissue. [Illustration: Fig. 7.—Bronchopneumonia with purulent bronchitis and peribronchial hemorrhage. ] Peribronchial Hemorrhage and Pneumonia In a considerable number of instances, namely, in 19 autopsies, hemorrhage about the small bronchi has been recognizable upon gross examination of the lung. A conspicuous zone of hemorrhage 2 or 3 mm. in thickness surrounds small (with no cartilage) often dilated bronchi and on longitudinal section may be tracted for a considerable distance along the bronchus (Fig. 7). In many additional instances peribronchial hemorrhage has been found by microscopic examination. In some instances the peribronchial zone of hemorrhage is firmer than the tissue elsewhere and it is occasionally difficult to determine whether the lesion is hemorrhage or pneumonia. In 7 instances frank red consolidation of peribronchial tissue was recognized at autopsy; this lesion will be considered later under peribronchial pneumonia. Hemorrhage about bronchi, like other evidences of severe injury to bronchi following influenza, is more frequently found in the lowermost parts of the lungs than elsewhere. It is invariably associated with severe bronchitis; the bronchi have contained purulent fluid in 15 of 19 instances of peribronchial hemorrhage and in 10 instances the lesion has been associated with dilatation of the bronchi. Microscopic examination furnishes further evidence of the severity of the bronchial changes which have brought about hemorrhage into the surrounding alveoli. The lumen of the bronchus contains blood and leucocytes; the epithelium is sometimes raised in places from the underlying basement membrane by blood; blood vessels of the bronchial wall are engorged, and there is hemorrhage into the tissue of the bronchus. More frequently the bronchial epithelium is completely lost and the denuded surface is often covered by a layer of fibrin intimately adherent to the inflamed mucosa. Transitions between simple hemorrhage and pneumonia are found, polynuclear leucocytes being mingled with red blood corpuscles. In several instances the alveoli in immediate contact with the bronchial wall have contained fibrin, whereas those in the surrounding zone have contained blood. Bacteria found in the bronchi in 10 instances of peribronchial hemorrhage have been as follows: