Post-mortem examination showed little of interest aside from the thorax. The left pleural cavity contained 75 cubic centimeters of slightly cloudy fluid. The right was almost completely obliterated by an organizing fibrinopurulent exudate which bound together the visceral and parietal layers. The left lung was partially collapsed and covered by a thickened pleura, bluish purple in color, which at the base and in the interlobar area was finely granular. Crepitation was present at the apex, the anterior surface, and the borders of the lung; elsewhere the consistency was increased. On section there was a frothy exudate from the apex and extreme base. These were deep red in color, while the intervening surface of the lung was paler, but broken by many small, white, elevated nodules which at first glance resembled tubercles (Fig. XXXIX). On close examination each of these was seen to have a small, depressed center from which pus could be expressed, and on dissection this was seen to be the wall of a bronchiole. The right lung was more voluminous and covered by a thick, grey, fibrinopurulent exudate except on the upper anterior border where there were a few small areas of interstitial emphysema. On section the pleural exudate was seen to be sharply demarcated from the lung parenchyma by a fine red line. The pseudotubercles of the other lung were here even more marked and from each exuded a yellow pus which partially obscured the pinkish-grey translucence of the surface (Fig. XL). The lumina of the larger bronchi were distended. The hilic and bronchial glands were enlarged and grey. Microscopic examination of sections from the lung showed an extensive bronchopneumonia. The alveoli of an occasional group of lobules were filled with serum or red blood cells, while still other areas showed foci of necrotizing pneumonia, actual miliary abscesses in which there were large clumps of bacteria (Fig. XLI). Throughout the sections, however, the striking change was an organization of the exudate, which varied from a few fibroblasts to a well defined connective tissue almost obliterating the normal architecture (Figs. XLI and XLIV). The alveolar walls in some areas showed edema only, in others they were almost replaced by a thin line of fibrous tissue, and in still others, by a hyperplasia of the epithelium which almost filled their lumina. The bronchi exhibited similar changes, their lumina were filled with an exudate of desquamated epithelium and leucocytes, which in some places was organizing (Fig. XI), and there was a regeneration of epithelium evidenced by a piling up of the cells and the presence of mitotic figures in them. The interstitial tissue showed some edema. The tracheal epithelium was intact, but a few leucocytes and lymphocytes were scattered through the submucosa.