Microscopic examination shows that the epithelium of the bronchi has undergone hypertrophy; the wall is infiltrated with lymphoid and plasma cells and thickened by new formation of fibrous tissue; there is similar thickening of adjacent alveolar septa and alveoli, often lined by cubical cells, are diminished in size. Connective tissue about the blood vessels and the interstitial septa are thickened and infiltrated with mononuclear cells. In parts of the lung the interstitial septa are edematous and contain polynuclear leucocytes, in some places in great number. Lymphatics are greatly dilated and filled with polynuclear leucocytes which in the center of some lymphatics have undergone necrosis. In one place a small abscess is in contact with a distended lymphatic. Lymphatics contain Gram-staining cocci in pairs and short chains, present in immense number where necrosis has occurred. =Autopsy 433.=—B. J., white, aged twenty-seven, from Arkansas, has been in military service one month. Onset of illness was on September 28, nineteen days before death, with cough and expectoration. Pneumonic consolidation was recognized two days later and 20 c.c. of cloudy fluid were aspirated from the left chest on the same day. Hemolytic streptococci were found in a culture from the throat nine days before death. =Anatomic Diagnosis.=—Unresolved bronchopneumonia with peribronchiolar and confluent lobular consolidation; interstitial suppuration of the right lower lobe; purulent bronchitis; fibrinopurulent pleurisy. The right pleural cavity contains 700 c.c. of yellowish gray purulent fluid containing flakes of fibrin. The left pleural cavity contains seropurulent fluid localized over the external part of the lung. The right lung is voluminous and free from consolidation save at the lower and posterior part of the lower lobe where the tissue is deep red and studded with firmer spots of yellow color clustered about the bronchi. In places the interstitial septa are thickened and yellow. Surrounding some of the bronchi near the apex of the left lung are red patches of consolidation. Culture from heart’s blood remained sterile. S. hemolyticus was grown from right pleural cavity, and S. hemolyticus and B. influenzæ were grown from the right lung. Culture from the left lung contained S. aureus and contaminating microorganisms.