Chronic bronchopneumonia is often overlooked at autopsy because newly formed connective tissue is not present in sufficient quantity to attract attention (Fig. 26). When the lesion is advanced conspicuous gray white patches of fibrous tissue may be seen about the bronchi (Autopsy 487; Fig. 27) and interlobular septa may be obviously thickened (Autopsy 472). The most distinctive feature of the lungs is the presence of small, firm, gray or yellowish gray nodules of consolidation which resemble miliary tubercles. They represent the peribronchiolar patches of bronchopneumonia present during the acute stage and have assumed the well-defined outline and firm consistence of tubercles because polynuclear leucocytes and red blood corpuscles have in large part disappeared, interstitial tissue is increased, and exudate is in process of organization. These nodules are grouped in clusters about the small bronchi. With unresolved bronchopneumonia the lungs are very voluminous and fail to collapse after they are removed from the chest and in some instances even after incision. The air containing tissue is usually dry. In our autopsies the lungs have been pink in color and often free from coal pigment, because those suffering with pneumonia have been in considerable part men from rural districts. Thick mucopurulent material exudes from the small bronchi which have been cut across; purulent bronchitis has been present in 20 of 21 instances of chronic bronchopneumonia. Bronchiectasis has been present in 13 instances; dilatation is often advanced, so that throughout the lungs are found bronchi with no cartilage distended to a diameter of 0.5 cm. In addition to the firm peribronchiolar tubercle-like nodules of consolidation there are scattered patches of gray lobular or confluent lobular consolidation. Yellowish nodules, grouped about bronchi and resembling those found elsewhere in air containing tissue, are occasionally seen scattered upon the cut surface of a patch of gray, confluent lobular consolidation (Autopsies 421, 423, 431). [Illustration: Fig. 26.—Unresolved bronchopneumonia with tubercle-like nodules of peribronchiolar consolidation best seen in lower lobe; bronchiectasis. Autopsy 425. ]