_Lesions._ The pneumonia is far more likely to be double than in the fibrinous form, and the area invaded, in its ratio with the high intensity of the fever, is usually less. The consolidations are especially common near the lower borders of the anterior parts of the lungs. There may, however, be a number of centres in each lung, to be accounted for by the inhalation of the germ and the starting of the morbid process at the various points on which it falls. This, like the double character of pneumonia is therefor in keeping with the contagious origin. Each centre of condensation shows a small area, hepatized, purulent or necrotic, with a surrounding zone of dark bluish red congestion. The consolidated areas are less dry and granular than in fibrinous pneumonia, seeming to be largely infiltrated with a still liquid exudate and dark blood, and thus tend to a greater tenacity, and less friability. Black areas of infarction form in the lung, the thrombosis of the arteries, cutting off the free normal circulation and the isolated portion fills up with dark blood globules and forms a sequestrum. In the inflammatory and still living parts the color is lighter with, it may be, some straw colored exudate, and always an active leucocytosis, as in other inflamed parts. When infiltration is located near the root of the lung, it is usually attached to the primary bronchi, or larger bronchia and may extend into the upper portion or almost the entire substance of the lung. Simple abscess is rare, yet purulent sacs containing the gangrenous masses or sequestra are common. Pleuritic areas are common over the congested and hepatized foci, yet as these are usually circumscribed in extent, an excessive hydrothorax is exceptional. Yet the pleuritic effusion may at times become abundant. Friedberger and Fröhner say seven gallons or more. It may become purulent or even septic, exhaling an offensive odor. Adhesions and fringes on the pleura are frequent. The _heart and pericardium_ may be affected, the first showing the pallid, soft, or parboiled appearance of high fever, with at times fatty degeneration or petechiæ, and the latter congestion, exudation, thickening, false membranes and liquid effusion. The enlargement of the _congested liver_ is a marked feature. It frequently attains the weight of 30 pounds. It may ooze dark blood freely from the cut surface, has usually a yellowish tinge, and shows points of fatty degeneration or even of commencing necrosis. The spleen is like the liver, charged with blood, and shows an increase of pulp and even petechiæ or circumscribed hæmorrhages. The _kidneys_ are congested, friable and petechiated. The _bronchial lymph glands_ and less constantly the mediastinal and abdominal ones, are congested, pink to dark red and somewhat enlarged. The gastric and intestinal mucosa may be congested, thickened, hæmorrhagic or ulcerated. The white tissues generally tend to an icteric hue, and the muscles assume a mahogany aspect.