The lungs are extremely voluminous (12, 17) due in part to an accumulation of liquid within them. This finds its way into the trachea and completely fills the latter structure with blood-stained, syrupy fluid, with purulent material, or with a mixture of these (2, 90, 107, 157, 162). At first the pleural surface is smooth and often quite even, but on closer inspection, a minute granulation is suggested. In many cases even close examination does not allow the conclusion that an exudation of anything but serum has occurred through this membrane, except in localized foci. These foci more frequently involve the interlobar pleura and that of the lower lobes (112, 143). The volume of the lungs, often great enough to obliterate the pericardial area, is one of the two most characteristic features of the external examination. The other feature is their color. Small, bright red hemorrhages may occur anywhere. The larger patches are the most striking. Violet, purple, or dark brown areas, irregular in shape and distribution, are more frequently found on that portion of the pleura over the lower two-thirds of the lung. Between the deeply colored zones, there are pale pink areas which involve the lowermost edge to the least degree, the anterior margin somewhat more, and the apex of the lung most of all. The darker portions just referred to may project above the surface and may be circumscribed, resembling huge, fresh hemorrhagic infarcts (41, 108). The alveolar walls are not seen through the pleural surfaces in these darker zones. The pale pink areas, usually at the level of the more intensely colored zones, may be elevated and the dilated air sacs are distinctly made out through the pleura (Fig. XIII). At the hilum, the lymph glands are large and soft. When cut, fluid escapes and is often blood-stained. The cross section may present a distinct, diffuse, hemorrhagic appearance (162). At the hilus, too, the lymphatics, distended here and there over the surface of the pleura, are most affected. The congested bronchial mucous membrane and the exudate in these structures has been described.