1. =Peritoneum.= Normally the peritoneum is moist-shining, grayish and translucent. It is cloudy, dry, lustreless, injected, swollen or covered with exudate in acute inflammation; thickened, hyaline (“iced” or “Zuckerguss”) in chronic inflammation. Note degree, character and location of adhesions. The most common pathologic conditions are inflammation, tuberculosis, secondary carcinoma and pseudomyxoma peritonei. Lymphomata are found in cases of typhoid fever and in leukæmia. Primary neoplasms (lymphangioma, endothelioma, carcinoma, lymphosarcoma, angiosarcoma, etc.) are rare. Ovarian cysts of the structure of cystadenoma may give rise to implantation-metastases over the peritoneum. The parasites are echinoccocus and cysticercus. 2. =Spleen.= Weight 150-250 grms., length 12 cm.; breadth 8 cm., thickness 3 cm. Varies greatly in size and weight. Describe shape, character of borders, number of notches, etc. Accessory spleens are common in the gastrosplenic omentum. _Capsule_ should be delicate, smooth, shining and transparent. Note _tension of capsule_ (loose, wrinkled, tense), adhesions, hyaline thickenings, exudates or neoplasms. _Color_ of spleen through capsule is bluish-red. Fresh anæmic infarcts appear as yellowish or reddish-yellow areas surrounded by a darker red zone. Cicatricial depressions on the surface of the spleen are usually the result of healed infarcts. _Consistence_ of spleen normally is that of muscle. In acute hyperplasias and congestions the spleen is softer and more friable (acute infections, typhoid fever). In chronic hyperplasias and congestions, atrophy, amyloid degeneration, etc., the consistence is firmer than normal, even to that of a wooden hardness in advanced amyloid disease. (Apply iodin test.) The large, firm spleen is characteristic of leukæmia, splenic anæmia, syphilis and chronic malaria. On section note the _pulp_, _follicles_ and _trabeculæ_. In the normal spleen the cut surface is dark red or bluish-red, smooth, and the trabeculæ and follicles easily seen. In acute hyperplasias the pulp swells up over, the trabeculæ as a thick red or grayish-red gruel-like substance. In chronic hyperplasias the pulp is atrophic, grayish-red, and firm. In subacute hyperplasias the cut-surface often presents a shagreened appearance. The _color_ of the cut-surface is blood-red in typhoid fever, grayish-red in septicæmias, chocolate-brown in potassium-chlorate poisoning and hemosiderosis due to other causes. In amyloid spleen the amyloid portions are glassy; when confined to the follicles the latter look like grains of boiled sago. The _follicles_ are about the size of medium pin-heads, grayish in color, not elevated and cannot be scraped out with the knife. They are more numerous and larger in young individuals than in adults. Note size and number, degenerations, etc. The _trabeculæ_ appear as fine gray lines, sharply outlined, increasing in size toward the hilus and capsule. They are more