On section note _color_, _blood-content_ and _consistence of cut-surface_, _relations of cortex and medulla_. The cortex is normally 0.5-1.0 cm. broad (increased in acute degenerations and inflammations, diminished in chronic inflammation and atrophy). Note number, size and color of the _glomeruli_. They appear as red pin-head points in congestion; in anæmia as small colorless granules; in the normal kidney as small reddish points against the lighter color of the labyrinths. In amyloid disease they are enlarged and glassy. Calcified glomeruli are white and opaque. In venous congestion the interlobular veins appear as bluish-red stripes; hæmorrhages appear as red points in the glomeruli and convoluted tubules, as red stripes in the collecting tubules. The blood-content is increased in chronic passive congestion and chronic alcoholism. On the cut-surface anæmic infarcts are usually wedge-shaped, with the base toward the cortical surface. The color of the kidney-parenchyma is usually gray; in fatty degeneration and cloudy swelling it becomes yellow or grayish-yellow. The areas of greatest degeneration appear as cloudy, opaque, yellowish points and stripes. Slight degenerations are shown by slight cloudiness of the cortex. The contrast between the grayish-white cortex and the dark-red medulla is often very striking in severe parenchymatous nephritis. In uric-acid infarction of the new-born ochre-yellow or vermilion-red stripes or lines are seen in the medullary pyramids; white lines indicate chalk-infarction; golden-yellow lines a bilirubin infarction. In gout whitish deposits of urates occur in the kidney; they are usually surrounded by scar-tissue. In purulent pyelonephritis yellow stripes of pus surrounded by hæmorrhage occur in the pyramids. Tuberculosis begins usually in the papillæ, destroying the pyramids first and then the cortex, forming a multilocular sac lined with caseating tissue. In hydronephrosis due to obstruction of the ureter the kidney becomes converted into a multilocular sac without ulceration or caseation of its papillæ. Note size of _pelvis_ and calices, contents, character of mucosa, concretions, etc. The normal mucosa is grayish-red and delicate; it is rose-red in inflammation and often shows petechiæ. In severe inflammations grayish-white sloughs encrusted with urates are often found. Concretions of urates, phosphates or oxalates may be present, often associated with decubital ulcers of the mucosa. Tuberculous ulcers of the pelvic mucosa are common. The _ureters_ are straight and about 4 mm. thick. Note size, contents, thickness of wall, changes in the mucosa, obstruction, dilatation, concretions, etc.