In cases of =older standing= the connective tissue has usually undergone a marked increase. The capsule is thick, dense and adherent. The cortical substance is shrunken with a great increase of the fibrous elements, and the same holds true of the medullary portion. In consequence of this, even in the cortical substance the white or gray color predominates. The parenchymatous tissue (glomeruli, tubules) have greatly shrunken. In connection with the contraction of the forming fibrous hyperplasia, there is a general shrinkage of the kidney in size, it may be to one-half its original volume. Trasbot reports a case of nephritis, of 8 months standing, in the dog, with a kidney half the normal size. In the end the parenchyma may have practically disappeared, and the kidney may have shrunken to a small, firm, white, fibrous mass. Abscess of the kidney is exceptionally met with (Laurent, Lafosse). _Lesions of distant organs_ are not uncommon. Bronchitis, pneumonia, pleurisy, insufficiency of the tricuspid or mitral valves, dilated heart, hypertrophied or fatty heart, congested or fibroid liver, arteritis, and dropsies are among such morbid conditions. _Prognosis._ This is almost always unfavorable. Death may be delayed for months or years, and partial transient recoveries may take place but a restoration to normal structure and function is not to be looked for. _Treatment._ This cannot be expected to be much more than palliative. The avoidance of overwork, and of the exposure to cold and wet, and the securing of a free action of the skin by warm buildings and clothing, are essential. The diet should be easily digested and non-stimulating, for _herbivora_ green food, carrots, roots, apples, silage, with a moderate allowance of oats to counteract weakness and anæmia; and for _carnivora_, milk, buttermilk, mush made of oat, wheat or barley meal, with, if necessary, a slight allowance of tender raw meat. Tonics fill a similar need. Iron and bitters may be combined. Or hydrochloric acid or nitromuriatic acid with bitters (nux, calumba, salicin, quassia) may be tried. These acids are especially valuable when the case has originated in or is maintained by calculi, indigestion or hepatic disorder. When the heart is defective in tone, it may be stimulated by small doses of digitalis, strophanthus, sparteine, caffein, or nitro-glycerine, or to a certain extent by strychnia or nux. These, however, must be used with judgment, if it is found that they aggravate the case by increasing the arterial tension. In those cases in which there is an excessive secretion of watery urine, the possible source of this in musty aliment should be avoided, and the flow checked by nux vomica, in moderate doses, and bromide or iodide of potassium in full doses. When, on the other hand, the urine becomes scanty and dense, the great danger of a toxic action must be met by agents that favor excretion. Pure water at