The principal rôle in the etiology of the diseases of the female genital organs must be assigned to pregnancy and childbirth. Anæmic women readily suffer during pregnancy from a further decrease in the corpuscular richness of the blood; those affected with valvular incompetence find their troubles much aggravated by pregnancy; where the kidneys are in an irritable condition, pregnancy not infrequently results in the onset of nephritis, those with disordered digestion often suffer from increased disturbance of the functions of the stomach and the intestinal tract; those with gall-stones are apt to suffer from exceptionally severe attacks of biliary colic, and acute yellow atrophy of the liver is especially apt to occur during pregnancy. In women in whom dilatations of the veins already exist, very great increase of the enlargement is apt to occur during pregnancy; and in the same circumstances, trifling telangiectases increase to extensive angiomata. Enlargements of the thyroid body undergo rapid increase during pregnancy, so that they may attain threatening proportions. In women in whom the abdominal walls are flaccid, the viscera may protrude during pregnancy through the enlarged lacunæ, giving rise to herniæ. The great relaxation of the peritoneal and other ligamentous attachments of the great abdominal glands, occurring during pregnancy and the puerperium results in displacements of these organs; hepatoptosis (migrating or movable liver), lienoptosis (splenoptosis or wandering spleen), nephroptosis (ren mobile, floating or movable kidney), and other varieties of enteroptosis (splanchnoptosis, visceroptosis, or Glénard’s disease). During pregnancy, previously sound teeth are apt to become carious, and already existing caries rapidly advances. New growths of various kinds originate at this period, those previously present exhibit rapid increase; and relapse after operations for the extirpation of malignant tumors is especially apt to occur. Even the bones are unfavorably influenced. A weakened nervous system is subject to a storm of changing nervous troubles, in some cases so severe as to lead to the outbreak of actual psychoses; while mental disorder already present tends, as a rule, to be seriously aggravated during pregnancy. In the eyes, serious disorders may occur, such as retinitis, and atrophy of the choroid with complete amaurosis. As regards the hearing, tinnitus aurium is not uncommon, and sometimes complete deafness occurs. Numerous diseases of the skin are apt to occur during pregnancy; in addition to the well-known pigmentation of the face, the areola mammæ, and other parts, we may have herpes, eczema, or pruritus.