The feeding of a diet containing oxidized lipids and low in vitamin E to pregnant rats induces the generalized Shwartzman reaction in these animals. The etiologic factor or factors can be concentrated by molecular distillation of the oxidized lipid. The addition of large amounts of tocopherol prevents the appearance of the disease. Oral administration of antibiotics reduces the incidence of the disease by 4 times. Pathologic changes in the placenta consist of: degeneration of the trophoblast, thrombosis and fibrin deposition in maternal vascular spaces, congestion of maternal blood spaces, hemorrhage into the uterine cavity, placental separation, intrauterine fetal death, decidual or uterine vein thrombosis, placentitis (10[degree]/o of the cases), and fetal resorption. The implications of these experimental observations for human toxemia have been discussed.