In the 47 cases of proved hyperthyroidism the blood cholesterol values range from 71 mg. per 100 cc. to 183 mg. The average of the basal metabolic rates in the 47 cases was plus 57%; the average cholesterol level, 130 mg. per 100 cc. In the 23 cases of myxedema, on the con-trary, the values range from 218 to 500 mg. The average of the basal metabolic rates in the 23 cases of myxedema was minus 30%; the average cholesterol level 321mg. per 100 cc. In earlier papers20 from this laboratory the maximum normal cholesterol level has been accepted as

230 mg. per 100 cc It willbe seen that the