Necrobiosis Lipoidica Diabeticorum. Presented by Dr. Arthur M. Greenwood, Boston, and Dr. Ethel M. Rockwood, Boston. Case 1.—M. R., a female, has had the disease for five years; the approximate duration of the diabetes, which is poorly controlled, is five years. The total cholesterol content of the blood was from 156 to 179 mg. (normal content, 230 mg.) ; the sugar content varied from 240 to 360 mg., and the nonprotein nitrogen content was 33 mg., per hundred cubic centimeters. Case 2.—Mrs. M. C. has had the disease for eight years; the approximate duration of the diabetes is nine years. The sugar content of the blood varied from 180 to 620 mg. per hundred cubic centimeters. This patient states that she sustained an injury, and she has received some roentgen therapy. Case 3.—Mrs. M. V. has had the disease for nine years; the approximate duration of the diabetes, which is