multiple carcinomas of the colon were seen at the Mayo Clinic from January 1, 1944, through December 31, 1953. 0 This represents a known rate of occurrence of 4.3 /0. A marked tendency to multiplicity has been observed in carcinoma of the colon associated with multiple polyposis or with chronic ulcerative colitis. Some evidence has been obtained of hereditary factors in predisposition to malignant disease of the colon. When the diagnosis of a malignant lesion of the colon or rectum has been made, the entire large bowel must be considered a potential source of malignant disease. An integral part of the management of carcinoma of the large bowel must be constant vigilance to ensure early diagnosis and adequate treatment of both simul­ taneous and interval lesions. References ALBRECHT, P.: Ober die Multiplizitat primarer maligner Geschwiilste. Oncologia (Basel) 5, 12 (1952).