ConclusionsIt can be concluded that polyposis of the colon is a multifaceted disease. The mendelian character of the disease cannot be denied in patients belonging to the same family, especially when they are less than 40 years of age. The occurrence of polyposis in patients more than 40 years of age, or in those in whom no familial antecedent can be traced, is more difficult to comprehend. Probably the occurrence of this type of polyposis is on the same basis as that of carcinoma of the colon and, if this is true, it might be termed primary multiple polyposis of the colon.