Statistical studies of a large series of individual cases of any disease offer considerable information, especially in regard to phenomena of its various stages, the incidence of different phases and their interrelationship. In particular, such a review enables one to see his mistakes and gives an opportunity to alter management accordingly. For these reasons I am offering this review of 1,000 consecutive cases of diabetes which have been under observation during the last five years. This study covers the period from March 1, 1921, through August, 1925, when the one-thousandth case was seen. The total number of patients admitted to the Cleveland Clinic during this period was 55,939; thus, the incidence of diabetes to all other diseases among our patients is nearly 1.8 per cent. AGE AND SEX INCIDENCE Chart 1 shows the distribution of these cases according to sex and in different age decades. It will be noted that