Appendicitis is well characterized by Professor Osler as "the most important of acute intestinal disorders;" and it may be said further to bear a somewhat similar relation to active digestive disturbances that pneumonia does to acute bronchial affections. The question most frequently asked by the people relates to the cause of the disease, the problem that most vexes the physician and surgeon is one of treatment, while the great frequency and fatality make its consideration of interest to' us all. Among the etiologic factors is considered age—being essentially a disease of the young. The study of 157 cases occurring in some of the Chicago hospitals during the past year shows an average age of 26 years, the oldest in this number being 62, the youngest 1½ years. As showing the rarity of cases in extremes of life, but one of these cases was found under 7, and but three over 50 years. The writer has successfully operated on two patients, aged respectively 4½ and 5½ 'years for the past two years. The list referred to shows the influence of sex to correspond very nearly