This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables. A study was made of all hernias in patients admitted to the wards of St. Luke's Hospital, New York, from 1926 to 1935 inclusive. Also included in the study were all hernias repaired from 1916 to 1925 inclusive which were observed postoperatively for nine months or longer. This gave a total of 4,442 hernias, of which 2,462, or 55.4 per cent, were incomplete indirect inguinal hernias. They made up 67.4 per cent of all inguinal hernias included in the study. Of these 2,462 hernias, 2,337 were repaired. Among the 1,668 which were followed for nine months or longer (the average follow-up time was thirty-six months), 120 recurrences were found, an incidence of 7.2 per cent. The average time after operation at which these recurrences were first noted was thirty-two and two-tenths months. ETIOLOGIC FACTORS Age at Onset. —The age at which the hernia was first noted must of necessity be