IT HAS been well substantiated that the proportion of aged in the population of the United States is increasing. In 1900, the average life expectancy was 48 years. By 1950, it had increased to 68.27 years. During the period 1930-1940, there was a 7% increase in the total population of this country, but during the same period the number of persons between the ages of 65 and 74 had increased 35% and the number over 75 years by 38%.1 As a natural consequence, there has been an increase in the number of patients undergoing surgery in the latter decades of life. At the University of Michigan Hospital there has been a 112% increase in the number of major abdominal operations in patients more than 50 years of age in 1950, as compared with the number in 1940. Furthermore, a steady increase in the relative number of patients over 60