To have been elected president of this society is a great honor and one of which I am most appreciative. I thank you most sincerely. However, nothing is free, and the time has arrived when I must render payment by delivering the President's Address.
Before embarking upon my chosen theme I should like to make some comments about a man to whom we all owe a great debt for his many contributions to pediatric research. I refer to Dr. John F. Enders. It was my privilege to work under him for four and a half years at a crucial time in my career and to have had a close association with him ever since. I will not attempt to discuss his accomplishments, but it is for his work on mumps, poliomyelitis, and measles that most of you know him best. In each instance his contributions have laid the foundations upon