In the Section on Practice of Medicine I have had the honor of acting as secretary, chairman and orator, no doubt by the active intervention of Frank Billings; but the Frank Billings Lectureship is so special a distinction that I cannot adequately express my appreciation of the honor. I enjoyed Frank Billings's friendship for a long time and realized his rare personality, his unusual genius as practitioner, consultant, teacher and leader of far reaching influence, and one of the most stimulating factors in the growth of the scientific element in the American Medical Association. In selecting a topic worthy of the occasion I was moved by long-standing interest in the subject and also by recalling the part played by many of my friends and Billings's pupils and associates in the investigation of the physiology and pathology of the coronary arteries, and especially by the long continued and successful work of