September 4, 1906-March 10, 1981

BY WILLIAM HAYES

MAX DELBRÜCK, or just Max as he was called by all his associates, was one of the outstanding natural scientists of our time. A man of rare intellectual ability, and clarity of thought and perception, he excelled in theoretical physics, biology, and philosophy, and possessed a deep knowledge and appreciation of the arts. His dedication to truth, and his intolerance of half-truths and intellectual pretension, were sometimes expressed with a disturbing frankness and abruptness of manner, often construed as arrogance by those who did not know him well. His disclaimer, ''I don't believe a word of it," when told of some new experimental result or hypothesis, became famous among his colleagues. In fact, Max was very gregarious and had a rich vein of friendship and affection in his nature which he was always ready to share with others of all ages.

Above all, Max was a born leader whose Socratic influence on those who worked with him was enormous, whose rare praise was something to be coveted and remembered, and whose criticism was welcomed with respect; although