THOMAS HENRY HUXLEY was born in Ealing, England, May 4th, 1825. Educated at Ealing School and at Charter Cross Hospital in London, he spent the first four years of his professional life (1846–50) as assistant surgeon on an English man-of-war. In 1855 he became Fullerian professor of Physiology at the Royal Institution, and it was as a physiologist and biologist that he achieved his greatest successes. He was a pupil of Darwin, and he had what Darwin wholly lacked—a combative disposition and a keen enjoyment of controversy. He seldom found an opponent intellectually able to cope with him, even when he was wrong; and as he was frequently right, he won many controversial victories which seemed to give him a high degree of satisfaction. But if he owed much of his reputation with his contemporaries to the public’s love of intellectual prize-fighting, his permanent reputation rests on a long list of essays and studies as a biologist and physiologist. Among the most popular of these are “Science and Culture,” “Lay Sermons,” and “Evolution and Ethics.” He died June 29th, 1895. His essay “On the Method of Zadig” stands at the head of its class, unsurpassed among the popular scientific essays of the century.