By the untimely death of Harold Ward Dudley, before he had completed his 48th year, Science has lost a devoted servant and a distinguished investigator. The wide influence which he had acquired, especially among those concerned with biochemistry, was due to his fine character and his personal charm, as well as to his already brilliant record of research ; and his services to the remarkable development of that branch of Science in this country, apart from the direct effect of his own investigations, involved a quiet and unselfish devotion of time and work to the interests of his colleagues. Dudley was born at Derby on October 30, 1887, the eldest son of the late Rev. Joshua Dudley, who, as a Methodist minister, was stationed for successive periods in different parts of the country. Harold Dudley’s schooling changed with these movements of his home. He was at Truro College, and at the King Edward VI Grammar School, Morpeth, from which he entered Leeds University, taking Chemistry as his subject, and specializing in Organic Chemistry. This brought him under the influence of the late J. B. Cohen, F.R.S., who died earlier in this year (see Obituary Notice, p. 503 of this issue). Cohen was not only a great and inspiring teacher ; there must have been something in his teaching of Organic Chemistry which aroused interest in its biological significance to account for the number of his pupils who have won success and distinction in biochemistry. It is sufficient to name, in order of seniority, Dakin, Raper, Hartley, Dudley, Woodman, Raistrick, and Wormall, and to note that four of these have been elected to our Fellowship for their work in biochemistry, to realize that the teaching of Cohen, himself no biologist, has had, through his pupils, a powerful influence on the development of this relatively young department of Science.