Evolution: The Modern Synthesis, a 1942 book by Julian Huxley (grandson of T.H. Huxley), defines the modern synthesis of evolutionary biology of the early 20th century.
In the book, Huxley tackles the subject of evolution at full length, in what became the defining work of his life. His role was that of a synthesiser, and it helped that he had met many of the other participants. His book was written whilst he was Secretary to the Zoological Society of London, and made use of his remarkable collection of reprints covering the first part of the century. It was published in 1942.
Reviews of the book in learned journals were enthusiastic: The American Naturalist called it "The outstanding evolutionary treatise of the decade, perhaps of the century. The approach is thoroughly scientific; the command of basic information amazing."
Allen & Unwin, London. (1942, reprinted 1943, 1944, 1945, 1948, 1955; 2nd ed, with new introduction and bibliography by the author, 1963; 3rd ed, with new introduction and bibliography by nine contributors, 1974). U.S. first edition by Harper, 1943.