Lyell’s death took place in 1875, eleven years after his definite acceptance of Darwin’s views. Darwin, in writing to Miss Arabella Buckley (now Mrs. Fisher, formerly secretary to Sir Charles Lyell), fully acknowledged the deep debt which he owed to Lyell’s teachings: “I never forget that almost everything which I have done in science I owe to the study of his great works.” Huxley says in his obituary of Charles Darwin (reprinted in “Darwiniana,” 1893, p. 268): “It is hardly too much to say that Darwin’s greatest work is the outcome of the unflinching application to Biology of the leading idea and the method applied in the ‘Principles’ to Geology.” Every biologist who realises--as who can help realising?--the boundless opportunities which Darwin’s work has opened for him, will feel that he too owes a deep personal debt to Darwin’s great teacher. CHAPTER XVII. INFLUENCE OF DARWIN UPON HOOKER AND ASA GRAY--NATURAL SELECTION AND DESIGN IN NATURE (1860–68). Hooker wrote on November 21st, speaking of the “glorious book” in the warmest terms. Later on in the year he wrote again in the same spirit, but speaking of the difficulty he found in assimilating the immense mass of details: “It is the very hardest book to read, to full profits, that I ever tried--it is so cram-full of matter and reasoning.” Hooker must, however, have been familiar with the arguments and proofs, and for this reason did not attempt any detailed discussion. It is unnecessary to say more of Hooker’s reception of the “Origin.” During their long friendship Darwin had discussed the difficulties and the evidences of his theory more fully with him than with any other man; and, as “a man sharpeneth the countenance of his friend,” the influence of Hooker was one of the most potent forces under which Darwin produced the greatest work of his life. Many years later, when Hooker was awarded, in 1887, the Copley Medal of the Royal Society, reviewing his past experiences and work in his speech at the anniversary dinner, he concluded by telling us that his long and intimate friendship with Charles Darwin was the great event of his scientific career. [Sidenote: ASA GRAY.] In sending a copy to Asa Gray, he wrote (November 11th):-- “I fully admit that there are very many difficulties not satisfactorily explained by my theory of descent with modification, but I cannot possibly believe that a false theory would explain so many classes of facts as I think it certainly does explain. On these grounds I drop my anchor, and believe that the difficulties will slowly disappear.”