fessor Owen, the Living Mammalia by Mr. Waterhouse, the Birds by Mr. Gould, the Fish by the Rev. L. Jenyns, and the Reptiles by Mr. Bell. It was through Mr. Darwin's labours in collecting specimens and making observations that all these works were produced, and he added to the description of each species an account of its habits and range. The Insects which he collected were the subject of papers by Mr. Waterhouse and others; the Plants from South America were described by Dr. Hooker, who also wrote a memoir for the Linnæan Society on the Flora of the Galapagos Archipelago; Professor Henslow published a list of Plants from the Keeling Islands, and the Cryptogamic Plants were described by Mr. Berkeley. When we add to these the works from Mr. Darwin's own hand, we can form some notion of the " 'capacity for taking pains" which distinguished the young naturalist.

Several short papers founded upon observations made during the voyage appeared within a few years of his return, and some of them were embodied in the larger works afterwards published. One, on the habits of the South American Ostrich, was read at a meeting of the Zoological Society in March, 1839, when Mr. Gould described the Rhea Darwinii, so called in honour of its discoverer, and spoke of Mr. Darwin's important contributions to science; two others, on the Planarian Worms of South America and on Sagitta and its Development, appeared in 1844; but most of Mr. Darwin's attention was directed at this time to geology. In May, 1837, he communicated to the Geological Society his views on Coral Reefs, which were afterwards published in the volume mentioned further on ;1 and he contributed two papers to the same society, on the Volcanic Phenomena and the Erratic Boulders of South America. In a

1 "I am very full of Darwin's new theory of Coral Islands, and have urged Whewell to make him read it at our next meeting. I must give up my volcanic crater theory for ever, though it costs me a pang at first."-Lyell to Sir John Herschell, May 24, 1837.

letter dated December, 1836, only a few weeks after the Beagle returned, Lyell, writing to tell Darwin of the great pleasure which he had derived from a paper of his, and offering to go through it with him before it was read in public, says "The idea of the Pampas going up at the rate of an inch in a century, while the western coast and the Andes rise many feet, and unequally, has long been a dream of mine. What a splendid field you have to write upon." In another letter, in March, 1838, Lyell returns to the subject, and gives an account of the meeting of the Geological Society at which Darwin read his paper on the Connection of Volcanic Phenomena and the Elevation of Mountain Chains. "He opened upon De la Bêche, Phillips, and others, his whole battery of the earthquakes and volcanoes of the Andes, and argued that spaces of a thousand miles long were simultaneously subject to earthquakes and volcanic eruptions, and that the elevation of the Pampas, Patagonia, &c., all depended on a common cause." So early had Mr. Darwin, then a young man of twenty-nine, taken his place among the leading geologists of his time.

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In 1842 the first of three volumes by Mr. Darwin on the Geology of the Beagle was published under the title of the Structure and Distribution of Coral Reefs; in 1844 appeared Geological Observations on the Volcanic Islands visited during the Voyage of H. M. S. Beagle, together with some Brief Notices on the Geology of Australia and the Cape of Good Hope"; and in 1846 the work was completed by "Geological Observations on South America." Each of these volumes was enough to make a considerable reputation for the writer, but the first was the most important. So close was Mr. Darwin's observation, and so cogent was his reasoning, that in four or five years the theory which he set forth was "in progress of adoption by men of science in every country. "This theory (says

i Quarterly Review, LXXXI. (1847), p. 492.

the Director General of the Geological Survey1) for simplicity and grandeur strikes every reader with astonishment. It is pleasant after the lapse of many years to recall the delight with which one first read the Coral Reefs, how one watched the facts being marshalled into their places, nothing being ignored or passed lightly over, and how step by step one was led up to the grand conclusion of wide oceanic subsidences. No more admirable example of scientific method was ever given to the world, and even if he had written nothing else, this treatise alone would have placed Darwin in the very front of investigators of nature." We have mentioned the direct results of the voyage of the Beagle; the indirect results can neither be mentioned nor measured. They are to be seen, as we have said, in almost every work which Mr. Darwin wrote; and the sum of them is a revolution in scientific belief. For this reason it has seemned well to occupy so much of this paper with the early years of Mr. Darwin as a student and a discoverer.

Mr. Darwin, as we have seen, had not been long at home before his valuable services were recognized by men of science, and he was soon elected a Fellow of the Royal Society. In the letter from which we have already quoted, Lyell advises him to accept no official appointment if he can avoid it; but not long afterwards we find him Secretary to the Geological Society, an office which he filled when the Journal of Researches was published in 1839. Two years later he retired, and it was fortunate for the world that thenceforth he acted upon Lyell's advice, and "worked exclusively for science.' It was before the Geological Society, on the 1st of November, 1837, that Mr. Darwin read a short paper on the "Formation of Mould "; and fortyfour years passed before he gave to the public the mature results of his investigations, in the interesting

1 Paper in Nature on "Mr. Darwin's work in Geology" by Archibald Geikie, LL.D,, F.R.S., 1882.