Darwin, however, had no idea of publishing his theory to the world until he was able to support it by a great mass of facts and observations. Lyell, again and again, warned him of the danger which he incurred of being forestalled by other workers; while his brother Erasmus constantly said to him, 'You will find that some one will have been before you[126]!'
The utmost that Darwin could be persuaded to do, however, was to enlarge his sketch of 1842 into one of 230 pages. This he did in the summer of 1844. His manner of procedure seems to have been that, keeping to the same general arrangement of the matter as he had adopted in his original sketch, he elaborated the arguments and added illustrations. Each of the 35 pages of the pencilled sketch, as it was dealt with, had a vertical line drawn across it and was thrown aside. While the 'pencilled sketch' of 1842 was little better than a collection of memoranda, which, though intelligible to the writer at the time, are sometimes difficult either to decipher or to understand the meaning of, the expanded work of 1844 was a much more connected and readable document, which Darwin caused to be carefully copied out. The work was done in the summer months, while he was absent from home, and unable therefore to refer to his abundant notes—Darwin speaks of it, therefore, as 'done from memory.'
The two sketches, as Mr Francis Darwin points out, were each divided into two distinct parts, though this arrangement is not adopted in the Origin of Species, as finally published. Charles Darwin on many occasions spoke of having adopted the Principles of Geology as his model. That work as we have seen consisted of a first portion (eventually expanded from one to two volumes), in which the general principles were enunciated and illustrated, and a second portion (forming the third volume), in which those principles were applied to deciphering the history of the globe in the past. I think that Darwin's original intention was to follow a similar plan; the first part of his work dealing with the evidences derived from the study of variation, crossing, the struggle for existence, etc., and the second to the proofs that natural selection had really operated as illustrated by the geological record, by the facts of geographical distribution, and by many curious phenomena exhibited by plants and animals. Although this plan was eventually abandoned—no doubt wisely—when the Origin came to be written, we cannot but recognise in it another illustration of the great influence exercised by Lyell and his works on Darwin—an influence the latter was always so ready to acknowledge.
On the 5th July 1844, Darwin wrote a letter to his wife in which he said, 'I have just finished my sketch of my species theory. If, as I believe, my theory in time be accepted, even by one competent judge, it will be a considerable step in science.' He goes on to request his wife, 'in case of my sudden death' to devote £400 (or if found necessary £500) to securing an editor and publishing the work. As editor he says 'Lyell would be the best, if he would undertake it,' and later, 'Lyell, especially with the aid of Hooker (and if any good zoological aid), would be best of all.' He then suggests other names from which a choice might be made, but adds 'the editor must be a geologist as well as naturalist.' Fortunately for the world Mrs Darwin was never called upon to take action in accordance with the terms of this affecting document[127].
It must be remembered that, at this time, Darwin was hard at work on the three volumes of the Geology of the Beagle, and on the second and revised edition of his Journal of Researches. This which he considered his 'proper work' he stuck to closely, whenever his health permitted. He had hoped to complete these books in three or four years, but they actually occupied him for ten, owing to constant interruptions from illness. His occasional neglect of this task, and indulgence in his 'species work,' as he called it, was always spoken of at this time by Darwin as 'idleness.' And when the geological and narrative books were finished, Darwin took up the systematic study of the Barnacles (Cirripedia), both recent and fossil, and wrote two monumental works on the subject. These occupied eight years, two out of which he estimated were lost by interruptions from illness. So absorbed was he in this work, that his children regarded it as the necessary occupation of a man,—and when a visitor in the house was seen not to be so employed one of them enquired of their mother, 'When does Mr —— do his Barnacles?' Huxley has left on record his view that in devoting so long a time to the study of the Barnacles Darwin 'never did a wiser thing,' for it brought him into direct contact with the principles on which naturalists found 'species[128].' And Hooker has expressed the same opinion.
Daring these years of labour in geology and zoology—interrupted only by the 'hours of idleness'—devoted to 'the species question,' Darwin, though leading at Down almost the life of a hermit, was nevertheless in frequent communication with two or three faithful friends who followed his labours with the deepest interest. Cautious as was Darwin himself, he found in his life-long friend Lyell, a still more doubting and critical spirit, and it is clear from what Darwin says that he derived much help by laying new ideas and suggestions before him. The year before Darwin's death he wrote of Lyell, 'When I made a remark to him on Geology, he never rested till he saw the whole case clearly, and often made me see it more clearly than I had done before.'
Lyell's father was a botanist of considerable repute, the friend of Sir William Hooker and his distinguished son Dr (now Sir Joseph) Hooker. While Darwin was writing his Journal of Researches, he handed the proof-sheets to Lyell with permission to show them to his father, who was a man of great literary judgment. The elder Lyell, in turn, showed them to young Mr Hooker, who was then preparing to join Sir James Ross, in his celebrated Antarctic voyage with H.M. ships Erebus and Terror. Hooker was then working hard to take his doctor's degree before joining the expedition as surgeon, but he kept Darwin's proof-sheets under his pillow, so as to get opportunities of reading them 'between waking and rising.' Before leaving England, however, Hooker in 1839 casually met and was introduced to Darwin, and thus commenced a friendship which resulted in such inestimable benefits to science. Before sailing with the Antarctic expedition the young surgeon received from Charles Lyell, as a parting gift, 'a copy of Darwin's Journal complete'; and he tells us that the perusal stimulated in him 'an enthusiasm in the desire to travel and observe[129].'
On Hooker's return from the voyage in 1843, a friendly letter from Darwin commenced that remarkable correspondence, which will always afford the best means of judging of the development of ideas in Darwin's mind. Hooker's wide knowledge of plants—especially of all questions concerning their distribution—was of invaluable assistance to Darwin, at a time when his attention was more particularly absorbed by geology and zoology, while botany had not as yet received much attention from him. Hooker's experience, gained in travel, his sound judgment and balanced mind made him a judicious adviser, while his caution and candour fitted him to become a trenchant critic of new suggestions, scarcely inferior in that respect to Lyell.
Darwin does not appear to have made the acquaintance of Huxley till a considerably later date; but we find the great comparative anatomist had in 1851 already become so deeply impressed by Darwin, that he said in writing to a friend he 'might be anything if he had good health[130].' Huxley used to visit Darwin at Down occasionally, and I have often heard the latter speak of the instruction and pleasure he enjoyed from their intercourse.
For many years of his life, Darwin used to come to London and stay with his brother or daughter for about a week at a time, and on these occasions—which usually occurred about twice in the year I believe—he would meet Lyell to 'talk Geology,' Hooker for discussions on Botany, and Huxley for Zoology.