The most striking proof of the excellence and value of Darwin's literary work is the fact that his numerous books have attained a circulation, in their original form, probably surpassing that of any other scientific writings ever produced--and that, in translations, they have appealed to a wider circle of readers than any previous naturalist has ever addressed! We have seen that the idea of Natural Selection 'flashed on' Darwin's mind in October 1838, and although he was himself inclined to think that his _complete_ satisfaction with it, as a solution of the problem of the origin of species, was delayed to a considerably later date, yet I believe that this was only the result of his over-cautious temperament, and we must accept the date named as being that of the real birth of the hypothesis. At this early date, too, it is evident that Darwin conceived the idea that he might accomplish for the principle of evolution in the organic world, what Lyell had done, in the _Principles_, for the inorganic world. To cite his own words, 'after my return to England it appeared to me that by following the example of Lyell in Geology, and by collecting all facts which bore in any way on the variation of animals and plants under domestication and nature, some light might perhaps be thrown on the whole subject[123].' 'In June 1842,' he says, 'I first _allowed_ myself' (how significant is the phrase!) 'the satisfaction of writing a brief abstract of my theory in pencil in 35 pages[124].' For many years it was thought that this first sketch of Darwin's great work had been lost. But after the death of Mrs Darwin in 1896, when the house at Down was vacated, the interesting MS. was found 'hidden in a cupboard under the stairs which was not used for papers of any value but rather as an overflow of matters he did not wish to destroy[125].' By the pious care of his son, this interesting MS.--hurriedly written and sometimes almost illegible--has been given to the world, and it proves how completely Darwin had, at that early date, thought out the main lines of his future _opus magnum_. 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]!'