days to the end of his university life, a person set apart for individual preparation for a special and peculiar career. When he bade farewell to Christ's College, Cambridge, in the summer of 1831, his actual education was yet to be acquired, but not through human instruction. He has himself declared: "I have always felt that I owe to the voyage the first real training or education of my mind.'*
It was therefore no professional scientist who eagerly accepted the unsalaried post of naturalist to the Beagle expedition around the world, but a modest, though confident, youth of twenty-two whose most important article of outfit was the first volume of the first edition of Lyell's "Principles of Geology," which had been published the year before, the second volume of which was not issued until after Darwin had reached South America. Thus it was providentially ordered that during the formative period covered by this epoch-making voyage, Darwin should remain as free as possible from human influences. If, instead of proceeding, raw as he was, directly from the seclusion of the university to the isolation of the voyage, he had directed his steps to the metropolis and had there mingled with the leaders in scientific thought, it is quite possible, if not probable, that he would have fallen under their authority and would have accepted the orthodox beliefs of his time. If that had been the case, we might be dominated to-day by the prohibitive doctrine of the immutability of species, instead of enjoying that freedom of thought and liberty of investigation to which Darwin made us heirs. But, happily for the intellectual world, during the five years which Darwin spent on the Beagle, under the intimate tutelage of mother nature, he laid, for our benefit, as well as for his own, the solid foundations of that never-failing habit of mind in which open-eyed teachableness ever supplemented unwavering honesty of purpose and fearlessness of approach.
After Darwin's return from the circumnavigation of the globe, he resided, for a little more than five years, in London, and that was the only portion of his life during which he was in actual personal contact with any considerable number of his fellow men. Even then, however, he was mostly engaged with his own thoughts, for he was arranging his collections and preparing for publication the results of his observations made while on the Beagle voyage. It was at the very beginning of this residence in London (July, 1837), while the things he had seen in South America and the Pacific Islands were still fresh in his memory that he opened his first note-book for facts in relation to the origin of species, about which he says he "had long reflected." For twenty-two years thereafter Mr. Darwin continued to pursue this revolutionizing subject with unexampled patience and, except as to two or three intimate friends, entirely within the privacy of his own mind.
In September, 1842, he went into retirement at Down, an out-of--
