He rarely went to London, on account of his health, and consequently kept up a very large correspondence with scientific friends, especially with Lyell, Hooker, and Huxley. He made it a rule to preserve every letter he received, and his friends were careful to preserve his; so that in the 'Life and Letters' published after his death by his son Frank--who in later years lived with his father and assisted him in his work--we have a most interesting record of the progress of his speculations, as well as a delightful revelation of his beautiful character. His house was large enough to accommodate several guests at a time; and it was his delight to receive here for a week's end not only his old friends and companions, but younger naturalists, and others, the companions of his sons and daughters. Over six feet in height, with a slight stoop of his high shoulders, with a brow of unparalleled development overshadowing his merry blue eyes, and a long gray beard and mustache,--he presented the ideal picture of a natural philosopher. His bearing was, however, free from all pose of superior wisdom or authority. The most charming and unaffected gayety, and an eager innate courtesy and goodness of heart, were its dominant notes. His personality was no less fascinating and rare in quality than are the immortal products of his intellect. The history of the great works which Darwin produced, and especially of his theory of the Origin of Species, is best given in his own words. The passage which is here referred to is a portion of an autobiographical sketch written by him in 1876, not for publication but for the use of his family, and is printed in the 'Life and Letters.' Taken together with the statement as to his views on religion, it gives a great insight both into the character and mental quality of the writer. It is especially remarkable as the attempt of a truly honest and modest man to account for the wonderful height of celebrity and intellectual eminence to which he was no less astonished than pleased to find himself raised. But it also furnishes the reader with an admirable _catalogue raisonne_ of his books, arranged in chronological order.