While the circumstances detailed in the preface to my second volume led to a great extension of the original plan of this work, I felt the exclusion of many of these charming family letters was not justified by the introduction of so much scientific detail, and thus I have added them as an additional chapter to this volume. To Galton's niece, Mrs Lethbridge, I owe the privilege of publishing the selection from letters which, after the death of his sister Emma in 1904, her Uncle wrote to her almost weekly. They give the most perfect characterisation of Galton in his relationship to his family.
One apology I must make if the reader feels that in the chapter on the last decade of Galton's life the biographer has introduced too much of himself. To me that last decade was essentially bound up with our joint work for a subject we both had closely at heart; and I believe that for Galton himself our common aim-the establishment of Eugenics as an accepted branch of sciencewas a leading, if not the principal, purpose of those years. My own enthusiasm may possibly have deceived me, but I believe Galton during that decade lived more in the struggles and difficulties of our infant Laboratory than in any other phase of his wide interests. The sympathy and help he always so readily tendered to his friends may again have misled me, but I think the history of the Laboratory he founded and finally endowed was also the essential history of his own life in those last years. At any rate such is the aspect of Galton's many-sided nature that I then saw most closely, and it is accordingly that which I am best fitted to render account of. To me his final crusade for eugenic principles was the crowning phase of a life whose labours in medicine, evolution, anthropology, psychology, heredity and statistics directly fitted him to be the teacher and prophet of the new faith.
I have to express my gratitude to various societies and editors of journals for permission to reproduce the illustrations that accompanied Francis Galton's letters and papers. In particular, to the Royal Institution for permission to use the figures illustrating Galton's lectures of 1877, to the Royal Anthropological Institute for permission to use the diagrams of Galton's memoir of 1885; and to the Editor of Nature for permission to use Galton's diagrams or other figures from that journal. The permission of the Royal Society to reproduce illustrations to Galton's memoirs was granted when my second volume was published. The copyright in Galton's books belongs to the University of London. The copyright in most of the letters and photographs belongs to those members of the Galton and Darwin families who provided me with them, and permission to reproduce them again must be obtained from those members, as well as from myself (if the second reproduction be made from this volume).
While I must again renew my thanks to many who have aided me in this as in the earlier volumes, I am under deep obligations to my colleagues Professor C. J. Sisson and Miss Ethel M. Elderton for assistance in the toil of proofreading; if in a few instances I have not followed their obviously better judgment, I trust they will not despise me for being of a perverse heart. To Dr Julia Bell I owe the expenditure of too many of her free hours for several years in the preparation of the ample index to this work ; while to my Wife,