Accordingly, I have not discussed with any fulness the value of his technical contributions to natural science; I have not drawn up a compendium of his philosophical views. One is a work for specialists; the other can be gathered from his published works. I have endeavoured rather to give the public a picture, so far as I can, of the man himself, of his aims in the many struggles in which he was engaged, of his character and temperament, and the circumstances under which his various works were begun and completed. So far as possible, I have made his letters, or extracts from them, tell the story of his life. If those of any given period are diverse in tone and character, it is simply because they reflect an equal diversity of occupations and interests. Few of the letters, however, are of any great length; many are little more than hurried notes; others, mainly of private interest, supply a sentence here and there to fill in the general outline. Moreover, whenever circumstances permit, I have endeavoured to make my own part in the book entirely impersonal. My experience is that the constant iteration by the biographer of his relationship to the subject of his memoir, can become exasperating to the reader; so that at the risk of offending in the opposite direction, I have chosen the other course. Lastly, I have to express my grateful thanks to all who have sent me letters or supplied information, and especially to Dr. J.H. Gladstone, Sir Mountstuart Grant Duff, Professor Howes, Professor Henry Sidgwick, and Sir Spencer Walpole, for their contributions to the book; but above all to Sir Joseph Hooker and Sir Michael Foster, whose invaluable help in reading proofs and making suggestions has been, as it were, a final labour of love for the memory of their old friend. CONTENTS. PREFACE TO THE AMERICAN EDITION. PREFACE TO THE ENGLISH EDITION. CHAPTER 1.1. 1825-1842. CHAPTER 1.2. 1841-1846. CHAPTER 1.3. 1846-1849. CHAPTER 1.4. 1848-1850. CHAPTER 1.5. 1850-1851. CHAPTER 1.6. 1851-1854. CHAPTER 1.7. 1851-1853. CHAPTER 1.8. 1854. CHAPTER 1.9. 1855. CHAPTER 1.10. 1855-1858. CHAPTER 1.11. 1857-1858. CHAPTER 1.12. 1859-1860. CHAPTER 1.13. 1859. CHAPTER 1.14. 1859-1860. CHAPTER 1.15. 1860-1863. CHAPTER 1.16. 1860-1861. CHAPTER 1.17. 1861-1863. CHAPTER 1.18. 1864. CHAPTER 1.19. 1865. CHAPTER 1.20. 1866. CHAPTER 1.21. 1867. CHAPTER 1.22. 1868. CHAPTER 1.23. 1869. ... LIST OF ILLUSTRATIONS. PLATE 1. PORTRAIT OF T.H. HUXLEY FROM A DAGUERROTYPE MADE IN 1846. PLATE 2. FACSIMILE OF SKETCH, "THE LOVES AND GRACES." PLATE 3. PORTRAIT FROM A PHOTOGRAPH BY MAULL AND POLYBLANK, 1857. PLATE 4. NUMBER 4 MARLBOROUGH PLACE--FROM THE GARDEN. AFTER A WATERCOLOUR SKETCH BY R. HUXLEY. PLATE 5. PORTRAIT FROM A PHOTOGRAPH BY ELLIOTT AND FRY; STEEL ENGRAVING IN "NATURE," FEBRUARY 5, 1874. CHAPTER 1.1. 1825-1842.