1863: The First Steps towards the Domestication of Animals (_Journal of Ethnological Society_); 1871: Gregariousness in Cattle and in Men (_Macmillan's Magazine_); 1872: Statistical Inquiries into the Efficacy of Prayer (_Fortnightly Review_); 1873: Relative Supplies from Town and Country Families to the Population of Future Generations (_Journal of Statistical Society_); Hereditary Improvement (_Fraser's Magazine_); Africa for the Chinese (_Times_, June 6); 1875: Statistics by Intercomparison (_Philosophical Magazine_); Twins, as a Criterion of the Relative Power of Nature and Nurture (_Fraser's Magazine_, and _Journal of Anthropological Institute_); 1876: Whistles for Determining the Upper Limits of Audible Sound (_S. Kensington Conferences_, in connection with the Loan Exhibition of Scientific Instruments, p. 61); 1877: Presidential Address to the Anthropological Department of the British Association at Plymouth (_Report of British Association_); 1878: Composite Portraits (_Nature_, May 23, and _Journal of Anthropological Institute_); 1879: Psychometric Experiments (_Nineteenth Century_, and _Brain_, part vi.); Generic Images (_Nineteenth Century; Proceedings of Royal Institution_, with plates); Geometric Mean in Vital and Social Statistics (_Proceedings of Royal Society_); 1880: Visualised Numerals (_Nature_, Jan. 15 and March 25, and _Journal of Anthropological Institute_); Mental Imagery (_Fortnightly Review; Mind_); 1881: Visions of Sane Persons (_Fortnightly Review_, and _Proceedings of Royal Institution_); Composite Portraiture (_Journal of Photographical Society of Great Britain_, June 24); 1882: Physiognomy of Phthisis (_Guy's Hospital Reports_, vol. xxv.); Photographic Chronicles from Childhood to Age (_Fortnightly Review_); The Anthropometric Laboratory (_Fortnightly Review_); 1883: Some Apparatus for Testing the Delicacy of the Muscular and other Senses (_Journal of Anthropological Institute_, 1883, etc.). _Memoirs in Eugenics_. 1901: Huxley Lecture, Anthropological Institute (_Nature,_ Nov. 1901); Smithsonian Report for 1901 (_Washington_, p. 523); 1904: Eugenics, its Definition, Scope and Aims (Sociological Paper, vol. i., _Sociological Institute_); 1905: Restrictions in Marriage, Studies in National Eugenics, Eugenics as a Factor in Religion (Sociological Papers, vol. ii.); 1907: Herbert Spencer Lecture, University of Oxford, on Probability the Foundation of Eugenics. The following books by the author have been referred or alluded to in the following pages:-- 1853: Narrative of an Explorer in Tropical South-Western Africa (_Murray)_; 1854: Art of Travel (several subsequent editions, the last in 1872, _Murray_); 1869: Hereditary Genius, its Laws and Consequences (_Macmillan_); 1874: English Men of Science, their Nature and their Nurture (_Macmillan_). CONTENTS PREFACE TO THE SECOND EDITION INTRODUCTION Origin and object of book.