The necessity for the publication of this work in England may be conceived, when we reflect on the laxly defined ideas which form an integral part of the intellectual heritage of even educated Englishmen, with regard to the problems of anthropology. We have been so often told, that all races of men have been demonstrably proved to be fertile _inter se_, that many have conceived that the laws regulating this presumed fertility are ascertained and fixed, beyond the reach of disproof, or even of doubt. The Author and Editor of the following pages are, however, of a different opinion; and are content to wait for the accumulation of future facts. To obviate any misconstruction which may be placed on my meaning on this topic, I shall quote the words of the great Dutch philosopher:-- “I invite not the vulgar, therefore, nor those whose minds, like theirs, are full of prejudices, to the perusal of this book. I would much rather that they should entirely neglect it, than that they should misconstrue its purpose and contents after the fashion usual with them.” I should have felt more gratification if the task of interpreting the thoughts of the great French master of our science had fallen into worthier hands than my own. The habitual methods of thought of Dr. PAUL BROCA are so exact, his style so terse, his knowledge of the literature of Anthropology so vast, and his power of application and concentration of ideas so powerful, that a just preference might have selected another Editor. It has scarcely been necessary for me to add a single foot-note to the lucid exposition of the Secretary of our parent Society. It is my pleasurable duty to thank my friend Dr. James Hunt, the President of our Society, for the kindness by which he placed in my hands the editorship of this volume, and for many most valuable suggestions regarding it. To my colleague Mr. J. Frederick Collingwood, for whose friendly assistance in the performance of the secretarial duties I am indebted for the leisure which has enabled me to edit this work, my thanks are also due. To the Council and to the Society I now commit this little tract, an earnest of the more important works which will be hereafter published during the year 1864, in the hope that it may ultimately advance the best interests of the science all sincere anthropologists must desire to aid. C. C. B. 4, ST. MARTIN’S PLACE, _March_, 1864. GLOSSARIAL NOTE. The significations of the following words, habitually used by Dr. Broca, are appended:-- AGENESIC. Mongrels of the first generation, entirely unfertile, either between each other, or with the two parent species, and consequently being unable to produce either direct descendants or mongrels of the second generation. DYSGENESIC. Mongrels of the first generation, nearly altogether sterile. _a._ Unfertile with each other, therefore with no direct descendants.