_b._ They sometimes, but rarely and with difficulty, breed with one or the other parent species. The mongrels of the second generation, produced by this interbreeding, are infertile. PARAGENESIC. Mongrels of the first generation having a partial fecundity. _a._ They are hardly fertile or infertile _inter se_, and when they produce direct descendants, these have merely a decreasing fertility, tending to necessary extinction at the end of some generations. _b._ They breed easily with one at least of the two parent species. The mongrels of the second generation, issued from this second breeding, are themselves and their descendants fertile _inter se_, and with the mongrels of the first generation, with the nearest allied pure species, and with the intermediate mongrels arising from these various crossings. EUGENESIC. Mongrels of the first generation entirely fertile. _a._ They are fertile _inter se_, and their direct descendants are equally so. _b._ They breed easily and indiscriminately with the two parent species; the mongrels of the second generation, in their turn are, themselves and their descendants, indefinitely fertile, both _inter se_ or with the mongrels of all kinds which result from the mixture of the two parent species. CONTENTS. PAGE DEDICATION v EDITOR’S PREFACE vii Glossarial Note x SECTION I. General remarks on the interbreeding of human races 1 Pretended examples of hybrid races (_note_ on the Griquas of Southern Africa) 3 Significations of the words _race_ and _type_ 12 SECTION II. On Eugenesic Hybridity in the Genus _Homo_ 16 SECTION III. Examples tending to prove that the interbreeding of certain human races is not Eugenesic 25 Remarks on the interpretation of human hybridity 26 Relative infecundity of the interbreeds between the White and Negro 28 Relative sterility of some Mulattoes in the first generation 30 Moral or physical inferiority of some Mulattoes _ib._ Malay and mixed breeds 40 Relative sterility of the interbreeds between the Europeans and the Australians or Tasmanians 45 Observations of Count Strzelecki; discussion 55 Conclusions on human hybridity 60 SECTION IV. Recapitulation and Conclusion 61