It is very significant when an author, despite of himself, confirms by his theories, facts which he had undertaken to disprove. I will not allude again to the story of infanticide, a hundred times more improbable here, than in cases where the child had been begotten by a European. Though it follows, from Mr. Thomson’s article, that Strzelecki’s assertion was too general, it results at the same time that the assertion was well founded. But this is not the place to search for the explanation of a phenomenon which, despite the efforts of Mr. Harvey, does not touch hybridity. If I have dwelt on the fact, it is because the polemics raised by Strzelecki’s observations have incontestably established that the _cohabitation_ of Whites and native Australian women is very common in Australia; and we do not comprehend under this name the sexual intercourse which is accidental and transitory, such as occurs when the women come to market, but the cohabitation under the same roof, and prolonged during several months, and even years. The scarcity of Australian Mulattoes can thus be attributed neither to the rarity nor to the transitory nature of sexual intercourse; neither can we admit, until we are better informed, that the relative sterility of such crossings is the consequence of some homœogenesic defect between the two races. In studying the cases preceding those just mentioned, we have put the question whether Mulattoes of the first degree were, between themselves, indefinitely prolific, to answer which we had to analyse a certain number of facts. In the present case the facts fail us, and the question can only be examined theoretically. No traveller or author has spoken of the alliance of Australian Mulattoes between themselves, nor of their recrossing on the parent stock. No writer has informed us whether these Mulattoes are robustious, intelligent, vivacious, or, on the contrary, weak, stupid, and short-lived. One thing appears to me certain, that the number of young Mulattoes who die at an early age, or who are not viable, must be relatively considerable, and this may perhaps have given rise to the accusation of infanticide, which I have already refuted. This defective progeny is also observed in the crossings of certain species of animals but little homœogenesic; and if it be true, as everything tends to establish, that the union of the Whites and the Australian women is but little prolific, we may suppose that Mulattoes sprung from such disparate unions, must enter the category of inferior cross-breeds. Are they very prolific between themselves? This seems not very probable, though we have no experimental knowledge of it. It is even doubtful whether they are very prolific with the Whites, for no one has mentioned the existence of Quadroon Mulattoes, which might be as easily recognised as the Quadroons of the Antilles. However small the number of hybrid women of the first degree may be, these women ought to have produced with the