Whites, if they had been very prolific, a progeny which ought to have become numerous in the population of a colony founded above seventy years; for there can be no doubt that there, as everywhere, the woman of colour selects by preference the alliance of men of a superior race. I am far from advancing these suppositions as demonstrated truths. I have studied and analysed all documents within my reach; but I cannot be responsible for facts not ascertained by myself, and which are too much in opposition to generally received opinions to be admitted without strict investigation. I, therefore, earnestly draw the attention of travellers, and especially of physicians resident in Australia to this subject, the importance of which I have endeavoured to point out. Until we obtain further particulars we can only reason upon the known facts; but these, it must be admitted, are so numerous and so authentic as to constitute if not a rigorous definitive demonstration, at least a strong presumption in favour of the doctrines of polygenists. From the whole of our researches on the hybridity of the human race we obtain the following results:-- 1. That certain intermixtures are perfectly eugenesic. 2. That other intermixtures are in their results notably inferior to those of eugenesic hybridity. 3. That Mulattoes of the first degree, issued from the union of the Germanic (Anglo-Saxon) race with the African Negroes, appear inferior in fecundity and longevity to individuals of the pure races. 4. That it is at least doubtful, whether these Mulattoes, in their alliances between themselves, are capable of indefinitely perpetuating their race, and that they are less prolific in their direct alliances than in their recrossing with the parent stocks, as is observed in paragenesic hybridity. 5. That alliances between the Germanic race (Anglo-Saxon) with the Melanesian races (Australians and Tasmanians) are but little prolific. 6. That the Mulattoes sprung from such intercourse are too rare to have enabled us to obtain exact particulars as to their viability and fecundity. 7. That several degrees of hybridity, which have been observed in the cross-breeds of animals of different species, seem also to occur in the various crossings of men of different races. 8. That the lowest degree of human hybridity in which the homœogenesis is so feeble as to render the fecundity of the first crossing uncertain, is exhibited in the most disparate crossings between one of the most elevated and the two lowest races of humanity. SECTION IV. RECAPITULATION AND CONCLUSION. The numerous and controverted questions which we had to discuss, have more than once interrupted the chain of our thesis. It may, therefore, be useful to present here a _résumé_ of the various parts of our argumentation. Zoologists have, in _each_ of the natural groups which constitute the genera, recognised _several_ types which they denominate species.[81]