The propositions, 1, 3, 4, and 5, are the only ones connected with our subject. They confirm, and even enhance, in certain respects, M. Jacquinot’s assertions, yet are they contested, and Dr. Nott himself has found it necessary to restrict their application. He had made his observations in South Carolina where he found the Mulattoes little prolific and short-lived. Having changed his residence, he obtained different results. At Mobile, New Orleans, Pensacola, towns on the Gulf of Mexico, he found among the Mulattoes many instances of manifest longevity and prolificacy, not merely in their crossed but in their direct alliances. What was the cause of this difference? Dr. Nott inquired whether the difference in the results might not depend upon the difference in the ethnological elements in the crossing. All the Europeans who have colonised America did not belong to the same race. The Caucasians, as is well known, are naturally divided in two groups:--the light-haired race, with grey or blue eyes, a white skin; and the brown races, with a deeper complexion and brown or black hair. The first occupy Northern Europe; the second, Southern Europe. There is thus a little less disparity, and a little more affinity between the Europeans of the South and the Negroes, than between the latter and the Northern Europeans, so that when we hear that intermixture succeeds better in the first than in the second case, it should not surprise us. But South Carolina, where the Mulattoes get on so indifferently, has been colonised by the Anglo-Saxons; whilst the shores of the Gulf of Mexico, where the Mulattoes are more prospering, have been colonised by the French (Louisiana) and by the Spaniards (Florida). Such is the explanation offered by Dr. Nott. Still in maintaining his conclusions on the issues of Negro women, and men of the Germanic race, he thinks that they are not applicable to the Mulattoes whose parents belong to a Caucasian race more or less dark in complexion. Analogous differences are often observed in animals in such crossings when they are placed in connections with species more or less approximate. Before, however, accepting Dr. Nott’s explanation, it may be as well to examine whether the fact may not be differently explained.