IV. Nevertheless, I do not deny the facts advanced by Etwick, Long, Nott, Yvan, and Simonnot. I accept them without so much as discussing them. But what do they prove in the presence of the remaining facts which are so numerous and so conclusive? At the most that the development of the mulatto race can be favoured, retarded, or hindered by _local_ circumstances. In other terms, that it depends upon the influences exercised by the whole of the conditions of life (_milieu_). We see, then, in the formation of the mixed races, the reappearance of this element, whose action plays so large a part in the natural history of man, and great attention should be paid to it. In the result of the crossing of the Negro and the White in Jamaica, Java, &c., its intervention could be foreseen. The two races are strangers to these countries, which are known to be very destructive to foreign races. The question of crossing is complicated in these cases, by the phenomena and difficulties of _acclimatisation_. Can we feel surprised that unions contracted under such conditions of existence should only present precarious guarantees for the future? We must here, moreover, take into account an element which is constantly neglected, and whose importance in questions of this nature has always struck me strongly. I mean _morality_. It therefore forms _one of the conditions of life_ (milieu). Now, if we pay attention to the details, which are not numerous, but which are very significant, given by some travellers upon the existence of Europeans in the colonies, in Jamaica in particular; if we compare these melancholy facts with those furnished by daily observation, an entirely new light will be thrown upon the questions of _crossing_ and _acclimatisation_. We shall be obliged to recognise that the death of the fathers, and the extinction of the descendants, are often only the consequence of, and the punishment for, the deplorable _moral conditions of life_, in which they have lived. V. But the _physical conditions of life_ have also their peculiar action. The following example may be quoted as a proof. M. Simonnot has noticed natives of Senegambia, “who combine a perfectly black skin, with all the characteristic forms of the Moor, even at all ages.” According to him, these _black Moors_ are a mixed race. If this is the case, it must, at least, be recognised that the white blood predominates considerably, since all the forms belong to this type. In order that the _colour_ of the Negro should be persistent, in spite of this profound semitic influence, a _local action_, that is, an _action of the conditions of life_, must have neutralised the ordinary laws of the mixture of races, and united the _colour_ of one race with the _features_ and _forms_ of another.