I even noted a fourth case, a very remarkable one, an even cross, Pierre and Pauline; and varieties are established, the differentiation of the mother, for example, often accords with the physical resemblance of the father; or, it is the contrary which takes place, so that, in the crossing, the physical and mental predominance remains with one parent or the other, according to circumstances.

The answer has been furnished by one of the greatest ethnologists, Theodor Waitz, who, after he had exposed the insufficiency of the accepted formulas, came to the conclusion that the differentiation of the blacks from the lighter peoples might be an error.