Relative sterility of some Mulattoes in the first generation

It would be imprudent to restrict ourselves to superficial observations, though positive observations are with difficulty collected. Mulattoes of the first degree are not a well defined and circumscribed caste, like the whites and negroes of pure blood. Mulatresses prefer to unite themselves with the white or with mestizoes whiter than themselves. Mulattoes are thus frequently obliged to intermix with either pure negresses, or with mulatresses issued from a recrossing with the Negro race. There are, nevertheless, a goodly number of unions between the mestizos of the first degree; but the individuals issued from these unions have no longer the same chances of intermarrying as those of the first generation. The number of individuals of the first degree must, therefore, rapidly decrease from generation to generation, and the result is, that even if these cross-breeds were indefinitely prolific between themselves, we could only, by way of exception, find mulattoes issued in a direct line to the third or fourth generation, from the direct and exclusive union of mestizoes of the first degree.