In the case of the human race, interbreeding between different peoples is going on all over the world, as I write these lines. The crossing of species of men of all kinds is not only a fact of the present day, but it has taken place in various quarters of the globe as far back as history carries us. It was much rarer in early times than it is now, for the reason that the earth was not so thickly populated as it is now, nor were the means of general travel anything like as perfect as we have them today. When the various races and tribes of men were far more distinctly separated, and great stretches of uninhabited wildernesses or bodies of water were to be found isolating their habitats, and the means of communication were extremely slow and limited, the several stocks were far more pure and unmixed. It is ease and rapidity of communication, and enormous increase of population, with the various habitats becoming overcrowded and thus crowding each other, that affords the constant opportunity for race crossing, and the more pressing and evident that these conditions become, the greater is the amount of cross-breeding among the peoples so situated. Under such conditions it is certain to take place, and just as certain to be followed by the appearance of half-breeds where it is going on. It matters little what races are thus brought in juxtaposition, crossing to a greater or less extent will occur. This will the more frequently be done without the law of marriage than within it, although intermarriage, too, under such circumstances, will be far from uncommon. In the city of New York the Chinese men, here in this country from China, have often married white women of their own station in life, and the crossing
