It has been ascertained by those who have profoundly studied the matter, that where two varieties of the same domestic animal--such, for example, as the totally distinct varieties of the pigeon--which have for generations bred perfectly true, are crossed, that in certain cases the progeny resulting from this cross resembles not so much either of its parent forms, but _reverts in colour, shape, and other characteristics, to that original parent stock from which both varieties have descended_. Thus, in the case of pigeons: if a white fantail, which breeds quite true, be crossed with a black barb, a variety which also breeds very true, the offspring being always black, yet the mongrels resulting from this cross may be black, brown, or mottled; but they may also resemble neither father nor mother in any way; they may have the brilliant blue colour, the black wing bar, the barred and white-edged tail feathers of the wild rock pigeon, from which original all the different domestic varieties of pigeon descended. Why this crossing of different varieties which each breed perfectly true should produce these unstable creatures with a tending to revert to the primitive original type of the race, is not known; that it does so, is certain. If, now, we apply the same law of inheritance to human creatures, and suppose that two wholly distinct human varieties cross, and take, for example, the Zulu and the Englishman--both of which varieties breed perfectly true, the Englishman always producing a white European and the Zulu a black Bantu; both races being characterized by the strongest social feeling, and both being remarkable for their bravery; if we leave this law of reversion out of consideration, the natural supposition would then be, that the offspring of such a cross, while in colour and other matters they represented a compromise between the two parent forms, would, as far as social feeling and courage are concerned, which are common to _both_ parent varieties, be at least as well endowed in these qualities as either parent variety. But it might not be so. If this law of reversion holds with human creatures (and we have no reason to assert that it cannot do so); and supposing that the original type from which in the remote past both Zulu and Englishman have descended was of a lower order as regards social feeling and courage, than that to which both Englishman and Zulu have attained to in the process of ages of development, then their offspring might revert to that lower type; and the vulgar dictum, that the Half-caste is more anti-social than either his parent forms would in this case be naturally and scientifically true.[32]