two generations—this is what is known to horse-men as in-breeding—and then for many after generations to breed with strangers, or very remote connections. And it is worthy of remark that, although there are two distinct theories, exactly opposite to each other, one in favor of in-breeding, the other of out-crossing, several of the best strains of blood on the English turf are directly traceable to an original incestuous connexion.
Some of the most distinguished families, for instance, of English racers, trace to Spanker, a very high-bred horse, and very close to Arab stock on both sides, and his own dam: and where no near connexion has existed for many years in the blood of any peculiar family, it is on the whole the most approved method, to breed in, that is, between close blood relations, for two, or perhaps three generations, and then to seek for some strain of blood as remote as possible by which to vary and reinvigorate the strain. This plan of breeding has been of late years very fashionable in England, and the result has been shown very beneficially in several families famous for their qualities of speed, endurance, and recuperation, at present on the turf. It is certain, on the other hand, that to persist too long in breeding, generation after generation, in and in, is the most prejudicial of all modes; and that animals so unnaturally connected in blood, degenerate in bone, in size, in stature, and ultimately in all qualities.
Whenever, therefore, it is known, or strongly suspected, that in any family too long and persistent an adherence has been had to one and the same blood, and still more, wherever the present generation is seen to have greatly degenerated in size, recourse should be had to a strain of blood as widely different as possible, in order to freshen and strengthen the stock.
