In the previous chapter I have told, as well as I could, how the English race-horse was developed by a commingling of Oriental blood with that of horses that had been used for sporting purposes in our mother country. I confess that my explanation must seem very slipshod to any who are looking for a mathematically exact exposition of facts. Nothing would have pleased me better than to have been able to gratify the natural craving that people have for exactness. But I cannot be less general than I have, for more specific information is not at my command. It was simply demonstrated by practical experiments that the mixture of the bloods mentioned produced a very fast and sturdy horse that was superior to what had previously been known in England, together with the more important fact that this new Anglo-Arab was a type that was reproducing and kept on improving in speed and staying qualities so long as the cardinal principle of breeding: “like produces like” was adhered to with the comprehensive intelligence which made the rule embrace performance, conformation and blood. To the narrow-minded the law “like produces like,” indicates that the progeny of the fastest stallion and the fastest mare, when breeding for speed, would be faster than either parent. It is a well-known fact that mares whose fleetness and gameness has been demonstrated by long careers on the turf are rarely successful as dams. Of course, there have been exceptions to this general statement, but notwithstanding these exceptions, the narrow-minded application of the rule breaks down just at this point. It is likeness in blood, conformation and general characteristics that the rule more particularly refers to. At any rate, the English had, by the middle of the eighteenth century, developed a distinctive type of horse of most marvelous fleetness and courage and with a blood prepotency that has been so great, that after a century and a half the Thoroughbred is as much improved over what he was at the beginning as the beginners were better than the common stock of England a century earlier. And this is the type that we call to-day in America the Thoroughbred.