"Count Lehndorff, in his admirable little book of "Recollections", (see 'Horse Breeding Recollections') called attention in 1883 to the desirability of breeding only from race mares if one wished to minimize the elements of uncertainty and increase the chances of success. He defined himself as meaning mares that had shown individual excellence and soundness enough to have gone through the strain of training and survived so as to have raced in some class. He made what has always seemed to me an unanswerable demonstration of his theory when he showed that of the dams of the winners of the Two Thousand Guineas, the Derby, Oaks and St. Leger for twenty years - 1860 to 1879, both inclusive -87% were mares with racing records. Investigations I have made as to other periods for the same races corroborated the theory to my satisfaction, and I therefore sought to know, as to my stud, what the racing record was, not only of its individual members, but of their families. Hence this volume, originally intended for my own greater convenience. As these records grew . . . I saw that they contained valuable historical matter likely to be interesting and useful to others. They show, among other things, a complete record of some of the great American racing families, not heretofore compiled, and so I have printed them for private circulation among friends . . ."