Crossing by selection has numerous advocates, and from all time, the best-informed, the most practical men, have been unanimous in proclaiming that _blood is only preserved and improved by blood_—that is to say, by selection. It is easy and not expensive, inasmuch as the necessary subjects are always at hand; it is natural, inasmuch as its simplicity is apparent to every mind. And, if it does not bring the rapid results so pleasing to those too eager for profit, it is, at least, always sure. For, without giving at first exceptional results, it never fails in its effects, by reason of the affinity existing between the different individuals, and by reason especially of their perfect conformity with the climate and soil. In fact, this conformity is not an indifferent matter, and it has been found by experience that animals, noted upon their native soil for their sureness in reproducing, and for the invariable transmission of their qualities to their descendants, frequently fail in these respects when imported into another country. Often, several years roll by before they recover that equilibrium of health and that tranquillity of animal functions, which permit them to reproduce in a sure, equal, and fixed manner, without which an improvement in the type cannot take place. Selection has long been practiced in Perche, and it has there produced for a long time the best results, which were interfered with only by the importation from Picardy, Caux, and Boulogne, of animals of inferior blood. Among the bovine species, we have curious examples of the value of selection, especially those furnished in Cotentin, where a breed exists the finest, best, and the most sought after in France. Crossing with foreign blood, which fashion, at one date or another, had wished to prescribe, has always been forbidden as a crime in this country. It is thus that the finest herds of La Manche, and especially those of M. Mannoury of Canisy near Saint-Lô have been formed. The success of this breeder began at Ebisey near Caen, where he commenced a few years ago and where the stock can be easily examined. A bull of the Cotentin race, the most perfect and best bred that could be found, put to heifers of the same breed, chosen among the finest types, was the starting point officially recorded. Selection, operating upon this progeny, as it had operated in the beginning, was continued without intermission, and, by these means it has produced a herd all the members of which are alike and constantly transmitting identical qualities. [Illustration: Decoration] CHAPTER III. CONSANGUINITY.