The heaviest and strongest of a class, united among themselves, will produce more surely the kind demanded than a too precipitate crossing. Nothing is more risky than crosses made without judgment. It is by them that harmony of form is destroyed, and a degenerate mongrel race is produced as the inevitable consequence. It is then important, in the reunion of types, never to lose sight of equality and similarity of conformation and qualities. But, at the same time, it is necessary to march with the age, study its tendencies, and be always ready to guide a movement which otherwise might drag you in its wake. We must not lose sight of the fact that the services required of the Percheron horse are not the same as formerly. The omnibus service, especially, which, scarcely ten years ago, was considered the mildest, has, at present, become the hardest, and the one which requires heavy horses, uniting speed with strength. On the other hand, as a consequence of the great changes in the life and means of conveyance of the wealthy, the Percheron race has been most prominently brought forward. Almost all ranks of the upper classes have now adopted the Percheron horse of the light kind for their private uses, hunts and drives in the country. The fondness for rapid traveling rendering these classes more exacting than formerly, the necessity has arisen of finding in Perche, specimens with weight and speed with a light and stylish form. Accordingly, it becomes necessary to find means of adding the greatest possible speed to the other valuable characteristics of the Percheron horse. To reach this result promptly, we should have recourse to the Arabian stallion, and this, surely, would be the quickest means. But as I do not find this Percheron race, in its present state, sufficiently prepared for this alliance, and as I think that it still needs two or three generations of preparatory crossings with itself, it will be necessary to commence, in order to attain this end, by close interbreeding. We should, at first, commence by exploring the Percheron centers devoted exclusively to the rearing of mares, and, in these places, we should particularly visit the localities in which they have no great development as to height. Here we would select a group of from fifteen to twenty fillies, the best, the finest limbed, the most compact, the fastest trotters, and having for an extreme maximum the height of 15½ to 16 hands. The same course should be pursued in the regions where the colts are raised, and there choice should be made of some light stallions, approaching, as much as possible, to the mares in form and qualities. All the best foals, then, should be in their turn subjected to couplings conducted with the same care, and among the third generation would be found types sufficiently confirmed, either as founders of a race among themselves, or for crossing with the Arab, of which we will speak in the following chapter.