Such was in all probability the origin of the celebrated horse Justin Morgan; an animal which not only did more to stamp excellence and impart value to the roadsters of New England than any other, but was the originator of the only distinct, indigenous breed of animals of which America can boast;--a breed which as fast and durable road horses and for any light harness work, is not equalled by any other, any where. In the present state of our knowledge it is scarcely conceivable how an animal possessing the endowments of Justin Morgan could have originated in any other way than from such a parentage as above indicated. On the other hand it is very certain that _contrast in character_, as well as in breed, has occasioned much of the disappointment of which breeders have had occasion to complain. The principle here laid down is one of broad application, and should never be lost sight of in attempts at improvement by crossing. Another point worthy special attention is that all crossing, to insure successful results, should be gentle rather than violent; that is, never couple animals possessing marked dissimilarity, but endeavor to remedy faults and to effect improvement by gradual approaches. Harmony of structure and a proper balancing of desirable characteristics, "an equilibrium of good qualities," as it has been happily expressed, can be secured only in this way. It may not be out of place here to say, that much of the talk about _blood_ in animals, especially horses, is sheer nonsense. When a "blood horse" is spoken of, it means, so far as it means any thing, that his pedigree can be traced to Arabian or Barbary origin, and so is possessed of the peculiar type of structure and great nervous energy which usually attaches to "thorough-bred" horses. When a bull, or cow, or sheep is said to be of "pure blood," it means simply that the animal is of some distinct variety--that it has been bred from an ancestry all of which were marked by the same peculiarities and characteristics.