The first cross is generally successful--a tolerable degree of uniformity is produced, resembling in external conformation the sire, which is usually of a superior breed; and thus the offspring are superior to the dams. These cross-bred animals are now paired amongst each other, and what is the consequence? Uniformity at once disappears; some of the offspring resemble the grandsire, and others the grandams, and some possess the disposition and constitution of the one and some of the other; and consequently a race of mongrels is perpetuated. If, however, the cross is really a good and desirable one, then, by means of rigorous and continued selection, pursued for several generations, that is, by casting aside, as regards breeding purposes, every animal that does not exhibit uniformity, or possess the qualifications we are desirous of perpetuating, a valuable breed of animals may in the course of time be established. By this system many varieties of sheep have been so far improved as to become almost new breeds; as for instance the New Oxford Downs which have frequently gained prizes at the great Agricultural Meetings as being the best long wooled sheep. To cross, however, merely for crossing sake--to do so without that care and vigilance which we have deemed so essential--is a practice which cannot be too much condemned. It is in fact a national evil and a sin against society, that is, if carried beyond the first cross, or if the cross-bred animals are used for breeding. A useful breed of animals may thus be lost, and a generation of mongrels established in their place, a result which has followed in numerous instances amongst every breed of animals. The principal use of crossing, however, is to raise animals for the butcher. In this respect it has not (with sheep) been adopted to the extent which it might to advantage. The male being generally an animal of a superior breed and of a vigorous nature, almost invariably stamps his external form, size and muscular development on the offspring, which thus bear a strong resemblance to him, whilst their internal nature derived from the dam, well adapts them to the locality, as well as to the treatment to which their dams have been accustomed.