But if the breeding is the other way--that is, if a scrub bull is used on pure-blood cows--the degeneration to the scrub status is in precisely the same ratio that we have just given for improvement when pure-blood males are constantly used. By using grade bulls, there is also a constant deterioration of blood, but not as rapid as when scrub bulls are used. The only safety is in using pure blood males. With these well selected and all other conditions maintained, the status is certain to be preserved, if improvements, in consequence of better care and selection, are not secured. COUPLING. Proper coupling, or rather the coupling of proper animals, has received little attention, and is now confined generally if not exclusively to professional breeders. But it is a subject to which the dairymen can as well as not pay attention with good results. By coupling proper animals, we mean having regard to individual points and qualities, never coupling those having the same defects, either in form or quality. For instance, to illustrate, a cow high on the rump may be safely bred to a bull low on the rump, or _vice versa_, the result, in all probability, being an offspring with a level rump. This is breeding together opposite extremes, depending on the one to correct the other. But if we breed two sloped rumps together, or two humped rumps, the result would be to exaggerate and intensify or strengthen this deformity in the offspring. So of quality or disposition. A nervous cow bred to a nervous or irritable bull, would be pretty sure to drop a calf that would be more nervous than either sire or dam. But if one of the parents is dull and sluggish and the other irritable and sensitive, the offspring might be an improvement on both. Again, a cow lacking in the quality of richness of milk, though giving a large flow, should not be coupled with a bull descended from a family having the same peculiarity of large flow lacking in richness. But if there is richness on one side and abundance on the other, the coupling of the two might reasonably be expected to result in improvement in the offspring, which might inherit both the large flow and the rich quality. Bad points and qualities are inherited as well as good ones. Hence, the constant aim and care must be to avoid developing what is objectionable as well as to develop what is desired. It must be constantly borne in mind that like begets like. All the trouble attending inbreeding, crossing or grading comes from not properly regarding this fact. Where inbreeding is followed, the only disadvantage arises from the fact that all the animals are likely to have the same defects of form, quality and constitution. But where these are all right, the advantage is that inbreeding fixes the features and qualities and secures the establishment of them in a type or breed. But crossing or grading animals having the same failing will prove just as disastrous as would inbreeding.