Page:The Evolution of British Cattle.djvu/150

 have called them; and that when the originally selected type had been steadied or fixed by inbreeding, the breed as a whole was gradually graded up to their standard by persistent mating with the selected type.

Within the above question lies another much smaller to a breed but larger to many an individual breeder: Is it possible for a second class herd to be raised to the first class without recourse to the assistance of first class stock? Again the answer must be the same: that it may be done; but in how many years, or in how many lifetimes? Few, if any, of our first class herds have been raised in this way. Some may have been raised by continued infusion of the highest into lower types—by grading, as it is called—but most of our great stock-breeders date their entry into the highest ranks from the time they acquired the highest class of stock and commenced to eliminate the lower.

Among stock-breeders generally there is a very strong aversion to in-breeding, although it was the method of the great pioneers and is still the method in a modified form, called line breeding, among breeders of the highest class. The origin of this aversion would be difficult to trace, although it has been frequently suggested to have been biblical. It existed in Bakewell's day and how long before we do not know; but if it existed in much earlier days it is difficult