HYGIENE OF BEEEDING 883 



great certainty to reproduce their like, the same cannot 

 be said of animals which have not the advantage of this 

 long and careful breeding. 



This explains why representatives of a newly-formed 

 breed, or ' chance ' animals, however good in themselves, 

 so frequently fail to reproduce their type. They are quite 

 likely to throw back to some ancestor of quite a different 

 type. Provided that the breed has not become efifete, it 

 may be taken as a rule that the longer and more carefully 

 any class of animal has been bred, the greater will be its 

 prepotency or certainty to reproduce its type, so that pedigree 

 is a most important point for consideration in the selection 

 of breeding-stock. 



The second reservation we would make is that it is never 

 safe to mate animals of widely different types in the hope 

 of striking the happy medium between the two parents in 

 the offspring. It is much more probable that the result 

 will be a bad representative of one type or the other, or a 

 throw-back to a remote ancestor of one of the parents of 

 quite a different type to either. If it is desired to modify 

 an existing type the process must be a gradual one, so that 

 the alteration becomes stamped on the stock as the change 

 takes place by slow degrees. 



It follows from the above that the breeder should only 

 select his stock from well-bred animals of long pedigree, 

 and should aim at close uniformity in type. Any marked 

 variation from the desired type should be rigidly rejected, 

 however excellent in other respects, otherwise annoying 

 variations will be liable to crop up at any time and destroy 

 the reputation of the stock for their true-breeding qualities. 



These last remarks apply more particularly to breeding 

 from representatives of well-established breeds. 



If, on the other hand, the breeder aims at producing 

 an entirely new breed from selected animals of various 

 breeds, he will require to resort to inbreeding to counteract 

 this tendency to uncertainty. 



By inbreeding is meant the mating of closely related 

 animals of the desired type, a sire not infrequently being 



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