POULTRY-CRAFT. 153 



by a male of another variety cannot be depended on to breed true. It is only 

 in rare instances that eggs laid ten days after contamination hatch chicks 

 which show in any way the influence of the foreign male. Few, perhaps 

 none, of the reported cases of the influence of a male of another breed 

 persisting for months or years, rest on indisputable evidence. The same 

 thing may be said of alleged cases of " mental impressions." 



212. Introducing New Blood. Inbreeding. It is commonly believed 

 by poultrymen that to maintain the vigor of a stock new blood must be 

 frequently introduced. Many go so far as to say that any inbreeding at all is 

 bad ; that it is from the outset the beginning of deterioration. If a man 

 inbreeds, and his stock is weak, the weakness is invariably attributed to 

 inbreeding. Most of the evils assigned to inbreeding are not due to 

 inbreeding, but to careless selection. There is no evidence that the breeding 

 of males and females of the nearest kin necessarily initiates degeneracy. 

 There is abundant evidence that with proper selection for stamina, and to 

 avoid common defects, very close inbreeding can be followed for a long time 

 without injuring the stock. There is also abundant evidence that breeding 

 unrelated fowls without careful attention to vigor, and avoidance of common 

 defects, is at once attended with precisely the same results as breeding fowls 

 of near kin under the same conditions. The prejudice (for it is nothing else) 

 against inbreeding, is one of the serious drawbacks to general improvement 

 of poultry. A breeder who does not confine his matings within narrow blood 

 lines slips back about as fast as he crawls forward. Nearly every new 

 breeder wastes a number of years trying to breed good stock without 

 inbreeding. Practical poultrymen will notably improve their stock by 

 inbreeding, then throw away results by bringing in new blood because of the 

 fear that they may carry inbreeding too far. In time nearly all breeders come 

 to admit that inbreeding is absolutely necessary (in breeding fancy fowls) in 

 color breeding, yet few can be found who do not think it unquestionably bad 

 for the practical breeder. As has already been said, there is not one law of 

 breeding for one class of breeders and another for another class. If 

 inbreeding is necessary to fix superiority in color, it is necessary to fix it in 

 shape ; if it is necessary to fix it in shape, it is necessary to fix superior laying 

 capacity or rapid growth, or vigor. Inbreeding is necessary hecause there 

 cannot be intelligent breeding without inbreeding. One who does not breed 

 within close lines cannot know his stock as far back as he must know it if it 

 is to be mated with reasonable assurance that the matings will produce the 

 desired results. To secure uniformity inbreeding is necessary, because the 

 number of inheritable differences must be kept as low as possible, and this 

 can only be done by close inbreeding. The vigor of a flock is sustained not 

 by regularly introducing new blood, but by selecting breeding birds for vigor. 

 Vigorous birds generally beget vigorous offspring ; weak birds weak offspring, 

 whether akin or not. 



