No. 627] GERM PLASM OF TIIK (>>Tlll( II 



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it with another most closely resemhliiia' it. U\\ juTliaits 

 lacking or surpassing in one or more ]i()iiit> : aiiotln'r -ca- 

 son he may resort to a different niatiiiu' to xm uic other 

 features. From different breeding sets he may rear two 

 or three hundred chicks in a season. The iu ooimin hi iug 

 mostly intermediates and showing much \aiiation he 

 selects when mature the most desirable aiiioii.i;- them as 

 breeders, or maybe, being weak in some particular i)oiiit, 

 he w^ill purchase or exchange with auothcr l)rci"(l('r in 

 whose birds the character is strong. 15y this method, 

 essentially one of hyl>ri(iizatiou, the ideal phiuie is being 

 slowly built up. Soiiiotinios by a fortunate mating one 

 breeder will be ahead and sometimes another, a success- 

 ful competitor at a Feather Show being immdated with 

 orders for breeding birds and eliieks and his fortune well 

 assured. Despite the variability in the progeny no 

 breeder can afford to ^'fix" his strain by a measure of 

 inbreeding, lest while doing this another may get ahead. 

 Taking all the economic and biological circumstances 

 into account the geneticist has little he can contribute to 

 such a i)ractical effort; he can but assist by endeavoring 



