1 88 THE BEGINNER IN POULTRY 



exceptional care is taken. The Cornell professors say, 

 in a Bulletin on Breeding for Constitutional Vigor: 

 " Close breeding can be followed with success only when 

 the first consideration is given to mating strong individ- 

 uals." A. S. Galbraith, the English poultry expert, 

 arguing for inbreeding, even to produce heavy egg 

 production, tells of an experiment of his own. Only 

 eggs from the best layers were set. Every hen laying 

 even one infertile egg during the laying season was re- 

 jected ; also, every one which had ever been ailing, though 

 but for a few hours. Not one exception was allowed. 

 I emphasize this, because the tendency of Beginners, 

 and of most breeders, one may admit, is to allow excep- 

 tions that spoil the work attempted, usually because the 

 exceptions are well up in fancy points. 



" Prepotency," the capacity of any parent to transmit 

 his qualities to his progeny (more than his share, the 

 dictionaries say), varies in different birds. It may be 

 intensified by inbreeding. Professor Pierce states the 

 danger thus : "Persistent, close inbreeding, such as the 

 mating of brother and sister for several generations, 

 often results in impaired fecundity, loss of size, and 

 decrease in constitution and vigor." Poultrymen call 

 such repetition of inbreeding " in-and-inbreeding." 

 The closest form is the mating of brother to sister, as they 

 have the same full parentage. Three lines of the same 

 blood may be started and carried by a line breeder : one 

 by mating brother to sister ; one by mating father to 

 daughter ; a third by mating mother with son. The 

 progeny are then bred together, to suit the theories and 

 plans of the breeder. Many years ago, Mr. I. K. Felch 

 published a chart, showing how the three lines of related 



