94 THE AMERICAN BREEDS OF POULTRY 



"more barred" than the female. It is easy to observe this difference 

 in ordinary farm-bred Plymouth Rock chicks that are two months 

 old. The pullets, on first notice, appear darker than their brothers, 

 and close inspection reveals the fact that the white bar in the cockerels 

 in much cleaner, much purer, and the black bar much sharper than 

 in the pullets, whose black bar runs into the white and whose white 

 bar is not a clean-cut white." When these males mature they are of 

 a lighter color than the pullets,. 



If a farmer does not know this natural tendency in the Barred 

 Rocks, he may buy a male as dark as his females and mate them 

 together; but if he is informed, he does not commit this blunder; 

 he accepts a male of lighter color if he desires to produce Standard 

 colored, clear, beautiful colored females; and he knows that if he is 

 to produce males that will be dark enough to match those Standard 

 colored females, he must have another pen and breed them from still 

 darker females. He therefore has two matings. 



Double mating. Double mating sounds formidable and intricate, 

 and while it is complex in theory, it is in practice the simpler kind 

 of mating. If you are to produce the highest type of male and the 

 highest type of female from the same pair, you must strike and 

 hold a balance like a boy on a teter-totter from whose center extend 

 the end of the plank in both directions. 



In double mating you mate a pen to produce pullets. This pen 

 contains females of Standard color to which you mate a male whose 

 dam was a fine female and whose sisters are fine females. It is 

 relatively easy to produce good pullets from such a pen. 



For cockerel breeding you use a male of Standard quality mated 

 to females whose sire was a good male and whose brothers are good 

 males. The pullets from such a pen are not expected to equal the 

 pullets from the pullet mating, but will prove to be good cockerel 

 breeders, and they are recognized and sold as "cockerel breeders" or 

 "cockerel breeding females." The males from the pullet mating are 

 pullet breeders, not that they will produce more pullets than cock- 

 erels, but because they will breed better pullets than cockerels. 



It is more difficult to produce good males and females from one 

 mating than it is to produce only good males or only good females 

 from a single mating. It is doubtful if the highest type specimens 

 of both sexes ever can be produced by the same pair in any kind of 

 livestock. Where a sex-limited factor enters in, as in the inheritance 

 of barring in the Barred Rock, the difficulty is beyond immediate 

 solution. 



To show what appears to be a natural tendency of lines to run to 

 males or females, the case may be cited of a breeder of a buff variety. 

 Here both the male and female are buff and there is not that pro- 

 nounced diversity of color type that one sees in the male and female 

 of many particolored varieties. 



It might appear that buff color could be single mated, that is, 



