116 POULTRY PRODUCTION 



tinued selection of highly fecund dams does not alter in any 

 way the mean egg production of the ihiughters; {h) the pro- 

 portion of highly fecund daughters is the same whether 

 tlie dam is of high or low fecundity, provided botli are mated 

 to the same male; (c) the daughters of a highly fecund dam 

 may show either high fecundity or low fecundity, depending 

 upon their sire; (d) the proportion of daughters of low fecun- 

 dity is the same whether the dam is of low or high fecundity, 

 provided both are mated to the same male." 



Cidodale,^ who worked with ithode Island Reds, secured 

 results which do not ai)i)ear to agree with Pearl's, in that 

 he found quite a marked correlation between the production 

 of pullets and the production of their dams. The daughters 

 of high producing hens wQxe, on the average, better producers 

 than the daughters of low producing hens mated to the 

 same male. It may be that egg production, or certain factors 

 which affect egg production markedly, are inherited dif- 

 ferently in the lihode Island Ued breed than in the liarred 

 Plymouth Pock. 



From the standpoint of the practical producer, it might 

 ])ro\'e fortunate if the transmission of high p^oducti^•e 

 powers were contineil to the male. Selection for high produc- 

 tion, further than is made possible through culling, is out of 

 the reach of the mass of ])roducers because it in\'olves pedigree 

 breeding, wliich, as pointed out elsewhere, is not practicable 

 on tlic general farm. The purchase of cockerels from high 

 producing families, however, is practicable. ^Vhatever the 

 exact mode of transmission of high production may finally 

 ])rove to be, it may be introduced into a flock of poor layers 

 through the use of males from high laying families of the 

 Barred PlAinouth Pock and Single T'omb ^Vhite Leghorn 

 breeds, as shown by Pippincott.- 



As shown by Goodale,' it is not possible on the basis of 

 l)rescnt knowledge to devise a set of detailefl instructions 

 that could be followed by a poultryman of ordinarN' intelli- 

 gence which would enalile him to proceed step by step in the 



1 Jour. Am. Assn. Inst, and Invent, in Poul. Husb., vol. v, No. \0 



2 Kansas Bulletin No. 223. 'Loo. cit. 



