INHERITANCE OF FECUNDITY 235 



This bird was mated with barred Fi 9 9 which had been pro- 

 duced by the following mating. 



B.P.R. o^ 559 ifhL, . fhU) X C.I.G. 9 9 of tjT^e fUU • ^^^^2 



i 



A. fliL-2 . i^Li^2-Winter record over 30 



and 



B. //1L2 . FliU -Winter record under 30 



Male 576 was mated only with 9 9 of the A class, 1* namely 

 those having a gametic constitution JhL-i . FL^k, and producing 

 two sorts of F-bearing gametes, Flik and FL^U. 



This same & 576 was mated with non-barred (black) Fi females 

 which had been produced in the following way. 



B.P.R. 99 some of which 



C.I.G. d^ 558 ] 



or \ X 



529 {JUU . fUU) J 



were of type fLJj^ . FkU, 

 and some /Z]?2 • FLikihoth 

 producing /^-bearing gam- 



I etes of two kinds FLik 



L and Fkk) 



A. fLiU . FLik, Winter record under 30 



B. flik . FLik, Winter record under 30 



C. fLik . Flik, Winter record under 30 



D. flik . FLik, Winter record zero. 



The three non-barred 9 9 with which cf 576 was bred were of 

 the B-C type, producing two kinds of F^bearing gametes, FLiU 

 and Flilo. They were thus identical, so far as concerns F-bearing 

 gametes with the barred Fi birds with which cf 576 was mated. 

 All the progeny may then be treated together since all did, as a 

 matter of fact, lead to the same result, having regard to the errors 

 of sampling in such statistically small lots. 



'* It would of course be desirable to have data from the other mating, cf 576 X 

 B 9 9 . If one could have foreseen what the mechanism of the inheritance of 

 fecundity was going to turn out to be, such matings would have been made. Actu- 

 ally these cross bred birds were being studied primarily with reference to color 

 characters, and the matings were made relative to that line of investigation. 

 Naturally highly fecund females would be chosen as breeders whenever possible, in 

 order to get more chickens for the color studies. Actually, however, all of the 

 possible gametic combinations in respect to fecundity were tested in Fa either from 

 one mating or another. 



