210 



RAYMOND PEARL 



No closer agreement between observation and expectation 

 than is here shown could be expected. The results of the matings 

 discussed in this section confirm completely the general conclu- 

 sions reached above from an examination of the matings of class 

 7 males. 



Matings of Barred Plymouth Rock males of class 3. 



Males of this class have a gametic constitution /LiLo . fhLi. 

 That is, they are homozygous with respect to the second, or ex- 

 cess, production factor, and heterozygous with respect to the first. 

 Two males of this type were used in the experiments. 



B.P.R. cf 65. Indicated constitution = fL^Li . fUL-i. 



This male was purchased in 1908 from^ Mr. Wesley B. Barton, 

 Dalton, Mass. Nothing is known of his breeding so far as con- 

 cerns fecundity, but in all probability no particular effort towards 

 breeding for high egg productiveness had ever been made in the 

 stock from which he came. He was bred as a cockerel in the 

 season of 1908 with the results set forth below. 



Matings: A. With 1 9 indicated to be of class 1 = /LiLo . FliU. 



9 Progeny 



Winter Production: Over 30 Under 30 



Observed 7 1 



Expected 6.75 2.25 



Mean winter production of all 



9 9 in indicated class 53.00 eggs 19.00 eggs 



B. Withl 9 indicated to be of class 6 = /ZiLo . FUi. 



9 Progeny 



Winter Production: Over 30 Under 30 



Observed 2 3 



Expected 2.5 2.5 



Mean winter production of all 



9 9 in indicated class 37.00 eggs 18.67 eggs 



All 9 Progeny 



Winter Production: Over 30 Under 30 



Observed 9 4 



Expected 9.25 J^.75 



Mean winter production 49.44 eggs 18.75 eggs 



Zero 



1 







eggs 



Zero 











Zero 



1 







eggs 



