MENDELIAN INHERITANCE OF FECUNDITY IN 

 THE DOMESTIC FOWL, AND AVERAGE 

 FLOCK PRODUCTION 1 



Dr. RAYMOND PEARL 



In 1912 I showed, 2 from extensive experimental data 

 that, in certain breeds of domestic poultry, winter egg 

 producing ability is inherited in a strictly Mendelian 

 manner. It was pointed out that there was much evidence 

 indicating that winter production was, on the whole, a 

 rather reliable index of total fecundity capacity. As was 

 to be expected, the novelty of the results presented in the 

 papers referred to led to their criticism from various 

 points of view, including that of the practical poultryman. 

 Most of these criticisms have been based upon some mis- 

 understanding of the nature of the results themselves. 

 Others, and particularly those of the poultry press, have 

 apparently been based on a purely conservative instinct 

 to resist the intrusion of any new idea which seems to 

 threaten those solid personal and editorial assets of (re- 

 puted) infallibility and "safe and sane" judgment. 



It has seemed to the writer more likely to conduce to 

 the advancement of knowledge in this field if he went 

 steadily about collecting more and more concrete objec- 

 tive evidence rather than engaging in polemic disputa- 

 tions with everyone whose opinion in regard to the valid- 

 ity or interpretation of the earlier results chanced to 

 differ from his own. As a result of this policy there has 

 accumulated a large mass of additional experimental data 

 confirming and extending the results of the earlier work. 



1 Papers from the Biological Laboratory of the Maine Agricultural Ex- 

 periment Station, No. 81. 



2 Pearl, R., "The Mode of Inheritance of Fecundity in the Domestic 

 Fowl," Jour. Exper. Zool, Vol. 13, pp. 153-268, 1912. Cf. also "The Men- 

 delian Inheritance of Fecundity in the Domestic Fowl," Amer. Nat., Vol. 

 XLVI, pp. 697-711, 1912. 



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