THE 



AMERICAN NATURALIST 



Vol. XLVI December, 1912 No. 552 



THE MENDELIAN INHERITANCE OF FECUND- 

 ITY IN THE DOMESTIC FOWL 1 



DR. RAYMOND PEARL 

 Maine Agricultural Experiment Station 



The investigation here reported was concerned with 

 the detailed analysis and interpretation of a rather ex- 

 tensive series of data regarding the inheritance of fe- 

 cundity in the domestic fowl. The basic data are derived 

 from trap-nest records extending over a period of years. 

 They include records from (a) pure Barred Plymouth 

 Rocks; (b) Cornish Indian Games; (c) the F, individ- 

 uals obtained by reciprocally crossing these two breeds ; 

 and (d) the F 2 individuals obtained by mating the Fj's 

 inter se and back upon the parent forms in all possible 

 combinations. The fully-pedigreed material made use of 

 in the present connection includes something over a 

 thousand adult females, each of which was trap-nested 

 for at least one year, and many for a longer period. This 

 material covers four generations. The birds of the 

 fifth generation have just completed their winter records 

 at the time of writing. Besides this fully pedigreed ma- 

 terial, the collection and study of which has occupied 



1 At the request of the editor of the American Naturalist the M]o ^ 



by the writer has been prepared. A detailed account has been published 

 in the Journal of Experimental Zoology, Vol. 33, No. 2, pp. 153-268, 

 August, 1912. 



r,97 



