306 MAINE AGRICULTURAI, IjXPERIMENT STATION. I912. 



may, however, be either homozygotic or heterozygotic in respect- 

 to Li, it not being a sex-limited character, and hence not in any 

 way coupled with or repelled by the factor F. That the female 

 fowl is heterozygotic in respect to the sex factor was suggested 

 by Spillman (50, 51) and has been demonstrated by the experi- 

 mental studies of Bateson (3), Goodale (12, 13), Hagedoorn 

 (14), Sturtevant (51) and Pearl and Surface (40, 41). 



Tables 5 to 8 inclusive show the constitution in respect to fe- 

 cundity of males and females of the breeds used in this work, 

 as indicated by the results obtained from breeding experiments. 

 These constitutions represent the 'Erbformeln which flow from 

 the facts, and, in determination of their adequacy, are to be 

 tested against the facts, hi these tables the columns headed 

 'Gametes produced' have been made up in accord with the gen- 

 eral Mendelian principle that in gametogenesis all possible com- 



TABLE 5 

 Constitution of Barred Plymouth Rock males in respect to fecundity 



Class 



Zygote 



Gametes Produced 



1 

 2 

 3 

 4 

 5 

 6 

 7 

 8 

 9 



fLiU . fLiU 

 fLiU . fLih 

 fLiLi . fhU, 

 fLiU . fhh 

 fLih . fLih 

 fLih . fhh 



fhL2 . fhL2 



fhLi . fhh 

 fhh .fhh 



fLiL2 



fLiLiJLih 



fLiL2, fliL2 



fLiL2, fLih, fhLiJhh 



fLih 



fLih, fhh 



fhL2 



fhUJhh 



fhh 



■ _ TABLE 6 



Constitution of Barred Plymouth Rock females in respect to fecundity 



Class 



Zygote 



/-Bearing 



(c? Producing) 

 Gametes 



Probable Winter Egg 

 F-Bearing | Production of 9 .of 

 (9 Producing) Indicated Zygotic 



Gametes ' Constitution 



fLiL2 



fLiLi 



fLih 



fLih 



fhh 



Fhh 



FLih 



Fhh 



FLih 



Fhh 



f hL2 . Fhh 



fLiL2, fhLi' 



fLiL2 



fLih, fhh 



fLih 



fhh 



fhLi 



Fhh. FLih 



FLih 



Fhh. FLih 



FLih 



Fhh 



Fhh 



Over 30 eggs 

 Over 30 eggs 

 Under 30 eggs 

 Under 30 eggs 

 Zero eggs 

 Under 30 eggs 



■^ The reason that gametes of the type fLih and fhh are not formed here will be evident 

 on consideration. Since no gametes of type FL2 can, by hypothesis, be formed this im- 

 plies that an interchange of the factors L2 and h between F and / gametes cannpt occur. 

 The experimental proof of the truth of this conviction has been furnished in the case of 

 the inheritance of the barred color pattern. 



