INHERITANCE OF FECUNDITY 



177 



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

 eral Mendehan principle that in gametogenesis all possible com- 

 binations of the factors present will be formed, within the bounds 

 of any limitation which may be imposed by such phenomena as 

 coupling, repulsion or linkage. The limitation of these possibili- 

 ties in the present instance has been set forth above : it consists 

 simply in the fact that F and Lo are never borne in the same 

 gamete. It should be said that these tables do not show at all the 

 proportions in which the several gametic types might, be expected 



TABLE 5 

 Constitution of Barred Plymouth Rock males in respect to fecundity 



TABLE 6 



Constitution of Barred Plymouth Rock females in respect to fecundity 



fLiU 

 fUU 

 fUh 

 fLih 

 f hh 

 f hU 



Fhh 



FLih 



Fhh 



FLih 



Fhh 



Fhh 



/-BEARING 



id' J'Roducing) 



GAMETES 



/Z/1L2, fhLi 

 /L1L2 



fLih, fhh 

 fLih 

 f hh 

 fhL, 



f-bearing 

 ( 9 proddcing) 



GAMETES 



Fhh, FLih 



FLih 



Fhh, FLih 



FLih 



Fhh 



Fhh 



j PROBABLE WINTER EGG 

 j PRODUCTION OF 9 OP 

 I INDICATED ZYGOTIC 

 CONSTITUTION 



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 FLz can, by hypothesis, be 

 formed this implies that an interchange of the factors Lz and h between F and / 

 gametes cannot occur. The experimental proof of the truth of this conviction 

 has been furnished in the case of the inheritance of the barred color pattern. 



