THE INHERITANCE OF FECUNDITY 



37* 



which carry the excess production factor L 2 are heterozygous in respect 

 to it. 



We have fecundity practically determined, then, by two physio- 

 logical factors, one of which is sex-correlated in its inheritance and the 

 ether not. 



Table II 



Showing Some Besults of Mating Together Barred Plymouth Bock Males and 

 Barred Plymouth Boclc Females of Different Fecundity Genotypes. 



Summarized Data 



The accordance between observed fact and theoretical expectation 

 on this interpretation of the results is shown in the following tables 



* The records of i refer to birds whose winter production record was exactly 

 30 eggs. Each one of the few birds of this sort is divided between the "Over 

 30" and the "Under 30" classes. 



