96 



MENDELISM 



eyed cinnamon forms corresponding to the various 

 green and yellow varieties. Cinnamon is recessive 

 and exhibits the same peculiar heredity. A point of 

 interest in connection with the Silky and Canary 

 cases is that in the course of the experimental work 

 occasional exceptions have been recorded to the 

 expectation demanded by the hypothesis. It is 



[9] Ffppli 



gives 



grametes 



Fpi j 



fpl 



ffppii [J J 

 gives 



gametes 



ffpi 



I fpi 



[rf]ffPPii [9] Ffppii 



ffppli [C?] FfPPii[fI 



gives 

 gametes 



fPi 

 fPi 



1} 



gives 

 gametes 



/Fpi 



\ fpi 



Sives 

 gametes 



gives 



gametes 



fpi 



fpi 



}^ ( 



FPi 

 fPp 



FfPpii 

 [?] 



ffPpii FfPpli FfPpii 

 [|f] [?] [?] 



ffPpIi ffPpii 

 [SI W] 



Fig. 



Scheme to illustrate the heterozygous nature of the pure Brown Leghorn hen. 

 For explanation see text.- 



possible that in the heterozygous hen the character 

 factor and the sex factor do not always repel 

 one another, but until more data are forthcoming 

 the nature of these rare exceptions must remain 

 undecided. 



Apart from birds, there is one other form in which 

 sex-limited inheritance of this particular type has 

 been recorded. In the common curiant moth {Abraxas 

 grossulariata) a paler variety {lacticolof) is known to 



