io6 MENDELISM CHAP. 



passed for unpigmented birds, for with the exception 

 of an occasional fleck of pigment their skin, comb, 



and wattles were as clear 

 Silky Brown Leghorn 



x * as in the Brown Leghorn 



(PL V., i and 4). Dissec- 



r ~~\ tion revealed the presence 



1 of a slight amount of 



-i 1 1 internal pigment. Such 



i d <S f ? ? 9'--F 2 birds bred together gave 



FlG - I9 ' some offspring with the 



Scheme illustrating the result of crossing a 



Silky hen with a Brown Leghorn cock, full pigmentation of the 

 Black sex signs denote deeply pigmented 



birds, and light sex signs those without pig- Silky, SOme Without any 

 mentation. The light signs with a black dot 



in the centre denote birds with a small pigment, and Others shoW- 

 amount of pigment. 



mg different degrees of 



pigment. None of the F 2 male birds, however, showed 

 the full deep pigmentation of the Silky. 



When, however, the cross was made the other way, 

 viz. Brown Leghorn hen X Silky cock, the result was 



different. While the 



Brown Leghorn Silky-. 

 FI male birds were o x J 



almost destitute of 



pigment as in the p x 3* F 



previous cross, the 



F! hens, on the other , , , , L, , , , 



hand, were nearly rf rf <$ d" ? -.? 9"- p * 



as deeply pigmented FlG - 20 - 



, r"ii Scheme illustrating the result of crossing a Brown Leg- 



aS the pure Silky horn hen with a Silky cock (cf. Fig. 19). 



