82 



INHERITANCE OF CHARACTERISTICS IN DOMESTIC FOWL. 



and that the whites and some of the Games are extracted types. This 

 conclusion is confirmed by further breeding. In pen 663 I bred 2 extracted 

 white hens of Cochin-Tosa origin to a white cock and got 12 chicks, of which 

 all were white, except that 3 showed a trace of reddish color. From the 

 extracted Games bred together I got 36 chicks, all Games. In the case of 

 this cross, consequently, barring is clearly heterozygous and confined to 

 the male sex.* 



(2) White Leghorn Bantam x Dark Brahma. — This cross was referred 

 to in my report of 1906. From the table given there it appears that I 

 got 5 barred fowl in F, out of a total of 51. In pen 701 I attempted to see 

 if I could fix this barring. I used the best barred cock of the Fj generation 

 and the best barred hens of Fj or Y^. The result was as shown in table 66. 



Table 66. — DistribiUion of color in F, or F, hybrids of the barred strain. 

 [Abbreviations: W.L. = White Leghorn; Dk.Br. = Dark Brahma.] 



♦Including 1 blue. 



flncluding 2 blue. 



This result suggests the interpretation that one of the parents, prob- 

 ably the male, contains both heterozygous black and barring, while the 

 other parent lacks the supermelanic coat and has homozygous barring. 

 Then of the offspring half will be barred and half will be black and, 

 consequently (since only the non-black show their barring), one-fourth 

 will appear barred, one-fourth will appear of the Dark Brahma type, 

 and half will be pure black or have the pattern obscured by the super- 

 melanic coat. 



(3) White Leghorn Bantam X Black Cochin. — In still another experiment 

 (pen 511) I crossed a White Leghorn bantam and a Black Cochin as described 

 in my report of 1906. Of 24 hybrids that developed, 10 were white or nearly 

 so, 7 were black, and 7 were barred black and white. The White Leghorn 

 was heterozygous in white (half of the offspring being not white) and hetero- 

 zygous to barring. In pen 650 the barred birds were mated together with 

 results as given in table 67. 



* Goodale, 1909, has shown that in Plymouth Rocks males may be and females usually are heterozygous in barring. 

 There is thus a clear difference between the barring of the Cochin XTosa hybrid and that of the Pljrmouth Rock. The 

 question of the heterozygous nature of the female sex, fully discussed by Goodale, will be considered by me in another place. 

 [Note at time of correcting proof.] 



