32 



The Journal of Heredity 



color of the feathers on the back. This 

 black occasionally "shows through" on 

 the surface and is often found to be 

 arranged in an imperfectly pencilled 

 or mossy pattern. 



Summary and Conclusions 



The buff and Columbian colorations 

 of fowls differ in one principal gene 

 determining the presence or absence of 

 buff in the plumage and probably 

 in multiple factors determining the 

 amount of black developed in wing, 

 tail, and hackle feathers. 



Buff and Columbian differ from 

 black by a gene determining the re- 

 striction of black to hackle, tail, and 

 wing. Its dominant allelomorph, 

 which is present in self black, deter- 

 mines the extension of black to all 

 parts of the plumage. 



Black fowls are genetically buffs 

 with the extension factor superposed. 

 When the gene for silver is present in 

 a black or "extended" fowl it "shows 

 through" in a pattern determined pos- 

 sibly in part by the residual heredity 



of the black, or by pattern factors con- 

 tributed by another variety. The ap- 

 pearance of fowls which have both 

 extension and silver make it seem 

 probable the the Dark Brahma variety 

 will be found to be of the genotvpe 

 £■"£"^55. 



Although in the present types, 

 black and Columbian, the plumage is 

 alike in both sexes, in the first and 

 later generations sexual dimorphism 

 appeared in the dark (extended) fowls. 

 This may possibly be traced to a re- 

 combination of pattern and extension 

 factors, which reacts to the sexual hor- 

 mones in a manner different from 

 either parental combination. 



The origin of the three colorations 

 considered is not certainly known. 

 Genetic and historical evidence indi- 

 cates that the buff and Columbian col- 

 orations may have diverged by a sin- 

 gle gene mutation. Extended black 

 varieties probably antedate the re- 

 stricted types, and it is probable that 

 the latter arose from the former by a 

 mutation in the extension factor. 



Table I. Crosses of Buff and CoIiDiibian Fou'ls. 



Down Colors 

 of Chicks 

 Parents Buff Columbian 



Buff $ X Columbian $ 37 



Fi Columbian $ X Buff $ 34 36 



BC Buff 9 X BC Buff S 83 



Columbian 9 X Buff 5 14 i3 



Buff 9 X Fi Columbian 10 13 



Table II. Crosses of Black and Columbian Fowls. 



Down Colors ,- Adult Colors and Sex ^ 



of Chicks , Extended Black — ■ , Restricted Black 



Parents Colum- Duckwing^ Black Birchen 9 Columbian Buff 



Black bian Buff white buff 9 white buff 6 9 S 9 



Black 9 X Columbian $ ... U ■■ ■■ 2 



Fi 9^ X Columbian $ 2 2 



Fi 9a X Buff i 7 2 6 I 2 



Fi 6 X Columbian 9 40 33 6 4 .. .. 3 3 7 5 •■ 4 



Fi S X Buff 9 19 12 10 2 2 .. 2 2 I 2 5 2 



Columbian 9 X Black ^...15 .. .. 3 •• 6 



Fi Black 9 S Columbian ^15 14 .. 5 .. .. 3 



F. Black 9 X Buff S 16 .. 13 .. 4 •• •■ 3 •■ •■ 2 r 



XoTE — The classes "white" and "buff," under Duckwing males and Birchen females, 

 refer to the color of the markings on necks, hackles, and wings. 



