490 NEWS AND NOTES LATE FEATHERING CLOSELY LINKED WITH COLUMBIAN COLOR IN CHICKENS

During recent studies with Columbian colored chickens (Jaap, 1955) it become evident that the sex-linked early feather-ing gene (k+) was much less frequent than expected. Three breed strains (the Dela-ware, the Columbian New Hampshire and the Columbian Cornish) were descendents from crosses between silver-colored late-feathering (SK) and gold-colored early-feathering (s+k+) breeds. According to previous linkage studies (Punnett, 1940) each of these stocks should have had a k+ (early feathering) frequency of approxi-mately 10 percent. By classification of fe-male chicks of these strains, as well as chicks from columbian-colored males crossed with early feathering females, the frequency of early feathering in these columbian-colored strains appeared to be about one percent. To further test whether 5 and K were more closely linked than observed in pre-vious reports (Punnett, 1940), the follow-ing mating was made. Five heterozygous Columbian males from a Delaware X New Hampshire cross were mated with 53 gold-colored early feathering (New Hampshire) females. The 1,596 chicks hatched in eight consecutive hatches were distributed as follows