INTRODUCTIONTHE desirability of establishing the sex-linked recessive gene for early feathering in all commercial strains of chickens is indicated by the increased protection from chilling and reduced feather picking and cannibalism which result. Of particular interest to broiler producers is the better dressed appearance of birds possessing this gene (Plumart and Mueller, 1954). Warren (1925 Warren (1944) and Mueller et al. (1952) described methods to classify early and late feathering chicks in two distinct groups. A method of phenotypic differentiation between homozygous and heterozygous late feathering genotypes would be desirable as it would eliminate the need of progeny tests. Phenotypic identification of genotype would be possible if the late feathering gene were incompletely dominant to its allele. This study was designed to provide information on the phenotypic expression of the sex-linked late feathering gene in homozygous, heterozygous, and hemizygous chicks.METHODS AND MATERIALSThe stock used consisted of Rhode Island …