XX.—Studies on Plumage in the Male Brown Leghorn Fowl

Abstract

In recent years intensive investigations on the plumage dimorphism characteristically developed in most breeds of domestic fowl have resulted in a great increase in our knowledge concerning the rôle of the endocrine glands, in particular the thyroid and sex organs, in relation to plumage differences. Since, however, the majority of these researches have been directed to the plumage exhibited by the adult bird, it is suggested that an analysis, both observational and experimental, of the earlier plumage phases shown successively from hatching to maturity might yield much valuable data concerning the nature of the hormonic stimuli involved.