Influence of Thyroid Preparations on the Plumage of Birds

Abstract

IN an earlier communication¹ we described experiments on the supposed influence of the thyroid hormone on the moulting mechanism of feathers in aquatic birds which manifested very striking resistance to thyroid feeding and to the injection of thallium acetate. After controlling the thyroid preparations which produced the shedding of feathers in hens and caused metamorphosis in tadpoles, the thyroid glands of ducks and geese have been examined. The great difference observed between them and the thyroid gland of the chicken was found to be due chiefly to different anatomical structure and to tremendous development of the corpuscula epibranchialia (corpuscula epithelialia or parathyreoidea of other authors) in ducks and geese.