Studies on the relation of gonadic structure to plumage characterisation in the domestic fowl.—I. Henny-feathering in an ovariotomised hen with active testis grafts

Abstract

Into a Brown Leghorn hen, ovariotomized when 4 days old, the testes of a brother were implanted. The bird first assumed the plumage characterization of the cock, but after a general moult her plumage became as that of a hen. Post-mortem examination revealed a small fragment of degenerate ovarian tissue left behind at the time of operation, an active right gonad of testicular structure, and abundant testicular tissue which had developed from the grafts. The situation is discussed and reasons given for holding the opinion that ovarian and testicular tissues in respect of their own individuation exert demands upon the general economy of the same kind, but different in degree; that the functioning of an ovary is physiologically more expensive than is that of the testes; and that it is possible to augment the demands of the testes until they become equivalent to the ovary. It is suggested that this hen became cocky-feathered because in her body at this time there was active testicular tissue, and that she later became henny-feathered because the amount of testicular tissue had become greatly increased and had exerted demands upon the body equivalent to those of an active ovary.