Studies in intersexuality.—II. Sex-reversal in the fowl

Abstract

Many instances of “hermaphroditism” and of the more or less complete assumption of the secondary sexual characters of the male by the old female bird, wild and domesticated, have been recorded, but in the great majority of such cases no accurate knowledge of the previous history of the individual has been available and each has been considered as an isolated case. It was thought that a study of these conditions as met with in the domestic fowl would be of genetic interest. In order to obtain specimens and information the poultry keepers of the country were circularised. It was found that:— (1) Rare cases of “hermaphroditism” have been encountered. A bird at the age of 4—6 months, instead of developing the distinctive male or female characters, grows slowly into a creature which is neither a pullet nor a cockerel and its characters remain indefinitely intermediate. (2) Rare cases are known of an otherwise perfectly normal laying hen with cocky plumage. In one such case, known to the present writer, the plumage following successive moults has been cocky—henny—cocky.