Demonstration of the appearance after castration of cock-feathering in a hen-feathered cockerel

Abstract

In the Seabright race of fowls the male is hen-feathered, i. e., the feathers on the back of the neck (the hackles) and those on the posterior portion of the back (the saddle) are short and less elongated, like those of the female. When the Seabright male or female is crossed to fowls of another race in which the male has the characteristic male-feathering, the F₁ males are hen-feathered, or at least the dominance of hen-feathering is more or less complete. In the second generation there are three hen-feathered to one cock-feathered male.

It has been shown by Goodale that removal of the ovary of the hen or of the duck leads to the development of the malefeathering. I tried to discover whether the removal of the testes in the hen-feathered males would cause them to develop the hackles and saddle feathers of ordinary cocks. My first operations were unsuccessful, owing to failure to completely remove the testis. This autumn Dr. H. D. Goodale performed the operation for me on F₂ hen-feathered birds that I had reared. At the time of operation some of the saddle feathers were removed. The new feathers that appeared were like those on the ordinary cock bird; not only did they have the characteristic shape but were bright red also. The result leads to the apparently paradoxical conclusion that the removal of the testes of the hen-feathered cock caused him to develop certain characteristic feathers peculiar to the ordinary male.

The most probable interpretation of the effects of removal of the ovary of the hen (an operation that leads her to develop the male plumage) is that the ovary secretes some substance that holds in check the development of the male plumage.