ACTION OF TESTOSTERONE ON THE ESTRADIOL-INDUCED FEMINIZATION OF THE MALE CHICK-EMBRYO

The early treatment of male chick embryos with estradiol induces the f eminization of their sex tract, i.e. both their gonads and Mullerian t ract exhibit female features. The additional treatment of estrogenized male embryos with testosterone propionate antagonizes the effects of estradiol on both gonads and Mullerian ducts. Our data give further su pport to the view that testosterone and estrogens act respectively as agonist and antagonist modulators of the secretion of the anti-Mulleri an hormone.