Intersexuality in Adult Brown Leghorn Male as a Result of Estrogenic Treatment During Early Embryonie Life. ∗

Abstract

Since the publication of Lillie's 1 work on the free-martin many investigators have attempted to duplicate this condition in birds by transplanting gonads of either sex onto the chorio-allantoic membrane. While these early attempts were probably invariably negative it is now known that early application of the chemically prepared sex hormones will cause varying modifications in development of the embryonic reproductive system of birds as well as other forms. 1-8

The present study records post-embryonic transformations in embryos that had been treated with estrogens prior to the period of sexual differentiation. Brown Leghorn eggs received single injections between the 3rd and 5th days of incubation and the treated embryos were allowed to hatch and mature. The estrogens used were progynon-B (1500 to 3000 R.U.) and theelin (0.5 to 1 mg). The quantity administered per injection was .05 or 0.5 cc. A total of 410 eggs were treated in this set of experiments of which 69 hatched. Of this number 51 (24 and 27) developed beyond the period of sexual differentiation and form the basis of this study.

The males of this experiment reveal an interesting sexual transformation. The sexes could invariably be distinguished at the period of sexual differentiation. Some males appeared quite normal at this time while in others feminizing effects were evident in the plumage, but in none of these cases did a complete henny plumage appear before the end of the first year though this has occurred in recent experiments. However, following the first molt many of them developed a henny plumage while others developed the plumage prevalent preceding the molt.† Head furnishings were invariably masculine though in some they became strikingly feminine during the molting period and remained so for a time, then again became masculine.