1 6o Gene H and Testosterone in the Fowl 



The experimental form used for this study was the Sebright bantam. This 

 is a small breed established about the year 1800 by Sir John Sebright, who 

 combined the color of a crested Polish, the size of a bantam, and the henny 

 plumage of another fowl in the "laced bantam" which later came to bear his 

 name.* The breed in its "golden" and "silver" phases was apparently soon 

 perfected and has remained practically unchanged for many years. Colored 

 illustrations done by Harrison Weir about 1870 show Sebrights that would be 

 favorably rated today. Because of its distinctive traits, stabilized genetics, and 

 small size, the Sebright has become a favorite with experimenters. 



A certain amount of lore concerning the control of differences between male 

 and female plumage dates back to the nineteenth century, but it was not until 

 well into the present century that the subject became a matter for active, 

 critical experiment and analysis. Work in this field is well summarized by 

 Pezard, Sand and Caridroit,° by Greenwood and Blyth," and by Domm.' 

 Briefly stated, it has been found that in the brown Leghorn and other hh 

 breeds presence of the testes or injected male hormones has little influence 

 on the plumage, but functional ovaries or circulating estrogens have a feminiz- 

 ing effect on developing feathers of either sex. These findings, which have 

 been verified on many breeds, might have been considered of general applica- 

 tion to all fowls had it not been for the atypical reaction characteristic of the 

 Sebright. 



Soon after Goodale^ had demonstrated the effect of ovariectomy in the 

 brown Leghorn it occurred to Professor T. H. Morgan that the Sebright testis 

 might produce a certain ainount of female hormone and thus account for the 

 henny plumage. His experiments"' ^"'^ showed that removal of the testis did 

 in fact lead to the production of cocky plumage in the hitherto hen-feathered 

 male. So-called luteal cells were tentatively identified in the Sebright testis 

 and for a time it seemed that the explanation had been found for henny 

 plumage, not only in the Sebright bantam but in wild species in which the 

 sexes are similar. This view was not long sustained. Nonidez^" showed that 

 the "luteal cells" were not gland cells; Roxas" demonstrated by exchange 



* The account of the synthesis of this breed is repeated in many of the older books on 

 poultry. Sir Thomas Sebright's report, which is quoted by Dr. Horner in Tegetmeier"s volume, 

 is apparently authentic and also cjuite plausible genetically. The statement in the Encyclo- 

 pedia Americana^ (1941 ed., vol. 3, p. 215), that "the golden and silver Sebright bantams origi- 

 nated in America," is apparently entirely withoiu foundation. We may also discount the 

 interesting notion of the Rev. Mr. Dixon^ (1848) who linked in some mysterious way the 

 sprightly virtues of the diminutive fowls with those of the dainty human inhabitants of 

 Bantam, Java. Some French writers have implied that bantams originated in England, but 

 the "grigs" of seventeenth century England were not the original dwarf fowls. Plin) is one 

 early writer who makes no attempt to trace them to some remote source, contenting himself 

 with: "Est et pumilionum genus non sterile in his, quod non in alio genere alitum, sed 

 quibus certa fecunditas rara, et incubatio ovis noxia." {Nat. Hist. X:77.) Probably dwarf 

 specimens have appeared from time to time in many large breeds, but with genes for nannism 

 once in their armamentarium it has been easy for breeders to produce bantam forms at will. 

 In the 1941 exhibit at the California State Fair a trio of "Black Minorca Bantams" deemed 

 worthy of a premium were said by their exhibitor to have had a full-sized black Minorca 

 grandparent. 



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