A CASE OF TRUE HERMAPHRODITISM IN THE FOWL 191 



DISCUSSION 



We desire now to review briefly some of the evidence on the 

 relation of the gonads to secondary sex characters with reference 

 particularly to partial or complete avian hermaphroditism. 



Cock-feathering in hens has long been known to be associated 

 with degeneration of the ovaries (Yarrell, '27; Brandt, '89). 

 This conclusion has been put on an experimental basis by the 

 castration experiment of Pezard, Guthrie, Goodale, and Morgan 

 and falls in line with the observations of Poll ('11) on sterile 

 hybrid ducks and of Smith and Thomas ('13) on sterile hybrid 

 pheasants. Evidence on the positive side is furnished by Goodale 

 ('10, '18), who succeeded in producing hen-feathering in cockerels 

 by means of ovarian transplantation. The ovary is, therefore, 

 shown to be responsible for hen-feathering. But Morgan ('19, 

 '21) carried the analysis a step further, making it reasonably 

 certain that the luteal cells are the endocrine cells involved. 

 For after castration of his hen-feathered Sebright and Campine 

 males, these birds became male-feathered; and in complete 

 harmony with the theory, Boring and Morgan ('18) found charac- 

 teristic luteal cells in the testis of these birds. 



Such are the facts relative to the internal secretion of the bird 

 ovary. The subject cannot be pursued further here. In table 2 

 the reader will find a summary of the facts in condensed form. 

 The table emphasizes the fertile suggestion of Goodale, that each 

 sex character acts like a unit — a view which it is well to bear in 

 mind. 



Passing now to a consideration of the avian testis, we find 

 the view expressed (Boring and Pearl, '18) that there is "only 

 a very general correspondence such as in body shape and carriage 

 between the secondary sex characters and the primary sex organs, 

 . . . . and that spurs, comb and wattles vary regardless of 

 primary sex organs." Certain well-known facts seem to sub- 

 stantiate this view; for example, laying hens occasionally have 

 spurs, capons and hens may exhibit certain phases of male be- 

 havior, and hens often crow. Such aberrant individuals have 

 been described as 'normal'; but until we know more about the 



