A CASE OF TRUE HERMAPHRODITISM IN THE FOWL 193 



more, there are structures in these birds and in those described 

 b}'" Tichomiroff which are highly suggestive of testicular tissue,* 

 and there is no reason, in view of the present state of our knowl- 

 edge of the testis, for denying the presence of cells that may give 

 rise to a testicular hormone.^ 



Sixth, when cocks are feminized (Goodale, '18), the comb 

 and wattles and plumage ''become indistinguishable from the 

 female form." This shows that male head furnishings are not a 

 function of zygotic maleness, like behavior for example (table 2) , 

 but may be changed to the female type only upon stimulation by 

 female hormone. When we compare the feminized cocks with 

 hen-feathered Sebrights or Campines, the contrast between the 

 male head furnishings of the latter and the female head furnish- 

 ings of the former is striking. Both classes have luteal cells and 

 hen feathers; the male Sebright or Campine has male comb and 

 wattles associated with testicular tissues. The hermaphrodites 

 listed in table 1 are like the hen-feathered males: they are hen- 

 feathered, they have large combs and wattles, they possess luteal 

 cells and testicular tissue. 



We believe, therefore, that the hermaphrodites that have been 

 described are to be interpreted quite in accord with the experi- 

 mental evidence that has accumulated in this field. 



CONCLUSION 



The evidence reviewed in the foregoing discussion appears 

 to the writers ample to establish a definite endocrine function 

 for both testis and ovary in relation to secondary sex characters 

 of birds. Yet it is also clear that our knowledge is lacking in many 

 details. The endocrine cells of the testis are an unknown quan- 

 tity, those of the ovary have been insufficiently interpreted. On 



* Attention is again called to the findings of Massaglia ('21), according to 

 which small, hard, atrophic testes which are hardly recognizable as such are still 

 capable of maintaining the cock's combs and wattles in the vasectomized animals. 



' It should be further pointed out in this connection that Boring and Pearl's 

 no. 1349 is most male-like in body shape (upon which the authors lay much stress) 

 although its gonads contain the most luteal cells, while their no. 1427 is described 

 as possessing no luteal cells, although the animal was very female in appearance, 

 with complete hen-feathering. 



