84 JOSE F. NONIDEZ 



The interstitial nature of the granule-laden cells described by 

 Boring and Pearl has been recently questioned by Goodale ('19). 

 After a comparative study of the cells present in the gonads with 

 other cells having granular contents, occurring in several organs 

 of the same animal, this observer concludes that both kinds of 

 elements are identical, and therefore, they cannot be regarded 

 as typical interstitial tissue in the ovary and testis. Goodale 

 suggests that the granule-laden cells are eosinophile leucocytes 

 escaped from the blood-stream. 



On account of these conflicting views it seemed advisable to 

 study this question anew, as well as other points regarding the 

 presence of a true interstitial gland in the testis and ovary of the 

 fowl. Much interest has been added to this problem by the 

 results of recent experimental work (Goodale, '13, '16; Pezard, 

 '18; Morgan, '15, '19). The fact that castration in the hen and 

 in hen-feathered males suppresses the female plumage, whose 

 place is taken by cock-feathering, strongly points to the occur- 

 rence of a common interstitial tissue in the gonads of both kinds 

 of birds. A further proof of this was found by Boring and Mor- 

 gan ('18) in the testis of a Sebright bantam cock, in which the 

 so-called lutear cells, typical of the ovary, were also present in 

 the albuginea. "WTiether the changes caused in the plumage of 

 cocks belonging to this breed, in which all the males are hen- 

 feathered, can be accounted for by the removal of a specific tissue 

 homologous to the interstitial tissue of the ovary, cannot be estab- 

 lished on a sound basis until a careful study of the histogenesis of 

 the gonads is made. The morphological similarity of the cells 

 regarded as interstitial in both sexes must not be taken as a 

 decisive proof of their functional similarity until their common 

 origin is traced- 



However, it was not thought advisable to take up this impor- 

 tant subject until the origin and true nature of the granule-laden 

 cells regarded as interstitial by Boring and Pearl could be estab- 

 lished on a sound basis. The present paper, therefore, deals 

 exclusively with the origin and distribution of such cells in the 

 ovary and testis of embryos and young chicks. A short descrip- 

 tion of the same cells in adult birds has also been included. As 



