130 



LUTEAR CELLS AND HEN-FEATHERING 



In Fig. 1, two groups of lutear cells, in the wall of an egg follicle of a 

 hen, are shown. In Fig. 2 three groups of lutear cells are seen between 

 the tubules of the testis of a male Sebright. In Fig. 3 lutear cells in the 

 regenerated testis of a Sebright male are shown. The bird had been 

 castrated but, since it did not change the character of its plumage, 

 after 6 months it was opened and this piece of testis was found and 

 removed. In Fig. 4 a piece of the testis of a hermaphrodite bird 

 described by Boring and Pearl shows a large group of lutear cells. 



Lutear cells 



Fig. 4. A group of lutear cells in a hermaphrodite fowl (from Boring and 

 Pearl) , 



CONCLUSIONS. 



The experimental evidence had made clear that some substance is 

 produced in the testis of the male Sebright that suppresses in him the 

 development of the secondary sexual plumage of the cock of his 

 species. The detection in his testis of lutear cells like those in hens 

 makes the conclusion highly probable that it is these cells that cause 

 the suppression of cock-feathering in both the Sebright male and in 

 hens of all fowls. Genetic work by Morgan^ had shown that one 

 or two Mendehan factor-differences are responsible for hen-feathering 



"Morgan, T. H., Am. Nat., 1917, li, 513; Proc. Soc. Exp. Biol, and Med., 

 1915-16, xiii, 31. 



