70 Scientific Proceedings (104). 



41 (1501) 



Castration of hen-feathered Campines. 

 By Thomas H. Morgan. 



[From Columbia University, New York City] 



A few races of domestic fowls, such as the Campines, have 

 two kinds of males, one showing the ordinary cock-feathering, and 

 the other the so called hen-feathering. Three young Campines of 

 a hen-feathered strain were castrated, one before the adult feathers 

 had appeared, one when they had begun to appear, and a third 

 that was like the last but exceptional in certain respects. This bird 

 will not be considered here. Both of the former birds developed 

 cock-feathering after castration. It is evident that removal of 

 the testes in this race produces the same effects as is produced in 

 the hen feathered Sebrights, as reported three years ago before 

 this Society. 



42 (1502) 



The vermilion gene and gynandromorphism. 



By A. H. Sturtevant. 



[From Columbia University and Carnegie Institution of 

 Washington.] 



Morgan and Bridges (1919, Carnegie Inst. Wash. publ. 278) 

 have recently described and discussed a large number of gynan- 

 dromorphs of Drosophila melanogaster. They conclude that all 

 female parts in gynandromorphs of this animal contain two 

 X-chromosomes, and that all male parts contain only one X. The 

 peculiarities of a given part are thus due to its own constitution, 

 and are not dependent on the rest of the body for their differen- 

 tiation. The same principle was found to hold for the characters 

 determined by the sex-linked genes, which are carried by the 

 X-chromosomes. 



I have recently obtained evidence indicating that the sex- 

 linked character vermilion forms an exception to this rule. A 



