THE EFFECTS OF CASTRATION OF HEN- 

 FEATHERED CAMPINES. 



T. H. MORGAN. 



In the Sebright Bantam I have shown (1913, '15, '17, '19, '20) 

 that castration changes the hen-feathered male into a cock- 

 feathered bird. There is only one type of male in the Sebright 

 race the hen-feathered bird. In a few other races of poultry, 

 two kinds of males are known, one hen-feathered, the other 

 cock-feathered. Both are fertile, and sometimes one type is 

 recognized as the standard, at other times and places the other 

 type. It is very probable, from evidence that will be given later, 

 that the hen-feathered Campine type is dominant over the cock- 

 feathered. This explains why it is more difficult to find a race 

 pure for hen-feathering ; because both the males and the females 

 of such a race may carry the recessive factor for cock-feathering. 

 It is known that many of the stocks, supposed to be hen-feath- 

 ered, occasionally " throw " cock-feathered males. Now that the 

 cause of this " reversion " is understood, it should not be diffi- 

 cult to produce a race pure for hen-feathering. In fact, even 

 the ordinary way of breeding, if combined with a strict selection, 

 would in time bring about such a result. 



For several years I have been desirous of performing on such 

 a dimorphic race as the Campines the same castration experi- 

 ment that had been successful in the Sebrights ; but it was essen- 

 tial to find first a stock that was pure for hen-feathering. For- 

 tunately the stock of Mr. Martling of Ridgefield, N. J., appears 

 to satisfy this condition. I have seen the birds in his flock for 

 three years, and in one year all of the juvenile cockerels before 

 any selection amongst them had been made. They were all hen- 

 feathered with the rare exception of a male that had " broken," 

 in the sense that a few feathers were changed in the direction of 

 cock-feathering. The history of one such bird, to be described 

 below, shows that the occurrence of these " breaks " does not 

 prove the impurity of such stocks. The statement of Mr. 



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