46 GONADECTOMY IN RELATION TO THE SECONDARY 



writer has never seen a hen-feathered male in a race where the females, 

 were of the Brown Leghorn or Dark Brahma type of color. Whether 

 or not the males of such a race would take the female's color on becom- 

 ing hen-feathered is unknown. 1 In Hamburgs, Seabrights, and Cam- 

 pines the normal male is colored like the female in some parts of 

 of the body at least, a color which is often very like that of the juvenile 

 male, so that it is impossible to ascertain whether or not the coloration 

 of hen-feathered males is female or not. In regard to the shape of the 

 feathers, a more definite statement can be made. The shape of the 

 feathers of the hen-feathered male is exactly like those of the juvenile 

 coat of the male, but as these are also the same shape as those of the 

 female, they furnish us no proof of the assumption! of a female character 

 by the male. In addition to normal male-feathered cocks in these races, 

 I have seen a third type, in Campines, in which part of the feathers of 

 the regions under discussion are male, while the rest are juvenile (or 

 female) . Such birds always looked ragged and are very suggestive of 

 the condition of young males at the molt between the juvenile and male 

 plumage. According to some experiments that have been reported by 

 various observers, it is certain that the hen-feathered condition is a 

 definitely inheritable character. 



Since the castrated male in normal races develops normal plumage, 

 and since the hen-feathered character is undoubtedly an inheritable 

 character, it seems better to refer the condition to a factor which alters 

 the form of plumage. Perhaps it is an inhibitor. Naturally, since 

 the female already has the same form of feathers, she will not exhibit 

 any modifications. If this had been the normal feathering of Gallus 

 bankivus, as it is in the turkey or duck, the appearance of a new form 

 of feather in the male alone would constitute a new secondary sexual 

 character. The assumed primitive male, however, would not be hen- 

 feathered. Looking at it from this standpoint, it is evident that we 

 must give due regard to the part played by inheritance. At present, 

 I believe we are unable to point to any female-like character in males 

 that is not also juvenile. 2 



INHERITANCE OF SECONDARY SEXUAL CHARACTERS. 



Disregarding for the moment Type II, it is apparent that the inherited 

 base for the secondary sexual characters in each sex is the same that 

 is, the characters in each sex, except for the secretion of the ovary, 

 would be alike. In other words, there is no problem of the mode of 

 inheritance of secondary sexual characters in birds such as there is in 

 insects, where these characters are independent of the gonads. The 

 secondary sexual characters are inherited in exactly the same fashion 



1 Morgan, 1915, has found that such males take on the female's color. 



2 Since this section was written, Morgan, 1915, has shown that the hen-feathered condition in 

 the male is due to an internal secretion of the testes. 



