SEXUAL CHARACTERS OF SOME DOMESTIC BIRDS. 45 



On the other hand, there are male characters which never seem to 

 occur in the unaltered female, such as male saddle feathers, sickle 

 feathers, black breast in Brown Leghorns (though self-colored brown 

 breasts occur, the individual feathers of which are stippled), while in 

 ducks vermiculated feathers, body pattern, etc., syrinx, bill color, etc., 

 have not been observed in the normal female. Brandt, however, cites 

 instances of fertile cock-feathered females. In general, then, it seems 

 highly probable that some intimate relation exists between the germinal 

 constitution of the female and the appearance in the normal individual 

 of certain characters usually found only in the male. Also, it is inter- 

 esting to note that these characters appear in the ducks of Type II, 

 described above. Obviously, there is some close relationship between 

 the gametic constitution of an individual and the internal secretion of 

 the germ glands. 



FEMALE CHARACTERS IN THE OTHERWISE NORMAL MALE. 



Instances of the occurrence of female characters in males, strictly 

 comparable to those just described for the female, are uncommon or 

 wholly lacking. It has already been shown that the only character of 

 this sort among capons is the brooding instinct. One reason for the 

 non-occurrence of such cases is found in the few characters that it is 

 impossible to confuse with juvenile conditions. Brandt records only two 

 or three doubtful instances of this sort among a large number where 

 females exhibited male characters. On the other hand, when female 

 characters occur in the male they either form part of a normal cycle, 

 such as the winter plumage of the bobolink, or the laterals in the summer 

 plumage of the drake, or they are breed characters, such as hen feather- 

 ing, discussed below. We may, perhaps, distinguish two categories of 

 secondary sexual characters, viz, those absolutely dependent on the 

 internal secretion of the gonad and those partially, at least, independent, 

 and if this be true then those male characters occurring sporadically in 

 females otherwise normal are in essentially the same class as the oc- 

 currence of female characters in the otherwise normal male. 



HEN-FEATHERED MALES. 



These birds are of great interest from several standpoints. The 

 classical example is that of the Seabright bantams, yet it is stated in 

 the history of this breed that the hen-leathering originated outside. 

 Doubtless, hen-feathered males have long existed. They frequently 

 occur as "sports" among Hamburgs, while among Campines two 

 types of males are recognized, the English or hen-feathered and Belgian 

 or normal type. These hen-feathered birds are fertile, though the 

 statement has been made for Seabrights that those which are most 

 strongly hen-feathered are inclined to be sterile. Possibly the reason 

 is to be found in an inherited condition of sterility. Hen-feathered 

 males have their other male characters well developed. However, the 



