SEX INHERITANCE 



107 



characters are not sex-linked since they are not 

 associated with a particular sex-chromosome, yet 

 they may be said to be "sex-limited." 



The first case is that of hen-feathering, shown 

 by certain breeds of poultry. In Sebright bantams 

 the males (Fig. 36, a) are hen-feathered. If either 

 a male or a female Sebright is crossed to a race 

 with normal cock-feathering the male offspring are 

 hen-feathered. In the F. generation there are both 



Fig. 3G. — a, Normal SebrisHt hon-foathered cock, h, castrated 



Sebright coclv. 



cock-feathered and hen-feathered males. This shows 

 that the dominant factors for hen-feathering are 

 not in the sex-chromosomes, for, if they were, the 

 Fo generation from one cross would give only hen- 

 feathered males, and from the reciprocal cross both 

 kinds of males. 



If a hen-feathered male is castrated the new 

 feathers that come in — immediately if old feathers 

 are ])lueked, otherwise at the next molt — are cock- 

 feathered (Fig. 36, b). It is obvious that something 



