284 THE PRINCIPLES OF [Part II. 



tinct at birth, and this case violates our rule. There is a 

 breed of pigeons in which the males alone are streaked 

 with black, and the streaks can be detected even in the 

 nestlings ; but they become more conspicuous at each suc- 

 cessive moult, so that this case partly opposes and partly 

 supports the rule. With the English Carrier and Pouter 

 pigeon the full development of the wattle and the crop 

 occurs rather late in life, and these characters, conform- 

 ably with our rule, are transmitted in full perfection to 

 the males alone. The following cases perhaps come with- 

 in the class previously alluded to, in which the two sexes 

 have varied in the same manner at a rather late period of 

 life, and have consequently transferred their new charac- 

 ters to both sexes at a corresponding late period ; and if 

 so, such cases are not opposed to our rule. Thus there 

 are sub-breeds of the pigeon, described by Neumeister, 30 

 both sexes of which change color after moulting twice or 

 thrice, as does likewise the Almond Tumbler ; neverthe- 

 less these changes, though occurring rather late in life, 

 are common to both sexes. One variety of the Canary-bird, 

 namely, the London Prize, offers a nearly analogous case. 

 With the breeds of the Fowl the inheritance of various 

 characters by one sex or by both sexes seems generally 

 determined by the period at which such characters are 

 developed. Thus, in all the many breeds in which the 

 adult male differs greatly in color from the female and 

 from the adult male parent-species, he differs from the 

 young male, so that the newly-acquired characters must 

 have appeared at a rather late period of life. On the 

 other hand, with most of the breeds in which the two 

 sexes resemble each other, the young are colored in nearly 

 the same manner as their parents, and this renders it proba- 



30 'Das Ganze der Taubenzucht,' 183*7, s. 21, 24. For the case of the 

 fitreakcd pigeons, see Dr. Chapuis, 'Le Pigeon Voyageur Beige,' 18G5, 

 p. 87 



