Chap. XV.] SEXUALLY-LIMITED INHERITANCE. 151 



somewhat larger crop, and of the male carrier-pigeon 

 having somewhat larger wattles, than their respective fe- 

 males ; for fanciers have not selected one sex more than the 

 other, and have had no wish that these characters should 

 be more strongly displayed in the male than in the female, 

 yet this is the case with both breeds. 



The same process would have to be followed, and the 

 same difficulties Avould be encountered, if it were desired 

 to make a breed with the females alone of some new 

 color. 



Lastly, our fancier might wish to make a breed with the 

 two sexes diifering from each other, and both from the 

 parent-species. Here the difficulty would be extreme, un- 

 less the successive variations were from the first sexually 

 limited on both sides, and then there would be no diffi- 

 culty. We see this with the fowl ; thus the two sexes of 

 the pencilled Hamburgs differ greatly from each other, 

 and from the two sexes of the aboriginal Gallus hankiva ; 

 and both are now kept constant to their standard of excel- 

 lence by continued selection, which would be impossible 

 unless the distinctive characters of both were limited in 

 their transmission. The Spanish fowl offers a more curious 

 case ; tlie male has an immense comb, but some of the succes- 

 sive variations, by the accumulation of which it was ac- 

 quired, appear to have been transferred to the female ; for 

 she has a comb many times larger than that of the females 

 of the parent-species. But the comb of the female differs in 

 one respect from that of the male, for it is apt to lop over ; 

 and within a recent period it has been ordered by the fancy 

 that this should always be the case, and success has quickly 

 followed the order. Now, the lopping of the comb must 

 be sexually limited in its transmission, otherwise it would 

 prevent the comb of the male from being perfectly upright, 

 which would be abhorrent to every fancier. On the other 

 hand the uprightness of the comb in the male must likewise 



