260 Reconciliation of apparent Discrepancies in the Mode 



while others, as especially the gadwall and gargany teal, are 

 rarely to be met with except in spring ; but at this season not 

 unfrequently. These statements are the result of several 

 years' observation; and it may be added, that particular 

 species, as the velvet scoter, are by no means rare in the 

 course of some winters, while a number of seasons sometimes 

 elapse without a single specimen making its appearance. 



But, to keep to the subject more immediately in hand, it 

 will be seen, on examination of all the young mallards, that 

 their assumption of the mature garb, astonishing as this will 

 seem, would appear to the inexperienced observer to be 

 wholly effected by a change of colour in the existing plu- 

 mage, with merely the exception of the two curling central 

 feathers of the tail, which must necessarily have been 

 changed. They occur in every stage of this apparent mu- 

 tation ; from having the under parts scarcely, if at all, differ- 

 ing from those of the female, to the exhibition of the same 

 lineated brown markings in all grades of obliteration. It 

 may, therefore, be supposed, that the earlier stages of the 

 transition had been passed through previously to their re- 

 appearance. 



In the widgeon, however, and many other species, it will 

 be found that the adult livery is obtained, in spring, by an 

 actual change of plumage, every feather being cast and re- 

 newed, except, of course, the wing and tail primaries. And 

 here it may be remarked, that the two central caudal feathers, 

 which in all birds visibly differ from the rest, being of softer 

 texture, and commonly of another colour, partake of the 

 nature of the tertiaries and wing-coverts ; and, in double- 

 moulting species, are, like them, very usually shed and re- 

 newed with the vernal renovation of the clothing plumage. 

 Their position differs from that of the other tail feathers, 

 having their points of insertion situate above even the line 

 formed by those of the rest. 



On first detecting this seeming discordancy in the mode of 

 assumption of the adult livery in different species, I took 

 some pains to ascertain which of them obtained the mature 

 colouring in the one way, and which in the other ; and may 

 here briefly state that, as a general, but not unexceptionable*, 

 rule, the young Fuligulinse (or diving ducks, which have a 

 lobated hind toe), and all the Merginae (or mergansers), the 

 latter very late in the season, undergo a change of feather 

 in the spring ; whereas the Anatinae (or ordinary ducks, with 

 the hind toe not lobated) agree, for the most part, in this 



* For instance, the red-headed pochard accords herein with the mallard. 



