in *whick Changes of Colour are effected in Moulting, 261 



particular with the mallard ; the shoveller, widgeon, and 

 shieldrake furnishing the exceptions. 



I had not, however, very extensively pursued this investi- 

 gation before I met with a pintail and shoveller ; the former 

 moulting, the latter merely changing its colours, which it had 

 effected to a very considerable extent, without the slightest 

 trace being any where discernible of a renewal of the feathers. 

 The pintail was a fine and healthy-looking specimen ; whereas 

 the other, I could not but remark, was in very poor con- 

 dition. 



I had previously noticed the highly interesting fact, which 

 had long puzzled me, that, in the same specimen, it was not 

 unusual to perceive new feathers shooting forth in abundance, 

 simultaneously with the most complete and surprising changes 

 of colour in those loose, and about to be shed ; and, as I knew, 

 from observation, that many species underwent their seasonal 

 changes exclusively in the one way or in the other, it became 

 difficult sometimes to assign to which class such specimens 

 should be referred. A golden plover, for instance, that is 

 now before me, is every where in deep moult, renewing both 

 its upper and under plumage ; while, coincidently, most of 

 the loose old feathers of the lower parts have changed, more 

 or less completely, from white to black, the hue of the new 

 feathers which are growing. I have known the young bay- 

 breasted merganser to exhibit patches of the dark adult 

 colour on the sides of the head, previously to any appearance 

 of a change of feather ; and, to give an instance still more 

 conclusively illustrative, if possible, of the fact of a change to 

 the summer hue in the old feathers preceding the vernal 

 moult, it may be mentioned, that I at present know of a 

 specimen of the long-tailed sarcelle, in which species the 

 scapulary feathers are considerably longer in winter than in 

 summer, which exhibits these plumes of their winter dimen- 

 sions, but partially coloured, and even deeply so, as in those 

 of summer ; the real moult having elsewhere perceptibly 

 commenced upon the same specimen. It would be easy to 

 enumerate a tedious variety of additional instances ; but I 

 shall confine myself to a few observations on the ptarmigan 

 genus, as erroneous impressions are very current concerning 

 the mode in which their seasonal changes are brought about, 

 occasioned by these very deceptive appearances. 



It has been asserted, that, in the common ptarmigan, the 

 time of moulting would seem to be confined to no particular 

 season ; and that the excessive periodical changes of hue, en 

 masse, observable in these birds are, therefore, independent of 

 a renewal of the feathers; a conclusion which is, indeed, 



u 3 



