478 Remarks on the Plumage of Birds. 



here in winter : and again, he observes of the razor-billed 

 auk, that in Devonshire it is M often obtained, though more 

 rarely in the adult plumage ; yet," he continues, " I pos- 

 sess one killed in February." 



As these remarks are calculated to revive a controversy 

 which has long been set at rest by an appeal to facts, I beg 

 to submit the following detail of the seasonal and progressive 

 changes to which these birds are subject, which, I trust, will 

 satisfactorily remove whatever doubts may at present be 

 entertained on the subject. When first excluded, they are 

 clad in a downy covering, which, in its tints and markings, 

 resembles that of the adult bird in summer aspectofplumage*; 

 the young razor-billed auk having even the singular white 

 line from the bill to the eye, which is noticeable in the 

 parent birds, but which gradually disappears previously to 

 the shedding of its down : the latter is replaced by feathers of 

 most delicately soft texture, the tints of which resemble those 

 of the adults in winter; this second plumage being only re- 

 tained for a few weeks, when the young birds undergo a com- 

 plete moult (including the primaries), and acquire the fully 

 adult garb, of much finer texture than the last, but resembling 

 it in colour. They thus continue till very early in the fol- 

 lowing year, when the older birds, some time before their 

 progeny, have the plumage of the cheeks and throat at first 

 but slightly tipped with brownish black, which gradually in- 

 creases, spreading backwards over each feather, till it pervades 

 the whole ; at which time the bird appears in its complete 

 summer livery, having undergone no vernal change of 

 feathers ; the white line, also, from the bill to the eye, con- 

 temporaneously making its appearance in the razor-billed 

 auks, of which species the altered portion of the cheeks and 

 throat continue of a much browner black than the other dark 

 parts of the plumage. A guillemot which I obtained in the 

 first week of the present month (July) had already com- 

 menced its annual moult, exhibiting many growing white 

 feathers on the cheeks and throat. 



It may be remarked, that it would be quite as well for 

 naturalists to distinguish betwixt birds that merely undergo 

 an alteration of colour in the same feather, from those which 

 renew their plumage twice in the year, by confining the ex- 

 pressions summer and winter plumage to the latter, modifying 

 these, in the former instance, by\ interposing the word aspect; 

 a plan which I have followed in the course of a work in which 



* In the case of the puffin, however, which undergoes no seasonal 

 changes, this first covering is sooty black. 



