THE BLACK aUILLEMOT. 
301 
been maintained that in the latter species tlie black plumage 
is permanent after the first summer. Until within a com- 
paratively recent period, those of the inhabitants who paid 
attention to the subject maintained this opinion, and also 
believed that immediately after the breeding season the old 
birds withdrew themselves for the winter. It is now an ac- 
knowledged fact that the latter impression is correct, but the 
theory as to the retention of the black plumage is, or should 
be, altogether discarded. Both were advocated by Dr L. 
Edmondston in a paper read before the Wernerian Society in 
1823, nor was it until many years afterwards that he dis- 
covered his views to be only partially correct. 
I am not acquainted with any account of the habits of the 
Black Guillemot in Orkney, except that given by Low, who 
observes — “ These birds are found in the winter-time almost 
wholly grey, and others spotted about the head, neck, and back 
with that colour ; but whether they change colour in winter, and 
put on this as the dress of the season, or if it is the last year’s 
brood not yet arrived at their proper colours, I am uncertain ; 
one thing I am certain of, that I have seen them of both colours 
late in the winter and early in the spring, so that in my 
opinion the change is not universal, or perhaps it is but in the 
hardest winters where this happens in general.” In a foot-note 
he alludes to the dingy colour of the feet in winter as charac- 
teristic of immaturity ; at the same time calling attention to the 
want of proof that the bare parts, having once acquired the 
(dolours proper to the adult, ever undergo any farther change. 
To those unacquainted with this species in its wild state, it 
must be perplexing indeed to obtain a specimen, say in August, 
evidently assuming the grey plumage of winter, just after 
having been assured by native ornithologists that the black 
plumage, once acquired, is never lost; or, when convinced of that 
error, to observe a black Tystie in mid-winter ; or, again, to 
meet with others in a similar state where none but grey ones 
were to be seen the day previously. Then, having made up 
his mind that adults leave in winter, he is again bewildered on 
