548 
WILLOCK. 
is known to breed on the coast where it was taken, the extraordinary 
weight of this bird can only be accounted for by supposing- that it was 
highly fed, while the old birds at this season are more exhausted ; but 
we have had old birds of superior weight sometimes. 
It now appears, he thinks, that this species, like the razor-bill, is at first, 
in its nestling feathers, like the parent birds, destitute of any white about 
the head and neck, but that after they take to the water, and before 
they can fly, a partial moulting takes place, and the throat and fore part 
of the neck become spotted with white feathers tipped with dusky, and 
which in a slight degree extend round behind the upper part of the 
neck. Now it must be remarked by every naturalist, that these newly- 
acquired white feathers tipped with dusky, must be again cast, and be 
replaced by entirely white ones, in order to render this bird similar in 
plumage to the lesser guillemot ; a circumstance, which, if not impossible, 
is highly improbable. Besides, if these two species were at any time by 
accident to be found alike in plumage, no one who has had the oppor- 
tunity we at this moment have, of placing all the species before him, the 
two guillemots and two auks, which have caused such discrepancy of 
opinion, together with their young at different ages, would hesitate a 
mvoment in deciding the matter. 
The size and weight of the spotted young guillemot, is essentially 
greater than the lesser guillemot is ever found to be ; the neck is 
longer, and, as an especial mark of distinction, the bill of this young bird 
is full one-third longer, and is furnished with an indenture in both man- 
dibles near the tip. This is an obvious mark of distinction, not, we 
beheve, before noticed in the foolish guillemot ; and of which the 
Willock is wholly destitute in the under mandible, though on the 
upper, nearer to the point, there is a very slight inclination to an in- 
denture. 
The circumstance of variation of colour in particular parts of the 
plumage in some of these species, especially the change to that of white, 
is well exemplified in the black guillemot, which has been found to vary 
so much, that the older naturalists had formed of them several species ; 
but no ornithologist of the present day can doubt the identity of the 
same bird in all its various plumage, by size, and other immutable cha- 
racters. Of the female, again, which has been called the lesser guille- 
mot, it is said that they are found in great abundance on the coasts of 
Scotland, extending even to the Orkney and Shetland Islands, and are 
sparingly scattered over the southern parts of the kingdom. Thus 
they are contented with a boreal station, even in the colder months, 
and never seek a southern region, but mostly continue on our northern 
