GREAT NORTHERN DIVER. 
255 
The young males do not obtain their perfect plumage until 
the second or third year. One which we saw, and which was con- 
jectured to be a yearling, had some resemblance to the female, 
with the exception of its upper parts being of a darker and purer 
brown or mouse colour, and its under parts of a more delicate 
white ; it had likewise a few spots on the back and scapulars ; but 
none of those markings on the neck which distinguish the full 
grown male. 
The conformation of the ribs and bones of this species is re- 
markable, and merits particular examination. 
In the account which some of the European ornithologists give 
of their Northern Diver, we presume there is an inaccuracy. They 
say it measures three feet six inches in length, and four feet eight 
in breadth ; and weighs sixteen pounds. If this be a correct state- 
ment, it would lead to the surmise that our Diver is a different 
species ; for of several specimens which we examined, the best and 
largest has been described for this work, the admeasurement of 
which bird comes considerably short of that of the European, men- 
tioned above. The weight, as has been stated, was eight pounds 
and a half. 
According to Temminck the adult male and female are alike 
in plumage. All the females which have passed under my exami- 
nation differed from the old males ; and it is the universal opinion 
among our sportsmen who reside on the coast, where the Loons 
are common, that the adults, of both sexes, may always be distin- 
guished by their garb. However, in confirmation of Temminck’s 
opinion, I can adduce the authority of the Prince of Musignano, 
Charles Lucian Bonaparte, who has informed me that he has in his 
collection a female, which was shot in the Delaware, and which 
differs in no respect from the adult male. 
On a re-examination of the Supplement to the Ornithological 
Dictionary of Montagu, I find, upon this subject, the following re- 
