204 MERGANSER. 



greater number white ; bastard wing black ; quills dusky ; tail 

 consisting of twenty feathers, * brown, bordered with greyish 

 white; the shape rounded, ending in a point in the middle; legs 

 orange ; claws black. The female differs in being smaller, and 

 having only the rudiment of a crest; the head and upper part of 

 the neck adjoining, dull ferruginous; chin white; fore part of the 

 neck and the breast ferruginous, mottled with black and white ; 

 neck behind, back, rump, and scapulars, cinereous; lower part 

 of the breast and belly white ; on each side of the breast the 

 same black and white feathers as in the male ; scapulars and wing 

 coverts much the same as in that sex, but have less white, and more 

 dusky in them; legs orange, but paler than in the male. 



Individuals of both sexes differ from each other in plumage; 

 some of the males have twice the proportion of white in the neck, 

 as in others, and the white on the wings more pure. The females 

 too, differ in being more or less bright in colour. 



We do not find that the sexes of this bird have been mistaken by 

 authors, but still the inquisitive naturalist will observe the same in- 

 ternal difference to exist, as in the great species. The male has a single 

 enlargement of the trachea about the middle of its length, in the 

 manner of the Golden Eye, and nearly in the same place, but differs 

 in being bony instead of cartilaginous ; and the bony plaits, most 

 curiously furrowed, or channelled transversely; besides this, the 

 lower part ends in a large, and remarkably bony cavity, of an 

 irregular heart-shape, with two openings on one side, and one 

 on the other ; all of which are covered with fine membranes, in the 

 same manner as in the Scaup, Gadwal, and Tufted Ducks; from the 

 bottom of this triangular bony box the two bronchiae arise, and 

 from thence lose themselves in the lungs. 



In the female the trachea continues nearly the same the whole 

 of its length. 



* Sometimes sixteen, and sometimes eighteen feathers, Pallas, Besck. d. Bert. N. ii. 

 s. 554. 



