RED-BREASTED MERGANSER. 57 



and overhanging ; both mandibles are thickly serrated ; irides red ; 

 head furnished with a long hairy crest which is often pendent, but occa- 

 sionally erected, as represented in the plate ; this and part of the neck 

 is black glossed with green ; the neck under this for two or three inches 

 is pure white ; ending in a broad space of reddish ochre spotted with 

 black, which spreads over the lower part of the neck and sides of the 

 breast ; shoulders, back, and tertials deep velvety black, the first marked 

 with a number of singular roundish spots of white ; scapulars white ; 

 wing coverts mostly white, crossed by two narrow bands of black ; 

 primaries black, secondaries white, several of the latter edged with 

 black ; lower part of the back, the rump and tail coverts gray speckled 

 with black ; sides under the wings elegantly crossed with numerous 

 waving lines of black ; belly and vent white ; legs and feet red ; the tail 

 dusky ash ; the black of the back passes up the hind neck in a narrow 

 band to the head. 



The female is twenty-one inches in length, and thirty in extent ; the 

 crested head and part of the neck are of a dull sorrel color ; irides 

 yellow ; legs and bill red, upper parts dusky slate ; wings black, 

 greater coverts largely tipped with white, secondaries nearly all white ; 

 sides of the breast slightly dusky ; whole lower parts pure white ; the 

 tail is of a lighter slate than the back. The crest is much shorter than 

 in the male, and sometimes there is a slight tinge of ferruginous on the 

 breast. 



The windpipe of the male of this species is very curious, and differs 

 something from that of the Goosander. About two inches from the 

 mouth it swells out to four times its common diameter, continuing of 

 that size for about an inch and a half. This swelling is capable of being 

 shortened or extended ; it then continues of its first diameter for two 

 inches or more, when it becomes flattish, and almost transparent for 

 other two inches ; it then swells into a bony labyrinth of more than 

 two inches in length by one and a half in width, over the hollow sides 

 of which is spread a yellowish skin like parchment. The left side of 

 this, fronting the back of the bird, is a hard bone. The divarications 

 come out very regularly from this at the lower end, and enter the 

 lungs. 



The intention of Nature in this extraordinary structure is probably 

 to enable the bird to take down a supply of air to support respiration 

 while diving ; yet why should the female, who takes the same submarine 

 excursions as the male, be entirely destitute of this apparatus ? 



