218 
ZOOLOGY, 
ward to Scotland; it plucks it down from its breast, build- 
ing with it a large loose warm nest under low bushes on the 
sea-coast, where it lays three or four pale, dull green eggs. 
With it is associated the rare king eider {Somateria speda- 
Ulis, Fig. 255, A), The canvas-back {FtcUgula valUsneria) 
feeds, as its specific name implies, on the wild celery (Val- 
Usneria) on the middle Atlantic coast in winter, whence it 
derives its delicious flavor. The summer duck (Aix sponsa, 
Fig. 256) breeds in trees. The original source of our do- 
mestic duck is the mallard, or A7ias boschas. It is known 
B 
Fig. 257.—^, Barnacle Goose; B, White-fronted Goose. From Nordenskiold. 
to cross with various other species. Upward of fifty kinds 
of hybrid ducks are recorded, some of which have proved 
to be fertile. The black duck {Anas olscura) is abundant 
on the shores of North-eastern America, and is frequently 
brought into the market. The wild goose {Branta Cana- 
densis) breeds in the Northern United States and in British 
America. While it usually breeds 
on the shores of rivers, it has been 
known in Colorado and Montana 
to nest in trees. Allied to it is 
the barnacle goose of Europe 
(Branta leucopsis, Fig. 257, A), 
which very rarely occurs in this 
country; also the white-fronted 
goose (Fig. 257, B), is an arctic 
bird. The swans are character- 
ized by their long necks, the trachea or wind-pipe being 
remarkably long, especially in the trumpeter swan, where 
Fig. 258.— Carolina Rail. 
