THE CANVAS-BACK DUCK. 323 
the Red-Head, though immeasurably inferior to the 
Canvas-Back, where both can feed on the valisneria, is 
as far superior to it when shot on sea-ways where both 
are compelled to feed on other species of sea-grass and 
weeds. Indeed, I consider the Duskey Duck, commonly 
known as the Black-Duck, a better bird on the Aoethers 
Atlantic sea-board than this fowl. 
The valisneria of which it is so fond, and to which it 
owes so much of its excellence, grows only on fresh 
shoals, in water from seven to nine feet, which are never 
left bare at the lowest tides. It is a long grass-like 
plant, with narrow leaves of five or six feet in length or 
upward, and is said to grow so thickly that a boat can 
scarcely be pulled through it; the root is white, and 
somewhat resembles celery, whence its common name, 
and on this only do the ducks feed, the Canvas-Back and 
Scaup-Duck, Puligula Marila—the Black-Head of the 
Chesapeake, and Broad-Bill of Long Island—for these 
three are one—being reported to dive for it, and uproot 
it, while the less vigorous and active Red-Head and 
Widgeon rob the rightful possessors of it when they rise 
to the surface after their long dive. 
_ The Red-Head closely resembles the Canvas-Back, and 
is often palmed off on the unwary as that bird, yet to an 
experienced eye the distinction is broadly apparent. In 
the first place the Canvas-Back is very considerably the 
larger bird, measuring two feet in length by three feet 
from wing to wing, and weighing, when in condition, 
