36 
THE CABINET OF NATURAL HISTORY, 
size and strength as indicating it; but they were greatly 
mistaken in the character they have given to this indolent, 
skulking animal, and have overlooked a much better ex- 
ample of true courage, and of other virtues also, in the 
bold and faithful dog.” 
[ To be continued. ] 
CANVAS-BACK DUCK. 
ANAS VALISINERIA. 
[Plate IV. Vol. 2.] 
Collection of S. P. Griffitts, Esq. 
This celebrated American species, as far as can be 
judged from the best figures and descriptions of foreign 
birds, is altogether unknown in Europe. It approaches 
nearest to the Pochard of England, Anas ferina, but dif- 
fers from that bird in being superior in size and weight, in 
the greater magnitude of its bill, and the general whiteness 
of its plumage. A short comparison of the two will eluci- 
date this point. The Canvas-back measures two feet in 
length, by three feet in extent, and when in the best order 
weighs three pounds and upwards. The Pochard, according 
to Latham and Bewick, measures nineteen inches in length, 
and thirty in extent, and weighs one pound twelve or 
thirteen ounces. The latter writer says of the Pochard, 
“ the plumage above and below is wholly covered with 
prettily freckled slender dusky threads, disposed trans- 
versely in close set zig-zag lines, on a pale ground, more 
or less shaded off with ash;” a description much more 
applicable to the bird figured beside it, the Red Head, and 
which very probably is the species meant. In the figure 
of the Pochard given by Mr. Bewick, who is generally 
correct, the bill agrees very well with that of our Red 
Head, but is scarcely half the size and thickness of that of 
the Canvas-back; and the figure in the Planches Enlumi- 
nees corresponds in that respect with Bewick’s. In short, 
either these writers are egregiously erroneous in their 
figures and descriptions, or the present Duck was altogether 
unknown to them. Considering the latter supposition the 
more probable of the two, I have designated this as a new 
species, and shall proceed to detail some particulars of its 
history. 
The Canvas-back Duck arrives in the United States from 
the north about the middle of October; a few descend to 
the Hudson and Delaware, but the great body of these 
birds resort to the numerous rivers belonging to and in 
the neighbourhood of the Chesapeake Bay, particularly 
the Susquehanna, the Patapsco, Potomac, and James’ 
Rivers, which appear to be their general winter rendez- 
vous. Beyond this, to the south, I can find no certain 
accounts of them. At the Susquehanna they are called Can- 
vas-backs, on the Potomac, White-backs, and on James’ 
River, Sheldrakes. They are seldom found at a great 
distance up any of these rivers, or even in the salt water 
bay; but in that particular part of tide water where a 
certain grass-like plant grows, on the roots of which they 
feed. This plant, which is said to be a species of Valisi- 
neria, grows on fresh water shoals of from seven to nine 
feet, (but never where they are occasionally dry,) in long 
narrow grass-like blades of four or five feet in length; the 
root is white, and has some resemblance to small celery. 
This grass is in many places so thick that a boat can with 
difficulty be rowed through it, it so impedes the oars. 
The shores are lined with large quantities of it torn up by 
the Ducks, and drifted up by the winds, lying like hay in 
wind rows. Wherever this plant grows in abundance the 
Canvas-backs may be expected, either to pay occasional 
visits, or to make it their regular residence during the 
winter. It occurs in some parts of the Hudson; in the 
Delaware, near Gloucester, a few miles below Philadel- 
phia; and in most of the rivers that fall into the Chesa- 
peake, to each of which particular places these Ducks 
resort; while in waters unprovided with this nutritive 
plant they are altogether unknown. 
On the first arrival of these birds in the Susquehanna, 
near Havre-de-grace, they are generally lean; but such is 
the abundance of their favourite food, that towards the 
beginning of November they are in pretty good order. 
They are excellent divers, and swim with great speed and 
agility. They sometimes assemble in such multitudes as 
to cover several acres of the river, and when they rise sud- 
denly, produce a noise resembling thunder. They float about 
these shoals, diving and tearing up the grass by the roots, 
which is the only part they eat. They are extremely shy, 
and can rarely be approached unless by stratagem. When 
wounded in the wing, they dive to such prodigious dis- 
tances, and with such rapidity, continuing it so persever- 
ingly, and with such cunning and active vigour, as almost 
always to render the pursuit hopeless. From the great 
demand for these Ducks, and the high price they uniformly 
bring in market, various modes are practised to get within 
gunshot of them. The most successful way is said to be, 
decoying them to the shore by means of a dog, while the 
gunner lies closely concealed in a proper situation. The 
dog, if properly trained, plays backwards and forwards 
along the margin of the water, and the Ducks observing 
his manoeuvres, enticed perhaps by curiosity, gradually 
