THE CANVAS-BACK DUCK. 233 



As most persons are probably aware, the Canvas-back 

 derives its name from the resemblance which the marking 

 of the back bears in its appearance to that of canvas, 

 being of a light grey, curiously covered with fine 

 dusky lines closely intersecting one another like crossed 

 threads. 



This peculiarity occurs also in the common Pochard or 

 Dun bird,* which being somewhat similar in many other 

 respects (though not in flavour or delicacy) is often sold 

 by London game-dealers as the genuine Canvas-back. 

 The following points of difference, however, if attended 

 to, would prevent any one from being so deceived. When 

 in good condition the male Canvas-back weighs about 

 three pounds, and the female about two pounds and 

 three-quarters, while the pochard averages only one 

 pound and three-quarters. The bill of the Canvas-back 

 runs high up on the forehead, is perfectly black, and 

 an inch longer than that of the Pochard; or three 

 inches instead of two. In the latter it is also naiTOwer 

 and slighter, and generally of a slate colour, with black 

 base and tip only. Further, the legs and feet of the 

 Canvas-back are larger, and of a much paler ash colour 

 than those of the other. There are likewise minor dif- 

 ferences in the colour and markings of the plumage. 



* Fuligula ferina, Yarr. 



