CANVAS-BACKS ON THE CHESAPEAKE. 53 



not pass unnoticed, viz. that its food so affects its 

 flesh that it is either the greatest table delicacy or 

 the reverse. On the Chesapeake, where they are pro- 

 cured in the greatest perfection, these birds, at the 

 period of their arrival, are poor in flesh and insipid 

 in taste. After a week or two of rest in this 

 favourite haunt they become fat, and reach the 

 greatest perfection in flavour. This is, doubtless, to 

 be attributed to the abundance of the aquatic plant, 

 Vallisneria Americana, which in Maryland and 

 Virginia is found most abundant, and appears there 

 to constitute their sole food. This plant, which much 

 resembles celery, and grows to several feet in length, 

 is firmly attached to the bottom, and is only procur- 

 able by diving. Many species of ducks, among which 

 may be enumerated Bed Heads (Anas ferind), and the 

 American Widgeon (Anas Americanus), also show a 

 marked preference for this aquatic vegetable ; but as 

 their strength and diving powers are inferior to 

 those of the canvas-back, they constantly follow the 

 latter, robbing them and bullying them out of the 

 result of their labours. 



The Chesapeake and its tributaries generally 

 are visited, about the end of October or early in 

 November, by canvas-backs. There they remain 

 throughout the winter, but being extremely shy, 

 they are easily frightened from their feeding-ground; 

 more especially as the season advances, if the 

 weather is mild. Frequently they go so far off 

 into open water, that the visitor or sportsman 



