49S 



ANATIDJi;. 



body white. The whole length is about twenty-one inches ; 

 the wing nine inches and a half. 



Young birds resemble adult females during their first 

 winter. The sex of the males, however, in any state of 

 plumage, may be ascertained by passing the finger and 

 thumb down the neck, along the line of the trachea ; the 

 male has an enlargement of the tube before it passes into 

 the body ; the tube of the trachea in the female is uniform 

 in its size throughout its whole length. Young males do 

 not obtain their fine plumage till after their second autumn 

 moult, and old males from early spring till their autumn 

 moult begins, lose the rich glossy green of the head and 

 neck, which degenerates into an obscure brown, while the 

 fine chestnut colour of the breast entirely disappears. 



