POCHARD. 417 



lum in either sex ; chin and throat pale greyish-brown ; 

 lower part of the neck in front dark brown ; all the under 

 surface of the body uniform dull greyish-white ; under tail- 

 coverts dark grey ; legs and feet as in the male. 



Young males at first resemble the females, obtaining 

 some change with the feathers of their first autumn moult ; 

 the alteration in the colour of the feather going on by slow 

 degrees afterwards. As late as the middle of January, 

 young males of the previous summer had not attained their 

 perfect plumage ; and the black on the breast of the young 

 males does not make its appearance during the first year. 



The nestling is described by Naumann as having the head 

 and neck dull rusty-brown ; upper parts blackish-brown ; 

 under parts yellowish-white ; bill and feet pale bluish. 



The trachea of the male is about eight inches long ; the 

 diameter of the tube large, tapering suddenly towards the 

 bottom ; the labyrinthic tympanum of beautiful form ; bron- 

 chial tubes short. The engraving below represents the sur- 

 face opposed to the left side of the bird. 



tf??'^^7-«f^r5Hr=--.v^^^'.^J 



VOL. IV, 



