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ANATIDJ3. 



Females are considerably smaller than males, measuring 

 but fourteen inches and a half in their whole length, and 

 but six inches and a half from the point of the wing to the 

 end of the longest quill-feather. 



Young males resemble females for the first twelvemonths, 

 and do not assume their white plumage till their second 

 autumn moult. Young females have no black patch on 

 the side of the head during their first winter ; the red 

 colour on the back of the neck covers a larger space ; 

 the white colour of the smaller wing-coverts is mixed with 

 ash-grey, and the under surface of the body is of a dull 

 white. Females probably assume the black patch on the 

 lore, and the more pure white colour on the wing-coverts 

 at their second autumn moult. 



A portion of the trachea of the male Smew is repre- 

 sented below on the left hand. The figure on the right is 

 from the lower portion of the windpipe of the female. 



