OF THE BEITISH ISLANDS. 453 



placed either in a hollow fallen log, or in a hole in the trunk of a tree or broken 

 stump. The first eggs are laid on the powdered wood at the bottom of the hole, 

 but as the clutch is completed a plentiful lining of down is added, plucked from 

 the body of the female. The eggs are seven or eight in number, creamy-white in 

 colour, smooth in texture, and with some gloss. They measure on an average 

 2'0 inches in length by 1'47 inch in breadth. The down tufts are moderate in 

 size and very pale greyish-white. The female usually conveys her chicks to the 

 nearest water in her bill. One brood only is reared in the year, and it would 

 appear that the duck and her young, or at least the young, keep company during 

 the winter. 



Diagnostic characters. (Nuptial plumage), Mergus, with the head 

 (crested) and neck white, except a large spot between the eye and the bill, and 

 another on each side of the nape, where they meet, which are black shot with 

 green (adult male) ; with the feathers of the forehead, crown, and nape (the 

 latter elongated into a crest) chestnut, and with a large black patch between 

 the eye and the bill (adult female). Length, 17 to 18 inches (male) ; 15 to 17 

 inches (female). 



