BLA.CK GUILLEMOT. 



387 



rump and patch on the \vin<]i; arc streaked with brown. After the first 

 autumn moult they resemble very closely the winter plumage of adults, 

 except that they retain the wing-coverts of the young in first plumage. 

 After the second autumn moult they are still easily recognized by traces 

 of brown on the white wing-patches, which arc not lost until the third 

 autumn moult. Young in down are uniform blackish brown. 



