THE ASSUMPTION AND CHANGES OF PLUMAGE IN BIRDS. 19 
Herring Guri.—Larus argentatus, Brunn. Lessrr BLACK-BACKED GuLL.—Larus 
fuscus, Id. 
The change of colour in the plumage of these Gulls commenced about the 14th of 
February, and from that time there has been a constant change of colour going on in 
the feathers. The moulting of these birds does not appear to expedite the change of 
colour. The new feathers have much the same hue as those that have been shed. 
Laucuine Guiu.—Larus ridibundus, Linn. 
The feathers on the head of this Gull began to change colour from white to black on 
the 11th of March. It was a change of colour, and not an act of moulting; no feather 
was shed, and the change was completed in four or five days. The plumage remained 
in this state as to colour till the 19th of July, a period of eighteen weeks and five days, 
when the black feathers were moulted, and the new feathers came white. The autumn 
moult lasted seven weeks. 
