518 BRITISH BIRDS. 
plumage differ from adults in having the primaries more or less tipped 
with black, with black shafts to these feathers and the secondaries, in only 
having the rudiments of a crest, and in having the bill dusky yellow 
and without corrugations. Birds of the year have the bill somewhat 
intermediate, the primaries are pure white, but the crest is not fully deve- 
loped, and both it and the neck are pure white. The nestling is covered 
with white down, and even at this early age has the bill widened and 
flattened at the tip. 
