26 The Bird 
or lengthened down, as gulls and ducks. A Red-winged 
Blackbird, or for that matter almost any passerine nest- 
ling, looks very odd when it rises up in the nest, gaping for 
food; the long gray streamers of down waving like an 
aureole around its head. In some water-birds this nest- 
ling down retains its usefulness for nearly two months, 
Fig. 15.—Feather from the head of a young Bobolink, with down still attached 
to its tip. ‘Twice natural size. 
The feathers which replace the down are, when they 
first appear above the skin, rolled tightly and bound up 
in the thin tissue of the horny sheaths, so that they 
resemble a bundle of withes wrapped together in a cloth. 
In many young birds the feathers remain in this condi- 
tion until they are nearly full grown, and a young cuckoo 
