ABOUT A BIRD’S UNDERWEAR. 29 
their needs, though some doubtless remain as a heri- 
tance from a past condition, as those on the helpless 
nestlings of hawks, owls and others. 
Arctic and water birds have the downs dense and 
fine, while many birds of southern origin have them 
comparatively scant. In those young birds which 
run at once from the nest when hatched (precocial) 
the down is found in great abundance. It is incased 
before hatching in a membranous tube to keep it dry, 
but this soon bursts when exposed and the little plumes 
expand, making the chick fluffy and comfortable. 
In such birds as remain long in the nest after 
hatching (altricial) there are various grades of the 
amount of nestling down, as noted. It has been ob- 
served that among those that evidently have nested 
long in holes (and lay white eggs usually) the young 
are noticeably naked. They have no need of swaddling 
clothes when so well protected. On the contrary, 
some of such birds as are hatched without a mother 
(megapodes) leave the eggs fully feathered and ready 
for fight, having doffed their down while in the shell. 
There is no nestling, however, without some down 
at hatching, and the style and extent of a little bird’s 
underwear tend at once to indicate whether its posi- 
tion be high or low in feathered society, just as an 
American Senator is said once to have exhibited his 
night robe to indicate his social standing. 
