98 STARLIGHT AND SUNSHINE. 
abandoned nest of the 
solitary vireo, distin- 
guished mainly from 
the others by the 
hairy lining and the employment of moss 
and lichen within the interior; one nest 
being plentifully lined with sheep wool from 
a neighboring pasture. The snow-bunting would be at a loss in 
its boreal nest without the fur of the arctic fox. Various of these 
cradle-building ingredients readily recommend their utility in the 
qualities of strength, plability, warmth, etc., while others again 
are only to be accounted for on the hypothesis of the passing 
whim or humor of the builder. Twigs, strips of tough bark, 
string, wiry roots, grass, spider silk, cocoons, vegetable strands 
of one kind and another, all appeal to our sense of the fitness of 
things, but what special advantage is indicated in the following 
instances of caprice? Here is the worm-eating warbler, for in- 
stance, whose nest is seldom free from dried hickory and chestnut 
