THE WORLD'S BIRDS. 93 



of eye ; feet slight, with shanks never excessively 

 long, and covered with few and large scales, 

 all three front toes generally present and free, 

 hind-toe with claw usually larger than any of them ; 

 wings varying, but always with the upper- and fore- 

 arm segments short ; tail varying, usually of twelve 

 feathers, and very commonly more or less forked, 

 usually of fair length. Head large ; body light. 



PLUMAGE AND COLOURATION. Feathering soft, very 

 varied in colour ; olive-green (rare in other 

 families) and brown being the commonest tints, 

 though all others found in birds occur ; often a 

 sex-difference or a seasonal change, the latter 

 usually in males only. Young sometimes like 

 adults, sometimes with a distinct plumage, which 

 is generally spotted or streaked. 



YOUNG. Helpless and either naked or but scantily 

 provided with hairy-looking down, except in 

 Lyre-birds ; they gape for food, and the inside 

 of mouth thus revealed is often brilliantly coloured ; 

 corners of mouth soft and expanded. 



NEST. Varying much, but always more or less 

 elaborate ; most often an open cup, but frequently 

 domed, and often hanging. Some build mud 

 nests, and some burrow ; but all these usually 

 line their nests, unlike most other hole-building 

 birds. 



EGGS. Smooth and oval ; two or more in number, 

 self-coloured or spotted ; even in allied forms 

 there is often much difference, more than in whole 

 families elsewhere. 



INCUBATION. Twelve days to three weeks. 



COURTSHIP. Various, 'and not so often noticeable as 

 in other groups as a rule. Purring out of the 

 feathers is a common form of display. 



FOOD. Most commonly insects and other small 

 animals, and berries ; some eat seeds and herbage, 



