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 

 famihes) 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. Puffing 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, 



