38 THE STORY CF BIRD-LIFE. 



a brilliant yellow colour, and on being plucked 

 out, it is said, grow again of the same colour 

 without any fresh innoculation. 



It rarely happens that a bird having once 

 donned a smart livery ever discards it for a 

 dull one, yet this happens in the case of the wild 

 duck. In the summer of every year he, as 

 it has been described, "goes into eclipse" and 

 assumes a plumage so like that of his mate as 

 to be almost indistinguishable. As at this time 

 of the year he has for the nonce lost his power 

 of flight, it is probable that this sombre dress is 

 a source of safety. In the autumn he re-assumes 

 the splendid dress in which we know him. 



As a rule, whatever bright colours or orna- 

 ments are developed follow late in life. There 

 are one or two exceptions to this rule. The 

 nestling Gouldian weaver finch of Australia for 

 instance has at the angle of the mouth three 

 small bead-like bodies of a brilliant opalescent 

 emerald green and blue ; the roof of the mouth 

 itself is marked by five black spots perfectly 

 symmetrically disposed. As the bird is quite 

 blind at this time it is difficult to see what 

 can be the reason or use of such ornaments. 

 The nestling of the red-tailed weaver finch of 

 Samoa again has a red wattle at the gape 

 which disappears in the adult; and many of 

 our British birds have yellow-gape-wattles. 



The curiously striped nestling of the great 

 crested grebe bears a heart-shaped, fleshy ex- 

 crescence of a brilliant coral-red colour on the 

 crown of the head. No trace of this is found 

 in the adult. The nestling of the coot has the 



