298 THE STORY OF THE BIRDS 



exceptions, however, only tend to prove the 

 truth of the rule. We have Ducks, for instance, 

 also certain Game Birds, Grebes, Rails, some 

 Owls, Pigeons, Nightjars, Herons, Cormorants, 

 and Storks, in all of which the eggs are very 

 conspicuous, and yet they are laid in open nests. 

 Now as regards the Ducks, certain Game Birds, 

 Grebes, and some Rails, we find that not only is 

 the parent's plumage very protective in coloura- 

 tion, thus shielding the conspicuous eggs from 

 view, but when the nest is left the hen bird is 

 very careful to cover the eggs with leaves and 

 other materials that effectually hide their showy 

 tints from view. That this seems certain is 

 proved in the case of the Ducks. Those species 

 with down of neutral and dull shades of colour 

 use it to conceal their eggs during absence from 

 the nest, but other species in which the down is 

 very light coloured as for instance the Golden- 

 Eye, the Goosander and the Smew resort to 

 holes in trees in which both the conspicuous 

 down and the conspicuous eggs are hidden from 

 sight. Then again, the hen Partridge and the 

 hen Pheasant, for example, lay their unmarked 

 eggs in open nests, but when they are sitting 

 upon them their own plumage is a most effec- 

 tual protection, whilst when they leave their 



