364 OUR RARER BIRDS 



instances coming into this particular group we have the eggs 

 of the Woodpeckers, the Kingfishers, the Titmice, the Willow 

 Warblers, the Wrens, the Owls, and the Martins, all of which 

 are pure white or, in some few cases, sparsely spotted, and 

 are laid in covered nests. This law is almost universal, and, 

 curiously enough, white eggs are correlated to a great extent 

 with brilliant plumage ; for we have already seen how so 

 many showy birds breed in covered nests. Indeed, it may 

 almost be laid down as an axiom in oology that brilliant 

 birds do not lay handsome eggs, and most of the finest marked 

 eggs are laid by species singularly plain in dress. 



To this rule, however, there are certain exceptions, and 

 many white or spotless eggs are laid in open nests. If these 

 examples are sufficiently numerous to merit the importance 

 of a separate group, the existence of any laws of colour might 

 be doubted by the casual observer. These instances are both 

 striking and numerous; .but when we come to study and 

 investigate them, we find that they only tend to prove the 

 existence of such laws in a very marked degree. The Ducks 

 all lay spotless eggs, light in colour, greenish-white, cream 

 colour, and pure white, and as they lie in the nest are very 

 conspicuous and readily seen at long distances. The 

 Pheasant and the Partridge also lay eggs of colours not much 

 aiding in their concealment. The Grebes may also be cited 

 as instances. But all these birds possess the singular habit 

 of covering their eggs with materials similar in colour to 

 surrounding objects when they leave their nests. We have 

 already observed this singular proceeding in many species. 

 It has been urged, and many naturalists are still of the 

 opinion, that birds do not cover their eggs for concealment, 

 but for warmth. The Pheasant (a native of hot climates) 

 covers her eggs when she leaves them; but the Grouse (a 

 resident almost among arctic snows) is never known to do 

 so. Now the former bird's eggs are certainly conspicuous in 



