THEIR REPRODUCTION (EGGS) 301 



surely chooses a patch of rougher shingle, where 

 its more heavily-marked eggs so closely harmo- 

 nise with surrounding objects that we may tramp 

 to and fro across its breeding-place in vain quest 

 of objects we know are there. And so we might 

 go on giving instance after instance of richly- 

 marked eggs deriving their sole safety from 

 enemies from the resemblance between them 

 and surrounding objects. Then again, we also 

 find that birds building open nests amongst 

 foliage lay eggs more or less green in tint, as 

 in the Crows, Thrushes, Warblers, and so on. 

 Many of the smaller birds, as we have already 

 seen in the previous chapter, take great pains 

 to conceal their nests by building them exter- 

 nally of materials very similar in colour to 

 objects surrounding them ; in the majority of 

 cases the eggs themselves are also of quiet 

 colours, or in those species where they are 

 more conspicuous, the dark thickets and shrubs 

 are selected, where they are seen with difficulty. 

 Here again, the objection may be similarly 

 urged, that as we found w^hite or unspotted 

 eggs in open nests, so also conversely do we 

 find many instances of spotted eggs deposited 

 in covered nests. We have, for instance, the 

 Jackdaw laying its spotted eggs in nests well 



