BIRDS' NESTS AND EGGS 367 



Sandpipers furnish instances innumerable of protectively- 

 coloured eggs. In all the instances given the sitting-bird 

 invariably leaves the eggs uncovered when it quits them, 

 and consequently their safety depends solely on their colour. 

 A passing word should here be given to the eggs of the 

 Gulls. Some of these species depend for the safety of their 

 eggs upon the colours which adorn them ; but some species 

 do not require such protection, the birds being well able 

 to guard them from any enemies by their own prowess. 

 The law of Inheritance explains this. The Gulls have 

 descended from a common ancestor a form probably inter- 

 mediate between a Gull and a Plover, which depended on the 

 colour of its eggs for their safety ; and consequently we find 

 a certain type of eggs peculiar to the whole group, of benefit 

 to the majority of species, of little or no service to a few, 

 but still retained by the law of Inheritance. 



Those birds building open nests amongst the foilage of 

 trees and shrubs, as a rule lay eggs more or less of a green 

 colour. The Crows in the topmost branches, the Thrushes in 

 the lower shrubs, and many of the. Warblers in the dense 

 undergrowth, may be cited as instances. Again, the Bullfinch 

 and the Greenfinch lay bluish-white eggs, spotted with red, 

 in open nests ; but these birds build in the darkest thickets 

 and hedgerows and amongst evergreens. 



A word as to the marvellous variation and beautiful colours 

 of the eggs of the Guillemot. The extraordinary amount of 

 variation in the colour of these eggs appears to be a grave 

 difficulty, and one which utterly refuses to conform to those 

 laws that govern the tints with which so many birds' eggs are 

 adorned. It is one of those very few instances where Nature 

 has seemingly run riot in her variations, in a similar manner 

 to those which occur in domesticated animals ; for once let 

 the checks to variation be removed, and its ramifications are 

 infinite and endless in a few generations. Why, we are apt 



