1903 Notes 011 the Nests and Eggs of Birds 131 



may therefore safely trace the nesting habits of birds to 

 a reptilian origin. 



The marvellously beautiful variety of colouration, the 

 great diversity of shape and size and substance, in the 

 shells of birds' eggs, the complexity of structure, and the 

 difference of situation in which the nests of various birds 

 are placed, are not works of chance, but the result of the 

 secret, silent, and vastly prolonged workings of those laws 

 of nature with which the writings of Darwin especially 

 have made us familiar. Exactly how the infinite variety 

 of ground tints and subsequent blotches, spots, or mark- 

 ings upon previously whole-coloured eggshells were brought 

 about we cannot say ; but why birds' eggs are now pro- 

 duced in size and colour manifold, and laid in domed or 

 open nests of rude or skilful architecture, we may safely 

 say is for the welfare of the several species. The neces- 

 sity of protectively coloured eggs or of cosy nest varies 

 with the previous life-history of the parents and the 

 subsequent safety of the young ; hence we find a variety 

 of nests and a still greater variety of eggs. Those birds 

 which lay many eggs and build most elaborate nests are 

 themselves more fragile, or have more foes to contend 

 with, than the bird which lays a single egg and makes 

 no nest whatever to receive it, or any attempt to conceal 

 it ; and those eggs which, in consequence of their ground 

 colour and markings, can only with great difficulty be 

 discerned in the midst of the natural surroundings in 

 which alone they are laid, are those which could be pro- 

 tected no better by any of the various means which are 

 resorted to by birds of different nesting habits. Take the 

 golden - crested wren, compared with the guillemot, as an 

 example of the first statement, and the ringed plover as 

 an instance of second assertion. The eggs of this latter 

 bird must be large, in order that the young may be able 

 to take care of themselves partly as soon as they are 

 hatched. Now, if these proportionately large eggs were 

 concealed from enemies by being covered with down as 

 those of a duck, or laid in a large nest like that of a 

 rail or a rook, or domed over as a wren protects hers, 

 the very attempt at such concealment would defeat its 



