INTRODUCTORY CHAPTERS. 9 



sticks the sea-weed stems which their home does produce. And 

 so too of the House-Sparrow, which builds a huge domed or well 

 covered-in nest, if it selects a tree or ivy for its site, but only 

 lines the bottom of the hole in thatch, or a wall, with abundant 

 feathers or hair or straw. The Wren, again, which usually 

 builds its nest so that it may easily be removed entire and com- 

 pact, may be found to avail itself of such a site for its nest, 

 that it may be built on the principle of application like the 

 Martin's to the wall beneath the eaves so that, when taken from 

 its site, it shall appear to have had a segment completely cut out 

 or sliced off from it. 



The adaptation of materials to site also, so as to secure a 

 greater degree of concealment by making the intrusive structure 

 assimilate in external fabric and hue to the surrounding objects, 

 is well worthy of noticing attention, as supplying not only fresh 

 sources of seeming unlikeness in nests of the same species of 

 birds, but also fresh ins! ances of the little feathered architect's 

 wonderful adaptive intelligence. 



The question, Why are Birds' Eggs, in so many cases, so vari- 

 ously and beautifully ornamented? W f hy are their hues and 

 markings made so attractive to look at ? has often been asked, 

 and two or three different answers or modes of answer have been 

 suggested. I have seen the idea started that the design of such 

 various colouring and marking is intended to facilitate conceal- 

 ment, by the adaptation of the general hue of the egg to that of 

 the recipient or supporting substances. The theory is at least 

 original and amusing ; but unfortunately less happy than when 

 applied to the plumage of the birds themselves which lay the 

 eggs. It is no easy thing to detect a Partridire as she sits, 

 lifeless-seeming, amid other objects not more still than herself, 

 and presenting no great contrast in colour to her feathers : but 

 there is no difficulty in seeing her eggs as they lie in the nest. 

 And so well aware is she of the fact, that she always covers her 

 eggs with some convenient and suitable material last year's oak 

 leaves, for example when leaving her nest deliberately, or not 

 under the impulses of alarm. The Hedge-sparrow's eggs again, 

 or any other blue egg, how can they be supposed to become less 

 conspicuous by their colour when reposing in some earth-brown 

 or hay-coloured nest-cup ? 



If it had been said that the Golden Plover's eggs, the Peewit's, 

 the Snipe's, the Norfolk Plover's not to name many others of 

 which the same might be alleged were of such general hue, 

 so shaded and so marked as to oe anything but conspicuous, as 

 to be indeed well calculated to escape any but a most scrutinising 

 notice, in the apologies for nests which usually contain them, 

 the entire truth of the remark would have appealed to every 



