Their Eggs and Nests. 15 



prevail. But really not more than might have been 

 looked for beforehand, if it were not that, in our 

 usual way of thinking about birds and other animals, 

 we lay so much stress upon Instinct, and do not so 

 much as admit to our notice the possibility that many 

 of their actions may be prompted by a measure of 

 intelligence, and not simply an unconsidering, un- 

 reasoning influence, which we term their Instinctive 

 endowment. No doubt Instinct teaches them both to 

 build and how to build their nests, and what materi- 

 als are the most suitable, and the sites that are most 

 eligible. But it is scarcely Instinct which sets the 

 Eagle and the Crow, when their abode is in a place 

 that does not furnish the sticks they commonly or 

 instinctively use for building their nests, to adopt 

 instead of sticks the sea- weed stems which their home 

 does produce. And so too of the House Sparrow, 

 which, if it selects a tree or ivy for its site, builds a 

 huge domed or well covered-in nest, 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 compact, 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 com- 

 pletely 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 



