124< THE DOMESTIC SWAN. 



astonishing to see with what assiduity she plies 

 her work of aggrandisement to a nest already 

 sufficient in strength and size to answer every 

 end. 



My swans generally form their nest on an 

 island quite above the reach of a flood, and still 

 the sitting bird never appears satisfied with the 

 quantity of materials which we provide for her 

 nest. I once gave her two huge bundles of 

 oaten straw, and she performed her work of 

 apparent supererogation by applying the whole 

 of it to her nest, already very large, and not 

 ejxposed to destruction, had the weather be- 

 come ever so rainy. This singular propensity, 

 amongst many others in the economy of birds, 

 puts speculation on our part quite out of the 

 question. We can no more account for this 

 seemingly unnecessary anxiety in the sitting 

 swan to augment the size of its nest, than we 

 can explain why the little long-tailed titmouse 

 invariably provides itself with a spherical nest, 

 warm as a winter's coat ; whilst a still more 

 delicate bird of passage from the hot countries 

 is content with one of hemispherical form, and so 

 scantily supplied with materials whereon to lay 

 its eggs, in this cold and changeable climate, 



