218 THE PHILOSOPHY OF BIRDS' NESTS. 



the materials of a nest? Consequently, they all lay 

 in holes of trees, the tops of rotten stumps, or in 

 deserted ants' nests, the soft materials of which they 

 can easily hollow out. 



Many terns and sandpipers lay their eggs on the 

 bare sand of the sea-shore, and no doubt the Duke of 

 Argyll is correct when he says, that the cause of 

 this habit is not that they are unable to form a nest, 

 but that, in such situations, any nest would be con- 

 spicuous and lead to the discovery of the eggs. The 

 choice of place is, however, evidently determined by 

 the habits of the birds, who, in their daily search 

 for food, are continually roaming over extensive tide- 

 washed flats. Gulls vary considerably in their mode of 

 nesting, but it is always in accordance with their struc- 

 ture and habits. The situation is either on a bare rock 

 or on ledges of sea-cliffs, in marshes or on weedy shores. 

 The materials are sea-weed, tufts of grass or rushes, 

 or the debris of the shore, heaped together with as 

 little order and constructive art as might be expected 

 from the webbed feet and clumsy bill of these birds, 

 the latter better adapted for seizing fish than for 

 forming a delicate nest. The long-legged, broad-billed 

 flamingo, who is continually stalking over muddy flats 

 in search of food, heaps up the mud into a conical 

 stool, on the top of which it lays its eggs. The bird 

 can thus sit upon them conveniently, and they are 

 kept dry, out of reach of the tides. 



Now I believe that throughout the whole class of 

 birds the same general principles will be found to hold 



