122 THE STORY OF BIRD-LIFE. 



beautiful structures in the animal world. We 

 shall find it placed on the ground, in burrows, 

 in hollow trees and in caverns, on the water, 

 in our hedgerows and bushes, in lofty trees, and 

 on ledges of the most precipitous clitfs. When- 

 ever and wherever the nest is found its every 

 detail should be carefully studied, for much 

 mystery still enwraps it. 



Of the most primitive are the ground-builders, 

 such as the little ringed plovers and terns of the 

 flat sandy beaches of our islands. Mere hollows 

 in the sand, these " nests " would most certainly 

 escape detection but for the chance discoveiy of 

 the treasures they contain — the eggs. We say 

 chance discovery advisedly for these eggs so 

 closely resemble the surrounding shingle that 

 they are almost impossible of detection save by 

 the most experienced. 



The ostriches and coursers of Africa and India, 

 apd the pratincoles of South Europe, India and 

 Australia, likewise deposit the eggs in a slight 

 depression in the ground. 



The tinamous of South America, the penguins, 

 many plovers and gulls make a slight depression 

 in the ground and give it a scanty lining of grass. 

 The ducks line a similar depression with down 

 plucked from their own breasts, and so on. 



Many birds seem to have found the pre- 

 paration of making even a slight hollow too 

 much trouble, or perhaps, unnecessary, and 

 deposit their eggs on the bare ground without 

 any further preparation whatsoever. The divers 

 thick-knees, sand-grouse and night-jars, are in- 

 stances of this. The auks and guillemots again 



