56 THE STORY OF BIRD-LIFE. 



of nuts which were placed in a tray that was 

 fixed outside the window of the rooms of a friend 

 of the writer in Merton College, Oxford, for the 

 special benefit of these birds, several were always 

 rejected, and these when opened were found to 

 be empty, without exception. 



Ill noting of these habits, we must not forget 

 that gradations leading up to them are not 

 wanting. Thus, the thrush brings snails to 

 some large stone whereon to beat them till 

 the shell is broken. Many birds are in the 

 habit of softening food with water before 

 swallowing. Crows will carry shell-fish high 

 into the air then drop them on to the rocks 

 below to break the shell. 



Some birds live largely by the exertions of 

 their weaker neighbours. The skua-gull, for 

 instance, is one of the most persistent of these 

 pirates. Powerful and bold, he waylays his 

 cousin the sea-gall when returning from a 

 heavy meal, and the latter, to escape, lightens 

 his weight by disgorging his too recently 

 swallowed dinner. Swift as light, the skua 

 descends, and catches it before it has reached 

 the sea. 



CHAPTER IV. 



BIRDS' FLIGHT, AND BIRDS' WINGS. 



We are wont to regard ourselves as the "Lords 

 of Creation," and to speak of all other living 

 things as the inferior animals. Yet a few of 

 these, in one respect, are a constant source of 



