72 THE WINGS. 



time the most common, called the crested, or eared, Or tippet 



Grebe, from a feathery orna- 

 ment like a tippet and ears, 

 weighs two pounds and a half, 

 or nearly forty times the 

 weight of a Swift, and yet its 

 spread of wing is only thirty 

 inches, being six inches less 

 than twice the spread of the 



Head of the Crested Grebe. Swift ' s win S' Sometimes, by 

 carefully watching these birds 



in clear water, opportunities occur of observing their progress 

 beneath the surface, when they may be seen flapping with 

 their short wings, as if flying, thus acquiring a much greater 

 .speed than they could by the use of their webbed feet alone. 

 There is one bird, however, the Water Crow (Turdus 

 cinctus), in size, shape, and wings very similar to the Black- 

 bird, which also dives ; but as it does not pursue fish, living 

 on spawn, or such sort of food as may be collected without 

 effort, the Diver's form of wing is not necessary, and 

 accordingly the only use of its wing, under water, is by 

 flapping or jerking it upwards, to prevent its rising ; for 

 as, like all other birds, it is much lighter than water, it 

 must of course use some power to keep itself beneath the 

 surface, and this it does by means of its wings. These 

 birds are chiefly found in wild parts of the country, abound- 

 ing in streams rushing over rocky beds. There they may 

 be seen perched upon a stone on the edge jor middle of the 

 water, from whence they wade beyond their depth, and 

 continue their course along the bottom, where they may be 

 observed struggling, to preserve a footing, and prevent them- 

 selves from rising, by a strange tumbling sort of motion of 

 their bodies, accompanied by quiverings of their wings, 

 which, acting upon the water above, helps to keep them 

 down. 



- Before we proceed to speak of migration, or that instinct 

 which induces birds to visit and retire from certain countries 



