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 
Swift’s wing. Sometimes, by 
carefully watching these birds 
in clear water, opportunities occur of observing their progress 
beneath the surface, when they may he 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 ; hut as it does not pursue fish, living 
on spawn, or such sort of food as may he 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 
he seen perched upon a stone on the edge or middle of the 
water, from whence they wade beyond their depth, and 
continue their course along the bottom, where they may he 
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 
