370 THE WORLD OK, LH VSIGA. 
and apparently enjoying the warmth of the sand. They walk 
with a most dignified carriage. On water they swim with ease, 
but seldom dive, preferring to take their prey as it appears at 
the surface. In the air they fly slowly yet gracefully, and often 
sweep in circles, as if displaying their agility. The web-footed 
birds glory in the agitations of the sea; nothing gives them 
so much delight as a violent storm, for instinct or experience 
has taught them that a storm casts up the mollusks, and other 
of the sea inhabitants which are usually beyond their reach, and 
brings them to the surface or leaves them on the beach. 
How often, as we have watched the horizon darken, and 
the storm-clouds gather, have we marked the striking contrast, 
as the white gulls and sea-swallows now rose and now fell above 
the waves, waiting in eager expectation for their coming feast. 
The largest of the sea-birds is the A/batross. No species of 
it exists in the North Atlantic, but it is abundant below the 
tropic of Capricorn. From the tip of one wing to the tip of the 
other, it often measures more than twelve feet. Strange to say, 
the largest of the sea-birds is nearly allied to the smallest, the 
Stormy Petrel, and both of them tread the waves in the manner 
indicated in the accompanying illustration. 
Those birds which remain long on the wing have small, light 
bodies, long tails, and large, powerful wings. The swimmers, on 
the other hand, have large bodies, small wings, and an apology 
fora tail. Their feathers are very downy, and they are lubricated 
with an oily secretion which prevents themfrom being wetted. 
The sea-birds, taking their whole nourishment from the water, 
live on marine vegetables, mollusks, and fishes. Fishermen 
hail the appearance of the Skua gulls, for they are the constant 
accompaniers of the herring-shoals. The gulls and the petrels 
throw themselves upon the sperm-whale and the dolphins, and 
tear out of them pieces of oily flesh. The albatross, the vulture 
of the ocean, can scent a dead whale from a great distance, and 
soon is found enjoying the carrion. 
The ducks have broad, flat bills, which are edged with rows 
of minute teeth, with which they tear the food they find on the 
surface of the water. The MWergansers are intrepid fishers, near 
