NESTS AND EGGS. 385 
Aquatic birds place their nests either in a simple recess 
behind two or three stones, or among grass and rushes sheltered 
by a shrub, or sometimes in the hollows of the rocks. The 
three-toed gull instinctively chooses the most inaccessible spot 
for her retreat, and she is rarely disturbed by the collector of 
eggs. Penguins and Patagonian penguins dig a horizontal hole 
in the sand. Puffins take possession of rabbit-burrows; they 
love society, and a number of them make their nests together, 
and hatch side by side. The place which they choose for their 
abode is often so perforated, that any one stepping on it would 
sink in to the knee. 
Sheldrakes (Aas tadorna) also have the custom of burrowing 
under the earth. The ancients gave these birds the name of 
“o1es-renards,” or fox-geese. Naumann saw in the little island 
of Sylt, a great number assembled in groups in artificial exca- 
vations. He counted as many as thirteen nests in a square space, 
with an entrance common to all. Above each nest was an 
opening, covered by a tuft of grass. When this tuft was lifted 
up, a sheldrake was found seated on her nest. Every inhabitant 
of the village appropriated several of these subterranean nests, 
from which he took twenty or thirty eggs every day for three 
weeks, taking care to leave six in each nest for incubation. 
In the neighbourhood of the Cape of Good Hope, albatrosses 
assemble in colonies to make their nests. They divide the land 
into regular squares, one for each nest. These squares com- 
municate with each other by means of roads, and the whole is 
defended by a wall of stones. 
Cormorants make their nests in the midst of reeds and rushes, 
or sometimes on the trunks of old willows, or on rocks, but always 
in the immediate neighbourhood of the sea. They build large, 
irregular nests, made of branches and pieces of wood roughly 
put together. Many of these nests may sometimes be seen on 
the same tree. 
At the beginning of this century, cormorants were rarely seen 
on the shores of the Baltic Sea. About the year 1810, several 
couples came to the neighbourhood of the Isle of Fioni, and built 
their nests among the rocks of the coast or in the woods. They 
gradually increased in number. In the spring of 1812, four pairs 
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