water; but this requires frequent renewal, or the duck would be drowned
as well as the hen."

"How long can a sea-bird remain at sea?"

"I should think not very long, although it has been supposed otherwise;
but we do not know so much of the habits of these birds as of others."

"Can they remain long under water?"

"The greater portion of them can not; ducks and that class, for
instance. Divers can remain some time; but the birds that remain the
longest under water are the semi-aquatic, whose feet are only
half-webbed. I have watched the common English water-hen for many
minutes walking along at the bottom of a stream, apparently as much in
its element as if on shore, pecking and feeding as it walked."

"You say that aquatic birds can not remain long at sea,--where do they
go to?"

"They resort to the uninhabited islands over the globe, rocks that
always remain above water, and the unfrequented shores of Africa and
elsewhere; there they congregate to breed and bring up their young. I
have seen twenty or thirty acres of land completely covered with these
birds or their nests, wedged together as close as they could sit. Every
year they resort to the same spot, which has probably been their
domicile for centuries,--I might say since the creation. They make no
nests, but merely scrape so as to form a shallow hole to deposit their
eggs. The consequence of their always resorting to the same spot is
that, from the voidings of the birds and the remains of fish brought to