The Swimming Birds or Natatores take their name from the Latin natare,
to swim. The toes are united by the extension of webs between them; and
the whole order of Swimming Birds can dive without the body becoming
wet, as their feathers are anointed with an oily liquid furnished by
certain glands in their skin, which renders them impervious to moisture.
This oily substance and the structure of their feathers—which are
smooth, three-cornered, and closely interlaced—cause the water to glide
off their polished surface; while the down beneath the feathers protects
their bodies from the cold of the most severe winters.
The Swimming Birds are very numerous both in species and individuals,
and inhabit all countries. According to some Naturalists these Birds
which frequent the sea constitute one-fourteenth part of all the Birds
on the globe, and the number of species is said to be nearly ten
thousand. They feed on vegetables, insects and Fishes, and build their
nests on the sand, in nooks and crannies of the rocks, or on the margin
of lakes and rivers.