its
movements, and a little manipulation of its neck effects the delivery of
the booty. It may then be let loose again, or, if considered to have
done its work, it is fed and restored to its perch. The activity the
bird displays under water is almost incredible to those who have not
seen its performances, and in a shallow river scarcely a fish escapes
its keen eyes, and sudden turns, except by taking refuge under a stone
or root, or in the mud that may be stirred up during the operation, and
so avoiding observation (see Salvin and Freeman, _Falconry_, 1859).

Nearly allied to the cormorant, and having much the same habits, is the
shag, or green cormorant of some writers (_P. graculus_). The shag
(which name in many parts of the world is used in a generic sense) is,
however, about one-fourth smaller in linear dimensions, is much more
glossy in plumage, and its nuptial embellishment is a nodding plume
instead of the white patches of the cormorant. The easiest diagnostic on
examination will be found to be the number of tail-feathers, which in
the former are fourteen and in the shag twelve. The latter, too, is more
marine in the localities it frequents, scarcely ever entering fresh or
indeed inland waters.

In the south of Europe a much smaller species (_P. pygmaeus_) is found.
This is almost entirely a fresh-water bird, and is not uncommon on the
lower Danube. Other species, to the number perhaps of thirty or more,
have been discriminated from other parts of the world, but all have a
great general similarity to one another. New Zealand and the west coast
of northern America are particularly rich in birds of this genus, and
the species found there are the most beautifully decorated of any. All,
however, are remarkable for their curiously-formed feet, the four toes
of each being connected by a web, for their long stiff tails, and for
the absence, in the adult, of any exterior nostrils. When gorged, or
when the state of the tide precludes fishing, they are fond of sitting
on an elevated perch, often with extended wings, and in this attitude
they will remain motionless for a considerable time, as though hanging
themselves out to dry. It was perhaps this peculiarity that struck the
observation of Milton, and prompted his well-known similitude of Satan
to a cormorant (_Parad. Lost_, iv. 194); but when not thus behaving they
themselves provoke the more homely comparison of a row of black bottles.
Their voracity is proverbial.