out of shot. On the approach of winter the old birds retire
to the west coast of Norway. They make their appearance
in the southern parts but rarely. The young birds, however,
migrate in considerable numbers to more temperate climes,
and are found at that period in the open parts of the Baltic,
in the Elbe, and on the coast of Holland.”
Vast numbers of the Black-throated Diver are bred in
I inland and Russia, and nests have been found on the
German shores of the Baltic. On migration this species
visits the coasts and inland waters of the Continent down to
the Mediterranean, but south of the Alps it is by far the rarest
of the family. Eastward it is found breeding across Northern
Siberia to the Amoor, and in winter it is common in Japan.
On the other side of the Pacific—where the birds are on the
average rather smaller than European examples, and have
consequently been distinguished by some American ornithologists
under the name of G. pctcijicus—this Diver is generally
distributed throughout the Fur countries to Hudson’s
Bay, on the shores of which it is common. Parry brought
home specimens from Melville Peninsula; and Richardson
says that the skins of this and the other species of Divers,
being tough and impervious to wet, are used by the Indians
and Esquimaux as an article of dress. Audubon states that
it does not breed in Labrador, but that young birds are found
in lexas from winter to April, the lines of migration following
the course of the great rivers, as well as the coast.
In the adult bird, the beak is dark bluish-black; the upper
mandible rather more decurved and the under one straighter
than in the Great Northern Diver; the irides red; forehead
dark grey, top of the head, and back of the neck light ash-
giey, back, rump, and tail-feathers nearly black; interscapular
and tertial feathers with a square patch of white on
each side of the shaft, forming a series of transverse bars ;
wing-coverts black, with a few specks of white; primary
quill-feathers black; chin and throat black, divided by a half
collar of short white lines; sides and bottom of the neck
streaked longitudinally with black and white lines; breast,
belly, and all the under surface of the body, pure white;
flanks and under tail-coverts dusky; legs and toes dark
brown outside, lighter pale brown within. The whole length
is about twenty-six inches ; wing from the carpal joint to the
end of the primaries, eleven inches and a half. Weight
from to 5-f lbs. Females are but little smaller than
males, and both sexes, when mature, have the throat black.
The Divers undergo a partial moult in the spring, and the
black-throat on its first assumption is generally varied with
a few white feathers.
A young Black-throated Diver obtained at Nagasaki on the
25th of December has the bill dark horn-colour; the upper
part of the head and neck ash-brown ; the part below the
eye, throat, and underparts dull white ; upper parts blackish,
the upper wing-coverts showing small white spots as in the
adult; axillaries white ; flank-feathers ashy-brown.
Young birds measure twenty-three or twenty-four inches
in length, and, except in size, they resemble the young ot
the Northern Diver; the back of the neck is, however, ot a
much purer grey, and there are none of the indications of
the neck-bands noticeable in the latter.
The form and structure of the legs and feet in these
Divers, and also in the Grebes, are worthy of particular
examination. Though almost useless on land, these members
are most efficient instruments in the water. The bones
are broad and flat, and almost as thin as the blade of a knife ,
when the backward stroke in swimming is given, the whole
surface of all these bones and their investing membranes is
brought to bear against the water ; but when the leg is to be
brought forward again to renew the impulse, the sharp edges
only are opposed to the fluid, and the position, as well as
the partially-rotatory motion, remind the observer of the
action of oars in rowing when used by skilful hands. Those
who have the opportunity of examining the legs of a Divei,
in a recently-killed specimen, while all the parts retain tlieii
perfect flexibility, will find a beautiful example of animal
mechanics.