are concerned, there can be no difficulty in recognizing the
two forms. It is, however, less easy to separate the immature
birds, unless the sex of the specimen is known, for a
young male of C. glacialis is as large as a young female of
C. adamsi. Both species are said by Mr. E. W. Nelson to
be found on the shores of the Arctic and Bering Seas, and the
latter, which he considers to have a circumpolar distribution,
is also found throughout the North Pacific, visiting Japan in
winter; indeed its range appears to extend along the Arctic
coast of Siberia, at least as far as the mouth of the Yenesei,
where Mr. Seebolim was told of a species larger than the
Black-throated Diver, which frequented the lakes of the
‘ tundras ’ and had a white bill. It has moreover been
stated that C. adamsi occurs on the coast of Scandinavia;
and an immature Diver, with a thickened and whitened
bill, shot on the coast of Suffolk, and belonging to Mr. J. H.
Gurney, was exhibited by Mr. Sclater at a meeting of the
Zoological Society (P. Z. S. 1859, p. 206), and supposed to
be an example of this species ; it must, however, be remembered
that in the young Great Northern Diver the bill
is frequently of a pale horn-colour, and, in the male, of large
dimensions.
During their breeding-season the Northern Divers frequent
islands, in lakes and pools of fresh water, forming a
flattened nest of dead herbage, among reeds and flags, from
eight or ten yards to a distance of forty yards from the
water’s edge. The frequent passage of the birds to and
from their nest to the water produces a path or track, by
which the nest is sometimes discovered. Mr. Proctor thus
notices what occurred to him, in reference to this species,
on his visit to Iceland :—“ It breeds on the lochs of fresh
water about a day’s journey from My-vatn ; a single egg was
deposited on the bare ground, but just out of water-mark,
rather under a rugged bank on some broken ground. I was
successful in finding two nests. I allowed the single egg to
remain in one of them, in the expectation that another egg
would be laid to it, but was disappointed. The old bird was
very shy, and always left the egg on our approach, when at
a great distance off, taking to the water and keeping so far
from the side as not to be within shot.”
The eggs are usually two in number, but Audubon says,
in his account of this species, that in North America three
are more frequently deposited. They are of a dark olive-
brown, with a few spots of umber-brown; average measurements,
3-5 by 2-25 in. The female when on her nest lies
flat upon her eggs, and if disturbed by the too near approach
of an intruder, makes her way to the water by scrambling,
sliding, and pushing herself along, occasionally running with
the body inclined forwards ; the thighs being closely attached
to the hinder part of the body, the motion is principally confined
to the tarsi and toes. The water gained, she immediately
and invariably dives rather than flies off, sometimes
using the wings under water. Though its wings are short,
the flight of the bird is strong and rapid, but it usually
resorts to diving to effect an escape.
Montagu, in the Appendix to the Supplement to his
Ornithological Dictionary, says, “ A Northern Diver taken
alive, was kept in a pond for some months, which gave us
an opportunity of attending to its manners. In a few days
it became extremely docile, would come at the call from
one side of the pond to the other, and would take food
from the hand. The bird had received an injury in the
head, which had deprived one eye of its sight, and the
other was a little impaired ; but, notwithstanding, it could,
by incessantly diving, discover all the fish that was thrown
into the pond. In defect of fish it would eat flesh. It is
observable that the legs of this bird are so constructed and
situated, as to render it incapable of walking upon them.
This is probably the case with all the Divers, as well as
the Grebes. When this bird quitted the water, it shoved
its body along upon the ground like a seal, by jerks, rubbing
the breast against the ground; and returned again to
the water in a similar manner. In swimming and diving,
the legs only are used, and not the wings, as in the Guillemot
and Auk tribes ; and by their situation so far behind,
and their little deviation from the line of the body, it is