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DIVERS, GREBES, AND CORMORANTS. 159 
at the least danger the alarm is given, and the in- 
cubating partner shuffles off in a floundering way 
to the water. A path is soon thus worn from the 
nest to the lake. The eggs are almost invariably 
two, elongated, and varying in ground colour from 
russet-brown to olive-brown, spotted sparingly with 
blackish-brown and paler brown. When the young 
are sufficiently matured, the inland haunts are 
deserted, and the nomad wandering life upon the 
sea resumed. 
BLACK-THROATED DIVER. 
The present species of Diver (much smaller than 
the preceding), the Colymbus arcticus of Linnzeus 
and most other writers, is the rarest of the three 
that visit the British Islands regularly, and perhaps 
we might also say the most beautiful in nuptial 
dress. All its showy colours and patterns, however, 
are on the head, neck, and upper parts, the under 
surface being white. The head is gray, the throat 
patch black, above which is a semi-collar of white 
striped vertically with black; the sides of the neck 
are also striped with black and white; whilst the 
black upper parts of the body are conspicuously 
marked with a regular series of nearly square white 
spots, becoming oval in shape on the wing coverts: 
the bill is black, the irides crimson. After the 
autumn moult all this finery is lost, and the upper 
parts become a nearly uniform blackish - brown. 
This Diver breeds sparingly in various parts of 
the Hebrides and the Highlands, from Argyll to 
