_Gasterosteus aculeatus_), which is found in Greenland, North America,
and Europe, but is quite absent from Asia. Then again, the Nine-spined
Stickleback (_Gasterosteus pungitius_) is confined to Western Europe
and North America, though an allied species, _Gasterosteus sinensis_,
lives in China and has probably penetrated there from the New World
across the old Behring Straits land-connection.

The Coleoptera _Diachila arctica_, _Elaphrus lapponicus_, and _Blethisa
multipunctata_ are good instances of species which have come to us from
North America by way of Greenland. I have already referred to the
Lepidoptera, but might add that eleven species of _Anarta_ occur in
Scandinavia, eight of which reappear again in Labrador, none of them,
however, being met with in Siberia. Then again, take the interesting
Crustacean _Lepidurus (Apus) glacialis_. It is found in Greenland,
Spitsbergen, Lapland, and Norway; and formerly, as we know from fossil
evidence, it ranged into Scotland. Another Phyllopod, viz.,
_Branchinecta paludosa_, inhabits Greenland, Lapland, and Norway. Mr.
Kennard suggests that the freshwater Snail _Planorbis glaber_ might also
belong to the same migration. And there are no doubt large numbers of
others.

Professor Emery mentions that Northern Europe possesses one peculiar
genus of Ant, viz., _Anergates_. This is closely allied to _Epoccus_,
another genus confined to North America. It seems probable, therefore,
that both of these have sprung from an Arctic genus which sent two
branches southward into the two continents without there being any
migration through Asia.

The general range of the Arctic plants and animals gives no reason to
suppose that the Greenland fauna and flora of the present day were
exterminated by the Glacial period and then reintroduced into that
country. Nor have we any evidence that such a fauna and flora migrated
across the British Islands northward. The Greenland animals and plants
too are altogether much more like the Lapland ones than those of
Scotland. It will also become evident to the reader of this work that no
very extensive migrations could have taken place during the post-glacial
period, and that almost everything points to a survival of both fauna
and flora in northern latitudes throughout the Glacial period.

If we take into consideration the palaeontological evidence of the two
races of Reindeer in Europe, one of which came to us from the north, and
that the Arctic Hare