There are in all groups of animals instances of species which are confined to Europe and North America, while unknown from the Asiatic continent, but none, as far as is known, have such a very discontinuous range as that of the animals and plants just referred to. In some cases the species still occur in Greenland, and in this way make it still clearer that their migration in former times took place from one continent to the other by way of that country. As an interesting instance of such distribution may be mentioned the Common Stickleback (_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.