22 THE MIGRATIOX OF BRITISH BIRDS 



Greenland by way of Iceland and the P^aroes. Such a 

 land mass would eftectually shut out the Gulf Stream 

 from the shores of Norway, and render the climate of 

 that area too rigorous for the luxuriant flora which 

 pala2ontological evidence proves to have occupied the 

 land after the Ice Age passed away. I would suggest 

 a greater extension of land between Greenland and 

 Europe in the form of islands ; and that a greater land 

 surface occupied this region during some portion of 

 Post-Glacial time (after the third glacial period) is con- 

 firmed in a remarkable way by the migratory birds that 

 follow this now submerged area, as we shall learn in a 

 later chapter. Professor Geikie's views on the geography 

 of this region during absolute Post-Glacial time (his first 

 age of forests), in which he maps out Europe and Green- 

 land united by an isthmus, seem therefore untenable. 



Evidence for the greater extension of land between 

 Greenland and l^^urope during early Post-Glacial time is 

 furnished by the flora, and to a less marked extent by 

 the fauna. So great an authority as Sir Joseph Hooker 

 has shown the Scandinavian or North-west European 

 character of the flora (through Iceland and the P'^aroes), 

 and the paucity of Arctic American elements. So far 

 as the mammals arc an indication, we have the Arctic 

 fo.x (remains of which have recently been found in the 

 south of England) and the polar bear, found also in 

 Iceland.^ On the other hand, three other species are 

 exclusively North American, although the fossil remains 

 of one of them, Ovihos (the musk sheep), occur in the 

 Post-Glacial gravels of Siberia, Germany, and I'rance, 



' There is, Iiowcver, always the stron;.,^ probability of these ani- 

 mals reachin;^ Iceland on lloatint^ ice. 



