292 Scientific Results of 



any admixture of American types, which nevertheless are 

 found on the opposite coast of Labrador and the Parry Islands. 

 3. A considerable proportion of the common Greenland plants 

 are nowhere found in Labrador and the Parry Islands, nor, 

 indeed, elsewhere in the New World. 4. The parts of Green- 

 land south of the Arctic circle, though warmer than those 

 north of it, and presenting a coast 400 miles in length, con- 

 tain scarcely any plants not found to the north of that circle. 

 5. A considerable number of Scandinavian plants which are 

 not natives of Greenland are nevertheless natives of Labrador 

 and the Parry Islands. 6. Certain Greenland and Scandi- 

 navian plants, which are nowhere found in the polar plains, 

 Labrador, or Canada, re-appear at considerable elevations on 

 the White, and the Alleghany, and other mountains of the 

 United States. No other flora known to naturalists presents 

 such a remarkable combination of peculiar features as this, 

 and the only solution hitherto offered is not yet fully accepted. 

 It is that the Scandinavian flora (which Dr. Hooker has shown 

 evidence of being one of the oldest on the globe) did, during 

 the warm period preceding the glacial — a period warmer than 

 the present — extend in force over the Polar regions, including 

 Greenland, the polar American islands, and probably much 

 now submerged land in places connecting or lying between 

 Greenland and Scandinavia, at which time Greenland no doubt 

 presented a much richer Scandinavian flora than it now does. 

 On the accession of the glacial period, this flora would be 

 driven slowly southward, down to the extremity of the Green- 

 land peninsula in its longitude, and down to the latitude of 

 the Alleghanies and White Mountains in their longitudes. 

 The effect in Greenland would be to leave there only the 

 more Arctic forms of vegetation, unchanged in habits or 

 features, the rest being, as it were, driven into the sea. But 

 the effect on the American continent would be to bring the 

 Scandinavian flora into competition with an American flora 

 that pre-occupied the lands into which it was driven. On the 



