182 ISLAND LIFE 



epochs of glaciation far exceeding what now prevails ; and 

 it is therefore necessary to examine the evidence pretty 

 closely in order to see if this view is more tenable in the 

 case of the north polar regions than we have found it to 

 be in that of the north temperate zone. 



The most recent of these milder climates is perhaps 

 indicated by the abundant remains of large mammalia — 

 such as the mammoth, woolly rhinoceros, bison and horse, 

 in the icy alluvial plains of Northern Siberia, and especially 

 in the Liakhov Islands in the same latitude as the North 

 Cape of Asia. These remains occur not in one or two 

 spots only, as if collected by eddies at the mouth of. a 

 river, but along the whole borders of the Arctic Ocean; 

 and it is generally admitted that the animals must have 

 lived upon the adjacent plains, and that a considerably 

 milder climate than now prevails could alone have enabled 

 them to do so. How long ago this occurred we do not 

 know, but one of the last intercalated mild periods of the 

 glacial epoch itself seems to offer all the necessary condi- 

 tions. Again, Sir Edward Belcher discovered on the dreary 

 shores of Wellington Channel in 75J° N. Lat., the trunk 

 and root of a fir tree which had evidently grown where it 

 was found. It appeared to belong to the species Abies alba, 

 or white fir, which now reaches 68° N. Lat. and is the most 

 northerly conifer known. Similar trees, one four feet in 

 circumference and thirty feet long, were found by Lieut. 

 Mecham in Prince Patrick's Island in Lat. 76° 12' N., and 

 other Arctic explorers have found remains of trees in high 

 latitudes which may all probably be referred to the same 

 mild period as that of the ice-preserved Arctic mammalia. 

 Similar indications of a recent milder climate are found 

 in Spitzbergen. Professor Nordenskjold says : " At various 

 l^laces on Spitzbergen, at the bottom of Lomme Bay, at 

 Cape Thordsen, in Blomstrand's strata in Advent Bay, 

 there are found large and well-developed shells of a bivalve, 

 Mytilus edulis, which is not now found living on the coast 

 of Spitzbergen, though on the west coast of Scandinavia it 

 everywhere covers the rocks near the sea-shore. These 

 shells occur most plentifully in the bed of a river which 

 runs through Reindeer Valley at Cape Thordsen. They 



