30 THE POLAR WORLD. 



than that which now reigns in Southern Sweden and Norway, eighteen degrees 

 nearer to the line. 



We know that at present the fir, the poplar, and the beech grow fifteen de- 

 grees farther to the north than the plantain and the miocene period no doubt 

 exhibited the same proportion. Thus the poplars and firs which then grew 

 in Spitzbergen along with plantains and lindens must have ranged as far as 

 the pole itself, supposing that point to .be dry land. 



In the miocene times the Arctic zone evidently presented a very different 

 aspect from that which it wears at present. Now, during the greater part of 

 the year, an immense glacial desert, which through its floating bergs and drift- 

 ice depresses the temperature of countries situated far to the south, it then 

 consisted of verdant lands covered with luxuriant forests and bathed by an 

 open sea. 



What may have been the cause of these amazing changes of climate ? The 

 readiest answer seems to be a different distribution of sea and land; but 

 there is no reason to believe that in the miocene times there was less land in 

 the Arctic zone than at present, nor can any possible combination of water and 

 dry land be imagined sufficient to account for the growth of laurels in Green- 

 land or of plantains in Spitzbergen. Dr. Oswald Heer is inclined to seek for 

 an explanation of the phenomenon, not in mere local terrestrial changes, but in 

 a difference of the earth's position in the heavens. 



We now know that our sun, with his attendant planets and satellites, per- 



ARCTIC MOONLIGHT. 



forms a vast circle, embracing perhaps hundreds of thousands of years, round 

 another star, and that we are constantly entering new regions of space untrav- 



