70 MIGRATION OF PLANTS. [CHAP. V 



beyond these the ocean and blue sky. It was like a vision seen in 

 the clouds, and we were occasionally reminded of &quot; the dissolving 

 views,&quot; when the landscape slowly faded away, and then, in a 

 few minutes, as the fog dispersed, regained its strength as gradual 

 ly, till every feature became again clear and well defined. 



We at length returned to the hotel in the dusk of the evening, 

 much delighted with our excursion, although too fatiguing for a 

 lady, my wife having been twelve hours on horseback. If an 

 inn should be built at the foot of the mountain, the exploit will 

 be comparatively an easy one, and in a few years a railway from 

 Boston, only 150 miles distant (100 miles of it being already 

 completed), will enable any citizen to escape from the summer 

 heat, and, having slept the first night at this inn, enjoy, the next 

 morning, if he is a lover of botany, the sight of a variety of rare 

 and beautiful Arctic plants in full flower, besides beholding a suc 

 cession of distinct zones of vegetation, scarcely surpassed on the 

 flanks of Mount Etna or the Pyrenees. 



If we attempt to speculate on the manner in which the pecu 

 liar species of plants now established on the highest summits of 

 the White Mountains, were enabled to reach those isolated spots, 

 while none of them are met with in the lower lands around, or 

 for a great distance to the north, we shall find ourselves engaged 

 in trying to solve a philosophical problem, which requires the 

 aid, not of botany alone, but of geology, or a knowledge of the 

 geographical changes which immediately preceded the present 

 state of the earth s surface. We have to explain how an Arctic 

 flora, consisting of plants specifically identical with those which 

 now inhabit lands bordering the sea in the extreme north of 

 America, Europe, and Asia, could get to the top of Mount 

 Washington. Now geology teaches us that the species living 

 at present on the earth are older than many parts of our existing 

 continents ; that is to say, they were created before a large part 

 of the existing mountains, valleys, plains, lakes, rivers, and seas 

 were formed. That such must be the case in regard to the 

 island of Sicily, I announced my conviction in 1833, after first 

 returning from that country.* And a similar conclusion is no 

 * Principles of Geology, 1st edition, vol. iii. chap. 9. 



