94. Dr, Dawsoii on the Flora 



islet anywhere on the coast of America from Cape Breton to the 

 arctic seas, and when winter wraps everything in a mantle of 

 snow, all these lands are in like manner under the same conditions. 

 So in the Post-pliocene period, though the islets of the White 

 Mountains may have experienced a less degree of winter cold, 

 they must have had very nearly the same summer temperature as 

 now; and as this is the season of growth for our alpine and arc- 

 tic plants, it is its character that determines the suitableness of the 

 locality to them. 



Those stupendous vicissitudes of land and water which have 

 changed the aspect of continents, and swept into destruction races 

 of gigantic quadrupeds, have dealt gently with these alpine plants, 

 which long ages ago looked out upon a waste of ice-laden waters 

 that had engulfed the Pliocene land with all its inhabitants, as 

 securely as they now look down upon the pleasant valleys of New 

 England. It is curious too that the humbler tenants of the sea 

 have shared a similar exemption. In the clay banks of the Saco, 

 on the shores of Lake Champlain, and mixed with the remains 

 of these very plants in the valley of the Ottawa, are shells that 

 now live in the Gulf of St. Lawrence and on the coast of Maine, 

 intermixed with other species that are now found only in a few 

 bays of the Arctic seas. Just as in the Post-pliocene clays of the 

 Ottawa, the remains of arctic plants are found in the same nodule 

 with those of Leda truncata, so now similar associations may be 

 taking place on the coasts at the mouth of the Great Fish River. 

 Truly, in nature as in grace, God hath chosen the weak things of 

 the world to confound those that are mighty, and has left in the 

 earth's geological history, monuments of his respect and regard 

 for the humblest of his works. 



We look in vain among the alpine plants so long isolated in 

 these mountains, for any evidence of decided change in specific 

 characters. The alpine plants for ages separated from their arc- 

 tic brethren, are true to their kinds, and shew little tendency to 

 vary, and none to adapt themselves to new forms in the sunny 

 plains below. This is especially noteworthy in Mount Washing- 

 ton and the neighboring peaks, because the soil of these is the 

 same with that of the valleys below. Several of the plants pecu- 

 liar to these hills, as the black crow-berry (Fmpetrum nigrum), 

 for instance, even when other conditions are favourable, shun rich 

 calcareous soils, and aft'ect these of granitic origin. In many cases 

 the difference in soil is a sufficient reason for the non-occurrence 



