INTRODUCTION OF FOREIGN SPECIIiS. I55 



rior, and in Nova Scotia is said to be the most common 

 of the larger species. That it should occur on the 

 extreme point of a cape extending far into the sea, and 

 on desolate islets along the coast, is consistent with the 

 supposition of its having been borne there by currents ; 

 while the common mode of distribution, bj numerical 

 increase and extension, or by direct introduction through 

 commercial agency, from Europe, does not explain why 

 it is found in such unfrequented spots only, on the bor- 

 ders of the sea alone, never upon the main land, and on 

 some islets, but not on others. Our own hypothesis is, 

 that having been very early introduced into the French 

 province of Acadia, (and also into Canada) by the 

 European colonists, and become numerous there, it has 

 been borne along the coast by counter currents and 

 eddies, to the places which it now occupies, where, being 

 protected from other animals, and from the operations of 

 agriculture, to which it would have been exposed on the 

 main land, and under the influence of a climate rendered 

 mild by the proximity of the sea, it has multi])lied to a 

 great extent.' 



J Since the above obsen'ations were penned, the author has again 

 vLsiled, after an interval of nine years, the locality upon Salt Island, 

 Cape Ann. Tliis island, which at extreme low water is connected with the 

 main by a narrow sand-bar, is a mass of granite elevated not more than 

 sLxty or seventy feet above the sea ; its seaward side is bold and precipitous, 

 and being open to the assaults of the waves, is denuded of soil to the very 

 smuinit. Its landward side, protected by the crest of the island from 

 storms coming- from the ocean, has a thin superstratum of soil, whicli sup- 

 ports a rank growth of coarse grass and low slirulss, tlie latter allbrding a ' 



