BRITISH AND FOREIGN 131 



There are several of these unconscious American importa- 

 tions in various parts of Britain, some of them, no doubt , 

 brought over with seed-corn or among the straw of packing- 

 cases, but others unconnected in any way with human 

 agency, and owing their presence here to natural causes. 

 That pretty little Yankee weed, the claytonia, now common 

 in parts of Lancashire and Oxfordshire, first made its 

 appearance amongst us, I believe, by its seeds being 

 accidentally included with the sawdust in which Wenham 

 Lake ice is packed for transport. The Canadian river- weed 

 is known first to have escaped from the botanical gardens 

 at Cambridge, whence it spread rapidly through the con- 

 genial dykes and sluices of the fen country, and so into 

 the entire navigable network of the Midland counties. But 

 there are other aliens of older settlement amongst us, aliens 

 of American origin which nevertheless arrived in Britain, 

 in all probability, long before Columbus ever set foot on the 

 low basking sandbank of Cat Island. Such is the jointed 

 pond-sedge of the Hebrides, a water- weed found abundantly 

 in the lakes and tarns of the Isle of Skye, Mull and Coll, 

 and the west coast of Ireland, but occurring nowhere else 

 throughout the whole expanse of Europe or Asia. How 

 did it get there ? Clearly its seeds were either washed by 

 the waves or carried by birds, and thus deposited on the 

 nearest European shores to America. But if Mr. Alfred 

 Eussel Wallace had been alive in pre-Columban days 

 (which, as Euclid remarks, is absurd), he would readily 

 have inferred, from the frequent occurrence of such un- 

 known plants along the western verge of Britain, that a 

 great continent lay unexplored to the westward, and would 

 promptly have proceeded to discover and annex it. As Mr. 

 Wallace was not yet born, however, Columbus took a mean 

 advantage over him, and discovered it first by mere right 

 of primogeniture. 



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