160 THE CANADIAN NATURALIST. [Juuc 



These additions were largely influenced by the constant play 

 of the Arctic current upon our shores. It acted as a circum- 

 polar distributor of species, and to it the wide range of many 

 Arctic and Boreal plants is evidently due. Entering the Polar 

 Sea between Norway and Spitzbcrgen, it sweeps round the ice- 

 bound shores of the Old World by Russia and Siberia. Aa 

 insignificant branch escapes into the Pacific by Behring's Straits, 

 but the main body of the current continues its course through 

 the Georgian Archipelago, and passes into the Atlantic again 

 between Greenland and Labrador. The retarded rotation of the 

 earth throws this current, when entering the Polar Sea, upon the 

 coast of the Old World; the accelerated rotation felt by the 

 same moving mass of water on its southward course causes it to 

 cling to the shores of America from Labrador to Florida, and 

 envelope the eastern part of the British Possessions, which are 

 fully exposed to its chilling influence. The principal body of 

 the current passes southward around Newfoundland, but a branch 

 goes westward between this island and Labrador, through the 

 Straits of Belleisle, and courses around the Gulf of St. Lawrence, 

 as has been already stated. 



It is the transporting power of this current as a whole, and of 

 this branch, in particular, which has more directly influenced the 

 vegetation of our country. 



Three of the largest rivers in the Old World, and an equal 

 number of those in the New, help to freshen the waters of this 

 great oceanic stream. The Spring floods of the great Siberian 

 water-courses sweep down into it vast quantities of drift-wood 

 and debris filled with the seeds of plants. Many of these are 

 carried onward in the floe-ice toward the American coast, where 

 they receive accessions from the McKenzie River, and in the 

 course of years work their way through the group of islands 

 between North America and Greenland. The Saskatchewan 

 River also contributes its quoti of organic relics to the burden 

 borne on the bosom of the Polar current from the Arctic regions 

 of the three continents. The peculiarity of all these great 

 water courses is, that their sources are in temperate latitudes, 

 while their embouchures are in Arctic or Sub-Arctic regions, and 

 thus the waste of vegetation which they bear downward toward 

 the sea, when they are swollen by melting snows, is cast upon the 

 ice about their mouths. The seeds of plants flourishing in the 

 regions from which these rivers flow might thus very readily be 



