British North American Plants. 421 



Microstylis monophyllos, Lindl. 

 Juncus articulatus, L. 

 J. Stygius, L. 



These facts clearly prove that if Europe is to be regarded 

 as the point of origin of these various species, their course 

 of distribution must have been westward to Eastern 

 America over some connecting links of communication. If 

 this distribution had been eastward across Asia to this con- 

 tinent, there would have been found full traces of its course 

 not only in Asia but in the vast area of country lying be- 

 tween Ontario and Quebec and the Pacific coast. And yet 

 there are about sixty European species which are not found 

 in Canada west of the Province of Ontario, and a consider- 

 able number of these are not in Japan. 



The large proportion of these identical species which are 

 arctic, antarctic, alpine, or high northern, would imply 

 means of communication between the two continents in 

 high latitudes or at high elevations, and the full representa- 

 tion of aquatic plants, especially among the Typhacece, 

 Lemnacece., Naidacece, and Juncaceos, would indicate ample 

 facilities for the natural distribution of fresh water plants, 

 as well as a coast line for the maritime plants. Currents, 

 no doubt, frequently account for eccentricities in range, but 

 in this case, the present gulf stream flows in the reverse 

 direction to the hitherto received notion of the course of 

 the migration. 



The third consideration that there were facilities for 

 migration, both eastward across Asia and westward to 

 America, and that Canada may even have been the point of 

 origin of many species now apparently native in both 

 Europe and America, is the most reasonable view to take. 

 It has been already shown that there are numerous Euro- 

 pean species at present thoroughly established throughout 

 the eastern half of Canada, though unknown in the western, 

 which have no representatives in Asia, whilst, on the other 

 hand, there are many European plants limited to the same 

 side of the American continent, which are fcund native in 

 Japan as well. The conclusion seems inevitable that there 

 must have been facilities for range in both directions. 



