STEJNEGER] ANIMALS AND PLANTS OF NORWAY 491 
proof of an uninterrupted land bridge. It has been shown that 
some plants travel considerable distances across the ocean and be- 
come established, “remember Jan Mayen”! to use Warming’s ex- 
pressive and effective slogan. Jan Mayen island is located 240 
miles (450 kilometers) from Greenland, the nearest land, exactly 
the distance between Scotland and western Norway, and it is about 
as certain as such an assertion can be, that its 39 vascular plants 
have come across the sea. Such a flora, however, in its composition 
shows its accidental character. On the other hand, the example 
of ‘‘ Gottska Sandee,” in the Baltic, a small island situated less than 
20 miles (37 kilometers) from the large island of Gotland and 50 
miles (93 km.) from the mainland of Sweden, a moraine bank 
emerged from the sea during the Littorina epoch of postglacial 
times, shows that complete plant associations may be transported 
over the sea. Sernander (Skandinaviska Vegetationens Spridnings- 
biologi, Upsala, 1901, p. 407) remarks expressly that “in none of 
its plant associations are any gaps noticeable in comparison with 
the corresponding associations on the mainland,’ but the distances 
here involved are slight, of course, compared with those between 
the Fzr6es and Scotland or between the latter and Norway. With 
regard to the Feroes it is difficult to believe that’ so complete a 
representation of the Scotch flora could have crossed a sea about 
170 mile (315 km.) wide, the distance from Scotland at the present 
level of the sea. If we assume, however, that the Fzroes were 
connected with Scotland during the maximum glaciation, and that 
this connection afterwards ceased through a gradual submergence, 
it is evident that the distance between land and land for a consider- 
able time cannot have been much more than 60 miles (111 km.). 
The conditions under such circumstances must have been favorable 
enough to have allowed the immigration of the temperate Atlantic 
species to which such a distance would not be prohibitive. This 
suggestion would explain the whole of the Feeroe situation, and I 
hope further on to show that it is the probable solution. 
Applying the above to the question of the invasion of the west 
Norway biota we conclude that the so-called Atlantic and Arctatlantic 
flora there cannot have crossed the North Sea as it is now limited. 
On the other hand, I am not prepared to deny the possibility of the 
whole assembly having crossed the 40 miles (74 km.) of the Nor- 
wegian channel, though I confess that I have my doubts whether 
such plants as the 27 species of Atlantic hepaticze could have been 
transported that distance over the sea. But the most important 
