460 SMITHSONIAN MISCELLANEOUS COLLECTIONS [voL. 48 
European lowlands, the other composed of Russo-Siberian types, 
were easily recognized end accounted for. As the flora of Norway, 
especially the western part, became better known, a third element 
obtruded itself, namely, the one which Professor Axel Blytt called 
“the Atlantic group” of plants. These plants’ he suggested had 
come from the “south and southwest,” but from the context 
(Forhandl. Vidensk. Selsk. Kristiania, 1893, 11, No. 5, p. 11) it is 
evident that he means the Danish peninsula, Jutland, the direction 
“south and southwest” being relative to his place of residence, 
Kristiania, not to western Norway.? Altogether the Norwegian 
botanists have been very vague in their statements regarding the 
origin of this flora, even Dr. Jens Holmboe, as late as 1903 (Skr. 
Vidensk. Selsk. Kristiania, 1903, 1, No. 2, p. 201) speaks of the 
“Tlex flora” having “immigrated across the sea from the south- 
west,” and of Calluna vulgaris he says (p. 213) that it is most 
reasonable to conclude that it has “ immigrated across the sea,” but 
by referring to the possibility of it crossing “an arm of the sea 
as broad as the Skagerak between Jutland and the south end of 
Norway ” he plainly indicates the way he thinks it has come. The 
Swedish botanist, Dr. R. Sernander (Skand. Veget. Spridningsbiol., 
IQOI, pp. 414-416), is more direct, for he speaks (p. 416) of the 
Ilex-plants coming “clear across the Skagerak.’* Most of the 
botanists, however, have held that the west Norwegian flora has 
wandered step by step and slowly from south Sweden to south- 
eastern Norway and thence along the south coast past Lindesnzs 
and Stavanger to Kristianssund and the Trondhjemsfjord. As 
this question has been discussed voluminously and in great detail 
by the botanists, and as from the standpoint of the terrestrial ani- 
mals it has received but little attention from the zoologists, the 
latter, as a rule and without questioning, have accepted the view of 
the majority of the botanists. 
In February, 1901 (Amer. Natural., Xxxv, pp. Iog-112) I had 
occasion to publish my theory that a certain number of animals 
‘ 1For a definition of this group see further on p. 484. 
*In his original paper on the immigration of the flora of Norway (Nyt 
Mag. Naturvid., xx1, 1876, p. 349) Blytt hints at the possibility of the “ At- 
lantic” flora having come to western Norway from a hypothetical “ North 
Sea land,” but because of the deep water along the west coast and of the 
Norway channel he thinks “it would be over bold to assume a land connec- 
tion between our west coast and such a North Sea land.” 
*And even under this supposition he is surprised that they can have 
reached as far north as they have, “past Lindesnes degree by degree of 
latitude up to Kristianssund” (p. 415). 
