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persisting during the iceage in different parts of the area north of the glacial börder, 
we must expect many endemisms there, but actual cireumstances are far better in 
accord with a total expulsion and postglacial reimmigration of tlie preglacial flora, 
i. e. the i)resent circumpolar species. Hooker (Outlines) called this flora Scandi- 
navian, but I must agree with Warming, that the name is not well chosen. Firstly 
even the northernmost part of the Scandinavian Peninsula is not an arctic but a 
teinperate land, where the circumpolar species, as far as they are not more or less 
generally dispersed over the temperate parts of Europé, and in many instances of 
Asia also, are found principally in alpine stations. Hooker also explains the abun- 
dance of species in northern Scandinavia as caused by the influence of the Gulf- 
stream, but he does not draw the conckision, that it ought to be compared with 
other temperate floras, not with arctic ones. If we take only the truly arctic types 
in the Scandinavian flora in the balance against those of arctic floras proper, we 
shall get the opposite result, viz., that the alpine (arctic) vegetation of Scandinavia 
is very poor in species. But as most of these species belong to the circumpolar 
flora of preglacial times, the Scandinavian species in Hooker's sense must have a wide 
range over different parts of the world. Special european types are, indeed, as 
Hooker points out, rare in the flora of northern Scandinavia, and even to the 
south, for instance in the mountains of southern and middle Norway they are very 
scarce. The cause for this must be sought in difficulty of migration from the 
central european mountains up to Scandinavia. But we have another small group 
of species common to the Alps and other central european mountains, the Caucasus, 
the Ural, and arctic Russia which enter northern Scandinavia; these are, in my 
opinion, also to reckon as european types, even if some of them may appear for 
instance in the Himalayas. 
The ancestors of the circumpolar plants may have lived in Tertiary times 
somewhere far up in the vicinity of the North Pole on lands uow entirely vanished, 
or they may have existed as alpine species in Greenland or elsewhere, while yet a 
vegetation, requiring a less severe climate, occupied the lowlands. In preglacial 
time this old pohir flora was compelled to wander gradually southward whereever 
there existed a way of migration. It must have been very uniform, so as to add 
nearly tlie same contingent of species to the more southern floras into which it merged, 
or which it replaced on its way southward. When after the maximum of glaciation it 
began its reimmigration northwards, it had got reinforcements of alpine species, 
different in different longitudes. The more the conditions where favorable for such an 
admixture of southern-alpine species to the flora wandering northwards in the wake 
of the melting icesheet or in proportion to the amelioration of climate, the more the 
new flora of the north came to possess of non-circumpolar plants. These *longi- 
tudinal contingents», as they may be styled, became smallest in Europé, larger in 
Asia, and most numerous in America. Greenland takes its own place; it has got, 
besides a considerable contingent of circumpolar plants, also a rather large share of 
anierican types, a great many of which have, as I have pointed out in my Plants 
