144 
ROLF NORDHAGEN. 
(from Ob— the Kirghiz-Steppe— the south of Ural — the Caspian — 
the Black Sea). — Nor is a chance transport with hirds across 
the Atlantic more imaginable. This explanation is in either case 
rather far from being an appeasement. 
Strong vvinds no doubt bears a prominent part in spreading 
seeds and spores over smaller distances, but as they are of 
rather a local nature, their carrying capacity must not be 
overestimated when areas as considerable as in the present 
case are concerned. — The author has therefore come to the 
result that a satisfactory theory can not be based upon these 
means of conveyance — the birds and the winds. 
Man has directly and indirectly assisted in introducing a 
very great number of plants to Europe, and among them many 
American species. Some of these plants are now troublesome 
weeds in Europe. But Ranunculus Cymbalaria can not be 
included in the category weeds. It is however not impossible 
that the plant has been brought to Norway with a ship from 
America. But Hvaler is a place with unimportant traffic ; the 
inhabitants are fishermen and peasants, and only a few small, 
local steamers call at the islands. There are no ballast places, 
no manufactories, and no rich weedflora. — Ranunculus Cym- 
balaria seems to be just as wild or spontaneous in Norway as 
for instance Eriocaulon in Ireland. And it is not at all more 
probable with respect to the former that it has been introduced 
by man, tban with the latter. 
As the plant grows near the sea on a place which is over- 
washed at spring flood, it is not unnatural to think of the sea- 
currents as means of conveyance in this case. It is a fact 
that the Gulf Stream transports wood and seeds of great 
many American plants to Scandinavia (cfr. Lindman, Sernander 
1. c.); and as Ranunculus Cymbalaria grows on sandy shores 
from Labrador to New Yersey, it is not improbable that seeds 
of this „sea side crowfoot“ (Britton & Brown) have been 
brought to Europe across the Atlantic with currents, either alone 
