118 



that the chief part of the present flora of the Færoes 

 (I am only speaking of the vascular piants) has migrated across 

 a post- glacial belt of land. The piants then have migrated 

 »step by step and in collected bodies«, as is held also by A. Blytt 

 (Englers Jahrbiicher, p. 47) with regard to the Norwegian flora. 



Apart from this, a few species have been introdiiced by the 

 agency of the wuids (and birds?). This, I think, explains why 

 some of the species have only been found either at a single place 

 or at a few piaces. As examples I may mention species such as 

 Salix glaiica and Dryas, which, being well adapted to be carried 

 by the wind, have been found on a few of the higher mountains 

 towards the north-east. If we regard them as survivals (relicts) 

 we shall be at a loss to explain why they do not occur on other 

 mountain summits of a similar height and having the same con- 

 ditions of life. — 



Lastly I will say a few words about man 's influence on 

 the immigration. In my »Phanerogamae and Pteridophyta«, 

 f denotes that the species has been lately introduced by human 

 agency and has not yet become naturalised, but besides these I 

 think that some of the others migrated into the Islands when man 

 began to cultivate the ground, and they are now found whereever 

 the land is cultivated, but they have as yet had too short a time to 

 extend beyond the cultivated area, though a few, e. g. Ranuncnliis 

 repens and TrifoUnm repens spread beyond and folio wing the moun- 

 tain paths even extend some way up the bilis. J. M. Norman^ 

 mentions similar cases in Arctic Norway. 



As examples of species introduced by man and now regarded 

 as indigenous may be mentioned: — 



Myosotis arnensis. Spergnla arvensis. 



— versicolor. Stellaria media. 



Senecio vnlgaris. Capsella bnrsa pastoris. 



Tanacetum vulgare. Lathyrus pratensis. 



Tiissilago Farfara. Trifolinm repens. 



Galeopsis Tetrahit. Vicia Cracca. 



Veronica Beccabnnga. Polygonum amphibium. 

 Cerastiam glomeratum. — aviculare. 



^ J. M. Norman: Norges arktiske Flora. II. Oversigtlig Fremstilling, 1ste Halv- 

 del. Kristiania 1895, p. 24 and p. 196. 



