678 



Færoes, which place it at least visits during the migratory llight; 

 moreover, it flies along the extreme west coast of Europe, doubt- 

 less to Africa; in Norway it appears to be totally absent, and in 

 Denmark it occurs extremely rarely. 



Ocean curien ts too are doubtless of no consequence to-day 

 as transporters of land-plants to the Færoes. Ostenfeld (p. 115) 

 has already mentioned that ocean currents are »as unfavourable as 

 possible,« and the condition of the oceanic plankton gives the same 

 proof (Ostenfeld; and pp. 558— 612 above). Besides, judging from 

 the bottles thrown out by the »Ingolf« expedition the polar current 

 from off the east coast of Iceland appears to run in a semi-circle, 

 from the east of Iceland, along the Færoes, and towards the north- 

 east. Hence, the seeds it might convey, must corae from the 

 northern regions 1 . 



Floating ice, icebergs, and floating timber are, at the 

 present day, undoubtedly of still less importance than ocean cur- 

 rents, or rightly, of no importance whatever. But I think it is 

 possible that in former times, especially in the late-glacial , or at 

 the beginning of the post-glacial period , they might have been in- 

 strumental in transporting the arctic species, which occur to-day in 

 the Færoes, from Iceland, Scotland, also perhaps from Norway or 

 from the north-west. These unquestionably first existed in the low- 

 lying districts of the islands, whence they were expelled to their 

 present habitats on the higher hills 2 . 



I am inclined to believe, now, more so than formerly, that the 

 wind (a factor to which Ostenfeld (p. 117) also assigns some im- 

 portance) is of great consequence as a means of transport 3 . 



1 See C.Wandel: »Stromflasker« : Den danske Ingolfexpedition, vol. I, No. 4, 1899. 



2 On the transport of seeds by ocean currents, ice, etc, see Warming: 

 Grønlands Vegetation, p. 200. — On the transport by floating timber. see parti- 

 cularly Kjellman: Vega Expeditionens Vetenskapliga lakttagelser, I, 188'2, p. 351. 

 On the transport of materials by floating ice, see also Eberlin: »Naturen«, 1.S.S7; 

 Fr. Nansen in Broggers work (p. 74) already cited p. G67. and in »Naturen« 1890, 

 p. 75. Amdrup: Meddelelserom Grønland, XXVII, p. 365. For accounts of the 

 occurrence of algæ on ocean ice, see Wille: in Botaniska Notiser, 1897, p. 8. — 

 P. T. Cleve, Microscopical examination of dust from drift-ice north of Jan Maven 



Ol'versikt af K. Vet. Akad. Forhandlingar. 1900, p. 393). 



:i See Warming: »Grønlands Vegetation« (p. 206) where I have given some 

 data. Wille (1. c.) has also given some, and he refers to Ehrenberg's papeis on 

 »Passatstaub und Blutregen«, and »Obersicht der seit 1847 fortgesetzten Unter- 



