664 



migration of the flora of Greenland, and having advocated the theory 

 that alter the Glacial Period it had immigrated in part across the sea, 

 I cannot abstain from taking up this interesting question for re- 

 newed consideration so far as the flora of the Færoes is conccrned, 

 which llora was also mentioned in my previous considerations 1 . 



Now, as then, I regard a post-glacial land connection ve ry 

 improbable, and not necessary for the immigration of the 

 Flora, which mav be assumed to have immigrated across the sea. 

 I shall shortly mention the two immigration-hypotheses. 



Immigration across land. The assumption of a land con- 

 nection between Scotland and Greenland, by means of the Færoes 

 and Iceland, is supported by the following data : — 



(1) The submarine ridge which connects the Shetlands-Færoes- 

 Iceland-Greenland, and occurs at a depth of about 300 fathoms 

 (227 — 330) only, and the existence of which has been proved by 

 English, Norwegian, and Danish investigations. The newer Danish 

 explorations (the »Ingolf« expedition) have further made clear how 

 important this ridge is in the biology of the sea, as it forms a very 

 sharp boundary between two deep-water faunas: — An Arctic- 

 Ocean-fauna north of the ridge, and an essentially different Atlantic- 

 Ocean-fauna south of it 2 . 



(2) The geological conformity existing between the islands in 

 question and a part of the east coast of Greenland (Lieut. Amdrup's 

 investigations on his journey along the east coast of Greenland in 

 the year 1900 3 proved, however, that the above- mentioned con- 

 formity did not begin until near Kangerlugsuak about 68° N. Lat., 

 or right to the north of the ridge). 



(3) Recently a third moment has been brought out, viz. the 

 faet that shells of littoral mussels occur at great ocean depths north 

 of the ridge. 



1 Eug. Warming: »Om Grønlands Vegetation« (witli resumé in Ffench). 

 Meddelelser om Grønland, vol. XII, 1888. See also »Tabellarisk Oversigt over 

 Grønlands, Islands og Færøernes Flora«, 1887, in Videnskabelige Meddelelser Ira 

 Naturhistorisk Forening i Kjøbenhavn 1887 



2 See various memoirs of Danish zoologists in »Den danske Ingolfexpedi- 

 tion«, Kjøbenhavn, and H.Jungersen in »Forhandlingar ved 15. Skandinav. Natur- 

 forskare motet«, Stoekholm, 1892, p. 271. Eug. Warming: Meddelelser om Grøn- 

 land, 1. c. p. 176. 



3 See Meddelelser om Grønland, XXVII (with resumé in French). 



