114 



tion of the connecting' strips of land. This then suggests with 

 some certainty that the lands were formerly connected, but it tells 

 us nothing with regard to this connection having been pre-glacial 

 or post-glacial, and we have no strong geological evidence to prove 

 either theory. A circumstance, which, however, seems to favour the 

 theory of a post-glacial land-bridge, has lately been mentioned by 

 the Danish zoologist Adolf J ensen ^ On investigating the mollusc 

 material brought home by the Danish Ingolf- Expedition it was 

 proved, that at several stations in the sea between Jan Mayen and 

 Iceland and towards the Færoes a large quantity of mussel shells 

 were found at a depth of upwards of 1300 fathoms, while living 

 specimens of these animals are never met with at a grcater dej)th 

 than some 100 fathoms. This in connection with the find of oto- 

 liths^ of several species of Gadus which are otherwise only found 

 along coasts seems to prove that an upheavel of enormous dimen- 

 sion (some 1200 fathoms) must have taken place since the days 

 when they were actually living. Mr. Adolf Jensen fixes this time 

 as late-glacial , and it seems to me that there is nothing wrong in 

 supposing that the subsequent sinking process was so gradual that 

 it extended far into the post-glacial period. (Further information 

 on this point can be found in the papers quoted). If in the future 

 this assumption should be proved to be correct, then the theory of 

 the land-connection would become a recognized faet, as an eleva- 

 tion of 3 — 400 fathoms would suffice to produce the connecting 

 bridge between East Greenland and Scotland. Moreover, as there 

 is no geological evidence against this theory, we may fairly base 

 the hesitation in accepting this assumption on an unwillingness 

 to believe that such enormous geological changes could have taken 

 place at so late a period, for almost all geologists have admitted 

 small upheavels in the post-glacial period (lake of Ancijlus) in the 

 case of Northern Europe. 



J. Geikie, who in his »Prehistoric Europe« propounds the 

 theory of the post -glacial connection of lands, says very little in 

 defence of it, as he has no geological evidence in its support and 

 his sole argument, the composition of the flora, has not been suf- 



^ Adolfs. Jensen: Om Levninger af Grundtvandsdyr paa store Havd3'b 

 mellem Jan Ma3'en og Island (Vidensk. Medd. f. d. Naturhist. Forening i Kjoben- 

 havn, 1900, p. 229). 



^ See Idem: Hvorfra stamme Otolitherne i »Ingolf«s Bundprover. Ibidem 

 1900, p. 243. 



