500 PREHISTORIC EUROPE. 



has passed gradually from an arctic to a temperate condition, 

 and is now milder than it has ever been since the close of 

 glacial times. I have come to think, however, that this is too 

 broad a statement, and now incline to the opinion that the cli- 

 mate of the postglacial period, although most probably never 

 so warm as that of the last interglacial epoch, was yet for some 

 time marked by a more genial temperature than we now enjoy, 

 and that this milder epoch was followed by what appears to 

 have been a relapse to colder conditions than the present. I 

 believe, further, that the geographical changes which took place 

 in our own and more northern latitudes during postglacial 

 times were on a far larger scale than most geologists perhaps 

 are aware. This belief has been forced upon me not only by 

 the geological evidence, but also by various considerations con- 

 nected with the present distribution of plants in Iceland and 

 Greenland. Notwithstanding all that has been written upon 

 that interesting subject, there are still many points which want 

 clearing up. Whence, and at what period, did Greenland, Ice- 

 land, and the Fserbe Islands obtain their flora, is a question 

 which has often been asked, but the answers given by eminent 

 botanists have never quite satisfied all geological scruples. 

 Although the subject is beset with difficulties and the evidence 

 is not so abundant as one might well wish, I shall yet venture 

 to say something about it. But, before doing so, it will be well 

 to summarise the main features of the evidence supplied by 

 the postglacial deposits. 



At the beginning of postglacial times the southern region 

 of Scandinavia was submerged for some 400 or 500 feet, and a 

 large part of the Cimbric peninsula was also under water, so 

 that the North Sea communicated with the Baltic across what 

 is now Holstein. The British area, however, would appear to 

 have been not less extensive than it is at present. Indeed, there 

 is reason to believe that England had some direct connection 

 with the Continent. The climate was still ungenial, but 

 was gradually becoming less so. This is shown particularly 

 by the character of the shells in the postglacial beds of 



