Reviews— Dr. James Geikieh Great Ice Age, 35 



occupied the fiords of Western Norway. The Baltic basin was 

 niled by an ice-stream which extended over North Germany and 

 -Uenmark. Subsequently a wide area in Scandinavia was submerged 

 ma cold sea. Large glaciers reached a long way down the Alpine 

 valleys, but not so far as in the preceding Glacial epoch. 



IX. Fourth inter-Glacial Epoch. At its climax, the conditions 

 were sufficiently temperate to allow of the growth of forests in 

 northern regions where they cannot live at the present day. Britain 

 was united with the Continent and the Baltic was chan"-ed into a 

 great lake. *=■ 



X. Fifth Glacial Epoch. The coast-lands of Scotland were sub- 

 merged to about 50 feet below their present level ; local or valley 

 moraines were formed in the British Isles, and their position indicates 

 that the height of the snow-line was then about 2500 feet. Most of 

 thecorrie rock-basins of the British Isles may be assigned to this 

 period. In the Alps the epoch is marked by the moraines of the 

 so-called " second post-Glacial stage." 



XL Fifth inter-Glacial Epoch. An elevation of the land took 

 place and the valley glaciers retreated. The upper " buried forests " 

 in the peat-bogs of North-west Europe show that the climate was 

 drier and very favourable to forest growth. 



XII. Sixth Glacial Epoch. The later raised beaches indicate a 

 slight submergence, not exceeding 20 to 30 feet, in Scotland. The 

 climate was more humid and more suitable for the growth of peat 



oln".*'! ^''^^^^^- ^^^ snow-line in Scotland was at an elevation of 



0000 reet. 



XIII. The Present. Distinguished by the retreat of the sea to its 

 present level, milder and drier climate, and the final disappearance 



01 permanent snow-fields. 



As in the case of Scotland, the above summary of the succession 

 of events during the Ice Age in Europe generally, brings before us 

 so many alternations involving radical changes of climate and re- 

 peated advances and retreats of the sea, that the question will 

 naturally arise whether the fresh evidence gained during the last 

 seventeen years is sufficient to support the idea that such 

 a marvellous series of changes can have taken place in such a 

 ^-'f^^l^V^^^o^^'^ geological history. Looking back to the edition 

 ot 1877, we there find that the glacial deposits of Europe were 

 considered to indicate tim periods of intense glacial conditions 

 and that during the first of these there was a subordinate intervai 

 ot milder chmate, and a more strongly marked milder period- 

 called the last inter-Glacial— intervened between the two severe 

 Glacial periods. Now, however, an alternate succession of no fewer 

 than SIX Glacial and five inter-Glacial epochs is put before us as 

 the latest interpretation of the evidence. But even acceptino- the 

 important additional evidence resulting from the more detailed 

 study of the glacial deposits of Northern and Central Europe it 

 seems to us insufficient to establish that multiple succession' of 

 boreal and temperate epochs which is pictured to us as recurrino- 

 see-saw fashion, during the later portion of the Ice Ao-e °' 



