[14] 



present west coast of Norway to Denmark, the Nether- 

 lands, across to Essex, central Norfolk (east Nor- 

 folk and Suffolk being part of North Sea), and up to the 

 Shetlands, at which point a turn was made south to a 

 few miles west of present west coast of Ireland, and 

 thence southward to a few miles west of present coast 

 of Brittany, in France, thus leaving the British Isles, 

 France, and the rest of Europe as one large continent. 

 To accomplish these enormous changes, a very long time 

 was required, during which the climate was gradually 

 becoming more temperate, being in older Pleiocene 

 times sub-tropical and in newer Pleiocene warm-tem- 

 perate ; while the fauna and flora gradually became less 

 tropical in kind. The older Pleiocene deposits are 

 divided into coralline crag and reg crag, while the newer 

 Pleiocene consist of Norwich crags and Weybourne 

 sands, on a level with which latter was the Cromer 

 forest, submerged by the North Sea during the earlier 

 Pleistocene period. 



At this point commence those enormous alterations in 

 the surface level and climate of this part of the world 

 which produced such extraordinary results, and during 

 which man made his first appearance in Britain. At the 

 very commencement of the Pleistocene era the tempera- 

 ture in Britain was lowered to such an extent as to pro- 

 duce a sudden disappearance of the semi-tropical fauna 

 and flora : the land had reached the high elevation of 

 500 feet above the present level, joining Scotland and 

 Scandinavia, and there had appeared in the North Sea 

 large blocks of ice, which rapidly increased in size and 

 quantity, and continually pushed farther south, until at 

 length, after a long lapse of time, the whole of Northern 

 Europe, Asia, and America as far as the latitude of 

 about 45 became like a huge ice-house, the Arctic cold 

 driving all life before it to a more southern latitude, those 

 forms which had lived in Britain during Meiocene and 

 Pleiocene times being the first to disappear on the earliest 

 sign of the approaching cold, and the Arctic flora and 

 fauna which took their place being afterwards compelled 

 also to move southward, owing to the intense severity 

 of the glaciation. 



When this state of things had lasted a very considerable 



