Glacial Epoch. 45 7 



extinct species. Such large mammalia, on any hypo- 

 thesis, did not originate in a small detached island like 

 England, but formed parts of large families that in- 

 habited the north of Europe, America, and Asia, at 

 'various comparatively late periods of geological time, 

 and they could only have passed into our area by 

 the union of England with the Continent. 



Again, in the south of England, at Selsey Bill, 

 there are post-Pliocene strata on the sea-shore, described 

 by Mr. Godwin-Austen, one of the beds containing 

 species of living marine shells, not belonging to icy 

 seas, and overlaid by icy Boulder-drift. In the former 

 there were found the remains of a well-known species of 

 elephant, E. antiquus, lying on clay, on which stumps 

 of trees, the remains of an old wood, still stand. 



These Boulder-clays were formed during a period of 

 cold, accompanied by the great glaciers that covered so 

 much of the north of Europe, as I have already explained. 

 While, or after the glaciers were largest, the country 

 slowly sank, and, severed from the mainland, became 

 merely groups of islands. But it was again elevated, 

 and there is evidence that it was then united to the 

 Continent, for we find in later deposits the remains of a 

 number of terrestrial animals, some of the species of 

 which are unknown in the older formations. The 

 Elephants which lived before this time must have been 

 driven out of our area by that submergence, unless some 

 of them, with other mammalia, managed to live on in 

 the extreme south of what is now England, which 

 apparently suffered a smaller change of level. Farther 

 north, such large animals as the Elephant, Ehinoceros, 

 and Hippopotamus could not have lived on mere groups 

 of icy islands, on which vegetation must have been 

 scanty. Thoy required a large amount of vegetation 



