OHAP. XVI.] 



THE BRITISH ISLES. 



315 



highlands where the greatest accumulations of ice would 

 necessarily occur during the glacial epoch, and they may well 

 be termed submarine lakes, of exactly the same nature as 

 those which occur in similar positions on land. 



Proofs of Former Elevation — Submerged Forests. — What renders 

 Britain particularly instructive as an example of a recent con- 

 tinental island is the amount of direct evidence that exists, of 

 several distinct kinds, showing that the land has been sufficiently 

 elevated (or the sea depressed) to unite it with the continent, 

 — and this at a very recent period. The first class of evidence 

 is the existence, all round our coasts, of the remains of sub- 

 marine forests often extending far below the present low-water 

 mark. Such are the submerged forests near Torquay in Devon- 

 shire, and near B^almouth in Cornwall, both containing stumps 

 of trees in their natural position rooted in the soil, with deposits 

 of peat, branches, and nuts, and often with remains of insects 

 and other land animals. These occur in very different conditions 

 and situations, and some have been explained by changes in the 

 height of the tide, or by pebble banks shutting out the tidal 

 waters from estuaries ; but there are numerous examples to 

 which such hypotheses cannot apply, and which can only be 

 explained by an actual subsidence of the land (or rise of the 

 sea-level) since the trees greAV. 



We cannot give a better idea of these forests than by quoting 

 the following account by Mr. Pengelly of a visit to one which 

 had been exposed by a violent storm on the coast of Devonshire, 

 at Blackpool near Dartmouth : — 



" We were so fortunate as to reach the beach at spring-tide 

 low-water, and to find, admirably exposed, by far the finest 

 example of a submerged forest which I have ever seen. It 

 occupied a rectangular area, extending from the small river or 

 stream at the western end of the inlet, about one furlong east- 

 ward ; and from the low- water line thirty yards up the strand. 

 The lower or seaward portion of the forest area, occupying about 

 two-thirds of its entire breadth, consisted of a brownish drab- 

 coloured clay, which was crowded with vegetable debris, such 

 as small twigs, leaves, and nuts. There were also numerous 

 prostrate trunks and branches of trees, lying partly imbedded 



