Migration of Animals. 483 



animals migrated into that region. The proof is 

 equally clear that Ireland during part of the Glacial 

 period, like England, was partly submerged, so as to 

 form a group of islands ; and, therefore, to allow of the 

 country being re-inhabited by large mammals, there 

 must have been ground over which these mammals 

 travelled into the Irish area after the re-elevation of the 

 country. 



An excellent surmise was offered us on this subject 

 by Professor Edward Forbes, who drew attention to 

 some remarkable observations made by Mr. Thompson 

 of Belfast with regard to the comparative number of 

 reptiles that are found in Belgium, in England, and in 

 Ireland. In Belgium there are in all 22 species of 

 serpents, frogs, toads, lizards, and the like. In England 

 the number of species is only 11, and in Ireland 5 ; and 

 the inference that Professor Forbes drew was, that these 

 reptiles migrated from east to west, across the old land 

 that joined our island to the Continent, before the 

 denudations took place that disunited them. Before 

 the breaking up of that land, a certain number had got 

 as far as England, and a smaller number as far as 

 Ireland, and the continuity of the land being broken up, 

 their further progress was stopped. 



These denudations, of course, did not cease with the 

 breaking up of the land that joined our territory to 

 the Continent ; and, in raised beaches and submerged 

 forests, there are proofs of several oscillations of the 

 relative levels of sea and land since that period. This 

 waste of territory is, indeed, going on still, and will 

 always go on while a fragment of Britain remains. 

 Before proceeding further I would advance one or two 

 proofs to show how steady the waste of our country is. 



Along the east coast of England, between Flam- 

 112 



