INTRODUCTION. XXIX 



Anatomy not only reveals the great fact of the former 

 existence in our present island of the same extinct spe- 

 cies of quadrupeds that co-existed on the Continent, but 

 becomes in an unexpected degree auxiliary to geographi- 

 cal science ; it throws light upon the former physical 

 configuration of Europe, and on the changes which it has 

 since undergone, and shows that the most striking of 

 those changes have taken place at a comparatively modern 

 period in the history of this planet. 



Amongst the purely geological phenomena which indi- 

 cate the movements and disturbances of the southern and 

 south-eastern parts of England during the pliocene period, 

 may be cited the patches of London clay, with overlying 

 lacustrine strata, which are met with on highly elevated 

 mounds of chalk, indicating considerable up-heaval of those 

 marine formations subsequent to their reception of pliocene 

 fresh-water deposits. Some of the deposits which, from 

 the abundance of Mammoth fossils in them, have re- 

 ceived from Dr. Mantell the name of" Elephant-bed,"* have 

 been spread out confusedly, either by successive waves, 

 or by ice-floes carried along by ocean currents. Mr. Lyell, 

 generalizing the various particular phenomena indicative 

 of these changes, says: "First, the south-eastern part 

 of England had acquired its actual configuration when 

 the ancient chalk-cliff was formed, a beach of sand and 

 shingle having been thrown up at the base of the cliff. 

 Afterwards the whole coast, or at least that part of it 

 where the Elephant-bed now extends, subsided to the 

 depth of fifty or sixty feet, and during the period of sub- 

 mergence, successive layers of white calcareous rubble were 

 accumulated so as to cover the ancient beach. Sub- 

 sequently, the coast was again raised, so that the ancient 



" Geology of the South East of England, 8vo., 1833, p. 31. 



