INTRODUCTION. XX1x 
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. 
