54 DIVERSIONS OF A NATURALIST 



it ground and tore the surface rode and carried large 

 and small masses — boulders and incredible millions of 

 tons of broken up fragments — and spread them over 

 East Anglia (where they form the so-called " glacial 

 drift"), and over regions still submerged in the North 

 Sea. Consequently the beach on the Suffolk seashore 

 has a specially variegated assortment of pebbles from 

 all sorts of more northerly situated rocks — though 

 small flint pebbles, derived directly from glacial drift and 

 by the drift from the chalk land-surface (the chalk itself 

 not now reaching the shore-line of East Anglia), are 

 greatly predominant. It is in the chalk that flint takes 

 its origin, being foi^nd there as large irregular nodules 

 and sheets. 



