MATERIALS 23 



dredging can bring to light the existing fauna of the 

 depths, and may even drag up samples of the soft sludge 

 of recent deposits. But the day is far distant when 

 mines and quarries will be opened in the rocks that 

 underlie the ocean bed ; until then, pelagic and abysmal 

 faunas of most past periods of geological history must 

 remain out of reach of practical Palaeontology. 



Although the greater part of the bed-rock next 

 below the surface of the British Isles is of sedimentary 

 origin, exposures of it are rare. Most of the country is 

 covered, to a varying and often great depth, with the 

 disintegrated rock-waste known as "drift." Even if 

 such a Herculean feat were possible, removal of this 

 superficial layer would evoke violent protest from 

 farmers, botanists, and all other terrestrial animals ; 

 moreover, it would result in their prompt extinction. 

 Nevertheless, many geologists and all Palaeontologists 

 must sympathize with the Walrus and the Carpenter in 

 their distress at the mask of drift that covers the face of 

 the Earth. Only along sea-cliffs, in hilly regions where 

 the soil creeps down from the slopes, or along the 

 courses of torrents, is the bed-rock laid bare by natural 

 agents. Meagre though these natural outcrops of rock 

 may be, they are more persistent, and often individually 

 more extensive, than the artificial excavations made in 

 railway cuttings, sewer-trenches, quarries, mines or bor- 

 ings. A railway cutting is dug out once for all (often by 

 the soulless agency of a steam-navvy), and it is usually 

 to the company's interest to obscure the sides of the 

 permanent way by " sloping " and plantation. Quarries 

 are, for the most part, small and temporary; with in- 

 creasing facilities of transport, drawing of stone tends to 

 become centralized in favourably situated localities (not 

 selected for their geological interest or fossiliferous 

 nature), and small local stone-pits soon become degraded. 



