CHAP. xxr. DESTRUCTIONS AND CREATIONS. 369 



the veins of molten matter were driven. But how, no 

 one can tell. There is a slow metamorphic action, as 

 well as a rapid one. 



"Yet no one has any reason to think that such a 

 thing as a universally destructive action ever occurred 

 since life began. There might be death from irruptive 

 forces in the sea at Norway or Iceland, yet none at 

 Caithness or Leith. No one supposes that, though all 

 fossils may have been obliterated in metamorphic strata, 

 all life was destroyed at the same time in the over- 

 lying waters. 



"Agassiz and Hugh Miller believed in many de- 

 structions of life, and in many new creations. But 

 Hugh, before he died, knew that it was not so. In his 

 Testimony of the Hocks, he traced existing forms 

 backwards, through all the various deposits, and found 

 no break until he came to the Chalk. ' If even then, 

 he said. By the expression ' If even then,' he referred 

 to the microscopic animals of the chalk, found to be still 

 alive in the North Sea, and in the seas between America 

 and Britain. 



" In dredging for a platform for the submarine cable, 

 microscopic shells, with flesh on them, were brought 

 up from a depth of a mile and a half. Ehrenberg, 

 Humboldt, and Sir Eoderick Murchison have said, that 

 those shells brought up from the deep sea bottom are 

 the same animal as those found entombed in chalk 

 hills in millions. 



" All metamorphic rocks are not of the same age ; 

 neither are all Silurian. Neither are Old Eed Sandstone, 



