MODERN GEOLOGY 



The hypothesis is this that the observed changes 

 of the surface of the earth, continued through indefinite 

 lapses of time, must result in conveying all the land at 

 last to the sea; in wearing continents away till the 

 oceans overflow them. What then ? Why, as the con- 

 tinents wear down, the oceans are filling up. Along 

 their bottoms the detritus of wasted continents is de- 

 posited in strata, together with the bodies of marine 

 animals and vegetables. Why might not this debris 

 solidify to form layers of rocks the basis of new con- 

 tinents ? Why not, indeed ? 



But have we any proof that such formation of rocks 

 in an ocean-bed has, in fact, occurred ? To be sure we 

 have. It is furnished by every bed of limestone, every 

 outcropping fragment of fossil - bearing rock, every 

 stratified cliff. How else than through such formation 

 in an ocean -bed came these rocks to be stratified? 

 How else came they to contain the shells of once living 

 organisms imbedded in their depths? The ancients, 

 finding fossil shells imbedded in the rocks, explained 

 them as mere freaks of "nature and the stars." Less 

 superstitious generations had repudiated this explana- 

 tion, but had failed to give a tenable solution of the 

 mystery. To Hutton it is a mystery no longer. To 

 him it seems clear that the basis of the present conti- 

 nents was laid in ancient sea-beds, formed of the de- 

 tritus of continents yet more ancient. 



But two links are still wanting to complete the chain 

 of Hutton 's hypothesis. Through what agency has the 

 ooze of the ocean-bed been transformed into solid rock ? 

 and through what agency has this rock been lifted 

 above the surface of the water to form new continents ? 



rot. m. 



