THE VEGETABLE WORLD. 277 



this way we see in the present day, upon the Brocken, great 

 blocks of granite crumbling in the course of a number of 

 years into a coarse granular sand. Then those masses of 

 dust and sand, washed together by mighty floods of 

 rain, which were continually precipitated with increasing 

 violence during the farther cooling of the earth, 

 into the deep, the great basin of the powerful ocean, 

 and here, when the water was more calm, became deposited 

 in layers at the bottom, till some new eruption lifted up 

 this sea-bottom and the strata deposited upon it, above 

 the surface of the water. It is clear that the masses of 

 rocks thus elevated must also be subject to the process of 

 weathering, and that the products of this, washed away 

 into new accumulations, must give rise to new deposits of 

 a different kind. Nevertheless, the original differences of 

 these deposits are not very distinct in subsequent times, 

 and they may be reduced to sandstone, limestone, and 

 clay or marl, which re-appear in every period. These pro- 

 cesses must have lasted for many hundred thousands of 

 years, until the firm crust of the earth gradually approached 

 the shape which it at present exhibits, and until the violent 

 strife between the still incandescent fluid mass and the 

 atmosphere of vapour had become moderated to a certain 

 degree of peace. This account of the formation of our 

 earth leads us to assume the existence of two essentially 

 different kinds of rocks namely, those unstratified, as 

 they cooled down from the molten condition, and the 

 stratified rocks produced by deposition from water. 



In some period of this gradual shaping out of the earth, 

 the first germs of organic existence originated, through 

 forces, which may indeed still be in action, but under 

 conditions and co-operation of those various forces such 



