2 i G FINAL CAUSES : THEIR BEARING 



that they gradually settled down, until the state of things 

 became at length comparatively fixed and stable, few geolo- 

 gists will be disposed to deny. The evidence which supports 

 this special theory of the development of our planet in its 

 capabilities as a scene of organized and sentient being, seems 

 palpable at every step. Look first at these Grauwacke rocks ; 

 and, after marking how in one place the strata have been up- 

 turned on their edges for miles together, and how in another 

 the Plutonic rock has risen molten from below, pass on to 

 the Old Red Sandstone, and examine its significant platforms 

 of violent death, — its faults, displacements, and dislocations ; 

 see, next, in the Coal Measures, those evidences of sinking 

 and ever-sinking strata, for thousands of feet together ; mark 

 in the Oolite those vast overlying masses of trap, stretching 

 athwart the landscape, far as the eye can reach ; observe 

 carefully how the signs of convulsion and catastrophe gradually 

 lessen as we descend to the times of the Tertiary, though even 

 in these ages of the maramiferous quadruped the earth must 

 have had its oft-recurring ague fits of frightful intensity ; 

 and then, on closing the survey, consider how exceedingly 

 partial and unfrequent these earth-tempests have become in 

 the recent periods. Yes ; we find everywhere marks of at 

 once progression and identity, — of progress made, and yet 

 identity maintained ; but it is in the habitation that we find 

 them, — not in the inhabitants. There is a tract of country 

 in Hindustan that contains nearly as many square miles as 

 all Great Britain, covered to the depth of hundreds of feet 

 by one vast overflow of trap. A tract similarly overflown, 

 which exceeds in area all England, occurs in Southern Africa. 

 The earth's surface is roughened with such, — mottled as 

 thickly by the Plutonic masses as the skin of the leopard by 

 its spots. The trap district which surrounds our Scottish 

 metropolis, and imparts so imposing a character to its scenery, 

 is too inconsiderable to be marked on geological maps of the 



