Il6 THE LAPSE OF TIME. 



parts, if not in all, is one gigantic mass of such re- 

 mains. 



In cliffs of sea-shore and river, in railway-cuttings, in 

 mine-shafts and quarries, we may often see layers of the 

 earth's crust in the order of their original deposition. 

 Except where the signs are present of some subsequent 

 violent interference, this order is uniform and invariable. 

 It is not that all the members of the series are inva- 

 riably present, far from it; but in order of deposition 

 the relations of higher and lower are never interchanged. 

 Every one of the many different layers which have been 

 distinguished by geologists has a distinctive group of 

 fossils. You may, if you please, suppose that for each 

 of these layers of the earth's crust there was a new 

 creation of living creatures, wonderfully like at each 

 successive step, though wonderfully different at long 

 intervals, as though they were the work of an artist 

 whose ideas moved but slowly ; but for such a supposi- 

 tion you have no authority ; the conception has neither 

 simplicity nor grandeur ; it does not even accord with 

 the facts, since, amid the general change of organic 

 structures, we find the permanence of a few ; and while 

 the groups of two successive layers have, each of them,, 

 numerous distinctive forms, it is impossible to draw any 

 definite boundary-line between the groups themselves, 

 which sometimes intermingle with an inextricable inter- 

 lacing on their confines. Nothing comes out more 

 clearly to the student of the rocks, than that the world 

 of to-day is the world of millions of years back ; from 

 one point of view ever-changing, yet ever essentially 



