GEOLOGY 25 



infer, each separate formation presents even an 

 approach to a consecutive history, my theory must 

 be given up. Even if it were consecutive, it would 

 only collect series of one district in our present state 

 of knowledge ; bat what probability is there that 

 any one formation during the immense period which 

 has elapsed during each period will generally present 

 a consecutive history. [Compare number living at 

 one period to fossils preserved look at enormous 

 periods of time.] 



Referring only to marine animals, which are 

 obviously most likely to be preserved, they must 

 live where (?) sediment (of a kind favourable for pre- 

 servation, not sand and pebble) 1 is depositing quickly 

 and over large area and must be thickly capped, 

 (illegible) littoral deposits: for otherwise denudation 

 (will destroy them), they must live in a shallow space 

 which sediment will tend to fill up, as movement 

 is (in?) progress if soon brought (?) up (?) subject 

 to denudation, [if] as during subsidence favour- 

 able, accords with facts of European deposits 2 , but 

 subsidence apt to destroy agents which produce 

 sediment 3 . 



I believe safely inferred (that) groups of marine (?) 

 fossils only preserved for future ages where sediment 

 goes on long (and) continuous(ly) and with rapid but 

 not too rapid deposition in (an) area of subsidence. 

 In how few places in any one region like Europe 

 will (?) these contingencies be going on ? Hence (?) in 



1 See Origin, Ed. i. p. 288, vi. p. 422. " The remains that do become 

 embedded, if in sand and gravel, will, when the beds are upraised, generally 

 be dissolved by the percolation of rain-water." 



2 The position of the following is not clear : " Think of immense 

 differences in nature of European deposits, without interposing new 

 causes, think of time required by present slow changes, to cause, on very 

 same area, such diverse deposits, iron-sand, chalk, sand, coral, clay ! " 



3 The paragraph which ends here is difficult to interpret. In spite of 

 obscurity it is easy to recognize the general resemblance to the discussion 

 on the importance of subsidence given in the Origin, Ed. i. pp. 290 et seq., 

 vi. pp. 422 et seq. 



