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1 8 RELICS OF PRIMEVAL LIFE 



these old animals ; though we can only actually do 



so by painfully hammering and chiselling them out 



of their rocky tombs, and this often in fragments 



which must be put together before we can fully 



realize the forms and structures of the animals to 



which they belonged. 



We may pause here, however, to remark that 



neither the geographical nor climatal conditions of 



the earth at this early time were similar to these 



with which we are now familiar. The marine 



animals of the Cambrian have left their remains f 



f 

 in beds of sediment, which now constitute rocks 



forming parts of our continents remote from the 

 sea, and much elevated above its level, showing 

 that large areas, then under the ocean, are now 

 dry land ; while there is no good evidence that the 

 sea and land have changed places. The facts rather 

 indicate that the continents have extended their 

 area at the expense of the ocean, which has, how- 

 ever, probably increased in depth. In evidence of 

 these statements, I need only mention that some of 

 the oldest rocks in the Scottish and Welsh hills, in 

 Scandinavia, in Russia and in Bohemia, are rich in 

 Cambrian marine fossils. In America, in like man- 

 ner, such rocks are found on the flanks of the 



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