SUPPOSED CASE OF A VAST UPHEAVAL. 357 



The deposits that had previously been slowly formed at the 

 bottom of this wide ocean, would be sprinkled with fossils 

 of but few species. The oceanic Fauna is not a rich one ; 

 its hydrozoa do not admit of preservation ; and the hard 

 parts of its few kinds of molluscs and crustaceans and in- 

 sects are mostly fragile. Hence, when the ocean-bed way 

 here and there raised to the surface — w^hen its strata ol 

 sediment with their contained organic fragments were torn 

 up and long washed about by the breakers before being re- 

 deposited — when the re-de})Osits were again and again sub- 

 ject to this violent abrading action by subsequent small ele- 

 vations, as they would mostly be ; what few fragile organic 

 remains they contained, would be in nearly all cases destroy- 

 ed. Thus such of the first-formed strata as survived the 

 repeated changes of level, would be practically " azoic ; " 

 like the Cambrian of our geologists. When by the wash- 

 ing away of the soft deposits, the hard sub-strata had been 

 exposed in the shape of rocky islets, and a footing had thus 

 been furnished, the pioneers of a new life might be expect- 

 ed to make their appearance. What would they be? 

 Not any of the surrounding oceanic species, for these are 

 not fitted for a littoral life ; but species flourishing on some 

 of the far-distant shores of the Pacific. Of such the first 

 to establish themselves would be sea-weeds and zoophytes ; 

 both because their swarming spores and gemmules would 

 be the most readily conveyed with safety, and because when 

 conveyed they would find fit food. It is true that Cirrhi- 

 peds and Lamellibranchs, subsisting on the minute creatures 

 which everywhere people the sea, would also find fit 

 food. 



But passing over the fact that the germs of such higher 

 forms are neither so abundant nor so well fitted to bear 

 long voyages, there is the more important fact that the m- 

 dividuals arising from these germs can reproduce only sex- 

 ually, and that this vastly increases the obstacles to the es* 



