MODERN DEPOSITS OF ORGANIC REMAINS. 337 



\vherc the prevailing currents cause the deposits to lie hero 

 of mud, and there of calcareous matter, it is proved that 

 different species of co-existing shells are being buried in 

 these respective formations. On our own coasts, the ma 

 rine remains found a few miles from shore, in banks where 

 fish congregate, are different from those found close to the 

 shore, where only littoral species flourish. A large propor 

 tion of aquatic creatures have structures that do not admit 

 of fossilization ; while of the rest, the great majority are 

 destroyed, when dead, by the various kinds of scavengers 

 that creep among the rocks and weeds. So that no one 

 deposit near our shores can contain anything like a true 

 representation of the Fauna of the surrounding sea ; much 

 less of the co-existing Faunas of other seas in the same lat 

 itude ; and still less of the Faunas of seas in distant lati 

 tudes. Were it not that the assertion seems needful, it 

 would be almost absurd to say, that the organic remain? 

 now being buried in the Dogger Bank, can tell us next 

 to nothing about the fish, crustaceans, mollusks, and corals 

 that are being buried in the Bay of Bengal. 



Still stronger is the argument in the case of terrestrial 

 life. With more numerous and greater contrasts between 

 the plants and animals of remote places, there is a far more 

 imperfect registry of them. Schouw marks out on the Earth 

 more than twenty botanical regions, occupied by groups of 

 forms so far distinct from each other, that, if fossilized, geo 

 logists would scarcely be disposed to refer them all to the 

 same period. Of Faunas, the Arctic differs from the Tem 

 perate ; the Temperate from the Tropical ; and the South 

 Temperate from the North Temperate. ISTay, in the South 

 Temperate Zone itself, the two regions of South Africa and 

 South America are unlike in their mammals, birds, reptiles, 

 fishes, mollusks, insects. The shells and bones now lying at 

 the bottoms of lakes and estuaries in these several regions, 

 have certainly not that similarity which is usually looked 



