14<i GENl^ VEB8T78 NATURE 



Either the geological record is sufficiently com- 

 plete to afford us a means of determining tlieordei 

 in which animals have made their appearance OB 

 the globe or it is not. If it is, the determination 

 of that order is little more than a mere matter ol 

 observation ; if it is not, then natural science 

 neither affirms nor refutes the " fourfold order," 

 but is simply silent. 



The series of the fossiliferous deposits, which 

 contain the remains of the animals which have 

 lived on the earth in past ages of its history, and 

 which can alone afford the evidence requiivd b\ 

 natural science of the order of appearance of theii 

 different species, may be grouped in the mam in 

 shown in the left-hand column of the following 

 table, the oldest being at the bottom : 



Fornmtioiis First known appearance of 



Quaternary. 

 Pliocene. 

 Miocene. 



Eocene. . Vertebrate air-population (Bats). 



Cretaceous. 

 Jurassic . . Vertebrate air-population (Birdsand 



Pterodactyles). 

 Triassic. 



rpprr Palaeozoic. 

 Middle Palteozoic . Vertebrate /a/td-population (Am- 



phibia, Reptilia [?]). 

 Lower Palaeozoic. 



Silurian . . Vertebrate water-population (Fisln-s). 



Invertebrate air and /^// 

 (Flying Insects and Scorpions). 

 Cambrian . Invertebrate Yf/<r-p<pulation 



earlier, if Eozoon is animal). 



