8 THE HISTORY OF CREATION. 



like the historian who divides the history of nations into 

 the three main divisions of Antiquity, the Middle Ages, and 

 Modern Times, and each of these sections again into subordi- 

 nate periods and epochs. But the historian by this sharp 

 systematic division, and by fixing the boundary of the 

 periods by particular dates, only seeks to facilitate his 

 survey, and in no way means to deny the uninterrupted 

 connection of events and the development of nations. 

 Exactly the same qualification applies to our systematic 

 division, specification, or classification of the organic history 

 of the earth. Here, too, a continuous thread runs through 

 the series of events unbroken. We must therefore dis- 

 tinctly protest against the idea that by sharply bounding 

 the larger and smaller groups of strata, and the periods 

 corresponding with them, we in any way wish to adopt 

 Cuvier's doctrine of terrestrial revolutions, and of repeated 

 new creations of organic populations. That this erroneous 

 doctrine has long since been completely refuted by Lyell, I 

 have already mentioned. (Compare vol. i. p. 127.) 



The five great main divisions of the organic history of 

 the earth, or the paleeontological history of development, 

 we call the primordial, primary, secondary, tertiary, and 

 quaternary epochs. Each is distinctly characterized by the 

 predominating development of certain animal and vegetable 

 gTOups in it, and we might accordingly symbolically desig- 

 nate the five epochs, on the one hand by the names of the 

 groups of the vegetable kingdom, and on the other hand by 

 those of the different classes of vertebrate animals. In this 

 case the first, or primordial epoch, would be the era of the 

 Tangles (Algse) and skull-less Vertebrates ; the second, or 

 primary epoch, that of the Ferns and Fishes ; the third, or 



