12 THE HISTORY OF CREATION. 



. dilated animals (spiders and insects) as well as of vertebrate 

 animals (amphibious animals, like newts and frogs). Jn the 

 Permian system there occur, in addition to the amphibious 

 animals, the more highly-developed reptiles, and, indeed, 

 forms nearly related to our lizards (Proterosaurus, etc.). But, 

 nevertheless, we may call the primary epoch that of Fishes, 

 because these few amphibious animals and reptiles are 

 insignificant in comparison with the immense mass of 

 palasozoic fishes. Just as Fishes predominate over the other 

 vertebrate animals, so Ferns, or Filices, predominate among 

 the plants of this epoch, and, in fact, real ferns and tree ferns 

 (leafed ferns, or Phylopteridse), as well as bamboo ferns 

 (Calamophytae) and scaled ferns (Lepidophytse). These 

 ferns, which grew on land, formed the chief part of the 

 dense palseolithic island forests, the fossil remains of which 

 are preserved to us in the enormously large strata of coal of 

 the Carboniferous system, and in the smaller strata of coal of 

 the Devonian and Permian systems. We are thus justified 

 in calling the primary epoch either the era of Ferns or that 

 of Fishes. 



The third great division of the palseontological history 

 of development is formed by the secondary epoch, or the 

 era of Fine Forests, which is also called the mesolithic or 

 mesozoic epoch. It extends from the end of the Permian 

 system to the end of the Chalk formation, and is again 

 divided into three great periods. The stratified systems de- 

 posited during this period are, first and lowest, the Triassio 

 system, in the middle the Jura system, and at the top the 

 Cretaceous system. The average thickness of these three 

 systems taken together is much less than that of the pi-i- 

 mary group, and amounts as a whole only to about 15,000 



