288 



PAST CLIMATES AND CLIMAXES. 



Thus, even from the geological standpoint, it seems reasonable to assume 

 that the deformative and eruptive disturbances "which began late in the 

 Upper Cretaceous and continued into the succeeding period" did not mark 

 the close of an era. This view is strongly supported by the persistence of the 

 dominant angiospermous vegetation, and its obvious, though delayed, effect 

 in producing the manmialian land fauna of the Tertiary. The causal and the 

 biological evidences of continuity from the Mesozoic to the Cenozoic appear 

 conclusive. Here, as with the transition from the Paleozoic to the Mesozoic, 

 vegetation as the middle hnk in the chain of sequence appears decisive, and 

 is taken as the basis for the recognition of eras, since its changes of dominance 

 seem to mark the end of causative processes and the beginning of a new animal 

 evolution. 



Division into eras. — ^Early in the development of the present treatment, 

 it was felt that the phylogenetic study of vegetation demanded the recognition 

 of eras based upon vegetation, and that the geological record warranted such 

 a division, as has just been shown. In order to harmonize the current clas- 

 sification with the new one, the terms Eozoic, Paleozoic, Mesozoic, and Cenozoic 

 were modified into Eophytic, Paleophytic, Mesophytic, and Cenophytic. It 

 was then discovered that Saporta (1881 : 160) had already distinguished these 

 four vegetation periods and had constructed the following table of concordance 

 between these and the corresponding geological formations. 

 Sapokta's Table of Eras and Periods. 



Great geologic 



formations or 



terrains. 



Geologic 



systems. 



, T^ X • ■ fLorenz. 



1. Protozoic or pn- Cambrian. 



""''^^- Isilurian. 



Phytologic 



epochs or 



great periods 



of vegetation. 



Divisions of 



phytologic 



ei)ochs: 



vegetation periods. 



Eophj^ic or pri- 1,^ . ,. , 

 mordial. Pnmordial. 



2. Paleozoic. 



[Devonian. 

 ./Carbonic. 

 [Permian. 



Triassic . . 



Mesozoic or secon- { 

 dary. 



Jurassic . 



Paleophytic or 

 carbonic. 



{Red sandstone. 

 Mussel chalk. 

 Keuper. 



fLias. 

 ■\Oolith. 



Cretaceous. . 



(Lower. 

 Middle. 

 Rouen. 

 Upper. 



Mesophytic 

 secondary. 



Devonic. 

 Lower Carbonic. 

 Upper Carbonic. 

 Permian. 



Trias. 



Infralias. 



Lias. 



Oolith. 



Wealdian. 



Urgonian. 



[Eocene. 

 Neozoic or tertiary./ Miocene. 

 (Pliocene. 



Cenomanian. 



Upper Cretaceous. 

 „ , .. . Paleocene. 

 N«^?Pl'y*"'°'te'- Eocene. 



Oligocene. 



Miocene. 



Pliocene. 



The vegetation eras here recognized are essentially the same as the phyto- 

 logic epochs of Saporta, though the Permian is regarded as belonging to the 

 Mesophytic. Likewise, Cenophytic rather than Neophytic is preferred as 



