THE FIRST FORESTS OF MODERN TYPE. 193 



lived in America in early Eocene times, but has since been 

 banished, thour^h it? former companion, the Onoclea, still 

 holds its ground. Such cases of specific persistence along 

 with great changes of habitat are very instruct! /e as to the 

 permanence of species. 



Count Saporta, whose just remarks on the marvellously 

 sudden incoming of the Cretaceous flora we have already 

 referred to, also notices the fact that the families and genera 

 represented in this flora are a most miscellaneous and uncon- 

 nected assemblage, showing either the simultaneous appearance 

 of many dissimilar types, or requiring us to believe in the 

 existence of these and of intermediate forms for a very long 

 period before that in which they are first found. This inay, 

 however, be placed in connection with the appearance of 

 an exogenous tree {Syringoxyion) in the Devonian, referred 

 to in a previous chapter. It would be a strange and now little 

 suspected case of imperfection of the record, if it should be 

 found that trees of this type were lurking in exceptional 

 corners through all the vast periods between ilie Devonian 

 and the Cretaceous, to burst forth in unwonted variety and 

 luxuriance in the latter period. 



The new Cretaceous flora appears first in beds which had 

 been recently elevated from the ocean of the great Cretaceous 

 subsidence ; and when it first flourished, in temperate regions at 

 least, the continents were of small dimensions, and broken up 

 into groups of islands. Farther, America would seem to have 

 had precedence of the Eastern Continent, and the Arctic of 

 the Temperate regions. Thus on the elevation of the later 

 Cretaceous land, plants previously established in the far north 

 spread themselves southward, over newly-raised lands, radiating 

 Tiom the polar regions into Europe, Asia, and America. This 

 seems the only way of accounting for the similarity of the 

 plants in these distant countries. The new flora of the Upper 

 Cretaceous in its journey southward met with a climate probably 

 warmer than the present, yet not so warm as to prevent trees 



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