256 EDWARD W. BERRY 



utterly impossible. In the first place it would mean that the 

 balance of the leaf-bearing Wilcox is of Lafayette age since the 

 two have a considerable number of species in common. McGee 

 seems to have had some premonition that the fossil plants when 

 studied would not bear out his conclusions since he writes: 



The testimony of the plant fossils is of course only suggestive; for not 

 only is the identification incomplete, but there are thus far no means of 

 comparing the stages in evolution of plant life in the upper Missouri and 

 Rocky Mountain regions and the lower Mississippi region respectively; it 

 can only be said that in the one region the geography was repeatedly revolu- 

 tionized in such way as greatly to modify climatal conditions, while in the 

 other the geography has undergone only minor changes of such character as 

 not to modify climate, so that the flora has undoubtedly persisted in the 

 remarkable fashion suggested by the present existence of Laramie or Lafay- 

 ette plants in Louisiana. 



This may be dismissed as a specious argument, for it can readily 

 be shown that no post-Miocene floras of the northern hemisphere 

 contain the types which are prominent in this flora. On the 

 other hand the climatic changes have been considerable, even the 

 Pliocene flora in this area of supposed slight change containing 

 species no longer present in the region or even in North America. 



In the second place the flora is closely allied to European floras 

 of unquestioned Eocene age, more especially to that described by 

 Saporta from France, and in its tout ensemble it denotes climatic 

 conditions very different from those which could possibly have 

 existed in Lafayette time. 



There are high-level gravels in northeastern Mississippi and 

 in northern Tennessee and beneath the loess along the Mississippi 

 bottom ("delta") as well as at various points along the Atlantic 

 Piedmont border. Whether these are river gravels of various 

 ages or whether we are dealing with the remnants of a high-level 

 early Pleistocene sea terrace is not clear, although a combination 

 of the two is the probable solution. 



