174 EDWAED W. BERRY 



One of the latter was found above 80° north latitude, which is 

 as near the North Pole as the remains of any trees have been 

 discovered. 



This species, Tilia Malmgreni, a leaf of which is shown on the 

 accompanying plate, was described by Heer and had typical 

 broad leaves about the size of those cf the existing European 

 lime. It has been recorded from rocks which are probably late 

 Eocene in age in Grinnell Land, Spitzbergen and Iceland, where 

 it is associated with volcanic rocks (basalts) that seem to have 

 characterized the earlier Tertiary throughout the North Tem- 

 perate and the Arctic regions. It affords perhaps the most strik- 

 ing illustration of the different climate and floral distribution 

 that is disclosed by a review of the ancestors of any of our trees, 

 and it is almost impossible for us to picture forests of broad 

 leaved temperate trees covering the present perpetually ice clad 

 wastes of Grinnell Land, and flourishing where the winter's night 

 lasted for six months. 



A second Eocene species occurs in the Kenai region of Al ,ska 

 and a third on Sachalen Island off the Asiatic coast immediately 

 north of Japan. A fourth has been found in the early Eocene of 

 Montana. This Eocene distribution would seem to indicate 

 that the linden stock originated somewhere in the far north, 

 but whether actually in the Polar region or in northern North 

 America or northern Asia it is impossible to say. The Montana 

 species is somewhat older than the other known Eocene forms 

 and this may mean that it is nearer than the others to the place 

 of origin of the genus, or it may be due simply to accidents of 

 preservation or of discovery since earlier forms in other areas 

 may not have been preserved at all or may still be awaiting 

 discovery in the rocks. 



No Oliogocene lindens are known and this must be ascribed 

 to the reasons mentioned at the close of the preceding paragraph 

 since in the succeeding Miocene times there was a great display 

 of a variety of lindens. They are found at this time from the 

 base to the top of the Miocene deposits of Europe, where plant 

 beds of this age are much more abundant than they are in either 

 North America or Asia. At least fourteen different Miocene 

 species are known and their remains include several of the char- 



