EUROPE BEFORE ARRIVAL OF MAN 



preceded them. The second was the immigra- 

 tion of deciduous trees from the polar regions. 

 Before the Cretaceous period no such trees had 

 been known in any part of the earth, and it is 

 the opinion of Count Saporta that the habit of 

 dropping the leaves was evolved in adaptation 

 to the extreme differences between summer and 

 winter temperatures which characterized the 

 polar regions. However that may be, it is cer- 

 tain that during the Eocene and Miocene pe- 

 riods deciduous trees and shrubs advanced from 

 Greenland and Spitzbergen into Europe, and 

 rapidly covered the face of the country, evolv- 

 ing gradually a great diversity of forms. By the 

 middle Eocene, along with cypresses, pines and 

 yews, fan-palms and pandanus and cactus of 

 giant size, the oak and the elm, the maple, wil- 

 low, beech, and chestnut, as well as the gum and 

 bread-fruit trees, flourished in Britain. The 

 climate of western and central Europe was trop- 

 ical, as is shown both by the abundance of palms 

 and by the presence of crocodiles and alligators 

 in large numbers, while the mollusks were such 

 as are now found only in tropical waters. 



But the most interesting feature of Eocene 

 Europe was the peculiar character of its mam- 

 malian fauna. At first we find marsupials, and 

 carnivora with marsupial affinities, showing that 

 the order of carnivora was then only beginning 

 to be evolved. Afterward came such creatures 

 17 



