144 HISTORY OF THE EUROPEAN FAUNA. 



had formerly a wider range in the British Islands, 

 should be included among these; but there are other 

 plants probably of Arctic origin, though not now 

 occurring in the Arctic Regions, and to these may 

 be classed the so-called American species of plants 

 which are found on the northern and western coasts 

 of Ireland, in the Hebrides, in Scotland, and in 

 North America. These are no doubt the relics of an 

 Arctic flora which flourished in high latitudes in past 

 times when the climate there was more temperate 

 A list of these species will be found on page 166. 



As none of them occur in Siberia, they must 

 either have found their way to North America and 

 to Europe from the Arctic Regions, or have travelled 

 from North America across the latter to Europe. 

 In any case a former land-connection between the 

 two continents must have existed. This becomes 

 the more evident when we examine the remarkable 

 results obtained by the late Professor Heer, who first 

 described the Tertiary plant-beds in North Greenland. 

 No less than 282 species of plants have been described 

 by this eminent botanist from these deposits. A large 

 number of the plants found were trees belonging to 

 the genus Sequoia^ Thujopsis^ and Salisburia, besides 

 beeches, oaks, planes, poplars, limes, and magnolias. 

 That they grew on the spot is proved by the fruits, 

 which have been obtained from these beds in various 

 stages of growth. 



From a similar deposit in Spitsbergen a large 

 number of fossil plants have also been brought to 



