ScHARFF — Oil the Origin of the European Fauna. 503 



Ireland, and the west of Scotland. The nortliern element chiefly 

 occurs in Scotland, the north of England, and the north and west of 

 Ireland. 



Though it may be admitted that a small percentage of the British p. 433 

 fauna reached the British Islands by occasional means of dispersal, the 

 bulk of it migrated on land. A land-connexion must therefore have 

 existed formerly between Great Britain and Ireland, and the Continent 

 of Europe. 



The late Edward Eorbcs believed that the Lusiranian or south- p. 444 

 western element in the Irish flora (it was not known at the time that 

 there was also a similar fauna) came to Ireland in Miocene times and 

 survived the Glacial Period on a now sunken land which lay to the 

 south-west of that island. Almost all other authorities are convinced 

 that both flora and fauna were entirely exterminated in Ireland during 

 the Pleistocene Epoch, and that what exists there now, migrated to it 

 after the Glacial Period. 



A short statement of the general conclusions arrived at with regard p. 444 

 to the geographical changes in Europe during later Tertiary times, 

 and the chief migrations of animals now follows, so as to facilitate 

 the comprehension of the principal arguments advanced in favour of 

 the view that there were two distinct invasions of northern species, 

 and that the Irish fauna is altogether pre-Glacial. 



To judge fi'om the range of the South-western European plants p. 445 

 and animals in Ireland, it is evident, as Eorbes suggested, that they 

 came long before the other southern species or the northern ones. 

 Last of all came the eastern or Siberian migrants. These never reached 

 Ireland, but as we have such abundant evidence of the time of their 

 arrival in Europe, the history of their migration is of great importance, 

 since it furnishes us with a clue to the date of earlier migrations. 



We have geological evidence that a vast migration jjroceeded from p. 445 

 Siberia, and entered Europe between the Caspian and the Ural Moun- 

 tains. A large number of Mammals came with this Siberian invasion, 

 and no fewer than twenty-nine species reached England, ten of which 

 still inhabit Great Britain. There is no evidence that any of them 

 ever lived in Ireland. 



In the succeeding pages I have endeavoured to ascertain the causes p. 450 

 of that migration and its geological date. Both Tcherski and Brandt, 

 the two highest authorities, are of opinion that the present Siberian 

 fauna lived in the country already in pre-Glacial times, and that, with 

 the addition of some now extinct forms, such as the Mammoth, it 

 flourished as far north as the New Siberian Islands. Since the advent 



