ScHAEFF — On the Origin of the European Fauna. 441 



difference of climate is much too slight, however, between these two 

 countries to produce such an absolute extinction of the northern fauna 

 and flora in the south of England, and we are forced to the conclusion 

 that they arrived from the north. Especially as a geologist of such 

 eminence as Prof . Judd tells us that (45, p. 1008): "Down to post- 

 Glacial times, Scotland and what are now its out-lying islands, re- 

 mained united with Scandinavia. But at a very recent period, and 

 indeed since the appearance of man in this part of our globe, the 

 separation of the two areas, so long united, was brought about." 



It was from Scandinavia, therefore, that our northern animals and 

 plants came. Many of them possibly originated there, but the home 

 of others lies no doubt far beyond even the confines of Scandinavia, in 

 the Arctic Regions. 



Thus Ireland had, as we have seen, two land-connexions with the 

 continent of Europe— one by way of the south of England to France, 

 and the other by way of Scotland to Scandinavia. 



Prof. Leith Adams believed (1 J, p. 100) as stated above, and in this 

 view he is supported by Mr. Alston (3, p. 6), that Scotland was 

 connected with Ireland long after the latter became disconnected from 

 England, and that the whole of the Irish Mammalian fauna migrated 

 to Ireland by way of Scotland. 



On the Time of the Migration. 



Before discussing the views current among zoologists and botanists 

 as to the geological period during which the Irish fauna and flora 

 migrated to Ireland, I should like again to draw attention to the fact 

 that the Eorest-bed is now more generally recognized as constituting 

 the most recent formation in the Pliocene Series, which is succeeded 

 by the Pleistocene. As the Glacial Period is supposed to have formed 

 a phase of the Pleistocene Epoch, the term "pre-Glacial " throughout 

 this memoir, will apply to the pre-Pleistocene times, and will include 

 the Eorest-bed. It must be remembered that I adopt these terms for 

 convenience sake only, and in order to make my views more clear, and 

 not because I agree with them. I shall endeavour to show later on 

 that it is not at all justifiable to place the Eorest-bed in the Pliocene 

 Series. 



The questions which I have dealt with in the preceding pages 

 have been comparatively simple and easily answerable, but the problem 

 as to the particular geological Epoch or Period during which the fauna 

 arrived in Ireland is an extremely difficult one. With the exception 

 of Prof. Eorbes, no one has really attempted to seriously set himself to 



