I40 THE MIGRATION OF BRITISH BIRDS 



low grounds, so that only a few of these could make 

 their way south into Ireland." 



The first part of Professor Geikie's remarks very 

 forcibly suggests that early Post-Glacial Ireland formed 

 one land mass in the south with England, and thus 

 presented no barrier to the emigration to that area of 

 the various alpine and sub-alpine floras (and of course 

 the hardiest species of birds), relics of which flonne exist 

 there down to the present time. But as the climate 

 moderated, this flora, which sought and now occupies 

 a congenial habitat on the Welsh, English, and Scotch 

 mountains, would to a very great extent disappear from 

 Ireland, owing to the absence of such suitable mountain 

 haunts ; and this flora was, as wc know, (and still is) 

 replaced by the dominant and southern Germanic types 

 which must also have entered Ireland before the con- 

 necting land masses in the south disappeared. The 

 fact insisted upon by Professor Geikie in support of 

 some of his views, that the mammalian fauna of Ireland 

 agrees more closely with that of Scotland than with 

 that of England, is due entirely to the smaller amount 

 of competition to which that fauna has been exposed by 

 the invading Germanic or southern types which have 

 established themselves in England so dominantly, 

 together with the later appearance of that fauna in 

 England, when the difficulties surrounding emigration 

 to the Irish area were rapidly increasing, or perhaps 

 almost insurmountable, due to progressing submergence 

 and widening of the water ways, as well as to the 

 similarity of climate and general conditions between 

 Scotland and Ireland. Singularly enough, Professor 

 Geikie shortly afterwards states that so far as the floras 



