490 Proceedings of the Royal Irish Academy. 



a more active evaporation of water, which niiist have been produced 

 by a warmer climate. 



To judge from the above opinions, and taking an average estimate 

 between the extremists on either side, it seems quite conceivable that 

 the present Irish fauna and flora could have survived the Glacial 

 Period in Ireland, if we supposed that perhaps a few local glaciers 

 existed in that country at the time. Such a suppositiou, however, is 

 altogether denied by Irish and other geologists, ilr. Close believes 

 that practically the whole of the present surface of Ireland was covered 

 by ice — at any rate for some time — during the Glacial Period (17). 

 According to Air. Xinahan, '• it would appear that at one time there 

 was a general south-south-westward movement of a thick sheet of ice 

 across Ireland" (51 a, p. 241). Prof. James Geikie informs us (35 «, 

 p. 415) that during the epoch of maximum glaciation all Ireland was 

 smothered in ice — only the tops of the higher mountains appearing 

 above the surface of the mer de glace as Kunatalcker. 



That under such conditions no fauna or flora to speak of could 

 have outlived the Glacial Period in Ireland is obvious. As I think, 

 however, that I have brought forward weighty reasons in favour of 

 the present fauna and flora having survived that period in Ireland, 

 we have, in order to uphold my contention, either to suppose that a 

 sufficient former southward extension of land existed on which the 

 animals and plants accommodated themselves during the glacial con- 

 ditions which prevailed on more northerly \imi% of the island, or that 

 the views of the geologists as above expressed are eiToneous. 



If the whole island had been glaciated in the manner indicated, 

 the whole fauna and flora would have had to seek refuge in a supposed 

 southern extension of Ireland. Prof. E. Forbes (33 ff, p. 14), as I have 

 already mentioned, believed that the Lusitanian element in the Irish 

 flora must have survived the Glacial Period on such a now sunken 

 part of the island, and that afterwards, as niore favourable conditions 

 set in, the remnants of it took possession of the south-western coun- 

 ties. It evidently never occurred to Prof. Forbes that the whole of 

 the present fauna and flora might be pre-Glacial, and could have been 

 driven to this submerged land to seek refuge from the ice. But if 

 such an emigration and immigration fi-om and to the present land 

 surface of Ireland had taken place, we certainly should perceive clear 

 indications of it in the composition of the Irish fauna and flora. 

 There is one thing absolutely certain, however, and that is, that the 

 most an< ient Lusitanian forms are more or less confined to the south- 

 west, the northern forms to the north and west, and the most eastern 



