456 Professor- Q. A. J. Cole— The Structure of Ireland. 



across the Atlantic and still preserved some of the plants which 

 invaded our Continent from the New World, Heer hailed this 

 hypothesis with delight, while Andrew Murray adopted it in 

 a somewhat modified form. Edward Forbes also occupied his 

 fertile mind with the problem, but could not convince himself that 

 the vast land which had evidently occupied a portion of the Atlantic 

 had any connection with America. Wollaston, too, who had a most 

 intimate knowledge of the Atlantic Islands, strongly supported the 

 view that their fauna reached them across dry land. 



Imbued, however, with the idea of the permanence of the great 

 ocean basins, Wallace vigorously attacked one and all of these 

 theories, and contended that there was not only no connection 

 between Europe and America across the Atlantic, but that the fauna 

 of the Atlantic Islands was derived from the adjoining continents of 

 Europe and Africa by winds and marine currents. The weight of 

 the arguments brought forward by Wallace silenced all critics for 

 a time, and the influence of his views is traceable in most of the 

 more recent writings on the subject. But since some leading 

 geologists have expressed themselves against the theory of the 

 permanence of the great ocean basins, the older views of a possible 

 land-connection between Europe and the Atlantic Islands, and also 

 between Europe and America, are again discussed. I have therefore 

 collected together a number of facts in the distribution of animals 

 which had not hitherto been utilised, in order to make a renewed 

 attempt from a zoological point of view to solve the Atlantis 

 problem. 



The results of my investigations tend to show that Madeira and 

 the Azores are the remains of an ancient tertiary area of land which 

 was joined to Europe, and that it probably became disconnected in 

 Miocene times. Since then this land once more became united with 

 our^ Continent, and may not have been finally severed until the 

 Pleistocene period. As regards the question of a land-bridge across 

 the Atlantic, many reasons can be given in favour of such a theory. 

 It must, however, have occupied a position farther south than the 

 land just alluded to. Uniting North Africa with Brazil and Guiana 

 in early tertiary times, it probably subsided during the Miocene 

 period, leaving only a few isolated peaks as islands in the midst of 

 the vast ocean which has since replaced it. 



VI. — On the Geological Structure of Ireland. 

 By Professor Grenvillb A. J. Cole, F.G.S.^ 



IN this illustrated lecture, the more prominent phases of the 

 geological history of Ireland were pointed out, mainly as an 

 explanation of the existing scenic features of the country. Probably 

 very little remains in Ireland of the old Huronian continent, unless 

 portions of it have appeared again in the cores of Caledonian folds. 

 The stratified, but metamorphosed, Dalradians of the west may be 



1 A paper read before the British Association, Belfast, Sept., 1902, in Section C 

 (Geology). 



