550 TRANSACTIONS OF SECTION C, 



passing considerably below sea-level, proves that at first the land stood higher than 

 at present, while the estuarine clays which overlie this peat demonstrate a more 

 recent submergence to a depth of not more than 15 or 20 feet above present sea- 

 level. This degree of submergence is marked also by the raised beach which almost 

 everywhere fringes the north-eastern coast of Ireland, and there is no adequate 

 evidence for any other epoch of submergence in Ireland between the beginning of 

 the Glacial Period and the present time. 



Liinerick District. — In the country around Limerick we had to deal with the 

 products of the Ivernian ice-sheet only, uncomplicated by exterior invasion ; and 

 here not even the staunchest supporter of Interglacial deglaciation and sub- 

 mergence could have found a basis for his hypothesis. Although the drifts occur 

 thickly on low ground falling to sea-level, as well as on the hills, and although 

 they include numerous eskers and broad fans of sand and gravel, not a single shell 

 fragment has been discovered in them, nor any other indication of marine agency. 

 On the other hand, there is abundant evidence that the boulder-clay and the 

 stratified drift were formed contemporaneously, the one by the ice-sheet itself, and 

 the other by the flood-waters in and around it. Another noteworthy point in this 

 district is that, in spite of its proximity to the west coast, with the broad estuary 

 of the Shannon offering at present an open passage thereto, the general movement 

 of the land-ice was south-eastward across the low ground, trending inland, and not 

 toward the coast. It appears, therefore, that tlie ice-sheet at the mouth of the 

 Shannon was sufficiently tbick to dominate that of the country to the east in this 

 part of Ireland. Farther to the northward, however, and also to the southward, 

 it is known that ice-lobes passed outward toward the Atlantic. 



I think that this review of the testimony from the areas which I have closely 

 investigated will serve to show how extraordinarily elusive is the evidence for even 

 the principal Interglacial epoch of the proposed scheme. I shall venture to claim 

 that in each of these areas all the available data concerning the superficial deposits 

 were systematically examined in the field and conscientiously sifted, without pre- 

 judice towards one opinion or another. Yet the only support which has been found 

 for the Interglacial hypothesis is from a single section in North Lincolnshire, and 

 although in this case the facts give some encouragement to the idea, they can be 

 as readily explained without recourse to it. 



In view of some evidence which we have still to consider, it is especially 

 remarkable that in the range of magnificent coast sections, not of these areas alone 

 but of the whole of our islands, there is not, so far as I am aware, a single known 

 occurrence of fossiliferous land deposits, peaty or otherwise, interbedded with 

 boulder-clays ; and we have, therefore, to depend entirely upon much less satisfac- 

 tory exposures in the interior of the country for evidence of this kind.^ 



After the experience above recorded, it is inevitable that I shall approach the 

 remainder of the British evidence for the Interglacial hypothesis in sceptical mood, 

 though, I hope, without dogmatism. In discussing this evidence from districts of 

 which my personal knowledge is scanty, or altogether wanting, I shall perforce have 

 to depend mainly upon the literature of the subject, although I am fully aware 

 that, of the opinionative churning of this literature there has already been more 

 than enough. 



East Anglia. — In East Anglia, the original opinion that the shelly ' middle 

 glacial ' sands and gravels represent a mild interglacial epoch of submergence is 

 no longer prevalent. Mr. F. W. Harmer ' points out that both the mollusca and 



' I did, indeed, at one time think that I had discovered an ancient soil with land 

 shells between two boulder-clays in the cliffs of Filey Bay, but after much examina- 

 tion I found that it was a recent soil, covered by a huge slip of boulder-clay from the 

 upper part of the cliff and then exposed in section by the cutting back of the coast. 



' ' The Later Tertiary History of East Anglia,' Proc. Geol. Assoc, vol. xvii. (1902), 

 pp. 458-462; and 'Pleistocene Deposits of East Anglia.' Proc. Yoris. Geol. and 

 Pohjtech. Soc.,\o\. sv. (1904), p, 322. 



