118 



PROP. T. M'KE]5r:NT HUGHES ON THE 



deposits in other caves in the neighbourhood did not prove that they 

 are of Postglacial age in this cavern, because there is evidence at 

 Crayford, in Kent, that the river-drift man was Preglacial in the 

 valley of the Thames. Palaeolithic implements are found over a 

 wide area in the Old "World — in the south of Europe and north of 

 Africa, in Egypt, Palestine, and in India ; and their distribution 

 can only be accounted for by the river-drift man having lived for 

 a long series of ages on the earth, long enough, indeed, to be pre- as 

 well as postglacial. 



With regard to the Mammalia found in the caves of the Yale of 

 Clwyd, nearly all were living in the eastern counties in the pre- 

 glacial age. There is clear proof (1) that the Pleistocene Mammalia 

 invaded Europe in the preglacial age ; (2) that they were driven 

 away from the British area by the results of the lowering of the 

 temperature and of the depression of the land ; and (3) that they 

 returned and occupied the British area after the retreat of the ice and 

 the re -elevation of the land. They therefore afford no evidence as 

 to the relation of the deposit in which they are found to the Glacial 

 period. 



Mr. Drew asked Dr. Hicks at what depth (behind the fence) did 

 the solid rock occur beneath the place where there was now material 

 tipped by the workmen. 



Dr. Hicks, in reply to Mr. Drew, said that the shaft exposing the 

 drift-section was at the furthest end of the cavern from the old 

 fence. 



Prof. Carvill Lewis regretted not having seen the cave itself, 

 though he had examined the glacial deposits of the neighbourhood 

 and of North Wales generally. He was glad to hear that the views 

 of the speakers this evening were in favour of a simplification of 

 glacial phenomena. From a study of glacial deposits' in many 

 parts of Great Britain and Ireland, he had been led to believe that 

 there had been only one advance of the ice and one retreat, one 

 slight elevation and one slight submergence, and that the submer- 

 gence in the non-glaciated area was contemporaneous with the 

 maximum extension of the ice in the glaciated area. There were 

 three main areas of local glacial dispersion in Wales, the glaciers 

 from each of these being defined by terminal moraines. But there 

 was also satisfactory evidence that an ice-lobe coming from Scotland 

 and filling the Irish Sea had impinged upon the extreme northern 

 border of Wales, and passing over Anglesey and along the west side 

 of the Snowdonian mountains on the one side, and into Cheshire and 

 along the east of the mountains on the other side, had pushed its 

 terminal moraine against the highlands and in the teeth of the 

 opposing local glaciers. The latter were both earlier and later than 

 the northern ice-lobe, and the two drifts were therefore often com- 

 mingled. The line dividing the northern ice-lobe from the Snow- 

 donian glaciers was close to the cave under discussion, and the 

 massive deposits near St. Asaph were probably washed out of the 

 common terminal moraine. The undoubted marine deposits, full of 



