114 P''^of. Hughes, Criticism of the Geological [Oct. 30, 



cause it to break up, and a large number of the fragments in the 

 ice have been carried by water on to it or in channels in and 

 under it. It would be difficult to say of any boulder that its 

 flattened sides had been produced by the grinding action of the 

 ice with its included grains. Moreover it would not be easy to 

 ascertain certainly whether any particular stone in our river 

 gravels, or in similar deposits at the foot of the Alps or Hima- 

 layas, had been derived directly from the parent rock or second 

 hand from a glacial drift, so that the comparison is attended with 

 many difficulties. 



It would appear then that many good observers have arrived 

 at the conclusion that these beds, whether on the south of the 

 great Himalayan range or on the flanks of the mountains which 

 form the watershed in South Eastern Africa or in the unstable 

 region of New South Wales, present many characters in common 

 and that there is evidence, stronger in s(ime cases and weaker in 

 others, that ice in some form or another has played an important 

 part in building up the boulder-bearing beds which they contain. 

 The vertical range and correlation of the beds is still unsettled, 

 the precise manner of intervention of the ice is doubtful. Many 

 a good case is weakened by being supported by weak and easily 

 refuted arguments and we must not dismiss all the evidence 

 advanced by competent observers because we find obvious errors 

 or irreconcilable statements here and there, but still we cannot 

 help bearing in mind the case of the Old Red Conglomerate in 

 England (see pp. 115 to 117). 



Supposing we admit the glacial origin of much of these 

 boulder deposits ranging over periods so vast that they are 

 referred to everything from Carboniferous to Trias and perhaps 

 to still newer beds, distributed over regions so far apart as India, 

 Africa and Australia. What then ? must we shift the poles ? 

 The evidence goes to show that they are marine strata into 

 which the boulders have been dropped. All we have to account 

 for is floating ice, not ice coming down to the sea where we now 

 find the boulders. Stranding ice will striate the solid floor and 

 melting ice will drop blocks whether ice-worn or subaerially 

 weathered that have fallen on it or been frozen up in it. How to 

 account for such ice in those regions is a question which I reserve 

 for a later communication in which I hope to deal with the earth 

 movements, but I would point out that if we admit the evidence 

 that the beds with the Glossopteris fauna belong to one age and 

 prove that glacial conditions then prevailed over the area in 

 which they are found, that is fatal to the astronomical theory 

 which requires alternate intensification of cold or heat at either 

 pole. 



