514 THE ORIGIN OF CERTAIN CANON-LIKE VALLEYS. [Nov. I907. 



closely resemble each other, even in small details, that the pre- 

 sumption is that they originated in a similar way. One of the 

 cases mentioned, that of the Pickering region, is admittedly of 

 Glacial origin. It seemed to strengthen his contention as to the 

 rest to find, on the high authority of Prof. Lapworth, that the 

 Ironbridge Gorge is so regarded. 



Owing to the short time at his disposal, the Author had not been 

 able to give more than an abridged summary of his paper. He hoped 

 that, if Mr. Spicer had the opportunity of reading it in full, some of 

 the difficulties suggested by him would disappear. He was unable, 

 however, to accept Mr. Spicer's explanation of the origin of the 

 phenomenal denudation to which the Chiltern region had been 

 subjected. That denudation was due, he believed, to abnormal 

 meteorological conditions obtaining during the Pleistocene Epoch, 

 wholly different from those of the present, caused by, as well as 

 contemporary with, the existence of the great European ice-sheet. 

 Similar phenomena are to be met with in many parts of the 

 Continent, south of the glaciated area. Bunter pebbles are not 

 uncommon in the Chalky Boulder-Clay of the Ouse region. They 

 came from the Pennines by way of the Fenland, and were 

 carried south-westwards by the ice as far as Buckingham. Those 

 found in the neighbourhood of Goring and on the hills near 

 Oxford, on the contrary, came principally from Staffordshire and, 

 as shown by Buckland 80 years ago, by the Evenlode Valley, 

 in the Drift of which, together with Cretaceous detritus from the 

 Lincolnshire "Wolds, they are exceedingly abundant. 



The Author believed that an overflow from the suggested ' Lake 

 Oxford ' may have taken place in the first instance by more than 

 one channel, as stated in his paper; but, owing to the greater 

 volume of water flowing through it, the excavation of Goring Gap 

 went on more rapidly, the latter finally capturing and retaining 

 the whole of the drainage of the region. 



