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permeated with water in large quantities, that its whole mass 

 is loosened, and falls away from season to season to a very 

 great extent. The effect of this upon our present subject 

 has an important bearing in two particulars. 



(a) It would entirely do away with the supposition that 

 any part of this "talus" now lying immediately against the 

 entrance of the cave, was existent during the glacial epoch, 

 and hence that the boulders relied upon by Messrs. Tidde- 

 man and Dawkins cannot be in situ as therein deposited, 

 and 



(b) That the floor level of the cave has been constantly 

 rising, having been reformed upon the masses of limestone 

 which had fallen from the roof These two important 

 deductions are amply verified by the present appearances 

 of the cliff and cavern. 



(3) In every instance with which I am acquainted the 

 clay which fills the caverns of Yorkshire and Derby- 

 shire has been introduced by the agency of running water, 

 generally by " pot holes," which communicate with the sur- 

 face, and which in wet seasons give passage to large volumes 

 of water laden with detritus, a portion of which is deposited 

 in such parts of the underground channels as are favourable 

 to, its accumulation. Such clays are likely to be laminated, 

 because of the mode af their deposition, at intervals, which 

 allowed one layer to harden before another was deposited 

 upon it. The clay which is found filling the Victoria Cave 

 is precisely such as we should look for under the circum- 

 stances before described. The glacial drift deposited clay 

 of the boulder type upon the surface; and the rains of ages 

 dissolved it away and carried it down these fissures into the 

 cavern, where a portion of it remained. That the cave is of 

 the precise character here indicated I can certify, for I was 

 able to get to the end of it after going for a considerable 

 distance through mud and water — the roof being only about 

 two or three feet from the floor. I there found that the end 



