572 Reports and Proceedings — 



anything, suggested a cold climate ; tliougli abundant, the species 

 were dwarfed, in striking contrast to those of the Greensand of 

 Southern England and the fauna of the succeeding Chalk. The 

 authors concluded that a tongue of land separated the Upper G-reen- 

 sand sea into two basins, the noi'thern of which received icebergs 

 from the Scottish- Scandinayian chain ; the climate of this was cold, 

 that of the southern basin much warmer. 



Discussion. — Mr. Seeley gave some history of the specimens in the "Wood- 

 "wardian Museum, on ■which the paper was partly founded, some of which had been 

 collected by the late Mr. Lucas Barrett, and others by himself. He thought that 

 some of the scratches on one of the specimens from Grantchester might be of modern 

 origin, and doubted whether the place of derivation of most of the blocks was Scot- 

 land. Besides the rocks mentioned, he had found fragments of Magnesian-limestone 

 and columns of Poteriocrinus. He could not agree with the authors as to the physical 

 geography of Britain during the Upper Greensand period. He considered that it was 

 from the denudation of the great barrier mentioned in the paper that much of the 

 material of the Upper Greensand was derived ; and disputed the value of concla- 

 sions as to climate founded on so small an area of induction. 



Mr. Walker did not agree with the author as to the absence of large Ammonites 

 in the Cambridge Greensand, and of fossils in the Gault of the neighbourhood of 

 Cambridge ; the latter had been found by Mr. Keeping at Up ware. He inquired in 

 what state of combination the phosphoric acid was supposed to be brought from 

 Scotland. 



Mr. Sollas, in reply, pointed out the angularity of some of the specimens, such as 

 to bim seemed inconsistent with any other means of transport than that of ice, and 

 the difiiculty attending the supposition that the blocks were derived from any other 

 than a northern source. He thought that the large Ammonites were derived from a 

 lower bed in the Gault than the upper point, from which he had supposed a large 

 portion of the Upper Greensand fossils had been derived. He considered that the 

 phosphoric acid had been conveyed along the sea-bottom, combined with some base, 

 and that the combination was in a comminuted condition. 



Mr. Jukes-Browne also replied, and pointed out that in his view the London and 

 Harwich anticlinal had been covered with a great thickness of Gault at the time of 

 the deposit of the Upper Greensand. 



Prof. Eamsay, in winding-up the discussion, expressed an opinion that the forms 

 of pebbles of glacial origin might be recognized by an experienced eye even though 

 the striae had been worn off, and that some of the pebbles exhibited showed traces of 

 such an origin. He called attention to the fact that the deposit of glaciated pebbles 

 in any particular locality did not in any way involve the existence of arctic conditions 

 at that spot, though they might exist elsewhere. 



Geologists' Association. — November 1st, 1872. — The Eev. T. 

 Wiltshire, M.A., F.G.S., etc., President, in the Chair.— "On the 

 Influence of Geological Eeasoning on other Branches of Knowledge." 

 By Hyde Clarke, Esq., D.C.L. After referring to his paper at the 

 installation of the Association, " On Geological Surveys," Mr. Clarke 

 said there was a direct and indirect action produced by geology, 

 which had operated remarkably on the substance and modes of 

 thought in the present day. Being a science of observation, it had 

 tended to confirm the practice of observation. The determination 

 of stratification of itself exercised a potent effect on modern thought, 

 because vdth it were connected the ideas of succession and pro- 

 gression. Eeasoning by analogy will always prevail in things 

 human against all objectors, because, after all, as in things human 

 the mind recognizes symmetry, so reasoning by analogies becomes 

 reasoning by probabilities. Thus, the analogies of stratification, 



