18G8.] ARGYLL ARGYLLSHIRE. 255 



position is supported, viz. that in diluvial soils, and even " in solid 

 strata, small valleys have been excavated by the streams which run 

 in them, or else b)^ postdiluvial floods"* ; while often below them, 

 and below the drift in which they are found, Preglacial valleys of 

 greater amplitude occui', whose now subterranean surface is covered 

 by gravel, sand, and conglomerate, distributed as if by atmospheric 

 agency before the expansion of the Glacial sea. 



Turning now to the sections of Hessle cliif, we see, upon the 

 wasted surface of the chalk, accumulations similar to those just 

 mentioned on the chalk cliffs north of Bridlington. They appear to 

 me to be of the same geological age, and I have regarded the ele- 

 phants and horses which they contained as of Preglacial date. 



I am disposed still to favour this opinion ; for though the removal 

 of the Hessle clay to a higher place in the series than was assigned to 

 it deprives me of one support to my argument, there are still grounds 

 to be relied on. In the first place, there is no proof that these 

 beds are marine, but a strong presumption to the contrary, from the 

 considerable abundance of land mammalia found in them, especially 

 Elephas pr'imigeniiis and horse. And, secondly, beds of this order, 

 composed of chalk and flint fragments, not only are not known to 

 occur in the midst of the Boulder- clay, but can hardly be imagined 

 to exist there. And, thirdly, the Boulder-clay rests on them without 

 conformity. 



February 5, 1868. 



Arthur Humphrys Foord, Esq., 12 Woodland Terrace, Black- 

 heath ; B,ev. Eobert Hunter, M.A., 9 Mecklenburgh Street, W.C. ; 

 Frederick Newman, Esq., Civil Engineer, 51 Belsize Eoad, St. 

 John's Wood ; and Hugh Seymour Tremenheere, Esq., Tremenheere, 

 Cornwall, were elected FeUows. 



The following communication was read : — 



1. On the Physical Geography of Argyllshire in connexion with its 

 Geological Structure. By His Grace the Duke of Argyll, K.T., 

 F.R.S., F.G.S. 



In a work published in 1865 upon '' The Scenery of Scotland viewed 

 in connexion with its Physical Geology," Mr. Geikie has set forth 

 with much ability certain theories upon that subject which seem to 

 be gaining ground with the younger school of geologists. 



Not believing in the truth of those theories, I have selected the 

 work referred to as the best text I could find for the purpose of 

 bringing them under discussion. Although a popular treatise, the 

 work of Mr. Geikie is at once elaborate and systematic. It states 

 the questions in dispute with great distinctness. I propose there- 

 fore in this paper to deal with the theory of the " Erosionists " as 

 I find it there defined and there defended. 



According to these theories subterranean movements and commo- 

 * Geol. of Yorkshire, vol. i. ed. i. p. 71, ed. ii. p. 43. 



