278 Reports and Proceedings — Geological Society of Glasgoiv. 



a " remarkable performance." The argument that if there had been 

 a submergence to the extent of 500 feet, we should find traces of 

 it in innumerable localities up to tbat level — though formerly it 

 appeared to himself unanswerable (second edition, p. 390) — Dr. 

 Geikie now dismisses by saying " it does not necessarily follow." 

 The submergence, he supposes, may have been sudden and of short 

 duration ; or marine life may have been scanty ; or all traces of it 

 may have been removed by a subsequent glaciation. With all 

 deference, these appear to be greater " freaks " and more " remark- 

 able performances " than any imagined on the other side ; and they 

 include not only the ice but also the sea and the solid land. The 

 last supposition, which is the most plausible, has been dealt with 

 elsewhere,^ and can be refuted in Dr. Geikie's own words (pp. 108, 

 109, 112, etc.). With regard to Clava, it can be maintained that 

 there is nothing in the deposit that necessitates having recourse to 

 a submergence ; but much, in addition to the absence of traces of it 

 at a similar level elsewhere, that is inconsistent with it. Dr. Geikie 

 spoke of the shelly clay having been " dragged forward underneath 

 an ice-sheet" for a distance of ten or twelve miles; but he can 

 hardly insist on this particular mode of transport, seeing he informs 

 us that " stones or boulders, once imbedded in the ice, might travel 

 for hundreds of miles without suffering abrasion " (p. 204). Even 

 the ajDparent extent of the deposit — which appeared to be Dr. 

 Geikie's principal, if not sole, difSculty — if granted as proved, did 

 not seem to be an insuperable objection to the ice-theory. Numerous 

 instances were known in which large masses of clay and sand, and 

 thin slabs of chalk, etc., had been transported uninjured by the ice. 

 But whatever weight attached to this objection depended entirely 

 upon the assumption that the deposit had all been transported by the 

 ice at once, or en masse; which, to use Dr. Geikie's words, "does not 

 necessarily follow." It may have been transported very gradually, and 

 accumulated in an extra-glacial lake, formed at this part by the ice- 

 sheet passing across a bend in that range of hills along whose base 

 its course lay. An examination of the locality showed the extreme 

 probability of this suggestion, which was submitted as at least 

 preferable to sudden and transient submergences of 500 feet — seas 

 with scarcely any marine life — and glaciers that cleared away all 

 traces of a former sea-bed, over only part of which they could have 

 passed. It not merely removed the objection i-eferred to, but also 

 accounted in some degree for several features of the deposit which, 

 on the theory of a submergence, seemed inexplicable — such as the 

 absence of all traces of currents in the clay, 3'et the worn and 

 rounded stones imbedded in the heart of it ; the sharp line of 

 distinction between it and the other parts of the section ; its wide 

 difference from these in composition, etc. Eeference was then made 

 to the frequent elevations and depressions which Dr. Geikie still 

 favoured during the Glacial period ; their want of harmony with 

 what had been observed in other parts of the northern hemisphei'e ; 

 their improbability in themselves, and especially in the repeated 

 1 Trans. Geol. Soc. Glas. vol. ix, pp. 109, 110. 



