674 MR DAVID MILNE HOME ON THE BOULDER-CLAY OF EUROPE. 



is drawn, that the deposit must have been formed, not in the sea, but in the 

 land, it being supposed that these remains were drifted into the boulder-clay 

 by rivers* But rivers flow into the sea, as well as into lakes. It is true that 

 the boulder-clay near Glasgow and near Falkirk, at both of which places 

 elephants' tusks were found, presented no marine shells. But it is equally true 

 that elephants' tusks have been found in what are allowed to be sea-beds. At 

 Kilmaurs (Ayrshire), two tusks of an elephant were found in a bed of stratified 

 mud 9 inches thick, which was overlaid by a bed of sand containing sea-shells, 

 these shells being covered by boulder-clay. (Journ. Lond. Geolog. Soc. vol. xx. 

 p. 217). In Dumbartonshire, the bones of a rein-deer were taken out of a bed of 

 laminated clay, associated with sea-shells. f (Edin. Phil. Journ. new series, 

 vol. vi. p. 105.) 



Mr Geikie, in support of his view, endeavours to explain the association of 

 sea-shells and the bones of terrestrial animals in boulder-clay, by suggesting that 

 the mass of earth and stones may have been pushed forward by a glacier " close 

 to the sea-shore, and sea-shells might either be thrown up by high tides over 

 the bones previous to their entombment, or be deposited above them during the 

 slow sinking of the land." He adds— "I mention this as a possibility, in order 

 that no difficulty need be felt in harmonising such a fact with the hypothesis 

 that the boulder-clay is a deposit from land ice, and not from icebergs." ("On the 

 Glacial Drift of Scotland," p. 94.) 



The possibility of the occurrence here suggested I admit. Its probability is 

 not so clear. But it is quite clear that the occurrence of elephants' bones at two 

 places in boulder-clay, where no sea- shells were found, is no conclusive proof 

 that the deposit must have been formed on the land, when, at two other places, 

 similar bones were found in pleistocene beds, which must have been at the 

 bottom of the sea when the bones were drifted into them. 



6. I now pass to other facts which indicate that the boulder-clay not only 

 has been disturbed and intruded on by some foreign agent, but has, in some 

 cases, been moved en masse by some agent of tremendous power. 



Thus Mr Cumming, in his " Memoir on the Isle of Man" ("Proc. Lond. Geol. 

 Soc." 4th Jan. 1854, p. 213), says — " There are appearances, as if the boulder-day 

 had been forced violently amongst the different beds of limestone. Fragments of 

 the latter are torn up and carried forward, and these remain angular, though 

 much scratched, at no great distance in the mass of clay which now covers the 

 limestone beds." 



The late Dr Fleming ("Lithology of Edinburgh," p. 60) pointed out "near 

 Gilmerton, a sandstone quarry, where the outcrop of the rocks is seen, covered 



* Geikie on Glacial Drift, p. 93. 



f Bones of elephants, rhinoceros, &c, are found in Siberia very generally associated with Arctic 

 sea-shells. (Lyell, "Principles," i. 183; Quart. Journ. Lond. Geolog. Society, 1st Feb. 1848.) 



