D, Bell — The Great Ice Age and Submergence. 325 



adequate solution of the difficulty." ^ But now be announces with 

 easy nonchalance that the difficulty does not exist — "it does not 

 necessarily follow ! " 



We may remark, in passing, that there are many things which 

 do not " necessarily follow," but which yet are the only probable 

 things we can accept or reason upon. That a submergence of 

 500 feet or 600 feet should leave traces of itself in the shape of 

 relics of marine life, more or less abundant, in the Boulder-clay 

 of the succeeding glaciation, seems to us as nearly a necessary 

 consequence as anything we know of in geology ; at all events, as in 

 many ways, and by many degrees, more probable than that such 

 traces should all have been removed or destroyed. But let us look 

 at Dr. Geikie's reasons for now making so light of the difficulty 

 which formerly oppressed him. 



(1) He says, "a depression of 500 feet or 600 feet would drown 

 only a narrow belt of coast-land, and a relatively small area in the 

 midland of Scotland." 



With a recollection of Lyell's old sketch-map, showing the change 

 that would be produced on the contour and extent of the British 

 Isles by a subsidence of 600 feet,^ we read this statement with 

 considerable astonishment. Let the reader look at any good 

 '' Orographical Map " of Scotland, such as that prefixed, for 

 example, to the volume already mentioned, "Fragments of Earth- 

 Lore." There he will see clearly the broad tracts that would be 

 submerged by a depression of 500 feet — in Caithness, around the 

 Moray Firth, in Aberdeenshire, in Strathmore, in Fife, in the Forth 

 and Clyde valley, in Berwickshire, Dumfries, Kirkcudbright, 

 Wigton, Ayr; in all cases running far up into the river valleys; 

 not to speak of innumerable detached areas and winding belts, in 

 some cases of considerable size, all along the western coast. Why, 

 a depression of 500 to 600 feet would drown nearly all the arable 

 land of the country, all the "broad lowland tracts," straths, and 

 " carses," described so graphically in the volume referred to. This 

 as regards Scotland ; while in England and Ireland the area sub- 

 merged would be relatively still more extensive — in fact, the greater 

 part of the country. We may take it, then, that the extent of the 

 area gives emphasis to the question,— If it were all submerged prior 

 to the last glaciation, why does its Upper Boulder-clay not contain 

 fragments of shells, and afford other indications of the former 

 presence of the sea ? 



Dr. Geikie adds (2) that "the submergence may not have been 

 long-continued," and (3) that " the conditions may not have favoured 

 the abundant development of marine life." But these seem to be 

 purely imaginary suppositions, thrown in without a word in their 

 favour. We need not, therefore, discuss them. 



(4) We pass on to notice the last and apparently chief reason 

 given by the author to account for the absence of marine organisms 

 in the Upper, or supposed post-submergence. Boulder-clay. It is, 



1 Second edition, p. 390. 



2 "Antiquity of Man," third edition, p. 278. 



