386 T. Mellara Reade—Oceans and Continents. 
My first difficulty in regard to accepting these views arises from 
the “ general” or undefined nature of the statements, which are put 
forward in a very crude form. The arguments relied on in favour 
of the fixity of continents and oceans are far from convincing, as I 
know of none, either general or particular, that cannot to my mind 
be as satisfactorily answered on the older hypothesis, that the land 
and water have in the world’s history interchanged places so that 
at one time or another every part of the ocean-bottom may have 
been land. 
Still further, in attempting to follow out the sequence of events by 
which oscillations of land and sea in a limited area could account for 
all those enormous and successive stratified marine deposits almost 
everywhere to be found on every continent, nay even on islands 
such as New Zealand, the mind actually fails to grasp what oa 
have been the formative process. 
All are agreed that subaerial waste of land is the main source of 
the detritus of which the rocks, of what on upheaval become other 
lands, are built. 
It follows that where the marine deposits were going on, 
equivalent land must have existed elsewhere. Now the more we 
limit the area of oscillation of land and sea, the more difficult the 
explanation of the phenomena of geology becomes. Professor 
Archibald Geikie, F.R.S.,' states, in ‘‘ Geographical Evolution ” :— 
“When the curtain of darkness begins to rise from our primeval 
Hurope, it reveals to us a scene marvellously unlike the existing 
continent. The land then lay chiefly to the north and north-west, 
probably extending as far as the edge of the great submarine plateau 
by which the European ridge is prolonged under the Atlantic for 
230 miles to the west of Ireland,” and he goes on to calculate that 
the Silurian system in Great Britain “alone contains (or did contain ?) 
180,000 cubic miles of detritus derived from this land. Also that 
then the shallow sea which spread from the Atlantic southward 
and eastward over most of Europe was tenanted by an abundant 
and characteristic series of invertebrate animals” (Trilobites, etc.). 
“But at the close of the Silurian period a vast series of disturb- 
ances took place, as the consequence of which we find the first rough 
outlines of the European continent were blocked out.” ‘Then 
comes the period of the Old Red Sandstone, with its vast lakes 
abounding in bone-covered fishes, etc.” “By the time of the Coal 
periods the aspect of the European area had still further changed.” 
“Tt then consisted of a series of low ridges or islands in the midst 
of a shallow sea, or of wide saltwater lagoons.” ‘All this time 
the chief area of high ground in Europe appears still to have lain. to 
the north and north-west.” 
The next scene “brings before us a series of salt lakes covering 
the centre of the continent from the north of Ireland to the west of 
Poland.” 
“These salt lakes of the Triassic period seem everywhere to have 
been quickly effaced by a widespread depression, which allowed 
* Geographical Evolution—Proc. Royal Geographical Society, 1879, pp. 422-43. 
