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out, and resorted over previous marine deposits, or on the 
bare sea bottom, and from these resorted beds there would 
be a passage up through the Lower limestone Shale to higher 
carboniferous beds. 
This view will quite explain why we seem to have a 
passage in one place, and in another a sharp line between 
the Old red conglomerate and Carboniferous rocks. 
It would appear probable, from the number and character 
of the corals and the plants imbedded in the earliest deposits 
of the period, that the climate was temperate or sub-tropical. 
This will not affect the question next to be considered: 
whether the Old red conglomerate may not be an ancient 
glacial drift, as we might then, as now, have in temperate 
zones a thick glacial drift the record of previous climatal 
conditions. 
Professor Ramsay first put forward the view that these 
conglomerates were of glacial origin, founding his opinion 
upon the following observations: (1). The manner of their 
occurrence in isolated patches in old valleys. (2). The 
character of the deposit, which is a coarse conglomerate, 
showing a very irregular accumulation. (3). The shape of 
the included fragments, which is very similar to that of the 
fragments of the same formations in the glacial drift; and, 
(4). The occurrence of scratched stones. 
But we must remember that any sub-aerial or fluviatile 
deposit, covered by an encroaching sea, must have that 
patchy character, that in its irregular accumulation, and the 
shape of the stones, it more resembles the gravel drift of 
the valleys than the Boulder clay; and the origin of this 
gravel drift is, at any rate, doubtfully glacial. I think 
we must be cautious, too, about referring the scratches on 
the stones to glacial action — though undoubtedly they are 
like those found in the true drift, and the shape of the stones 
is also the same. Yet they have never been found except 
