ORIGIN OF DEPOSITS. Ovi 
These facts establish the point that fresh-water agency, even at the 
present day, is capable of producing a variety of results over a widely 
extended surface. The gentlest depositions may take place upon the 
drying flats, when the waters are quiet during the subsiding flood; 
or there may be coarser beds, with transported logs imbedded within 
them, produced from the action of flowing waters. 
Where and how did the coal plants grow are the most difficult ques- 
tions connected with this subject. The great number of leaves im- 
bedded together, and all perfect, is certainly proof of no long transpor- 
tation. Moreover, existing rivers give evidence that such material 
brought down in the body of the current would be scattered far and 
-wide, and mostly borne away to the sea, instead of being collected in 
large accumulations. Ordinary river flats do not contain such beds. 
Again, the leaves are so neatly compacted in thin even layers with 
clay, that the deposits have no resemblance to accumulations of leaves 
in the soil on which they grew. ‘The extreme tenuity of the slaty 
structure produced by the leaves, and the clean pale colour of the 
deposited clay, look more like an effect produced beneath water after 
a quiet transportation to some moderate distance. ‘This would seem 
to have been the mode of origin of the clay layers containing leaves, 
if not of the beds of coal themselves: and as the latter are often made 
up of alternations of more and less clayey layers, and show a thin 
striping, as if from a gradual deposition of the material, it may be true 
also of the coal beds. It will be remembered that there is no uni- 
formity in the character of the layers above and below the coal beds, 
although commonly those immediately adjoining the coal are more soft 
clayey than elsewhere. The tables on page 471 and beyond, give 
the facts on this point. 
The plants, therefore, either grew on lands near where the leaves 
were deposited, from which they were perhaps borne off by the gentle 
rise of waters attending a flood ;—the rise and movement of the waters 
being gentle, because the inundation in these parts covered low lands 
at a distance from the main current: or, they constituted a floating 
vegetation, as some geologists have suggested. The remarkable 
abundance of floating plants at the Lake de Bay, on Luzon,—which 
float out in great quantities by the canal to Manilla harbour, there 
to be deposited (see beyond),—seemed to the writer a direct illustra- 
tion (though on a small scale) of a common condition in the coal era. 
In favour of this view, we may remark that the productions of nature 
have had reference in all time to the condition of the globe. In 
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