MODE OF DEPOSIT. 
119 
parallel to the original line of deposit or 
the bedding of the rock; they are also 
found inclined at all angles ; and in numer¬ 
ous well attested instances have been dis¬ 
covered vertical, with their roots imbedded 
in the indurated mud beneath. The deli¬ 
cate markings of the Ferns, the flutings of 
the Calamites, the symmetrical markings of 
the Lepidodendron, all so nicely preserved, 
shew that their deposit was unaccompanied 
by great continued violence. Yet it must 
have been by catastrophe, for after allowing 
for the various rates at which plants macer¬ 
ated in water decay, we cannot reconcile 
the facts to the tranquil gradual subsidence 
of a forest into a lake, or its tardy conver¬ 
sion into a peat bog. We find a coarse 
muddy deposit, containing shells of fresh¬ 
water mollusks, then a layer of coal plants 
and coal; over this a bed of sandstone; 
another layer of coal; another stratum of 
mud with shells; and so on for several suc¬ 
cessions; each of which requires time for 
its separate organisms to live, flourish, and 
become immensely numerous: each platform 
of life existing on the settled ruins of the 
