Ch. III.] 
OF SUCCESSIVE FORMATIONS. 
27 
largest portion of the whole, is either suffering degradation^ 
or remaining stationary without loss or increment. The reader 
will assent at once to this proposition, when he reflects that 
the dry land is, for the most part, wasting by the action of 
rain, rivers, and torrents, while the effects of vegetation have, 
as we have shown, only a conservative tendency, being very 
rarely instrumental in adding new masses of mineral matter 
to the surface of emerged lands ; and when he also reflects that 
part of the bed of the sea is exposed to the excavating action 
of currents, while the greater part, remote from continents 
and islands, probably receives no new deposits whatever, being 
covered for ages with the clear blue waters uncharged with 
sediment. Here the relics of organic beings, lying in the ooze 
of the deep, may decompose like the leaves of the forest in 
autumn, and leave no wreck behind, but merely supply 
nourishment, by their decomposition, to succeeding races of 
marine animals and plants. 
The other part of the terraqueous surface is the receptacle 
of new deposits, and in this portion alone, as we pointed out in 
the last volume, the remains of animals and plants become 
fossilized. Now the position of this area, where new forma- 
tions are in progress, and where alone any memorials of the 
state of organic life are preserved, is always varying, and must 
for ever continue to vary ; and, for the same reason, that por- 
tion of the terraqueous globe which is undergoing waste, also 
shifts its position, and these fluctuations depend partly on the 
action of aqueous, and partly of igneous causes. 
In illustration of these positions we may observe, that the 
sediment of the Rhone, which is thrown into the lake of Ge- 
neva, is now conveyed to a spot a mile and a half distant from 
that where it accumulated in the tenth century, and six miles 
from the point where the delta began originally to form. We 
may look forward to the period when the lake will be filled up, 
and then a sudden change will take place in the distribution 
of the transported matter; for the mud and sand brought 
down from the Alps will thenceforth,, instead of being deposited 
