Vlll 
the present surface of the earth, and perhaps to prepare it for 
the support of man, as all these changes appear to have been 
effected anterior to the existence of the human race. 
In the more ancient oceans existed animals of gigantic size, 
no living analogies of which are known, while about three hun- 
dred species of Ammonites floated upon the surface, or lived 
in vast colonies in the depth of the sea; and yet not a solitary 
species has been spared by those revolutions of a “past eterni- 
ty” which now offer to our minds the fascinating study of re- 
lics, abstracting us from the present and leading to the contem- 
plation of a former world. But in proportion as we advance 
in the ascending series of stratification, we find the organic re- 
mains approaching more and more to the existing order of na- 
ture, until at last we arrive at those not to be distinguished 
from the present inhabitants of the sea. “ Life therefore” ob- 
serves Cuvier, “has been often disturbed on this earth by ter- 
rible events — calamities which, at their commencement, have 
perhaps moved and overturned to a great depth the entire outer 
crust of the globe, but which, since these first commotions, 
tions, have uniformly acted at a less depth and less generally. 
Numberless living beings have been the victims of these catas- 
trophies ; some have been destroyed by sudden inundations, 
others have been laid dry in consequence of the bottom of the 
seas being instantaneously elevated. Their races even have 
become extinct, and have left no memorials of them except 
some small fragment which the naturalist can scarcely recog- 
nize. 
“Such are the conclusions which necessarily result from the 
objects that we meet with at every step of our enquiry, and 
which we can always verify by examples drawn from almost 
every country. Every part of the globe bears the impress of 
these great and terrible events so distinctly, that they must be 
visible to all who are qualified to read their history in the re- 
mains which they have left behind. 
“ But what is still more astonishing and not less certain, there 
have not been always living creatures on the earth, and it is 
easy for the observer to discover the period at which animal 
productions began to be deposited. 
Philadelphia , October 1st , 1832. 
