EFFECT OF POLYPES ON MINERAL STRATA. 445 
The same system appears to have prevailed from 
the first commencement of life in the most an- 
cient seas, throughout that long series of ages 
whose duration is attested by the varied succes- 
sion of animal and vegetable exuviae, which are 
buried in the strata of the earth. In all these 
strata the calcareous habitations of such minute 
and apparently unimportant creatures as Polypes, 
have formed large and permanent additions to 
the solid materials of the globe, and afford a stri- 
king example of the influence of animal life upon 
the mineral condition of the earth.* 
If there be one thing more surprising than an- 
other in the investigation of natural phenomena, 
it is perhaps the infinite extent and vast imjDort- 
ance of things apparently little and insignificant. 
* Among the Corals of the Transition Series are many existing- 
genera, and Mr. de la Beche has justly remarked (Manual of 
Geology, p. 454) that wherever there is an accumulation of 
Polypifers such as would justify the appellation of coral banks 
or reefs, the genera Astrea and Caryophyllia are present ; genera 
Vv^hich are among architects of coral reefs in the present seas. 
A large part of the Limestone called Coral Rag^ which forms 
the elevated plains of Bullington and Cunmer, and the hills of 
Wytham, on three sides of the valley of Oxford, is filled with 
continuous beds and ledges of petrified corals of many species, 
still retaining the position in which they grew at the bottom of an 
ancient sea ; as coral banks, are now forming in the intertropical 
regions of the present ocean. 
The same fossil coralline strata extend through the calcareous 
hills of the N. W. of Berkshire, and N. of Wilts ; and again recur 
in equal or still greater force in Yorkshire, in the lofty summits 
on the W. and S. W. of Scarborough. 
