470 
THE GEOLOGIST. 
tliirty-two tliousaiid. Taking the like sum as representative of a similar increase 
of s]iccics in tlie vegetable kingdom ; and wc obtain then, as a final result, the 
conclusion tliat the creative action as exerted in the direct creation of species, 
commencing in the pre-Silurian period at unity, has been successively and cou- 
tiuuously intcnsilied ever since, uutil now it has obtained an intensity sixty-four 
o r MOLLUS C A. 
First Appeabancb op Life. 
DiagTammatic View of the Actnal Increase of Species of MoUusca, illustrating the increasing 
intensities of creative action at the periods stated, if the thcoiy of the dii'ect creations of 
species bo admitted. 
[Each line of the Tree of Numerical Increase of Specific Forms represents 100 species.] 
thousand times greater than when it commenced ; or upwards of twenty-one 
thousand times greater than it was at that point in past time — the Silurian era 
— to which we can trace back the records of its action. 
The radiata, the vertebrata, or any other class, exhibit the like results 
with the moUnsca, confirming the impression of the proHficness of exist- 
ing species as due to the natiu-al sub-division by natural transmutating 
