imals to herd and
combine with their own kind, would fall into specific groups--these
remnants in the course of time moulding and accommodating their being
anew to the change of circumstances, and to every possible means of
subsistence--and the millions of ages of regularity which appear to have
followed between the epochs, probably after this accommodation was
completed, affording fossil deposit of regular specific character.

. . . . . .

"In endeavouring to trace ... the principle of these changes of fashion
which have taken place in the domiciles of life the following questions
occur: Do they arise from admixture of species nearly allied producing
intermediate species? Are they the diverging ramifications of the
living principle under modification of circumstance? or have they
resulted from the combined agency of both?

"_Is there only one living principle? Does organized existence, and
perhaps all material existence, consist of one Proteus principle of
life_ capable of gradual circumstance-suited modifications and
aggregations without bound, under the solvent or motion-giving principle
of heat or light? There is more beauty and unity of design in this
continual balancing of life to circumstance, and greater conformity to
those dispositions of nature that are manifest to us, than in total
destruction and new creation. It is improbable that much of this
diversification is owing to commixture of species nearly allied; all
change by this appears very limited and confined within the bounds of
what is called species; the progeny of the same parents under great
difference of circumstance, might in several generations even become
distinct species, incapable of co-reproduction.

"The self-regulating adaptive disposition of organized life may, in
part, be traced to the extreme fecundity of nature, who, as before
stated, has in all the varieties of her offspring a prolific power much
beyond (in many cases a thousand fold) what is necessary to fill up the
vacancies caused by senile decay. As the field of existence is limited
and preoccupied, it is only the hardier, more robust, better suited to
circumstance individuals, who are able to struggle forward to maturity,
these inhabiting only the situations to which they have _superior
adaptation and greater power of occupancy than any other kind; the
weaker and less circumstance-suited being prematurely destroyed_. This
principle is in constant action; it regulates the col