life. The result is an alteration of
previous characteristics, and a new stable race is established by an
"acquired anomaly."(20)
Other Instances of Dissatisfaction with the Theory of Descent.
What was with Virchow only a suggestion of the need for caution, or
controversial matter to be subsequently allowed for or contradicted, had
more serious consequences to others, and led to still greater hesitancy as
regards evolutionist generalisations and speculations, and sometimes to
sharp antagonism to them.
One of the best known of the earlier examples of this mood is Kerner von
Marilaun's large and beautiful work on "Plant Life."(21) He does, indeed,
admit that our species are variations of antecedent forms, but only in a
very limited sense. Within the stocks or grades of organisation which have
always existed, variations have come about, through "hybridisation,"
through the crossing of similar, but relatively different forms; these
variations alter the configuration and appearance in detail, but neither
affect the general character nor cause any transition from "lower" to
"higher."
Kerner disposes of the chief argument in favour of the theory of descent,
the homology of individual organs, by explaining that the homology is due
to the similarity of function in the different organisms. A similar
argument is used in regard to "ontogeny recapitulating phylogeny."
Palaeontology does not disclose in the plant-world any "synthetic types,"
which might have been the common primitive stock from which many now
divergent branches have sprung, nor does it disclose any "transition
links" really intermediate, for instance, between cryptogams and
gymnosperms, or between gymnosperms and angiosperms. That the higher races
are apparently absent from the earlier strata is not a proof that they
have never existed. The peat-bog flora must have involved the existence of
a large companion-flora, without which the peat could not have been
formed, but all trace of this is absent in the still persistent vestiges
of these times.(22) Life, with energy and matter, has existed as a
phenomenon of the universe from all eternity, and thus its chief forms and
manifestations have not "arisen," but have always been. If facts such as
these contradict the Kant-Laplace theory of the universe, then the latter
must be corrected in the light of them, not conversely. The extreme
isolation of Kerner and his theory is probably due especially to this
co
|