a considerable advance of our problem, although, and
partly because, he did not entirely agree with Darwin's views as laid
down in the first edition of "The Origin of Species", which after all
was the great impulse given to Murray's work. Like Forbes he did not
shrink from assuming enormous changes in the configuration of the
continents and oceans because the theory of descent, with its necessary
postulate of great migrations, required them. He stated, for instance,
"that a Miocene Atlantis sufficiently explains the common distribution
of animals and plants in Europe and America up to the glacial epoch."
And next he considers how, and by what changes, the rehabilitation and
distribution of these lands themselves were effected subsequent to
that period. Further, he deserves credit for having cleared up a
misunderstanding of the idea of specific centres of creation. Whilst for
instance Schmarda assumed without hesitation that the same species,
if occurring at places separated by great distances, or apparently
insurmountable barriers, had been there created independently (multiple
centres), Lyell and Darwin held that each species had only one single
centre, and with this view most of us agree, but their starting point
was to them represented by one individual, or rather one single pair.
According to Murray, on the other hand, this centre of a species is
formed by all the individuals of a species, all of which equally undergo
those changes which new conditions may impose upon them. In this respect
a new species has a multiple origin, but this in a sense very different
from that which was upheld by L. Agassiz. As Murray himself puts it: "To
my multiple origin, communication and direct derivation is essential.
The species is compounded of many influences brought together through
many individuals, and distilled by Nature into one species; and, being
once established it may roam and spread wherever it finds the conditions
of life not materially different from those of its original centre."
(Murray, "The Geographical Distribution of Mammals", page 14. London,
1866.) This declaration fairly agrees with more modern views, and
it must be borne in mind that the application of the single-centre
principle to the genera, families and larger groups in the search for
descent inevitably leads to one creative centre for the whole animal
kingdom, a condition as unwarrantable as the myth of Adam and Eve being
the first representatives of Manki