worlds were entirely unlike, while those of North America
and northern Eurasia were in many cases the same.

We will first bring together, as Flourens and also Butler have done, his
scattered fragmentary views, or rather suggestions, on the fixity of
species, and then present his thoughts on the mutability of species.
"The species" is then "an abstract and general term."[127] "There only
exist individuals and _suites_ of individuals, that is to say,
species."[128] He also says that Nature "imprints on each species its
unalterable characters;" that "each species has an equal right to
creation;"[129] that species, even those nearest allied, "are separated
by an interval over which nature cannot pass;"[130] and that "each
species having been independently created, the first individuals have
served as a model for their descendants."[131]

Buffon, however, shows the true scientific spirit in speaking of final
causes.

"The pig," he says, "is not formed as an original, special, and
perfect type; its type is compounded of that of many other animals.
It has parts which are evidently useless, or which, at any rate, it
cannot use." ... "But we, ever on the lookout to refer all parts to
a certain end--when we can see no apparent use for them, suppose
them to have hidden uses, and imagine connections which are without
foundation, and serve only to obscure our perception of Nature as
she really is: we fail to see that we thus rob philosophy of her
true character, which is to inquire into the 'how' of these
things--into the manner in which Nature acts--and that we substitute
for this true object a vain idea, seeking to divine the 'why'--the
ends which she has proposed in acting" (tome v., p. 104, 1755, _ex_
Butler).

The volumes of the _Histoire naturelle_ on animals, beginning with
tome iv., appeared in the years 1753 to 1767, or over a period of
fourteen years. Butler, in his _Evolution, Old and New_, effectually
disposes of Isidore Geoffroy St. Hilaire's statement that at the
beginning of his work (tome iv., 1753) he affirms the fixity of species,
while from 1761 to 1766 he declares for variability. But Butler asserts
from his reading of the first edition that "from the very first chapter
onward he leant strongly to mutability, even if he did not openly avow
his belief in it.... The reader who turns to Buffon himself will find
that the idea that Buffon took a less advanced position in his old age
th