ore openly towards Lamarck. He
writes:--

"The characters of species are neither absolutely fixed, as has been
maintained by some; nor yet, still more, indefinitely variable as
according to others. They are fixed for each species as long as that
species continues to reproduce itself in an unchanged environment; but
they become modified if the environment changes."[328]

This is all that Lamarck himself would expect, as no one could be more
fully aware than M. Geoffroy, who, however, admits that degeneration may
extend to generic differences.[329]

I have been unable to find in M. Isidore Geoffroy's work anything like a
refutation of Lamarck's contention that the modifications in animals and
plants are due to the needs and wishes of the animals and plants
themselves; on the contrary, to some extent he countenances this view
himself, for he says, "hence arise notable differences of habitation and
climate, and these in their turn induce secondary differences in diet
_and even in habits_."[330] From which it must follow, though I cannot
find it said expressly, that the author attributes modification in some
measure to changed habits, and therefore to the changed desires from
which the change of habits has arisen; but in the main he appears to
refer modification to the direct action of a changed environment.

_Mr. Herbert Spencer._

"Those who cavalierly reject the theory of Lamarck and his followers as
not adequately supported by facts," wrote Mr. Herbert Spencer,[331]
"seem quite to forget that their own theory is supported by no facts at
all"--inasmuch as no one pretends to have seen an act of direct
creation. Mr. Spencer points out that, according to the best
authorities, there are some 320,000 species of plants now existing, and
about 2,000,000 species of animals, including insects, and that if the
extinct forms which have successively appeared and disappeared be added
to these, there cannot have existed in all less than some ten million
species. "Which," asks Mr. Spencer, "is the most rational theory about
these ten millions of species? Is it most likely that there have been
ten millions of special creations? or, is it most likely that by
continual modification _due to change of circumstances_, ten millions of
varieties may have been produced as varieties are being produced still?"

. . . . . .

"Even could the supporters of the development hypothesis merely show
that the production of species by the pro