principal parts: there has been no change whatever in the general type
of each species; the plan of the inner parts has been preserved without
variation. However long a time we may imagine for the succession of
ages, whatever number of generations we may suppose, the individuals of
to-day present to us in each genus the same forms as they did in the
earliest ages; and this is more especially true of the greater species,
whose characters are more invariable and nature more fixed; for the
inferior species have, as we have said, experienced in a perceptible
manner all the effects of different causes of degeneration. Only it
should be remarked in regard to these greater species, such as the
elephant and hippopotamus, that in comparing their fossil remains with
the existing forms we find the earlier ones to have been larger. Nature
was then in the full vigour of her youth, and the interior heat of the
earth gave to her productions all the force and all the extent of which
they were capable ... if there have been lost species, that is to say
animals which existed once, but no longer do so, these can only have
been animals which required a heat greater than that of our present
torrid zone."[129]

The context proves Buffon to have been thinking of such huge creatures
as the megatherium and mastodon, but his words seem to limit the
extinction of species to the denizens of a hot climate which had turned
colder. It is not at all likely that Buffon meant this, as the passage
quoted at p. 146 of this work will suffice to show. The whole paragraph
is ironical.

I can see nothing to justify the conclusion drawn from this passage by
Isidore Geoffroy, that Buffon had modified his opinions, and was
inclined to believe in a more limited mutability than he had done a few
years earlier. His exoteric position is still identical with what it was
in the outset, and his esoteric may be seen from the spirit which is
hardly concealed under the following:--

"I shall be told that analogy points towards the belief that our own
race has followed the same path, and dates from the same period as
other species; that it has spread itself even more widely than they; and
that if man's creation has a later date than that of the other animals,
nothing shows that he has not been subjected to the same laws of nature,
the same alterations, and the same changes as they. We will grant that
the human species does not differ essentially from others in the matte