ddle position between the denial
of all mutability, and the admission that in the course of sufficient
time any conceivable amount of mutability is possible. I will give a
considerable part of what I have found in the first six volumes of
Buffon to bear one way or the other on his views concerning the
mutability of species; and I think the reader, so far from agreeing with
M. Isidore Geoffroy that Buffon began his work with a belief in the
fixity of species, will find, that from the very first chapter onward,
he leant strongly to mutability, even if he did not openly avow his
belief in it.

In support of this assertion, one quotation must suffice:--

"Nature advances by gradations which pass unnoticed. She passes from one
species, and often from one genus to another by imperceptible degrees,
so that we meet with a great number of mean species and objects of such
doubtful characters that we know not where to place them."[61]

The reader who turns to Buffon himself will find the idea that Buffon
took a less advanced position in his old age than he had taken in middle
life is also without foundation.

Mr. Darwin has said that Buffon "does not enter into the causes or means
of the transformation of species." It is not easy to admit the justice
of this. Independently of his frequently insisting on the effect of all
kinds of changed surroundings, he has devoted a long chapter of over
sixty quarto pages to this very subject; it is to be found in his
fourteenth volume, and is headed "De la Degeneration des Animaux," of
which words "On descent with modification" will be hardly more than a
literal translation. I shall give a fuller but still too brief outline
of the chapter later on, and will confine myself here to saying that the
three principal causes of modification which Buffon brings forward are
changes of climate, of food, and the effects of domestication. He may
be said to have attributed variation to the direct and specific action
of changed conditions of life, and to have had but little conception of
the view which he was himself to suggest to Dr. Erasmus Darwin, and
through him to Lamarck.

Isidore Geoffroy, writing of Lamarck, and comparing his position with
that taken by Buffon, says, on the whole truly, that "what Buffon
ascribes to the general effects of climate, Lamarck maintains to be
caused, especially in the case of animals, by the force of habits; _so
that, according to him, they are not, properly speaking