in the next paragraph, that if we choose to look at the
matter in this light, well--in that case--we ought to see not only the
ass and the horse, but _the zebra too_, as members of the same family;
"the number of their points of resemblance being infinitely greater than
those in respect of which they differ."[126] Thus, at the close of his
work on the quadrupeds, he thinks it well, as at the commencement
seventeen years earlier, to emphasize--in his own quiet way--his
perception that the principles on which he has been insisting should be
carried much farther than he has chosen to carry them.

His conclusion is, that "after comparing all the animals and bringing
them each under their proper genus, we shall find the two hundred
species we have already described to be reducible into a sufficiently
small number of families or main stocks from which it is not impossible
that all the others may be derived."[127]

The chapter closes thus:--

"To account for the origin of these animals" (certain of those peculiar
to America), "we must go back to the time when the two continents were
not yet separated, and call to mind the earliest geological changes. At
the same time, we must consider the two hundred existing species of
quadrupeds as reduced to thirty-eight families. And though this is not
at all the state of Nature as she is in our time, and as she has been
represented in this volume, and though, in fact, it is a condition which
we can only arrive at by induction, and by analogies almost as
difficult to lay hold of as is the time which has effaced the greater
number of their traces, I shall, nevertheless, endeavour to ascend to
these first ages of Nature by the aid of facts and monuments which yet
remain to us, and to represent the epochs which these facts seem to
indicate."[128]

The fifteenth volume contains a description of a few more monkeys, as
also of some animals which Buffon had never actually seen, a great part
being devoted to indices.

_Supplement._

The first four volumes of the Supplement to Buffon's 'Natural History,'
1774-1789, contain little which throws additional light upon his
opinions concerning the mutability of species. At the beginning,
however, of the fifth volume I find the following:--

"On comparing these ancient records of the first ages of life [fossils]
with the productions of to-day, we see with sufficient clearness that
the essential form has been preserved without alteration in its