the history of the Ancon sheep, and of the six-fingered Maltese family,
given by Reaumur, it appears that the new form appeared at once in full
perfection.

I may illustrate what I mean by a chemical example. In an organic
compound, having a precise and definite composition, you may effect all
sorts of transmutations by substituting an atom of one element for an
atom of another element. You may in this way produce a vast series of
modifications--but each modification is definite in its composition, and
there are no transitional or intermediate steps between one definite
compound and another. I have a sort of notion that similar laws of
definite combination rule over the modifications of organic bodies, and
that in passing from species to species "Natura fecit saltum."

All my studies lead me to believe more and more in the absence of any
real transitions between natural groups, great and small--but with what
we know of the physiology of conditions [?] this opinion seems to me to
be quite consistent with transmutation.

When I say that no evidence, or hardly any, would justify one in
believing in the view of a new species of Elephant, e.g. out of the
earth, I mean that such an occurrence would be so diametrically contrary
to all experience, so opposed to those beliefs which are the most
constantly verified by experience, that one would be justified in
believing either that one's senses were deluded, or that one had not
really got to the bottom of the phenomenon. Of course, if one could vary
the conditions, if one could take a little silex, and by a little
hocus-pocus a la crosse, galvanise a baby out of it as often as one
pleased, all the philosopher could do would be to hold up his hands and
cry, "God is great." But short of evidence of this kind, I don't mean to