ed forms of life, and which are
those produced by secondary laws. They admit variation as a vera causa
in one case, they arbitrarily reject it in another, without assigning
any distinction in the two cases. The day will come when this will
be given as a curious illustration of the blindness of preconceived
opinion. These authors seem no more startled at a miraculous act of
creation than at an ordinary birth. But do they really believe that at
innumerable periods in the earth's history certain elemental atoms have
been commanded suddenly to flash into living tissues? Do they believe
that at each supposed act of creation one individual or many were
produced? Were all the infinitely numerous kinds of animals and plants
created as eggs or seed, or as full grown? and in the case of mammals,
were they created bearing the false marks of nourishment from the
mother's womb? Undoubtedly some of these same questions cannot be
answered by those who believe in the appearance or creation of only a
few forms of life or of some one form alone. It has been maintained
by several authors that it is as easy to believe in the creation of a
million beings as of one; but Maupertuis' philosophical axiom "of least
action" leads the mind more willingly to admit the smaller number; and
certainly we ought not to believe that innumerable beings within each
great class have been created with plain, but deceptive, marks of
descent from a single parent.

As a record of a former state of things, I have retained in the
foregoing paragraphs, and elsewhere, several sentences which imply that
naturalists believe in the separate creation of each species; and I have
been much censured for having thus expressed myself. But undoubtedly
this was the general belief when the first edition of the present work
appeared. I formerly spoke to very many naturalists on the subject of
evolution, and never once met with any sympathetic agreement. It is
probable that some did then believe in evolution, but they were either
silent or expressed themselves so ambiguously that it was not easy to
understand their meaning. Now, things are wholly changed, and almost
every naturalist admits the great principle of evolution. There are,
however, some who still think that species have suddenly given birth,
through quite unexplained means, to new and totally different forms.
But, as I have attempted to show, weighty evidence can be opposed to the
admission of great and abrupt modifica