be the use of grafting a good kind of fruit
onto a stock of poorer quality? The very permanency of the grafts thus
produced is proof of the persistency with which cells reproduce only
"after their kind."

IV

How can we fail to see the bearings of these facts on the doctrine of
the transformation of species among ordinary plants and animals, which
are merely isolated and self-contained groups of cells? Do not these
facts constitute strong presumptive evidence that among animals and
plants, though there may be variation in plenty within certain limits,
perhaps within even much wider limits than used to be thought possible,
yet among these distinct organisms, little and big, new forms develop
only after their ancestral type, in full accord with the record given in
the first chapter of the Bible?

But we are now prepared to examine in more detail the facts as now known
to modern science regarding "species" of plants and animals.

V

WHAT IS A "SPECIES"?

I

We have seen that there is no way to account for the origin of matter,
of energy, or of life, except by postulating a real Creation.

We have seen that cells continue to maintain their identity, and
reproduce only "after their kind."

We must now deal with the higher forms of cell aggregates, which we call
plants and animals. It has long been held that these at least are
mutable, that one kind of plant or of animal may in the course of ages
be transformed into a distinctly different type; and of late years there
has accumulated a very voluminous literature dealing with the various
intricacies of this problem of the origin of species. How can we deal
with such a large subject in a brief way? It seems best to confine our
attention in this chapter to an attempt to answer the question, What is
a species? and are "species" natural groups clearly delimited by nature?

II

The term "species" was at first used very loosely by scientific writers.
It meant very little more than our vague word _kind_ does at the
present time. Not until the time of Linnaeus (1707-1778) did the term
acquire a definite and precise meaning. The aphorism of the great
botanist, "_species tot sunt diversae quot diversae formae ab initio sunt
creatae_"--"just so many species are to be reckoned as there were forms
created in the beginning,"--was at least an attempt to use the term in a
well-defined sense. Of course, this definition assumed the "fixity" of
species; but with the wide