ct involved is now _Aphidius testaceipes_.
The systematist who studies only dried corpses will soon be out of
date."[22]

[Footnote 22: F.M. Webster, of the U.S. Dept. of Agriculture, in
_Science_, April 12, 1912, p. 565.]

IV

Now all this is not given to intimate that there is no scientific
justification for the term "species," but to make plain to my
non-professional readers what every well-informed biologist already
knows, namely, that at the present time the "species question" is still
in a very unsatisfactory state. The facts given above would strongly
suggest that there probably is indeed such a thing as a species, in the
sense assigned by Linnaeus, who as we have seen wished to make it a
designation covering all the descendants of each distinct kind
originally created. But this original aim of Linnaeus is to-day not
merely ignored but treated with lofty contempt; for according to the
prevailing theories of evolution, all the manifold diversities of life
in our modern world have come about gradually as the result of a slow
development by natural process, and hence it would be vain beyond
measure to attempt to determine the limits of a "species" in the sense
understood by Linnaeus.

But we may conclude, from the facts presented above, that if there is
such a naturally delimited group as a "species" in the Linnaean sense of
the word, it by no means coincides with what now passes under this name,
but might include many so-called species, often a whole genus, or even
several.

With this in mind, we must pass on to consider the next step in our
study, as to whether new "species" are now coming into being in our
modern world under scientific observation, either natural or
artificial.

VI

MENDELISM AND THE ORIGIN OF SPECIES

"Had Mendel's work come into the hands of Darwin, it is not too much to
say that the history of the development of evolutionary philosophy would
have been very different from that which we have witnessed."[23]

[Footnote 23: William Bateson, "Mendel's Principles of Heredity," p.
316.]

I

From the latter part of the eighteenth century, attempts were
continually being made to explain the origin of all organic forms by
some system of development or evolution. Buffon had dwelt on the
modifications directly induced by the environment. Lamarck had made much
use of this idea, claiming that such modifications were transmitted to
posterity, and claiming the same for the structura