CHICAGO

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THE ORIGIN OF SPECIES

The origin of species is a natural phenomenon.
LAMARCK

The origin of species is an object of inquiry.
DARWIN

The origin of species is an object of experimental investigation.
DeVRIES.

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PREFACE BY THE AUTHOR

THE purpose of these lectures is to point out the means and methods by
which the origin of species and varieties may become an object for
experimental inquiry, in the interest of agricultural and horticultural
practice as well as in that of general biologic science. Comparative
studies have contributed all the evidence hitherto adduced for the
support of the Darwinian theory of descent and given us some general
ideas about the main lines of the pedigree of the vegetable kingdom, but
the way in which one species originates from another has not been
adequately explained. The current belief assumes that species are slowly
changed into new types. In contradiction to this conception the theory