come reproduced in the offspring.

Professor Cope, the American paleontologist, was a strong believer in
the effect of activity, both upon the individual and upon his
descendants. He believed that the insistent beating of the foot of an
animal upon the hard soil of the drying Tertiary plateau, had
influenced the production of a firmer nail, which spread around the
entire end of the toe and made the hoof of the ungulate. He believed
that the use of the teeth in grinding produced a stronger and better
molar tooth, and that the offspring shared in this advantage. Since
Weissmann's time, however, every Lamarckian feels it necessary to
suggest some method by which the altered body of the parent can
produce modifications in the germ plasms from which the young are to
spring. One of our later biologists begins to talk of some effect
comparable with wireless telegraphy or induced electricity. He
believes that organs in the adult, not necessarily by direct action,
but by action from a distance, may alter the germ. Of this, there is
no proof at present. Others have suggested that just as the ductless
glands pour into the blood chemical substances which materially affect
the growth and development of other portions of the body, so similar
enzymes, or other chemical substances, may be sent into the blood,
which subsequently bathes the germ cells of the coming generation and
produces the change. But of this, again, there is no proof. We may
believe that acquired characters are transmitted, but we certainly do
not have a very clear idea as to how it can be done.

One of the strongest objections to Darwin's idea of evolution by
natural selection of small and favorable variations, is that the
process is too inconceivably slow to account for the enormous progress
which has been made. The answer has always been that our observation
ran back so short a time that we really have no clear idea of how
rapid evolution may have been. Again, it has been answered that
transitional geological periods, in which there is much change in the
physical geography of a country, will produce more rapid evolution
than we at present are experiencing.

Hugo DeVries, of Amsterdam, believes he has found the answer to this
difficulty. Outside of his botanical garden an American species of
Evening Primrose had run wild. In looking over a number of these
plants he found, every here and there, certain peculiar members of the
species. They differed noticeably to