view; that he would abandon the theory of evolution unless
acquired characters had been inherited, but that facts in support of
this theory are meager. "Biologists in the above instance, as well as in
others, differ in theory as to fundamental principles of evolution. He
who imagines that the theory of organic evolution has been proved to the
point of demonstration, has but to read the contentions of evolutionists
themselves with regard to the most important things involved in the
theory, in order to satisfy his mind that there is great diversity of
opinion." (Fairhurst.)

The general abandonment of the Darwinian hypothesis by biologists,
adverted to in our next chapter, is mainly due to the failure of
heredity to account for the gradual modification of organs and of
habits.

Various expedients are resorted to by Haeckel and a few others in their
attempts to bolster up a theory which has broken so signally on the
rock of heredity. Principal among these is the reference to unlimited
time. It is asserted that, after all, such minute differences might, in
the course of many ages, result in new and more perfect organs. However,
here a new and unexpected difficulty presents itself. The physicist, who
has measured the heat of the sun, rises up and says that the age of the
earth, as estimated by specialists like Lord Kelvin, is not nearly so
great as is demanded by the Darwinian. The period which the physicists,
in their mercy, appear to be willing to grant the inhabitable globe is
from twenty to forty million years. But the evolutionists maintain with
great fervor that this period is far too short for the production of
such complicated types of organism as now live on the earth; they demand
from two hundred to a thousand million years! And so these two groups of
scientists, the evolutionistic biologist and the physicists are
hopelessly at odds.

A new generation of evolutionists has within the past twenty years
arisen which holds that the changes in the organizations of plants and
animals do not come by slow growth of favorable characteristics, but
arise suddenly. Such is the "Mutation" theory of Hugo de Vries. But
science has failed to receive this and similar theories with the same
acclaim which once greeted Darwin's _"Origin of Species."_ Naturalists
have become cautious. They remember the inglorious collapse of the
Darwinian regime and they are slow to hail another "Abraham of
scientific thought." They are, in a gener