instances which have been adduced, we have applied tests
to show that the transmutation which takes place is by
transforming influence, and not by Natural Selection.
The effect of this argument can only be weakened in two
ways, either by showing that changed conditions do not
produce the effects attributed to them in the cases just
cited ; or by a change of front, by understanding Natural
Selection in some other sense than that which the strict
definition of the theory indicates.
We have already seen that the argument based upon
the assumption that the modifications of “ the body ” can
not be inherited is rendered invalid by the admission that
the sexual elements may be modified, and that these
modifications can be inherited. Sometimes the transform
ing influences of changed conditions have been depreciated
in order that the power of Natural Selection may be
unduly appreciated. I am not aware that any writer has
done this in a formal manner, and with full consciousness
of what he was doing ; but by collating some passages
from the works of Mr. Darwin, we shall be able to see
how, no doubt unconsciously, this process of depreciating
the transforming influence of changed conditions has taken
place. Mr. Darwin asserts the efficacy of the principle as
a law of nature, elsewhere he qualifies this statement ;
then he appeals to our ignorance, or to the all-pervading
mystery which is associated with the subject ; then he
declares that it is not easy to discover how far a given
effect is due to Natural Selection, and how far it is due to
transforming influence ; then the efficacy of the principle
of transforming influence is denied ; and finally, Natural
Selection is substituted for the discarded principle of trans
formation. We have now to consider what grounds there
are for making these assertions, and how far the conclu
sions arrived at can be justified.