sumption of amphibian powers of independent growth on
the part of certain groups of our body-cells--literally, a "rebellion of
the cells."

These are but a handful of scores of instances that could be adduced,
showing that the majority of the processes upon which we rely in
combating disease and preserving life are the result of the hereditary
experiences of our cells. Intelligent physicians are receding completely
from that curiously warped and jaundiced view which led us to regard
heredity chiefly as a factor in the _production_ of disease. It was,
perhaps, natural enough, since it was inevitably only its injurious, or,
so to speak, malicious, effects which were brought to our attention to
be corrected. But, just as in the growth of our ethnic religions it is
Evil that is worshiped first as strongest and most aggressive, and the
recognition of the greater power of good comes only at a later stage, so
it has been in pathology.

Not only do we regard heredity as a comparatively small and steadily
receding factor in the production of disease, but we fully and frankly
recognize it as the strongest and most important single force in its
prevention. All our processes of repair, all the reactions of the body
against the attack of accident or of disease, are hereditary endowments,
worked out with infinite pains and labor through tens of thousands of
generations. The utmost that we can do with our drugs and remedies is to
appeal to and rouse into action the great healing power of nature, the
classic "_Vis medicatrix Naturae_," an incarnation of our past
experiences handed down by heredity. Enormously valuable and important
as are the services to human welfare, health, and happiness which can be
rendered by the destruction of the living external causes of disease and
the prevention of contagion, our most permanent and substantial
victories are won by appealing to and increasing this long-descended and
hard-won power of individual resistance.

"But," says some one at once, "I thought there were a large number of
hereditary diseases." Fifty years ago there were a score of such, twenty
years ago the score had sunk to five or six. Now there is scarcely one
left. There is no known disease which is directly inherited as such.
There is scarcely even a disease in which we now regard heredity as
playing a dominant or controlling part. Among the few diseases in which
there is serious dispute as to this are tuberculosis, insanity,
epil