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in the work of reparation. Every organism that starts out upon its
career of development depends upon nourishing materials for its growth,
and upon this renewing process for its development. Nutrition is all the
while necessary to prolong the life of the individual, but at length its
vigor wanes, its functions languish, and, finally, the light of earthly
life goes out. Although the single organization decays and passes away,
nevertheless the species is uninterruptedly continued; the tidal wave of
life surges higher on the shores of time, for reproduction is as
constant and stable as the attractive forces of the planetary system.

It is a fact, that many species of the lower order of animals which once
existed are now extinct. It has been asserted and denied, that fossil
remains of man have been found, indicating that races which once existed
have disappeared from the face of the earth. The pyramids are unfolding
a wonderful history, embracing a period of forty-five hundred years,
which the world of science receives as literally authentic, and admits,
also, that fifty-four hundred years are _probably_ as correctly
accounted for. The extinction of races is not at all improbable. At the
present time, the aboriginal inhabitants of this continent seem to be
surely undergoing gradual extinguishment! It, therefore, seems to be
possible for a weaker race to deteriorate, and finally become extinct,
unless the causes of their decadence can be discovered and remedied. All
people are admonished to earnestly investigate the essential conditions
necessary for their continuance, for the rise and fall of nations is in
obedience to natural principles and operations. Viewed from this
standpoint, it is possible that a careful study of the human
temperaments and their relations to reproduction may be of greater
moment than has hitherto been supposed, and a proper understanding of
them may tend to avert that individual deterioration, which, if suffered
to become general, would end in national disaster and the extinction of
the race.

Until recently, even naturalists believed that descendants were strictly
like their parents in form and structure. Now it is known that the
progeny may differ in both form and structure from the parent, and that
these may produce others still more unlike their ancestry. But all these
peculiar and incidental deviations finally return to the original form,
showing that these changes have definite limits, and t