mewhat more complex as well as more active, they ought, in
accordance with the alleged general law, and other things being equal,
to be less prolific. But other things are not equal; and it is to the
inequality of the other things that this apparent anomaly is
attributable.

One more objection has to be met. Cases may be named of men conspicuous
for activity, bodily and mental, who were also noted, not for less
generative power than usual, but for more. The cases are analogous to
some before-named in which more abundant food simultaneously aggrandises
the individual and adds to the production of new individuals--the
differences between cases being that instead of a better external supply
of material there is a better internal utilisation of materials. Some
peculiarity of organic balance, some potency of the digestive juices,
gives to the system a perpetual high tide of rich blood that serves at
once to enhance the vital activities and to raise the power of
propagation. The _proportion_ between individuation and genesis remains
the same: both are increased by the increase of the common stock of
materials.

_Human Population in the Future_

Any further evolution in the most highly-evolved of terrestrial
beings--man--must be of the same nature as evolution in general. It must
be an advance towards completion of that continuous adjustment of
internal to external relations which was shown to constitute life.

Looking at the several possibilities, and asking what direction this
further evolution, this more complete moving equilibrium, this better
adjustment of inner to outer relations, this more perfect co-ordination
of action is likely to take:--the conclusion is that it must take mainly
the direction of a higher intellectual and emotional development. There
is abundant scope for development in ascertaining the conditions of
existence to which we must conform; and in acquiring a greater power of
self-regulation.

What are those changes in the environment to which, by direct or
indirect equilibration the human organism has been adjusting itself, is
adjusting itself now, and will continue to adjust itself? And how do
they necessitate a higher evolution of the organism? In all cases
pressure of population is the original cause. Were it not for the
competition this entails, so much thought and energy would not be spent
on the business of life; and growth of mental power would not take
place. Difficulty in getting a livin