of Biology_, is faulty in its
reasoning,[9] though legitimate in its conclusion concerning the
increasing difficulty of evolution in proportion with the increasing
number and complexity of faculties to be evolved. But this increasing
difficulty of complex evolution is only overcome by _some_
favourably-varying individuals and species--not by all. And as the
difficulty increases we find neglect and decay of the less-needed
faculties--as with domesticated animals and civilized men, who lose in
one direction while they gain in another. The increasing difficulty of
complex evolution by natural selection is no proof whatever of
use-inheritance[10] except to those who confound difficulty with
impossibility.

ALLEGED RUINOUS EFFECTS OF NATURAL SELECTION.

Mr. Spencer further contends that natural selection, by unduly
developing specially advantageous modifications without the necessary
but complex secondary modifications, would render the constitution of a
variety "unworkable" (p. 23). But this seems hardly feasible, seeing
that natural selection must continually favour the most workable
constitutions, and will only preserve organisms in proportion as they
combine general workableness with the special modification. On the other
hand, according to Mr. Spencer himself, use-inheritance must often
disturb the balance of the constitution. Thus it tends to make the jaws
and teeth unworkable through the overcrowding and decay of the
teeth--there being, as his illustrations show, no simultaneous or
concomitant or proportional variation in relation to altered degree of
use or disuse.

ADVERSE CASE OF NEUTER INSECTS.

Mr. Spencer also holds that most mental phenomena, especially where
complex or social or moral, can only be explained as arising from
use-inheritance, which becomes more and more important as a factor of
evolution as we advance from the vegetable world and the lower grades of
animal life to the more complex activities, tastes, and habits of the
higher organizations (preface, and p. 74). But there happens to be a
tolerably clear proof that such changes as the evolution of complicated
structures and habits and social instincts _can_ take place
independently of use-inheritance. The wonderful instincts of the working
bees have apparently been evolved (at least in all their later social
complications and developments) without the aid of use-inheritance--nay,
in spite of its utmost opposition. Working bees, being infer