In mammals like otters, foxes, stoats, hares, and elephants, what a
complex of tides and currents there must be in the brain-mind! We may
think of a stream with currents at different levels. Lowest there are
the _basal appetites_ of hunger and sex, often with eddies rising to the
surface. Then there are the _primary emotions_, such as fear of
hereditary enemies and maternal affection for offspring. Above these are
_instinctive aptitudes_, inborn powers of doing clever things without
having to learn how. But in mammals these are often expressed along
with, or as it were through, the controlled life of _intelligent
activity_, where there is more clear-cut perceptual influence.
[Illustration: _Photo: W. P. Dando._