e antennae. A poor ant without antennae is as lost as a blind man who is
also deaf and dumb. This appears from its complete social inactivity,
its isolation, its incapacity to guide itself and to find its food. It
can, therefore, be boldly supposed that the antennae and their power of
smell, as much on contact as at a distance, constitute the social sense
of ants, the sense which allows them to recognise one another, to tend
to their larvae, and mutually help one another, and also the sense which
awakens their greedy appetites, their violent hatred for every being
foreign to the colony, the sense which principally guides them--a little
helped by vision, especially in certain species--in the long and patient
travels which they have to undertake, which makes them find their way
back, find their plant-lice, and all their other means of subsistence.

As the philosopher Herbert Spencer has well pointed out, the visceral
sensations of man, and those internal senses which, like smell, can only
make an impression of one kind as regards space--two simultaneous odours
can only be appreciated by us as a mixture--are precisely those by which
we can gain little or no information relative to space. Our vision, on
the contrary, which localises the rays from various distant points of
space on various distinct points of our retina at the same time, is our
most relational sense, that which gives us the most vast ideas of space.

But the antennae of insects are an olfactory organ turned inside out,
prominent in space, and, further, very mobile. This allows us to suppose
that the sense of smell may be much more relational than ours, that the
sensations thence derived give them ideas of space and of direction
which may be qualitatively different from ours.

Taste exists in insects, and has been very widely written on, but
somewhat inconclusively. The organs of taste probably are to be found in
the jaws and at the base of the tongue. This sense can be observed in
ants, bees, and wasps; and everyone has seen how caterpillars especially
recognise by taste the plants which suit them.

Much has been written on the hearing of insects; but, in my judgment,
only crickets and several other insects of that class appear to perceive
sounds. Erroneous views have been due to confusing hearing with
mechanical vibrations.

We must not forget that the specialisation of the organ of hearing has
reached in man a delicacy of detail which is evidently not fo