Ant colonies > Internal structure of ants > Sense organs

Sense organs


The Sense-Organs

The sense-organs of ants, like those of insects in general, are modifications of the integument and the terminations of sensory nerves. Hence there can be no sense-organs in the interior of the body unless they have been carried in secondarily on infoldings of the integument.

As there are no openings anywhere in the chitinous investment of the insect's body, except those at the anterior and pos­terior ends of the midgut, the nerve terminations are never freely exposed on the surface, but always covered with at least a very delicate layer of chitin.

The number and diversity of sense-organs in insects is very great, but nevertheless, attempts have been made to trace them all back to a common primitive type. One of the most recent of these attempts is that of Berlese (1907) who finds that nearly all these organs admit of hypothetical derivation from a "protaesthesis," a sensilla, or sense-bud, consisting of one or a few chitin-secreting hypodermal cells, a gland cell and a nerve cell.

It is possible to show that this type of structure keeps recurring in the various sense-organs of even such highly-specialized insects as the ants.