_The Senses of Insects._ The eyes of insects are sometimes so large as to envelop the head like an Elizabethan ruffle, and the creature's head, as in the common house fly, seems all eyes. And this is almost literally the case, as the two great staring eyes that almost meet on the top of the head to form one, are made up of myriads of simple eyes. Each facet or simple eye is provided with a nerve filament which branches off from the main optic nerve, so that but one impression of the object perceived is conveyed to the brain; though it is taught by some that objects appear not only double but a thousand times multiplied. But we should remember that with our two eyes we see double only when the brain is diseased. Besides the large ordinary compound eyes, many insects possess small, simple eyes, like those of the spider. The great German anatomist, Johannes Mueller, believed that the compound eyes were adapted for the perception of distant objects, while those nearer are seen by the simple eyes. But it may be objected to this view that the spiders, which have only simple eyes, apparently see both near and remote objects as well as insects. The sense of touch is diffused all over the body. As in the hairs of the head and face of man, those of insects are delicate tactile organs; and on the antennae and legs (insects depending on this sense rather than that of sight) these appendages are covered with exquisitely fine hairs. It is thought by some that the senses of hearing and smell are lodged in the antennae, these organs thus combining the sense of feeling with those of hearing and smelling. And the researches of anatomists lend much probability to the assertion, since little pits just under the skin are found, and even sometimes provided with grains of sand in the so-called ear of the lobster, etc., corresponding to the ear bones of the higher animals, the pits being connected with nerves leading to the brain. We have detected similar pits in the under side of the palpi of the Perla. It seems not improbable that these are organs of smell, and placed in that part of the appendage nearest the mouth, so as to enable the insect to select its proper food by its odor. Similar organs exist on the caudal appendages of a kind of fly (Chrysopila), while the long, many-jointed caudal filaments of the cockroach are each provided with nearly a hundred of these little pits, which seem to be so many noses. Thus Lespes, a Swiss anatomist, in his remarks on the auditory sacs, which he says are found in the antennae of nearly all insects, declares that as we have in insects compound eyes, so we have compound ears. We might add that in the abdominal appendage of the cockroach we have a compound nose, while in the feelers of the Perla, and the caudal appendage of the Chrysopila, the "nose" is simple. We might also refer here to Siebold's discovery of ears at the base of the abdomen of some, and in the forelegs of other kinds, of grasshoppers. Thus we need not be