"As we became still more familiar, our new friend was invited to join in our evening amusements, to which he contributed his full share by flitting round the room, at times settling upon our persons, and permitting us to handle and caress him. He announced his being awake by a shrill chirp, which was more acute than that of the cricket. Now was the proper time for feeding him. I before stated that he only took his food alive. It was observed that not only was motion necessary, but that generally some noise on the part of the fly was required to induce him to accept it; and this fact was soon discovered by the children, who were entertained by his taking flies from their fingers as he flew by them, before he was bold enough to settle upon their hands to devour his victims. They quickly improved upon this discovery, and, by imitating the booming of a bee, induced the Bat, directed by the sound, to settle upon their faces, wrapping his wings round their lips, and searching for the expected fly. We observed that, if he took a fly while on the wing, he frequently settled to masticate it; and, when he had been flying about a long time, he would rest upon a curtain, pricking his ears, and turning his head in all directions, when, if a fly were made to buzz, or the sound imitated, he would proceed directly to the spot, even on the opposite side of the room, guided, it would appear, entirely by the ear. Sometimes he took his victim in his mouth, even though it was not flying; at other times he inclosed it in his wings, with which he formed a kind of bag-net. This was his general plan when in his cage, or when the fly was held in our fingers, or between our lips." From these observations Mr. Sowerby concludes that many of the movements of the Bat upon the wing are directed by his exquisite sense of hearing. May not the sensibility of this organ be naturally greater in these animals, whose organs of vision are too susceptible to bear daylight, when those organs, from their nature, would necessarily be of most service?--such as the cat, who hunts by the ear, and the mole, who, feeding in the dark recesses of his subterranean abode, is very sensible of the approach of danger, and expert in avoiding it. In the latter case, large external ears are not required, because sound is well conveyed by solids, and along narrow cavities. In the cases of many Bats, and of owls, the external ears are remarkably developed. Cats combine a quickness of sight with acute hearing. They hunt by the ear, but they follow their prey by the eye. Some Bats are said to feed upon fruits: have they the same delicacy of hearing, feeling, &c., as others?