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by the acuteness of the sensation of touch in the wing, that this singular phenomenon is to be accounted for. During the flight of a blinded bat, whenever it approaches any object, the air set in motion by its wings reacts against their surface with a greater or less degree of force, and being in this manner warned of the nearness of any object, it avoids coming in contact with it by changing its course.
One advantage of the bat's peculiar structure is that his soft wings, though used with great celerity, stir the air, but make no sound. His large ears catch every hum of his prey, and he noiselessly flits through the gray and dusky twilight, glutting a voracious appetite on insects, which, but for the exertions of bats and other creatures, would soon swarm so profusely as to render the earth loathsome or almost uninhabitable. When not seeking for prey, the cry of the bat much resembles that of a mouse. Some species of bat live exclusively on insects, others eat fruit as well as insects, and all will partake of any raw or dressed meat, whether fresh or tainted, which happens to come within their reach. White observes that it is a common notion that bats will descend chimneys " and gnaw men's bacon," and adds that the story is by no means improbable, as a tame bat did not refuse raw flesh, though insects seemed to be most acceptable. The common bat often enters larders, and has been seen clinging to a joint of meat in the act of making a hearty meal upon it. Of this circumstance we are assured by Mr. Bell. "Bats," says White, "drink on the wing Hke swallows, by sipping the surface as they play over pools and streams. They love to frequent water, not only for the sake of drinking, but also on account of the insects, which are found over it in the greatest plenty."
Bats vary greatly in size, from that of the smallest common mouse to the enormous bat of Java, which we shall presently describe. There are a great number of species and varieties, among which are some of singular structure in the form of the wing, size of the ears, and the remarkable membranous appendage to the nose. This last peculiarity somewhat resembles in shape a horseshoe, it borders the upper lip, and encloses the nostrils within its arch. It has been supposed to increase the animal's sense of smell. In the flight of the bat, the tail and membrane, extending between the two hind legs, act as a rudder, enabling the animal to turn more or less abruptly. Mr. Bell, who first noticed the circumstance, observes, "that the bat can, in ascending or descending any rough surface, hook its tail upon such projections as may occur, so as to add to its security. When a bat traverses the wires of a cage, this action of the tail is particularly conspicuous." The body of the bat is covered with soft close hair or fur of different shades of either yellow, grey, or reddish brown. The teeth are very strong, especially the canine ones. These keen and pointed teeth enable them to bite with much force; and bats of a considerable age and size can inflict a serious wound. In the countries where the fruit-eating bats abound, they thus commit fearful havoc among the fruits on the trees. By a wise and beautiful regulation of Providence, all animals not migratory sleep through that part of the year in which the food they usually live on is difficult to obtain. The bats, therefore, in all but warm climates, on the approach of cold evenings at the latter end of autumn, seek some dark place in old ruins, caverns, or the hollows of trees, and may be found hanging in clusters together, as a defence against the cold, and gradually become perfectly torpid. Pennant states that on one occasion, as he was informed by the Rev. Dr. Backhouse, 185 bats were taken from under the eaves of Queen's College, Cambridge, and on the next night 63 more, all in a torpid condition. In the East bats will intrude into inhabited houses, and seek shelter in the cellars. Professor Green mentions a cavern he explored in Albany, where he found some hundreds of bats, who had selected this unfrequented spot to pass the winter. They did not appear to be much disturbed by the light of the torches, but on being touched with sticks, they flew into a more remote part of the cavern, and again settled themselves in clusters; their eyes were shut, and no breathing could be observed. On opening one
of these bats the stomach was found to be entirely empty. While the Professor was making some experiments in his laboratory at Princeton, in a cold dark evening in December, a good fire in the stove and the room warm, a small reddish-coloured bat, which had secreted itself behind some of the cases which contained the philosophical apparatus, made its appearance. It flew a short time about the room and then retired, but was seen once or twice afterwards during the winter.
The bat's natural posture of repose is at all times that of suspension with the head downward. In this posture the wings serve as a sort of mantle or cloak; and in this they also sometimes cover up their young, although they will at other times fly about with two young ones at the breast in the act of sucking. These young ones will, together, frequently exceed the weight of the parent, but they retain their hold with great tenacity. The bat, like all animals who suckle their young, has been known to exhibit the most devoted attachment to them, and to forego all efforts at selfpreservation, in order to be near, when she could