Sir Charles Bell, in his valuable treatise on the "Hand," considers the skeleton of the Bat as one of the best examples of the moulding of the bones of the extremity to correspond with the condition of the animal. Contemplating this extraordinary application of the bones of the extremity, and comparing them with those of the wing of a bird, we might say that this is an awkward attempt--"a failure." But, before giving expression to such an opinion, we must understand the objects required in this construction. It is not a wing intended merely for flight, but one which, while it raises the animal, is capable of receiving a new sensation, or sensations, in that exquisite degree, so as almost to constitute a new sense. On the fine web of the Bat's wing nerves are distributed, which enable it to avoid objects in its flight during the night, when both eyes and ears fail. Could the wing of a bird, covered with feathers, do this? Here, then, we have another example of the necessity of taking every circumstance into consideration before we presume to criticise the ways of nature. It is a lesson of humility. In this animal the bones are light and delicate; and whilst they are all marvellously extended, the phalanges of the fingers are elongated so as hardly to be recognised, obviously for the purpose of sustaining a membranous web, and to form a wing. In 1839 there was received at the Surrey Zoological Gardens, from Sumatra, a specimen of the Vampire Bat. This was a young male; the body was black, and the membranous wing, in appearance, resembled fine black kid. He was rarely seen at the bottom of his cage, but suspended himself from the roof or bars of the cage, head downwards, his wings wrapped round his body; when spread, these wings extended nearly two feet. Although this specimen was the Vampire Bat to which so many bloodthirsty feats have been attributed, his appearance was by no means ferocious; he was active, yet docile, and the only peculiarity to favour belief in his blood-sucking propensity was his long pointed tongue. The species has popularly been accused of destroying, not only the large mammiferous animals, but also men, when asleep, by sucking their blood. "The truth," says Cuvier, in his "Regne Animal," "appears to be, that the Vampire inflicts only small wounds, which may, probably, become inflammatory and gangrenous from the influence of climate." In this habit, however, may have originated the celebrated Vampire superstition. Lord Byron, in his beautiful poem of "The Giaour," thus symbolises the tortures that await the "false infidel:"--