A very singular animal is the bat, and seems to belong to several classes and orders. The specimen we present here (_Atalapha cinerea_) is very rare in this part of the country, and was taken in Lincoln Park, Chicago. It flies through the air like a bird and, possessing mammæ like the quadrupeds, suckles its young. The double jaw is provided with three kinds of teeth. With the canines and incisors it tears its prey like carnivorous animals, and with the molars or grinders it cracks nuts like rodents, which it resembles in the narrow, oval form of its head. An imperfect quadruped when on the ground, it drags itself along, embarrassed by the mantle of its wings, which fold up around its legs like an umbrella when closed. When it undertakes to fly it does so in an awkward manner. It first crawls painfully along, and with great difficulty extends its long fingers, spreading out the membrane which covers and binds them together. The ungainly creature then quickly flaps its broad wings, tough as leather, but thin and transparent; a bird without plumage, it now flies abroad in pursuit of insects--nocturnal like itself--or in search of ripe fruit, to which some species are particularly destructive. None of the bats like to raise themselves into the air from a perfectly level surface, and, therefore, use all their endeavors to climb to some elevated spot, from whence they may launch themselves into the air. They climb with great ease and rapidity, being able to hitch their sharp and curved claws into the least roughness that may present itself, and can thus ascend a perpendicular wall with perfect ease and security. In so doing they crawl backward, raising their bodies against the tree or wall which they desire to scale, and drawing themselves up by the alternate use of the hinder feet. When they have attained a moderate height, they are able to fling themselves easily into the air and to take immediate flight. They have the power of rising at once from the ground, but always prefer to let themselves fall from some elevated spot. One reason why bats take their repose suspended by their hind feet is said to be that they are then in the most favorable position for taking to the air. There may be, and probably are, other reasons for the curious reversed attitude. Even among the birds examples are found of a similar mode of repose. Members of the genus _Colius_, an African group of birds, sleep suspended like the bats, clinging with their feet and hanging with their heads downward. But these birds cannot assume this attitude for the purpose of taking flight, as their wings are used as readily as those of most other feathered creatures, and, therefore, there must be other reasons to account for the strange attitude.