Pursuant to our intention of laying a _natural_ classification of the Animal Kingdom before our readers, we shall now proceed to describe the SWIFTS, although we are well aware that many modern naturalists consider that they should not be grouped with the Swallows. The family of the SWIFTS (_Cypseli_) are small or moderate-sized birds, with a long slender body, short neck, broad flat head, and small delicate beak, which is broad at its base, slightly curved, and somewhat compressed at its tip. The gape is uncommonly wide; the wings are narrow and curved like a sabre; the tail is very variously formed, being sometimes long, sometimes short, and more or less deeply incised at its extremity; the feet and toes are stunted, the latter armed with short, powerful, and much curved claws. The plumage is thick and composed of small feathers, it is usually of a dusky hue, but occasionally exhibits considerable metallic lustre. The various members of this family are found throughout all the divisions of our earth, except its most northern portions, and inhabit every situation from the sea-coast to the snow boundary of lofty mountain ranges. From early morning till late in the evening, they may be seen skimming through the air with astonishing rapidity, or soaring to such an elevation as to be almost beyond the reach of our vision. So powerful are their wings that no amount of exertion appears to fatigue them; their pinions, which when extended form a crescent, are wielded with a force and rapidity rivalling the activity of the Humming Birds--they dart with the velocity of an arrow upon their prey, or indulge in every conceivable variety of flight or motion, as they skim through what may certainly be called their native element; even when among the branches of trees, they display considerable agility, but are perfectly helpless upon the ground. All the members of this family are of a restless disposition; they spend but a few hours of the night in repose, and require a very large amount of food to enable them to support their prolonged exertions, so that they consume insects in enormous quantities, seizing them whilst upon the wing. [Illustration: THE KLECHO (_Dendrochelidon klecho_).]