C, The Click-beetle or Skip-jack, Elater obscurus. The line beside it shows its natural size. D, The true Wire-worm or grub of the click-beetles. Enlarged to four times the natural length. _a_, tail; _b_, head.] Though the two-winged flies or Diptera have only two wings well grown and of full size, the second or hinder pair of wings which other insects possess of full size, are present in them in a very much dwindled condition. Since most of our common flies are very small it is difficult to see this dwindled pair of wings, which lie close behind the first or large pair, and are called the "balancers," or "halteres." The daddy-long-legs (Fig. 22, A) is big as flies go, and with a pocket lens, or even without one, you can readily see the dwindled second pair of wings standing out clearly from the body behind the attachment of the first pair. These "balancers" are of the shape of a tennis racket, or a ball-headed club. They serve no longer as organs of flight, but as auditory organs. A minute parasitic insect (Stylops) which lives in bees has only one pair of wings, but in this case it is the hinder pair which are developed, the front pair being shrunk to rudimentary lappets. The daddy-long-legs, or common crane-fly, is a little less than an inch long and a little more than an inch across the spread wings. Its power of flight is not well developed, and its six long legs are moved so slowly and awkwardly that one would say that its powers of walking and running are also feeble. Their strange movements have led some unknown poet to imagine the "daddy" saying: "My six long legs, all here and there, Oppress my bosom with despair."