The last joint of the _tarsus_ is armed with a pair of double claws, and between them lies a hollow cup-shaped cushion, somewhat like that which enables the house-fly to walk on glass or other very smooth surfaces, only that the _pulvillus_ of the fly is double. The edge of the cup is fringed with _ciliæ_, or very minute hairs, of such delicacy that a powerful lens is required to see them. Under the microscope, the object is one of great interest. The claws serve for hanging from the roof or sides of hives, and for clinging to each other at swarming or wax-making times, the cushion for walking on smooth surfaces. It is worthy of remark that all the joints of the legs are covered with hairs more or less stiff, and all pointing downwards. Their uses are to collect pollen, and to act as brushes and combs to all the external parts of the body, which need constant cleansing from flower-dust, and other matters less useful to the bee. [Illustration: Fig. 30.--Wing of Bee.] Passing now to the wings, new marvels and beauties await our observation. These organs are four in number, the forward pair being considerably larger than the hinder. Each wing consists of a double membrane, dotted all over with fine hairs, whose purposes are to protect the delicate structure from wet, and from particles of various kinds which would adhere to it, and injure its surface. As a support for this expanded tissue, there is a ramification of stronger material, constituting nervures, and acting like the ribs of an umbrella. With these are associated air-vessels, or _tracheæ_, for the circulation of air, and, possibly, to assist in giving buoyancy to the organ. By another set of tubes a portion of the nutritive fluid is conveyed to certain parts of the wing, though no general circulation seems to take place in it. The substance of which the expanded portion, as well as the nervures, is composed, is very tough, and, as our readers may remember, the natural order to which the bees are assigned is named _Hymenoptera_, from the strongly _membranous wings_ they possess.