FLEA, Fufae, a Linntean genus of apterous insects, now commonly regarded by entomologists as constituting a distinct order• suctoria, sipTionaptera, aphaniptera. The species are not numerous, and little subdivision of .the genus has been attempted. It has been suggested as probable, that further ;nvestiation may lead to a recognition of the fleas as belonging to some of the larger orders, with parts modified to suit their para sitical life. All the species are very similar to tire CoataroN FLEA (P. irritan.$), which is plentiful in all parts of the world, living by sucking the blood of man, and of some species of quadrupeds and birds. It abounds particularly in the nests of poultry, pigeons, and swallows, and wherever sand and dust accumulate in the chinks of floors, etc.; and it is to be found also plentifully in beds, wherever clelnliness is neglected. The abundance of fleas in some countries is an intolerable nuisance to travelers, amid also to residents. Such is said to be particularly the case in many parts of Australia, where the general dryness and varmth encourage their growth to an extent against which the precautionary measures of housewives are almost entirely unavailing. The female F. is rather larger than the male, but the sexes are otherwise very similar. The head is small, very compressed, rounded above, and has on each side a small round eye. The mouth has two lisncet like'-At $dibles, the maxilla; Wing represetited by two conical scales, the mandibles and maxilla forming a suctoriai beak, with a slender bristle-like tongue, the whole inclosed between two three-jointed plates. The thorax consists of three segments, the second and third of which bear a scale on each side; the scales are regardecLas rudimentary wings. There is no marked division between the thorax and
the abdomen, which consists of nine segments, much burger than those of the thorax, but much compressed. The whole body is covered with a tough integument. The activity of the F., its power of leaping, and its extraordinary strength, are well known. Its strength has been sometimes applied to the drawing of miniature carriages, canon, etc., which the public have been invited to witness through a magnifying-glass, as an amus ing spectacle. Fleas undergo a complete metamorphosis. The female lays about a dozen eggs of a white color, and slightly viscous. The larva is a lively little worm, at first white, afterwards reddish, and destitute of feet. When about to change. into a pupa, it incloses itself in a little silk cocoon, from which emerges the perfect flea. Cleanliness and careful attention are the principal means of keeping beds and houses free of fleas; but where these inc• found insufficient, as is apt to be case in some climates, and in Cottages where there is much wood-work with certain strongly aromatic plants are employed, of which the odors appear to be detestableto them, as the different eompositcs known by the name of fleabane, and also wormwood, the merits of which last are thus extolled by Tosser: Other species of fleas infest particular animals, as the dog, fox, mole, etc.—The chigoe (q.v.), or jigger of the West Indies, nearly allied to the true fleas, is far more troublesome than any of them.