FLUXION, in medicine, an unnatural flow or determination of blood or other humor toward any organ; a catarrh.
In mathematics, a method of calcula tion resulting from the operation of fluents, or flowing numbers.
FLY, in zoology, a name applied al most indiscriminately to all insects possessing wings; being often extended to all insects of the sub-order Diptera, and often also restricted to the family Muscidie. The fly is characterized as pos sessing a pair of veined and membranous wings, with two movable bodies called balancers (halteres), placed a little be hind them. The mouth is formed of be tween two and six setaceous pieces of scaly texture, and these pieces are either inclosed in a proboscis-like sheath, or covered by one or two lamina, which form it. The head is globular or hemi spherical. The mouth is only formed for transmitting fluids, and is conse quently very delicate in structure. The sucker performs the part of a lancet, and pierces the envelope of vegetable or ani mal fluids, in order to allow of the fluid itself being transmitted up into the mouth of the insect. The antenna are
united in front, and are approximated at the base. Above the true wings of the insect and a little behind them, are the balancers or halteres; these are almost membranous, and are furnished with two little knobs at their extremities, which are capable of dilatation. The legs of this class of insects are long and slender; and the feet, it is well known, are fur nished with skinny palms, to enable them to stick on glass and other smooth bodies by means of the pressure of the atmos phere.
In machinery, that part of a machine which, being put in motion, regulates the rest. In nautical language that part of a compass on which the 32 points are drawn, and to which the needle is at tached underneath; the compass-card. In printing, that part of the machinery of a printing press which withdraws the sheet, and lays it aside after the impres sion is made.