F. are developed in depressions of the skin, lined by an inversion of the epidermis which surrounds the bulb from which each feather springs; they grow, much in the seine manner as hairs, by the addition of new cells from the bulb, which becomes modi fied into the horny and fibrous stem, and by the elongation of previously existing cells. They are, when first formed, living vascular parts, growing by nutrient vessels; but when they are fully formed, the vessels become atrophied, and the F. become dried up, and gradually die from the summit to the base. For a full account of the development of the different parts, we must refer to prof. Owen's article, "Ayes," and to prof. Hux ley's article, " Tegumentary Appendages," in the Cyclopcedia of Anatomy and Physiology.
F. grow with great rapidity, and in some birds attain a length of more than 2 feet. They are almost alwayS renewed annually, and in many species oftener; hence it may readily be conceived how much vital energy must be exhibited in their development, and how critical the period of molting must be. The plumage is generally changed several times before it attains the state which is regarded as characteristic of the adult bird; these changes may occupy a period usually ranging from one to five years.
- Notwithstanding their extravascuiar nature, F., as is well known, undergo a change of color after they are completely formed. In yearling birds, the winter plumage, which succeeds the autumnal molt, gradually assumes brighter tints, the new color commenc ing at the part of the vane nearest the body, and gradually exteuding outwards till it pervades the whole feather. Dr. Weinland, an American naturalist, is of opinion, from a comparison of bleached specimens in museums, with recent ones taken from the bird, that the brightness and fading of the colors are due to the increase or diminution of an oily matter. Thus, the microscopic examination of the vane of F. from the breast of a fresh merganser showed numerous lacume containing a reddish oil-like fluid; some weeks after, the same F. having become nearly white from exposure to light, disclosed air bubbles instead of the reddish fluid. If this fluid is an actual oil, as is most probably the case, it could make its way into the non-vascular tissue by mere physical imbi bition; and on the varying quantities of this oil the variations of plumage would depend.
The property possessed by the plumage of most birds, of keeping the surface pro tected from moisture, is well known. This is due to two causes. Most birds are provided with an oil-gland at the base of the tail, whose secretion is distributed over the F. by means of the bill; and, additionally, the shedding of water is partly due to a thin plate of air entangled by the feathers.
The F. vary in form in different parts of the body, and afford zoological characters for the distinction of species. Hence, they have received distinct names, such as pri maries, secondaries, tertiaries, etc., in ornithology. These terms are explained in the article I3inns.
The chief uses to which F. are applied in the arts are three--pens, due to the peculiar elasticity of the barrels; bed-feathers, due to the combined softness and elasticity of the barbs; and ornament, due to the graceful forms and delicate tints of the whole feather. The mode of preparing the barrels for pens is described under QUILLS.
Bed-feathers were used in England in the time of Henry VII. ; but it is not known how much earlier. At the present day, goose-feathers are preferred, the white rather than the gray. What are called poultry F., such as those of the turkey, duck, and fowl, are less esteemed, on account of their deficient elasticity. Wild-duck F. are soft and
elastic, but contain an oil difficult to remove. The following is one among several modes of preparing F. for beds. Clean water is saturated with quicklime; the F. are put into a tub; the lime-water is added to the depth of a few inches; the F. are well steeped and stirred for three or four days; they are taken out, drained, washed in clean water, dried upon nets, shaken occasionally while drying, and finally beaten to expel any dust. The larger establishments, however, now prepare bed-feathers by steaming, which is found to be a more profitable and efficient process. The down, which is of so light and exquisite a texture as to have become the symbol of softness, is mostly taken from the breasts of birds, and forms a warm and delicate stuffing for beds, pillows, and coverlets. The most valuable is that obtained from the eider-duck, described under EIDER.
F. used for head-dresses, or other purposes of ornament, are selected according to the forms and colors which they display. The ostrich., a very valuable kind of feather, may be taken as an example of the way in which ornamental F. generally are prepared by the plamassier. The mode of catching the bird itself is noticed under OSTRICH: it suffices here to state that the hunters endeavor to avoid injuring the F. by blood or blows. When brought to England, the F. are assorted according to quality; those from the back and above the wings are the best, the wing-feathers next best, and the tail feathers least valued. The F. of the male are rather more prized than those of the female. They are cleaned for use by repeated soakings and washings in water, some times with and sometimes without soap. There is also a process of bleaching by means of burning sulphur. When dried by being hung upon cords, the F. pass into the hands of the dresser, who opens the fibers by shaking,.gives pliancy to the ribs by scraping them with bits of of glass, and curls the filaments by passing the edge of a blunt knife over them. If the F., Whether of the Ostrich or any other bird, remain in the natural color, little more has to be done; but if a change of tint be required, the F. easily take dye-materials—such as safflower and lemon-juice for rose-color or pink, Brazil-wood for deed red, Brazil-wood and cudbear for crimson, indigo for blue, turmeric or weld for yellow, etc. A process of bleaching is adopted before the dyeing, except for black.
The kinds of F. chiefly used for ornament are those of the ostrich, adjutant, rhea or American ostrich, emu, osprey, egrett, heron, antrenga, bird of paradise, swan, turkey, peacock, argus pheasant, ibis, eagle, and grebe. White ostrich F. are prepared chiefly for ladies' head-dresses; and black for the Highland regiments and for funereal trappings. The white and gray marabout-stork F., imported from Calcutta, aie beautifully soft and light, and are in request for head-dresses, muffs, and boas; the white kinds will sometimes sell for their weight in gold. The flossy kinds of rhea feather are used for military plumes, and the long brown wing F. for brooms and brushes. Osprey and egrett F. are mostly used for military plumes by hussar troopers. Bird of paradise F. are much sought after by oriental princes for turban-plumes. Cocks' F. are used for ladies' riding-hats and for military plumes. Dr. Macgown, who was United States consul at Ningpo a few years ago, has described, in the American Journal of Science and Art, an ingenious process which the Chinese adopt for combining brilliant-colored F. with bits of colored metal into garlands, chaplets, frontals, tiaras, and other ornamental articles.