COMPOSITiE. 238 COMPOSITION. misia; (8) Senecionew, represented by Senecio, Pctasites, Arnica, Caealia ; (9) Valeiidiilacea', typilicd l)y Calendula; (10) Arctolidew, repre- sented by Arctotis, an African and Australian genus; (11) Vynareie, svliicli embraces the genera Articuni, Carduus, Cnicus, Cynara, Onopordon, Centaurea, etc. (12) Mutisiew, not found in the United States, but represented elsewhere by Mutisia, Gerbera, etc. ; and Liguliflore.i;, with (13) Ck-horiew, represented by Cichorium, Tra- gopogon, Picris, Hieraceuni, Leontodon, Taraxa- cum, Lactuca, Sonchus, Chondrilla. etc. When the large niniiber of species of this family are considered, a small proportion only, aside from those cultivated for their flowers or foliage, are found to be of economic importance. Among the most important may be mentioned chicory, dan- delion, lettuce, salsify, artichokes (both globe and Jerusalem ) , sunflowers, tansy, chamomile, etc. Many are grown for their flowers. When cultivated the disk flowers are often changed in form, and the flowers are then said to be doubled, as in the case of dahlias, zinnias, asters, chry- santhemums, coreopsis, etc. Medicinal proper- ties are claimed for many, as arnica, worm- wood, elecampane, artemisia. coltsfoot, tussilago, blessed thistle, etc. The seeds of a number con- tain oil that is of importance, as the sunflower, madia, etc. The plants of this order exhibit a number of interesting adaptations in their natural history. The Composita- are generally considered as the highest expression of development in the plant world, and they exhibit a number of modifica- tions by which they have become the most nu- merous and aggressive of all plants. In many genera the gradations between species are so con- fusing as to make their proper classification well- nigh imjjossible. The distribution of the fruit has been brought about by many special modifica- tions. In the dandelion, thistle, and others, the calyx develops, after the fertilization of the flower, into a plumose pappus by which the fruits are scattered by the winds. In the tickseed and bur-marigold the acheiies are crowned with sev- eral barbed awns that catch in the hairs of ani- mals and the clothing of man, aiding materially in their wide dissemination. In the burdock and cockle-bur the involucre is furnished with curved hooks which serve to aid in the dispersal of these plants. Other seeds, such as those of the !Madia, the tarweeds, are covered, especially upon their involucres, with a very thick adhesive exudation that adheres to anything with which the seeds come in contact, and these are carried away often to great distances. The means devised for the fertilization of the flowers is admirably adapted to secure numerous progeny. The flowers being small and crowded together, several can take advantage of the visit of a single insect laden with ])ollen. Some are wind-pollenized, their close position aiding in it. The mechanism of the individual flower for pol- lination is curiously perfect. When the flower ojX'ns, the style, with itsstigmatic surfaces close- ly pressed together, forces its way out through the stamen-tube, earning the' pollen out where it can come in contact with insect visitors or be blom away by the wind. .t this time the flower is not ready lor its own fertilization. When re- ceptive, the style has ))rotruded from the tube and the stigmas separate, curving backward. If they do not receive pollen from another flower to thus secure the desired cross-fertilization, they continue to curl backward until they come in cont;ict with the pollen, some of which still remains upon their own style, and they thus be- come self-fertilized. In this way the setting of seed is assured to every flower. In conclusion, the reniarkal)le success of this order may be at- tributed to a number of factors, such as the massing of the flowers, resulting in greater con- spicuousness, to attract insect visitors, one visit- or fertilizing numy flowers; a simple floral mech- anism to protect and distribute the pollen, and the special devices described above to secure the dispersal of the seeds. See articles on various memliers of the order. COMPOSITE NUMBERS. See Primes. COMPOSITE ORDER. See Column. COMPOSITE SHIPS. Ships built with iron or steel frames and wooden planking. In some eases the framing is stiffened by keel-plates, stringers, deck-plates, longitudinals, etc. The planking is bolted to the frames, and sometimes additionally pinned edgewise to the planks on each side. It is almost invariably sheathed with copper as a protection against fouling— indeed, it is chiefly to provide against fouling that ships are composite built. See SHirnLiLUixu. COMPOSITION (from OF., Fr. composltimi, from Lat. i-oiiiiiositio, connection, from compo- iicre, to put together) . In painting, that ordered arrangement of light and shade, of color and line, which shall directly impress the beholder with tile thought and idea the artist wishes to express. The most important requisite of com- position is unity. Every object must form a harmonious part of the whole, and be in distinct relation to the rest of the picture. As Millet said: "A work should be all of a piece, and people and things should be there for an end." 'hatever their color or shajie, all. objects in the picture should be seen under like conditions of light, shade, and atmosphere. There should be some object or objects of special interest, to which the remainder of the picture should be strictly subordinated. The subject treated and the indiiduality of the artist usually determine the composition of a picture. There are, however, some generally accepted maxims in regard to linear composition which should be mentioned. The perpendicular line is one of dignity and severity, and its pre- dominance in a picture produces a simple, majestic eft'eet (e.g. the early Italian portraits). The predominance of the horizontal line produces an efl'ect of repose or solemnity, as is seen in the composition of most landscapes. The tlowing or waving line is the line of beauty and grace, and it is for this reason that the drawing of the human figure is esteemed so' important. There have been many theories of composition, more or less arl)itrary. The Italians generally use the pyramidal composition, in which the !Madonna forms the apex of the pyramid, with a balanced group of standing or kneeling saints on either side, .^s art advanced, they also used the oval eom])osition, in which the figures form a circle on the canvas (e.g. Raphael's "Madonna della Sedia"). the arch (Correggio's "Corona- tion of the Virgin"), the diamond shape (Sistine IMadoniia ) . and others. In landscape the themes of composition were even more numerous. In modern composition there is greater freedom.
