VIOLET. 151 VIOLIN. is the wild species from which the common pansy (ir hpart's-casp socnis to have boon dovolopod. It Ikis iiiiiiiiiicrahlc varieties and tniiiis which sur- pass the natural species in lieauty and diversity of color. The pansy runs in strains rather than in varieties, and llorisls frecpiently fjroup the varieties according to diU'erent arbitrary schemes. This species belongs to the leafy-steinmed violets. The name pansy is derived from the French word peiisf'e, thought. A strain of this species Icnown as Viola tricolor arrriisls has become nat- uralized in some places in the United States. The sweet violet ('iola odorata), one of the stem- less species, is common in grassy places in SWEET-SCENTED VIOLET (Viola odorMa) Europe and Northern Asia. The flowers are either deep blue or more rarely white. Under cultivation many varieties have been obtained, including dwarf and double forms with a great diversity in the color of the flowers. The wild plants are not as fragrant as the improved garden varieties. Viola Canadensis is an Ameri- can species of which the cultivated varieties are frequently grown on sloping banks and rocker- ies. The bird's-foot violet (Viola pedata } , nn- other American species, is the parent of several handsome cultivated varieties. Viola altaica, a species native to Siberia, has been introduced into cultivation, and by itself, or by hybridiza- tion with Tio/(J tricolor, has become the parent of many garden violets. Viola bi flora is a pretty species widely distributed in the Northern Hemi- sphere. It produces small yellow flowers usually in jiairs from April to June. Dogtooth violet is t!ie. common name of the genus Erythronium (q.v. ), a genus unrelated to the violets proper. Violets are of easy cultivation on various soils, but they prefer cool, shady positions, a rich, moist, sandy loam, with good drainage to keep the roots free from water. They are propagated chiefly by cuttings or divisions. Cuttings are made from vigorous shoots in the spring and set in fine sandy soil in a cool greenhouse or frame, and the resulting plants are transplanted to their permanent quarters in the fall. Propagation by division consists in dividing the plants after the flowering period and replanting them immediate- ly. Such plants flower the following spring. There are several so-called diseases that attack violets. Rust or spot (Cercospora viola") causes the formation of circular grayish spots with dark centres upon the leaves. Jlismanagement seems to aid in the spread of this disease. Badly infested plants and aflfected leaves should be de- stroyed to prevent the ripening of the spores. A spot disease attributed to Alternaria viola" at- tacks the parts above ground and is most troublesome upon rapiilly growing plants. The spots have light-colored centres surrounded by darker zones, which become lighter in old spots. Care in the selection of ])lants, careful culture, removal of all diseased leaves and plants, and propagation of stocky, vigorous plants are sug- gested as preventive means. An anthracnose (tllccosporium violce) , which is often quite de- structive, begins at the edge of the leaf and con- tinues to spread until the whole plant is all'ected. Many of these diseases can be prevented by [irop- er management of the plants. Eungicides may be used, but they usually discolor the leaves by the deposit of copper. Nematoda (q.v.). which are sometimes troublesome, may be destroyed by steam sterilizing the soil before the plants are set. VIOLET FAMILY. See Violace.«. VIOLET SNAIL. A small pelagic peetinl- branch gastropod moUusk of the genus Janthina, nearly related to the _ ___ wentletraps (q.v.). ~ =5 Several species are known, all inhabit- ants of the open sea, where they cling to floating seaweeds and the like. Their shells are fragile, purple in color, and in shape like small turban- shells (q.v.). They are especially interest- ing from the curious float which they con- struct tn a II n'n n r t A jantliinaswn iroin aDove, siiucu 10 support showiug its bubble raft oteggs. their egg - capsules. This is a gelatinous raft in which a cluster of eggs is entangled with air bubbles, buoying them up ; and thus the collection is dragged about by the mollusk until the young hatch. They occur in shoals and feed upon jelly-fishes. VIOLIN (It. violino, diminutive of viola, viol). The most popular of stringed instruments played with the bow. In its primitive form it is a development of the lyre and monochord (qq.v.), the strings from the former, and the principal parts, the elongated resonant-box with its sound- holes, finger-board, and movable bridge, from the latter. The true history of the violin begins with the invention of the bow, which was first applied to the crwth, or crowd ( q.v..) , some time before the thirteenth century, when the viole, or vielle, of the troubadours made its appearance. The rebec ( q.v. ) , the geige, the fidel, and many kinds of viols and violas underwent various changes until toward the middle of the sixteetith century the true violin model appeared, and superseded all other instruments of the same class, except the viola, the violoncello, and the double bass. The primitive violins had no contour, and it was not until the thirteenth century that the body of the vielle was scooped out at the ribs, forming a kind of waist. The corner blocks were adiled about the fifteenth century, and it is supposed they originated in Germany. The foundation on which violin-making was to rest was the viol with the double corners. These produced a new constructive feature, the 'bouts,' the ribs which VIOLET BNAIL, A Janthinasp<"n from above,
