Page:The New International Encyclopædia 1st ed. v. 20.djvu/885

* YUCCA. 747 YUKAGIRS. great panicle. The llowers are hell-shapod and ilrooping, white Willi a purple stripe on llie out- side of each segment of the perianth. The libres of the leaves of Yucca (jluuca are used by the American Indians to make cloth cordage and baskets. The libre of the yuccas is similar to that of the agaves and brnmelias, and probably is often included under the name pita flux or pita fibre. Yiirra aloifolia is counnnn in the sand dunes of the .Sdiitli. YUCCA MOTH. Any one of several species of the curious tineine geinis Pronuba, of the family Prodoxidoe, all of the species of which are confined to yucca plants for food. The species of Pronuba are small white moths with narrow wings sometimes spotted with black. Their mouth-parts are perfectly adapted for the fertilization of the yucca flowers, which are rot fitted for self-fertilization, or for fertiliza- tion by other insects. The moth, having collected a mass of pollen, lays an egg in the pistil, and pushes the pollen into the orifice, thus insuring fertilization and the development of the pod, in which the larva then develops. This instance of symbiosis (q.v. ), which was worked out by the late C. V. Riley, is one of the most remarkable in biology. The yucca moths of the genvis Pro- doxus have no relation to the fertilization of the plant, but lay their eggs in the llower stem, in which their larva; bore. Since some of the yuccas do not flower every year, these insects may pass more than a year in the pupal stage. YUCHI, yoo'che. A North American Indian tribe. See Uchee. YUEN-SAN, won'siin'. See WOKS.^•. YUEN or YUAN (12S0-1367). A Mongol, and consequently an alien, dynasty that occupied the throne of China for eighty-eight years — the twenty-third of the twenty-five dynasties that have ruled in that country since B.C. 2205, when the first one was founded. The Yuen was founded by Kublai Khan, grandson of Genghis Khan, and successor of Mangn. who in 1260 found the north- ern provinces of China in the hands of the Kin Tatars, and a native dynasty, the Sung (q.v.). in the south. Having successively vanquished these, he ascended the throne in 1280, chose the dynastic name of Yuen, and made Peking his capital. Though he displaced the Chinese high ofiicials with uncivilized Mongols, in utter disre- gard of the Chinese practice of appointing only literati, he seems to have ruled wisely on the whole. He completed the grand canal between Hang-chow and Tien-tsin ; inaugurated road-mak- ing and the planting of trees; introduced the use of paper money; and favored Buddhism, but pro- scribed Taoism, and ordei-ed all Taoist books to be burned, except the Tao-teh-King of Lao-tse. He attempted the conquest of Japan, but the for- midable armada and army he dispatched for that purpose were utterly annihilated by the Jap- anese and the terrific storms which the.y en- countered. Of his eight successors only three are worthy of mention : Timur, his grand- son (1294-1300), who proved himself honest and energetic and labored Ijard to correct abuses and improve the administration. Superfluous of- fices were abolished, the tax system was reformed and the lands of the powerful ecclesias- tionl establishments were taxed: but ill health Vou xx.^s. jnovcd a serious iiandicap, and he died at the age of forty-two. Kaisun, his successor (1307-10), was devoted to linddhisni, wine, and women, and accomplished little. His most im- portant achicvenient was the redemption by the Uovcrnmcut of the children who in times of famine had been sold. Ayuli Palpata, the fourth Emperor (1311-20), also professed to have the welfare of the people at heart, but his devotion to Huddhism led to the expenditure of vast sums on priests and ceremonies, and grinding taxation was the result. Disorders spread, risings oc- curred, the rulers spent their time in debauchery, and in 1307, during the reign of the ninth Em- peror, Cliu Yuan-Chang, a temple servant at the head of a largo army overthrew the corrupt Yuen, and in the following year ascended the throne as the first of the Ming or 'Illustrious' dyna.sty (1368-1043), and became known as Hung-Wu (q.v.), making his capital south of the Yang-tse, in the present Nanking. YUGA, yu'ga ( Skt., yoke,, period of time, generation). In Hindu mythology and astron- omy, the name of a long period of years corre- sponding to an age of the world. Four such eras are mentioned: Krla-Yuii", TrCtd-Yuiju, Dvfiparn Yuijd. and Kali-Yuga. The first was the golden age of the world, but each succeeding period be- came shorter and more evil, until the last, or Kali-yuga (q.v.). The Kali-yuga is said to have begun in the year B.C. 3101. A description of these immense world-periods, w'hich comprise myriads of years, is. found in Mann (q.v.), the ilahahhSrata (q.v.), and the Purdnas (q.v.). Conceived as a day of the gods, each of these long mundane eras is believed to be preceded by a period called sandhya, or twilight, and fol- lowed by a similar period sandhyumsa, or portion of twilight. The precise length is given in divine years and reduced afterwards to terms of human years. The Krita-Yuga consists of 4000 divine years, its Sandhya of 400, and its Sandhyamsa likewise of 400 divine j'ears. The Trcta-Vuga consists of 3000, and its Sandhya and Sandhyamsa of 300 divine j'ears each ; the Dvapara-Yuga of 2000 divine years, with 200 such 3'ears as its Sandhya, and 200 as its Sandhyamsa; and the Kali-Yuga of 1000 di- vine years, wdth 100 such years as its Sandhya, and 100 as its Sandhyamsa. Since a divine year comprises 360 solar years of mortals, a year of men being a day of the gods, these Yugas, with their Sandhvas and Sandhvamsas, would several- ly represent 1,728,000, l"296,000, 864,000, and 432,000, or in the aggregate 4,320,000 solar years of mortals. This cycle is called a Mahd- yufja, or 'great Yuga,' and a thousand such, com- jirising 4,320,000,000 years, make up a day and night of Brahma. As a designation of time Y'uga is confined almost wholly to philosophical and descriptive works, for it plays no actual role in the strictly scientific works of Hindu astronomy. The term Yuga is sometimes, though exceptional- ly, applied also to other divisions of time. Con- sult Thibaut, Astronomie. Astrologie und Mathe- ■ matil; (Strassburg, 1899). YUKAGIRS, yoo-kii'gerz. A stock once con- sisting of many tribes, as Omoks, Anauls, and Cheliags, occupying much of Siberia east of the River Lena. They call them- selves Andondomni, or men. They num-