meiosis \mI-'o-s3s\ or reduction division Division of a gamete- producing cell in which the nucleus splits twice, resulting in four sex cells (gametes, or eggs and sperm), each possessing half the number of chro¬ mosomes of the original cell. Meiosis is characteristic of organisms that reproduce sexually and have a diploid set of nuclear chromosomes (see ploidy). Before meiosis, chromosomes replicate and consist of joined sis¬ ter strands (chromatids). Meiosis begins as homologous paternal and maternal chromosomes line up along the midline of the cell. The chro¬ mosomes exchange genetic material by the process of crossing-over (see linkage group), in which chromatid strands from homologous pairs entangle and exchange segments to produce chromatids containing genetic material from both parents. The pairs then separate and are pulled to opposite ends of the cell, which then pinches in half to form two daughter cells, each containing a haploid set (half the usual number) of double-stranded chromosomes. In the second round of meiotic division, the double-stranded chromosomes of each daughter cell are pulled apart, resulting in four haploid gametes. When two gametes unite during fer¬ tilization, each contributes its haploid set of chromosomes to the new individual, restoring the diploid number. See also MITOSIS.
MeVr \ma-'ir\ (fl. 2nd century ad) Rabbi and scholar of Palestine. He fled Palestine during the persecutions that followed the Bar Kokhba revolt in ad 132-35 but later returned and helped reestablish the Sanhedrin. The patriarch of the Sanhedrin eventually threatened him with excommunica¬ tion over a question of protocol, and he left for Asia Minor, where he had been born. Known for his great dialectical skill, he is cited repeatedly in the Talmud and is remembered as the greatest of the tannaim, a group of masters of the Jewish oral law. Legends of his miraculous powers sprang up during the Middle Ages.
Meir \me-'ir\, Golda orig. Goldie Mabovitch later Goldie Myerson (b. May 3, 1898, Kiev,
Russian Empire—d. Dec. 8, 1978,
Jerusalem) Ukrainian-born Israeli stateswoman, fourth prime minister of Israel (1969-74). Her family immigrated to Milwaukee, Wis.,
U.S., in 1906, where she became a leader of the Milwaukee Labor Zion¬ ist Party. In 1921 she and her husband immigrated to Palestine, where she emerged as a forceful negotiator with British authorities during World War II (1939-45). A signer of Israel’s dec¬ laration of independence in 1948, she served in the Knesset (parliament;
1949-74) and held the posts of min¬ ister of labour (1949-56) and foreign minister (1956-66). As prime min¬ ister, she sought diplomatic solutions to ease the region’s tensions. The failure of her government to anticipate an Arab attack during the Yom Kip- pur War of 1973 (see Arab-Israeli wars) led her to resign six months later.
Meir of Rothenburg orig. Meir ben Baruch (b. c. 1215, Worms, Franconia—d. May 2, 1293, Ensisheim Fortress, Alsace) German Jewish scholar. After studying in France, he served as rabbi in several commu¬ nities in Germany, notably Rothenburg, where he opened a Talmudic school. He became famous as an authority on rabbinic law, writing notes and commentary on the Talmud and acting for nearly half a century as
the supreme court of appeals for Jews of Germany and surrounding coun¬ tries. Persecution prompted him to flee Germany with a group of follow¬ ers in 1286, but he was caught and imprisoned for the rest of his life in an Alsatian fortress.
Meissen porcelain \'ml-s 3 n\ German hard-paste, or true, porcelain produced at the Meissen factory, near Dresden in Saxony (now Ger¬ many), from 1710 until the present day. It was the first successfully pro¬ duced true porcelain in Europe and dominated the style of European por¬ celain until c. 1756. The high point of the Meissen factory was reached after 1731 with the modeling of Johann Joachim Kandler. The onion pattern, introduced c. 1739, was widely copied. Meissen porcelain is marked with crossed blue swords.
Meissonier \,ma-s 3 n-'ya\, Juste- Aurele (b. 1693/95, Turin,
Savoy—d. July 31, 1750, Paris,
France) French goldsmith, designer, and architect. Appointed goldsmith and cabinetmaker to Louis XV in 1726, he became a leading originator of the influential Rococo style. His highly inventive work included fantastic grottoes, animated metalwork designs, snuffboxes, watch cases, sword hilts, and tureens. His sketches for inte¬ rior decoration, furniture, and goldsmith designs became widely known through engravings. Few of his architectural plans were realized.
meistersinger Vml-stor-.siq-or, 'ml-star-.ziq-orV German "master singer" Any of certain German musicians and poets, chiefly of the arti¬ san and trading classes, in the 14th to 16th centuries. These amateur guilds spread throughout Germany until most towns had one. Their main activ¬ ity was monthly singing contests. Because of their educational aims of fostering morality and religious belief, they came to be instrumental in promulgating the Protestant message during the Reformation, though their music is not regarded as highly distinguished. The most famous meis¬ tersinger, Hans Sachs (1494-1576), devoted his art exclusively to the Lutheran cause after 1530.
Meitner Vmlt-narV, Lise (b. Nov. 7, 1878, Vienna, Austria—d. Oct. 27, 1968, Cambridge, Cambridgeshire, Eng.) German physicist. She worked at Berlin’s Kaiser Wilhelm Institute (1912-38), also teaching at the Uni¬ versity of Berlin (1926-38). At a laboratory that she set up with Otto Hahn, the two isolated the radioactive isotope protactinium-231. In the 1930s, with Hahn and Fritz Strassmann (1902-80), she investigated the products of neutron bombardment of uranium. She left Germany in 1938 for Sweden. After Hahn and Strassmann demonstrated that barium appears in neutron-bombarded uranium, she and her nephew Otto Frisch (1904-79) explained the physical characteristics of this division and in 1939 proposed the term fission for the process. She shared the 1966 Enrico Fermi Award with Hahn and Strassmann. Element 109, meitnerium, is named in her honour.
Mekhilta Vmo-'kil-tsX Hebrew commentary on the Book of Exodus. One of the exegetic commentaries known as the Halakhic Midrashim, the Mekhilta presents a composite of three kinds of materials concerning the Book of Exodus: exegeses of certain passages, propositional and argu¬ mentative essays on theological principles, and topical articles on the written and oral Torah. It was produced by a Talmudic school founded by Ishmael ben Elisha c. ad 300 and known as the House of Ishmael. The name Mekhilta (Hebrew: “measure”) refers to its use as a rule or norm for con¬ duct. See also Halakhah, Midrash, Talmud.
Meknes \mek-'nes\ City (pop., 1994: 459,958), north-central Morocco. It was one of Morocco’s four imperial cities, founded in the 10th century by a Berber tribe. Originally a group of villages among olive groves, it became the Moroccan capital in 1673 under Maulay Isma’Il, who built palaces and mosques that earned for Meknes the name “Versailles of Morocco.” After his death it declined, and in 1911 it was occupied by the French. It is now a commercial centre for agricultural products, fine embroidery, and carpets.
Mekong Vma-'koqX River Chinese Lancang Jiang or Lan-Ts'ang Chiang Vlan-'tsaq-'je-'agX Longest river of Southeast Asia. Rising in