agaric \'a-gar-ik\ Any fungus of the family Agaricaceae, including the familiar commercially grown mushroom. Agarics have SPORE-bearing cells (basidia) located on thin sheets called gills. Best known of the agarics is the genus Agaricus (Psalliota ), which includes some 60 species, the most prominent being the edible meadow, or field, mushroom, A. campestris, and the common cultivated mushroom, A. bisporus.
Agartala \3-'g3r-t9-b\ City (pop., 2001 prelim.: 189,387), capital of Tripura state, India. It lies near the Bangladesh border on the Haroa River in an intensively cultivated plain. The commercial centre of the area, it also contains a maharaja’s palace, a temple, and several colleges affili¬ ated with the University of Calcutta.
Agassi Va-go-seV, Andre (Kirk) (b. April 29, 1970, Las Vegas, Nev., U.S.) U.S. tennis player. Agassi won the Wimbledon men’s singles in 1992, the U.S. Open in 1994, and the Australian Open in 1995. By 1997 he had dropped to 122 in the international rankings, but he recovered to become the world’s top-ranked player by 2000. In 2001 he married retired German tennis player Steffi Graf. Agassi is known for his aggressive style and demeanour on and off the court.
Agassiz \'a-go-se\, Alexander (Emmanuel Rodolphe) (b. Dec. 17, 1835, Neuchatel, Switz.—d. March 27, 1910, at sea, mid-Atlantic Ocean) Swiss-born U.S. marine zoologist, oceanographer, and mining engineer. The son of Louis Agassiz, he emigrated in 1849 to the U.S., where he conducted significant systematic zoological work on echinoderms (e.g., starfish). He developed and supervised what became the world’s foremost copper mine (Calumet, Mich.) while also improving conditions for min¬ ers. He also pursued marine and coral reef studies. His observations made
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Agassiz ► Agent Orange I 27
on an 1875 trip to the western coast of South America led him to chal¬ lenge Charles Darwin’s theory of coral reef formation.
Agassiz, Elizabeth Cabot orig. Elizabeth Cabot Cary (b. Dec. 5, 1822, Boston, Mass., U.S.—d. June 27, 1907, Arlington Heights, Mass.) U.S. naturalist and educator. She was educated at home, and in 1850 she married Louis Agassiz. She helped organize and manage several of his field expeditions, and together they founded a marine laboratory in Buzzards Bay, Mass. After his death she pursued her idea of a college for women to be taught by the Harvard University faculty. She was instrumen¬ tal in launching the Society for the Collegiate Instruction of Women (1882); she served as its president until 1894, when it was renamed Rad- cliffe College, and she continued as president until 1899.
Agassiz Va-go-seV (Jean) Louis (Rodolphe) (b. May 28, 1807, Motier, Switz.—d. Dec. 14, 1873, Cambridge, Mass., U.S.) Swiss-born U.S. naturalist, geologist, and teacher. After studies in Switzerland and Germany, he moved to the U.S. in 1846. He did landmark work on gla¬ cier activity and extinct fishes. He became famous for his innovative teaching methods, which encouraged learning through direct observation of nature, and his term as a zoology professor at Harvard University revo¬ lutionized the study of natural history in the U.S.; every notable Ameri¬ can teacher of natural history in the late 19th century was a pupil either of Agassiz or of one of his students. In addition, he was an outstanding science administrator, promoter, and fund-raiser. He was a lifelong oppo¬ nent of Charles Darwin’s theory of evolution. His second wife, Elizabeth Agassiz, cofounder and first president of Radcliffe College, and his son, Alexander Agassiz, were also noted naturalists.
agate \'a-got\ Common, semiprecious silica mineral, a variety of chal¬ cedony that occurs in bands of vary¬ ing colour and transparency.
Varieties are characterized by pecu¬ liarities in the shape and colour of the bands, which are seen in sections cut at right angles to the layers.
Agate is found throughout the world, commonly in cavities in eruptive rocks and in geodes. Brazil and Uru¬ guay are major producers of agates; they are also found in Oregon, Wash¬ ington, Idaho, Montana, and other western U.S. states. Agate is essen¬ tially quartz. Much commercial agate is artificially dyed to make the naturally dull-gray stones more colourful.
Agate Fossil Beds National Monument Natural “depository” of an extinct animal community on the Niobrara River, northwestern Nebraska, U.S. The beds, laid down as sedimentary deposits 20 million years ago, bear the remains of prehistoric mammals. Discovered c. 1878, the site was named for its proximity to rock formations containing agates. A national monument since 1965, it covers 2,269 acres (918 hectares).
Agatha, Saint (fl. 3rd century ad?, Sicily; feast day February 5) Leg¬ endary Christian martyr. Born in Palermo or Catania, she resisted the advances of a Roman prefect sent to govern Sicily. After brutal torture she was sent to the stake, but as the fire was lit a great earthquake occurred, and the crowd demanded her release. She was led away to prison, where she died. Though she appears in lists of martyrs as early as the 6th century, the legend may be unfounded.
Agathocles \3-'ga-th3-klez\ (b. 361 bc, Thermae Himeraeae, Sicily—d. 289) Tyrant of Syracuse (317-304?) and self-styled king of Sicily (304?- 289). He moved to Syracuse as a youth and served in its army. After two failed attempts, he overthrew the Syracusan oligarchy (317) and took power. He waged wars with other Sicilian Greek cities (316-313?) and with Carthage (311), almost capturing Carthage itself before he was defeated (307). He concluded a favourable treaty (306) that curtailed Carthaginian expansion in Sicily. Harsh domestic measures kept him in power, and he declared himself king of Sicily; his reign was peaceful thereafter. He restored Syracusan liberty in his will, but after his death the Carthaginians were once again a power in Sicily.
agave \o-'ga-ve\ family Family Agavaceae of the lily order (Liliales), comprising more than 700 species of short-stemmed, often woody plants found in tropical, subtropical, and temperate areas. They have narrow,
lance-shaped, sometimes fleshy or toothed leaves, which are clustered at the base of the plant. Most have large flower clusters. The fruit is a cap¬ sule or berry. Plants of the genus Agave are important primarily for the fibres obtained from their leaves. Sisal hemp, from A. sisalana, is the most valuable hard fibre. Some species of Agave contain a sap that is fermented to produce the intoxicating drinks known as tequila, pulque, and mescal. Many species of yucca are popular as ornamentals; other ornamentals in the agave family include plants of the genera Dasylirion, Nolina, Cordyline, Dracaena , and Sansevieria.
age set Formally organized social group consisting of every male (or female) of comparable age. In societies where the practice traditionally occurs (e.g., the Nuer of the southern Sudan or the Masai of Kenya and Tanzania), a person belongs, either from birth or from a determined age, to a named age set that passes through a series of life stages, or age grades, each of which has a distinctive status or social and political role. See also rite of passage; social status.
Agee Va-je\, James (b. Nov. 27, 1909, Knoxville, Tenn., U.S.—d. May 16, 1955, New York, N.Y.) U.S. poet and novelist. Agee attended Harvard University. In the 1930s and ’40s, film reviews for Time and The Nation made him a pioneer in serious film criticism. His lyrical Let Us Now Praise Famous Men (1941), with photographs by Walker Evans, docu¬ ments the daily lives of poverty-stricken Alabama sharecroppers. After 1948 Agee worked mainly as a screenwriter, notably on The African Queen (1951) and The Night of the Hunter (1955). He is best known for his autobiographical novel A Death in the Family (1957, Pulitzer Prize).
Agenais \azh-'ne, a-zho-'na\ or Agenois \a-zhe-'nwa\ Historical region, southwestern France. In ancient Gaul, Agenais was the country of the Nitiobriges, then a Gallo-Roman civitas, whose limits became those of the diocese of Agen. It was acquired by the dukes of Aquitaine in 1036. When Eleanor of Aquitaine married the future Henry II of England in 1152, Agenais became the possession of the English kings. It alternated between French and British rule until it was reunited to the French crown in 1615.