Clovis complex Widely distributed prehistoric culture of North America characterized by leaf-shaped flint projectile points with fluted sides. The complex also includes bone tools, hammerstones, scrapers, and unfluted points. It derives its name from the first site examined, in 1932, near Clovis, N.M. Clovis projectile points, dating from c. 10,000 bc, have been found in association with mammoth bones and indicate the existence of a big-game hunting tradition among the earliest settlers of North America. See also Folsom complex.
clown Comic character of mime and pantomime and the circus. The clown developed from the bald-headed, padded buffoons who performed in the farces and mimes of ancient Greece and from the professional comic actors of the Middle Ages. The Italian commedia dell'arte introduced the
Clover (Trifolium)
KEN BRATE-PHOTO RESEARCHERS
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422 I club moss ► cnidarian
harlequin, and the clown’s whiteface makeup was introduced with the 17th-century French character Pierrot. The distinctive clown costume of oversized shoes, hat, and giant ruff around the neck was established by the popular German clown character Pickelherring. The first circus clown, Joseph Grimaldi, appeared as “Joey” in England (1805) and specialized in pantomime, pratfalls, and slapstick. Famous 20th-century clowns included the Swiss pantomimist Grock (Adrian Wettach), the U.S. circus star Emmett Kelly, and the longtime star of the Moscow circus, Oleg Popov.
club moss Any of about 200 species of primitive vascular plants that constitute the genus Lycopodium (order Lycopodiales), mainly native to tropical mountains but also common in northern forests of both hemi¬ spheres. They are evergreen plants with needlelike leaves and, often, cone¬ like clusters of small leaves (strobili; see cone), each with a kidney-shaped spore capsule at its base. Representative species include running pine, or stag’s horn moss (L. clavatum), ground cedar (L. complanatum ‘flabel- liforme’), shining club moss (L. lucidulum), fir club moss (L. selago ), ground pine (L. obscurum), and alpine club moss (L. alpinum).
Cluj-Napoca Vkliizh-'na-po-kaV German Klausenburg Hungarian Kolozsvar \'ko-lozh-,var\ City (pop., 2002: 702,755), northwestern Romania. Located in the Some§ul Mic River valley on the site of an ancient town, Cluj took shape in the 12th century, became a thriving com¬ mercial and cultural centre, and in 1405 was declared a free town. It became the capital of Transylvania in the 16th century. In 1920 Transyl¬ vania was incorporated into Romania. In the mid-1970s the city was joined with neighbouring Napoca. It is home to a university; its institute of speleology (the study of caves) was the first in the world.
Cluny Monastery founded in 910 by William the Pious, duke of Aquita¬ ine. Established as a pious donation for the cure of the souls of the duke and his wife and family, the monastery at Cluny came to offer a more austere reading of the Benedictine Rule. It was dedicated to the apostles St. Peter and St. Paul, and in practice it came under the protection of the pope. William also established the independence of the monastery from all temporal rulers, religious or secular, and allowed the monks to elect the abbot. These liberties enabled the community to develop its empha¬ sis on the liturgy and prayers for the dead, which inspired a reputation for holiness and attracted numerous benefactors. Cluniac monks were sent to reform monasteries throughout Europe and created a great web of related communities. Cluny’s influence on the church in the 11th—12th century has been widely recognized, and its abbots were greatly esteemed. Its predominance was eroded by the rise of the Cistercian order, and in the later Middle Ages the monastery declined. It was suppressed during the French Revolution and closed in 1790. Its Romanesque Basilica of St. Peter and St. Paul (largely demolished in the 19th century) was the world’s largest church until the erection of Saint Peter's Basilica.
Clurman, Harold (Edgar) (b. Sept. 18, 1901, New York, N.Y., U.S.—d. Sept. 9, 1980, New York City) U.S. director and drama critic. He was an actor from 1924 and was a founding member of the experi¬ mental Group Theatre. He directed a wide range of Broadway plays, including Awake and Sing! (1935), Member of the Wedding (1950), Touch of the Poet (1957), and Incident at Vichy (1965), and he wrote drama reviews for The New Republic (1949-53) and The Nation (1953-80).
cluster of galaxies Gravitationally bound grouping of galaxies, num¬ bering from the hundreds to the tens of thousands. Large clusters of gal¬ axies often exhibit extensive X-ray emission from intergalactic gas heated to tens of millions of degrees. Also, interactions of galaxies with each other and with the intracluster gas may deplete galaxies of their own interstellar gas. The Milky Way Galaxy belongs to the Local Group, which lies on the outskirts of the Virgo Cluster.
clutch Device for quickly and easily connecting or disconnecting a pair of rotatable coaxial shafts. Clutches are usually placed between the driv¬ ing motor and the input shaft to a machine and provide a convenient means for starting and stopping the machine and permitting the driving motor or engine to be started in an unloaded state (as in an automobile). Mechani¬ cal clutches provide either a positive (no-slip) or a friction-dependent drive; centrifugal clutches provide automatic engagement. An overrun¬ ning clutch transmits torque in one direction only and permits the driven shaft of a machine to freewheel (continue rotating after the driver stops); on bicycles, such clutches permit the rider to coast without moving the pedals.
Clutha River Vklti-thoN River, New Zealand. The longest river in South Island, it rises in the Southern Alps and flows southeast 200 mi (320 km) to the sea. Its valley supports sheep, beef, grain, and fruit farming in the upper reaches and vegetable and dairy farming in the delta. The large Roxburgh hydroelectric station is located 45 mi (72 km) upstream.
Clyde, River River, southern Scotland. Scotland’s most important river, it flows about 100 mi (160 km) from the Southern Uplands to the Atlan¬ tic Ocean. The upper Clyde is a clear fishing stream flowing north, but at Biggar it changes course and winds northwest to the Falls of Clyde. Beyond the falls, the widening Vale of Clyde, famous for the breeding of Clydesdale horses, is intensively cultivated. The Clydeside shipyards bor¬ der the river for 20 mi (32 km) below Glasgow. At Dumbarton it reaches its estuary, the Firth of Clyde, which extends about 65 mi (105 km).
Clydesdale \ , klldz-,dal\ Breed of heavy draft horse that originated in Lanarkshire, Scotland, near the River Clyde. Though introduced to North America c. 1842, the Clydesdale never became a popular draft horse there. They average 17-18 hands (68-72 in., or 173-183 cm) in height and 2,000 lbs (900 kg) in weight. Their coloration is usually bay, dark brown, or black, with prominent white markings. They are noted for their high leg action while walking or trotting. The breed is characterized by feather (long hair) on the legs, an attractive head, and well-formed legs and feet.
cnidarian \nl-'dar-e-3n\ or coelenterate \si-'len-t9-,rat\ Any of about 9,000 species of mostly marine aquatic invertebrates, constituting the phylum Cnidaria (or Coelenterata), that are unique in possessing spe¬ cialized stinging cells (cnidocytes) borne on the tentacles. Cnidocytes contain fluid-filled capsules (nematocysts) with a harpoonlike coiled
tentacle mouth
Cnidarian body forms. A cnidarian may display either the sessile polyp form or the free-swimming medusa form; some pass through both forms during their life cycle. Both possess a hollow cavity with a single opening surrounded by tentacles. The polyp has a basal disc by which it attaches to the substrate; the mouth typically faces away from the substrate. In the medusa (jellyfish) form, the tentacles and mouth face downward. The outer cell layer (ectoderm) and inner cell layer (endo- derm) are separated by the jellylike mesoglea. The mouth is also used to expel wastes. Digestion begins within the gastrovascular cavity and is completed by endo- derm cells.