diminishing returns, law of Economic law stating that if one input used in the manufacture of a product is increased while all other inputs
Dik-dik (Madoqua)
JACK CANNON-OSTMAN AGENCY
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548 I Dimitrov ► Dinwiddie
remain fixed, a point will eventually be reached at which the input yields progressively smaller increases in output. For example, a farmer will find that a certain number of farm labourers will yield the maximum output per worker. If that number is exceeded, the output per worker will fall.
Dimitrov Vdi-'me-.trofV Georgi (Mikhailovich) (b. June 18, 1882, Kovachevtsi, Bulg.—d. July 2, 1949, near Moscow, Russia, U.S.S.R.) Bulgarian communist leader. He helped found the Bulgarian Communist Party in 1919. After leading a communist uprising in 1923 that provoked fierce government reprisals, he was forced to live abroad and became head of the central European section of the Comintern in Berlin (1929-33). He won worldwide fame for his defense against Nazi accusations in the Reichs¬ tag fire trial of 1933. He headed the Comintern in Moscow (1935—43), then returned to Bulgaria, where he served as prime minister (1945-49). He effected the communist consolidation of power that formed the Bul¬ garian People’s Republic in 1946.
Dinarchus or Deinarchus \dl-'nar-k9s\ (b. c. 360 bc —d. after 292) Professional speechwriter at Athens. He rose to fame through his speeches against Demosthenes and others accused of misusing the treasury. His work, however, reflects the decline of Attic oratory; his surviving speeches show little creativity, abuse instead of reason, and plagiarism.
cTlndy, Vincent See Vincent d’lNDY
Dinesen Vde-no-sonV Isak orig. Karen Christence Dinesen later Baroness Blixen-Finecke (b. April 17, 1885, Rungsted, Den.—d. Sept. 7, 1962, Rungsted) Danish writer. Dinesen married her cousin, a baron, and they moved to Kenya; Out of Africa (1937; film, 1985), a memoir of her years on their coffee plantation (1914-31), reveals a deep love of Africa and its people. Her characteristic writings took the form of highly polished narratives in the Romantic tradition, set in the past and pervaded with an aura of supematuralism; they incorporate themes of eros and dreams. Her collections include Seven Gothic Tales (1934) and Win¬ ter’s Tales (1942).
Ding Ling Vdig-'ligX or Ting Ling orig. Jiang Wei (b. 1904, Changde, Hunan province, China—d. March 4, 1986, Beijing) Chinese writer. She had written three collections, many of which contained stories centred on young, unconventional Chinese women, before publishing the proletarian-oriented Flood (1931), acclaimed as a model of Socialist Real¬ ism. She later expressed dissatisfaction with the government officials, for which she was censured and imprisoned during the Cultural Revolution; she was eventually reinstated in the party. Her later works include critical essays and fiction, some published in I Myself Am a Woman (1989).
dingo Australian wild dog ( Canis dingo, C. familiaris dingo, or C. lupus dingo), apparently introduced from Asia 3,500^1,000 years ago. It has short, soft fur, a bushy tail, and erect, pointed ears. It is about 4 ft (1.2 m) long, including the 12-in. (30-cm) tail, and stands about 24 in. (60 cm) tall at the shoulder. Its colour varies from yellowish to reddish brown, often with white underparts, paws, and tail tip. Dingoes hunt alone or in small groups. They formerly preyed mostly on kangaroos but now feed mainly on rabbits and sometimes on livestock. They contributed, through competition for resources, to the extermination of the Tasmanian wolf and the Tasmanian devil on the Australian mainland.
Dinka Cattle-herding people of the Nile basin in southern Sudan. They speak an eastern Sudanic language of the Nilo-Saharan family and are closely related to the Nuer. Numbering about four million, they are divided into independent groups of 1,000-30,000 persons. Leadership is provided by priest-chiefs. In recent years they have been involved in civil war. See also Nilot.
dinoflagellate V.dl-no-'fla-jo-lotX Any of numerous one-celled, aquatic organisms that have two dissimilar flagella and characteristics of both plants (algae) and animals (protozoans). Most are microscopic and marine. The group is an important component of phytoplankton in all but the colder seas, and it is an important link in the food chain. Dinoflagel- lates also produce part of the luminescence sometimes seen in the sea.
Under favourable conditions, dinoflagellate populations may reach 60 million organisms per litre of water. Such rapid growths, called blooms, result in the red tides that discolour the sea and poison fish and other marine animals. See also Ceratium.
dinosaur Any of the extinct reptiles that were the dominant land ani¬ mals during most of the Mesozoic Era (248-65 million years ago). The various species appeared at different times, and not all overlapped. The shape of the teeth reveal whether a given dinosaur was a carnivore or herbivore. Dinosaurs are classified as either ornithischians or saurischians, based on pelvic girdle structure. Most had a long tail, which they held straight out, apparently to maintain balance. Most, if not all, were egg layers. Some were probably warm-blooded. Dinosaur fossils have been found on every continent, including Antarctica. Most types of dinosaurs flourished until late in the Cretaceous Period (65 million years ago), then disappeared within the next million years. Two theories for the cause of this mass extinction, following some 140 million years of existence, are that mountain-building cycles altered habitat and changed climate or that an asteroid hit the Earth, resulting in immense dust clouds that blocked sunlight for several years. Birds are thought to be living descendants of the dinosaurs. See also carnosaur; sauropod.
Skeletons of an ornithischian dinosaur (Stegosaurus) and a saurischian dinosaur (Deinonychus). The skeleton of Stegosaurus shows a pelvic arrangement resembling that of birds, with a long ilium and a pubis having a short blade that extends back¬ ward into a long thin process lying below and parallel to the ischium. The pelvic girdle of Deinonychus shows the triangular outline formed by the ischium, pubis, and ilium characteristic of the saurischians.
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Dinosaur National Monument National preserve, northwestern Colorado and northeastern Utah, U.S. It was set aside in 1915 to preserve rich fossil beds that include dinosaur remains. It was enlarged in 1938 and again in 1978 to its present 330 sq mi (855 sq km). It protects the canyons of the Green and Yampa rivers, which contain highly coloured geologic formations.
Dinwiddie \din-'wid-e\, Robert (b. 1693, Germiston, near Glasgow, Scot.—d. July 27, 1770, Clifton, Bristol, Eng.) British colonial adminis¬ trator. He entered government service in 1727 and was appointed surveyor general for the southern part of America (1739-51). As lieutenant gov¬ ernor of Virginia, he sent George Washington in 1753 to prevent the French from controlling the western frontier, an action that helped pre¬ cipitate the French and Indian War. He tried to obtain intercolonial coop¬ eration for the war effort, an issue taken up at the Albany Congress. In 1758 he returned to England.
Dingo ( Canis dingo , C. familiaris dingo, or C. lupus dingo).
G.R. ROBERTS