You are using an outdated browser. Please upgrade your browser to improve your experience and security.
  • lycopene (chemical compound)

    Lycopene, an organic compound belonging to the isoprenoid series and responsible for the red colour of the tomato, the hips and haws of the wild rose, and many other fruits. Lycopene is an isomer of the carotenes, the yellow colouring matter, both having the same molecular formula, C40H56, but

  • Lycoperdaceae (former family of fungi)

    Lycoperdaceae, former family of fungi in the order Agaricales (phylum Basidiomycota, kingdom Fungi), now placed in the family Agaricaceae. Phylogenetic analyses have shown Lycoperdaceae to be a subgroup within Agaricaceae, though the group does not have a defined status in the taxonomic

  • Lycoperdon (fungus genus)

    Agaricales: Agaricaceae: Lycoperdon is a genus of 50 cosmopolitan species of small common puffballs. Calvatia contains about 35 species, including the giant puffball (C. gigantea), which can be as large as 120 cm (4 feet) across.

  • Lycoperdon gemmatum (fungus)

    Lycoperdaceae: L. perlatum (gemmatum) has spotlike scars on the surface and is edible only when young. These fungi are found in the woods or on sawdust in summer and autumn.

  • Lycoperdon perlatum (fungus)

    Lycoperdaceae: L. perlatum (gemmatum) has spotlike scars on the surface and is edible only when young. These fungi are found in the woods or on sawdust in summer and autumn.

  • Lycopersicon esculentum (fruit)

    Tomato, (Solanum lycopersicum), flowering plant of the nightshade family (Solanaceae), cultivated extensively for its edible fruits. Labelled as a vegetable for nutritional purposes, tomatoes are a good source of vitamin C and the phytochemical lycopene. The fruits are commonly eaten raw in salads,

  • Lycopersicon pimpinelli folium (fruit)

    Tomato, (Solanum lycopersicum), flowering plant of the nightshade family (Solanaceae), cultivated extensively for its edible fruits. Labelled as a vegetable for nutritional purposes, tomatoes are a good source of vitamin C and the phytochemical lycopene. The fruits are commonly eaten raw in salads,

  • Lycophidion capense (snake)

    wolf snake: The Cape wolf snake (Lycophidion capense), abundant from Egypt to South Africa, is a small, drab species with a metallic sheen and lives chiefly on lizards. It can grow to lengths of about 50 cm (20 inches). The common wolf snake (Lycodon aulicus) is a small,…

  • Lycophron of Chalcis (Greek poet)

    Lycophron of Chalcis, Greek poet and scholar best known because of the attribution to him of the extant poem Alexandra. Invited to work in the Alexandrian library (c. 285 bc), Lycophron there wrote a treatise on comedy and numerous tragedies, of which only a few fragments survive. The Alexandra is

  • Lycophyta (plant division)

    Lycophyte, (division Lycopodiophyta or Lycophyta), any spore-bearing vascular plant that is one of the club mosses and their allies, living and fossil. Present-day lycophytes are grouped in 6 genera (some botanists divide them into 15 or more): Huperzia, Lycopodiella, and Lycopodium, the club

  • lycophyte (plant division)

    Lycophyte, (division Lycopodiophyta or Lycophyta), any spore-bearing vascular plant that is one of the club mosses and their allies, living and fossil. Present-day lycophytes are grouped in 6 genera (some botanists divide them into 15 or more): Huperzia, Lycopodiella, and Lycopodium, the club

  • Lycopodiaceae (plant)

    Club moss, (family Lycopodiaceae), order of a single family (Lycopodiaceae), comprising some 400 species of seedless vascular plants. The taxonomy of the family has been contentious, with the number of genera varying depending on the source. The plants are mainly native to tropical mountains but

  • Lycopodiales (plant order)

    lycophyte: Annotated classification: Order Lycopodiales (club mosses) Living and extinct plants with primary growth only; homosporous; 4 living genera, mostly tropical: Huperzia (300 species), Lycopodium (40 species), Lycopodiella (40 species), and Phylloglossum (1 species), the latter of which is restricted to Australia and New Zealand; includes the

  • Lycopodiella (plant genus)

    lycophyte: …into 15 or more): Huperzia, Lycopodiella, and Lycopodium, the club mosses or “ground pines”; Selaginella, the spike mosses; the unique tuberous plant Phylloglossum; and Isoetes, the quillworts. There are more than 1,200 species, widely distributed but especially numerous in the tropics. Representative extinct genera are Lepidodendron and Sigillaria, which were…

  • Lycopodiophyta (plant division)

    Lycophyte, (division Lycopodiophyta or Lycophyta), any spore-bearing vascular plant that is one of the club mosses and their allies, living and fossil. Present-day lycophytes are grouped in 6 genera (some botanists divide them into 15 or more): Huperzia, Lycopodiella, and Lycopodium, the club

  • Lycopodites (extinct plant genus)

    lycophyte: Annotated classification: …New Zealand; includes the extinct Lycopodites. Order Selaginellales (spike mosses) Living and extinct plants with primary growth only; heterosporous; the sole living genus is Selaginella, with nearly 800 species, widely distributed around the world; Selaginellites is an extinct genus.

  • Lycopodium (plant genus)

    lycophyte: Lycopodiella, and Lycopodium, the club mosses or “ground pines”; Selaginella, the spike mosses; the unique tuberous plant Phylloglossum; and Isoetes, the quillworts. There are more than 1,200 species, widely distributed but especially numerous in the tropics. Representative extinct genera are Lepidodendron and Sigillaria, which were tree lycophytes,…

  • Lycopodium alpinum (plant)

    club moss: Major genera and species: Alpine club moss (Diphasiastrum alpinum), with yellowish or grayish leaves, is native to cold woods and Alpine mountains in northern North America and Eurasia. Ground cedar (D. digitatum), native to northern North America, produces fanlike branches resembling juniper branchlets.

  • Lycopodium clavatum (plant)

    club moss: Major genera and species: …club moss, also known as running pine or stag’s horn moss (Lycopodium clavatum), has creeping stems to 3 metres (about 10 feet) long and has 10-centimetre- (about 4-inch-) high ascending branches. The scalelike green leaves are set closely together. Running pine is native to open, dry woods and rocky places…

  • Lycopodium digitatum (plant)

    club moss: Major genera and species: Ground cedar (D. digitatum), native to northern North America, produces fanlike branches resembling juniper branchlets.

  • Lycopodium obscurum (plant, Lycopodium obscurum)

    club moss: Major genera and species: Ground pine (Dendrolycopodium obscurum), a 25-cm- (10-inch-) tall plant, has underground-running stems. It is native to moist woods and bog margins in northern North America, to mountain areas farther south, and to eastern Asia.

  • Lycopolis (Egypt)

    Asyū?, capital of Asyū? mu?āfa?ah (governorate) and one of the largest settlements of Upper Egypt. It lies on the west bank of the Nile River, almost midway between Cairo and Aswān. The irrigated Nile River valley is about 12 miles (20 km) wide at that point. Known as Syut in ancient Egypt, the

  • lycopsid (plant)

    Edward Charles Jeffrey: …reclassified all vascular plants into Lycopsida and Pteropsida; while later classifications have refined plant groupings, these two divisions remain as two of the four classes of vascular plants. His work on lycopsids furthered the investigation of the morphology and evolutionary trends in primitive vascular plants. Jeffrey’s The Anatomy of Woody…

  • Lycopsida (plant)

    Edward Charles Jeffrey: …reclassified all vascular plants into Lycopsida and Pteropsida; while later classifications have refined plant groupings, these two divisions remain as two of the four classes of vascular plants. His work on lycopsids furthered the investigation of the morphology and evolutionary trends in primitive vascular plants. Jeffrey’s The Anatomy of Woody…

  • Lycopsis (plant genus)
  • Lycopteridae (fossil fish family)

    osteoglossomorph: Annotated classification: ?Family Lycopteridae Small freshwater fishes resembling hiodontiforms. 4 genera, 6 species. Early Cretaceous of northeastern Asia. Family Notopteridae (knifefishes or featherbacks). Long anal fin confluent with reduced caudal; dorsal fin small or absent. 8 species in 4 genera: Papyrocranus (2 species) and Xenomystus (1

  • Lycosa (spider genus)

    wolf spider: …are mostly of the genus Lycosa, a large group that includes L. tarentula of southern Europe (see tarantula).

  • Lycosidae (arachnid)

    Wolf spider, any member of the spider family Lycosidae (order Araneida), a large and widespread group. They are named for the wolflike habit of chasing and pouncing upon prey. About 125 species occur in North America, about 50 in Europe. Numerous species occur north of the Arctic Circle. Most are

  • Lycra (fibre)

    polyurethane: …synthetic fibre known generically as spandex is composed of at least 85 percent polyurethane by weight. Such fibres are generally used for their highly elastic properties. Trademarked fibres in this group are Lycra, Numa, Spandelle, and Vyrene. Such fibres have, for many textile purposes, largely replaced natural and synthetic rubber…

  • Lyctinae (insect)

    Powderpost beetle, (subfamily Lyctinae), any of approximately 70 species of beetles (insect order Coleoptera) that range in colour from reddish brown to black and in size from 1 to 7 mm (up to 0.3 inch). The larvae bore through seasoned wood, reducing it to a dry powder. They do not enter

  • Lycurgus (Athenian statesman)

    Lycurgus, Athenian statesman and orator noted for his efficient financial administration and vigorous prosecutions of officials charged with corruption. Lycurgus supported Demosthenes’ opposition to Macedonian expansion. During the 12 years (338–326) following the Athenian defeat by Macedonia at

  • Lycurgus (Spartan lawgiver)

    Lycurgus, traditionally, the lawgiver who founded most of the institutions of ancient Sparta. Scholars have been unable to determine conclusively whether Lycurgus was a historical person and, if he did exist, which institutions should be attributed to him. In surviving ancient sources, he is first

  • Lycus (Greek mythology)

    Antiope: …and imprisoned by her uncle Lycus. On the way back from Sicyon, or after escaping from prison, Antiope bore Amphion and Zethus, who were brought up by herdsmen. Later she joined them; they recognized her, and they deposed Lycus and killed his wife, Dirce. According to one story, because of…

  • Lycus (river, Lebanon)

    Al-Kalb River, river, west-central Lebanon, flowing westward and emptying into the Mediterranean Sea north of Beirut. Apart from a small section near the coast the river is seasonal; in summer its only source is a spring at the J?ītā Cave. The river is about 19 miles (30 km) in length. The ravine

  • Lydd (England, United Kingdom)

    Lydd, town (parish), Shepway district, administrative and historic county of Kent, southeastern England. Nearby is the complex shingle (gravel) spit of Dungeness, on the coast of the English Channel. Until the 14th century the town was on an island and was a member of the Cinque Ports, but it now

  • Lydda (Israel)

    Lod, city, central Israel, on the Plain of Sharon southeast of Tel Aviv–Yafo. Of ancient origin, it is mentioned several times in the Bible: in a New Testament account (Acts 9:32), the apostle Peter healed the paralytic at Lod. The city was a well-known centre of Jewish scholars and merchants from

  • Lyde, John Baslington (Australian musician)

    Lobby Loyde, (John Baslington Lyde), Australian rock musician (born May 18, 1951 , Longreach, Queen., Australia —died April 21, 2007, Melbourne, Australia), championed the loud, aggressive musical style that dominated Australian pub rock and influenced such heavy metal bands as AC/DC and the

  • Lydekker’s Line (faunal boundary)

    biogeographic region: Wallacea: …and to the east by Lydekker’s Line (Figure 5), which runs along the border of Australia’s continental shelf (the Sahul Shelf); it includes a mixture of Oriental and Australian fauna. Weber’s Line (Figure 5), which runs west of the Moluccas, represents the area where the two types of fauna are…

  • Lydgate, John (English writer)

    John Lydgate, English poet, known principally for long moralistic and devotional works. In his Testament Lydgate says that while still a boy he became a novice in the Benedictine abbey of Bury St. Edmunds, where he became a priest in 1397. He spent some time in London and Paris; but from 1415 he

  • Lydgate, Tertius (fictional character)

    Tertius Lydgate, fictional character, an ambitious, progressive physician in the novel Middlemarch (1871–72) by George

  • Lydhveldidh ísland

    Iceland, island country located in the North Atlantic Ocean. Lying on the constantly active geologic border between North America and Europe, Iceland is a land of vivid contrasts of climate, geography, and culture. Sparkling glaciers, such as Vatna Glacier (Vatnaj?kull), Europe’s largest, lie

  • Lydia (ancient region, Anatolia)

    Lydia, ancient land of western Anatolia, extending east from the Aegean Sea and occupying the valleys of the Hermus and Cayster rivers. The Lydians were said to be the originators of gold and silver coins. During their brief hegemony over Asia Minor from the middle of the 7th to the middle of the

  • Lydia (work by Valerius Cato)

    Publius Valerius Cato: Lydia, which may have been a collection of amorous poems, was praised by the Neoterian poet Ticida.

  • Lydian language

    Lydian language, one of the ancient Anatolian languages. Documents in Lydian number more than a hundred, including inscriptions on stone and coins and graffiti on various objects. The vast majority were found by American excavators in and around Sardis, the ancient Lydian capital. A few graffiti

  • Lydian mode (music)

    Lydian mode, in music, fifth of the eight medieval church modes. See church

  • Lydian stone (metallurgy)

    Touchstone, black siliceous stone used to ascertain the purity of gold and silver. Assaying by “touch” was one of the earliest methods employed to assess the quality of precious metals. The metal to be assayed is rubbed on the touchstone, adjacent to the rubbing on the touchstone of a sample of a

  • Lydite (metallurgy)

    Touchstone, black siliceous stone used to ascertain the purity of gold and silver. Assaying by “touch” was one of the earliest methods employed to assess the quality of precious metals. The metal to be assayed is rubbed on the touchstone, adjacent to the rubbing on the touchstone of a sample of a

  • Lydon, John (British musician)

    the Sex Pistols: The original members were vocalist Johnny Rotten (byname of John Lydon; b. January 31, 1956, London, England), guitarist Steve Jones (b. May 3, 1955, London), drummer Paul Cook (b. July 20, 1956, London), and bassist Glen Matlock (b. August 27, 1956, London). A later member was bassist Sid Vicious (byname…

  • lye (chemical compound)

    Lye, the alkaline liquor obtained by leaching wood ashes with water, commonly used for washing and in soapmaking; more generally, any strong alkaline solution or solid, such as sodium hydroxide or potassium hydroxide (see sodium;

  • Lye, Len (New Zealand film producer)

    motion-picture technology: Noncellular animation: …1930s with the films of Len Lye, a New Zealander also known for his abstract sculpture. McLaren, too, experimented with a wide range of techniques for animating directly on film; he even created many of his scores by stenciling directly onto the sound track rather than recording in the traditional…

  • Lye, Les (Canadian actor)

    Les Lye, (Leslie Earnest Lye), Canadian television actor (born Nov. 18, 1924, Toronto, Ont.—died July 21, 2009, Ottawa, Ont.), amused audiences as the only regular adult performer on all 143 episodes (1979–90) of the Canadian children’s comedy show You Can’t Do That on Television, on which he

  • Lye, Leslie Earnest (Canadian actor)

    Les Lye, (Leslie Earnest Lye), Canadian television actor (born Nov. 18, 1924, Toronto, Ont.—died July 21, 2009, Ottawa, Ont.), amused audiences as the only regular adult performer on all 143 episodes (1979–90) of the Canadian children’s comedy show You Can’t Do That on Television, on which he

  • Lyell, Charles (Scottish geologist)

    Charles Lyell, Scottish geologist largely responsible for the general acceptance of the view that all features of the Earth’s surface are produced by physical, chemical, and biological processes through long periods of geological time. The concept was called uniformitarianism (initially set forth

  • Lyell, Mount (region, Tasmania, Australia)

    Mount Lyell, mining area, western Tasmania, Australia. The site, discovered in the 1880s, derives its name from a 2,900-ft (880-m) peak in the west coast range, which was named after Charles Lyell, the 19th-century English geologist. First mined for gold and later silver, the area achieved most of

  • Lyell, Sir Charles, Baronet (Scottish geologist)

    Charles Lyell, Scottish geologist largely responsible for the general acceptance of the view that all features of the Earth’s surface are produced by physical, chemical, and biological processes through long periods of geological time. The concept was called uniformitarianism (initially set forth

  • lygaeid bug (insect)

    Lygaeid bug, (family Lygaeidae), any of a group of insects in the true bug order, Heteroptera, that includes many important crop pests. There are between 3,000 and 5,000 species of lygaeid bugs, which vary from brown to brightly patterned with red, white, or black spots and bands. The large

  • Lygaeidae (insect)

    Lygaeid bug, (family Lygaeidae), any of a group of insects in the true bug order, Heteroptera, that includes many important crop pests. There are between 3,000 and 5,000 species of lygaeid bugs, which vary from brown to brightly patterned with red, white, or black spots and bands. The large

  • Lygdamis (Cimmerian king)

    Anatolia: The Cimmerians, Lydia, and Cilicia, c. 700–547 bce: …time the Cimmerian leader was Tugdamme (Lygdamis), who is identified in Greek tradition as the victor over Sardis in 652 and is also said to have attacked Ephesus. A nonaggression pact signed between Ashurbanipal and Tugdamme, if correctly dated after the mid-650s, confirms the Greek data concerning Tugdamme’s involvement in…

  • Lygeum spartum (plant)

    esparto: …gray-green needlegrasses (Stipa tenacissima and Lygeum spartum) in the family Poaceae that are indigenous to southern Spain and northern Africa; the term also denotes the fibre obtained from those grasses. Esparto fibre has great strength and flexibility, and both species have for centuries been used for making ropes, sandals, baskets,…

  • Lygodium (plant)

    fern: Distribution and abundance: …the giant polypody (Microsorum scolopendrium), climbing ferns (Lygodium japonicum and L. microphyllum), green cliff brake (Cheilanthes viridis), silver fern (Pityrogramma calomelanos), Japanese holly fern (Cyrtomium falcatum), rosy maidenhair (Adiantum hispidulum), Cretan brake (Pteris cretica), and ladder brake (P. vittata). Two Old World species (Cyclosorus dentatus and Macrothelypteris torresiana) were introduced…

  • Lygosoma (reptile)

    skink: Slender skinks (Lygosoma and many other genera), snake-eyed skinks (Ablepharus and Cryptoblepharus), and skinks of the genus Plestiodon (formerly Eumeces) are also common. Slender skinks are found throughout the Old World tropics, with a few species in the New World. They have thick tails and…

  • Lygus mendax (insect)

    plant bug: The apple red bug (Lygus mendax) is red and black and about 6 mm long. The front part of the thorax and the wings are usually red, and the posterior thorax and the inner edge of the wings are usually black. It is an important apple…

  • Lygus pratensis (insect)

    plant bug: The tarnished plant bug (Lygus pratensis), a well-known pest in North America, feeds on many plants, ranging from trees to grasses and cereals. It is about 6 mm long and is dark in colour—with yellow, black, and red markings. The use of insecticides and the elimination…

  • lying (deception)

    Lying, any communicative act that aims to cause receivers of the communication to adopt, or persist in, a false belief. However, because of its generality, this definition invites questions about its key terms. There is no universally accepted definition of lying. Rather, there exists a spectrum of

  • Lying Days, The (work by Gordimer)

    Nadine Gordimer: In 1953 a novel, The Lying Days, was published. Both exhibit the clear, controlled, and unsentimental style that became her hallmark. Her stories concern the devastating effects of apartheid on the lives of South Africans—the constant tension between personal isolation and the commitment to social justice, the numbness caused…

  • Lying Lover, The (work by Steele)

    Sir Richard Steele: Early life and works.: …with his only stage failure, The Lying Lover, which ran for only six nights, being, as Steele said, “damned for its piety.” Sententious and ill-constructed, with much moralizing, it is nevertheless of some historical importance as one of the first sentimental comedies.

  • Lying-In Hospital (hospital, Dublin, Ireland)

    Dublin: City layout: …Street, Bartholomew Mosse constructed his Rotunda Hospital, the “Lying-In,” which remains a maternity hospital to this day. The rotunda itself is now the historic Gate Theatre. Behind the hospital is Parnell (formerly Rutland) Square, laid out in 1750, with many of its original Georgian houses still intact. One of these,…

  • Lykke-Per (work by Pontoppidan)

    Henrik Pontoppidan: …work, the novel Lykke-Per (1898–1904; Lucky Per, originally published in eight volumes), in which the chief character bears some resemblance to Pontoppidan himself. He is a clergyman’s son who rebels against the puritanical atmosphere of his home and seeks his fortune in the capital as an engineer. The novel’s theme…

  • Lykostomo (valley, Greece)

    Vale of Tempe, narrow valley between the southern Olympus (Modern Greek: ólympos) and northern Ossa (Kíssavos or óssa) massifs of northeastern Thessaly (Thessalía), Greece. The valley is lined by cliffs that rise to 1,650 feet (500 m) on the south; in places it is only 90 to 165 feet (27 to 50 m)

  • Lyle, Marcenia (American athlete)

    Toni Stone, American baseball player who, as a member of the Negro American League’s Indianapolis Clowns, was the first woman to ever play professional baseball as a regular on a big-league team. Stone’s love for the game began when she was a child. At age 10 she played in a league sponsored by a

  • Lyly, John (English writer)

    John Lyly, author considered to be the first English prose stylist to leave an enduring impression upon the language. As a playwright he also contributed to the development of prose dialogue in English comedy. Lyly was educated at Magdalen College, Oxford, and went to London about 1576. There he

  • Lyman series (physics)

    ionosphere and magnetosphere: Photon absorption: (The Lyman series is a related sequence of wavelengths that describe electromagnetic energy given off by energized atoms in the ultraviolet region.) Lyman α emissions are weakly absorbed by the major components of the atmosphere—O, O2, and N2—but they are absorbed readily by NO and have…

  • Lymantria dispar (insect)

    Gypsy moth, (Lymantria dispar), lepidopteran that is a serious pest of both deciduous and evergreen trees. The European strain was accidentally introduced into eastern North America about 1869, and by 1889 it had become a serious pest of deciduous forests and fruit trees. By the end of the 20th

  • Lymantriidae (insect)

    Tussock moth, (family Lymantriidae), any of a group of moths (order Lepidoptera), the common name for which is derived from the hair tufts, or tussocks, found on most larval forms. The family, which occurs in both Eurasia and the New World, includes several species that are destructive to shade

  • Lyme disease (pathology)

    Lyme disease, tick-borne bacterial disease that was first conclusively identified in 1975 and is named for the town in Connecticut, U.S., in which it was first observed. The disease has been identified in every region of the United States and in Europe, Asia, Africa, and Australia. Lyme disease is

  • lyme grass (plant)

    Wild rye, (genus Elymus), genus of some 50–100 species of perennial grasses in the family Poaceae, native to temperate and cool parts of the Northern Hemisphere. Wild ryes are named for their similarity to true rye (Secale cereale) and are generally good forage plants. Wild rye plants are typically

  • Lyme Regis (England, United Kingdom)

    Lyme Regis, town (parish), West Dorset district, administrative and historic county of Dorset, southwestern England. It is built on a steep-sided hill above a small harbour and shingle (gravel) beach on Lyme Bay of the English Channel. The harbour is flanked by a jetty to the east and a massive

  • Lymeswold (cheese)

    dairy product: Varieties of cheese: The resulting “Blue-Brie” has a bloomy white edible rind, while its interior is marbled with blue Penicillium roqueforti mold. The cheese is marketed under various names such as Bavarian Blue, Cambazola, Lymeswold, and Saga Blue. Another combination cheese is Norwegian Jarlsberg. This cheese results from a marriage…

  • Lymexylidae (insect)

    coleopteran: Annotated classification: Family Lymexylidae (ship-timber beetles) About 60 species; worldwide distribution; damage wood; examples Lymexylon, Hylecoetus. Superfamily Scarabaeoidea (Lamellicornia) Antennae 10-segmented with last 3 to 7 segments forming a lamellate (platelike) club; body stout; larvae without cerci (appendages at end of abdomen); males

  • Lymexyloidea (insect superfamily)

    coleopteran: Annotated classification: Superfamily Lymexyloidea Antennae short, more or less serrate; abdomen with 6 or 7 visible segments. Family Lymexylidae (ship-timber beetles) About 60 species; worldwide distribution; damage wood; examples Lymexylon, Hylecoetus. Superfamily

  • Lymnaeacea (gastropod superfamily)

    gastropod: Classification: Superfamily Lymnaeacea Small to large, spiral-shelled snails of ponds, lakes, and rivers; 1 limpet group (Lancidae) and larger typical group (Lymnaeidae). Superfamily Ancylacea Limpets (Ancylidae), ramshorns (Planorbidae), and

  • Lymnaeidae (gastropod family)

    gastropod: Classification: …and larger typical group (Lymnaeidae). Superfamily Ancylacea Limpets (Ancylidae), ramshorns (Planorbidae), and pond snails (Physidae); all restricted to freshwater habitats. Superorder Stylommatophora

  • Lymon, Frankie, and the Teenagers (American music group)

    Frankie Lymon and the Teenagers, American vocal group popular in the mid-1950s, prime exponents of the doo-wop vocal style. The members were Frankie Lymon (b. Sept. 30, 1942, New York, N.Y., U.S.—d. Feb. 28, 1968, New York), Herman Santiago (b. Feb. 18, 1941, New York), Jimmy Merchant (b. Feb. 10,

  • lymph (physiology)

    Lymph, pale fluid that bathes the tissues of an organism, maintaining fluid balance, and removes bacteria from tissues; it enters the blood system by way of lymphatic channels and ducts. Prominent among the constituents of lymph are lymphocytes and macrophages, the primary cells of the immune

  • lymph gland (anatomy)

    Lymph node, any of the small, bean-shaped masses of lymphoid tissue enclosed by a capsule of connective tissue that occur in association with the lymphatic vessels. As part of the lymphatic system, lymph nodes serve as filters for the blood, providing specialized tissues where foreign antigens can

  • lymph heart (animal anatomy)

    lymph: …mammals have muscular swellings called lymph hearts at intervals of the lymphatic vessels to pump lymph through them.

  • lymph node (anatomy)

    Lymph node, any of the small, bean-shaped masses of lymphoid tissue enclosed by a capsule of connective tissue that occur in association with the lymphatic vessels. As part of the lymphatic system, lymph nodes serve as filters for the blood, providing specialized tissues where foreign antigens can

  • lymph nodule (anatomy)

    Lymph nodule, small, localized collection of lymphoid tissue, usually located in the loose connective tissue beneath wet epithelial (covering or lining) membranes, as in the digestive system, respiratory system, and urinary bladder. Lymph nodules form in regions of frequent exposure to

  • lymph vessel (anatomy)

    prenatal development: Lymphatic vessels: The lymph vessels develop independently in close association with the veins. Linkages produce the thoracic duct, which is the main drainage return for lymph. Masses of lymphocytes accumulate about lymphatic vessels and organize as lymph nodes. The spleen has somewhat similar tissue, but its channels are…

  • Lympha (Roman mythology)

    nymph: …streams and water goddesses (called Lymphae) with whom the Greek nymphs tended to become identified.

  • lymphangitis (pathology)

    Lymphangitis, bacterial infection of the lymphatic vessels. The condition is caused by streptococcus or staphylococcus organisms that have entered the body through a skin wound. The inflamed lymph vessels are visible as red streaks under the skin that extend from the site of infection to the groin

  • lymphatic capillary (anatomy)

    renal system: Lymphatic network: Lymphatic capillaries form a network just inside the renal capsule and another, deeper network between and around the renal blood vessels. Few lymphatic capillaries appear in the actual renal substance, and those present are evidently associated with the connective tissue framework, while the glomeruli contain…

  • lymphatic leukemia (pathology)

    blood disease: Leukemia: …leukemia: myelogenous, or granulocytic, and lymphocytic. These terms refer to the types of cell that are involved. Each of these types is further subdivided into acute and chronic categories, referring to the duration of the untreated disease. Before the advent of modern chemotherapy, patients with acute leukemia usually died within…

  • lymphatic system (anatomy)

    Lymphatic system, a subsystem of the circulatory system in the vertebrate body that consists of a complex network of vessels, tissues, and organs. The lymphatic system helps maintain fluid balance in the body by collecting excess fluid and particulate matter from tissues and depositing them in the

  • lymphatic system diseases

    lymphedema: …which poor function of the lymphatic system allows fluid to build up in the tissues. Lymphedema is traditionally classified into two forms: primary, which is genetic, and secondary, which arises from an outside cause. However, each of those forms can have aspects of the other; for example, some cancer patients…

  • lymphatic vessel (anatomy)

    prenatal development: Lymphatic vessels: The lymph vessels develop independently in close association with the veins. Linkages produce the thoracic duct, which is the main drainage return for lymph. Masses of lymphocytes accumulate about lymphatic vessels and organize as lymph nodes. The spleen has somewhat similar tissue, but its channels are…

  • lymphedema (pathology)

    Lymphedema, an abnormal condition in which poor function of the lymphatic system allows fluid to build up in the tissues. Lymphedema is traditionally classified into two forms: primary, which is genetic, and secondary, which arises from an outside cause. However, each of those forms can have

  • lymphedema praecox (pathology)

    lymphedema: …from birth to age two; lymphedema praecox (also called Miege disease), which occurs usually around puberty; and lymphedema tarda, which occurs after age 35. The most common cause of secondary lymphedema is filariasis, in which the parasitic nematode Wuchereria bancrofti takes up residence in the lymphatic system and causes an…

  • lymphoblast (cell)

    Lymphoblast, immature white blood cell that gives rise to a type of immune cell known as a lymphocyte. The nucleus contains moderately fine chromatin (readily stainable nuclear material) and has a well-defined nuclear membrane. There are one or two nucleoli, and the cytoplasm is small or moderate

  • Lymphocryptovirus (virus genus)

    herpesvirus: …is composed of the genera Lymphocryptovirus, Macavirus, Percavirus, and Rhadinovirus, include Epstein-Barr virus, baboon, orangutan, and gorilla herpesviruses, and herpesvirus saimiri. The replication rate of gammaherpesviruses is variable.

Check out Britannica's new site for parents!
Subscribe Today!
色色影院-色色影院app下载