spike moss, (family Selaginellaceae), family of more than 700 species of mossy or fernlike seedless vascular plants of the order Selaginellales. The family consists of a single genus, Selaginella. They are widely distributed in all parts of the world, particularly in the tropics. Many are forest

lycophyte: Annotated classification: Order Selaginellales (spike mosses) Living and extinct plants with primary growth only; heterosporous; the sole living genus is Selaginella, with more than 700 species, widely distributed around the world; Selaginellites is an extinct genus. Order Isoetales

lycophyte: Annotated classification: …widely distributed around the world; Selaginellites is an extinct genus. Order Isoetales (quillworts) Living and extinct plants with secondary growth; heterosporous, with endosporic gametophytes; Isoetites is an extinct genus; for many years the species of

Selayar, largest of an island group off the southwestern tip of Celebes (Sulawesi), which is administered from Makassar as part of South Sulawesi propinsi (province), Indonesia. The other islands are Pasi, Bahuluang, Pulasi, and Tambulongang. All the islands are mountainous, but fertile lowlands

Sigfrid Siwertz: …for the novel Selambs (1920; Downstream) and for his short stories.

Selandian Stage, division of Paleocene rocks, representing all rocks deposited worldwide during the Selandian Age (61.6 million to 59.2 million years ago) of the Paleogene Period (66 million to 23 million years ago). The Selandian Stage is named for marine strata in the Seeland region of Denmark.

Selangor, region of western West Malaysia (Malaya), occupying part of a coastal alluvial plain on the Strait of Malacca. In 1974, a 94-square-mile (243-square-kilometre) portion of Selangor, centring on Kuala Lumpur, was designated a wilayapersekutuan (federal territory). Selangor’s history and

Selangor Civil War, (1867–73), series of conflicts initially between Malay chiefs but later involving Chinese secret societies for control of tin-rich districts in Selangor. Following the disputed recognition of Abdul Samad as sultan in 1860, Malay chiefs gradually became polarized into two

Tanimbar Islands: …vegetation along the shore, and Selaru to the south of Yamdena, rather flat and with much grassland. The group, the total area of which is some 2,100 square miles (5,439 square km), lies outside the zone of historic volcanic activity. Because there are few rivers, there is a lack of…

hummingbird: The broad-tailed hummingbird (S. platycercus) breeds in the western United States and Central America and the Allen’s hummingbird breeds in the coastal regions of California.

hummingbird: …hummingbird is the rufous (Selasphorus rufus), which breeds from southeastern Alaska to northern California. The broad-tailed hummingbird (S. platycercus) breeds in the western United States and Central America and the Allen’s hummingbird breeds in the coastal regions of California.

hummingbird: …and Central America and the Allen’s hummingbird breeds in the coastal regions of California.

Haile Selassie I was the emperor of Ethiopia from 1930 to 1974 who sought to modernize his country and who steered it into the mainstream of post-World War II African politics. He brought Ethiopia into the League of Nations and the United Nations and made Addis Ababa the major centre for the

Sahle Selassie was the ruler (1813–47) of the kingdom of Shewa (Shoa), Ethiopia. He was the grandfather of Emperor Menilek II (reigned 1889–1913) and the great-grandfather of Emperor Haile Selassie I. His name means “Clemency of the Trinity.” A member of the Amhara royal family, Sahle Selassie

Makassar Strait, narrow passage of the west-central Pacific Ocean, Indonesia. Extending 500 miles (800 km) northeast–southwest from the Celebes Sea to the Java Sea, the strait passes between Borneo on the west and Celebes on the east and is 80 to 230 miles (130 to 370 km) wide. It is a deep

Sunda Strait, channel, 16–70 miles (26–110 km) wide, between the islands of Java (east) and Sumatra, that links the Java Sea (Pacific Ocean) with the Indian Ocean (south). There are several volcanic islands within the strait, the most famous of which is Krakatoa, which erupted on August 27, 1883,

Selayar, largest of an island group off the southwestern tip of Celebes (Sulawesi), which is administered from Makassar as part of South Sulawesi propinsi (province), Indonesia. The other islands are Pasi, Bahuluang, Pulasi, and Tambulongang. All the islands are mountainous, but fertile lowlands

Atle Selberg: …the study of sieves—particularly the Selberg sieve—which are generalizations of Eratosthenes’ method for locating prime numbers. In 1949 he gave an elementary (but by no means simple) proof of the prime number theorem, a result that had theretofore required advanced theorems from analysis. Many of Selberg’s papers were published in…

Atle Selberg was a Norwegian-born American mathematician who was awarded the Fields Medal in 1950 for his work in number theory. In 1986 he shared (with Samuel Eilenberg) the Wolf Prize. Selberg attended the University of Oslo (Ph.D., 1943) and remained there as a research fellow until 1947. He

Roundell Palmer, 1st earl of Selborne was a British lord high chancellor (1872–74, 1880–85) who almost singlehandedly drafted a comprehensive judicial-reform measure, the Supreme Court of Judicature Act of 1873. Under this statute, the complex duality of English court systems—common law and

Roundell Palmer, 1st earl of Selborne was a British lord high chancellor (1872–74, 1880–85) who almost singlehandedly drafted a comprehensive judicial-reform measure, the Supreme Court of Judicature Act of 1873. Under this statute, the complex duality of English court systems—common law and

William Waldegrave Palmer, 2nd earl of Selborne was the first lord of the Admiralty (1900–05) in Great Britain and high commissioner for South Africa (1905–10). He helped initiate the rebuilding of the fleet into a force strong enough to oppose a greatly expanded German navy in World War I and

William Waldegrave Palmer, 2nd earl of Selborne was the first lord of the Admiralty (1900–05) in Great Britain and high commissioner for South Africa (1905–10). He helped initiate the rebuilding of the fleet into a force strong enough to oppose a greatly expanded German navy in World War I and

Otto Perl: …author and cofounder of the Selbsthilfebund der Körperbehinderten (Self-Help Alliance of the Physically Handicapped, or Otto Perl Alliance; 1919–31), the first emancipatory self-help organization representing the interests of the physically disabled in Germany.

Selby, town (parish) and district, administrative county of North Yorkshire, historic county of Yorkshire, northern England, just south of York. It lies mainly in the floodplain of the Rivers Aire and Ouse. The district includes pre-Norman settlements along the right bank of the River Ouse, the

Selby: district, administrative county of North Yorkshire, historic county of Yorkshire, northern England, just south of York. It lies mainly in the floodplain of the Rivers Aire and Ouse.

Kid McCoy was an American professional boxer whose trickery and cruelty in the ring made him an infamous figure in boxing history. (Read Gene Tunney’s 1929 Britannica essay on boxing.) A former sparring partner of welterweight champion Tommy Ryan, McCoy pleaded with Ryan for a title match as a

Alexander Selkirk was a Scottish sailor who was the prototype of the marooned traveler in Daniel Defoe’s novel Robinson Crusoe (1719). The son of a shoemaker, Selkirk ran away to sea in 1695; he joined a band of buccaneers in the Pacific and by 1703 was sailing master of a galley on a privateering

patent troll: American inventor George Selden is frequently cited as an early example of a patent troll. From 1903 to 1911, Selden, who never built a car, used his patent on the automobile to collect royalties from other automobile companies. In information technology, a series of rulings in American…

John Selden was a legal antiquarian, Orientalist, and politician who was the leading figure in the Antiquarian Society, the centre of English historical research during the 17th century. Called to the bar in 1612, Selden practiced as a conveyancer, rarely appearing in court. His first major book,

George Seldes was an American journalist. He became a reporter in 1909. From 1918 to 1928 he worked for the Chicago Tribune; he quit to pursue independent journalism. In You Can’t Print That (1928) he criticized censorship and strictures on journalists, a continuing theme in his career. He reported

angiography: …early 1950s by Swedish cardiologist Sven-Ivar Seldinger.

Selebi-Phikwe, mining town, eastern Botswana. Selebi-Phikwe is located 62 miles (100 km) southeast of Francistown. Situated in the centre of a large copper-nickel mine and a smelter complex, it was one of the fastest-growing towns in the country in the late 20th century, although its growth has

Selebi-Phikwe, mining town, eastern Botswana. Selebi-Phikwe is located 62 miles (100 km) southeast of Francistown. Situated in the centre of a large copper-nickel mine and a smelter complex, it was one of the fastest-growing towns in the country in the late 20th century, although its growth has

Rock criticism: such as Q, Mojo, and Select. These glossy monthlies took a markedly different approach to rock journalism, replacing confrontational interviews and expansive think pieces with star profiles and short, consumer-oriented record reviews. British readers who craved writing with reach and edge were forced to look to specialist magazines such as…

Robert Burns: After Edinburgh: …first five volumes of Thomson’s A Select Collection of Original Scotish Airs for the Voice (1793–1818) contain the bulk of Burns’s songs. Burns spent the latter part of his life in assiduously collecting and writing songs to provide words for traditional Scottish airs. He regarded his work as service to…

The Supreme Court of the United States is the final court of appeal and final expositor of the Constitution of the United States, and, as such, it makes decisions that have far-reaching consequences on issues ranging from freedom of speech to commerce. The table provides a list of select milestone

Gary Snyder: In addition, The Selected Letters of Allen Ginsberg and Gary Snyder and Distant Neighbors: The Selected Letters of Wendell Berry and Gary Snyder were published in 2009 and 2014, respectively.

Mary Wollstonecraft Shelley: Death and legacy: Feldman and Diana Scott-Kilvert, and Selected Letters of Mary Wollstonecraft Shelley (1995), edited by Betty T. Bennett. Among the many tributes to her is the Mary Wollstonecraft Shelley scholarship, an annual award given to horror writers who identify as women.

Ralph Ellison: Juneteenth and other posthumous publications: The Selected Letters of Ralph Ellison was released in 2019.

Rebecca West: Selected Letters of Rebecca West, edited by Bonnie Kime Scott, was published in 2000. The critic and author Anthony West was the son of Dame Rebecca and the English novelist H.G. Wells.

Willa Cather: …and 566 were collected in The Selected Letters of Willa Cather (2013).

William Styron: …to My Father (2009) and Selected Letters of William Styron (2012).

Nikolay Gogol: Creative decline of Nikolay Gogol: …iz perepiski s druzyami (1847; Selected Passages from Correspondence with My Friends), a collection of 32 discourses eulogizing not only the conservative official church but also the very powers that he had so mercilessly condemned only a few years before. It is no wonder that the book was fiercely attacked…

Derek Walcott: The verse in Selected Poems (1964), The Castaway (1965), and The Gulf (1969) is similarly lush in style and incantatory in mood as Walcott expresses his feelings of personal isolation, caught between his European cultural orientation and the black folk cultures of his native Caribbean. Another Life (1973)…

James Tate: His Selected Poems (1991), which includes poetry from nine of his previous volumes, won the Pulitzer Prize, and Worshipful Company of Fletchers (1994) received the National Book Award. In 1995 he won the Academy of American Poets’ Wallace Stevens Award. Tate’s later collections include Memoir of…

Gwendolyn Brooks: In the Mecca: Brooks published Selected Poems in 1963, followed in 1968 by In the Mecca, half of which is a long narrative poem about people in the Mecca, a vast, fortresslike apartment building erected on the South Side of Chicago in 1891, which had long since deteriorated into a…

Conrad Aiken: …his poetry is contained in Selected Poems (1929), which won the Pulitzer Prize for poetry in 1930, and Collected Poems (1953), including a long sequence “Preludes to Definition,” which some critics consider his masterwork, and the often anthologized “Morning Song of Senlin.” Aiken served as the poetry consultant to the…

Stanley Kunitz: …some 30 new poems in Selected Poems 1928–1958 (1958), which won the Pulitzer Prize in 1959.

Rosario Castellanos: , The Selected Poems, by Magda Bogin), a polemical allusion to a well-known verse by Spanish Romantic poet Gustavo Adolfo Bécquer, in which he tells his beloved that she is poetry.

Shirley Ann Grau: … (1973), Nine Women (1985), and Selected Stories (2003).

Roman Jakobson: Jakobson’s Selected Writings, 6 vol. (1962–71), are concerned with phonological studies, the word, language, poetry, grammar, Slavic epic studies, ties, and traditions. His The Sound Shape of Language, with Linda R. Waugh, was published in 1979.

selection, in biology, the preferential survival and reproduction or preferential elimination of individuals with certain genotypes (genetic compositions), by means of natural or artificial controlling factors. The theory of evolution by natural selection was proposed by Charles Darwin and Alfred

selection coefficient, in genetics, a measure of the relative reduction in the contribution that a particular genotype (genetic composition) makes to the gametes (sex cells) as compared with another genotype in the population. It expresses the relative advantage or disadvantage of specific traits

selection rule, in quantum mechanics, any of a set of restrictions governing the likelihood that a physical system will change from one state to another or will be unable to make such a transition. Selection rules, accordingly, may specify “allowed transitions,” those that have a high probability

GPS: Triangulation: …2000, a feature known as selective availability (S/A) intentionally degraded the civilian signal’s accuracy; S/A was terminated in part because of safety concerns related to the increasing use of GPS by civilian marine vessels and aircraft. Unaugmented civilian GPS now gives an error variance, for horizontal distances, of 30 metres…

selective breeding, the practice of mating individuals with desired traits as a means of increasing the frequency of those traits in a population. In selective breeding, the breeder attempts to isolate and propagate the genotypes (genetic constitutions) that are responsible for an organism’s

library: Current-awareness service: …have adopted a practice of selective dissemination of information (sometimes referred to as SDI), whereby librarians conduct regular searches of databases to find references to new articles or other materials that fit a particular patron’s interest profile and forward the results of these searches to the patron.

antiestrogen: Selective estrogen-receptor modulators (SERMs), such as tamoxifen and raloxifene, produce estrogen action in those tissues (e.g., bone, brain, liver) where that action is beneficial and have either no effect or an antagonistic effect in tissues, such as the breast and uterus, where estrogen action may…

selective feeding, food procurement in which the animal exercises choice over the type of food being taken, as opposed to filter feeding, in which food is taken randomly. Selective feeders may be broadly divided into herbivores and carnivores, which take plant and animal food, respectively, and

collective action problem: The challenges of common goods: …groups by the use of selective incentives. These selective incentives might be extra rewards contingent upon taking part in the action or penalties imposed on those who do not. However, in order for positive selective incentives to work, individuals who take part in collective action must be identified; and for…

3D printing: A related process is called selective laser sintering (SLS); here the nozzle head and liquid binder are replaced by precisely guided lasers that heat the powder so that it sinters, or partially melts and fuses, in the desired areas. Typically, SLS works with either plastic powder or a combined metal-binder…

assortative mating, in human genetics, a form of nonrandom mating in which pair bonds are established on the basis of phenotype (observable characteristics). For example, a person may choose a mate according to religious, cultural, or ethnic preferences, professional interests, or physical traits.

antidepressant: SSRIs were introduced in the 1980s, and shortly thereafter they became some of the most commonly used antidepressants, primarily because they have fewer side effects than tricyclics or MAOIs. SSRIs include fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft). SSRIs are also used in the treatment…

conscription: …form—even during total war—has been selective service.

Enoch Herbert Crowder: …officer and administrator of the Selective Service Act in World War I.

Selective Service Acts, U.S. federal laws that instituted conscription, or compulsory military service. Conscription was first implemented in the United States during the American Civil War (1861–65). However, it was common for wealthy men to hire substitutes to fulfill their service obligation. In

Selective Service System, independent federal agency in the United States created to administer the military draft nationwide to conscript troops quickly in the event of war. Founded in 1940, the Selective Service System oversees the military registration of all draft-age males (that is, age 18

sleep: Sleep deprivation: Studies of selective sleep deprivation have confirmed the attribution of need for both stage 3 NREM and REM sleep, because an increasing number of experimental arousals are required each night to suppress both stage 3 and REM sleep on successive nights of deprivation and because both show…

misophonia, disorder marked by low tolerance of and unusually strong negative physiological, emotional, and behavioral reactions to specific sounds or to stimuli related to such sounds. In some persons with misophonia, the triggering stimulus may activate the fight-or-flight response, resulting in

strike: …devising new tactics that include selective strikes, which target the sites that will cause the company the greatest economic harm, and rolling strikes, which target a succession of employer sites, making it difficult for the employer to hire replacements because the strike’s location is always changing.

Arthur Eddington: Philosophy of science: …epistemology, which he called “selective subjectivism” and “structuralism”—i.e., the interplay of physical observations and geometry. He believed that a great part of physics simply reflected the interpretation that the scientist imposes on his data. The better part of his philosophy, however, was not his metaphysics but his “structure” logic.…

Selective Service Acts: …Asia, Congress narrowly passed the Selective Training and Service Act, instituting the first peacetime draft in U.S. history. Pres. Franklin Delano Roosevelt signed the bill into law on September 16, 1940, and all males of ages 21 to 36 were required to register with the resurrected Selective Service System—although, for…

kin selection: …play when evaluating the genetic fitness of a given individual. It is based on the concept of inclusive fitness, which is made up of individual survival and reproduction (direct fitness) and any impact that an individual has on the survival and reproduction of relatives (indirect fitness). Kin selection occurs when…

radio technology: Concepts of selectivity and sensitivity: Radio-frequency communication requires the receiver to reject all but the desired signal. Were the number of frequency channels equal to the demand, each channel could be given its correct width in the tuning stages of a receiver. Thus, for audio broadcasting each…

nervous system: Passive transport: membrane channels: …at one region called the selectivity filter. This filter makes each channel specific to one type of ion.

word processing: …Machines Corporation (IBM) produced the Selectric Typewriter, a relatively high-speed, automatic typewriter that had a magnetic tape data-storage unit and retrieval device. The development of electronic digital minicomputers and microcomputers during the late 1960s and ’70s gave rise to faster word-processing systems with greater capabilities.

supersymmetry: …been given the names of selectrons and squarks. Similarly, known bosons such as the photon and the gluon should have fermionic supersymmetric partners, called the photino and the gluino. There has been no experimental evidence that such “superparticles” exist. If they do indeed exist, their masses could be in the…

antiparkinson drug: COMT and MAO-B inhibitors: …known of these agents is selegiline, which extends the effects of levodopa and often is prescribed in combination with levodopa and carbidopa.

Central African Republic: The 21st century: …new rebel coalition, known as Seleka, launched an incursion in the northern part of the country. The group, which included factions of former rebel movements, accused Bozizé of not implementing aspects of a previous peace agreement. It demanded his ouster from the presidency and called for him to stand trial…

Jennifer Lopez: Selena and film stardom: …landed the lead role in Selena (1997), a biopic of the murdered Tejano singer. Lopez’s immersive performance as Selena earned her rave reviews and a Golden Globe nomination. She went on to star in a number of thrillers and action dramas, including Anaconda (1997), U Turn (1997), Out of Sight…

Selena: Success as a solo artist and murder: …released her debut solo album, Selena, that same year. Several albums followed, including Ven Conmigo (1990; “Come with Me”) and Entre a Mi Mundo (1992; “Enter My World”). Her pop duet single, “Buenos Amigos” (“Good Friends”), with Salvadoran singer Álvaro Torres introduced her to a broader audience. In 1992 Selena…

Selena was an American singer who was a vivacious entertainer and whose fluid voice celebrated the sound of Tejano, a fast-paced, accordion-based Latin dance music that combines elements of jazz, country, and German polka. It is sung in Spanish and is rooted in the Hispanic community in South

Selena Gomez: Music career: …as the front woman of Selena Gomez & the Scene, an electronic-influenced pop band that produced several dance hits. The group released the albums Kiss & Tell (2009), A Year Without Rain (2010), and When the Sun Goes Down (2011) before announcing its separation in 2012. Gomez then forged a…

Selena: Success as a solo artist and murder: With Selena Live! (1993), Selena won the 1994 Grammy Award for best Mexican-American album, becoming the first female Tejano singer to win a Grammy in that category. Her expanding interests in 1994 included beginning a clothing line and opening two boutiques. That same year she released…

Selena: Early life and performing with Los Dinos: …formed a family band called Selena y Los Dinos. Her sister, Suzette, played drums and her brother, Abraham III (“A.B.”), played bass guitar. Her father wrote many of the Spanish-language songs that the group performed in the family’s restaurant. At that time Selena was not fluent in Spanish, so she…

Selena: Legacy: A Netflix show, Selena: The Series, premiered in 2020 and ran for two seasons.

Asiatic black bear, (Ursus thibetanus), member of the bear family (Ursidae) found from southern Iran to the Himalayas, Southeast Asia, and parts of eastern Asia, including Japan. The Asiatic black bear is omnivorous, eating insects, fruit, nuts, bees and honey, small mammals, and birds as well as

Selene, in Greek and Roman religion, the personification of the moon as a goddess. She was worshipped at the new and full moons. According to Hesiod’s Theogony, her parents were the Titans Hyperion and Theia; her brother was Helios, the sun god (sometimes called her father); her sister was Eos

Kaguya, Japan’s second unmanned mission to the Moon, launched by the Japan Aerospace Exploration Agency in September 2007. Its proper name, Selene (Selenological and Engineering Explorer), was derived from the ancient Greek goddess of the Moon. Kaguya, chosen from among many suggestions received

carangid: …most unusual-looking carangids is the lookdown (Selene vomer), with an exceptionally thin body and high “forehead.” The first rays of the second dorsal fin extend into filaments that reach to the tail. Many of these fishes are valued for food or sport. Certain species, however, such as the greater amberjack…

Selenga River, river in Mongolia and east-central Russia. It is formed by the confluence of the Ider and Delger rivers. It is Mongolia’s principal river and is the most substantial source of water for Lake Baikal. The Delger rises in the Sangilen Mountains on the border between Mongolia and the

Selenga River, river in Mongolia and east-central Russia. It is formed by the confluence of the Ider and Delger rivers. It is Mongolia’s principal river and is the most substantial source of water for Lake Baikal. The Delger rises in the Sangilen Mountains on the border between Mongolia and the

moonlight cactus, (genus Selenicereus), genus of about 20 species of cacti (family Cactaceae), native to tropical and subtropical America, including the West Indies. They are widely grown in suitable climates in Central and South America and have escaped from cultivation. The queen-of-the-night

cereus: The queen-of-the-night (S. grandiflorus), the best-known night-blooming cereus, is often grown indoors. The saguaro (Carnegiea gigantea) and the organ pipe cactus (Stenocereus thurberi) are also sometimes referred to as cereus.

lady’s slipper: Genera: …six species in the genus Selenipedium, also native to tropical America, may be 5 metres (16 feet) tall. The leaves are folded, and the flowers are borne on a spike at the tip of the plant. S. vanillocarpum has vanilla-scented seedpods. All Selenipedium species are considered endangered or threatened according…

selenite, a crystalline variety of the mineral gypsum

selenium (Se), a chemical element in the oxygen group (Group 16 [VIa] of the periodic table), closely allied in chemical and physical properties with the elements sulfur and tellurium. Selenium is rare, composing approximately 90 parts per billion of the crust of Earth. It is occasionally found

selenium cell, photoelectric device used to generate or control an electric current. Selenium photocells are commonly used in photographic-exposure meters, burglar alarms, electronic-door opening and counting devices, electronic control systems in factory assembly lines, and industrial colour

selenium: Compounds: In its compounds selenium exists in the oxidation states of −2, +4, and +6. It manifests a distinct tendency to form acids in the higher oxidation states. Although the element itself is not poisonous, many of its compounds are exceedingly toxic.