Seymour Papert: …he cowrote (with Marvin Minsky) Perceptrons: An Introduction to Computational Geometry (1969), a seminal work about artificial intelligence (AI). Papert was also instrumental in the creation of the school’s Artificial Intelligence Laboratory (1970; now the MIT Computer Science and Artificial Intelligence Laboratory), which had previously been part of Project MAC,…

human behaviour: Judgment: Finally, infants create perceptual categories by which to organize experience, a category being defined as a representation of the dimensions or qualities shared by a set of similar but not identical events. Infants will treat the different colours of the spectrum, for example, according to the same categories…

perceptual constancy, the tendency of animals and humans to see familiar objects as having standard shape, size, colour, or location regardless of changes in the angle of perspective, distance, or lighting. The impression tends to conform to the object as it is or is assumed to be, rather than to

perceptual learning, process by which the ability of sensory systems to respond to stimuli is improved through experience. Perceptual learning occurs through sensory interaction with the environment as well as through practice in performing specific sensory tasks. The changes that take place in

coloration: Coloration changes in populations: The phenomenon—known as a perceptual set or a search image—is exemplified by the predator of the European snail Cepaea. Predators encounter one morph and form a search image; they continue to hunt for that one form until its increasing rarity causes the predator to hunt randomly, encounter a different…

painting: Volume and space: Perceptual space is the view of things at a particular time and from a fixed position. This is the stationary window view recorded by the camera and represented in the later periods of ancient Greek and Roman paintings and in most Western schools of painting…

psychomotor learning: Age: …differences in human performance on psychomotor apparatus are associated with chronological age. Scores obtained from nearly all the devices mentioned above are sensitive to age differences. Researchers generally report a rapid increase in psychomotor proficiency from about the age of five years to the end of the second decade, followed…

Perceval, hero of Arthurian romance, distinguished by his quality of childlike (often uncouth) innocence, which protected him from worldly temptation and set him apart from other knights in Arthur’s fellowship. This quality also links his story with the primitive folktale theme of a great fool or

Spencer Perceval was a lawyer, politician, and British prime minister from 1809 until his assassination in 1812. The second son of the 2nd Earl of Egmont, Perceval was educated at Harrow and at Trinity College, Cambridge. He was called to the bar by Lincoln’s Inn in 1786 and became a king’s counsel

Chrétien de Troyes: …Le Chevalier au lion; and Perceval, ou Le Conte du Graal. The non-Arthurian tale Guillaume d’Angleterre, based on the legend of St. Eustace, may also have been written by Chrétien.

perch, either of two species of fish, the common and the yellow perch (Perca fluviatilis and P. flavescens, sometimes considered as single species, P. fluviatilis) of the family Percidae (order Perciformes). The name also is widely, and sometimes confusingly, applied to a variety of other fishes.

rod, old English measure of distance equal to 16.5 feet (5.029 metres), with variations from 9 to 28 feet (2.743 to 8.534 metres) also being used. It was also called a perch or pole. The word rod derives from Old English rodd and is akin to Old Norse rudda (“club”). Etymologically rod is also akin

perciform: Annotated classification: Family Percichthyidae (perch trouts) Eocene to present. Dull-coloured, small perchlike freshwater and marine fishes of Australia, Chile, and Argentina. Dorsal fin deeply notched. About 11 genera, about 34 species. Family Chandidae (Ambassidae) (Asiatic glassfishes, or glass perches) Small fishes similar in body

Guido Cavalcanti: …when he went into exile: “Perch’io non spero di tornar giamai” (“Because I hope not ever to return”), a line that some hear echoed in T.S. Eliot’s refrain from “Ash Wednesday,” “Because I do not hope to turn again.”

Perche, region of northern France on the border of Normandy, mainly in the east of the Orne département, with extensions into neighbouring départements. Formerly a county, it was united with the French crown in 1525. It is largely hilly country, the Perche Hills having summits of about 1,000 feet

perched rock, boulder balanced on a pinnacle rock, another boulder, or in some other precarious position. Some perched rocks form in place, as where rainwash (and in some cases wind) has removed fine material from around the boulder. Others may be transported by tectonic forces (involved in

Percheron, heavy draft-horse breed that originated in the Perche region of France. The breed probably stems from the Flemish “great horse” of the Middle Ages; modified by Arabian blood to develop a coach-horse type, it was changed again in the 19th century by introduction of draft-type blood to

passeriform, (order Passeriformes), any member of the largest order of birds and the dominant avian group on Earth today. The passeriform birds are true perching birds, with four toes, three directed forward and one backward. Considered the most highly evolved of all birds, passerines have

perching duck, any of the species of the tribe Cairinini, family Anatidae (order Anseriformes), waterfowl that typically inhabit wet woodlands, nest in holes in trees, and perch on branches by means of their long-clawed toes. The tribe is widely represented, especially in the tropics. Perching

explosive: Chlorates and perchlorates: Interest in the chlorates and perchlorates (salts of chloric or perchloric acid) as a base for explosives dates back to 1788. They were mixed with various solid and liquid fuels. Many plants were built in Europe and the United States for the manufacture of…

oxyacid: …it can be predicted that perchloric acid, HClO4, is a stronger acid than sulfuric acid, H2SO4, which should be a stronger acid than phosphoric acid, H3PO4. For a given nonmetal central atom, the acid strength increases as the oxidation number of the central atom increases. For example, nitric acid, HNO3,…

tetrachloroethylene, a colorless, dense, nonflammable, highly stable liquid belonging to the family of organic halogen compounds. ). Tetrachloroethylene is a powerful solvent for many organic substances. By the mid-20th century it had become the most widely used solvent in dry cleaning (displacing

perciform: Annotated classification: Family Percichthyidae (perch trouts) Eocene to present. Dull-coloured, small perchlike freshwater and marine fishes of Australia, Chile, and Argentina. Dorsal fin deeply notched. About 11 genera, about 34 species. Family Chandidae (Ambassidae) (Asiatic glassfishes, or glass perches) Small fishes similar in body

perciform: Annotated classification: Family Percidae (perches, walleyes, darters) Eocene to present. Spinous and soft dorsal fins usually well separated; anal fin with 1 or 2 spines and short-based; scales ctenoid; bodies rather elongated. All freshwater, temperate species; perches and pike perches Holarctic with a few brackish-water species and a…

Charles Percier and Pierre Fontaine were a pair of French architects and interior designers who carried out many building and decorative projects during the reign of Napoleon I and helped create the influential Empire style (q.v.) of interior decoration. Percier and Fontaine became acquainted with

perciform, (order Perciformes), any member of the largest group of fishes in the world, represented by more than 6,000 species placed in about 150 families. Perciforms are bony fishes that occur in abundance in both marine and freshwater areas of the world, ranging from shallow freshwater ponds to

perciform, (order Perciformes), any member of the largest group of fishes in the world, represented by more than 6,000 species placed in about 150 families. Perciforms are bony fishes that occur in abundance in both marine and freshwater areas of the world, ranging from shallow freshwater ponds to

snail darter, Rare species (Percina tanasi) of darter that originally was found only in the Little Tennessee River in the southeastern U.S. It became the subject of a legal controversy in 1978, when its status as an endangered species delayed for two years the construction of Tellico Dam. The

African spiny mouse: kempi) and Percival’s spiny mouse (A. percivali), possess the ability to slough off patches of skin when attempting to escape capture from predators. The wounds that remain, which may be painful in appearance, may shrink dramatically within the first 24 hours after the injury. They are covered…

echolocation: , Percival’s trident bat [Cloeotis percivali]). The pulses are repeated at varying rates (often in a single individual, depending upon the situation), beginning at about one per second. The rate may reach several hundred per second (e.g., in a bat close to its target).

oxycodone: …widely prescribed drug known as Percocet contains oxycodone in combination with acetaminophen.

perciform: Annotated classification: Superfamily Percoidea (basses, perches, sunfishes, and relatives) About 73 families grouped together because they show no great morphological specialization away from the general bass, grouper, or perch kind of fish taken as a model. Most inhabit shores of tropical and temperate seas or lakes. 2 aspects…

perciform: Annotated classification: …most generalized group, the suborder Percoidei, which contains the sea basses, sunfishes, perches, and fishes of many other families. The order is likely not monophyletic. As the subordinal name implies, the fishes composing it are “percoid,” or perchlike in appearance. The fishes in the other suborders have presumably evolved from…

coffee: Brewing and drinking: In percolation, water is brought to a boil in an urn and fed up a tube to a basket holding the coffee. After filtering through the coffee, the water drips back to the urn, where it is forced back up the tube and recirculated until the…

wastewater treatment: On-site septic tanks and leaching fields: …and also by conducting a percolation test, or “per test.” The perc test measures the rate at which water seeps into the soil in small test holes dug on the disposal site. The measured perc rate can be used to determine the total required area of the absorption field or…

glacier: Mass balance: …even in summer; in the percolation zone some surface melting may occur, but the meltwater refreezes at a shallow depth; in the soaked zone sufficient melting and refreezing take place to raise the whole winter snow layer to the melting temperature, permitting runoff; and in the superimposed-ice zone refrozen meltwater…

oxycodone, semisynthetic drug with potent pain-relieving effects that is derived from thebaine, an alkaloid that occurs naturally in the opium poppy (Papaver somniferum). Oxycodone was synthesized from thebaine in 1916 and was first used clinically the following year. Today it is prescribed for

fish: Annotated classification: Series Percomorpha (perches and perchlike fishes) Pelvic fin with 1 spine and 5 rays (or number of rays reduced); pelvic fin connected to postcleithrum or coracoid via a ligament; anterior pelvic process displaced ventrally; ctenoid scales. 9 included orders. Order Stephanoberyciformes (whalefishes, bigscale

perciform: Annotated classification: Family Percophidae (duckbills) Forms resemble flatheads of family Platycephalidae; body long, slender; head flattened; eyes on top of head, close together; separate spinous and soft dorsal fins; dorsal and anal fins long-based; jaws large. About 40 species; marine, from shallow down to about 200 metres (about 660…

paracanthopterygian: General features: …are about 9 species of percopsiforms, or trout-perches, and about 385 species of ophidiiforms (that is, the pearlfishes and cusk-eels).

trout-perch, either of two species of small, dark-spotted fishes of the genus Percopsis (family Percopsidae), found in freshwaters of North America. The larger species, P. omiscomaycus, grows about 15 cm (6 inches) long and is found in central North America. The second, P. transmontana, is about 10

percussion, in medicine, diagnostic procedure that entails striking the body directly or indirectly with short, sharp taps of a finger or, rarely, a hammer. The procedure was first described in 1761 by the Austrian physician Leopold Auenbrugger von Auenbrugg. Although generally ignored by his

percussion instrument: Developments after 1800: Now, modern rhythm bands frequently include one or two single castanets or a pair attached to a long handle for ease in clicking.

percussion instrument: Idiophones: …triangles and simple percussion sticks; percussion beams, such as the semanterion; percussion disks and plaques, single and in sets; xylophones, lithophones (sonorous stones), and metallophones (sets of tuned metal bars); percussion tubes, such as stamping tubes, slit drums, and tubular chimes; and percussion vessels varying from struck gourds and pots…

percussion instrument: Idiophones: …the same area, while the percussion board o-le-polotu of Samoan and Tongan chiefs accompanies solo songs. Slit drums can be huge. Made from a tree trunk, living slit drums in Vanuatu are carved with the faces of ancestors, and in New Guinea roofed drum houses are built over large horizontal…

bullet: By the 1860s, percussion caps, which detonate upon being struck a sharp blow by the firing pin of a gun, had been incorporated into a metal cartridge case containing all the components for a complete round that could be used in breech-loading rifles. In the 1880s, the introduction…

drilling machinery: Percussive drilling is slower than rotary drilling but has a number of special applications, such as for shallow holes. In percussive drilling, blows are applied successively to a tool attached to rods or a cable, and the tool is rotated so that a new portion…

drilling machinery: Percussive drilling is slower than rotary drilling but has a number of special applications, such as for shallow holes. In percussive drilling, blows are applied successively to a tool attached to rods or a cable, and the tool is rotated so that a new portion…

percussion instrument, any musical instrument belonging to either of two groups, idiophones or membranophones. Idiophones are instruments whose own substance vibrates to produce sound (as opposed to the strings of a guitar or the air column of a flute); examples include bells, clappers, and

percussion lock, in firearms, ignition system of small arms that utilizes an explosive that detonates when sharply struck. Discovered in 1805 by Alexander Forsyth (1786–1843), the percussion lock revolutionized firearms theory and opened the way to the development of self-contained metal cartridges

hand tool: Percussive tools: …what is technically called the centre of percussion—i.e., a unique point associated with a rotation, in this case the arc through which the tool is swung before delivering its blow and coming to rest. The tool’s centre of gravity is readily found because it is the balance point, or location…

hand tool: Percussive tools: Several tools involve a violent propulsion to deliver a telling blow. These have been named percussive tools, and their principal representatives are the ax and hammer. Under these two names are found an immense number of variations. The percussive group may also be…

pancreatic cancer: Diagnosis and prognosis: One example is called percutaneous transhepatic cholangiography (PTC), in which a needle is used to inject a dye directly into the liver, followed by X-ray imaging. Other X-ray imaging techniques include angiography, in which X-rays are used to view blood vessels to determine if the cancer has spread through…

cardiovascular disease: Angina pectoris: …are two alternative treatments—medication or coronary angioplasty (balloon dilation of the localized obstruction by a special catheter). When coronary arteriography reveals a severe blockage of the left main coronary artery or proximally in one or more of the major arteries, coronary artery bypass graft surgery may be necessary.

human genetic disease: Prenatal diagnosis: Both percutaneous umbilical blood sampling (PUBS) and preimplantation testing are rare, relatively high-risk, and performed only in very unusual cases. Preimplantation testing of embryos derived by in vitro fertilization is a particularly new technique and is currently used only in cases of couples who are at…

human genetic disease: Prenatal diagnosis: Both percutaneous umbilical blood sampling (PUBS) and preimplantation testing are rare, relatively high-risk, and performed only in very unusual cases. Preimplantation testing of embryos derived by in vitro fertilization is a particularly new technique and is currently used only in cases of couples who are at…

Christopher Walken: Film and television work: …War with Grandpa (2020), and Percy (2020). He later appeared in the sci-fi TV series Severance (2022– ), in which employees can undergo a procedure that separates their home and work lives. For his performance, Walken earned an Emmy nomination.

Mars: Spacecraft exploration: …Mars 2020 mission carried the Perseverance rover, which had a drill designed to collect core samples that could be taken to Earth for analysis. Perseverance landed on February 18 in Jezero crater near a dried-up river delta and was designed to search for signs of ancient microbial life. The rover…

Percy Family, English family renowned in history and ballad for its role in medieval, Tudor, and Stuart times. The family was founded by William de Percy (c. 1030–96), a follower of William I the Conqueror, who bestowed on him a great fief in Yorkshire and Lincolnshire. His grandson William (d.

English literature: Popular and secular verse: The manuscript known as the Percy Folio, a 17th-century antiquarian collection of such material, may be a fair sampling of the repertoire of the late medieval itinerant entertainer. In addition to a number of popular romances of the type satirized long before by Chaucer in “Sir Thopas,” the Percy manuscript…

Rick Riordan: …known for his hugely popular Percy Jackson and the Olympians book series, which blends Greek mythology with modern-day characters and settings.

Algernon Percy, 10th earl of Northumberland was an English Roman Catholic moderate during the turbulent reign of Charles I of England. He became a peer as Baron Percy in 1627 and succeeded his father, the 9th earl, as earl of Northumberland in 1632. During the years immediately preceding the

Algernon Percy, 10th earl of Northumberland was an English Roman Catholic moderate during the turbulent reign of Charles I of England. He became a peer as Baron Percy in 1627 and succeeded his father, the 9th earl, as earl of Northumberland in 1632. During the years immediately preceding the

Jamestown Colony: First years (1607–09): A nobleman named George Percy, the eighth son of an earl, took his place as the colony’s leader.

Henry IV, Part 1: Plot: …his son but also by Hotspur, the young rebel military leader, and by Hal’s roguish companion Falstaff. Secondary characters (many of them comic) are numerous. The plot shifts rapidly between scenes of raucous comedy and the war against the alliance of the Welsh and the rebellious Percy family of Northumberland.

Percy Family: …union of Agnes and Josceline, Henry de Percy (1273–1314) was one of Edward I’s most active agents in the subjugation of Scotland until the success of Robert de Bruce made him withdraw into England. Summoned to Parliament as a baron in the time of Edward I, he later, as one…

Henry Percy, 8th earl of Northumberland was an English Protestant member of the predominantly Roman Catholic Percy family, who nevertheless died in their cause. Brother of the 7th earl, Henry Percy served both Mary I and Elizabeth I in several capacities. During the northern rebellion, in which his

Henry Percy, 9th earl of Northumberland was an English Roman Catholic who was imprisoned in the Tower of London from 1605 to 1621 on suspicion of complicity in the Gunpowder Plot (q.v.). On the death of his father, the 8th earl, in 1585, he succeeded to the earldom and settled in London. Although

John Percy was a British metallurgist. He turned to metallurgy after obtaining a medical degree, and in 1848 he devised a process for extracting silver from its ores, which soon came into widespread use. He improved the Bessemer process for making steel, and he was the first to survey British iron

Lucy Hay, countess of Carlisle was an intriguer and conspirator during the English Civil Wars, celebrated by many poets of the day, including Thomas Carew, William Cartwright, Robert Herrick, and Sir John Suckling. The second daughter of Henry Percy, 9th earl of Northumberland, she married James

Sir Henry Percy was an English rebel who led the most serious of the uprisings against King Henry IV (reigned 1399–1413). His fame rests to a large extent on his inclusion as a major character in William Shakespeare’s Henry IV. He was the eldest son of Henry Percy, 1st earl of Northumberland, and

Thomas Percy was a participant in the Gunpowder Plot (1605), which aimed to blow up the Houses of Parliament (Palace of Westminster) during the state opening of Parliament, while James I and his chief ministers met within, in reprisal for increasing oppression of Roman Catholics in England. Thomas

Thomas Percy was an English antiquarian and bishop whose collection of ballads, Reliques of Ancient English Poetry (1765), awakened widespread interest in English and Scottish traditional songs. The basis of Percy’s collection was a tattered 15th-century manuscript of ballads (known as the Percy

Thomas Percy, 7th earl of Northumberland was an English conspirator during the reign of Elizabeth I, seeking the release of Mary, Queen of Scots, and the free exercise of the Roman Catholic religion. His father, Sir Thomas Percy (son of the 5th earl), was attainted and executed at Tyburn for his

Thomas Percy, earl of Worcester was an English noble, brother of Henry Percy, 1st Earl of Northumberland, and uncle of Sir Henry Percy, called “Hotspur,” and a party to their rebellions against Henry IV of England. Thomas Percy served with distinction in France during the reign of Edward III; he

Walker Percy was an American novelist who wrote of the New South transformed by industry and technology. Orphaned in late childhood after his father, a lawyer, committed suicide and his mother died in an automobile accident, Percy went with his brothers to live with their father’s cousin, a

Percy Family: The family was founded by William de Percy (c. 1030–96), a follower of William I the Conqueror, who bestowed on him a great fief in Yorkshire and Lincolnshire. His grandson William (d. 1175) was the last of the house in the direct line, leaving two daughters and coheiresses, Maud, who…

Perdiccas was a general under Alexander the Great who became regent of the Macedonian empire after Alexander’s death. Perdiccas served with distinction in Alexander’s campaigns and, upon Alexander’s death, led the aristocratic party that supported the claim of the unborn child of Roxana,

Argead Dynasty: …the founder of the dynasty, Perdiccas I, led the people who called themselves Macedonians eastward from their home on the Haliacmon (modern Aliákmon) River. Aegae (Edessa) became the capital, and by the reign of Amyntas I (6th century bc) Macedonian power extended eastward beyond the Axius (Axiós) River to dominate…

Argead Dynasty: Alexander’s son Perdiccas II (reigned c. 450–c. 413) asserted his succession against various brothers and united the Greek cities of Chalcidice in a federation centring on the city of Olynthus. Perdiccas’ son Archelaus (reigned c. 413–399) adopted a strongly philhellenic policy, introducing Greek artists to his new…

Philip II: Early life and accession: …elder brothers Alexander II and Perdiccas III, who each reigned for a few years, strove unsuccessfully against insubordination of their regional vassal princes, intervention of the strong Greek city Thebes, and invasion by the Illyrians of the northwest frontier.

Juana de Ibarbourou: …and vitality and, finally, in Perdida (1950; “Lost”), to an expression of despair. She was deeply affected by her own illness and the deaths of her parents and husband.

Patagonia: Drainage and soils: …other streams, such as the Perdido, terminate in basins containing salt flats or salt ponds. The canyon bottoms consist mostly of deep beds of coarse alluvial sands and gravels, which act as groundwater reservoirs to supplement the scanty surface water.

The Winter’s Tale: Meanwhile, the baby girl, named Perdita, is brought up by a shepherd and his wife in Polixenes’ kingdom of Bohemia. She appears in Act IV as a young and beautiful shepherdess who has been discovered by Polixenes’ son Florizel. Needless to say, her true status is eventually discovered once she…

partridge: …partridge of Europe is the gray partridge (Perdix perdix), called Hungarian (or hun) partridge in North America, where it was introduced in 1889 (Virginia) and again, much more successfully, in 1908–09 (Alberta). It ranges throughout the British Isles and across Europe to the Caspian region. The gray partridge has a…

Guatemala: Guatemala in the 21st century: …was followed in 2004 by Óscar Berger Perdomo, who, in trying to heal internal wounds, turned over the former presidential palace and army headquarters to the Academy of Mayan Languages and Maya TV. Perdomo also placed Nobel laureate Menchú in charge of further implementing the 1996 accords. In July 2006…

David Perdue is an American business executive and politician who served in the U.S. Senate (2015–21), representing Georgia. He is a member of the Republican Party. In 2024 President-elect Donald Trump picked Perdue to serve as U.S. ambassador to China in his upcoming administration. Perdue spent

David Perdue is an American business executive and politician who served in the U.S. Senate (2015–21), representing Georgia. He is a member of the Republican Party. In 2024 President-elect Donald Trump picked Perdue to serve as U.S. ambassador to China in his upcoming administration. Perdue spent

Georgia: Georgia since c. 1900: …the election in 2003 of Sonny Perdue, the first Republican governor since 1868.

children’s literature: Overview: …start of Paul Faucher’s admirable Père Castor series, imaginatively conceived, beautifully designed educational picture books for the very young—not literature, perhaps, but historically comparable to Comenius. Finally, in 1934 appeared the first of Marcel Aymé’s miraculous stories about two little girls and the talking animals whose adventures they shared. These…

Père David’s deer, (Elaphurus davidianus), large, rare Asian deer in the family Cervidae (order Artiodactyla). The only member of its genus, it is unknown in nature within historical times. Presumably native to northern China, it is now found only in zoos, private animal collections, and game

macaque: Species: Another short-tailed species is the Père David’s macaque (M. thibetana), which lives in mountain forests of southern China; it is sometimes called the Tibetan macaque but is not in fact found there. Often confused with the stump-tail, Père David’s macaque is in fact more closely related to the longer-tailed Assam…

St. Charles de Foucauld ; canonized May 15, 2022, feast day December 1) was a French soldier, explorer, and ascetic who dedicated his life to Christian study and prayer in the Sahara in the early 20th century. He was made a saint of the Roman Catholic Church in 2022. Foucauld came from an

Louis XII was the king of France from 1498, noted for his disastrous Italian wars and for his domestic popularity. Son of Charles, duc d’Orléans, and Marie de Clèves, Louis succeeded his father as duke in 1465. In 1476 he was forced to marry Jeanne of France, daughter of his second cousin King

sansculotte: >Père Duchesne, did much to spread the image of the sansculotte: a woodcut on the front page of each issue showed a man in Revolutionary costume, holding a musket and smoking a pipe.

St. Nicholas Day: Traditions: In France, Père Fouettard, who legend holds tried to cook three boys in a barrel of brine, is said to whip naughty children or give them coal. In Germany, Knecht Ruprecht serves as St. Nicholas’s servant and gives children who do not know their prayers sticks, stones,…

Michel del Castillo: …“My Brother, the Idiot”), and De père franƈais (1998; “The French Father”).

Le Père Goriot, novel by Honoré de Balzac, originally published in French in the Revue de Paris in 1834 and published in book form in 1835. The novel is considered one of the best works of Balzac’s panoramic series La Comédie humaine (“The Human Comedy”), and it was the first to feature characters

Pere Ubu, American avant-garde art rock band generally considered to be a major force and influence in postpunk music. Their notable albums included The Modern Dance (1978), The Tenement Year (1988), and Raygun Suitcase (1995). Formed in Cleveland in 1975 by music critics Thomas and Laughner (both

Dora Maar: Portrait of Ubu (1936; also called Père Ubu), a monstrous close-up image by Maar of what may be an armadillo fetus (she would never confirm), became an icon of the movement.