Botany called plant science, plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist; the term "botany" comes from the Ancient Greek word βοτάνη meaning "pasture", "grass", or "fodder". Traditionally, botany has included the study of fungi and algae by mycologists and phycologists with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists study 410,000 species of land plants of which some 391,000 species are vascular plants, 20,000 are bryophytes. Botany originated in prehistory as herbalism with the efforts of early humans to identify – and cultivate – edible and poisonous plants, making it one of the oldest branches of science. Medieval physic gardens attached to monasteries, contained plants of medical importance, they were forerunners of the first botanical gardens attached to universities, founded from the 1540s onwards.
One of the earliest was the Padua botanical garden. These gardens facilitated the academic study of plants. Efforts to catalogue and describe their collections were the beginnings of plant taxonomy, led in 1753 to the binomial system of Carl Linnaeus that remains in use to this day. In the 19th and 20th centuries, new techniques were developed for the study of plants, including methods of optical microscopy and live cell imaging, electron microscopy, analysis of chromosome number, plant chemistry and the structure and function of enzymes and other proteins. In the last two decades of the 20th century, botanists exploited the techniques of molecular genetic analysis, including genomics and proteomics and DNA sequences to classify plants more accurately. Modern botany is a broad, multidisciplinary subject with inputs from most other areas of science and technology. Research topics include the study of plant structure and differentiation, reproduction and primary metabolism, chemical products, diseases, evolutionary relationships and plant taxonomy.
Dominant themes in 21st century plant science are molecular genetics and epigenetics, which are the mechanisms and control of gene expression during differentiation of plant cells and tissues. Botanical research has diverse applications in providing staple foods, materials such as timber, rubber and drugs, in modern horticulture and forestry, plant propagation and genetic modification, in the synthesis of chemicals and raw materials for construction and energy production, in environmental management, the maintenance of biodiversity. Botany originated as the study and use of plants for their medicinal properties. Many records of the Holocene period date early botanical knowledge as far back as 10,000 years ago; this early unrecorded knowledge of plants was discovered in ancient sites of human occupation within Tennessee, which make up much of the Cherokee land today. The early recorded history of botany includes many ancient writings and plant classifications. Examples of early botanical works have been found in ancient texts from India dating back to before 1100 BC, in archaic Avestan writings, in works from China before it was unified in 221 BC.
Modern botany traces its roots back to Ancient Greece to Theophrastus, a student of Aristotle who invented and described many of its principles and is regarded in the scientific community as the "Father of Botany". His major works, Enquiry into Plants and On the Causes of Plants, constitute the most important contributions to botanical science until the Middle Ages seventeen centuries later. Another work from Ancient Greece that made an early impact on botany is De Materia Medica, a five-volume encyclopedia about herbal medicine written in the middle of the first century by Greek physician and pharmacologist Pedanius Dioscorides. De Materia Medica was read for more than 1,500 years. Important contributions from the medieval Muslim world include Ibn Wahshiyya's Nabatean Agriculture, Abū Ḥanīfa Dīnawarī's the Book of Plants, Ibn Bassal's The Classification of Soils. In the early 13th century, Abu al-Abbas al-Nabati, Ibn al-Baitar wrote on botany in a systematic and scientific manner. In the mid-16th century, "botanical gardens" were founded in a number of Italian universities – the Padua botanical garden in 1545 is considered to be the first, still in its original location.
These gardens continued the practical value of earlier "physic gardens" associated with monasteries, in which plants were cultivated for medical use. They supported the growth of botany as an academic subject. Lectures were given about the plants grown in the gardens and their medical uses demonstrated. Botanical gardens came much to northern Europe. Throughout this period, botany remained subordinate to medicine. German physician Leonhart Fuchs was one of "the three German fathers of botany", along with theologian Otto Brunfels and physician Hieronymus Bock. Fuchs and Brunfels broke away from the tradition of copying earlier works to make original observations of their own. Bock created his own system of plant classification. Physician Valerius Cordus authored a botanically and pharmacologically important herbal Historia Plantarum in 1544 and a pharmacopoeia of lasting importance, the Dispensatorium
Carl Linnaeus known after his ennoblement as Carl von Linné, was a Swedish botanist and zoologist who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern taxonomy". Many of his writings were in Latin, his name is rendered in Latin as Carolus Linnæus. Linnaeus was born in the countryside of Småland in southern Sweden, he received most of his higher education at Uppsala University and began giving lectures in botany there in 1730. He lived abroad between 1735 and 1738, where he studied and published the first edition of his Systema Naturae in the Netherlands, he returned to Sweden where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on several journeys through Sweden to find and classify plants and animals. In the 1750s and 1760s, he continued to collect and classify animals and minerals, while publishing several volumes, he was one of the most acclaimed scientists in Europe at the time of his death. Philosopher Jean-Jacques Rousseau sent him the message: "Tell him I know no greater man on earth."
Johann Wolfgang von Goethe wrote: "With the exception of Shakespeare and Spinoza, I know no one among the no longer living who has influenced me more strongly." Swedish author August Strindberg wrote: "Linnaeus was in reality a poet who happened to become a naturalist." Linnaeus has been called Princeps botanicorum and "The Pliny of the North". He is considered as one of the founders of modern ecology. In botany and zoology, the abbreviation L. is used to indicate Linnaeus as the authority for a species' name. In older publications, the abbreviation "Linn." is found. Linnaeus's remains comprise the type specimen for the species Homo sapiens following the International Code of Zoological Nomenclature, since the sole specimen that he is known to have examined was himself. Linnaeus was born in the village of Råshult in Småland, Sweden, on 23 May 1707, he was the first child of Christina Brodersonia. His siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, Emerentia Linnæa, his father taught him Latin as a small child.
One of a long line of peasants and priests, Nils was an amateur botanist, a Lutheran minister, the curate of the small village of Stenbrohult in Småland. Christina was the daughter of the rector of Samuel Brodersonius. A year after Linnaeus's birth, his grandfather Samuel Brodersonius died, his father Nils became the rector of Stenbrohult; the family moved into the rectory from the curate's house. In his early years, Linnaeus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and showed flowers to Linnaeus and told him their names. Soon Linnaeus was given his own patch of earth. Carl's father was the first in his ancestry to adopt a permanent surname. Before that, ancestors had used the patronymic naming system of Scandinavian countries: his father was named Ingemarsson after his father Ingemar Bengtsson; when Nils was admitted to the University of Lund, he had to take on a family name. He adopted the Latinate name Linnæus after a giant linden tree, lind in Swedish, that grew on the family homestead.
This name was spelled with the æ ligature. When Carl was born, he was named Carl Linnæus, with his father's family name; the son always spelled it with the æ ligature, both in handwritten documents and in publications. Carl's patronymic would have been Nilsson, as in Carl Nilsson Linnæus. Linnaeus's father began teaching him basic Latin and geography at an early age; when Linnaeus was seven, Nils decided to hire a tutor for him. The parents picked a son of a local yeoman. Linnaeus did not like him, writing in his autobiography that Telander "was better calculated to extinguish a child's talents than develop them". Two years after his tutoring had begun, he was sent to the Lower Grammar School at Växjö in 1717. Linnaeus studied going to the countryside to look for plants, he reached the last year of the Lower School when he was fifteen, taught by the headmaster, Daniel Lannerus, interested in botany. Lannerus gave him the run of his garden, he introduced him to Johan Rothman, the state doctor of Småland and a teacher at Katedralskolan in Växjö.
A botanist, Rothman broadened Linnaeus's interest in botany and helped him develop an interest in medicine. By the age of 17, Linnaeus had become well acquainted with the existing botanical literature, he remarks in his journal that he "read day and night, knowing like the back of my hand, Arvidh Månsson's Rydaholm Book of Herbs, Tillandz's Flora Åboensis, Palmberg's Serta Florea Suecana, Bromelii Chloros Gothica and Rudbeckii Hortus Upsaliensis...."Linnaeus entered the Växjö Katedralskola in 1724, where he studied Greek, Hebrew and mathematics, a curriculum designed for boys preparing for the priesthood. In the last year at the gymnasium, Linnaeus's father visited to ask the professors how his son's studies were progressing. Rothman believed otherwise; the doctor offered to have Linnaeus live with his family in Växjö and to teach him physiology and botany. Nils accepted this offer. Rothman showed Linnaeus that botany was a serious sub
An arthropod is an invertebrate animal having an exoskeleton, a segmented body, paired jointed appendages. Arthropods form the phylum Euarthropoda, which includes insects, arachnids and crustaceans; the term Arthropoda as proposed refers to a proposed grouping of Euarthropods and the phylum Onychophora. Arthropods are characterized by their jointed limbs and cuticle made of chitin mineralised with calcium carbonate; the arthropod body plan consists of each with a pair of appendages. The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting. Arthopods are bilaterally symmetrical and their body possesses an external skeleton; some species have wings. Their versatility has enabled them to become the most species-rich members of all ecological guilds in most environments, they have over a million described species, making up more than 80 per cent of all described living animal species, some of which, unlike most other animals, are successful in dry environments. Arthropods range in size from the microscopic crustacean Stygotantulus up to the Japanese spider crab.
Arthropods' primary internal cavity is a haemocoel, which accommodates their internal organs, through which their haemolymph – analogue of blood – circulates. Like their exteriors, the internal organs of arthropods are built of repeated segments, their nervous system is "ladder-like", with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, their brains are formed by fusion of the ganglia of these segments and encircle the esophagus; the respiratory and excretory systems of arthropods vary, depending as much on their environment as on the subphylum to which they belong. Their vision relies on various combinations of compound eyes and pigment-pit ocelli: in most species the ocelli can only detect the direction from which light is coming, the compound eyes are the main source of information, but the main eyes of spiders are ocelli that can form images and, in a few cases, can swivel to track prey.
Arthropods have a wide range of chemical and mechanical sensors based on modifications of the many setae that project through their cuticles. Arthropods' methods of reproduction and development are diverse; the evolutionary ancestry of arthropods dates back to the Cambrian period. The group is regarded as monophyletic, many analyses support the placement of arthropods with cycloneuralians in a superphylum Ecdysozoa. Overall, the basal relationships of Metazoa are not yet well resolved; the relationships between various arthropod groups are still debated. Aquatic species use either external fertilization. All arthropods lay eggs, but scorpions give birth to live young after the eggs have hatched inside the mother. Arthropod hatchlings vary from miniature adults to grubs and caterpillars that lack jointed limbs and undergo a total metamorphosis to produce the adult form; the level of maternal care for hatchlings varies from nonexistent to the prolonged care provided by scorpions. Arthropods contribute to the human food supply both directly as food, more indirectly as pollinators of crops.
Some species are known to spread severe disease to humans and crops. The word arthropod comes from the Greek ἄρθρον árthron, "joint", πούς pous, i.e. "foot" or "leg", which together mean "jointed leg". Arthropods are invertebrates with jointed limbs; the exoskeleton or cuticles consists of a polymer of glucosamine. The cuticle of many crustaceans, beetle mites, millipedes is biomineralized with calcium carbonate. Calcification of the endosternite, an internal structure used for muscle attachments occur in some opiliones. Estimates of the number of arthropod species vary between 1,170,000 and 5 to 10 million and account for over 80 per cent of all known living animal species; the number of species remains difficult to determine. This is due to the census modeling assumptions projected onto other regions in order to scale up from counts at specific locations applied to the whole world. A study in 1992 estimated that there were 500,000 species of animals and plants in Costa Rica alone, of which 365,000 were arthropods.
They are important members of marine, freshwater and air ecosystems, are one of only two major animal groups that have adapted to life in dry environments. One arthropod sub-group, insects, is the most species-rich member of all ecological guilds in land and freshwater environments; the lightest insects weigh less than 25 micrograms. Some living crustaceans are much larger; the embryos of all arthropods are segmented, built from a series of repeated modules. The last common ancestor of living arthropods consisted of a series of undifferentiated segments, each with a pair of appendages that functioned as limbs. However, all known living and fossil arthropods have grouped segments into tagmata in which segments and their limbs are specialized in various ways; the three-
The French Revolution was a period of far-reaching social and political upheaval in France and its colonies beginning in 1789. The Revolution overthrew the monarchy, established a republic, catalyzed violent periods of political turmoil, culminated in a dictatorship under Napoleon who brought many of its principles to areas he conquered in Western Europe and beyond. Inspired by liberal and radical ideas, the Revolution profoundly altered the course of modern history, triggering the global decline of absolute monarchies while replacing them with republics and liberal democracies. Through the Revolutionary Wars, it unleashed a wave of global conflicts that extended from the Caribbean to the Middle East. Historians regard the Revolution as one of the most important events in human history; the causes of the French Revolution are still debated among historians. Following the Seven Years' War and the American Revolution, the French government was in debt, it attempted to restore its financial status through unpopular taxation schemes, which were regressive.
Leading up to the Revolution, years of bad harvests worsened by deregulation of the grain industry and environmental problems inflamed popular resentment of the privileges enjoyed by the aristocracy and the Catholic clergy of the established church. Some historians hold something similar to what Thomas Jefferson proclaimed: that France had "been awakened by our Revolution." Demands for change were formulated in terms of Enlightenment ideals and contributed to the convocation of the Estates General in May 1789. During the first year of the Revolution, members of the Third Estate took control, the Bastille was attacked in July, the Declaration of the Rights of Man and of the Citizen was passed in August, the Women's March on Versailles forced the royal court back to Paris in October. A central event of the first stage, in August 1789, was the abolition of feudalism and the old rules and privileges left over from the Ancien Régime; the next few years featured political struggles between various liberal assemblies and right-wing supporters of the monarchy intent on thwarting major reforms.
The Republic was proclaimed in September 1792 after the French victory at Valmy. In a momentous event that led to international condemnation, Louis XVI was executed in January 1793. External threats shaped the course of the Revolution; the Revolutionary Wars beginning in 1792 featured French victories that facilitated the conquest of the Italian Peninsula, the Low Countries and most territories west of the Rhine – achievements that had eluded previous French governments for centuries. Internally, popular agitation radicalised the Revolution culminating in the rise of Maximilien Robespierre and the Jacobins; the dictatorship imposed by the Committee of Public Safety during the Reign of Terror, from 1793 until 1794, established price controls on food and other items, abolished slavery in French colonies abroad, de-established the Catholic church and created a secular Republican calendar, religious leaders were expelled, the borders of the new republic were secured from its enemies. After the Thermidorian Reaction, an executive council known as the Directory assumed control of the French state in 1795.
They suspended elections, repudiated debts, persecuted the Catholic clergy, made significant military conquests abroad. Dogged by charges of corruption, the Directory collapsed in a coup led by Napoleon Bonaparte in 1799. Napoleon, who became the hero of the Revolution through his popular military campaigns, established the Consulate and the First Empire, setting the stage for a wider array of global conflicts in the Napoleonic Wars; the modern era has unfolded in the shadow of the French Revolution. All future revolutionary movements looked back to the Revolution as their predecessor, its central phrases and cultural symbols, such as La Marseillaise and Liberté, fraternité, égalité, ou la mort, became the clarion call for other major upheavals in modern history, including the Russian Revolution over a century later. The values and institutions of the Revolution dominate French politics to this day; the Revolution resulted in the suppression of the feudal system, emancipation of the individual, a greater division of landed property, abolition of the privileges of noble birth, nominal establishment of equality among men.
The French Revolution differed from other revolutions in being not only national, for it intended to benefit all humanity. Globally, the Revolution accelerated the rise of democracies, it became the focal point for the development of most modern political ideologies, leading to the spread of liberalism, radicalism and secularism, among many others. The Revolution witnessed the birth of total war by organising the resources of France and the lives of its citizens towards the objective of military conquest; some of its central documents, such as the Declaration of the Rights of Man and of the Citizen, continued to inspire movements for abolitionism and universal suffrage in the next century. Historians have pointed to many events and factors within the Ancien Régime that led to the Revolution. Rising social and economic inequality, new political ideas emerging from the Enlightenment, economic mismanagement, environmental factors leading to agricultural failure, unmanageable national debt, political mismanagement on the part of King Louis XVI have all been cited as laying the groundwork for the Revolution.
Over the course of the 18th century, there emerged what the philosopher Jürgen Habermas called the idea of the "public sphere" in France and elsewhere
Insects have a range of mouthparts, adapted to particular modes of feeding. The earliest insects had chewing mouthparts. Specialization has been for piercing and sucking, although a range of specializations exist, as these modes of feeding have evolved a number of times. In this page, the individual mouthparts are introduced for chewing insects. Specializations are described thereafter. Like most external features of arthropods, the mouthparts of hexapoda are derived. Insect mouthparts show a multitude of different functional mechanisms across the wide diversity of species considered insects, it is common for significant homology to be conserved, with matching structures formed from matching primordia, having the same evolutionary origin. On the other hand structures that physically are identical, share identical functionality as well, may not be homologous. Examples of chewing insects include dragonflies and beetles; some insects do not have chewing mouthparts as adults but do chew solid food when they feed while they still are larvae.
The moths and butterflies are major examples of such adaptations. A chewing insect has a pair of one on each side of the head; the mandibles are caudal to the anterior to the maxillae. The mandibles are the largest and most robust mouthparts of a chewing insect, it uses them to masticate food items. Two sets of muscles move the mandibles in the coronal plane: abductor muscles move insects' mandibles apart; this they do in opening and closing their jaws in feeding, but in using the mandibles as tools, or in fighting. In carnivorous chewing insects, the mandibles are serrated and knife-like, with piercing points. In herbivorous chewing insects mandibles tend to be broader and flatter on their opposing faces, as for example in caterpillars. In males of some species, such as of Lucanidae and some Cerambycidae, the mandibles are modified to such an extent that they do not serve any feeding function, but are instead used to defend mating sites from other males. In some ants and termites, the mandibles serve a defensive function.
In bull ants, the mandibles are toothed, used both as hunting appendages. In bees, that feed by use of a proboscis, the primary use of the mandibles is to manipulate and shape wax, many paper wasps have mandibles adapted to scraping and ingesting wood fibres. Situated beneath the mandibles, paired maxillae manipulate and, in chewing insects masticate, food; each maxilla consists of two parts, the proximal cardo, distal stipes. At the apex of each stipes are two lobes, the inner lacinia and outer galea. At the outer margin, the typical galea is a cupped or scoop-like structure, located over the outer edge of the labium. In non-chewing insects, such as adult Lepidoptera, the maxillae may be drastically adapted to other functions. Unlike the mandibles, but like the labium, the maxillae bear lateral palps on their stipites; these palps serve as organs of touch and taste in feeding, in inspection of potential foods. In chewing insects and abductor muscles extend from inside the cranium to within the bases of the stipites and cardines much as happens with the mandibles in feeding, in using the maxillae as tools.
To some extent the maxillae are more mobile than the mandibles, the galeae and palps can move up and down somewhat, in the sagittal plane, both in feeding and in working, for example in nest building by mud-dauber wasps. Maxillae in most insects function like mandibles in feeding, but they are more mobile and less sclerotised than mandibles, so they are more important in manipulating soft, liquid, or particulate food rather than cutting or crushing food such as material that requires the mandibles to cut or crush. Like the mandibles, maxillae are innervated by the sub-esopharyngeal ganglia; the labium is a quadrilateral structure, formed by paired, fused secondary maxillae. It is the major component of the floor of the mouth. Together with the maxillae, the labrum assists manipulation of food during mastication; the role of the labium in some insects however, is adapted to special functions. In these insects, the labium folds neatly beneath the head and thorax, but the insect can flick it out to snatch prey, inject venom to kill and digest the prey, to bear it back to the head, where the chewing mouthparts can demolish it and swallow the particles.
The labium is attached at the rear end of the structure called cibarium, its broad basal portion is divided into regions called the submentum, the proximal part, the mentum in the middle, the prementum, the distal section, furthest anterior. The prementum bears; these structures are homologous to the galea of maxillae. The labial palps borne on the sides of labium are the counterparts of maxillary pal
Natural History Museum, London
The Natural History Museum in London is a natural history museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum and the Victoria and Albert Museum; the Natural History Museum's main frontage, however, is on Cromwell Road. The museum is home to life and earth science specimens comprising some 80 million items within five main collections: botany, mineralogy and zoology; the museum is a centre of research specialising in taxonomy and conservation. Given the age of the institution, many of the collections have great historical as well as scientific value, such as specimens collected by Charles Darwin; the museum is famous for its exhibition of dinosaur skeletons and ornate architecture—sometimes dubbed a cathedral of nature—both exemplified by the large Diplodocus cast that dominated the vaulted central hall before it was replaced in 2017 with the skeleton of a blue whale hanging from the ceiling.
The Natural History Museum Library contains extensive books, journals and artwork collections linked to the work and research of the scientific departments. The museum is recognised as the pre-eminent centre of natural history and research of related fields in the world. Although referred to as the Natural History Museum, it was known as British Museum until 1992, despite legal separation from the British Museum itself in 1963. Originating from collections within the British Museum, the landmark Alfred Waterhouse building was built and opened by 1881 and incorporated the Geological Museum; the Darwin Centre is a more recent addition designed as a modern facility for storing the valuable collections. Like other publicly funded national museums in the United Kingdom, the Natural History Museum does not charge an admission fee; the museum is an exempt charity and a non-departmental public body sponsored by the Department for Culture and Sport. Catherine, Duchess of Cambridge is a patron of the museum.
There are 850 staff at the Museum. The two largest strategic groups are Science Group; the foundation of the collection was that of the Ulster doctor Sir Hans Sloane, who allowed his significant collections to be purchased by the British Government at a price well below their market value at the time. This purchase was funded by a lottery. Sloane's collection, which included dried plants, animal and human skeletons, was housed in Montagu House, Bloomsbury, in 1756, the home of the British Museum. Most of the Sloane collection had disappeared by the early decades of the nineteenth century. Dr George Shaw sold many specimens to the Royal College of Surgeons and had periodic cremations of material in the grounds of the museum, his successors applied to the trustees for permission to destroy decayed specimens. In 1833 the Annual Report states that, of the 5,500 insects listed in the Sloane catalogue, none remained; the inability of the natural history departments to conserve its specimens became notorious: the Treasury refused to entrust it with specimens collected at the government's expense.
Appointments of staff were bedevilled by gentlemanly favoritism. J. E. Gray complained of the incidence of mental illness amongst staff: George Shaw threatened to put his foot on any shell not in the 12th edition of Linnaeus' Systema Naturae; the huge collection of the conchologist Hugh Cuming was acquired by the museum, Gray's own wife had carried the open trays across the courtyard in a gale: all the labels blew away. That collection is said never to have recovered; the Principal Librarian at the time was Antonio Panizzi. The general public was not encouraged to visit the Museum's natural history exhibits. In 1835 to a Select Committee of Parliament, Sir Henry Ellis said this policy was approved by the Principal Librarian and his senior colleagues. Many of these faults were corrected by the palaeontologist Richard Owen, appointed Superintendent of the natural history departments of the British Museum in 1856, his changes led Bill Bryson to write that "by making the Natural History Museum an institution for everyone, Owen transformed our expectations of what museums are for".
Owen saw that the natural history departments needed more space, that implied a separate building as the British Museum site was limited. Land in South Kensington was purchased, in 1864 a competition was held to design the new museum; the winning entry was submitted by the civil engineer Captain Francis Fowke, who died shortly afterwards. The scheme was taken over by Alfred Waterhouse who revised the agreed plans, designed the façades in his own idiosyncratic Romanesque style, inspired by his frequent visits to the Continent; the original plans included wings on either side of the main building, but these plans were soon abandoned for budgetary reasons. The space these would have occupied are now taken by the Earth Galleries and Darwin Centre. Work began in 1873 and was completed in 1880; the new museum opened in 1881, although the move from the old museum was not completed until 1883. Both the interiors and exteriors of the Waterhouse building make extensive use of
Paris is the capital and most populous city of France, with an area of 105 square kilometres and an official estimated population of 2,140,526 residents as of 1 January 2019. Since the 17th century, Paris has been one of Europe's major centres of finance, commerce, fashion and the arts; the City of Paris is the centre and seat of government of the Île-de-France, or Paris Region, which has an estimated official 2019 population of 12,213,364, or about 18 percent of the population of France. The Paris Region had a GDP of €681 billion in 2016, accounting for 31 percent of the GDP of France, was the 5th largest region by GDP in the world. According to the Economist Intelligence Unit Worldwide Cost of Living Survey in 2018, Paris was the second most expensive city in the world, after Singapore, ahead of Zurich, Hong Kong and Geneva. Another source ranked Paris as most expensive, on a par with Singapore and Hong-Kong, in 2018; the city is a major rail and air-transport hub served by two international airports: Paris-Charles de Gaulle and Paris-Orly.
Opened in 1900, the city's subway system, the Paris Métro, serves 5.23 million passengers daily, is the second busiest metro system in Europe after Moscow Metro. Gare du Nord is the 24th busiest railway station in the world, the first located outside Japan, with 262 million passengers in 2015. Paris is known for its museums and architectural landmarks: the Louvre was the most visited art museum in the world in 2018, with 10.2 million visitors. The Musée d'Orsay and Musée de l'Orangerie are noted for their collections of French Impressionist art, the Pompidou Centre Musée National d'Art Moderne has the largest collection of modern and contemporary art in Europe; the historical district along the Seine in the city centre is classified as a UNESCO Heritage Site. Popular landmarks in the centre of the city include the Cathedral of Notre Dame de Paris and the Gothic royal chapel of Sainte-Chapelle, both on the Île de la Cité. Paris received 23 million visitors in 2017, measured by hotel stays, with the largest numbers of foreign visitors coming from the United States, the UK, Germany and China.
It was ranked as the third most visited travel destination in the world in 2017, after Bangkok and London. The football club Paris Saint-Germain and the rugby union club Stade Français are based in Paris; the 80,000-seat Stade de France, built for the 1998 FIFA World Cup, is located just north of Paris in the neighbouring commune of Saint-Denis. Paris hosts the annual French Open Grand Slam tennis tournament on the red clay of Roland Garros. Paris will host the 2024 Summer Olympics; the 1938 and 1998 FIFA World Cups, the 2007 Rugby World Cup, the 1960, 1984, 2016 UEFA European Championships were held in the city and, every July, the Tour de France bicycle race finishes there. The name "Paris" is derived from the Celtic Parisii tribe; the city's name is not related to the Paris of Greek mythology. Paris is referred to as the City of Light, both because of its leading role during the Age of Enlightenment and more because Paris was one of the first large European cities to use gas street lighting on a grand scale on its boulevards and monuments.
Gas lights were installed on the Place du Carousel, Rue de Rivoli and Place Vendome in 1829. By 1857, the Grand boulevards were lit. By the 1860s, the boulevards and streets of Paris were illuminated by 56,000 gas lamps. Since the late 19th century, Paris has been known as Panam in French slang. Inhabitants are known in French as Parisiens, they are pejoratively called Parigots. The Parisii, a sub-tribe of the Celtic Senones, inhabited the Paris area from around the middle of the 3rd century BC. One of the area's major north–south trade routes crossed the Seine on the île de la Cité; the Parisii minted their own coins for that purpose. The Romans began their settlement on Paris' Left Bank; the Roman town was called Lutetia. It became a prosperous city with a forum, temples, an amphitheatre. By the end of the Western Roman Empire, the town was known as Parisius, a Latin name that would become Paris in French. Christianity was introduced in the middle of the 3rd century AD by Saint Denis, the first Bishop of Paris: according to legend, when he refused to renounce his faith before the Roman occupiers, he was beheaded on the hill which became known as Mons Martyrum "Montmartre", from where he walked headless to the north of the city.
Clovis the Frank, the first king of the Merovingian dynasty, made the city his capital from 508. As the Frankish domination of Gaul began, there was a gradual immigration by the Franks to Paris and the Parisian Francien dialects were born. Fortification of the Île-de-la-Citie failed to avert sacking by Vikings in 845, but Paris' strategic importance—with its bridges prevent