Pierre Barrère was a French

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 physician and naturalist

Naturalist

Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...

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Pierre Barrère practised in Perpignan from 1717.In 1722, he voyaged to Cayenne

Cayenne

Cayenne is the capital of French Guiana, an overseas region and department of France located in South America. The city stands on a former island at the mouth of the Cayenne River on the Atlantic coast. The city's motto is "Ferit Aurum Industria" which means "Work brings wealth"...

 where he stayed for five years as a Professor

Professor

A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...

 of botany

Botany

Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...

 and doctor in the military hospital.

Ornithology

In 1745 he published his Ornithologiae Specimen Novum, sive Series Avium in Ruscinone, Pyrenaeis Montibus, atque in Galliâ Aequinoctiali Observatarum, in Classes, genera & species, novâ methodo, digesta at Perpignan.
His classification, entirely based on the form of the beak and feet, divided the birds into four groups : les palmipèdes, les demi-palmipèdes, les fissipèdes et les demi-fissipèdes. Within these groups there was no rank above genera

Genera

Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

 and species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 and these were more or less disordered. His very artificial classification was soon abandoned. The work was dedicated to Buffon

Georges-Louis Leclerc, Comte de Buffon

Georges-Louis Leclerc, Comte de Buffon was a French naturalist, mathematician, cosmologist, and encyclopedic author.His works influenced the next two generations of naturalists, including Jean-Baptiste Lamarck and Georges Cuvier...

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Medicine

He published Observations anatomiques tirées des ouvertures d’un grand nombre de cadavres in 1753 at Perpignan.

Fossils

He published in 1746 his Observations sur l'origine et la formation des pierres figurées, et sur celles qui, tant extérieurement qu'intérieurement, ont une figure régulière & déterminée at Paris. He was interested in the origin and the nature of fossils and described many from Catalonia

Catalonia

Catalonia is an autonomous community in northeastern Spain, with the official status of a "nationality" of Spain. Catalonia comprises four provinces: Barcelona, Girona, Lleida, and Tarragona. Its capital and largest city is Barcelona. Catalonia covers an area of 32,114 km² and has an...

 and the Pyrenees

Pyrenees

The Pyrenees is a range of mountains in southwest Europe that forms a natural border between France and Spain...

.He proposed that the fossils of marine Molluscs proved the presence of an ancient ocean.

His account of Guyana

Barrère published two more works, these on his observations in Guyana

Guyana

Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...

.These were Essai sur l'histoire naturelle de la France équinoxiale, ou Dénombrement des plantes, des animaux et des minéraux qui se trouvent dans l'isle de Cayenne, les isles de Remire, sur les côtes de la mer et dans le continent de la Guyane (1741)and Nouvelle Relation de la France équinoxiale, contenant la description des côtes de la Guiane, de l'île de Cayenne, le commerce de cette colonie, les divers changements arrivés dans ce pays, et les mœurs et coutumes des différents peuples sauvages qui l'habitent ; avec les figures dessinées sur les lieux (1743).