Editing Louis Agassiz (section)

==Early work==
[[File:Jean Louis Agassiz 1870.jpg|left|thumb|Agassiz in 1870]]
In 1819 to 1820, the German biologists [[Johann Baptist von Spix]] and [[Carl Friedrich Philipp von Martius]] undertook an expedition to [[Brazil]]. They returned home to Europe with many natural objects, including an important collection of the [[freshwater fish]] of Brazil, especially of the [[Amazon River#Fish|Amazon River]]. Spix, who died in 1826, likely from a tropical disease, did not live long enough to work out the history of those fish, and Martius selected Agassiz for this project.

Agassiz threw himself into the work with an enthusiasm that would go on to characterize the rest of his life's work. The task of describing the Brazilian fish was completed and published in 1829. It was followed by research into the history of fish found in [[Lake Neuchâtel]]. Enlarging his plans, he in 1830 issued a prospectus of a ''History of the Freshwater Fish of Central Europe''. In 1839, however, the first part of the publication appeared, and it was completed in 1842.{{sfn|Woodward|1911|p=367}}

In November 1832, Agassiz was appointed professor of natural history at the [[University of Neuchâtel]], at a salary of about US$400 and declined brilliant offers in Paris because of the leisure for private study that that position afforded him.<ref name="BDA1906p61">{{harvnb|Johnson|1906|p=61}}</ref> The [[fossil fish]] in the rock of the surrounding region, the [[slate]]s of [[Glarus]] and the [[limestone]]s of Monte [[Bolca]], soon attracted his attention. At the time, very little had been accomplished in their scientific study. Agassiz as early as 1829, planned the publication of a work. More than any other, it would lay the foundation of his worldwide fame. Five volumes of his ''Recherches sur les poissons fossiles'' (''Research on Fossil Fish'') were published from 1833 to 1843. They were magnificently illustrated, chiefly by [[Joseph Dinkel]].<ref>{{cite web | url = https://www.geolsoc.org.uk/Geoscientist/Archive/February-2013/Agassizs-Fossil-Fish | title = Agassiz's Fossil Fish | publisher = The Geological Society}}</ref> In gathering materials for that work, Agassiz visited the principal museums in Europe. Meeting Cuvier in Paris, he received much encouragement and assistance from him.{{sfn|Woodward|1911|p=367}}

In 1833, he married Cecile Braun, the sister of his friend [[Alexander Braun]] and established his household at [[Neuchâtel]]. Trained to scientific drawing by her brothers, his wife was of the greatest assistance to Agassiz, with some of the most beautiful plates in ''fossil'' and ''freshwater'' fishes being drawn by her.<ref name="BDA1906p61" />

[[File:Louis Aggasiz and Benjamin Peirce.jpg|thumb|upright=1.2|With [[Benjamin Peirce]] ]]
Agassiz found that his palaeontological analyses required a new ichthyological classification. The fossils that he examined rarely showed any traces of the soft tissues of fish but instead, consisted chiefly of the teeth, scales, and fins, with the bones being perfectly preserved in comparatively few instances. He therefore adopted a classification that divided fish into four groups (ganoids, placoids, cycloids, and ctenoids), based on the nature of the scales and other dermal appendages. That did much to improve fish [[taxonomy (biology)|taxonomy]], but Agassiz's classification has since been superseded.{{sfn|Woodward|1911|p=367}}

With Louis de Coulon, both father and son, he founded the ''Societé des Sciences Naturelles'', of which he was the first secretary and in conjunction with the Coulons also arranged a provisional museum of natural history in the orphan's home.<ref name="BDA1906p61" /> Agassiz needed financial support to continue his work. The [[British Association for the Advancement of Science|British Association]] and the [[Earl of Ellesmere]], then [[Francis Egerton, 1st Earl of Ellesmere|Lord Francis Egerton]], stepped in to help. The 1290 original drawings made for the work were purchased by the Earl and presented by him to the [[Geological Society of London]]. In 1836, the [[Wollaston Medal]] was awarded to Agassiz by the council of that society for his work on fossil ichthyology. In 1838, he was elected a foreign member of the [[Royal Society]]. Meanwhile, [[invertebrate]] animals engaged his attention. In 1837, he issued the "Prodrome" of a monograph on the recent and fossil [[Echinodermata]], the first part of which appeared in 1838; in 1839–1840, he published two quarto volumes on the fossil echinoderms of Switzerland; and in 1840–1845, he issued his ''Études critiques sur les mollusques fossiles'' (''Critical Studies on Fossil Mollusks'').{{sfn|Woodward|1911|p=367}}

Before Agassiz's first visit to England in 1834, [[Hugh Miller]] and other geologists had brought to light the remarkable fossil fish of the [[Old Red Sandstone]] of the northeast of Scotland. The strange forms of ''[[Pterichthys]]'', ''[[Coccosteus]]'', and other genera were then made known to geologists for the first time. They were of intense interest to Agassiz and formed the subject of a monograph by him published in 1844–1(45: ''Monographie des poissons fossiles du Vieux Grès Rouge, ou Système Dévonien (Old Red Sandstone) des Îles Britanniques et de Russie'' (''Monograph on Fossil Fish of the Old Red Sandstone, or Devonian System of the British Isles and of Russia'').{{sfn|Woodward|1911|p=367}} In the early stages of his career in Neuchatel, Agassiz also made a name for himself as a man who could run a scientific department well. Under his care, the University of Neuchâtel soon became a leading institution for scientific inquiry.{{citation needed|date=May 2018}}

[[File:Louis Agassiz H3.jpg|thumb|upright|Portrait photograph by [[John Adams Whipple]], ''circa'' 1865]]
In 1842 to 1846, Agassiz issued his ''Nomenclator Zoologicus'', a classification list with references of all names used in zoological genera and groups.

He was elected as a member of the [[American Philosophical Society]] in 1843.<ref>{{Cite web|title=APS Member History|url=https://search.amphilsoc.org/memhist/search?creator=&title=&subject=&subdiv=&mem=&year=1843&year-max=1843&dead=&keyword=&smode=advanced|access-date=2021-04-12|website=search.amphilsoc.org}}</ref>