Louis Agassiz


Louis Agassiz : biography

May 28, 1807 – December 14, 1873

In 1832 he was appointed professor of natural history in the University of Neuchâtel. The fossil fish there soon attracted his attention. The fossil-rich stones furnished by the slates of Glarus and the limestones of Monte Bolca were known at the time, but very little had been accomplished in the way of scientific study of them. Agassiz, as early as 1829, planned the publication of the work which, more than any other, laid the foundation of his worldwide fame. Five volumes of his Recherches sur les poissons fossiles ("Research on Fossil Fish") appeared at intervals from 1833 to 1843. They were magnificently illustrated, chiefly by Joseph Dinkel. In gathering materials for this work Agassiz visited the principal museums in Europe, and meeting Cuvier in Paris, he received much encouragement and assistance from him. They had known him for seven years at the time.

Agassiz found that his palaeontological labours made necessary a new basis of ichthyological classification. The fossils rarely exhibited any traces of the soft tissues of fish. They consisted chiefly of the teeth, scales and fins, even the bones being perfectly preserved in comparatively few instances. He therefore adopted a classification which divided fish into four groups: Ganoids, Placoids, Cycloids and Ctenoids, based on the nature of the scales and other dermal appendages. While Agassiz did much to place the subject on a scientific basis, this classification has been superseded by later work.

As Agassiz’s descriptive work proceeded, it became obvious that it would over-tax his resources unless financial assistance could be found. The British Association came to his aid, and the Earl of Ellesmere—then Lord Francis Egerton—gave him yet more efficient help. The 1,290 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; and 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 1839–40 he published two quarto volumes on the fossil Echinoderms of Switzerland; and in 1840–45 he issued his Etudes critiques sur les mollusques fossiles ("Critical Studies on Fossil Mollusks").

Before his first visit to England in 1834, the labours of Hugh Miller and other geologists brought to light the remarkable fish of the Old Red Sandstone of the northeast of Scotland. The strange forms of the Pterichthys, the 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 special monograph by him published in 1844–45: Monographie des poissons fossiles du Vieux Gres Rouge, ou Systeme Devonien (Old Red Sandstone) des Iles Britanniques et de Russie ("Monograph on Fossil Fish of the Old Red Sandstone, or Devonian System of the British Isles and of Russia"). 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.

He was the only person to name a species after Mary Anning during her lifetime. She was a paleontologist who was known around the world for important finds, but because of her gender, usually omitted from formal recognition for her work. In the early 1840s he named two fossil fish species after her—Acrodus anningiae, and Belenostomus anningiae—and another after her friend, Elizabeth Philpot. Agassiz was grateful for the help the women had given him in examining fossil fish specimens during his visit to Lyme Regis in 1834.


  • " (1833–1843)
  • History of the Freshwater Fishes of Central Europe (1839–1842)
  • Etudes sur les glaciers (1840)
  • (1840–1845)
  • (1842–1846)
  • (1844–1845)
  • (1848)
  • (with AA Gould) Principles of Zoology for the use of Schools and Colleges (Boston, 1848)
  • (Boston: Gould, Kendall and Lincoln, 1850)
  • (Boston: Little, Brown, and Co., 1857–1862)
  • Geological Sketches (Boston: Ticknor & Fields, 1866)
  • (1868)
  • [Essay on classification] (Trans. Felix Vogeli. Paris: Bailière, 1869)
  • Geological Sketches (Second Series) (Boston: J.R. Osgood, 1876)
  • , by Louis Agassiz (1962, Cambridge)