Louis Agassiz and the Classification of Brazil’s Fish

Drawing of "Sudis Pirarueú" from Agassiz et al., Selecta Genera et Species Piscium Brasiliensium, Tabula XVI.

Louis Agassiz (1807–1873) was a young student at the University of Munich when Johann von Spix and Carl Friedrich von Martius returned from their expedition to Brazil. Among the many items and specimens the German naturalists brought back were fish. The methodology they had followed on their journey through what was then part of the Portuguese Empire was typical of naturalists in the field: They observed, collected, and in some cases classified. Then, back in Europe, they studied the amassed material. Their journey through the exuberant and unfamiliar natural environment had lasted three years (1817–1820). In this geographical and temporal context, the fish and marine species were rarities that few scientists could address with authority within the framework of European natural history. The observant naturalists were nonetheless able to classify species unknown in Europe while also learning about these species’ natural environments.

Spix, who knew more about animals than Martius, had returned from the expedition with health problems from which he would never recover. He did however manage to compose the trip report with his companion. The three-volume account of their travels in Brazil made space to describe new species of apes, birds, and reptiles.1 Fish, on the other hand, did not find their way into the account. Spix died in 1826 and the work was unsuitable for Martius, who was more of a botanist. Martius immediately thought of contacting the foremost specialist in the field, Georges Cuvier. The French naturalist was the figure par excellence in zoology and had been at work on a treatise that would occupy the last years of his life: La Histoire naturelle des poissons. It was customary for naturalists from different regions of Europe to send descriptions of new species and already-classified fossils in support of this type of long-term work. Contributions to the classification of species were made in the name of science. Cuvier himself had been in charge of making these requests among different European scientific academies.2 When Martius got wind of the project, he decided to send the fish species that had been prepared by Spix because he was aware of the material’s importance and novelty. Hardly any naturalists of the time had visited Brazil, and none had collected such samples of its fauna.

Meanwhile, the Swiss student Agassiz found himself in the right place at the right time. He boarded at the house of the embryologist Ignatius Döllinger, who saw potential in the young student. Under Döllinger, Agassiz learned a great deal about animal science, had access to museum collections, and was socialized in the manner necessary for any scientific practice.3 As part of his standard professional training, Agassiz studied in Lausanne and Heidelberg. He also carried out his own field research on the species of Lake Neuchâtel, such practical experience now a must for those with aspirations in the field of descriptive and classificatory natural history.

See caption. The black-and-white sketch has him in profile, facing right.
“Louis Agassiz at the age of nineteen. From a pastel drawing.” Source: Elizabeth Cary Agassiz, ed., Louis Agassiz, His Life and Correspondence (Boston: Houghton, Mifflin and Company, 1885), Biodiversity Heritage Library, https://doi.org/10.5962/bhl.title.1801, vol. 1, frontispiece.

In France, Cuvier decided to include the German travelers’ draft corpus in his own work, having received permission from Martius. If properly classified and described, their findings would end up expanding the species in his Règne animal, a work that was increasingly fed by travelers’ input on species new to natural historians. Now someone was needed to properly classify the Brazilian species in the common language of naturalists. The young Swiss student was chosen for the job.

Louis Agassiz suddenly encountered his life's work. The collection of species gathered on a scientific voyage of great proportions was now in his hands. Through Martius, Agassiz gained access to the material and was entrusted with the freedom to develop the work. Naturalists translated animals, plants, minerals, and even human beings into a common language—one of natural history’s standard practices in the first half of the nineteenth century. Agassiz's work consisted in presenting Brazilian fish to the interested public and adding their scientific names to the long list of the world’s species. Without having traveled to Brazil as yet, he was able to speak with authority about its fauna. Some of the fish, duly preserved and prepared either as museum pieces or as material for research, are still in display cases at the Bavarian State Collection of Zoology in Munich.

Agassiz’s work came to fruition when Selecta Genera et Species Piscium Brasiliensium, dedicated to King Maximilian I, who headed a list of prominent subscribers in the book’s front matter, was published in Bavaria in 1829. The lengthy book was published in Latin and directly credits Cuvier.4 It was, as we have seen, a work created collectively, from the fieldwork that involved collecting, describing, and later analyzing the material to the publication that expressed gratitude to all those who had made the trip and the work with the fish possible. The publication also served to bring Agassiz closer to Cuvier, for there was no better letter of introduction for definitive acceptance into the world of science than participating in a work of such proportions and bringing it to completion. Although it is true that Agassiz was treated as a specialist in the subject before having become one, he had done well with the task entrusted to him. At the same time, his correspondence and some of his texts show that even with the successful publication of his work on Brazil’s fish, Agassiz was still a novice. He needed to expand his knowledge, and to do so establish more contacts, participate in a scientific expedition as a naturalist, and earn a doctorate. He accomplished the last in 1829.

Communication between Martius and Cuvier remained active, but Agassiz had yet to meet the Frenchman in person. In this case, the possibility of meeting the master depended on Martius as an intermediary. A suitable pretext would be advantageous in approaching Cuvier, who had a reputation for being rather distant. Animal science, specifically paleontology, was taking off at the beginning of the nineteenth century as a field linked to natural history. Agassiz had shown interest in fossils since at least his time in Heidelberg, where some specimens had caught his attention, and he saw in Cuvier's work something in common with his own interests. This could be the key to his making contact. He decided to make his approach via letters, as Martius himself had done. Martius also guided the young Swiss academic well in terms of the tone and content of his communications.

Fish as seldom-studied species were decisive both for Agassiz's career as a naturalist and for his success with Cuvier in France. There were many key paleontological studies on vertebrate fauna, especially mammals and reptiles, but there was little material on fish. The collections housed in museums in Vienna, Paris, Munich, and Strasbourg had yet to be deeply studied. This was Agassiz’s goal. When he finally met Cuvier in Paris, he impressed the man with his obvious knowledge of the subject. Cuvier also felt that the young Swiss scholar shared his interests and so made his books, collections, and notes available to him. He also introduced Agassiz to colleagues with whom he worked at the National Museum of Natural History and invited him to attend his renowned lectures.

See caption.
Accompanying illustration for “Tabula B. Sceleton Sudis gigantis.” Source: Louis Agassiz, Johann Baptist von Spix, and Carl Friedrich Phillip von Martius, Selecta Genera et Species Piscium Brasiliensium quos in Itinere per Brasiliam Annis MDCCCXVII–MDCCCXX (Munich: Typis. C Wolf, 1829), Biodiversity Heritage Library, https://doi.org/10.5962/bhl.title.9366, foldout near back of book. The table itself is located on p. 6.

Cuvier’s death in 1832 represented a turning point in Agassiz's life. The loss of the French naturalist, while a seemingly great misfortune for the European sciences, allowed Agassiz to become the foremost expert in marine fossils. As Cuvier’s disciple, Agassiz inherited access to the collection of marine species upon which the Frenchman had based his observations and soon succeeded Cuvier as the leading authority in the field.5 His reputation and cultural capital in Europe as the man "who knew fish" grew, and his excellent relations, with Alexander von Humboldt for example, served him incalculably in the development of further projects. Still working in Switzerland, Agassiz further broadened his research horizons quite successfully as one of the discoverers of the glacial period.

Agassiz would finally visit the country (and see its nature and fossils) that had indirectly helped him project himself as a paleontologist in 1865. Based out of Boston by now, he was able to carry out an expedition similar to Spix and Martius’ of 1817. The Thayer Expedition, as it is officially known, was a trip to Brazil with the purpose, besides doing what naturalists do when they travel, of gathering as much evidence as possible to refute the theories of Agassiz’s new enemy in science: Charles Darwin.6

Nelson Javier Chacón Lesmes is a historian and research fellow (wissenschaftlicher Mitarbeiter) at the Catholic University of Eichstätt-Ingolstadt.

Featured image (top): “Sudis Pirarueú,” in Agassiz et al., Selecta Genera et Species Piscium Brasiliensium, Tabula XVI.

  1. Johann Baptist von Spix and Carl Friedrich Phillip von Martius, Reise in Brasilien auf Befehl Sr. Majestät Maximilian Joseph I., Königs von Baiern in den Jahren 1817 bis 1820, 3 vols. (Munich: M. Lindauer, 1823–1831), i:25–350, HathiTrust Digital Library, https://catalog.hathitrust.org/Record/008398205. ↩︎
  2. William Coleman, “A Note on the Early Relationship between Georges Cuvier and Louis Agassiz,” Journal of the History of Medicine and Allied Sciences 18, no. 1 (January 1963): 52. ↩︎
  3. Christoph Irmscher, Louis Agassiz: Creator of American Science (Boston: Houghton Mifflin Harcourt, 2013), 41–85. ↩︎
  4. Louis Agassiz, Johann Baptist von Spix, and Carl Friedrich Phillip von Martius, Selecta Genera et Species Piscium Brasiliensium quos in Itinere per Brasiliam Annis MDCCCXVII–MDCCCXX (Munich: Typis. C Wolf, 1829), Biodiversity Heritage Library, https://doi.org/10.5962/bhl.title.9366. ↩︎
  5. Louis Menand, The Metaphysical Club: A Story of Ideas in America (New York: Farrar Straus and Giroux, 2001), 98–101. ↩︎
  6. Louis Agassiz and Elizabeth Cabot Cary Agassiz, A Journey in Brasil (Boston: Ticknor and Fields, 1868), Biodiversity Heritage Library, https://doi.org/10.5962/bhl.title.1787; Jules Marcou, Life, Letters and Works of Louis Agassiz (New York: Macmillan and Co, 1896), vol. 1, Biodiversity Heritage Library, https://doi.org/10.5962/bhl.title.1810; David Starr Jordan, “Agassiz on Recent Fishes,” The American Naturalist 32, no. 375 (March 1898): 173–76, https://www.jstor.org/stable/2452461. ↩︎
Suggested Citation: Nelson Javier Chacón Lesmes, “Louis Agassiz and the Classification of Brazil’s Fish,” History of Knowledge, August 12, 2021, https://historyofknowledge.net/2021/08/12/louis-agassiz-and-the-classification-of-brazils-fish/.