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.
In 1737, the Swedish naturalist Carl Linnaeus bitterly complained about the haphazard naming practices of his contemporaries. “The names bestowed on plants by the ancient Greeks and Romans I commend,” he wrote, “but I shudder at the sight of most of those given by modern authorities: for those are for the most part a mere chaos of confusion, whose mother is barbarity, whose father dogmatism, and whose nurse prejudice.”1 But even after the many editions of Linnaeus’s Systema Naturae ostensibly brought order to the chaos of naming things in the natural world and structuring Western scientific understanding of it, the problem of accurately describing new natural phenomena persisted.