MEYEN, FRANZ JULIUS FERDINAND

(b. Tilsit, Prussia [now Sovetsk, U.S.S.R.], 28 June 1804; d. Berlin, Germany, 2 September 1840)

botany.

Meyen’s father, who was president of the commercial court in Tilsit, died in 1811. Meyen attended the Gymnasium in Tilsit until 1819, when he had to begin an apprenticeship to an apothecary in Memel, Prussia. In 1821 his brother in Berlin offered him the chance to continue his schooling so that he could enter a university. From 1823 to 1826 Meyen studied medicine at the Friedrich Wilhelms Institute where military physicians were trained. At the same time, however, he also attended the zoology lectures of H. Lichtenstein and K. A. Rudolphi and the botany lectures of Johann Horkel, K. A. Sehultz, and H. F. Link at the University of Berlin. He received his medical degree in October 1826 with a dissertation entitled “De primis vitae phaenomenis in fluidis formativis et de circulatione sanguinis in parenchymaie.” Until 1830 he was a military physician in Berlin, Cologne, Bonn, and Potsdam. In this period he published three monographs and eleven journal articles.

In 1830, through the influence of Alexander von Humboldt, Meyen obtained the post of doctor on the royal cargo ship Prinzess Louise. His assignment, during a world cruise lasting nearly two years, was to collect natural history specimens and make scientific observations. He made long excursions in the western part of South America, climbing the Andes in Chile and Peru up to the snow line. Later in the voyage he spent some time in the Sandwich Islands (Hawaii), the Philippines, and China. Wherever he went, he collected plants, and in China took an interest in Chinese gardening.

Upon returning to Prussia, Meyen began to prepare his material; he published a general account of the voyage in 1834–1835, The scientific presentation of the collections appeared in the Nova Acta Leopoldina (XVI, XVII, and XIX [1832–1834, 1835, 1843]). At first Meyen published only the articles on zoology and ethnography; of the plants he described only the lichens (with J. von Flotow).

In August 1834 Meyen was named extraordinary professor in the Philosophy Faculty of the University of Berlin. He received this appointment—which followed his being granted an honorary doctorate by the University of Bonn—on the basis of the description of his voyage and of his earlier works. He then continued his study of phytotomy and plant physiology. Meyen’s most important scientific publication was Phytotomie. Written when he was twenty-five, it presented the new field of microscopic plant anatomy. The book appeared at the beginning of about ten years of intensive microscopic investigations of plants and animals. At the end of this period the Schleiden-Schwann cell theory had fully emerged. Meyen’s Phytotomie did not in every respect represent progress, but its comprehensive summary of the subject provided a strong impetus to further research. In response to the much-discussed question of the type and number of the elementary plant organs, Meyen described the cells, spiral tubes, and sap vessels. For the various forms of cellular tissue he introduced new designations —mesenchyma and pleurenchyma—to be added to those already used by Link—parenchyma and prosenchyma.

Before Meyen’s research, only the structure of the cellular reticulum was considered important, but he investigated the contents of the cell as well. Most notably, he described in detail the movements that could be observed within it. As early as 1827 he published a paper entitled “Über die eigentümliche Säftebewegung in den Zellen der Pflanzen.” This movement had first been observed in 1774 by Bonaventura Corti in the cells of Chara. For this reason Meyen’s cognomen as a member of the Imperial Leopoldine-Caroline Academy of Science was Corti. In Phytotomie he also treated movements of fluids throughout the plant. He viewed the lactiferous tubes as circulatory organs and “as the highest thing that the plant produces.” The fluid circulating within them corresponded, he thought, to the blood of animals.

In 1837 there appeared the first volume of Meyen’s other major work: Neues System der Pflanzen-Physiologie. Meyen expressed the wish that the book be considered a continuation and improvement of his Phytotomie. This first volume is in fact a reworking of Phytotomie; once again the content of plant cells is examined and described more fully than in the writings of other contemporary students of microscopic plant anatomy. The amalgamation of physiological and morphological problems, more evident here than in Phytotomie, corresponded to the conception of the relationship between anatomy and physiology held in zoology since the beginning of the nineteenth century. In the preface to the Neues System Meyen stated that the time had arrived “when one could attempt to study plant physiology in just the same way as animal physiology.”

For his essay “Ueber die neusten Fortschritte der Anatomie und Physiologie der Gewächse” Meyen received, among other honors, the prize offered by the Teyler Society of Haarlem for the best paper on that subject. For his “Ueber die Secretions-Organe der Pflanzen” he was awarded the prize of the Royal Society of Science of Göttingen. Both these awards were presented in 1836.

Meyen’s importance for botany lies much less in discovery than in the intensive and wide-ranging study of microscopic anatomy in connection with physiology. The breadth of his interests can be seen from the fact that he published the “Jahresberichte über die Resultate der Arbeiten im Felde der physiologischen Botanik” for the years 1834–1839 for A. F. A. Wiegmann’s Archiv für Naturgeschichte. He also wrote a work on plant geography and one on plant pathology.

BIBLIOGRAPHY

Meyen’s most important works are Phytotomie (Berlin, 1830); Ueber die Bewegunx der Säfte in den Pflanzen. Ein Schreiben an die Königliche Akademie der Wissenschaften zu Paris (Berlin, 1834); and Neues System der Pflanzen-Physiohgie, 3 vols. (Berlin, 1837–1839).

A biography with a complete bibliography is J. T. C. Ratzeburg, “Meyen’s Lebenslauf,” in Nova acta Academiae Caesareae Leapotdina Carolinae germanicae naturae curiosorum, 19 (1843), xiii–xxxii.

Hans Querner