Franz Meyen and Vegetation Regions

Humboldt was generous in his support for young researchers and helped many at the start of their careers, but if he can be said to have had a favorite, that person was Franz Meyen (1804–40). When Humboldt first met him, Meyen was working as a physician. Humboldt secured for him the post of professor of botany at the University of Berlin and remained close to him. For his part, Meyen followed in Humboldt's footsteps, exploring South America from 1830 to 1832 and making scientific observations during climbs in the Andes. His travels led Meyen to develop his own ideas on plant geography, which he published in 1834 as Grundri? der Pflanzengeographie (Outline of plant geography). In this work Meyen showed the influence of climate, soil, and other environmental factors on the type of vegetation, and he used isolines—lines joining places with similar values for a specified variable, first used by Humboldt—to delineate the boundaries of regions with a distinctive type of vegetation. He also discussed in the book the origin and spread of cultivated plants and their uses. Humboldt did much to promote Meyen's book. Meyen was a brilliant botanist, with an interest in every aspect of the subject. In the same year as he published Grundri?, Meyen also published a book entitled Uber die neuesten Fortschritte der Anatomie und Physiologie der Gewachse (On the latest research into the anatomy and physiology of plants). His book Phytotomie, published in 1830, was one of the first works on the microscopic anatomy of plants.

He developed a cellular theory of plant structure, which he outlined in a book entitled Untersuchungen uber den Inhalt der Pflanzen-Zellen (Inquiries into the contents of plant cells), published in 1828. Franz Julius Ferdinand Meyen was born at Tilsit, Prussia (now Sovetsk, Russia), on June 28, 1804, the son of a bookkeeper who worked in a small store. Meyen left high school early and began studying pharmacy at Memel, East Prussia (now Klaipeda, Lithuania), but in 1821 he moved to the University of Berlin and changed to medicine, in which he qualified in 1826. He practiced for four years as an army doctor and as a physician in Berlin, Cologne, and Bonn, before setting off on his exploration of South America on board the Prinzess Luise. He visited Brazil, Peru, and Bolivia and then crossed the Pacific, visiting a number of islands including Oahu, Hawaii. He spent a short time in China and at the island of St. Helena. On his return to Germany he was appointed professor of botany at the University of Berlin, where he remained until his death in Berlin on September 2, 1840.