(b. Moutier-Grandval, Switzerland, 6 April 1865; d. Geneva, Switzerland, 28 April 1934),
botany, algology, plant physiology.
Chodat received the doctorate in systematic botany at Geneva in 1887. He became Privatdozent at the University of Geneva in 1888; was appointed professor of medical and pharmaceutical botany in 1889; and succeeded Jean Marc Thury as director of the Institut de Botanique in 1900. His early research culminated in the voluminous Monographia Polygalacearum (1893), which attracted worldwide attention. Besides floristics and ecology—not only of France and Switzerland, but also of Paraguay, Argentina, Spain, and the Balearic Islands—Chodat was interested in plant anatomy, cytology, teratology, and pathology.
It was in algology that Chodat showed his remarkable abilities. As early as 1893 he began studying the structure and polymorphism of lacustrine algae and was one of the the first to obtain a pure culture of isolated algae, thereby opening a new chapter in the study of the metabolism and genetics of algae. He was interested in symbiosis and made a culture of the algae linked with the fungus mycelia in lichens. Chodat became interested in the selection of yeasts, and consequently in fermentation in general. He was also a superb chemist, as is shown in his research on the catalyst peroxidase.
Chodat was a brilliant plant anatomist and was considered one of the finest flowering plant experts of his day. Deeply involved with applied botany, he discovered the cause of the vine disease known as court noué and showed that its cause was an acarid; from then on, the disease was called acariasis. In cytology he dealt with cellular division, plasmolysis, and accumulated reserves in the cytoplasm. He was one of the first to apply biometry to genetic problems. Chodat also conducted practical research in horticulture and grain culture. He traveled extensively and was always interested in the flora of the countries he visited. He collaborated on the monumental Handbuch der biologischen Arbeitsmethoden from its very inception.
I. Original Works. Chodat’s first major work was Monographia Polygalacearum (Geneva, 1893). His Principes de botanique appeared in 3 eds. (Geneva-Paris, 1907, 1911, 1920). A complete bibliography of 462 items is in the article by Lendner (below).
II. Secondary Literature. On Chodat or his work, see E. Fischer, “L’oeuvre scientifique de R. Chodat,” in Bulletin de la Société botanique de Genève, 25 (1932), 23–33; and A. Lendner, “Prof. Dr. R. Chodat,” in Actes de la Société helvétique des sciences naturelles (1934), 259–550.
P. E. Pilet