Costantin, Julien NoëL

(b. Paris, France, 16 August 1857; d. Paris, 17 November 1936)

botany.

Although born into a well-to-do commercial family, Costantin prepared for the baccalauréat at his own expense and, after studying mathématiques speciales at the Lycée Charlemagne for two years, was accepted at the École Polytechnique and at the École Normale Supérieure. He chose to attend the latter, where he eventually became agrégé-préparateur. He received his doctorate in 1883 and soon became an aide-naturaliste in Van Tieghem’s laboratory at the Muséum d’Histoire Naturelle. His next position was as maître de conferences at the École Normale. He later returned to the Muséum as a professor, holding the chair of culture (1901) and then the chair of vegetable anatomy and physiology (1919), succeeding Van Tieghem, whose daughter he married. He was a member of the Academie des Sciences (1912) and the Académie d’Agriculture (1923), and he edited the Annales des sciences naturelles (botanique).

Costantin was a convinced Lamarckian, and his works were intended first and foremost to establish the influence exerted by environment on the structure of higher plants. For example, he placed the stalk, which is normally aerial, in a subterranean environment and showed, for instance, how a cell that would normally become a lignified fiber could evolve into a parenchymatous cell. Thus function, cellular structure, and the form of the organs are linked. Costantin undertook an analogous study of the action of an aquatic environment. All his life he sought to provide a solid foundation for the theory of inheritance of acquired characters.

For many years mushrooms and their cultivation were his principal interest; then, after 1914, he devoted all his research to the action of symbiosis in the development and maintenance of life. For Costantin and his pupil Joseph Magrou, tuberization of the potato is the result of mycorrhizal symbiosis. Degeneration is caused by an impairment of this symbiosis. Cultivation and selection in mountainous regions, where the soil is rich in endophytes, appeared to Costantin to be the remedy for this degeneration.

BIBLIOGRAPHY

Costantin’s principal works are Les mucédinées simples (1888); Végétaux et milieux cosmiques (1898); La nature tropicale (1899); Le transformisme appliqué a l’agriculture (1906); La vie des orchidées (1917); Atlas en couleurs; L’origine de la vie sur le globe (1923); with Dufour, two Flores des champignons, with Faydeau, Les plantes (popularization) (1922).

In addition, see Les orchidées cultivées (1912); Atlas des orchidées cultivées (1912); and Examen critique du Lamarckisme (1930). All the above were published in Paris.

L. Plantefol