Louis Mangin

During this time frame, he was also a lecturer on natural sciences at the Sorbonne (from 1890).

From 1904 to 1931, he was a professor (Chaire de cryptogamie) at the Muséum national d'histoire naturelle, and was director of the museum from 1919 until his retirement in 1931.

His early research dealt largely with plant anatomy and physiology; his doctoral thesis involving the adventitious roots of monocotyledons.

With Gaston Bonnier (1853–1922), he performed extensive research of plant respiration, transpiration and carbon assimilation.

[1] In the early 1890s he is credited with the discovery of callose, a fundamental substance found in the cell membrane of plants.