Mohl, Hugo von (1805–1872)

German botanist who coined the term protoplasm (the living fluid material inside cells), describing it for the first time (although the Czech cell physiologist Johannes Purkinje had already used this term 1829, he had not applied it to plant cells). Mohl was also the first to describe the cell membrane, nucleus, utricle, and the relevance of osmosis with regard to plant cell function. He constructed a prototype of a light microscope, which he used to study and report on the structure of plant cells, and wrote a manual 1846 on its construction and applications.

Mohl was born in Stuttgart and received a classical education, although his personal preference was always for the botanical sciences. He studied medicine at Tübingen, but went on to study botany. He obtained his doctorate 1828 with a thesis on the constitution of the stomata (pores) of plants. Following a period of innovative work on stomatal development, he was appointed professor of physiology in Bern 1832 and professor of botany in Tübingen 1835. He was a corresponding member of the Institut de France from 1838 and was awarded the Order of the Crown of Wür Hemberg 1843.