Alfred Kahl

Alfred Detlef Fritz Kahl was a German schoolteacher who took up microscopy in mid-life and became a leading authority on ciliated protozoa. In a burst of scientific productivity that lasted just nine years, he published 1800 pages of scholarly work, in which he described 17 new ciliate families, 57 genera, and about 700 previously unknown species. During his brief career as a protozoologist, he redescribed and illustrated nearly all the species of ciliates known in his time, and fit them into a taxonomic scheme that remains influential today.