Conrad Gessner (also Konrad Gesner, Conrad Geßner, Conrad von Gesner, Conradus Gesnerus, Conrad Gesner; 26 March 1516 – 13 December 1565) was a Swiss naturalist and bibliographer. He was well known as a botanist, physician and classical linguist. His five-volume Historiae Animalium (1551–1558) is considered the beginning of modern zoology, and the flowering plant genus Gesneria and its family Gesneriaceae are named after him.
In 1545 he published his remarkable Bibliotheca Universalis (ed. by J. Simler, 1574), supposedly a catalogue (in Latin, Greek and Hebrew) of all writers who had ever lived, with the titles of their works, etc. (Wikipedia)