Born Mar. 26, 1516, in Zurich; died there Dec. 13, 1565. Swiss naturalist, philologist, and bibliographer.

From 1537, Gesner was a professor at Lausanne and from 1541 a physician in Zurich, where he died of the plague. He was the author of A History of Animals (vols. 1-5, 1551-87), the first zoological encyclopedia of that time. Proceeding basically from Aristotle’s classification, Gesner described animals in detail in the sequence four-legged viviparous and oviparous animals, birds, fish and water animals, and snakes and insects. In each volume the material was placed in alphabetical order by the animals’ names. Some related forms were grouped around one typical animal. Gesner’s work played an important role in the extension and systematization of zoological knowledge. For a period of more than 100 years it was repeatedly published and translated. Gesner also collected and studied plants. He published works on philology, and he was the author of the first universal bibliographic work, The Universal Library (1545-55).