COHN, FERDINAND JULIUS

COHN, FERDINAND JULIUS (1828–1898), German botanist and pioneer bacteriologist. Cohn was born in Breslau, the eldest son of Isaac Cohn, who held the post of Austro-Hungarian consul. He joined the faculty of the University of Breslau in 1851 as a lecturer in botany and in 1872 was appointed professor, the first Jew in Prussia to be granted that rank. Cohn long advocated the establishment of botanical gardens for the rigorous study of functional botany and in 1888 founded the Institute of Plant Physiology. He is generally credited with pioneering the investigation of heat production in plants and encouraging a generation of students to pursue careers in other phases of plant physiology. Cohn's most significant work, however, involved his seminal contribution to the nascent science of bacteriology. He was the first to classify bacteria as plants rather than protozoa, and in 1872 initiated a systematic classification of bacteria based upon their morphological as well as their physiological characteristics. He devised methodological tools which not only afforded a means for assessing biochemical characteristics of bacteria but which also led to the isolation of pure cultures. As the author of the first monograph on bacteria, Untersuchungen ueber die Entwicklungsgeschichte der mikroskopischen Algen und Pilze (1854), he directed the attention of both medical men and biologists to the research and clinical opportunities associated with microbiology at the Botanic Institute in Breslau. He founded and for a long time edited the Beitraege zur Biologie der Pflanzen. Cohn was awarded the Linnaeus Gold Medal. On his 70th birthday he was made an honorary citizen of Breslau and after his death a monument was erected to his memory. -BIBLIOGRAPHY: P. Cohn, Ferdinand Cohn: Blaetter der Erinnerung (1901). (George H. Fried)