Dr. Julius Cohn is the first scientist to define and systematically classify bacteria. Hence, Dr.Cohn is considered a 'founder of modern bacteriology'. His contributions include systematic classification of bacteria, discovery of bacterial spore, help in disproving the fallacy of spontaneous generation, and establishing a journal "Beitrage zur Biologie der Pflanzen" which served as an important vehicle for the publications of many pioneer bacteriological papers. Cohn’s work also helped to establish the recognition of bacteria as a separate group of living organisms different from plants or animals.
Dr. Julius Cohn divided bacteria into four groups based on their morphology: i. Sphaerobacteria (spherical), ii. Microbacteria (short rods or cylinders), iii. Desmobacteria (longer rods or threads) and iv. Spirobacteria (screws or spirals). He insisted putting bacteria into the Plant kingdom, because of their similarity with well-known algae.
Dr. Ferdinand Julius Cohn was born in the German Jewish ghetto of Breslau, Silesia (now Wroclaw, Poland), on January 24, 1828. Ferdinand Julius Cohn was not as famous as Louis Pasteur and Robert Koch because he worked on the classification of bacteria, thus he did not attract as much the attention of the general public as those who worked on the relationships of microorganisms with human diseases.