Why did Julius Cohnheim consider Robert Koch's anthrax demonstration important?

Julius Cohnheim considered Robert Koch’s 1876 demonstration of the anthrax life cycle to be of immense importance because it provided the first convincing proof of a definite causal relationship between a specific microorganism and a specific infectious disease.1

Upon witnessing Koch’s presentation in Breslau, which detailed how dormant spores could survive in pastures and later develop into the bacteria that cause anthrax, Cohnheim was deeply impressed. He famously remarked, "It leaves nothing more to be proved," and further described the work as the greatest discovery ever made regarding bacteria. By demonstrating the complete life cycle of the organism, Koch’s research effectively bridged the gap in understanding why the disease recurred in grazing animals, marking a pivotal moment in the history of pathology.12