Spreading Germs discusses how modern ideas on the nature and causes of infectious diseases were constructed and spread within the British medical profession during the last third of the nineteenth century. Michael Worboys challenges many existing interpretations, arguing that at various times there were many germ theories that developed in different ways and did not always embrace science and the use of laboratories. It was the discipline of bacteriology that institutionalized the various new ideas and practices during the 1880s, and in a way that was more evolutionary than revolutionary.