Spreading Germs discusses how modern ideas on the bacterial causes of communicable diseases were constructed and spread within the British medical profession in the last third of the nineteenth century. Michael Worboys surveys many existing interpretations of this pivotal moment in modern medicine. He shows that there were many germ theories of disease, and that these were developed and used in different ways across veterinary medicine, surgery, public health and general medicine. The growth of bacteriology is considered in relation to the evolution of medical practice rather than as a separate science of germs.