When I was first approached to write this book for the Studies in Biology series, I was delighted. As a student this series had a profound influence on me, and I was an avid reader of the books. They provided an easily affordable access to a very wide range of topics in biology, and I still use one or two books from my student days.

I was also very daunted at the prospect of writing such a short book to cover so vast a topic as microbiology. It is a subject that impinges on almost every aspect of human existence. To attempt to cover the whole of the subject would have been an impossible task. Consequently, some very difficult decisions have had to be made, and some very interesting material has had to be omitted. It is to be regretted that we could not expand upon topics such as the story of the near collapse of Winchester Cathedral as a result of fungal decomposition of the oak raft that supported the structure, following drainage of nearby farm-land.

My co-authors and I have confined ourselves to a consideration of the aspects of microbiology in which we have research experience: bacteriology, mycology and virology. We have also tried to concentrate on the fundamental problems in the subject. What constitutes microbes? How do they differ from higher organisms and from each other? How can microbes be controlled, visualised, enumerated and cultured?