About a dozen years have elapsed since the last revision of our previous texts. Over the interim, several good microbiology texts by other authors have come and gone. Now, once again, there is a need for an authori- tative, up-to-date microbiology book for introductory students who have little background in chemistry and biology, a book that is easy to read, conveys the important microbiological principles and concepts without excessive detail, and eliminates unnecessary scientific jargon.