If a picture is worth a thousand words, think about how long it takes your students to read a thousand words. Case studies are effective and stimulating ways to teach a variety of subjects, including the biological sciences. In learning the details of a particular case, students develop skills in both deductive and inductive reasoning, hypothesis forming, and developing tests for hypotheses, among others. Reading and developing case studies takes up a great deal of time, however, and this is not always practical in a class like introductory biology in which time is critical and large amounts of information must be covered. Here the authors present the use of photographs as case studies for biology teaching--not as a substitute for regular lecture time, but as a supplement to it. (Contains 2 figures.)