When I was asked to help organize an American Association for the Advancement of Science symposium about how mathematical models have con- tributed to biology, I agreed immediately. The subject is of immense importance and wide-spread interest. However, too often it is discussed in biologically sterile environments by "mutual admiration society" groups of "theoreticians", many of whom have never seen, and most of whom have never done, an original scientific experiment with the biolog- ical materials they attempt to describe in abstract (and often prejudiced) terms. The opportunity to address...