PREFACE<br >Several years ago in San Francisco I wandered into a Chinese restau-<br >rant for lunch with friends who were attending a scientific conference<br >with me. I usually look forward to my fortune cookit~for that fleeting<br >bit of wisdom that often makes one s day. On this occasion， however，<br >I was rudely shifted out of my blissful postprandial torpor by a rather<br >devastating message:<br > Stiff in opinion， always in the wrong!<br > This unsettling message is now posted on my office door to remind<br >me and all wh~ enter of the curious malady to which we in academic<br >settings are particularly prone. With this in mind， 1 have tried hard in<br >this book about hormones and other chemical messengers to keep the<br >opinion guarded and the scientific facts at the forefront， even when it<br >has occasionally resulted in slight hurdles for readers unfamiliar with<br >my subject.<br > Many of the topics discussed in these pages are in the process of a<br >rapid evolution created by the remarkable productivity of numerous<br >investigative laboratories throughout the world. Consequently， some<br >of the ideas expressed in this book will no doubt be rendered obsolete<br >within the next five or ten years. Nevertheless， I have not backed away<br >frot~t these rapidly changing areas; they are intriguing to me， and my<br >purpose in writing this book is to share with the general reader my<br >own excitement about chemical messengers and how they influence<br >~~ur lives.<br >