"A spinal tap! What for? We have the MRI, CT, EEG, EMG, SEP, MMPI, and I even did a history and physical. Just what can we learn from the CSF?" A familiar conversation with the house staff—just give them this book. There has not been a good book on spinal fluid for many years. This likely reflects our distraction in high-technology brain imaging procedures. We have neglected one of the best diagnostic methods easily available to us. There are 11 chapters, with the major contributions by the two editors. They cover history, anatomy and physiology, production and flow, collection, injection, infections, proteins, immunology, cytology, and cytopathology. The authors are all experienced clinicians so that theory is introduced as it relates to clinical problems. The illustrations are excellent and the color plates are superb. The chapters on cytopathology illustrate the potential diagnostic possibilities offered by examination of the spinal fluid. House