The demand for an atlas of CSF cytology has made a second edition necessary very soon. The number of those who have learned to appreciate the value of this simple diagnostic procedure has apparently increased. Optimal methods of cell preparation, lim­ ited technical requirements and immediate availabil­ ity of the results have all contributed to this develop­ ment. In the current edition, primary emphasis has again been placed on selection of informative illustrations and on quality of reproduction. Some figures have been replaced, and some added. The text has been expanded and improved where it seemed appro­ priate. Malignant lymphomas are treated as a sepa­ rate topic, rather than as part of the chapter on he­ moblastoses. I should like to thank Prof. Dr. HANSJORG RIEHM of the pediatric department at Kli­ nikum Charlottenburg, Freie UniversiHit Berlin (Director: Prof. Dr. HANS HELGE), for his suggestion in this regard, as well as for the material for figures on plate 47 (a-d). My technical assistent, Mrs. CHRISTINE LIGNER, again deserves my special thanks. Her suggestions and her careful cytologic work have been significant contributions to the success of this atlas.