The authors hope that this book, designed primarily for the student and clinician, will be helpful to the cytogeneticist as well. They hope also that progress in the field of medical cytogenetics has reached a sufficient "plateau" so that a book recording its present status may have some permanence.
The first of the authors' hopes is fulfilled. The book not only outlines the fundamentals of cytogenetics clearly and in sufficient detail to be of help to the student and the clinician, but it also has a bibliography extensive enough to be of assistance to the worker in the field.
Whether their second hope will be fulfilled is not nearly so clear. The accumulation of knowledge in the field of cytogenetics is still continuing. Even the rules are still changing. For example, the recent conference in Chicago on standardization in human cytogenetics produced a modified nomenclature which will almost surely become