The study of the mechanisms of animal cell division is a mature field. Division has long been considered a central event in the life of cells and it has, as a consequence, stimulated much curiosity and thought, many observations, and numerous ingenious experiments and measurements. The literature of the field is rich and reliable, but it does not appear to have developed in a markedly systematic or orderly fashion; therefore, persons seeking a broad acquaintance with the available information can easily miss important work or ideas. The purpose of the book is to lead the reader into the literature. It was not possible to do full justice to the work of all the investigators who have made significant contributions.

Although the time period during which cytokinesis has been actively investigated is by modern standards lengthy, the number of persons actively contributing new information and ideas at any one time has been small, and the rate of progress has been slow. Whether they proved to be right or wrong, the work and thoughts of the older workers are important, and the gradual emergence of the personalities of these workers from the yellowing pages of their writings has been an enjoyable aspect of this protracted writing project.