A survey of three types of cell population models is presented in this
paper. The main issue in all the surveyed works is whether or not the
re exists; a stable type distribution (s.t.d). In the last few years,
many efforts were directed towards describing the most general models
which still exhibit s.t.d. Progress made in the case of size density m
odels are discussed. A slightly extended version of a time continous d
aughter cell model, studied in Arino et al. (1991), is presented. Rece
ntly, some authors have undertaken the task of comparing models of var
ious origins and types. Such works are alluded to in a discussion.