(Accepted,for pitblicatioii 2 October 197 I) SUMMARY Various features of the growth curve of a synchronous culture of bacteria are related to the generation time distribution of the cells, and the parent-progeny generation time correlation coefficients. It is suggested that the examination of synchronous growth enables the parameters of the generation time distribution, and the correlation coefficients, to be extracted relatively simply and their de- pendence upon environment to be investigated. Methods of estimating the degree of synchronization. and some corrections for the effects of imperfect synchroniza- tion, are suggested.