Method of autoradiography was used in order to study the kinetics of population of the cornea epithelium cells of mice. Intervals of different duration were found to exist in the DNA synthesis within the limits of S-period of one mitotic cycle. On the basis of personal and literature data a hypothesis has been put forward of a successive pattern of replication in the cells of eukaryots according to which synthesis of a fragment of the DNA daughter thread (or a chromosome subunit) occurs at each moment in a restricted site of a single matrix thread of DNA (matrix chromosome subunit). No DNA synthesis takes place at this moment in the complementary site of the second matrix thread (matrix chromosome subunit), the fragment (chromosome subunit) of one matrix thread being somewhat larger than the complementary fragment (chromosome subunit of the other matrix thread.