[Quantitative criteria for assessing the stages in the postnatal period of mammalian development]

Methods of mathematical statistics have been used to develop a quantitative method for periodization of the systems of mammalian organism in the postnatal development period. The method has been evaluated as to 32 histomorphological indices of blood system, thyroid gland and adrenal glands. The distinguished dependences are shown to fit adequately the qualitative changes noted in the published works of other authors.