[The statement of nuclear volume, DNA content and nuclear form in tissue sections (author's transl)]

15 days after amputation of the forelimb of young postmethamorphic Triturus vulgaris DNA-content and volume of the nuclei of the mesodermal blastema cells have been investigated in longitudinal sections of 2 microns in thickness by Feulgen-photometric and electronic determination of area. Discrimination of the DNA-synthesis phase was carried out using microautoradiography after "in vivo" labeling with tritiated thymidine. Volume and DNA-content of the nuclear sections have been found to be positive correlated. The DNA-synthesising part of the population shows characteristic differences to the mean value of volume and DNA-content of the remaining population. The factor circumference 2/area is suitable to characterize the differentiation degree of cells.