[Ageing an expression of interrelation between organs and tissue of organism (author's transl)]

The authors starts from results of investigations carried out by himself, dealing with biological cell criteria of organ cultures after the donor animals had been X-rayed on their entire bodies. He discusses the problem whether ageing is an inherent character in all cells. After juvenile rats had been X-rayed, organ cultures of their milts and kidneys showed alterations analogous to those of "old" donor animals. These alterations could not be detected if the animals were killed immediately after X-raying and the cultures were taken then. The alteration of biological cell criteria are discussed as an expression of interrelations between organs and tissues of organism.