A historical review of the problem of mitogenetic radiation.

The 'miracle of caryokinesis' was the starting point that stimulated Alexander G. Gurwitsch to carry out his famous 'mitogenetic' experiments in 1923. The results obtained confirmed his hypothesis of a weak radiation from cells, which is able to trigger the growth of other cells. Extensive experimental work within the first two decades after this discovery indicated that the problem of mitogenetic radiation is generally related to the biological significance of UV-radiation. Both 'energetic' and 'informational' aspects have to be considered, namely radiation effective in activating molecules, and that involved in arranging them into larger units. The molecular organization of biological structures is evidently governed by nonequilibrium conditions needing the uptake or emission of radiation. These concepts of A. G. Gurwitsch can be linked with modern approaches based on hypotheses of coherence in biology, 'synergetics' and 'dissipative structures'. However, the question of causal interrelationships between this part of non-equilibrium radiation and biological matter on different levels of evolution has to be solved now.