[The rhythm of melatonin synthesis in the epiphysis and its control by light].

The paper deals with the central regulation of the circadian rhythm of the melatonin in the pineal gland by light according to the literature. Examples of the effects of melatonin and their inclusion in the total endocrine complexity are pointed out. Possibilities for a therapy of chronobiological diseases with bright light resulting from animal experiments are discussed in connection with requirements for a future application to the therapy of human beings.