A Berlin surgeon and an early associate of Sigmund FREUD who believed that there are two cycles that govern the behavior of living organisms: the 28-day female cycle and the 23-day male cycle. Some organisms, including humans, followed one or other of these cycles or some multiple of them: 46, 69 . . . or 56, 78 . . . days. Others, again including humans, had cycles that were combinations of both the basic 23- and 28-day periods, for example 23 plus 28, that is, 51 days.