The amazing fact is that while Swoboda was concentrating his studies of the rhythms in life and in man on observations in the field of psychology, some three hundred miles away in Berlin a practicing physician, Wilhelm Fliess, was accumulating a vast amount of research material in order to confirm 23-day and 28-day rhythms he had observed while diagnosing many of his patients. Fliess was a nose and throat specialist, but the breadth of his medical and biological interest was far-reaching. He showed great knowledge in many fields of Science, and records indicate that he was elected president of the Germanie Academy of Sciences in 1910.

Fliess enjoyed a large and prosperous practice in Berlin and lectured extensively. His research led him to reason that a periodic process must affect both man and woman and that these rhythms could be traced throughout life. Believing that each individual inherits both male and female sexual characteristics, he concluded that everyone has elements of bisexuality in his makeup. He also concluded that there was a connection between the rhythms he had observed and evolution, the creation of organisms, and life itself.

Anxious to find out why some children, exposed to a contagious disease, would remain immune for days, only to succumb on a periodic day. By tracing illnesses, the outbreak of fevers, and deaths back to birth. Fliess became convinced that a 23-day and a 28-day rhythm was fundamental to life. Fliess recorded his discoveries of 23-day and 28-day rhythms in his book Der Ablauf Des Lebens (The Course of Life),e a 564-page volume with which he expected of arouse the interest of the medical profession, He was disappointed. Reviewers reported that although the work contained a vast amount of mathematical research and statistics, it only confused the reader. A critic conceded: "Fliess shows an astoundingly varied knowledge of medicine, mathematics, genealogy, botany, zoology, astrology, and psychology." Three additional books, containing further documentation and reprints of the lectures Fliess had presented at numerous medical and scientific meetings, were published between l909 and 1925 under the titles Mom Leben und Mom Tod (Of Life andDeath), DasJahrim Lebendigen (The Year in the Living), Zur Periodenlehre (The Theory of Periodicity), a collection of lectures. Fliess was assisted in his research by a mathematician, and subsequently by Hans Schlieper, another medical doctor who produced his own works on the subject of rhythms in life under the titles Der Rhythmus im Leberedigen (Periodicity of Life), and Das Jahr im Raum (The Year in Space).

In his research into rhythmical repetition in life, Fliess also studied inherited characteristics, especially left-handedness which he ascribed to a greater influence of the sensitivity (feminine) rhythm reflecting a higher degree of creative feelings such as is often observed in artists, composers, and writers. He recorded births and deaths in connection with family tree studies and established a mathematical connection in blood re- lationship going back over many generations. Sensing that nature seemed to have given a "clock" to many of her children, Fliess continued exploring the regular patterns affecting all phases of life. He Concluded that the 23-day (masculine) rhythm affected the physical condition of man.