["Doghearted" women: the origins of the counting method]

The so called counting-method of contraception was widely used even by the Greeks, though its scientific explanation has been elaborated only in the 1930s by Knaus and Ogino. The Greeks however misunderstood the process of conception and did not follow the periods of humans, but those of other mammals, so their method probably proved to be inefficient. The theory nevertheless, in spite of all experiences, survived for centuries and was still in use even in the 16th century. Author attempts to give an answer to this fact: according to her opinion, based on medical, historical, and literary sources, the mystery could be explained by the Greek concept of genders, and the identification of dogs with women.