[Monsters of Phlegon--hermaphrodites, sex-changers and other strange beings in Phlegon's marvellous stories].

The 1st-2nd century greek writer, Phlegon was a representative of the genre "paradoxography". In his book entitled Peri thaumasion (Book of wonders) he collected 35 extraordinary stories among which he described hermaphrodites, sex-changers and strange births. Phlegon's stories are only a part of the more than 79 ancient writings from Greek and Roman literature that describe children born with congenital defects. The article discusses the aspects of hermaphroditism in ancient times as well as ancient teratology. These stories might have had a core of truth. Although it is extremely difficult to identify a single potential cause for it, already ancient writers tried to give an explanation. With the help of modern teratology sciences many teratogenous causes can be partly identified. A part of the most probable factors among these were the same as today: malnutrition, viruses, alcohol, vitamin deficiencies etc., but lead poisoning has also be taken into account as a principal cause.