Woodcut of the mythological seven-headed Hydra killed by Hercules. Illustration from 'The historie of serpents' by Edward Topsell (1572-1625?) published in London in 1687. Topsell's main source was 'Historiae animalium' by Conrad Gesner (1516-1565) published in 1551. He translated and edited Gesner's text, adding long additional sections. The engravings are exact reproductions of those in Gesner's work. This book complemented Topsell's 'Historie of foure-footed beastes', published the year before. It summarized all real and mythical zoological knowledge collected since antiquity, but it was soon rendered obsolete by new discoveries.
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