At a Hamburg exhibition, the attention of the visitors was drawn to a dummy of a seven-headed hydra. It was bought by the burgomaster for big money and described in scientific literature as a miraculous wonder of nature. And only one person, having looked at the hydra, stated that it was not a wonder of nature at all but a skilful article made by hand; the heads and legs belonged to weasels and the body was covered with snake skin. This expert was the Swedish naturalist Carl von Linné, aka Carl Linneaus, who laid the foundations of scientific classification of animate nature.