HYDRA

In Mythology, a fabulous many-headed monster, which was said to infest the lake Lerna in Peloponnesus. According to the fable, on one of its heads being cut off it was immediately succeeded by another, unle the wound was cauterized. It was one of the labours of Hercules to destroy this monster, which he is said to have accomplished by the constant application of firebrands to the wounds as the heads were cut off. The term hydra is sometimes used in a metaphorical sense for any manifold evil. Hy'dra. This once dreaded name is restricted in modern Zoology to a genus of minute fresh-water Polyps. The term Hydrus was applied by Linnaeus to a genus of water-snakes. Hy'dra. One of the ancient constellations in the southern hemisphere. [s. 582]