Hydra

(hid rah.) (Myth.) A fabulous seven-or nine headed monster which had its habitat in the Lerncan mora . When one of the heads was cut off, it was immediately succeeded by another, unle the wound were cauterized. Therefore, Hercules killed this monster by applying firebrands to each part after cutting off of a head.-(Zool.) A gen. of minute polyps, found in stagnant pools of water. These animals present us with the simplest kind of structure which has yet been ascertained. One of the most remarkable points in their history is their power of being multiplied by mechanical division.-(Ast.) The Water-serpent, a Southern constellation remarkable for its great extension, and often divided into 4 parts, viz.: Hydra, Hydra and Crater (the Cup), Hydra and Corvus (the Crow), and Hydrsæ continuatio (the continuation of Hydra). [s. 468]