Ergot (from the Old French argot, a cock's spur) is one stage in the development of Claviceps purpurea, a fungus belonging to the order Pyrenomycetes, which attacks the pistils of grasses and sedges, but especially of rye, Secale cereale. It gets its common name, and that of Secale cornutum, or "spurred rye," used in pharmacy, from its spur-like form. Its ascospores are filiform, and on germinating, produce hyphal germ-tubes at several points. If these come in contact with the ovary of a grass they penetrate it, covering it with a felted, white "hymenium." This bears numerous cylindric "sterigmata," or "basidia," each bearing a spherical "gonidium" or "acrospore" at its apex. A sugary juice or "honey-dew" oozes out of deep furrows in the attacked ovary, carrying with it the gonidia, and is greedily eaten by insects, in which method this slimy stage, formerly described as a distinct genus under the name Sphacelia, is propagated. Each gonidium is capable of reproducing the sphacelia. The mycelium at the base of the ovary next forms a more compact mass or "sclerotium," which becomes dark-violet externally and grows into the spur-shaped mass or "ergot," sometimes over an inch in length. This generally rests till the following autumn or spring, and then gives rise to several "stromata," each consisting of a short stalk and a globular head or "capitulum." Sunk in the outer surface of these heads are the numerous flask-shaped cavities or "perithecia," in which are the club-shaped "asci." Each ascus contains several of the filiform ascospores. The preparations of this drug are a liquid extract, infusion, and tincture. It is sometimes administered hypodermically in the form of the injectio ergotini hypodermica. Ergot possesses the property of stimulating unstriped muscle to contraction, and is employed in checking haemorrhage, and to promote contraction of the uterus. A curious group of symptoms known as "ergotism" sometimes occurs in those who have eaten rye bread contaminated with ergot. In such persons gangrene affecting the extremities is one of the most marked phenomena.