Bot. Pl. -i. [mod.L., a. Gr. ἀσκός bag, sac.] A membranous tubular cell, esp. the swollen sac-like cell at the end of the branches of the hyphæ in certain fungi and lichens, in which the reproductive sporules or sporidia develop.
1830. Lindley, Nat. Syst. Bot., 332. These cases (thecæ) are … contained in other membranous cases (asci).
1875. Bennett & Dyer, trans. Sachs’ Bot., 240. With the development and escape of the spores the ascus disappears.
