Also 8 cist. [ad. mod.L. cystis (in earlier use: see CYSTIS): in mod.F. kyste.]
1. Biol. A thin-walled hollow organ or cavity in an animal body (or plant) containing a liquid secretion; a bladder, sac, vesicle.
c. 1720. W. Gibson, Farrier’s Dispens., ii. I. (1734), 36. Under their [vipers’] tongue is a little Cyst or bag where the poison is deposited.
1796. Morse, Amer. Geog., I. 228. The Ink or Cuttle fish … is furnished with a cyst of black liquor.
1866. Treas. Bot., Cyst … the hollow spaces in parenchyma in which oily matter collects, as in the rind of the orange.
2. Path. A closed cavity or sac of a morbid or abnormal character, containing liquid or semi-solid matter.
1731–1800. Bailey, Cist … a Tumour where the obstructed Matter collects as in a Bag.
1807–26. S. Cooper, First Lines Surg. (ed. 5), 25. In abscesses of long standing, the cysts are often of very considerable thickness.
fig. 1884. [Sir I. Hamilton], Jaunt in a Junk, vi. 71. As it were, form an indelible cyst of penal associations round the very idea.
b. spec. The sac enclosing a hydatid, or larval form of a species of Tænia or tape-worm, found parasitic in man and various other animals. (Cf. ACEPHALOCYST.)
1713. Cheselden, Anat. (1726), 181. The liver full of hydatids, and cysts of hydatids adhering to it.
1888. Rolleston & Jackson, Anim. Life, 231. The cyst in which the Cysticercus lies is formed by the irritated tissues of its host.
3. Biol. and Cryptogamic Bot. A cell or cavity containing reproductive bodies, embryos, etc.; e.g., the spore-case of certain fungi.
1857. Berkeley, Cryptog. Bot., 134. Müller informs us that in C. tuberculosa, he has repeatedly seen two kinds of cysts, one scarlet, and constituting antheridia, the other larger and at length producing spores.
1867. J. Hogg, Microsc., II. i. 263. They occasionally develop an enveloping cyst, and thus become encysted zoospores.
4. Comb., as cyst-fluid, -wall, -worm; cyst-like a.
1836–9. Todd, Cycl. Anat., II. 220/2. Cyst-like tumours. Ibid. (1847–9), IV. 95/2. Atrophy of the renal textures dependent on cyst-formation.
1871. T. Holmes, Syst. Surg. (ed. 2), V. 917. The cyst-worms of one animal give rise to tape-worms in another, and vice versâ.
