A RACH NIT IS

(Lat.), n. f. A*r(asr)-a?k(a?ch?)-ni(ne)'ti2s. Gen, arachnit'idis. From apaxvn, a spider's web (see also -it is*), Fr., arachnite. Ger., A rach nit is, Spinnenwebenhautentziindung. It, aracnite. Sp., aracnitis. Inflammation of the arachnoid membrane, to which structure alone, however, inflammation is rarely limited. [D,1; M.] Cf. MENINGITIS— A, of the ventricles. Inflammation of the arachnoid membrane sald to line the ventricles of the brain. It is held by some anatomists that no such lining exists, and it has been puerta that, as meningitis elsewhere is usually present, the ventricular trouble may be regarded rather as a result of ** contiguous sympathetic effusion ” than as an extension of the inflammatory exudation by continuity. [D, 1.]—Rhachidian a. Spinal a. See Spinal MENINGITIS.