zona

zona is defined in Webster's Unabridged Dictionary (1913) with 1 sense. The full text of each entry is reproduced verbatim below.

Definitions

  1. 1.A zone or band; a layer. Zona pellucida. Etym: [NL.] (Biol.) (a) The outer transparent layer, or envelope, of the ovum. It is a more or less elastic membrane with radiating striæ, and corresponds to the cell wall of an ordinary cell. See Ovum, and Illust. of Microscope. (b) The zona radiata. -- Zona radiata Etym: [NL.] (Biol.), a radiately striated membrane situated next the yolk of an ovum, or separated from it by a very delicate membrane only.

Source: Webster's Unabridged Dictionary, 1913 edition (public domain, via GCIDE / Project Gutenberg).

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