Definify.com
Webster 1913 Edition
Zona
‖
Zo′na
,Noun.
pl.
Zonae
. [L., a girdle. See
Zone
.] A zone or band; a layer.
Zona pellucida
. [NL.]
(Biol.)
(a)
The outer transparent layer, or envelope, of the ovum. It is a more or less elastic membrane with radiating striae, and corresponds to the cell wall of an ordinary cell. See
Ovum
, and Illust. of Microscope
. (b)
The zona radiata.
– Zona radiata
[NL.]
(Biol.)
, a radiately striated membrane situated next the yolk of an ovum, or separated from it by a very delicate membrane only.