from
The Collaborative International Dictionary of English v.0.48
Oosphere \O"o*sphere\ ([=o]"[-o]*sf[=e]r), n. [Gr. w,'o`n an egg
+ E. sphere.]
[1913 Webster]
1. (Bot.) An unfertilized, rounded mass of protoplasm,
produced in an oogonium.
[1913 Webster]
Note: After being fertilized by the access of antherozoids it
becomes covered with a cell wall and develops into an
oospore, which may grow into a new plant like the
parent.
[1913 Webster]
2. (Bot.) An analogous mass of protoplasm in the ovule of a
flowering plant; an embryonic vesicle. --Goodale.
[1913 Webster]