Webster’s Revised Unabridged Dictionary · 1913
Spermosphere
Sper′mo·sphere (spẽr′mō·sfēr), n. [Spermo- + sphere.] (Physiol.) A mass or ball of cells formed by the repeated division of a male germinal cell (spermospore), each constituent cell (spermoblast) of which is converted into a spermatozoid; a spermatogemma.