Source : Webster's Revised Unabridged Dictionary (1913)

Spermosphere \Sper"mo*sphere\, 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.