The Collaborative International Dictionary of English v.0.48:

Spermoblast \Sper"mo*blast\, n. [Spermo- + -blast.] (Physiol.)
   One of the cells formed by the division of the spermospore,
   each of which is destined to become a spermatozoid; a
   spermatocyte; a spermatoblast.
   [1913 Webster]