资料来源 : Webster's Revised Unabridged Dictionary (1913)

Sporosac \Spo"ro*sac\, n. [Spore + sac.] (Zo["o]l.)
   (a) A hydrozoan reproductive zooid or gonophore which does
       not become medusoid in form or structure. See Illust.
       under {Athecata}.
   (b) An early or simple larval stage of trematode worms and
       some other invertebrates, which is capable or reproducing
       other germs by asexual generation; a nurse; a redia.