The Collaborative International Dictionary of English v.0.48:

Karyomiton \Kar`y*om"i*ton\ (k[a^]r`[i^]*[o^]m"[i^]*t[o^]n), n.
   [NL., Gr. ka`ryon a nut + mi`tos a thread.] (Biol.)
   The reticular network of fine fibers, of which the nucleus of
   a cell is in part composed; -- in opposition to kytomiton,
   or the network in the body of the cell. --W. Flemming.
   [1913 Webster] karyoplasm