*idioplasm*

‖n. [ NL., fr. Gr. 'i`dios proper, peculiar + &unr_; a form, mold. ] (Biol.) That portion of the cell protoplasm which is the seat of all active changes, and which carries on the function of hereditary transmission; -- distinguished from the other portion, which is termed nutritive plasma. See Hygroplasm. [ 1913 Webster ]