The nervous system of Clonorchis sinensis was demonstrated by Koelle-Gomoris thiocholine method

as modified by Douglas-Bueding for localization of acetylcho-linesterase (AchE) and the nonspecific choliaesteraso (ChE). AchE and ChE activities were found in the ganglia

longitudial nerve fibres of the fluke. The results suggested that the amount of AchE should be more than that of ChE.In the 90-day-adult

the central nervous system is revealed as two compact cerebral ganglia which arc connected by a thick transverse commissure in the postero-dorsal region of the pharynx. Four pairs of anterior ncr.ve trunks and three post-eriorones emerge from the cerebral ganglia. The innermost anterior pairs of nerve trunks are pharyngcl nerves innervating the pharynx. The nerves of three pairs of anterior trunks (anterodorsal

antero-ventral

aiitero-later al ) terminate in a ring surrounding the oral opening. The posterior longitudinal nerves are postero-ventral nerves

postero-dorsal nerves and posterolateral nerves. The postero-vcntral nerves are the stoutest and longest ones whose branches innervate the acetabulum

forming a nerve network. All longitudial nerve trunks are connected to each other by a lot of thin transverse commissurses which are further jioned with one another by some thinner connectives forming a nerve network. The nerve network in the ventral of the fluke is more complicated than that in the dorsal

so does thai: in the anterior body than that in the posterior body