الملخص

Abstract The nervous system of Ophiotaenia europea appeared distinct after reaction with the enzymatic technique (AchE) as the sites appeared as brown in color . All other parts appeared as yellow white which made the detection of the nervous system fairly easy . The nervous system of the worm consists of two cerebral ganglia connected together by transverse cerebral commissure forming the cerebral ring which is in turn connected to small rostellar ring , which is the first to be discovered in this species . The rostellar ring is formed from the connection of 4 rostellar ganglia .From each cerebral ganglion six pairs of trunks arises two thin pairs lateral and one distinct pairs ventro- lateral lie between the lateral and the margin . From rostellar ganglia about 18 very slender nerves arise and run parallel to other nerve cords , they become as network in each of the mature segment .the nerves trunks both stout and slender are connected each other by a number of transverse commissures which vary with respect to the different proglottides . This worm is unique in distribution of the post- lateral ganglia at the connection of the transverse commissures and along the lateral and medial nerve trunks .Furthermore the ganglia present at the connection of transverse commissure are smaller than those present at lateral and medial nerve trunks. A positive reaction was also observed in the gonad anlagen and in the reproductive organs.