The anatomy of Cysticercus taeniae-taeniaeformis (Batsch 1786) (Cysticercus fasciolaris Rud. 1808), from the liver of Rattus norvegicus (Erx.), including an account of spiral torsion in the species and some minor abnormalities in structure

Abstract

1. The musculature and excretory and nervous systems of Cysticercus taeniae-taeniaeformis are described.2. The nervous system consists often longitudinal nerve cords in the strobila and of a brain and complicated system of nerves in the scolex. The nervous system of the scolex shows several variations on the earlier description by Bartels (1902).3. Minor abnormalities have been found in the form of multiplication of the lateral margins and duplication of the ventral excretory vessels.4. Three specimens showed spiral torsion of the internal organs involving the musculature and excretory and nervous systems of the strobila. The number of turns of the spiral and the positions of the chiasmata are variable. It is suggested that the spiral twisting occurs before growth and strobilation in the neck region has begun, the chiasmata being carried back as new segments are formed.