Interpretive tracing adapted from fig. 4 of Appleton and White (1989) [6] showing a paraxial section of the polar region of an intra-uterine egg of Trichuris trichiura. Note in the original image the textural difference between the Spatio Externum and the Spatio Internum and the electron density difference between the Outer Layer of the Polar Plug and the Inner Layer of the Polar Plug. Original labels replaced with terms from the proposed new terminological scheme.