Note 156 — Chapter VII · THE ELEMENTARY STRUCTURE OF THE NERVOUS SYSTEM.
Reading edition
Even so eminent an authority as W. Krause holds this both with regard to the varicose aspect and the double contour: Handbuch der menschlichen Anatomie, 1876, I. 367. Butschli, however, describes the nerves in a living Nematode as varicose: Archiv für Anat., 1873, p. 78; and I have somewhere met with an observation of the double contour being visible in the living animal.