TO ANY research worker in the anatomy of the ear, the name of Friedrich Siebenmann (Fig 1) has become a household word. In his anatomical description of the middle ear, he made great use of metal casts of the middle ear cavities. I can still remember these curious lead objects which F. R. Nager, probably Siebenmann's most outstanding pupil, used in his courses on otolaryngology in memory of his great teacher. Siebenmann's exhaustive studies of the shape and course of the blood vessels in the inner ear were based on intravenous injections with subsequent corrosion of the entire ear. Since the colored reproductions of the blood vessels in the labyrinth of the inner ear, which appeared in 1894, these classical discoveries have remained unchallenged, supported as they were by Siebenmann's authority and have appeared again and again in the relevant textbooks. Some very important new findings of Dr. D. Nabeya,