Up to this time, it has been said, that the otogenous suppurative meningitis were infected most through labyrinth, and that the infections through labyrinth were more than half of total cases. Researched histologically about 20 in 88 cases, and obtained next results. The otogenous suppurative meningitis is infected most through the cell of petrous apex, and rare through labyrinth. Even in cases, which show clinically labyrinthitis, the infection from labyrinth to meninges is histologically few.
Studying 61 cases of tympanogenous labyrinthitis (1927-1938) the author has concluded as follows. When meningitis developes from the labyrinthitis secondary to acute or subacute otitis media, it happens for the most part in the manifest stadium of labyrinthitis and occasionally after a radical operation of mid-ear. The labyrinthitis of cholesteatomatous origin, especially after a lapse of manifest stadium, is not so dangerous when a radical operation is undertaken.
On the base of clinical statistics the meningitis combined with tympanogenous labyrinthitis has used to be considered as labyrinthogenous. By way of the histopathological study about the animal experiment and 20 cases autopsy, the auther has proved, on the contrary to the above mentioned opinion, that the most of the labyrinthitis has a tendency to circumscribe and rarely developes meningitis, therefore it is unreasonable to estimate the danger of labyrinthitis only on the ground of clinical statistics.
The author obeserved the Mitochondria in the specimens of the labyrinth which were made of normal guinea-pigs through vital fixation without narcosis. Besides the above-mentioned items, in the Epithelium-cells of the Crista spiralis, the Cells of Claudius, the Epithelium-cells of Sulcus spirolis interna, the Organ of Corti, the Epithelium-cells of the Sulcus spiralis extenra, the Epithelium-cells of Stria vascularis and also in the nerve fibres of the Spiral lamina minute investigations of the Mitochondria were made.
In my experiment, as the other writers have reported, histological changes in the labyrinth of guinea-pigs were obeserved not in an experiment in which a large dose of nicotin was given them in a short time, but in one in which it was given them little by little for a long time. These changes, especially pathological changes of the Mitochondria in the labyrinth are stated in my essay.