THE most vexing problem of the operative treatment of otosclerosis is the fact that in many instances the operative fistula still heals with bony closure in spite of all improvements of the surgical technic. In attempts to solve the problem animals have been widely used, but it seems doubtful that a complete answer will ever be furnished by animal experiments alone. Otosclerosis is a disease which occurs exclusively in man and has never been observed in animals. This seems to indicate that there are basic differences between the human capsule and that of animals.
Under these circumstances the study and the analysis of the changes which take place during the healing of human fistulas have gained particular importance.
Fistula in the osseous wall of a semicircular canal either follows disease of the middle ear or is the result of operative trauma.
The lateral semicircular canal, being more accessible from the