The ductus reuniens and utriculo-endolymphatic valve in the presence of endolymphatic hydrops in guinea-pigs.

Described in the foregoing are postoperative changes in the ductus reuniens and the utriculo-endolymphatic valve of the membranous labyrinth of the inner ear upon obstruction of the endolymphatic duct in normal guinea-pigs. The ductus reuniens was postoperatively dilated more than three times that of the normal ear, and dilated to a maximum degree within the first 12 hours. The utriculo-endolymphatic valve was found to be open two days after the operation, and there was a tendency for the number of animals with an open valve to increase with time. At three weeks and also at two months after the operation, there were some animals whose utricles were compressed by the dilated saccules, and as a result, their utricular ducts and utriculo-endolymphatic valves appeared narrowed.